Marie T. Filbin: In Memoriam

Marie T. Filbin: 1955–2014 Marie T. Filbin, Distinguished Professor of Biology at Hunter College in New York City, died on January 15, 2014 while visiting her family in Ireland. Following some early breakthrough work on the biochemistry of peripheral myelination, Marie’s most significant scientific contributions were in the understanding of the molecular mechanisms of the inhibition of axonal growth and the facilitation of axonal regeneration. Marie was a passionate and highly effective advocate for research in spinal cord injury and a tireless campaigner on behalf of patients with spinal cord disease, with some of whom she developed a deeply caring and lifelong personal relationship. Marie was the very antithesis of a ‘‘stuffy’’ scientist— she lived her life with flair and style, infectious charm, great (and occasionally irreverent) good humor, passion for her work, devotion to her friends and family, and was a remarkable mentor to her students. Marie Therese Filbin was born in 1955 in the town of Lurgan, Northern Ireland, where her family had been in business for generations. She attended the University of Bath, where she received a PhD in Biochemistry in 1981 for work on the characterization of nicotinic acetylcholine receptors in the locust. In 1982, she moved to the University of Maryland for postdoctoral training without (she admitted) much detailed career planning but driven by a strong sense of adventure and discovery. The move to Baltimore proved fortuitous, however, when in 1984 she joined Gihan Tennekoon in the Department of Neurology at Johns Hopkins. In a seminal paper published with Dr. Tennekoon, Marie showed that that the tightly wound myelin leaflets that surround peripheral nerves are bound together by P0, the most abundant myelin protein, which functions as a hemophilic adhesion molecule (Filbin et al., 1990). At Hopkins, Marie was exposed to a group of researchers and clinicians with a strong interest in disorders of myelin in the peripheral and central nervous systems, and this experience helped to shape the direction of her future career. It was also a time during which she cemented some of the strongest and longest bonds of friendship and collaboration that would remain throughout her life. In 1990, Marie moved to New York City to take a faculty position in the Biology Department at Hunter College, the flagship institution of the City College of New York system. She continued to work on P0 in her own lab for the next several years, defining the conditions necessary for P0 to mediate myelin adhesion—including demonstrating that the protein needs to interact with the myelin cytoskeleton, directly or indirectly, for peripheral myelin adhesion to take place. As she began to focus on the integrated role of different myelin proteins during the process of remyelination, Marie became aware of the molecular dissonance between the mechanisms of axonal regrowth and remyelination. At this point, her focus changed to the role of inhibitory molecules within the white matter of the CNS that retard or prevent neural regeneration. She was the first to show that myelin-associated glycoprotein (MAG)— a transmembrane protein in both the central and peripheral nervous system—is an important inhibitor of neurite growth after injury (Mukhopadhyay et al., 1994). After several meticulous and elegant papers aimed at elucidating underlying mechanisms, she eventually showed that the inhibitory effect of MAG is mediated through the NoGo receptor (Domeniconi et al., 2002). Realizing that myelin is present in varying degrees in any in vivo sys-