The amnion plays an important role during pregnancy and parturition. Though referred to as a single structure, this fetal tissue is regionally divided into placental amnion, reflected amnion, and umbilical amnion. Histological differences between placental amnion and reflected amnion led us to hypothesize that the amnion is biologically heterogeneous. The gene expression profiles of placental a...

BACKGROUND The human amnion plays a pivotal role in parturition. Two of its compartments, the placental amnion and the reflected amnion, have distinct transcriptome and are functionally coordinated for parturition. This study was conducted to determine the microRNA (miRNA) expression pattern and its significance in the placental amnion and the reflected amnion in association with labor at term....

CONTEXT Prostaglandin-endoperoxide synthase 2 (PTGS2) is a key enzyme involved in parturition. PTGS2 mRNA was found to be differentially expressed between placental amnion (amnion overlying the placental disc) and reflected amnion (amnion of the extraplacental chorioamniotic membranes) in term placentas. OBJECTIVE The aim was to evaluate the spatial and temporal regulation of PTGS2 expression...

The region of the amnion overlying the placenta plays an active role in fluid exchange between amniotic fluid and fetal blood perfusing the surface of the placenta, whereas little transfer occurs across the reflected amnion that contacts the membranous chorion. Because aquaporins (AQPs) facilitate rapid movement of water across cells, we hypothesized that AQP gene expression in placental amnion...

Very high concentrations of prorenin protein occur in human amniotic fluid and amnion. The source of amniotic fluid prorenin is likely the decidua, as it has the highest levels of prorenin mRNA (REN). Conversely, REN mRNA levels in amnion and chorion are very low. This study aimed to investigate whether decidual prorenin could cross the amnion and accumulate in amniotic fluid. Late gestation am...

We demonstrated previously that preproendothelin mRNA is present in avascular human amnion tissue and in human amnion cells maintained in primary monolayer culture. In this investigation we sought to identify the specific endothelin (ET) gene that is expressed in amnion and to determine whether endothelin is produced by amnion. Using oligonucleotides specific for ET-1, ET-2, and ET-3 mRNA, we i...

Current evidence suggests that amniotic fluid volume (AFV) is actively regulated by vesicular transport of amniotic fluid outward across the amnion and into the underlying fetal vasculature in the placenta. Our objective was to determine whether gene expression profiles of potential stimulators, inhibitors, and mediators of vesicular transport are altered in response to changes in intramembrano...

Smad5 is an intracellular mediator of bone morphogenetic protein (Bmp) signalling. It is essential for primordial germ cell (PGC) development, for the development of the allantois and for amnion closure, as demonstrated by loss of Bmp signalling. By contrast, the appearance of ectopic PGC-like cells and regionalized ectopic vasculogenesis and haematopoiesis in thickened Smad5(m1/m1) amnion are ...

The amnion rupture sequence is a heterogeneous group of congenital deformities in which rupture of the amnion occurs early in gestation. Fragments of the amnion may adhere to, or encircle and constrict, embryonic parts. This may interrupt normal morphogenesis and cause deformity or even mutilation of formed structures; large cranial defects are a common feature. In contrast to other causes of c...

Biological dressings including human amniotic membrane have been used to cover wounds or skin defects and enhance healing by providing a structural format to the underlying tissue. Human amniotic membrane was first used as wound dressing in 1910 by JS Davis [1]. The amniotic membrane obtained from human placenta possesses most of the characteristics of an ideal skin substitute even after proces...