Will I have a seizure today? It's a question that many people with epilepsy ask themselves every day. For many people with epilepsy, not knowing when they are going to have a seizure can have a huge impact on their lives. Here, Dr. Marion Hogg, FutureNeuro researcher and Honorary Lecturer in the Department of Physiology and Medical Physics in RCSI writes about her latest research and progress towards developing a device that could predict when a person with epilepsy has a seizure.
Transfer RNAs (tRNAs) are a small molecule that plays an essential role in building proteins in the cell. They bring the individual building blocks of protein, called amino acids, to the ribosome where they are joined together in a specific order to form a new protein. Recently tRNAs have been shown to be cut when cells are experiencing stressful conditions, like a seizure.
Last year, we discovered here in FutureNeuro that some of the tRNA fragments are found in blood and were higher in people with epilepsy, hours before they had a seizure. We think that measuring these tRNA fragments in blood may allow us to identify when a seizure is likely to happen, providing a warning system for people with epilepsy.
We are now working with a team in DCU, to see if we can adapt sensing technology they have created to develop a test that can quickly detect these fragments.
This is the subject of our latest paper, Quantification of tRNA fragments by electrochemical direct detection in small volume biofluid samples, which has just been published in the journal, Scientific Reports.
In the paper, we outline the current methods we use to test for these fragments, which requires laboratory equipment and has significant turn-around times, meaning it is of little practical use to people with epilepsy, especially as an early warning system. So, for our discovery to be of benefit to people with epilepsy we require a portable, point-of-care, tRNA fragment quantification device.
This is where co-author Dr. Hazel McArdle and her team in DCU come in.
Hazel’s team have previously developed a device called the TORNADO that detects the amount of a molecule called microRNA-134 in plasma from people with epilepsy. microRNA’s are tiny, hard to detect molecules which are used by cells to increase or decrease the production of things like proteins in the body. A higher level of miR134 in the blood can diagnose epilepsy in patients.
Before Hazel’s team developed TORNADO, the main method of detecting miRNA was qPCR, which requires larger quantities of blood and equipment to be able to accurately measure the levels of microRNA’s in blood.
Image Credit: Nicole Di Nardo, Brandyard
Being able to detect them using a portable device, using only a small amount of blood has meant that diagnosis and monitoring of conditions can be carried out quickly and efficiently.
Therefore, we used a similar approach to develop a sensor for quantifying tRNA fragments.At the moment, this method is time consuming and requires benchtop equipment, but we envision integrating this sensor into a portable, point-of-care device that could be used at home.
Previously we have incorporated our sensors into TORNADO, which is capable of detecting the target in approximately an hour and a half. We are working to develop a similar device to detect tRNA fragments. The challenge is to make the device smaller, so only a finger prick of blood is required (similar to a glucose monitoring device), at the same time as keeping big enough amounts of tRNA fragments in the sample to allow accurate quantification.
We are also aiming to reduce the time it takes to produce a result to under 15 minutes, while giving an even more accurate result. We believe that a device such as this could transform the daily lives of people with epilepsy. Knowing if a seizure is imminent would allow people with epilepsy to plan their lives accordingly, avoiding potentially harmful situations and take fast acting anti-epileptic medications to avert seizures.
You can read the full paper in the latest edition of Scientific Reports and we have also produced a blog post for the Nature Research Device & Materials Engineering Community