%0 Journal Article
%T microRNA-1 inhibits cardiomyocyte proliferation in mouse neonatal hearts by repressing CCND1 expression
%A Gan, Jingyi
%A Tang, Florence Mei Kuen
%A Su, Xianwei
%A Lu, Gang
%A Xu, Jing
%A Lee, Henry Siu Sum
%A Lee, Kenneth Ka Ho
%J Annals of Translational Medicine
%D 2019
%B 2019
%9 
%! microRNA-1 inhibits cardiomyocyte proliferation in mouse neonatal hearts by repressing CCND1 expression
%K 
%X Background: The functions of microRNA-1 (miR-1) in cardiac hypertrophy, and cardiomyocyte differentiation have been investigated. However, the mechanism on how miR-1 could repress cardiomyocyte proliferation has not been fully elucidated.  Methods: We address this issue by investigating whether miR-1 affected the proliferation of neonatal cardiomyocyte and identify some of the genes targeted by miR-1. miR-1 was over-expressed in neonatal cardiomyocytes and the effect on cell cycle and growth were analyzed by flow cytometry and Brdu-incorporation assay. Relevant vectors carrying the luciferase reporter were constructed for validation of miR-1 binding to its matching sites on the 3’-untranslated region of the predicated target mRNAs. Cardiomyocytes were co-transfected with the vectors and miR-1 mimics, then luciferase reporter assay was performed. Lastly, we examined the expression of target genes in cardiomyocytes after transfection with miR-1 mimics, as well as their normal expression pattern in 2- and 13-day-old mice hearts.  Results: We have demonstrated that miR-1 was the most significantly upregulated miRNA in 13-day-old mouse hearts compared with 2-day-old hearts. We also showed that miR-1 could repress cardiomyocyte G1/S phase transition, proliferation and viability. IGF1 and CCND1 were identified as candidate target genes regulated by miR-1. In addition, overexpression of miR-1 could suppress the expression of these two genes at the mRNA level. It could also correspondingly inhibit CCND1 expression at the protein level but not for IGF1.  Conclusions: Our results suggest that miR-1 plays an important role in inhibiting cardiomyocyte proliferation in the developing neonatal mouse heart by directly suppressing the cell-cycle regulator, CCND1.
%U https://atm.amegroups.org/article/view/29263
%V 7
%N 18
%P 455
%@ 2305-5847