宿主LncRNAs LNC_002与Linc00152调控肠道病原菌感染炎症反应的分子机制研究

Recent Studies have shown that LncRNAs are closely related to many human diseases. However, the function of LncRNA in regulating intestinal inflammatory response caused by pathogenic bacteria has not been reported. Salmonella typhimurium is a widely distributed bacterial pathogen, which can lead to gastrointestinal diseases in human and animal. Our previous studies found that the expression profiles of LncRNAs changed significantly after HCT116 cells with Salmonella typhimurium infection. The expressions of LNC_002 and Linc00152 were significantly different. Moreover, overexpression of LNC_002 and Linc00152 significantly inhibit the expression of pro-inflammatory factors caused by Salmonella typhimurium infection and enhance the migration or infection of HCT116 cells. Analysis of LNC_002 sequence showed that some miRNAs had the potential ability to bind to it. RIP result showed that Linc00152 may affect the expression of downstream genes by binding with transcription regulator YAP1. Therefore, based on the above research, we applied human intestinal epithelial cells and intestinal Organoid as a model to further study the function and molecular mechanism of LNC_002 and Linc00152 molecules in regulating the host inflammatory response caused by Intestinal pathogens.

LncRNAs与人类多种疾病存在着密切联系，然而LncRNAs如何调控病原菌引起的肠道炎症反应的功能未见报道。 鼠伤寒沙门氏菌是一种分布广泛的细菌病原体，可导致人畜的胃肠道疾病。我们前期研究发现鼠伤寒沙门氏菌感染HCT116细胞后，LncRNAs的表达谱发生了明显变化。其中，LNC_002和 Linc00152的表达差异较为显著。而且，LNC_002与Linc00152过表达后能明显抑制鼠伤寒沙门氏菌以及其它肠道病原菌感染引起的促炎症因子的表达并能促进HCT116细胞的迁移或侵染。对LNC_002的序列分析，发现了miRNA有与之结合的潜能。通过RIP实验，发现Linc00152可能与转录调控因子YAP1结合来影响下游基因的表达。本申请拟在以上研究基础上，以人的肠上皮细胞和肠道类器官为模型，深入研究LNC_002和 Linc00152在调控肠道病原菌感染引起宿主炎症反应的功能和分子机制。

肠道微生物可以通过调控宿主的表观遗传机制，例如调控长链非编码RNA，来参与宿主的多种疾病的发生和发展。然而，微生物诱导长链非编码RNA表达的机制尚不清楚。在本研究中，我们用一种常见的肠道病原菌，鼠伤寒沙门氏菌SL1344，感染了结肠癌细胞并进行了转录组测序。通过对测序结果的分析，我们发现，宿主细胞lncRNAs的表达谱发生了显著的改变。其中，LINC00152的表达明显增加，而且我们发现LINC00152的表达可以被脂多糖LPS调控。LINC00152的过表达能抑制沙门氏菌对宿主细胞的侵染并能抑制炎症反应。通过对临床样本的分析，我们发现LINC00152在CRC样本中的表达要高于癌旁组织。我们的结果也证明了LINC00152过表达能促进肿瘤细胞的迁移和侵袭。与此一致，我们观察到结肠癌组织中革兰氏阴性菌的丰度和LPS的含量显著增加。综上所述，我们的数据说明了，结肠癌组织中富含的革兰氏阴性细菌可能通过调节LINC00152的表达促进肿瘤生长。此外，我们还证明了脂多糖可以通过在LINC00152启动子上引入组蛋白乳酸化以抑制转录抑制因子YY1结合的方式，来促进LINC00152的表达。我们的结果为肠道菌群如何影响人类疾病的宿主表观遗传学提供了新的见解。