Abstract: FR-PO936
Transcription Factor HNF-1β Regulates Axonal Guidance Genes During Kidney Development
Session Information
- Development, Stem Cells, Regenerative Medicine - II
October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Development, Stem Cells, and Regenerative Medicine
- 501 Development, Stem Cells, and Regenerative Medicine: Basic
Authors
- Shao, Annie, University of Minnesota, Minneapolis, Minnesota, United States
- Aboudehen, Karam S., University of Minnesota, Minneapolis, Minnesota, United States
- Chan, Siu Chiu, University of Minnesota, Minneapolis, Minnesota, United States
- Igarashi, Peter, University of Minnesota, Minneapolis, Minnesota, United States
Background
Mutations of the transcription factor hepatocyte nuclear factor 1β (HNF-1β) represent the most common genetic cause of congenital anomalies of the kidney and urinary tract (CAKUT). HNF-1β plays essential roles in kidney development through the regulation of branching morphogenesis, nephrogenesis, and nephron patterning. However, the molecular mechanisms whereby mutations of HNF-1β cause CAKUT remain incompletely understood. Here, we used chromatin immunoprecipitation and deep sequencing (ChIP-seq) to identify novel transcriptional targets of HNF-1β in the developing mouse kidney.
Methods
Chromatin was extracted from wild-type E14.5 mouse metanephroi, immunoprecipitated with an anti-HNF-1β antibody, and sequenced using next-generation sequencing. HNF-1β binding sites were mapped to the mouse genome, and nearby genes were identified. The functions of HNF-1β target genes were determined using Ingenuity Pathway Analysis (IPA). The expression of HNF-1β target genes in wild-type and HNF-1β-deficient mIMCD3 cells was measured using RNA-seq.
Results
ChIP-seq identified 8,490 HNF-1β binding sites in chromatin from E14.5 mouse kidneys, including peaks at known HNF-1β developmental genes, such as Wnt9 and Pax8. 6,104 binding sites were novel and were not previously detected by ChIP-seq in mIMCD3 cells. IPA analysis of HNF-1β target genes revealed that axonal guidance was the highest scoring canonical pathway. HNF-1β binding sites were identified near 63 axonal guidance genes, including netrins (Ntn4), netrin receptor (Unc5c), semaphorins (Sema4a, Sema3g, Sema3d, Sema6a), and ephrins (Eph4b). RNA-seq analysis showed altered expression of core axonal guidance genes in HNF-1β-deficient cells compared to wild-type cells, suggesting that they were directly regulated by HNF-1β.
Conclusion
HNF-1β regulates the transcription of axonal guidance genes in the developing mouse kidney. In addition to their roles in axonal guidance, netrins, semaphorins, and ephrins are essential for branching morphogenesis in epithelial organs such as the lung. Dysregulation of axonal guidance genes may underlie branching defects in HNF-1β mutant kidneys.
Funding
- NIDDK Support