A study of microRNAs from dried blood spots in newborns after perinatal asphyxia: a simple and feasible biosampling method

Abstract

BACKGROUND: The potential of microRNAs (miRNAs) as bedside biomarkers in selecting newborns with hypoxic-ischemic encephalopathy (HIE) for neuroprotection has yet to be explored. Commonly, blood-based biomarker tests use plasma or serum which don't allow evaluation of both intracellular and extracellular changes.METHODS: We describe a technique to extract and compare expression of miRNAs from a single small 6 mm diameter dried blood spot (DBS) stored at room temperature with those from EDTA-blood, plasma and urine. Three miRNAs (RNU6B, let7b and miR-21RNA) were quantified via extraction and quantitative RT-PCR performed from a DBS and compared with levels from EDTA-blood, plasma and urine. Secondarily, candidate miRNAs let7b, miR21, miR-29b, miR-124 and miR-155 in DBS were evaluated as potential biomarkers for HIE.RESULTS: Candidate miRNAs were extractable in all biosamples from newborns, with the highest expression in DBS. There was a good correlation between miRNAs levels in DBS and EDTA-blood at -80°C. No significant difference was observed in the miRNA levels between the favorable and unfavorable outcome groups for babies with HIE.CONCLUSIONS: Dried blood spots may be useful for studying the potential of miRNAs as biomarkers for brain injury.Pediatric Research (2015); doi:10.1038/pr.2015.276.</p