Angiogenesis in Health and Disease

What function does VEGF-A stimulate in endothelial cells?

Which growth factor promotes vasodilation by stimulating the production of NO?

What is the role of Ang-1 in angiogenesis?

What is the function of Notch signaling in angiogenesis?

What is the primary role of angiogenesis in the context of injury?

What is the primary function of vascular endothelial growth factor (VEGF) in angiogenesis?

Which growth factor stimulates the proliferation of endothelial cells and the migration of macrophages and fibroblasts?

What is necessary for the stabilization of newly formed vessels?

What is the outcome of the suppression of endothelial proliferation and migration in angiogenesis?

What is the purpose of therapies aimed at inhibiting angiogenesis?

What is the role of nitric oxide in angiogenesis?

What is the outcome of the migration of endothelial cells towards the area of tissue injury?

Angiogenesis

Critical in healing at sites of injury, development of collateral circulations at sites of ischemia, and tumor growth beyond original blood supply
Involves sprouting of new vessels from existing ones, consisting of:
- Vasodilation in response to nitric oxide and increased permeability induced by VEGF
- Separation of pericytes from the abluminal surface and breakdown of the basement membrane
- Migration of endothelial cells toward the area of tissue injury
- Proliferation of endothelial cells just behind the leading front of migrating cells
- Recruiting pericytes for small capillaries and smooth muscle cells for larger vessels to form mature vessel
- Suppression of endothelial proliferation and migration and deposition of the basement membrane

Signaling Pathways and Growth Factors

Vascular endothelial growth factors (VEGFs), mainly VEGF-A, stimulate both migration and proliferation of endothelial cells, initiating capillary sprouting
Fibroblast growth factors (FGFs), mainly FGF-2, stimulate proliferation of endothelial cells and migration of macrophages and fibroblasts to the damaged area
Angio-poietins 1 and 2 (Ang 1 and Ang 2) play a role in angiogenesis and structural maturation of new vessels
PDGF recruits smooth muscle cells and TGF-ß suppresses endothelial proliferation and migration, and enhances production of ECM proteins

Notch Signaling

Regulates sprouting and branching of new vessels through "cross-talk" with VEGF
Ensures proper spacing of new vessels to effectively supply healing tissue with blood

This quiz assesses understanding of angiogenesis, the process of new blood vessel formation, in various contexts, including injury, ischemia, and tumor growth. It explores the mechanisms and potential therapeutic applications.