Umeå University's logo

umu.sePublications
Change search
Refine search result
1 - 6 of 6
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Forsgren, Elin
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Using patient-derived cell models to investigate the role of misfolded SOD1 in ALS2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Protein misfolding and aggregation underlie several neurodegenerative proteinopathies including amyotrophic lateral sclerosis (ALS). Superoxide dismutase 1 (SOD1) was the first gene found to be associated with familial ALS. Overexpression of human mutant or wild type SOD1 in transgenic mouse models induces motor neuron (MN) degeneration and an ALS-like phenotype. SOD1 mutations, leading to the destabilization of the SOD1 protein is associated with ALS pathogenesis. However, how misfolded SOD1 toxicity specifically affects human MNs is not clear. The aim of this thesis was to develop patient-derived, cellular models of ALS to help understand the pathogenic mechanisms underlying SOD1.

    To understand which cellular pathways impact on the level of misfolded SOD1 in human cells, we established a model using patient-derived fibroblasts and quantified misfolded SOD1 in relation to disturbances in several ALS-related cellular pathways. Misfolded SOD1 levels did not change following reduction in autophagy, inhibition of the mitochondrial respiratory chain, or induction of endoplasmic reticulum (ER)-stress. However, inhibition of the ubiquitin-proteasome system (UPS) lead to a dramatic increase in misfolded SOD1 levels. Hence, an age-related decline in proteasome activity might underlie the late-life onset that is typically seen in SOD1 ALS.

    To address whether or not SOD1 misfolding is enhanced in human MNs, we used mixed MN/astrocyte cultures (MNCs) generated in vitro from patient-specific induced pluripotent stem cells (iPSCs). Levels of soluble misfolded SOD1 were increased in MNCs as well as in pure iPSC-derived astrocytes compared to other cell types, including sensory neuron cultures. Interestingly, this was the case for both mutant and wild type human SOD1, although the increase was enhanced in SOD1 FALS MNCs. Misfolded SOD1 was also found to exist in the same form as in mouse SOD1 overexpression models and was identified as a substrate for 20S proteasome degradation. Hence, the vulnerability of motor areas to ALS could be explained by increased SOD1 misfolding, specifically in MNs and astrocytes.

    To investigate factors that might promote SOD1 misfolding, we focussed on the stability of SOD1 mediated by a crucial, stabilizing C57-C146 disulphide bond and its redox status. Formation of disulphide bond is dependent on oxidation by O2 and catalysed by CCS. To investigate whether low O2 tension affects the stability of SOD1 in vitro we cultured fibroblasts and iPSC-derived MNCs under different oxygen tensions. Low oxygen tension promoted disulphide-reduction, SOD1 misfolding and aggregation. This response was much greater in MNCs compared to fibroblasts, suggesting that MNs may be especially sensitive to low oxygen tension and areas with low oxygen supply could serve as foci for ALS initiation.

    SOD1 truncation mutations often lack C146, and cannot adopt a native fold and are rapidly degraded. We characterized soluble misfolded and aggregated SOD1 in patient-derived cells carrying a novel SOD1 D96Mfs*8 mutation as well as in cells fom an unaffected mutation carrier. The truncated protein has a C-terminal fusion of seven non-native amino acids and was found to be extremely prone to aggregation in vitro. Since not all mutation carriers develop ALS, our results suggested this novel mutation is associated with reduced penetrance.

    In summary, patient derived cells are useful models to study factors affecting SOD1 misfolded and aggregation. We show for the first time that misfolding of a disordered and disease associated protein is enhanced in disease-related cell types. Showing that misfolded SOD1 exists in human cells in the same form as in transgenic mouse models strengthens the translatability of results obtained in the two species. Our results demonstrate disulphide-reduction and misfolding/aggregation of SOD1 and suggest that 20S proteasome could be an important therapeutic target for early stages of disease. This model provides a great opportunity to study pathogenic mechanisms of both familial and sporadic ALS in patient-derived models of ALS. 

    Download full text (pdf)
    fulltext
    Download (pdf)
    spikblad
  • 2.
    Forsgren, Elin
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Lehmann, Manuela
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Weygandt Mathis, Mackenzie
    Keskin, Isil
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Zetterström, Per
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Clinical chemistry.
    Nijssen, Jik
    Lowry, Emily
    Garcia, Alejandro
    Sandoe, Jackson
    Hedlund, Eva
    Wichterle, Hynek
    Henderson, Christopher
    Eggan, Kevin
    Kiskinis, Evangelos
    Andersen, Peter
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Marklund, Stefan
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Clinical chemistry.
    Gilthorpe, Jonathan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Enhanced protein misfolding in patient-derived models of amyotrophic lateral sclerosisManuscript (preprint) (Other (popular science, discussion, etc.))
  • 3.
    Forsgren, Elin
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Nordin, Frida
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Nordström, Ulrika
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Rofougaran, Reza
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Danielsson, Jens
    Marklund, Stefan
    Umeå University, Faculty of Medicine, Department of Medical Biosciences.
    Gilthorpe, Jonathan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Andersen, Peter
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    A Novel mutation D96Mfs*8 in SOD1 identified in a Swedish ALS patient results in a truncated and heavily aggregation-prone proteinManuscript (preprint) (Other (popular science, discussion, etc.))
  • 4.
    Keskin, Isil
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Forsgren, Elin
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Andersen, Peter M.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Lange, Dale J.
    Synofzik, Matthis
    Nordström, Ulrika
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Zetterström, Per
    Umeå University, Faculty of Medicine, Department of Medical Biosciences.
    Marklund, Stefan L.
    Umeå University, Faculty of Medicine, Department of Medical Biosciences.
    Gilthorpe, Jonathan D.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Low oxygen tension induces misfolding and aggregation of superoxide dismutase in ALS patient-derived motor neuronsManuscript (preprint) (Other academic)
  • 5.
    Keskin, Isil
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Forsgren, Elin
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Lange, Dale J.
    Weber, Markus
    Birve, Anna
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Synofzik, Matthis
    Gilthorpe, Jonathan D.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Andersen, Peter M.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Marklund, Stefan L.
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Clinical chemistry.
    Effects of Cellular Pathway Disturbances on Misfolded Superoxide Dismutase-1 in Fibroblasts Derived from ALS Patients2016In: PLOS ONE, E-ISSN 1932-6203, Vol. 11, no 2, article id e0150133Article in journal (Refereed)
    Abstract [en]

    Mutations in superoxide dismutase-1 (SOD1) are a common known cause of amyotrophic lateral sclerosis (ALS). The neurotoxicity of mutant SOD1s is most likely caused by misfolded molecular species, but disease pathogenesis is still not understood. Proposed mechanisms include impaired mitochondrial function, induction of endoplasmic reticulum stress, reduction in the activities of the proteasome and autophagy, and the formation of neurotoxic aggregates. Here we examined whether perturbations in these cellular pathways in turn influence levels of misfolded SOD1 species, potentially amplifying neurotoxicity. For the study we used fibroblasts, which express SOD1 at physiological levels under regulation of the native promoter. The cells were derived from ALS patients expressing 9 different SOD1 mutants of widely variable molecular characteristics, as well as from patients carrying the GGGGCC-repeat-expansion in C9orf72 and from non-disease controls. A specific ELISA was used to quantify soluble, misfolded SOD1, and aggregated SOD1 was analysed by western blotting. Misfolded SOD1 was detected in all lines. Levels were found to be much lower in non-disease control and the non-SOD1 C9orf72 ALS lines. This enabled us to validate patient fibroblasts for use in subsequent perturbation studies. Mitochondrial inhibition, endoplasmic reticulum stress or autophagy inhibition did not affect soluble misfolded SOD1 and in most cases, detergent-resistant SOD1 aggregates were not detected. However, proteasome inhibition led to uniformly large increases in misfolded SOD1 levels in all cell lines and an increase in SOD1 aggregation in some. Thus the ubiquitin-proteasome pathway is a principal determinant of misfolded SOD1 levels in cells derived both from patients and controls and a decline in activity with aging could be one of the factors behind the mid-to late-life onset of inherited ALS.

    Download full text (pdf)
    fulltext
  • 6.
    Keskin, Isil
    et al.
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Forsgren, Elin
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Lehmann, Manuela
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Andersen, Peter M.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Brännström, Thomas
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Lange, Dale J.
    Synofzik, Matthis
    Nordström, Ulrika
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Zetterström, Per
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Clinical chemistry.
    Marklund, Stefan L.
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Clinical chemistry.
    Gilthorpe, Jonathan D.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    The molecular pathogenesis of superoxide dismutase 1-linked ALS is promoted by low oxygen tension2019In: Acta Neuropathologica, ISSN 0001-6322, E-ISSN 1432-0533, Vol. 138, no 1, p. 85-101Article in journal (Refereed)
    Abstract [en]

    Mutations in superoxide dismutase 1 (SOD1) cause amyotrophic lateral sclerosis (ALS). Disease pathogenesis is linked to destabilization, disorder and aggregation of the SOD1 protein. However, the non-genetic factors that promote disorder and the subsequent aggregation of SOD1 have not been studied. Mainly located to the reducing cytosol, mature SOD1 contains an oxidized disulfide bond that is important for its stability. Since O2 is required for formation of the bond, we reasoned that low O2 tension might be a risk factor for the pathological changes associated with ALS development. By combining biochemical approaches in an extensive range of genetically distinct patient-derived cell lines, we show that the disulfide bond is an Achilles heel of the SOD1 protein. Culture of patient-derived fibroblasts, astrocytes, and induced pluripotent stem cell-derived mixed motor neuron and astrocyte cultures (MNACs) under low oxygen tensions caused reductive bond cleavage and increases in disordered SOD1. The effects were greatest in cells derived from patients carrying ALS-linked mutations in SOD1. However, significant increases also occurred in wild-type SOD1 in cultures derived from non-disease controls, and patients carrying mutations in other common ALS-linked genes. Compared to fibroblasts, MNACs showed far greater increases in SOD1 disorder and even aggregation of mutant SOD1s, in line with the vulnerability of the motor system to SOD1-mediated neurotoxicity. Our results show for the first time that O2 tension is a principal determinant of SOD1 stability in human patient-derived cells. Furthermore, we provide a mechanism by which non-genetic risk factors for ALS, such as aging and other conditions causing reduced vascular perfusion, could promote disease initiation and progression.

    Download full text (pdf)
    fulltext
1 - 6 of 6
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf