Microglia and C9orf72 in neuroinflammation and ALS and frontotemporal dementia

Area of Science:

• Neuroimmunology
• Neurodegenerative Diseases
• Genetics of Neurological Disorders

Background:

• Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Dementia (FTD) are neurodegenerative disorders with overlapping clinical, pathological, and genetic features.
• Activated microglia, a type of immune cell in the central nervous system, are consistently observed in ALS/FTD pathology, but their precise role is not fully understood.
• The C9orf72 gene, the most frequent genetic cause of ALS/FTD, has been found to play a role in myeloid cells, suggesting a potential link between microglial function and disease.

Purpose of the Study:

• To review the contribution of microglia to the pathogenesis of ALS and FTD.
• To explore the relationship between autoimmunity and ALS/FTD.
• To investigate the potential dual role of C9orf72 and other ALS/FTD genes in both neuronal and myeloid cell function, potentially explaining shared immune dysregulation and neurodegeneration.

Main Methods:

• Literature review synthesizing current research on microglia in ALS/FTD.
• Analysis of the role of C9orf72 in myeloid cells and its implications for neuroinflammation.
• Exploration of potential links between autoimmune processes and ALS/FTD pathogenesis.

Main Results:

• Microglia are implicated as active contributors to ALS/FTD pathogenesis.
• The C9orf72 gene's function in myeloid cells suggests a direct link between immune cell activity and neurodegenerative processes.
• A potential connection between autoimmunity and ALS/FTD is highlighted, suggesting shared mechanisms involving immune system dysregulation.

Conclusions:

• Altered microglial function is a key factor in ALS/FTD pathogenesis.
• The C9orf72 gene may exert a 'dual effect,' impacting both neuronal and immune cells, contributing to neurodegeneration and immune system alterations.
• Understanding the interplay between genetics, microglia, and autoimmunity is crucial for developing novel therapeutic strategies for ALS and FTD.