Kidney Week

Abstract: FR-OR119

Single Nucleus RNA Sequencing of Early Human Diabetic Nephropathy Reveals Transcriptional Changes That Promote Potassium Secretion

Session Information

• Translating Discovery to Patients with Diabetic Kidney Disease
  November 08, 2019 | Location: 207, Walter E. Washington Convention Center
  Abstract Time: 06:06 PM - 06:18 PM

Category: Diabetic Kidney Disease

• 601 Diabetic Kidney Disease: Basic

Authors

• Wilson, Parker C., Washington University in St. Louis, St. Louis, Missouri, United States

Parker C. Wilson, MD, PhD



Dr. Parker Wilson is a renal and molecular pathologist at Washington University in St. Louis. His research interest focuses on the application of next generation sequencing and novel bioinformatics techniques to better understand kidney disease.

• Wu, Haojia, Renal Division Washington University School of Medicine, Saint Louis, Missouri, United States

Haojia Wu,

• Kirita, Yuhei, Washington University School of Medicine in St. Louis, Saint Louis, Missouri, United States

Yuhei Kirita,

• Uchimura, Kohei, Washington University School of Medicine, Saint Louis, Missouri, United States

Kohei Uchimura,

• Rennke, Helmut G., Brigham and Women's Hospital, Boston, Massachusetts, United States

Helmut G. Rennke,

• Waikar, Sushrut S., Harvard Medical School, Boston, Massachusetts, United States

Sushrut S. Waikar,

• Welling, Paul A., University of Maryland School of Medicine, Baltimore, Maryland, United States

Paul A. Welling,

• Humphreys, Benjamin D., Washington University School of Medicine, Saint Louis, Missouri, United States

Benjamin D. Humphreys,

Background

Diabetic nephropathy is characterized by damage to both the glomerulus and tubulointerstitium, but relatively little is known about cell-specific transcriptional changes. We hypothesized that single nucleus RNA sequencing (snRNAseq) of cryopreserved human diabetic kidney samples would reveal genes and signaling networks in early diabetic nephropathy.

Methods

We analyzed three diabetic and three healthy human kidney samples. Diabetics had elevated A1c (mean = 7.9 +/- 1.5%) and two of three patients had proteinuria. Baseline serum creatinine (mean = 1.06 +/- 0.23 mg/dl) was not different between groups. Nuclear preparations of cryopreserved samples were processed using 10x Genomics Chromium 5’ kit and sequenced by NovaSeq. Reads were counted with zUMIS v2.0 and analyzed with Seurat v2.3.

Results

A total of 23,980 single nuclei were sequenced representing all glomerular and tubulointerstitial cell types. Infiltrating T-cells and B-cells were increased in diabetic samples. Side by side comparison showed cell-type-specific transcriptional changes important for ion transport, angiogenesis, and immune cell activation. In particular, the diabetic loop of Henle, late distal convoluted tubule, and principal cells show gene changes consistent with increased potassium secretion, including alterations in Na-K⁺-ATPase, WNK1, NEDD4L, and mineralocorticoid receptor (Figure 1; green=upregulated, red=downregulated). These effects were accompanied by increased expression of CASR and decreased expression of CLDN16 in the loop of Henle, which regulate calcium and magnesium reabsorption. We also identify strong angiogenic signatures in glomerular cell types, proximal convoluted tubule, distal convoluted tubule and principal cells.

Conclusion

Early diabetes induces gene expression changes in the distal nephron coordinate to promote potassium secretion and angiogenesis.

Funding

• NIDDK Support