The TREX1 Dinosaur Bites the Brain through the LINE

Area of Science:

• Neuroscience
• Genetics
• Molecular Biology

Background:

• TREX1 mutations are linked to Aicardi-Goutières syndrome, a neurological disorder.
• Accumulation of DNA in the cytoplasm can trigger inflammatory responses.
• Stem cell-derived organoids provide a model for studying human neurological development and disease.

Purpose of the Study:

• To characterize the nature and origin of accumulated single-stranded DNA (ssDNA) in the cytoplasm of neurons and astrocytes.
• To investigate the role of TREX1 mutations in ssDNA accumulation within neural cells.
• To explore the implications of these findings for understanding Aicardi-Goutières syndrome.

Main Methods:

• Utilized stem cell-derived organoids modeling TREX1 mutations.
• Analyzed cytoplasmic ssDNA in differentiated neurons and astrocytes.
• Investigated the source of accumulated ssDNA using molecular techniques.

Main Results:

• Identified significant accumulation of ssDNA in the cytoplasm of neurons and astrocytes in TREX1 mutated organoids.
• Demonstrated that the accumulated ssDNA originates from LINE-1 (long interspersed nuclear element-1) endogenous retroelements.
• Established a link between TREX1 deficiency, LINE-1 activity, and cytoplasmic ssDNA accumulation in neural cells.

Conclusions:

• TREX1 mutations lead to the accumulation of LINE-1-derived ssDNA in the cytoplasm of neural cells.
• This accumulation may contribute to the neuroinflammation observed in Aicardi-Goutières syndrome.
• Findings provide novel insights into the molecular mechanisms underlying neurological aspects of Aicardi-Goutières syndrome.