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Circulating Bmp10 acts through endothelial Alk1 to mediate flow-dependent arterial quiescence
Derek W Laux1, Sarah Young, James P Donovan
1Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Development (Cambridge, England)
|July 19, 2013
Summary
Blood flow activates activin receptor-like kinase 1 (ALK1) signaling, crucial for limiting artery size. This study identifies Bmp10 as the key ligand, revealing how flow and Bmp10 together regulate vascular development and prevent arteriovenous malformations (AVMs).
Area of Science:
- Vascular Biology
- Molecular Signaling
- Developmental Biology
Background:
- Blood flow is vital for vascular development, but the molecular mechanisms are unclear.
- Activin receptor-like kinase 1 (ALK1) is involved in vascular homeostasis, with its expression dependent on blood flow.
- Loss of ALK1 function in zebrafish embryos leads to dysregulated arterial genes and increased endothelial cell numbers, mimicking flow deprivation.
Purpose of the Study:
- To investigate the molecular pathways by which blood flow regulates vascular development.
- To determine the role of ALK1 signaling in response to blood flow.
- To identify the ligand responsible for ALK1 activation in embryonic arteries.
Main Methods:
- Utilized zebrafish embryos as a model system.
- Manipulated alk1 expression in flow-deprived arteries.
- Investigated the interaction between blood flow, Bmp10, and Alk1 signaling.
- Analyzed gene expression and endothelial cell number.
Main Results:
- Restoring alk1 expression alone did not rescue Alk1 activity or normalize endothelial cells in flow-deprived arteries.
- Identified cardiac-derived Bmp10 as the crucial ligand for endothelial Alk1.
- Demonstrated that circulating Bmp10 acts via endothelial Alk1 to limit endothelial cell number and stabilize nascent arteries.
- Showed that blood flow enhances Alk1 activity by inducing alk1 expression and distributing Bmp10.
Conclusions:
- Blood flow and Bmp10 cooperatively activate endothelial Alk1 signaling to limit arterial caliber during development.
- This pathway is essential for maintaining vascular homeostasis and preventing AVMs.
- Impaired flow response may initiate AVM development, highlighting the clinical relevance of ALK1 mutations.
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