CD36 fatty acid translocase plays a key role in supplying heart with its major energy substrate, long-chain fatty acids (FA). Previously, we found that the spontaneously hypertensive rat (SHR) harbors a deletion variant of Cd36 gene that results in reduced transport of long-chain FA into cardiomyocytes and predisposes the SHR to cardiac hypertrophy. In the current study, we analyzed the effects of mutant Cd36 on susceptibility to ischemic ventricular arrhythmias and myocardial infarction in adult SHR-Cd36 transgenic rats with wild-type Cd36 compared with age-matched SHR controls. Using an open-chest model of coronary artery occlusion, we found that SHR-Cd36 transgenic rats showed profound arrhythmogenesis resulting in significantly increased duration of tachyarrhythmias (207 ± 48 s vs. 55 ± 21 s, P < 0.05), total number of premature ventricular complexes (2,623 ± 517 vs. 849 ± 250, P < 0.05) and arrhythmia score (3.86 ± 0.18 vs. 3.13 ± 0.13, P < 0.001). On the other hand, transgenic SHR compared with SHR controls showed significantly reduced infarct size (52.6 ± 4.3% vs. 72.4 ± 2.9% of area at risk, P < 0.001). Similar differences were observed in isolated perfused hearts, and the increased susceptibility of transgenic SHR to arrhythmias was abolished by reserpine, suggesting the involvement of catecholamines. To further search for possible molecular mechanisms of altered ischemic tolerance, we compared gene expression profiles in left ventricles dissected from 6-wk-old transgenic SHR vs. age-matched controls using Illumina-based sequencing. Circadian rhythms and oxidative phosphorylation were identified as the top KEGG pathways, while circadian rhythms, VDR/RXR activation, IGF1 signaling, and HMGB1 signaling were the top IPA canonical pathways potentially important for Cd36-mediated effects on ischemic tolerance. It can be concluded that transgenic expression of Cd36 plays an important role in modulating the incidence and severity of ischemic and reperfusion ventricular arrhythmias and myocardial infarct size induced by coronary artery occlusion. The proarrhythmic effect of Cd36 transgene appears to be dependent on adrenergic stimulation.

• MeSH
• antigeny CD36 genetika   metabolismus   MeSH
• genetická predispozice k nemoci MeSH
• infarkt myokardu genetika   metabolismus   patologie   MeSH
• krevní tlak MeSH
• krysa rodu Rattus MeSH
• potkani inbrední SHR MeSH
• srdeční arytmie genetika   metabolismus   MeSH
• stanovení celkové genové exprese * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• antigeny CD36 MeSH

Increased circulating levels of resistin have been proposed as a possible link between obesity and insulin resistance; however, many of the potential metabolic effects of resistin remain to be investigated, including systemic versus local resistin action. We investigated potential autocrine effects of resistin on lipid and glucose metabolism in 2- and 16-mo-old transgenic spontaneously hypertensive rats (SHR) expressing a nonsecreted form of mouse resistin under control of the aP2 promoter. To search for possible molecular mechanisms, we compared gene expression profiles in adipose tissue in 6-wk-old transgenic SHR versus control rats, before development of insulin resistance, by digital transcriptional profiling using high-throughput sequencing. Both young and old transgenic rats showed moderate expression of the resistin transgene in adipose tissue but had serum resistin levels similar to control SHR and undetectable levels of transgenic resistin in the circulation. Young transgenic rats exhibited mild glucose intolerance. In contrast, older transgenic rats displayed marked glucose intolerance in association with near total resistance of adipose tissue to insulin-stimulated glucose incorporation into lipids (6 ± 2 vs. 77 ± 19 nmol glucose·g(-1)·2 h(-1), P < 0.00001). Ingenuity Pathway Analysis of differentially expressed genes revealed calcium signaling, Nuclear factor-erythroid 2-related factor-2 (NRF2)-mediated oxidative stress response, and actin cytoskeletal signaling canonical pathways as those most significantly affected. Analysis using DAVID software revealed oxidative phosphorylation, glutathione metabolism, pyruvate metabolism, and peroxisome proliferator-activated receptor (PPAR) signaling as top Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. These results suggest that with increasing age autocrine effects of resistin in fat tissue may predispose to diabetes in part by impairing insulin action in adipose tissue.

• MeSH
• glukózový toleranční test MeSH
• inzulinová rezistence genetika   fyziologie   MeSH
• krysa rodu Rattus MeSH
• polymerázová řetězová reakce MeSH
• potkani inbrední SHR MeSH
• potkani transgenní MeSH
• resistin genetika   metabolismus   MeSH
• stanovení celkové genové exprese metody   MeSH
• stárnutí genetika   metabolismus   MeSH
• tuková tkáň metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• resistin MeSH