State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
Sci Rep. 2016 Sep 6;6:32705. doi: 10.1038/srep32705.
Coculture between mesenchymal stem cells (MSCs) and articular chondrocytes (ACs) represents a promising strategy for cartilage regeneration. This study aimed at elaborating how ACs were regulated by MSCs. Rabbit ACs (rACs) and rabbit MSCs (rMSCs) were seeded separately in a Transwell system to initiate non-contact coculture in growth medium without chondrogenic factors. Cell morphology, cell proliferation, production of extracellular matrix (ECM), and gene expression of rACs were characterized. Upon coculture, rACs underwent a morphological transition from a rounded or polygonal shape into a fibroblast-like one and proliferation was provoked simultaneously. Such effects were dependent on the amount of rMSCs. Along with these changes, ECM production and gene expression of rACs were also perturbed. Importantly, when a ROCK inhibitor (Y27632) was supplemented to coculture, the effects except that on cell proliferation were inhibited, suggesting the involvement of RhoA/ROCK signaling. By applying an inhibitor (BIBF1120) of VEGFR1/2/3, FGFR1/2/3 and PDGFRα/β in coculture, or supplementing FGF-1, VEGF-A and PDGFbb in monoculture, it was confirmed that the paracrine factors by rMSCs mediated the compounding effects on rACs. These findings shed light on MSCs-ACs interactions and might confer an insight view on cell-based cartilage regeneration.
间充质干细胞（MSCs）与关节软骨细胞（ACs）的共培养代表了软骨再生的一种很有前途的策略。本研究旨在阐述 ACs 是如何被 MSCs 调控的。将兔关节软骨细胞（rACs）和兔间充质干细胞（rMSCs）分别接种在 Transwell 系统中，在不含软骨形成因子的生长培养基中启动非接触共培养。对 rACs 的细胞形态、细胞增殖、细胞外基质（ECM）的产生以及基因表达进行了表征。共培养后，rACs 从圆形或多边形形态转变为成纤维细胞样形态，并同时引发增殖。这种效应依赖于 rMSCs 的数量。随着这些变化，rACs 的 ECM 产生和基因表达也受到干扰。重要的是，当向共培养物中添加 Rho 相关蛋白激酶（ROCK）抑制剂（Y27632）时，除细胞增殖外的所有效应均受到抑制，提示 RhoA/ROCK 信号通路的参与。在共培养物中应用 VEGFR1/2/3、FGFR1/2/3 和 PDGFRα/β 的抑制剂（BIBF1120）或在单核培养物中补充 FGF-1、VEGF-A 和 PDGFbb 后，证实了 rMSCs 的旁分泌因子介导了对 rACs 的复合作用。这些发现揭示了 MSCs-ACs 相互作用的机制，并可能为基于细胞的软骨再生提供了新的视角。
