Two groups in China have independently succeeded in converting skin cells directly into neurons using different chemical cocktails.
'The small molecules that are used in this chemical approach are cell permeable; cost-effective; easy to synthesise, preserve, and standardise; and their effects can be reversible,' says Professor Hongkui Deng, who co-led the research of the group based at Peking University Stem Cell Research Center.
While Professor Deng's group worked with mouse cells, a group at the Shanghai Institutes for Biological Sciences transformed human cells from both healthy individuals and Alzheimer's patients.
Professor Gang Pei, who co-led the Shanghai research, said: 'These results lay the groundwork for future Alzheimer's research, giving scientists a safe and accurate platform to test the effects of possible drugs.'
The small molecules used in this approach work by entering the cell's DNA-containing nucleus and altering the activity of certain genes. Skin-cell specific genes were down-regulated while neuron-specific genes were up-regulated. Though they each used different small molecules in their protocols, both groups achieved functional neurons that were able to form synapses and produce electrical impulses.
Dr Dusko Ilic, a stem-cell expert at King's College London who was not involved in the study, said: 'These studies are proof of principle that such simplistic approach is possible and they should encourage other groups to follow their example.'
He added: 'Although we do not know yet how these transdifferentiated neurons would behave in vivo, the implications for regenerative medicine could be enormous.'
Both groups are aiming to gain a better understanding of the biology behind the technique in order to improve its efficiency.
'In addition, we are attempting to generate specific neuronal subtypes and patient-specific functional neurons for translational medicine by using pure chemicals,' said Professor Deng.
The studies were published side-by-side in Cell Stem Cell.