Dalla Lana School of Public Health

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• All welcome. Registration:

The STAGE International Speaker Seminar Series is proud to host a talk by:

Dr. Louise Laurent
Professor and Director of Perinatal Research,
Department of Obstetrics, Gynecology, & Reproductive Sciences
Co-Director of the Center for Perinatal Discovery and the EXCITE Lab
Member of the Stem Cell Program and the Institute for Genomic Medicine
University of California San Diego

Talk Title: Spatial and Single-Nucleus Multiomic Mapping of Human Placental Development

Date: Friday, June 5, 2026

Time: 1:00-2:00 pm ADT (Halifax)

Format: Hybrid (In-person and Zoom)

In-person Location:
Collaborative Health Education Building
Room 266,
Dalhousie University
5793 University Ave.,
Halifax, NS

All welcome. Registration: https://stage.utoronto.ca/events/stage-isss-louise-laurent/

Abstract: This project aims to map how cellular composition, molecular programs, and tissue architecture evolve during placental development. To do this, we have generated single-nucleus and high-resolution spatial multiomic data from placental samples collected across gestation.

We first produced datasets using bulk RNA-seq and ATAC-seq, single-nucleus multiome profiling (10x Genomics), and whole-transcriptome spatial profiling (GeoMx, Bruker Spatial Biology). These data informed the design of a 300-plex placenta-focused gene panel for targeted spatial transcriptomics and antibody panels for spatial proteomics.

Xenium (10x Genomics) using the targeted transcript panel was then performed to enable high-resolution mapping of cell types and states across gestation. This was complemented by spatial proteomics using a 28-plex placenta-focused antibody panel for imaging mass cytometry (Standard BioTools) on term placentas, which was expanded to a 59-plex panel for PhenoCycler-Fusion (Quanterix) on placentas across gestation. To capture spatial continuity through tissue depth, the multimodal G4X assay (Singular Genomics) was applied to 20 serial sections from representative cases in each trimester. Each section was profiled with a 16-plex protein panel, the same 300-plex transcript panel, and virtual H&E imaging. Adjacent sections were co-registered using BigWarp, enabling accurate 2.5D segmentation and downstream analysis. In parallel, extracellular matrix composition was characterized using matrisome-focused mass spectrometry.

This integrated approach captures coordinated, gestation-dependent changes across multiple biological axes. Trophoblast subtypes show shifts in abundance and transcriptional programs consistent with stage-specific functions. The placental vasculature exhibits progressive maturation and, for the first time, spatial profiling enables separation of arterial and venous vessels with distinct molecular signatures. Immune cell populations also change across gestation in both composition and localization. Integration of transcriptomic, proteomic, and ECM data further highlights evolving cell-cell and cell-matrix interactions.

Together, these data provide a multimodal, spatially resolved framework for studying human placental development across gestation and establish a reference atlas of placental organization and function.

Profile: Louise C Laurent, MD/PhD is a Professor and a founding Co-Director for the Center for OB/GYN Research Innovation in the Department of Obstetrics, Gynecology, and Reproductive Sciences at the University of California, San Diego. She was a recipient of a training fellowship from the California Institute of Regenerative Medicine, a fellowship from the NIH Reproductive Scientist Development Program, and a fellowship from the NIH/NICHD Women’s Reproductive Health Research Career Development Program. She received her residency training in Obstetrics and Gynecology and her clinical fellowship training in Maternal Fetal Medicine at UC San Diego. As a student in the laboratory of Vikas P. Sukatme, M.D., Ph.D., at the University of Chicago, she cloned and characterized EGR1, a zinc finger transcription factor. Her graduate research as a MSTP student at UCSF included a large-scale mutagenesis and molecular tracking strategy to define the regions of the HIV genome necessary for viral replication in the laboratory of Patrick O. Brown, M.D./Ph.D. As a clinical fellow, she worked with Jeanne Loring, Ph.D. at The Scripps Research Institute to delineate the expression of miRNAs in human embryonic stem cells. Her basic science research focuses on applying genomic and epigenomic methods to understanding the molecular regulation of pluripotency and differentiation and identifying the molecular basis of placental dysfunction in human pregnancy. She also has a translational science program, which includes projects aimed at discovering biomarkers for prediction and early diagnosis of adverse pregnancy outcomes.

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