Scientists from St. Petersburg State University, together with researchers from the Karolinska Institute (Sweden), have shown for the first time that inside a living mammal, it is possible to create cells of the central nervous system that will perform their usual functions and restore the damaged spinal cord in case of injuries. It turned out that the cells in the lining of the central canal of the spinal cord can be transformed into oligodendrocytes - they form the "insulating material" around the axons of nerve cells. The results of the work were published in an article in the prestigious scientific journal Science.
Professional neuroscientists are well aware that the phrase "nerve cells do not repair" is just a naive warning against unnecessary anxiety, which has little to do with scientific facts. In the brain of even an adult, neurogenesis, that is, the formation of new neurons, still occurs. This ability is enough to keep cognitive functions in order, but not to, for example, restore the spinal cord of a driver who injured his spine in a car accident. After such an injury, a "glial" scar appears in the nervous tissue - and the former functions of the spinal cord cannot be fully restored.
Yet a group of researchers from the Karolinska Institute and St. Petersburg State University, led by the pioneer in the field of brain stem cell research, Professor Jonas Friesen, was able to take a step towards learning how to restore damaged tissues of the central nervous system inside a living organism. The experiments were carried out on mice using transgenic technologies. Scientists have shown that with various spinal cord injuries in mice, it is possible to control the formation of full-fledged oligodendrocytes, which will perform their functions of myelination of the axons of the nerve cells of the damaged tissue. It is oligodendrocytes, wrapping their processes around the axons of nerve cells, form the so-called myelin sheaths - a special "insulating material" that promotes the rapid propagation of nerve impulses in the central nervous system (CNS).
Oligodendrocyte production was derived from ependymal cells that line the central canal of the spinal cord. For this, in these cells, using genetic technologies, they artificially caused the appearance of a special protein, the transcription factor Olig2, which normally controls the program for the formation of specific properties (differentiation) of oligodendrocyte cells in the CNS during embryonic development.
“The recovery processes in the nervous system, unfortunately, are extremely limited,” said Oleg Shuplyakov, one of the authors of the article in Science, head of the synapse biology laboratory at the Institute of Translational Biomedicine, professor at St. Petersburg State University and the Karolinska Institute. “We know that primitive vertebrates, such as salamanders, have such abilities by nature, but not humans. Perhaps thanks to such scientific research in the future, we will be able to completely restore damage to the central nervous system in humans. "
The next steps of the researchers are a detailed study of programs for triggering the differentiation of nerve cells of various modalities in vertebrates, as well as the development of medical technologies that will help restore the functions of the central nervous system after injuries of the central nervous system and in neurodegenerative diseases in humans.
Today, scientists from the Institute of Translational Biomedicine of St. Petersburg State University are actively cooperating with colleagues from the Karolinska Institute, one of the largest medical universities in Europe. Within the framework of a cooperation agreement, they conduct joint research, and also develop programs for the training of young specialists.
“A publication in Science is a good example of scientific international collaboration. The ability to work and think together allows for a broader approach to problem solving, a multidisciplinary approach and world-class results that could not be obtained in one laboratory. For several years now, the Institute of Translational Biomedicine, St. Petersburg State University, has been working on the search for new methods for restoring the functions of the spinal cord and brain, and on the development of new methods of reprogramming and cell differentiation. The unique genetic technologies developed within the framework of this work will give a new impetus to these areas and allow the Institute's specialists to solve the key problems of modern biomedicine in a new way, ”says the director of the Institute of Translational Biomedicine, St. Petersburg State University, scientific director of the N. I. Pirogov Clinic of High Medical Technologies, St. Petersburg State University Professor Raul Gainetdinov.
The study was supported by the St. Petersburg State University grant No. 51132811.