ORCID Profile
0000-0002-5776-2052
Current Organisation
University of Adelaide
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Publisher: Cold Spring Harbor Laboratory
Date: 28-06-2020
DOI: 10.1101/2020.06.25.20139709
Abstract: During early human placental development, extravillous cytotrophoblasts (EVT) invade the uterine vasculature to sequester a maternal blood supply. The impact of this on placental gene expression has not been established for normal pregnancy. Using RNA sequencing, we profiled placental chorionic villous tissues from 96 pregnancies at 6-23 weeks of gestation. We identified 1,048 genes that were differentially expressed between 6-10 weeks’ and 11-23 weeks’ of gestation. These are predominantly genes that are enriched in transcription factor signalling, inflammatory response and cell adhesion. Using a co-expression network and gene set enrichment analyses, we reveal three distinct phases of gene expression coincident with phases of maternal blood flow to the placenta that impact immune function and are likely driven by oxygen tension, potentially in a sex-specific manner. These data represent a comprehensive transcriptional profile of early placental development and point to significant environmental, genetic and regulatory triggers that drive gene expression.
Publisher: Cold Spring Harbor Laboratory
Date: 07-03-2022
DOI: 10.1101/2022.03.03.22271882
Abstract: The human placenta is a rapidly developing transient organ that is key to pregnancy success. Early development of the conceptus occurs in a low oxygen environment before oxygenated maternal blood begins to flow into the placenta at ∼10-12 weeks’ gestation. This process is likely to substantially affect overall placental gene expression. Transcript variability underlying gene expression has yet to be profiled. In this study, accurate transcript expression profiles were identified for 84 human placental chorionic villus tissue s les collected across 6-23 weeks’ gestation. Differential gene expression (DGE), differential transcript expression (DTE) and differential transcript usage (DTU) between 6-10 weeks’ and 11-23 weeks’ gestation groups were assessed. In total, 229 genes had significant DTE yet no significant DGE. Integration of DGE and DTE analyses found that differential expression patterns of in idual transcripts were commonly masked upon aggregation to the gene-level. Of the 611 genes that exhibited DTU, 534 had no significant DGE or DTE. The four most significant DTU genes ADAM10, VMP1, GPR126 , and ASAH1 , were associated with hypoxia-responsive pathways. Transcript usage is a likely regulatory mechanism in early placentation. Identification of functional roles will facilitate new insight in understanding the origins of pregnancy complications.
Publisher: Cold Spring Harbor Laboratory
Date: 22-08-2020
DOI: 10.1101/2020.08.19.20177873
Abstract: MicroRNAs (miRNAs) are increasingly seen as important regulators of placental development and opportunistic biomarker targets. Given the difficulty in obtaining s les from early gestation and subsequent paucity of the same, investigation of the role of miRNAs in early gestation human placenta has been limited. To address this, we generated miRNA profiles using 96 placentas from presumed normal pregnancies, across early gestation, in combination with matched profiles from maternal plasma. Placenta s les range from 6–23 weeks’ gestation, a time period that includes placenta from the early, relatively low but physiological (6–10 weeks’ gestation) oxygen environment, and later, physiologically normal oxygen environment (11–23 weeks’ gestation). We identified 637 miRNAs with expression in 86 s les (after removing poor quality s les), showing a clear gestational age gradient from 6–23 weeks’ gestation. We identified 374 differentially expressed (DE) miRNAs between placentas from 6–10 weeks’ versus 11–23 weeks’ gestation. We see a clear gestational age group bias in miRNA clusters C19MC, C14MC, miR-17∼92 and paralogs, regions that also include many DE miRNAs. Proportional change in expression of placenta-specific miRNA clusters was reflected in maternal plasma. The presumed introduction of oxygenated maternal blood into the placenta (between ∼10–12 weeks’ gestation) changes the miRNA profile of the chorionic villus, particularly in placenta-specific miRNA clusters. Data presented here comprise a clinically important reference set for studying early placenta development and may underpin the generation of minimally invasive methods for monitoring placental health.
Publisher: Informa UK Limited
Date: 19-08-2021
Publisher: MDPI AG
Date: 19-04-2022
DOI: 10.3390/IJMS23094506
Abstract: The human placenta is a rapidly developing transient organ that is key to pregnancy success. Early development of the conceptus occurs in a low oxygen environment before oxygenated maternal blood begins to flow into the placenta at ~10–12 weeks’ gestation. This process is likely to substantially affect overall placental gene expression. Transcript variability underlying gene expression has yet to be profiled. In this study, accurate transcript expression profiles were identified for 84 human placental chorionic villus tissue s les collected across 6–23 weeks’ gestation. Differential gene expression (DGE), differential transcript expression (DTE) and differential transcript usage (DTU) between 6–10 weeks’ and 11–23 weeks’ gestation groups were assessed. In total, 229 genes had significant DTE yet no significant DGE. Integration of DGE and DTE analyses found that differential expression patterns of in idual transcripts were commonly masked upon aggregation to the gene-level. Of the 611 genes that exhibited DTU, 534 had no significant DGE or DTE. The four most significant DTU genes ADAM10, VMP1, GPR126, and ASAH1, were associated with hypoxia-responsive pathways. Transcript usage is a likely regulatory mechanism in early placentation. Identification of functional roles will facilitate new insight in understanding the origins of pregnancy complications.
No related grants have been discovered for Konstantinos Bogias.