The Protective Effects And Mechanism Of D-pinitol On Diabetic Cardiomyopathy And Vascular Lesion

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The protective effects and mechanism of D-pinitol on STZ-induced diabetic cardiomyopathy in SAMP-8 miceBackgroundDiabetic cardiomyopathy(DCM)is an important complication of diabetes and refers to a cardiomyopathy that occurs in people with diabetes and cannot be explained by hypertension,coronary atherosclerosis,and other heart disease.DCM is considered to be a driver of heart failure and increased mortality in diabetic patients.Current research suggests that the causes of DCM mainly include myocardial cell metabolic disorders,myocardial calcium transport defects,coronary microcirculation disorders,myocardial interstitial fibrosis,and autonomic neuropathy of the heart.The clinical manifestations are based on metabolic disorders and microvascular disease,which cause extensive focal necrosis of the myocardium,subclinical cardiac dysfunction,and finally progress to heart failure,arrhythmia and cardiogenic shock,and even severe death in critically ill patients.At present,the pathogenesis of DCM has not been fully elucidated,and there is no specific treatment for treatment.Increased oxidative stress and excessive autophagy caused by poor glycemic control are currently considered to be one of the pathogenesis of DCM.D-pinitol is a derivative of D-chiroinositol.In recent years,it has been found that D-pinitol can act as an insulin analog to regulate blood glucose,However,its specific role and mechanism in DCM has not been studied.Therefore,this study explored the effects of D-pinitol on myocardial oxidative stress,myocardial apoptosis,autophagy and related signaling pathways in STZ-induced diabetic mice,and explored the effect and mechanism of D-pinitol on diabetic cardiomyopathy.Objective1.To investigate the protective effect of D-pinitol on diabetic cardiomyopathy in SAMP-8 mice;2.To investigate the protective mechanism of D-pinitol on diabetic cardiomyopathy in SAMP-8 mice.Methods1.Establishment of a diabetes model:DM model was established by SAMP-8 mice that injected with streptozotocin(STZ,50mg/kg/day)for five consecutive days.Blood samples were collected by tail snipping and obtained once before STZ injection and 1,2 weeks after STZ injection with a handheld glucometer.2.Grouping and gavage treatment:mice were randomly assigned to four groups(n = 20 in each group):SAMR-1 group(SAMR-1 mouse,);Aging Control group(SAMP-8 mouse injected with citric acid buffer);DM group(SAMP-8 mouse injected with STZ and treated with double distilled water);DMT(SAMP-8 mouse injected with STZ and treated with D-pinitol 100mg/kg/day for 10 weeks).3.blood glucose and body weight:once before STZ injection and 2,4,8 and 12 weeks after STZ injection,blood glucose and body weight were measured.4.Cardiac ultrasound detection:at the 13th week after modeling,the mice in each group underwent transthoracic echocardiography and measured left ventricular ejection fraction and other related indicators.5.Detection of related indicators:we evaluated the cardiac fibrosis using Masson staining;Oxidative stress was measured using ELISA methods;cardiomyocyte apoptosis was confirmed using TUNEL analyze;Autophagosomes and myocardial ultrastructure were examined used transmission electron microscopy;BNP?ANP??-MHC and ?-MHC gene expression by RT-PCR.Immunoblotting was also used to analyze the expression of Nrf2,Nrf2?bcl-2?caspase 3?caspase 9?STBD1?LC3B?Beclin-1?p62?Atg8?PI3K?Akt and mTOR.Results1.At 4 weeks,8 weeks and 12 weeks after modeling,blood glucose in the DMT group was significantly lower than that in the DM group;at 8 weeks and 12 weeks after modeling,the body weight of the DMT group was higher than that of the DM group;2.The results showed that compared with the SAMP-8 group,in the DM group showed decreased left ventricular ejection fraction,increased cardiac hypertrophy,disorganized myocardial fiber arrangement,increased collagen fiber synthesis,increased apoptosis of myocardial cells,decreased antioxidant factor synthesis,increased oxidative factor synthesis,increased autophagosome formation;3.Compared with DM group,DMT group showed increased left ventricular ejection fraction,decreased myocardial hypertrophy and fibrosis,decreased apoptosis of myocardial cells,decreased oxidative stress,and decreased autophagosome formation.Furthermore,we found that PI3K/Akt/mTOR pathway was reactivated by D-pinitol treatment.Conclusion1.D-pinitol has protective effect on STZ-induced SAMP-8 mice with diabetic cardiomyopathy;2.D-pinitol can regulate blood glucose,improve oxidative stress,inhibit myocardial cell apoptosis,regulate sugar autophagy,and regulate PI3K/Akt/mTOR signaling pathway to play a protective role in diabetic cardiomyopathy in SAMP-8 mice.Part ? The protective mechanism of D-pinitol on AGEs-induced vascular smooth muscle cell proliferation and migrationBackgroundDiabetic macroangiopathy is another risk factor that threatens the safety of patients with diabetes,characterized by progressive atherosclerosis and vascular remodeling.The increase of arterial membrane extracellular matrix(ECM)and smooth muscle cells proliferation and their relationship play a key role in the pathogenesis of diabetic macroangiopathy.The aim at present study was to investigate the inhibition effect of D-pinitol on advanced glycation end products(AGEs)-induced cell proliferation and migration in vascular smooth muscle cells(VSMC)that isolated from mouse aorta,to explore the protective effect of D-pinitol on diabetic macrovascular.Objective1.To explore the effects of different concentrations of D-pinitol on the proliferation and migration of VSMC;2.To investigate the effect of D-pinitol on the expression of related proteins in VSMC.MethodsGlycosylation injury model was established by VSMCs treated with AGEs,then different concentrations of D-pinitol were added in the models.Cell proliferation and migration were detected by Cell Counting Kit-8(CCK-8)assay and cell scratch,respectively.Transforming growth factor-betal(TGF-?1),p-smad2,p-smad3 and Asporin protein expression was also determined.Results1.Compared to control groups,it confimed that the cell proliferation and migration increased significantly,TGF-?l-smad2/3-Asporin pathway was upregualted in VSCM treated with AGEs(P<0.01);2.Cell proliferation and migration and TGF-?1-smad2/3-Asporin pathway were also inhibited by a concentration-dependent D-pinitol treatment(P<0.05 or P<0.01).Conclusion1.D-pinitol inhibited AGEs-induced cell proliferation and migration in mouse aortic smooth muscle cells.2.Asporin may participate in the VSMC extracellular matrix remodeling via TGF-?/smad pathway.