Gene Expression Linked to Gestational Age, Providing Clue to Factors of Preterm Birth
Preterm birth is a leading cause of infant mortality, but the mechanisms that precede preterm labor remain elusive. Researchers led by Alison Sanders, PhD, a postdoctoral fellow in the Department of Preventive Medicine at the Icahn School of Medicine at Mount Sinai found that increased levels of microRNA (miRNA) were directly related to shortened gestational periods.
The study entitled “MicroRNA Expression in the Cervix during Pregnancy is Associated with Length of Gestation” was published in the journal Epigenetics.
In a follow-up study entitled “Altered miRNA Expression in the Cervix during Pregnancy associated with Lead and Mercury” published in the journal Epigenomics, Dr. Sanders and colleagues established a link between mercury and lead exposure and cervical miRNA expression. Together, these studies show the influence miRNAs have on gestational age at the time of delivery, and environmental contaminants that factor into miRNA expression.
“Improvements in preterm birth prediction promise to have two major impacts on patient care,” said Heather Burris, MD, Assistant Professor of Pediatrics, Harvard Medical School, and co-author of the study. “First, new biomarkers with improved prediction ability could help to better target therapies for pregnancies at risk for preterm delivery. Second, novel interventions could be designed to interrupt the cascade of molecular events that occur to trigger labor and produce preterm birth.”
MicroRNA expression is tissue-specific, but a single miRNA can regulate the expression of hundreds of target genes downstream. They play a critical role in embryonic development, the body’s inflammatory response, and signaling pathways that are vital to labor and delivery. The researchers identified six miRNAs that had higher expression in pregnancies with shorter gestations, an important step in increasing the ability to predict and prevent preterm labor.
In a follow up study, Dr. Sanders and her colleagues delved into miRNA expression, seeking to understand environmental factors that prompt miRNA to express abnormally in the cervix. The researchers focused on lead and mercury exposure as possible causes. Metals are common environmental contaminants and studying their relation to epigenetic changes helps clarify the role of environmental factors in gestation and preterm birth.
“There have been no previous studies evaluating the effects of metals on cervical miRNA,” said Dr. Sanders. “These findings are suggestive of a possible environmentally mediated mechanism of miRNA gene regulation during pregnancy.”
Taken together, these studies provide insight into the influences epigenetic factors like miRNA have on preterm birth and what environmental factors underpin this miRNA expression.
About the Mount Sinai Health System
The Mount Sinai Health System is an integrated health system committed to providing distinguished care, conducting transformative research, and advancing biomedical education. Structured around seven hospital campuses and a single medical school, the Health System has an extensive ambulatory network and a range of inpatient and outpatient services—from community-based facilities to tertiary and quaternary care.
The System includes approximately 6,100 primary and specialty care physicians; 12 joint-venture ambulatory surgery centers; more than 140 ambulatory practices throughout the five boroughs of New York City, Westchester, Long Island, and Florida; and 31 affiliated community health centers. Physicians are affiliated with the renowned Icahn School of Medicine at Mount Sinai, which is ranked among the highest in the nation in National Institutes of Health funding per investigator. The Mount Sinai Hospital is ranked as one of the nation’s top 10 hospitals in Geriatrics, Cardiology/Heart Surgery, and Gastroenterology, and is in the top 25 in five other specialties in the 2015-2016 “Best Hospitals” issue of U.S. News & World Report. Mount Sinai’s Kravis Children’s Hospital also is ranked in seven out of ten pediatric specialties by U.S. News & World Report. The New York Eye and Ear Infirmary of Mount Sinai is ranked 11th nationally for Ophthalmology, while Mount Sinai Beth Israel is ranked regionally.
# # #