SIRT1 inhibits IL-1β mRNA transcription in lipopotysaccharide tolerant THP-1 cells / 中华流行病学杂志

ABSTRACT

Objective To explore the role of silent information regulation 2 homolog 1 (SIRTl) in the regulation of IL-lβ mRNA transcription in lipopolysaccharide(LPS) tolerant THP-1 cells. Methods THP-1 human promonocyte model of endotoxin tolerance that simulates the sepsis leukocyte phenotype was used. Chromatin immunoprecipitation assay (ChIP) and real-timePCR were applied to quantify the binding of SIRTl and histone H3 lys9/H4 lysl6 acetylation to IL-1β promoter. IL-1β mRNA transcription was studied after knocking down the SIRTl. Results Thebinding of SIRTl to IL-1β promoter increased about 5 times in tolerant THP-1 cells (P<0.05) , which was accompanied by the low level of histone H3 lys9/H4 lysl6 acetylation (P<0.05, compared with normal cells). Knocking-down of SIRTl increased the transcription of IL-1β mRNA up to the level of 68% of normal cells (P<0.05) ,which was accompanied by the increase of histone H3 lys9/H4 lysl6 acetylation (P<0.05). However,there was no significant difference of p65 lys310 acetylation between normal and tolerant cells. Conclusion SIRTl inhibited the IL-1 β mRNA transcription in tolerant THP-1 cells but had not related to p65 lys310 acetylation. However, it was related to IL-1 p promoter acetylation.