Zebrafish model for functional screening of flow-responsive genes controlling endothelial cell proliferation

Area of Science:

• Vascular biology
• Genetics
• Zebrafish models

Background:

• Local hemodynamics, specifically wall shear stress (WSS), are crucial for maintaining arterial homeostasis and endothelial cell (EC) function.
• Understanding the genetic regulation of EC proliferation in response to blood flow is essential for vascular health.

Purpose of the Study:

• To identify genes that regulate endothelial cell proliferation in response to varying blood flow conditions.
• To investigate the role of WNK1 in vascular homeostasis and its expression in diseased arteries.

Main Methods:

• Utilized a zebrafish model to study EC proliferation under suppressed and normal blood flow conditions.
• Employed quantitative reverse transcription PCR (qRT-PCR) to analyze gene expression in isolated ECs.
• Used a knockdown approach to assess the function of candidate genes in zebrafish vasculature.
• Performed immunofluorescent staining on mammalian arteries to examine WNK1 expression patterns.

Main Results:

• Suppressed blood flow in zebrafish embryos led to reduced EC proliferation in intersegmental vessels (ISVs).
• WNK1 negatively regulated EC proliferation under no-flow conditions.
• Fzd5, Gsk3β, Trpm7, and Bmp2a promoted EC proliferation under flow conditions.
• WNK1 was observed at sites of low WSS in murine aortas and in ECs overlying human atherosclerotic plaques.

Conclusions:

• WNK1 plays a role in regulating EC proliferation, particularly under low flow conditions.
• WNK1 expression in ECs at sites of low WSS and in diseased arteries suggests a potential role in influencing vascular homeostasis by reducing EC proliferation.