ROLE OF HSP72 IN THE CARDIAC REMODELING INDUCED BY HIGH FAT DIET

Abstract

IntroductionPrevious study demonstrated that HSP72 protects against obesity‐induced insulin resistance. However, the potential role of HSP72 in the cardiac remodeling induced by high fat (HF) diet remains unknown.ObjectiveThe aim of this study is to investigate the role of HSP72 in the cardiac remodeling induced by HF diet.MethodsMale wild‐type (WT) and HSP72 transgenic (HSP72 Tg) mice were fed a normal diet or a HF diet for 10 weeks. Body weight was monitored weekly. Fasting glucose levels were measured and intraperitoneal glucose tolerance test (iGTT) was performed. Systolic blood pressure (SBP) was evaluated by tail‐cuff plethysmograph. Western Blot was used to evaluate the cardiac HSP72 and HSP90 levels. Cardiac hypertrophy will be determined by heart weight normalized by tibia length. Histological analysis will be performed to evaluate the cardiomyocyte diameter and the interstitial fibrosis.ResultsHF diet increased the body weight and the fasting glucose levels in WT mice. However, HSP72 Tg were resistant to HF diet‐induced increase in body weight.In addition, HF diet induced glucose intolerance in WT mice. HF diet did not change the SBP in WT mice. The cardiac HSP70 levels were increased in HSP72 Tg when compared to those observed in WT mice. On the other hand, cardiac HSP90 levels were similar between WT and HSP72 Tg mice.ConclusionsThese results demonstrate that HF diet increases the body weight and fasting glucose levels, as well as induces glucose intolerance in WT mice. In addition, cardiac HSP70 levels were increased on HSP72 Tg mice, supporting the use of these mice to investigate a potential role of HSP72 in the cardiac remodeling induced by HF diet.