title: Klotho depletion contributes to increased inflammation in kidney of the db/db mouse model of diabetes via RelA (serine)536 phosphorylation.
abstract: OBJECTIVE
  Klotho is an antiaging hormone present in the kidney that extends the lifespan, regulates kidney function, and modulates cellular responses to oxidative stress. We investigated whether Klotho levels and signaling modulate inflammation in diabetic kidneys.
  
  
  METHODS
  Renal Klotho expression was determined by quantitative real-time PCR and immunoblot analysis. Primary mouse tubular epithelial cells were treated with methylglyoxalated albumin, and Klotho expression and inflammatory cytokines were measured. Nuclear factor (NF)-κB activation was assessed by treating human embryonic kidney (HEK) 293 and HK-2 cells with tumor necrosis factor (TNF)-α in the presence or absence of Klotho, followed by immunoblot analysis to evaluate inhibitor of κB (IκB)α degradation, IκB kinase (IKK) and p38 activation, RelA nuclear translocation, and phosphorylation. A chromatin immunoprecipitation assay was performed to analyze the effects of Klotho signaling on interleukin-8 and monocyte chemoattractant protein-1 promoter recruitment of RelA and RelA serine (Ser)(536).
  
  
  RESULTS
  Renal Klotho mRNA and protein were significantly decreased in db/db mice, and a similar decline was observed in the primary cultures of mouse tubule epithelial cells treated with methylglyoxal-modified albumin. The exogenous addition of soluble Klotho or overexpression of membranous Klotho in tissue culture suppressed NF-κB activation and subsequent production of inflammatory cytokines in response to TNF-α stimulation. Klotho specifically inhibited RelA Ser(536) phosphorylation as well as promoter DNA binding of this phosphorylated form of RelA without affecting IKK-mediated IκBα degradation, total RelA nuclear translocation, and total RelA DNA binding.
  
  
  CONCLUSIONS
  These findings suggest that Klotho serves as an anti-inflammatory modulator, negatively regulating the production of NF-κB-linked inflammatory proteins via a mechanism that involves phosphorylation of Ser(536) in the transactivation domain of RelA.
authors: Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA.
authors: Yanhua
authors: Y
authors: Zhao
authors: Srijita
authors: S
authors: Banerjee
authors: Nilay
authors: N
authors: Dey
authors: Wanda S
authors: WS
authors: LeJeune
authors: Partha S
authors: PS
authors: Sarkar
authors: Reynolds
authors: R
authors: Brobey
authors: Kevin P
authors: KP
authors: Rosenblatt
authors: Ronald G
authors: RG
authors: Tilton
authors: Sanjeev
authors: S
authors: Choudhary
references: Mol Endocrinol. 2007 Sep;21(9):2203-17
references: 17595324
references: J Biol Chem. 2004 Sep 3;279(36):37815-21
references: 15218020
references: Int J Immunopathol Pharmacol. 2010 Jan-Mar;23(1):51-9
references: 20377994
references: Biol Chem. 2008 Mar;389(3):233-41
references: 18177265
references: J Biol Chem. 2002 Apr 19;277(16):13840-7
references: 11839743
references: Proc Natl Acad Sci U S A. 2007 Feb 13;104(7):2331-6
references: 17287345
references: Genes Dev. 2004 Sep 15;18(18):2195-224
references: 15371334
references: FASEB J. 2010 Sep;24(9):3438-50
references: 20466874
references: Biochem Soc Trans. 1997 May;25(2):250S
references: 9191294
references: Mol Cell Biol. 1999 Jul;19(7):4798-805
references: 10373529
references: Mech Ageing Dev. 2005 Dec;126(12):1274-83
references: 16144705
references: Nature. 1997 Nov 6;390(6655):45-51
references: 9363890
references: Exp Eye Res. 2007 May;84(5):905-13
references: 17359975
references: Life Sci. 2000 Jun 8;67(3):291-300
references: 10983873
references: Diabetes. 2009 Dec;58(12):2893-903
references: 19720799
references: Cell Signal. 2004 Sep;16(9):1023-32
references: 15212763
references: Circulation. 2002 Oct 15;106(16):2067-72
references: 12379575
references: Kidney Int. 2008 Sep;74(6):732-9
references: 18547997
references: Annu Rev Cell Biol. 1994;10:405-55
references: 7888182
references: Diabetologia. 2009 Oct;52(10):2169-81
references: 19633828
references: Biochem Biophys Res Commun. 2001 Feb 2;280(4):1015-20
references: 11162628
references: Isr Med Assoc J. 2006 Jan;8(1):36-9
references: 16450750
references: Nephrol Dial Transplant. 2005 Dec;20(12):2636-45
references: 16204278
references: Mol Cell Biol. 2003 Nov;23(21):7780-93
references: 14560022
references: Nature. 1997 Oct 9;389(6651):610-4
references: 9335502
references: J Clin Invest. 2005 Dec;115(12):3494-505
references: 16294222
references: J Clin Invest. 1996 Feb 15;97(4):1111-6
references: 8613535
references: Biochem Biophys Res Commun. 2008 Jun 27;371(2):294-7
references: 18439422
references: J Biol Chem. 2005 Nov 11;280(45):38029-34
references: 16186101
references: Am J Physiol Renal Physiol. 2008 Nov;295(5):F1563-73
references: 18768588
references: Nature. 1990 Apr 12;344(6267):678-82
references: 2157987
references: Pflugers Arch. 2009 May;458(1):39-52
references: 18758808
references: Diabetes. 1996 Jul;45(7):954-9
references: 8666148
references: J Biol Chem. 2001 Jun 1;276(22):18934-40
references: 11259436
references: FASEB J. 2007 Sep;21(11):2642-54
references: 17431096
references: J Am Med Dir Assoc. 2007 Oct;8(8):489-92
references: 17931571
references: Diabetes. 2006 May;55(5):1252-9
references: 16644679
references: J Immunol. 2003 Jun 1;170(11):5630-5
references: 12759443
references: Methods. 2001 Dec;25(4):402-8
references: 11846609
references: J Biol Chem. 2008 Nov 7;283(45):30725-34
references: 18782771
references: J Biol Chem. 2000 Oct 20;275(42):32592-7
references: 10938077
references: Endocrine. 2009 Jun;35(3):341-6
references: 19367378
references: J Anim Sci. 2008 Apr;86(14 Suppl):E94-104
references: 17940160
references: Circ Res. 2006 Sep 29;99(7):723-30
references: 16960103
references: Science. 2005 Sep 16;309(5742):1829-33
references: 16123266
references: Mol Cell Biol. 2002 Aug;22(16):5962-74
references: 12138205
references: J Biomed Biotechnol. 2010;2010:513853
references: 20625492