Dataset Information
Klotho depletion contributes to increased inflammation in kidney of the db/db mouse model of diabetes via RelA (serine)536 phosphorylation.
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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.Research design and 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)-?B activation was assessed by treating human embryonic kidney (HEK) 293 and HK-2 cells with tumor necrosis factor (TNF)-? in the presence or absence of Klotho, followed by immunoblot analysis to evaluate inhibitor of ?B (I?B)? degradation, I?B 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-?B activation and subsequent production of inflammatory cytokines in response to TNF-? stimulation. Klotho specifically inhibited RelA Ser(536) phosphorylation as well as promoter DNA binding of this phosphorylated form of RelA without affecting IKK-mediated I?B? 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-?B-linked inflammatory proteins via a mechanism that involves phosphorylation of Ser(536) in the transactivation domain of RelA.
SUBMITTER: Zhao Y
PROVIDER: S-EPMC3121423 | biostudies-literature | 2011 Jul
REPOSITORIES: biostudies-literature
Publications
Klotho depletion contributes to increased inflammation in kidney of the db/db mouse model of diabetes via RelA (serine)536 phosphorylation.
Diabetes 20110518 7
<h4>Objective</h4>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.<h4>Research design and methods</h4>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 ex ...[more]
