Pathophysiology of Huntington's disease: from huntingtin functions to potential treatments

Drugs used to treat Huntington's disease act on the symptoms but do not slow the disease process itself. This review focuses on recent pathogenetic findings and on emerging therapeutic approaches.

Basic research is providing novel insights into the complex molecular pathways involved in the pathogenesis of Huntington's disease. Several mechanisms have been identified that mediate neuronal dysfunction and death; these include neuronal aggregation of the mutated protein, transcriptional dysregulation, excitotoxicity, altered energy metabolism, impaired axonal transport, and altered synaptic transmission. Recent experimental works have identified potential new therapeutic targets. In particular, they emphasize the role of altered histone modifications in transcriptional dysregulation, the synergistic action of glutamatergic and dopaminergic pathways in inducing excitotoxicity, the neuroprotective effect of brain-derived neurotrophic factor expression and transport restoration, and the possibility of reducing the expression of the mutant protein huntingtin and its deleterious effects by using short interfering mRNAs.

Successful neuroprotective therapy for Huntington's disease patients is likely to involve a combined approach targeting both cellular and molecular mediators that account for the toxicity of mutated huntingtin.