A group of researchers from Duke University (USA) created the first functional human muscle from pluripotent stem cells. In this way, a new pathway was opened towards regenerative therapies, the study of rare diseases and the personalization of therapies.
It is based on the use of induced pluripotent stem cells (iPS). This refers to adult cells, which are taken for example from the skin or blood, and are “reprogrammed” so that they look and act like embryonic stem cells. They are capable of transforming into any type of cell.
In this line, with the use of iPS the experts can increase the amount of myogenic progenitor cells in an unlimited way. They resemble muscle stem cells, which – as Professor Nenad Bursac explained – “can form an entire muscle from a single cell.”
The researchers managed to grow the iPS by adding a molecule called Pax7, which sends them the signal to develop as muscle cells. This process had already been done before, but they were not robust enough and, therefore, the muscle was not functional.
The researcher argued that what made the difference was the particular way in which they performed the cell culture and the use of a three-dimensional matrix. This method allows the cells to grow and develop much faster and more durably than the two-dimensional cultures normally used. So, once the cells started to become muscle, Bursac and Rao stopped supplying the Pax7 molecule to them. provide them with the necessary support and food to reach a complete maturation.
Similarly, the study showed that after two to four weeks of three-dimensional culture, the resulting muscle cells form fibers that contract and react to stimuli. This reaction is the same as the electrical pulses and biochemical signals manifested by muscle fibers.
For the research, muscle fibers were implemented in adult mice, where they survived and worked for at least three weeks at a time. They were progressively integrated into the native tissue through vascularization.
Although the resulting muscle is not as hard as the native tissue, researchers believe it has potential for every medical area even for a endodontist in Tijuana Mexico. Currently, the goal is to get more robust muscles. This new approach opens up possibilities for use in regenerative therapies and for the future study of rare diseases, which for Bursac is an “especially exciting” perspective.