RESUMO
Objective:To explore the expression level of interleukin-1 receptor-associated kinase-1 (IRAK1) in the peripheral blood of rheumatoid arthritis (RA) patients and analyze its relevance between disease activity and CD4 + T cell subsets. Methods:① The concentration of IRAK1 in the peripheral blood of 77 RA patients and 24 healthy controls were detected by enzyme linked immunosorbent assay (ELISA). ② The demo-graphic and clinical data of the RA group including disease activity score with 28 joints (DAS28), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), CD4 + T cell subsets in peripheral blood. ③Independent sample t test or Mann-Whitney U test were used to compare the differences between the two groups. Spearman rank correlation test and multiple linear regression were used to analyze the correlation between IRAK1 expression level and clinical data. Results:① The IRAK1 level of the peripheral blood of RA patients was significantly higher than in the normal controls ( P<0.001). ② Compared to normal controls, the peripheral blood of the RA group, the absolute numbers and proportion of regulatory T (Treg) cells were decreased ( P<0.001), the absolute numbers and proportion of helper T (Th) 17 and the ratio of Th17/Treg were increased. Moreover, the ratio of Th17/Treg was also increased. ③ With the increase of disease activity in RA patients, the expression of IRAK1 also increased. The expression of IRAK1 in the peripheral blood of RA group was positively correlated with ESR, number of joints involved and DAS28, and had statistically significant difference between the two groups ( r=0.23, P<0.05; r=0.24, P<0.05; r=0.27, P<0.05). Meanwhile, it was sign-ificantly negatively correlated with the percentage of Treg ( r=-0.27, P<0.05), and was significantly positively correlated with the ratio of Th17/Treg ( r=0.23, P<0.05) . However, there was no significant correlation with the ratio of Th1/Th2( P>0.05). Furthermore, multiple stepwise regression analysis showed that the expression of IRAK1 in the peripheral blood of RA group was positively correlated with ESR and the number of joints involved ( β=0.34, P=0.019; β=0.27, P=0.004), and it was inversely correlated with percentage of Treg ( β=-0.23, P=0.047, R2=0.219). Conclusion:IRAK1 expression in the peripheral blood of RA patients is up-regulated and correlated with disease activity. The decrease of Treg and the imbalance of Th17/Treg caused by high expression of IRAK1 may be one of the main factors for the occurrence and development of RA. Interfering the expression of IRAK1 may be a potential new target for RA treatment.
RESUMO
Objective:To explore the effect and mechanism of different concentrations of metformin on bleomycin (BLM)-induced systemic sclerosis (SSc) mice model.Methods:C57BL/6 mice were divided into the normal group, the model group, the high, the medium and the low metformin (MET) treatment groups randomly. All mice were sacrificed after BLM and metformin treatment for 4 weeks. Local skin was exminedby histopathological staining method to measure the thickness of dermis and collagen, and immunohistochemistry and real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) were used to detect the protein and mRNA levels of Interleukin (IL)-17, forkhead box P3 (Foxp3) and α-smooth muscle actin (α-SMA). Flow cytometry was used to detect the percentage of effector T cell (Teff) and regulatory cells (Treg) in splenic mononuclear cells. The data such as dermal collagen thickness, α-SMA, IL-17, Foxp3, Teff and Treg levels were statistically analyzed by one-way analysis of variance. The data such as dermal collagen thickness, α-SMA, IL-17, Foxp3, Teff and Treg levels were analyzed by one-way analysis of variance, and least significant difference (LSD)- t or Kruskal-Wallis test was used for comparison between groups. Results:Compared with the normal group, remarkable fibrotic lesions appeared in the skin of mice in the model group, and the levels of T-helper cells (Th)1, Th2, Th17, and T follicular helper cells (Tfh) cells were increased, accompanied by a significant decrease in the level of Treg cells. After high-dose metformin treatment, the dermal thickness [(131±25) μm], collagen thickness [(119±18) μm], and α-SMA [(3.0±0.5)/HPH] were significantly reduced( F=14.390, P<0.01; F=40.245, P<0.01; F=44.626, P<0.01). Th1[(27.00±6.68)%], Th17[(0.56±0.20)%], Tfh[(6.4±1.6)%] cells ware significantlyreduced ( F=32.390, P<0.01; F=16.083, P<0.01; F=16.546, P<0.01), and Treg[(11.23±1.52)%] cells were significantly increased ( F=10.171, P<0.01). Conclusion:Metformin can effectively reverse the local skin changesin BLM-induced SSc mouse model, and show immune regulation and anti-fibrosis effects by restoring the Teff/Treg balance.