Plasma microRNAs as Biomarkers for Mild Brain Injury

Plasma microRNA could serve as biomarkers for the detection and diagnosis of mild traumatic brain injury, a recent study from the University of Eastern Finland (UEF) has found.

Mild traumatic brain injury is extremely difficult to detect as it is almost invisible to most imaging techniques, and visible signs in daily life may be masked by compensation for increased task difficulty.

Blood biomarkers can satisfy the demand for timely, accurate, easily accessible and affordable tests for mild traumatic brain injury. They are minimally invasive and can provide molecular information about the injury on an ongoing basis.

MicroRNAs (miRNAs) are non-coding sections of RNA that play a key role in gene expression. The researchers sequenced DNA in blood plasma taken from animal models subjected to mild and severe traumatic brain injury. They selected the miRNAs which showed the greatest potential for use as biomarkers for further analysis with polymerase chain reaction (PCR). They wanted biomarkers that were both sensitive and specific to traumatic brain injury in an animal model.

Dr Noora Puhakka, A. Virtanen Institute for Molecular Sciences, UEF, said, “We have been developing a suitable analysis and measurement method especially for miRNAs that can be found in small amounts in plasma, and this method is based on digital droplet PCR.

“Humans and animals share many identical miRNAs, and this makes them excellent candidates for translational studies, where results achieved in animal models are sought to be applied in humans. However, it has proven challenging to reproduce results from different studies and different sets of data. This is why assessing the quality of measurement methods, and reproducibility, is an extremely important part of biomarker research.”
The study a pair of possible biomarker candidates to diagnose mild traumatic brain injury both in the animal model and in human patients.  

“We found two interesting biomarkers in the animal model, the plasma miRNAs miR-9a-3p and miR-136-3p, which we then decided to analyse in blood samples taken from patients with traumatic brain injury. Elevated levels of these biomarkers allowed us to identify some of the patients who had experienced a mild traumatic brain injury,” Dr Puhakka explained.

“Both of these miRNAs are more abundant in the brain than in other tissues, and their elevated levels in plasma could possibly be due to brain injury and the level of its seriousness. However, further research in larger patient cohorts is still needed.”

Source: News-Medical.Net

Journal information: Gupta, S. D., et al. (2021) Plasma miR-9-3p and miR-136-3p as Potential Novel Diagnostic Biomarkers for Experimental and Human Mild Traumatic Brain Injury. International Journal of Molecular Sciences. doi.org/10.3390/ijms22041563.