myelin

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…

A cell recycling process helps trigger an immune response against myelin, the protective layer covering nerve cell axons to aid in signal transmission, a multiple sclerosis (MS) study indicates. When University of Zurich researchers eliminated the process, mice developed much milder forms of an MS-like disease. Loss of myelin is the…

A University of Cambridge researcher, Robin Franklin, has been awarded the 2017 Barancik Prize for Innovation in MS Research for his work on myelin repair and as a potential way of treating multiple sclerosis (MS). Franklin is a senior scientist at the Wellcome Trust-MRC Cambridge Stem Cell…

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.

Immune cells that destroy myelin in multiple sclerosis (MS) access the brain and spinal cord via two different routes, a new mouse study shows. This suggests that therapies which target these entry routes may shield the brains of MS patients from further damage. The study, “Caveolin1 Is Required for…

Myelin-producing Brain Cells Regenerated Using Stem Cells in Early Study We know that when the myelin coating of our nerve axons is destroyed, MS symptoms result. So a process that halts or reverses that destruction is the goal of a lot of MS research. This is a…

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…

A blood-clotting protein called fibrinogen prevents myelin production and blocks the neuron remyelination repair process in mice, a study finds. The study, “Fibrinogen Activates BMP Signaling in Oligodendrocyte Progenitor Cells and Inhibits Remyelination after Vascular Damage,” appeared in the journal Neuron. Its conclusions offer new insights and…

The generation of a thin myelin sheath during remyelination — one that continues to protect nerve cells over time — is indicative of the long-term health and activity of the central nervous system (CNS) in demyelinating diseases such as multiple sclerosis (MS), a new study shows. These findings, which aim…

Common Allergy Treatment Restores Protective Neuron Coating in MS, Trial Suggests This is the kind of news we all hope to hear. A treatment that will repair our frayed “wires” and, in doing so, restore some of the function that MS has stolen from us. This is…

of the neurons.

In case you missed them, here are some news stories that appeared in MS News Today that caught my eye over the past week: Q Therapeutics Approved to Start Trial of Cell Therapy Aiming to Restore Myelins Those of us with MS know that if something can…

A cell therapy intended to boost myelin regeneration — Q-Cells by Q Therapeutics — has received a green light from the U.S. Food and Drug Administration to proceed with a clinical trial in patients with transverse myelitis (TM), a disease that like multiple sclerosis is characterized by myelin damage. FDA approval of the company’s Investigational New…

In case you missed them, here are some news stories that appeared in MS News Today that caught my eye over the past week. Experts Call for Tighter Regulation of Stem Cell Therapies in Use at Clinics Worldwide I read a lot of comments on various social…

A herpes virus that lies dormant in many people can hinder the repair of the neuron-protecting myelin sheath whose deterioration causes multiple sclerosis, a study reports. The finding about the HHV-6 virus may help explain differences in the symptoms and progression of the disease from person to person, researchers said.

Researchers managed to change the immune system — replacing inflammation with immune tolerance — in a mouse model of multiple sclerosis (MS) using so-called quantum dots, or nano-sized particles carrying pieces of myelin. Experiments with this advanced technological solution may help researchers design MS therapies that are based on promoting regulatory T-cells rather…

A common acne medicine called minocycline can reduce the rate of multiple sclerosis progression in patients who are at early stages of the disease, according to a Phase 3 clinical trial. The finding was from the MinoCIS trial (NCT00666887) of minocycline, which goes by the brand name Mynocan and other…

PODS (POlyhedrin Delivery System), a new technology designed to transport any protein in the human body, may open up new approaches in treating multiple sclerosis (MS) and other diseases, says its British developer, Cell Guidance Systems. Created by Hajime Mori, a professor at Japan’s Kyoto Institute of Technology, PODS is…

A physical scaffold that allows lab-grown brain cells to grow in a three-dimensional manner is giving scientists a whole new way of studying the regeneration of myelin, nerve coatings whose damage is at the heart of multiple sclerosis. The scaffold is allowing researchers to test large numbers of compounds for…

Scientists at the University of Maryland have developed an experimental treatment to control the immune system and recover movement in a paralyzed mouse model of multiple sclerosis (MS). The team presented its research April 2 during the 253rd National Meeting & Exposition of the American Chemical Society in San Francisco. In…

Using a small RNA molecule belonging to the family of microRNAs (miRs), scientists could restore myelin in nerve cells and improve limb function in mouse models of human multiple sclerosis (MS). The study, “miR-219 Cooperates with miR-338 in Myelination and Promotes Myelin Repair in the CNS,” was published in…

Regulatory T-cells in the central nervous system trigger the maturation of stem cells that increase the production of myelin at injured neurons — a discovery that places the idea of regeneration in multiple sclerosis (MS) in a whole new light. Myelin is a substance essential to the functioning of the…

People with multiple sclerosis (MS) are three to six times more likely to develop epilepsy than the general population, a study says. Researchers believe the loss of myelin in certain neurons — a hallmark of MS — is what causes the seizures. The study was published in the journal…

The absence of epigenetic factors in myelin-producing oligodendrocyte cells make sure that myelin production is switched off in the adult brain. Targeting these factors may be a way of triggering myelin regeneration in multiple sclerosis (MS), and a step toward personalized medicine for this disease, Dr. Patrizia Casaccia said in a talk…

Two Cleveland Clinic researchers were awarded multi-year grants by the National Institutes of Health (NIH), under its Outstanding Investigator Award, to find new treatments for multiple sclerosis (MS) and other complex diseases. Bruce Trapp, PhD, an expert in myelin biology and MS, will receive about $7 million over eight years under the…

Australia has granted a patent to RegeneRx Biopharmaceuticals for an active ingredient in a therapy that could benefit multiple sclerosis (MS) patients. The patent is for Thymosin beta 4 (Tβ4), the driving force in the company’s RGN-352 treatment. RGN-352 promotes myelination, or the production of protective myelin sheaths for damaged neurons and other nerve…

Researchers have found a microbial protein from the Haemophilus influenza pathogen that is recognized by antibodies in a subpopulation of multiple sclerosis (MS) patients. The finding supports the idea of a link between microbial infections and neurodegenerative diseases like MS, whose causes are uncertain. Haemophilus influenza is an opportunistic pathogen…

A specific type of channel that facilitates calcium flow is needed for normal development of cells that produce a shield, called myelin, around nerve fibers — a finding that could open up new approaches to regenerating the myelin-producing cells (called oligodendrocytes) lost in multiple sclerosis (MS). Researchers now hope to…