Stem cells will help in the development of painkillers

Scientists from the Karolinska Institutet in Sweden have found that the absence of a certain protein in the embryonic stem cells prevents the development of neurons responsible for the perception of pain, temperature and itch. This discovery may help in the development of new painkillers.

Previous research in the genetics of the development of the nervous system found five genes that are associated with aberrant pain. A person born with a mutation in one of these genes (PRDM12) is unable to feel pain, which leads to serious problems.

“But the exact mechanism the causes the faulty pain function is unknown”, – says Saida Hadjab, senior researcher at the Department of Neuroscience, Karolinska Institutet. and lead author of the study, whose results were published on March 26, 2019 in Cell Reports.

To establish the cause of this phenomenon, scientists conducted an experiment in mice, blocking the expression of the PRDM12 gene in stem cells, giving rise to various types of neurons. The researchers found that mice did not develop neurons that are responsible for the perception of pain, temperature and itching.

“We identified the molecule, a protein, that is required for the development of pain neurons from the stem cells”, – says Dr Hadjab. “It’s surprising that the protein has such broad functionality.”

In another experiment on chickens, the researchers, on the contrary, increased the expression of the PRDM12 gene in neuronal stem cells, believing that this would lead to the development of more neurons of pain sensitivity, but their guesses were not confirmed.

“This shows that the protein PRDM12 needs helper substances, or cofactors”, – Dr Hadjab continues. “On the other hand, the development of all other cell types that usually form from these stem cells was stopped.”

In adult animals, the PRDM12 gene continues to be expressed and only in the neurons responsible for pain, but scientists do not yet know what role the protein plays in these mature cells. Perhaps incorrect gene regulation can contribute to chronic pain and other neuropathic pain conditions.

“To find out more about this, we should start by removing the protein from adult animals’ pain neurons to see what happens”, – says Dr. Hadjab, who plans to lead further studies in this field at Karolinska Institutet. “Will they no longer be able to feel pain? If we can then identify the cofactors, we can develop new targeted drugs that can reduce pain symptoms in people with pain conditions.”