Reprogramming of lipids and amino acids metabolism is an early event in myocardium of type 1 diabetic rhesus monkeys

Diabetic cardiomyopathy (DC) refers to the abnormal myocardial structure and performance induced by diabetes. Although numerous studies have been carried out, the pathophysiological mechanisms of cardiovascular disorders during diabetes have not been fully clarified. Here, we compared the cardiomyopathy of healthy rhesus monkeys and rhesus monkeys with a history of streptozocin induced type 1 diabetes (T1D) over 7 years. Through comparing the cardiac function using echocardiography, and detecting the serum biochemical indexes, and changes of left ventricle (LV), we found that decreased systolic function, higher blood glycosylated hemoglobin A1c (HbA1 C ) level, hyperglycemia, and hyperlipidemia were early events in diabetic rhesus monkeys. In addition, cardiac histological analysis showed mildly fibrosis and early myocardial hypertrophy, as evidenced by increased Sirius red stained area and cross-sectional area of left ventricle. Transcriptome results revealed that the nutrients metabolism and extracellular matrix related pathways were markedly changed in the left ventricle of diabetic monkeys. Targeted metabolomics and targeted lipid metabolomics further revealed that disturbed amino acid metabolism and lipid accumulation in the LV of diabetic monkeys manifested by accumulated branched chain amino acids (BCAAs) and triglycerides (TAGs), and reduced contents of sphingolipids, glycerophospholipids, cholesteryl esters and carnitines. In conclusion, we reported here for the first time that diabetes lasting for more than 7 years leads to some early pathological changes of myocardium in rhesus monkeys. The cardiac function is mildly compromised and the reprogramming of lipids and amino acids metabolism might play important roles in the progression of DC.