Probing DNA damage in Rett syndrome neurons uncovers a role for MECP2 regulation of PARP1

Area of Science:

• Neuroscience
• Genetics
• Molecular Biology

Background:

• Rett syndrome is a neurodevelopmental disorder characterized by loss of motor skills and cognitive function.
• Neurons in Rett syndrome models exhibit senescence and P53 activity, but the underlying cause of dysfunction is unclear.

Purpose of the Study:

• To investigate the molecular mechanisms driving neuronal dysfunction in Methyl-CpG-binding protein 2 (MECP2)-null neurons.
• To explore the role of DNA damage and repair pathways in Rett syndrome pathogenesis.

Main Methods:

• Utilized human induced pluripotent stem cell (hiPSC)-derived isogenic lines to model MECP2 deficiency.
• Investigated the interaction between MECP2 and DNA repair proteins, specifically PARP1.
• Assessed the impact of restoring PARP1 activity on neuronal function.

Main Results:

• MECP2-null neurons exhibit elevated DNA damage, which triggers molecular and physiological dysfunction.
• MECP2 directly interacts with and regulates the activity of PARP1, a key DNA repair enzyme.
• Restoring PARP1 activity in MECP2-deficient neurons ameliorated DNA damage, senescence, dendritic defects, and metabolic issues.

Conclusions:

• Neuronal dysfunction in Rett syndrome is driven by elevated DNA damage, not solely senescence or P53 activity.
• MECP2 plays a crucial role in regulating DNA repair via PARP1.
• Modulating PARP1 activity presents a potential therapeutic strategy for Rett syndrome.