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Menelaou K, Prater M, Tunster S, Blake G, Geary Joo C, Cross JC, Hamilton R, Watson E. Blastocyst transfer in mice alters the placental transcriptome and growth. Reproduction 2019; 159:115-132. [PMID: 31751309 PMCID: PMC6993209 DOI: 10.1530/rep-19-0293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 11/18/2019] [Indexed: 12/18/2022]
Abstract
Assisted reproduction technologies (ART) are becoming increasingly common. Therefore, how these procedures influence gene regulation and feto-placental development are important to explore. Here, we assess the effects of blastocyst transfer on mouse placental growth and transcriptome. C57Bl/6 blastocysts were transferred into uteri of B6D2F1 pseudopregnant females and dissected at embryonic day 10.5 for analysis. Compared to non-transferred controls, placentas from transferred conceptuses weighed less even though the embryos were larger on average. This suggested a compensatory increase in placental efficiency. RNA-sequencing of whole male placentas revealed 543 differentially expressed genes (DEGs) after blastocyst transfer: 188 and 355 genes were down-regulated and up-regulated, respectively. DEGs were independently validated in male and female placentas. Bioinformatic analyses revealed that DEGs represented expression in all major placental cell types and included genes that are critical for placenta development and/or function. Furthermore, the direction of transcriptional change in response to blastocyst transfer implied an adaptive response to improve placental function to maintain fetal growth. Our analysis revealed that CpG methylation at regulatory regions of two DEGs was unchanged in female transferred placentas and that DEGs had fewer gene-associated CpG islands (within ~20 kb region) compared to the larger genome. These data suggested that altered methylation at proximal promoter regions might not lead to transcriptional disruption in transferred placentas. Genomic clustering of some DEGs warrants further investigation of long-range, cis-acting epigenetic mechanisms including histone modifications together with DNA methylation. We conclude that embryo transfer, a protocol required for ART, significantly impacts the placental transcriptome and growth.
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Affiliation(s)
- Katerina Menelaou
- K Menelaou, Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom of Great Britain and Northern Ireland
| | - Malwina Prater
- M Prater, Centre for Trophoblast Research, University of Cambridge, Cambridge, United Kingdom of Great Britain and Northern Ireland
| | - Simon Tunster
- S Tunster, Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom of Great Britain and Northern Ireland
| | - Georgina Blake
- G Blake, Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom of Great Britain and Northern Ireland
| | - Colleen Geary Joo
- C Geary Joo, Clara Christie Centre for Mouse Genomics, University of Calgary, Calgary, Canada
| | - James C Cross
- J Cross, Comparative Biology and Experimental Medicine, University of Calgary, Calgary, Canada
| | - Russell Hamilton
- R Hamilton, Centre for Trophoblast Research, University of Cambridge, Cambridge, United Kingdom of Great Britain and Northern Ireland
| | - Erica Watson
- E Watson, Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3EG, United Kingdom of Great Britain and Northern Ireland
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Nicotine protects fetus against LPS-induced fetal growth restriction through ameliorating placental inflammation and vascular development in late pregnancy in rats. Biosci Rep 2019; 39:BSR20190386. [PMID: 31209145 PMCID: PMC6603276 DOI: 10.1042/bsr20190386] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 05/14/2019] [Accepted: 06/12/2019] [Indexed: 01/19/2023] Open
Abstract
Our previous work has shown that nicotine suppressed lipopolysaccharide (LPS)-induced placental inflammation by inhibiting cytokine release as well as infiltration of leukocytes into the placenta through the cholinergic anti-inflammatory pathway. Nicotine also increased fetal survival and restored pup weight. In the present study, we aim to further investigate if fetal growth restriction (FGR) occurs with LPS treatment, and evaluate the protective effects of nicotine on fetuses in late gestation of rats. Pregnant Sprague–Dawley rats were divided into control group, nicotine group, LPS group and LPS + nicotine group. Rats were first pretreated with nicotine or vehicle by subcutaneous injection on gestation day (GD)14 and GD15, followed by LPS or vehicle intraperitoneal injection on GD16, and were killed on GD18. Loss of fetuses, number and weights of live fetuses and weights of placentas were recorded. Placentas were collected to evaluate placental pathology and determine inflammatory cytokines and vascular endothelial growth factor (VEGF) levels. We found that LPS treatment increased levels of placental inflammatory cytokines and placental pathological damage, decreased levels of VEGF, reduced number of live fetuses and induced FGR. Pretreatment with nicotine reversed LPS-induced high levels of placental inflammatory cytokines, low levels of placental VEGF and placental pathological damage, then rescued the number and weights of live fetuses. These data demonstrated that activation of the cholinergic anti-inflammatory pathway by nicotine protected fetus against LPS-induced FGR through ameliorating placental inflammation and vascular development in late pregnancy in rats. It may be an alternative therapeutic strategy for inflammation- induced FGR in late pregnancy.
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