Schematic diagram of the signalling pathways regulated by NIPA1-SO. Our study has uncovered an athero-protective role of the lncRNA NIPA1-SO, which, by interacting with a single transcription factor, is capable of inhibiting monocyte adhesion and foam cell formation, two fundamental processes in atherosclerosis. The transcription factor FUBP1 negatively regulates NIPA1 expression; this inhibitory effect is increased by the interaction of NIPA1-SO with FUBP1, resulting in lower transcription of NIPA1. A reduction in NIPA1 protein results in increased BMPR2 protein due to a reduction in NIPA1-mediated BMPR2 endocytosis and degradation, leading to higher levels of Smad1/5/8 phosphorylation (pSmad1/5/8), which, through complexation with Smad4, inhibit transcription of the adhesion molecules VCAM1 and ICAM1, reducing monocyte adhesion to endothelial cells. Further, the pSmad1/5/8:Smad4 complex promotes ABCA1 and ABCG1 transcription, both of which promote cholesterol efflux via high-density lipoprotein (HDL) particles, thereby inhibiting foam cell formation. Display omitted •Human atherosclerotic plaques have reduced expression of the long non-coding RNA NIPA1-SO and increased levels of NIPA1.•NIPA1-SO inhibits monocyte adhesion to endothelial cells and decreases cholesterol accumulation.•Increasing the expression of NIPAI-SO or knockout of NIPA1 reduces atherosclerosis in an animal model. Long non-coding RNAs (lncRNAs) are emerging as important players in gene regulation and cardiovascular diseases. However, the roles of lncRNAs in atherosclerosis are poorly understood. In the present study, we found that the levels of NIPA1-SO were decreased while those of NIPA1 were increased in human atherosclerotic plaques. Furthermore, NIPA1-SO negatively regulated NIPA1 expression in human umbilical vein endothelial cells (HUVECs). Mechanistically, NIPA1-SO interacted with the transcription factor FUBP1 and the NIPA1 gene. The effect of NIPA1-SO on NIPA1 protein levels was reversed by the knockdown of FUBP1. NIPA1-SO overexpression increased, whilst NIPA1-SO knockdown decreased BMPR2 levels; these effects were enhanced by the knockdown of NIPA1. The overexpression of NIPA1-SO reduced while NIPA1-SO knockdown increased monocyte adhesion to HUVECs; these effects were diminished by the knockdown of BMPR2. The lentivirus-mediated-overexpression of NIPA1-SO or gene-targeted knockout of NIPA1 in low-density lipoprotein receptor-deficient mice reduced monocyte-endothelium adhesion and atherosclerotic lesion formation. Collectively, these findings revealed a novel anti-atherosclerotic role for the lncRNA NIPA1-SO and highlighted its inhibitory effects on vascular inflammation and intracellular cholesterol accumulation by binding to FUBP1 and consequently repressing NIPA1 expression.