2012 Volume No 23 – pages 121-134
|
Title: Hydrostatic pressure acts to stabilise a chondrogenic phenotype in porcine joint tissue derived stem cells |
Author: T Vinardell, RA Rolfe, CT Buckley, EG Meyer, M Ahearne, P Murphy, DJ Kelly |
|
Address: Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin, Dublin 2, Ireland |
|
E-mail: kellyd9 at tcd.ie |
|
Key Words: Hydrostatic pressure, cartilage, synovial membrane, infrapatellar fat pad, transforming growth factor (TGF)-β3, stem cells, chondrocytes |
|
Publication date: February 23rd 2012 |
|
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. |
|
Article download: Pages
121-134 (PDF file) |
|