Summary: A new study finds that specific microRNAs in the blood change after prolonged sleep loss and psychological stress. These microRNA alterations can serve as biomarkers to predict individual cognitive performance following sleep deprivation.
Source: University of Pennsylvania
Researchers at the Perelman School of Medicine at the University of Pennsylvania report that microRNAs (miRNAs) circulating in blood may hold the key to predicting how a person’s thinking and attention are affected by sleep loss. Although prior research has linked insufficient sleep to higher risks of cancer, cardiovascular disease, and Alzheimer’s disease, as well as impaired cognition, people vary widely in how severely sleep deprivation affects them. The new study identifies blood miRNA signatures associated with total sleep deprivation and psychological stress that reliably predict individual differences in cognitive performance.
This investigation is the first to demonstrate that circulating miRNAs change after 39 hours of total sleep deprivation (TSD) and when sleep loss is combined with acute psychological stress, and that those changes correlate with real-time measures of cognitive function. The authors suggest these miRNA profiles could be used to identify people most vulnerable to the cognitive consequences of sleep loss and who could benefit from targeted interventions such as controlled naps, strategic caffeine use, or other countermeasures.
MiRNAs are short, non-coding RNA molecules that regulate gene expression by binding to target messenger RNAs and typically repressing their translation into proteins. Because miRNAs influence networks of genes, shifts in miRNA levels in blood can reflect broad physiological responses, including responses to sleep deprivation and stress.
The study (presentation #0012) was scheduled for SLEEP 2018, the 32nd Annual Meeting of the Associated Professional Sleep Societies LLC (APSS), held at the Baltimore Convention Center in early June.
Thirty-two healthy adult volunteers completed a controlled five-day laboratory protocol. The design included two baseline nights with 8 hours of sleep each, followed by a 39-hour period of continuous wakefulness (total sleep deprivation), and then two recovery nights allowing 8 to 10 hours of sleep. Throughout the protocol, researchers repeatedly measured attention, memory, and cognitive throughput—the speed and accuracy with which participants completed cognitive tasks—to track changes in performance over time.
Blood plasma samples were collected at six time points across the study timeline and analyzed for miRNA expression. When comparing samples taken before the study to those taken during sleep deprivation, the investigators found that 10 miRNAs changed in response to TSD alone, while 18 miRNAs showed altered expression when TSD was combined with psychological stress. These miRNA shifts matched periods of impaired cognitive function observed in the behavioral testing.
Importantly, baseline miRNA profiles—blood samples drawn before participants underwent sleep deprivation—predicted how individuals would perform when sleep deprived. Fourteen specific miRNAs were reliable predictors of attention performance during TSD, seven miRNAs predicted cognitive throughput, and ten miRNAs predicted memory performance. In other words, a person’s pre-existing circulating miRNA signature indicated their vulnerability to distinct types of cognitive decline under conditions of insufficient sleep and stress.
“These findings show for the first time that miRNAs can track responses to total sleep deprivation and its detrimental combination with psychological stress and predict robust individual differences in various types of cognitive performance,” said senior author Namni Goel, PhD, an associate professor of Psychology in Psychiatry. “As such, miRNAs are viable biomarkers of sleep deprivation, psychological stress, and cognitive vulnerability in humans and can be used to identify individuals ahead of time who are in need of countermeasures or interventions such as caffeine or naps to mitigate or prevent impairments associated with insufficient sleep.”
Study details: Controlled laboratory experiment with 32 healthy adults, two baseline nights, 39 hours of total sleep deprivation, repeated cognitive testing and six blood draws for plasma miRNA analysis. The research linked specific circulating miRNA changes to attention, memory, and cognitive throughput impairments during sleep loss and stress.
Funding: Supported by NASA (NNX14AN49G).
Source: Gregory Richter — University of Pennsylvania
Publisher: Organized by NeuroscienceNews.com
Image source: NeuroscienceNews.com image in the public domain
Original research: Findings presented at SLEEP 2018.
This study highlights the potential of blood-based miRNA signatures as predictive, minimally invasive biomarkers for cognitive vulnerability to sleep deprivation and stress. Further research will be needed to validate these markers in larger and more diverse populations, to determine their stability over time, and to develop practical screening tools that could guide personalized countermeasures to protect performance in situations that demand sustained attention, such as shift work, medical practice, transportation, and military operations.