title: Acute laminar shear stress reversibly increases human glomerular endothelial cell permeability via activation of endothelial nitric oxide synthase.
abstract: Laminar shear stress is a key determinant of systemic vascular behavior, including through activation of endothelial nitric oxide synthase (eNOS), but little is known of its role in the glomerulus. We confirmed eNOS expression by glomerular endothelial cells (GEnC) in tissue sections and examined effects of acute exposure (up to 24 h) to physiologically relevant levels of laminar shear stress (10-20 dyn/cm(2)) in conditionally immortalized human GEnC. Laminar shear stress caused an orientation of GEnC and stress fibers parallel to the direction of flow and induced Akt and eNOS phosphorylation along with NO production. Inhibition of the phophatidylinositol (PI)3-kinase/Akt pathway attenuated laminar shear stress-induced eNOS phosphorylation and NO production. Laminar shear stress of 10 dyn/cm(2) had a dramatic effect on GEnC permeability, reversibly decreasing the electrical resistance across GEnC monolayers. Finally, the laminar shear stress-induced reduction in electrical resistance was attenuated by the NOS inhibitors l-N(G)-monomethyl arginine (l-NMMA) and l-N(G)-nitroarginine methyl ester (l-NAME) and also by inhibition of the PI3-kinase/Akt pathway. Hence we have shown for GEnC in vitro that acute permeability responses to laminar shear stress are dependent on NO, produced via activation of the PI3-kinase/Akt pathway and increased eNOS phosphorylation. These results suggest the importance of laminar shear stress and NO in regulating the contribution of GEnC to the permeability properties of the glomerular capillary wall.
authors.affiliation: Academic Renal Unit, University of Bristol, Southmead Hospital, Bristol, United Kingdom.
authors.forename: Heather S
authors.initials: HS
authors.lastname: Bevan
authors.forename: Sadie C
authors.initials: SC
authors.lastname: Slater
authors.forename: Hayley
authors.initials: H
authors.lastname: Clarke
authors.forename: Paul A
authors.initials: PA
authors.lastname: Cahill
authors.forename: Peter W
authors.initials: PW
authors.lastname: Mathieson
authors.forename: Gavin I
authors.initials: GI
authors.lastname: Welsh
authors.forename: Simon C
authors.initials: SC
authors.lastname: Satchell
mesh_terms: D002199:Capillary Permeability / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D017097:Electric Impedance; D004730:Endothelium, Vascular / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007678:Kidney Glomerulus / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000502:physiology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors / Q000378:metabolism; D033081:Shear Strength; D013314:Stress, Mechanical; D019323:omega-N-Methylarginine / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D019331:NG-Nitroarginine Methyl Ester; D052250:Nitric Oxide Synthase Type III; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt; D019323:omega-N-Methylarginine