Effects of endurance training on autophagy and apoptotic signaling in visceral adipose tissue of prolonged high fat diet-fed rats.

Purpose: Autophagy and apoptosis play critical roles in both development and tissue homeostasis in response to (patho)physiological stimuli, such as high-fat diet (HFD) and endurance training (ET). Therefore, we aimed to investigate how ET modulates autophagy and apoptotic-related signaling in visceral adipose tissue of long-standing HFD-fed rats.Methods: The study was conducted over a 17-week period on Sprague-Dawley rats, which were divided into four groups (n = 8/group): standard diet sedentary (STD+SED), high-fat diet sedentary (HFD+SED), standard diet ET (STD+ET) and high-fat diet ET (HFD+ET). After 9 weeks of dietary regimens, ET groups were trained for 8 weeks on treadmill (5 days/week at 25 m/min for 60 min/day), while maintaining dietary regimens. Autophagy and apoptotic-signaling markers in epididymal white adipose tissue (eWAT) were determined using RT-qPCR, Western blot and spectrometry techniques.Results: ET reduced body weight, visceral fat mass and HOMA-IR in standard and HF diet-fed animals. Moreover, ET reverted the HFD-induced increases in the percentage of larger adipocytes and also reduced the percentage of smaller adipocytes. The HFD decreased pre-adipocyte factor 1 (DLK1/PREF1) and increased the pro-apoptotic markers (Bax protein and caspase 3-like activity), while having no impact on autophagy markers. However, ET increased DLK1/PREF1 and Bcl-2 in both diet types, while decreasing Bax and caspases 9, 8 and 3-like activities in HFD feeding rats. Additionally, Beclin-1 and p62 protein significantly increased in ET groups of both diet types.Conclusions: Data demonstrate that 8 weeks of ET was effective in attenuating apoptotic-related signaling in long-standing HFD-fed rats. Moreover, HFD and ET had no impact on VAT autophagy markers. [ABSTRACT FROM AUTHOR]

Copyright of European Journal of Nutrition is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)