Sharing and networking in Liverpool

From Sunday morning to Tuesday evening last week, there was a lot of talk of MND research going on in Liverpool. The reason for this ‘hotspot’ of discussions was due to the annual meeting of an international consortium of MND researchers taking place at the University of Liverpool. The 10th International Consortium on SOD1 and ALS (ICOSA) meeting took place last weekend (4 – 5 March).

In 2001, five laboratories came together to form ICOSA, where the aim was to share knowledge to design better-informed experiments to understand the rare, inherited SOD1 form of MND. MND Association grantee, Prof Samar Hasnain was one of its founding members. Success of this philosophy of sharing knowledge prior to publication has resulted in several leading groups joining the effort, looking at other causes of inherited MND too.

A tradition of ICOSA meetings is to hold an open meeting for sharing latest results with a wider audience, following their closed meeting. Thus, on Tuesday 6 March, an open meeting was held to allow the exchange of the latest results and ideas between ICOSA members and the UK MND research community.

I attended this one day meeting in Liverpool and I’ve written a mini report on the meeting below, including a couple of highlights.

The first few presenters demonstrated the truly international nature of this collaboration – they had travelled from the snowy landscape of northern Sweden, the sweltering heat (at least in August!) of mid-state Florida and from RIKEN, the large natural sciences research centre, in Japan .

The researchers represented were a mixture of physicists, biochemists and neurologists – an unusually broad spectrum of knowledge and speciality for an MND research meeting. Essentially, their core, joint interest was in understanding how the structure of a protein has such a marked change leading to MND developing or the disease progressing.

The structure of a protein is essentially about folding. The correct folding will mean that the protein can do its job. Folded incorrectly the protein won’t be able to work. An example of incorrectly folded protein is the protein clumps or ‘aggregates’ seen within motor neurones in MND. There is a whole chain of events that lead the appearance of these clumps of protein – and researchers at the meeting discussed every step along the way.

How do proteins fold and why is it important?

When the instructions for making a protein (ie genes) are read and edited by DNA and RNA respectively, they are reading or editing instructions to arrange a set of building blocks in a particular order – there are 20 different types of building block – our amino acids. ALL of our proteins within our bodies are made from specific arrangements of this core set of 20 building blocks. The arrangement of the building blocks determines where the protein folds, in which direction and the shape it makes. There are many possible folding arrangements a protein could make, but it will always try and fold itself into the lowest energy shape (a good way to think about this is the shape where the protein is ‘most comfortable’).

Geneticists know a lot about the beginning of the process (what the sequence of building blocks will be) and biochemists and pathologists know a lot about the end of this process (what the protein does and a what it looks like in the cell when it clumps together) – but the physicists of the MND research world are working on the bit in the middle (precisely where which building block is, in the folded protein).

A change to the sequence of the building blocks, as seen in the proteins made from mutated genes that cause MND, will lead to unusual folding, and damage to the cell – due to the loss of normal function or a trigger for toxicity. So having a complete picture of a protein ‘lifespan’ is really important in understanding what goes wrong in MND and how to fix it.

Unravelling questions about SOD1

People with the SOD1 form of the rare, inherited type of MND have a mistake in the assembly of one building block in the instruction to make the SOD1 protein. Over 160 different, single building block mistakes have been found in this form of MND so far. All of them lead to the development of MND. So that means 160 damaging variations in the folding of the SOD1 protein.

Over 70 other delegates and I heard the latest on how mimicking the effects of these mutations (by changing building blocks of the protein) in SOD1 mouse models tells us more about this cause of MND. It’s even possible to study the different effects of the toxic protein on different cell types essential for motor neurone function. (Although motor neurones carry the messages, they are supported by groups of ‘glia’ cells around them).

Where (the) ‘FUS’ is

Prof Larry Hayward presented his research on a protein called ‘FUS’; mutations in this gene causes another form of the rare inherited MND. The damaged ‘FUS’ protein is found in a completely different place in motor neurones than usual. Images of motor neurones where the FUS is in the centre of motor neurones, as usual, looked a bit like fried eggs; but the location of the damaged FUS in the outside of the cell reminded me of ring donuts! By stressing motor neurones, he showed a video of the proteins moving from the centre to the outside of the cell; and back to the centre when the stress was removed. This all happens very quickly, in a matter of minutes!

C9orf72 – a hot topic

Another highlight of the meeting was the presentation by MND Association grantee Prof Huw Morris on both how the C9orf72 gene mistake was found last year, and also on what’s happened since the results of this finding were announced. In the five and a half months since the 21 September announcement, another 26 reports have been published in this area of MND research. That’s slightly more than one report a week! (To put this in context there are roughly 36 MND reports published a week, total, across a broad range of topics). He commented that one factor that kept him focussed in the long search for this gene defect was the people with MND in his care.

Drug scaffolding to correct damaged folding

Above I mentioned that the physicists work out the precise folding of proteins, knowing where each of the building blocks is within its final shape. They do this by isolating the protein they want to study and placing it in increasingly high concentrations of salt solution to remove literally every molecule of water, until the protein itself comes out of solution and forms crystals. These crystals are then analysed by x-ray crystallography and other analytical chemistry techniques.

For a protein made from a mutated SOD1 gene, x-ray crystallography studies found a hole in the protein folding that may explain why it forms clumps within motor neurones. MND Association funded researcher Dr Neil Kershaw from the University of Liverpool presented the latest results from his research in designing a drug that will ‘prop up’ incorrectly folded SOD1, in the hope that this will remove its damaging effects.

I hope that this report demonstrates that in between the ‘big news’ stories about MND research, steady progress continues to be made in understanding MND and searching for treatments for it.

Cogane produces encouraging results in MND Association-funded study

Prof Linda Greensmith

Thanks to funding and some strategic ‘match-making’ by the MND Association, a new drug may have taken one step closer to beginning clinical trials in MND after producing promising results in an animal model of the disease.

The drug, known as Cogane, was developed by the biotechnology company Phytopharm. It had already demonstrated in laboratory tests that it could help to protect neurones by promoting the production of natural, nerve nourishing substances called neurotrophic factors and early animal testing had hinted at its potential beneficial effects in MND. However, its journey towards clinical testing in MND had hit a road block because it hadn’t been extensively put through its paces in large numbers of the most widely used animal model of the disease, the SOD1 mouse. Without robust data from this model, there would have been little to encourage further investment in Cogane’s development.

So up stepped the Association to introduce Phytopharm to Professor Linda Greensmith at University College London, a leading MND researcher with considerable expertise in SOD1 mouse testing. With funding from the Association, Prof Greensmith and her team were able to conduct a rigorous study of the effects of Cogane, administered to the mice after they had developed MND-like symptoms.

The drug produced some significant improvements in muscle strength and motor neurone survival and managed to produce positive effects even in mice that had reached the later stages of the disease. To give more substance to these preliminary but very encouraging results, the research team will now go on to the painstaking work of examining more closely Cogane’s effects on the motor neurones and other key cells that play a critical role in the progression of MND. 

After the disappointment of the Trophos trial results, it’s great to be able to share some positive news on the drug development front. We know from long experience that it’s wise to limit our excitement over positive results from the mouse model – after all, plenty of drugs have shown promise at this stage and have then gone on to fail in clinical trials. However, Prof Greensmith’s experience and expertise mean that Cogane will have been tested with the utmost rigor. As she herself commented, the results indicate that “Cogane has significant potential as a therapy for ALS and merits further evaluation”.  We don’t yet know what Phytopharm’s next steps will be – these may become clearer once the more detailed data from Prof Greensmith’s work have been published, which could take the best part of a year. Let’s hope that we have a given Cogane enough of a boost to push it out of the drug development ‘doldrums’.

Read the Phytopharm press release.

Promising news for keeping the motor neurone neighbourhood safe

There was standing room only in the first of the dedicated scientific sessions of the Symposium last week. All had gathered to hear Prof Stan Appel inform them of the latest chapter of this story on the role of inflammation in MND.

Listening to his presentation I got the gist of the overall positive message – a real step forward in MND research – but to report in any more detail of how and why was a step too far for my brain when I was in Sydney! Reading through my notes when I got back to the office, I was determined to get to the bottom of this science. It helped me to write a non-technical summary of it as I went. It’s perhaps a bit more technical than our normal blog posts – but I couldn’t resist the opportunity to (try and) share my new found knowledge. So here goes:

Inflammation is one response of the immune system. The immune system is a community of cells that exist within your body to protect it from damage and to maintain its status quo. Given its important function, it is perhaps reassuring to know that how it works is mind-blowingly complex!

In the brain and spinal cord, a slightly different defence system exists in comparison to the rest of the body. It is now common knowledge that motor neurones are surrounded by cells that support their function – known as glial cells. Within the community of these glial cells there are ‘police’ cells called microglia. Prof Appel’s lab has contributed many elegant studies to a consensus of research showing that in MND these police cells operate a delicate balance between protecting the environment around motor neurones and triggering a toxic atmosphere. Gradually the toxic atmosphere prevails.

In Sydney, Prof Appel discussed another component of this defence system, ‘regulator T-cells’. Continuing the police analogy, T-cells patrol the blood, rather than the brain and spinal cord tissue of microglia. As their name suggests, regulator T cells regulate the response rate of removing toxins and maintaining a healthy environment, in particular they regulate microglia by sending out specific chemical signals.

Prof Appel wanted to know how the interaction of T-cells with microglia is affected in MND. He found that a large ‘police presence’ (or high numbers) of regulator T-cells influence microglia to maintain their protection of motor neurones. In other words, large numbers of regulator T-cells kept motor neurone death at low level, showing itself as a slower phase of disease progression. As the levels of regulator T-cells get lower, the microglia turn toxic and the rate of progression of the disease speeds up. These conclusions were based on studies in mice models of MND and in patients at different stages of MND – by analysing blood samples for the presence of regulator T-cells and comparing this with what they knew of their symptoms.

This information presents two opportunities to MND researchers – firstly if therapies can be developed to maintain the levels of these regulator T-cells they may slow down the disease; and in the meantime, chemical markers in the blood, used in these studies, may be a valuable biomarker to measure the rate of progression.

Changing fashions of MND models

Models of MND are important both to understand the causes of MND and to quickly, efficiently and accurately screen and develop new treatments for it.

A number of key developments both in terms of technological know-how and new understanding of genetics of MND have led to the development of new models discussed at on the last day of the symposium.

Stem cells
The session was opened with a presentation on what is arguably the most glittering and exciting of these new models, that of using so called ‘iPS’ cells. The principle behind iPS cells (induced pluripotent stem cells to give them their full name), is that it’s possible to take a skin cell from someone with MND, coax it back into basic stem-cell-like state and then change it into motor neurones. The idea that this was even possible was scientific heresy say five years ago. The beauty of this technique is that you then have living human motor neurones in dish in the laboratory.

Dr Kevin Eggan from Harvard University Massachusetts USA is one of the leading lights in this technology and he treated us to an update of his latest research. “In itself, ALS is an interesting test tube for stem cell research” he said, adding “this is my first ALS meeting, I’ve enjoyed it and learnt a lot”. Aswell as being the first time that it was possible to study the cells directly affected in MND (motor neurones), iPS techniques also allow researchers to study the behaviour of motor neurones at as close to the actual disease conditions as possible.

Are they really motor neurones?
In the first part of this talk Dr Eggan explained and demonstrated that the cells that he and his colleagues have grown really are motor neurone-like and that they do behave like motor neurones. However he did caution that this model is not the panacea of ALS models, it’s an arrow in a quiver of techniques.

How do these motor neurones behave?
The second half of his talk concentrated on whether these human motor neurone models behave differently to motor neurones grown from skin cells of unaffected people.

When given the same growing conditions, motor neurones derived from people with SOD1 mistakes (mutations) were found to be less plentiful when growing ‘in a dish’ than those derived from healthy individuals. The SOD1 motor neurones also display a different pattern of electrical activity (transmitting electrical activity, is, after all, one of the main functions of motor neurones). The next steps of this research will be to double check that the effects seen in cells with SOD1 mutations really are due to this faulty gene and investigate the effects of other known genetic causes of MND in these cells.

Of mice and men
Moving from a new model to an old and arguably less fashionable one, Dr Greg Cox was given the title of “Are mice a good model for human ALS”. His first slide was to turn this question on its head and state that humans are a terrible model for mouse ALS! His point was that there are so many things that are unknown in human MND that generating a truly accurate mouse model for it was an almost impossible task. Saying this, he went on to discuss three key essentials for any mouse model, so called face, construct and predictive validity. Towards the end of his presentation he shared some results of one of this own studies, explaining that there is an area of our genetic code, not identified in MND before, that seems to carry a mistake that causes symptoms of MND.

Read our press release from day three of the symposium.

Mediating the delicate balance between protection and damage

The Opening Session theme on how the disease progresses within the Central Nervous System (CNS) continued with the presentation by Prof Stan Appel from Baylor College of Medicine, Huston on neuroinflammation.

Examination of post-mortem brain and spinal cords from people with MND shows clear evidence of inflammation (although Prof Appel was quick to point out that this is not the same as occurs in ‘primary’ inflammatory conditions such as multiple sclerosis). Similar patterns are seen in human MND spinal cord and in SOD1 mice, suggesting that at least for this aspect of the disease, SOD1 mice may be a good model of human MND.

He went on to explain how migroglia, the ‘innate’ immune cells of the CNS, help mediate a delicate balance between protection and damage. The speed of progression in MND appears to be dictated by this balance.

Prof Appel showed that SOD1 mice exhibit two phases of disease: an early slow phase, where the microglia release a series of protective factors, and a rapid secondary progressive phase where levels of these protective markers fall and are replaced by a rise in ‘pro-inflammatory’ toxic factors. Of course, strains of lab mice are so inbred that they are genetically very similar and develop the disease in a uniform manner. Humans on the other hand are very different, as is the way the disease progresses between one individual and the next, so the two stages of disease are not easy to demonstrate in MND patients. However, by examining the inflammatory factors present in patients with very rapid progression against those with slower progression, he was able to show that the factors associated with the second ‘rapid progression’ phase in mice were also present in the rapidly progressing patients. He suggested that this may assist clinicians in predicting how the disease is likely to progress in patients at an early stage in the disease.

It is relatively easy in cell culture studies to tilt this balance from protective to toxic, but could the balance be tilted the other way in patients, as a therapeutic strategy? Certainly, in response to a question from the floor, he suggested that greater attempts should be made in this direction, commenting, “The whole issue of immunosuppressant drugs in MND needs to be re-opened. But – you can’t just take down all immune responses in an uncontrolled way. You need drugs that are much more selective”.

Read our official day one symposium press release on our website.

Prof Siddharthan Chandran talks about the recipe for stem cell success at our Annual Conference

Neural Progenitor cells, courtesy of Prof Chandran lab, University of Edinburgh

We invited Prof Siddharthan Chandran to be our keynote speaker at our Annual Conference and below we’ve provided a brief overview of his presentation which we hope you’ll find useful as either a recap if you attended or as an insight into MND and stem cells if you couldn’t make it on the day.

About Prof Chandran

Prof Chandran is Professor of Neurology at the University of Edinburgh and Director of the Euan MacDonald Centre for MND Research which is based at the university. He is leading the Association’s largest stem cell research programme which pulls together world-class researchers from leading institutes in Edinburgh, London and New York. Working together, the international research teams are manipulating stem cells to provide a unique tool for studying MND and developing new drugs. It’s research programmes like this, that really demonstrate our role as a leader in funding and promoting cutting-edge MND research. Naturally we were only too pleased to introduce Prof Chandran to our conference delegates.

Origins of understanding the power of stem cells

Prof Chandran began his talk on a mythological level with the story of Prometheus, who was punished by the Greek God Zeus by being chained to a rock and having his liver eaten daily by an eagle, only to have it grow back the next day to endure the torture again. Not a very nice story, but Prof Chandran went on to explain that through this myth, the Greeks had stumbled onto the origins of understanding the nature of stem cells. The liver is one of the only solid organs that we have that has the power to regenerate itself when damaged. Although this wasn’t the moral of the myth, it’s still an important historical reference that demonstrates that the potential of stem cells as a regenerative tool is not a new concept.

From science fiction to science fact

If Prof Chandran, while at university, had suggested that in the future it would be possible to create stem cells from a skin sample, he said that he would have been ridiculed and the idea would’ve been seen as pure science fiction. Yet here we are, now living in ‘the future’ and this technology is a reality, the newest finding of which was the discovery of stem cell-like cells called ‘induced pleuripotent stem cells’ (or iPS cells for short) in 2008 by a Japanese research group. By delivering a cocktail of chemicals to skin cells donated by a living person, they were able to turn back the clock of the skin cells to turn them into iPS cells. This finding is now the cornerstone of many new stem cell research projects, which has arguably revolutionised the field.

Future treatment potential, but currently regeneration is impractical

There are many ways that stem cells could be used in the future to treat MND, but using them to regenerate motor neurones is not currently a practical solution. But why isn’t this practical? In his talk, Prof Chandran explained…

Crossing wires

The brain is a very complex organ and can be related to a ball of wiring, with each wire being linked to a specific place within the brain and body. If this were to be wired up inaccurately, then it would cause pandemonium in our bodies, with movement instructions meant for our feet to possibly end in our hands, mouth or elbow for example – something we’d definitely not want to happen!

Prof Chandran went onto explain that each neurone has its own ‘postcode’ in the brain, and depending on where it ‘lives’, he explained that its function will vary.

The function of each motor neurone will also intuitively denote what muscle it’s supposed to connect to. The way that our neurones grow toward a muscle is an extremely well orchestrated affair, with chemical messages throughout the body that either attract, or repulse it. However, as our bodies develop in the womb, this system is switched off – meaning that any new motor neurones trying to grow from scratch in the brain will find it near to impossible to know where it’s supposed to go.

It is therefore a very complicated issue to try and regenerate motor neurones in humans to ensure that the motor neurone firstly starts in the right place, and secondly that the neurone has the right instructions in place to guide it toward its target muscle.  However, these aren’t the only issues that researchers face…

Being sure it’s a motor neurone

In our search for using stem cells as a treatment for MND, there is also an issue of making sure that stem cells turn into the cells you want them to be, and Prof Chandran eloquently explained this by using a video of heart cells, generated using stem cell technology and saying that you definitely wouldn’t want these cells beating away in your brain instead of your motor neurones!

But how do researchers turn stem cells into the ‘right’ sort of cell? Prof Chandran explained that this is done quite simply, by giving them the right recipe of chemical ingredients to tell them what to become when they’re older.

Neurones are slow growers

Even if researchers could somehow ensure that ‘new’ motor neurones could be created and would connect to the right ‘postcode’ of the brain, neurones are very slow growing. As some of our motor neurones would have to grow over a metre to reach its target muscle, the amount of time that it would take to regenerate motor neurones would be implausible in terms of using them as a treatment. There just isn’t a way to speed this up at the moment.

For all of the above reasons, this is why stem cells cannot currently be used to regenerate motor neurones as a treatment for MND. However, this is not to say that they don’t have other uses…

Using stem cells to learn more about MND

Stem cells are great tools for recreating diseases in a dish, as they are able to divide to create large numbers of cells and are able to turn (with the right receipe) into any type of cell, such as a motor neurones.

In his laboratory, Prof Chandran’s research group have created living human motor neurones grown in a dish from skin cells donated by people with an inherited form of MND using iPS cell technology. In his presentation, he showed us that within 100 days, his laboratory is able to create a billion (10¹², referred to as a trillion in USA) cells from a stem cell. He has also shown that these motor neurones generated from stem cells connect to muscle cells and are electrically active – which means that to all intents and purposes, they are real motor neurones.

He then explained that his MND Association funded project is creating these motor neurones and support cells from a skin biopsy of somebody with MND with faults in a gene called TDP-43. They can then use these new cells as a tool to investigate the disease process and hopefully in the future to test the effectiveness of therapies in this model.

Realising the potential of stem cells

As well as using stem cells to create new models in the laboratory, to discover new medicines, stem cells could potentially be used in a different way to treat the disease. These treatments would not aim to regenerate the motor neurones, but instead would attempt to slow down, or even stop the disease.

Realistically, researchers could use neurone support cells to provide a protective environment to lasting motor neurones – in fact, there are plans in place to test such a treatment which is estimated to being enrolling in 2014 (see stem cell conference blog article for more information).

Overall, Prof Chandran’s talk was extremely well received with delegates commenting to us that “Prof Chandran was the best speaker I can recall” and Prof Chandran’s talk was: “clear, hopeful, excellent. He inspired confidence and spoke in language I could understand”

We’re pleased that so many people who attended our AGM and Annual Conference enjoyed Prof Chandran’s talk, with 91.2% of delegates saying that it was “excellent” (from our survey of 57 people who attended).

Find out more about stem cells on our website.

Stay up-to-date with news on our next conferences by following our conference team on Twitter @mndconference

Thinking outside the neurone and toward the stars

Neural Progenitor cells, courtesy of Prof Chandran lab, University of Edinburgh

By using spinal cord donations from people with MND, an American group of researchers have created a new, human ‘in a dish’ model of MND. Their results were published in the journal Nature Biotechnology.

Human neuronal progenitor cells, which have the potential to turn into brain cells but not other types of cell, were extracted from post-mortem spinal cords and programmed to turn into living neurone support cells called astrocytes. The research group, led by Dr Brian Kaspar from Ohio USA, is hopeful that these human astrocytes grown in the laboratory can be used to learn more about the causes of MND.

Astrocytes and MND

Astrocytes, so called because of their star-like appearance, have been known to be involved with MND for many years now. Normally, astrocytes support and nourish nerve cells but in MND, they can become toxic to motor neurones, causing them to degenerate. However, before now, there hasn’t been a way to prove that this really does happen in people as it’s impossible to extract these cells while the person is still alive.

Using post mortem samples to find the answers

This research group used post-mortem spinal cord donations from people with MND to create a new, human astrocyte model, grown in laboratory dishes.

They were then able to demonstrate in the lab that these human astrocytes are toxic to healthy human motor neurones, causing them to degenerate. This verifies that astrocytes can cause MND in people, and not just in animal models.

They then went on to show that the healthy motor neurones could be protected if they stopped a protein called SOD1, which can be faulty in MND, from being created. This was found in astrocytes created from a person with a SOD1 form of inherited MND and remarkably, also from astrocytes created from people with the randomly occurring, sporadic form.

Reaching for the stars

By using post-mortem spinal cord donations from people with MND, and thinking ‘outside the neurone’ this research group were able to successfully create a new human ‘in a dish’ model of disease. There are still many unanswered questions left to explore with this new model, such as how the astrocytes cause the motor neurones to degenerate. By understanding more about this process, new treatments could be investigated to stop astrocytes from being toxic and slow down, or stop MND.

Find out more about tissue donation for general research purposes.

Reference:

Published in Nature Biotechnology: doi:10.1038/nbt.1957

Come fly with me

The Fly. Courtesy of MND Association funded researcher Dr Frank Hirth, based at King's College London

Although millions of years of evolution separate humans from insects, a tiny fruit fly called Drosophila melanogaster has been one of the most extensively studied organisms for more than a century, leading to many advances in research. But why are flies so useful? And can we really learn anything from them?

Why fly?

It is easy to see that this fly has advantages in the laboratory. They are very small and easy to keep, but still large enough to study in detail with relatively simple microscopes. They breed easily from 10 days old, producing many genetically identical offspring from each mating. This makes it easy to study several generations over a matter of weeks.

Simple yet sophisticated

Although considered a simple species, the fly is actually quite sophisticated, with structures that are equivalent to organs such as the heart, kidneys and gut.  The brain and nervous system are considered particularly complex, making the fly valuable for the study of neurodegenerative diseases.

Genetically the fruit fly is also much simpler than a human – it has approximately half the number of genes that we do. But it’s not the number of genes you have that counts; it’s what you do with them!

Luckily, about three-quarters of the genes implicated in human disease have a related gene in the fly, with a high level of similarity between the two. Many methods and techniques have been developed, so researchers can switch the fly’s genes on and off at various points in its life-cycle, or in different parts of the body, and then observe the consequences.

MND fly research

Between 2004 and 2009, only about four scientific papers per year described studies using these fruit flies for MND research. In conjunction with the recent upsurge in genetic discoveries related to MND, there has been a rapid increase to twelve publications in 2010, and a further seven already in 2011.

The MND Association is a leader in funding and promoting cutting edge research and we are currently funding two PhD studentships making extensive use of the fruit fly. You can find out more about these projects on our website:

Understanding disease mechanisms of MND in the fruit fly

How does faulty TDP-43 affect MND in fruit flies?

Learning to fly toward drug discovery

There is considerable interest in using the fly to test potential drugs for MND, as there has been some success in this approach in other conditions.  Like the zebrafish model many more substances can be tested than would be possible with a mouse model, and the results may tell scientists more than a cell-based screen. However, this is not yet a routine approach to drug discovery – historically fruit flies have not been used in this way by pharmaceutical companies. It remains to be seen whether any promising compounds identified using fly models will actually progress to being drugs for the treatment of human diseases.    

For such an approach to be useful for MND, there needs to be a reliable and relevant fly model. Recently published work has been focussed on exploring the role of proteins known to be involved in MND such as TDP-43 and FUS. When they publish their work, researchers often hint that their models will be useful in the development of new treatments, even if this was not their main aim.

The use of the fly to discover new medicines may still be some way off, but we can be sure that the tiny fruit fly is already contributing to research in a very big way.

Earning their stripes – Zebrafish lead the way to learning more about MND

Zebrafish are increasingly becoming the organism of choice to study both early development and disease. But why are zebrafish important to MND research and can we really learn anything from a fish?

Shall I compare thee to a zebrafish?
Amazingly, we share many of our genes with our finned-friend the zebrafish which means that we really can compare what happens in zebrafish with what happens in humans.

With transparent embryos, zebrafish offer a unique view into the developing fish which means that researchers can study their neurones under a microscope – a feat that is not possible in humans or other mammals. We can also learn about how the disease progresses in fish by measuring their muscle strength by the amount they move, and by measuring their progress swimming against a current in a tube. 

Unlike us, zebrafish are also able to regenerate motor neurones if they become damaged. Interestingly – it is not that we do not have this capacity; we have extra signals that tell our motor neurones not to regenerate.

Zebrafish can therefore be used in MND research to gain a greater understanding of the processes that govern both the degeneration and regeneration of motor neurones to develop new and better treatments.

In the past 30 years, the number of scientific articles published about zebrafish has increased 465 fold. Not only does this show the increased use of this model, but also represents our collective increase in understanding more about human diseases and human development.

We’re fishing our way to a world free of MND
One of our newest projects, set to begin later this year, will be using a new zebrafish model of MND to screen over 2,000 potential new drugs to test for their effectiveness. This work will be carried out at the University of Sheffield by Dr Tennore Ramesh and Prof Pam Shaw.

This project will join the ranks of many other MND Association funded projects that are developing new models of MND to learn more about the causes of MND so that we can be in a better position to develop treatments.

We have also recently supported the development of new guidelines for the use of models in MND research in order to improve our confidence in pre-clinical (laboratory) studies and hopefully the success rate of MND clinical trials.

Zebrafish will not be able to provide us with all of the answers as to what causes the disease, or how we can treat it. But, when used in combination with a number of other exciting disease models, including chick embryos, flies and mice, we can push MND research to a new and exciting level.

Painting the way to new motor neurones from stem cells

A study led by MND Association funded researcher Prof Siddharthan Chandran from the University of Edinburgh has developed a new method to create a diverse group of motor neurones from stem cells. The research, published in the journal Nature Communications could be used to create more accurate and clinically relevant laboratory dish models to learn more about the differences in vulnerability and connectivity of motor neurones in MND.

 Why are the subtypes of motor neurones important to MND research?
When we first start to develop as embryos in the womb, chemical messages are used as cues to tell our cells what to turn in to. At the start of this process our cells can be thought of as blank canvases that have the potential to turn into any type of cell. Mixtures of ‘colourful’ chemicals are then used to create a unique ‘hue’ signal in order for the cell to know what to become.

So, depending on the ‘hue’ of chemicals around them, neuronal precursor cells will turn into different subtypes of motor neurone. In their fully formed state, these motor neurones subtly vary in their chemical makeup (due to acting on the different ‘hue’ signals given), their vulnerability to degenerate in MND, as well as the way they connect and communicate with other cells.

The subtle differences in subtypes of motor neurone have not been replicated in a laboratory dish model of MND to date. However, being able to develop such a model would provide MND researchers with a true spectrum of the way that MND affects the different subtypes of motor neurones. They would then also be able to develop new and better treatments that can target specific types of motor neurones that may be more vulnerable to MND.

What did the researchers do to find this?
The collaborative research group from Universities of Edinburgh, Cardiff and Cambridge tested a new method for creating different types of motor neurones in a dish from human embryonic stem cells.

To do this, they first added a chemical that accelerates the process of turning stem cells into neurone precursor cells – it’s the equivalent of being able to add a ‘quick drying’ additive to a painting. By adding this chemical, which has been given the catchy name of SB431542, the process of changing an embryonic stem cell into motor neurone progenitor cells is sped up from approximately 30 days to just 12 days.

They then tested whether a certain chemical called ‘retinoic acid’ is needed for the process of making different types of motor neurone. By measuring the chemical makeup of the functional motor neurones produced without retinoic acid, they were able to determine that they had produced a different type of motor neurone that is different from those created with the use of retinoic acid.

What’s next?
By defining a new process to create new and better models using stem cell technology, a new multi-motor neurone type model could be created for MND to study the similarities and differences between motor neurones in MND.

By learning more about these differences, we could learn more about how and why some motor neurones remain spared in MND.

To find out more about the future of stem cell research, please read Dr Brian Dickie’s account of the recent stem cell conference. Or, download a copy of our stem cell information sheet.

Journal Reference: Patani, R. et al. Retinoid-independent motor neurogenesis from human embryonic stem cells reveals a medial columnar ground state. Nat. Commun. 2:214 doi: 10.1038/ncomms1216 (2011).