1.Introduction
Preeclampsia (PE) is a kind of
pregnancy complications diagnosed with newly occurring hypertension and
proteinuria after 20 gestation weeks1, which is a
primary reason that lead to the death of pregnant women, fetus and
newborn
and is also related to fetal growth retardation and premature
births. As the pathogenesis of PE has
not been fully interpreted, the current understanding is still based on
abnormal placenta and
inflammation2.
Under normal physiological conditions, placentation is closely
correlated with spiral artery formation and
placental trophoblasts cells
invasion. In the process of PE, when the adaptation process of spiral
arteries cannot be performed ideally, manifesting an obvious decline in
the proportion of vascular remodeling which may result obstructive
lesions. Besides, the insufficient trophoblastic invasion will cause the
hypoxia and inflammation reaction, which in turn promote the
trophoblastic apoptosis.
Under physiological conditions, placental trophoblast cells located at
the maternal-fetal interface produce a variety of growth factors, such
as neurotrophic
factors3. Studies
have indicated that neurenergen contributes to angiogenesis and energy
homeostasis, probably playing a important role in early vascular
development of fetus4, 5. Brain-derived neurotrophic
factor (BDNF) , belonging to the
member of neurotrophin family, plays a leading part in the formation of
new vessels with the placental environment from the early phase of
embryo development by binding the tyrosine kinase receptor
B(TkrB)6. The TrkB signaling pathway is a new
paracrine pathway that can regulate the growth of human trophoblast and
promote trophoblast differentiation, proliferation and survival, so this
signaling pathway plays an important role in the growth of human
trophoblasts. Besides, BDNF can penetrate the maternal-fetal barrier,
contributing to fetal
phylogeny7.
Previous study8, 9 have demonstrated that there is an
association between BDNF and PE. The level of expression of BDNF showed
an obvious difference between PE pregnant women and healthy
women8, 10.
With the understanding of the PE pathogenesis, many researchers begin to
focus on the important role of single-nucleotide
polymorphism (SNP) in process of
PE. Previous studies have indicated
that certain candidate genetic loci SNPs associated with thrombosis,
inflammation, oxidative stress and the renin angiotensin
system11, 12 are related to the occurrence of
PE13. BDNF Val66Met (rs6265)(G to A) may cause
transfer of amino acid residues from valine (Val) in position 66
(nucleotide 196) to Methionine (Met) at the
anterior region of BDNF, which have
a functional effect on the BDNF activity14.
In this study, we focus on exploring
the relationship between BDNF
Val166Met site and occurrence of PE,
meantime initially discuss the transmission from mother to infant of
this SNP and the connection between BDNF Val66Met and
new born poor prognosis associated
with PE.