Abstract: SA-OR16
Estrogen Signaling Is an Essential Regulator of Nephron Segmentation
Session Information
- Genetics, Development, and Therapies
November 05, 2022 | Location: W308, Orange County Convention Center‚ West Building
Abstract Time: 05:15 PM - 05:24 PM
Category: Development‚ Stem Cells‚ and Regenerative Medicine
- 500 Development‚ Stem Cells‚ and Regenerative Medicine
Authors
- Wesselman, Hannah M., University of Notre Dame, Notre Dame, Indiana, United States
- Wingert, Rebecca A., University of Notre Dame, Notre Dame, Indiana, United States
Background
Despite many significant advances in understanding nephron segment patterning, numerous questions remain about the underlying genes and signaling pathways that orchestrate cell fate and regulate differentiation. In an effort to identify novel regulators of nephron segmentation, our lab conducted a high throughput drug screen using a bioactive chemical library and developing zebrafish, which are a conserved vertebrate model and particularly conducive to large-scale screening approaches. 17β-Estradiol (E2), which is the dominant form of estrogen in vertebrates, was a particularly interesting hit from this screen. While E2 has been extensively studied in the context of gonad development, the mechanism of E2 action in nephron development and segmentation remains poorly understood.
Methods
We evaluated the effects of E2 on segmentation using high throughput chemical screens and analyzed segmentation phenotypes using whole mount in situ hybridization (WISH). Knockdown of estrogen receptors was achieved via morpholino injection and CRISPR-Cas9 mutagenesis. Changes in cell dynamics (e.g. cell death and proliferation) were also analyzed via immunofluorescence.
Results
Exogenous estrogen treatments revealed changes in distal segment composition. Interestingly, xenoestrogens ethinylestradiol and genistein yielded the same changes in distal segments. Upon treatment with an Esr2 antagonist, PHTPP, we observed the opposite phenotypes. Similarly, genetic knockdown of Esr2 analogs revealed phenotypes consistent with that of PHTPP treatment. Inhibition of E2 signaling also resulted in decreased expression of essential distal transcription factors.
Conclusion
Taken together, these data suggest that estrogenic compounds are essential for distal segment fate during nephrogenesis, and add to our understanding of hormone function during kidney organogenesis. Considering the presence of sex differences observed in kidney morphology and renal disease, exploring the influence of sex hormones in the kidney is of upmost importance.