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Abstract: TH-PO906

Insulin Resistance Impacts the Host Defense Transcriptome in Kidney Intercalated Cells

Session Information

Category: Diabetic Kidney Disease

  • 601 Diabetic Kidney Disease: Basic

Authors

  • Schwartz, Laura, The Research Institute at Nationwide Children's, Columbus, Ohio, United States
  • Eichler, Tad, The Research Institute at Nationwide Children's, Columbus, Ohio, United States
  • Bender, Kristin, The Research Institute at Nationwide Children's, Columbus, Ohio, United States
  • Zhao, Jing, The Ohio State University, Columbus, Ohio, United States
  • Yan, Pearlly, The Ohio State University Comprehensive Cancer Cen, Columbus, Ohio, United States
  • Bundschuh, Ralf, The Ohio State University, Columbus, Ohio, United States
  • Spencer, John David, The Research Institute at Nationwide Children's, Columbus, Ohio, United States
Background

Urinary tract infection (UTI) is a common problem in women. Select populations have increased UTI risk, including those with insulin resistance and diabetes. The kidney’s intercalated cells (IC) play a key role in preventing UTI by regulating urine pH, releasing cytokines, secreting antimicrobial peptides (AMPS), and creating a barrier with apposing principal cells to prevent bacterial invasion. Our data show that insulin receptor (IR) deletion in murine ICs inhibits IC-insulin signaling and increases UTI risk in vivo while having no impact on glucose homeostasis or urine acidification. Here, we profile the transcriptome of ICs isolated from IR knockout (IRKO) mice and controls (IRflox) to identify insulin-mediated host defense mechanisms.

Methods

To delete the IR gene Insr in murine ICs, V-ATPase-Cre transgenic mice were bred with IR floxed mice. A tdT reporter was added to aid fluorescence-assisted cell sorting (FACS) of ICs and visualize IC-specific Cre-recombination. Limited cell RNAseq was performed on FACS-isolated ICs and read count data were analyzed for differentially expressed genes (DEG) using the R package edgeR. DEGs with fold-change >1.5 and a false discovery rate adjusted p-value < 0.05 were defined as differentially expressed. Pathway and gene ontology term enrichment analyses of DEGs were performed using the Enrichr tool and DAVID.

Results

FACS-enriched IC cells expressed IC-specific genes, like Aqp6 and Atp6v0d2. Differential expression analysis revealed downregulation of 138 genes and upregulation of 232 genes in IRKO IC vs IRflox IC. A decrease in Insr as well as other downstream IR-regulated genes was confirmed in IRKO ICs. Functional annotation analysis identified enriched KEGG pathways including adherens junction, insulin resistance, and adipocytokine signaling. Gene ontology terms involved in innate immunity and intracellular trafficking were enriched. AMPs, including members of the defensin and ribonuclease A families, were downregulated.

Conclusion

These data suggest that IR-signaling impacts the IC host defense transcriptome and identifies IR-sensitive transcripts that may aid in pathogen defense by maintaining paracellular boundaries, regulating intracellular trafficking, and expressing AMPs. These studies may uncover new immune targets to prevent/treat diabetes-associated infections.

Funding

  • NIDDK Support