Nav: Home

Eye muscles are resilient to ALS

January 26, 2017

Amyotrophic Lateral Sclerosis, commonly known as ALS, is an incurable neurodegenerative disease that affects all voluntary muscles in the body leading to paralysis and breathing difficulties. Eye muscles, in contrast to other muscles, generally retain their mobility even in the final stages of the disease.

A dissertation at Umeå University in Sweden has studied the two mechanisms that could be of importance to the eye muscles' retained function in ALS patients. The research also attempts to provide clues to novel treatment methods based upon these findings.

Eye muscles are very specialised and differ greatly from other muscles in several areas, for instance in their neuromuscular junctions formed between muscle fibres and nerve cells. Previous research has suggested that ALS causes a break-down starting in the nerve connection and spreading inwards to nerve cell bodies in the brain and spinal cord.

"We could see that the nerve connection to the eye muscles remains intact even in stages of the disease where a large proportion of neuromuscular junctions had been lost in leg muscles," says Anton Tjust, doctoral student at the Department of Integrative Medical Biology and the Department of Clinical Sciences at Umeå University, and author of the dissertation.

"The loss of connection between nerves and muscles can be seen in rather early stages of the degenerative process. We can hence establish that eye muscle protection mechanisms are active at a relatively early stage of the disease. Our results do not, however, ascertain if the disease starts in the nerve connection or in the cell body."

A previous study, by the research team that Anton Tjust is a part of, showed that certain fibre types present in the eye muscles seem to decrease in number in ALS. In the dissertation, it is confirmed that some muscle fibre types in the eye muscles show changes in the final stages of the disease. One of these specialised fibre types, so-called multiply-innervated muscle fibres, decreased by up to a third in certain patients.

"It seems like certain muscle fibre types in the eye muscles are not at all resilient to ALS, it is rather other fibre types in the eye muscles that preserve their functions so well. However, pinpointing these particular fibre types still remains to be done," says Anton Tjust.

The researchers have also investigated muscle stem cells in eye muscles and other muscle types. Muscle stem cells in the eye muscles have been suggested to be more efficient than muscle stem cells in arm and leg muscles. The researchers aimed to answer if muscle stem cells in eye muscles can contribute to its preservation despite ALS, and whether these cells decrease in number in arm and leg muscles at advanced stages of ALS.

"We found that the number of muscle stem cells in the eye muscles didn't differ greatly between healthy controls and ALS patients. Furthermore, the number of muscle stem cells in the eye muscles were relatively moderate, which is the opposite of what has previously been declared. However, an accumulation of muscle stem cells in the front part of the eye muscles could be seen, which could explain the current impression that eye muscles are rich in muscle stem cells," says Anton Tjust.

The research team measured the number of activated and maturing muscle stem cells in arm and leg muscles in deceased ALS patients, as well as in age-matched controls. The result showed that muscles in patients where the ALS had reached very advanced stages had a normal or even increased amount of muscle stem cells in various stages of activation and maturity. Nevertheless, only moderate levels of muscle stem cells were seen in the eye muscles of both healthy donors and deceased ALS patients. Based upon these findings, the researchers draw the conclusion that these stem cells do not wear out as the disease progresses in leg and arm muscles and have a very limited role in the retained eye muscle function in ALS patients.

"The fact that the eye muscles actually retain their function so well in ALS patients suggests that there nevertheless is some form of protective mechanism. Since ALS is a death sentence for patients and a tragedy to the entire family, we as researchers have an obligation to continue conducting research until we have an efficient treatment to offer," says Anton Tjust.
-end-
Umeå University is located in the north of Sweden characterised by strong research conducted in a vast number of fields, and many of our researchers belong to the global elite in for instance global health, epidemiology, molecular biology, ecology, plant physiology and Arctic research. Umeå University is one of Sweden's largest teaching universities that offers a wide-spanning and attractive selection of courses and programmes, and stimulating environments for working and studying for the over 4,300 employees and 31,000 students. It was from Umeå University that the work in discovering the gene-editing tool CRISPR-Cas9 was led.

Umea University

Related Stem Cells Articles:

More selective elimination of leukemia stem cells and blood stem cells
Hematopoietic stem cells from a healthy donor can help patients suffering from acute leukemia.
Computer simulations visualize how DNA is recognized to convert cells into stem cells
Researchers of the Hubrecht Institute (KNAW - The Netherlands) and the Max Planck Institute in Münster (Germany) have revealed how an essential protein helps to activate genomic DNA during the conversion of regular adult human cells into stem cells.
First events in stem cells becoming specialized cells needed for organ development
Cell biologists at the University of Toronto shed light on the very first step stem cells go through to turn into the specialized cells that make up organs.
Surprising research result: All immature cells can develop into stem cells
New sensational study conducted at the University of Copenhagen disproves traditional knowledge of stem cell development.
The development of brain stem cells into new nerve cells and why this can lead to cancer
Stem cells are true Jacks-of-all-trades of our bodies, as they can turn into the many different cell types of all organs.
Healthy blood stem cells have as many DNA mutations as leukemic cells
Researchers from the Princess Máxima Center for Pediatric Oncology have shown that the number of mutations in healthy and leukemic blood stem cells does not differ.
New method grows brain cells from stem cells quickly and efficiently
Researchers at Lund University in Sweden have developed a faster method to generate functional brain cells, called astrocytes, from embryonic stem cells.
NUS researchers confine mature cells to turn them into stem cells
Recent research led by Professor G.V. Shivashankar of the Mechanobiology Institute at the National University of Singapore and the FIRC Institute of Molecular Oncology in Italy, has revealed that mature cells can be reprogrammed into re-deployable stem cells without direct genetic modification -- by confining them to a defined geometric space for an extended period of time.
Researchers develop a new method for turning skin cells into pluripotent stem cells
Researchers at the University of Helsinki, Finland, and Karolinska Institutet, Sweden, have for the first time succeeded in converting human skin cells into pluripotent stem cells by activating the cell's own genes.
In mice, stem cells seem to work in fighting obesity! What about stem cells in humans?
This release aims to summarize the available literature in regard to the effect of Mesenchymal Stem Cells transplantation on obesity and related comorbidities from the animal model.
More Stem Cells News and Stem Cells Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Making Amends
What makes a true apology? What does it mean to make amends for past mistakes? This hour, TED speakers explore how repairing the wrongs of the past is the first step toward healing for the future. Guests include historian and preservationist Brent Leggs, law professor Martha Minow, librarian Dawn Wacek, and playwright V (formerly Eve Ensler).
Now Playing: Science for the People

#566 Is Your Gut Leaking?
This week we're busting the human gut wide open with Dr. Alessio Fasano from the Center for Celiac Research and Treatment at Massachusetts General Hospital. Join host Anika Hazra for our discussion separating fact from fiction on the controversial topic of leaky gut syndrome. We cover everything from what causes a leaky gut to interpreting the results of a gut microbiome test! Related links: Center for Celiac Research and Treatment website and their YouTube channel
Now Playing: Radiolab

The Flag and the Fury
How do you actually make change in the world? For 126 years, Mississippi has had the Confederate battle flag on their state flag, and they were the last state in the nation where that emblem remained "officially" flying.  A few days ago, that flag came down. A few days before that, it coming down would have seemed impossible. We dive into the story behind this de-flagging: a journey involving a clash of histories, designs, families, and even cheerleading. This show is a collaboration with OSM Audio. Kiese Laymon's memoir Heavy is here. And the Hospitality Flag webpage is here.