Antisense oligonucleotide-mediated disruption of mRNA localisation inhibits angiogenesis

Abstract mRNA localisation is a critical posttranscriptional mechanism that confers a spatiotemporal dimension to the control of gene expression. Among diverse outcomes, this process can result in compartmentalised protein synthesis and consequently, elicit localised cellular responses. Targeting mRNAs to their destination is often determined by localisation elements (LEs) contained in untranslated regions within targeted transcripts. Although mRNA localisation has been widely explored in the context of subcellular biology, its roles in tissue function are only just beginning to emerge. A defined set of transcripts accumulate at the leading edge of endothelial tip cells that guide emerging vessels during sprouting angiogenesis. This includes RAB13 and NET1 mRNAs, which encode proteins implicated in cytoskeletal remodelling processes underpinning cell motility. In this study, we tested the anti-angiogenic potential of antisense oligonucleotide (ASO)-based strategies designed to perturb RAB13 and NET1 localisation. Upon confirming that ASOs targeting LEs mislocalise these mRNAs without altering steady-state levels of the encoded proteins, we applied them to a series of in vitro, ex vivo and in vivo angiogenesis assays. Remarkably, the mislocalisation of RAB13 and NET1 inhibits chemotaxis and vessel sprouting in response to pro-angiogenic stimuli. Furthermore, vessel sprouting from mouse choroidal explants and retinal angiogenesis are also hindered by mRNA mislocalisation. Altogether, our strategy for disrupting spatial control of gene expression in endothelial cells opens new mechanistic avenues for the manipulation of vessel formation.