Pgam5 aggravates hyperglycemia-induced myocardial dysfunction through disrupting Phb2-dependent mitochondrial...

Area of Science:

• Cardiovascular Biology
• Mitochondrial Biology
• Diabetic Complications

Background:

• Diabetic cardiomyopathy is a major complication of diabetes, characterized by myocardial dysfunction.
• Hyperglycemia is a key driver of diabetic cardiomyopathy, leading to cellular and mitochondrial damage.
• The roles of Phosphoglycerate Mutase Family Member 5 (Pgam5) and Prohibitin 2 (Phb2) in this context are not fully understood.

Purpose of the Study:

• To investigate the protective roles of Pgam5 and Phb2 against hyperglycemia-induced myocardial dysfunction.
• To elucidate the molecular mechanisms involving mitochondrial dynamics, including fission and mitophagy.
• To assess the therapeutic potential of modulating Pgam5 and Phb2 in diabetic cardiomyopathy.

Main Methods:

• Primary cardiomyocytes were exposed to hyperglycemia.
• Pgam5 was downregulated using siRNA; Phb2 was overexpressed using adenovirus.
• Mitochondrial function was assessed via membrane potential (JC-1) and reactive oxygen species (ROS) levels.
• Gene expression related to mitochondrial fission and mitophagy was analyzed by qPCR.

Main Results:

• Hyperglycemia impaired cardiomyocyte viability and mitochondrial function (decreased membrane potential, increased ROS).
• Pgam5 knockdown preserved cardiomyocyte viability and mitochondrial function.
• Pgam5 regulated genes involved in mitochondrial fission (Drp1, Mff, Fis1) and mitophagy (Parkin, Bnip3, Fundc1).
• Phb2 overexpression counteracted hyperglycemia-induced mitochondrial dysfunction and normalized antioxidant enzyme levels.

Conclusions:

• Pgam5 knockdown and Phb2 overexpression exhibit protective effects against hyperglycemia-induced cardiac damage.
• Pgam5 and Phb2 are critical regulators of mitochondrial dynamics (fission and mitophagy) in diabetic cardiomyopathy.
• Modulating Pgam5 and Phb2 represents a potential therapeutic strategy for diabetic cardiomyopathy.