Growth factors

Proteins that are transmitted from cell to cell as signal transmitters and thus pass on information. Growth factors regulate various intracellular processes in the sense of "signal proteins" and play a particular role in cell proliferation. The signal transmission is usually achieved by binding the growth factor to a specific receptor in the cell membrane. Growth factors are either secreted, i.e. released by cells into the environment, or are membrane-bound. In order to be able to exert their effect, growth factors require a specific receptor. When this receptor binds to its ligand inside the cell, it generates a signal that leads to the activation or deactivation of genes. A typical example of the mode of action of growth factors is angiogenesis or the course of epithelial proliferation, e.g. in psoriasis (here, the interleukins 17(IL-17) and 22 (IL-22) produced by Th-17 lymphocytes play an important role in keratinocyte hyperplasia).

A large number of growth factors with different signal inductions are known today. These include:

• Family of EGF factors "EGF=Epidermal Growth Factor": see EGF receptorsbelow
• Fibroblast Growth Factor (FGF): 2 main forms: basic and acidic fibroblast growth factor
• Granulocyte Macrophage Colony Stimulating Factor(GM-CSF)
• Hepatocyte Growth Factor ( HGF)
• Insulin-like growth factor (IGF)
• Interleukin-1B, -8 (IL-1B, IL-8); IL-17, IL-22: see also Interleukins
• Nerve Growth Factor (NGF)
• Platelet-Derived Growth Factor (PDGF)
• Connective Tissue Growth Factor (CTGF)
• Transforming Growth Factor (TGF) see below TGF-beta
• Vascular Endothelial Growth Factor ( VEGF): see also Angiogenesis.