Kidney Week

Abstract: TH-PO903

Effects of Esculin Treatment on P2X₇ Receptor and Klotho in Experimental Diabetic Nephropathy

Session Information

• Diabetic Kidney Disease: Basic - I
  November 07, 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

• Serralha, Robson Souza, Universidade Federal de São Paulo, Sao Paulo, Brazil

Robson Souza Serralha,

• Rodrigues, Adelson, UNIFESP, Sao Paulo, Brazil

Adelson Rodrigues,

• Rodrigues, Inri, Universidade Federal de Sao Paulo, Sao Paulo, Brazil

Inri Rodrigues,

• Bertolini, Angela, Universidade Federal de Sao Paulo, Sao Paulo, Brazil

Angela Bertolini,

• Lima, Deyse, UNIFESP, Sao Paulo, Brazil

Deyse Lima,

• Nascimento, Moises, Universidade Federal de Sao Paulo, Sao Paulo, Brazil

Moises Nascimento,

• Mouro, Margaret G., UNIFESP, Sao Paulo, Brazil

Margaret G. Mouro,

• Silva, Manoel, Universidade Federal de Sao Paulo, Sao Paulo, Brazil

Manoel Silva,

• Punaro, Giovana, UNIFESP, Sao Paulo, Brazil

Giovana Punaro,

• Higa, Elisa Mieko Suemitsu, Medicine Department/Unifesp, Sao Paulo, Brazil

Elisa Mieko Suemitsu Higa,

Group or Team Name

• Laboratory of Nitric Oxide and Oxidative Stress

Background

P2X₇ is a purinergic receptor which is activated under high concentrations of extracellular ATP, a common situation seen in diabetes mellitus, induced by the hyperglycemia. This receptor promotes calcium influx, which in large quantities activates biochemical processes culminating in programmed cell death. Constant activation of P2X₇ induces inflammatory responses and oxidative stress. A previous study in our Laboratory showed a correlation between P2X₇ and Klotho, since the latter can control phosphate metabolism. Coumarin derivates, as esculin, reduces oxidative damage seen in intestinal inflammation, arthritis and cognitive impairment related to diabetes. However, their pharmacodynamics are not yet fully understood. Thus, we aimed to evaluate the effects of esculin treatment on P2X₇ receptor expression and Klotho in the kidneys of diabetic rats.

Methods

Male Wistar rats, 7 weeks old, received a single dose of streptozotocin (60 mg/kg; i.v.) for diabetes induction; control received only the drug vehicle. Diabetes was considered at blood glucose levels greater than 200 mg/dL. The animals received daily doses of esculin (50 mg/kg, p.o.), during 8 weeks, forming CTL+ESC and DM+ESC groups. 24-hours urine and a small aliquot of blood were collected for biochemical analysis and the rats were euthanized at the end of the protocol. The kidneys were collected for Western blotting. Statistical analysis was performed in GraphPad Prism 6 and the results are described as mean ± SEM; significance for p<0.05.

Results

The diabetic rats presented 50% increase in P2X₇ protein content when compared to CTL. DM group treated with ESC had a 46% decrease in P2X_7; Klotho levels increased after ESC. We previously showed that Klotho, depleting phosphate, reduced P2X₇ and protected the rats against diabetic nephropathy. Furthermore, DM treated with ESC also presented lower proteinuria (38.72±4.82 vs 45.42±3.0) and urinary TBARS (indicative of lipoperoxidation) (232.3±28.83 vs 282.0±7.2) when compared with untreated ones.

Conclusion

Our data suggest that decreased P2X_7, perhaps via increasing Klotho, could be one of possible pathways for esculin to promote beneficial effects on the kidneys of diabetic animals.

Funding

• Government Support - Non-U.S.