New findings on embryonic heart valves may prevent congenital heart defects in newborns

January 05, 2016

ITHACA, N.Y. - Cornell biomedical engineers have discovered natural triggers that could reduce the chance of life-threatening, congenital heart defects among newborn infants. Those triggers can override developmental, biological miscues, leading to proper embryonic heart and valve formation.

More than 40,000 babies in the United States - or about 1 in 100 births - are born annually with a congenital heart defect, making it the most common defect, according to the Children's Heart Foundation.

"The heart is the first organ to form in the embryo. It morphs dynamically and rapidly all the while pumping nutrients to the developing body," said senior author Jonathan Butcher, associate professor at Cornell's Nancy E. and Peter C. Meinig School of Biomedical Engineering.

The early embryonic heart originates as a looped tube, without valves or pumping chambers. During the last few weeks of the first trimester, these heart chambers form, but need something to maintain one-way blood flow.

"Wispy globular masses (called cushions because of their shape in the heart wall) need to condense and elongate to form thin robust leaflets capable of fast and resilient opening and closing," Butcher said. "It is this maturation process that's likely disrupted in many clinical cases."

Until this study, scientists did not know how - or if - mechanical forces drove the biological remodeling of cushions into valves. Medical science understood that the embryonic heart needed blood flow to grow, but the valve component's role was not entirely understood, Butcher said.

The researchers found that cyclic stretches and stressing forces activate sensitive enzymes called GTPases, specifically RhoA and Rac1, which coordinate the embryonic heart's maturation. Without the enzymes activating at the proper times, heart valves do not form correctly.

"We identified a mechanism that transduced - or translated - a mechanical force into a biological response," Butcher said. "That biological response over time creates these thin, flexible, formative leaflets. If this tissue fails to get thinner, that's a problem. If the tissue fails to elongate, that's a problem. And these are all problems we see in the clinic."

This work lays a foundation for hemodynamically informed surgical interventions to potentially retard valve malformation - or to restore it, Butcher said.
-end-
The research, which is published in Current Biology, was supported by the National Science Foundation, the National Institutes of Health and the American Heart Association.

Cornell University has television, ISDN and dedicated Skype/Google+ Hangout studios available for media interviews.

Cornell University

Related Congenital Heart Defects Articles from Brightsurf:

Cutting-edge, whole-heart imaging provides new details on heart defects
A cutting-edge technique that allows scientists to zoom into tiny details in a 3D image of a whole animal heart may lead to new insights on congenital heart disease.

Congenital heart defects may not increase the risk of severe COVID-19 symptoms
People with congenital heart disease had a lower-than-expected risk for severe symptoms from COVID-19, a new study has found.

Rare congenital heart defect rescued by protease inhibition
A research team at the Greenwood Genetic Center (GGC) has successfully used small molecules to restore normal heart and valve development in an animal model for Mucolipidosis II (ML II), a rare genetic disorder.

Gout treatment may aid patients with congenital heart disease
A drug used to treat gout, probenecid, may improve heart function in individuals with a particular heart defect, according to results from a small pilot study run by a University of Cincinnati researcher.

Congenital heart disease more deadly in low-income countries
Even though mortality from congenital heart disease (CHD) has declined over the last three decades as diagnosis and treatments have advanced, a new study shows that the chances for a child to survive a CHD diagnosis significantly differs based on the country where he or she is born.

Genomics experts dispute nine genes linked to congenital heart condition
The Clinical Genome Resource's (ClinGen) expert panel has critically reevaluated the scientific evidence for all 17 reported genes linked to long QT syndrome, disputing nine of the genes and revealing only three of the genes to be definitively associated with the most common form of the disease.

Physicians should consider HCQ to reduce the risk of recurrent congenital heart block
New research findings presented at the 2019 ACR/ARP Annual Meeting discovered that hydroxychloroquine (HCQ) significantly reduces the recurrence rate of congenital heart block in subsequent pregnancies of women with anti-SSA/ Ro antibodies, regardless of their health status.

Faulty signalling pathway linked to congenital heart condition
Faulty signalling pathway causes the heart to develop unnaturally while in the embryo stage, according to Duke-NUS Medical School researchers.

A new framework to study congenital heart defects
In a new study published in the scientific journal Nature, a team of researchers at the Gladstone Institutes, in collaboration with the University of Luxembourg, reveal for the first time the full spectrum of cells that come together to make a heart at the earliest stages of embryo formation.

Greater prevalence of congenital heart defects in high intensity oil and gas areas
Mothers living near more intense oil and gas development activity have a 40-70% higher chance of having children with congenital heart defects (CHDs) compared to those living in areas of less intense activity, according to a new study from researchers at the Colorado School of Public Health.

Read More: Congenital Heart Defects News and Congenital Heart Defects Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.