interleukin-8 and baricitinib

To investigate the ex vivo effect of the JAK1/2 inhibitor baricitinib on expression of pro-inflammatory mediators in rheumatoid arthritis (RA) fibroblast like synoviocytes (FLS) stimulated with TNFα, IL-1β and oncostatin M (OSM), and in RA synovial membrane cells (SMCs).. RA and osteoarthritis (OA) SMCs, were isolated from arthroplasty specimens of RA (n=8) and OA (n=8) patients, respectively, using enzymatic digestion followed by cell propagation to obtain RA (n=5) and OA (n=3) FLS. Normal FLS and normal human foreskin fibroblasts (HSF) were purchased from commercial sources. Fibroblasts were stimulated with cytokines with or without baricitinib. RA SMCs were cultured in the presence of baricitinib without stimulation. JAK/STAT activation and levels of mRNA and proteins of the various inflammatory cytokines (IL-6, IL-8, MCP-1, RANTES and IP-10) were determined by qPCR, ELISA and MSD.. Baricitinib inhibited OSM-induced JAK signalling in RA synovial fibroblasts and effectively suppressed subsequent expression of the proinflammatory mediators IL-6, MCP-1 and IP-10. However, baricitinib was not effective in altering levels of spontaneously released TNFα, IL-6 and IL-8 in RA SMC. Although both TNFα and IL-1β signal independently of the JAK/STAT pathway, in HSF, but not in RA FLS, baricitinib significantly inhibited TNFα- and IL-1β-induced MCP-1 and IP-10 protein levels in a dose dependent manner. Furthermore, baricitinib did not inhibit TNFα- and IL-1β-induced expression of IL-6, IL-8 and MCP-1 in RA FLS.. These findings are consistent with known signalling pathways employed by OSM, TNFα and IL-1β, but our data suggest that in HSF, baricitinib may have anti-inflammatory effects via downstream modulation of cytokines and chemokines produced in response to TNFα or IL-1β.

Topics: Anti-Inflammatory Agents; Arthritis, Rheumatoid; Azetidines; Cells, Cultured; Chemokine CCL5; Chemokine CXCL10; Fibroblasts; Humans; Inflammation Mediators; Interleukin-6; Interleukin-8; Janus Kinase Inhibitors; Janus Kinases; Oncostatin M; Purines; Pyrazoles; RNA, Messenger; Signal Transduction; STAT Transcription Factors; Sulfonamides; Synovial Membrane; Synoviocytes; Tumor Necrosis Factor-alpha

Hutchinson-Gilford progeria syndrome (HGPS) is a segmental premature aging disease caused by a mutation in

Topics: 3T3-L1 Cells; Adipocytes; Adipogenesis; Adolescent; Animals; Azetidines; Boron Compounds; Cell Differentiation; Cellular Senescence; Child; Child, Preschool; Cyclin-Dependent Kinase Inhibitor p16; Fatty Acid-Binding Proteins; Female; Fibroblasts; Humans; Interleukin-8; Janus Kinases; Lamin Type A; Male; Mice; PPAR gamma; Progeria; Protein Kinase Inhibitors; Purines; Pyrazoles; Skin; Stem Cells; Sulfonamides

Neutrophils play a crucial role in the pathophysiology of rheumatoid arthritis (RA) via the release of reactive oxygen species (ROS), proteases and cytokines. Orally active Janus kinase (JAK) inhibitors (JAKi), e.g. baricitinib and tofacitinib, have high clinical efficacy in RA but are linked with neutropenia and increased infections. Our aim was to determine the effect of JAK inhibition with baricitinib and tofacitinib on healthy control and RA neutrophil lifespan and function. RA (n = 7) and healthy control (n = 7) neutrophils were treated with baricitinib or tofacitinib for 30 min, prior to incubation in the absence or presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) or interferon (IFN)-γ. JAKi prevented GM-CSF- and IFN-γ-induced apoptosis delay in RA and healthy control neutrophils in a dose-dependent manner. Baricitinib decreased the rate of chemotaxis towards interleukin (IL)-8, but not f-Met-Leu-Phe (fMLP) in RA neutrophils. While healthy control neutrophils incubated with GM-CSF became primed to produce ROS in response to stimulation with fMLP and phorbol-12-myristate-12-acetate (PMA), RA neutrophils produced increased levels of ROS without the need for priming. JAKi prevented ROS release from primed healthy control neutrophils in response to fMLP, but had no effect on ROS production by RA neutrophils. Baricitinib reversed GM-CSF priming of ROS production in response to fMLP in healthy control, but not RA, neutrophils. We conclude that incubation with JAKi prevents chemotaxis of RA neutrophils towards IL-8, but does not prevent the production of ROS or increase the level of apoptosis. This may be due to the in-vivo exposure of RA neutrophils to priming agents other than those that activate JAK/signal transducer and activator of transcription (STAT) signalling.

Topics: Adult; Aged; Aged, 80 and over; Arthritis, Rheumatoid; Azetidines; Case-Control Studies; Cell Movement; Cells, Cultured; Female; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Interleukin-8; Janus Kinases; Male; Middle Aged; Neutrophils; Piperidines; Protein Kinase Inhibitors; Purines; Pyrazoles; Pyrimidines; Pyrroles; Reactive Oxygen Species; Respiratory Burst; Sulfonamides; Tetradecanoylphorbol Acetate; United Kingdom