piperidines and Acute-Phase-Reaction

Levocabastine is a selective topical H1 antagonist, effective in the treatment of seasonal allergic rhinitis and conjunctivitis.. We evaluated the possible effects of levocabastine eye drops on early (EPR) and late phase (LPR) inflammatory changes induced by allergen-specific conjunctival challenge (ASCC). We focused our attention on the possible effect of levocabastine on expression of the intracellular adhesion molecule-1 (ICAM-1) on epithelial cells. Such a phenomenon is likely to play an important role in allergic inflammation.. The study was a double-blind, placebo-controlled, randomized trial, performed in cross-over, outside the pollen season. Ten out-patients suffering from allergic rhinoconjunctivitis due to parietaria judaica (wall parietary) were enrolled. Patients randomly received levocabastine eye drops (0.5 mg/mL) or placebo eyedrops, one drop in the left eye (right eye as control), 30 min before ASCC. Clinical evaluation (hyperaemia, burning-itching, lacrimation and eyelid swelling) and cytological assessment (number of neutrophils, eosinophils and lymphocytes, and ICAM-1 expression on conjunctival epithelium) were evaluated at baseline, 30 min and 6 h after ASCC. In parallel, we evaluated the in vitro effect of levocabastine at concentrations ranging from 2 x 10(-9) M to 2 x 10(-5) M on ICAM-1 expression and shedding by a continuously cultured differentiated epithelial cell line (WK).. Levocabastine reduced symptom scores during EPR (15 min and 30 min, P < 0.002), inflammatory cell infiltration during EPR (P < 0.002 for neutrophils, eosinophils and lymphocytes) and ICAM-1 expression on epithelium both during EPR (P < 0.002) and LPR (P < 0.02). LPR symptom scores and inflammatory cell infiltration were only slightly modified by levocabastine treatment. In vitro levocabastine at 2 x 10(-5) M concentration was able to down-regulate basal ICAM-1 expression, although it exerted no effect on ICAM-1 release by epithelium.. Levocabastine exerts anti-allergic activity, in that it reduces in vivo inflammatory cell infiltration due to ASCC, and also adhesion molecule expression on conjunctival epithelium. The latter phenomenon may be due, at least in part, to a direct effect of levocabastine on epithelial cells.

Topics: Acute-Phase Reaction; Administration, Topical; Adolescent; Adult; Cells, Cultured; Cross-Over Studies; Double-Blind Method; Drug Administration Routes; Epithelium; Eye; Female; Humans; Hypersensitivity, Delayed; Intercellular Adhesion Molecule-1; Male; Middle Aged; Piperidines

Inhibition of intracellular signal transduction is considered to be a therapeutic target for chronic inflammation. The new Janus kinase (JAK)3 inhibitor CP690,550 has shown efficacy in the treatment of rheumatoid arthritis (RA). We investigated the influence of JAK/STAT inhibition using CP690,550 on the induction of acute-phase serum amyloid A (SAA), which is triggered by interleukin 6 (IL-6) stimulation in rheumatoid fibroblast-like synoviocytes (RA-FLS).. IL-6-stimulated gene expression of the acute-phase serum amyloid A genes (A-SAA; encoded by SAA1+SAA2) and SAA4 was analyzed by reverse transcriptase-polymerase chain reaction. The intracellular signaling pathway mediating the effects of CP690,550 on IL-6-stimulated JAK/STAT activation was assessed by measuring the phosphorylation levels using Western blots.. IL-6 trans-signaling induced A-SAA messenger RNA (mRNA) expression in RA-FLS. By contrast IL-6 stimulation did not affect SAA4 mRNA expression, which is expressed constitutively in RA-FLS. IL-6 stimulation elicited rapid phosphorylation of JAK2 and STAT3, which was blunted by CP690,550. CP690,550 abrogated IL-6-mediated A-SAA mRNA expression in RA-FLS. Similarly, CP690,550 inhibited IL-6-mediated A-SAA mRNA expression in human hepatocytes.. Our data indicated that CP690,550 blocked IL-6-induced JAK2/STAT3 activation, as well as the induction of A-SAA. Inhibition of IL-6-mediated proinflammatory signaling pathways by CP690,550 may represent a new antiinflammatory therapeutic strategy for RA and AA amyloidosis.

Topics: Acute-Phase Reaction; Arthritis, Rheumatoid; Cells, Cultured; Enzyme Inhibitors; Humans; Interleukin-6; Janus Kinase 2; Janus Kinase 3; Janus Kinases; Piperidines; Pyrimidines; Pyrroles; RNA, Messenger; Serum Amyloid A Protein; Signal Transduction; STAT3 Transcription Factor; Synovial Membrane

The signal transducer and activator of transcription 3 (STAT3) is an IL-6-inducible transcription factor that mediates the hepatic acute phase response (APR). Using gamma-fibrinogen (FBG) as a model of the APR, we investigated the requirement of an IL-6-inducible complex of STAT3 with cyclin-dependent kinase 9 (CDK9) on gamma-FBG expression in HepG2 hepatocarcinoma cells. IL-6 induces rapid nuclear translocation of Tyr-phosphorylated STAT3 that forms a nuclear complex with CDK9 in nondenaturing co-immunoprecipitation and confocal colocalization assays. To further understand this interaction, we found that CDK9-STAT3 binding is mediated via both STAT NH2-terminal modulatory and COOH-terminal transactivation domains. Both IL-6-inducible gamma-FBG reporter gene and endogenous mRNA expression are significantly decreased after CDK9 inhibition using the potent CDK inhibitor, flavopiridol (FP), or specific CDK9 siRNA. Moreover, chromatin immunoprecipitation (ChIP) experiments revealed an IL-6-inducible STAT3 and CDK9 binding to the proximal gamma-FBG promoter as well as increased loading of RNA Pol II and phospho-Ser2 CTD Pol II on the TATA box and coding regions. Finally, FP specifically and efficiently inhibits association of phospho-Ser2 CTD RNA Pol II on the gamma-FBG promoter, indicating that CDK9 kinase activity mediates IL-6-inducible CTD phosphorylation. Our data indicate that IL-6 induces a STAT3.CDK9 complex mediated by bivalent STAT3 domains and CDK9 kinase activity is necessary for licensing Pol II to enter a transcriptional elongation mode. Therefore, disruption of IL-6 signaling by CDK9 inhibitors could be a potential therapeutic strategy for inflammatory disease.

Topics: Active Transport, Cell Nucleus; Acute-Phase Reaction; Cell Line, Tumor; Cell Nucleus; Cyclin-Dependent Kinase 9; Fibrinogen; Flavonoids; Gene Expression Regulation; Hepatitis; Humans; Interleukin-6; Models, Biological; Multiprotein Complexes; Piperidines; Promoter Regions, Genetic; Protein Binding; Protein Kinase Inhibitors; Protein Structure, Tertiary; RNA Polymerase II; RNA, Small Interfering; STAT3 Transcription Factor; Transcription, Genetic