BET Bromodomain Involves in Inflammatory Genes Transcription via Regulation of NF-κB Signaling Pathway / 现代生物医学进展

ABSTRACT

Objective:To explore bromodomain and extra-terminal (BET) inhibition in the regulation of vascular endothelial cells activation and early atherosclerosis formation and its potential molecular mechanisms.Methods:1.Human umbilical vein endothelial cells (HUVEC) and mouse heart endothelial cells (MHEC) were isolated,and tumor necrosis factor α (TNFα) was used to activate in flammatory genes transcription in the presence or absence of JQ1,a specific BET inhibitor.The groups are as follows(1)Normal control group;(2) TNFα(25 ng/mL)group;(3) TNFα+JQ 1 group.The gene mRNA and protein expression of inflammatory cytokines were measured by both real-time PCR and flow cytometry (FCM).2.LDL receptor-deficient (LDLR-/-) mice were randomly divided into 2 groupsJQ1 group (n=8,JQlintraperitoneal,50 mg/kg,daily) and control group (n=8,DMSO,daily).After 8 weeks feeding with high cholesterol diet,vascular cell adhesion molecule-1 (VCAM-1) expression in aortic arch was measured by immunohistochemistry.The activity of nuclear factor kappa B (NF-κB) signaling was monitored by 5XκB luciferase reporter assay in HEK293.Results:TNFα dramatically induced the mRNA and protein expression of inflammatory genes and JQ 1 significantly downregulated the induction of them (E-selectin,P-selectin,VCAM-1,IL-8)(P＜0.01).Immunohistochemistry detection indicated that JQ1 significantly downregulated the expression of VCAM-1 in aortic arch induced by 8 weeks high cholesterol diet feeding comparing to control group.In addition,BET bromodomain inhibition downregulated TNFα upregulated NF-κB transcriptional activity (P＜0.01).Conclusions:Our study demonstrated that BET bromodomain was involved in NF-κB mediated inflammatory genes expression;inhibition of BET bromodomain suppressed vascular endothelial activation in vitro,and attenuated early atherogenesis in vivo.