Effect of dedifferentiation on tendon differentiation of rat bone marrow mesenchymal stem cells

Abstract

Objective To investigate the differentiation potential of rat bone marrow mesenchymal stem cells in dedifferentiation process. Methods Bone marrow mesenchymal stem cells (BMSCs) of Sprague Dawley rats were isolated and cultured using a whole bone marrow adherent method. BMSCs were induced to dedifferentiate with culture medium containing growth differentiation factor (GDF-5), and then its tendon differentiation was further induced with culture medium containing GDF-5. After 3 weeks, the expression of type Ⅰ (Col Ⅰ), Collagen type Ⅲ (ColⅢ), tenascin-C (TNC), basic Helix-Loop-Helix (scleraxis, SCX) and Tenomodulinwas detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting. Results are given as mean±standard deviation. Statistical analysis was performed using Student’s t-test. Multiple comparisons were done using one way ANOVA test. Statistical signicance was set at P<0.05. Results The gene expression of Scx, Col Ⅰ, Col Ⅲ and TNC in experimental group (0.635±0.557, 0.590±0.020, 0.447±0.063, 0.613±0.061 respectively) was significantly higher than that in induced differentiation group (0.416±0.054, 0.406±0.173, 0.294±0.013, 0.373±0.042, t=17.857, P<0.01; t=12.948, P<0.01; t=7.747, P<0.01; t=-5.212, P<0.05) and control group (0.197±0.019, 0.201±0.014, 0.216±0.037, 0.190±0.014, t=31.077, P<0.01; t=14.419, P<0.01; t=15.054, P<0.01; t=8.013, P<0.05). Western blotting indicated that the expression of Col Ⅰ, TNC and Tenomodulin in experimental group (1.705±0.159, 1.587±0.018, 1.616±0.019 respectively)was higher than that in positive control group (1.160±0.018, 1.164±0.016, 1.092±0.022, t=4.825, P<0.05; t=17.395, P<0.05; t=3.961, P<0.05 respectively) and negative group (0.643±0.047, 0.441±0.02l, 0.673±0.015 respectively, t=13.299, P<0.05; t=37.618, P<0.05; t=9.349, P<0.05 respectively). Conclusion GDF-5 can induce the differentiation of bone marrow mesenchymal stem cells into tendon cells, and the dedifferentiation process can improve the ability of bone marrow mesenchymal stem cells to differentiate into tendon cells. Key words: Bone mesenchymal stem cells; Dedifferentiation; Growth differentiation factor-5; Differentiation; Tendon cells