miR-208b Reduces the Expression of Kcnj5 in a Cardiomyocyte Cell Line
Julia Hupfeld,
Maximilian Ernst,
Maria Knyrim,
Stephanie Binas,
Udo Kloeckner,
Sindy Rabe,
Katja Quarch,
Danny Misiak,
Matthew Fuszard,
Claudia Grossmann,
Michael Gekle,
Barbara Schreier
Affiliations
Julia Hupfeld
Julius-Bernstein Institute of Physiology, Medical Faculty of the Martin Luther University Halle-Wittenberg, 06112 Halle (Saale), Germany
Maximilian Ernst
Julius-Bernstein Institute of Physiology, Medical Faculty of the Martin Luther University Halle-Wittenberg, 06112 Halle (Saale), Germany
Maria Knyrim
Julius-Bernstein Institute of Physiology, Medical Faculty of the Martin Luther University Halle-Wittenberg, 06112 Halle (Saale), Germany
Stephanie Binas
Julius-Bernstein Institute of Physiology, Medical Faculty of the Martin Luther University Halle-Wittenberg, 06112 Halle (Saale), Germany
Udo Kloeckner
Julius-Bernstein Institute of Physiology, Medical Faculty of the Martin Luther University Halle-Wittenberg, 06112 Halle (Saale), Germany
Sindy Rabe
Julius-Bernstein Institute of Physiology, Medical Faculty of the Martin Luther University Halle-Wittenberg, 06112 Halle (Saale), Germany
Katja Quarch
Julius-Bernstein Institute of Physiology, Medical Faculty of the Martin Luther University Halle-Wittenberg, 06112 Halle (Saale), Germany
Danny Misiak
Institute of Molecular Medicine, Medical Faculty of the Martin Luther University Halle-Wittenberg, Charles Tanford Protein Center, 06120 Halle (Saale), Germany
Matthew Fuszard
Zentrum für Medizinische Grundlagenforschung, Core Facility—Proteomic Mass Spectrometry, Proteinzentrum Charles Tanford, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany
Claudia Grossmann
Julius-Bernstein Institute of Physiology, Medical Faculty of the Martin Luther University Halle-Wittenberg, 06112 Halle (Saale), Germany
Michael Gekle
Julius-Bernstein Institute of Physiology, Medical Faculty of the Martin Luther University Halle-Wittenberg, 06112 Halle (Saale), Germany
Barbara Schreier
Julius-Bernstein Institute of Physiology, Medical Faculty of the Martin Luther University Halle-Wittenberg, 06112 Halle (Saale), Germany
MicroRNAs (miRs) contribute to different aspects of cardiovascular pathology, among them cardiac hypertrophy and atrial fibrillation. Cardiac miR expression was analyzed in a mouse model with structural and electrical remodeling. Next-generation sequencing revealed that miR-208b-3p was ~25-fold upregulated. Therefore, the aim of our study was to evaluate the impact of miR-208b on cardiac protein expression. First, an undirected approach comparing whole RNA sequencing data to miR-walk 2.0 miR-208b 3′-UTR targets revealed 58 potential targets of miR-208b being regulated. We were able to show that miR-208b mimics bind to the 3′ untranslated region (UTR) of voltage-gated calcium channel subunit alpha1 C and Kcnj5, two predicted targets of miR-208b. Additionally, we demonstrated that miR-208b mimics reduce GIRK1/4 channel-dependent thallium ion flux in HL-1 cells. In a second undirected approach we performed mass spectrometry to identify the potential targets of miR-208b. We identified 40 potential targets by comparison to miR-walk 2.0 3′-UTR, 5′-UTR and CDS targets. Among those targets, Rock2 and Ran were upregulated in Western blots of HL-1 cells by miR-208b mimics. In summary, miR-208b targets the mRNAs of proteins involved in the generation of cardiac excitation and propagation, as well as of proteins involved in RNA translocation (Ran) and cardiac hypertrophic response (Rock2).
