摘要
目的 探讨SOCS1和SOCS3低甲基化对川崎病Th1/Th2细胞失衡的影响.方法 急性期川崎病患儿36例,健康同年龄对照组16名.酶联免疫吸附试验（ELISA）检测血浆白细胞介素（IL）-6蛋白浓度;实时荧光定量聚合酶链反应（PCR）检测CD4＋T细胞SOCS1、SOCS3、T-bet、干扰素（IFN）-γ、GATA3、IL-4基因mRNA表达;流式细胞术检测外周血Th1/Th2细胞比例和CD4＋T细胞磷酸化STAT3（pSTAT3）蛋白平均荧光强度（MFI）;甲基化特异性定量PCR（MethySYBR PCR）检测CD4＋T细胞SOCSl基因外显子2、SOCS3基因5＇端非翻译区（5＇-UTR）3个可能的STAT3结合位点CpG岛甲基化水平.采用t检验进行统计分析.结果 ①急性期川崎病患儿血浆IL-6浓度[分别为（51.8±16.3）pg/ml和（8.6±2.0）pg/ml]、CD4＋T细胞pSTAT3 MH水平[分别为（52±14）和（10±4）]显著上调（P＜0.05）.其中川崎病合并冠状动脉损伤组（川崎病-CAL＋）IL-6和pSTAT3 MFI水平均明显高于无冠状动脉损伤组[IL-6为（87.2±27.4）pg/ml与（36.2±12.8）pg/ml,P＜0.05;pSTAT3 MFI为（75±15）和（42±11）,P＜0.05].②急性期川崎病患儿Th1、Th2细胞比例及相关因子（T-bet、IFN-γ、GATA3和IL-4）表达明显增高（P＜0.05）,Th1/Th2比值低于健康对照组（P＜0.05）.其中川崎病-CAL＋组Th1、Th2细胞比例及相关因子表达水平高于川崎病-GAL-组（P＜0.05）,而Th1/Th2比值则略低于后者（P＜0.05）.③急性期川崎病患儿CD4＋T细胞SOCS1和SOCS3 mRNA水平显著高于同年龄对照组（P＜0.05）,其中川崎病-CAL＋组 SOCS1和SOCS3 mRNA表达低于川崎病-CAL-组（P＜0.05）;健康对照组SOCS1基因外显子2、SOCS3基因5＇-UTR区第3个STAT3结合位点的CpG岛完全去甲基化,急性期川崎病患儿呈低甲基化状态（P＜0.05）,其中川崎病-CAL＋组去甲基化水平明显低于川崎病-CAL组（P＜0.05）;各组SOCS3基因5＇-UTR区第1、2个STAT3结合位点CpG岛均处于完全去甲基化状态（P＞0.05）.结论 SOCS1和SOCS3基因低甲基化所致表达相对不足可能是川崎病Th1/Th2细胞失衡的因素之一.
Objective To investigate the effect of SOCS1 and SOCS3 hypomethylation on homeostasis of Th1/Th2 in Kawasaki disease（KD）. Methods Thirty-six children with KD and sixteen age-matched healthy children consented to participate in this study. Protein concentration of IL-6 in plasma was measured by ELISA. Transcriptional levels of SOCS1, SOCS3, T-bet, IFN-γ, GATA3 and IL-4 were assessed by realtime PCR. The proportion of Th1 and Th2 cells, and mean fluorescence intensity（MFI）for phosphorylated STAT3（pSTAT3）protein in CD4＋ T cells was analyzed by flow cytometry. A quantitative methylation specific PCR based on SYBR Green was used to evaluate methylation status of CpG islands in SOCSl exon2, and three potential binding sites for STAT3 in 5＇-untraslated region（5＇-UTR）of SOCS3 in CD4＋T cells. Comparisons between groups were performed with t-test. Results ①Compared with healthy volunteers, plasma IL-6 concentration[（51.8±16.3）pg/ml vs（8.6±2.0）pg/ml, respectively]and MFI for pSTAT3[（52±14）vs（10±4）, respectively]in CD4＋ T cells were elevated significantly during acute phase of KD（P〈0.05）, and the two items in KD patients with coronary artery lesion（KD-CAL＋）were found to be higher than those in KD patients without coronary artery lesion（KD-CAL-）[IL-6：（87.2±27.4）pg/ml vs（36.2±12.8）pg/ml, P〈0.05; pSTAT3 MFI：（75±15）vs（42±11）, P〈0.05]. ② The proportions of Th1 and Th2 cells and transcription levels of Th-associating factors（T-bet, IFN-γ, GATA3 and IL-4）in CD4＋ T cells increased significantly in acute KD（P〈0.05）, while the rate of Thl div Th2 in KD patients was found to be lower than that in normal controls（P〈0.05）. In addition, the proportions of Th1 and Th2 cells and expressions levels of Th-associating factors in KD-CAL＋ group were higher than those in KD-CAL-group, as well as the rate of Thl div Th2 cells in KD -CAL＋ group were lower than that in KD-CAL- group（P〈0.05）. ③ The mRNA levels of SOCSl and SOCS3 in CD4＋ T cells increased significantly during acute phase of KD（P〈0.05）, while the two items in KDCAL＋ group were lower than those in KD-CAL- group（P〈0.05）. Furthermore, CpG islands in SOCSl exon2 and the third potential binding site for STAT3 in SOCS3 5＇-UTR were hypomethylated in acute KD, while those in healthy volunteers were fully demethylated（P〈0.05）. Demethylation levels of the two items mentioned above in the KD-CAL＋ group were lower than those in the KD-CAL-group（P〈0.05）. CpG islands in the other two binding sites for STAT3 in SOCS3 5＇-UTR were fully demethylated among all the groups（P〉0.05）.Conclusion Relative insufficiency of SOCS1 and SOCS3 expression caused by hypomethylation may be one contributing factor for the imbalance of Th1/Th2 in KD.
出处
《中华风湿病学杂志》
CAS
CSCD
北大核心
2010年第11期732-737,共6页
Chinese Journal of Rheumatology
基金
国家自然科学基金（30973241）
深圳市科学技术项月（200902103,201002114）
