miR-570 interacts with mitochondrial ATPase subunit g (ATP5L) encoding mRNA in stored platelets

Abstract

Loss of platelet quality during ex vivo storage is a major concern in the transfusion medicine field and it has been known that platelet mitochondrial dysfunction is associated with storage time. In the last decade, small noncoding RNAs also known as microRNAs (miRNAs) have been reported to regulate key cellular processes through their target sequence interactions with selected mRNAs. In this study, we focused on understanding the mechanisms of platelet mitochondrial dysfunction during storage through miRNA regulation of mRNAs. RNA was isolated from day 0, day 5, and day 9 of stored human leukocyte-depleted platelets and subjected to differential miRNA and mRNA profiling. The miRNA profiling identified several miRNAs at low levels including a set of 12 different miR-548 family members (miR-548a-3p, miR-548aa, miR-548x, miR-548ac, miR-548c-3p, miR-603, miR-548aj, miR-548ae, miR-548z, miR-548u, miR-548al, and miR-570-3p). The mRNA profiling identified, among many, the mitochondrial ATP synthase subunit g (ATP5L) mRNA at high levels during storage. Target Scan algorithm for potential targets of miR-570-3p also identified ATP5L as one of its targets. We further identified two target sites for miR-570-3p in the 3′ untranslated region (3′UTR) of ATP5L mRNA. While ATP5L is a subunit of F₀ATPase complex, its function is not established yet. Overexpression of miR-570-3p in platelets resulted in reduced levels of ATP5L mRNA and concomitant ATP loss. These experimental results provide first-time insights into the miRNA–mRNA interactions underlying mitochondrial dysfunction in ex vivo stored platelets and warrants further investigation.

Keywords:

• ATP5L
• microarray
• microRNA
• platelets
• storage lesion

Acknowledgments

We thank Dr. Valerie W. Hu from the Department of Biochemistry and Molecular Biology, The George Washington University School of Medicine and Health Sciences, for allowing us to use the Ingenuity Pathway Analysis software.

Declaration of interest

The authors report no conflicts of interest.

Funding

Chintamani D. Atreya received funding for this study from the Center for Biologics Evaluation and Research (CBER), U.S. Food and Drug Administration. Neetu Dahiya and Tewarit Sarachana are recipients of a postdoctoral fellowship at the Center for Biologics Evaluation and Research administered by the Oak Ridge Institute for Science and Education through an interagency agreement between the U.S. Department of Energy and the U.S. Food and Drug Administration. The collaborative work performed by the coauthors Kevin G. Becker, William H. Wood, and Yongqing Zhang at the National Institute on Aging, NIH, was supported by their Intramural Research Program.