Usually, when we talk about genes, we mean strings of DNA that contain the recipes to make proteins. However, there are other genes, known as ‘micro-RNAs’ are genes that control the activity of thousands of other genes. This might mean they turn on genes, so that they start to produce protein, turn them up or down, so they produce more or less protein, or switch them off, so they stop producing protein altogether. In doing so, microRNAs can ‘micromanage’ the activity of whole cells and even organs, ensuring that they’re doing what they’re supposed to be doing in the body. If you have a mutation in one of these genes, it is likely to lead to disease or disability.
microRNAs in the ear
There are several microRNA genes that are involved in hearing, but one of the most important is MIR96, or microRNA-96. We already know that MIR96 is involved in ensuring that the sound-sensing cells, the hair cells, form correctly in the inner ear. Mutations in MIR96 cause hearing loss in people, especially hearing loss that gets worse over time; they are likely to interfere with how the hair cells work, or are maintained throughout life, in some way. What we don’t know is how MIR96 controls this process, what genes it controls, and how the mutations disrupt its normal activity. And that’s what this new project is all about.
What is the aim of the new research project?
We’re funding Dr Morag Lewis, at King’s College London, to carry out research into this area. The main aim of her project is to study mice, which have been genetically engineered to have the same mutations in the microRNA-96 gene as are seen in people with hearing loss. These mice provide a good model for studying the changes that these mutations cause in the inner ear, and the hair cells. Knowing more about these changes, and the genes and processes involved, could ultimately help to develop treatments for hearing loss.
How will she do this?
Morag will study the changes caused by mutations in the microRNA-96 gene in a number of ways. She will measure the hearing of these mice by measuring the electrical activity of the hearing part of the brain, a test which can also be used in people with hearing loss. She will also examine the inner ears of these mice in fine detail using a microscope. Morag aims to better understand how the hair cells and their associated nerve cells are affected by these mutations.
She will also measure the activity of every single gene in the body (the genome) to discover what and how gene activity has changed in the inner ears of these mice. This will help her to explore how genes involved in hearing interact with each other, to discover new genes involved in hearing, and identify genes whose activity could be targeted by drugs to treat hearing loss.
Why does this research matter?
We hope that this research will benefit people with hearing loss by:
- Improving our understanding of what can go wrong in the inner ear and how that affects hearing. This will help us develop appropriate drug treatments for different types of hearing loss.
- Discovering new genes involved in hearing, so that people who have hearing loss due to mutations in these genes will be able to find out the reason for their hearing loss. This is very helpful for patients and their families.
- Identifying genes whose activity can be targeted by drugs to prevent hearing loss or restore hearing. To do that, we need to know which genes are important for hearing and how their activity needs to be changed by the drugs.
Find out more
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You can find out more about the research we’re funding in our biomedical research section.
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