Martha Bhattacharya, a postdoctoral research scholar in developmental biology at Washington University School of Medicine in St. Louis, Mo., was awarded an MDA development grant totaling $180,000 over a period of three years to study how and why axons degenerate.
Axons are the long extensions of motor neurons (muscle-controlling nerve cells) that link up with muscles. Signals are sent down the axon to cause the muscle to contract. When an axon degenerates, it can no longer carry those signals, leading to weakness.
“In neuromuscular diseases where motor neuron dysfunction is the primary cause of disability, such as amyotrophic lateral sclerosis (ALS) and Charcot-Marie-Tooth (CMT) disease, axonal degeneration is a unifying pathological hallmark of disease progression,” Bhattacharya says.
To study axonal degeneration, she and her colleagues developed a fruit fly research model that allows the identification of necessary components of the axonal degeneration cascade. Using this system, she has identified several key steps in the process, including one involving a protein called G-protein coupled receptor (GPCR), and another called protein kinase.
“These receptors are highly desirable drug targets,” Bhattacharya says, and pharmaceutical companies have a great deal of experience designing drugs to influence their behavior. “For the GPCR, we will determine its signaling mechanism in mammalian neurons and test its ability to protect neuromuscular synapses after injury. For the kinase, we will examine the effects of loss of this protein on mouse axons and synapses,” the sites of information exchange between nerve and muscle.
Learning more about the details of axonal degeneration also will help researchers understand more about the entire disease process, potentially leading to other targets for therapeutic intervention.
Funding for this MDA grant began Feb. 1, 2013.