myelin

University at Buffalo researchers are working on ways to improve multiple sclerosis patients’ cognitive function and to repair damage to the mylein coating that protects nerve cells. The National Multiple Sclerosis Society awarded the researchers more than $1.1 million to conduct the studies. One, “The Effects of Working Memory…

Clene Nanomedicine says its pre-clinical studies demonstrate the remyelination effects of CNM-Au8, supporting its potential to treat multiple sclerosis (MS) and other demyelinating disorders. Clene presented its data in a session, “Nanocrystalline Gold As a Novel Remyelination Therapeutic for Multiple Sclerosis,” that took place at the third annual Americas…

A novel imaging approach enables assessment of key nervous system deterioration in multiple sclerosis (MS), a new study in mice suggests. The research, “Development of a PET radioligand for potassium channels to image CNS demyelination,” was published in the journal Scientific Reports. MS is characterized by damage to myelin (a process called demyelination), which is an insulating sheath around axons (the long projections of neurons) that enables effective neuronal communication. As a result, patients experience a variety of symptoms, including muscle stiffness and weakness, fatigue and pain. Although existing MS medications suppress immune responses and reduce flare-ups, none can cure the disease. Despite the importance of demyelination in MS, scientists and clinicians do not currently have a way to directly image myelin damage. Magnetic resonance imaging (MRI) is used, but it does not enable the distinction between demyelination and inflammation, which are common in patients with MS. Upon myelin damage, voltage-gated potassium channels (cellular membrane proteins) become exposed. As a result, cells leak potassium, which impairs proper neuronal communication. This prompted researchers to develop a tracer that targets potassium channels. "In healthy myelinated neurons, potassium channels are usually buried underneath the myelin sheath," Brian Popko, PhD, the study’s senior author, said in a press release. Popko is a professor of neurological disorders and director of the Center for Peripheral Neuropathy at The University of Chicago. Exposed potassium channels can be targeted by the MS medication 4-aminopyridine (4-AP; dalfampridine), which partially repairs nerve conduction and mitigates MS symptoms. Using mouse models of MS, the researchers demonstrated that 4-AP binding to potassium channels is greater in demyelinated axons in comparison with well-myelinated axons. The greater binding of 4-AP led to its accumulation in damaged axons. Then, the team evaluated several fluorine-containing derivatives of 4-AP, and found that the most effective in binding to potassium channels was 3-fluoro-4-aminopyridine (3F4AP), which can be labeled with radioactive 18F. This labeling enables detection of demyelinated regions with a novel strategy based in positron emission tomography (PET). "3F4AP is the first tracer whose signal increases with demyelination, potentially solving some of the problems of its predecessors," said Pedro Brugarolas, PhD, first author of the study. Existing PET tracers bind to myelin. This translates to decreases in signal in the presence of myelin loss, “which can be problematic for imaging small lesions” Brugarolas noted. Importantly, the findings in mice were confirmed in monkeys. Experiments showed that the radiolabeled 3F4AP enters the primate brain and accumulates in areas with less myelin. Collectively, “these data indicate that [18F]3-F-4-AP may be a valuable PET tracer for detecting [central nervous system] demyelination noninvasively,” the team wrote. "We think that this PET approach can provide complementary information to MRI which can help us follow MS lesions over time," Popko said. The novel PET strategy enables the evaluation of therapies to repair myelination and also could help assess how much myelin loss is involved in other neurological disorders, such as traumatic brain injury and spinal cord injury, but also in diseases not commonly linked to demyelination, "such as brain ischemia, psychiatric disorders, and neurodegenerative diseases, including Alzheimer's," Popko concluded.

A combination therapy of low-dose methylprednisolone and interferon (IFN)-beta-secreting stem cells is effective in a mouse model of multiple sclerosis (MS), a new Korean study suggests. The research, “Effective combination of methylprednisolone and interferon β-secreting mesenchymal stem cells in a model of multiple sclerosis,” appeared in the…

The nerve-cell-protecting myelin sheath’s failure to remove cholesterol after the membrane has been damaged limits its ability to regenerate, German researchers report. Their finding has important implications for multiple sclerosis because a hallmark of the disease is nerve cell deterioration stemming from damaged myelin. Cholesterol is a waxy, fatty substance…

Researchers at GlaxoSmithKline (GSK) have identified the histamine receptor 3 (H3R) as a potential new therapeutic target for promoting remyelination in patients with multiple sclerosis (MS). Their study “Histamine Receptor 3 negatively regulates oligodendrocyte differentiation and remyelination,” appeared in the journal PLOS One. Regrowth of myelin is known as…

Tailored molecular treatments for specific disabilities may be a breakthrough for multiple sclerosis (MS) patients, finds a new study by researchers at University of California-Los Angeles (UCLA). The study, “Cell-specific and region-specific transcriptomics in the multiple sclerosis model: Focus on astrocytes,” appeared in the journal Proceedings…

Protamine — an agent used to stop the anticoagulant effects of heparin — was seen to trigger remyelination in mice with myelin damage. But while pointing a way forward for studies of myelin regeneration in multiple sclerosis (MS), the research team underscored that protamine itself is not an optimal treatment candidate.

The Mayo Clinic has developed a test that allows doctors to distinguish other inflammatory demyelinating diseases from multiple sclerosis in the early stages of a disorder. The test, the first of its kind in the United States, looks for an antibody against a protein known as myelin oligodendrocyte glycoprotein…

Editor’s note: Tamara Sellman continues her occasional series on the MS alphabet with this first of two columns about terms starting with the letter M. Symptoms of MS Memory problems Memory loss is a common complaint for people with MS. Even for those with no physical or…

Researchers, using two different kinds of stem cells in rats, were able to regenerate oligodendrocytes — myelin-producing brain cells that are defective in multiple sclerosis (MS). They were also able to grow adult neural stem cells in laboratory cultures and prod them to develop into oligodendrocytes. The exact cause of MS is unknown — including what triggers attacks on myelin — but the loss of oligodendrocytes seen in the disease is known to play a role in its progression. Nerve cells in the brain send their signals through their axons, long arm-like structures that extend out from the centers of the nerve cells. The signals are electrical pulses transmitted along the length of an axon. Oligodendrocytes provide the insulation — called myelin — that wraps around axons, speeding up the transmission of electrical signals through the nerve cells. Loss or malfunction of oligodendrocytes means that signaling in the brain is impaired. It is this slowing of signaling that is thought to cause MS symptoms. Researchers from the Heinrich-Heine-University, Germany, with support from British and Chilean colleagues, designed a novel approach to regenerate oligodendrocytes, according to a press release. Stem cells are immature cells that give rise to differentiated cells — cells with a specific function, such as oligodendrocytes. Adult neural stem cells can divide and produce nerve cells and other brain cells, including oligodendrocytes. However, in normal circumstances, the regeneration of cells that take place in the human brain is not enough to repair the damage seen in MS. The researchers set out to find conditions that would promote the differentiation of adult human NSCs into oligodendrocytes. They discovered that another type of stem cell, mesenchymal stem cells (MSCs), could provide the signals required. First they tested their system in rats, and found that by using factors produced by human MSCs, they could induce the growth of new oligodendrocytes in the animals. Then they grew adult NSCs in the laboratory, and using the same factors from human MSCs were able to promote the establishment of oligodendrocytes in the cultured cells.

The Japanese company MediciNova‘s anti-inflammatory agent ibudilast slows multiple sclerosis patients’ brain shrinkage and their loss of the protective myelin coating around nerve cells, a Phase 2 clinical trial shows. Robert J. Fox of Ohio’s Cleveland Clinic Neurological Institute presented the results at the 7th Joint ECTRIMS-ACTRIMS Meeting in Paris, Oct. 25-28.

There’s been some internet buzz recently about the possibility of an over-the-counter allergy drug that helps to repair the myelin that MS damages. The drug is clemastine fumarate, and I suspect that some of that buzz may have been generated by headlines found on Twitter and…