Regionally distinct trophoblast regulate barrier function and invasion in the human placenta
Abstract
The human placenta contains two specialized regions: the villous chorion where gases and nutrients are exchanged between maternal and fetal blood, and the smooth chorion which surrounds more than 70% of the developing fetus but whose cellular composition and function is poorly understood. Here, we use single cell RNA sequencing to compare the cell types and molecular programs between these two regions in the second trimester human placenta. Each region consists of progenitor cytotrophoblasts (CTBs) and extravillous trophoblasts (EVTs) with similar gene expression programs. While CTBs in the villous chorion differentiate into syncytiotrophoblasts, they take an alternative trajectory in the smooth chorion producing a previously unknown CTB population which we term smooth-chorion-specific CTBs (SC-CTBs). Marked by expression of region-specific cytokeratins, the SC-CTBs form a stratified epithelium above a basal layer of progenitor CTBs. They express epidermal and metabolic transcriptional programs consistent with a primary role in defense against physical stress and pathogens. Additionally, we show that SC-CTBs closely associate with EVTs and secrete factors that inhibit the migration of the EVTs. This restriction of EVT migration is in striking contrast to the villous region where EVTs migrate away from the chorion and invade deeply into the decidua. Together, these findings greatly expand our understanding of CTB differentiation in these distinct regions of the human placenta. This knowledge has broad implications for studies of the development, functions, and diseases of the human placenta.
Data availability
Sequencing data have been deposited in GEO under the accession code GSE198373Processed data have been deposited on Figshare at https://figshare.com/projects/Regionally_distinct_trophoblast_regulate_barrier_function_and_invasion_in_the_human_placenta/135191.Code to generate the processed data have been deposited on GitHub at https://github.com/marshbp/Regionally-distinct-trophoblast-regulate-barrier-function-and-invasion-in-the-human-placenta.
-
Regionally distinct trophoblast regulate barrier function and invasion in the human placentaNCBI Gene Expression Omnibus, GSE198373.
Article and author information
Author details
Funding
National Institutes of Health (P50 HD055764)
- Bryan Marsh
- Robert Blelloch
National Institutes of Health (R37 HD076253)
- Yan Zhou
- Mirhan Kapidzic
- Susan Fisher
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Claudia Gerri, Max Planck Institute of Molecular Cell Biology and Genetics
Ethics
Human subjects: The University of California, San Francisco (UCSF) Institutional Review Board approved this study (11-05530). All donors gave informed consent.
Version history
- Preprint posted: March 22, 2022 (view preprint)
- Received: March 22, 2022
- Accepted: July 6, 2022
- Accepted Manuscript published: July 7, 2022 (version 1)
- Version of Record published: July 26, 2022 (version 2)
Copyright
© 2022, Marsh et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 2,156
- Page views
-
- 522
- Downloads
-
- 11
- Citations
Article citation count generated by polling the highest count across the following sources: Crossref, PubMed Central, Scopus.
Download links
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Further reading
-
- Developmental Biology
- Neuroscience
Mammals harbor a limited number of sound-receptor hair cells (HCs) that cannot be regenerated after damage. Thus, investigating the underlying molecular mechanisms that maintain HC survival is crucial for preventing hearing impairment. Intriguingly, Pou4f3-/- or Gfi1-/- HCs form initially but then rapidly degenerate, whereas Rbm24-/- HCs degenerate considerably later. However, the transcriptional cascades involving Pou4f3, Gfi1, and Rbm24 remain undescribed. Here, we demonstrate that Rbm24 expression is completely repressed in Pou4f3-/- HCs but unaltered in Gfi1-/- HCs, and further that the expression of both POU4F3 and GFI1 is intact in Rbm24-/- HCs. Moreover, by using in vivo mouse transgenic reporter assays, we identify three Rbm24 enhancers to which POU4F3 binds. Lastly, through in vivo genetic testing of whether Rbm24 restoration alleviates the degeneration of Pou4f3-/- HCs, we show that ectopic Rbm24 alone cannot prevent Pou4f3-/- HCs from degenerating. Collectively, our findings provide new molecular and genetic insights into how HC survival is regulated.
-
- Developmental Biology
- Evolutionary Biology
Genome-wide association studies (GWAS) identified thousands of genetic variants linked to phenotypic traits and disease risk. However, mechanistic understanding of how GWAS variants influence complex morphological traits and can, in certain cases, simultaneously confer normal-range phenotypic variation and disease predisposition, is still largely lacking. Here, we focus on rs6740960, a single nucleotide polymorphism (SNP) at the 2p21 locus, which in GWAS studies has been associated both with normal-range variation in jaw shape and with an increased risk of non-syndromic orofacial clefting. Using in vitro derived embryonic cell types relevant for human facial morphogenesis, we show that this SNP resides in an enhancer that regulates chondrocytic expression of PKDCC - a gene encoding a tyrosine kinase involved in chondrogenesis and skeletal development. In agreement, we demonstrate that the rs6740960 SNP is sufficient to confer chondrocyte-specific differences in PKDCC expression. By deploying dense landmark morphometric analysis of skull elements in mice, we show that changes in Pkdcc dosage are associated with quantitative changes in the maxilla, mandible, and palatine bone shape that are concordant with the facial phenotypes and disease predisposition seen in humans. We further demonstrate that the frequency of the rs6740960 variant strongly deviated among different human populations, and that the activity of its cognate enhancer diverged in hominids. Our study provides a mechanistic explanation of how a common SNP can mediate normal-range and disease-associated morphological variation, with implications for the evolution of human facial features.