title: Cadmium attenuates bradykinin-driven nitric oxide production by interplaying with the localization pattern of endothelial nitric oxide synthase.
abstract: Cadmium, a ubiquitous heavy metal, interferes with endothelial functions and angiogenesis. Bradykinin is a Ca-mobilizing soluble peptide that acts via nitric oxide to promote vasodilation and capillary permeability. The objective of the present study was to explore the Cd implications in bradykinin-dependent endothelial functions. An egg yolk angiogenesis model was employed to evaluate the effect of Cd on bradykinin-induced angiogenesis. The results demonstrate that 100 nmol/L Cd attenuated bradykinin-dependent angiogenesis. The results of the in vitro wound healing and tube formation assays by using EAhy 926, a transformed endothelial cell line, suggest that Cd blocked bradykinin-mediated endothelial migration and tube formation by 38% and 67%, respectively, while nitric oxide supplementation could reverse the effect of Cd on bradykinin-induced endothelial migration by 94%. The detection of nitric oxide by using a DAF-2DA fluorescent probe, Griess assay, and ultrasensitive electrode suggests that Cd blocked bradykinin-induced nitric oxide production. Fluorescence imaging of eNOS-GFP transfected endothelial cells, immunofluorescence, and Western blot studies of Cd and bradykinin-treated cells show that Cd interfered with the localization pattern of eNOS, which possibly attenuates nitric oxide production in part. Additionally, Ca imaging of Cd- and bradykinin-treated cells suggests that Cd blocked bradykinin-dependent Ca influx into the cells, thus partially blocking Ca-dependent nitric oxide production in endothelial cells. The results of this study conclude that Cd blunted the effect of bradykinin by interfering with the Ca-associated NOS activity specifically by impeding subcellular trafficking of eNOS.
authors.affiliation: Vascular Biology Lab, Life Sciences Division, AU-KBC Research Centre, MIT Campus, Anna University, Chennai 600044, Tamil Nadu, India.
authors.forename: Syamantak
authors.initials: S
authors.lastname: Majumder
authors.forename: Ravi
authors.initials: R
authors.lastname: Gupta
authors.forename: Himabindu
authors.initials: H
authors.lastname: Reddy
authors.forename: Swaraj
authors.initials: S
authors.lastname: Sinha
authors.forename: Ajit
authors.initials: A
authors.lastname: Muley
authors.forename: Gopi Krishna
authors.initials: GK
authors.lastname: Kolluru
authors.forename: Suvro
authors.initials: S
authors.lastname: Chatterjee
mesh_terms: D000818:Animals; D001920:Bradykinin / Q000502:physiology*; D002104:Cadmium / Q000633:toxicity*; D002417:Cattle; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*
chemical_list: D002104:Cadmium; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; D001920:Bradykinin