Abstract
Klotho is an anti-aging protein mainly expressed in the kidney. Reduced Klotho expression closely correlates with the development and progression of chronic kidney disease (CKD). Klotho is also a downstream gene of Peroxisome Proliferation-Activated Receptor γ (PPARγ), a major transcription factor whose functions are significantly affected by post-translational modifications including acetylation. However, whether PPARγ acetylation regulates renal Klotho expression and function in CKD is unknown. Here we test whether renal damage and reduced Klotho expression in the adenine CKD mouse model can be attenuated by the pan histone deacetylase (HDAC) inhibitor trichostatin A. This inhibition up-regulated Klotho mainly through an enhancement of PPARγ acetylation, stimulation of PPARγ binding to Klotho promoter, and PPARγ-dependent increase in Klotho transcription, with a substantial control of the regulation occurring via PPARγ acetylations on K240 and K265. Consistently trichostatin A-induced reversal of Klotho loss and renoprotective effects were abrogated in PPARγ knockout mice, supporting that PPARγ is an essential acetylation target for Klotho restoration and renal protection. Intriguingly, the kidneys of adenine-fed CKD mice displayed deregulated HDAC3 up-regulation. Selective HDAC3 inhibition effectively alleviated Klotho loss and kidney injury, whereas the protective effects were largely abolished when Klotho was knocked down by siRNA, suggesting that aberrant HDAC3 and Klotho loss are crucial components involved in the renal damage of mice with CKD. Our study identified an important signaling cascade and key components contributing to the pathogenesis of CKD. Thus, targeting Klotho loss by HDAC3 inhibition has promising therapeutic potential for the reduction of CKD progression.