Wenqian Zhang, Xiao-Huan Liu, Jin-Ting Zhou, Cheng Cheng, Jing Xu, Jun Yu, Xiaoming Li
{"title":"Apolipoprotein A-IV restrains fat accumulation in skeletal and myocardial muscles by inhibiting lipogenesis and activating PI3K-AKT signalling.","authors":"Wenqian Zhang, Xiao-Huan Liu, Jin-Ting Zhou, Cheng Cheng, Jing Xu, Jun Yu, Xiaoming Li","doi":"10.1080/13813455.2022.2163261","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>One of the pathological characteristics of obesity is fat accumulation of skeletal muscles (SKM) and the myocardium, involving mechanisms of insulin resistance and abnormal lipid metabolism. Apolipoprotein A-IV (ApoA-IV) is an essential gene in both glucose and lipid metabolisms.</p><p><strong>Materials and methods: </strong>Using high-fat diet (HFD) induced obese <i>apoA-IV</i>-knockout mice and subsequent introduction of exogenous recombinant-ApoA-IV protein and adeno-associated virus (AAV)-transformed <i>apoA-IV</i>, we examined lipid metabolism indicators of SKM and the myocardium, which include triglyceride (TG) content, RT-PCR for lipogenic indicators and western blotting for AKT phosphorylation. Similarly, we used high-glucose-fed or palmitate (Pal)-induced C2C12 cells co-cultured with ApoA-IV protein to evaluate glucose uptake, the phosphoinositide 3-kinase (PI3K)-AKT pathway, and lipid metabolisms.</p><p><strong>Results: </strong>In stable obese animal models, we find ApoA-IV-knockout mice show elevated TG content, enhanced expression of lipogenic enzymes and diminished phosphorylated AKT in SKM and the myocardium, but both stable hepatic expression of AAV-<i>apoA-IV</i> and brief ApoA-IV protein administration suppress lipogenesis and promote AKT phosphorylation. In a myoblast cell line C2C12, ApoA-IV protein suppresses Pal-induced lipid accumulation and lipogenesis but enhances AKT activation and glucose uptake, and the effect is abolished by a PI3K inhibitor.</p><p><strong>Conclusion: </strong>We find that ApoA-IV reduces fat accumulation by suppressing lipogenesis and improves glucose uptake in SKM and the myocardium by regulating the PI3K-AKT pathway.</p>","PeriodicalId":8331,"journal":{"name":"Archives of Physiology and Biochemistry","volume":" ","pages":"491-501"},"PeriodicalIF":2.5000,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Archives of Physiology and Biochemistry","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1080/13813455.2022.2163261","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2023/1/3 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"ENDOCRINOLOGY & METABOLISM","Score":null,"Total":0}
引用次数: 0
Abstract
Background: One of the pathological characteristics of obesity is fat accumulation of skeletal muscles (SKM) and the myocardium, involving mechanisms of insulin resistance and abnormal lipid metabolism. Apolipoprotein A-IV (ApoA-IV) is an essential gene in both glucose and lipid metabolisms.
Materials and methods: Using high-fat diet (HFD) induced obese apoA-IV-knockout mice and subsequent introduction of exogenous recombinant-ApoA-IV protein and adeno-associated virus (AAV)-transformed apoA-IV, we examined lipid metabolism indicators of SKM and the myocardium, which include triglyceride (TG) content, RT-PCR for lipogenic indicators and western blotting for AKT phosphorylation. Similarly, we used high-glucose-fed or palmitate (Pal)-induced C2C12 cells co-cultured with ApoA-IV protein to evaluate glucose uptake, the phosphoinositide 3-kinase (PI3K)-AKT pathway, and lipid metabolisms.
Results: In stable obese animal models, we find ApoA-IV-knockout mice show elevated TG content, enhanced expression of lipogenic enzymes and diminished phosphorylated AKT in SKM and the myocardium, but both stable hepatic expression of AAV-apoA-IV and brief ApoA-IV protein administration suppress lipogenesis and promote AKT phosphorylation. In a myoblast cell line C2C12, ApoA-IV protein suppresses Pal-induced lipid accumulation and lipogenesis but enhances AKT activation and glucose uptake, and the effect is abolished by a PI3K inhibitor.
Conclusion: We find that ApoA-IV reduces fat accumulation by suppressing lipogenesis and improves glucose uptake in SKM and the myocardium by regulating the PI3K-AKT pathway.
期刊介绍:
Archives of Physiology and Biochemistry: The Journal of Metabolic Diseases is an international peer-reviewed journal which has been relaunched to meet the increasing demand for integrated publication on molecular, biochemical and cellular aspects of metabolic diseases, as well as clinical and therapeutic strategies for their treatment. It publishes full-length original articles, rapid papers, reviews and mini-reviews on selected topics. It is the overall goal of the journal to disseminate novel approaches to an improved understanding of major metabolic disorders.
The scope encompasses all topics related to the molecular and cellular pathophysiology of metabolic diseases like obesity, type 2 diabetes and the metabolic syndrome, and their associated complications.
Clinical studies are considered as an integral part of the Journal and should be related to one of the following topics:
-Dysregulation of hormone receptors and signal transduction
-Contribution of gene variants and gene regulatory processes
-Impairment of intermediary metabolism at the cellular level
-Secretion and metabolism of peptides and other factors that mediate cellular crosstalk
-Therapeutic strategies for managing metabolic diseases
Special issues dedicated to topics in the field will be published regularly.