Gene transfer of inducible nitric oxide synthase affords cardioprotection by upregulating heme oxygenase-1 via a nuclear factor-{kappa}B-dependent pathway.
Gene transfer of inducible nitric oxide synthase affords cardioprotection by upregulating heme oxygenase-1 via a nuclear factor-{kappa}B-dependent pathway.
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DOI：
10.1161/circulationaha.108.778688
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发表时间：
2009-09-29
期刊：
影响因子：
37.8
通讯作者：
Bolli R
中科院分区：
文献类型：
--
作者：
Li Q;Guo Y;Ou Q;Cui C;Wu WJ;Tan W;Zhu X;Lanceta LB;Sanganalmath SK;Dawn B;Shinmura K;Rokosh GD;Wang S;Bolli R
虽然诱导型一氧化氮合酶（iNOS）是已知的赋予强大的保护心肌梗死，这种有益的行动的机制仍不清楚。腺病毒介导的iNOS基因转染小鼠后48-72 h，不仅iNOS蛋白表达增加，HO-1 mRNA和蛋白表达也增加，HO-2蛋白表达无变化。iNOS基因转移显著减少野生型小鼠的梗死面积，但这种作用在HO-1-/-小鼠中完全消失。iNOS基因转染后48 h，NF-κB B明显激活。在心肌细胞限制性表达IκBα显性失活突变体（IκBα S32 A，S36 A）的转基因小鼠中，基础HO-1水平和iNOS基因转移引起的HO-1上调均受到抑制。小鼠心脏的染色质免疫沉淀分析提供了直接证据，即在iNOS基因转移后48 h，NF-κB亚基p50和p65被募集到HO-1基因启动子（−468 bp至−459 bp）。本研究首次证明了心脏iNOS和心脏HO-1之间存在密切的功能偶联：iNOS通过增加NF-κB与HO-1基因启动子区域的结合（从−468 bp到−459 bp）上调HO-1，然后HO-1介导iNOS的心脏保护作用。这些结果也揭示了NF-κB在基础和iNOS诱导的心肌HO-1表达中的重要作用。总的来说，本研究结果显着扩大了我们的理解，心脏HO-1的调节和机制，iNOS发挥其心脏保护作用。
Although inducible nitric oxide synthase (iNOS) is known to impart powerful protection against myocardial infarction, the mechanism for this salubrious action remains unclear. Adenovirus-mediated iNOS gene transfer in mice resulted, 48-72 h later, in increased expression not only of iNOS protein but also of HO-1 mRNA and protein; HO-2 protein expression did not change. iNOS gene transfer markedly reduced infarct size in wild-type mice, but this effect was completely abrogated in HO-1-/- mice. At 48 h after iNOS gene transfer, NF-κB was markedly activated. In transgenic mice with cardiomyocyte-restricted expression of a dominant negative mutant of IκBα (IκBαS32A,S36A), both the basal HO-1 levels and the upregulation of HO-1 by iNOS gene transfer were suppressed. Chromatin immunoprecipitation analysis of mouse hearts provided direct evidence that NF-κB subunits p50 and p65 were recruited to the HO-1 gene promoter (−468 bp to −459 bp) 48 h after iNOS gene transfer. This study demonstrates, for the first time, the existence of a close functional coupling between cardiac iNOS and cardiac HO-1: iNOS upregulates HO-1 by augmenting NF-κB binding to the region of the HO-1 gene promoter from −468 bp to −459 bp, and HO-1 then mediates the cardioprotective effects of iNOS. These results also reveal an important role of NF-κB in both basal and iNOS-induced expression of cardiac HO-1. Collectively, the present findings significantly expand our understanding of the regulation of cardiac HO-1 and of the mechanism whereby iNOS exerts its cardioprotective actions.