Navigation Links
Genes provide clues to gender disparity in human hearts
Date:1/24/2013

Healthy men and women show little difference in their hearts, except for small electrocardiographic disparities. But new genetic differences found by Washington University in St. Louis researchers in hearts with disease could ultimately lead to personalized treatment of various heart ailments.

Generally, men are more susceptible to developing atrial fibrillation, an irregular, rapid heartbeat that may lead to stroke, while women are more likely to develop long-QT syndrome, a rhythm disorder that can cause rapid heartbeats and sudden cardiac death.

While prior studies have clearly established differences in the development of heart disease between men and women, very few studies had looked at the molecular mechanisms behind those differences in human hearts.

Igor Efimov, PhD, the Lucy and Stanley Lopata Distinguished Professor of Biomedical Engineering in the School of Engineering & Applied Science at Washington University in St. Louis, and a former doctoral student, Christina Ambrosi, PhD, analyzed 34 human hearts looking for genetic differences that might explain gender differences in heart disease.

The team took advantage of the unique opportunity at the university to obtain failing human hearts at the time of transplantation from Barnes-Jewish Hospital and non-failing hearts unsuitable for transplantation from Mid-America Transplant Services, a St. Louis-based organ procurement service.

The team screened for 89 major genes in electrophysiology, ion channel subunits, calcium handling proteins and transcription factors important in cardiac conduction and in the development of arrhythmia and the left atria and ventricles in human hearts.

"What was striking in this study is that we expected very large gender differences in expression of genes in the ventricles, but we did not find such differences," says Efimov, also a professor of medicine, of radiology and of cell biology and physiology at Washington University School of Medicine. "Unexpectedly, we found huge gender differences in the atria."

The results showed that women with failing hearts have a weaker system of gene expression than men males showed overall higher expression levels of nearly all of the 89 genes than women.

Women showed particularly lower atrial expression levels of several important genes encoding for potassium channels, including Kv4.3, KChIP2, Kv1.5 and Kir3.1. In fact, the atria of women with heart disease had less than half of the KChIP2 mRNA than atria in men.

Results of the research were published in PLOS ONE.

Efimov says while there are still many questions that need to be answered to explain these molecular differences, one factor that could be contributing to the difference is estrogen.

"When women have the highest levels of estrogen, they are least vulnerable to arrhythmia women are protected by estrogen," he says. "But after menopause, women develop atrial fibrillation at the same rate as men. We don't understand this and need to study this in humans."

Another potential factor is circadian rhythm, Efimov says.

"Humans are much more likely to die suddenly from heart disease early in the morning, between 5-7 a.m.," he says. "In the cardiac system in mice, it has been shown that there is an oscillation of gene expression, so certain genes expressed at 5 a.m. could be different by threefold at 5 p.m."

Efimov says the study on human hearts is unique to Washington University, as much cardiac research elsewhere is done mostly in animal models. In the future, the team would like to expand the research into pediatric hearts, taking advantage of Washington University's leading pediatric heart transplant program to learn more about pediatric physiology.


'/>"/>

Contact: Igor Efimov
igor@wustl.edu
314-935-8612
Washington University in St. Louis
Source:Eurekalert

Related medicine news :

1. Researchers ID Genes That May Determine Mental Illness
2. 2 repressor genes identified as essential for placental development
3. Genes Associated With Autism Also Related to Schizophrenia
4. Genes Might Cause Some to Shun Pork
5. Blond Genes May Vary Around the World
6. Mystery of the missing breast cancer genes
7. Living longer - variability in infection-fighting genes can be a boon for male survival
8. Genes Might Be Key to Parkinsons Spread
9. Strategy discovered to activate genes that suppress tumors and inhibit cancer
10. Study Ties Genes to Lower Urinary Tract Symptoms, Prostate Cancer Risk
11. Obesity genes may influence food choices, eating patterns
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:10/12/2017)... ... October 12, 2017 , ... ... that we intend to develop to enable prevention of a major side effect ... hearing loss, especially in pediatric patients. For cisplatin, hearing loss is FDA listed ...
(Date:10/12/2017)... ... 2017 , ... HMP , a leader in healthcare events and education, today ... Digital Award for ‘Best B-to-B Healthcare Website.’ Winners were announced during the Eddie & ... award competition recognizes editorial and design excellence across a range of sectors. This year’s ...
(Date:10/12/2017)... ... October 12, 2017 , ... On Saturday, October 21, the Health ... Miles by Moonlight to raise money for the American Heart Association Heart Walk. Teams ... Teams will work together to keep their treadmills moving for 5 hours. Treadmills will ...
(Date:10/12/2017)... ... October 12, 2017 , ... Health Literacy Innovations ... literacy software tool, and the Cancer Patient Education Network (CPEN), an independent professional ... announce a new strategic alliance. , As CPEN’s strategic partner, HLI will ...
(Date:10/12/2017)... ... October 12, 2017 , ... Vohra Chief Medical Officer Dr. ... colleagues, skilled nursing facility medical directors and other clinicians at various events in ... , "At many of these conferences we get to educate other physicians, facility ...
Breaking Medicine News(10 mins):
(Date:9/27/2017)... and NEW YORK , Sept. 27, 2017 /PRNewswire/ ... health and big data solutions, today announced that its MyDario product is ... your local TV listings for when The Dr. Oz Show airs in ... The nine-time ... month. ...
(Date:9/25/2017)... , Sept. 25, 2017  EpiVax, Inc., a ... design, and immune-engineering today announced the launch of ... development of personalized therapeutic cancer vaccines. EpiVax has ... exclusive access to enabling technologies to the new ... will lead EpiVax Oncology as Chief Executive Officer. ...
(Date:9/22/2017)... Md. , Sept. 22, 2017  As the ... Republican Senators Bill Cassidy (R-LA) and ... Information notes that the medical device industry is in ... medical device tax, the 2.3% excise tax on medical ... But they also want covered patients, increased visits and ...
Breaking Medicine Technology: