FUNCTIONING HUMAN MUSCLE GROWN FROM STEM CELLS
Forget hitting the gym, this is a much more efficient way of building muscle: a team at Duke University has grown functioning human skeletal muscle using induced pluripotent stem cells.
The researchers say that this breakthrough could help them treat diseases such as muscular dystrophy.
The muscles were grown using pluripotent stem cells. These are cells taken from adult non-muscle tissues, such as skin or blood, and reprogrammed to revert to a nascent state. These stem cells were grown into muscle tissue by flooding them with a molecule called Pax7 – a key component in the formation of muscle tissue.
The team then grew the cells in a 3D scaffold, encouraging them to form muscle fibres that could contract and respond to external stimuli, just like living muscle. The team then transplanted the muscle into mice, where it began to integrate into the existing tissue. It was not as strong as naturally grown muscle, but still holds promise for treating degenerative muscle diseases.
“The prospect of studying rare diseases is especially exciting for us,” said Prof Nenad Bursac. “When a child’s muscles are already withering away 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 fibres to test.”
Cross-section of muscle fibre grown from induced pluripotent stem cells. The green areas are muscle cells, the blue areas are cell nuclei, and the red areas are the surrounding support matrix