We owe our longevity to stem cellsthat are deep inside certain tissues of our body and replace old cells. In recent years, science has made significant progress in the treatment of certain genetic diseases by editing the genome of stem cells. To do this, they are first removed from the body, edit, making the necessary changes in their genome, and then placed back into the patient's body. But such a procedure brings with it a number of difficulties. Scientists from Harvard University report that all this can soon be avoided. For the first time, researchers conducted successful editing of stem cell genes right inside the body. The results of their work are reported in the journal Cell Reports.
Stem cell genome editing is a complex process.
The process of treating genetic diseases cancompare with an attempt to clear the river of debris. If you just collect all the garbage on the bottom of the river downstream, then over time the river will become dirty again, if you do not solve the problem with the garbage upstream. Similarly, treatment of diseased cells is ineffective. It will not help unless you resort to the use of stem cells that can quickly replace damaged or old cells with new and healthy ones.
The current editing processStem cells include their removal from the body, subsequent genetic changes and eventually the reverse integration of the edited cells back into the body. At all stages of this very complex procedure, there is a high risk of errors and failures: stem cells may simply die inside the culture cup, the patient’s immune system may begin the process of rejecting the edited stem cells after their transplantation, or the new cells will not have any expected positive effect.
"When you extract stem cells fromorganism, you extract them from a very complex environment that nourishes and supports them. Extraction creates a real shock for them, ”explains Amy Wagers, a leading specialist in this study.
“Isolating stem cells changes them. Cell transplantation changes them. The possibility of introducing genetic changes in their genome without unnecessary additional interaction with them is a key objective of our research. ”
Based on previous work on the genestem cell editing, the Harvard team of scientists used adeno-associated viruses (AAV) to deliver the substance necessary for editing the genome into cells. These viruses do not cause disease in humans and, accordingly, cause only a very weak immune response.
To test the method, scientists usedlaboratory mice. For the introduction of AAV viruses in various types of rodent cells (skin, blood, muscles, and progenitor cells (refer to the initial stage of cell development)), scientists used the technology of CRISPR gene editing. In order to visualize the result in stem cells, reporter genes were also activated, which are highlighted with a fluorescent red color.
Scientists expected success. Researchers report that up to 60 percent of skeletal muscle stem cells, up to 27 percent of skin stem cells and up to 38 percent of mouse bone tissue stem cells were highlighted in red, indicating that they were successfully edited. Following this, scientists add that other skin cells have also been subsequently modified, which speaks in favor of transferring genetic information from edited stem cells to other cell types.
A team of Harvard scientists reports thatA scientific breakthrough may lead to the development of new treatments for genetic diseases, especially such as muscular dystrophy, which is associated with the problem of tissue repair.
“Until now, the concept of delivering healthy genes tostem cells using adeno-associated viruses were not practical because these cells, while in a living organism, divide so quickly that the delivered genes dissolve very quickly from them, ”says Sharif Tabebordbar.
“Our research demonstrates the possibilityconstant editing of the genome of stem cells and their daughter cells in their natural environment. This opens up great potential for further improvement of this method of gene editing, as well as the development on its basis of more reliable and effective methods of treatment of various forms of genetic diseases. "
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