| Objective:To observe the effect of globular adiponectin(gAd)on the apoptosis of cardiomyocytes and the expression of TGF-β1 / smads signaling pathway in type 2 diabetes mellitus(T2DM)rats.Reveal the effect of globular adiponectin(gAd)on diabetic cardiomyopathy.Methods:30 Sprague-Dawley(SD)rats were randomly divided into normal control group(NC group,n = 8)and model group(n = 22).NC group was fed with normal diet,and the model group was fed with high fat and high sugar.After 8 weeks,fasting for 12 hours,the model group to a small dose of STZ(30mg / kg)one-time intraperitoneal injection,NC group by intraperitoneal injection of the same dose of sodium citrate buffer.72 hours later,the blood glucose meter measured tail vein random blood glucose ≥ 16.7mmol / L,and the emergence of polyuria,polydipsia,eat,apathetic and other phenomena that T2 DM modeling success.The rats were fed with the same diet for 12 weeks,at the end of 12 weeks,rats were examined for tail vein blood glucose,remove death and blood glucose recovery,and finally 19 rats became DCM model.DCM model group were randomly divided into gAd intervention group(DA group,n = 10),diabetic cardiomyopathy group(DCM group,n = 9).DA rats were injected with gAd 10 ug / kg intraperitoneally every day.Rats in DCM group and NC group were injected intraperitoneally with equal dose of normal saline every day.Eight weeks after the drug intervention,8 rats in each group were followed up for another experiment.Cardiac ultrasound was used to evaluate cardiac function,Calculate the heart weight index,Abdominal aortic blood detection related biochemical indicators,The same part of the left ventricular myocardium,TUNEL staining was used to observe the apoptosis of cardiomyocytes,HE staining to observe the general morphology of myocardial tissue,Immunohistochemistry was used to detect the expression of related protein,Real-time quantitative polymerase chain reaction(RT-PCR)method was used to detect the mRNA content of related factors in myocardium,Western blot was used to detect the expression of related factors in myocardium.Results:1.Fasting blood glucose in rats showed:The blood glucose level of DCM group was higher than that of NC group(P <0.05),the blood glucose level of DA group was lower than that of DCM group,but the difference was not statistically significant(P> 0.05)2.Cardiac quality index statistics show that:DCM group(3.20 ± 0.21)was higher than NC(2.56 ± 0.22)group(P <0.05),DA group(2.82 ± 0.39)was lower than that of DCM group(P <0.05).3.Heart function:Compared with NC group,the cardiac function of DCM rats was significantly decreased,and the cardiac function was improved after gAd intervention.4.TUNEL staining results show:The apoptosis of cardiomyocytes in DCM group was higher than that in NC group(P <0.05),the apoptosis of cardiomyocytes in DA group was lower than that in DCM group(P <0.05).5: HE staining to observe the morphology of myocardial tissue:The morphology of cardiomyocytes in NC group was normal under light microscope,the nuclei are neatly arranged;The size of cells in DCM group was different,the morphological disorder,the nucleus became pleomorphic,the intercellular stroma increased,and the cardiomyocytes were broken.The myocardial cells of DA group had pathological changes,but less than that of DCM group.6.Related indicators Immunohistochemical analysis results:Type Ⅰ collagen in the NC group of myocardial cell stroma was not significantly expressed,In the DCM group,the expression of myocardium was more,the expression of DA in the DA group was lower than that in the DCM group,Scattered in the distribution of expression.The mean gray value was NC group(183.67 ± 9.50)vs DCM group(164.00 ± 4.00)(P <0.05),DCM group(164.00 ± 4.00)vs DA group(176.14 ± 7.34)(P <0.05).TGF-β1 is rarely distributed in the cytoplasm of NC group,Cytoplasm light stain,No obvious expression;In the DCM cytoplasm is widely distributed,Positive expression;In the DA group,the cytoplasm was lighter and weakly expressed.The mean gray value was NC group(210.00 ± 6.20)vs DCM group(182.80 ± 5.63)(P <0.05),DCM group(182.80 ± 5.63)vs DA group(200.50 ± 4.51)(P <0.05).Smad3 was less expressed in NC cells,In the DCM group,the cells showed strong positive expression,Weakly positive expression in the cytoplasm of DA cells;The mean gray value was NC group(205.33 ± 4.73)vs DCM group(190.25 ± 6.34)(P <0.05),DCM group(190.25 ± 6.34)vs DA group(199.83 ± 4.62)(P <0.05).Smad7 showed strong positive expression in the cytoplasm of NC group,In the DCM cells in a small amount of expression,the expression of DA in the DA group was higher than that in the DCM group,but was lower than that in the NC group.The mean gray value was NC group(182.60 ± 11.39 vs vs DCM(207.40 ± 3.13)(P <0.05),DCM group(207.40 ± 3.13)vs DA group(188.75 ± 8.54)(P <0.05).7.The results of RT-PCR showed that:The contents of TGF-β1 and smad3 mRNA in myocardium in DCM group were significantly higher than those in NC group(P <0.05),eight weeks after gAd intervention,the DA group was decreased compared with DCM group(P <0.05).Smad7 mRNA content in DCM group was lower than that in NC group(P <0.05),eight weeks after drug intervention,the DA group was more than DCM group(P <0.05).8.Western blot results show:The expression of TGF-β1 and smad3 in myocardium,in DCM group was higher than that in NC group(P <0.05),eight weeks after gAd intervention,DA group was lower than DCM group(P <0.05).The expression of smad7 protein in DCM group was lower than that in NC group(P <0.05),after the intervention,the expression of DA group was more than that of DCM group(P <0.05).Conclusion:1.gAd can improve the cardiac function of type 2 diabetic rats;2.gAd may play an important role in protecting the heart of type 2 diabetic rats by anti-cardiomyocyte apoptosis;3.gAd may inhibit the activation of TGF-β1 / smads signaling pathway,and thus play a role in anti-fibrosis,protect the myocardium. |
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