Hepatocyte growth factor (HGF) or scatter factor (SF) is a
paracrine Paracrine signaling is a form of cell signaling, a type of cellular communication in which a cell produces a signal to induce changes in nearby cells, altering the behaviour of those cells. Signaling molecules known as paracrine factors diffuse ove ...
cellular growth,
motility
Motility is the ability of an organism to move independently, using metabolic energy.
Definitions
Motility, the ability of an organism to move independently, using metabolic energy, can be contrasted with sessility, the state of organisms th ...
and
morphogenic factor. It is secreted by
mesenchymal cell
Mesenchymal stem cells (MSCs) also known as mesenchymal stromal cells or medicinal signaling cells are multipotent stromal cells that can differentiate into a variety of cell types, including osteoblasts (bone cells), chondrocytes (cartilage cel ...
s and targets and acts primarily upon
epithelial cell
Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ...
s and
endothelial cell
The endothelium is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel ...
s, but also acts on
haemopoietic progenitor cells and
T cell
A T cell is a type of lymphocyte. T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell r ...
s. It has been shown to have a major role in embryonic organ development, specifically in
myogenesis
Myogenesis is the formation of skeletal muscular tissue, particularly during embryonic development.
Muscle fibers generally form through the fusion of precursor myoblasts into multinucleated fibers called ''myotubes''. In the early development o ...
, in adult organ regeneration, and in wound healing.
Function
Hepatocyte growth factor regulates cell growth, cell motility, and
morphogenesis
Morphogenesis (from the Greek ''morphê'' shape and ''genesis'' creation, literally "the generation of form") is the biological process that causes a cell, tissue or organism to develop its shape. It is one of three fundamental aspects of devel ...
by activating a
tyrosine kinase
A tyrosine kinase is an enzyme that can transfer a phosphate group from ATP to the tyrosine residues of specific proteins inside a cell. It functions as an "on" or "off" switch in many cellular functions.
Tyrosine kinases belong to a larger cla ...
signaling cascade after binding to the proto-oncogenic
c-Met
c-Met, also called tyrosine-protein kinase Met or hepatocyte growth factor receptor (HGFR), is a protein that in humans is encoded by the ''MET'' gene. The protein possesses tyrosine kinase activity. The primary single chain precursor protein is ...
receptor.
Hepatocyte growth factor is secreted by
mesenchymal cell
Mesenchymal stem cells (MSCs) also known as mesenchymal stromal cells or medicinal signaling cells are multipotent stromal cells that can differentiate into a variety of cell types, including osteoblasts (bone cells), chondrocytes (cartilage cel ...
s and acts as a multi-functional
cytokine
Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrin ...
on cells of mainly epithelial origin. Its ability to stimulate
mitogenesis
A mitogen is a small bioactive protein or peptide that induces a cell to begin cell division, or enhances the rate of division (mitosis). Mitogenesis is the induction (triggering) of mitosis, typically via a mitogen. The mechanism of action of a ...
, cell motility, and matrix invasion gives it a central role in
angiogenesis
Angiogenesis is the physiological process through which new blood vessels form from pre-existing vessels, formed in the earlier stage of vasculogenesis. Angiogenesis continues the growth of the vasculature by processes of sprouting and splitting ...
,
tumorogenesis
Carcinogenesis, also called oncogenesis or tumorigenesis, is the formation of a cancer, whereby normal cells are transformed into cancer cells. The process is characterized by changes at the cellular, genetic, and epigenetic levels and abnorm ...
, and tissue regeneration.
Structure
It is secreted as a single inactive polypeptide and is cleaved by serine proteases into a 69-kDa alpha-chain and 34-kDa beta-chain. A disulfide bond between the alpha and beta chains produces the active, heterodimeric molecule. The protein belongs to the
plasminogen
Plasmin is an important enzyme () present in blood that degrades many blood plasma proteins, including fibrin clots. The degradation of fibrin is termed fibrinolysis. In humans, the plasmin protein (in the zymogen form of plasminogen) is encode ...
subfamily of S1 peptidases but has no detectable
protease
A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalyzes (increases reaction rate or "speeds up") proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the ...
activity.
Clinical significance
Human HGF plasmid DNA therapy Human HGF plasmid DNA therapy of cardiomyocytes is being examined as a potential treatment for coronary artery disease (a major cause of myocardial infarction (MI)), as well as treatment for the damage that occurs to the heart after MI. After MI, ...
of
cardiomyocytes
Cardiac muscle (also called heart muscle, myocardium, cardiomyocytes and cardiac myocytes) is one of three types of vertebrate muscle tissues, with the other two being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that ...
is being examined as a potential treatment for
coronary artery disease
Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves the reduction of blood flow to the heart muscle due to build-up of atherosclerotic pla ...
as well as treatment for the damage that occurs to the heart after
myocardial infarction
A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which may ...
.
As well as the well-characterised effects of HGF on
epithelial cell
Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ...
s,
endothelial cell
The endothelium is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel ...
s and
haemopoietic progenitor cells, HGF also regulates the chemotaxis of T cells into heart tissue. Binding of HGF by c-Met, expressed on T cells, causes the upregulation of c-Met,
CXCR3
Chemokine receptor CXCR3 is a Gαi protein-coupled receptor in the CXC chemokine receptor family. Other names for CXCR3 are G protein-coupled receptor 9 (GPR9) and CD183. There are three isoforms of CXCR3 in humans: CXCR3-A, CXCR3-B and chemoki ...
, and
CCR4
C-C chemokine receptor type 4 is a protein that in humans is encoded by the ''CCR4'' gene. CCR4 has also recently been designated CD194 (cluster of differentiation 194).
The protein encoded by this gene belongs to the G protein-coupled receptor f ...
which in turn imbues them with the ability to migrate into heart tissue.
HGF also promotes angiogenesis in ischemia injury.
HGF may further play a role as an indicator for prognosis of chronicity for
Chikungunya
Chikungunya is an infection caused by the ''Chikungunya virus'' (CHIKV). Symptoms include fever and joint pains. These typically occur two to twelve days after exposure. Other symptoms may include headache, muscle pain, joint swelling, and a ra ...
virus induced
arthralgia
Arthralgia (from Greek ''arthro-'', joint + ''-algos'', pain) literally means ''joint pain''. Specifically, arthralgia is a symptom of injury, infection, illness (in particular arthritis), or an allergic reaction to medication.
According to MeSH, ...
. High HGF levels correlate with high rates of recovery.
Excessive local expression of HGF in the
breast
The breast is one of two prominences located on the upper ventral region of a primate's torso. Both females and males develop breasts from the same embryological tissues.
In females, it serves as the mammary gland, which produces and secret ...
s has been implicated in
macromastia
Breast hypertrophy is a rare medical condition of the breast connective tissues in which the breasts become excessively large. The condition is often divided based on the severity into two types, macromastia and gigantomastia. Hypertrophy of the ...
.
HGF is also importantly involved in normal
mammary gland
A mammary gland is an exocrine gland in humans and other mammals that produces milk to feed young offspring. Mammals get their name from the Latin word ''mamma'', "breast". The mammary glands are arranged in organs such as the breasts in primat ...
development.
HGF has been implicated in a variety of
cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
s, including of the
lung
The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of t ...
s,
pancreas
The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an end ...
,
thyroid
The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans it is in the neck and consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the thyroid isthmus. The thy ...
,
colon, and
breast
The breast is one of two prominences located on the upper ventral region of a primate's torso. Both females and males develop breasts from the same embryological tissues.
In females, it serves as the mammary gland, which produces and secret ...
.
Increased expression of HGF has been associated with the enhanced and scarless
wound healing
Wound healing refers to a living organism's replacement of destroyed or damaged tissue by newly produced tissue.
In undamaged skin, the epidermis (surface, epithelial layer) and dermis (deeper, connective layer) form a protective barrier again ...
capabilities of
fibroblast
A fibroblast is a type of cell (biology), biological cell that synthesizes the extracellular matrix and collagen, produces the structural framework (Stroma (tissue), stroma) for animal Tissue (biology), tissues, and plays a critical role in wound ...
cells isolated from the
oral mucosa
The oral mucosa is the mucous membrane lining the inside of the mouth. It comprises stratified squamous epithelium, termed "oral epithelium", and an underlying connective tissue termed ''lamina propria''. The oral cavity has sometimes been descri ...
tissue.
Circulating plasma levels
Plasma from patients with advanced heart failure presents increased levels of HGF, which correlates with a negative prognosis and a high risk of mortality. Circulating HGF has been also identified as a prognostic marker of severity in patients with hypertension.
Circulating HGF has been also suggested as a precocious biomarker for the acute phase of bowel inflammation.
Pharmacokinetics
Exogenous
In a variety of contexts, exogeny or exogeneity () is the fact of an action or object originating externally. It contrasts with endogeneity or endogeny, the fact of being influenced within a system.
Economics
In an economic model, an exogeno ...
HGF administered by
intravenous injection
Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutri ...
is cleared rapidly from circulation by the
liver
The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for ...
, with a
half-life
Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable ato ...
of approximately 4 minutes.
Modulators
Dihexa is an orally active, centrally penetrant
small-molecule
Within the fields of molecular biology and pharmacology, a small molecule or micromolecule is a low molecular weight (≤ 1000 daltons) organic compound that may regulate a biological process, with a size on the order of 1 nm. Many drugs ar ...
compound that directly binds to HGF and potentiates its ability to activate its receptor, c-Met.
It is a strong inducer of
neurogenesis
Neurogenesis is the process by which nervous system cells, the neurons, are produced by neural stem cells (NSCs). It occurs in all species of animals except the porifera (sponges) and placozoans. Types of NSCs include neuroepithelial cells (NECs) ...
and is being studied for the potential treatment of
Alzheimer's disease
Alzheimer's disease (AD) is a neurodegeneration, neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in short-term me ...
and
Parkinson's disease
Parkinson's disease (PD), or simply Parkinson's, is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms becom ...
.
Interactions
Hepatocyte growth factor has been shown to
interact
Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...
with the protein product of the c-Met oncogene, identified as the HGF receptor (
HGFR).
Both overexpression of the Met/HGFR receptor protein and
autocrine Autocrine signaling is a form of cell signaling in which a cell secretes a hormone or chemical messenger (called the autocrine agent) that binds to autocrine receptors on that same cell, leading to changes in the cell. This can be contrasted with pa ...
activation of Met/HGFR by simultaneous expression of the hepatocyte growth factor ligand have been implicated in oncogenesis.
Hepatocyte growth factor interacts with the sulfated glycosaminoglycans heparan sulfate and dermatan sulfate.
The interaction with heparan sulfate allows hepatocyte growth factor to form a complex with c-Met that is able to transduce intracellular signals leading to cell division and cell migration.
See also
*
Epidermal growth factor
Epidermal growth factor (EGF) is a protein that stimulates cell growth and differentiation by binding to its receptor, EGFR. Human EGF is 6-k Da and has 53 amino acid residues and three intramolecular disulfide bonds.
EGF was originally descr ...
*
Insulin-like growth factor 1
Insulin-like growth factor 1 (IGF-1), also called somatomedin C, is a hormone similar in molecular structure to insulin which plays an important role in childhood growth, and has anabolic effects in adults.
IGF-1 is a protein that in humans is ...
*
Epithelial–mesenchymal transition
The epithelial–mesenchymal transition (EMT) is a process by which epithelial cells lose their cell polarity and cell–cell adhesion, and gain migratory and invasive properties to become mesenchymal stem cells; these are multipotent stromal ...
*
Madin-Darby Canine Kidney Cells
Madin-Darby canine kidney (MDCK) cells are a model mammalian cell line used in biomedical research. MDCK cells are used for a wide variety of cell biology studies including cell polarity, cell-cell adhesions (termed adherens junctions), collective ...
References
Further reading
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External links
*
Hepatocyte growth factoron the
Atlas of Genetics and Oncology
* UCSD Signaling Gateway Molecule Page o
HGF*
{{Growth factor receptor modulators
Growth factors
Developmental genes and proteins
Cytokines
World Anti-Doping Agency prohibited substances