Mechanism Of The G-protein-coupled Bile Acid Receptor Gpbar1 (TGR5) Inhibiting Kidney Inflammation

BackgroundKidney inflammation plays an important role in a variety of kidney-related diseases,particular in,chronic renal disease and terminal nephropathy.Therefor,that is great significance to the concern to prevent or delay kidney inflammation ESRD develop during treatment of renal disease.Activation of NF-κB signaling pathway is the central link for macrophages based inflammatory cell infiltration,the generation of pro-inflammatory cytokines and the process of inflammatory factors in renal tissue injury about inflammation in the kidney.However,G-protein coupled receptors TGR5 is a membrane type bile acid receptor,whose main role is to affect a variety of physiological metabolism,especially lipid metabolism.TGR5 can regulate a variety of metabolic syndrome,including insulin resistance,type II diabetes,obesity,dyslipidemia,fatty liver.But a growing number of studies have found that in addition to bile acid receptor can influence metabolism,also with bile acid binding,causing downstream produce a series of biological effects,thus plays an important role in the body immune inflammatory,energy balance and metabolism.The current study found,TGR5 can thus play its role in suppressing inflammation by inhibiting NF-ΚB signaling pathways.But there is no research on TGR5 and reveal the relationship between inflammation of the kidneys.Therefore,we introduced a renal carcinoma cell line HEK293 cells,and TGR5 transfected into the cell,the role of its analysis TGR5 in the kidney inflammation,and to explore the mechanism.ObjectivesTGR5 inhibit inflammation in various tissues.The purpose of this study is to reveal the relationship between TGR5 and kidney inflammation,and explore its mechanism.Methods1、We TNF-α-induced inflammation of the kidneys and P65 in renal carcinoma cell line HEK293 cells.Using Real-Time PCR analysis the expression of several inflammatory cytokines when active or inactive TGR5 receptor.Thus proving after activation TGR5,inflammatory signaling factor expression has received a rejection.2、We transfected with NF-κB luciferase plasmid to renal carcinoma cell line HEK293 cells,treated with TNF-α and P65.Analysis the activation of NF-ΚB signaling pathway when TGR5 active or inactive by luciferase reporter test,thus proving TGR5 can inhibit NF-ΚB signaling pathway..3、In human renal cell carcinoma(HEK293)by TNF-α treatment,the amount of nuclear transfer within the P65 increased significantly,but that is significantly reduced the amount of P65 nuclear transfer after TGR5 is activated.4、Treated with TNF-α in renal cancer cell lines HEK293 cells,extracts nuclear protein.Anlyzing the extent of P65 protein nuclear transfer when TGR5 active or inactive by western blotting.Results.1、In human renal cell carcinoma(HEK293),treatment with TNF-α and P65,some inflammatory factors upregulated,including IL-1a,IL-1β,IP-10,MCP-1.But after when TGR5 is activated,these genes upregulated significantly reduced..2、After transfection NF-κB luciferase plasmid into human renal carcinoma cell line(HEK293),and activat with TNF-α and P65.The luciferase expression increased significantly,But the level of luciferase expression was significantly inhibited after TGR5 is activated.3、In human renal cell carcinoma(HEK293)by TNF-α treatment,phosphorylated IκB-α protein was significantly increased.But after the TGR5 is activated IκB-α protein phosphorylation was reduced.4、Treated with TNF-α in renal cancer cell lines HEK293 cells,the amount of nuclear transfer within the P65 increased significantly,but significantly reduced the amount of P65 nuclear transfer after TGR5 is activated..Conclusions:The bile acid receptor TGR5 after being activated its ligand,inhibit the expression of a variety of inflammation-related signal factors.And,TGR5 can inhibit NB-κB signaling pathway in the kidney cells.Therefore,TGR5 ligands may have anti-inflammatory effects of kidney,kidney inflammation will be used as a potential target for drug therapy.