Posts tagged oligodendrocyte precursor cells
Articles and news from the latest research reports.
Scientists decode mechanisms of cell orientation in the brain
Transmembrane protein NG2 controls orientation of cell migration toward the wound / Publication in the prestigious Journal of Neuroscience
When the central nervous system is injured, oligodendrocyte precursor cells (OPC) migrate to the lesion and synthesize new myelin sheaths on demyelinated axons. Scientists at the Institute of Molecular Cell Biology at Johannes Gutenberg University Mainz (JGU) have now discovered that a distinct protein regulates the direction and movement of OPC toward the wound. The transmembrane protein NG2, which is expressed at the surface of OPCs and down-regulated as they mature to myelinating oligodendrocytes, plays an important role in the reaction of OPC to wounding. The results of this study have recently been published in the renowned Journal of Neuroscience.
The myelin sheath functions to electrically isolate axons of many nerve fibers and is synthesized by oligodendrocytes which mature from the OPC. In the case of injury, neural cells send out signaling molecules which attract the OPC. The NG2 protein helps OPCs to react to some of these and move in a directed and orientated fashion. “We were able to prove in cell biological experiments that NG2 orientates OPC toward the lesion and ensures targeted OPC migration toward the wound through the regulation of cell polarity”, explained Dr. Fabien Binamé, lead author of the study. Supported by funding of the German Research Foundation (DFG), Dr. Fabien Binamé is currently carrying out his research at the Institute of Molecular Cell Biology headed by Professor Jacqueline Trotter.
"The function and mode of operation of NG2 is not yet fully understood", added co-author Dominik Sakry, who was also involved in the study. "But it looks as if the NG2-associated regulatory mechanism becomes apparent only in cases of injury of the nervous system."
Diseases such as Multiple Sclerosis or brain tumors go hand in hand with damage of nerve tissue. “The results of our study on NG2-mediated basic mechanisms of cell orientation and migration could aid in understanding the repair of damaged demyelinated tissue, or be important for treatment of highly active migratory brain tumors which often express high levels of NG2”, said Professor Jacqueline Trotter, head of the JGU Institute of Molecular Cell Biology.
New target for Alzheimer’s disease treatment
Researchers have found new evidence that insulating cells, the cells that protect our nerves, can be made and added to the central nervous system throughout our lifetime.
Chief investigator on the paper, Menzies Research Institute Tasmania’s Dr Kaylene Young, says there is now evidence that these cells may not be the passive by-standers to brain function that we once thought.
“Previously it was thought that most insulating cells in an adult brain were born before reaching adulthood,” Dr Young said.
“This research shows that new insulating cells are made from an immature cell type found in our brains, called oligodendrocyte precursor cells (OPCs).
“In fact, new insulation is added to brain circuits every day, which changes the way the circuits function.
“This process is likely to be very important for learning, memory, vision and co-ordination.”
“This finding may have important implications for sufferers of Alzheimer’s Disease, multiple sclerosis and other neurological disorders.
Alzheimer’s disease is the most common form of dementia. There are over 321,600 Australians living with dementia and without a medical breakthrough, the number of people with dementia is expected to be almost 900,000 by 2050. (Alzheimer’s Australia)
In Alzheimer’s Disease (AD) many nerve cells die. This causes patients with AD to progressively lose their ability to think clearly and remember things, and they can also experience problems with movement and co-ordination.
A single insulating cell in the brain supports the health and function of many nerve cells.
We know from diseases like multiple sclerosis that losing insulation makes nerve cells extremely vulnerable to damage and death.
This may also be true for AD, and there is an increasing amount of evidence that supports the idea that insulating cells are damaged before nerve cells and could contribute directly to nerve cell loss.
By studying brain scans from patients with AD, researchers previously found that the amount of insulation that is damaged matched the level of the patient’s dementia. The more damaged the insulation, the worse the person’s memory problems.
Dr Young’s research team are now investigating ways to hijack the natural ability of OPCs to make new insulating cells, and repair the insulation damage that is seen in the brains of AD patients.
“Stimulating OPCs in the brain is an appealing possibility since they are found throughout all brain regions, meaning that they are already where they need to be to make new insulating cells!
“We expect that increasing brain insulation, to re-wrap the nerve cells, will prevent more nerve cells from dying. Protecting nerve cells would prevent the rapid mental deterioration seen in people after they are diagnosed with AD,” Dr Young said.
This work was published this month, in the international journal, Neuron and involved collaboration with researchers in the United Kingdom and Japan.
(Source: utas.edu.au)