[衰老性肌肉减少症大鼠骨骼肌中基质金属蛋白酶-1和金属蛋白酶组织抑制剂-1的表达]

[Expressions of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinases 1 in skeletal muscles of aged rats with sarcopenia].

作者信息

Zhu Shiyu, Lü Ankang, Zhao Yuxing, Pu Die, Liao Zhiyin, Sun Yue, Chen Jinliang, Xiao Qian

机构信息

Department of Geriatrics, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.

出版信息

Nan Fang Yi Ke Da Xue Xue Bao. 2020 Jan 30;40(1):104-109. doi: 10.12122/j.issn.1673-4254.2020.01.17.

DOI:10.12122/j.issn.1673-4254.2020.01.17

PMID:32376563

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7040751/

Abstract

OBJECTIVE

To investigate the changes of skeletal muscle mass and strength and the expressions of matrix metalloproteinase-1 (MMP-1), tissue inhibitor of metalloproteinases-1 (TIMP-1) and collagen-1 in the skeletal muscle of aged rats with sarcopenia.

METHODS

With 11 young (6-month-old) SD rats as control group, 18 aged (25-month-old) SD rats were divided into two groups (n=9) according to the relative lean mass determined dual X-ray absorptiometry (DXA), namely aged control group and aged sarcopenia group (the relative lean mass was 2SD higher in aged control than in aged sarcopenia group. The forelimb grip strength of the rats was measured using an electronic grip strength meter. The extracellular matrix (ECM) of the rat's gastrocnemius was observed with HE staining and sirius Red staining, and the protein expressions of collagen-1, MMP-1, and TIMP-1 in the muscular tissues were detected with Western blotting.

RESULTS

Compared with the young rats, the aged control rats had significantly lower relative grip strength ( < 0.01) and increased expressions of collagen-1 and TIMP-1 ( < 0.05) and ECM content in the skeletal muscles, but the relative lean mass and MMP-1 protein expression were comparable between the two groups (>0.05). Compared with the aged control rats, the aged sarcopenic rats had significantly lowered relative lean mass ( < 0.01) and MMP-1 expressions of ( < 0.05) and increased expressions of collagen-1 and TIMP-1 proteins and ECM content in the muscular tissues ( < 0.05) without significant changes in the relative grip strength (>0.05).

CONCLUSIONS

MMP-1/TIMP-1 imbalance in the skeletal muscle during aging affects ECM metabolism and leads to increased collagen fibers, which in turn affects the skeletal muscle mass and function and contribute to the onset of sarcopenia.

摘要

目的

探讨少肌症老龄大鼠骨骼肌质量、力量的变化以及基质金属蛋白酶-1（MMP-1）、金属蛋白酶组织抑制剂-1（TIMP-1）和Ⅰ型胶原在骨骼肌中的表达情况。

方法

选取11只年轻（6月龄）SD大鼠作为对照组，将18只老龄（25月龄）SD大鼠根据双能X线吸收法（DXA）测定的相对瘦体重分为两组（n = 9），即老龄对照组和老龄少肌症组（老龄对照组的相对瘦体重比老龄少肌症组高2个标准差）。用电子握力计测量大鼠前肢握力。采用HE染色和天狼星红染色观察大鼠腓肠肌的细胞外基质（ECM），并用蛋白质免疫印迹法检测肌肉组织中Ⅰ型胶原、MMP-1和TIMP-1的蛋白表达。

结果

与年轻大鼠相比，老龄对照大鼠的相对握力显著降低（P < 0.01），骨骼肌中Ⅰ型胶原和TIMP-1的表达增加（P < 0.05），ECM含量增加，但两组间相对瘦体重和MMP-1蛋白表达无差异（P > 0.05）。与老龄对照大鼠相比，老龄少肌症大鼠的相对瘦体重显著降低（P < 0.01），MMP-1表达降低（P < 0.05），肌肉组织中Ⅰ型胶原和TIMP-1蛋白表达增加，ECM含量增加（P < 0.05），相对握力无显著变化（P > 0.05）。