Abstract：
BACKGROUND: Leucine (Leu) is an essential amino acid that facilitates skeletal muscle satellite cell differentiation, yet its mechanism remains underexplored. Sestrin2 (SESN2) serves as a Leu sensor, binding directly to Leu, while ribophorin II (RPN2) acts as a signaling factor in multiple pathways. This study aimed to elucidate Leu\'s impact on mouse C2C12 cell differentiation and skeletal muscle injury repair by modulating RPN2 expression through SESN2, offering a theoretical foundation for clinical skeletal muscle injury prevention and treatment.
RESULTS: Leu addition promoted C2C12 cell differentiation compared to the control, enhancing early differentiation via myogenic determinant (MYOD) up-regulation. Sequencing revealed SESN2 binding to and interacting with RPN2. RPN2 overexpression up-regulated MYOD, myogenin and myosin heavy chain 2, concurrently decreased p-GSK3β and increased nuclear β-catenin. Conversely, RPN2 knockdown yielded opposite results. Combining RPN2 knockdown with Leu rescued increased p-GSK3β and decreased nuclear β-catenin compared to Leu absence. Hematoxylin and eosin staining results showed that Leu addition accelerated mouse muscle damage repair, up-regulating Pax7, MYOD and RPN2 in the cytoplasm, and nuclear β-catenin, confirming that the role of Leu in muscle injury repair was consistent with the results for C2C12 cells.
CONCLUSIONS: Leu, bound with SESN2, up-regulated RPN2 expression, activated the GSK3β/β-catenin pathway, enhanced C2C12 differentiation and expedited skeletal muscle damage repair. © 2024 Society of Chemical Industry.
RESULTS: Leu addition promoted C2C12 cell differentiation compared to the control, enhancing early differentiation via myogenic determinant (MYOD) up-regulation. Sequencing revealed SESN2 binding to and interacting with RPN2. RPN2 overexpression up-regulated MYOD, myogenin and myosin heavy chain 2, concurrently decreased p-GSK3β and increased nuclear β-catenin. Conversely, RPN2 knockdown yielded opposite results. Combining RPN2 knockdown with Leu rescued increased p-GSK3β and decreased nuclear β-catenin compared to Leu absence. Hematoxylin and eosin staining results showed that Leu addition accelerated mouse muscle damage repair, up-regulating Pax7, MYOD and RPN2 in the cytoplasm, and nuclear β-catenin, confirming that the role of Leu in muscle injury repair was consistent with the results for C2C12 cells.
CONCLUSIONS: Leu, bound with SESN2, up-regulated RPN2 expression, activated the GSK3β/β-catenin pathway, enhanced C2C12 differentiation and expedited skeletal muscle damage repair. © 2024 Society of Chemical Industry.
摘要：
背景：亮氨酸（Leu），促进骨骼肌卫星细胞分化的必需氨基酸，然而，其机制仍未得到充分开发。Sestrin2（SESN2）用作Leu传感器，直接绑定到Leu，而核蛋白II（RPN2）在多个途径中充当信号因子。本研究旨在阐明Leu通过SESN2调控RPN2表达对小鼠C2C12细胞分化及骨骼肌损伤修复的影响,为临床骨骼肌损伤的防治提供理论依据。
结果：与对照组相比，添加Leu可促进C2C12细胞分化，通过MYOD上调促进早期分化。测序显示SESN2与RPN2结合并相互作用。RPN2过表达上调MYOD,MYOG,和MYH2，同时降低p-GSK3β，核β-连环蛋白增加。相反，RPN2敲低产生相反的结果。与不存在Leu相比，将RPN2敲低与Leu相结合可挽救增加的p-GSK3β和减少的核β-连环蛋白。HE染色结果显示添加Leu加速小鼠肌肉损伤修复,上调Pax7，MYOD，细胞质中的RPN2，和核β-连环蛋白，证实Leu在肌肉损伤修复中的作用与C2C12细胞的结果一致。
结论：列伊，与SESN2结合，上调RPN2表达，激活GSK3β/β-catenin通路，增强C2C12分化，加速骨骼肌损伤修复。本文受版权保护。保留所有权利。
结果：与对照组相比，添加Leu可促进C2C12细胞分化，通过MYOD上调促进早期分化。测序显示SESN2与RPN2结合并相互作用。RPN2过表达上调MYOD,MYOG,和MYH2，同时降低p-GSK3β，核β-连环蛋白增加。相反，RPN2敲低产生相反的结果。与不存在Leu相比，将RPN2敲低与Leu相结合可挽救增加的p-GSK3β和减少的核β-连环蛋白。HE染色结果显示添加Leu加速小鼠肌肉损伤修复,上调Pax7，MYOD，细胞质中的RPN2，和核β-连环蛋白，证实Leu在肌肉损伤修复中的作用与C2C12细胞的结果一致。
结论：列伊，与SESN2结合，上调RPN2表达，激活GSK3β/β-catenin通路，增强C2C12分化，加速骨骼肌损伤修复。本文受版权保护。保留所有权利。
