Hypoxia impacts human MSC response to substrate stiffness during chondrogenic differentiation.

Details

Serval ID
serval:BIB_CA4E7A3DECF2
Type
Article: article from journal or magazin.
Collection
Publications
Title
Hypoxia impacts human MSC response to substrate stiffness during chondrogenic differentiation.
Journal
Acta biomaterialia
Author(s)
Foyt D.A., Taheem D.K., Ferreira S.A., Norman MDA, Petzold J., Jell G., Grigoriadis A.E., Gentleman E.
ISSN
1878-7568 (Electronic)
ISSN-L
1742-7061
Publication state
Published
Issued date
15/04/2019
Peer-reviewed
Oui
Volume
89
Pages
73-83
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Abstract
Tissue engineering strategies often aim to direct tissue formation by mimicking conditions progenitor cells experience within native tissues. For example, to create cartilage in vitro, researchers often aim to replicate the biochemical and mechanical milieu cells experience during cartilage formation in the developing limb bud. This includes stimulating progenitors with TGF-β <sub>1/3</sub> , culturing under hypoxic conditions, and regulating mechanosensory pathways using biomaterials that control substrate stiffness and/or cell shape. However, as progenitors differentiate down the chondrogenic lineage, the pathways that regulate their responses to mechanotransduction, hypoxia and TGF-β may not act independently, but rather also impact one another, influencing overall cell response. Here, to better understand hypoxia's influence on mechanoregulatory-mediated chondrogenesis, we cultured human marrow stromal/mesenchymal stem cells (hMSC) on soft (0.167 kPa) or stiff (49.6 kPa) polyacrylamide hydrogels in chondrogenic medium containing TGF-β <sub>3</sub> . We then compared cell morphology, phosphorylated myosin light chain 2 staining, and chondrogenic gene expression under normoxic and hypoxic conditions, in the presence and absence of pharmacological inhibition of cytoskeletal tension. We show that on soft compared to stiff substrates, hypoxia prompts hMSC to adopt more spread morphologies, assemble in compact mesenchymal condensation-like colonies, and upregulate NCAM expression, and that inhibition of cytoskeletal tension negates hypoxia-mediated upregulation of molecular markers of chondrogenesis, including COL2A1 and SOX9. Taken together, our findings support a role for hypoxia in regulating hMSC morphology, cytoskeletal tension and chondrogenesis, and that hypoxia's effects are modulated, at least in part, by mechanosensitive pathways. Our insights into how hypoxia impacts mechanoregulation of chondrogenesis in hMSC may improve strategies to develop tissue engineered cartilage. STATEMENT OF SIGNIFICANCE: Cartilage tissue engineering strategies often aim to drive progenitor cell differentiation by replicating the local environment of the native tissue, including by regulating oxygen concentration and mechanical stiffness. However, the pathways that regulate cellular responses to mechanotransduction and hypoxia may not act independently, but rather also impact one another. Here, we show that on soft, but not stiff surfaces, hypoxia impacts human MSC (hMSC) morphology and colony formation, and inhibition of cytoskeletal tension negates the hypoxia-mediated upregulation of molecular markers of chondrogenesis. These observations suggest that hypoxia's effects during hMSC chondrogenesis are modulated, at least in part, by mechanosensitive pathways, and may impact strategies to develop scaffolds for cartilage tissue engineering, as hypoxia's chondrogenic effects may be enhanced on soft materials.
Keywords
Acrylic Resins/chemistry, Acrylic Resins/pharmacology, Cell Differentiation, Cell Hypoxia, Chondrogenesis, Humans, Hydrogels/chemistry, Hydrogels/pharmacology, Mechanotransduction, Cellular, Mesenchymal Stem Cells/cytology, Mesenchymal Stem Cells/metabolism, Stress, Mechanical, Transforming Growth Factor beta1/metabolism, Transforming Growth Factor beta3/metabolism, Cartilage, Hypoxia, Mechanotransduction, Mesenchymal stem cell, Tissue engineering
Pubmed
Web of science
Open Access
Yes
Create date
12/01/2024 11:14
Last modification date
13/01/2024 8:10
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