Hyun Joong Yoon1, Kee Oh Chay1, Sung Yeul Yang2. 1. Department of Biochemistry, Medical School, The Research Institute of Medical Science, Chonnam National University, 264 Seoyang-ro, Hwasun-eup, Hwasun-gun, Jeollanam-do, 58128, South Korea. 2. Department of Biochemistry, Medical School, The Research Institute of Medical Science, Chonnam National University, 264 Seoyang-ro, Hwasun-eup, Hwasun-gun, Jeollanam-do, 58128, South Korea. syyang@jnu.ac.kr.
Abstract
BACKGROUND: Nitric oxide synthases (NOSs) are a unique family of enzymes that catalyze the production of nitric oxide (NO) from L-arginine. Atherogenic action of oxidized low-density lipoproteins (oxLDL) may be mediated partly by the formation of NO in endothelial cells. OBJECTIVE: The objective of this study was to identify sources of reactive oxygen species (ROS) causing native LDL (nLDL)-induced senescence of cultured human umbilical vein endothelial cells (HUVECs). METHODS: HUVECs were treated with nLDL and NO production was assessed using Griess reagent as substrate and spectrophotometry in the absence or presence of specific inhibitors of endothelial NOS (eNOS) and inducible NOS (iNOS). In addition, expression levels of eNOS and iNOS were measured with ELISA and western blotting, and ROS was evaluated using 2',7'-dichlorofluorescin diacetate (DCF-DA) and a fluorescence microplate reader. RESULTS: NO formation in nLDL-treated HUVECs was significantly increased. Long-term treatment with nLDL up-regulated both eNOS and iNOS proteins. Such increase of NO production in HUVECs induced by nLDL was significantly suppressed by treatment with iNOS-selective inhibitor 1400 W, but not by the eNOS-selective inhibitor L-NIO. Native LDL treatment uncoupled Hsp90, the regulatory binding protein of eNOS, from the enzyme in HUVECs. Native LDL also significantly increased ROS production in HUVECs. CONCLUSION: These findings suggest that oxidative stress originated from induction of iNOS and eNOS could be a causative factor for nLDL-induced senescence of HUVECs.
BACKGROUND:Nitric oxide synthases (NOSs) are a unique family of enzymes that catalyze the production of nitric oxide (NO) from L-arginine. Atherogenic action of oxidized low-density lipoproteins (oxLDL) may be mediated partly by the formation of NO in endothelial cells. OBJECTIVE: The objective of this study was to identify sources of reactive oxygen species (ROS) causing native LDL (nLDL)-induced senescence of cultured human umbilical vein endothelial cells (HUVECs). METHODS: HUVECs were treated with nLDL and NO production was assessed using Griess reagent as substrate and spectrophotometry in the absence or presence of specific inhibitors of endothelial NOS (eNOS) and inducible NOS (iNOS). In addition, expression levels of eNOS and iNOS were measured with ELISA and western blotting, and ROS was evaluated using 2',7'-dichlorofluorescin diacetate (DCF-DA) and a fluorescence microplate reader. RESULTS: NO formation in nLDL-treated HUVECs was significantly increased. Long-term treatment with nLDL up-regulated both eNOS and iNOS proteins. Such increase of NO production in HUVECs induced by nLDL was significantly suppressed by treatment with iNOS-selective inhibitor 1400 W, but not by the eNOS-selective inhibitor L-NIO. Native LDL treatment uncoupled Hsp90, the regulatory binding protein of eNOS, from the enzyme in HUVECs. Native LDL also significantly increased ROS production in HUVECs. CONCLUSION: These findings suggest that oxidative stress originated from induction of iNOS and eNOS could be a causative factor for nLDL-induced senescence of HUVECs.
Entities:
Keywords:
Human umbilical vein endothelial cell; Inducible nitric oxide synthase; Native low density lipoprotein; Nitric oxide; Reactive oxygen species
Authors: Maggie Lind; Alan Hayes; Martin Caprnda; Daniel Petrovic; Luis Rodrigo; Peter Kruzliak; Anthony Zulli Journal: Biomed Pharmacother Date: 2017-06-24 Impact factor: 6.529
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