Kidney Week

Abstract: FR-PO476

Hypoxia Increases Erythrocyte Death Rate and Oxidative Stress Induced by Indoxyl Sulfate

Session Information

• Anemia and Iron Metabolism: Basic
  October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Anemia and Iron Metabolism

• 201 Anemia and Iron Metabolism: Basic

Authors

• Moreno-Amaral, Andrea Novais, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil

Andrea Novais Moreno-Amaral,

• Dias, Gabriela Ferreira, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil

Gabriela Ferreira Dias,

• Tozoni, Sara Soares, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil

Sara Soares Tozoni,

• Borges Bonan, Natalia, PUC-PR, CURITIBA, Brazil

Natalia Borges Bonan,

• Pecoits-Filho, Roberto, Pontificia Universidade Catolica do Parana, Curitiba, Paraná, Brazil

Roberto Pecoits-Filho,

• Kotanko, Peter, Renal Research Institute, New York, New York, United States

Peter Kotanko,

Group or Team Name

• CARe - CKD Anemia Research Group

Background

Prolonged intradialytic hypoxemia has been associated with higher erythropoietin requirements and poor clinical outcomes in dialysis patients. We analyzed the erythrocyte (RBC) response to indoxyl sulfate under hypoxic conditions.

Methods

RBC from 10 healthy subjects were incubated for 24h with buffer (CON-RBC) or IS (0.01; 0.09; and 0.17 mM) in normoxia (22% O₂) or hypoxia (5% O₂) conditions. Flow cytometry was used to determine: a) Eryptosis by phosphatidylserine exposure (PS) (by Annexin-Phycoerythrin) and intracellular Ca²⁺influx (by Fluo-3AM), b) reactive oxygen species (ROS) production (by DCFH-DA probe) and reduced glutathione (GSH) content (by ThiolTracker Violet).

Results

Eryptosis increased in an IS dose-dependent manner in both normoxia and hypoxia, but the effect was more pronounced with hypoxia (Table 1). Similarly, IS exposure increased ROS production and decrease GSH content in an IS dose-dependent manner, and the response was also amplified by hypoxia (Table 1).

Conclusion

IS exposure increased eryptosis and oxidative stress and, this effect was amplified by hypoxia. These results suggest that the eryptotic effect of uremia may be aggravated by hypoxia. This may represent a novel mechanism in the development of renal anemia.