Vasohibin 1 selectively regulates secondary sprouting and lymphangiogenesis in the zebrafish trunk.

Marta Bastos De Oliveira,Katarzyna Koltowska,Simone Jung,Ines Fechner,Eireen Bartels-Klein,Baptiste Coxam,Anna Szymborska,Katja Meier,Holger Gerhardt,Renae Skoczylas,Ilse Geudens

doi:10.1242/dev.194993

Marta Bastos De Oliveira, Katarzyna Koltowska + Show 9 more

Open Access

https://doi.org/10.1242/dev.194993

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Abstract

ABSTRACTPrevious studies have shown that Vasohibin 1 (Vash1) is stimulated by VEGFs in endothelial cells and that its overexpression interferes with angiogenesis in vivo. Recently, Vash1 was found to mediate tubulin detyrosination, a post-translational modification that is implicated in many cell functions, such as cell division. Here, we used the zebrafish embryo to investigate the cellular and subcellular mechanisms of Vash1 on endothelial microtubules during formation of the trunk vasculature. We show that microtubules within venous-derived secondary sprouts are strongly and selectively detyrosinated in comparison with other endothelial cells, and that this difference is lost upon vash1 knockdown. Vash1 depletion in zebrafish specifically affected secondary sprouting from the posterior cardinal vein, increasing endothelial cell divisions and cell number in the sprouts. We show that altering secondary sprout numbers and structure upon Vash1 depletion leads to defective lymphatic vessel formation and ectopic lymphatic progenitor specification in the zebrafish trunk.

Highlights

Blood vessel formation and patterning is essential for tissue growth and homeostasis in vertebrate development and physiology
We propose that Vasohibin 1 (Vash1)-controlled endothelial tubulin detyrosination supports differential endothelial specification during cell division and sprout elongation to achieve venous and lymphatic vessel formation in the zebrafish trunk
We identified Vash1 as a novel regulator of Endothelial cells (EC) sprouting from the posterior cardinal vein (PCV) and the subsequent formation of lymphatic vessels in the zebrafish trunk

Summary

INTRODUCTION

Blood vessel formation and patterning is essential for tissue growth and homeostasis in vertebrate development and physiology. Quantification of the Prox1-positive nearest neighbour revealed that the Prox1positive cells in the PCV are always within close proximity of the venous sprout in vash KD embryos, but not in the control MO injected siblings (Fig. 4E-G) These results suggest that Vash plays a role in lymphatic progenitor cell specification, potentially by controlling Prox distribution in daughter cells post cell division. Detyrosinated microtubules appear abundant in secondary sprouts, in comparison with primary sprouts or established ISVs. Vash regulates formation of trunk lymphatic vasculature Closer examination of Tg[fli1a:EGFPy1,kdr-l:ras-Cherry] embryos further revealed defects in the formation of lymphatic structures. Quantification revealed a significant reduction in the percentage of somites with a TD fragment in vash KD embryos (20%±4.18) compared with controls (78%±4.4) (Fig. 6G) At this developmental stage, we observed a variable degree of under-development of the intestinal vascular system in the vash morphants (Fig. S6A-I). Vash zebrafish morphants and mutants show a decrease in lymphatic progenitors and, as a consequence, a decrease in mature lymphatic vasculature of the trunk

DISCUSSION

Findings

MATERIALS AND METHODS