The mutant Moonwalker TRPC3 channel links calcium signaling to lipid metabolism in the developing cerebellum

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• The Moonwalker (Mwk) mouse model exhibits dominantly inherited cerebellar ataxia.
• This condition is linked to a gain-of-function mutation in the TRPC3 channel, a transient receptor potential (TRP) channel.
• Purkinje cells are crucial for motor coordination, and their development is impaired in Mwk mice.

Purpose of the Study:

• To investigate the molecular mechanisms underlying Purkinje cell developmental defects in Mwk mice.
• To identify effector pathways regulated by mutant TRPC3 that influence Purkinje cell dendritic arborization.
• To explore the connection between altered calcium signaling, lipid metabolism, and cerebellar development.

Main Methods:

• Transcriptomic analysis of developing Purkinje cells isolated via laser-capture microdissection.
• Analysis of gene and protein expression changes related to lipid metabolism.
• Experimental manipulation using ceramide treatment on organotypic cerebellar slices.

Main Results:

• Impaired dendritic growth and synapse formation were observed in developing Mwk Purkinje cells.
• Alterations in calcium signaling pathways were associated with these developmental deficits.
• Significant changes in lipid metabolism molecules were identified, with disturbed lipid homeostasis in Mwk cerebellums.
• Ceramide treatment demonstrated a positive effect on Mwk Purkinje cell dendritic outgrowth.

Conclusions:

• Mutant TRPC3 channels disrupt Purkinje cell development through altered calcium signaling and lipid metabolism.
• This study reveals a mechanistic link between TRPC3, calcium signaling, and lipid metabolism in regulating cerebellar development.
• Findings offer insights into potential therapeutic targets for cerebellar ataxia related to TRPC3 dysfunction.