The Ablation of Mitochondrial Protein Phosphatase Pgam5 Confers Resistance Against Metabolic Stress

Area of Science:

• Mitochondrial biology
• Metabolic regulation
• Stress response

Background:

• Phosphoglycerate mutase family member 5 (PGAM5) is a mitochondrial protein phosphatase implicated in stress responses.
• In vivo functions of PGAM5, particularly in whole-body metabolism, remain largely unexplored.

Purpose of the Study:

• To investigate the in vivo role of PGAM5 in metabolic regulation and response to metabolic challenges.
• To elucidate the mechanisms underlying PGAM5's involvement in stress adaptation and energy homeostasis.

Main Methods:

• Generation and analysis of Pgam5-deficient mice.
• Assessment of metabolic parameters under cold stress, fasting, and high-fat diet conditions.
• Measurement of serum lipids, brown adipose tissue (BAT) lipid content, mitochondrial integrity, and fibroblast growth factor 21 (FGF21) levels.

Main Results:

• Pgam5-deficient mice exhibited resistance to metabolic insults, including cold stress and fasting, with improved thermoregulation and survival rates.
• Reduced serum triglycerides and BAT lipid content were observed in Pgam5-deficient mice.
• PGAM5 deficiency led to impaired mitochondrial integrity in BAT but induced significant upregulation of FGF21, enhancing BAT thermogenesis and lipid metabolism.

Conclusions:

• PGAM5 plays a crucial role in whole-body metabolism, particularly in adapting to mitochondrial stress.
• Enhanced lipid metabolism and FGF21 induction contribute to the metabolic resilience of Pgam5-deficient mice.
• PGAM5 deficiency confers resistance to diet-induced obesity and metabolic challenges.