Scientists have grown the first ever functioning human muscle from skin cells in a groundbreaking new study.
Researchers from Duke University took skin cell samples then successfully converted them into stem cells that began growing human muscle.
This breakthrough will allow scientists to grow far more muscle cells starting from scratch, leading to developments in gene and cellular therapies.
The findings have the potential for understanding and treating muscular diseases caused by genetic mutations once these methods are applied to humans.
Researchers from Duke University have successfully grown human muscle from skin cells in a scientific breakthrough that has the potential to fix genetic malfunctions
The findings build on work published in 2015 when researchers at Duke University grew the first functioning human muscle tissue from muscle cells.
However in the new study published in Nature Communications, the researchers instead started with human induced pluripotent stem cells.
These are cells taken from adult non-muscle tissues, such as skin or blood, and ‘reprogrammed’ to revert to a basic state.
The pluripotent stem cells were then grown while being filled with a molecule called Pax7, which signals the cells to start becoming muscle.
As the cells multiplied they became very similar to adult muscle stem cells, yet not as strong.
‘Starting with pluripotent stem cells that are not muscle cells, but can become all existing cells in our body, allows us to grow an unlimited number of myogenic progenitor cells,’ said Nenad Bursac, professor of biomedical engineering at Duke University.
‘These progenitor cells resemble adult muscle stem cells called ”satellite cells” that can theoretically grow an entire muscle starting from a single cell’ Bursac added.
The biomedical engineers then implanted the newly grown muscle fibers into adult mice and showed that they survive and function for at least three weeks while integrating into the existing tissue.
While previous studies had been able to accomplished this, none were able to then grow these cells into functioning human muscle.
‘It’s taken years of trial and error, making educated guesses and taking baby steps to finally produce functioning human muscle from pluripotent stem cells,’ said Lingjun Rao, a postdoctoral researcher in and first author of the study.
‘What made the difference are our unique cell culture conditions and 3-D matrix, which allowed cells to grow and develop much faster and longer than the 2-D culture approaches that are more typically used,’ said Rao.
The findings offer the possibility of more advances cell therapies, drug discoveries and the ability to grow larger amounts of muscles.
This is a potential new method for regenerative therapies and for creating models of rare diseases for future studies and individualized health care.
‘The prospect of studying rare diseases is especially exciting for us,’ said Bursac.
‘When a child’s muscles are already withering way from something like Duchenne muscular dystrophy, it would not be ethical to take muscle samples from them and do further damage. But with this technique, we can just take a small sample of non-muscle tissue, like skin or blood, revert the obtained cells to a pluripotent state, and eventually grow an endless amount of functioning muscle fibers to test,’ Bursac said.