Abstract: Objective To investigate the interaction between Notch and LPS-LPS-Toll like receptor-4（TLR4）-NF-κB inflammatory signaling pathways in HepG2 cells stimulated with lipopolysaccharide （LPS）.Methods HepG2 cells were cultured with LPS and cell RNAs were extracted,and Notch signaling pathway receptors and their ligands mRNA were detected by quantitative reverse transcription polymerase chain reaction. Western blot analysis was used to detect Notch intracellular domain（NICD） and NF-κB protein expression levels after the γ-secreting enzyme inhibitor （DAPT）,LPS or combination of LPS and DAPT activation,respectively.Results After LPS activation of HepG2 cells,the mRNA level of Notch 1 was 2.25 times（P<0.001）,Jag 1 was 2.47 times（P<0.001）,NOTCH 3 was 0.0700 times （P>0.05）,Jag 2 was 0.420 times （P>0.05）,and Dll 4 was 0.947 times （P<0.01） increased,while NOTCH 2 was 0.857 times（P<0.01）,NOTCH 4 was 0.283 times（P>0.05）,Dll 1 was 0.750 times（P<0.01）,and Dll 3 was 0.393 times（P>0.05） decreased;the expression of NICD and NF-κB proteins in LPS-intervened cells increased obviously,while those in DAPT-intervened cells decreased greatly as compared to those in the control. Conclusion Our findings reveals that the interaction might be going on between Notch and TLR4-NF-κB signaling pathways in HepG2 cells stimulated by LPS. The inhibition of Notch signaling pathway could significantly alleviate the inflammatory response caused by LPS-TLR4.

Key words: HepG2 cells, LPS, Notch, NF-κB, Inflammatory signaling pathways