title: p65 down-regulates DEPTOR expression in response to LPS stimulation in hepatocytes.
abstract: DEPTOR, a novel endogenous inhibitor of mTOR, plays an important role in regulating the inflammatory response in vascular endothelial cells (ECs) and in mouse skeletal muscle. However, the regulatory mechanism of DEPTOR transcription and its effects on liver inflammation are unknown presently. Here we reported the role of DEPTOR in regulating inflammatory response in mouse liver-derived Hepa1-6 cells and in a mouse model with LPS-induced hepatic inflammation. The results revealed that DEPTOR over-expression in Hepa1-6 liver cells increased the mRNA levels of the pro-inflammatory cytokines interleukin-6 (IL-6) and monocyte chemotactic protein-1 (MCP-1). Contrasting results were observed in Hepa1-6 cells with DEPTOR interference. Treatment Hepa1-6 cells with rapamycin, a specific inhibitor of mTORC1, increased MCP-1 mRNA, but have no significant effect on IL-6 mRNA. DEPTOR expression was down-regulated in Hepa1-6 cells with the treatment of inflammatory stimuli LPS or the over-expression of p65/NF-κB, a key inflammatory transcription factor. NF-κB antagonist (PDTC) and inhibitor (IκBα) blocked the effect of LPS on DEPTOR expression. The study in vivo showed that DEPTOR mRNA and protein were significantly reduced in a mouse model with LPS-induced hepatic inflammation, which was accompanied by a concurrent activation of the mTOR signaling pathway. Further, the transcriptional regulation of DEPTOR was explored, which revealed that DEPTOR promoter activity was significantly down-regulated by NF-κB. The progressive deletions and mutations demonstrated that the NF-κB binding motif situated at -145/-127 region is an essential component required for the DEPTOR promoter activity. Chromatin immunoprecipitation (ChIP) assays determined that p65 can directly interact with the DEPTOR promoter DNA. Those results indicate DEPTOR regulates liver inflammation at least partially via mTORC1 pathway, and is down-regulated by LPS through p65.
authors.affiliation: Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: yuy07@webmail.hzau.edu.cn.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Yu
authors.affiliation: Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Jin
authors.affiliation: Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: An
authors.initials: A
authors.lastname: Yu
authors.affiliation: Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Sun
authors.affiliation: Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Chen
authors.affiliation: Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: yangzq@mail.hzau.edu.cn.
authors.forename: Zaiqing
authors.initials: Z
authors.lastname: Yang
mesh_terms: D000818:Animals; D002460:Cell Line; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006520:Hepatitis, Animal / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D000076222:Mechanistic Target of Rapamycin Complex 1; D051379:Mice; D008810:Mice, Inbred C57BL; D046912:Multiprotein Complexes / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D000072000:NF-KappaB Inhibitor alpha / Q000235:genetics / Q000378:metabolism; D011392:Proline / Q000031:analogs & derivatives / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D020123:Sirolimus / Q000494:pharmacology; D058570:TOR Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D013859:Thiocarbamates / Q000494:pharmacology; D051996:Transcription Factor RelA / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: C491766:Ccl2 protein, rat; D018932:Chemokine CCL2; C000599491:DEPTOR protein, rat; D015850:Interleukin-6; D047908:Intracellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides; D046912:Multiprotein Complexes; D012333:RNA, Messenger; C498145:Rela protein, rat; D013859:Thiocarbamates; D051996:Transcription Factor RelA; C066229:prolinedithiocarbamate; D000072000:NF-KappaB Inhibitor alpha; D011392:Proline; D000076222:Mechanistic Target of Rapamycin Complex 1; D058570:TOR Serine-Threonine Kinases; D020123:Sirolimus
keywords: Inflammation; NF-κB; Promoter; Transcription; mTOR