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Bano, Fouzia
Publications (10 of 16) Show all publications
Prittinen, J., Zhou, X., Bano, F., Backman, L. J. & Danielson, P. (2022). Microstructured collagen films for 3D corneal stroma modelling. Connective Tissue Research, 63(5), 443-452
Open this publication in new window or tab >>Microstructured collagen films for 3D corneal stroma modelling
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2022 (English)In: Connective Tissue Research, ISSN 0300-8207, E-ISSN 1607-8438, Vol. 63, no 5, p. 443-452Article in journal (Refereed) Published
Abstract [en]

Purpose/aim: Corneal injury is a major cause of impaired vision around the globe. The fine structure of the corneal stroma plays a pivotal role in the phenotype and behavior of the embedded cells during homeostasis and healing after trauma or infection. In order to study healing processes in the cornea, it is important to create culture systems that functionally mimic the natural environment.

Materials and methods: Collagen solution was vitrified on top of a grated film to achieve thin collagen films with parallel microgrooves. Keratocytes (corneal stromal cells) were cultured on the films either as a single layer or as stacked layers of films and cells. SEM and F-actin staining were used to analyze the pattern transference onto the collagen and the cell orientation on the films. Cell viability was analyzed with MTS and live/dead staining. Keratocytes, fibroblasts, and myofibroblasts were cultured to study the pattern’s effect on phenotype.

Results: A microstructured collagen film-based culture system that guides keratocytes (stromal cells) to their native, layerwise perpendicular orientation in 3D and that can support fibroblasts and myofibroblasts was created. The films are thin and transparent enough to observe cells at least three layers deep. The cells maintain viability in 2D and 3D cultures and the films can support fibroblast and myofibroblast phenotypes.

Conclusions: The films provide an easily reproducible stroma model that maintains high cell viability and improves the preservation of the keratocyte phenotype in keratocytes that are differentiated to fibroblasts.

Place, publisher, year, edition, pages
Taylor & Francis Group, 2022
Keywords
collagen, cornea, keratocyte, stroma, Vitrigel
National Category
Ophthalmology
Identifiers
urn:nbn:se:umu:diva-190877 (URN)10.1080/03008207.2021.2007901 (DOI)000729669400001 ()34894951 (PubMedID)2-s2.0-85121425675 (Scopus ID)
Funder
Stiftelsen Kronprinsessan Margaretas arbetsnämnd för synskadade, 2013/10Swedish Society of Medicine, 504541Swedish Research Council, 2017-01138Region Västerbotten, 549761
Available from: 2021-12-29 Created: 2021-12-29 Last updated: 2023-10-18Bibliographically approved
Nadeem, A., Nagampalli, R., Toh, E., Alam, A., Myint, S. L., Heidler, T., . . . Persson, K. (2021). A tripartite cytolytic toxin formed by Vibrio cholerae proteins with flagellum-facilitated secretion. Proceedings of the National Academy of Sciences of the United States of America, 118(47), Article ID e2111418118.
Open this publication in new window or tab >>A tripartite cytolytic toxin formed by Vibrio cholerae proteins with flagellum-facilitated secretion
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2021 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 118, no 47, article id e2111418118Article in journal (Refereed) Published
Abstract [en]

Vibrio cholerae, responsible for outbreaks of cholera disease, is a highly motile organism by virtue of a single flagellum. We describe how the flagellum facilitates the secretion of three V. cholerae proteins encoded by a hitherto-unrecognized genomic island. The proteins MakA/B/E can form a tripartite toxin that lyses erythrocytes and is cytotoxic to cultured human cells. A structural basis for the cytolytic activity of the Mak proteins was obtained by X-ray crystallography. Flagellum-facilitated secretion ensuring spatially coordinated delivery of Mak proteins revealed a role for the V. cholerae flagellum considered of particular significance for the bacterial environmental persistence. Our findings will pave the way for the development of diagnostics and therapeutic strategies against pathogenic Vibrionaceae.

National Category
Biochemistry and Molecular Biology
Research subject
Biochemistry
Identifiers
urn:nbn:se:umu:diva-191257 (URN)10.1073/pnas.2111418118 (DOI)000727697700014 ()34799450 (PubMedID)2-s2.0-85121209218 (Scopus ID)
Funder
Swedish Research Council, 2016-05009Swedish Research Council, 2018-02914Swedish Research Council, 2019-01720Swedish Research Council, 2007-08673The Kempe Foundations, SMK-1756.2The Kempe Foundations, SMK-1553The Kempe Foundations, JCK-1728Swedish Cancer Society, 2017-419The Kempe Foundations, SMK-1961Swedish Research Council
Available from: 2022-01-12 Created: 2022-01-12 Last updated: 2023-05-11Bibliographically approved
Szuba, A., Bano, F., Linares, G. C., Iv, F., Mavrakis, M., Richter, R. P., . . . Koenderink, G. H. (2021). Membrane binding controls ordered self-assembly of animal septins. eLIFE, 10, Article ID e63349.
Open this publication in new window or tab >>Membrane binding controls ordered self-assembly of animal septins
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2021 (English)In: eLIFE, E-ISSN 2050-084X, Vol. 10, article id e63349Article in journal (Refereed) Published
Abstract [en]

Septins are conserved cytoskeletal proteins that regulate cell cortex mechanics. The mechanisms of their interactions with the plasma membrane remain poorly understood. Here, we show by cell-free reconstitution that binding to flat lipid membranes requires electrostatic interactions of septins with anionic lipids and promotes the ordered self-assembly of fly septins into filamentous meshworks. Transmission electron microscopy reveals that both fly and mammalian septin hexamers form arrays of single and paired filaments. Atomic force microscopy and quartz crystal microbalance demonstrate that the fly filaments form mechanically rigid, 12- to 18-nm thick, double layers of septins. By contrast, C-terminally truncated septin mutants form 4-nm thin monolayers, indicating that stacking requires the C-terminal coiled coils on DSep2 and Pnut subunits. Our work shows that membrane binding is required for fly septins to form ordered arrays of single and paired filaments and provides new insights into the mechanisms by which septins may regulate cell surface mechanics.

Place, publisher, year, edition, pages
eLife Sciences Publications Ltd, 2021
National Category
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy) Biological Sciences Cell Biology Condensed Matter Physics
Identifiers
urn:nbn:se:umu:diva-216588 (URN)10.7554/elife.63349 (DOI)000648513100001 ()33847563 (PubMedID)2-s2.0-85105650161 (Scopus ID)
Available from: 2023-12-15 Created: 2023-12-15 Last updated: 2023-12-18Bibliographically approved
Giubertoni, G., Ortíz, A. P., Bano, F., Zhang, X., Linhardt, R. J., Green, D. E., . . . Bakker, H. J. (2021). Strong reduction of the chain rigidity of hyaluronan by selective binding of Ca2+ ions. Macromolecules, 54(3), 1137-1146
Open this publication in new window or tab >>Strong reduction of the chain rigidity of hyaluronan by selective binding of Ca2+ ions
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2021 (English)In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 54, no 3, p. 1137-1146Article in journal (Refereed) Published
Abstract [en]

The biological functions of natural polyelectrolytes are strongly influenced by the presence of ions, which bind to the polymer chains and thereby modify their properties. Although the biological impact of such modifications is well recognized, a detailed molecular picture of the binding process and of the mechanisms that drive the subsequent structural changes in the polymer is lacking. Here, we study the molecular mechanism of the condensation of calcium, a divalent cation, on hyaluronan, a ubiquitous polymer in human tissues. By combining two-dimensional infrared spectroscopy experiments with molecular dynamics simulations, we find that calcium specifically binds to hyaluronan at millimolar concentrations. Because of its large size and charge, the calcium cation can bind simultaneously to the negatively charged carboxylate group and the amide group of adjacent saccharide units. Molecular dynamics simulations and single-chain force spectroscopy measurements provide evidence that the binding of the calcium ions weakens the intramolecular hydrogen-bond network of hyaluronan, increasing the flexibility of the polymer chain. We also observe that the binding of calcium to hyaluronan saturates at a maximum binding fraction of ∼10–15 mol %. This saturation indicates that the binding of Ca2+ strongly reduces the probability of subsequent binding of Ca2+ at neighboring binding sites, possibly as a result of enhanced conformational fluctuations and/or electrostatic repulsion effects. Our findings provide a detailed molecular picture of ion condensation and reveal the severe effect of a few, selective and localized electrostatic interactions on the rigidity of a polyelectrolyte chain.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2021
National Category
Biomaterials Science Biophysics Physical Sciences
Identifiers
urn:nbn:se:umu:diva-216589 (URN)10.1021/acs.macromol.0c02242 (DOI)000618908000005 ()33583956 (PubMedID)2-s2.0-85100217367 (Scopus ID)
Available from: 2023-12-15 Created: 2023-12-15 Last updated: 2023-12-18Bibliographically approved
Frost, R., Débarre, D., Jana, S., Bano, F., Schünemann, J., Görlich, D. & Richter, R. P. (2020). A method to quantify molecular diffusion within thin solvated polymer films: A case study on films of natively unfolded nucleoporins. ACS Nano, 14(8), 9938-9952
Open this publication in new window or tab >>A method to quantify molecular diffusion within thin solvated polymer films: A case study on films of natively unfolded nucleoporins
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2020 (English)In: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 14, no 8, p. 9938-9952Article in journal (Refereed) Published
Abstract [en]

We present a method to probe molecular and nanoparticle diffusion within thin, solvated polymer coatings. The device exploits the confinement with well-defined geometry that forms at the interface between a planar and a hemispherical surface (of which at least one is coated with polymers) in close contact and uses this confinement to analyze diffusion processes without interference of exchange with and diffusion in the bulk solution. With this method, which we call plane–sphere confinement microscopy (PSCM), information regarding the partitioning of molecules between the polymer coating and the bulk liquid is also obtained. Thanks to the shape of the confined geometry, diffusion and partitioning can be mapped as a function of compression and concentration of the coating in a single experiment. The method is versatile and can be integrated with conventional optical microscopes; thus it should find widespread use in the many application areas exploiting functional polymer coatings. We demonstrate the use of PSCM using brushes of natively unfolded nucleoporin domains rich in phenylalanine–glycine repeats (FG domains). A meshwork of FG domains is known to be responsible for the selective transport of nuclear transport receptors (NTRs) and their macromolecular cargos across the nuclear envelope that separates the cytosol and the nucleus of living cells. We find that the selectivity of NTR uptake by FG domain films depends sensitively on FG domain concentration and that the interaction of NTRs with FG domains obstructs NTR movement only moderately. These observations contribute important information to better understand the mechanisms of selective NTR transport.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2020
Keywords
diffusion absorption confinement polymer film reflection interference contrast microscopy fluorescence recovery after photobleaching, permeability barrier
National Category
Biomaterials Science Nano Technology Biological Sciences Biophysics Polymer Chemistry Physical Chemistry
Identifiers
urn:nbn:se:umu:diva-216590 (URN)10.1021/acsnano.0c02895 (DOI)000566341000058 ()32667780 (PubMedID)2-s2.0-85090077126 (Scopus ID)
Funder
EU, European Research Council, 306435EU, European Research Council, 840295
Available from: 2023-12-15 Created: 2023-12-15 Last updated: 2023-12-18Bibliographically approved
Bar, L., Dejeu, J., Lartia, R., Bano, F., Richter, R. P., Coche-Guérente, L. & Boturyn, D. (2020). Impact of antigen density on recognition by monoclonal antibodies. Analytical Biochemistry, 92(7), 5396-5403
Open this publication in new window or tab >>Impact of antigen density on recognition by monoclonal antibodies
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2020 (English)In: Analytical Biochemistry, ISSN 0003-2697, E-ISSN 1096-0309, Vol. 92, no 7, p. 5396-5403Article in journal (Refereed) Published
Abstract [en]

Understanding antigen–antibody interactions is important to many emerging medical and bioanalytical applications. In particular, the levels of antigen expression at the cell surface may determine antibody-mediated cell death. This parameter has a clear effect on outcome in patients undergoing immunotherapy. In this context, CD20 which is expressed in the membrane of B cells has received significant attention as target for immunotherapy of leukemia and lymphoma using the monoclonal antibody rituximab. To systematically study the impact of CD20 density on antibody recognition, we designed self-assembled monolayers that display tunable CD20 epitope densities. For this purpose, we developed in situ click chemistry to functionalize SPR sensor chips. We find that the rituximab binding affinity depends sensitively and nonmonotonously on CD20 surface density. Strongest binding, with an equilibrium dissociation constant (KD = 32 nM) close to values previously reported from in vitro analysis with B cells (apparent KD between 5 and 19 nM), was obtained for an average inter-antigen spacing of 2 nm. This distance is required for improving rituximab recognition, and in agreement with the known requirement of CD20 to form clusters to elicit a biological response. More generally, this study offers an interesting outlook in the understanding of the necessity of epitope clusters for effective mAb recognition.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2020
National Category
Biochemistry and Molecular Biology Physical Chemistry
Identifiers
urn:nbn:se:umu:diva-216592 (URN)10.1021/acs.analchem.0c00092 (DOI)000526569200089 ()32200619 (PubMedID)2-s2.0-85088920918 (Scopus ID)
Available from: 2023-12-15 Created: 2023-12-15 Last updated: 2023-12-18Bibliographically approved
Bano, F., Tammi, M. I., Kang, D. W., Harris, E. N. & Richter, R. P. (2018). Single-molecule unbinding forces between the polysaccharide hyaluronan and its binding proteins. Biophysical Journal, 114(12), 2910-2922
Open this publication in new window or tab >>Single-molecule unbinding forces between the polysaccharide hyaluronan and its binding proteins
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2018 (English)In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 114, no 12, p. 2910-2922Article in journal (Refereed) Published
Abstract [en]

The extracellular polysaccharide hyaluronan (HA) is ubiquitous in all vertebrate tissues, where its various functions are encoded in the supramolecular complexes and matrices that it forms with HA-binding proteins (hyaladherins). In tissues, these supramolecular architectures are frequently subjected to mechanical stress, yet how this affects the intermolecular bonding is largely unknown. Here, we used a recently developed single-molecule force spectroscopy platform to analyze and compare the mechanical strength of bonds between HA and a panel of hyaladherins from the Link module superfamily, namely the complex of the proteoglycan aggrecan and cartilage link protein, the proteoglycan versican, the inflammation-associated protein TSG-6, the HA receptor for endocytosis (stabilin-2/HARE), and the HA receptor CD44. We find that the resistance to tensile stress for these hyaladherins correlates with the size of the HA-binding domain. The lowest mean rupture forces are observed for members of the type A subgroup (i.e., with the shortest HA-binding domains; TSG-6 and HARE). In contrast, the mechanical stability of the bond formed by aggrecan in complex with cartilage link protein (two members of the type C subgroup, i.e., with the longest HA-binding domains) and HA is equal or even superior to the high affinity streptavidin⋅biotin bond. Implications for the molecular mechanism of unbinding of HA⋅hyaladherin bonds under force are discussed, which underpin the mechanical properties of HA⋅hyaladherin complexes and HA-rich extracellular matrices.

Place, publisher, year, edition, pages
Biophysical society, 2018
National Category
Biomaterials Science Biological Sciences Physical Sciences Biophysics
Identifiers
urn:nbn:se:umu:diva-216594 (URN)10.1016/j.bpj.2018.05.014 (DOI)000436471800017 ()29925027 (PubMedID)2-s2.0-85048481362 (Scopus ID)
Funder
EU, European Research Council, FP7-ERC-2012-StG-306435NIH (National Institutes of Health), R01HL130864
Available from: 2023-12-15 Created: 2023-12-15 Last updated: 2023-12-18Bibliographically approved
Bano, F., Banerji, S., Howarth, M., Jackson, D. G. & Richter, R. P. (2016). A single molecule assay to probe monovalent and multivalent bonds between hyaluronan and its key leukocyte receptor CD44 under force. Scientific Reports, 6, Article ID 34176.
Open this publication in new window or tab >>A single molecule assay to probe monovalent and multivalent bonds between hyaluronan and its key leukocyte receptor CD44 under force
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2016 (English)In: Scientific Reports, E-ISSN 2045-2322, Vol. 6, article id 34176Article in journal (Refereed) Published
Abstract [en]

Glycosaminoglycans (GAGs), a category of linear, anionic polysaccharides, are ubiquitous in the extracellular space, and important extrinsic regulators of cell function. Despite the recognized significance of mechanical stimuli in cellular communication, however, only few single molecule methods are currently available to study how monovalent and multivalent GAG·protein bonds respond to directed mechanical forces. Here, we have devised such a method, by combining purpose-designed surfaces that afford immobilization of GAGs and receptors at controlled nanoscale organizations with single molecule force spectroscopy (SMFS). We apply the method to study the interaction of the GAG polymer hyaluronan (HA) with CD44, its receptor in vascular endothelium. Individual bonds between HA and CD44 are remarkably resistant to rupture under force in comparison to their low binding affinity. Multiple bonds along a single HA chain rupture sequentially and independently under load. We also demonstrate how strong non-covalent bonds, which are versatile for controlled protein and GAG immobilization, can be effectively used as molecular anchors in SMFS. We thus establish a versatile method for analyzing the nanomechanics of GAG·protein interactions at the level of single GAG chains, which provides new molecular-level insight into the role of mechanical forces in the assembly and function of GAG-rich extracellular matrices.

Place, publisher, year, edition, pages
Springer Nature, 2016
National Category
Biomaterials Science Biological Sciences Physical Sciences
Identifiers
urn:nbn:se:umu:diva-216595 (URN)10.1038/srep34176 (DOI)000384170900001 ()27679982 (PubMedID)2-s2.0-84990855872 (Scopus ID)
Available from: 2023-12-15 Created: 2023-12-15 Last updated: 2023-12-18Bibliographically approved
Bano, F., Carril, M., Di Gianvincenzo, P. & Richter, R. P. (2015). Interaction of hyaluronan with cationic nanoparticles. Langmuir, 31(30), 8411-8420
Open this publication in new window or tab >>Interaction of hyaluronan with cationic nanoparticles
2015 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 31, no 30, p. 8411-8420Article in journal (Refereed) Published
Abstract [en]

The polysaccharide hyaluronan (HA) is a main component of peri- and extracellular matrix, and an attractive molecule for materials design in tissue engineering and nanomedicine. Here, we study the morphology of complexes that form upon interaction of nanometer-sized amine-coated gold particles with this anionic, linear, and regular biopolymer in solution and grafted to a surface. We find that cationic nanoparticles (NPs) have profound effects on HA morphology on the molecular and supramolecular scale. Quartz crystal microbalance (QCM-D) shows that depending on their relative abundance, cationic NPs promote either strong compaction or swelling of films of surface-grafted HA polymers (HA brushes). Transmission electron and atomic force microscopy reveal that the NPs do also give rise to complexes of distinct morphologies–compact nanoscopic spheres and extended microscopic fibers–upon interaction with HA polymers in solution. In particular, stable and hydrated spherical complexes of single HA polymers with NPs can be prepared when balancing the ionizable groups on HA and NPs. The observed self-assembly phenomena could be useful for the design of drug delivery vehicles and a better understanding of the reorganization of HA-rich synthetic or biological matrices.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2015
National Category
Biomaterials Science Biological Sciences Physical Sciences
Identifiers
urn:nbn:se:umu:diva-216596 (URN)10.1021/acs.langmuir.5b01505 (DOI)000359278000026 ()26146006 (PubMedID)2-s2.0-84938634955 (Scopus ID)
Available from: 2023-12-15 Created: 2023-12-15 Last updated: 2023-12-18Bibliographically approved
Bano, F., Sluysmans, D., Wislez, A. & Duwez, A.-S. -. (2015). Unraveling the complexity of the interactions of DNA nucleotides with gold by single molecule force spectroscopy. Nanoscale, 7(46), 19528-19533
Open this publication in new window or tab >>Unraveling the complexity of the interactions of DNA nucleotides with gold by single molecule force spectroscopy
2015 (English)In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 7, no 46, p. 19528-19533Article in journal (Refereed) Published
Abstract [en]

Addressing the effect of different environmental factors on the adsorption of DNA to solid supports is critical for the development of robust miniaturized devices for applications ranging from biosensors to next generation molecular technology. Most of the time, thiol-based chemistry is used to anchor DNA on gold – a substrate commonly used in nanotechnology – and little is known about the direct interaction between DNA and gold. So far there have been no systematic studies on the direct adsorption behavior of the deoxyribonucleotides (i.e., a nitrogenous base, a deoxyribose sugar, and a phosphate group) and on the factors that govern the DNA–gold bond strength. Here, using single molecule force spectroscopy, we investigated the interaction of the four individual nucleotides, adenine, guanine, cytosine, and thymine, with gold. Experiments were performed in three salinity conditions and two surface dwell times to reveal the factors that influence nucleotide–Au bond strength. Force data show that, at physiological ionic strength, adenine–Au interactions are stronger, asymmetrical and independent of surface dwell time as compared to cytosine–Au and guanine–Au interactions. We suggest that in these conditions only adenine is able to chemisorb on gold. A decrease of the ionic strength significantly increases the bond strength for all nucleotides. We show that moderate ionic strength along with longer surface dwell period suggest weak chemisorption also for cytosine and guanine.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2015
National Category
Biomaterials Science Biological Sciences Biophysics Physical Sciences
Identifiers
urn:nbn:se:umu:diva-216597 (URN)10.1039/C5NR05695K (DOI)000365203000022 ()26538184 (PubMedID)2-s2.0-84948138546 (Scopus ID)
Available from: 2023-12-15 Created: 2023-12-15 Last updated: 2023-12-18Bibliographically approved
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