Alternative RNA splicing in the endothelium mediated in part by Rbfox2 regulates the arterial response to low flow.

Patrick A Murphy,Vincent L Butty,Phillip A Sharp,Amy L Kimble,Richard O Hynes,Paul L Boutz,Christopher B Burge,Shahinoor Begum

doi:10.7554/elife.29494

Patrick A Murphy, Vincent L Butty + Show 6 more

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https://doi.org/10.7554/elife.29494

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Abstract

Low and disturbed blood flow drives the progression of arterial diseases including atherosclerosis and aneurysms. The endothelial response to flow and its interactions with recruited platelets and leukocytes determine disease progression. Here, we report widespread changes in alternative splicing of pre-mRNA in the flow-activated murine arterial endothelium in vivo. Alternative splicing was suppressed by depletion of platelets and macrophages recruited to the arterial endothelium under low and disturbed flow. Binding motifs for the Rbfox-family are enriched adjacent to many of the regulated exons. Endothelial deletion of Rbfox2, the only family member expressed in arterial endothelium, suppresses a subset of the changes in transcription and RNA splicing induced by low flow. Our data reveal an alternative splicing program activated by Rbfox2 in the endothelium on recruitment of platelets and macrophages and demonstrate its relevance in transcriptional responses during flow-driven vascular inflammation.

Highlights

Exposure of arterial endothelium to low and disturbed flow initiates a process of endothelial activation, resulting in increased expression of adhesion molecules and the rolling, adhesion and extravasation of leukocytes (Gimbrone and Garcıa-Cardena, 2013; Ley et al, 2007)
Low flow induces a program of alternative splicing in the arterial intima To determine the extent of alternative splicing changes in the arterial intima under low-flow conditions, we prepared pools of intimal RNA from the carotid arteries of mice exposed to low flow for 48 hr (Figure 1A)
We report that recruitment of circulating hematopoietic cells to the arterial endothelium under low flow initiates an alternative splicing response regulated in part by Rbfox2

Summary

Introduction

Exposure of arterial endothelium to low and disturbed flow initiates a process of endothelial activation, resulting in increased expression of adhesion molecules and the rolling, adhesion and extravasation of leukocytes (Gimbrone and Garcıa-Cardena, 2013; Ley et al, 2007). Subsequent work revealed transcriptional programs induced by steady flow and suppressed by low and disturbed flow in vitro and in vivo (Dai et al, 2004). Many of these programs could be recapitulated by Erk activation and increased expression of the transcription factor Klf (Dekker et al, 2006; Lin et al, 2005; Parmar et al, 2006). Exposure of arterial endothelium to low flow initiates a program of endothelial dysfunction characterized by transcriptional changes and alterations in the expression of leukocyte recruitment molecules

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