Placental growth factor
Encyclopedia
Placental growth factor is a protein
that in humans is encoded by the PGF gene
.
Placental growth factor (PGF) is a member of the VEGF (vascular endothelial growth factor
) sub-family - a key molecule in angiogenesis
and vasculogenesis
, in particular during embryogenesis
. The main source of PGF during pregnancy is the placental trophoblast
. PGF is also expressed in many other tissues, including the villous trophoblast.
lesions is associated with plaque
inflammation and neovascular growth
.
PGF expression within human atherosclerotic lesions
is associated with plaque inflammation and neovascular growth.
Serum levels of PGF and sFlt-1
(soluble fms-like tyrosine kinase-1, also known as soluble VEGF receptor-1) are altered in women with preeclampsia
. Studies show that in both early and late onset preeclampsia, maternal serum levels of sFlt-1 are higher and PGF lower in women presenting with preeclampsia. In addition, placental sFlt-1 levels were significantly increased and PGF decreased in women with preeclampsia as compared to those with uncomplicated pregnancies. This suggests that placental concentrations of sFlt-1 and PGF mirror the maternal serum changes. This is consistent with the view that the placenta
is the main source of sFlt-1 and PGF during pregnancy.1
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
that in humans is encoded by the PGF gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
.
Placental growth factor (PGF) is a member of the VEGF (vascular endothelial growth factor
Vascular endothelial growth factor
Vascular endothelial growth factor is a signal protein produced by cells that stimulates vasculogenesis and angiogenesis. It is part of the system that restores the oxygen supply to tissues when blood circulation is inadequate....
) sub-family - a key molecule in angiogenesis
Angiogenesis
Angiogenesis is the physiological process involving the growth of new blood vessels from pre-existing vessels. Though there has been some debate over terminology, vasculogenesis is the term used for spontaneous blood-vessel formation, and intussusception is the term for the formation of new blood...
and vasculogenesis
Vasculogenesis
Vasculogenesis is the process of blood vessel formation occurring by a de novo production of endothelial cells.-Process:Though similar to angiogenesis, the two are different in one aspect: The term angiogenesis denotes the formation of new blood vessels from pre-existing ones, whereas...
, in particular during embryogenesis
Embryogenesis
Embryogenesis is the process by which the embryo is formed and develops, until it develops into a fetus.Embryogenesis starts with the fertilization of the ovum by sperm. The fertilized ovum is referred to as a zygote...
. The main source of PGF during pregnancy is the placental trophoblast
Trophoblast
Trophoblasts are cells forming the outer layer of a blastocyst, which provide nutrients to the embryo and develop into a large part of the placenta. They are formed during the first stage of pregnancy and are the first cells to differentiate from the fertilized egg...
. PGF is also expressed in many other tissues, including the villous trophoblast.
Clinical significance
Placental growth factor-expression within human atheroscleroticAtherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...
lesions is associated with plaque
Atheroma
In pathology, an atheroma is an accumulation and swelling in artery walls that is made up of macrophage cells, or debris, that contain lipids , calcium and a variable amount of fibrous connective tissue...
inflammation and neovascular growth
Neovascularization
Neovascularization is the formation of functional microvascular networks with red blood cell perfusion. Neovascularization differs from angiogenesis in that angiogenesis is mainly characterized by the protrusion and outgrowth of capillary buds and sprouts from pre-existing blood vessels.In...
.
PGF expression within human atherosclerotic lesions
Atherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...
is associated with plaque inflammation and neovascular growth.
Serum levels of PGF and sFlt-1
Soluble fms-like tyrosine kinase-1
Soluble fms-like tyrosine kinase-1 is a tyrosine kinase protein that disables proteins that cause blood vessel growth.Soluble Flt-1 is a splice variant of VEGF receptor 1 which is produced by a variety of tissues.1 These proteins act as a receptor of vascular endothelial growth factor , a...
(soluble fms-like tyrosine kinase-1, also known as soluble VEGF receptor-1) are altered in women with preeclampsia
Pre-eclampsia
Pre-eclampsia or preeclampsia is a medical condition in which hypertension arises in pregnancy in association with significant amounts of protein in the urine....
. Studies show that in both early and late onset preeclampsia, maternal serum levels of sFlt-1 are higher and PGF lower in women presenting with preeclampsia. In addition, placental sFlt-1 levels were significantly increased and PGF decreased in women with preeclampsia as compared to those with uncomplicated pregnancies. This suggests that placental concentrations of sFlt-1 and PGF mirror the maternal serum changes. This is consistent with the view that the placenta
Placenta
The placenta is an organ that connects the developing fetus to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mother's blood supply. "True" placentas are a defining characteristic of eutherian or "placental" mammals, but are also found in some snakes and...
is the main source of sFlt-1 and PGF during pregnancy.1