SOCS家族基因多态性影响创伤患者预后的分子机制研究

Complications after trauma,such as sepsis and Multiple Organ Dysfucntion Syndrome is the main cause of death in severe trauma patients. There is still no effective early diagnosis methods. Suppressor of Cytokine Signaling (SOCS) gene family plays an important role in the inflammation-related disease, including sepsis. Our research found two polumorphisms out of SOCS gene family, CIS rs414171A/T and SOCS7 rs3748726T/C，which have close relationship with the incidence of complications after trauma through clinical association studies. In order to clarify the functional significance of the two loci, this project will verify their relationship with the expression level of CIS and SOCS7 gene.Furthermore,their effects on activity and methylation levelof CIS gene promoter, and the mRNA stability and miRNA binding will be investigate respectively. A serial of in vitro experiments, such as report gene, EMSA, ChIP will be done to further prove our hypothesis. We will also constructed an early diagnose scoring model for severe trauma patients based on known risk factors, as well as these two loi to verify and evaluate the usage of genetic factors in early diagnosis of complications after trauma using multiple-center sample. This study aimed to clarify the mechanism of the two polymorphic loci affecting the prognosis of patients with severe trauma from the function level, and to investigate their diagnostic value for complications after trauma as well.

创伤并发症(脓毒症、MODS)是创伤患者后期死亡的主要原因，尚缺乏有效预警诊断方法。细胞因子信号抑制物(SOCS)基因家族在脓毒症等疾病的发病机制中起重要作用。课题组前期通过临床关联研究，发现CIS rs414171A/T和SOCS7 rs3748726T/C与严重创伤患者并发症发生率明显相关。为明确这两个位点的功能意义，本课题拟在验证其与在体基因表达水平之间关系的基础上，分别从其影响CIS基因启动子活性、甲基化水平，以及SOCS7 mRNA稳定性和与miRNA结合等方面，利用报告基因、EMSA、ChIP等系列体外实验，系统阐明该两个位点发挥作用的具体机制；进一步在已知创伤并发症危险因素的基础上，复合SOCS家族基因多态性位点，利用多中心样本，建立并评价预警诊断创伤并发症的遗传危险度评分模型。研究旨在从功能水平上明确该两个多态性位点影响严重创伤患者预后的分子机制，并探讨其临床预警诊断价值。

细胞因子信号抑制物（SOCS）基因家族是一类反馈性阻断细胞因子信号转导过程的负性调控因子，在脓毒症等疾病的发病机制中起重要作用。CIS rs414171A/T 和SOCS7 rs3748726T/C 被发现与脓毒症、多器官功能衰竭发病率密切相关，可能为功能性多态性位点。为明确这两个多态性位点的功能意义，我们首先利用多中心大样本，进一步验证了此两位点与创伤并发症发生率之间的相关性，发现在重庆（n=806）和云南（n=281）人群中CIS rs414171A/T 和SOCS7 rs3748726T/C分别与脓毒症的发病率和/或MODS评分升高相关，且在重庆、云南和合并人群中差异显著。报告基因实验提示位于启动子区的CIS rs414171位点显著影响CISH基因启动子活性，进而影响其转录水平。在体实验进一步证实CIS rs414171 影响CIS 基因转录且与外周血IL-10和TNF-α表达水平显著相关。RNAfold软件预测SOCS7 rs3748726可能影响SOCS7mRNA稳定性。报告基因检测显示转染pGL3-SOCS7突变型载体的细胞其荧光强度和荧光素酶mRNA表达水平均显著高于野生型。为建立以基因多态性为基础的创伤并发症预警诊断公式，我们利用Meta分析和文献调研，筛选出77个可能的多态性位点。经过临床关联分析，进一步筛选出17个与创伤后并发症发生密切相关多态性位点，并建立了创伤并发症遗传风险评分公式（WGRS）。发现WGRS>4的高遗传评分创伤感染患者全身反应较重，且sepsis 与 MODS发生风险显著增加3倍以上。