Dataset Information

Hu antigen R is required for NOX-1 but not NOX-4 regulation by inflammatory stimuli in vascular smooth muscle cells.

ABSTRACT: OBJECTIVE:NOX-1 and NOX-4 are key enzymes responsible for reactive oxygen species (ROS) generation in vascular smooth muscle cells (VSMC). The RNA-binding protein Hu antigen R (HuR) is implicated in posttranscriptional regulation of gene expression; however, its role regulating NOX is unknown. We investigated transcriptional and posttranscriptional mechanisms underlying angiotensin II (AngII) and IL-1? regulation of NOX-1 and NOX-4 in VSMC and their implications in cell migration. METHODS:Rat and human VSMC were stimulated with AngII (0.1??mol/l) and/or IL-1? (10?ng/ml). NOX-1 and NOX-4 mRNA and protein levels, NOX-1 and NOX-4 promoter and 3'UTR activities, NADPH oxidase activity, ROS production, and cell migration were studied. RESULTS:IL-1? increased NOX-1 expression, NADPH oxidase activity and ROS production, and decreased NOX-4 expression and H2O2 production in VSMC. AngII potentiated the IL-1?-mediated induction of NOX-1 expression, NADPH oxidase activity, ROS production, and cell migration. However, AngII did not influence IL-1?-induced NOX-4 downregulation. AngII?+?IL-1? interfered with the decay of NOX-1 mRNA and promoted HuR binding to NOX-1 mRNA. Moreover, HuR blockade reduced NOX-1 mRNA stability and AngII?+?IL-1?-induced NOX-1 mRNA levels. IL-1? decreased NOX-4 expression through a transcriptional mechanism that involved response elements situated in the proximal promoter. AngII and/or IL-1?-induced cell migration were prevented by NOX-1 and HuR blockade and were augmented by NOX-4 overexpression. CONCLUSION:In VSMC HuR-mediated mRNA stabilization is partially responsible for AngII?+?IL-1?-dependent NOX-1 expression, whereas transcriptional mechanisms are involved in decreased NOX-4 expression induced by IL-1?. NOX4 and HuR regulation of NOX-1 contributes to VSMC migration, important in vascular inflammation and remodeling.

SUBMITTER: Aguado A

PROVIDER: S-EPMC4947528 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature

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Hu antigen R is required for NOX-1 but not NOX-4 regulation by inflammatory stimuli in vascular smooth muscle cells.

Aguado Andrea A Fischer Thierry T Rodríguez Cristina C Manea Adrian A Martínez-González José J Touyz Rhian M RM Hernanz Raquel R Alonso M Jesús MJ Dixon Dan A DA Briones Ana M AM Salaices Mercedes M

Journal of hypertension 20160201 2

<h4>Objective</h4>NOX-1 and NOX-4 are key enzymes responsible for reactive oxygen species (ROS) generation in vascular smooth muscle cells (VSMC). The RNA-binding protein Hu antigen R (HuR) is implicated in posttranscriptional regulation of gene expression; however, its role regulating NOX is unknown. We investigated transcriptional and posttranscriptional mechanisms underlying angiotensin II (AngII) and IL-1β regulation of NOX-1 and NOX-4 in VSMC and their implications in cell migration.<h4>Met ...[more]

PMID: 26682942

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Project description:RationaleCoronary artery disease (CAD) is a major cause of morbidity and mortality worldwide. Recent genome-wide association studies revealed 163 loci associated with CAD. However, the precise molecular mechanisms by which the majority of these loci increase CAD risk are not known. Vascular smooth muscle cells (VSMCs) are critical in the development of CAD. They can play either beneficial or detrimental roles in lesion pathogenesis, depending on the nature of their phenotypic changes.ObjectiveTo identify genetic variants associated with atherosclerosis-relevant phenotypes in VSMCs.Methods and resultsWe quantified 12 atherosclerosis-relevant phenotypes related to calcification, proliferation, and migration in VSMCs isolated from 151 multiethnic heart transplant donors. After genotyping and imputation, we performed association mapping using 6.3 million genetic variants. We demonstrated significant variations in calcification, proliferation, and migration. These phenotypes were not correlated with each other. We performed genome-wide association studies for 12 atherosclerosis-relevant phenotypes and identified 4 genome-wide significant loci associated with at least one VSMC phenotype. We overlapped the previously identified CAD loci with our data set and found nominally significant associations at 79 loci. One of them was the chromosome 1q41 locus, which harbors MIA3. The G allele of the lead risk single nucleotide polymorphism (SNP) rs67180937 was associated with lower VSMC MIA3 expression and lower proliferation. Lentivirus-mediated silencing of MIA3 (melanoma inhibitory activity protein 3) in VSMCs resulted in lower proliferation, consistent with human genetics findings. Furthermore, we observed a significant reduction of MIA3 protein in VSMCs in thin fibrous caps of late-stage atherosclerotic plaques compared to early fibroatheroma with thick and protective fibrous caps in mice and humans.ConclusionsOur data demonstrate that genetic variants have significant influences on VSMC function relevant to the development of atherosclerosis. Furthermore, high MIA3 expression may promote atheroprotective VSMC phenotypic transitions, including increased proliferation, which is essential in the formation or maintenance of a protective fibrous cap.

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Dataset Information

Hu antigen R is required for NOX-1 but not NOX-4 regulation by inflammatory stimuli in vascular smooth muscle cells.

Publications

Hu antigen R is required for NOX-1 but not NOX-4 regulation by inflammatory stimuli in vascular smooth muscle cells.

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