G6PC3

Granulocyte Colony-Stimulating Factor (G-CSF) is a glycoprotein that stimulates the bone marrow to produce granulocytes and stem cells and release them into the bloodstream. It is a cytokine and hormone that plays a critical role in hematopoiesis, the process of blood cell production.

Structure and Function

G-CSF is a 174-amino acid protein with a molecular weight of approximately 19.6 kDa. It is produced by various tissues, including the endothelium, macrophages, and a number of other immune cells. The primary function of G-CSF is to regulate the production and release of neutrophils from the bone marrow.

Mechanism of Action

G-CSF binds to the G-CSF receptor (G-CSFR) on the surface of hematopoietic stem cells and progenitor cells in the bone marrow. This binding activates intracellular signaling pathways, including the JAK/STAT, PI3K/AKT, and MAPK pathways, leading to the proliferation, differentiation, and survival of neutrophil precursors.

Clinical Applications

G-CSF is used clinically to treat neutropenia, a condition characterized by an abnormally low number of neutrophils. It is particularly useful in patients undergoing chemotherapy, which often results in neutropenia. G-CSF reduces the risk of infection in these patients by increasing neutrophil counts.

Recombinant Forms

Recombinant forms of G-CSF, such as filgrastim and pegfilgrastim, are widely used in clinical practice. Filgrastim is a non-glycosylated form of G-CSF produced in Escherichia coli, while pegfilgrastim is a pegylated form that has a longer half-life, allowing for less frequent dosing.

Side Effects

Common side effects of G-CSF administration include bone pain, headache, and fatigue. More serious side effects can include splenic rupture and acute respiratory distress syndrome (ARDS), although these are rare.

Research and Development

Ongoing research is exploring the use of G-CSF in other conditions, such as myocardial infarction and stroke, due to its potential to mobilize stem cells and promote tissue repair.

Also see

• Hematopoiesis
• Neutropenia
• Cytokines
• Chemotherapy
• Stem cell mobilization