Environmental Factor, September 2009, National Institute of Environmental Health Sciences
Birnbaum Opens Workshop on Epigenetics
By Eddy Ball
NIEHS and National Toxicology Program Director Linda Birnbaum, Ph.D., presented opening remarks at the National Academies workshop on epigenetics July 30-31 at the organization's Keck Building in Washington. The theme of the meeting was "Use of Emerging Science and Technologies to Explore Epigenetic Mechanisms Underlying the Developmental Basis for Disease," with several NIEHS-funded scientists on hand to offer their perspectives on the issues.
Birnbaum's overview at the meeting (http://nas-sites.org/emergingscience/meetings/epigenetics/) , "Developmental Basis of Disease: A New Paradigm in Environmental Health Sciences," opened with a reference the Barker hypothesis, which proposes that abnormal developmental diet could lead to increased susceptibility to disease later in life. She noted a recent shift in focus of teratology studies - investigations into abnormal development -which has moved from the immediate and short term "apical" endpoints of death, birth defects and low birth weight to encompass later adverse health outcomes of early exposure to chemicals. She said that this broadening range of concern and new technologies have triggered a paradigm shift in toxicology.
"While people talked about functional changes [before]," Birnbaum explained, "we did not know how to measure them until the use of 'omics technology allowed us to 'see' functional changes at the gene expression and proteomics level." It became increasingly evident, she continued, that developmental exposure - in uteri and neonatal - can lead to increased susceptibility to disease by alterations in programming, which set the stage for abnormal tissue development and disease later in life.
Recognizing the developmental basis of disease, Birnbaum continued, "changes everything,... [shifting] the focus from curing a disease to prevention and intervention strategies to reduce disease occurrence." It offers opportunities for prevention and intervention strategies by offering the possibility of discovering "an 'imprint' left by developmental programming such as altered methyl marks," she explained, that may be useful for identification of exposed individuals and as a biomarker for disease susceptibility."
Birnbaum closed her talk with the questions that would occupy attendees at the workshop. She challenged her audience to understand better what changes are occurring and what the most sensitive life stages are; to discover whether epigenetic alterations are correlative or causative and what tools need to be developed to characterize the relationships between early exposures and outcomes years or even generations later; and to determine the implications for disease prevention, regulation and interventions in this generation and the next.
Participating as panelists were NIEHS Associate Director in the Office of Risk Assessment Research Chris Portier, Ph.D., and Principal Investigator and Chief of the Laboratory of Molecular Carcinogenesis Trevor Archer, Ph.D. (http://www.niehs.nih.gov/research/atniehs/labs/lmc/cge/index.cfm) NIEHS grantee Wan-yee Tang, Ph.D., of the University of Cincinnati made a presentation on "Epigenetic Markers for Transplacental Exposure to Airborne Polycyclic Aromatic Hydrocarbons and Childhood Asthma." Superfund Research Program grantee Kim Boekelheide, Ph.D., of Brown University, served as a panelist.
The workshop was part of the National Academies series on "Emerging Science for Environmental Health Decisions." The series continues with a meetings in Washington on "Computational Toxicology: From Data to Analyses to Applications" September 21-22 and on "The Exposome: A Powerful Approach for Evaluating Environmental Effects on Chronic Diseases" December 8-9.