Oxidative Stress-Induced miR-200c Disrupts the Regulatory Loop Among SIRT1, FOXO1, and eNOS

Abstract

We demonstrated that miR-200c directly targets SIRT1, eNOS, and FOXO1; via this mechanism, miR-200c decreased NO and increased the acetylation of SIRT1 targets, that is, FOXO1 and p53. FOXO1 acetylation inhibited its transcriptional activity on target genes, that is, SIRT1 and the ROS scavengers, catalase and manganese superoxide dismutase. In keeping, miR-200c increased ROS production and induced p66Shc protein phosphorylation in Ser-36; this mechanism upregulated ROS and inhibited FOXO1 transcription, reinforcing this molecular circuitry. These in vitro results were validated in three in vivo models of oxidative stress, that is, human skin fibroblasts from old donors, femoral arteries from old mice, and a murine model of hindlimb ischemia. In all cases, miR-200c was higher versus control and its targets, that is, SIRT1, eNOS, and FOXO1, were downmodulated. In the mouse hindlimb ischemia model, anti-miR-200c treatment rescued these targets and improved limb perfusion. Innovation and Conclusion: miR-200c disrupts SIRT1/FOXO1/eNOS regulatory loop. This event promotes ROS production and decreases NO, contributing to endothelial dysfunction under conditions of increased oxidative stress such as aging and ischemia. Antioxid. Redox Signal. 27, 328-344.

SIRT1 and SIRT6 Signaling Pathways in Cardiovascular Disease Protection

“…During the aging-related downregulation of SIRT1, a malfunction of SIRT1-eNOS axis can explain the impaired NO production (29,120,136,137). Indeed, SIRT1 protection against ROS-induced premature senescence is accompanied by increased eNOS activity, as supported by observations that the endogenous inhibitor of SIRT1, miR-217, suppresses eNOS activity with a concomitant progression of endothelial senescence ( Fig.…”

“…Treatment with anti-miR-200c rescued SIRT1, eNOS, and FOXO1 activities and improved limb perfusion in the mouse hindlimb ischemia model, indicating that distruption of SIRT1/FOXO1/eNOS regulatory loop by miR-200c takes part in endothelial dysfunction under conditions of increased oxidative stress (29).…”

“…As recently demonstrated by in vitro and in vivo models of oxidative stress, including old mice femoral arteries and murine hindlimb ischemia models, microRNA (miR)-200c decreases NO and increases acetylation of FOXO1 and p53 (29). In particular, acetylation of FOXO1 inhibits its transcriptional activity on SIRT1, catalase (CAT), and MnSOD target genes.…”

“…The known mechanisms through which p66 Shc determines the increase of intracellular ROS levels include activation of membrane-bound NADPH oxidases and downregulation of glutathione peroxidase (GPx)-1, MnSOD, and Ref-1 (29,33,45,55,95,151,194).…”

microRNA‐mRNA network model in patients with achalasia

“…Dysregulation of the miR‐200c was observed in a variety of cancers and noteworthy, it has been reported to be associated with neuronal cell death . miR‐200b physiologically limits the endothelial nitric oxide synthase (eNOS) expression during hypoxia leading to a loss of NO bioavailability, and miR‐200c destabilizes NOS3 transcript in response to oxidative stress . Of note, inhibition of miRNA‐200b resulted in increased neuronal apoptosis and microglia‐mediated neurotoxic effect .…”