When diagnosing MND, it is important to look at the activity and impact of the motor neurones themselves – is the electrical message being carried down the nerve properly, and is it reaching the end of the nerve in the muscle? Malfunctions in the electrical activity at the muscle end of the nerve cell result in the muscle twitching that many people with MND experience.
One of the tests used to diagnose MND is an electromyography or EMG test. It involves putting needles into a muscle to measure electrical activity. It can be a painful and unpleasant experience, which doctors and patients are only willing to do when necessary.
There is evidence that ultrasound imaging may be able to detect the same malfunctions in the electrical activity of muscle as EMG, by looking at the way the muscle behaves when electrical activity occurs. Ultrasound images produce the typical grey scale images, for example pictures from baby scans, and can be used to provide images of any muscles in the body. Continue reading →
There is a critical need to find a biomarker for MND to speed up diagnosis, monitor disease progression and improve clinical trials. A biomarker is a biological change that can be detected in a person to signal that they have MND, and that can be measured over time to monitor how the disease is progressing.
Previous research has suggested micro RNAs (miRNAs) present in the blood might be a biomarker for MND. miRNAs are short forms of RNA, the cell’s copy of our genetic material DNA. They are stable in the blood, can be easily measured with a blood test, and evidence suggests that they are linked to MND progression. To put it simply, if the biomarker hunt was a music festival, miRNAs would be a headlining act that a lot of people are excited about! Continue reading →
Developing a way to rapidly diagnose and track how MND progresses over time is a ‘holy grail’ of MND research. The search for so called ‘biomarkers’ is an area that researchers funded by the MND Association are actively pursuing.
MND Association grantees Dr Andrea Malaspina and Dr Ian Pike (Blizard Institute, Queen Mary University of London) and Prof Linda Greensmith (University College London) are currently working on a project to find these biomarkers (our reference: 871-791). People with MND have been helping the researchers by regularly donating blood and spinal cord fluid samples.
Queen Mary University of London (QMUL) Blizard Institute MND group
Biomarkers in Oxford (BioMOx) is a research project with the aim of identifying a diagnostic biomarker for MND, which could be used to track the progression of this condition.
What are biomarkers?
The aim is to identify biomarkers, or ‘biological fingerprints’ for MND. This could be through testing blood and spinal fluid (CSF) samples from people with MND, or using MRI scans and other imaging techniques to look at changes in the brain.
By understanding the very earliest changes detected in these samples at the start of MND (the biomarker), it is hoped that they could be used to work towards disease prevention and to develop more targeted therapy for those already affected by MND.
For example, including a biomarker element in future clinical trials will help us learn more about the disease and identify participants most likely to benefit from the drug being tested.
Being able to track the progression of the disease could also help with effective care-planning for people with MND. Continue reading →
Induced pluripotent stem cell (iPSC) technology has enabled researchers to create and study living human motor neurones in the lab, derived originally from patient skin cells.
This project (our reference 80-970-797) is a collaboration between the labs of Professors Chris Shaw and Jack Price at King’s College in London and Siddharthan Chandran in Edinburgh. It aims to use the already collected white blood cell samples within the UK MND DNA Bank to create a larger number of new iPSC models of MND. Ultimately creating an MND iPSC cell bank, these models will enable researchers to better understand the disease and screen potential new drugs. Continue reading →
In a previous research project funded by the MND Association, Prof Kevin Talbot and colleagues from the University of Oxford developed a new TDP-43 mouse model of MND. Compared to other mouse models of MND, this one accurately reflects the symptoms of the disease and levels of the TDP-43 protein as seen in humans.
Location of TDP-43 protein (shown in red) in healthy nerve cells, and how it moves into different parts of the cell in MND
This model of MND also shows how the TDP-43 protein becomes displaced from the nucleus (command centre of the cell) out into the cell cytoplasm, which makes up the cell body. Once TDP-43 has moved to the cytoplasm it is very difficult to shift, as it forms protein aggregates or clumps. It is thought that these clumps contribute to motor neurone cell death.
Prof Talbot’s latest project, together with researcher Dr David Gordon, is using cultured nerve cells from this new mouse model to screen a large library of drugs (our project reference: 831-791).
In the next two years, they will create an automated computerised imaging system that can detect the TDP-43 protein within the nerve cells (and see if it has moved out of the nucleus). With this imaging software the researchers aim to screen thousands of drug compounds in a short space of time, including some which have been approved for other illnesses. A ‘good’ drug will make TDP-43 stay in the correct location within the nerve cell’s nucleus. Continue reading →
We know that damage to C9orf72 (both the gene and the protein it makes) is a crucial step in why some people get MND and why some people get frontotemporal dementia. There are three possible reasons why C9orf72 is toxic. 1) the way the gene is damaged alters how it normally works. 2) the formation of clumps of RNA – a by-product of the damage and not normally seen in cells, and 3) the formation of very short, new and unwanted proteins called ‘dipeptide repeats’ or ‘DPRs’, again these are not normally seen..
There’s evidence of all three types of toxicity within the motor neurone, but we don’t know how they work together or if one is more toxic than another. We also know that the protein TDP-43 forms clumps in motor neurones affected by the C9orf72 gene. Continue reading →
A team at the Sheffield Institute for Translational Neuroscience are creating a zebrafish model to study the C9orf72 gene mutation in MND, and work out its role in the brain and spinal cord (our reference 864-792).
Zebrafish are a good way of modelling what happens in human MND. We know that many of the genes linked to causing MND in humans are also found in zebrafish. For example, changes to a gene called SOD-1 in humans are linked to about 20% of all cases of inherited MND, and when you genetically change the same gene in zebrafish they develop symptoms similar to MND.
A faulty or changed C9orf72 gene is associated with about 40% of all cases of the inherited form of MND. This change (or mutation) is also found in people with a form of dementia called frontotemporal dementia (FTD). FTD can alter abilities in decision-making and behaviour. Continue reading →
Previous research in humans and zebrafish has shown that before symptoms arise in MND, early changes occur in the interneurones. This type of nerve cell provide a link between the upper and lower motor neurones in the brain and spinal cord.
The job of one type of interneurone (called inhibitory interneurones) is to apply the brakes on motor neurones. They work just like brakes on a bike stop the wheels from moving.
The interneurones control when chemical signals/messages (or action potentials) can be passed along the nerve cell. In MND these brakes are less effective (so to use the bike analogy, the brakes might be rusty or not connected properly).
Interneurones are being studied in more detail in a project led by Dr Jonathan McDearmid (University of Leicester), in collaboration with Dr Tennore Ramesh and Prof Dame Pamela Shaw (Sheffield Institute for Translational Neuroscience) (our reference: 835-791). Continue reading →
During the early stages of MND it is proposed that motor neurones are more susceptible to an imbalance of oxygen within the cells, known as oxidative stress. Prof Dame Kay Davies, at the University of Oxford, has previously shown that increasing the levels of the gene Oxr1 can protect motor neurones from death caused by oxidative stress and delay MND in mice. You can read about this work here. Continue reading →