Abstract: SA-PO231
Fibroblast Growth Factor 23 Bioactivity Induces General and Cell Type-Specific Kidney Genomic Reprogramming as Detected by Single-Cell Multiomics
Session Information
- CKD-MBD: Basic and Translational
October 26, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Bone and Mineral Metabolism
- 501 Bone and Mineral Metabolism: Basic
Authors
- Solis, Emmanuel, Indiana University School of Medicine, Indianapolis, Indiana, United States
- Agoro, Rafiou, Indiana University School of Medicine, Indianapolis, Indiana, United States
- Jennings, Kayleigh Nicole, Indiana University School of Medicine, Indianapolis, Indiana, United States
- Marambio, Yamil, Indiana University School of Medicine, Indianapolis, Indiana, United States
- Liu, Sheng, Indiana University School of Medicine, Indianapolis, Indiana, United States
- Meyer, Mark B., University of Wisconsin-Madison, Madison, Wisconsin, United States
- Wan, Jun, Indiana University School of Medicine, Indianapolis, Indiana, United States
- White, Kenneth E., Indiana University School of Medicine, Indianapolis, Indiana, United States
Background
FGF23 functions with its co-receptor Klotho (KL) to regulate phosphate and 1,25D synthesis in the kidney, and this control is dysregulated in diseases such as CKD. The identification of pathways regulated by FGF23 are limited by bulk methodologies, thus significant knowledge gaps remain. Herein, we undertook a novel approach to test FGF23 bioactivity at single-cell resolution, hypothesizing that FGF23 bioactivity would enact cell type-specific transcriptional and genomic changes that could provide insight into the processes driving regulation of phosphate and 1,25D.
Methods
Male and female C57BL/6 mice were injected with recombinant FGF23 over time (0, 1, 4, and 12h) and pooled male/female Multiome (scRNAseq/ scATACseq from the same cell) kidney datasets were generated. Female Xist gene and male Y chromosome markers were used to perform ‘sex hashing’ of cell populations. Data was validated by qPCR.
Results
Dimensionality reduction via UMAP identified 38 distinct clusters in the kidney including unique epithelial, endothelial, and immune cell populations based upon known gene markers. Sex-specific genes, female Xist and male Kdm5d and Eif2s3y showed segregation between female and male mice. KL was detected in PT, LOH, CNT, and DCT. In response to FGF23, Cyp24a1 mRNA and promoter chromatin accessibility increased in PT-S1 whereas Cyp27b1 had the converse regulation, showing that FGF23 induces rapid chromatin remodeling. Notably, Hbegf and Egr1 mRNAs and accessibility increased across all KL-expressing cell types. Indeed, negative MAPK regulator Dusp6 showed increased mRNA expression at 4 and 12h in both PT and DCT. Furthermore, within PT-S1, novel FGF23-regulated genes Slc5a12, Fut9, and Pah, all decreased at 4h. Finally, DCT showed decreased accessibility and mRNA of Pde10a and increased mRNA expression of Dcdc2A at 12h, supporting differential activity of FGF23 depending upon nephron site.
Conclusion
In summary, temporal FGF23 delivery paired with Multiome analyses demonstrated that FGF23 directs both rapid and more chronic renal cell events. Our studies pinpoint transcriptional and chromatin reprogramming that could provide novel pathways for treatment interventions.
Funding
- NIDDK Support