title: Effect of angiotensin II on the WNK-OSR1/SPAK-NCC phosphorylation cascade in cultured mpkDCT cells and in vivo mouse kidney.
abstract: In our recent study using Wnk4(D561A/+) knockin mice, we determined that the WNK-OSR1/SPAK-NaCl cotransporter (NCC) phosphorylation cascade is important for regulating NCC function in vivo. Phosphorylation of NCC was necessary for its plasma membrane localization. Previously, angiotensin II infusion was shown to increase apical membrane expression of NCC in rats. Therefore, we investigated whether angiotensin II was an upstream regulator for the WNK-OSR1/SPAK-NCC cascade in cultured cells and in vivo kidney. In mpkDCT cells, the phosphorylation of OSR1 and NCC was increased 30 min after the addition of angiotensin II (10(-9)-10(-7)M) but returned to baseline after 18 h. In mice, a 5-min infusion of angiotensin II (5 ng/g/min) increased NCC phosphorylation in the kidney at 30 min and 2h after the injection but returned to baseline 24h later. This increase was inhibited by angiotensin II receptor blocker (valsartan) but not by aldosterone receptor blocker (eplerenone). Ten-day infusions of angiotensin II (720 ng/day) also increased phosphorylation of OSR1 and NCC in the mouse kidney, and both valsartan and eplerenone inhibited the increased phosphorylation. Although angiotensin II is identified as an upstream regulator for the WNK-OSR1/SPAK-NCC cascade in vivo, aldosterone appears to be the major regulator of this signal cascade in the long-term regulation by angiotensin II.
authors.affiliation: Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima Bunkyo, Tokyo 113-8519, Japan.
authors.forename: Gulibaha
authors.initials: G
authors.lastname: Talati
authors.forename: Akihito
authors.initials: A
authors.lastname: Ohta
authors.forename: Tatemitsu
authors.initials: T
authors.lastname: Rai
authors.forename: Eisei
authors.initials: E
authors.lastname: Sohara
authors.forename: Shotaro
authors.initials: S
authors.lastname: Naito
authors.forename: Alain
authors.initials: A
authors.lastname: Vandewalle
authors.forename: Sei
authors.initials: S
authors.lastname: Sasaki
authors.forename: Shinichi
authors.initials: S
authors.lastname: Uchida
mesh_terms: D000804:Angiotensin II / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011955:Receptors, Drug / Q000378:metabolism*; D064486:Solute Carrier Family 12, Member 3; D027981:Symporters / Q000378:metabolism*
chemical_list: D011955:Receptors, Drug; C578875:Slc12a3 protein, mouse; D064486:Solute Carrier Family 12, Member 3; D027981:Symporters; D000804:Angiotensin II; C499024:Prkwnk4 protein, mouse; C486407:Stk39 protein, mouse; C534421:OXSR1 protein, mouse; D017346:Protein Serine-Threonine Kinases