Differential expression analysis of absent in melanoma 2-inflammasome pathway associated protein in rheumatoid arthritis and osteoarthritis synovium / 中华风湿病学杂志

ABSTRACT

Objective:To compare the expression levels of absent in melanoma 2 (AIM2) inflammasome pathways in rheumatoid arthritis (RA) and osteoarthritis (OA) synovial specimens.Methods:Synovial tissue samples were collected from 41 RA and 26 OA patients, respectively. Horseradish peroxidase immunohi stochemical staining was used to detect AIM2 inflammasome pathway-related proteins, including AIM2, apoptosis-associated speck-like protein containing a CARD(ASC), caspase-1, and interleukin-1 (IL-1β). A semi-quantitative score (H-score) was performed according to the degree of positiveness. Correlation analysis between H-score results and clinical indicators of erythrocyte sedimentation tate (ESR) and C-reactive protein (CRP) were performed. The H score between RA and OA was analyzed by t test and Spearman correlation analysis were utilized for correlation analysis between H score and ESR and CRP.Results:The H scores of AIM2 protein in RA synovial tissues was (132±7) and (54±8) in OA synovial tissues ( t=7.42, P<0.01). The H scores of ASC protein in RA synovial tissues was (107±9) and (74±6) in OA synovial tissues ( t=2.36, P<0.05). The H scores of caspase-1 protein in RA synovial tissues was (99±5) and (74±10) in OA synovial tissues ( t=2.15, P<0.05). The H scores of IL-1β protein in RA synovial tissues was (118±11) and (76±7) in OA synovial tissues ( t=3.30, P<0.05) . In the correlation analysis, AIM2 was positively correlated with ESR [ r=0.74, P<0.01, 95% CI(0.38, 0.9)], and ASC was positively correlated with ESR [ r=0.5, P<0.05, 95% CI(0.16, 0.74)], IL-1β was positively correlated with ESR [ r=0.62, P<0.05, 95% CI (0.31, 0.81)], and the difference was statistically significant ( P<0.05). At the same time, AIM2 was positively correlated with CRP [ r=0.65, P<0.05, 95% CI(0.25, 0.86)]; ACS was positively correlated with CRP [ r=0.42, P<0.05, 95% CI(0.05, 0.69)]. IL-1β was positively correlated with C-reactive Protein [ r=0.41, P<0.05, 95% CI(0.05, 0.67)] and positively correlated with C-reactive protein, and the difference was statistically significant ( P<0.05). Conclusion:The expression of AIM2 inflammasome pathway-related proteins in RA synovium, including AIM2, ASC, caspase-1, and IL-1β, is higher than that of OA and are positively correlated with disease activity. Activation of AIM2 inflammasome pathway may be associated with the pathogenesis of RA disease activity.