Astrocyte dysfunction and neuronal network hyperactivity in a CRISPR engineered pluripotent stem cell model of...

Area of Science:

• Neuroscience
• Cell Biology
• Genetics

Background:

• Frontotemporal dementia (FTD) is a leading cause of early-onset dementia, with familial forms accounting for up to 40% of cases.
• Mutations in the CHMP2B gene are implicated in FTD, affecting endosomal-lysosomal pathway crucial for cellular protein recycling.

Purpose of the Study:

• To create a human in vitro model of FTD using genome-edited stem cells.
• To investigate the roles of both neurons and astrocytes in FTD pathogenesis using a novel co-culture system.

Main Methods:

• Generation of a CHMP2B-mutated human embryonic stem cell line via genome editing.
• Independent differentiation of neurons and astrocytes from stem cells, followed by co-culture.
• Analysis of cellular and network-level changes in the FTD model.

Main Results:

• Identified alterations in the endolysosomal system of astrocytes in the FTD model.
• Observed increased glutamate uptake and response in FTD astrocytes.
• Detected neuronal network hyperactivity and excessive synchronization, potentially driven by astrocyte dysfunction.

Conclusions:

• Astrocyte alterations in the endolysosomal system precede neuronal impairments in this FTD model.
• Astrocytes play a critical role in FTD development, potentially initiating neuronal network changes.
• This study emphasizes the specific contribution of astrocytes to FTD pathogenesis.