Platelet-derived growth factor

From Wikipedia, the free encyclopedia

This article or section is in need of attention from an expert on the subject.
Please help recruit one or improve this article yourself. See the talk page for details.
Please consider using {{Expert-subject}} to associate this request with a WikiProject

Platelet-derived growth factor (PDGF) is one of the numerous growth factors, or proteins that regulate cell growth and division. In particular, it plays a significant role in angiogenesis, the growth of blood vessels from already existing blood vessel tissue. Uncontrolled angiogenesis is a characteristic of cancer.

1 Types/Classification
2 Function
3 History
4 Structure
5 Clinical significance
6 See also
7 References
8 External links

[edit] Types/Classification

There are five different isoforms of PDGF that activate cellular response through two different receptors. Known ligands include A (PDGFA), B (PDGFB), C (PDGFC) and D (PDGFD) and an AB heterodimer and receptors alpha (PDGFRA) and beta(PDGFRB).

PDGFR is characterized as a tyrosine kinase receptor, providing a link to certain types of cancer. It is involved in the PI3K pathway. It has also been shown that the cis oncogene is derived from the PDGF B-chain gene. PDGF-BB is the highest-affinity ligand for the PDGFR-beta; PDGFR-beta is a key marker of hepatic stellate cell activation in the process of fibrogenesis.

[edit] Function

PDGF plays a role in embryonic development, cell proliferation, cell migration, and angiogenesis. PDGF has also been linked to several diseases such as atherosclerosis, fibrosis and malignant diseases.

In addition, PDGF (Platelet derived growth factor) has demonstrated that not only is it a cell proliferator, but a required element in cellular division for fibroblast, a type of connective tissue. Specifically, fibroblasts have PDGF receptors on their plasma membranes that allow for their signal transductions from PDGFs. These plasma membrane receptors are called tyrosine kinases that allow the signal transduction and inevitably the cell division stimulation to occur. In essence, the PDGFs allow a cell to skip the G1 checkpoints in order to divide.

[edit] History

PDGF was one of the first growth factors characterized, and has led to an understanding of the mechanism of many growth factor signaling pathways.

[edit] Structure

PDGF is known to exist as a dimer, and activates its signaling pathway by a ligand-induced receptor dimerization and autophosphorylation. PDGF receptors also contain many auto-phosphorylation sites, which serve to mediate binding of SH2 sites and subsequently signal corresponding pathways.

[edit] Clinical significance

Like many other growth factors that have been linked to disease, PDGF has provided a market for protein receptor antagonists to treat disease. Such antagonists usually include specific antibodies that target the molecule of interest, which only act in a neutralizing manner.

However, recent developments have allowed some biotechnology companies to circumvent this problem by creating specialized molecules that not only bind the protein of interest, but also destroy it in an enzymatic fashion.

The "c-Sis" oncogene is derived from PDGF.^[1]^[2]

[edit] See also

[edit] References

^ McClintock J, Chan I, Thaker S, Katial A, Taub F, Aotaki-Keen A, Hjelmeland L (1992). "Detection of c-sis proto-oncogene transcripts by direct enzyme-labeled cDNA probes and in situ hybridization". In Vitro Cell Dev Biol 28A (2): 102-8. PMID 1537750.
^ MeSH Proto-Oncogene+Proteins+c-sis