Scientists have identified the relationship between immunity and the ability to resist fibrosis

MOSCOW, February 16 Specialists from Lomonosov Moscow State University found that immunity can reduce the human body’s ability to resist the development of fibrosis — the growth of connective tissue in place of damaged tissues of other types, leading to almost half of deaths in developed countries, and proposed way to create new drugs for fibrosis, the Russian Science Foundation reported.
As scientists note, fibrosis can occur due to injuries or infectious diseases in almost any organ and lead to a deterioration in their functioning.
Connective tissue grows and replaces any other damaged tissue. Due to the fact that the connective tissue is not able to perform the functions of what was previously in its place, the performance of the corresponding organ deteriorates. According to statistics, such consequences of fibrosis explain almost half of the deaths in developed countries.

The inflammatory process plays a key role in the development of fibrosis. On the one hand, it is useful for the body, since it allows it to fight infections, but on the other hand, becoming chronic, it leads to extensive fibrosis and, accordingly, damage to the organ. Chronic inflammation is provided by certain cells of the immune system — the so-called M2 macrophages. However, how they cause such an effect remains not fully understood, and therefore it is practically impossible to stop the development of fibrosis.
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MSU scientists studied the role of M2 macrophages in the development of fibrosis. The authors of the work took into account the fact that stem cells are responsible for proper tissue repair (without fibrosis). They inhibit the transformation of normal tissue cells into myofibroblasts, a type of cell responsible for the onset and progression of fibrosis. This means that when stem cells function normally, disease does not occur.

To test how stem cells are affected by M2 macrophages, the authors of the work kept stem cells together with proteins obtained from macrophages for two days. The experiment showed that the addition of such compounds leads to aging of stem cells, as a result of which they lose the ability to suppress the formation of myofibroblasts and can no longer provide restoration of normal tissues.
The authors also conducted an experiment that confirmed that aging stem cells are not able to suppress the development of fibrosis.
«Experiments have shown that M2 macrophages cause aging of stem cells, causing them to lose their ability to fight fibrosis. This discovery can be used in the development of drugs to prevent fibrosis, for example, by creating compounds that will selectively inhibit the activity of M2 macrophages and thereby protect stem cells from their influence,” said project participant, senior researcher at the Institute of Regenerative Medicine of Moscow State University Olga Grigorieva.