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2022, Vol. 26 ›› Issue (14): 2144-2149Effects of transforming growth factor beta1 and Ras homolog gene family member A on cell morphology and cytoskeleton during chondrocyte differentiationChen Yuting1, He Feiming1, Xiang Wei1, 2, Wang Chao1, 2, Cao Weiwei1, Wang Weishan2, Liu Wei1
Abstract: BACKGROUND: The important pathological change of osteoarthritis is the degeneration of articular cartilage. Transforming growth factor β1 and Ras homolog gene family member A play an important role in maintaining the stability of articular cartilage and the occurrence and development of osteoarthritis, respectively. OBJECTIVE: To investigate the effects of transforming growth factor-β1 and Ras homolog gene family member A on chondrocyte morphology, cytoskeleton and expression of related factors during chondrocyte differentiation, and the mutual regulation relationship between transforming growth factor-β1, Ras homolog gene family member A and SRY related HMG box-9. METHODS: Exogenous transforming growth factor β1 at different concentrations was added to stimulate ATDC5 cells to detect the protein expression of Ras homolog gene family member A and SRY related HMG box-9 at different times. Transforming growth factor-β1, LY-364947 (a potent ATP-competitive inhibitor of transforming growth factor-β receptor I) and lysophosphatidic acid (a Ras homolog gene family member A agonist) were used in different combinations to deal with ATDC5 cells for 72 hours. The protein expression levels of Ras homolog gene family member A, SRY related HMG box-9 and transforming growth factor-β were detected, and the changes in cell morphology and cytoskeleton were also observed. RESULTS AND CONCLUSION: With the increase of transforming growth factor-β1 concentration and time, the expression levels of Ras homolog gene family member A and SRY related HMG box-9 proteins increased significantly (P < 0.001). Compared with the control group, lysophosphatidic acid significantly increased the expression levels of Ras homolog gene family member A and SRY related HMG box-9 protein (P < 0.001), but lysophosphatidic acid treatment had no effect on the protein expression level of transforming growth factor-β1 (P > 0.05). The combination of transforming growth factor-β1 and lysophosphatidic acid significantly increased the protein levels of transforming growth factor-β1, Ras homolog gene family member A, and SRY related HMG box-9 in the treated cells (P < 0.001). LY-364947 decreased the protein levels of RhoA and SRY related HMG box-9 (P < 0.001), and significantly reduced the activation effects of lysophosphatidic acid on Ras homolog gene family member A and SRY related HMG box-9 (P < 0.001). Compared with the control group, after treatment with transforming growth factor-β1, lysophosphatidic acid and their combination, the cell morphology was elongated, the intracellular actin filaments were arranged in a more orderly manner, and the number of actin filaments aggregated at the cell edge was increased. LY-364947 made the morphology of cells become polygonal, the arrangement of actin filaments was disordered, and the actin filaments at the edge of cells decreased. The changes in cell morphology and cytoskeleton by LY-364947+lysophosphatidic acid treatment were similar to those in the LY-364947 treatment group. Therefore, in ATDC5 cells, transforming growth factor-β1 has a superposition effect on Ras homolog gene family member A and SRY related HMG box-9 protein expression in concentration, dose and time. Transforming growth factor-β1 may be the upstream factor of Ras homolog gene family member A and SRY related HMG box-9, regulates the expression of Ras homolog gene family member A and SRY related HMG box-9 to regulate the function of cytoskeleton, and thus participates in the development and progression of osteoarthritis. Key words:osteoarthritis, transforming growth factor-β1, Ras homolog gene family member A, SRY related HMG box-9, cytoskeleton |