Breaking News
December 13, 2018 - Single tau molecule holds clues to help diagnose neurodegeneration in its earliest stages
December 13, 2018 - AHA Scientific Statement: Low Risk of Side Effects for Statins
December 13, 2018 - What Is Acute Flaccid Myelitis?
December 13, 2018 - How bereaved people control their thoughts without knowing it
December 13, 2018 - Health care democratization underway, according to 2nd annual Stanford Medicine Health Trends Report | News Center
December 13, 2018 - Going Beyond a Single Color
December 13, 2018 - London-based startup launches ‘thedrug.store’ aiming to clean up CBD industry
December 13, 2018 - Loss of tight junction barrier protein results in gastric cancer development
December 13, 2018 - Novel way to efficiently deliver anti-parasitic medicines
December 13, 2018 - RKI publishes new data on disease prevention and utilization of medical services
December 13, 2018 - High-tech, flexible patches sewn into clothes could help to stay warm
December 13, 2018 - Restoring Hair Growth on Scarred Skin? Mouse Study Could Show the Way
December 13, 2018 - Probiotic use may reduce antibiotic prescriptions, researchers say
December 13, 2018 - Drug repositioning strategy identifies potential new treatments for epilepsy
December 13, 2018 - Chronic rhinitis associated with hospital readmissions for asthma and COPD patients
December 13, 2018 - Food poisoning discovery could save lives
December 13, 2018 - Cloned antibodies show potential to treat, diagnose life-threatening fungal infections
December 13, 2018 - Exercise may reduce colorectal cancer risk after weight loss
December 13, 2018 - Russian scientists create hardware-information system for brain disorders treatment
December 13, 2018 - Moderate alcohol consumption linked with lower risk of hospitalization
December 13, 2018 - Nurturing Healthy Neighborhoods | NIH News in Health
December 13, 2018 - Rise in meth and opioid use during pregnancy
December 13, 2018 - Researchers gain new insights into pediatric tumors
December 13, 2018 - FSU study finds racial disparity among adolescents receiving flu vaccine
December 13, 2018 - Drug cocktail induces cancer cell death by switching off energy supply
December 13, 2018 - Baculovirus virion completely eliminates liver-stage parasites in mouse model
December 13, 2018 - Researchers create noninvasive technology that detects when nerve cells fire
December 13, 2018 - Allen Institute for Immunology to partner with CU Anschutz to understand dynamics of human immune system
December 13, 2018 - Inability to do daily living tasks delays discharge of mental health patients
December 13, 2018 - Treating patients with hypertension induced albuminuria
December 13, 2018 - New substance could improve efficacy of established breast cancer treatments
December 13, 2018 - Scientists develop new stem cell line to study conversion of stem cells into muscle
December 13, 2018 - Re-programming the body’s energy pathway boosts kidney self-repair
December 13, 2018 - Research findings could help improve treatment of anxiety and post-traumatic stress disorders
December 13, 2018 - The Microbiome Movement announce Microbiotica as official industry partner
December 13, 2018 - New study reveals potential benefits of cEEG monitoring for infant ICU patients
December 13, 2018 - Whole-body imaging PET/MRI offers information to guide treatment options for prostate cancer
December 13, 2018 - International investigators fight against the negative campaign on benzodiazepines
December 13, 2018 - Targeting biochemical pathway may lead to new therapies for alleviating symptoms of anxiety disorders
December 13, 2018 - FDA Approves Tolsura (SUBA®-itraconazole capsules) for the Treatment of Certain Fungal Infections
December 13, 2018 - Are scientists studying the wrong kind of mice?
December 13, 2018 - Computer memory: A scientific team builds a virtual model of a key brain region
December 13, 2018 - Visual inspection alone is insufficient to diagnose skin cancer
December 13, 2018 - Paternal grandfather’s access to food associated with grandson’s mortality risk
December 13, 2018 - Our brain senses angry voices in a flash, study shows
December 13, 2018 - PM2.5 Exposure Linked to Asthma Rescue Medication Use
December 13, 2018 - Can’t exercise? A hot bath may help improve inflammation, metabolism, study suggests
December 13, 2018 - Can artificial intelligence help doctors with the human side of medicine?
December 13, 2018 - Virginia Tech and UC San Diego researchers team up to develop nonopioid drug for chronic pain
December 13, 2018 - NIH offers support for HIV care and prevention research in the southern United States
December 12, 2018 - Activating brain region could revive the urge to socialize among opioid addicts
December 12, 2018 - Relationship impairment appears to interfere with seeking mental health treatment in men
December 12, 2018 - Sleep, Don’t Cram, Before Finals for Better Grades
December 12, 2018 - Effective treatments for urticarial vasculitis
December 12, 2018 - Gun violence is a public health issue: One physician’s story
December 12, 2018 - The Science of Healthy Aging
December 12, 2018 - Yes to yoghurt and cheese: New improved Mediterranean diet
December 12, 2018 - Researchers uncover a number of previously unknown insecticide resistance mechanisms
December 12, 2018 - Regulating the immune system’s ‘regulator’
December 12, 2018 - In breaking bad news, the comfort of silence
December 12, 2018 - Study finds upward link between alcohol consumption and physical activity in college students
December 12, 2018 - FDA issues warning letter to Zhejiang Huahai Pharmaceutical involved in valsartan recall
December 12, 2018 - Weight history at ages 20 and 40 could help predict patients’ future risk of heart failure
December 12, 2018 - Presence of antiphospholipid antibodies tied to first-time MI
December 12, 2018 - DNA analysis finds that stethoscopes are teaming with bacteria
December 12, 2018 - New study could help inform research on preventing falls
December 12, 2018 - Women and men with heart attack symptoms receive different care from EMS
December 12, 2018 - Disrupted biological clock can contribute to onset of diseases, USC study shows
December 12, 2018 - New publications generate controversy over the value of reducing salt consumption in populations
December 12, 2018 - New data from TAILORx trial confirms lack of chemo benefit regardless of race or ethnicity
December 12, 2018 - Specific class of biomarkers can accurately indicate the severity of cancer
December 12, 2018 - Meds Taken Do Not Vary With ADL Impairment in Heart Failure
December 12, 2018 - Long-term study shows that HIV-2 is deadlier than previously thought
December 12, 2018 - People living near oil and gas wells show early signs of cardiovascular disease
December 12, 2018 - IONTAS founder and pioneer in phage display technology attends Nobel Prize Award Ceremony
December 12, 2018 - People who eat red meat have high levels of chemical associated with heart disease, study finds
December 12, 2018 - New method uses water molecules to unlock neurons’ secrets
December 12, 2018 - Genetics study offers hope for new acne treatment
December 12, 2018 - New computer model predicts prostate cancer progression
December 12, 2018 - Nobel Laureates lecture about immune checkpoint therapy for cancer treatment
Study provides new way to treat multiple sclerosis

Study provides new way to treat multiple sclerosis

image_pdfDownload PDFimage_print

Nerve cells stripped of their insulation can no longer carry vital information, leading to the numbness, weakness and vision problems often associated with multiple sclerosis. A new study shows an overlooked source may be able to replace that lost insulation and provide a new way to treat diseases like MS.

Cells called neurons make the central nervous system work by passing electrical signals along threadlike connections called axons. Axons do their work best when wrapped in an insulating coating of a fatty substance called myelin.

“When you lose myelin, axons don’t conduct at their normal speed or don’t conduct at all,” says Ian Duncan, a neuroscientist at the University of Wisconsin-Madison’s School of Veterinary Medicine. “And if enough of them are affected — such as in a big area of demyelination in MS — you develop clinical symptoms related to that part of the nervous system.”

Myelin is made by oligodendrocytes, cells that can reach out to several nearby axons to wrap parts of them in the protective myelin sheath.

Consensus has held that once an axon is robbed of its myelin, the only way to bring it back is by starting with fresh oligodendrocytes. Only oligodendrocytes arising from precursors called oligodendrocyte progenitor cells can apply a new coat of myelin to axons, goes the dogma. Thus, MS treatments aimed at remyelination have focused on recruiting progenitor cells in demyelinated areas (called plaques), and spurring them to develop.

However, researchers led by Duncan have shown in a study published today in the Proceedings of the National Academy of Sciences that starting from progenitor cells is not the only route to remyelination. In cats and rhesus macaques experiencing a severe loss of myelin, Duncan found fully developed oligodendrocytes already in place were reaching out and beginning to coat affected axons with myelin once again.

The catch, if there is one, is that to be helpful and remyelinate damaged axons, the adult oligodendrocytes may still need to have connections to surviving myelin segments — called “internodes” — on other axons.

“If this cell is still biologically active and maintaining these internodes, it can re-extend processes out to these demyelinated segments,” says Duncan, whose work is supported by the National Multiple Sclerosis Society. “Those processes can make new myelin sheaths, which end up being thinner and shorter than the previous internodes.”

But even thinner myelin will restore nerve function, as Duncan and colleagues reported in 2009.

Cats fed irradiated food for several months develop severe myelin loss throughout the nervous system. When the cats returned to a regular diet, nerve function was restored because of extensive myelin repair.

The cats’ demyelination problems are unusual as a lab model of the disease.

“The de facto model to study demyelination and remyelination is in a mouse fed a toxin called cuprizone,” Duncan says. “But the toxin kills oligodendrocytes. So, studying the mouse, you naturally wouldn’t see any of the original oligodendrocytes beginning remyelination.”

In the new study, the researchers looked at the cats’ nervous tissue and found a unique myelin mosaic — axons surrounded by thick layers of myelin (formed during development when the axons themselves grew) were interspersed with other axons surrounded by thin layers of myelin.

“The most likely explanation of that mosaic appearance is surviving oligos,” Duncan says. “Thick myelin sheaths are never seen following remyelination, just thin sheaths. And surviving adult oligodendrocytes are adjacent to these sites of demyelination, making them likely candidates for myelin repair.”

Sure enough, the researchers found oligodendrocytes connected to both thick and thin myelin sheaths in the cat spinal cord.

They also found this association when they reached back to a decades-old monkey model of demyelination. Neuroscientist Dimitri Agamanolis tried to make a model of another human demyelinating disease — called sub-acute combined degeneration and caused by Vitamin B12 deficiency — at Case Western Reserve University in the 1970s. Agamanolis had saved preserved blocks of sampled nervous tissue from the monkeys, and he shared them with Duncan. The monkeys’ myelin lesions resembled those in the cats.

“You see in the monkeys, too, single oligodendrocytes connected to mature myelin sheaths that also have processes extended out to and surrounding demyelinated axons,” Duncan says.

The UW-Madison researchers enlisted Grahame Kidd and the private research lab Renovo Neural in Cleveland to reconstruct stacks of electron microscope images of cat nerve cells into 3D representations that show oligodendrocytes reaching up and down the spinal cord, sustaining mature myelin and remyelinating damaged sheaths.

The process may not be playing out in human MS patients fast enough to help mitigate the progression of the disease, Duncan says. Or too many oligodendrocytes may lose so many of their internodal connections that they become inactive or die.

But the discovery of the mature myelin-producing cells’ capacity for repair opens new opportunities to slow or reverse the disease.

“Right now, the emphasis is on promoting the numbers of oligo progenitors and their differentiation, particularly into adult oligodendrocytes,” says Duncan. “What this work provides is a different target.”

That target will call for new therapeutic approaches — finding drugs, for example, that rally the oligodendrocytes to reach out with new lifelines to damaged myelin sheaths.

“In fighting complex diseases, such as MS, the more tools you have on hand, the better,” Duncan says. “If these adult cells are recruitable in some fashion, we should be looking at ways to do it.”

Source:

Discovery opens new opportunities to slow or reverse MS

Tagged with:

About author

Related Articles