MECP2 mutations affect ciliogenesis: a novel perspective for Rett syndrome and related disorders

Area of Science:

• Neuroscience
• Cell Biology
• Genetics

Background:

• Mutations in the MECP2 gene are the primary cause of Rett syndrome (RTT), a severe neurological disorder.
• MeCP2 protein, primarily known as a transcriptional repressor, has diverse cellular functions beyond gene regulation, some of which are implicated in RTT pathogenesis.
• MeCP2 localizes to the nucleus and centrosomes, with centrosomes serving as the origin of primary cilia, which are crucial cellular sensory organelles.

Purpose of the Study:

• To investigate the role of MeCP2 in primary cilia formation and function.
• To determine if MeCP2 deficiency impacts ciliogenesis and related signaling pathways in the context of Rett syndrome.
• To explore potential therapeutic interventions targeting cilia defects in RTT.

Main Methods:

• Assessing ciliogenesis in cultured cells (neurons, RTT fibroblasts) and mouse brain models with MeCP2 deficiency.
• Analyzing the Sonic Hedgehog signaling pathway, which is regulated by primary cilia.
• Investigating the role of microtubule instability and testing HDAC6 inhibition as a rescue strategy.

Main Results:

• MeCP2 deficiency was found to disrupt ciliogenesis in various cell types and in the mouse brain.
• Impaired primary cilia led to dysregulation of the Sonic Hedgehog pathway, critical for brain development.
• Microtubule instability was identified as a contributing factor, and HDAC6 inhibition successfully rescued neuronal defects.

Conclusions:

• Defects in primary cilia represent a novel pathogenic mechanism in Rett syndrome.
• These cilia defects contribute to the neurological and developmental abnormalities observed in RTT.
• Targeting primary cilia dysfunction presents a promising therapeutic avenue for RTT and related neurological disorders.