Potential Use of miRNAs as Platelet Biomarkers of Storage.

MicroRNAs (miRNAs) are a class of small endogenous noncoding regulatory RNAs, which control cellular gene expression in eukaryotes at post-transcriptional level. MicroRNAs have been shown to play a role in cell differentiation and apoptosis by down regulating the translation of their target mRNAs. Differential expression profiles of miRNAs often help in identifying specific miRNAs as biomarkers of interest to a variety of cellular states, such as cancer. One of the key cellular components of blood that is of interest to transfusion medicine to control bleeding is ‘platelet concentrates (PCs)’. Platelets are stored at room temperature (22 ⁰C) for up to 5 days for transfusion and during storage platelets undergo physiological changes often termed as storage lesions that adversely affect their survival in vivo following transfusion. Therefore identifying markers that truly reflect the cellular status at any given time during storage would help in developing efficacy biomarkers for stored platelets. Since mature platelets do not have a nucleus, but they do contain numerous mRNAs and undergo translational regulation, we hypothesized that miRNAs as translational regulators could play a crucial role in platelet biology and therefore may serve as biomarkers of platelets during storage. In this study, we explored differential miRNA profiling of 52-apoptosis-associated miRNAs of platelets using PCs obtained from the National Institutes of Health (NIH) blood bank and were stored at room temperature (22 ⁰C) for up to 9 days. Samples were collected at day 0, day 2, and day 9. Out of 52 miRNAs analyzed by microarray, we observed that while two miRNAs levels had increased, another two miRNA levels decreased drastically from day 0 to day 9 (Table 1).

The differential microarray analysis presented here clearly suggests that miRNAs certainly have the potential to be useful as biomarkers of platelets during storage. Further analysis of the targets of these miRNAs in platelets will help understand the underlying mechanisms of platelet lesions.

The findings and conclusions in this abstract have not been formally disseminated by the Food and Drug Administration and should not be construed to represent any Agency determination or policy.