Xin yixue (Apr 2023)

SIRT1-mediated intermittent fasting improves adipose tissue mitochondrial function and inflammation in high-fat diet-induced obese mice

  • Deng Xiaojie, Wang Tian, Xu Fen, Liang Hua

DOI
https://doi.org/10.3969/j.issn.0253-9802.2023.04.005
Journal volume & issue
Vol. 54, no. 4
pp. 254 – 260

Abstract

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Objective To investigate the role of SIRT1 in the effect of intermittent fasting on mitochondrial function and inflammation in white adipose tissue（WAT） of obese mice induced by high-fat diet. Methods Male C57BL/6 mice aged 5-6 weeks were randomly divided into the control diet （CD） group （n = 5）， high‐fat diet （HFD） group （n = 5） and high-fat diet intermittent fasting （HFD-IF， alternate-day fasting 24 h） group （n = 5） and fed for 12 weeks. The pathological changes of WAT were observed by HE staining. The expression levels of SIRT1， p-AMPK， FOXO1 and mitochondrial function， inflammation-related genes in WAT of each group were detected. AAV-shSIRT1 virus was delivered by tail-vein injection into mice to knockdown SIRT1. HFD and HFD-IF were given. The parameters above were determined. Results HE staining indicated that the adipose cell volume was decreased in the HFD-IF group. Western blot showed that the expression levels of SIRT1， p-AMPK and FOXO1 in adipose tissues were significantly down-regulated in the HFD mice （all P < 0.05）， which were significantly up-regulated after intermittent fasting （all P < 0.05）. qPCR revealed that the expression levels of mitochondrial functional genes， including Tfam， Nrf1 and Pgc-1a were dramatically down-regulated in the HFD group （all P < 0.001）， whereas those of inflammatory markers， such as TNF-α，MCP-1 and F4/80， was significantly up-regulated （all P < 0.01）. After intermittent fasting， the expression levels of genes related to mitochondrial function were up-regulated （all P < 0.05）， whereas those of inflammatory markers were down-regulated （all P < 0.05）. After knockdown of SIRT1， the trend of up-regulating or down-regulating the expression levels of these parameters was weakened or even absent in the HFD-IF group （all P < 0.05）. Conclusion SIRT1 mediates intermittent fasting in improving high-fat diet-induced obesity via ameliorating adipose tissue mitochondrial function and inflammation.

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