A new study may lead to new cures and treatments for Marfan syndrome. Researchers at Johns Hopkins have made great progress testing in mice. Follow the original story here.
On average, mice are a pretty robust species. When affected by disease similar to Marfan Syndrome, however, they face high rates of heart failure. Researchers at Johns Hopkins have found that introducing the type of stress that would be no sweat for normal mice can be catastrophic for these test mice. This part isn’t very surprising.
Current treatment for Marfan syndrome is complicated and limited. We know plenty about it’s effects, just not how to reverse them.
Marfan syndrome affects an average of 1 in every 5000 people. It targets connective tissue. Symptoms includes longer limbs, fingers, and toes. It also affects blood vessels and heart valves. Enlargement of the aorta, leaking heart valves, and muscle weakness can all lead to heart failure for those with Marfan syndrome. To learn more about Marfan syndrome, click here.
This is where the new mouse studies come in. Researchers at Johns Hopkins have been able to reverse heart failure in mice with a new treatment.
The key lies in targeting a specific cellular pathway in heart tissue. When heart failure occurs in human patients, it is often difficult to distinguish between failure due to genetic defect, or failure due to stress. This is where the mouse study focused its efforts.
Researchers used a technique called transverse aortic constriction (TAC) to induce stress on two types of mice during the experiment. The first type were similar to wild mice. The second group had symptoms similar to Marfan syndrome. Using TAC, researchers discovered that stress normal and tolerable for wild mice had severe effects on Marfan mice. They decided to further investigate to find out how.
In the Marfan mice, hearts were becoming enlarged due to an abnormal growth chemical. Nearby cells in the body known as fibroblasts were responsible for emitting these chemical directives. As researchers tracked the signals, they observed a protein called transforming growth factor beta. It’s believed that transforming growth factor beta is present in increased amounts in people with Marfan syndrome and can be connected to many of the syndrome’s symptoms.
Repeating their experiments, researchers focused their efforts on this aspect of the disorder. They introduced therapeutic drugs that inhibited the growth factor. As a result, researchers were able to reverse the factors leading to heart failure in all of the Marfan test mice. The study’s head researcher cautions that much more testing is required, but hopes for further developments.
“Research into why some severely affected children with Marfan syndrome result in heart failure is critical. Mice studies are a first step in understanding the mechanisms involved in initiating this process. While we are excited about this new research, we know that this is just a first step and much more research is needed to understand how this can translate into human therapies.” – Josephine Grima, PhD, Chief Science Officer, The Marfan Foundation.