title: Inhibition of dynamin-2 confers endothelial barrier dysfunctions by attenuating nitric oxide production.
abstract: Hypoxia induces barrier dysfunctions in endothelial cells. Nitric oxide is an autacoid signalling molecule that confers protection against hypoxia-mediated barrier dysfunctions. Dyn-2 (dynamin-2), a large GTPase and a positive modulator of eNOS (endothelial nitric oxide synthase), plays an important role in maintaining vascular homeostasis. The present study aims to elucidate the role of dyn-2 in hypoxia-mediated leakiness of the endothelial monolayer in relation to redox milieu. Inhibition of dyn-2 by transfecting the cells with K44A, a dominant negative construct of dyn-2, elevated leakiness of the endothelial monolayer under hypoxia. Sodium nitroprusside (nitric oxide donor) and uric acid (peroxynitrite quencher) were used to evaluate the role of nitric oxide and peroxynitrite in maintaining endothelial barrier functions under hypoxia. Administration of nitric oxide and uric acid recovered hypoxia-mediated leakiness of K44A-overexpressed endothelial monolayer. Our study confirms that inhibition of dyn-2 induces leakiness in the endothelial monolayer by increasing the load of peroxynitrite under hypoxia.
authors.affiliation: Vascular Biology Lab, AUKBC Research Centre, Anna University, Chennai, India.
authors.forename: Hima bindu Reddy
authors.initials: Hb
authors.lastname: Seerapu
authors.forename: Geetha Priya
authors.initials: GP
authors.lastname: Subramaniam
authors.forename: Syamantak
authors.initials: S
authors.lastname: Majumder
authors.forename: Swaraj
authors.initials: S
authors.lastname: Sinha
authors.forename: Swathi
authors.initials: S
authors.lastname: Bisana
authors.forename: Sahil
authors.initials: S
authors.lastname: Mahajan
authors.forename: Gopi Krishna
authors.initials: GK
authors.lastname: Kolluru
authors.forename: Ajit
authors.initials: A
authors.lastname: Muley
authors.forename: Jamila H
authors.initials: JH
authors.lastname: Siamwala
authors.forename: Govindan
authors.initials: G
authors.lastname: Illavazagan
authors.forename: Suvro
authors.initials: S
authors.lastname: Chatterjee
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D002199:Capillary Permeability / Q000502:physiology*; D002460:Cell Line; D034285:Dynamin II / Q000037:antagonists & inhibitors* / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D000860:Hypoxia / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis*; D020030:Nitric Oxide Donors / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D009599:Nitroprusside / Q000378:metabolism; D030421:Peroxynitrous Acid / Q000378:metabolism; D014527:Uric Acid / Q000378:metabolism
chemical_list: D000975:Antioxidants; D020030:Nitric Oxide Donors; D030421:Peroxynitrous Acid; D009599:Nitroprusside; D014527:Uric Acid; D009569:Nitric Oxide; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III; D034285:Dynamin II