NADPH oxidases (NOX) constitute the main reactive oxygen species (ROS) source in blood vessels. An oxidative stress situation due to ROS overproduction can lead into endothelial dysfunction, a molecular mechanism that precedes cardiovascular diseases (CVDs) such as atherosclerosis, myocardial infarction, and stroke. NOX5 is the last discovered member of the NOX family, studied in a lesser extent due to its absence in the rodent genome. Our objective was to describe the phenotypic alterations produced by an oxidative stress situation derived from NOX5 overexpression in an endothelial in vitro model. The in vitro model consists of the hCMEC/D3 cell line, derived from brain microvascular endothelium, infected with a recombinant NOX5-β adenovirus. After an initial proteomic analysis, three phenotypic alterations detected in silico were studied: cell proliferation and apoptosis, general and mitochondrial metabolism, and migration capacity. NOX5 infection of hCMEC/D3 generates a functional protein and an increase in ROS production. This model produced changes in the whole cell proteome. The in silico analysis together with in vitro validations demonstrated that NOX5 overexpression inhibits proliferation and promotes apoptosis, metabolic alterations and cell migration in hCMEC/D3 cells. NOX5 overexpression in endothelial cells leads to phenotypic changes that can lead to endothelial dysfunction, the onset of atherosclerosis, myocardial infarction, and stroke.

NADPH oxidases (NOXs) have been described as critical players in vascular remodeling, a mechanism modulated by matrix metalloproteinases. In this study, we describe for the first time the upregulation of MMP-10 through the activation of NOX5 in endothelial cells. In a chronic NOX5 overexpression model in human endothelial cells, MMP-10 production was measured at different levels: extracellular secretion, gene expression (mRNA and protein levels), and promoter activity. Effects on cell migration were quantified using wound healing assays. NOX5 overexpression increased MMP-10 production, favoring cell migration. In fact, NOX5 and MMP-10 silencing prevented this promigratory effect. We showed that NOX5-mediated MMP-10 upregulation involves the redox-sensitive JNK/AP-1 signaling pathway. All these NOX5-dependent effects were enhanced by angiotensin II (Ang II). Interestingly, MMP-10 protein levels were found to be increased in the hearts of NOX5-expressing mice. In conclusion, we described that NOX5-generated ROS may modulate the MMP-10 expression in endothelial cells, which leads to endothelial cell migration and may play a key role in vascular remodeling.

Cardiovascular diseases and the ischemic heart disease specifically constitute the main cause of death worldwide. The ischemic heart disease may lead to myocardial infarction, which in turn triggers numerous mechanisms and pathways involved in cardiac repair and remodeling. Our goal in the present study was to characterize the effect of the NADPH oxidase 5 (NOX5) endothelial expression in healthy and infarcted knock-in mice on diverse signaling pathways. The mechanisms studied in the heart of mice were the redox pathway, metalloproteinases and collagen pathway, signaling factors such as NFκB, AKT or Bcl-2, and adhesion molecules among others. Recent studies support that NOX5 expression in animal models can modify the environment and predisposes organ response to harmful stimuli prior to pathological processes. We found many alterations in the mRNA expression of components involved in cardiac fibrosis as collagen type I or TGF-β and in key players of cardiac apoptosis such as AKT, Bcl-2, or p53. In the heart of NOX5-expressing mice after chronic myocardial infarction, gene alterations were predominant in the redox pathway (NOX2, NOX4, p22phox, or SOD1), but we also found alterations in VCAM-1 and β-MHC expression. Our results suggest that NOX5 endothelial expression in mice preconditions the heart, and we propose that NOX5 has a cardioprotective role. The correlation studies performed between echocardiographic parameters and cardiac mRNA expression supported NOX5 protective action.