Evidence for a possible inhibitory interaction between the HO-1/CO- and Akt/NO-Pathways in human endothelial cells
Evidence for a possible inhibitory interaction between the HO-1/CO- and Akt/NO-Pathways in human endothelial cells
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DOI：
10.1007/s10557-007-6051-1
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发表时间：
2007-10-01
影响因子：
3.4
通讯作者：
Griese, Daniel P.
中科院分区：
文献类型：
--
作者：
Batzlsperger, Christian A.;Achatz, Stefan;Griese, Daniel P.
目的探讨血红素加氧酶1 （HO-1）作为炎症和心血管疾病潜在治疗靶点的作用机制。最近的证据表明HO-1/CO-与蛋白激酶Akt/ no通路之间可能存在相互作用。本研究旨在研究HO-1持续过表达对内皮细胞的影响。方法构建逆转录病毒载体，在人脐静脉内皮细胞中过表达HO-1、Akt和绿色荧光蛋白。暴露于血红素和H2O2后测定[H-3]胸腺嘧啶掺入和脂质过氧化。Western blot检测HO-1、Akt及其下游靶内皮no合成酶的表达。采用瓜氨酸转化法测定no合成酶活性。结果ho -1过表达可降低HUVEC的增殖率和dna合成，但对血红素和H2O2诱导的氧化应激有较强的保护作用。磷酸化akt和eNOS在HO-1-HUVEC中下调。HO-1-HUVEC中enos活性降低。与akt -逆转录病毒联合感染恢复了细胞增殖率和enos的表达和活性。结论持续升高的ho -1活性对氧化应激有保护作用，但抑制akt介导的细胞增殖和enos的表达。这种抑制反馈机制可能限制了HO-1作为治疗血管疾病的靶点。
Objective The protective properties of heme oxygenase 1 (HO-1) give reason to study this mechanism as a potential therapeutic target for inflammatory and cardiovascular diseases. Recent evidence suggests a possible interaction between the HO-1/CO- and the protein kinase Akt/NO-pathway. This study was designed to examine the effects of continuous HO-1 overexpression in endothelial cells.Methods Oncoretroviral vectors were constructed to achieve constitutive overexpression of HO-1, Akt, and green fluorescence protein in human umbilical vein endothelial cells. [H-3]thymidine-incorporation and lipid-peroxidation were measured following exposure to heme and H2O2. Expression of HO-1, Akt and its downstream-target endothelial NO-synthase were quantified by Western blot analysis. NO-synthase-activity was measured using the citrulline-conversion-assay.Results HO-1-overexpression reduced proliferative rates and DNA-synthesis of HUVEC, but provided potent protection from oxidative stress induced by heme and H2O2. Phosphorylated-Akt and eNOS was downregulated in HO-1-HUVEC. eNOS-activity was reduced in HO-1-HUVEC. Co-infection with the Akt-retrovirus restored proliferative rates and eNOS-expression and -activity.Conclusion Continuously elevated HO-1-activity protects EC from oxidative stress but inhibits Akt-mediated proliferation and eNOS-expression. This inhibitory feedback mechanism could be a limitation of HO-1 as a target for the treatment of vascular disease.