MicroRNA-1 and microRNA-133 repress the spontaneous myocardial differentiation of mouse embryonic stem cells

MicroRNA-1 and microRNA-133 repress the spontaneous myocardial differentiation of mouse embryonic stem cells

Tomohide Takaya1, Koh Ono2, Teruhisa Kawamura1, Rieko Takanabe1, Shinji Kaichi3, Tatsuya Morimoto1, Hiromichi Wada1, Toru Kita2, Akira Shimatsu1, Koji Hasegawa1.

  1. Division of Translational Research, Kyoto Medical Center, National Hospital Organization, Kyoto, Japan.
  2. Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
  3. Department of Pediatrics, Graduate School of Medicine, Kyoto University, Kyoto, Japan.

The 17th Asian Pacific Congress of Cardiology (Kyoto, Japan), 2009/05/21 (Poster).

Abstract

MicroRNAs (miRNAs) are a class of 17-25 nt non-coding small RNAs that mediate post-transcriptional gene repression by inhibiting protein translations or destabilizing RNA transcripts of the target genes. This mechanism play essential roles in various biological processes including the self-renewal and differentiation of embryonic stem (ES) cells. miRNA-1 (miR-1) and miRNA-133 (miR-133) are abundantly expressed in the adult heart and involved in cardiac hypertrophy. We investigated the role of these miRNAs in spontaneous myocardial differentiation of ES cells. The expression levels of miR-1 and miR-133 in mouse ES cells were increased during spontaneous differentiation by 2-dimensional culture but reduced during forced myocardial differentiation by trichostatin A, a histone deacetylase inhibitor. The overexpression of miR-1 or miR-133 in ES cells by lentiviral infection reduced the expression of cardiac-specific genes such as Nkx2.5, atrial natriuretic factor (ANF), and α-myosin heavy chain (α-MHC), during the differentiation of ES cells. The results of luciferase assays revealed that miR-1 recognizes and targets the 3' untranslated region (UTR) of cyclin-dependent kinase-9 (Cdk9) in ES cells. Cdk9 has pivotal role in myocardial differentiation of ES cells by forming transcriptional complex with p300/GATA4. Thus, miR-1 may have repressive function in myocardial differentiation of ES cells, in part, through inhibiting the translation of Cdk9.