BACKGROUND: MicroRNAs (miRNAs), the negative regulators of cellular mRNAs, are present in mature red blood cells (RBCs) in abundance relative to other blood cells. So far, there are no studies aimed at identifying large-scale miRNA profiles during storage of RBCs.

STUDY DESIGN AND METHODS: RNA samples from each RBC bag stored at 4°C were collected on Days 0, 20, and 40 and subjected to miRNA profiling by using a membrane-based array. Fifty-two selected miRNAs of cellular apoptotic pathway represent the array. Through bioinformatics analyses, we identified potential target genes for selected miRNAs.

RESULTS: Differential profiling of RBCs for 52 miRNAs revealed two distinguishable patterns during storage: Forty-eight miRNAs demonstrated no trend at all, while four miRNAs, miR-96, miR-150, miR-196a, and miR-197, demonstrated an increase up to Day 20 and subsequently decreased during storage. We selected miR-96 and subjected it to standard bioinformatics analyses for target gene predictions, which identified several mRNAs including the RBC proapoptotic calpain small subunit-1 (CAPNS1) as potential targets of miR-96. To validate these predictions, we selected CAPNS1 mRNA as an example and confirmed its presence in the RBCs. Future experimental verification would help define miR-96–CAPNS1 interaction, if any, in the stored RBCs.

CONCLUSIONS: This study for the first time provided a differential profile of stored RBCs for selected miRNAs related to cellular apoptotic pathway and opened new avenues toward identification of novel in vitro RBC biomarkers of storage lesions. Future studies focusing on target gene-miRNA interactions in stored RBCs would also unravel underlying mechanisms of storage lesions.