Histone deacetylase 3 facilitates TNF a -mediated NF-?B activation through suppressing CTSB induced RIP1 degradation and is required for host defense against bacterial infection

Histone deacetylases (HDACs), as important enzymes regulating acetylation, participate in a series of cell physiological process. Here we reported that HDAC3-deficient macrophages had elevated expression of multiple cathepsins and over-expressed cathepsins such as cathepsin B (CTSB) caused remarkable degradation of receptor (TNFRSF)-interacting serine-threonine kinase 1 (RIP1), which resulted in reduced TNFa mediated NF-?B activation and inflammatory response. Consistent with these findings, mice with macrophage specific knockout of HDAC3 were impaired in inflammatory response and susceptible to pseudomonas aeruginosa infection. Thus, our studies uncovered important roles of HDAC3 in the regulation of cathepsin-mediated lysosomal degradation and RIP1-mediated inflammatory response in macrophages as well as in host defense against bacterial infection. Overall design: Total RNA profiling of gene expression upon knock-out of Hdac3 in RAW264.7 cells