The expression level and value of miR-21,miR-19a and JAK/STAT pathway in peripheral monocytes of juvenile idiopathic arthritis / 中华风湿病学杂志

ABSTRACT

Objective To explore the expression of miR-21 and miR-19a in juvenile idiopathic arthritis (JIA) and the relationship among the key target genes (SOCS3,STAT3) in JAK/STAT pathways.Methods The venous blood from 33 cases of active JIA in Guangzhou Women and Children Medical Center were collected.All cases were divided into two groupsthe systemic group (n=20),polyarthritis group (n=13).Twenty subjects were used as the normal control group.Peripheral blood mononuclear cells (PBMCs) were extracted and separated with Ficoll.miRNA was extracted and purified and real-time quantitative polymerase chain reaction (RT-PCR) was used to obtain cDNA.Target genes of miRNA were detected through Targetscan and RNA22.U6 was used for reference of miR-19a,miR-21 and β-actin were used for STAT3,SOCS3,IL-6,TNF-α mRNA.All the expression were detected by fluorescence quantitative PCR among the groups and calculated the result in standardized 2-ΔΔCT value,non-parametric test was used to test the differences.Results The expression of miR-21 were significantly reduced in the case group than the control group (Z=2.11,P=0.036),in which miR-21 was 7(7-8.5) times reduced than the SJIA group,6.49 (6-7) times than the pJIA group,the difference was statistically significant (Z=2.615,P=0.014 9;Z=2.654,P=0.0291).But no significant difference of miR-21 expression could be found between the SJIA and PJIA groups (Z=0.221,P =0.827 1).The expression of miR-19a was significantly reduced in the case group than the control group (Z=2.41,P=0.014),in which miR-19a was 11.3 (10-12.1) times to the SJIA group,12.2 (12-13.5) times to the pJIA group,the difference was statistically significant (Z=2.334,P=0.015 7;Z=2.414,P=0.026 6).But no significant difference could be detected in the miR-21 expression between the SJIA and the PJIA groups (Z=0.538,P=0.596).Software estimated that STAT3,SOCS3,TNF-α were the target genes of miR-21 and miR-19a in the JAK/STAT pathways respectively.Fluorescence quantitative PCR had shown that mRNA expression of STAT3 [6.24(2.81,7.54) and 3.97(1.81,5.75),P=0.001,0.008],TNF-α [3.03(2.07,3.80) and 3.42(2.46,4.68),P=0.002,0.001],IL-6[4.75(3.59,6.32) and 3.52(2.31,7.51),P=0.006,0.036],SOCS3[2.54(1.77,4.00) and 3.57(1.95,3.83),P=0.003,0.001] was higher in the case Group (SJIA group,the PJIA group) than the control group;STAT3 mRNA expression was negatively correlated with the miR-21 (r=-0.585 4,P=0.006 7;r=-0.613 4,P=0.044 7) and there was statistically significant difference.TNF-α,SOCS3 mRNA expression in the case group (SJIA group,PJIA group) was negatively correlated with the miR-19a.TNF-α (r=-0.664 2,P=0.001 4),SOCS3 (r=-0.790 3,P=0.000 1) of the SJIA group,was higher than those of the PJIA group TNF-α (r=-0.626 1,P=0.039 3),SOCS3 (r=-0.8824,P=0.003),the difference was significant.Conclusion The expression of miR-21,miR-19a in PBMC in the JIA patients are lower than the control group.The high expression of the target genes,miR-21,miR-19a of STAT3,SOCS3,TNF-α suggest that these genes might associate with,activating of JAK/STAT pathway.