Stem cell scientists in Germany have converted stem cells from the spinal cord of mice into immature nerve cells by changing the sugars attached to various proteins.
Animal cells sit in a gooey matrix called the “extracellular matrix” (ECM). The ECM is a witch’s brew of long chains of acidic sugars, proteins, and proteins with chains of sugars attached to them. Cells have receptors called “integrins” that let them bind to ECM components and the cells do just about everything they do while embedded in the ECM.
Most of the sugars attached to the proteins in the ECM are either acidic or have sulfate (SO4-2) groups attached to them. The German group used a reagent called sodium chlorate (bleach) to alter the sulfates on the ECM sugars. Sodium chlorate prevents the attachment of sulfates to the ECM components and without the sulfates, the character of the ECM is rather different, and cells can detect these subtle changes in the ECM.
Neural stem cells (NSCs) form neurons, the cells that conduct nerve impulses, and other cell types, such as glial cells, which support the neurons, and oligodendrocytes, which surround and coat the extensions of the neurons. These coatings allow nerve impulses to travel much faster from neuron to neuron.
Once grown in the ECM that had been modified with sodium chlorate, NSCs from spinal cord were able to differentiate into nerve cell that failed to mature. Therefore, the modified ECM directed the cells to form nerve cells, but inhibited their maturation. Even the electrophysiology of the cells showed that they were immature.
Prof. Dr. Stefan Wiese, lead scientist on this work and head of the Ruhr University Bochum (RUB) molecular cell biology work group commented on these results in the following way: “Influencing precursor cells pharmacologically so that they transform into a particular type of cell can help in cell replacement therapies in future. Therapies, for example, for Parkinson’s, multiple sclerosis or amyotrophic lateral sclerosis could then become more efficient.”
If cells can be differentiated into immature cells, then they can be introduced into a damaged area, where they will divide and then respond to external cues to differentiate into the cell types required to heal the damaged area. Therefore, this simple strategy could potentially expand the abilities of NSCs to heal are variety of maladies.
“If sodium chlorate stops the nerve cells in an early developmental phase, this could enable them to integrate into the nervous system following a transplant better than mature nerve cells would do,” Wiese said.