Neuroinflammation and neurodegeneration in Huntington's disease: genetic hallmarks, role of metals and organophosphates

Huntington's disease (HDs) is a fatal, autosomal dominant, and hereditary neurodegenerative disorder characterized by progressive motor dysfunction, cognitive decline, and psychiatric disturbances. HD is well linked to mutation in the HTT gene, which leads to an abnormal expansion of trinucleotide CAG repeats, resulting in the production of the mHTT protein and responsible for abnormally long poly-Q tract. These abnormal proteins disrupt cellular processes, including neuroinflammation, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction, ultimately leading to selective neuronal loss in the brain. Epidemiological studies reveal significant regional variability in HDs prevalence, with the highest rates observed in North America and the lowest in Africa. In addition to genetic factors, environmental influences such as exposure to metals, and chemicals, and lifestyle factors like alcohol and tobacco use may exacerbate disease progression. This review explores the molecular mechanisms underlying HDs and emphasize the role of neuroinflammatory mediators and environmental factors, in HD research. Understanding these complex interactions is crucial for developing targeted interventions that can slow or halt the progression of this devastating disease.