Spatial omics reveals molecular changes in focal cortical dysplasia type II

Area of Science:

• Neuroscience
• Genetics
• Biochemistry

Background:

• Focal cortical dysplasia (FCD) is a group of epileptogenic lesions caused by abnormal brain development.
• Somatic mutations in genes like mTOR lead to mosaicism, complicating the study of FCD's functional consequences.

Purpose of the Study:

• To comprehensively characterize the impact of mTOR mutations on the brain in FCD type II.
• To identify molecular changes and potential therapeutic strategies for FCD.

Main Methods:

• Utilized a multimodal approach in a preclinical mouse model (Rheb) of FCD type II.
• Employed spatial omics techniques including Mass Spectrometry Imaging (MSI) for proteomic and lipidomic analysis.
• Combined MSI with laser capture microdissection (LMD) and label-free proteomics.
• Analyzed surgical resections and postmortem human cortex using bulk transcriptomics.

Main Results:

• MSI revealed disrupted neuronal migration and reduced sulfatides, impacting brain myelination.
• Proteomics identified altered myelination pathways involving oligodendrocytes.
• Comparative analysis of mouse and human data highlighted conserved pathways related to myelination.

Conclusions:

• The study strengthens the understanding of functional consequences of somatic mutations in FCD type II.
• The preclinical mouse model demonstrates translational value for studying FCD.
• Identified myelination pathways offer potential targets for future therapeutic strategies.