TY - JOUR
T1 - Gene transfer of inducible nitric oxide synthase affords cardioprotection by upregulating heme oxygenase-1 via a nuclear factor-κb-dependent pathway
AU - Li, Qianhong
AU - Guo, Yiru
AU - Ou, Qinghui
AU - Cui, Chuanjue
AU - Wu, Wen Jian
AU - Tan, Wei
AU - Zhu, Xiaoping
AU - Lanceta, Lilibeth B.
AU - Sanganalmath, Santosh K.
AU - Dawn, Buddhadeb
AU - Shinmura, Ken
AU - Rokosh, Gregg D.
AU - Wang, Shuyan
AU - Bolli, Roberto
PY - 2009/9
Y1 - 2009/9
N2 - BACKGROUND-: Although inducible nitric oxide synthase (iNOS) is known to impart powerful protection against myocardial infarction, the mechanism for this salubrious action remains unclear. METHODS AND RESULTS-: Adenovirus-mediated iNOS gene transfer in mice resulted 48 to 72 hours later in increased expression not only of iNOS protein but also of heme oxygenase (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 hours after iNOS gene transfer, nuclear factor-κB was markedly activated. In transgenic mice with cardiomyocyte-restricted expression of a dominant negative mutant of IκBα (IκBα), both basal HO-1 levels and upregulation of HO-1 by iNOS gene transfer were suppressed. Chromatin immunoprecipitation analysis of mouse hearts provided direct evidence that nuclear factor-κB subunits p50 and p65 were recruited to the HO-1 gene promoter (-468 to-459 bp) 48 hours after iNOS gene transfer. CONCLUSIONS-: 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 nuclear factor-κB binding to the region of the HO-1 gene promoter from-468 to-459 bp, and HO-1 then mediates the cardioprotective effects of iNOS. These results also reveal an important role of nuclear factor-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.
AB - BACKGROUND-: Although inducible nitric oxide synthase (iNOS) is known to impart powerful protection against myocardial infarction, the mechanism for this salubrious action remains unclear. METHODS AND RESULTS-: Adenovirus-mediated iNOS gene transfer in mice resulted 48 to 72 hours later in increased expression not only of iNOS protein but also of heme oxygenase (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 hours after iNOS gene transfer, nuclear factor-κB was markedly activated. In transgenic mice with cardiomyocyte-restricted expression of a dominant negative mutant of IκBα (IκBα), both basal HO-1 levels and upregulation of HO-1 by iNOS gene transfer were suppressed. Chromatin immunoprecipitation analysis of mouse hearts provided direct evidence that nuclear factor-κB subunits p50 and p65 were recruited to the HO-1 gene promoter (-468 to-459 bp) 48 hours after iNOS gene transfer. CONCLUSIONS-: 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 nuclear factor-κB binding to the region of the HO-1 gene promoter from-468 to-459 bp, and HO-1 then mediates the cardioprotective effects of iNOS. These results also reveal an important role of nuclear factor-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.
KW - Gene therapy
KW - Heme oxygenase-1
KW - Myocardial infarction
KW - NF-kappaB
KW - Nitric oxide synthase
UR - http://www.scopus.com/inward/record.url?scp=70349667171&partnerID=8YFLogxK
U2 - 10.1161/CIRCULATIONAHA.108.778688
DO - 10.1161/CIRCULATIONAHA.108.778688
M3 - Article
C2 - 19752329
AN - SCOPUS:70349667171
SN - 0009-7322
VL - 120
SP - 1222
EP - 1230
JO - Circulation
JF - Circulation
IS - 13
ER -