SPAK-knockout mice manifest Gitelman syndrome and impaired vasoconstriction.
Polymorphisms in the gene encoding sterile 20/SPS1-related proline/alanine-rich kinase (SPAK) associate with hypertension susceptibility in humans. SPAK interacts with WNK kinases to regulate the Na(+)-K(+)-2Cl(-) and Na(+)-Cl(-) co-transporters [collectively, N(K)CC]. Mutations in WNK1/4 and N(K)CC can cause changes in BP and dyskalemia in humans, but the physiologic role of SPAK in vivo is unknown. We generated and analyzed SPAK-null mice by targeting disruption of exons 9 and 10 of SPAK. Compared with SPAK(+/+) littermates, SPAK(+/-) mice exhibited hypotension without significant electrolyte abnormalities, and SPAK(-/-) mice not only exhibited hypotension but also recapitulated Gitelman syndrome with hypokalemia, hypomagnesemia, and hypocalciuria. In the kidney tissues of SPAK(-/-) mice, the expression of total and phosphorylated (p-)NCC was markedly decreased, but that of p-OSR1, total NKCC2, and p-NKCC2 was significantly increased. We observed a blunted response to thiazide but normal response to furosemide in SPAK(-/-) mice. In aortic tissues, total NKCC1 expression was increased but p-NKCC1 was decreased in SPAK-deficient mice. Both SPAK(+/-) and SPAK(-/-) mice had impaired responses to the selective α(1)-adrenergic agonist phenylephrine and the NKCC1 inhibitor bumetanide, suggesting that impaired aortic contractility may contribute to the hypotension of SPAK-null mice. In summary, SPAK-null mice have defects of NCC in the kidneys and NKCC1 in the blood vessels, leading to hypotension through renal salt wasting and vasodilation. SPAK may be a promising target for antihypertensive therapy.
Yang
Sung-Sen
SS
Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
Lo
Yi-Fen
YF
Wu
Chin-Chen
CC
Lin
Shu-Wha
SW
Yeh
Chien-Ju
CJ
Chu
Pauling
P
Sytwu
Huey-Kang
HK
Uchida
Shinichi
S
Sasaki
Sei
S
Lin
Shih-Hua
SH
D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000503:physiopathology*; D001794:Blood Pressure / Q000502:physiology; D004195:Disease Models, Animal; D004232:Diuretics / Q000494:pharmacology; D005260:Female; D005665:Furosemide / Q000494:pharmacology; D053579:Gitelman Syndrome / Q000378:metabolism* / Q000503:physiopathology*; D006852:Hydrochlorothiazide / Q000494:pharmacology; D007022:Hypotension / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D017346:Protein Serine-Threonine Kinases / Q000172:deficiency* / Q000235:genetics; D049992:Sodium Chloride Symporters / Q000378:metabolism; D028021:Sodium-Potassium-Chloride Symporters / Q000378:metabolism; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*
D004232:Diuretics; D049992:Sodium Chloride Symporters; D028021:Sodium-Potassium-Chloride Symporters; D006852:Hydrochlorothiazide; D005665:Furosemide; C486407:Stk39 protein, mouse; C534421:OXSR1 protein, mouse; D017346:Protein Serine-Threonine Kinases
Biochem Biophys Res Commun. 1997 Aug 18;237(2):318-24
9268708
Arch Biochem Biophys. 1998 Jul 15;355(2):233-40
9675032
J Hum Genet. 1999;44(2):116-20
10083736
J Biol Chem. 2003 Dec 26;278(52):52848-56
14563843
Biochem J. 2008 Jan 15;409(2):321-31
18092945
Kidney Int. 2008 Dec;74(11):1403-9
18800028
Am J Physiol. 1995 Dec;269(6 Pt 1):C1496-505
8572179
J Cell Sci. 2008 Mar 1;121(Pt 5):675-84
18270262
Nat Genet. 1996 Jan;12(1):24-30
8528245
Am J Physiol Heart Circ Physiol. 2002 Nov;283(5):H1846-55
12384462
Am J Physiol Heart Circ Physiol. 2007 Oct;293(4):H2039-53
17693546
Biochem Biophys Res Commun. 2010 Mar 19;393(4):844-8
20175999
J Clin Endocrinol Metab. 2005 May;90(5):2500-7
15687331
Endocrinology. 2010 Apr;151(4):1829-36
20181799
Curr Opin Nephrol Hypertens. 2008 Sep;17(5):519-25
18695394
Am J Physiol. 1999 Jun;276(6):C1383-90
10362601
Br J Pharmacol. 2004 Jun;142(3):479-84
15148259
Am J Kidney Dis. 2007 May;49(5):693-700
17472852
Naunyn Schmiedebergs Arch Pharmacol. 2002 Mar;365(3):193-9
11882915
Proc Natl Acad Sci U S A. 2009 Mar 17;106(11):4384-9
19240212
Pflugers Arch. 2004 Oct;449(1):42-55
15293051
Am J Physiol Heart Circ Physiol. 2007 May;292(5):H2100-5
17259435
Oncogene. 2000 Aug 31;19(37):4290-7
10980603
J Cell Sci. 2008 Oct 15;121(Pt 20):3293-304
18843116
J Biol Chem. 2006 Sep 29;281(39):28755-63
16887815
Biochem J. 2005 Oct 1;391(Pt 1):17-24
16083423
Science. 2001 Aug 10;293(5532):1107-12
11498583
Nat Genet. 1996 Jun;13(2):183-8
8640224
Proc Natl Acad Sci U S A. 2009 Jan 6;106(1):226-31
19114657
Kidney Int. 2007 Jan;71(1):74-8
17082757
Am J Physiol Renal Physiol. 2007 Oct;293(4):F1231-7
17652376
J Biol Chem. 2002 Dec 27;277(52):50812-9
12386165
Hypertension. 2003 May;41(5):1131-5
12668585
J Biol Chem. 1997 Jun 27;272(26):16364-73
9195943
Am J Physiol Cell Physiol. 2001 Aug;281(2):C579-84
11443057
Genome Res. 2003 Mar;13(3):476-84
12618378
Ann Saudi Med. 2005 Nov-Dec;25(6):453-8
16438452
Cell Metab. 2007 May;5(5):331-44
17488636
Biochem J. 2006 Jul 1;397(1):223-31
16669787
Am J Physiol Heart Circ Physiol. 2007 May;292(5):H2035-6
17308011
J Biol Chem. 2005 Dec 30;280(52):42685-93
16263722
Hum Mol Genet. 2009 Oct 15;18(20):3978-86
19633012
Scott Med J. 1986 Jan;31(1):43-4
3961473
EMBO Mol Med. 2010 Feb;2(2):63-75
20091762
J Biol Chem. 1998 Oct 30;273(44):29150-5
9786924