This is a first: a group of researchers claim to have succeeded in transforming human stem cells into sensory interneurons. A remarkable advance that could soon change the lives of people suffering from paralysis.
Sensory interneurons are those cells that you will find in the spinal cord that govern the sense of touch, and so allow us to experience the world around us.
But in case of paralysis, this faculty of tactile sensitivity can be altered or even lost. This unique sense not only shapes our life experiences, but also helps keep us alive. Without these cells, we would not be able to perceive the potential danger of a hot stove for example. In an effort to restore this sense to people with paralysis, researchers have attempted to modify human stem cells to become sensory interneurons. This successful experiment was published in the Journal Stem Cell Report.
A previous analysis had already explored a few months ago how certain proteins contributed to the development of sensory interneurons in chicken embryos. This new study, led by the same researchers, has therefore adopted the same process by applying it to human stem cells. The researchers say they have added the protein (BMP4), which establish the structure of bone with a signaling molecule (retinoic acid), to human embryonic stem cells.
This mixture has allowed the creation of two distinct types of sensory interneurons: the Dl1 sensory interneurons, which help us to determine where our body is in relation to our environment, and the Dl3 sensory interneurons, which allow us to feel pressure.
The team also explains that they have also discovered that they can create the same mixture of sensory interneurons by adding signaling molecules to induced pluripotent stem cells.
These are created from the patient’s own cells and then reprogrammed. This could give researchers the opportunity to better explore the restorative treatments that work with patients’ bodies, and to reduce –if not eliminate — potential rejections.
The group is currently implanting new sensory ICI and IDI interneurons into the mouse spinal cord to understand if the cells integrate into the nervous system and become fully functional. This is a critical step towards defining the clinical potential of these cells.
“It’s a long way,” notes Samantha Butler, lead author of the study. “We have not figured out how to restore touch, but we have taken an important first step in developing some of the protocols to create sensory interneurons.”
The researchers hope that these results could prove useful in the development of restorative therapies for patients with paralysis.