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In heart failure patients, there is too much of a particular enzyme in the heart


Researchers uncover crucial role of a particular enzyme in heart failure

Almost two million people in Germany suffer from heart failure (heart failure). As a result of this disease, the heart is no longer able to provide the body with sufficient blood and oxygen. Researchers have now found that there is too much of a particular enzyme in the heart of patients with diastolic heart failure. The results are of great importance for the development of new drugs for heart disease.

Impaired pump performance

70 milliliters per stroke, 8,000 liters a day - these are the impressive amounts of blood that a healthy human heart pumps through the body every day. However, this pumping performance is often impaired, especially in the elderly, because the organ no longer fills with sufficient blood. Those affected suffer from so-called diastolic heart failure, one of the most common cardiovascular diseases in Germany. Researchers have now gained new knowledge about the disease that could contribute to the development of new drugs.

Almost two million Germans suffer from heart failure

"Around 1.8 million people in Germany suffer from heart failure, which experts call heart failure," writes the German Heart Foundation on its website.

According to the experts, heart failure describes the reduced pumping function of the heart.

The disease can be divided into different forms, one of which is the so-called "diastolic heart failure". This has a special position because “the pumping power of the heart can be normal,” says the heart foundation.

Too much of the PP5 enzyme in the heart

An international team of researchers headed by Prof. Wolfgang Linke from the Institute of Physiology II at the University of Münster has now been able to show that in patients with diastolic heart failure there is too much of the enzyme PP5 in the heart, the function of which has so far been completely unknown.

As stated in a communication, the results of the scientists published in the journal "Nature Communications" are of great importance for the development of new drugs for heart disease.

Enzyme inhibits the titin feather

When blood flows into the ventricles, the so-called diastole, the organ expands. If the blood then flows out again, it contracts (systole).

Millions of small compartments in the heart muscle fibers are responsible for this movement - the sarcomeres.

Inside them is the protein titin, which has the function of a mechanical spring, which develops a restoring force when the muscle compartments are stretched - similar to a rubber band.

“In order for the ventricles to fill up with blood sufficiently during diastole, the titin feather must have the right elasticity. This is the only way the heart can expand enough and allow enough blood to flow in, ”says Linke.

“In our study, we were able to show that the enzyme PP5 docks at a specific point on the titin spring and inhibits it. The spring loses elasticity and that is exactly the problem, ”explains the study author.

Hope for patients with diastolic heart failure

In their work, the researchers demonstrate that patients with a weak heart have an excess of PP5 in the organ.

In addition, they found that PP5 also inhibits heart growth because it interferes with a titin-mediated mechanism in the heart muscle cells that promotes this growth.

The results give hope to patients with diastolic heart failure: Based on the findings, drugs could be developed that slow down PP5 activity and thus stop the “stiffening” of the heart muscle cells.

"We are already working with such substances in our laboratories, but it always takes some time from a new therapeutic approach to the final medication," says Linke. (ad)

Author and source information

Video: Living with Heart Failure Patient Interviews (August 2020).