Brain Microbiota in Huntington's Disease Patients

Area of Science:

• Neuroscience and Microbiology
• Neurodegenerative Diseases Research

Background:

• Huntington's disease (HD) is a genetic neurodegenerative disorder caused by a triplet expansion in the Huntingtin gene (HTT).
• The delayed onset of HD symptoms, despite early gene expression, remains a significant puzzle in medical science.
• Investigating potential microbial involvement in HD pathogenesis is crucial for understanding neuronal pathology.

Purpose of the Study:

• To explore the presence and types of microbial infections within brain tissue of Huntington's disease patients.
• To determine if mutated Huntingtin (HTT) could compromise immune cells and neural tissue, facilitating microbial colonization.
• To identify specific fungal and bacterial species associated with HD brains.

Main Methods:

• Utilized immunohistochemistry to detect fungal structures in the striatum and frontal cortex of HD patient brains.
• Employed next-generation sequencing (NGS) for accurate identification of fungal and bacterial species.
• Used Polymerase Chain Reaction (PCR) to further identify bacterial species.

Main Results:

• Observed diverse fungal structures, including intranuclear inclusions, in seven HD patients.
• Identified unique fungal genera, such as Ramularia, not previously described in other neurodegenerative diseases.
• Detected prevalent bacterial genera including Pseudomonas, Acinetobacter, and Burkholderia, with characteristic filamentous structures in HD brains.

Conclusions:

• This study provides the first evidence of brain microbiota in Huntington's disease patients.
• Microbial colonization may represent a risk factor for HD and could explain the disease's delayed onset.
• Findings open new avenues for research and therapeutic strategies for Huntington's disease.