The neurons of the brain are protected by an insulating layer called myelin. In certain diseases like multiple sclerosis, the protective myelin layer around neurons is damaged and lost, leading to death of neurons and disability. New research published in The FEBS Journal reveals the importance of a protein called C1QL1 for promoting the replacement of the specialised cells that produce myelin. The findings could have important implications for the ongoing effort to develop new and improved therapies for the treatment of demyelinating diseases.
In experiments conducted in mice, deleting the gene that codes for C1QL1 caused a delay in the rate at which oligodendrocytes (the cells that make myelin) mature, leading to reduced myelination of neurons.
After mice were fed a drug that destroys myelin, recovery of oligodendrocytes and myelination were delayed in mice lacking the C1QL1 protein. Causing mice to express more C1QL1, however, led to increased numbers of oligodendrocytes and more myelination upon drug withdrawal, suggesting that C1QL1 helps to restore the damaged myelin layer. Thus, investigational therapies that boost C1QL1 may hold promise against demyelinating diseases.
“Our basic research on C1QL1 is nascent, but there is potential that it is relevant for a novel treatment for multiple sclerosis,” said corresponding author David C. Martinelli, PhD, of the University of Connecticut Health Center. “New drug treatment options for patients with multiple sclerosis could have a large impact on their quality of life.”
Researchers from have found a potential new way to improve the treatment of multiple sclerosis (MS) using a novel combined therapy. The results, published in the Journal of Clinical Investigation, builds on two harmonised Phase I clinical trials, focusing on the use of Vitamin D3 tolerogenic dendritic cells (VitD3-tolDCs) to regulate the immune response in MS patient.
Multiple Sclerosis (MS) is a long-term disease where the immune system mistakenly attacks the protective myelin sheath around nerve cells. This leads to nerve damage and worsening disability. Current treatments, like immunosuppressants, help reduce these harmful attacks but also weaken the overall immune system, leaving patients vulnerable to infections and cancer. Scientists are now exploring a more targeted therapy using special immune cells, called tolerogenic dendritic cells (tolDCs), from the same patients.
TolDCs can restore immune balance without affecting the body’s natural defences. However, since a hallmark of MS is precisely the dysfunction of the immune system, the effectiveness of these cells for auto transplantation might be compromised. Therefore, it is essential to better understand how the disease affects the starting material for this cellular therapy before it can be applied.
In this study, researchers from Barcelona’s Germans Trias i Pujol Institute and Josep Carreras Leukaemia Research Institute, examined CD14+ monocytes, mature dendritic cells (mDCs), and Vitamin D3-treated tolerogenic dendritic cells (VitD3-tolDCs) from MS patients who had not yet received treatment, as well as from healthy individuals. The clinical trials (NCT02618902 and NCT02903537) are designed to assess the effectiveness of VitD3-tolDCs, which are loaded with myelin antigens to help “teach” the immune system to stop attacking the nervous system. This approach is groundbreaking as it uses a patient’s own immune cells, modified to induce immune tolerance, in an effort to treat the autoimmune nature of MS.
The study, led by Dr Eva Martinez-Cáceres and Dr Esteban Ballestar, with Federico Fondelli as first author, found that the immune cells from MS patients (monocytes, precursors of tolDCs) have a persistent “pro-inflammatory” signature, even after being transformed into VitD3-tolDCs, the actual therapeutic cell type. This signature makes these cells less effective compared to those derived from healthy individuals, missing part of its potential benefits.
Using state-of-the-art research methodologies, the researchers identified a pathway, known as the Aryl Hydrocarbon Receptor (AhR), that is linked to this altered immune response. By using an AhR-modulating drug, the team was able to restore the normal function of VitD3-tolDCs from MS patients, in vitro. Interestingly, Dimethyl Fumarate, an already approved MS drug, was found to mimic the effect of AhR modulation and restore the cells’ full efficacy, with a safer toxic profile.
Finally, studies in MS animal models showed that a combination of VitD3-tolDCs and Dimethyl Fumarate led to better results than using either treatment on its own. This combination therapy significantly reduced symptoms in mice, suggesting enhanced potential for treating human patients.
These results could lead to a new, more potent treatment option for multiple sclerosis, offering hope to the millions of patients worldwide who suffer from this debilitating disease. This study represents a significant step forward in the use of personalised cell therapies for autoimmune diseases, potentially revolutionising how multiple sclerosis is treated.
The team is now preparing to move into Phase II trials to further explore these findings.
This is a pseudo-colored image of high-resolution gradient-echo MRI scan of a fixed cerebral hemisphere from a person with multiple sclerosis.
Credit: Govind Bhagavatheeshwaran, Daniel Reich, National Institute of Neurological Disorders and Stroke, National Institutes of Health
A key feature of multiple sclerosis (MS) is that it causes the patient’s own immune system to attack and destroy the myelin sheaths in the central nervous system. To date, it hasn’t been possible to visualise the myelin sheaths well enough to use this information for the diagnosis and monitoring of MS. Now researchers have developed a new magnetic resonance imaging (MRI) procedure that maps the condition of the myelin sheaths more accurately than was previously possible.
The researchers successfully tested the procedure on healthy people for the first time, and published their results in Magnetic Resonance in Medicine.
In the future, the MRI system with its special head scanner could help doctors to recognise MS at an early stage and better monitor the progression of the disease.
This technology, developed by the researchers at ETH Zurich and University of Zurich, led by Markus Weiger and Emily Baadsvik from the Institute for Biomedical Engineering, could also facilitate the development of new drugs for MS. But it doesn’t end there: the new MRI method could also be used by researchers to better visualise other solid tissue types such as connective tissue, tendons and ligaments.
Quantitative myelin maps
Conventional MRI devices capture only inaccurate, indirect images of the myelin sheaths because these devices typically work by reacting to water molecules in the body that have been stimulated by radio waves in a strong magnetic field.
But the myelin sheaths, which wrap around the nerve fibres in several layers, consist mainly of fatty tissue and proteins. That said, there is some water – known as myelin water – trapped between these layers.
Standard MRIs build their images primarily using the signals of the hydrogen atoms in this myelin water, rather than imaging the myelin sheaths directly.
The ETH researchers’ new MRI method solves this problem and measures the myelin content directly.
It puts numerical values on MRI images of the brain to show how much myelin is present in a particular area compared to other areas of the image.
A number 8, for instance, means that the myelin content at this point is only 8 percent of a maximum value of 100, which indicates a significant thinning of the myelin sheaths.
Essentially, the darker the area and the smaller the number in the image, the more the myelin sheaths have been reduced.
This information ought to enable doctors to better assess the severity and progression of MS.
Measuring signals within millionths of a second
It is difficult however to image the myelin sheaths directly, since the signals that the MRI triggers in the tissue are very short-lived; the signals that emanate from the myelin water last much longer.
“Put simply, the hydrogen atoms in myelin tissue move less freely than those in myelin water. That means they generate much briefer signals, which disappear again after a few microseconds,” Weiger says, adding: “And bearing in mind a microsecond is a millionth of a second, that’s a very short time indeed.” A conventional MRI scanner can’t capture these fleeting signals because it doesn’t take the measurements fast enough.
To solve this problem, the researchers used a specially customised MRI head scanner that they have developed over the past ten years together with the companies Philips and Futura.
This scanner is characterised by a particularly strong gradient in the magnetic field.
“The greater the change in magnetic field strength generated by the three scanner coils, the faster information about the position of hydrogen atoms can be recorded,” Baadsvik says.
Generating such a strong gradient calls for a strong current and a sophisticated design.
As the researchers scan only the head, the magnetic field is more contained and concentrated than with conventional devices.
In addition, the system can quickly switch from transmitting radio waves to receiving signals; the researchers and their industry partners have developed a special circuit for this purpose.
The researchers have already successfully tested their MRI procedure on tissue samples from MS patients and on two healthy individuals. Next, they want to test it on MS patients themselves. Whether the new MRI head scanner will make its way into hospitals in the future now depends on the medical industry. “We’ve shown that our process works,” Weiger says. “Now it’s up to industry partners to implement it and bring it to market.”
