A biological mechanism was found that allows improvement in muscle recovery processes

Researchers have discovered that a relatively rare form of the protein calcineurin is important in muscle repair processes after injury, and is a promising candidate for developing strategies to treat damaged muscles

Muscle is a relatively stable tissue, which normally does not undergo many cell divisions. However, in cases of various injuries, for example in injuries or after strenuous training, a complicated and complex system is activated that enables the repair of the damage and the preservation of the muscle mass. Key players that enable the repair are the stem cells in the muscle, called satellite cells. When these cells are activated, they are able to divide, differentiate and integrate within the existing muscle fibers, and even give rise to new muscle fibers.

One of the proteins participating in the control of these processes is the enzyme calcineurin (Cn). This protein consists of two subunits: a catalytic subunit that enables its activity, and a catalytic subunit. In addition, it has several protein forms as a result of different processing processes of the RNA by which it is created (processes of alternative splicing). One of the forms of calcineurin is called CnAβ1. This form is expressed in the satellite cells in the muscle, and it lacks the control subunit. As a result, it is constantly active.

A group of researchers from EMBL and Imperial College London, led by Prof. Nadia Rosenthal and Dr. Enrique Lara-Pezzi, discovered that the expression level of the CnAβ1 protein in muscle increases following injury, and that it is important in controlling The processes of division and administration of satellite cells. According to the research findings, the stem cells in which there was an increase in CnAβ1 expression divided faster. On the other hand, the cells in which the protein was silenced stopped dividing and became muscle fibers. When they tested transgenic mice that overexpress CnAβ1 in the muscle cells, it was found that there is an improvement in the healing processes of the muscles after injury, and at the same time a decrease in inflammation and scarring was observed (so that there is more room for the construction of new muscle fibers).

In an attempt to find the molecular mechanism mediating the effect of CnAβ1 on the muscle, the researchers discovered that CnAβ1 apparently has an important role in inhibiting the activity of another protein, called FoxO. This protein is a transcription factor involved in the control of genes associated with cell cycle arrest. By inhibiting this CnAβ1 allows cells to divide sufficiently to repair the muscle damage.

According to Prof. Rosenthal, the positive effect that CnAβ1 has on muscle healing places it as a possible target in the design of drugs to treat injuries and degenerative muscle diseases.

For the abstract of the scientific article