Dr. Lee’s primary interest is to understand the role of signaling molecules in regulating embryonic development and adult tissue homeostasis. He has focused on the superfamily of secreted proteins that are structurally related to transforming growth factor-Β (TGF-Β). Members of this growth factor family have been shown to play important roles in regulating the development and function of many different tissues, and as a result, many of these factors have shown enormous therapeutic potential for a wide range of clinical applications. Using molecular genetic approaches, he and his lab have identified a large number of novel mammalian TGF-Β family members that we have designated growth/differentiation factors (GDFs). They have been using a variety of experimental approaches, including genetic manipulation of mice, to attempt to understand the precise biological functions of these molecules. We are particularly interested in understanding the roles of these molecules in regulating tissue growth.
Much of his work has focused on a molecule that he and his team have designated myostatin. They have shown that myostatin is expressed specifically in developing and adult skeletal muscle and that mice engineered to lack myostatin exhibit dramatic increases in skeletal muscle mass throughout the body. Based on these and other studies, they believe that myostatin normally acts to block skeletal muscle growth.
Dr. Lee and his team are currently attempting to elucidate the mechanism of action of myostatin as well as the mechanisms by which the activity of myostatin is regulated. Their long term goal is to attempt to exploit the biological properties of myostatin to develop novel therapeutic strategies for treating patients with muscle degenerative and wasting conditions, such as muscular dystrophy, sarcopenia, and cachexia resulting from diseases like cancer, AIDS and sepsis.
In a paper published in the Proceedings of the National Academy of Sciences, researchers show that JAX Mighty Mice stayed relatively mighty during their time in microgravity, while the normal control mice lost considerable muscle mass and bone density.
A recent paper from a team including JAX Professor Se-Jin Lee shows that a signaling pathway once thought to protect heart cells from damage actually promotes breakdown with aging.