Sayed Ramy Ka, Fernández-Ortiz Marisol, Fernández-Martínez José, Aranda Martínez Paula, Guerra-Librero Ana, Rodríguez-Santana César, de Haro Tomás, Escames Germaine, Acuña-Castroviejo Darío, Rusanova Iryna
Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Sohag University, Sohag 82524, Egypt.
Centro de Investigación Biomédica, Departamento de Fisiología, Facultad de Medicina, Instituto de Biotecnología, Parque Tecnológico de Ciencias de la Salud, Universidad de Granada, 18016 Granada, Spain.
Antioxidants (Basel). 2021 Mar 27;10(4):524. doi: 10.3390/antiox10040524.
Muscular aging is a complex process and underlying physiological mechanisms are not fully clear. In recent years, the participation of the NF-kB pathway and the NLRP3 inflammasome in the chronic inflammation process that accompanies the skeletal muscle's aging has been confirmed. microRNAs (miRs) form part of a gene regulatory machinery, and they control numerous biological processes including inflammatory pathways. In this work, we studied the expression of four miRs; three of them are considered as inflammatory-related miRs (miR-21, miR-146a, and miR-223), and miR-483, which is related to the regulation of melatonin synthesis, among other targets. To investigate the changes of miRs expression in muscle along aging, the impact of inflammation, and the role of melatonin in aged skeletal muscle, we used the gastrocnemius muscle of wild type (WT) and NLRP3-knockout (NLRP3) mice of 3, 12, and 24 months-old, with and without melatonin supplementation. The expression of miRs and pro-caspase-1, caspase-3, pro-IL-1β, bax, bcl-2, and p53, was investigated by qRT-PCR analysis. Histological examination of the gastrocnemius muscle was also done. The results showed that age increased the expression of miR-21 ( < 0.01), miR-146a, and miR-223 ( < 0.05, for both miRs) in WT mice, whereas the 24-months-old mutant mice revealed decline of miR-21 and miR-223 ( < 0.05), compared to WT age. The lack of NLRP3 inflammasome also improved the skeletal muscle fibers arrangement and reduced the collagen deposits compared with WT muscle during aging. For the first time, we showed that melatonin significantly reduced the expression of miR-21, miR-146a, and miR-223 ( < 0.05 for all ones, and < 0.01 for miR-21 at 24 months old) in aged WT mice, increased miR-223 in NLRP3 mice ( < 0.05), and induced miR-483 expression in both mice strains, this increase being significant at 24 months of age.
肌肉衰老过程复杂，其潜在的生理机制尚未完全明确。近年来，已证实NF-κB信号通路和NLRP3炎性小体参与了骨骼肌衰老伴随的慢性炎症过程。微小RNA（miRs）是基因调控机制的一部分，它们控制着包括炎症通路在内的众多生物学过程。在本研究中，我们检测了4种miRs的表达；其中3种被认为是炎症相关miRs（miR-21、miR-146a和miR-223），以及miR-483，其除了其他作用靶点外，还与褪黑素合成的调控有关。为了研究miRs表达在肌肉衰老过程中的变化、炎症的影响以及褪黑素在老年骨骼肌中的作用，我们使用了3月龄、12月龄和24月龄的野生型（WT）和NLRP3基因敲除（NLRP3）小鼠的腓肠肌，部分小鼠给予或未给予褪黑素补充。通过qRT-PCR分析检测miRs以及前半胱天冬酶-1、半胱天冬酶-3、前白细胞介素-1β、bax、bcl-2和p53的表达。同时对腓肠肌进行了组织学检查。结果显示，年龄增长使WT小鼠中miR-21（<0.01）、miR-146a和miR-223（两者均<0.05）的表达增加，而24月龄的突变小鼠与同年龄的WT小鼠相比，miR-21和miR-223表达下降（<0.05）。与衰老过程中的WT肌肉相比，NLRP3炎性小体的缺失还改善了骨骼肌纤维排列并减少了胶原蛋白沉积。我们首次发现，褪黑素显著降低了老年WT小鼠中miR-21、miR-146a和miR-223的表达（均<0.05，24月龄时miR-21<0.01），增加了NLRP3小鼠中miR-223的表达（<0.05），并在两种小鼠品系中均诱导了miR-483的表达，这种增加在24月龄时具有显著性。
