Τίτλος:
Enhanced activity of NLRP3 inflammasome in peripheral blood cells of patients with active rheumatoid arthritis
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
Introduction: Interleukin-1β (IL-1β) is a major inflammatory cytokine, produced predominantly by innate immune cells through NLRP3-inflammasome activation. Both intrinsic and extrinsic danger signals may activate NLRP3. Genetic variations in NLRP3-inflammasome components have been reported to influence rheumatoid arthritis (RA) susceptibility and severity. We sought to assess the activity of NLRP3-inflammasome in patients with active RA compared to healthy individuals. Method: Intracellular protein expression of NLRP3, ASC, pro- and active caspase-1, pro- and active IL-1β was assessed by immunoblotting both at baseline and upon inflammasome activation. NLRP3 function (IL-1β secretion) was assessed upon priming of TLR2 (Pam(3)CysSK(4), TLR3 (poly(I:C)) or TLR4 (LPS) and ATP sequential treatment. We used caspase inhibitors (casp-1, 3/7 and 8) to assess their contribution to IL-1β maturation. All experiments were performed in whole blood cells. Results: Active RA patients (n = 11) expressed higher basal intracellular levels of NLRP3 (p < 0.008), ASC (p < 0.003), active caspase-1 (p < 0.02) and pro-IL-1β (p < 0.001). Upon priming with TLR4 (LPS) and ATP, RA-derived cell extracts (n = 7) displayed increased expression of NLRP3 (p < 0.01) and active caspase-1 (p < 0.001). Secreted IL-1β in culture supernatants from whole blood cells activated with TLR4 (LPS) or TLR3 agonist (poly(I:C)) plus ATP was higher in RA patients (n = 20) versus controls (n = 18) (p < 0.02 for both). Caspase-1 inhibition significantly reduced IL-1β secretion induced by all stimuli, whereas caspase-8 inhibition affected only TLR4 and TLR3 cell priming. Conclusion: Patients with active RA have increased expression of NLRP3 and NLRP3-mediated IL-1β secretion in whole blood cells upon stimulation via TLR3 and TLR4 but not TLR2. In these patients, IL-1β secretion seems to be predominately driven by caspase-1 and caspase-8. Targeting NLRP3 or downstream caspases may be of benefit in suppressing IL-1β production in RA. © 2015 Choulaki et al.
Συγγραφείς:
Choulaki, C.
Papadaki, G.
Repa, A.
Kampouraki, E.
Kambas, K.
Ritis, K.
Bertsias, G.
Boumpas, D.T.
Sidiropoulos, P.
Περιοδικό:
Arthritis Research and Therapy
Εκδότης:
BioMed Central Ltd.
Λέξεις-κλειδιά:
adenosine triphosphate; caspase 3; caspase 7; caspase 8; cryopyrin; inflammasome; interleukin 1beta; interleukin 1beta converting enzyme; lipopolysaccharide; membrane protein; polyinosinic polycytidylic acid; protein ASC; toll like receptor 2; toll like receptor 3; toll like receptor 4; unclassified drug; carrier protein; cryopyrin; inflammasome; NLRP3 protein, human, adult; Article; blood cell; cell level; clinical article; controlled study; cytokine release; disease activity; drug targeting; enzyme activity; enzyme inhibition; female; human; human cell; immunoblotting; male; pathophysiology; protein analysis; protein expression; protein function; protein induction; protein synthesis inhibition; rheumatoid arthritis; supernatant; blood; enzyme linked immunosorbent assay; immunology; leukocyte; middle aged; rheumatoid arthritis; Western blotting, Arthritis, Rheumatoid; Blotting, Western; Carrier Proteins; Enzyme-Linked Immunosorbent Assay; Female; Humans; Inflammasomes; Leukocytes; Male; Middle Aged; NLR Family, Pyrin Domain-Containing 3 Protein
DOI:
10.1186/s13075-015-0775-2
