General, Research, Technology

Stem cells restore the heart in a different way than we thought

Stem cell therapy for quite some timeproved its worth. For example, it can help the heart recover from a heart attack. A few decades ago it was suggested that the stem cells of the heart help repair by replacing damaged or dead tissues with new ones, as if growing. It sounds quite logical and justified. Only now, as it turned out, everything is not happening exactly as scientists had imagined. This process is much more interesting.

Stem cells may play an unexpected role in the regeneration process.

How do stem cells really work?

As reported on the website of the Medical CenterCincinnati Children's Hospital, experts at the hospital concluded that injecting live or even dead stem cells into damaged heart tissue in mice causes an increase in the activity of the heart cells themselves. Thus, table cells only “trigger” regeneration mechanisms, and do not completely replace damaged tissues. Partial stem cell replacement naturally occurs. But most of the resulting tissue is a derivative of the heart tissue.

The innate immune response to stem administrationcells dramatically changes cellular activity around the damaged area of ​​the heart. Says Jeffrey Molkentin, lead author of the study and director of the Center for Molecular Cardiovascular Biology at the Cincinnati Children's Hospital Medical Center. This secondary healing process suggests that our own body can have a ton of regenerative properties that we don’t even know about.

The results prompted Dr. Molkentin.and his colleagues conclude that there is a need to "reassess the current planned clinical trials based on cell therapy to find out how this therapy actually works." We regularly report on discoveries related to stem cells not only on our website, but also on the Yandex.Zen page. There are even unique materials there, so be sure to subscribe.

Read also: Scientists have found out how stem cells “understand” what cell they need to turn into

But let's get back to the discovery of Americanspecialists. The study was conducted with two types of stem cells of the heart, which are currently used in clinical trials - bone marrow mononuclear cells and precursors of cardiomyocytes (heart cells). In fact, these cells are almost no different from each other, and different things from them - this is just “origin”. When the researchers discovered the pattern described above, they also tested the administration of dead stem cells, as well as an inert chemical called zymosan (a substance designed to trigger an innate immune response) in laboratory animals. As a result, in all cases, scientists received approximately the same positive result of the healing of heart tissue.

Dead stem cells or zymosan preparations,tested in this study, changed the response of the immune cells of the body itself, which significantly reduced the formation of extracellular connective tissue in the damaged areas, and also improved the mechanical properties of the heart scar.

Electron microscopy of heart cells: immune cells (marked in red and green) flow into the damaged area of ​​the damaged heart of the mouse three days after the researchers introduced the stem cells of the heart (the injection area is indicated in yellow)

However, the authors also note that mostprevious studies of the use of stem cells in the heart were "not developed correctly, since the cells were introduced into the vascular system of the subjects, or into the vessels of the heart." Scientists from Cincinnati say that a much greater effect can be achieved if stem cells or zymosan preparations are injected directly into and around the heart attack region. Doctors will also study these features of therapy in the near future.