Bariatric Surgery Ameliorates Diabetic Cardiac Dysfunction by Inhibiting ER Stress in a Diabetic Rat Model

Background Cardiac dysfunction is a severe complication of diabetes,with no effective treatment.Currently, bariatric surgery is moreandmorewidelyusedtoattenuate diabetes-associated diseases. The mechanism is not clear. Endoplasmic reticulum (ER) stress-dependent apoptosis has been observed in the pro- gression of diabetic myocardium damage. Therefore, this re- search was designed to investigate the effects of different bariat- ric procedures on cardiac dysfunction via ER stress-induced cardiomyocyte apoptosis pathway in a diabetic rat model. Methods Duodenal-jejunal bypass (DJB), sleeve gastrectomy (SG), and sham surgery were performed in diabetic rats. Echocardiographic examination,H&Estaining,Masson stain- ing, and TUNEL staining were performed to measure the diabetes-caused heart damages.ERstress-associated signaling molecules like glucose-regulated protein 78 (GRP78), protein kinase RNA (PKR)-like ER protein kinase (PERK), p-PERK, inositol-requiring enzyme 1ɑ (IRE1ɑ), p-IRE1ɑ, activating transcription factor 6 (ATF6), C/EBP homologous protein (CHOP), and caspase 12 weremeasured and comparedamong DJB group, SG group, and sham group. Results Compared with shamgroup, DJBandSGgroups both had significantly lower GRP78, PERK, p-PERK, CHOP, and caspase 12, though there was no statistical change on IRE1ɑ, p-IRE1ɑ,and ATF6.DJB andSGgroupsalsoshowed im- proved heart function and lower cardiomyocyte apoptosis in diabetic rats. * Sanyuan Hu husanyuan1962@hotmail.com 1 Department of General Surgery, Qilu Hospital of Shandong University, 107#,Wenhua Xi Road, Jinan 250012, Shandong, People’s Republic of China Conclusion DJB and SG ameliorated cardiac dysfunction by inhibiting PERK-mediated pathway. And no difference was ob- served on the effects of DJB and SG on ER stress-dependent myocardium damage in diabetic rats.