Abstract: TH-PO680

Comparison of Glomerular Endothelial Cell Gene Expression Profiles in Diabetic Mice with or without eNOS Deficiency

Session Information

Category: Diabetes

  • 501 Diabetes Mellitus and Obesity: Basic - Experimental

Authors

  • Fu, Jia, National Clinical Research Center of Kidney Diseases, Nanjing, JIangSu, China
  • Wei, Chengguo, Icahn School of Medicine at Mount Sinai, New York, New York, United States
  • Zhang, Weijia, Icahn School of Medicine at Mount Sinai, New York, New York, United States
  • Schlondorff, Detlef O., Icahn School of Medicine at Mount Sinai, New York, New York, United States
  • Chuang, Peter Y., Connecticut Kidney Center, LLC, Orange, Connecticut, United States
  • Liu, Zhihong, National Clinical Research Center of Kidney Diseases, Nanjing, JIangSu, China
  • He, John C., Icahn School of Medicine at Mount Sinai, New York, New York, United States
  • Lee, Kyung, Icahn School of Medicine at Mount Sinai, New York, New York, United States
Background

Glomerular endothelial cell (GEC) injury is a key early event in DN, but the underlining mechanisms remain unclear. In order to assess the key molecular changes in GECs in early DN, we performed a transcriptomic analysis of GECs isolated from diabetic and nondiabetic mice. Two diabetic models were used: 1) streptozotocin (STZ)-induced diabetic mice and 2) STZ-induced diabetic eNOS-/- mice to take advantage of the accelerated DN development with eNOS-deficiency.

Methods

GECs were isolated from transgenic mice expressing histone H2B-fused enhanced yellow fluorescent protein (EYFP) under the Flk-1 promoter. Flk1-EYFP mice were crossed with wildypte or eNOS-/- mice, and diabetes was induced with STZ. Vehicle-injected mice served as controls. All mice were sacrificed at 10 weeks post-injection, and GECs were sorted for mRNA sequencing. Differentially expressed genes (DEGs) from GECs of diabetic mice were analyzed. Key altered pathways were validated by qPCR and immunostaining in second set of experimental mice, and kidney biopsies were performed over time in diabetic and control mice to determine GEC numbers.

Results

DEGs in both diabetic models showed significant alterations in genes related to apoptosis, oxidative stress, cell migration, and proliferation. GECs from diabetic eNOS-/- mice further exhibited altered expressions in genes related to vascular endothelial cell function and epigenetic regulation. We confirmed by immunostaining that GECs indeed exhibited increased oxidative stress and apoptosis in diabetic wildtype mice, which were further exacerbated in diabetic eNOS-/- mice. We also confirmed that epigenetic regulation was altered specifically in diabetic eNOS-/- GECs. Interestingly, we observed a biphasic change in GECs of diabetic eNOS-/- mice that was characterized by an increase at 6-weeks post-diabetes induction, followed by a significant loss by 10-weeks post-induction, suggesting that an early angiogenic process precedes increased apoptosis and failure of regeneration at the subsequent phase of DN injury.

Conclusion

Our results reveal several novel mechanisms of GEC injury in early DN, which can serve as a basis for further exploration into the mechanism of early diabetic GEC injury and for potential new therapeutic intervention to prevent GEC injury in early DN.

Funding

  • NIDDK Support