Abstract: SA-PO497
Comparison of Nrf2-Inducing Compounds on Renal Tubule Cell Responses Associated with Diabetes
Session Information
- Diabetic Kidney Disease: Basic - III
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Diabetic Kidney Disease
- 601 Diabetic Kidney Disease: Basic
Authors
- Davis, Laura, University of Louisville, Louisville, Kentucky, United States
- Rane, Madhavi J., University of Louisville, Louisville, Kentucky, United States
- Isaacs, Susan M., University of Louisville, Louisville, Kentucky, United States
- Barati, Michelle T., University of Louisville, Louisville, Kentucky, United States
Background
The transcription factor Nrf2 regulates cell stress responses. Though many reports suggest the therapeutic potential of Nrf2 inducing compounds in models of kidney disease, use of these agents in clinical settings is limited. Our lab found disparate effects of two Nrf2 inducing compounds, Dimethyl fumarate (DMF) and Protandim (a dietary supplement with no previously reported findings in renal cells), on renal tubule cell morphology and actin cytoskeleton. Due to varying interactions of inducers with the Nrf2 inhibitor, Keap1, and ultimately Nrf2 target gene induction, this study tested the hypothesis that DMF and Protandim differentially regulate renal tubule cell responses associated with disease.
Methods
Human renal proximal tubule cells were treated with 5µg/ml Protandim or 10µM DMF, before or after culture in high glucose (HG; 25mM) concentrations to mimic diabetes. Cell viability was examined via MTT Assay (reduction of (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide [MTT] in viable cells), matrix protein secretion tested via fibronectin immunoblot of cell culture medium, and cell structural proteins (E-Cadherin and α/β tubulin) analyzed via Immunofluorescent staining. Results analyzed by two-way ANOVA with post hoc.
Results
Culture in HG for 24h increased MTT reduction. When cells were treated with inducers for an additional 24h after culture in HG, DMF reversed the effects of HG on MTT reduction. When cells were instead pre-treated with inducers for 24h prior to culture in HG for an additional 24h, DMF again tended to reverse the effects of HG on MTT reduction. Pre-treatment with DMF and Protandim prior to culture in HG showed a trend (P=0.07) of lowering HG-induced fibronectin production. Alternatively, treatment with inducers after HG conditions exhibited the same trend with Protandim but an opposing trend with DMF. Expression of E-cadherin decreased with DMF and protein distribution was more punctate, while α/β tubulin expression and/or polymerization increased with Protandim.
Conclusion
Protandim and DMF differentially regulate renal tubule cell matrix protein secretion and cell structural protein expression and distribution, responses known to be altered with diabetes. The differential effects of Nrf2 inducers on renal cells may lead to different outcomes if/when used for treatment of kidney diseases.
Funding
- NIDDK Support