New Approach to Treating Muscular Dystrophy With Stem Cells
Scientists from the Lillehei Heart Institute (University of Minnesota) have developed a new efficient process of making muscle cells from human stem cells and for the first time ever effectively treated with these cells muscular dystrophy in a mice model. The research was focused on producing muscle progenitor cells from induced pluripotent cells (iPS), derived from skin cells by their reprogramming. The study results were published in May 4 issue of Cell Stem Cell
iPS cells are broadly used in the experiments with new stem cell treatment methods. They have properties of embryonic stem cells, but usually are derived by reprogramming adult cells. Being patient-specific, these cells are not rejected if transplanted back to the patient. Moreover, the use of these cells does not require embryo destruction.
The researchers from University of Minnesota were the first to show induced pluripotent stem cells can be an effective treatment for muscular dystrophies. Earlier, the researchers of the above mentioned university also pioneered the use of mice embryonic stem cells for muscular dystrophy treatment
. However, there is a lag in translating results received in animal studies to the human stem cell research.
Up until now, it was impossible to derive skeletal muscle progenitor cells from human stem cells in sufficient quantities to make them engraft in the recipients’ body. Using iPS cells overcomes this obstacle and can pave way for developing new treatment approaches.
In their experiments, the researchers modified iPS cell and ES cell lines with the PAX7 gene. This gene regulates the levels of the Pax7 protein which controls regeneration of muscle tissue after an injury. With such a modification conducted at the right time, the researchers could prompt stem cells to differentiate into muscle progenitor cells.
When transplanted to mice with muscular dystrophy, myogenic progenitor cells ensured muscle regeneration and improvement in muscle function. The procedure proved to be more effective than transplantation of myoblasts, cells derived from adult muscle biopsies, which had been tested earlier in clinical trials. While myoblasts did not engraft after transplantation, myogenic progenitor cells successfully gave rise to new muscle cells and helped restore lost functions.
To ensure safety of the method developed, the researchers plan to test another way of delivering the Pax7 gene into stem cells. In the mentioned study, they used viruses to genetically modify stem cells, but viruses sometimes cause mutations, which can bring risks to the stem cell treatment. Meanwhile, the study remains a milestone in developing effective treatment for muscular dystrophy.