A Pilot Study of Salivary MicroRNA Changes Due to High G-Load

Area of Science:

• Aerospace Medicine
• Biomarkers
• Physiology

Background:

• High G-load poses risks to flight safety, necessitating understanding of physiological responses.
• Salivary microRNAs (miRNAs) are potential biomarkers for physiological changes.
• Previous studies on concussion suggest miRNAs' relevance in neurological responses.

Purpose of the Study:

• To establish a methodology for detecting salivary miRNAs in humans before and after high G-load exposure.
• To investigate the relationship between salivary miRNA levels and high G-load or G-induced loss of consciousness (G-LOC).

Main Methods:

• 25 healthy pilot trainees provided saliva samples pre- and post-centrifuge training.
• Reverse transcription-quantitative polymerase chain reaction analyzed four specific miRNAs (miR-107, miR-34a-5p, miR-27a-5p, miR-30a-3p).
• Samples were collected at three time points: pre-training, 3 hours post-training, and 20 hours post-training.

Main Results:

• Salivary miRNAs were successfully analyzed in 84% (21/25) of subjects.
• miR-107 levels were significantly lower 20 hours post-training compared to 3 hours post-training.
• miR-34a-5p levels at 3 hours post-training were significantly different between subjects who experienced G-LOC and those who did not.

Conclusions:

• Saliva is a viable source for detecting miRNA changes following high G-load exposure.
• Reverse transcription-quantitative polymerase chain reaction can detect these salivary miRNA alterations.
• Salivary miRNAs show potential as biomarkers for G-load effects and G-LOC.