Intussusceptive angiogenesis--the alternative to capillary sprouting.

Area of Science:

• Vascular Biology
• Angiogenesis Research
• Cell Biology

Background:

• Sprouting angiogenesis is a well-established mechanism of new blood vessel formation.
• Intussusceptive angiogenesis (IA) is a newer concept, initially observed in lung capillary network growth.
• IA involves the insertion of transcapillary tissue pillars that enlarge, enabling capillary network expansion.

Purpose of the Study:

• To explore the mechanism and ubiquity of intussusceptive angiogenesis.
• To investigate the role of IA in tumor vascularization and other vascular processes.
• To identify the cellular components and potential regulatory factors involved in IA.

Main Methods:

• Morphological analysis of blood vessel formation.
• Investigation across multiple organs and species.
• Review of existing literature on growth factors and receptors in IA.

Main Results:

• IA is a ubiquitous phenomenon in vertebrates, found in all investigated organs.
• IA plays a significant role in tumor vascularization.
• Six distinct modes of pillar formation have been identified, involving endothelial cell junctions and interstitial tissue invasion.
• IA contributes to vascular tree formation (arborization) and vascular remodeling.
• While growth factors are implicated, detailed regulation of IA remains poorly understood.

Conclusions:

• Intussusceptive angiogenesis is a fundamental and widespread mechanism for vascular development and adaptation.
• The cellular and molecular regulation of IA requires further investigation for a comprehensive understanding.