Abstract: TH-OR091
Redefining the Origin and Lineage Fate Decisions Required for Metanephric Mesenchyme Specification
Session Information
- Shaping Pediatric Kidney Disease: Developmental Insights, Stem Cell Systems, Novel Biomarkers, and More
October 22, 2026 | Location: Room 603, Convention Center
Abstract Time: 04:30 PM - 04:40 PM
Category: Development, Stem Cells, and Regenerative Medicine
- 700 Development, Stem Cells, and Regenerative Medicine
Authors
- Ferran-Heredia, Carlos, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States
- McCracken, Kyle, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
Group or Team Name
- Mccracken Lab
Background
The mammalian kidney arises from two embryonic tissues: the metanephric mesenchyme (MM) and the ureteric bud (UB). The MM is a specialized population in the posterior intermediate mesoderm (IM) that contributes to the nephron and stromal progenitors. Although the origin of the UB and its reciprocal interactions with the MM are well characterized, the embryonic origin of the MM remains undefined. We hypothesized that identifying the origin of the MM would provide critical insight into NPC self-renewal and differentiation.
Methods
We used in vivo genetic lineage tracing and wholemount IF to test whether the MM derives from neuromesodermal progenitors (NMPs). We used an inducible Sox2-CreER model to assess whether Sox2+ NMPs at E7.5 contribute to the nephron and stromal kidney progenitors. Alternative lineage tracing models were then used to compare meso-endoderm derived structures and delineate lineage fate decisions required for MM specification. Whole mount IF was used to visualize the various progenitor stages while scRNA-seq was used to profile these progenitors and identify novel subpopulations within the presumptive-MM.
Results
Inducible lineage tracing of NMPs with Sox2-CreER demonstrated robust contribution of NMPs to the nephron and stromal populations in the developing kidney but not the ureteric bud, which derives from more anterior IM. Posterior endoderm and anterior mesoderm were unlabeled, confirming this strategy identified descendants of the lineage-restricted NMPs rather than pluripotent cells. scRNA-seq and complementary lineage tracing has allowed us to define the cell-fate decisions as NMPs differentiate toward the MM.
Conclusion
We conclude that the MM derives from NMPs rather than meso-endodermal primitive streak progenitors, challenging the conventional view of kidney development. Re-assessment of published methods for generating nephron-containing kidney organoids from human pluripotent stem cells found that they do not progress through a neuro-mesodermal competent state but instead through a meso-endodermal state. Therefore, existing in vitro protocols do not mimic the steps of MM formation as defined by our in vivo genetic lineage tracing results. We anticipate that resolving these discrepancies between in vitro and in vivo NPC specification will address the lack of self-renewal and other limitations of current hPSC-derived NPC differentiation protocols.
Acknowledgment
Thank you to my lab members Parna Dutta and Min Shi with help on the scRNA-seq experiments. The TAGE and SCGF cores at Cincinnati Childrens Research Foundation were instrumental in completion of the project.