Prdm16 amplifies Notch signaling and suppresses venous lineage specification to prevent arteriovenous malformations during vascular development

Abstract

Rationale: Proper functionality of the circulatory system requires correct arteriovenous (AV) endothelial cell (EC) differentiation. While Notch signaling and its downstream effector Hes-Related Family bHLH Transcription Factor with YRPW Motif (Hey)2 favor arterial specification, transcription factor (TF) chicken ovalbumin upstream transcription factor 2 (Coup-TFII) inhibits canonical Notch activity to induce venous identity. However, transcriptional programs that compete with Coup-TFII to orchestrate arterial specification upstream of Notch remain largely unknown. We identified positive regulatory domain-containing protein (Prdm)16 as an arterial EC-specific TF, but its role during arterial EC specification and development remains unexplored. Objective: To unravel the role of Prdm16 during arterial endothelial lineage specification and artery formation. Methods and Results: Transcriptomic data of freshly isolated arterial and venous ECs from humans and mice revealed that Prdm16 is exclusively expressed by arterial ECs throughout development. This expression pattern was independent of hemodynamic factors and conserved in zebrafish. Accordingly, loss of prdm16 in zebrafish perturbed AV endothelial specification and caused AV malformations in an EC-autonomous manner. This coincided with reduced canonical Notch activity in arterial ECs and was amplified when prdm16 and notch pathway members were concomitantly knocked down. In vitro studies further indicated that Prdm16 not only amplified Notch signaling, but also physically and functionally interacted with Hey2 to drive proper arterial specification. Conclusion: We showed that Prdm16 plays a pivotal role during arterial development through its physical and functional interaction with canonical Notch. As both Hey2 and Prdm16 have been associated with diverse vascular disorders including migraine and atherosclerosis, Prdm16 represents an attractive new target to treat these vascular disorders.

PRDM16 expression and function in mammalian cochlear development

“…Previous studies found an interplay between Prdm16 and Notch signaling in different systems. Prdm16 modulates Notch signaling during arterial specification 49,50 . Loss of the Notch target genes, Hes1, 3 & 5 cause downregulation of Prdm16 expression in the ventricular zone of the developing telencephalon 51 .…”

“…Prdm16 modulates Notch signaling during arterial specification. 49 , 50 Loss of the Notch target genes, Hes1, 3 & 5 cause downregulation of Prdm16 expression in the ventricular zone of the developing telencephalon. 51 Prdm16 has also been demonstrated to be a key regulator in the cell fate choice between skeletal muscle and brown adipose in common progenitors during embryogenesis and also influences beige adipose function and its metabolic function postnatally.…”

Multiomic Analysis and CRISPR Perturbation Screens Identify Endothelial Cell Programs and Novel Therapeutic Targets for Coronary Artery Disease

“…29 In fact, the combined genetic effect of these 2 variants was a 5 mm Hg reduction in mean arterial pressure, and as a result a reduced risk of CAD, peripheral arterial disease, and stroke. In addition to the regulation of vascular tone, functional studies in cultured ECs have also implicated EC angiogenesis ( PRDM16 , 30 FLT1 loci), EC barrier function ( JCAD , 31 ARHGEF26 32 ), and leukocyte adhesion ( PLPP3 33 ) in atherosclerosis.…”