Potential Source for New Biomarkers in Sleep Disorders
A study just published in the journal PLOS One shows that there are circadian molecules in saliva that are disrupted in children with sleep disorders. These results advance our understanding of circadian rhythms and hold promise for advancing the diagnosis and treatment of sleep disorders among children.
The study measured levels of human microRNAs (miRNA) and microbial RNAs in the saliva of healthy children and adults on repeated days at specific time points. Sets of miRNA were identified that oscillate in circadian fashion and correlated with collection times. Some of the miRNAs that oscillated in a circadian fashion, termed CircaMiR, also correlated with circadian-oscillating microbial RNA, termed CircaMicrobes, as well as targeted genes that regulate circadian function and metabolism.
In contrast, measured levels of CircaMiRs and CircaMicrobes from children with sleep disorders did not correlate with the time of day when samples were taken.
Steven Hicks, MD, PhD.from Penn State Hershey and lead investigator said, "seeing shifts in the diurnal patterns of RNA expression in biofluids like saliva," said Hicks, "could have diagnostic potential in diseases with altered circadian rhythm and may one day provide a basis for targeted miRNA therapy of circadian disruptions."
Frank Middleton, PhD, noted that this suggests that use of peripheral miRNA expression as a biomarker of human disease could be greatly confounded by failing to account for time of collection.