The main interest of the Li Lab is to understand the molecular mechanisms of inherited neurodegeneration caused by a CAG repeat expansion in the disease genes. Currently, we focus on Huntington's disease (HD), an autosomal dominant genetic disease that is characterized by massive neuronal loss in selective brain regions and affects about 5/100,000 people in North America. The HD protein, huntingtin, forms aggregates in neurons, abnormally interacts with other proteins, and eventually kills neurons. However, it is unclear how mutant huntingtin causes selective neurodegeneration and why the clinical symptoms often occur in mid-life in HD.
To address these important issues, we will use a variety of approaches, including genetic manipulation of animal models, molecular and cell biological analysis of protein transport, and biochemical study of protein-protein interactions, to investigate the relationship between gene mutation and disease phenotypes. Specifically, we are currently investigating the effects of mutant proteins on the function of neurons and glia in the brain, gene transcription, and intracellular trafficking. The goal of our studies is to provide mechanistic insight into the pathogenesis of neurodegeneration caused by polyQ expansion and to help develop effective therapeutic strategies.