Kathleen Groesch

Angiogenesis in implantation

ProblemImplantation failure and early pregnancy loss are common following natural conceptions and they are particularly important clinical hurdles to overcome following assisted reproduction attempts. The importance of adequate vascular development and maintenance during implantation has recently become a major focus of investigation.Materials and methodsReview of current published literature was undertaken to summerize the cells and cell products that regulate tissue vascularity during implantation.ResultsVascular development at the maternal fetal interface can be regulated by a number of different cell types; two principal candidates are trophoblast and natural killer cells. A wide range of soluble factors, some with well established angiogenic functions as well as other more novel factors, can contribute to vascular development and maintenance at the maternal–fetal interface.ConclusionsRobust vascular development occurs during implantation and early placentation of normal pregnancies. Studies to define the extent and mechanisms by which defects in vascularity contribute to human implantation failure and early miscarriage need to be undertaken.

Differential Regulation of Human PlGF Gene Expression in Trophoblast and Nontrophoblast Cells by Oxygen Tension

OBJECTIVE To determine the mechanism for differential effects of low oxygen tension on human PlGF gene transcription in trophoblast and nontrophoblast cells. STUDY DESIGN Human PlGF reporter clones and real-time RT-PCR were used to compare the effects of hypoxia on gene transcription in human trophoblast and nontrophoblast cell lines. Overexpression of HIF-1alpha, inhibition of HIF-1 function and biochemical assessments of HIF-1 co-factor interactions were used to characterize hypoxia response mechanisms regulating PlGF transcription. RESULTS PlGF transcription is specifically inhibited by low oxygen tension in trophoblast but is induced in some nontrophoblast cells. Overexpression of HIF-1alpha in normoxic cells or inhibition of HIF-1 function in hypoxic cells did not significantly alter transcription patterns of the PlGF gene in either cell type. CONCLUSIONS These results suggest that transcriptional repression of PlGF gene expression occurs in human trophoblast exposed to low oxygen tension but that PlGF transcription is stimulated in certain hypoxic nontrophoblast cells. However, regulation of PlGF transcription is not mediated by functional HIF-1 activity in either cell type.

Nitric oxide generation affects pro- and anti-angiogenic growth factor expression in primary human trophoblast

OBJECTIVES Preeclampsia is associated with reduced trophoblast placenta growth factor (PGF) expression, elevated soluble fms-like tyrosine kinase-1 (sFlt-1) and decreased bioactivity of nitric oxide (NO). Elevated sFlt-1 reduces bio-availability of PGF and vascular endothelial growth factor (VEGF) leading to maternal endothelial dysfunction. Although NO can regulate gene expression, its ability to regulate trophoblast expression of angiogenic growth factors is not known. STUDY DESIGN Human primary term trophoblast and JEG-3 choriocarcinoma cells were cultured under 21%O(2) or 1%O(2) conditions in the presence or absence of NO donor (SNP) or inhibitor (L-NAME). Effects on PGF, VEGF and Flt-1 isoform mRNA expression were determined by quantitative real-time PCR. Changes in expression of soluble protein isoforms of FLT-1 was monitored by ELISA. RESULTS Hypoxia decreased PGF mRNA but increased VEGF, sFlt-1 and Flt-1 mRNA expression in trophoblast. Generation of NO in trophoblast under 1%O(2) culture conditions significantly reversed sFlt-1 mRNA and protein expression, independent of mFlt-1. Conversely NO generation in hypoxic trophoblast increased VEGF and PGF mRNA expression. CONCLUSIONS NO production in primary human trophoblast cultures had divergent effects on pro-angiogenic (PGF, VEGF) versus anti-angiogenic (sFlt-1) mRNA expression, resulting in an enhanced pro-angiogenic gene expression environment in vitro.

Dysregulation of promyelocytic leukemia (PML) protein expression in preeclamptic placentae.

Promyelocytic leukemia (PML) protein is a nucleoprotein that can regulate a variety of cellular stress responses. The aim of this study was to determine qualitative and quantitative changes in PML expression in preeclamptic placentae. Immunoblot, quantitative reverse transcription polymerase chain reaction (qRT-PCR), and immunohistochemistry techniques were used to determine PML gene expression and localization in normal (n = 6) and preeclamptic (n = 6) placentae and primary cells. Promyelocytic leukemia protein was immunolocalized within nuclei of villus mesenchyme, but largely absent in trophoblast nuclei, with a trend for increased PML reactivity in preeclamptic placenta. Immunoblot analyses of nuclear extracts confirmed relative increases (∼3-fold) of PML expression in preeclamptic placentae (P < .05). Conversely, less PML messenger RNA (mRNA; ∼2-fold) was detected in preeclamptic versus normal placental samples. In vitro, PML expression could be increased by hypoxia in cultured endothelial cells but not trophoblast. Increased PML protein expression in preeclamptic villi suggests it could contribute to decreased vascularity and placental growth and/or function.

Deep Epigastric Vessel Location in the Gravid Abdomen.

LESS-CLSH (n=20) LAVH (n=36) p value Surgery time (mins) 155.8 40.7 120.3 35.5 0.003 Blood loss 405.6 315.7 316.0 186.0 0.446 Two Phase Laparoendoscopic Single-Site Cervical Ligament-Sparing Hysterectomy: An Initial Experience in a Single Center Complication 0 (0%) 7 (1.9%) 0.361 VAS pain score at 0-4 hrs 6.5 2.1 8.2 1.1 \0.001 VAS pain score at 24 hrs 3.3 1.5 5.1 1.4 \0.001 VAS pain score at 48 hrs 1.2 0.4 2.6 1.3 0.0018 Hospitalisation 4.0 1.1 5.3 0.8 \0.001

1141584386 Cell type specific regulation of human placenta growth factor

Background:  Maternal serum levels of PlGF are significantly lower in preeclamptic patients than in normal pregnant women. PlGF mRNA expression is cell type specific with high levels in trophoblast but comparatively low levels in most nontrophoblast. Despite two consensus hypoxia response elements (HREs), PlGF expression is down regulated by hypoxia in trophoblast, but increased in other cell types. These observations suggest unique regulatory mechanisms control PlGF expression. We sought to characterize PlGF promoter regions which function to regulate transcription rates in different cell types and under hypoxia.