Effect of Irbesartan on AGEs-RAGE and MMPs systems in rat type 2 diabetes myocardial-fibrosis model

To investigate the effect of Irbesartan on the changes of myocardial advanced glycation end products and their receptor (AGEs-RAGE), and matrix metalloproteinases (MMPs) systems in rat type 2 diabetes myocardial fibrosis model. All male Sprague-Dwaley rats were randomly divided into four groups: control (CON), high glucose and high-caloric diet (HC), type 2 diabetes (T2DM) and Irbesartan + T2DM (Ir+T2DM) groups. At 12th week, the fasting blood glucose (FBG) and fasting serum insulin (FINS) levels, insulin resistance index (IRI), insulin sensitivity index (ISI), body weight (BW), the ratio of heart weight/body weight (H/B), left ventricular weight index (LVWI), and cardiac col I, col III contents, plasma MMP-2, MMP-9 levels were evaluated. The protein expressions of col I, AGE, RAGE, MMP-2, MMP-14, and TIMP-2 were analyzed by Western blot. In the T2DM group, FBG, H/B, LVWI, IRI were increased ( P < 0.01), while FINS, BW, ISI were decreased in contrast to the CON and HC groups ( P < 0.05–0.01). In the Ir+ T2DM group, BW was higher, IRI, H/B, LVWI were lower than in the T2DM group. Compared with the CON and HC groups, the contents of col I and col III, the protein expressions of col I, AGE, RAGE, TIMP-2 and MMP-14 were increased, MMP-2 protein expression, the ratios of MMP-2/TIMP-2 and MMP-14/TIMP-2, MMP-2, and MMP-9 levels were decreased in the T2DM group ( P < 0.01). After Irbesartan treatment, all parameters were reversed. Irbesartan can ameliorate myocardial fibrosis in type 2 diabetes rat model, the likely mechanisms may be related to the down-regulation of AGEs-RAGE system and changes of MMPs pathway. Impact statement There are about 425 million diabetes patients (20–79 years) in the world according to the International Diabetes Federation Diabetes Atlas – 8th Edition. The cardiovascular complication is one of the major causes of death in diabetes patients. Myocardial fibrosis is one of the serious pathological changes, so investigating the pathogenesis of myocardial fibrosis has the significant value. Our study aims to investigate the effect of Irbesartan (the angiotensin II receptor antagonist) on the changes of AGE-RAGE system and MMP family components, and analyzes the potential mechanisms in type 2 diabetes-induced myocardial fibrosis. Our results provide the theoretical base for better understanding the pathogenesis in type 2 diabetes-induced myocardial complication. It is useful for clinicians to select the effective therapeutic measures for treatment of type 2 diabetes-induced organ fibrosis.