Jak/STAT signaling pathway regulates nox1 and nox4-based NADPH oxidase in human aortic smooth muscle cells.
OBJECTIVE
Oxidative stress mediated by Nox1- and Nox4-based NADPH oxidase (Nox) plays a key role in vascular diseases. The molecular mechanisms involved in the regulation of Nox are not entirely elucidated. Because JAK/STAT regulates many genes linked to inflammation, cell proliferation, and differentiation, we questioned whether this pathway is involved in the regulation of Nox1 and Nox4 in human aortic smooth muscle cells (SMCs).


RESULTS
Cultured SMCs were exposed to interferon gamma (IFNgamma) for 24 hours. Using lucigenin-enhanced chemiluminescence and dihydroethidium assays, real-time polymerase chain reaction, and Western blot analysis, we found that JAK/STAT inhibitors significantly diminished the IFNgamma-dependent upregulation of Nox activity, Nox1 and Nox4 expression. In silico analysis revealed the presence of highly conserved GAS elements within human Nox1, Nox4, p22phox, p47phox, and p67phox promoters. Transient overexpression of STAT1/STAT3 augmented the promoter activities of each subunit. JAK/STAT blockade reduced the Nox subunits transcription. Chromatin immunoprecipitation demonstrated the physical interaction of STAT1/STAT3 proteins with the predicted GAS elements from Nox1 and Nox4 promoters.


CONCLUSIONS
JAK/STAT is a key regulator of Nox1 and Nox4 in human vascular SMCs. Inhibition of JAK/STAT pathway and the consequent Nox-dependent oxidative stress may be an efficient therapeutic strategy to reduce atherogenesis.
Manea
Adrian
A
Institute of Cellular Biology and Pathology "Nicolae Simionescu," 8, BP Hasdeu St, Bucharest, PO Box 35-14, Romania.
Tanase
Laurentia Irina
LI
Raicu
Monica
M
Simionescu
Maya
M
D001013:Aorta, Thoracic / Q000166:cytology; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D053614:Janus Kinase 2 / Q000009:adverse effects / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000201:enzymology*; D000074624:NADPH Oxidase 1; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000235:genetics* / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000502:physiology; D050794:STAT1 Transcription Factor / Q000378:metabolism*; D050796:STAT3 Transcription Factor / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D014162:Transfection
D004791:Enzyme Inhibitors; D010750:Phosphoproteins; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; C079789:neutrophil cytosol factor 67K; D007371:Interferon-gamma; D000074624:NADPH Oxidase 1; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C402799:NOX1 protein, human; C498910:NOX4 protein, human; C086986:CYBA protein, human; C060505:neutrophil cytosolic factor 1; C507924:JAK2 protein, human; D053614:Janus Kinase 2