Seven microRNAs that circulate in the blood may serve as biomarkers that help clinicians to diagnose Friedreich’s ataxia, according to results of a recent study.
High levels of one of these molecules, called miR-323-3p, also has the potential to identify those patients with disease-associated cardiomyopathy (heart failure), the researchers report.
Their study, titled “Circulating miR-323-3p is a biomarker for cardiomyopathy and an indicator of phenotypic variability in Friedreich’s ataxia patients,” was published in the journal Scientific Reports.
microRNAs are tiny RNA molecules that work by regulating protein production. They bind to an mRNA molecule (a transcript of the DNA coding information required to make a protein) to block the production of a given protein. One microRNA can bind to many different mRNA molecules, which make microRNAs powerful regulators of gene expression and protein production.
microRNAs are produced within cells, but some are released into fluids such as the blood. Because these molecules are highly resistant to degradation, circulating microRNAs can be ideal candidates in the search for biomarkers that help to identify certain diseases.
Using blood samples and modern sequencing techniques, researchers identified a group of 164 miRNAs that were differently expressed (different levels of activity) in 25 Caucasians with Friedreich’s ataxia — including eight patients (32 percent) who also had also cardiomyopathy — compared to 17 healthy controls.
Of these miRs with an altered expression between patient and control groups, seven had higher expression levels in patients. These molecules were called miR-128-3p, miR-625-3p, miR-130b-5p, miR-151a-5p, miR-330-3p, miR-323a-3p, and miR-142-3p.
Further analysis showed that miR-323a-3p was significantly higher in the eight FA patients with cardiomyopathy compared to other patients. Indeed, researchers observed a strong association between high miR-323a-3p levels and cardiomyopathy.
“Our results open new avenues for developing more personalized therapies focused on specific patients’ symptoms,” the researchers wrote. “We identified seven miRNAs, all of which are associated with key molecular mechanisms underlying FRDA [Friedreich’s ataxia] physiopathology. We found that miR-323-3p is a candidate for diagnosing cardiomyopathy in FRDA patients.”
“To maximize the likelihood of detecting the onset or progression of cardiomyopathy, we suggest combining standard cardiac diagnostic procedures with the use of circulating microRNAs,” they added. “This approach could provide more clinical information for evaluating cardiomyopathy progression in FRDA.”