Stem-cell scientists at McMaster University have developed a way to directly convert adult human blood cells to sensory neurons, providing the first objective measure of how patients may feel things like pain, temperature, and pressure, the researchers reveal in an open-access paper in the journal Cell Reports. Currently, scientists and physicians have a limited understanding of the complex issue of pain and how to treat it. “The problem is that unlike blood, a skin sample or even a tissue biopsy, you can’t take a piece of a patient’s neural system,” said Mick Bhatia, director of the McMaster Stem Cell and Cancer Research Institute and research team leader. “It runs like complex wiring throughout the body and portions cannot be sampled for study. “Now we can take easy to obtain blood samples, and make the main cell types of neurological systems in a dish that is specialized for each patient,” said Bhatia. “We can actually take a patient’s blood sample, as routinely performed in a doctor’s office, and with it we can produce one million sensory neurons, [which] make up the peripheral nerves. We can also make central nervous system cells.”
Testing pain drugs
The new technology has “broad and immediate applications,” said Bhatia: It allows researchers to understand disease and improve treatments by asking questions such as: Why is it that certain people feel pain versus numbness? Is this something genetic? Can the neuropathy that diabetic patients experience be mimicked in a dish? It also paves the way for the discovery of new pain drugs that don’t just numb the perception of pain. Bhatia said non-specific opioids used for decades are still being used today. “If I was a patient and I was feeling pain or experiencing neuropathy, the prized pain drug for me would target the peripheral nervous system neurons, but do nothing to the central nervous system, thus avoiding addictive drug side effects,” said Bhatia.