The splicing-regulatory lncRNA NTRAS sustains vascular integrity

Vascular integrity is essential for organ homeostasis to prevent edema formation and infiltration of inflammatory cells. Long non-coding RNAs (lncRNAs) are important regulators of gene expression and often expressed in a cell type-specific manner. By screening for endothelial-enriched lncRNAs, we identified the undescribed lncRNA NTRAS to control endothelial cell functions. Silencing of NTRAS induces endothelial cell dysfunction in vitro and increases vascular permeability and lethality in mice. Biochemical analysis revealed that NTRAS, through its CA-dinucleotide repeat motif, sequesters the splicing regulator hnRNPL to control alternative splicing of tight junction protein 1 (TJP1; also named zona occludens 1, ZO-1) pre-mRNA. Deletion of the hnRNPL binding motif in mice (Ntras( increment CA/ increment CA)) significantly repressed TJP1 exon 20 usage, favoring expression of the TJP1 alpha- isoform, which augments permeability of the endothelial monolayer. Ntras( increment CA/ increment CA) mice further showed reduced retinal vessel growth and increased vascular permeability and myocarditis. In summary, this study demonstrates that NTRAS is an essential gatekeeper of vascular integrity.

Automated summary

This study identifies a previously unknown lncRNA NTRAS that plays a crucial role in maintaining vascular integrity by controlling endothelial cell functions. Silencing of NTRAS leads to endothelial cell dysfunction and increased vascular permeability and lethality.