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

Researchers reveal the crucial role of a particular enzyme in heart failure

Almost two million people in Germany suffer from cardiac insufficiency (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 discovered that in patients with diastolic heart failure, there is too much of a specific enzyme in the heart. The results are of great importance for the development of new drugs for heart disease.

Impaired pumping capacity

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. Especially with older people, however, this pumping capacity is often impaired because the organ is no longer filled with sufficient blood. Those affected suffer from the so-called diastolic heart failure, one of the most common cardiovascular diseases in Germany. Researchers have now gained new insights into the disease, which could contribute to the development of new drugs.

In patients with diastolic heart failure, too much of the PP5 enzyme is present in the heart. That's what researchers have discovered. The function of the enzyme was still completely unknown. (Image: Robert Kneschke / fotolia.com)

Almost two million Germans suffer from heart failure

"Around 1.8 million people in Germany suffer from heart failure, which in professional circles is referred to as heart failure," writes the German Heart Foundation on its website.

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

The disease can be divided into various forms, one of which is the so-called "diastolic heart failure". This has a special position, as it "the pumping power of the heart can be normal," said the Heart Foundation.

Too much of the enzyme PP5 in the heart

An international team of researchers led by Prof. Wolfgang Linke from the Institute of Physiology ll of the University of Münster has now shown that in patients with diastolic heart failure too much of the enzyme PP5 is present in the heart, whose function was still completely unknown.

According to a statement, scientists' findings published in the journal Nature Communications are of great importance for the development of new medicines for heart disease.

Enzyme inhibits the titin spring

When blood enters the heart chambers, called diastole, the organ expands. If the blood then flows out again, it contracts (systole).

Millions of small pockets in the cardiac muscle fibers are responsible for this movement - the sarcomeres.

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

"In order for the heart chambers to adequately fill with blood during diastole, the titin spring must have the proper elasticity. Only in this way can the heart expand enough and allow enough blood to flow in, "says Linke.

"In our study we were able to show that the enzyme docks PP5 at a specific site of the titin spring and inhibits it. The spring loses its elasticity and that's the problem, "explains the study author.

Hope for patients with diastolic heart failure

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

In addition, they found that PP5 also inhibits heart growth by affecting a mechanism mediated by the titin molecule in cardiomyocytes, which promotes this growth.

The results provide hope for patients with diastolic heart failure: Based on the findings, drugs could be developed that slow down PP5 activity and thus stop the cardiomyocyte's "stiffening".

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