肝组织选择性细胞通讯类基因转录调控网络的构建

Transcriptional regulation of genes involved in liver-selective cell communication

目的探讨肝脏组织选择性基因表达的转录调控机制。方法按照基因功能的差异对组织选择性Affymetrix探针集(共3919条探针)进行聚类,挑选肝组织选择性细胞通讯类(LSCC)基因进行研究。收集各基因上游的500个碱基序列,用3种软件分别预测这些基因的转录因子(TFs)以及转录因子结合位点(TFBS),并进行文献挖掘,最后构建基因转录调控网络。结果获得含23个基因的肝组织选择性细胞通讯类探针集,两种软件预测分别得到50和72个TFs,两者交集有18个相同TFs,得分最高前10条TFBS序列基本上与预测的TFs相对应,文献挖掘结果提示LSCC基因和TFs除具有肝组织的选择性、转录因子的一般性词汇外,还与白蛋白、糖尿病、葡萄糖、脂类、代谢、JNK等显著相关。调控网络显示LSCC基因和TFs具有参与糖、脂代谢调节,结合、转运功能,凝血信号转导,炎症应答等功能,未进入网络的PPP2R1B基因与网络中DUSP10基因部分功能相似。结论LSCC基因和预测的TFs参与肝脏多种重要功能的调控,这些功能整合在复杂的转录调控网络中,转录因子JUN可能是发挥调控作用的重要靶点,推测PPP2R1B也可能参与JUN的调控。

Objective To explore the mechanism of transcription regulation of the liver-selective genes responsible for cell communication. Methods Tissue-selective Affymetrix probe sets （3919 probes in total） were clustered by functional categories. Liver-selective cell communication （LSCC） genes were selected for further analysis. The 500-bp upstream sequences of all the LSCC genes were extracted for predicting the transcription factor binding＇sites （TFBS） of known transcription factors （TFs） using 3 programs; literature mining was then performed for these LSCC genes and TFs, and the transcription regulatory network were constructed. Results The binding sites of 50 and 72 transcription factors were predicted from the upstream sequences of 23 LSCC genes by two programs respectively. Among them, 18 transcription factors were found in common. The top 10 TFBS sequences were basically consistent to the predicted TFs. Literature mining indicated that LSCC genes and TFs were closely related to such terms as albumin, diabetes, glucose, lipid, metabolism, and JNK, in addition to those associated with hepatic tissue and TFs. These observations suggested that LSCC genes and TFs were involved in the regulation of glucose and lipid metabolism, binding and transport, coagulation signal cascades, inflammatory response, etc. PPP2R1B, which was out of the network, showed a partial functional similarity to DUSP10 in the network. Conclusions LSCC genes and the predicted TFs may be involved in the regulation of many important functions of the liver, which are integrated into a sophisticated transcription regulatory network, JUN may be the key target for regulation, and PPP2R1B is presumed to participate in the regulation of JUN.