title: Ischemia/reperfusion reduces transcription factor Sp1-mediated cystathionine beta-synthase expression in the kidney.
abstract: Cystathionine beta-synthase (CBS) is a key enzyme that catalyzes the rate-limiting step for homocysteine (Hcy) metabolism via the trans-sulfuration pathway and is also responsible for the production of H(2)S through the desulfhydration reaction. Our recent studies demonstrate that renal ischemia/reperfusion decreased the CBS activity leading to Hcy accumulation and H(2)S reduction in the kidney, which in turn contributed to kidney injury. Both Hcy and H(2)S play important roles in physiological and pathological processes. In this study we investigated the molecular mechanism by which CBS activity was regulated in the kidney. The left kidney of Sprague-Dawley rat was subjected to 45 min of ischemia followed by 6 h of reperfusion. Ischemia/reperfusion caused a significant decrease in CBS mRNA and protein levels in the kidney. As a consequence, there was a marked reduction in the CBS enzyme activity. Transfection of kidney proximal tubular cells with transcription factor (Sp1) small interfering RNA caused a marked reduction in CBS mRNA, indicating a pivotal role for Sp1 in regulating CBS expression in kidney cells. Electrophoretic mobility shift assay and chromatin immunoprecipitation assay detected a lower Sp1 activity in kidneys subjected to ischemia/reperfusion as compared with that in a sham-operated group. ERK-mediated phosphorylation of Sp1 was responsible for a decreased transcriptional activity of Sp1 in the kidney upon ischemia/reperfusion. These results suggest that reduced kidney CBS gene expression during ischemia/reperfusion is mediated via a decrease in Sp1 transcriptional activity. Regulation of CBS-mediated Hcy and H(2)S homeostasis may offer a renal protective effect against ischemia/reperfusion injury.
authors.affiliation: Department of Animal Science, University of Manitoba, St Boniface Hospital Research Centre, Winnipeg, Manitoba R2H 2A6, Canada.
authors.forename: Nan
authors.initials: N
authors.lastname: Wu
authors.forename: Yaw L
authors.initials: YL
authors.lastname: Siow
authors.forename: Karmin
authors.initials: K
authors.lastname: O
mesh_terms: D000818:Animals; D001483:Base Sequence; D003541:Cystathionine beta-Synthase / Q000096:biosynthesis*; D005786:Gene Expression Regulation; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007668:Kidney / Q000201:enzymology* / Q000378:metabolism; D008297:Male; D008954:Models, Biological; D008969:Molecular Sequence Data; D010766:Phosphorylation; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000473:pathology*; D016329:Sp1 Transcription Factor / Q000378:metabolism*
chemical_list: D034741:RNA, Small Interfering; D016329:Sp1 Transcription Factor; D003541:Cystathionine beta-Synthase
references.citation: Arch Biochem Biophys. 1998 Feb 1;350(1):95-103
references.pmid: 9466825
references.citation: Mol Endocrinol. 2008 Jun;22(6):1449-63
references.pmid: 18372343
references.citation: J Biol Chem. 1999 Jan 15;274(3):1207-15
references.pmid: 9880488
references.citation: J Biol Chem. 2001 Feb 16;276(7):4964-71
references.pmid: 11053446
references.citation: Am J Physiol Endocrinol Metab. 2005 May;288(5):E1002-10
references.pmid: 15644462
references.citation: J Biol Chem. 1998 Sep 25;273(39):25179-84
references.pmid: 9737978
references.citation: J Thromb Haemost. 2005 Aug;3(8):1646-54
references.pmid: 16102030
references.citation: Cancer Res. 2007 Jul 1;67(13):6121-9
references.pmid: 17616668
references.citation: J Cell Physiol. 2002 Jul;192(1):81-92
references.pmid: 12115739
references.citation: Arterioscler Thromb Vasc Biol. 2006 May;26(5):1043-50
references.pmid: 16497994
references.citation: J Biol Chem. 2004 Mar 5;279(10):8558-66
references.pmid: 14670973
references.citation: Clin Exp Pharmacol Physiol. 2002 Sep;29(9):852-4
references.pmid: 12165055
references.citation: Nat Protoc. 2006;1(1):179-85
references.pmid: 17406230
references.citation: J Biol Chem. 2001 Nov 23;276(47):43570-9
references.pmid: 11562358
references.citation: Proc Natl Acad Sci U S A. 2007 Sep 25;104(39):15560-5
references.pmid: 17878306
references.citation: Biochem Biophys Res Commun. 2000 Apr 21;270(3):947-52
references.pmid: 10772931
references.citation: Biochem Biophys Res Commun. 2002 May 24;293(5):1485-8
references.pmid: 12054683
references.citation: J Biol Chem. 2002 Sep 20;277(38):34808-14
references.pmid: 12093818
references.citation: Circ Res. 2004 Jan 9;94(1):28-36
references.pmid: 14630727
references.citation: Arterioscler Thromb Vasc Biol. 2009 Feb;29(2):173-9
references.pmid: 18988885
references.citation: J Am Soc Nephrol. 2001 Oct;12(10):2181-2189
references.pmid: 11562419
references.citation: J Biol Chem. 2009 Aug 14;284(33):22457-22466
references.pmid: 19531479
references.citation: EMBO J. 2001 Aug 1;20(15):3910-6
references.pmid: 11483494
references.citation: J Biol Chem. 2002 Nov 8;277(45):42680-5
references.pmid: 12213817
references.citation: Annu Rev Med. 1998;49:31-62
references.pmid: 9509248
references.citation: Am J Nephrol. 2008;28(2):254-64
references.pmid: 17989498
references.citation: Genomics. 1998 Sep 15;52(3):312-24
references.pmid: 9790750
references.citation: Hepatology. 2008 Feb;47(2):659-67
references.pmid: 18098324
references.citation: BMJ. 2002 Nov 23;325(7374):1202
references.pmid: 12446535
references.citation: Kidney Int. 2004 Jul;66(1):303-12
references.pmid: 15200438
references.citation: Mol Cell Biol. 2009 May;29(10):2483-8
references.pmid: 19273606
references.citation: J Inorg Biochem. 2001 Dec 15;87(4):245-51
references.pmid: 11744062
references.citation: J Biol Chem. 1995 Oct 27;270(43):25879-84
references.pmid: 7592774
references.citation: Proc Natl Acad Sci U S A. 2003 May 27;100(11):6801-6
references.pmid: 12743362
references.citation: Biochim Biophys Acta. 2006 Jul;1762(7):656-65
references.pmid: 16837172
references.citation: J Biol Chem. 1996 Jun 21;271(25):14692-7
references.pmid: 8663083
references.citation: Biochemistry. 2004 Nov 23;43(46):14684-95
references.pmid: 15544339
references.citation: Biochem J. 1982 Aug 15;206(2):267-77
references.pmid: 7150244
references.citation: Am J Physiol Renal Physiol. 2009 Jul;297(1):F27-35
references.pmid: 19439522
references.citation: Trends Pharmacol Sci. 2003 Dec;24(12):609-11
references.pmid: 14654297
references.citation: Circ Res. 2004 May 28;94(10):1318-24
references.pmid: 15105297
references.citation: Blood. 2004 Jul 1;104(1):256-62
references.pmid: 15031204
references.citation: J Biol Chem. 2004 Dec 10;279(50):52082-6
references.pmid: 15520012
references.citation: J Biol Chem. 1997 May 23;272(21):13489-95
references.pmid: 9153193
references.citation: J Biol Chem. 2008 Jan 18;283(3):1282-1292
references.pmid: 18024959
references.citation: Biochem J. 2001 Jul 1;357(Pt 1):97-105
references.pmid: 11415440
references.citation: Biochem J. 1997 Nov 15;328 ( Pt 1):287-92
references.pmid: 9359866
references.citation: Mamm Genome. 1996 Oct;7(10):754-7
references.pmid: 8854863
references.citation: J Biol Chem. 2002 Jun 7;277(23):20631-9
references.pmid: 11904305
references.citation: J Biol Chem. 2002 Mar 15;277(11):9598-605
references.pmid: 11779871
references.citation: J Biol Chem. 2006 Feb 10;281(6):3642-50
references.pmid: 16332679
references.citation: Am J Physiol Renal Physiol. 2007 May;292(5):F1354-63
references.pmid: 17264313
references.citation: Am J Physiol Renal Physiol. 2008 Oct;295(4):F912-22
references.pmid: 18701635
references.citation: Kidney Int. 1991 Mar;39(3):476-500
references.pmid: 2062034
references.citation: J Biol Chem. 2003 May 9;278(19):16802-8
references.pmid: 12615917