LncRNA NIPA1-SO Confers Atherosclerotic Protection By Suppressing The Transmembrane Protein NIPA1

Background:In recent years,cardiovascular diseases have become the leading cause of death in urban and rural areas of China,with atherosclerosis being an important cause of acute cardiovascular events.It is important to understand the pathogenesis of atherosclerosis,to control the development of atherosclerosis,and to find new therapeutic targets for atherosclerosis.It has been shown that long non-coding RNAs(lncRNAs)have powerful gene regulatory functions and are important in the development of cardiovascular diseases.However,the specific mechanisms of lncRNA action on atherosclerosis have not been fully elucidated,and we have conducted further studies on this topic.In this article,we investigated the regulatory role of lncRNA NIPA1-SO on the expression levels of transmembrane protein NIPA1,bone morphogenetic protein type Ⅱ receptor(BMPR2)and its effects on the development of atherosclerotic disease.Methods:The levels of NIP A1-SO and NIP A1 in normal human intima tissues and atherosclerotic plaques were detected.Human umbilical vein endothelial cells(HUVECs)were transfected with lentivirus overexpression of NIPA1-SO and NIPA1-SO knocked out by shRNA to detect NIPA1 expression.The interaction of NIPA1-SO with transcription factors FUBP1 and NIPA1 genes was analyzed in HUVECs by RNA purification(ChIRP),RNA immunoprecipitation(RIP),and chromatin immunoprecipitation(ChIP).The adhesion of monocytes to HUVECs was examined after NIPA1-SO overexpression and NIPA1-SO knockout,and the changes of these effects after BMPR2 knockout.In low density lipoprotein receptor deficient(LDLR-/-)mice,lentivirus-mediated overexpression of NIPA1-SO or gene-targeted knockout of NIPA1 was used to detect changes in monocyte endothelial adhesion and the formation of atherosclerotic lesions.Results:Analyses of human arterial tissues showed that the levels of NIPA1-SO were decreased,whilst NIPA1 was increased,in atherosclerotic plaques compared with normal intimal tissues.NIPA1 expression was reduced in human umbilical vein endothelial cells(HUVECs)transfected with a lentivirus to over-express NIPA1-SO,but increased in cells transfected with a shRNA to knock-down NIPA1-SO.Chromatin isolation by RNA purification(ChIRP),RNA immunoprecipitation(RIP),and chromatin immunoprecipitation(ChIP)analyses of HUVECs revealed that NIPA1-SO interacted with the transcription factor FUBP1 and the NIPA1 gene.Further,the effect of NIPA1-SO on NIPA1 protein level was reversed by siRNA-mediated knock-down of FUBP1.Augmented NIPA1-SO expression increased,whilst NIPA1-SO knock-down decreased,BMPR2 levels,and these effects were enhanced by siRNA-mediated knock-down of NIPA1.Over-expression of NIPA1-SO reduced,whilst NIPA1-SO knock-down increased,monocyte adhesion to HUVECs,and these effects were diminished by knock-down of BMPR2.Lentivirus-mediated over-expression of NIPA1-SO or gene-targeted knockout of NIPA1 in low-density lipoprotein receptor-deficient(LDLR-/-)mice fed a high-fat diet(HFD)reduced monocyte-endothelium adhesion and atherosclerotic lesion formation.NIPA1-SO plays a protective role against atherosclerosis,whilst the gene it negatively regulates,NIPA1,promotes atherogenesis.Conclusions:Our findings reveal a novel anti-atherosclerotic role of the lncRNA NIPA1-SO and highlight its inhibitory effects on vascular inflammation and intracellular cholesterol accumulation through binding to FUBP1 and consequently repressing NIPA1 expression.