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  • 1.
    Ahlgren, Ulf
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Exploring the pancreas with optical projection tomography2012In: Imaging in Medicine, ISSN 1755-5191, Vol. 4, no 1, p. 5-7Article in journal (Refereed)
  • 2.
    Ahlgren, Ulf
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Imaging shows insulin-producing cells in diabetes2013In: TrAC. Trends in analytical chemistry, ISSN 0165-9936, E-ISSN 1879-3142, Vol. 44, p. III-IIIArticle in journal (Other (popular science, discussion, etc.))
  • 3.
    Ahlgren, Ulf
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Gotthardt, Martin
    Department of Nuclear Medicine, Nijmegen, Netherlands.
    Approaches for imaging islets2010In: Advances in Experimental Medicine and Biology, ISSN 0065-2598, E-ISSN 2214-8019, Vol. 654, p. 39-57Article in journal (Refereed)
    Abstract [en]

    The establishment of improved technologies for imaging of the pancreas is a key element in addressing several aspects of diabetes pathogenesis. In this respect, the development of a protocol that allows for non-invasive scoring of human islets, or islet beta-cells, is of particular importance. The development of such a technology would have profound impact on both clinical and experimental medicine, ranging from early diagnosis of diabetes to the evaluation of therapeutic regimes. Another important task is the development of modalities for high-resolution imaging of experimental animal models for diabetes. Rodent models for diabetes research have for decades been instrumental to the diabetes research community. The ability to image, and to accurately quantify, key players of diabetogenic processes with molecular specificity will be of great importance for elucidating mechanistic aspects of the disease. This chapter aims to overview current progress within these research areas.

  • 4.
    Ahlgren, Ulf
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Hörnblad, Andreas
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Optical imaging of islets: new possibilities by the development of infrared fluorescent proteins2009In: Islets, ISSN 1938-2022, Vol. 1, no 2, p. 163-164Article in journal (Refereed)
    Abstract [en]

    The capacity to record the spatial and quantitative distribution of cellular subtypes involved in diabetogenic processes is a key element in experimental diabetes research. A non-invasive technique to accurately monitor parameters such as pancreatic β-cell mass (BCM) and its distribution would provide a stepping stone in understanding different aspects of diabetes pathogenesis. It would also assist in the development of therapeutic regimes by providing a tool for the evaluation of anti-diabetic drugs or other curative or diagnostic measures. At present, a range of imaging modalities are being explored for this purpose. Whereas nuclear imaging techniques, characterised by their high tissue penetration depth but relatively low spatial resolution, appear most promising for the study of humans and large animals, optical imaging enables a route to cost-effective, high sensitivity, high resolution imaging in rodent models for disease. In this commentary, the potential impact of infrared fluorescent proteins (IFPs), as recently reported by Shu et al in Science, for imaging of the pancreas in small animals will be discussed.

  • 5.
    Ahlgren, Ulf
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Kostromina, Elena
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Imaging the pancreatic beta cell: chapter 132011In: Type 1 diabetes: pathogenesis, genetics and immunotherapy / [ed] David Wagner, InTech, 2011Chapter in book (Refereed)
    Abstract [en]

    This book is a compilation of reviews about the pathogenesis of Type 1 Diabetes. T1D is a classic autoimmune disease. Genetic factors are clearly determinant but cannot explain the rapid, even overwhelming expanse of this disease. Understanding etiology and pathogenesis of this disease is essential. A number of experts in the field have covered a range of topics for consideration that are applicable to researcher and clinician alike. This book provides apt descriptions of cutting edge technologies and applications in the ever going search for treatments and cure for diabetes. Areas including T cell development, innate immune responses, imaging of pancreata, potential viral initiators, etc. are considered.

  • 6.
    Alanentalo, Tomas
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Optical projection tomography based 3D-spatial and quantitative assessments of the diabetic pancreas2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The gastrointestinal tract comprises a number of digestive organs including the stomach and pancreas. The stomach is involved in the digestion and short term storage of food while the pancreas is a mixed endocrine and exocrine gland which provides the body with hormones and enzymes essential for nutritional utilisation. The pancreas consists of three different cell lineages, acinar, ductal and endocrine cells. The endocrine cells, organised in the islets of Langerhans, are scattered throughout the exocrine parenchyma and regulate blood glucose levels by production of hormones such as glucagon and insulin.

    The Nkx family of homeodomain proteins controls numerous processes during development. Previous studies have identified two members belonging to the Nkx6 subfamily of Nkx proteins, Nkx6.1 and Nkx6.2. We have described the cloning and embryonic expression pattern of Nkx6.3. All three members of the Nkx6 gene family were shown to be expressed in partially overlapping domains during the development of the gastrointestinal tract and the central nervous system. Nkx6.2 was also identified as a transient marker for pancreatic exocrine cells.

    Analysing gene expression patterns and morphological features in tissues and organs is often performed by stereologic sampling which is a labour-intensive two dimensional approach that rely on certain assumptions when calculating e.g. β-cell mass and islet number in the pancreas. By combined improvements in immunohistochemical protocols, computational processing and tomographic scanning, we have developed a methodology based on optical projection tomography (OPT) allowing for 3D visualisation and quantification of specifically labelled objects within intact adult mouse organs. In the pancreas, this technique allows for spatial and quantitative measurements of total islet number and β-cell mass. We have further developed a protocol allowing for high resolution regional analyses based on global OPT assessments of the pancreatic constitution. This methodology is likely to facilitate detailed cellular and molecular analysis of user defined regions of interest in the pancreas, at the same time providing information on the overall disease state of the gland.

    Type 1 diabetes mellitus (T1D) can occur at any age and is characterized by the marked inability of the pancreas to secrete insulin due to an autoimmune destruction of the insulin producing β-cells. Information on the key cellular and molecular events underlying the recruitment of lymphocytes, their infiltration of the islets of Langerhans and consequent β-cell destruction is essential for understanding the pathogenesis of T1D. Using the developed methodology we have recorded the spatial and quantitative distribution of islet β-cells and infiltrating lymphocytes in the non obese diabetic (NOD) mouse model for T1D. This study shows that the smaller islets, which are predominantly organised in the periphery of the organ, are the first to disappear during the progression of T1D. The larger islets appear more resistant and our data suggest that a compensatory proliferative process is going on side by side with the autoimmune-induced β-cell destruction. Further, the formation of structures resembling tertiary lymphoid organs (TLOs) in areas apparently unaffected by insulitis suggests that local factors may provide cues for the homing of these lymphocytes back to the pancreas.

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  • 7.
    Alanentalo, Tomas
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Asayesh, Amir
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Morrison, Harris
    Lorén, Christina E
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Holmberg, Dan
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Medical Biosciences, Medical and Clinical Genetics.
    Sharpe, James
    Ahlgren, Ulf
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Tomographic molecular imaging and 3D quantification within adult mouse organs.2007In: Nature Methods, ISSN 1548-7091, E-ISSN 1548-7105, Vol. 4, no 1, p. 31-33Article in journal (Refereed)
  • 8.
    Alanentalo, Tomas
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Chatonnet, Fabrice
    Karlen, Mattias
    Sulniute, Rima
    Ericson, Johan
    Andersson, Elisabet
    Ahlgren, Ulf
    Cloning and analysis of Nkx6.3 during CNS and gastrointestinal development2006In: Gene expression patterns, ISSN 1567-133X, Vol. 6, no 2, p. 162-170Article in journal (Refereed)
  • 9.
    Alanentalo, Tomas
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Hahn, Max
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Willekens, Stefanie M. A.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Ahlgren, Ulf
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Mesoscopic Optical Imaging of the Pancreas: Revisiting Pancreatic Anatomy and Pathophysiology2021In: Frontiers in Endocrinology, E-ISSN 1664-2392, Vol. 12, article id 633063Article, review/survey (Refereed)
    Abstract [en]

    The exocrine-endocrine multipart organization of the pancreas makes it an exceedingly challenging organ to analyze, quantitatively and spatially. Both in rodents and humans, estimates of the pancreatic cellular composition, including beta-cell mass, has been largely relying on the extrapolation of 2D stereological data originating from limited sample volumes. Alternatively, they have been obtained by low resolution non-invasive imaging techniques providing little detail regarding the anatomical organization of the pancreas and its cellular and/or molecular make up. In this mini-review, the state of the art and the future potential of currently existing and emerging high-resolution optical imaging techniques working in the mm-cm range with μm resolution, here referred to as mesoscopic imaging approaches, will be discussed regarding their contribution toward a better understanding of pancreatic anatomy both in normal conditions and in the diabetic setting. In particular, optical projection tomography (OPT) and light sheet fluorescence microscopy (LSFM) imaging of the pancreas and their associated tissue processing and computational analysis protocols will be discussed in the light of their current capabilities and future potential to obtain more detailed 3D-spatial, quantitative, and molecular information of the pancreas.

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  • 10.
    Alanentalo, Tomas
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Hörnblad, Andreas
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Mayans, Sofia
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Medical and Clinical Genetics.
    Nilsson, Anna Karin
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Sharpe, James
    Larefalk, Åsa
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Medical and Clinical Genetics.
    Ahlgren, Ulf
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Holmberg, Dan
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Medical and Clinical Genetics.
    Quantification and 3-D imaging of the insulitis-induced destruction of β-cells in murine type 1 diabetes2010In: Diabetes, ISSN 0012-1797, E-ISSN 1939-327X, Vol. 59, no 7, p. 1756-1764Article in journal (Refereed)
    Abstract [en]

    Objective: The aim of this study was to refine the information regarding the quantitative and spatial dynamics of infiltrating lymphocytes and remaining beta-cell volume during the progression of type 1 diabetes in the NOD mouse model of the disease.

    Research design and methods: Using an ex vivo technique, optical projection tomography (OPT), we quantified and assessed the 3D spatial development and progression of insulitis and beta-cell destruction in pancreas from diabetes prone NOD and non-diabetes prone congenic NOD.H-2b mice between 3 and 16 weeks of age.

    Results: Together with results showing the spatial dynamics of the insulitis process we provide data of beta-cell volume distributions down to the level of the individual islets and throughout the pancreas during the development and progression of type 1 diabetes. Our data provide evidence for a compensatory growth potential of the larger insulin(+) islets during the later stages of the disease around the time point for development of clinical diabetes. This is in contrast to smaller islets, which appear less resistant to the autoimmune attack. We also provide new information on the spatial dynamics of the insulitis process itself, including its apparently random distribution at onset, the local variations during its further development, and the formation of structures resembling tertiary lymphoid organs at later phases of insulitis progression.

    Conclusions: Our data provides a powerful tool for phenotypic analysis of genetic and environmental effects on type 1 diabetes etiology as well as for evaluating the potential effect of therapeutic regimes.

  • 11.
    Alanentalo, Tomas
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Lorén, Christina E
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Larefalk, Asa
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Medical and Clinical Genetics.
    Sharpe, James
    Holmberg, Dan
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Medical and Clinical Genetics.
    Ahlgren, Ulf
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    High-resolution three-dimensional imaging of islet-infiltrate interactions based on optical projection tomography assessments of the intact adult mouse pancreas2008In: Journal of Biomedical Optics, ISSN 1083-3668, E-ISSN 1560-2281, Vol. 13, no 5, p. 054070-Article in journal (Refereed)
    Abstract [en]

    A predicament when assessing the mechanisms underlying the pathogenesis of type-1 diabetes (T1D) has been to maintain simultaneous global and regional information on the loss of insulin-cell mass and the progression of insulitis. We present a procedure for high-resolution 3-D analyses of regions of interest (ROIs), defined on the basis of global assessments of the 3-D distribution, size, and shape of molecularly labeled structures within the full volume of the intact mouse pancreas. We apply a refined protocol for optical projection tomography (OPT)-aided whole pancreas imaging in combination with confocal laser scanning microscopy of site-directed pancreatic microbiopsies. As such, the methodology provides a useful tool for detailed cellular and molecular assessments of the autoimmune insulitis in T1D. It is anticipated that the same approach could be applied to other areas of research where 3-D molecular distributions of both global and regional character is required.

  • 12. Ali, Yusuf
    et al.
    Diez, Juan
    Selander, Lars
    Zheng, Xiaofeng
    Edlund, Helena
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Diabetes Research Institute, University of Miami Leonard M. Miller School of Medicine, Miami, FL, USA.
    Berggren, Per-Olof
    The anterior chamber of the eye is a transplantation site that supports and enables visualisation of beta cell development in mice2016In: Diabetologia, ISSN 0012-186X, E-ISSN 1432-0428, Vol. 59, no 5, p. 1007-1011Article in journal (Refereed)
    Abstract [en]

    In vivo imaging of the developing pancreas is challenging due to the inaccessibility of the tissue. To circumvent this, on embryonic day 10.5 (E10.5) we transplanted a mouse developing pancreatic bud into the anterior chamber of the eye (ACE) to determine whether the eye is a useful transplant site to support pancreas development. We transplanted an E10.5 dorsal pancreatic bud into the ACE of a syngeneic recipient mouse. Using a mouse insulin promoter-green fluorescent protein (MIP-GFP) mouse as the tissue donor, we non-invasively imaged the pancreatic bud as it develops at single beta cell resolution across time. The transplanted pancreatic bud rapidly engrafts and vascularises when transplanted into the ACE. The pancreatic progenitor cells differentiate into exocrine and endocrine cells, including cells expressing insulin, glucagon and somatostatin. The morphology of the transplanted pancreatic bud resembles that of the native developing pancreas. Beta cells within the transplanted pancreatic bud respond to glucose in a manner similar to that of native fetal beta cells and superior to that of in vitro developed beta cells. Unlike in vitro grown pancreatic explants, pancreatic tissue developing in the ACE is vascularised, providing the developing pancreatic tissue with a milieu resembling the native situation. Altogether, we show that the ACE is able to support growth, differentiation and function of a developing pancreatic bud across time in vivo.

  • 13.
    Andreae, Laura C
    et al.
    MRC Centre for Developmental Neurobiology, King's College London, New Hunt's House, Guy's Campus, London, UK.
    Lumsden, Andrew
    MRC Centre for Developmental Neurobiology, King's College London, New Hunt's House, Guy's Campus, London, UK.
    Gilthorpe, Jonathan D
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Chick Lrrn2, a novel downstream effector of Hoxb1 and Shh, functions in the selective targeting of rhombomere 4 motor neurons2009In: Neural development, ISSN 1749-8104, Vol. 4, p. 27-Article in journal (Refereed)
    Abstract [en]

    Background; Capricious is a Drosophila adhesion molecule that regulates specific targeting of a subset of motor neurons to their muscle target. We set out to identify whether one of its vertebrate homologues, Lrrn2, might play an analogous role in the chick.

    Results; We have shown that Lrrn2 is expressed from early development in the prospective rhombomere 4 (r4) of the chick hindbrain. Subsequently, its expression in the hindbrain becomes restricted to a specific group of motor neurons, the branchiomotor neurons of r4, and their pre-muscle target, the second branchial arch (BA2), along with other sites outside the hindbrain. Misexpression of the signalling molecule Sonic hedgehog (Shh) via in ovo electroporation results in upregulation of Lrrn2 exclusively in r4, while the combined expression of Hoxb1 and Shh is sufficient to induce ectopic Lrrn2 in r1/2. Misexpression of Lrrn2 in r2/3 results in axonal rerouting from the r2 exit point to the r4 exit point and BA2, suggesting a direct role in motor axon guidance.

    Conclusion; Lrrn2 acts downstream of Hoxb1 and plays a role in the selective targeting of r4 motor neurons to BA2.

  • 14. Annicotte, Jean-Sébastien
    et al.
    Fayard, Elisabeth
    Swift, Galvin H
    Selander, Lars
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Edlund, Helena
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Tanaka, Toshiya
    Kodama, Tatsuhiko
    Schoonjans, Kristina
    Auwerx, Johan
    Pancreatic-duodenal homeobox 1 regulates expression of liver receptor homolog 1 during pancreas development.2003In: Molecular and Cellular Biology, ISSN 0270-7306, E-ISSN 1098-5549, Vol. 23, no 19, p. 6713-6124Article in journal (Refereed)
    Abstract [en]

    Liver receptor homolog 1 (LRH-1) and pancreatic-duodenal homeobox 1 (PDX-1) are coexpressed in the pancreas during mouse embryonic development. Analysis of the regulatory region of the human LRH-1 gene demonstrated the presence of three functional binding sites for PDX-1. Electrophoretic mobility shift assays and chromatin immunoprecipitation analysis showed that PDX-1 bound to the LRH-1 promoter, both in cultured cells in vitro and during pancreatic development in vivo. Retroviral expression of PDX-1 in pancreatic cells induced the transcription of LRH-1, whereas reduced PDX-1 levels by RNA interference attenuated its expression. Consistent with direct regulation of LRH-1 expression by PDX-1, PDX-1(-/-) mice expressed smaller amounts of LRH-1 mRNA in the embryonic pancreas. Taken together, our data indicate that PDX-1 controls LRH-1 expression and identify LRH-1 as a novel downstream target in the PDX-1 regulatory cascade governing pancreatic development, differentiation, and function.

  • 15. Aquino, Jorge B
    et al.
    Hjerling-Leffler, Jens
    Koltzenburg, Martin
    Edlund, Thomas
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Villar, Marcelo J
    Ernfors, Patrik
    In vitro and in vivo differentiation of boundary cap neural crest stem cells into mature Schwann cells.2006In: Experimental Neurology, ISSN 0014-4886, Vol. 198, no 2, p. 438-49Article in journal (Refereed)
  • 16.
    Aripaka, Karthik
    et al.
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Gudey, Shyam Kumar
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Zang, Guangxiang
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Schmidt, Alexej
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Åhrling, Samaneh Shabani
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Österman, Lennart
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Medical and Clinical Genetics.
    Bergh, Anders
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    von Hofsten, Jonas
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Landström, Maréne
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    TRAF6 function as a novel co-regulator of Wnt3a target genes in prostate cancer2019In: EBioMedicine, E-ISSN 2352-3964, Vol. 45, p. 192-207Article in journal (Refereed)
    Abstract [en]

    Background: Tumour necrosis factor receptor associated factor 6 (TRAF6) promotes inflammation in response to various cytokines. Aberrant Wnt3a signals promotes cancer progression through accumulation of β-Catenin. Here we investigated a potential role for TRAF6 in Wnt signaling.

    Methods: TRAF6 expression was silenced by siRNA in human prostate cancer (PC3U) and human colorectal SW480 cells and by CRISPR/Cas9 in zebrafish. Several biochemical methods and analyses of mutant phenotype in zebrafish were used to analyse the function of TRAF6 in Wnt signaling.

    Findings: Wnt3a-treatment promoted binding of TRAF6 to the Wnt co-receptors LRP5/LRP6 in PC3U and LNCaP cells in vitro. TRAF6 positively regulated mRNA expression of β-Catenin and subsequent activation of Wnt target genes in PC3U cells. Wnt3a-induced invasion of PC3U and SW480 cells were significantly reduced when TRAF6 was silenced by siRNA. Database analysis revealed a correlation between TRAF6 mRNA and Wnt target genes in patients with prostate cancer, and high expression of LRP5, TRAF6 and c-Myc correlated with poor prognosis. By using CRISPR/Cas9 to silence TRAF6 in zebrafish, we confirm TRAF6 as a key molecule in Wnt3a signaling for expression of Wnt target genes.

    Interpretation: We identify TRAF6 as an important component in Wnt3a signaling to promote activation of Wnt target genes, a finding important for understanding mechanisms driving prostate cancer progression.

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  • 17.
    Asayesh, Amir
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Spleno-pancreatic development assessed by 3D molecular imaging2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The development of different organs and tissues along the gastrointestinal tract, including the pancreas, depends on signalling between the endoderm and the adjacent mesenchyme. The Nkx gene Bapx1 is involved in spatial control of organ-positioning in the spleno-pancreatic region, and deficiency in this gene results in unacceptable proximity of the splenic mesenchyme to the pancreas. This permits agitating signals from the splenic mesenchyme to induce an in vivo (and in vitro) transformation of pancreatic epithelium to a cystic structure with gut like features. Also, wild type splenic mesenchyme is competent to induce a similar transformation. These findings illustrate the importance for strict control of organ positioning during spleno-pancreatic development.

    Several growth factors and receptors involved in pancreatic development are activated by protease processing. Some of these growth factors have been implicated as substrates for members of the A Disintegrin And Metalloprotease (ADAM) family. The ADAMs 9, 10, and 17 are expressed during pancreatic development and in the adult pancreas, suggesting a possible role for these ADAMs in pancreatic development and function.

    Animal model systems are widely used to investigate gene function during development and disease. However, spatial, molecular, and quantitative phenotype screening in animals is a time consuming effort. Optical Projection Tomography is a 3-dimensional imaging technique that, in combination with improvements in sample preparation and computer processing, can be used to visualize and quantify characteristics of intact adult mouse organs such as the total β-cell content in the pancreas.

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    FULLTEXT01
  • 18.
    Asayesh, Amir
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Alanentalo, Tomas
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Khoo, Nelson K S
    Ahlgren, Ulf
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Developmental expression of metalloproteases ADAM 9, 10, and 17 becomes restricted to divergent pancreatic compartments.2005In: Developmental Dynamics, ISSN 1058-8388, E-ISSN 1097-0177, Vol. 232, no 4, p. 1105-1114Article in journal (Refereed)
  • 19.
    Asayesh, Amir
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Sharpe, James
    Watson, Robert P
    Hecksher-Sørensen, Jacob
    Hastie, Nicholas D
    Hill, Robert E
    Ahlgren, Ulf
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Spleen versus pancreas: strict control of organ interrelationship revealed by analyses of Bapx1-/- mice.2006In: Genes & Development, ISSN 0890-9369, E-ISSN 1549-5477, Vol. 20, no 16, p. 2208-2213Article in journal (Refereed)
  • 20. Baeyens, Luc
    et al.
    Lemper, Marie
    Leuckx, Gunter
    De Groef, Sofie
    Bonfanti, Paola
    Stange, Geert
    Shemer, Ruth
    Nord, Christoffer
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Scheel, David W
    Pan, Fong C
    Ahlgren, Ulf
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Gu, Guoqiang
    Stoffers, Doris A
    Dor, Yuval
    Ferrer, Jorge
    Gradwohl, Gerard
    Wright, Christopher VE
    Van de Casteele, Mark
    German, Michael S
    Bouwens, Luc
    Heimberg, Harry
    Transient cytokine treatment induces acinar cell reprogramming and regenerates functional beta cell mass in diabetic mice2014In: Nature Biotechnology, ISSN 1087-0156, E-ISSN 1546-1696, Vol. 32, no 1, p. 76-83Article in journal (Refereed)
    Abstract [en]

    Reprogramming of pancreatic exocrine cells into cells resembling beta cells may provide a strategy for treating diabetes. Here we show that transient administration of epidermal growth factor and ciliary neurotrophic factor to adult mice with chronic hyperglycemia efficiently stimulates the conversion of terminally differentiated acinar cells to beta-like cells. Newly generated beta-like cells are epigenetically reprogrammed, functional and glucose responsive, and they reinstate normal glycemic control for up to 248 d. The regenerative process depends on Stat3 signaling and requires a threshold number of Neurogenin 3 (Ngn3)-expressing acinar cells. In contrast to previous work demonstrating in vivo conversion of acinar cells to beta-like cells by viral delivery of exogenous transcription factors, our approach achieves acinar-to-beta-cell reprogramming through transient cytokine exposure rather than genetic modification.

  • 21.
    Berghard, Anna
    et al.
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Hägglund, Anna-Carin
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Bohm, Staffan
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Carlsson, Leif
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Lhx2-dependent specification of olfactory sensory neurons is required for successful integration of olfactory, vomeronasal, and GnRH neurons2012In: The FASEB Journal, ISSN 0892-6638, E-ISSN 1530-6860, Vol. 26, no 8, p. 3464-3472Article in journal (Refereed)
    Abstract [en]

    Inactivation of the LIM-homeodomain 2 gene (Lhx2) results in a severe defect in specification of olfactory sensory neurons (OSNs). However, the ramifications of lack of Lhx2-dependent OSN specification for formation of the primary olfactory pathway have not been addressed, since mutant mice die in utero. We have analyzed prenatal and postnatal consequences of conditionally inactivating Lhx2 selectively in OSNs. A cell-autonomous effect is that OSN axons cannot innervate their target, the olfactory bulb. Moreover, the lack of Lhx2 in OSNs causes unpredicted, non-cell-autonomous phenotypes. First, the olfactory bulb shows pronounced hypoplasia in adults, and the data suggest that innervation by correctly specified OSNs is necessary for adult bulb size and organization. Second, absence of an olfactory nerve in the conditional mutant reveals that the vomeronasal nerve is dependent on olfactory nerve formation. Third, the lack of a proper vomeronasal nerve prevents migration of gonadotropin-releasing hormone (GnRH) cells the whole distance to their final positions in the hypothalamus during embryo development. As adults, the conditional mutants do not pass puberty, and these findings support the view of an exclusive nasal origin of GnRH neurons in the mouse. Thus, Lhx2 in OSNs is required for functional development of three separate systems.—Berghard, A., Hägglund, A.-C., Bohm, S., and Carlsson, L. Lhx2-dependent specification of olfactory sensory neurons is required for successful integration of olfactory, vomeronasal, and GnRH neurons.

  • 22.
    Bergman, Marie-Louise
    et al.
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Instituto Gulbenkian de Ciencia, Oeiras, Portugal.
    Cilio, Corrado M
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Endocrine Research Unit, Wallenberg Laboratory, Malmö University Hospital MAS, University of Lund, 205 02 Malmö Sweden.
    Penha-Gonçalves, Carlos
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Instituto Gulbenkian de Ciencia, Oeiras, Portugal.
    Lamhamedi-Cherradi, Salah-Eddine
    INSERM U25, Hopital Necker, Paris, France.
    Löfgren, Anna
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Colucci, Francesco
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Lejon, Kristina
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Garchon, Henri-Jean
    INSERM U25, Hopital Necker, Paris, France.
    Holmberg, Dan
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Instituto Gulbenkian de Ciencia, Oeiras, Portugal.
    CTLA-4-/- mice display T cell-apoptosis resistance resembling that ascribed to autoimmune-prone non-obese diabetic (NOD) mice2001In: Journal of Autoimmunity, ISSN 0896-8411, E-ISSN 1095-9157, Vol. 16, no 2, p. 105-113Article in journal (Refereed)
    Abstract [en]

    The genes conferring susceptibility to autoimmune (insulin-dependent) diabetes mellitus (IDDM) are, in most cases, not defined. Among the loci so far identified as associated with murine IDDM (Idd1-19), only the nature of Idd1 has been assessed. Here we show that thymocytes and peripheral lymphocytes of the non-obese diabetic (NOD) mouse are relatively resistant to apoptosis induced by gamma-irradiation. By linkage analysis of F2 progeny mice, we map this trait to a locus on chromosome 1 containing the Idd5 diabetes susceptibility region. By the use of congenic mice, we confirm the linkage data and map this locus to a 6 cM region on proximal chromosome 1. Ctla4, being localized in this chromosomal region and mediating crucial functions in T cell biology, is a logical candidate gene in the Idd5 susceptibility region. In line with this, we demonstrate that T cells from Ctla4(-/-)deficient mice show a similar resistance to gamma-irradiation-induced apoptosis as observed in the NOD mice. This reinforces the notion that CTLA-4 contributes to the pathogenesis of autoimmune diabetes.

  • 23.
    Bergman, Marie-Louise
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Duarte, Nadia
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Instituto Gulbenkian de Ciencia, Oeiras, Portugal .
    Campino, Susana
    Instituto Gulbenkian de Ciencia, Oeiras, Portugal .
    Lundholm, Marie
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Motta, Vinicius
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Lejon, Kristina
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Penha-Gonçalves, Carlos
    Instituto Gulbenkian de Ciencia, Oeiras, Portugal.
    Holmberg, Dan
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Instituto Gulbenkian de Ciencia, Oeiras, Portugal.
    Diabetes protection and restoration of thymocyte apoptosis in NOD Idd6 congenic strains2003In: Diabetes, ISSN 0012-1797, E-ISSN 1939-327X, Vol. 52, no 7, p. 1677-1682Article in journal (Refereed)
    Abstract [en]

    Type 1 diabetes in the nonobese diabetic (NOD) mouse is a multifactorial and polygenic disease. The NOD-derived genetic factors that contribute to type 1 diabetes are named Idd (insulin-dependent diabetes) loci. To date, the biological functions of the majority of the Idd loci remain unknown. We have previously reported that resistance of NOD immature thymocytes to depletion by dexamethazone (Dxm) maps to the Idd6 locus. Herein, we refine this phenotype using a time-course experiment of apoptosis induction upon Dxm treatment. We confirm that the Idd6 region controls apoptosis resistance in immature thymocytes. Moreover, we establish reciprocal Idd6 congenic NOD and B6 strains to formally demonstrate that the Idd6 congenic region mediates restoration of the apoptosis resistance phenotype. Analysis of the Idd6 congenic strains indicates that a 3-cM chromosomal region located within the distal part of the Idd6 region controls apoptosis resistance in NOD immature thymocytes. Together, these data support the hypothesis that resistance to Dxm-induced apoptosis in NOD immature thymocytes is controlled by a genetic factor within the region that also contributes to type 1 diabetes pathogenesis. We propose that the diabetogenic effect of the Idd6 locus is exerted at the level of the thymic selection process.

  • 24.
    Bergqvist, Ingela
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Eriksson, Maria
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Saarikettu, Juha
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Eriksson, Björn
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Corneliussen, Brit
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Grundström, Thomas
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Holmberg, Dan
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    The basic helix-loop-helix transcription factor E2-2 is involved in T lymphocyte development2000In: European Journal of Immunology, ISSN 0014-2980, E-ISSN 1521-4141, Vol. 30, no 10, p. 2857-2863Article in journal (Refereed)
    Abstract [en]

    E2A, HEB and E2-2 genes encode a group of basic helix-loop-helix (bHLH) transcription factors that are structurally and functionally similar. Deletion of the genes encoding either of these proteins leads to early lethality and a block in B lymphocyte development. Evidence for a function in T lymphocyte development has, however, only been reported for E2A and HEB. To further elucidate the role of E2-2 at developmental stages that have proven difficult to study due to the early lethality phenotype of mice defective in E2-2, we generated and analyzed mice conditionally mutated in the E2-2 gene. These mice are mosaic with respect to E2-2 expression, consisting of cells with either one functional and one null mutated E2-2 allele or two null mutated alleles. Using this experimental model, we find that cells with a homozygous null mutated E2-2 gene are under-represented in B lymphocyte as well as T lymphocyte cell lineages as compared to other hematopoietic or non-hematopoietic cell lineages. Our data suggests that E2-2 deficiency leads to a partial block in both B and T lymphocyte development. The block in T cell development appears to occur at an early stage in differentiation, since skewing in the mosaicism is observed already in CD4+8+ double-positive thymocytes.

  • 25.
    Boucher, Marie-Josée
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Selander, Lars
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Carlsson, Lennart
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Edlund, Helena
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Phosphorylation marks IPF1/PDX1 protein for degradation by glycogen synthase kinase 3-dependent mechanisms.2006In: The Journal of Biological Chemistry, ISSN 0021-9258, Vol. 281, no 10, p. 6395-403Article in journal (Refereed)
  • 26. Boucher, Marie-Josée
    et al.
    Simoneau, Mélanie
    Edlund, Helena
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    The homeodomain-interacting protein kinase 2 regulates insulin promoter factor-1/pancreatic duodenal homeobox-1 transcriptional activity2009In: Endocrinology, ISSN 0013-7227, E-ISSN 1945-7170, Vol. 150, no 1, p. 87-97Article in journal (Refereed)
    Abstract [en]

    The homeodomain transcription factor insulin promoter factor (IPF)-1/pancreatic duodenal homeobox (PDX)-1 plays a crucial role in both pancreas development and maintenance of beta-cell function. Targeted disruption of the Ipf1/Pdx1 gene in beta-cells of mice leads to overt diabetes and reduced Ipf1/Pdx1 gene expression results in decreased insulin expression and secretion. In humans, mutations in the IPF1 gene have been linked to diabetes. Hence, the identification of molecular mechanisms regulating the transcriptional activity of this key transcription factor is of great interest. Herein we analyzed homeodomain-interacting protein kinase (Hipk) 2 expression in the embryonic and adult pancreas by in situ hybridization and RT-PCR. Moreover, we functionally characterized the role of HIPK2 in regulating IPF1/PDX1 transcriptional activity by performing transient transfection experiments and RNA interference. We show that Hipk2 is expressed in the developing pancreatic epithelium from embryonic d 12-15 but that the expression becomes preferentially confined to pancreatic endocrine cells at later developmental stages. Moreover, we show that HIPK2 positively influences IPF1/PDX1 transcriptional activity and that the kinase activity of HIPK2 is required for this effect. We also demonstrate that HIPK2 directly phosphorylates the C-terminal portion of IPF1/PDX1. Taken together, our data provide evidence for a new mechanism by which IPF1/PDX1 transcriptional activity, and thus possibly pancreas development and/or beta-cell function, is regulated.

  • 27.
    Burguière, Anne-Cecile
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Nord, Hanna
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    von Hofsten, Jonas
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Alkali-like myosin light chain-1 (myl1) is an early marker for differentiating fast muscle cells in zebrafish2011In: Developmental Dynamics, ISSN 1058-8388, E-ISSN 1097-0177, Vol. 240, no 7, p. 1856-1863Article in journal (Refereed)
    Abstract [en]

    During myogenesis, muscle precursors become divided into either fast- or slow-twitch fibres, which in the zebrafish occupy distinct domains in the embryo. Genes encoding sarcomeric proteins specific for fast or slow fibres are frequently used as lineage markers. In an attempt to identify and evaluate early definitive markers for cells in the fast-twitch pathway, we analysed genes encoding proteins contributing to the fast sarcomeric structures. The previously uncharacterized zebrafish alkali-like myosin light chain gene (myl1) was found to be expressed exclusively in cells in the fast-twitch pathway initiated at an early stage of fast fibre differentiation. Myl1 was expressed earlier, and in a more fibre type restricted manner, than any of the previously described and frequently used fast myosin light and heavy chain and troponin muscle markers mylz2, mylz3, tnni2, tnnt3a, fMyHC1.3. In summary, this study introduces a novel marker for early differentiating fast muscle cells.

  • 28.
    Burén, Jonas
    et al.
    Umeå University, Faculty of Social Sciences, Department of Food, Nutrition and Culinary Science. Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Ericsson, Madelene
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Department of Medical Biosciences, Physiological chemistry.
    Damasceno, Nágila Raquel Teixeira
    Department of Nutrition, School of Public Health, University of Sao Paulo, Sao Paulo, Brazil.
    Sjödin, Anna
    Umeå University, Faculty of Social Sciences, Department of Food, Nutrition and Culinary Science.
    A ketogenic low‐carbohydrate high‐fat diet increases ldl cholesterol in healthy, young, normal‐weight women: A randomized controlled feeding trial2021In: Nutrients, E-ISSN 2072-6643, Vol. 13, no 3, p. 1-12, article id 814Article in journal (Refereed)
    Abstract [en]

    Ketogenic low‐carbohydrate high‐fat (LCHF) diets are popular among young, healthy, normal‐weight individuals for various reasons. We aimed to investigate the effect of a ketogenic LCHF diet on low‐density lipoprotein (LDL) cholesterol (primary outcome), LDL cholesterol sub-fractions and conventional cardiovascular risk factors in the blood of healthy, young, and nor-mal‐weight women. The study was a randomized, controlled, feeding trial with crossover design. Twenty‐four women were assigned to a 4 week ketogenic LCHF diet (4% carbohydrates; 77% fat; 19% protein) followed by a 4 week National Food Agency recommended control diet (44% carbo-hydrates; 33% fat; 19% protein), or the reverse sequence due to the crossover design. Treatment periods were separated by a 15 week washout period. Seventeen women completed the study and treatment effects were evaluated using mixed models. The LCHF diet increased LDL cholesterol in every woman with a treatment effect of 1.82 mM (p < 0.001). In addition, Apolipoprotein B‐100 (ApoB), small, dense LDL cholesterol as well as large, buoyant LDL cholesterol increased (p < 0.001, p < 0.01, and p < 0.001, respectively). The data suggest that feeding healthy, young, normal‐weight women a ketogenic LCHF diet induces a deleterious blood lipid profile. The elevated LDL cholesterol should be a cause for concern in young, healthy, normal‐weight women following this kind of LCHF diet.

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  • 29.
    Burén, Jonas
    et al.
    Umeå University, Faculty of Social Sciences, Department of Food, Nutrition and Culinary Science. Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Ericsson, Madelene
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Damasceno, Nágila Raquel Teixeira
    Department of Nutrition, School of Public Health, University of Sao Paulo, Sao Paulo, Brazil.
    Sjödin, Anna
    Umeå University, Faculty of Social Sciences, Department of Food, Nutrition and Culinary Science.
    Reply to Ravnskov, U. Is High Cholesterol Deleterious? An Alternative Point of View. Comment on “Burén et al. A Ketogenic Low-Carbohydrate High-Fat Diet Increases LDL Cholesterol in Healthy, Young, Normal-Weight Women: A Randomized Controlled Feeding Trial. Nutrients 2021, 13, 814”2021In: Nutrients, E-ISSN 2072-6643, Vol. 13, no 7, article id 2127Article in journal (Refereed)
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  • 30.
    Carlsson, Anna
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Forsgren, Lars
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Nylander, P-O
    Hellman, Urban
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Medical and Clinical Genetics.
    Forsman-Semb, Kristina
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Medical and Clinical Genetics.
    Holmgren, Gösta
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Medical and Clinical Genetics.
    Holmberg, Dan
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Holmberg, Monica
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Identification of a susceptibility locus for migraine with and without aura on 6p12.2-p21.1.2002In: Neurology, ISSN 0028-3878, E-ISSN 1526-632X, Vol. 59, no 11, p. 1804-1807Article in journal (Refereed)
    Abstract [en]

    Migraine is the most common type of chronic episodic headache. To find novel susceptibility genes for familial migraine with and without aura, a genomewide screen was performed in a large family from northern Sweden. Evidence of linkage was obtained on chromosome 6p12.2-p21.1, with a maximum two-point lod score of 5.41 for marker D6S452. The patients with migraine shared a common haplotype of 10 Mb between markers D6S1650 and D6S1960.

  • 31.
    Carlsson, Leif
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Periodiskt uttryck av genen Lhx2 reglerar hårväxten2010In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 107, no 24-25, p. 1616-Article in journal (Other academic)
  • 32.
    Chakraborty, Chaitali
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Nissen, Itzel
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Vincent, Craig A.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Hägglund, Anna-Carin
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Hörnblad, Andreas
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Remeseiro, Silvia
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Rewiring of the promoter-enhancer interactome and regulatory landscape in glioblastoma orchestrates gene expression underlying neurogliomal synaptic communication2023In: Nature Communications, E-ISSN 2041-1723, Vol. 14, no 1, article id 6446Article in journal (Refereed)
    Abstract [en]

    Chromatin organization controls transcription by modulating 3D-interactions between enhancers and promoters in the nucleus. Alterations in epigenetic states and 3D-chromatin organization result in gene expression changes contributing to cancer. Here, we map the promoter-enhancer interactome and regulatory landscape of glioblastoma, the most aggressive primary brain tumour. Our data reveals profound rewiring of promoter-enhancer interactions, chromatin accessibility and redistribution of histone marks in glioblastoma. This leads to loss of long-range regulatory interactions and overall activation of promoters, which orchestrate changes in the expression of genes associated to glutamatergic synapses, axon guidance, axonogenesis and chromatin remodelling. SMAD3 and PITX1 emerge as major transcription factors controlling genes related to synapse organization and axon guidance. Inhibition of SMAD3 and neuronal activity stimulation cooperate to promote proliferation of glioblastoma cells in co-culture with glutamatergic neurons, and in mice bearing patient-derived xenografts. Our findings provide mechanistic insight into the regulatory networks that mediate neurogliomal synaptic communication.

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  • 33.
    Chambers, Julia
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Characterization of two insulin resistance associated genes in adipocytes2018Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 34.
    Cheddad, Abbas
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Nord, Christoffer
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Hörnblad, Andreas
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Prunskaite-Hyyryläinen, Renata
    Oulu Center for Cell-Matrix Research, Biocenter Oulu, Laboratory of Developmental Biology and Department of Medical Biochemistry and Molecular Biology, Institute of Biomedicine, University of Oulu, Finland.
    Eriksson, Maria
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Georgsson, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Vainio, Seppo
    Oulu Center for Cell-Matrix Research, Biocenter Oulu, Laboratory of Developmental Biology and Department of Medical Biochemistry and Molecular Biology, Institute of Biomedicine, University of Oulu, Finland.
    Ahlgren, Ulf
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Improving signal detection in emission optical projection tomography via single source multi-exposure image fusion2013In: Optics Express, E-ISSN 1094-4087, Vol. 21, no 14, p. 16584-16604Article in journal (Refereed)
    Abstract [en]

    We demonstrate a technique to improve structural data obtained from Optical Projection Tomography (OPT) using Image Fusion (IF) and contrast normalization. This enables the visualization of molecular expression patterns in biological specimens with highly variable contrast values. In the approach, termed IF-OPT, different exposures are fused by assigning weighted contrasts to each. When applied to projection images from mouse organs and digital phantoms our results demonstrate the capability of IF-OPT to reveal high and low signal intensity details in challenging specimens. We further provide measurements to highlight the benefits of the new algorithm in comparison to other similar methods.

  • 35.
    Cheddad, Abbas
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Svensson, Christoffer
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Sharpe, James
    Georgsson, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Ahlgren, Ulf
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Image processing assisted algorithms for optical projection tomography2012In: IEEE Transactions on Medical Imaging, ISSN 0278-0062, E-ISSN 1558-254X, Vol. 31, no 1, p. 1-15Article in journal (Refereed)
    Abstract [en]

    Since it was first presented in 2002, optical projection tomography (OPT) has emerged as a powerful tool for the study of biomedical specimen on the mm to cm scale. In this paper, we present computational tools to further improve OPT image acquisition and tomographic reconstruction. More specifically, these methods provide: semi-automatic and precise positioning of a sample at the axis of rotation and a fast and robust algorithm for determination of postalignment values throughout the specimen as compared to existing methods. These tools are easily integrated for use with current commercial OPT scanners and should also be possible to implement in "home made" or experimental setups for OPT imaging. They generally contribute to increase acquisition speed and quality of OPT data and thereby significantly simplify and improve a number of three-dimensional and quantitative OPT based assessments.

  • 36.
    Chen, Changchun
    et al.
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Tuck, Simon
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Byström, Anders S
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Defects in tRNA modification associated with neurological and developmental dysfunctions in Caenorhabditis elegans elongator mutants2009In: PLoS genetics, ISSN 1553-7404, Vol. 5, no 7, p. e1000561-Article in journal (Refereed)
    Abstract [en]

    Elongator is a six subunit protein complex, conserved from yeast to humans. Mutations in the human Elongator homologue, hELP1, are associated with the neurological disease familial dysautonomia. However, how Elongator functions in metazoans, and how the human mutations affect neural functions is incompletely understood. Here we show that in Caenorhabditis elegans, ELPC-1 and ELPC-3, components of the Elongator complex, are required for the formation of the 5-carbamoylmethyl and 5-methylcarboxymethyl side chains of wobble uridines in tRNA. The lack of these modifications leads to defects in translation in C. elegans. ELPC-1::GFP and ELPC-3::GFP reporters are strongly expressed in a subset of chemosensory neurons required for salt chemotaxis learning. elpc-1 or elpc-3 gene inactivation causes a defect in this process, associated with a posttranscriptional reduction of neuropeptide and a decreased accumulation of acetylcholine in the synaptic cleft. elpc-1 and elpc-3 mutations are synthetic lethal together with those in tuc-1, which is required for thiolation of tRNAs having the 5'methylcarboxymethyl side chain. elpc-1; tuc-1 and elpc-3; tuc-1 double mutants display developmental defects. Our results suggest that, by its effect on tRNA modification, Elongator promotes both neural function and development.

  • 37. Chotard, Laëtitia
    et al.
    Mishra, Ashwini K
    Sylvain, Marc-André
    Tuck, Simon
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Lambright, David G
    Rocheleau, Christian E
    TBC-2 regulates RAB-5/RAB-7-mediated endosomal trafficking in Caenorhabditis elegans2010In: Molecular Biology of the Cell, ISSN 1059-1524, E-ISSN 1939-4586, Vol. 21, no 13, p. 2285-2296Article in journal (Refereed)
    Abstract [en]

    During endosome maturation the early endosomal Rab5 GTPase is replaced with the late endosomal Rab7 GTPase. It has been proposed that active Rab5 can recruit and activate Rab7, which in turn could inactivate and remove Rab5. However, many of the Rab5 and Rab7 regulators that mediate endosome maturation are not known. Here, we identify Caenorhabditis elegans TBC-2, a conserved putative Rab GTPase-activating protein (GAP), as a regulator of endosome to lysosome trafficking in several tissues. We show that tbc-2 mutant animals accumulate enormous RAB-7-positive late endosomes in the intestine containing refractile material. RAB-5, RAB-7, and components of the homotypic fusion and vacuole protein sorting (HOPS) complex, a RAB-7 effector/putative guanine nucleotide exchange factor (GEF), are required for the tbc-2(-) intestinal phenotype. Expression of activated RAB-5 Q78L in the intestine phenocopies the tbc-2(-) large late endosome phenotype in a RAB-7 and HOPS complex-dependent manner. TBC-2 requires the catalytic arginine-finger for function in vivo and displays the strongest GAP activity on RAB-5 in vitro. However, TBC-2 colocalizes primarily with RAB-7 on late endosomes and requires RAB-7 for membrane localization. Our data suggest that TBC-2 functions on late endosomes to inactivate RAB-5 during endosome maturation.

  • 38.
    Chotiwan, Nunya
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Chakri Naruebodindra Medical Institute, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Samut Prakan, Thailand.
    Rosendal, Ebba
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Willekens, Stefanie M. A.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Schexnaydre, Erin
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM). Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Nilsson, Emma
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Lindquist, Richard
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Hahn, Max
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Mihai, Ionut Sebastian
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Morini, Federico
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Zhang, Jianguo
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM). Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Ebel, Gregory D.
    Department of Microbiology, Immunology and Pathology, Colorado State University, CO, Fort Collins, United States.
    Carlson, Lars-Anders
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM). Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Henriksson, Johan
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Ahlgren, Ulf
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Marcellino, Daniel
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Överby, Anna K.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Type I interferon shapes brain distribution and tropism of tick-borne flavivirus2023In: Nature Communications, E-ISSN 2041-1723, Vol. 14, no 1, article id 2007Article in journal (Refereed)
    Abstract [en]

    Viral tropism within the brain and the role(s) of vertebrate immune response to neurotropic flaviviruses infection is largely understudied. We combine multimodal imaging (cm-nm scale) with single nuclei RNA-sequencing to study Langat virus in wildtype and interferon alpha/beta receptor knockout (Ifnar-/-) mice to visualize viral pathogenesis and define molecular mechanisms. Whole brain viral infection is imaged by Optical Projection Tomography coregistered to ex vivo MRI. Infection is limited to grey matter of sensory systems in wildtype mice, but extends into white matter, meninges and choroid plexus in Ifnar-/- mice. Cells in wildtype display strong type I and II IFN responses, likely due to Ifnb expressing astrocytes, infiltration of macrophages and Ifng-expressing CD8+ NK cells, whereas in Ifnar-/-, the absence of this response contributes to a shift in cellular tropism towards non-activated resident microglia. Multimodal imaging-transcriptomics exemplifies a powerful way to characterize mechanisms of viral pathogenesis and tropism.

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  • 39. Collin, Shaun P.
    et al.
    Davies, Wayne I. L.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). School of Biological Sciences, The University of Western Australia, Perth, WA, Australia;The Oceans Graduate School, The University of Western Australia, Perth, WA, Australia;The Oceans Institute, The University of Western Australia, Perth, WA, Australia;Centre for Ophthalmology and Visual Science, Lions Eye Institute, The University of Western Australia, Perth, WA, Australia.
    Editorial: Biodiversity of Sensory Systems in Aquatic Vertebrates2020In: Frontiers in Ecology and Evolution, E-ISSN 2296-701X, Vol. 8, article id 192Article in journal (Refereed)
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  • 40. Comai, Glenda Evangelina
    et al.
    Tesarova, Marketa
    Dupe, Valerie
    Rhinn, Muriel
    Vallecillo-Garcia, Pedro
    da Silva, Fabio
    Feret, Betty
    Exelby, Katherine
    Dolle, Pascal
    Carlsson, Leif
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Pryce, Brian
    Spitz, Francois
    Stricker, Sigmar
    Zikmund, Tomas
    Kaiser, Jozef
    Briscoe, James
    Schedl, Andreas
    Ghyselinck, Norbert B.
    Schweitzer, Ronen
    Tajbakhsh, Shahragim
    Local retinoic acid signaling directs emergence of the extraocular muscle functional unit2020In: PLoS biology, ISSN 1544-9173, E-ISSN 1545-7885, Vol. 18, no 11, article id e3000902Article in journal (Refereed)
    Abstract [en]

    Coordinated development of muscles, tendons, and their attachment sites ensures emergence of functional musculoskeletal units that are adapted to diverse anatomical demands among different species. How these different tissues are patterned and functionally assembled during embryogenesis is poorly understood. Here, we investigated the morphogenesis of extraocular muscles (EOMs), an evolutionary conserved cranial muscle group that is crucial for the coordinated movement of the eyeballs and for visual acuity. By means of lineage analysis, we redefined the cellular origins of periocular connective tissues interacting with the EOMs, which do not arise exclusively from neural crest mesenchyme as previously thought. Using 3D imaging approaches, we established an integrative blueprint for the EOM functional unit. By doing so, we identified a developmental time window in which individual EOMs emerge from a unique muscle anlage and establish insertions in the sclera, which sets these muscles apart from classical muscle-to-bone type of insertions. Further, we demonstrate that the eyeballs are a source of diffusible all-trans retinoic acid (ATRA) that allow their targeting by the EOMs in a temporal and dose-dependent manner. Using genetically modified mice and inhibitor treatments, we find that endogenous local variations in the concentration of retinoids contribute to the establishment of tendon condensations and attachment sites that precede the initiation of muscle patterning. Collectively, our results highlight how global and site-specific programs are deployed for the assembly of muscle functional units with precise definition of muscle shapes and topographical wiring of their tendon attachments.

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  • 41. Correa-Medina, Mayrin
    et al.
    Bravo-Egana, Valia
    Rosero, Samuel
    Ricordi, Camillo
    Diez, Juan
    Edlund, Helena
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Pastori, Ricardo L
    MicroRNA miR-7 is preferentially expressed in endocrine cells of the developing and adult human pancreas.2009In: Gene Expression Patterns, ISSN 1567-133X, E-ISSN 1872-7298, Vol. 9, no 4, p. 193-9Article in journal (Refereed)
    Abstract [en]

    MicroRNAs (miRNA) are small non-coding RNAs that inhibit gene expression through binding to complementary messenger RNA sequences. miRNAs have been predicted to target genes important for pancreas development, proper endocrine cell function and metabolism. We previously described that miRNA-7 (miR-7) was the most abundant and differentially expressed islet miRNA, with 200-fold higher expression in mature human islets than in acinar tissue. Here we have analyzed the temporal and spatial expression of miR-7 in human fetal pancreas from 8 to 22 weeks of gestational age (wga). Human fetal (8-22wga) and adult pancreases were processed for immunohistochemistry, in situ hybridization, and quantitative RT-PCR of miRNA and mRNA. miR-7 was expressed in the human developing pancreas from around 9wga and reached its maximum expression levels between 14 and 18wga, coinciding with the exponential increase of the pancreatic endocrine hormones. Throughout development miR-7 expression was preferentially localized to endocrine cells and its expression persisted in the adult pancreas. The present study provides a detailed analysis of the spatiotemporal expression of miR-7 in developing human pancreas. The specific localization of miR-7 expression to fetal and adult endocrine cells indicates a potential role for miR-7 in endocrine cell differentiation and/or function. Future functional studies of a potential role for miR-7 function in islet cell differentiation and physiology are likely to identify novel targets for the treatment of diabetes and will lead to the development of improved protocols for generating insulin-producing cells for cell replacement therapy.

  • 42.
    Cova, Giovanni
    et al.
    Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France.
    Taroni, Chiara
    Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France.
    Deau, Marie-Céline
    Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France.
    Cai, Qi
    Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France.
    Mittelheisser, Vincent
    Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France.
    Philipps, Muriel
    Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France.
    Jung, Matthieu
    Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France; Plateforme GenomEast, Infrastructure France Génomique, Illkirch, France.
    Cerciat, Marie
    Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France; Plateforme GenomEast, Infrastructure France Génomique, Illkirch, France.
    Le Gras, Stéphanie
    Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France; Plateforme GenomEast, Infrastructure France Génomique, Illkirch, France.
    Thibault-Carpentier, Christelle
    Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France; Plateforme GenomEast, Infrastructure France Génomique, Illkirch, France.
    Jost, Bernard
    Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France; Plateforme GenomEast, Infrastructure France Génomique, Illkirch, France.
    Carlsson, Leif
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Thornton, Angela M.
    Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, MD, Bethesda, United States.
    Shevach, Ethan M.
    Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, MD, Bethesda, United States.
    Kirstetter, Peggy
    Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France.
    Kastner, Philippe
    Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France; Faculté de Médecine, Université de Strasbourg, Strasbourg, France.
    Chan, Susan
    Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France; Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, France; Université de Strasbourg, Illkirch, France.
    Helios represses megakaryocyte priming in hematopoietic stem and progenitor cells2021In: Journal of Experimental Medicine, ISSN 0022-1007, E-ISSN 1540-9538, Vol. 218, no 10, article id e20202317Article in journal (Refereed)
    Abstract [en]

    Our understanding of cell fate decisions in hematopoietic stem cells is incomplete. Here, we show that the transcription factor Helios is highly expressed in murine hematopoietic stem and progenitor cells (HSPCs), where it is required to suppress the separation of the platelet/megakaryocyte lineage from the HSPC pool. Helios acts mainly in quiescent cells, where it directly represses the megakaryocyte gene expression program in cells as early as the stem cell stage. Helios binding promotes chromatin compaction, notably at the regulatory regions of platelet-specific genes recognized by the Gata2 and Runx1 transcriptional activators, implicated in megakaryocyte priming. Helios null HSPCs are biased toward the megakaryocyte lineage at the expense of the lymphoid and partially resemble cells of aging animals. We propose that Helios acts as a guardian of HSPC pluripotency by continuously repressing the megakaryocyte fate, which in turn allows downstream lymphoid priming to take place. These results highlight the importance of negative and positive priming events in lineage commitment.

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  • 43. Crabtree, Judy S
    et al.
    Scacheri, Peter C
    Ward, Jerrold M
    McNally, Sara R
    Swain, Gary P
    Montagna, Cristina
    Hager, Jeffrey H
    Hanahan, Douglas
    Edlund, Helena
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Magnuson, Mark A
    Garrett-Beal, Lisa
    Burns, A Lee
    Ried, Thomas
    Chandrasekharappa, Settara C
    Marx, Stephen J
    Spiegel, Allen M
    Collins, Francis S
    Of mice and MEN1: Insulinomas in a conditional mouse knockout.2003In: Molecular and Cellular Biology, ISSN 0270-7306, E-ISSN 1098-5549, Vol. 23, no 17, p. 6075-6085Article in journal (Refereed)
    Abstract [en]

    Patients with multiple endocrine neoplasia type 1 (MEN1) develop multiple endocrine tumors, primarily affecting the parathyroid, pituitary, and endocrine pancreas, due to the inactivation of the MEN1 gene. A conditional mouse model was developed to evaluate the loss of the mouse homolog, Men1, in the pancreatic beta cell. Men1 in these mice contains exons 3 to 8 flanked by loxP sites, such that, when the mice are crossed to transgenic mice expressing cre from the rat insulin promoter (RIP-cre), exons 3 to 8 are deleted in beta cells. By 60 weeks of age, >80% of mice homozygous for the floxed Men1 gene and expressing RIP-cre develop multiple pancreatic islet adenomas. The formation of adenomas results in elevated serum insulin levels and decreased blood glucose levels. The delay in tumor appearance, even with early loss of both copies of Men1, implies that additional somatic events are required for adenoma formation in beta cells. Comparative genomic hybridization of beta cell tumor DNA from these mice reveals duplication of chromosome 11, potentially revealing regions of interest with respect to tumorigenesis.

  • 44.
    Dahl, Lina
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Stem cell function and organ development: analysis of Lhx2 function in hematopoietic stem cells and eye development2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    When a multicellular organism suffers damages to tissues/organs it heals itself by either substituting the lost cellular matrix by scar formation or by regenerating the lost tissue. Regeneration likely occurs by a recapitulation of the developmental process that formed the organ. Many processes regulating organ development are based on epithelial-mesenchymal interactions and a strict control of organ specific stem/progenitor cells. Elucidation of the molecular basis of these processes is therefore vital in order to develop novel therapies in regenerative medicine. The LIM homebox gene Lhx2 is interesting in this context since Lhx2 has been shown to be important for the formation of several organs by regulating epithelial-mesenchymal interactions and progenitor cell function. Targeted inactivation of Lhx2 leads to a lethal anemia due to malformed liver and severe neural abnormalities such as hypoplasia of the forebrain and anophtalmia. Thus, elucidation of the mechanisms of the function of Lhx2 in different organ systems would give important insights into the molecular mechanisms regulating epithelial-mesenchymal interactions and stem/progenitor cell function.

    To elucidate the function of Lhx2 in the hematopoietic system Lhx2 was initially expressed in hematopoietic progenitor cells derived from ES cells differentiated in vitro using retroviral vectors. This approach led to the generation of hematopoietic stem cell (HSC)-like cell lines suggesting that Lhx2 could impact HSC function. However neither the specificity nor the efficiency of the Lhx2-induced phenotype could be determined using this approach. To be able to elucidate the function of Lhx2 in the hematopoietic system, an ES cell line with inducible Lhx2 expression was generated. Lhx2 expression induces self-renewal of a distinct hematopoietic progenitor cell from which HSC-like cell lines were established. Down-regulation of Lhx2 in these HSC-like cell lines leads to a rapid loss of stem cell character, providing a good model to study the molecular function of Lhx2 in hematopoietic stem/progenitor cells. A global gene expression analysis was performed comparing the Lhx2+ stem cell population to the Lhx2- differentiated progeny. This approach identified genes putatively linked to self-renewal/differentiation of HSCs. A considerable proportion of the genes showed an overlapping gene expression pattern with Lhx2 expression in tissue of non-hematopoietic origin suggesting that Lhx2 function in stem/progenitor cells partly overlap with Lhx2 function during organ development.

    In order to define other Lhx2-dependent progenitor cell populations and to generate a tool to analyze the function of Lhx2 in organ development a new transgenic mouse model was generated. By using a specific part of the Lhx2 promoter to drive expression of Cre recombinase in vivo (Lhx2-Cre mice) we have been able to define the first eye committed progenitor cells in the forebrain. By using the Lhx2-Cre mice it will be possible to distinguish the function of genes during eye development from their function in the patterning of the forebrain e.g. the eye field transcription factors. Conditional inactivation of Lhx2 in these eye specific progenitor cells causes an immediate developmental arrest. The transgene is also active in Lhx2-/- embryonic forebrain, but re-expression of Lhx2 in Lhx2-/- progenitor cells only promote formation of retinal pigment epithelium cells. Analysis of genes expressed by the Lhx2+ stem cell population allowed us to define novel genes putatively linked to Lhx2 function in eye development. Thus, we have defined the progenitor cells in the forebrain committed to eye development and the expansion and patterning of these progenitors are dependent on Lhx2. Although commitment to eye development is Lhx2-independent, Lhx2 might be important for the acquisition of the oligopotent fate of these progenitor cells.

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  • 45.
    Dahl, Lina
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Richter, Karin
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Carlsson, Leif
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Lhx2 promotes self-renewal of a distinct multipotent hematopoietic progenitor cell in embryoid bodies2008In: PLoS one, ISSN 1932-6203, Vol. 3, no 4, p. e2025-Article in journal (Refereed)
    Abstract [en]

    The molecular mechanisms regulating the expansion of the hematopoietic system including hematopoietic stem cells (HSCs) in the fetal liver during embryonic development are largely unknown. The LIM-homeobox gene Lhx2 is a candidate regulator of fetal hematopoiesis since it is expressed in the fetal liver and Lhx2−/− mice die in utero due to severe anemia. Moreover, expression of Lhx2 in embryonic stem (ES) cell-derived embryoid bodies (EBs) can lead to the generation of HSC-like cell lines. To further define the role of this transcription factor in hematopoietic regulation, we generated ES cell lines that enabled tet-inducible expression of Lhx2. Using this approach we observed that Lhx2 expression synergises with specific signalling pathways, resulting in increased frequency of colony forming cells in developing EB cells. The increase in growth factor-responsive progenitor cells directly correlates to the efficiency in generating HSC-like cell lines, suggesting that Lhx2 expression induce self-renewal of a distinct multipotential hematopoietic progenitor cell in EBs. Signalling via the c-kit tyrosine kinase receptor and the gp130 signal transducer by IL-6 is necessary and sufficient for the Lhx2 induced self-renewal. While inducing self-renewal of multipotential progenitor cells, expression of Lhx2 inhibited proliferation of primitive erythroid precursor cells and interfered with early ES cell commitment, indicating striking lineage specificity of this effect.

  • 46.
    Dakhel, Soran
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Davies, Wayne I. L.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Joseph, Justin V.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Tomar, Tushar
    PamGene International B.V, 's-Hertogenbosch, Wolvenhoek 10, Netherlands.
    Remeseiro, Silvia
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Gunhaga, Lena
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Chick fetal organ spheroids as a model to study development and disease2021In: BMC Molecular and Cell Biology, E-ISSN 2661-8850, Vol. 22, no 1, article id 37Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Organ culture models have been used over the past few decades to study development and disease. The in vitro three-dimensional (3D) culture system of organoids is well known, however, these 3D systems are both costly and difficult to culture and maintain. As such, less expensive, faster and less complex methods to maintain 3D cell culture models would complement the use of organoids. Chick embryos have been used as a model to study human biology for centuries, with many fundamental discoveries as a result. These include cell type induction, cell competence, plasticity and contact inhibition, which indicates the relevance of using chick embryos when studying developmental biology and disease mechanisms.

    RESULTS: Here, we present an updated protocol that enables time efficient, cost effective and long-term expansion of fetal organ spheroids (FOSs) from chick embryos. Utilizing this protocol, we generated FOSs in an anchorage-independent growth pattern from seven different organs, including brain, lung, heart, liver, stomach, intestine and epidermis. These three-dimensional (3D) structures recapitulate many cellular and structural aspects of their in vivo counterpart organs and serve as a useful developmental model. In addition, we show a functional application of FOSs to analyze cell-cell interaction and cell invasion patterns as observed in cancer.

    CONCLUSION: The establishment of a broad ranging and highly effective method to generate FOSs from different organs was successful in terms of the formation of healthy, proliferating 3D organ spheroids that exhibited organ-like characteristics. Potential applications of chick FOSs are their use in studies of cell-to-cell contact, cell fusion and tumor invasion under defined conditions. Future studies will reveal whether chick FOSs also can be applicable in scientific areas such as viral infections, drug screening, cancer diagnostics and/or tissue engineering.

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  • 47.
    Davies, Wayne I. L.
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Sghari, Soufien
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Upton, Brian A.
    Nord, Christoffer
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Hahn, Max
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Ahlgren, Ulf
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Lang, Richard A.
    Gunhaga, Lena
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Distinct opsin 3 (Opn3) expression in the developing nervous system during mammalian embryogenesis2021In: eNeuro, E-ISSN 2373-2822, Vol. 8, no 5, article id ENEURO.0141-21.2021Article in journal (Refereed)
    Abstract [en]

    Opsin 3 (Opn3) is highly expressed in the adult brain, however, information for spatial and temporal expression patterns during embryogenesis is significantly lacking. Here, an Opn3-eGFP reporter mouse line was used to monitor cell body expression and axonal projections during embryonic and early postnatal to adult stages. By applying 2D and 3D fluorescence imaging techniques, we have identified the onset of Opn3 expression, which predominantly occurred during embryonic stages, in various structures during brain/head development. In ad-dition, this study defines over twenty Opn3-eGFP-positive neural structures never reported before. Opn3-eGFP was first observed at E9.5 in neural regions, including the ganglia that will ultimately form the trigeminal, facial and vestibulocochlear cranial nerves (CNs). As development proceeds, expanded Opn3-eGFP expression coincided with the formation and maturation of critical components of the central and peripheral nervous systems (CNS, PNS), including various motor-sensory tracts, such as the dorsal column-medial lemniscus (DCML) sensory tract, and olfactory, acoustic, and optic tracts. The widespread, yet distinct, detection of Opn3-eGFP already at early embryonic stages suggests that Opn3 might play important functional roles in the developing brain and spinal cord to regulate multiple motor and sensory circuitry systems, including proprio-ception, nociception, ocular movement, and olfaction, as well as memory, mood, and emotion. This study presents a crucial blueprint from which to investigate autonomic and cognitive opsin-dependent neural development and resultant behaviors under physiological and pathophysiological conditions.

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  • 48.
    Dennhag, Nils
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Department of Medical Biosciences. Masterprogrammet i biomedicin.
    Analysis of Paired box protein Pax3 and Pax7 mutant Zebrafish Danio rerio2015Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
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  • 49.
    Dennhag, Nils
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB). Umeå University, Faculty of Medicine, Department of Clinical Sciences.
    Kahsay, Abraha
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Nissen, Itzel
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Chermenina, Maria
    Umeå University, Faculty of Medicine, Department of Clinical Sciences.
    Nord, Hanna
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Liu, Jiao
    Arner, Anders
    Liu, Jing-Xia
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Backman, Ludvig J.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Remeseiro, Silvia
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM). Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    von Hofsten, Jonas
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Domellöf, Fatima Pedrosa
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB). Umeå University, Faculty of Medicine, Department of Clinical Sciences. Umeå University, Faculty of Medicine, Department of Medical Biosciences.
    fhl2b expression ameliorates muscular dystrophyManuscript (preprint) (Other academic)
  • 50. Doma, Eszter
    et al.
    Mayer, Isabella Maria
    Brandstoetter, Tania
    Maurer, Barbara
    Grausenburger, Reinhard
    Menzl, Ingeborg
    Zojer, Markus
    Hoelbl-Kovacic, Andrea
    Carlsson, Leif
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Heller, Gerwin
    Kollmann, Karoline
    Sexl, Veronika
    A robust approach for the generation of functional hematopoietic progenitor cell lines to model leukemic transformation2021In: Blood Advances, ISSN 2473-9529 , E-ISSN 2473-9537, Vol. 5, no 1, p. 39-53Article in journal (Refereed)
    Abstract [en]

    Studies of molecular mechanisms of hematopoiesis and leukemogenesis are hampered by the unavailability of progenitor cell lines that accurately mimic the situation in vivo. We now report a robust method to generate and maintain LSK (Lin-, Sca-1+, c-Kit+) cells, which closely resemble MPP1 cells. HPCLSKs reconstitute hematopoiesis in lethally irradiated recipient mice over >8 months. Upon transformation with different oncogenes including BCR/ABL, FLT3-ITD, or MLL-AF9, their leukemic counterparts maintain stem cell properties in vitro and recapitulate leukemia formation in vivo. The method to generate HPCLSKs can be applied to transgenic mice, and we illustrate it for CDK6-deficient animals. Upon BCR/ABLp210 transformation, HPCLSKs Cdk6-/- induce disease with a significantly enhanced latency and reduced incidence, showing the importance of CDK6 in leukemia formation. Studies of the CDK6 transcriptome in murine HPCLSK and human BCR/ABL+ cells have verified that certain pathways depend on CDK6 and have uncovered a novel CDK6-dependent signature, suggesting a role for CDK6 in leukemic progenitor cell homing. Loss of CDK6 may thus lead to a defect in homing. The HPCLSK system represents a unique tool for combined in vitro and in vivo studies and enables the production of large quantities of genetically modifiable hematopoietic or leukemic stem/progenitor cells.

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