REDD1 Ablation Attenuates the Development of Renal Complications in Diabetic Mice

Area of Science:

• Nephrology
• Endocrinology
• Molecular Biology

Background:

• Diabetic kidney disease (DKD) is a major complication of diabetes, characterized by glomerular injury.
• Chronic hyperglycemia is a key driver of DKD pathogenesis.
• The role of stress response proteins in DKD remains incompletely understood.

Purpose of the Study:

• To investigate the role of the stress response protein regulated in development and DNA damage response 1 (REDD1) in DKD.
• To determine if REDD1 mediates hyperglycemia-induced oxidative stress and renal injury.

Main Methods:

• Streptozotocin-induced diabetes model in wild-type (WT) and REDD1 knockout (KO) mice.
• Assessment of renal physiology, including albuminuria and hypertrophy.
• Histopathologic examination of kidney tissue.
• In vitro studies using cultured human podocytes exposed to hyperglycemic conditions.
• Measurement of reactive oxygen species (ROS) and cell death.

Main Results:

• Diabetic WT mice exhibited increased renal REDD1 expression, albuminuria, and glomerular damage.
• Diabetic REDD1 KO mice showed protection against renal dysfunction and histopathologic damage.
• Hyperglycemia increased REDD1 expression, ROS levels, and cell death in cultured podocytes.
• REDD1 deletion in vivo and in vitro reduced ROS and prevented podocyte loss.
• Pharmacological suppression of GSK3β mimicked the protective effects of REDD1 deletion.

Conclusions:

• REDD1 plays a significant role in mediating hyperglycemia-induced oxidative stress and renal injury in DKD.
• Targeting REDD1 may offer a therapeutic strategy for managing diabetic kidney disease.
• REDD1-dependent GSK3β activation is implicated in the pathogenesis of DKD.