HGF, or hepatocyte growth factor, is classified as a morphogenic, motility, and paracrine cellular growth factor. It is often discussed and talked about under the name SF - or scatter factor. This growth factor has been linked to various roles in organ development and regeneration. It is also primarily seen as one of the key growth factors in wound healing.
The main functions of HGF are regulatory. It serves to regulate cell growth as well as cell motility. It’s also heavily linked to morphogenesis regulation too. Morphogenesis is the process in which an organism begins to develop its shape. HGF has also been linked with the stimulation of mitogenesis as well - which is the triggering process of cell mitosis.
Hepatocyte growth factor can be referred to as a cytokine with multiple functions on various cells. Primarily, all the functions occur at an epithelial origin. By having the ability to regulate cell motility and mitogenesis, this also gives HGF a role in various other processes such as tissue regeneration, tumorigenesis, and angiogenesis. Angiogenesis is where new blood cells are created, which is essential for wound healing. Tumorigenesis is how normal cells are transformed into cancer cells.
HGF is currently under examination to see if it is a viable treatment option for patients suffering from coronary artery disease. It is also being considered for treatments referring to heat damage. This is all down to its ability to help with wound healing, organ regeneration, and organ development.
Mechanisms & Interactions
HGF carries out its functions by activating a tyrosine kinase signaling pattern. It does this by binding to a c-Met receptor of the proto-oncogenic classification. Hepatocyte growth factor itself is produced by mesenchymal cells. These are multipotent stromal cells that are found throughout the body and can be a variety of different cell types, including; fat cells, bone cells, muscle cells, and cartilage cells).
Hepatocyte growth factor will largely deal with both epithelial and endothelial cells. However, it is also known to interact with some other cells, mainly hematopoietic, T cells, and progenitor. It has also proven to interact with the HGF receptor (HGFR). This receptor is a protein produced by the c-Met oncogene.
Furthermore, studies have shown interactions between HGF and the sulfated glycosaminoglycans heparan sulfate, along with dermatan sulfate. This interaction with heparan sulfate triggers a formation between HGF and c-Met. The consequence of which is a pattern if signals that cause cell division and migration.
Hepatocyte growth factor is structured as a 69-kDa alpha-chain and 34-kDa beta-chain. This structure is formed largely due to the fact it is secreted via a single inactive polypeptide. But, it is also cleaved by serine proteases.
The alpha and beta chains are bonded by a disulfide which helps produce the heterodimeric molecule. While the polypeptide that secretes HGF is inactive, it becomes an active molecule in this bond.
Interestingly, hepatocyte growth factor has no detectable protease activity. This is despite the fact that it is part of a subfamily of S1 peptidases known as plasminogen.