Activation of FoxO1/ PGC-1α prevents mitochondrial dysfunction and ameliorates mesangial cell injury in diabetic rats

Area of Science:

• Nephrology
• Endocrinology
• Molecular Biology

Background:

• Diabetic nephropathy is characterized by hyperglycemia-induced mitochondrial reactive oxygen species (ROS).
• Forkhead-box class O1 (FoxO1) and peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α) are key regulators of oxidative stress.
• The interplay between FoxO1 and PGC-1α in diabetic kidney disease remains incompletely understood.

Purpose of the Study:

• To investigate the in vivo and in vitro association between FoxO1 and PGC-1α in the context of diabetic nephropathy.
• To elucidate the role of the FoxO1/PGC-1α pathway in high-glucose-induced kidney mesangial cell (MC) injury and mitochondrial dysfunction.
• To determine if FoxO1/PGC-1α activation can protect against diabetic kidney damage.

Main Methods:

• Utilized streptozotocin-induced diabetic rat models and high-glucose treated rat kidney mesangial cells (MCs) in vitro.
• Assessed protein expression, mitochondrial function, and ROS generation.
• Employed chromatin immunoprecipitation to identify direct transcriptional targets and lentiviral vectors for gene overexpression.
• Utilized small interfering RNA (siRNA) to knockdown PGC-1α.

Main Results:

• High glucose inhibited FoxO1, leading to decreased PGC-1α expression, mitochondrial dysfunction, and increased ROS in MCs.
• Constitutive FoxO1 activation upregulated PGC-1α, partially reversing high-glucose-induced damage.
• PGC-1α was confirmed as a direct transcriptional target of FoxO1.
• FoxO1 overexpression in diabetic rats increased PGC-1α, NRF-1, and Mfn2, while reducing oxidative stress markers and proteinuria.

Conclusions:

• FoxO1 directly targets PGC-1α, forming a protective pathway against hyperglycemia.
• Activation of the FoxO1/PGC-1α axis mitigates mitochondrial dysfunction and ROS production in diabetic nephropathy.
• Targeting the FoxO1/PGC-1α pathway represents a potential therapeutic strategy for diabetic kidney disease.