Growth factor

related topics
{disease, patient, cell}
{acid, form, water}
{group, member, jewish}

A growth factor is a naturally occurring substance capable of stimulating cellular growth,[1] proliferation and cellular differentiation. Usually it is a protein or a steroid hormone. Growth factors are important for regulating a variety of cellular processes.

Growth factors typically act as signaling molecules between cells. Examples are cytokines and hormones that bind to specific receptors on the surface of their target cells.

They often promote cell differentiation and maturation, which varies between growth factors. For example, bone morphogenic proteins stimulate bone cell differentiation, while fibroblast growth factors and vascular endothelial growth factors stimulate blood vessel differentiation (angiogenesis).

Contents

Growth factors versus cytokines

Growth factor is sometimes used interchangeably among scientists with the term cytokine.[2] Historically, cytokines were associated with hematopoietic (blood forming) cells and immune system cells (e.g., lymphocytes and tissue cells from spleen, thymus, and lymph nodes). For the circulatory system and bone marrow in which cells can occur in a liquid suspension and not bound up in solid tissue, it makes sense for them to communicate by soluble, circulating protein molecules. However, as different lines of research converged, it became clear that some of the same signaling proteins the hematopoietic and immune systems used were also being used by all sorts of other cells and tissues, during development and in the mature organism.

While growth factor implies a positive effect on cell division, cytokine is a neutral term with respect to whether a molecule affects proliferation. While some cytokines can be growth factors, such as G-CSF and GM-CSF, others have an inhibitory effect on cell growth or proliferation. Some cytokines, such as Fas ligand, are used as "death" signals; they cause target cells to undergo programmed cell death or apoptosis.

Full article ▸

related documents
Analgesic
Azotemia
Transient ischemic attack
Tricyclic antidepressant
Shigella
Erythromycin
Ramsay Hunt syndrome type II
Fallopian tube
Waterhouse-Friderichsen syndrome
Wart
Rift Valley fever
Heart disease
Neurofibromatosis
Herd immunity
Nose-picking
Rhinovirus
Ulcerative colitis
Melanocyte
Alpers' disease
Human anatomy
Pneumonic plague
John Cade
Fibroblast
Placenta
Hemolysis
Lithotriptor
Mastectomy
Capillary
Disease
Duodenum