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Researcher
Dr Sarah Annesley
Institution
La Trobe University, Melbourne, Victoria, Australia
Start date
June 2025
Funding
ME Research UK
Background
Dr Annesley leads a research laboratory at La Trobe University where she researches neurological disorders including ME/CFS and long COVID. Her team looks at how energy is produced by immune cells, and how the expression or activity of genes is altered in ME/CFS.
We have previously funded Dr Annesley’s studies investigating mitochondrial dysfunction in the illness, including a PhD project looking more closely at the specific abnormalities that have been identified.
In this new project, the team turns their attention to platelets. These cells are involved in blood coagulation, but also play important roles in the immune system, and may behave abnormally in ME/CFS.
Dr Annesley explains more:
“Platelets are cells that circulate in our bloodstream and become activated (or switched on) by viruses and other stressors. Most people know platelets for their role in blood clotting, but they’re also important for activating (or switching on) other cells in the immune system. In other conditions like multiple sclerosis, abnormal platelet activity is a key early event. We think abnormal platelet activity might also be happening in ME/CFS.
“Platelet activation uses a lot of energy. But unlike most cells, platelets don’t have DNA to help them control what proteins they produce. Instead, they rely heavily on microRNAs, which act like switches to turn protein production on or off. Some of these proteins are essential for generating the energy platelets need to do their job.
“Our early research has found that certain microRNAs are altered in people with ME/CFS –and some of these changes are in microRNAs that control the expression of proteins related to energy production and platelet function.
“In this new project, we’ll study blood samples from women with ME/CFS and compare them to healthy controls to look for differences in microRNA profiles. We’ll also test whether these changes in microRNAs can actually cause changes in platelet activity and energy production using cellular models.
“If our hypothesis is correct, it could open the door to new treatment possibilities – including therapies based on microRNAs, which are already being explored for other illnesses.”
Objectives
The team will recruit 30 participants from each of the following groups:
- women with ME/CFS who reported an onset following a suspected viral infection (excluding SARS-CoV-2),
- women with ME/CFS who developed ME/CFS following a SARS-CoV-2 infection, and
- age-matched healthy controls.
Blood samples will be collected from the participants, and then platelets isolated from these samples will be assessed for their microRNA signature (i.e. the combination and level of each of the microRNAs in the sample).
The team will also measure the expression of proteins extracted from these platelets, particularly those proteins involved in metabolism. This information will allow them to analyse what influence the microRNA signature has on metabolism and platelet activation.
Potential benefits
As well as improving our understanding of some of the mechanisms underlying the disease, the researchers hope that the identification of dysregulated microRNAs in platelets will lead the way to biomarkers for ME/CFS and the development of a diagnostic test.
These findings may also suggest new avenues for treatment, such as microRNA modulators, several of which are currently being trialled for some neurological conditions and cancers.
Dr Annesley explains more about the study in this video:
