The importance of placental cathepsins for pregnancy: their role in differentiation, invasion and vascular remodelling.

Lead Research Organisation: Babraham Institute
Department Name: Epigenetics

Abstract

The placenta is the organ that mediates and regulates nutrition of the growing fetus during pregnancy. To accomplish this function, specialized cells of the placenta (called trophoblast) invade into the surrounding tissue and redirect the maternal blood circulation towards the embryo.
Providing the fetus with the correct amount of blood is critical for the outcome of pregnancy. Our porject investigates the precise molecular role of two specific genes in the process of placental cell invasion and their role in establishing the connection to the blood supply.
The two genes under investigation promote differentiation of the invasive placental cell type. They are also likely to affect the development of the blood vessels that carry maternal blood including oxygen and nutrients towards the placenta.
The experiments are aimed to analyze the capacity of these genes to enhance the cells’ capacity to invade into surrounding tissue. Their impact on number and density of blood vessels that support embryonic (or tumour) growth will be examined. Human placental malformations and placenta-derived tumours will be analyzed for a potential deregulation of members of this gene family.
This analysis will help us gain insights into the differentiation of invasive trophoblast cells and their vascular interactions that are of critical importance for the success of pregnancy.

Technical Summary

The placenta governs nutrient and gas exchange between mother and fetus and is an absolute requirement for intra-uterine development. To exert these functions, specialized fetal placental cells, called trophoblast giant cells in mice and extravillous cytotrophoblasts in humans, invade into the uterus and interact with maternal blood vessels. In previous work, I have identified two proteases (Cts7 and Cts8) that are abundantly present in this invasive cell population during mouse embryogenesis. Expression of these proteases promotes differentiation of the invasive cell type from mouse placental (trophoblast) stem cells in culture. In addition to increasing the number of invasive giant cells, Cts7/Cts8 may also contribute to invasiveness by proteolytic degradation of extracellular matrix components.
The proposed project is aimed to identify the intracellular site(s) of function of these proteases in trophoblast differentiation. This goal will be achieved by restricting Cts7 and Cts8 distribution to various compartments within the cell. Qualitative and quantitative changes in protein composition will be identified by comparing cellular protein content between expressing and non-expressing cells. This analysis is carried out in collaboration with Dr. Coorssen at the University of Calgary who is an expert in comparative proteome analyses.
A main goal of the proposal is to establish model systems to prove the differentiation- (and possibly invasion-) enhancing effects of Cts7 and Cts8 in vivo. The influence of Cts7/Cts8 expression on growth, invasion and metastasis of teratocarcinoma-like tumours will be examined. During mouse embryogenesis, expression of the two proteases will be induced ubiquitously as well as specifically in the precursor population of trophoblast giant cells. Placentas of these embryos will be investigated for an increase in the giant cell population and for a more pronounced invasion of fetal cells into the uterus. Cts7 and Cts8 also co-localize with the anti-angiogenic peptide endostatin in the trophoblast invasion zone. Fetuses and tumours overexpressing Cts7/Cts8 will therefore be assessed for differences in overall vascularization and for the frequency of interaction of trophoblast cells with arteries.
Defects in appropriate trophoblast invasion are the underlying cause of preeclampsia that affects 7-10% of human pregnancies. Also, unrestricted invasion renders trophoblast-derived tumours extremely malignant. Placentas from preeclamptic pregnancies and choriocarcinomas will be analyzed for deregulation of expression or ectopic expression of human members of this protease family.
This project is expected to significantly advance knowledge of invasion-regulating factors such as Cts7/Cts8 that are of great importance to better understand, diagnose and assess abnormal human development.

Publications

10 25 50
 
Description Research Advisory Board, Wellbeing of Women
Geographic Reach National 
Policy Influence Type Participation in advisory committee
Impact I served as member of the scientific advisory committee to the charity Wellbeing of Women, which reviews and makes decisions on grant funding in the general field of reproductive medicine. Some of the work funded through WoW has led to improvements in health care, novel diagnostic methods, etc.
 
Description BBSRC PhD Studentship
Amount £26,000 (GBP)
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom
Start 10/2006 
End 09/2010
 
Description Cambridge Centre for Trophoblast Research, Project extension grant
Amount £25,000 (GBP)
Organisation University of Cambridge 
Sector Academic/University
Country United Kingdom
Start 10/2008 
End 03/2009
 
Description Synergy Grant, BBSRC CSG funding
Amount £120,000 (GBP)
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom
Start 10/2006 
End 09/2008
 
Description Wellcome Trust Strategic Award
Amount £254,000 (GBP)
Funding ID WT100160MA 
Organisation Wellcome Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 04/2013 
End 03/2018
 
Title DMDD 
Description As part of the Wellcome Trust funded Strategic Award "Deciphering the Mechanisms of Developmental Diseases", we have generated a database in which we collect phenoytping data of the mouse placenta at various gestational stages. 
Type Of Material Database/Collection of data 
Year Produced 2014 
Provided To Others? Yes  
Impact Broad survey of embryonic lethal gene mutations for defects in embryonic and placental development. Efforts will lead, for the first time, to a global overview of the number and identity of genes, and the molecular pathways they regulate, involved in the development of the placenta as an essential organ ensuring reproductive success and health of the baby. 
URL http://www.nimr.mrc.ac.uk/news/deciphering-the-mechanisms-of-developmental-disorders-progress-report...
 
Description Analysis of Geminin function in development and trophoblast differentiation 
Organisation Medical Research Council (MRC)
Department MRC Cancer Cell Unit
Country United Kingdom 
Sector Public 
PI Contribution Analysis of Geminin overexpression and knockdown in trophoblast stem cells
Collaborator Contribution Identification of Geminin as a key cell cycle regulator in early cell lineage decisions and trophoblast differentiation
Impact 16847348
 
Description Analysis of cathepsin protease expression in the human placenta 
Organisation Imperial College London
Department Institute of Reproductive and Developmental Biology
Country United Kingdom 
Sector Academic/University 
PI Contribution Temporal and spatial expression of all 11 cysteine cathepsin proteases in normal and abnorml human placentae studied by RT-PCR, Northern blotting and immunostaining, and functional approaches in trophoblast cell lines
Collaborator Contribution provision of placental samples; scientific input in data analysis and interpretation; contribution to paper writingprovision of placental samples; scientific input in data analysis and interpretation
Impact 16440214
Start Year 2006
 
Description Analysis of cathepsin protease expression in the human placenta 
Organisation University of Cambridge
Department Department of Physiology, Development and Neuroscience
Country United Kingdom 
Sector Academic/University 
PI Contribution Temporal and spatial expression of all 11 cysteine cathepsin proteases in normal and abnorml human placentae studied by RT-PCR, Northern blotting and immunostaining, and functional approaches in trophoblast cell lines
Collaborator Contribution provision of placental samples; scientific input in data analysis and interpretation; contribution to paper writingprovision of placental samples; scientific input in data analysis and interpretation
Impact 16440214
Start Year 2006
 
Description Epigenetic lineage barrier established by methylation of Elf5 
Organisation Babraham Institute
Country United Kingdom 
Sector Private 
PI Contribution Analysis of DNA methylation differences between trophoblast and embryonic stem cells; identification and functional analysis of Elf5
Collaborator Contribution Contribution to differential methylation analysis and validation; contribution to functional analysis of transcription factor Elf5
Impact 17021040 18584034 18836439
Start Year 2006
 
Description Identification of causative genes for placental abnormalities in mice 
Organisation Uppsala University
Country Sweden 
Sector Academic/University 
PI Contribution Expression and functional analysis of a number of genes throughout development
Collaborator Contribution Identification of a considerable number of genes with significant roles in placental development
Impact 17177860 18425848
 
Description Member, Board of Managers at Centre for Trophoblast Research 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Supporters
Results and Impact As member of the Board of Managers at the CTR in Cambridge we make decisions on the award of PhD scholarships, postdoctoral fellowships and direct the general focal points of local research activity in the field of placental biology.

PhD students admitted to the University of Cambridge; postdoctoral researchers' career path enhanced
Year(s) Of Engagement Activity 2013,2014,2015,2016
 
Description School visit 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? Yes
Geographic Reach Local
Primary Audience Schools
Results and Impact presented basic research topic (intrauterine development and essential function of placenta) to primary school children

awareness and excitement of young people for science
Year(s) Of Engagement Activity 2006,2007,2008,2009,2010
 
Description School's Day 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? Yes
Geographic Reach Local
Primary Audience Schools
Results and Impact provided basic explanation of early development and the importance of the placenta for growth of a baby; hands-on experience for students in staining and microscopic analysis of a mouse placenta

rose awareness of research activities and importance of basic research to understand common pregnancy-associated diseases
Year(s) Of Engagement Activity 2006,2007,2008,2009,2010