Pendrin protein abundance in the kidney is regulated by nitric oxide and cAMP.
Pendrin is a Cl(-)/HCO(3)(-) exchanger, expressed in the apical regions of some intercalated cell subtypes, and is critical in the pressor response to angiotensin II. Since angiotensin type 1 receptor inhibitors reduce renal pendrin protein abundance in mice in vivo through a mechanism that is dependent on nitric oxide (NO), we asked if NO modulates renal pendrin expression in vitro and explored the mechanism by which it occurs. Thus we quantified pendrin protein abundance by confocal fluorescent microscopy in cultured mouse cortical collecting ducts (CCDs) and connecting tubules (CNTs). After overnight culture, CCDs maintain their tubular structure and maintain a solute gradient when perfused in vitro. Pendrin protein abundance increased 67% in CNT and 53% in CCD when NO synthase was inhibited (N(G)-nitro-L-arginine methyl ester, 100 μM), while NO donor (DETA NONOate, 200 μM) application reduced pendrin protein by ∼33% in the CCD and CNT. When CNTs were cultured in the presence of the guanylyl cyclase inhibitor 1H-[1,2,4] oxadiazolo[4,3-a]quinoxalin-1-one (10 μM), NO donors did not alter pendrin abundance. Conversely, pendrin protein abundance rose when cAMP content was increased by the application of an adenylyl cyclase agonist (forskolin, 10 μM), a cAMP analog (8-bromo-cAMP, 1 mM), or a phosphodiesterase inhibitor (BAY60-7550, 50 μM). Since NO reduces cellular cAMP in the CNT, we asked if NO reduces pendrin abundance by reducing cAMP. With blockade of cGMP-stimulated phosphodiesterase II, NO did not alter pendrin protein abundance. We conclude that NO acts through cAMP to reduce pendrin total protein abundance by enhancing cAMP degradation.
Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA.
Monika
M
Thumova
Vladimir
V
Pech
Otto
O
Froehlich
Diana
D
Agazatian
Xiaonan
X
Wang
Jill W
JW
Verlander
Young Hee
YH
Kim
Susan M
SM
Wall
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D027321:Anion Transport Proteins / Q000096:biosynthesis*; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D007685:Kidney Tubules, Collecting / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D009603:Nitroso Compounds / Q000494:pharmacology; D010069:Oxadiazoles / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D000076988:Sulfate Transporters; D014227:Triazines / Q000494:pharmacology
C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; C539142:2-(3,4-dimethoxybenzyl)-7-(1-(1-hydroxyethyl)-4-phenylbutyl)-5-methylimidazo(5,1-f)(1,2,4)triazin-4 (3H)-one; D027321:Anion Transport Proteins; D004791:Enzyme Inhibitors; D007093:Imidazoles; D020030:Nitric Oxide Donors; D009603:Nitroso Compounds; D010069:Oxadiazoles; D011810:Quinoxalines; C494849:Slc26a4 protein, mouse; D000076988:Sulfate Transporters; D014227:Triazines; C094210:2,2'-(hydroxynitrosohydrazono)bis-ethanamine; D005576:Colforsin; D015124:8-Bromo Cyclic Adenosine Monophosphate; D009569:Nitric Oxide; D000242:Cyclic AMP; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester