Abstract
Aim: Since RAP1B is critical for platelet functions, including hemostasis, this study was conducted to identify RAP1B regulating microRNAs (miRNAs) in ex vivo stored platelets.
Background: Previous studies with platelets identified factors affecting RAP1B activity but regulatory miRNAs that affect RAP1B protein expression have not been reported.
Objective: To understand the functional significance of miRNA mediated regulation of RAP1B in stored platelets, using microRNA, miR-181a as an example.
Methods: A Tagged RNA Affinity approach (MS2-TRAP) was employed to identify miRNAs that bound to the 3` untranslated region (3`UTR) of the RAP1B mRNA in HeLa cells as an assay system. And subsequently, the mRNA 3’UTR:miRNA interactions were verified in platelets through the ectopic expression of miR-181a mimic and appropriate controls. The interaction of such miRNAs with RAP1B mRNA was also validated by qRT-PCR and Western analysis.
Results: Sixty-two miRNAs from MS2 assay were then compared with already known 171 platelet abundant miRNAs to identify a common set of miRNAs. This analysis yielded six miRNAs (miR- 30e, miR-155, miR-181a, miR-206, miR-208a and miR-454), which are also predicted to target RAP1B mRNA. From this pool, miR-181a was selected for further study since RAP1B harbors two binding sites for miR-181a in its 3′UTR. Ectopic expression of miR-181a mimic in platelets resulted in lowering the endogenous RAP1B at both mRNA and protein levels. Further, miR-181a ectopic expression reduced the surface expression of the platelet activation marker, P-selectin.
Conclusion: MicroRNA-181a can target RAP1B and this interaction has the potential to regulate platelet activation during storage.
Keywords: microRNA, miR-181a, MS2-TRAP, platelet activation, platelets, RAP1B.
Graphical Abstract
[http://dx.doi.org/10.1172/JCI77993] [PMID: 25705885]
[http://dx.doi.org/10.1007/s00109-015-1346-3] [PMID: 26423530]
[http://dx.doi.org/10.1182/blood-2009-04-218768] [PMID: 19628710]
[http://dx.doi.org/10.1172/JCI22973] [PMID: 15696195]
[http://dx.doi.org/10.1182/blood-2005-07-3023] [PMID: 16357324]
[http://dx.doi.org/10.1111/j.1538-7836.2009.03289.x] [PMID: 19192113]
[http://dx.doi.org/10.1371/journal.pone.0145689] [PMID: 26714318]
[http://dx.doi.org/10.1182/blood-2018-03-838714] [PMID: 30131434]
[http://dx.doi.org/10.1074/jbc.M202212200] [PMID: 11970953]
[http://dx.doi.org/10.1155/2012/412089] [PMID: 22745904]
[http://dx.doi.org/10.1074/jbc.M111.239608] [PMID: 21940635]
[http://dx.doi.org/10.2174/2211536607666180521094532] [PMID: 29779489]
[http://dx.doi.org/10.1182/blood-2010-09-299719] [PMID: 21415270]
[http://dx.doi.org/10.1073/pnas.0510928103] [PMID: 16495412]
[http://dx.doi.org/10.1016/j.cell.2009.01.002] [PMID: 19167326]
[http://dx.doi.org/10.1016/j.tcb.2015.07.011] [PMID: 26437588]
[http://dx.doi.org/10.1016/j.ymeth.2012.07.004] [PMID: 22813890]
[http://dx.doi.org/10.1038/nsmb.1651] [PMID: 19668211]
[http://dx.doi.org/10.1080/09537104.2016.1203405] [PMID: 27561077]
[http://dx.doi.org/10.3109/09537104.2011.560305] [PMID: 21438667]
[http://dx.doi.org/10.1371/journal.pone.0050746] [PMID: 23226537]
[http://dx.doi.org/10.1186/1758-907X-1-11] [PMID: 20459656]
[http://dx.doi.org/10.1073/pnas.1630797100] [PMID: 12902540]
[http://dx.doi.org/10.1161/01.CIR.102.16.1931] [PMID: 11034941]