Stem Cell

Human Skin Cells Successfully Converted into Motor Neurons

Human Skin Cells Successfully Converted into Motor Neurons

Scientists have discovered how adult skin cells can be converted into motor neurons without transitioning them through a stem cell state.

The findings promise to help researchers better understand motor neuron diseases, such as amyotrophic lateral sclerosis (ALS).

The study, “MicroRNAs Induce a Permissive Chromatin Environment that Enables Neuronal Subtype-Specific Reprogramming of Adult Human Fibroblasts,” was published in the Cell Stem Cell journal.

Growing motor neurons — the nerve cells damaged in ALS — from easily obtained cells is a promising approach to treating motor neuron diseases. But the process has been hampered by scientists’ lack of understanding of all the molecular players that regulate the process.

Researchers at the Washington University School of Medicine in St. Louis have identified four molecular players that allow skin cells to convert themselves into motor neurons.

Prior studies had used differentiated cells — those with an assigned function — to make a new cell type. But first cells needed to enter a stem cell state, creating so-called induced pluripotent stem cells, or iPS. Under the right conditions, iPS could be reprogrammed into any cell type.

The process the Washington University researchers use does not require skin cells to enter the iPS stage. Instead, they’re directly converted into motor neurons. This has many advantages, including overcoming ethical issues, since this pluripotent state is similar to…