# Understanding Kidney Endothelial Maturity and Mesenchymal Transition in Vascularized Human Kidney Organoids

> **NIH NIH F30** · UNIVERSITY OF PITTSBURGH AT PITTSBURGH · 2024 · $51,254

## Abstract

As high as 60% of all in-hospital cases of acute kidney injury events are a result of nephrotoxic drug exposure.
In injury, studies have demonstrated that susceptible endothelial cells are capable of transdifferentiating to a
pathogenic myofibroblast phenotype through a process known as endothelial to mesenchymal transition
(EndMT). This transition is difficult to study in vivo due to the highly regulated spatiotemporal morphological
changes of individual cells and modified cell-cell communications with resident epithelial cells. In vitro human
kidney organoid models are well suited for studying kidney disease, due to their capacity to recapitulate nephron
epithelial cell types, however, organoids have notoriously lacked endothelial cells, which renders modeling
endothelial injury moot. Our group has developed a novel method for generating highly dense endothelialized
human kidney organoids using a transgenic vasculogenic induced pluripotent stem cell line. These organoids
contain a robust endothelial network that closely interacts with all nephron cell types previously found in human
kidney organoids. Based on preliminary immunofluorescence, electron microscopy and transcriptomic data, I
hypothesize that kidney organoid co-culture of engineered endothelial cells enables the induction of
kidney-specific endothelial maturation (Specific Aim 1). To examine this, I will use electron microscopy,
immunofluorescence, and western blotting to understand whether there is a morphological presence of
fenestrations and an endothelial glycocalyx layer. I will also compare transcriptomically, engineered endothelial
cells to published datasets of human kidney endothelial cells, examining pathways of endothelial maturity and
kidney specificity, while simultaneously determining whether kidney organoid co-culture enables advanced
alignment with human clinical samples. In addition, based on preliminary immunofluorescence data, I
hypothesize that following nephrotoxic exposure, endothelialized human kidney organoid endothelial
cells undergo EndMT, and this process is critically regulated by TGFb (Specific Aim 2). Endothelialized
organoids injured with nephrotoxin, doxorubicin, will be examined with immunofluorescence and FACS by
tracking GFP+ engineered endothelial cells through injury to understand quantitatively the percentage change
of mesenchymal transition. TGFb inhibition will also be used to understand whether this process can be
ameliorated. Uninjured, injured, and injured + TGFb inhibition endothelialized human kidney organoids will be
compared transcriptomically with snRNAseq to determine computational alignment to existing published
datasets of injured endothelial cells having undergone EndMT and to determine upregulated pathways of TGFb
as well as master transcription factor regulators. The studies in this proposal represent a significant and
innovative step forward for the field of kidney disease because these studies uncover critical knowledge in
under...

## Key facts

- **NIH application ID:** 10898302
- **Project number:** 1F30DK137453-01A1
- **Recipient organization:** UNIVERSITY OF PITTSBURGH AT PITTSBURGH
- **Principal Investigator:** Joseph Cole Maggiore
- **Activity code:** F30 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $51,254
- **Award type:** 1
- **Project period:** 2024-04-04 → 2027-04-03

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10898302

## Citation

> US National Institutes of Health, RePORTER application 10898302, Understanding Kidney Endothelial Maturity and Mesenchymal Transition in Vascularized Human Kidney Organoids (1F30DK137453-01A1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10898302. Licensed CC0.

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