Colony-stimulating factors (CSFs) activate intracellular signaling pathways that can cause the cells to proliferate and differentiate into a specific kind of blood cell (usually white blood cells. For red blood cell formation, see erythropoietin).
Colony stimulating factors circulate in the blood, acting as hormones, and are also secreted locally. An example is erythropoietin, which is produced in the kidney and regulates the formation of red blood cells from progenitor cells in the bone marrow.
Colony-stimulating factors include CSF1, CSF2 and CSF3.
Colony-stimulating factor 1, also known as MCSF and CSF1, is a secreted cytokine which influences hematopoietic stem cells to differentiate into macrophages or other related cell types. MCSF controls the survival, proliferation, and differentiation of mononuclear phagocytes and regulates cells of the females reproductive tract. MCSF may also play an autocrine and/or paracrine role in cancers of the ovary, endometrium, breast, and myeloid and lymphoid tissues.
Granulocyte-macrophage colony-stimulating factor, also known as GM-CSF and CSF2, is a cytokine that controls the production, differentiation, and function of granulocytes and macrophages. GM-CSF can be used as a medication to stimulate the production of white blood cells following chemotherapy. It may also be used as a vaccine adjuvant in HIV-infected patients. GM-CSF is found in high levels in joints with rheumatoid arthritis and blocking GM-CSF may reduce the inflammation or damage.
Colony stimulating factor 3 (granulocyte), also known as G-CSF and CSF3, is a glycoprotein that stimulates the bone marrow to produce granulocytes and stem cells and release them into the bloodstream. G-CSF stimulates the survival, proliferation, differentiation, and function of neutrophil precursors and mature neutrophils. G-CSF is a potent inducer of HSCs mobilization from the bone marrow into the bloodstream, although it has been shown that it does not directly affect the hematopoietic progenitors that are mobilized. Beside the effect on the hematopoietic system, G-CSF can also act on neuronal cells as a neurotrophic factor.