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Expression of microRNA-122 contributes to apoptosis in H9C2 myocytes

Xiaoyan Huang1, Fang Huang, Deye Yang

  • 1Division of Cardiology, The First Affiliated Hospital of Wenzhou Medical College, Wenzhou, China.

Journal of Cellular and Molecular Medicine
|March 29, 2012
PubMed

Insights

MicroRNAs regulate gene expression and heart development. This study found miR-122 is up-regulated in Pax-8 knockout mice, contributing to cardiac apoptosis and heart defects.

Area of Science:

  • Molecular Biology
  • Developmental Biology
  • Cardiovascular Biology

Background:

  • MicroRNAs (miRNAs) are key regulators of gene expression and crucial for heart development.
  • Pax-8 gene knockout mice exhibit significant cardiac abnormalities, suggesting a role for Pax-8 in heart formation.

Purpose of the Study:

  • To investigate the role of miRNAs in regulating cardiac apoptosis and development in Pax-8 knockout mice.
  • To identify specific miRNAs involved in the pathogenesis of heart defects associated with Pax-8 deficiency.

Main Methods:

  • Differential miRNA expression profiling using microarrays in Pax-8(-/-) and Pax-8(+/-) mice.
  • Validation of miRNA expression by real-time quantitative PCR.
  • Assessment of cardiac morphology, apoptosis, and cellular changes in knockout mice and in vitro myocyte models.

Main Results:

  • MicroRNA microarrays revealed differential miRNA expression between Pax-8(-/-) and Pax-8(+/-) mice.
  • miR-122 was significantly upregulated (1.92-fold) in Pax-8(-/-) mice.
  • Pax-8(-/-) mice displayed ventricular septum defects and increased apoptosis in the left ventricular wall and interventricular septum.

Conclusions:

  • miR-122 is upregulated in the myocytes of Pax-8 knockout mice.
  • Upregulated miR-122 may contribute to apoptotic gene expression and the development of heart defects in Pax-8 deficient mice.
  • These findings highlight a novel role for miR-122 in Pax-8-mediated cardiac development and pathogenesis.

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