Experts are studying the body's healing of circulatory disorders
The human body needs oxygen-rich blood to supply the tissues and organs. Through the arteries, this blood reaches the brain, muscles and human heart, for example, in order to supply them with sufficient oxygen. Researchers have now found that arteries and so-called phagocytes are able to work together to heal circulatory disorders. To do this, they control the creation of specialized repair cells.
In their current study, scientists from the Hannover Medical School (MHH) found that blood vessels promote their own regeneration by controlling the development of special repair cells. The doctors published the results of their study in the English-language journal "Nature".
What is ischemia?
There are various causes that can cause the vital blood flow to our organs to be interrupted. Such a circulatory disorder (ischemia) causes poor blood circulation or even a complete loss of blood flow to tissues or organs. Ischemia can lead to damage to organs, tissues and blood vessels themselves, the doctors explain. The human body's immune system responds to this with inflammation.
Uncontrolled inflammation increases the damage to the tissue
Unfortunately, such inflammation often goes uncontrolled, the experts say. Damage to the tissue is thus further increased. However, researchers have now been able to determine in their investigation that the blood vessels promote their own regeneration. For this, specialized repair cells are used, the formation of which is controlled by the blood vessels, explain the scientists from the team led by Professor Dr. Florian Limbourg from the MHH Clinic for Kidney and Hypertension Diseases.
Arteries can create specialized repair cells
If arteries are damaged, they have a specific signaling molecule on the inside. This molecule controls the transformation of certain immigrant inflammatory cells (monocytes) into specialized repair cells (macrophages). The repair cells can repair the damaged arteries and even promote their growth, the experts say. In other words, the blood vessels normally train the inflammatory cells so that they can initiate regeneration.
Effects of a disturbed signal process
However, if this signaling process is disturbed, this leads to the so-called monocytes being converted into aggressive phagocytes. These phagocytes then heat up the existing inflammation and also prevent vascular repair.
Healing repair cells could be grown in a test tube for the first time
Hopefully, this discovery will lead to new cell-based therapy strategies for critical circulatory disorders, explains author Professor Limbourg of the Hannover Medical School. For the first time, scientists have now managed to grow the healing repair cells in a test tube.
Damaged cells produce a signal in the cell wall
A very old evolutionary signaling principle is used by the body for communication between the arteries and the immune cells. After damage, cells build a signal on the inside of the blood vessels (endothelial cells) into the cell wall. This is known as the Notch ligand Delta-like 1 and it activates the specific receptor called Notch2, the study authors explain. The so-called Notch2 reseptor then controls the maturation of the monocytes in the repair cells, add the MHH doctors. The current project of the researchers at the Hannover Medical School was funded by the German Research Foundation (DFG) and the Integrated Research and Treatment Center for Transplantation (IFB-Tx). (as)