Effects of Exercise Training on the Autophagy-Related Muscular Proteins Expression in Ovariectomized Rats.

Weiquan Zhong,Huimin Bu,Honghua Yuan,Lianlian Wu,Renwei Wang,Xiangrong Shi

doi:10.3389/fphys.2019.00735

Abstract

Ovariectomy disrupts estrogen production and homeostasis. However, whether exercise training (ET) could counteract the ovariectomy-induced effect on muscular autophagy has remained elusive. This study examined muscular autophagy in ovariectomized (OVX) rats following 8 weeks of swimming ET. Here, 40 6-month-old female Sprague-Dawley rats were randomly divided into five groups: sham-operated control (Sham), OVX control (OVX), OVX with 60-min ET (OVX-60ET), 90-min ET (OVX-90ET), and 120-min ET (OVX-120ET) for 6 days/week. According to the results of Western blotting, the expression levels of autophagy-related proteins in the OVX gastrocnemius muscle, including mammalian target of rapamycin, uncoordinated 51-like kinase 1, Beclin-1, autophagy-related gene (Atg-7), and microtubule-associated protein light chains 3 were significantly decreased (all P < 0.05), while there was an elevation on the p62 level. ET appreciably mitigated the OVX-induced negative effects on muscle quality and the autophagy pathway, which seemed to be dependent on ET volume. The most optimal outcomes were observed in the OVX-90ET group. The OVX-120 group had an adversely augmented catabolic process associated with gastrocnemius muscle atrophy. In conclusion, the expression levels of autophagy proteins are decreased in OVX rats, which can be appreciably mitigated following 8 weeks of swimming ET.

Highlights

Declination of ovarian function in aging women is accompanied by decreasing estrogen
The gastrocnemius skeletal muscle tissues were homogenized in a lysis buffer (Biyuntian, Haimen, China) with a polytron homogenizer and an ultrasonic processor on ice
The sham-operated control (Sham) group had an increase in body mass (77 g) as a result of natural growth during the study; the OVX group had (141 g) an increase in body mass, in which more than 80% (P < 0.01) of that was in the Sham group, despite the fact that all animals accessed food and water freely without restriction

Summary

Introduction

Declination of ovarian function in aging women is accompanied by decreasing estrogen. Estrogen supply has been utilized through modifications of autophagy in rodent studies to enhance insulin sensitivity (Kawakami et al, 2018) in order to maintain osteocyte viability (Florencio-Silva et al, 2018), promote recovery of neuromuscular function (Lin et al, 2016), protect. Autophagy in Trained OVX Rats skeletal muscle, and restore physical activity (Cabelka et al, 2019). Menopause-induced morbidities are exacerbated by the high prevalence of physical inactivity associated with aging (Gomes et al, 2017), especially in older woman (Chan et al, 2018). The effects of exercise training (ET) on muscular autophagy in the absence of estrogen have remained elusive

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Conclusion