Pericytes from infantile hemangioma display proangiogenic properties and dysregulated angiopoietin-1

Area of Science:

• Vascular biology
• Developmental biology
• Oncology

Background:

• Infantile hemangioma (IH) is a common neonatal vascular tumor characterized by rapid proliferation.
• IH comprises immature endothelial cells and pericytes, contributing to disorganized blood vessel growth.
• The specific role of IH-derived pericytes (Hem-pericytes) in vascular stabilization remains unclear.

Purpose of the Study:

• To isolate and characterize pericytes from infantile hemangioma (IH) tissue.
• To test the hypothesis that Hem-pericytes have a diminished capacity for blood vessel stabilization.
• To investigate the proangiogenic properties of Hem-pericytes.

Main Methods:

• Isolation of patient-derived pericytes from IH tissue (Hem-pericytes).
• In vitro assessment of Hem-pericyte proliferation, migration, and contractility.
• In vivo microvessel formation assays using Hem-pericytes and endothelial cells.
• Quantification of vascular endothelial growth factor-A and angiopoietin 1 expression.

Main Results:

• Hem-pericytes demonstrated enhanced microvessel formation in vivo compared to control retinal pericytes.
• In vitro, Hem-pericytes exhibited rapid growth, impaired endothelial cell stabilization, and elevated vascular endothelial growth factor-A levels.
• Hem-pericytes displayed reduced contractility and lower angiopoietin 1 levels, particularly during the proliferating phase of IH.

Conclusions:

• Successful isolation of patient-derived Hem-pericytes was achieved.
• Hem-pericytes possess proangiogenic properties, contributing to excessive vascularization in IH.
• Reduced angiopoietin 1 levels in Hem-pericytes correlate with their diminished ability to stabilize blood vessels in infantile hemangioma.