title: Irbesartan inhibits human T-lymphocyte activation through downregulation of activator protein-1.
abstract: 1 Irbesartan is a promising antihypertensive drug with beneficial effects on atherosclerotic processes. In the progression of atherosclerosis, human T-lymphocytes play an important role, but it is not yet known how irbesartan modulates human T-lymphocytes activation. To gain insight into the mechanisms by which irbesartan acts, we investigated its effects on human T-lymphocytes. 2 Primary human T-lymphocytes were isolated from whole blood. Cytokines were determined by ELISA. Activator protein-1 (AP-1) and related protein activities were determined by electrophoretic mobility shift assays, kinase assays, Western blotting and transfection assays. 3 Irbesartan inhibited the production of both tumor necrosis factor-alpha and interferon-gamma by activated T-cells, especially at therapeutic concentrations. Further investigation at the molecular level indicated that the inhibition of activated human T-lymphocytes specifically correlated with the downregulation of AP-1 DNA-binding activity. In the Jurkat T-cell line, irbesartan also inhibited AP-1 transcriptional activity. Finally, we revealed that irbesartan is unique in its ability to inhibit the activation of both c-Jun NH2-terminal protein kinase and p38 MAPK. 4 Our studies show that irbesartan may modulate inflammation-based atherosclerotic diseases through a cell-mediated mechanism involving suppression of human T-lymphocytes activation via downregulation of AP-1 activity.
authors.affiliation: Division of Cardiology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, No 325, Section 2, Cheng-Kung Road, Neihu 114, Taipei, Taiwan, ROC.
authors.forename: Shu-Meng
authors.initials: SM
authors.lastname: Cheng
authors.forename: Shih-Ping
authors.initials: SP
authors.lastname: Yang
authors.forename: Ling-Jun
authors.initials: LJ
authors.lastname: Ho
authors.forename: Tien-Ping
authors.initials: TP
authors.lastname: Tsao
authors.forename: Deh-Ming
authors.initials: DM
authors.lastname: Chang
authors.forename: Jenn-Haung
authors.initials: JH
authors.lastname: Lai
mesh_terms: D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology; D001713:Biphenyl Compounds / Q000494:pharmacology*; D015153:Blotting, Western; D002470:Cell Survival / Q000187:drug effects; D016207:Cytokines / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D024202:Electrophoretic Mobility Shift Assay; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D000077405:Irbesartan; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D019169:Jurkat Cells; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects*; D016328:NF-kappa B / Q000378:metabolism; D009841:Oligonucleotides / Q000235:genetics / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects; D013601:T-Lymphocytes / Q000187:drug effects* / Q000378:metabolism; D013777:Tetrazoles / Q000494:pharmacology*; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D001713:Biphenyl Compounds; D016207:Cytokines; D007375:Interleukin-1; D016328:NF-kappa B; D009841:Oligonucleotides; D013777:Tetrazoles; D018808:Transcription Factor AP-1; D014409:Tumor Necrosis Factor-alpha; D006861:Hydrogen Peroxide; D008156:Luciferases; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D000077405:Irbesartan