Platelet-derived growth factor receptor-beta promotes early endothelial cell differentiation

Area of Science:

• Developmental biology
• Hematopoiesis
• Angiogenesis

Background:

• Platelet-derived growth factor BB (PDGF-BB) is known to stabilize vasculature by recruiting perivascular cells expressing PDGF receptor-beta (PDGFR-beta).
• The precise role and expression patterns of PDGFR-beta during early vascular and hematopoietic development remain incompletely understood.

Purpose of the Study:

• To investigate the expression of PDGFR-beta on early hematopoietic/endothelial (hemangio) precursors.
• To determine the functional role of PDGFR-beta signaling in hemangioprecursor differentiation and vascular development.

Main Methods:

• Analysis of PDGFR-beta coexpression with CD31, VEGFR-2, and CD41 in mouse yolk sac and embryonic stem cell models.
• Utilizing genetically modified mouse models with altered PDGFR-beta activity (D894N mutation) and PDGF-BB expression (Rosa26 locus).
• Quantification of hematopoietic cell populations (CD41+) and assessment of vascular remodeling.

Main Results:

• PDGFR-beta was identified on early hemangioprecursors coexpressing CD31, VEGFR-2, and CD41.
• PDGFR-beta expression on hemangioprecursors decreased over time, appearing later on perivascular cells.
• Activation of PDGFR-beta on hemangioprecursors accelerated endothelial differentiation while suppressing hematopoietic differentiation.
• Genetic alterations leading to increased PDGFR-beta signaling reduced the number of CD41+ cells and enhanced vascular remodeling.

Conclusions:

• PDGFR-beta is expressed on early hemangioprecursor cells, playing a regulatory role in both vascular and hematopoietic development.
• The study identifies a novel function of PDGFR-beta in modulating the balance between endothelial and hematopoietic lineages during embryogenesis.
• Findings suggest PDGFR-beta signaling is a key factor in vascular remodeling and the development of blood and blood vessel systems.