title: Prevention of VEGF-mediated microvascular permeability by C-peptide in diabetic mice.
abstract: OBJECTIVE
  Human C-peptide has a beneficial effect on the prevention of diabetic neuropathy, nephropathy, and vascular complications; however, its role in protection against increased vascular permeability in diabetes remains unclear. Our purpose was to explore the potential protective role of C-peptide against microvascular permeability mediated by vascular endothelial growth factor (VEGF)-induced reactive oxygen species (ROS) generation in diabetes.
  
  
  RESULTS
  Generation of intracellular ROS, real-time changes in intracellular Ca(2+), ROS-dependent stress fibre formation, and the disassembly of the adherens junctions were studied by a confocal microscopy in human umbilical vein endothelial cells (HUVECs). VEGF-induced vascular leakage was investigated in the skin of diabetic mice using a Miles vascular permeability assay. Microvascular leakage in the retina of streptozotocin diabetic mice was investigated using a confocal microscopy after left ventricle injection of fluorescein isothiocyanate (FITC)-dextran. C-peptide inhibited the VEGF-induced ROS generation, stress fibre formation, disassembly of vascular endothelial cadherin, and endothelial permeability in HUVECs. Intradermal injection of C-peptide prevented VEGF-induced vascular leakage. Consistent with this, intravitreal injection of C-peptide prevented the extravasation of FITC-dextran in the retinas of diabetic mice, which was also prevented by anti-VEGF antibody and ROS scavengers in diabetic mice. Conclusions/interpretation C-peptide prevents VEGF-induced microvascular permeability by inhibiting ROS-mediated intracellular events in diabetic mice, suggesting that C-peptide replacement is a promising therapeutic strategy to prevent diabetic retinopathy.
authors.affiliation: Department of Molecular and Cellular Biochemistry, Institute of Medical Scicence, Kangwon National University School of Medicine, Kangwon-do 200-701, Korea.
authors.forename: Young-Cheol
authors.initials: YC
authors.lastname: Lim
authors.forename: Mahendra Prasad
authors.initials: MP
authors.lastname: Bhatt
authors.forename: Mi-Hye
authors.initials: MH
authors.lastname: Kwon
authors.forename: Donghyun
authors.initials: D
authors.lastname: Park
authors.forename: Seungkoo
authors.initials: S
authors.lastname: Lee
authors.forename: Jongseon
authors.initials: J
authors.lastname: Choe
authors.forename: Jongyun
authors.initials: J
authors.lastname: Hwang
authors.forename: Young-Myeong
authors.initials: YM
authors.lastname: Kim
authors.forename: Kwon-Soo
authors.initials: KS
authors.lastname: Ha
mesh_terms: D022005:Adherens Junctions / Q000378:metabolism; D000818:Animals; D002096:C-Peptide / Q000502:physiology*; D015820:Cadherins / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002199:Capillary Permeability; D002478:Cells, Cultured; D003925:Diabetic Angiopathies / Q000209:etiology* / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D017382:Reactive Oxygen Species / Q000378:metabolism; D012160:Retina / Q000378:metabolism; D022502:Stress Fibers / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D002096:C-Peptide; D015820:Cadherins; D017382:Reactive Oxygen Species; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; D002118:Calcium
keywords: C-peptide; Diabetes mellitus; Microvascular permeability; Retinopathy; VEGF