Cardiovascular System - Blood Vessel Development: Difference between revisions
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== Endothelial Tube Formation == | == Endothelial Tube Formation == | ||
[[Image: | [[Image:File:Blood vessel lumen formation.jpg]] | ||
<center>Blood vessel lumen formation</center> | |||
<ref><pubmed>16799567</pubmed></ref> | <ref><pubmed>16799567</pubmed></ref> |
Revision as of 18:39, 15 October 2010
Introduction
Blood develops initially within the core of "blood islands" in the mesoderm. During development, there follows a series of "relocations" of the stem cells to different organs within the embryo. In the adult, these stem cells are located in the bone marrow. At the time when blood first forms, there are no bones!
Angioblasts initially form small cell clusters (blood islands) within the embryonic and extraembryonic mesoderm. These blood islands extend and fuse together making a primordial vascular network. Within these islands the peripheral cells form endothelial cells while the core cells form blood cells (haemocytoblasts).
Recent work has shown that the formation of the initial endothelial tube is by a process of coalescence of cellular vacuoles within the developing endothelial cells, which fuse together without cytoplasmic mixing to form the blood vessel lumen.
Blood Vessel Formation
(Image: Developmental biology: The hole picture Keith Mostov and Fernando Martin-Belmonte Nature 442, 363-364 27 July 2006)
Some Recent Findings
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Endothelial Progenitors
Recent work has shown that the formation of the initial endothelial tube is by a process of coalescence of cellular vacuoles within the developing endothelial cells, which fuse together without cytoplasmic mixing to form the blood vessel lumen.
Endothelial Tube Formation
File:File:Blood vessel lumen formation.jpg
Stimulators of Angiogenisis (Blood Vessel Growth)
- Peptide growth factors
- Vascular endothelial growth factor-Aa,b, -Bb, -Cb, -D
- [-E], -F (VEGF-Aa,b, -Bb, -Cb, -Db, -E, -F)
- Placenta growth factor (PlGF)
- Angiopoietin-1 (Ang-1)
- Angiopoietin-2 (Ang-2) [modulator in the presence of angiogenic activity]
- Acidic fibroblast growth factor (FGF-1)
- Basic fibroblast growth factor (FGF-2)
- Platelet-derived growth factor (PDGF)
- Transforming growth factor-a (TGF-a)
- Transforming growth factor-b (TGF-b)
- Hepatocyte growth factor (HGF)
- Insulin-like growth factor-I (IGF-I)
- Multifunctional cytokines/immune mediators
- Tumour necrosis factor-a (low-dose)
- Monocyte chemoattractant protein-1 (MCP-1)
- CXC-chemokines
- Interleukin-8 (IL-8)
- Enzymes
- Platelet-derived endothelial cell growth factor
- (PD-ECGF; thymidine phosphorylase)
- Angiogenin (ribonuclease A homologue)
- Hormones
- Oestrogens
- Prostaglandin-E1, -E2
- Follistatin
- Proliferin
- Oligosaccharides
- Hyaluronan oligosaccharides
- Gangliosides
(data from table 1 Vascular morphogenesis in the ovary, Augustin H.G Bailliere's Clinical Obstetrics and Gynaecology 14:867-882, 2000)
Inhibitors of Angiogenisis (Blood Vessel Growth)
- Peptide growth factors and proteolytic peptides
- Angiopoietin-2 (Ang-2) [in the absence of angiogenic activity]
- Angiostatin
- Endostatin
- 16 kDa prolactin fragment
- Laminin peptides
- Fibronectin peptides
- Inhibitors of enzymatic activity
- Tissue metalloproteinase inhibitors
- (TIMP-1, -2, -3, -4)
- Plasminogen activator inhibitors
- (PAI-1, -2)
- Multifunctional cytokines/immune mediators
- Tumour necrosis factor-a (high-dose)
- Interferons
- Interleukin-12
- CXC-chemokines
- Platelet factor-4 (PF-4)
- Interferon-gamma-inducible protein-10 (IP-10)
- Gro-beta
- Extracellular matrix molecules
- Thrombospondin
- Hormones/metabolites
- 2-Methoxyestradiol (2-ME)
- Proliferin-related protein
- Oligosaccharides
- Hyaluronan, high-molecular-weight species
(data from table 1 Vascular morphogenesis in the ovary, Augustin H.G Bailliere's Clinical Obstetrics and Gynaecology 14:867-882, 2000)
Vascular Endothelial Growth Factor
Growing blood vessels follow a gradient generated by tagret tissues/regions of Vascular Endothelial Growth Factor (VEGF) to establish a vascular bed. Recent findings suggest that Notch signaling acts as an inhibitor for this system, preventing sprouting of blood vessels.
Notch is a transmembrane receptor protein involved in regulating cell differentiation in many developing systems.
Links: OMIM - VEGFA | OMIM - Notch
Cardiac Blood Vessels
Earliest vessels in the heart wall develop subepicardially (beneath the outside surface of the heart) near the apex at Carnegie stage 15, which then extends centripetally and at stage 17 coronary arterial stems communicate with the aortic lumen.
(Text modified from: [10])
References
<pubmed>10948449</pubmed> <pubmed>12406884</pubmed>
Search Pubmed Now
Click on the listed keywords below (used to search the external database) the most current references on Medline will be displayed.
[TITL+development[WORD]+review[WORD]&doptcmdl=DocSum blood[TITL]+development[WORD]+review[WORD]]
Blood Vessel Development Terms
- angioblasts stem cells in blood islands generating endothelial cells
- angiogenesis the formation of blood vessels also called vasculogenesis in the embryo
- blood islands earliest sites of blood vessel and blood cell formation, seen mainly on yolk sac chorion
- vascular endothelial growth factor (VEGF) protein growth factor family that stimulates blood vessel growth, a similar factor can be found in the placenta (PIGF).
Glossary Links
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Cite this page: Hill, M.A. (2024, April 23) Embryology Cardiovascular System - Blood Vessel Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Cardiovascular_System_-_Blood_Vessel_Development
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G