Growth Factors

An organic compound known as a growth factor plays a huge role in the differentiation of cells, the repair of wounds, and the proliferation of newly formed cells. In most cases, protein hormones or steroid hormones are released during this process. The growth factors play a crucial role in regulating numerous functions of the cells in the body.

Hepatocyte Growth Factors (HGFs).

Hepatocyte growth factor/scatter factor (HGF/SF), a multifunctional protein that affects both epithelium and endothelial cells, is produced by fibroblasts and other mesenchymal cells.

Because it aids the liver’s stem cells in regenerating through a number of signaling pathways, hepatocyte growth factor (HGF) is regarded as a mitogen for the organ. It effectively promotes hepatic tissue healing by promoting collagen deposition and progenitor cell growth and expansion. In addition, various body cells produce different growth factors, and various growth factors can trigger signaling pathways that produce secondary growth factors.

Vascular Endothelial Growth Factors (VEGFs)

Vascular endothelial growth factor (VEGF) is a growth factor with significant pro-angiogenic action that also increases vascular permeability, encourages cell migration, and has mitogenic and anti-apoptotic effects on endothelial cells. Because of these results, it effectively controls both healthy and unhealthy angiogenic processes. The VEGF family in humans consists of several members, including placenta growth factor (PlGF), VEGF-A (which has several isoforms), VEGF-B, VEGF-C, VEGF-D, VEGF-E (viral VEGF), VEGF-F (snake venom VEGF), and, more recently, endocrine gland-derived vascular endothelial growth factor (EG-VEGF).

Platelet-Derived Growth Factors (PDGFs)

One of the many growth factors that control cell division and development is platelet-derived growth factor (PDGF). In particular, PDGF is important for the development of new blood vessels from tissue that already contains them, for the proliferation of mesenchymal cells like fibroblasts, osteoblasts, tenocytes, vascular smooth muscle cells, and mesenchymal stem cells, as well as for the directed migration of mesenchymal cells known as chemotaxis. A dimeric glycoprotein known as platelet-derived growth factor (PDGF) can have two A subunits (PDGF-AA), two B subunits (PDGF-BB), or one of each. (PDGF-AB).

Fibroblast Growth Factors (FGFs).

A typical growth factor that has demonstrated potential impacts on tissue repair and regeneration is fibroblast growth factor (FGF). It now has 22 members and was initially discovered as a protein that encouraged fibroblast growth. FGFs bind to and activate fibroblast growth factor receptors (FGFRs), which have numerous biological effects. The primary signaling pathway activated by FGFR stimulation is the RAS/MAP kinase pathway. FGFs have been used to regenerate damaged tissues like skin, blood vessels, muscles, adipose, tendon/ligament, cartilage, bone, teeth, and nerves thanks to their potential biological activities.

Insulin-Like Growth Factors (IGFs)

IGF, formerly known as somatomedin, is any of a number of peptide hormones that mainly stimulate growth. However, they also can lower blood glucose levels. 

IGFs share the ability to stimulate growth with other growth factors, including nerve growth factor, platelet-derived growth factor, and epidermal growth factor. However, they differ from these substances in that they are the only ones in humans with well-described endocrine actions.

Epidermal Growth Factors (EGFs)

The first growth factor was called epidermal growth factor (EGF). An endopeptidase cleaves the transmembranous glycoprotein known as EGF precursor to produce active EGF. It attaches to the epidermal growth factor receptor along with the other members of the family of epidermal growth factors (EGFR). Following ligand attachment, EGFR (ErbB-1) forms dimers either by itself or with its homologs ErbB-2, ErbB-3, or ErbB-4, which boosts the activity of intracellular tyrosine kinase. Cell proliferation, decreased apoptosis, and angiogenesis are just a few of the outcomes of this activating signaling pathway.