Effects of Resistance Training on Matrix Metalloproteinase Activity in Skeletal Muscles and Blood Circulation During Aging

Abstract

Aging is a complex, multifactorial process characterized by the accumulation of deleterious effects, including biochemical adaptations of the extracellular matrix (ECM). The purpose of this study was to investigate the effects of 12 weeks of resistance training (RT) on metalloproteinase 2 (MMP-2) activity in skeletal muscles and, MMP-2 and MMP-9 activity in the blood circulation of young and old rats. Twenty-eight Wistar rats were randomly divided into four groups (n = 7 per group): young sedentary (YS); young trained (YT), old sedentary (OS), and old trained (OT). The stair climbing RT consisted of one training session every 2 other day, with 8–12 dynamic movements per climb. The animals were euthanized 48 h after the end of the experimental period. MMP-2 and MMP-9 activity was measured by zymography. There was higher active MMP-2 activity in the lateral gastrocnemius and flexor digitorum profundus muscles in the OT group when compared to the OS, YS, and YT groups (p ≤ 0.001). Moreover, there was higher active MMP-2 activity in the medial gastrocnemius muscle in the OT group when compared to the YS and YT groups (p ≤ 0.001). The YS group presented lower active MMP-2 activity in the soleus muscle than the YT, OS, OT groups (p ≤ 0.001). With respect to active MMP-2/9 activity in the bloodstream, the OT group displayed significantly reduced activity (p ≤ 0.001) when compared to YS and YT groups. In conclusion, RT up-regulates MMP-2 activity in aging muscles, while down-regulating MMP-2 and MMP-9 in the blood circulation, suggesting that it may be a useful tool for the maintenance of ECM remodeling.

Skeletal Muscle Extracellular Matrix – What Do We Know About Its Composition, Regulation, and Physiological Roles? A Narrative Review

“…These data support the hypothesis that age-associated changes in the ECM might be driven by a decreased degradation capacity rather than by increased synthesis of collagenous structures. Especially, MMPs seem to play an important role in these processes (de Sousa Neto et al, 2018). This is further supported by findings that suggest a diminished resistance exercise-induced remodeling capacity of ECM structures in aged muscles (Wessner et al, 2019).…”

“…In terms of ECM adaptations to prolonged resistance training, only data from animal studies exist. de Sousa Neto et al (2018) reported that 12 weeks of resistance training consisting of ladder climbs with progressive, additional loads equivalent to 65-100% of each individual's maximum carrying capacity upregulated MMP-2 activity in the plantarflexor muscles of old rats, while down-regulating MMP-2 and MMP-9 in blood circulation. The authors' conclusion that resistance training might, therefore, be a useful tool to maintain ECM remodeling at older age has recently received empirical support by another training study in rats that used the same training protocol and showed a reduced deposition of connective tissue in trained older muscles (Guzzoni et al, 2018).…”

Variable Expressed Methylation Sites of Aging-related Genes in Asthma

“…In our study, we further explored the methylation change of the previous screened aging-related genes in peripheral venous blood of asthma patients. Indeed, the involvement of these screened 9 aging-related genes in asthma have been extensively studied by previous literatures [42][43][44][45][46][47][48][49].…”

Remodeling the Skeletal Muscle Extracellular Matrix in Older Age—Effects of Acute Exercise Stimuli on Gene Expression

“…An early study by Suominen et al [ 38 ] found prolyl hydroxylase activity to be increased after 8 weeks of endurance training. The only studies to document the effects of prolonged resistance training on muscle ECM have been performed in rodents and suggest that the deposition of connective tissue in older muscles may be reduced by resistance training [ 39 , 40 ]. Acute studies in young humans indicate that genes associated with both the synthesis and degradation of intramuscular connective tissue may be activated through (particularly eccentric) resistance exercise [ 41 , 42 , 43 ].…”