Department of Orthopedics Trauma and Microsurgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, PR China; Department of Joint Surgery and Sports Medicine, Zhongnan Hospital of Wuhan University, Wuhan 430071, PR China.
Department of Surgery, the Hospital of Hubei Provincial Government, Wuhan 430071, PR China.
Cell Signal. 2020 Jul;71:109606. doi: 10.1016/j.cellsig.2020.109606. Epub 2020 Mar 19.
The proliferation of fibroblasts creates an environment favoring post-operative tendon adhesion, but targeted therapy of this pathology remains in its infancy. In this study, we explored the effect of heat shock protein 72 (HSP72), a major inducible member of the heat shock protein family that can protect cells against many cellular stresses including heat shock, on fibroblast proliferation in tendon adhesion, with its underlying mechanisms investigated. HSP72 expression was examined in an established rat model of tendon injury using RT-qPCR and immunoblot analysis. After conducting ectopic expression and depletion experiments in fibroblast NIH3T3 cells, we determined the effects of HSP72 on the expression of α-SMA and STAT3 signaling pathway-related genes, fibroblast proliferation, as well as collagen production. The mRNA (65.46%) and protein (63.65%) expression of HSP72 was downregulated in the rat model of tendon injury. The in vitro experiments revealed that overexpression of HSP72 inhibited fibroblast proliferation (42.57%) and collagen production (45.60%), as well as reducing α-SMA expression (42.49%) and the extent of STAT3 phosphorylation (55.46%). Moreover, we observed that HSP72 overexpression reduced inflammation as well as the number of inflammatory cell infiltration and fibroblasts in vivo. Furthermore, the inhibited extent of STAT3 phosphorylation contributed to the impaired fibroblast proliferation and collagen production evoked by upregulated HSP72. In summary, the present study unveils an inhibitory role of HSP72 in tendon adhesion via inactivation of the STAT3 signaling pathway. This finding may enable the development of new therapeutic strategies for the prevention against tendon adhesion.
成纤维细胞的增殖会形成一种有利于术后肌腱粘连的环境，但针对这种病理的靶向治疗仍处于起步阶段。在这项研究中，我们探讨了热休克蛋白 72（HSP72）对肌腱粘连中成纤维细胞增殖的影响，HSP72 是热休克蛋白家族中的主要诱导成员，可保护细胞免受包括热休克在内的多种细胞应激，同时研究了其潜在机制。我们使用 RT-qPCR 和免疫印迹分析在已建立的肌腱损伤大鼠模型中检查了 HSP72 的表达。在 NIH3T3 成纤维细胞中进行异位表达和耗竭实验后，我们确定了 HSP72 对 α-SMA 和 STAT3 信号通路相关基因表达、成纤维细胞增殖以及胶原产生的影响。在肌腱损伤大鼠模型中，HSP72 的 mRNA（65.46%）和蛋白（63.65%）表达下调。体外实验表明，HSP72 的过表达抑制了成纤维细胞的增殖（42.57%）和胶原产生（45.60%），同时降低了 α-SMA 表达（42.49%）和 STAT3 磷酸化程度（55.46%）。此外，我们观察到 HSP72 过表达减少了炎症以及炎症细胞浸润和纤维母细胞的数量。此外，STAT3 磷酸化的抑制程度有助于解释 HSP72 上调引起的成纤维细胞增殖和胶原产生受损。综上所述，本研究揭示了 HSP72 通过失活 STAT3 信号通路在肌腱粘连中发挥抑制作用。这一发现可能为预防肌腱粘连提供新的治疗策略。
