title: Induced peroxidase and cytoprotective enzyme expressions support adaptation of HUVECs to sustain subsequent H2O2 exposure.
abstract: H2O2 mediates autocrine and paracrine signaling in the vasculature and can propagate endothelial dysfunction. However, it is not clear how endothelial cells withstand H2O2 exposure and promote H2O2-induced vascular remodeling. To understand the innate ability of endothelial cells for sustaining excess H2O2 exposure, we investigated the genotypic and functional regulation of redox systems in primary HUVECs following an H2O2 treatment. Primary HUVECs were exposed to transient H2O2 exposure and consistent H2O2 exposure. Following H2O2 treatments for 24, 48 and 72 h, we measured O2(-) production, mitochondrial membrane polarization (MMP), and gene expressions of pro-oxidative enzymes, peroxidase enzymes, and cytoprotective intermediates. Our results showed that the 24 h H2O2 exposure significantly increased O2(-) levels, hyperpolarized MMP, and downregulated CAT, GPX1, TXNRD1, NFE2L2, ASK1, and ATF2 gene expression in HUVECs. At 72 h, HUVECs in both treatment conditions were shown to adapt to reduce O2(-) levels and normalize MMP. An upregulation of GPX1, TXNRD1, and HMOX1 gene expression and a recovery of NFE2L2 and PRDX1 gene expression to control levels were observed in both consistent and transient treatments at 48 and 72 h. The response of endothelial cells to excess levels of H2O2 involves a complex interaction amongst O2(-) levels, mitochondrial membrane polarization and anti- and pro-oxidant gene regulation. As a part of this response, HUVECs induce cytoprotective mechanisms including the expression of peroxidase and antioxidant enzymes along with the downregulation of pro-apoptotic genes. This adaptation assists HUVECs to withstand subsequent exposures to H2O2.
authors.affiliation: Department of Biomedical Engineering, Wayne State University, Detroit, MI 48201, United States. Electronic address: hemang@wayne.edu.
authors.forename: Hemang
authors.initials: H
authors.lastname: Patel
authors.affiliation: Department of Biomedical Engineering, Wayne State University, Detroit, MI 48201, United States. Electronic address: ej8568@wayne.edu.
authors.forename: Juan
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Biomedical Engineering, Wayne State University, Detroit, MI 48201, United States. Electronic address: kavdia@wayne.edu.
authors.forename: Mahendra
authors.initials: M
authors.lastname: Kavdia
mesh_terms: D000222:Adaptation, Physiological; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004790:Enzyme Induction; D005979:Glutathione Peroxidase / Q000096:biosynthesis; D051547:Heme Oxygenase-1 / Q000096:biosynthesis; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051267:NF-E2-Related Factor 2 / Q000378:metabolism; D016877:Oxidants / Q000633:toxicity*; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects*; D010544:Peroxidases / Q000096:biosynthesis* / Q000235:genetics; D054464:Peroxiredoxins / Q000096:biosynthesis; D013481:Superoxides / Q000378:metabolism; D054481:Thioredoxin Reductase 1 / Q000096:biosynthesis; D013997:Time Factors; D000094765:Glutathione Peroxidase GPX1
chemical_list: D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D016877:Oxidants; D013481:Superoxides; D006861:Hydrogen Peroxide; D010544:Peroxidases; C515940:PRDX1 protein, human; D054464:Peroxiredoxins; D005979:Glutathione Peroxidase; C496541:HMOX1 protein, human; D051547:Heme Oxygenase-1; C516124:TXNRD1 protein, human; D054481:Thioredoxin Reductase 1; D000094765:Glutathione Peroxidase GPX1; C000722067:GPX1 protein, human
keywords: ASK1; Cytoprotection; Endothelial dysfunction; GPX1; HMOX1; HUVEC; Hydrogen peroxide; Redox homeostasis; Systems biology; TXNRD1; UCP1