NAD+-dependent SIRT1 Deacetylase Participates in Epigenetic Reprogramming during Endotoxin Tolerance

• Published in: The Journal of biological chemistry Vol. 286; no. 11; pp. 9856 - 9864
• Main Authors: Liu, Tie Fu, Yoza, Barbara K., El Gazzar, Mohamed, Vachharajani, Vidula T., McCall, Charles E.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 18-03-2011; American Society for Biochemistry and Molecular Biology
• Subjects: Cell Line; Chromatin Immunoprecipitation (ChIP); Chromatin Remodeling; Drug Resistance - drug effects; Drug Resistance - genetics; Endotoxin Tolerance; Endotoxins - pharmacology; Epigenesis, Genetic; Histones - genetics; Histones - metabolism; Humans; Immunology; Inflammation; Innate Immunity; Interleukin-1beta - biosynthesis; Interleukin-1beta - genetics; Lipopolysaccharide (LPS); Macrophage; NAD; NAD - genetics; NAD - metabolism; Promoter Regions, Genetic; Protein Biosynthesis - drug effects; Protein Biosynthesis - genetics; Protein Stability - drug effects; Sepsis - genetics; Sepsis - metabolism; SIRT1; Sirtuin 1 - genetics; Sirtuin 1 - metabolism; Toll-Like Receptor 4 - agonists; Toll-Like Receptor 4 - genetics; Toll-Like Receptor 4 - metabolism; Toll-like Receptors (TLR); Transcription Factor RelA - genetics; Transcription Factor RelA - metabolism; Transcription Factor RelB - genetics; Transcription Factor RelB - metabolism; Tumor Necrosis Factor-alpha - biosynthesis; Tumor Necrosis Factor-alpha - genetics; NAD; Toll-like Receptors (TLR); Chromatin Remodeling; Innate Immunity; Endotoxin Tolerance; Inflammation; SIRT1; Chromatin Immunoprecipitation (ChIP); Lipopolysaccharide (LPS); Macrophage
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M110.196790

Gene-selective epigenetic reprogramming and shifts in cellular bioenergetics develop when Toll-like receptors (TLR) recognize and respond to systemic life-threatening infections. Using a human monocyte cell model of endotoxin tolerance and human leukocytes from acute systemic inflammation with sepsis, we report that energy sensor sirtuin 1 (SIRT1) coordinates the epigenetic and bioenergy shifts. After TLR4 signaling, SIRT1 rapidly accumulated at the promoters of TNF-α and IL-1β, but not IκBα; SIRT1 promoter binding was dependent on its co-factor, NAD+. During this initial process, SIRT1 deacetylated RelA/p65 lysine 310 and nucleosomal histone H4 lysine 16 to promote termination of NFκB-dependent transcription. SIRT1 then remained promoter bound and recruited de novo induced RelB, which directed assembly of the mature transcription repressor complex that generates endotoxin tolerance. SIRT1 also promoted de novo expression of RelB. During sustained endotoxin tolerance, nicotinamide phosphoribosyltransferase (Nampt), the rate-limiting enzyme for endogenous production of NAD+, and SIRT1 expression increased. The elevation of SIRT1 required protein stabilization and enhanced translation. To support the coordination of bioenergetics in human sepsis, we observed elevated NAD+ levels concomitant with SIRT1 and RelB accumulation at the TNF-α promoter of endotoxin tolerant sepsis blood leukocytes. We conclude that TLR4 stimulation and human sepsis activate pathways that couple NAD+ and its sensor SIRT1 with epigenetic reprogramming.