Researchers investigate impact of fungal toxin on birth defects

Oct 26 2010

A Creighton University School of Medicine researcher has been awarded a $2.7 million grant by the National Institutes of Health (NIH) to investigate a possible link between the ingestion of tortillas and corn-based food products contaminated with a fungal toxin and increased risk for birth defects.

The three-year award is a collaborative effort among investigators at Creighton, the U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS) in Athens, Georgia; Duke University Medical Center in Durham, N.C., and Centro de Investigaciones en Nutricion y Salud (CIENSA) in Guatemala.
Janee Gelineau-van Waes, D.V.M., Ph.D., principal investigator and associate professor in Creighton's Department of Pharmacology, will use the grant to continue her research studying a potential connection between exposure to fumonisin during early pregnancy and an increased risk for having a baby with a neural tube defect (NTD).

NTDs are one of the most common congenital malformations (one per 1,000 births) and include defects such as anencephaly and spina bifida. NTDs occur when the embryonic neural tube, which forms the brain and spinal cord, fails to close properly during the first few weeks of pregnancy.

Fumonisin is a mycotoxin produced by a common fungal contaminant of corn worldwide.

In animals, the toxin disrupts sphingolipid metabolism, causing diseases such as leukoencephalomalacia in horses, pulmonary edema in pigs and cancer in laboratory rodents. In humans, ingestion of fumonisin-contaminated corn is associated with increased risk for esophageal cancer and having a baby with a NTD.

An unusually high incidence of NTDs (six to 10 cases per 1,000 births) has been observed in regions of Guatemala, China, and South Africa where corn is a dietary staple and fumonisin contamination is frequent.

Gelineau-van Waes and USDA scientists have shown that early gestational exposure to the toxin disrupts sphingolipid metabolism and induces NTDs in mice.

In the new study, preliminary data obtained from mice will be used to validate biomarkers of exposure in blood and urine samples collected from women in Guatemala. The human samples, collected by CIENSA scientists, will be analyzed by the USDA-ARS Mycotoxin Research Unit.

Creighton researchers will use mouse models to investigate underlying signaling mechanisms that result in failure of neural tube closure after fumonisin exposure, and collaborative studies with Duke University will focus on identifying genetic mutations that increase susceptibility.

Source :  Creighton University School of Medicine