Regulation of HSP25 expression and phosphorylation in functionally overloaded rat plantaris and soleus muscles
Regulation of HSP25 expression and phosphorylation in functionally overloaded rat plantaris and soleus muscles
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DOI：
10.1152/japplphysiol.01022.2005
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发表时间：
2006-02-01
影响因子：
3.3
通讯作者：
Huey, KA
中科院分区：
文献类型：
--
作者：
Huey, KA
功能超负荷（FO）是肌肉肥大以及肌纤维氧化和机械应激的强大诱因。热休克蛋白 25 (HSP25) 可以抵御这两种应激源，并且其表达可以通过肌肉负荷和激活的变化来调节。本研究的主要目的是检验慢性 FO 增加肥大大鼠后肢肌肉中 HSP25 表达和磷酸化 (pHSP25) 的假设。对比目鱼肌和跖肌的可溶性和不溶性部分中的HSP25和pHSP25水平进行定量，以确定3天或7天的FO是否增加HSP25和/或pHSP25向不溶性部分的易位。测量 p38 蛋白和磷酸化 (p-p38) 以确定其与 pHSP25 变化的关联。 FO 时，比目鱼肌和跖肌中的 HSP25 mRNA 显示出时间依赖性增加。三天或七天的 FO 增加了两块肌肉可溶性部分中的 HSP25 和 pHSP25，其中跖肌的反应更大。在不溶性部分中，3 天或 7 天后，两块肌肉中的 HSP25 均增加，而 pHSP25 仅在 7 天的跖肌中增加。 p38 和 p-p38 在两个时间点的跖肌中均增加。在比目鱼肌中，p-p38 仅在 7 天后才增加。这些结果表明 FO 与 HSP25 表达和磷酸化的变化相关，并表明其在肌肉肥大期间发生的重塑中的作用。不溶性部分中 HSP25 的增加表明，它可能有助于在肌肉重塑的应激过程中稳定肌动蛋白和/或其他细胞骨架蛋白。
Functional overload (FO) is a powerful inducer of muscle hypertrophy and both oxidative and mechanical stress in muscle fibers. Heat shock protein 25 (HSP25) may protect against both of these stressors, and its expression can be regulated by changes in muscle loading and activation. The primary purpose of the present study was to test the hypothesis that chronic FO increases HSP25 expression and phosphorylation (pHSP25) in hypertrophying rat hindlimb muscle. HSP25 and pHSP25 levels were quantified in soluble and insoluble fractions of the soleus and plantaris to determine whether 3 or 7 days of FO increase translocation of HSP25 and/or pHSP25 to the insoluble fraction. p38 protein and phosphorylation (p-p38) was measured to determine its association with changes in pHSP25. HSP25 mRNA showed time-dependent increases in both the soleus and plantaris with FO. Three or seven days of FO increased HSP25 and pHSP25 in the soluble fraction in both muscles, with a greater response in the plantaris. In the insoluble fraction, HSP25 was increased after 3 or 7 days in both muscles, whereas pHSP25 was only increased in the 7-day plantaris. p38 and p-p38 increased in the plantaris at both time points. In the soleus, p-p38 only increased after 7 days. These results show that FO is associated with changes in HSP25 expression and phosphorylation and suggest its role in the remodeling that occurs during muscle hypertrophy. Increases in HSP25 in the insoluble fraction suggest that it may help to stabilize actin and/or other cytoskeletal proteins during the stress of muscle remodeling.