Study: Neutrophils important for self-healing after a heart attack

Study: Neutrophils important for self-healing after a heart attack

Healing process after a heart attack is significantly influenced by neutrophils
With a heart attack, numerous cardiac muscle cells die within a short period of time and an infarction is often fatal. If the affected survive, inflammation develops in the affected tissue, which is triggered by neutrophils, explains the Ludwig Maximillians University in Munich (LMU). A recent study by the research team led by Professor Sabine Steffens from the Institute for Epidemiology and Prophylaxis of Circulatory Diseases at the LMU Clinic has now shown that neutrophils are also instrumental in ending inflammation.

The inflammation, which neutrophils trigger after a heart attack, is crucial for the healing process, according to the researchers. However, widespread inflammation also has harmful consequences for health. However, according to the current findings of the researchers, the neutrophils are also involved in ending the inflammatory process. Prof. Steffens and colleagues have published the results of their study in the trade journal "European Heart Journal".

Inflammation with positive and negative consequences
From previous studies it was already known that neutrophils (neutrophils for short) trigger inflammation in the affected tissue after a heart attack. The immune system responds to the large number of dead heart muscle cells with inflammation. “Neutrophils migrate into the damaged heart muscle immediately after an infarction. They can release various substances that render pathogens harmless and can trigger an acute inflammatory reaction, ”said the LMU. This would trigger the healing process after a heart attack, in which the dead tissue is broken down. Ultimately, however, the inflammation causes scars to form and the heart muscle to expand, the researchers explain. The result is often heart failure, which requires permanent follow-up treatment.

Neutrophils start and stop inflammation
According to the LMU, Sabine Steffens' group was able to "demonstrate for the first time in a mouse model that the neutrophils are not only the cause of the inflammation, but also crucial for the healing of the infarct." They release substances that promote the development of certain monocytes that in turn drive the repair process forward. According to Professor Sabine Steffens, “Inflammation is not only harmful, but is even necessary in moderation for the wound to proceed properly.” So far, the positive role of neutrophils has been overlooked. The current study shows that neutrophils are also crucially involved, that the inflammation resolves and the tissue can stabilize. "Our result is surprising, since neutrophils have so far only been assigned a harmful effect after an acute heart attack," said the professor of clinical pathobiochemistry.

New treatment approaches possible
The new results show that the function of the neutrophils is not yet fully understood, the researchers conclude. This also has implications for current therapeutic approaches that rely on a reduction in the number of neutrophils after a heart attack in order to control the inflammatory process. “It depends on the right balance. There could be a limit from which the positive effects of the neutrophils topple, ”emphasizes Prof. Steffens. According to the expert, an excessive reduction in the neutrophils could lead to an impairment of the healing process. Instead, it may be a promising approach to boost the development of those monocytes that speed up the repair process. In further studies, it is now important to uncover the signaling pathways and regulatory processes that lead to their formation. (fp)

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