Expression of heat shock protein 27 correlates with actin cytoskeletal dynamics and contractility of cultured human bladder smooth muscle cells

• Published in: Experimental cell research Vol. 338; no. 1; pp. 39 - 44
• Main Authors: Wang, Yongquan, Xiong, Zhiyong, Gong, Wei, Zhou, Peng, Xie, Qiubo, Zhou, Zhansong, Lu, Gensheng
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.10.2015; Elsevier BV
• Subjects: Actin cytoskeleton; Actin Cytoskeleton - metabolism; Bladder smooth muscle cells; Contraction; Gene Expression; HEK293 Cells; HSP27; HSP27 Heat-Shock Proteins - genetics; HSP27 Heat-Shock Proteins - metabolism; Humans; Muscle Contraction; Myocytes, Smooth Muscle - physiology; Urinary Bladder - cytology; Actin cytoskeleton; Bladder smooth muscle cells; Contraction; HSP27
• ISSN: 0014-4827; 1090-2422
• DOI: 10.1016/j.yexcr.2015.08.002

Heat shock protein 27 (HSP27) is one of the most important chaperone proteins that modulates smooth muscle contraction. Here we investigated the effects of HSP27 expression on cytoskeleton dynamics and contractile function of human bladder smooth muscle cells (BSMCs) in vitro. Cultured human BSMCs were transfected with lentiviral vectors expressing either HSP27 or HSP27-siRNAs. Normal BSMCs cells and cells transfected with the empty lentivirus were used as control. Cells were then cultured on Flexcell flexible membrane dishes and mechanical stretch (14.8% elongation) was applied. The stretch caused significant disruption of actin cytoskeletal structure and decrease in F/G-actin ratio in BSMCs with HSP27 over-expression, knock-down and control groups (P<0.05) as indicated by phalloidin-FITC staining. It was also shown that the structure of actin filaments in HSP27 over-expressed cells recovered and F/G-actin ratio significantly increased at 12h after stretching compared to unstretched cells (P<0.05), but not in HSP27 knock-down cells, suggesting that HSP27 promoted the recovery of cytoskeletal structure in BSMCs from stretch-induced injury. In addition, the contractile force of BSMCs was enhanced by over-expression of HSP27 and attenuated by knock-down of HSP27 (P<0.05), suggesting a pivotal role of HSP27 in regulating bladder smooth muscle contraction. •Heat shock protein 27 (HSP27) modulates smooth muscle contraction.•Overexpression of HSP27 promoted cells recovered from stretching.Moreover, the contraction protection function of HSP27 may depend on the activation of phosphorylation of Ser 78 and 82•Overexpression of HSP27 significantly increased F/G-actin ratio after stretching.•HSP27 plays pivotal role in regulating bladder smooth muscle contraction.