Study links prenatal exposure to arsenic to disease susceptibility later in life

April 7, 2014

Protein changes associated with prenatal exposure to arsenic may hold the key to understanding the workings of adult-onset diseases tied to arsenic in the environment, a study at UNC has found.

Dr. Rebecca Fry

In an article published online March 27 in Toxicological Sciences by the Oxford Journals, Rebecca C. Fry, PhD, associate professor of environmental sciences and engineering at the UNC Gillings School of Global Public Health and colleagues identified biological pathways that were altered at the protein level by in utero arsenic exposure.

The study’s results suggest that the proteins may be used as biomarkers for exposure to arsenic and predictors of disease risk.

Fry and her colleagues used a large-scale screen of protein levels to identify more than 100 proteins that were altered in the cord blood of infants in Mexico exposed to arsenic prenatally. Almost half of the proteins were found to be regulated by the protein tumor necrosis factor, a potential master regulator of the health effects of such exposure. The results provide insights into links between early life exposure to arsenic and susceptibility to disease.

Inorganic arsenic in drinking water is a worldwide problem — more than 100 million people are exposed to arsenic levels that exceed World Health Organization limits. Long-term exposure to the toxic metal can result in chronic health conditions in adulthood that include cardiovascular disease, diabetes and cancer. A mother’s exposure to arsenic during pregnancy puts the infant at risk for being born preterm with low birth weight and increased susceptibility to infections and sometimes can lead to stillbirth.

Fry’s study also found that high levels of arsenic can play a role in inflammation and immune response that may underlie health conditions in later life.

The study was a cooperative effort between researchers at UNC and the University of Juárez in Durango. A total of 200 mother-infant pairs took part in the study. Each mother provided researchers with urine and drinking water samples as well as umbilical cord blood from her infant. The researchers measured arsenic levels in the mothers’ urine and compared that with cord blood samples from the newborns. From that group, Fry and her colleagues selected 50 mother-infant pairs representing a range of arsenic levels and conducted the protein analysis on this subset.

Members of the interdisciplinary research team affiliated with the Gillings School are Kathryn A. Bailey, PhD, a postdoctoral researcher in environmental sciences and engineering at the time of the study; Jessica Laine, doctoral student, and Andrew Olshan, PhD, Barbara Sorenson Hulka Distinguished Professor in Cancer Epidemiology and chair, both of the Department of Epidemiology; Julia Rager, PhD, Lisa Smeester and Elizabeth Sebastia, researchers in environmental sciences and engineering; and Zuzana Drobna, PhD, research assistant professor, and Miroslav Styblo, PhD, associate professor, both in the Department of Nutrition.