Stem Cell Research May Restore Sense of Touch
Posted on February 23, 2018
Scientists at the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research successfully manipulated human stem cells to become sensory interneurons.
Sensory interneurons are cells critical to the sense of touch. They relay information from the rest of the body to the central nervous system and activate the sense of touch.
The UCLA breakthrough could mean the advancement of stem cell therapy to restore feeling to individuals who have lost feeling in parts of their body.
Paralysis occurs because of a variety of factors, including trauma, congenital conditions, autoimmune diseases and damage to the nerves. Other causes include the use of some medications, exposure to toxins and drug use.
One in 50 Americans is living with paralysis, according to statistics from the Christopher & Dana Reeve Foundation, a charitable organization dedicated to finding treatments and cures for individuals who have suffered paralysis caused by spinal cord injuries and other neurological disorders.
The organization is named for actor Christopher Reeve and his wife, Dana. Christopher was paralyzed in 1995 in a horse-riding accident.
Individuals who have suffered paralysis experience both physical and emotional side effects because of their condition.
“Paralysis means not feeling the touch of a loved one. It also means that affected individuals are more susceptible to cuts, burns and other wounds and complications of those injuries because they cannot feel that they are hurt,” said Dr. Joel Singer.
Singer is a New York physician who treats patients living with paralysis.
“Many people know that spinal cord injuries, brain injuries and stroke may cause paralysis, but so do conditions like muscular dystrophy and multiple sclerosis,” Singer said.
The majority of research efforts to treat paralysis have been aimed at restoring the ability to walk, but UCLA researchers decided to work toward restoring touch. They argued that touch and walking go hand in hand.
“The ability to feel one’s body in relation to the space around it is critical to processing the environment around you,” Singer said.
In a previous project, the UCLA researchers uncovered how sensory interneurons are affected by proteins known as bone morphogenetic proteins, or BMPs.
The researchers analyzed the influence of BMPs on the sensory interneurons of chicken embryos.
This early research prompted the scientists to test their findings on humans.
The study authors applied a specific type of BMP, known as BMP4, in combination with retinoic acid, to human embryonic stem cells. The result was the development of two types of sensory cells: DI1 and DI3 sensory interneurons. DI1 sensory interneurons play a role in proprioception, which gives individuals a sense of where their body is in space. DI3 sensory interneurons are critical in the sense of touch and give people the ability to feel pressure.
The UCLA researchers found that the same results occurred when they added the BMP4 and retinoic acid to adult induced pluripotent stem cells.
These are mature cells taken from the skin or other tissues and then reprogrammed into other cell types. Successful application using pluripotent stem cells is a critical component for successful future treatments because the ability to use an individual’s stem cells for treatment means no chance of rejection or suppression by the body.
“The body will not reject autologous – its own – stem cells,” Singer said.
Singer uses autologous adipose fat stem cell therapy to treat patients with paralysis or other health conditions.
“Using the body’s own tissues to heal itself from paralysis means less risk of complications than other conventional treatments,” Singer said.
Some individuals with paralysis do not respond to or cannot tolerate mainstream medical treatment, which leaves them at risk for additional health risks.
“Depending on the severity of paralysis or the areas affected, additional health problems may develop,” said Singer.
The UCLA researchers are not finished. The next phase of their research will focus on creating the types of interneurons separately, which will help scientists identify how each cell type affects the ability to feel things. Additionally, the researchers also hope to identify additional growth factors and combinations of growth factors that can help create other sensory cell types.
The current project of the UCLA study team involves implanting the newly created DI1 and DI3 sensory interneurons into the spinal cords of mice to identify if and how the interneurons blend into the nervous system.
University of California – Los Angeles Health Sciences. “Scientists make cells that enable the sense of touch: Researchers are the first to create sensory interneurons from stem cells.” ScienceDaily. ScienceDaily, 11 January 2018.