Battsetseg Batchuluun1, Toyoshi Inoguchi2, Noriyuki Sonoda3, Shuji Sasaki4, Tomoaki Inoue5, Yoshinori Fujimura6, Daisuke Miura7, Ryoichi Takayanagi8. 1. Department of Internal Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: battsetseg.batchuluun@gmail.com. 2. Department of Internal Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; Innovation Center for Medical Redox Navigation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: toyoshi@intmed3.med.kyushu-u.ac.jp. 3. Department of Internal Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; Innovation Center for Medical Redox Navigation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: noriyuki@intmed3.med.kyushu-u.ac.jp. 4. Department of Internal Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: ssasaki@intmed3.med.kyushu-u.ac.jp. 5. Department of Internal Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: tomo-i@intmed3.med.kyushu-u.ac.jp. 6. Innovation Center for Medical Redox Navigation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: fujimu@redoxnavi.med.kyushu-u.ac.jp. 7. Innovation Center for Medical Redox Navigation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: daipon@agr.kyushu-u.ac.jp. 8. Department of Internal Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: takayana@intmed3.med.kyushu-u.ac.jp.
Abstract
OBJECTIVE: Metformin and glucagon like peptide-1 (GLP-1) prevent diabetic cardiovascular complications and atherosclerosis. However, the direct effects on hyperglycemia-induced oxidative stress in endothelial cells are not fully understood. Thus, we aimed to evaluate the effects of metformin and a GLP-1 analog, liraglutide on high glucose-induced oxidative stress. METHODS: Production of reactive oxygen species (ROS), activation of protein kinase C (PKC) and NAD(P)H oxidase, and changes in signaling molecules in response to high glucose exposure were evaluated in human aortic endothelial cells with and without treatment of metformin and liraglutide, alone or in combination. PKC-NAD(P)H oxidase pathway was assessed by translocation of GFP-fused PKCβ2 isoform and GFP-fused p47phox, a regulatory subunit of NAD(P)H oxidase, in addition to endogenous PKC phosphorylation and NAD(P)H oxidase activity. RESULTS: High glucose-induced ROS overproduction was blunted by metformin or liraglutide treatment, with a further decrease by a combination of these drugs. Exposure to high glucose caused PKCβ2 translocation and a time-dependent phosphorylation of endogenous PKC but failed to induce its translocation and phosphorylation in the cells treated with metformin and liraglutide. Furthermore, both drugs inhibited p47phox translocation and NAD(P)H oxidase activation, and prevented the high glucose-induced changes in intracellulalr diacylglycerol (DAG) level and phosphorylation of AMP-activated protein kinase (AMPK). A combination of these drugs further enhanced all of these effects. CONCLUSIONS: Metformin and liraglutide ameliorate high glucose-induced oxidative stress by inhibiting PKC-NAD(P)H oxidase pathway. A combination of these two drugs provides augmented protective effects, suggesting the clinical usefulness in prevention of diabetic vascular complications.
OBJECTIVE:Metformin and glucagon like peptide-1 (GLP-1) prevent diabetic cardiovascular complications and atherosclerosis. However, the direct effects on hyperglycemia-induced oxidative stress in endothelial cells are not fully understood. Thus, we aimed to evaluate the effects of metformin and a GLP-1 analog, liraglutide on high glucose-induced oxidative stress. METHODS: Production of reactive oxygen species (ROS), activation of protein kinase C (PKC) and NAD(P)H oxidase, and changes in signaling molecules in response to high glucose exposure were evaluated in human aortic endothelial cells with and without treatment of metformin and liraglutide, alone or in combination. PKC-NAD(P)H oxidase pathway was assessed by translocation of GFP-fused PKCβ2 isoform and GFP-fused p47phox, a regulatory subunit of NAD(P)H oxidase, in addition to endogenous PKC phosphorylation and NAD(P)H oxidase activity. RESULTS: High glucose-induced ROS overproduction was blunted by metformin or liraglutide treatment, with a further decrease by a combination of these drugs. Exposure to high glucose caused PKCβ2 translocation and a time-dependent phosphorylation of endogenous PKC but failed to induce its translocation and phosphorylation in the cells treated with metformin and liraglutide. Furthermore, both drugs inhibited p47phox translocation and NAD(P)H oxidase activation, and prevented the high glucose-induced changes in intracellulalr diacylglycerol (DAG) level and phosphorylation of AMP-activated protein kinase (AMPK). A combination of these drugs further enhanced all of these effects. CONCLUSIONS:Metformin and liraglutide ameliorate high glucose-induced oxidative stress by inhibiting PKC-NAD(P)H oxidase pathway. A combination of these two drugs provides augmented protective effects, suggesting the clinical usefulness in prevention of diabetic vascular complications.
Authors: Mohamed I Saad; Taha M Abdelkhalek; Moustafa M Saleh; Maher A Kamel; Mina Youssef; Shady H Tawfik; Helena Dominguez Journal: Endocrine Date: 2015-08-14 Impact factor: 3.633
Authors: Łukasz Bułdak; Krzysztof Łabuzek; Rafał Jakub Bułdak; Grzegorz Machnik; Aleksandra Bołdys; Marcin Basiak; Okopień Bogusław Journal: Exp Ther Med Date: 2016-01-11 Impact factor: 2.447