Role of cardiac isoform of alpha-2 macroglobulin in diabetic myocardium

Abstract

Earlier studies from one of the investigator's laboratory have demonstrated the presence of a high molecular weight protein (182 kDa) in the blood serum of laboratory animals subjected to pressure-induced cardiac hypertrophy and suggested that this protein may be involved in the development of cardiac hypertrophy. Studies have shown that this protein is also involved in earlier stages of cardiac complications associated with diabetes, but the role of this protein in diabetic heart is less understood. So we aimed to check whether this protein is having any protective role in diabetic heart. The protein was purified from serum of rats induced with cardiac hypertrophy and the purified protein was injected through tail vein of diabetic rats for further studies. The results of various antioxidant enzymes and the TBARS levels have indicated the antioxidant activity of this protein. Real-time PCR analysis of gene expression revealed the upregulation of certain muscle-specific genes like β-MHC, MLC-2, and skeletal α actin in diabetic group and also in presence of 182-kDa protein. The results further showed a down regulation of genes such as cardiac α-actin and α- MHC implicating the role of this protein in the development of cardiac hypertrophy in diabetes. Increased cardiac hypertrophy as revealed by the expression of various genes and improved antioxidant potential in presence of 182 kDa protein in diabetes at the earlier stages is beneficial for counteracting the myocardial damage associated with diabetes.

α-2-Macroglobulin in Saliva Is Associated with Glycemic Control in Patients with Type 2 Diabetes Mellitus

“…To date, no study had reported a correlation between saliva levels of A2MG and percentage of HbA1. Studies performed by Takada and Soman et al [ 9 , 16 ] have shown similar results; however, the levels of A2MG were detected only in blood. Presently, emerging biotechnologies are advancing our knowledge of biomarkers and there is sufficient evidence establishing that the majority of compounds found in blood may also be found in saliva [ 6 ].…”

Inhibitory Effect of Oligomeric Polyphenols from Peanut-skin on Sugar Digestion Enzymes and Glucose Transport

“…Polyphenols also exert hypoglycemic effects (Sowmya et al, 2010). Serum glucose levels are affected by dietary carbohydrates, and thus maintenance of proper serum glucose concentrations is important for human health.…”

“…In the small intestine, the digestion of carbohydrates is regulated by α-glucosidase, and the resulting monosaccharides are transported across intestinal cells via glucose transporters. It is well known that oral administration of tea-, fruit-, and medicinal plant-extracts with maltose and starch suppressed postprandial hyperglycemia in rats and humans (Sowmya et al, 2010;Fadzelly et al, 2006;Deguchi et al, 2010;Ndong et al, 2007). One of the reasons for this effect is that polyphenols inhibit α-amylase and α-glucosidase activities (Tsujita et al, 2013;Adisakwattana et al, 2011;Gu et al, 2011;Ma et al, 2010); another is that polyphenols inhibit glucose transport via its transporter (Ovádi et al, 2005;Kobayashi et al, 2000).…”

Relationship between Salivary Alpha-2 Macroglobulin and HbA1c among Patients with Type-2 Diabetes Mellitus: A Cross-sectional Study

“…[7] and Soman et al . [8] have shown that increased levels of A2MG in blood of diabetic patients. There is sufficient evidence establishing that the majority of compounds found in blood may also be found in saliva.…”