Medical Research Centre, Affiliated Hospital of Jining Medical University, Jining, Shandong Province, China.
Department of Respiratory and Critical Care, Affiliated Hospital of Jining Medical University, Jining, Shandong Province, China.
Cell Commun Signal. 2024 Feb 1;22(1):93. doi: 10.1186/s12964-024-01497-x.
Physical exercise directly stretching the peripheral nerve promotes nerve regeneration; however, its action mechanism remains elusive. Our present study aimed to investigate the effects of mechanosensitive channel of large conductance (MscL) activated by mechanical stretching on the cultured Schwann cells (SCs) and explore the possible mechanism.
Primary SCs from neonatal mice at 3-5 days of age were derived and transfected with the lentivirus vector expressing a mutant version of MscL, MscL-G22S. We first detected the cell viability and calcium ion (Ca) influx in the MscL-G22S-expressing SCs with low-intensity mechanical stretching and the controls. Proteomic and energy metabolomics analyses were performed to investigate the comprehensive effects of MscL-G22S activation on SCs. Measurement of glycolysis- and oxidative phosphorylation-related molecules and ATP production were respectively performed to further validate the effects of MscL-G22S activation on SCs. Finally, the roles of phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway in the mechanism of energy metabolism modulation of SCs by MscL-G22S activation was investigated.
Mechanical stretching-induced MscL-G22S activation significantly increased the cell viability and Ca influx into the SCs. Both the proteomic and targeted energy metabolomics analysis indicated the upregulation of energy metabolism as the main action mechanism of MscL-G22S-activation on SCs. MscL-G22S-activated SCs showed significant upregulation of glycolysis and oxidative phosphorylation when SCs with stretching alone had only mild upregulation of energy metabolism than those without stimuli. MscL-G22S activation caused significant phosphorylation of the PI3K/AKT/mTOR signaling pathway and upregulation of HIF-1α/c-Myc. Inhibition of PI3K abolished the MscL-G22S activation-induced upregulation of HIF-1α/c-Myc signaling in SCs and reduced the levels of glycolysis- and oxidative phosphorylation-related substrates and mitochondrial activity.
Mechanical stretching activates MscL-G22S to significantly promote the energy metabolism of SCs and the production of energic substrates, which may be applied to enhance nerve regeneration via the glia-axonal metabolic coupling.
物理运动直接拉伸周围神经可促进神经再生，但作用机制尚不清楚。本研究旨在探讨机械拉伸激活的大电导机械敏感通道（MscL）对培养雪旺细胞（SCs）的影响，并探讨可能的机制。
从小鼠 3-5 天龄的新生鼠中分离原代SCs，并转染表达 MscL 突变体（MscL-G22S）的慢病毒载体。我们首先检测了低强度机械拉伸和对照组中表达 MscL-G22S 的SCs 的细胞活力和钙离子（Ca）内流。蛋白质组学和能量代谢组学分析用于研究 MscL-G22S 激活对SCs 的综合影响。分别测定糖酵解和氧化磷酸化相关分子和 ATP 产生，以进一步验证 MscL-G22S 激活对SCs 的影响。最后，研究了 MscL-G22S 激活对SCs 能量代谢调节中磷脂酰肌醇-3-激酶（PI3K）/蛋白激酶 B（AKT）/哺乳动物雷帕霉素靶蛋白（mTOR）信号通路的作用。
机械拉伸诱导的 MscL-G22S 激活显著增加了SCs 的细胞活力和 Ca 内流。蛋白质组学和靶向能量代谢组学分析均表明，上调能量代谢是 MscL-G22S 激活对SCs 的主要作用机制。与单独拉伸刺激的SCs 仅有轻度的能量代谢上调相比，MscL-G22S 激活的SCs 表现出明显的糖酵解和氧化磷酸化上调。MscL-G22S 激活导致 PI3K/AKT/mTOR 信号通路的显著磷酸化和 HIF-1α/c-Myc 的上调。PI3K 抑制消除了 MscL-G22S 激活诱导的SCs 中 HIF-1α/c-Myc 信号的上调，并降低了糖酵解和氧化磷酸化相关底物和线粒体活性的水平。
机械拉伸激活 MscL-G22S 可显著促进SCs 的能量代谢和能量底物的产生，这可能通过胶质细胞-轴突代谢偶联来增强神经再生。
