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Abstract: TH-PO341

Tight Junction Component-Encoding Gene Regulation in Renal Collecting Duct Principal Cells

Session Information

Category: Fluid‚ Electrolyte‚ and Acid-Base Disorders

  • 1001 Fluid‚ Electrolyte‚ and Acid-Base Disorders: Basic

Authors

  • Cao, Shuang, Charite Universitatsmedizin Berlin, Berlin, Germany
  • Leiz, Janna, Charite Universitatsmedizin Berlin, Berlin, Germany
  • Hinze, Christian, Charite Universitatsmedizin Berlin, Berlin, Germany
  • Schmidt-Ott, Kai M., Charite Universitatsmedizin Berlin, Berlin, Germany
Background

Tight junctions mediate epithelial barrier characteristics and paracellular transport. In renal collecting ducts, the molecular composition of tight junctions is important for the renal regulation of osmolarity and electrolyte balance. It is incompletely understood how gene regulatory networks in collecting duct principal cells control tight junction component-encoding gene expression.

Methods

We conducted bioinformatic predictions based on mouse and human single-nuclei sequencing data sets and performed in situ hybridization on mouse kidney sections and CRISPRi-based knockdown experiments in inner medullary collecting duct (IMCD3) cells.

Results

Renal single-cell regulatory network prediction based on coregulation and motif enrichment identified a series of candidate collecting duct principal cell transcription factors predicted to be important for tight junction-encoding gene regulation, which included the transcription factor Ets homologous factor (Ehf). In situ hybridization validated co-expression of Ehf and its predicted target claudin 7 (Cldn7) in mouse collecting ducts in vivo. In vitro CRISPRi-mediated knockdown of Ehf in IMCD3 cells was successfully achieved and its effects on tight junction component-encoding gene expression are currently being evaluated.

Conclusion

Preliminary data suggest that the transcription factor Ehf regulates tight junction component-encoding genes in collecting duct principal cells.

In situ hybridization validate co-expression of Ehf and Cldn7

Ehf knockdown show the mRNA level change of TJs

Funding

  • Government Support – Non-U.S.