The valosin-containing protein promotes cardiac survival through the inducible isoform of nitric oxide synthase
| Autor: | Paulo Lizano, Hongyu Qiu, Xiangzhen Sui, Huacheng Dai, Lin Yan, Hobin Kang, Christophe Depre, Eman Rashed |
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| Rok vydání: | 2013 |
| Předmět: |
Male
Physiology Immunoprecipitation Cell Survival Valosin-containing protein Muscle Proteins Nitric Oxide Synthase Type II Cell Cycle Proteins Biology Nitric oxide Rats Sprague-Dawley chemistry.chemical_compound Mice Valosin Containing Protein Physiology (medical) Heat shock protein Animals HSP20 Heat-Shock Proteins Myocytes Cardiac Protein kinase B PI3K/AKT/mTOR pathway Cells Cultured Heat-Shock Proteins Adenosine Triphosphatases NF-kappa B Original Articles NFKB1 Molecular biology Rats Nitric oxide synthase Isoenzymes chemistry biology.protein Cardiology and Cardiovascular Medicine Proto-Oncogene Proteins c-akt Molecular Chaperones |
| Zdroj: | Cardiovascular research. 99(4) |
| ISSN: | 1755-3245 |
| Popis: | Aims Expression of the heat shock protein 22 (Hsp22) in the heart stimulates cardiac cell survival through activation of the Akt pathway and expression of the inducible nitric oxide (NO) synthase (iNOS), the mediator of ischaemic preconditioning and the most powerful prophylaxis against cardiac cell death. The goal of the present study was to elucidate the downstream effector by which Hsp22 and Akt increase iNOS expression. We tested both in vivo and in vitro the hypothesis that such an effector is the valosin-containing protein (VCP), an Akt substrate, which activates the transcription factor NF-κB, using a transgenic mouse with cardiac-specific over-expression of Hsp22, as well as isolated rat cardiac myocytes. Methods and results Using two-dimensional gel electrophoresis and mass spectrometry combined with immunoprecipitation, we found that Hsp22 and Akt co-localize and interact together with VCP. Adeno-mediated over-expression of VCP in isolated cardiac myocytes activated NF-κB and dose-dependently increased the expression of iNOS, which was abolished upon NF-κB inhibition. Over-expression of a dominant-negative (DN) mutant of VCP did not increase iNOS expression. VCP, but not its DN mutant, protected against chelerythrine-induced apoptosis, which was suppressed by inhibition of either NF-κB or iNOS. VCP-mediated activation of the NF-κB/iNOS pathway was also prevented upon inhibition of Akt. Conclusion We conclude that the Akt substrate, VCP, mediates the increased expression of iNOS downstream from Hsp22 through an NF-κB-dependent mechanism. |
| Databáze: | OpenAIRE |
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