miRNA转录后调控对PXR-OATP1B1表达的影响及其与lncRNA相互作用的分子学机制研究

MiRNA is an important micromolecule family related to gene regulation, PXR can effect the genetic transcription of OATPlBl as a key regulator. Therefore, it’s widely concerned whether miRNA can regulate PXR-OATPlBl pathway based on post-transcriptional control. It was found that the different expression levels of miR-148a in human plasma were closely related to pharmacokinetic characteristics of fluvastatin transported by OATPlBl, but it is remained unknown that whether this phenomenon have something to do with Effect of miRNA on PXR regulating the Expression of OATP1B1. It has been reported that miRNA inhibits the translation of PXR 3'UTR significantly by binding to PXR 3'UTR region and affect the activities of metabolic enzyme subsequently. By our reporter gene assay, it was shown that the inhibition of PXR protein expression was based on the post-transcriptional control of miR-148a.However, it was unknown that how berberine influencing the regulation of 3’UTR region which was worth studying. Thus, our project aims at thoroughly studying the relationship between berberine and miRNA on the post-transcriptional control of PXR by modern molecular biology technology. To explore the molecular mechanisms of miRNA effecting on PXR/OATP1B1 based on post-transcriptional control and molecular mechanisms interacting with lncRNA so as to carve out new ways to study the rule of drugs transported by OATP1B1.

miRNA是基因调控的重要小分子家族，PXR为OATPlBl基因转录的关键因子，因此miRNA转录后调控对PXR-OATPlBl是否产生影响备受关注。我们发现人体血浆miR-148a不同表达与OATP1B1转运氟伐他汀药动学变化密切关联，该现象是否为miRNA调控PXR进而影响OATP1B1所致尚属未知。文献报道miRNA与PXR 3’UTR区结合导致转录后调控；我们实验显示miR-148a转录后调控抑制PXR蛋白表达，这与小檗碱结合3’UTR区上调表达不同确应研究其原由。资料显示lncRNA特异吸附miRNA影响其功能，提示lncRNA对miRNA转录后调控PXR是否起作用值得关注。故而借助分子生物学技术，研究小檗碱与miRNA调控PXR作用部位与效应的关联，探究miRNA转录后调控PXR/OATP1B1及与lncRNA相互作用的机制，可为阐明OATP1B1转运药物的规律增添新内容。

miRNA是基因调控的重要小分子家族，PXR为OATP1B1基因转录的关键因子，因此miRNA转录后调控对PXR-OATP1B1是否产生影响备受关注。我们发现人体血浆miR-148a不同表达与OATP1B1转运氟伐他汀药动学变化密切关联，该现象是否为miRNA调控PXR进而影响OATP1B1所致尚属未知。文献报道miRNA与PXR 3’UTR区结合导致转录后调控；我们实验显示miR-148a转录后调控抑制PXR蛋白表达，这与小檗碱结合3’UTR区上调表达不同确应研究其原由。资料显示lncRNA特异吸附miRNA影响其功能，提示lncRNA对miRNA转录后调控PXR是否起作用值得关注。故而借助分子生物学技术，研究小檗碱与miRNA调控PXR作用部位与效应的关联，探究miRNA转录后调控PXR/OATP1B1及与lncRNA相互作用的机制。瞬时共转染pcDNA3.1-HOTAIR或HOTAIR Smart Silence和pGL/OATP1B1-WT报告基因后，荧光素酶活性上调100%或下调54.3%，进一步确定，LncRNA HOTAIR可阻遏miR-206/miR-613在OATP1B1 3'-UTR结合位点上转录后调控 OATP1B1 的蛋白表达。此外，我们在PXR沉默的HepG2细胞模型发现，与mimic control相比，miR-148a/192对OATP1B1 mRNA的表达明显改变，提示miR-148a/192作用于OATP1B1可能由PXR介导。我们还发现小檗碱和小檗红碱呈浓度依赖性的增加OATP1B1 mRNA 和蛋白的表达。在AhR、PXR-CYP450/RXRα-OATP1B1 调控通路上，小檗碱和小檗红碱能够促进 AhR、PXR、FXR、LXRα 和 RXRα 的核易位并激活，显著提高他汀类药的代谢和转运能力，这为小檗碱与他汀类药物正确的联合应用于调血脂治疗提供更多的实验依据；亦为AhR、PXR、RXRα-CYP450/OATP1B1的调控机制增添新的内容。