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Updated: May 12, 2026
Visualization of Cell Cycle Variations and Determination of Nucleation in Postnatal Cardiomyocytes
Published on: February 24, 2017
MicroRNA profiling during rat ventricular maturation: A role for miR-29a in regulating cardiomyocyte cell cycle
Xiaoqing Cao1, Jue Wang, Zhenhua Wang
1State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100037, China.
Abstract:
Recent studies demonstrated that the mammalian heart possesses some capacity to proliferate. We observed cardiomyocyte proliferation within 4 weeks of age (P4W) in rats. We found 95 microRNAs that are differentially expressed in P4W cardiomyocytes. MicroRNA-29a was among the most highly up-regulated microRNAs in P4W cardiomyocytes. Overexpression of microRNA-29a suppressed the proliferation of H9c2 cell line. MicroRNA-29a inhibition induced cardiomyocytes to proliferate, accelerated the G1/S and G2/M transition, and up-regulated the cell cycle gene expression. Cyclin D2 (CCND2) was identified as a direct target of microRNA-29a. These findings indicate that microRNA-29a is involved in cardiomyocyte proliferation during postnatal development.
Insights
The mammalian heart can regenerate. MicroRNA-29a, a small RNA molecule, was found to regulate cardiomyocyte proliferation in developing rat hearts, impacting cell cycle progression.
Area of Science:
- Cardiovascular Biology
- Molecular Cardiology
- Developmental Biology
Background:
- Mammalian heart regeneration capacity is limited but present.
- Cardiomyocyte proliferation occurs in postnatal development.
- MicroRNAs (miRNAs) are key regulators of gene expression.
Purpose of the Study:
- To investigate the role of microRNAs in postnatal cardiomyocyte proliferation.
- To identify specific miRNAs involved in regulating cardiomyocyte cell cycle.
- To elucidate the molecular mechanisms underlying miRNA-mediated control of cardiomyocyte proliferation.
Main Methods:
- Differential expression analysis of microRNAs in postnatal day 4 week (P4W) rat cardiomyocytes.
- Functional studies using H9c2 cell line to assess the impact of microRNA-29a.
- Validation of microRNA-29a targets using molecular biology techniques.
Main Results:
- 95 differentially expressed microRNAs were identified in P4W cardiomyocytes.
- MicroRNA-29a was significantly upregulated in P4W cardiomyocytes.
- MicroRNA-29a overexpression inhibited proliferation, while its inhibition promoted proliferation and cell cycle transition by targeting Cyclin D2 (CCND2).
Conclusions:
- MicroRNA-29a acts as a negative regulator of cardiomyocyte proliferation during postnatal development.
- MicroRNA-29a influences cardiomyocyte cell cycle progression, targeting CCND2.
- These findings highlight the therapeutic potential of targeting microRNA-29a for cardiac repair.
