Endothelial cilia mediate low flow sensing during zebrafish vascular development

Area of Science:

• Developmental Biology
• Cardiovascular Research
• Cell Biology

Background:

• Blood flow is crucial for vascular morphogenesis.
• The mechanism by which endothelial cells sense low embryonic blood flow is unknown.
• Primary cilia are hypothesized to be involved in flow sensing.

Purpose of the Study:

• To investigate the role of endothelial primary cilia in sensing blood flow during early embryonic development.
• To determine if endothelial cilia can detect low shear forces.
• To elucidate the link between cilia-mediated flow sensing and vascular morphogenesis.

Main Methods:

• Noninvasive, high-resolution live imaging of zebrafish embryos.
• Observation of endothelial cilia deflection in response to blood flow.
• Correlation analysis between cilia deflection angle and intracellular calcium levels.
• Genetic and pharmacological manipulation of shear stress, ciliogenesis, and calcium channel (PKD2) expression.

Main Results:

• Endothelial cilia deflect at the onset of blood flow in zebrafish embryos.
• Cilia deflection angle correlates with endothelial calcium levels.
• Impaired cilia function or altered shear stress disrupts vascular morphogenesis.
• PKD2 channel activity is essential for proper flow sensing and vascular development.

Conclusions:

• Endothelial primary cilia are highly sensitive mechanosensors capable of detecting low shear forces.
• Cilia-mediated calcium signaling is critical for regulating vascular morphogenesis.
• This study provides in vivo evidence for the role of primary cilia in embryonic vascular development.