Effects Of Uncoupling Protein 2 On The Correlative Parameters About Myocardial Apoptosis Of Diabetic Mellitus In Mice

ObjectiveTo observe the relationship between myocardial apoptosis of diabetic mellitus and uncoupling protein2 (UCP2), the inner mitochondrial membrane anion-carrier protein.MethodsDiabetic animal models were induced by streptozotocinon on UCP2 knock- out mice( UCP2-/-) and C57BL/6 mice,rearing for 7 and 28 days each group. Hochest fluorescence staining detected morphological changes of myocardial cells at each time ,in left venticle of diabetic mice. The terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL ) was used to explain apoptosis at the DNA level. However,The expressions of relative protein for myocardial apoptosis,caspase-3 and caspase-9,were investigated using westen blot.ResultsHochest staining results showed cells nuclear condensation,granular fluorescence and other typical features of apoptosis in DM-28-day group. Myocardium of diabetic mice exhibited concentration of chromatin at 7 days and aggravated at 28 days,with high fluorescence intensity . However, slight concentration of chromatin was detected on UCP2-/- + DM-28-day mice in comparison with DM mice at 28 days. The number of TUNEL-positive myocytes increased significantly in the DM-28-day group in comparison to the UCP2KO+DM-28-day group (P <0.05); The number of TUNEL-positive myocytes decreased significantly in the UCP2KO+DM-28-day group in comparison to the DM-28-day group (P<0.05), whereas decreased slightly in the UCP2KO+DM-7-day group in comparison to the DM-7-day group (P>0.05). Image analysis showed that the expression of cleaved-caspase-3 protein levels incraesed significantly in DM-28-day group in comparison with DM-7-day group(P>0.05), which was opposite to the expression of pro-caspase-9. the expression of cleaved-caspase-3 protein levels decraesed slightly in UCP-/- +DM-7-day group in comparison with DM-7-day group(P>0.05), which was opposite to the expression of pro-caspase-9.The expression of cleaved-caspase-3 protein levels decraesed significantly (P<0.05)in UCP-/- +DM-28-day group in comparison with DM-28-day group,which was opposite to the expression of pro-caspase-9.ConclusionUCP2 may be one of the most important factors which contributed to myocardial apoptosis of diabetic mellitus.