January 18, 2011

Five Hopkins researchers named AAAS fellows

Five Johns Hopkins researchers have been elected by their peers as fellows of the American Association for the Advancement of Science.

Chia-Ling Chien and Marc M. Greenberg, of the Krieger School of Arts and Sciences; Valeria Culotta, of the Bloomberg School of Public Health; and Se-Jin Lee and Mark Mattson, of the School of Medicine, are among 503 new fellows from around the world. Election as an AAAS fellow honors scientifically or socially distinguished efforts to advance science or its applications.

The names of the awardees will be published in the “AAAS News and Notes” section of Science on Jan. 28. The newly elected fellows will be awarded a certificate and a rosette pin during the AAAS Fellows Forum at the 2011 AAAS annual meeting to be held on Saturday, Feb. 19, in Washington, D.C.

As part of the section for physics, Chia-Ling Chien, the Jacob L. Hain Professor of Physics in the Krieger School and director of the university’s Materials Research Science and Engineering Center, was elected for his distinguished contributions to the fields of condensed matter physics and materials research, particularly for magnetic and superconducting nanostructures and copper oxide superconductivity, and the newly discovered iron superconductors. His current research interests include fabrication of nanostructured materials and the study of their structural, electronic, magnetic and superconducting properties, magnetoelectronics and electric tweezers.

As part of the section on biological sciences, Valeria Culotta, a professor in the departments of Biochemistry and Molecular Biology and of Environmental Health Sciences at the Bloomberg School, was elected for her studies on the role of metals in biology. Metals such as copper, iron and manganese are essential nutrients for virtually all life, but excess levels or inappropriate handling can lead to cell damage and disease. In her research, Culotta has shown that cells in higher organisms have evolved with “metal-trafficking pathways” that guide each metal to its proper destination in the cell and has discovered numerous genes and proteins for metal trafficking. Culotta discovered a family of proteins known as copper chaperones that have evolved to ferry copper ions to specific copper-containing proteins. These copper chaperones have since been implicated in certain motor neuron disorders and diseases of copper metabolism, such as Wilson’s and Menkes diseases.

As part of the chemistry section, Marc M. Greenberg, a professor in the Krieger School and director of the Chemistry-Biology Interface graduate program, was elected for distinguished contributions to the field of mechanistic bioorganic chemistry, specifically with respect to how nucleic acids are damaged and repaired. Greenberg’s research group studies the structure, reactivity and function of nucleic acids. DNA plays a critical role as the carrier of genetic information, and the DNA damage and repair processes are important in aging and a variety of genetically based diseases, such as cancer. Greenberg is studying how DNA damage occurs and how it can be detected, and the biological results of this damage and how it can be fixed. His research group co-pioneered the approach for studying how nucleic acids are oxidized using organic chemistry to generate reactive intermediates that are produced by ionizing radiation, antitumor antibiotics and other DNA-damaging agents.

Se-Jin Lee, a professor in the Department of Molecular Biology and Genetics at the School of Medicine, was elected for his discovery of the protein hormone myostatin, a master regulator of skeletal muscle mass and homeostasis. Muscle cells make myostatin, which circulates through the body and blocks muscle growth. Lee showed in laboratory mice that removal of the myostatin gene results in “mighty mice” that have twice the muscle mass of ordinary mice. By exploring the components in the cell that regulate myostatin, Lee has identified several potential therapeutic targets for diseases such as muscular dystrophy and muscle wasting in AIDS patients and the elderly. The pharmaceutical industry is conducting multiple clinical trials for these diseases based upon Lee’s findings. He continues to study how problems with myostatin communication contribute to disease progression, and he is exploring how manipulating proteins that interact with myostatin can become beneficial treatments for certain muscle diseases.

Mark Mattson, a professor in the Department of Neuroscience at the School of Medicine and chief of the Laboratory of Neurosciences at the National Institute on Aging, was named a fellow for revealing the cellular mechanisms involved in neural plasticity—the ability of neurons to adapt during processes such as learning or injury—and development of neurodegenerative disorders. Mattson studies how dietary intake affects the structure and function of the brain. He found that dietary restriction in mice stimulates the production of new neurons and helps learning and memory, processes normally weakened by aging. Reducing food intake causes the body to turn on genes that have protective effects on the brain because they help the body deal with environmental stress and promote growth. Mattson is continuing to search for other cellular mechanisms that also may be protective against the effects of aging and neurodegenerative diseases, such as Alzheimer’s.