Streptozotocin-induced diabetes in mice significantly reduced left ventricular ejection fraction to 50.67% compared to 71.25% in controls, accompanied by increased expression of two MMP-2 isoforms.
High glucose and experimental Type 1 diabetes induce the expression of two specific MMP-2 isoforms, which may play a role in the pathogenesis of diabetic cardiomyopathy.
Absolute Event Rate: 50.67% vs 71.25%
p-value: p=0.012
BACKGROUND: Diabetic cardiomyopathy (DM CMP) is defined as cardiomyocyte damage and ventricular dysfunction directly associated with diabetes independent of concomitant coronary artery disease or hypertension. Matrix metalloproteinases (MMPs), especially MMP-2, have been reported to underlie the pathogenesis of DM CMP by increasing extracellular collagen content. PURPOSE: We hypothesized that two discrete MMP-2 isoforms (full length MMP-2, FL-MMP-2; N-terminal truncated MMP-2, NTT-MMP-2) are induced by high glucose stimulation in vitro and in an experimental diabetic heart model. METHODS: Rat cardiomyoblasts (H9C2 cells) were examined to determine whether high glucose can induce the expression of the two isoforms of MMP-2. For the in vivo study, we used the streptozotocin-induced DM mouse heart model and age-matched controls. The changes of each MMP-2 isoform expression in the diabetic mice hearts were determined using quantitative real-time polymerase chain reaction (qRT-PCR). Immunohistochemical stains were conducted to identify the location and patterns of MMP-2 isoform expression. Echocardiography was performed to compare and analyze the changes in cardiac function induced by diabetes. RESULTS: Quantitative RT-PCR and immunofluorescence staining showed that the two MMP-2 isoforms were strongly induced by high glucose stimulation in H9C2 cells. Although no definite histologic features of diabetic cardiomyopathy were observed in diabetic mice hearts, left ventricular systolic dysfunction was determined by echocardiography. Quantitative RT-PCR and IHC staining showed this abnormal cardiac function was accompanied with the increases in the mRNA levels of the two isoforms of MMP-2 and related to intracellular localization. CONCLUSION: Two isoforms of MMP-2 were induced by high glucose stimulation in vitro and in a Type 1 DM mouse heart model. Further study is required to examine the role of these isoforms in DM CMP.
Lee et al. (Wed,) conducted a other in Diabetic cardiomyopathy (n=16). Streptozotocin-induced diabetes vs. Age-matched controls was evaluated on Left ventricular ejection fraction (LVEF) (p=0.012). Streptozotocin-induced diabetes in mice significantly reduced left ventricular ejection fraction to 50.67% compared to 71.25% in controls, accompanied by increased expression of two MMP-2 isoforms.