Stem cell treatments for muscular dystrophy and other degenerative diseases of muscle might be a realistic possibility, since scientists have discovered protocols to make muscle cells from human pluripotent stem cells.
Tiziano Barberi, Ph.D., chief investigator in the Australian Regenerative Medicine Institute (ARMI) at Monash University in Clayton, Victoria, and Bianca Borchin, a graduate student in the Barberi laboratory, have developed techniques to generate skeletal muscle cells. Barberi and Borchin isolated muscle precursor cells from human pluripotent stem cells (hPSCs), after which they applied a purification technique that allows these cells to differentiate further into muscle cells.
Pluripotent stem cells, such as embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs), have the ability to become any cell in the human body, including skeletal muscles, which control movement. Once the stem cells begin to differentiate, controlling that process is very challenging, but essential in order to produce only the desired cells. Barberi and Borchin used a technique known as fluorescence activated cell sorting (FACS) to identify those cells that contained the precise combination of protein markers that are expressed in muscle precursor cells. FACS also enabled them to successfully isolate those muscle precursor cells.
“There is an urgent need to find a source of muscle cells that could be used to replace the defective muscle fibers in degenerative disease. Pluripotent stem cells could be the source of these muscle cells,” Dr. Barberi said. “Beyond obtaining muscle from hPSCs, we also found a way to isolate the muscle precursor cells we generated, which is a prerequisite for their use in regenerative medicine.”
Borchin said there were existing clinical trials based on the use of specialized cells derived from hPSCs in the treatment of some degenerative diseases, but deriving muscle cells from pluripotent stem cells proved to be challenging. “These results are extremely promising because they mark a significant step towards the use of hPSCs for muscle repair,” she said.
“The production of a large number of pure muscle precursor cells does not only have potential therapeutic applications, but also provides a platform for large-scale screening of new drugs against muscle disease,” Dr. Barberi added.
This study was published early online Nov. 27 in Stem Cell Reports. This study does not address the immune response against dystrophin that has plagued gene therapy and stem cell-based muscular dystrophy clinical trials that has been noted in previous posts. The use of embryonic stem cells, in particular, would create muscles that are not tissue matched to the patient and would generate robust inflammation against the implanted muscles. Thus embryonic stem cells would generate a “cure” that would be much worse than the disease itself. Nevertheless, adapting the Barberi-Borchin protocol to induced pluripotent stem cells would produce skeletal muscle cells that are tissue matched to the patient.
Beyond the Dish 