Poly(ADP-ribose) polymerase-2 is a lipid-modulated modulator of muscular lipid homeostasis

Area of Science:

• Biochemistry
• Molecular Biology
• Metabolic Regulation

Background:

• Poly(ADP-ribose) polymerase-2 (PARP2) is recognized for its role in DNA repair.
• Emerging evidence suggests PARP2 also functions as a significant metabolic regulator.
• Understanding PARP2's metabolic functions is crucial for metabolic research.

Purpose of the Study:

• To investigate the role of PARP2 in lipid metabolism.
• To determine the effects of PARP2 ablation on the lipidome and cellular processes.
• To identify potential lipid species that modulate PARP2 activity.

Main Methods:

• Gene silencing (ablation) of PARP2 in mice.
• Lipidome analysis to detect changes in lipid profiles.
• Analysis of gene expression, including sterol regulatory element-binding proteins.
• Biophysical characterization of cell membranes.
• In silico and wet chemistry studies to identify lipid modulators.

Main Results:

• PARP2 ablation led to significant alterations in the lipidome.
• Silencing PARP2 increased sterol regulatory element-binding protein expression and de novo cholesterol synthesis in skeletal muscle.
• Enhanced muscular cholesterol promoted dihydrotestosterone biosynthesis, resulting in stronger skeletal muscle fibers.
• Changes in cell membrane dynamics were observed, indicating altered biophysical properties.
• Specific lipid species, including artificial steroids, were identified that can decrease PARP2 expression.

Conclusions:

• PARP2 plays a critical role in regulating lipid metabolism.
• PARP2 influences cholesterol biosynthesis and anabolic steroid production in skeletal muscle.
• Lipidome modifications impact cell membrane biophysics.
• PARP2 activity is modulated by specific lipid species, suggesting a feedback mechanism.