Establishing the novel ex-vivo focal demyelination model of Multiple Sclerosis in other laboratories to reduce and replace live animal use.

Lead Research Organisation: CARDIFF UNIVERSITY
Department Name: Welsh School of Pharmacy

Abstract

Current therapies for treating multiple sclerosis (MS) patients are inadequate for managing progressive MS, so new therapies are needed. The central nervous system of MS patients has some areas that seem relatively unaffected (the neuronal fibres retain their insulating sheath called myelin), whereas other areas are damaged (the myelin is lost, compromising neuronal function and health). This is a dynamic situation, whereby the body continually repairs the damage, but ultimately fails with disease progression.
Much research aims to enhance remyelination (repairing the myelin sheath) as a key area for new therapeutic intervention, thus protecting the health and function of the neurons. However, to test new remyelination based therapies, laboratory animals must be used to model MS, and these models are costly, often don't faithfully replicate the "patchy" nature of the human disease, and shed limited light on how the therapy worked.

We have recently made a better laboratory model of MS, that allows this patchy nature of MS demyelination to be recapitulated in a dish, without using live animals in the process. Researchers can now, for the first time, study the complex interplay between the "healthy" and "damaged" tissue in a dish. This advancement means that new remyelination therapies can be tested faster, more effectively, with better understanding of how they are working, and greatly reduces the number of animals required.

Where previously one live adult animal would give one experimental result for one region of their nervous system (i.e., either the brain or spinal cord), our new model uses slices of euthanised newborn mouse brain or spinal cord cultured in dishes and analysed separately. This gives researchers six brain slices AND 10 spinal cord slices - all from a single animal. Where 100s of lab animals would be used for a single therapeutic test, now the tissue of a few animals can be used instead, with the added benefit of better understanding how the therapy works too. It is also important to mention that previously an experimental animal may have had to experience suffering during the interventions required to create the MS condition, whereas no intervention is carried out on a live animal with this new model that we have developed, thus replacing the use of live animals.

Having seen the power of this model to increase scientific value and reduce the use of animals, we are now keen to transfer these skills and knowledge to other research groups working on MS. Dr. Dombrowski and Prof. Fitzgerald, both running independent research groups at Queen's University Belfast, approached us to use this model in their laboratories.

This grant has three aims. Firstly, to finance a researcher to bring the skills and knowledge associated with the new MS model to the Belfast laboratories. The primary aim is to reduce the number of animals needed in their research, by replacing their existing live animal models with our new model. Secondly, we aim to encourage widespread adoption of this model throughout the UK, Europe and elsewhere, by making training videos and detailed protocols freely available online, thus leading to better MS research capabilities with lower animal use.
Lastly, we will optimise the production of the materials required to make this new MS model, so that it can easily be rolled out to large number of laboratories in a simple, cost-effective and reproducible manner.

We foresee that the immediate and tangible benefits that this new model of MS will bring to researchers will be a major attraction driving them to adopt it. These include reduced costs (live animal experiments are costly), the ability to work on multiple nervous system regions concomitantly and gaining better insight into how the therapeutic is working. This grant is required to catalyse and drive this adoption, spreading the knowledge and protocols required for this model, reducing animal use worldwide.

Technical Summary

Until recently the only means of mimicking the patchy and dynamic nature of demyelination in multiple sclerosis (MS) was by using animal models such as the EAE model, or stereotactic injections of a myelin toxin into the brain or spinal cord, resulting in focal lesions. However, the labs of Williams and Newland recently created a focal demyelination model using brain and spinal cord slices in culture (Eigel et al., Acta Biomaterialia, 2019, 97, 216) which replicates both the patchy nature (areas of unaffected tissue directly adjacent to demyelinated tissue) and the dynamic process of spontaneous remyelination. Cryogel scaffolds, which are extremely soft (causing no tissue damage) yet robust (easy to pick up with tweezers etc) are used to deliver the demyelinating agent lysophosphatidylcholine to brain and spinal cord slice culture to cause these focal lesions.

This project seeks to transfer the skills and knowledge of this model firstly to the Dombrowski lab and the Fitzgerald lab, then to other groups around the world to replace live animal models and reduce the total number of animals required in this field of research.

A technician will learn the techniques in the Williams lab, create detailed protocols, record training videos and set up the model in the Dombrowski and Fitzgerald groups. In addition, standardisation of templates with a micro-stereolithography based 3D printer, from which the cryogel scaffolds can be reproducibly manufactured, will allow the Newland lab to roll out designs to other groups yet allow customisation for specific shape requirements.

Other groups have requested this model as it is cost effective and reduces animal use, allows new research questions to be asked, it is easy to handle/store/load/place the cryogel scaffolds requiring no additional lab equipment, and finally it has been well validated through comparison with in vivo cryogel use and with MS post-mortem tissue (Zoupi et al., Acta Neuropathologica, 2021).

Publications

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