title: Netrin-1 restores cell injury and impaired angiogenesis in vascular endothelial cells upon high glucose by PI3K/AKT-eNOS.
abstract: Diabetic foot ulceration (DFU) represents a common vascular complication of diabetes mellitus (DM) with high morbidity and disability resulting from amputation. Netrin-1 level was decreased in type 2 DM patients and has been identified as a protective regulator against diabetes-triggered myocardial infarction and nephropathy. Unfortunately, its role and molecular mechanism in DFU remain poorly elucidated. Here, netrin-1 levels were reduced in DM and DFU patients relative to healthy controls, with netrin-1 levels being the lowest in DFU patients. Moreover, exposure to high glucose (HG) also suppressed netrin-1 expression in human umbilical vein endothelial cells (HUVECs). Elevated netrin-1 expression by infection with Ad-netrin-1 adenovirus vector protected against HUVEC injury in response to HG by ameliorating the inhibitory effects on cell viability, lactate dehydrogenase (LDH) and malondialdehyde (MDA) levels, cell apoptotic rate and caspase-3 activity. Importantly, HG-impaired angiogenesis was improved after netrin-1 overexpression by elevating cell migration, capillary-like tube formation and VEGF production. Mechanism assay substantiated that netrin-1 elevation increased the phosphorylation levels of AKT and eNOS, and NO production, which was notably suppressed by HG, indicating that netrin-1 overexpression restored HG-triggered impairment of the PI3K/AKT-eNOS pathway. More intriguingly, preconditioning with LY294002 (PI3K/AKT antagonist) orNG-monomethyl-l-arginine (eNOS inhibitor) antagonized netrin-1-induced activation of the PI3K/AKT-eNOS pathway. Concomitantly, treatment with these antagonists also attenuated the protective role of netrin-1 in endothelial dysfunction upon HG stimulation. These results suggest that elevation of netrin-1 may restore HG-triggered impairment of HUVEC and angiogenesis by activating the PI3K/AKT-eNOS pathway, indicating a potential agent for wound healing in DFU patients.
authors.affiliation: Department of Endocrinology and Metabolism DiseaseXijing Hospital, Forth Military Medical University, Xi'an, Shaanxi, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Xing
authors.affiliation: Department of Endocrinology and Metabolism DiseaseXijing Hospital, Forth Military Medical University, Xi'an, Shaanxi, People's Republic of China.
authors.forename: Jingbo
authors.initials: J
authors.lastname: Lai
authors.affiliation: Department of Endocrinology and Metabolism DiseaseXijing Hospital, Forth Military Medical University, Xi'an, Shaanxi, People's Republic of China.
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Endocrinology and Metabolism DiseaseXijing Hospital, Forth Military Medical University, Xi'an, Shaanxi, People's Republic of China.
authors.forename: Nana
authors.initials: N
authors.lastname: Zhang
authors.affiliation: Department of Endocrinology and Metabolism DiseaseXijing Hospital, Forth Military Medical University, Xi'an, Shaanxi, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Ming
authors.affiliation: Institute of Plastic and Reconstructive SurgeryXijing Hospital, Forth Military Medical University, Xi'an, Shaanxi, People's Republic of China.
authors.forename: Hengxin
authors.initials: H
authors.lastname: Liu
authors.affiliation: Institute of Plastic and Reconstructive SurgeryXijing Hospital, Forth Military Medical University, Xi'an, Shaanxi, People's Republic of China xizhanghdejhd@tom.com.
authors.forename: Xi
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000256:Adenoviridae / Q000235:genetics / Q000378:metabolism; D016022:Case-Control Studies; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D002470:Cell Survival; D002478:Cells, Cultured; D002867:Chromones / Q000494:pharmacology; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D017719:Diabetic Foot / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D005260:Female; D005786:Gene Expression Regulation; D005822:Genetic Vectors / Q000737:chemistry / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008875:Middle Aged; D009025:Morpholines / Q000494:pharmacology; D018919:Neovascularization, Physiologic / Q000187:drug effects; D000075388:Netrin-1 / Q000819:agonists / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics* / Q000378:metabolism; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D019323:omega-N-Methylarginine / Q000494:pharmacology
chemical_list: D002867:Chromones; D009025:Morpholines; C000617351:NTN1 protein, human; D000075388:Netrin-1; D019323:omega-N-Methylarginine; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D008315:Malondialdehyde; D007770:L-Lactate Dehydrogenase; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; C505407:CASP3 protein, human; D053148:Caspase 3; D005947:Glucose
keywords: PI3K/AKT; diabetic foot ulcer; eNOS; endothelial dysfunction; high glucose; netrin-1