title: Hydrostatic pressure acts to stabilise a chondrogenic phenotype in porcine joint tissue derived stem cells.
abstract: Hydrostatic pressure (HP) is a key component of the in vivo joint environment and has been shown to enhance chondrogenesis of stem cells. The objective of this study was to investigate the interaction between HP and TGF-β3 on both the initiation and maintenance of a chondrogenic phenotype for joint tissue derived stem cells. Pellets generated from porcine chondrocytes (CCs), synovial membrane derived stem cells (SDSCs) and infrapatellar fat pad derived stem cells (FPSCs) were subjected to 10 MPa of cyclic HP (4 h/day) and different concentrations of TGF-β3 (0, 1 and 10 ng/mL) for 14 days. CCs and stem cells were observed to respond differentially to both HP and TGF-β3 stimulation. HP in the absence of TGF-β3 did not induce robust chondrogenic differentiation of stem cells. At low concentrations of TGF-β3 (1 ng/mL), HP acted to enhance chondrogenesis of both SDSCs and FPSCs, as evident by a 3-fold increase in Sox9 expression and a significant increase in glycosaminoglycan accumulation. In contrast, HP had no effect on cartilage-specific matrix synthesis at higher concentrations of TGF-β3 (10 ng/mL). Critically, HP appears to play a key role in the maintenance of a chondrogenic phenotype, as evident by a down-regulation of the hypertrophic markers type X collagen and Indian hedgehog in SDSCs irrespective of the cytokine concentration. In the context of stem cell based therapies for cartilage repair, this study demonstrates the importance of considering how joint specific environmental factors interact to regulate not only the initiation of chondrogenesis, but also the development of a stable hyaline-like repair tissue.
authors.affiliation: 1Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Ireland.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Vinardell
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Rolfe
authors.forename: Conor T
authors.initials: CT
authors.lastname: Buckley
authors.forename: Eric G
authors.initials: EG
authors.lastname: Meyer
authors.forename: Mark
authors.initials: M
authors.lastname: Ahearne
authors.forename: Paula
authors.initials: P
authors.lastname: Murphy
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Kelly
mesh_terms: D000818:Animals; D002356:Cartilage / Q000166:cytology* / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects / Q000378:metabolism*; D020219:Chondrogenesis / Q000187:drug effects*; D024121:Collagen Type X / Q000187:drug effects / Q000378:metabolism; D006025:Glycosaminoglycans / Q000378:metabolism; D053823:Hedgehog Proteins / Q000187:drug effects / Q000378:metabolism; D006874:Hydrostatic Pressure; D057071:Patellofemoral Joint / Q000166:cytology* / Q000378:metabolism; D010641:Phenotype; D055758:SOX9 Transcription Factor / Q000187:drug effects / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D013552:Swine; D013583:Synovial Membrane / Q000166:cytology / Q000378:metabolism; D053782:Transforming Growth Factor beta3 / Q000008:administration & dosage*
chemical_list: D024121:Collagen Type X; D006025:Glycosaminoglycans; D053823:Hedgehog Proteins; D055758:SOX9 Transcription Factor; D053782:Transforming Growth Factor beta3