Selenium and selenium-dependent antioxidants in chronic kidney disease

Area of Science:

• Biochemistry
• Nephrology
• Oxidative Stress Biology

Background:

• Oxidative stress, resulting from an imbalance between reactive oxygen species (ROS) production and antioxidant defenses, is implicated in various diseases, including chronic kidney disease (CKD).
• Glutathione peroxidases (GSH-Px), crucial enzymes in ROS metabolism, require selenium (Se) as a cofactor and are synthesized in the kidney.
• CKD, particularly in patients undergoing hemodialysis, is characterized by significantly reduced levels of both Se and plasma GSH-Px.

Purpose of the Study:

• To explore the role and significance of selenium and glutathione peroxidases in the context of chronic kidney disease.
• To investigate the impact of reduced Se and GSH-Px on renal disease processes and associated conditions like cardiovascular disease and cancer.
• To examine the effects of selenium supplementation and kidney transplantation on plasma GSH-Px levels in CKD patients.

Main Methods:

• Review and analysis of existing literature on oxidative stress, CKD, selenium, and glutathione peroxidases.
• Examination of clinical data regarding Se and GSH-Px levels in CKD patients, including those on hemodialysis.
• Assessment of the impact of interventions such as Se supplementation and kidney transplantation on GSH-Px levels.

Main Results:

• Plasma GSH-Px and Se levels are notably diminished in patients with CKD, especially those on hemodialysis.
• Selenium supplementation leads to a modest increase in GSH-Px, likely due to residual kidney function.
• Kidney transplantation rapidly and effectively restores plasma GSH-Px levels.

Conclusions:

• Selenium is a critical cofactor for GSH-Px, and its deficiency contributes to impaired antioxidant capacity in CKD.
• The kidney's role in synthesizing plasma GSH-Px highlights the organ's importance in systemic antioxidant defense.
• Restoration of kidney function through transplantation effectively reverses GSH-Px deficiency, underscoring the link between renal health and oxidative balance.