Tenascin-C expression and its associated pathway in BMSCs following co-culture with mechanically stretched ligament fibroblasts

The occurrence of pelvic organ prolapse (POP) is closely associated with alterations in the extracellular matrix proteins of the supporting ligament. Bone marrow mesenchymal stem cells (BMSCs) have the potential to differentiate into a variety of cell types, including osteoblasts, chondroblasts and adipocytes. Therefore, BMSCs have the potential to improve the clinical outcomes of POP. Tenascin-C is a large glycoprotein that is present in the ECM and is involved in morphogenetic movements, and tissue patterning and repair. The aim of the present study was to investigate the effect of mechanical stretching on tenascin-C expression during the differentiation of BMSCs induced by pelvic ligament fibroblasts. BMSCs were isolated from 7-day-old Sprague Dawley rats. Fibroblasts were obtained from rat pelvic ligaments and, at the fourth passage, were subjected to 10% deformation with 1 Hz, periodic one-way mechanical stretch stimulation, followed by co-culture with BMSCs. The co-culture with stretched fibroblasts increased tenascin-C and transforming growth factor (TGF)-β expression levels, compared with groups without mechanical stimulation. Neutralizing anti-TGF-β1 antibodies, and inhibitors of TGF-β receptor, mitogen-activated protein kinase (MAPK) kinase and MAPK, decreased tenascin-C expression levels induced by TGF-β and mechanical stretching. The results of the present study suggested that the regulation of tenascin-C expression levels in BMSCs co-cultured with mechanically stretched pelvic ligament fibroblasts is mediated via the soluble growth factor TGF-β and the MAPK signaling pathway. In addition, these results indicated that in an indirect co-culture system, pelvic ligament fibroblasts with mechanical stretch stimulation may promote the synthesis of tenascin-C and BMSC differentiation into pelvic ligament fibroblasts.