Michael S Dodd, Lucy Ambrose, Vicky Ball, Kieran Clarke, Carolyn A Carr, Damian J Tyler
{"title":"The age-dependent development of abnormal cardiac metabolism in the peroxisome proliferator-activated receptor α-knockout mouse.","authors":"Michael S Dodd, Lucy Ambrose, Vicky Ball, Kieran Clarke, Carolyn A Carr, Damian J Tyler","doi":"10.1016/j.atherosclerosis.2024.118599","DOIUrl":null,"url":null,"abstract":"<p><strong>Background and aims: </strong>Peroxisome proliferator-activated receptor α (PPARα) is crucial for regulating cardiac β-oxidation in the heart, liver, and kidney. Ageing can induce cardiac metabolic alterations, but the role of PPARα has not been extensively characterised. The aim of this research was to investigate the role of PPARα in the aged heart.</p><p><strong>Methods: </strong>Hyperpolarized [1-<sup>13</sup>C]pyruvate was used to evaluate in vivo cardiac carbohydrate metabolism in fed and fasted young (3 months) and old (20-22 months) PPARα knockout (KO) mice versus controls. Cine MRI assessed cardiac structural and functional changes. Cardiac tissue analysis included qRT-PCR and Western blotting for Pparα, medium chain acyl-CoA dehydrenase (MCAD), uncoupling protein (UCP) 3, glucose transporter (GLUT) 4 and PDH kinase (PDK) 1,2, and 4 expression.</p><p><strong>Results: </strong>PPARα-KO hearts from both young and old mice showed significantly reduced Pparα mRNA and a 58-59 % decrease in MCAD protein levels compared to controls. Cardiac PDH flux was similar in young control and PPARα-KO mice but 96 % higher in old PPARα-KO mice. Differences between genotypes were consistent in fed and fasted states, with reduced PDH flux when fasted. Increased PDH flux was accompanied by a 179 % rise in myocardial GLUT4 protein. No differences in PDK 1, 2, or 4 protein levels were observed between fed groups, indicating the increased PDH flux in aged PPARα-KO mice was not due to changes in PDH phosphorylation.</p><p><strong>Conclusions: </strong>Aged PPARα-KO mice demonstrated higher cardiac PDH flux compared to controls, facilitated by increased myocardial GLUT4 protein levels, leading to enhanced glucose uptake and glycolysis.</p>","PeriodicalId":8623,"journal":{"name":"Atherosclerosis","volume":null,"pages":null},"PeriodicalIF":4.9000,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Atherosclerosis","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1016/j.atherosclerosis.2024.118599","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CARDIAC & CARDIOVASCULAR SYSTEMS","Score":null,"Total":0}
引用次数: 0
Abstract
Background and aims: Peroxisome proliferator-activated receptor α (PPARα) is crucial for regulating cardiac β-oxidation in the heart, liver, and kidney. Ageing can induce cardiac metabolic alterations, but the role of PPARα has not been extensively characterised. The aim of this research was to investigate the role of PPARα in the aged heart.
Methods: Hyperpolarized [1-13C]pyruvate was used to evaluate in vivo cardiac carbohydrate metabolism in fed and fasted young (3 months) and old (20-22 months) PPARα knockout (KO) mice versus controls. Cine MRI assessed cardiac structural and functional changes. Cardiac tissue analysis included qRT-PCR and Western blotting for Pparα, medium chain acyl-CoA dehydrenase (MCAD), uncoupling protein (UCP) 3, glucose transporter (GLUT) 4 and PDH kinase (PDK) 1,2, and 4 expression.
Results: PPARα-KO hearts from both young and old mice showed significantly reduced Pparα mRNA and a 58-59 % decrease in MCAD protein levels compared to controls. Cardiac PDH flux was similar in young control and PPARα-KO mice but 96 % higher in old PPARα-KO mice. Differences between genotypes were consistent in fed and fasted states, with reduced PDH flux when fasted. Increased PDH flux was accompanied by a 179 % rise in myocardial GLUT4 protein. No differences in PDK 1, 2, or 4 protein levels were observed between fed groups, indicating the increased PDH flux in aged PPARα-KO mice was not due to changes in PDH phosphorylation.
Conclusions: Aged PPARα-KO mice demonstrated higher cardiac PDH flux compared to controls, facilitated by increased myocardial GLUT4 protein levels, leading to enhanced glucose uptake and glycolysis.
期刊介绍:
Atherosclerosis has an open access mirror journal Atherosclerosis: X, sharing the same aims and scope, editorial team, submission system and rigorous peer review.
Atherosclerosis brings together, from all sources, papers concerned with investigation on atherosclerosis, its risk factors and clinical manifestations. Atherosclerosis covers basic and translational, clinical and population research approaches to arterial and vascular biology and disease, as well as their risk factors including: disturbances of lipid and lipoprotein metabolism, diabetes and hypertension, thrombosis, and inflammation. The Editors are interested in original or review papers dealing with the pathogenesis, environmental, genetic and epigenetic basis, diagnosis or treatment of atherosclerosis and related diseases as well as their risk factors.