OBJECTIVE To investigate the protective effect against diabetes cardiovascular complications of low molecular weight fucoidan(LMWF)from L.japonica in Qindao, China. METHODS LMWF(50,100 and 200mg·kg-1·d-1)or ...OBJECTIVE To investigate the protective effect against diabetes cardiovascular complications of low molecular weight fucoidan(LMWF)from L.japonica in Qindao, China. METHODS LMWF(50,100 and 200mg·kg-1·d-1)or probucol(100mg·kg-1·d-1)were given orally to Goto-Kakizaki type 2 diabetic rats for 12 weeks.Basal blood pressure,acetylcholine-or flow-mediated relaxation of mesenteric and paw arteries,endothelium-dependent dilation of aorta,eNOS phosphorylation and NO production were measured using laser Doppler flowmetry,force myograph,HE staining,Western blot and an NO assay,respectively.The establishment of diabetic cardiomyopathy(DCM)model and were evaluated by echocardiography and isolated heart perfusion.Ventricle staining with HE or Sirius red was performed to investigate the structural changes in myocardium.Oxidative stress and apoptosis were evaluated by enzyme activities,protein expressions and cell stainings in both myocardial tissues and cultured cardiomyocytes.RESULTS In aorta,LMWF robustly ameliorated the basal hypertension and impairment of endothelium-dependent relaxation in the aorta,as well as mesenteric and paw arteries in diabetic rats.In addition,the reduction in endothelial nitric oxide synthase(eNOS)phosphorylation at Ser1177,eNOS expression and NO production due to diabetes were partially reversed by LMWF treatment.However,probucol,a lipid-modifying drug with antioxidant properties,displayed only mild effects.Moreover,LMWF induced,in a dose-dependent manner,endothelium-dependent vasodilation and eNOS phosphorylation at Ser1177 in normal aorta,and also promoted Ser1177 phosphorylation and NO synthesis in primary cultured vasoendothelial cells.On DCM,LMWF has a beneficial effect by enhancing myocardial contractility and mitigating cardiac fibrosis as well as the production of reactive oxygen species(ROS)and myocyte apoptosis in diabetic hearts.CONCLUSION These data demonstrate for the first time that fucoidan protects vasoendothelial and cardiac function against diabetic injury in type 2diabetes rats via,at least in part,preservation of eNOS function,amelioration of PKCβ-mediated oxidative stress and subsequent cardiomyocyte apoptosis.Fucoidan is therefore a potential candidate drug for protection of endothelium and heart in diabetic cardiovascular complications.展开更多
基金The project supported by National Natural Science Foundation of China(81370339)Promotion Project of Beijing Education Committee(TJSHJ201510025005)
文摘OBJECTIVE To investigate the protective effect against diabetes cardiovascular complications of low molecular weight fucoidan(LMWF)from L.japonica in Qindao, China. METHODS LMWF(50,100 and 200mg·kg-1·d-1)or probucol(100mg·kg-1·d-1)were given orally to Goto-Kakizaki type 2 diabetic rats for 12 weeks.Basal blood pressure,acetylcholine-or flow-mediated relaxation of mesenteric and paw arteries,endothelium-dependent dilation of aorta,eNOS phosphorylation and NO production were measured using laser Doppler flowmetry,force myograph,HE staining,Western blot and an NO assay,respectively.The establishment of diabetic cardiomyopathy(DCM)model and were evaluated by echocardiography and isolated heart perfusion.Ventricle staining with HE or Sirius red was performed to investigate the structural changes in myocardium.Oxidative stress and apoptosis were evaluated by enzyme activities,protein expressions and cell stainings in both myocardial tissues and cultured cardiomyocytes.RESULTS In aorta,LMWF robustly ameliorated the basal hypertension and impairment of endothelium-dependent relaxation in the aorta,as well as mesenteric and paw arteries in diabetic rats.In addition,the reduction in endothelial nitric oxide synthase(eNOS)phosphorylation at Ser1177,eNOS expression and NO production due to diabetes were partially reversed by LMWF treatment.However,probucol,a lipid-modifying drug with antioxidant properties,displayed only mild effects.Moreover,LMWF induced,in a dose-dependent manner,endothelium-dependent vasodilation and eNOS phosphorylation at Ser1177 in normal aorta,and also promoted Ser1177 phosphorylation and NO synthesis in primary cultured vasoendothelial cells.On DCM,LMWF has a beneficial effect by enhancing myocardial contractility and mitigating cardiac fibrosis as well as the production of reactive oxygen species(ROS)and myocyte apoptosis in diabetic hearts.CONCLUSION These data demonstrate for the first time that fucoidan protects vasoendothelial and cardiac function against diabetic injury in type 2diabetes rats via,at least in part,preservation of eNOS function,amelioration of PKCβ-mediated oxidative stress and subsequent cardiomyocyte apoptosis.Fucoidan is therefore a potential candidate drug for protection of endothelium and heart in diabetic cardiovascular complications.
