Abstract: SA-OR18
ASH2L Is Essential for the Ureteric Bud Lineage Development
Session Information
- Genetics, Development, and Therapies
November 05, 2022 | Location: W308, Orange County Convention Center‚ West Building
Abstract Time: 05:32 PM - 05:41 PM
Category: Development‚ Stem Cells‚ and Regenerative Medicine
- 500 Development‚ Stem Cells‚ and Regenerative Medicine
Authors
- Zhao, Ziyi, Xin Hua Hospital of Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Lin, Fujun, Xin Hua Hospital of Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Jiang, Gengru, Xin Hua Hospital of Shanghai Jiao Tong University School of Medicine, Shanghai, China
Background
Ureteric bud (UB) induction/branching morphogenesis are the fundamental processes during kidney development, of which GDNF-RET/GFRA1 signaling pathway occupies a central place. Histone modifications have a crucial role in kidney development by placing active/silencing histone marks at different gene regions to fine-tune genes expression. Given that ASH2L, a core subunit in KMT2 enzymes which mediate H3K4 methylation, is widely expressed in UB derivatives, we examined the role of ASH2L in UB lineage morphogenesis during mouse kidney development.
Methods
We inactivated Ash2l expression in the UB lineage using the Cre/loxP system by crossing transgenic Hoxb7creEGFP mice to Ash2lfl/fl mice and analyzed the phenotype of the Ash2l mutants and their littermate controls. Kidney histology and UB branching morphogenesis were studied in Ash2l mutants. E16.5 metanephroi were digested and the UB lineage cells were sorted by FACS and processed for RNA-seq or CUT&Tag-seq. Differentially expressed genes were validated by RT-qPCR and RNA-scope.
Results
Conditional inactivation of Ash2l in the UB lineage results in malformatted kidneys at birth. The budding/branching events of the UB is severely delayed both in vivo and in vitro. Molecularly, inactivation of Ash2l leads to downregulated expression of GDNF-RET/GFRA1 signaling pathway components via repression of H3K4 tri-methylation on promotor regions, resulting in eventually UB cell cycle arrest.
Conclusion
Our study uncovers the novel role of ASH2L during the UB lineage development and H3K4 methylation as the upstream epigenetic regulator of GDNF-RET/GFRA1 signaling pathway. Our study also offers new insights into the role of active histone marks in the molecular pathogenesis of CAKUT.
The mutants show malformatted kidneys at birth (a). The budding/branching events of the UB is severely delayed both in vivo (b) and in vitro (c).
Funding
- Government Support – Non-U.S.