Growth differentiation factor-5 induces tenomodulin expression via phosphorylation of p38 and promotes viability of murine mesenchymal stem cells from compact bone

Abstract

Growth differentiation factor (GDF)-5 serves a role in tissue development and tenomodulin serves an important role in the development of tendons. The effects of GDF-5 on mesenchymal stem cells (MSCs), particularly with regards to tendon bioengineering, are poorly understood. The present study aimed to investigate the effects of GDF-5 on cell viability and tenomodulin expression in MSCs from murine compact bone. MSCs were isolated from murine compact bones and confirmed by flow cytometric analysis. In addition, the adipogenic, osteoblastic and chondrocyte differentiation capabilities of the MSCs were determined. MSCs were treated with GDF-5 and the effects of GDF-5 on MSC viability were determined. The mRNA and protein expression levels of tenomodulin were detected by reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. MSCs from murine compact bone were successfully isolated. GDF-5 had optimal effects on cell viability at 100 ng/ml (+36.9% of control group without GDF-5 treatment, P<0.01) and its effects peaked after 6 days of treatment (+56.6% of control group, P<0.001). Compared with the control group, treatment with 100 ng/ml GDF-5 for 4 days enhanced the mRNA expression levels of tenomodulin (3.56±0.94 vs. 1.02±0.25; P<0.05). In addition, p38 was activated by GDF-5, as determined by enhanced expression levels of phosphorylated p38 (p-p38). The GDF-5-induced protein expression levels of p-p38 and tenomodulin were markedly inhibited following treatment with SB203580, an inhibitor of p38 mitogen-activated protein kinase. These results suggested that GDF-5 treatment may increase tenomodulin protein expression via phosphorylation of p38 in MSCs from murine compact bone. These findings may aid the future development of tendon bioengineering.