Marc R. Freeman, PhD, named Howard Hughes Medical Institute investigator

Neurobiologist joins five other HHMI investigators at UMMS

By Jim Fessenden

UMass Medical School Communications

May 09, 2013

Marc R. Freeman, PhD, associate professor of neurobiology and a leader in the study of glial cells, was named a Howard Hughes Medical Institute (HHMI) investigator today.

“This is a tremendously exciting moment for me and my lab,” Dr. Freeman said. “Being named an HHMI investigator provides us the stability to continue chasing down the most interesting questions about basic glia biology.”

“The Howard Hughes Medical Institute recognizes exceptionally creative thinkers and innovative scientists who are pushing the boundaries of scientific knowledge into new and unexpected avenues from which breakthroughs arise,” said Chancellor Michael F. Collins. “This award allows Dr. Freeman the freedom to take risks and pursue novel ideas that can dramatically change the landscape of neurobiology. All of us at UMass Medical School are incredibly proud of what he has accomplished.”

A member of the UMMS faculty since 2004, Freeman was a postdoctoral associate when he became interested in glial cells, the brain’s most abundant and overlooked cell type. Working on a type of neural stem cell division that generated both neurons and glia, he realized how little was actually known about glial cells and saw a tremendous opportunity to explore new territory.

“At the time, there were all these new genetic, genomic and computational tools becoming available to study glia in Drosophila,” said Freeman. “So about two years into my post doc I decided to switch from neurons to glia.”

Although they comprise more than half of all human brain cells, glial cells often take a backseat to their better known cousin, the neuron, among neurobiologists who thought these cells played only supporting roles in the central nervous system. That thinking has begun to change, thanks in part to the work done in the Freeman lab. Experiments by Freeman have shown that glial cells are major players in the development, function and health of the nervous system.

Freeman came to UMMS with the intention of answering fundamental questions about glia biology, but his work had unforeseen implications for human diseases and health. His interest in the glial cell’s response to injury led to the identification of a suicide mechanism in axons, the projections from neurons that transmit messages to other cells. When injured or severed, the axon activates a program that signals the glia to consume the injured axon. Freeman found that mutations in one gene in this pathway, however, resulted in severed axons surviving about 50 times as long after injury.

This and other findings have shed new light on the basic biology governing neurodegenerative diseases and how the nervous system responds to traumatic injury. Discoveries made in the Freeman lab are poised to provide critical insights that may one day lead to new treatments and therapeutics for a host of neurological conditions.

“When we started out I didn’t have any intention of studying any diseases,” said Freeman. “But as is often the case when you study fundamental processes in biology, you find connections that are very important for understanding and potentially treating human disease.”

Freeman now plans to probe this axon degeneration pathway more deeply in the hopes of identifying ways to help neurons survive damage caused by traumatic injuries to the nerves or fend off the effects of neurodegenerative disease.

HHMI encourages its investigators to push their research into new areas of inquiry. By employing scientists as HHMI investigators—rather than awarding them research grants—HHMI gives scientists the freedom to explore and, if necessary, to change direction in their research. Moreover, they have support to follow their ideas through to fruition—even if that process takes many years. Freeman is one of 27 new HHMI investigators announced today.

“One of the projects we’re really excited about involves understanding how glial cells select a neuron’s axon for ensheathment,” said Freeman explaining that glia help form the insulation that allows neurons to rapidly transmit signals over long distances in the nervous system. “HHMI allows us the freedom to start with no preliminary data but dive headlong into and answer these types of fundamental questions.”

“HHMI has a very simple mission,” HHMI President Robert Tjian, PhD, said. “We find the best original-thinking scientists and give them the resources to follow their instincts in discovering basic biological processes that may one day lead to better medical outcomes. This is a very talented group of scientists. And while we cannot predict where their research will take them, we’re eager to help them move science forward.”

Freeman joins five other HHMI Investigators at UMMS: Melissa J. Moore, PhD, the Eleanor Eustis Farrington Chair in Cancer Research and professor of biochemistry & molecular pharmacology; 2006 Nobel Laureate Craig C. Mello, PhD, the Blais University Chair in Molecular Medicine and distinguished professor of molecular medicine and cell & developmental biology; Phillip D. Zamore, PhD, the Gretchen Stone Cook Chair of Biomedical Sciences and professor of biochemistry & molecular pharmacology; Roger J. Davis, PhD, the H. Arthur Smith Chair in Cancer Research and professor of molecular medicine and biochemistry & molecular pharmacology; and Michael R. Green, MD, PhD, the Lambi and Sarah Adams Chair in Genetic Research and professor of molecular medicine and biochemistry & molecular pharmacology.