Resident vascular progenitor cells--diverse origins, phenotype, and function

Area of Science:

• Vascular Biology
• Stem Cell Biology
• Regenerative Medicine

Background:

• Blood vessel integrity is crucial for organogenesis and tissue homeostasis.
• Loss of vascular integrity significantly impacts health, particularly in pre- and postnatal development.
• Vascular cell dynamics during neovascularization and remodeling challenge the view of vessels as composed solely of mature cells.

Purpose of the Study:

• To review the spectrum of resident stem/progenitor cells in blood vessels.
• To discuss the implications of vascular stem cells for disease pathogenesis and treatment.
• To explore the concept of local vascular wall stem cell niches.

Main Methods:

• Literature review of studies documenting stem/progenitor cells in macro- and micro-vessels.
• Analysis of findings related to embryogenesis and adult life.
• Examination of evidence for stem cell residence within vessel wall compartments, particularly the tunica adventitia.

Main Results:

• Diverse stem/progenitor cells for vascular and non-vascular progeny exist within blood vessel mural layers.
• During embryogenesis, definitive hematopoietic stem cells and mesoangioblasts emerge from the dorsal aorta.
• Adult blood vessels harbor ancestral cells capable of endothelial, smooth muscle, and mesenchymal differentiation.

Conclusions:

• Vascular walls contain resident stem/progenitor cells, not just terminally differentiated cells.
• These cells reside in specific niches, notably the tunica adventitia.
• Understanding these vascular stem cells is key for developing treatments for cardiovascular and other diseases.