Expression and clinical significance of interleukin-2/Janus kinase 3/signal transduction and transcriptional activator 5 in peripheral blood of patients with ankylosing spondylitis / 中华风湿病学杂志

ABSTRACT

Objective:To detect the expression of interleukin 2 (IL-2)/Janus kinase 3/signal transduction and transcriptional activator 5 (JAK3/STAT5) signaling pathway in peripheral blood of patients with ankylosing spondylitis (AS) and explore its mechanism in the development and progression of AS.Methods:Clinical data, peripheral blood and laboratory tests of 30 patients with active AS (ASA), 30 patients with stable AS (ASS) and 50 healthy subjects (HC) were collected. The mRNA expression levels of JAK3, signal transduction and transcription activator 5a (STAT5a) and signal transduction and transcription activator 5b (STAT5b) were detected by quantitative real-time-polymerase chain reaction (RT-qPCR). The expression levels of JAK3, STAT5a and STAT5b proteins and phosphorylated proteins were detected by Western-blot. Plasma IL-2 concentration was determined by enzyme-linked immunosorbent assay (ELISA). Two independent samples t-test or one-way analysis of variance were used for measurement data consistent with normal distribution, LSD- t test was used for pairwise comparison between the three groups, Mann-Whitney U test or Kruskal-Wallis H test was used for non-normal distribution, χ2 test was used for correlation analysis of categorical variables. Spearman correlation analysis was used for correlation analysis between variables, and receiver operating characteristic (ROC) curve was used to evaluate the value of JAK3, STAT5a and STAT5b mRNA expression levels in monitoring AS activity. Results:① The mRNA expression levels of JAK3, STAT5a and STAT5b were significantly different among the three groups ( F=65.98, P<0.001; F=21.15, P<0.001; F=13.67, P<0.001). JAK3 mRNA expression in ASA group (2.5±0.9) was significantly higher than that in ASS group (1.1±0.4) and healthy subjects (1.0±0.5), the difference was statistically significant (both P<0.001). The mRNA expression level of STAT5a in ASA group (1.4±0.3) was significantly higher than that in ASS group (0.9±0.3) and healthy subjects group (1.0±0.3), the difference was statistically significant (both P<0.001). STAT5b mRNA expression level in ASA group (1.5±0.6) was significantly higher than that in ASS group (1.0±0.4) and healthy subjects (1.0±0.4), the difference was statistically significant (both P<0.001). The expression level of JAK3 mRNA in HLA-B27 positive group (1.9±1.0) was higher than that in HLA-B27 negative group (1.4±0.6), and the difference was statistically significant ( t=-2.22, P=0.032). The phosphorylation levels of JAK3, STAT5a and STAT5b showed statistically significant differences among the three groups ( F=91.56, P<0.001; F=25.15, P< 0.001; F=178.59, P<0.001). The phosphorylation level of JAK3 protein in ASA group (1.04±0.08) was significantly higher than that in ASS group (0.568±0.019) and healthy subjects (0.536±0.064), the difference was statistically significant (both P<0.001). The phosphorylation level of STAT5a protein in ASA group (1.166±0.096) was significantly higher than that in ASS group (0.923±0.018) and healthy subjects (0.911±0.017), the difference was statistically significant (both P<0.001). The phosphorylation level of STAT5b protein in ASA group (0.81±0.05) was significantly higher than that in ASS group (0.21±0.03) and healthy subjects (0.24± 0.07), the difference was statistically significant (both P<0.001). The difference of plasma IL-2 concentration among the three groups was statistically significant ( F=3.32, P=0.040). The IL-2 concentration in the ASA group [(110±40) pg/ml] was significantly higher than that in the ASS group [(89±40) pg/ml] and the healthy group [(88±39) pg/ml], the difference was statistically significant ( P=0.044, P=0.016). ② Spearman correlation analysis showed that STAT5a mRNA expression level was positively correlated with platelets in AS patients ( r=0.353, P=0.006). JAK3 mRNA expression level in ASA group was positively correlated with IL-2 concentration ( r=0.766, P<0.001), and negatively correlated with estimated glomerular filtration rate ( r=-0.485, P=0.007). STAT5a mRNA expression level was positively correlated with erythrocyte sedimentation rate ( r= 0.680, P<0.001), and STAT5b mRNA expression level was positively correlated with hypersensitive C-reactive protein (CRP) ( r=0.823, P<0.001). ③ The ROC curve showed that JAK3 mRNA expression level predicted the area under ROC curve (AUC) of ASA with a 95% CI of 0.920 (0.853, 0.987), sensitivity and specificity of 86.7% and 90.0%, respectively. STAT5a mRNA expression level predicted the AUC 95% CI of ASA was 0.874 (0.787, 0.961), and the sensitivity and specificity were 96.7% and 66.7%, respectively. STAT5b mRNA expression level predicted the AUC 95% CI of ASA was 0.749 (0.617, 0.881), and the sensitivity and specificity were 73.3% and 80.0%, respectively. Conclusion:This study suggests that IL-2/JAK3/STAT5 may be involved in the pathogenesis of AS, and JAK3 mRNA can be used as a biological indicator to monitor the activity of AS disease.