Physicians Blood vessels educate inflammatory cells and convert them into repair cells

Experts are investigating the body's own cure of circulatory disorders

The human body needs oxygenated blood to supply the tissues and organs. Through the arteries, for example, this blood reaches the brain, the muscles, and the human heart to supply them with sufficient oxygen. Researchers have now found that arteries and so-called phagocytes are able to work together to help cure circulatory disorders. For this they control the formation of specialized repair cells.

Scientists at the Hannover Medical School (MHH) found in their current study that blood vessels promote their own regeneration by controlling the formation of special repair cells. The physicians published the results of their study in the English-language journal "Nature".

Our arteries supply oxygen to organs and tissues in the human body. Occurring circulatory disorders can have dangerous effects. However, blood vessels can promote their own regeneration by transforming so-called inflammatory cells into special repair cells. (Image: psdesign1 - fotolia)

What is ischemia?

There are several causes that can cause the vital circulation in our organs to be disrupted. Such a circulatory disorder (ischemia) causes a poor circulation or even a complete loss of blood flow to tissues or organs. An ischemia can cause affected organs, tissues and also blood vessels themselves to be damaged, explain the physicians. The immune system of the human body then react with inflammation.

An uncontrolled inflammation intensifies the damage to the tissue

Unfortunately, such inflammation is often uncontrolled, say the experts. Thus damage to the tissue is further intensified. However, researchers have now found in their investigation that the blood vessels promote their own regeneration. For this purpose, specialized repair cells are used whose formation is controlled by the blood vessels, explain the scientists from the team led by Professor. Florian Limbourg from the MHH Clinic for Kidney and Hypertension Diseases.

Arteries can develop specialized repair cells

When arteries are damaged, they have a certain signaling molecule on their inside. This molecule controls the transformation of certain invading inflammatory cells (monocytes) into specialized repair cells (macrophages). The repair cells can repair the damaged arteries and even promote their growth, say the experts. In other words, the blood vessels usually educate the inflammatory cells so that they can initiate regeneration.

Effects of a disturbed signal process

However, disrupting this signaling process causes the so-called monocytes to transform into aggressive scavenger cells. These phagocytes then continue to heat the existing inflammation and additionally prevent vascular repair.

Healing repair cells were first cultured in a test tube

Hopefully, this discovery will lead to new cell-based treatment strategies for critical circulatory disorders, explains author Professor Limbourg of the Hannover Medical School. For the first time, scientists have managed to grow the healing repair cells in a test tube.

Damaged cells produce a signal in the cell wall

A very old evolutionary signal principle is used by the body for communication between the arteries and the immune cells. After damage, cells build up a signal on the inside of the blood vessels (endothelial cells) into the cell wall. This is called Notch ligand Delta-like 1 and it activates the specific receptor called Notch2, explain the authors of the study. The so-called Notch2-Reseptor then controls the maturation of the monocytes in the repair cells, add the doctors of the MHH. The current project of the researchers of the Hannover Medical School was funded by the German Research Foundation (DFG) and the Integrated Research and Treatment Center Transplantation (IFB-Tx). (As)