AUTHOR=Rysenkova Karina D. , Troyanovskiy Konstantin E. , Klimovich Polina S. , Bulyakova Taisiya R. , Shelomentseva Ekaterina M. , Shmakova Anna A. , Tanygina Daria Yu. , Ivashkina Olga I. , Anokhin Konstantin V. , Karagyaur Maxim N. , Zvereva Maria I. , Rubina Kseniya A. , Tkachuk Vsevolod A. , Semina Ekaterina V. 

TITLE=Identification of a Novel Small RNA Encoded in the Mouse Urokinase Receptor uPAR Gene (Plaur) and Its Molecular Target Mef2d

JOURNAL=Frontiers in Molecular Neuroscience

VOLUME=15

YEAR=2022

URL=https://www.frontiersin.org/journals/molecular-neuroscience/articles/10.3389/fnmol.2022.865858

DOI=10.3389/fnmol.2022.865858

ISSN=1662-5099

ABSTRACT=<p>Urokinase receptor (uPAR) is a glycosylphosphatidylinositol (GPI)-anchored receptor of urokinase (uPA), which is involved in brain development, nerve regeneration, wound healing and tissue remodeling. We have recently shown that <italic>Plaur</italic>, which encodes uPAR, is an early response gene in murine brain. Assumingly, diverse functions of <italic>Plaur</italic> might be attributed to hypothetical, unidentified microRNAs encoded within introns of the <italic>Plaur</italic> gene. Using a bioinformatic approach we identified novel small RNAs within the <italic>Plaur</italic> gene and named them Plaur-miR1-3p and Plaur-miR1-5p. We confirmed <italic>Plaur</italic>-dependent expression of Plaur-miR1-3p and Plaur-miR1-5p in the mouse brain and mouse neuroblastoma Neuro2a cells. Utilizing an <italic>in silico MR-microT</italic> algorithm in DianaTools we selected two target genes – <italic>Mef2d</italic> and <italic>Emx2</italic> with the highest binding scores to small RNAs selected from identified Plaur-Pre-miR1. Furthermore, sequencing of mouse brain samples for Plaur-miR1-5p target genes revealed two more genes—<italic>Nrip3</italic> and <italic>Snrnp200</italic>. The expression of <italic>Emx2, Mef2d</italic>, and <italic>Snrnp200</italic> in the mouse brain and <italic>Mef2d</italic> and <italic>Snrnp200</italic> in Neuro2a cells correlated with expression of <italic>Plaur</italic> and small RNAs—Plaur-miR1-3p and Plaur-miR1-5p. Finally, we demonstrated elevated MEF2D protein expression in the mouse brain after <italic>Plaur</italic> induction and displayed activating effects of Plaur-miR1-5p on <italic>Mef2d</italic> expression in Neuro2a cells using Luciferase reporter assay. In conclusion, we have identified Plaur-miR1-3p and Plaur-miR1-5p as novel small RNAs encoded in the <italic>Plaur</italic> gene. This finding expands the current understanding of <italic>Plaur</italic> function in brain development and functioning.</p>