title: Involvement of IRAKs and TRAFs in anti-β₂GPI/β₂GPI-induced tissue factor expression in THP-1 cells.
abstract: Our previous study has shown that Toll-like receptor 4 (TLR4) and its signalling pathway contribute to anti-β₂-glycoprotein I/β₂-glycoprotein I (anti-β₂GPI/β₂GPI)-induced tissue factor (TF) expression in human acute monocytic leukaemia cell line THP-1 and annexin A2 (ANX2) is involved in this pathway. However, its downstream molecules have not been well explored. In this study, we have established that interleukin-1 receptor-associated kinases (IRAKs) and tumour necrosis factor receptor-associated factors (TRAFs) are crucial downstream molecules of anti-β₂GPI/β₂GPI-induced TLR4 signaling pathway in THP-1 cells and explored the potential mechanisms of their self-regulation. Treatment of THP-1 cells with anti-β₂GPI/β₂GPI complex induced IRAKs and TRAFs expression and activation. Anti-β₂GPI/β₂GPI complex firstly induced expression of IRAK4 and IRAK1, then IRAK1 phosphorylation and last IRAK3 upregulation. In addition, anti-β₂GPI/β₂GPI complex simultaneously and acutely enhanced mRNA levels of TRAF6, TRAF4 and zinc finger protein A20 (A20), while chronically increased A20 protein level. Moreover, anti-β₂GPI/β₂GPI complex-induced IRAKs and TRAFs expression and activation were attenuated by knockdown of ANX2 by infection with ANX2-specific RNA interference lentiviruses (LV-RNAi-ANX2) or by treatment with paclitaxel, which inhibits TLR4 as an antagonist of myeloid differentiation protein 2 (MD-2) ligand. Furthermore, both IRAK1/4 inhibitor and a specific proteasome inhibitor MG-132 could attenuate TRAFs expression as well as TF expression induced by anti-β₂GPI/β₂GPI complex. In conclusion, our results indicate that IRAKs and TRAFs play important roles in anti-β₂GPI/β₂GPI-stimulated TLR4/TF signaling pathway in THP-1 cells and contribute to the pathological processes of antiphospholipid syndrome (APS).
authors: Department of Clinical Laboratory and Hematology, Jiangsu University, Zhenjiang, Jiangsu, PR China.
authors: Guoying
authors: G
authors: Xu
authors: Haiping
authors: H
authors: Wen
authors: Hong
authors: H
authors: Zhou
authors: Donglin
authors: D
authors: Guo
authors: Fang
authors: F
authors: Zhou
authors: Dongdong
authors: D
authors: Chen
authors: Hongxiang
authors: H
authors: Xie
authors: Ting
authors: T
authors: Wang
authors: Haibo
authors: H
authors: Wang
mesh_terms: D017306:Annexin A2 / Q000235:genetics / Q000378:metabolism*; D000906:Antibodies / Q000276:immunology / Q000378:metabolism*; D000936:Antigen-Antibody Complex / Q000378:metabolism*; D016736:Antiphospholipid Syndrome / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D006801:Humans; D053592:Interleukin-1 Receptor-Associated Kinases / Q000378:metabolism*; D007976:Leupeptins / Q000494:pharmacology; D009000:Monocytes / Q000378:metabolism* / Q000473:pathology; D017239:Paclitaxel / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D053449:TNF Receptor-Associated Factor 4 / Q000235:genetics / Q000378:metabolism; D048029:TNF Receptor-Associated Factor 6 / Q000235:genetics / Q000378:metabolism; D013925:Thromboplastin / Q000235:genetics / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000378:metabolism; D047988:Tumor Necrosis Factor Receptor-Associated Peptides and Proteins / Q000378:metabolism*; D053482:beta 2-Glycoprotein I / Q000276:immunology
chemical_list: C472822:ANXA2 protein, human; D017306:Annexin A2; D000906:Antibodies; D000936:Antigen-Antibody Complex; D004791:Enzyme Inhibitors; D007976:Leupeptins; D034741:RNA, Small Interfering; C495345:TLR4 protein, human; D053449:TNF Receptor-Associated Factor 4; D048029:TNF Receptor-Associated Factor 6; D051197:Toll-Like Receptor 4; D047988:Tumor Necrosis Factor Receptor-Associated Peptides and Proteins; D053482:beta 2-Glycoprotein I; D013925:Thromboplastin; C507768:IRAK1 protein, human; C507773:IRAK4 protein, human; D053592:Interleukin-1 Receptor-Associated Kinases; D017239:Paclitaxel; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde