ABSTRACT
Aim Toinvestigatetheeffectofginkgolide B on apoptosis in high glucose-treated endothelial cells.Methods Humanumbilicalveinendothelial cells(HUVECs)were used in the present study.The level of transmigration of HUVECs was analyzed by Tr-answell experiment.Apoptosis was detected by flow cy-tometry.Reactive Oxygen Species (ROS ) was meas-ured by immunofluorescence kit.The protein expres-sionwasanalyzedbyWesternblot.Result Highglu-cose treatment resulted in a reduction in transmigration of HUVECs and ginkgolide B recovered the phenome-non in glucose-treated endothelial cells.The level of ROS generation was increased in high glucose-treated group,whereas ginkgolide B inhibited ROS genera-tion.Immunofluorescence data showed high glucose in-creased apoptosis,whereas ginkgolide B inhibited ap-optosis in high glucose-treated HUVECs.Moreover, the expressions of Bax and caspase-3 were increased and Bcl-2 was reduced in high glucose-treated group. In contrast,ginkgolide B abolished the expressions of Bax and caspase-3 and increased Bcl-2 expression. Moreover,high glucose enhanced the expression and phosphorylation of p53,while ginkgolide B suppressed the expression and phosphorylation of p53 induced by highglucose.Conclusions GinkgolideBcaninhibit apoptosis and improve transmigration function in high glucose-treated HUVECs.Ginkgolide B has protection against high glucose-induced endothelial cell injury.
ABSTRACT
Aim To investigate the effect of ginkgolide B on TLR4 expression in glucose-treated endothelial cells.Methods Human umbilical vein endothelial cells (HUVECs)were stimulated by high concentra-tion of glucose.TLR4,inflammatory protein expression and Akt phosphorylation were analyzed by Western blot.Transcription factor NF-κB nuclear translocation was analyzed by immunofluorescence.Results The expression of TLR4 and PAF receptor was increased in high glucose-treated HUVECs. In contrast, both ginkgolide B and CV3988 dose-dependently decreased TLR4 and PAF receptor expression in high glucose-treated cells,respectively.Ginkgolide B decreased in-flammatory protein ICAM-1 ,VCAM-1 expression.Mo-reover,ginkgolide B potently abolished Akt phospho-rylation and NF-κB p65 nuclear translocation.Conclu-sion Ginkgolide B can reduce TLR4,PAF receptor, ICAM-1 and VCAM-1 expression in high dose of glu-cose-treated HUVECs,the mechanism might be linked to inhibition of Akt phosphorylation and NF-κB activa-tion.
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Aim To investigate the effect of resveratrol on ROS level and PECAM-1 expression in ox-LDL-stimulated platelets. Methods The expression of PE-CAM-1 , Sirt1 and p38 MAPK phosphorylation in ox-LDL-stimulated platelets was determined by Western blot. The level of ROS was measured by immunofluo-rescence kit. Results ox-LDL induced platelet aggre-gation by 14%, whereas resveratrol inhibited platelet aggregation by 50%. Resveratrol decreased ROS level by 3 . 2 fold and completely suppressed PECAM-1 expression in ox-LDL-treated platelets. Resveratrol re-covered Sirt1 expression in ox-LDL-treated platelets. EX527 ( a Sirt1 inhibitor ) increased ROS level and PECAM-1 expression in ox-LDL-stimulated platelets. Meanwhile, resveratrol also suppressed p38MAPK phosphorylation induced by ox-LDL. Conclusion Resveratrol can inhibit platelet aggregation, decrease ROS production and PECAM-1 expression in ox-LDL-stimulated platelets. The mechanism maybe associated with recovery of Sirt1 expression. Moreover, resveratrol can decrease PECAM-1 expression, which may be linked to abolishing p38MAPK phosphorylation.
ABSTRACT
Objective To determine the molecular pathway of reconstituted basement membrane extract(BME)embedment in the context of promoting islet cell survival.Methods Mouse islet cells were isolated and embedded in BME for in vitro culture.Caspase-3,integrin-α1 and 5,PDX-1,Akt,FAK and phospho Erk were detected using Western blot.Results Islet cells embedded with BME were partially protected from apoptosis indicated by a lower caspase-3 level and an increased phosphoAkt activity compared with untreated control.In addition,an increase of α3-integrin,FAK protein level and FAK activity were observed as well.Furthermore,the expression of PDX-1 and phosphoErk at the 48 h mark were preserved,suggesting the positive effect of BME to islet activity.Conclusion These results indicate that the embedment of BME construction can up-regulate α3 integrin and its signal transduction,which may improve viability and function of islet cells.
ABSTRACT
Pancreas and islet transplantation is the only treatment that can cure type 1 diabetes mellitus. Less invasive and more targeted surgical and immunosuppressive regimens make islet transplantation a more attractive treatment for type 1 diabetes. Current methods of islet isolation and purification cause hypoxic stress to which β cells are extremely vulnerable. Transplanted islets need to re-establish their vascular system in order to obtain sufficient oxygen and nutrient supply for stable engraftment. However, this process takes at least 7- 14 days to complete. Massive (＞50%) β cells are dead before revascularization due to hypoxia, especially the core of the islets. Therefore, the obvious critical problem is the circulatory deficit to which the islets are susceptible in the immediate post-transplant period.In the current study, we reviewed various hypoxic-related insults to islets before complete engraftment, and feasible strategies to reduce hypoxic-induced apoptosis based on our experimental experiences together with that of others and investigated the possibility of revascularization in islet transplantation.