Glucocorticoids suppress mitochondrial oxidant production via upregulation of uncoupling protein 2 in hyperglycemic endothelial cells

Domokos Gerö, Csaba Szabo

    Research output: Contribution to journalArticle

    10 Citations (Scopus)

    Abstract

    Diabetic complications are the leading cause of morbidity and mortality in diabetic patients. Elevated blood glucose contributes to the development of endothelial and vascular dysfunction, and, consequently, to diabetic micro- and macrovascular complications, because it increases the mitochondrial proton gradient and mitochondrial oxidant production. Therapeutic approaches designed to counteract glucose-induced mitochondrial reactive oxygen species (ROS) production in the vasculature are expected to show efficacy against all diabetic complications, but direct pharmacological targeting (scavenging) of mitochondrial oxidants remains challenging due to the high reactivity of some of these oxidant species. In a recent study, we have conducted a medium-throughput cell-based screening of a focused library of well-annotated pharmacologically active compounds and identified glucocorticoids as inhibitors of mitochondrial superoxide production in microvascular endothelial cells exposed to elevated extracellular glucose. The goal of the current study was to investigate the mechanism of glucocorticoids' action. Our findings show that glucocorticoids induce the expression of the mitochondrial UCP2 protein and decrease the mitochondrial potential. UCP2 silencing prevents the protective effect of the glucocorticoids on ROS production. UCP2 induction also increases the oxygen consumption and the "proton leak" in microvascular endothelial cells. Furthermore, glutamine supplementation augments the effect of glucocorticoids via further enhancing the expression of UCP2 at the translational level. We conclude that UCP2 induction represents a novel experimental therapeutic intervention in diabetic vascular complications. While direct repurposing of glucocorticoids may not be possible for the therapy of diabetic complications due to their significant side effects that develop during chronic administration, the UCP2 pathway may be therapeutically targetable by other, glucocorticoid-independent pharmacological means.

    Original languageEnglish (US)
    Article numbere0154813
    JournalPLoS One
    Volume11
    Issue number4
    DOIs
    StatePublished - Apr 1 2016

    Fingerprint

    Endothelial cells
    glucocorticoids
    Oxidants
    oxidants
    Glucocorticoids
    endothelial cells
    Up-Regulation
    Endothelial Cells
    Diabetes Complications
    Proteins
    proteins
    blood vessels
    therapeutics
    protons
    Protons
    reactive oxygen species
    Reactive Oxygen Species
    Pharmacology
    Glucose
    Diabetic Angiopathies

    ASJC Scopus subject areas

    • Agricultural and Biological Sciences(all)
    • Biochemistry, Genetics and Molecular Biology(all)
    • Medicine(all)

    Cite this

    Glucocorticoids suppress mitochondrial oxidant production via upregulation of uncoupling protein 2 in hyperglycemic endothelial cells. / Gerö, Domokos; Szabo, Csaba.

    In: PLoS One, Vol. 11, No. 4, e0154813, 01.04.2016.

    Research output: Contribution to journalArticle

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