Potential link between mutant huntingtin, cell loss and cell death in Huntington's disease

Florida Atlantic UniversityJul 2 2012

Using an in vitro cell model of Huntington's disease (HD), researchers at Florida Atlantic University's Charles E. Schmidt College of Medicine have discovered a novel mechanism and potential link between mutant huntingtin, cell loss and cell death or apoptosis in the brain, which is responsible for the devastating effects of this disease. Apoptosis has been proposed as one of the mechanisms leading to neuronal death in HD.

Dr. Jianning Wei, Ph.D., assistant professor of biomedical science in the Schmidt College of Medicine, has received a $428,694 grant from the National Institutes of Health (NIH) for a project titled "Regulation of BimEL phosphorylation in the pathogenesis of Huntington's disease." With this grant, she will further her research and investigation of the molecular and physiological functions of BimEL, a protein known to promote cell death, in a rodent HD model to better understand the pathogenesis of this disease and develop treatments and therapies to prevent or slow down its progression. Wei's previous findings may also represent a universal mechanism in the pathogenesis of neurodegenerative diseases that are involved with protein misfolding and aggregation — a phenomenon that occurs in many highly debilitating disorders including neurodegenerative diseases.

HD is a fatal, inherited disease caused by abnormal repeats of a small segment in an individual's DNA or genetic code. The production of malfunctioning proteins in the body are results of this mutation, and the more repeat the protein contains, the worse the disease. A person who has the disease carries one normal copy of the gene and one mutated copy in his or her cells. Although the mutated forms of these genes are known for their devastating effects, their normal forms are critical for nerve function, embryonic development and other bodily processes. Similar mutations in other proteins are involved in several other neurodegenerative diseases.

"HD is a highly complex genetic, neurological disorder that causes certain nerve cells in the brain to waste away, and the underlying molecular mechanism of this disease still remains elusive," said Wei. "We are continuing our research to identify the pathways in the brain that are altered in response to mutant proteins, as well as to understand the cellular processes impacted by the disease in order to facilitate the development of effective pharmacological interventions."

Named after American physician George Huntington, HD is characterized by a selective loss of neurons in the brain and affects the basal ganglia, which controls motor control, cognition, learning and emotions. It also affects the outer surface of the brain or the cortex, which controls thought, perception, and memory. It is estimated that more than 250,000 Americans have HD or are at risk of inheriting the disease from an affected parent.

"The vital research that Dr. Wei and her colleagues are conducting at Florida Atlantic University will help to shed light on a very devastating and difficult disease for which there are currently no treatments available to stop or reverse its course," said Dr. David J. Bjorkman, M.D., M.S.P.H., dean of FAU's Charles E. Schmidt College of Medicine.

This project is supported by the National Institute of Neurological Disorders and Stroke of the National Institutes of Health through grant number 2R15NS066339-02A1.