Shi Hua-Cai, Chen Rui, She Yan-Ling, Zhou Shan-Yao, Lei Si, Guo Jun
Guangdong Traditional Medical and Sports Injury Rehabilitation Research Institute, Guangdong Second Provincial General Hospital, Guangzhou 510317, China.
Zhongguo Ying Yong Sheng Li Xue Za Zhi. 2021 Sep;37(5):566-570. doi: 10.12047/j.cjap.6074.2021.037.
To investigate the effects of Atrolnc-1 on immobilization induced muscular atrophy in mice hindlimbs. Male C57BL/6 mice were randomly divided into control group and immobilization group (=10 per group). The control group did not receive any treatment. The right hindlimb of the Iimmobilization group was fixed by self-made plastic tube. After 2 weeks' immobilization, the gastrocnemius muscle was separated. Hematoxylin-eosin (HE) staining was used to observe the morphological changes and the cross-sectional area was calculated. The expressions of Atrogin-1 and atrophy-specific long non-coding RNA Atrolnc-1 were detected by quantitative real-time PCR (QRT-PCR). Western blot (WB) was used to detect the expressions of muscular atrophy fbox-1 protein (MAFbx/Atrogin-1), muscle ring finger1 (MuRF-1) in whole cell and phosphonated of nuclear factor kappaB (p-NF-κB) in cytoplasm and nucleus. The gastrocnemius muscle was atrophy after 2 weeks' immobilization. Compared with the control group, the wet weight of gastrocnemius muscle was decreased (＞0.05) and the permillage of wet weight/weight of gastrocnemius muscle was decreased significantly (＜0.05). HE staining showed that the number of muscle fibers in the immobilization group were reduced, the muscle fibers were dissolved and arranged disorderly and the interstitial inflammatory cells were infiltrated; the cross-sectional area of muscle fibers was decreased (＜0.01).The expression level of atrolnc-1 was increased in immobilization group (＜0.01). The expression level of p-NF-κB in cytoplasm was decreased (＜0.01), while the expression level of p-NF-κB was increased in nucleus ( ＜0.01). Besides, the expressions of atrogin-1 (＜0.01) and MuRF-1 (＜0.01) were increased. Immobilization induced gastrocnemius atrophy in mice may be related to the activation of NF-κB by Atrolnc-1 and then promote MuRF-1 expression.
为研究Atrolnc-1对小鼠后肢固定性肌肉萎缩的影响。将雄性C57BL/6小鼠随机分为对照组和固定组（每组n = 10）。对照组不接受任何处理。固定组小鼠右后肢用自制塑料管固定。固定2周后，分离腓肠肌。采用苏木精-伊红（HE）染色观察形态学变化并计算横截面积。通过定量实时PCR（QRT-PCR）检测Atrogin-1和萎缩特异性长链非编码RNA Atrolnc-1的表达。采用蛋白质免疫印迹法（WB）检测全细胞中肌肉萎缩相关蛋白1（MAFbx/Atrogin-1）、肌肉环形指蛋白1（MuRF-1）以及细胞质和细胞核中磷酸化核因子κB（p-NF-κB）的表达。固定2周后腓肠肌出现萎缩。与对照组相比，腓肠肌湿重降低（P＞0.05），腓肠肌湿重/体重百分比显著降低（P＜0.05）。HE染色显示，固定组肌纤维数量减少，肌纤维溶解、排列紊乱，间质有炎性细胞浸润；肌纤维横截面积减小（P＜0.01）。固定组Atrolnc-1表达水平升高（P＜0.01）。细胞质中p-NF-κB表达水平降低（P＜0.01），而细胞核中p-NF-κB表达水平升高（P＜0.01）。此外，Atrogin-1（P＜0.01）和MuRF-1（P＜0.01）表达增加。小鼠固定性腓肠肌萎缩可能与Atrolnc-1激活NF-κB进而促进MuRF-1表达有关。
