Exploring the Involvement of NLRP3 and IL-1β in Osteoarthritis of the Hand: Results from a Pilot Study

• Main Authors: Antonella Fioravanti (Author), Sara Tenti (Author), Megan McAllister (Author), Melody Chemaly (Author), Amanda Eakin (Author), Joseph McLaughlin (Author), Anthony J. Bjourson (Author), Elena Frati (Author), Victoria McGilligan (Author), Sara Cheleschi (Author), David S. Gibson (Author)
• Format: Book
• Published: Hindawi Limited, 2019-01-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Hand osteoarthritis (HOA) includes different subsets; a particular and uncommon form is erosive HOA (EHOA). Interleukin- (IL-) 1β plays a crucial role in the pathogenesis of osteoarthritis (OA); it is synthesized as an inactive precursor which requires the intervention of a cytosolic multiprotein complex, named inflammasome, for its activation. The aim of this study was to investigate the involvement of IL-1β and the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome in patients with EHOA and nonerosive HOA (NEHOA) compared to healthy controls. In particular, we evaluated the gene expression of IL-1β and NLRP3, the serum levels of IL-1β, IL-6, IL-17, and tumor necrosis factor- (TNF-) α, and the protein levels of IL-1β and NLRP3. We also assessed the relationships between IL-1β and NLRP3 and clinical, laboratory, and radiological findings. Fifty-four patients with HOA (25 EHOA and 29 NEHOA) and 20 healthy subjects were included in the study. Peripheral blood mononuclear cell (PBMC) gene and protein expressions of IL-1β and NLRP3 were quantified by quantitative real-time PCR and western blot. IL-1β, IL-6, IL-17, and TNF-α serum levels were determined by ELISA. IL-1β gene expression was significantly reduced (p=0.0208) in EHOA compared to healthy controls. NLRP3 protein levels were significantly increased in the NEHOA group versus the control (p=0.0063) and EHOA groups (p=0.0038). IL-1β serum levels were not significantly different across the groups; IL-6, IL-17, and TNF-α were not detectable in any sample. IL-1β concentrations were negatively correlated with the Kellgren-Lawrence score in the whole population (r=−0.446; p=0.0008) and in NEHOA (r=−0.608; p=0.004), while IL-1β gene expression was positively correlated with the number of joint swellings in the EHOA group (r=0.512; p=0.011). Taken together, our results, showing poorly detectable IL-1β concentrations and minimal inflammasome activity in the PBMCs of HOA patients, suggest a low grade of systemic inflammation in HOA. This evidence does not preclude a possible involvement of these factors at the local level.

Item Description

0962-9351
1466-1861
10.1155/2019/2363460