MicroRNA-101 inhibited postinfarct cardiac fibrosis and improved left ventricular compliance via the FBJ osteosarcoma oncogene/transforming growth factor-β1 pathway

Circulation. 2012 Aug 14;126(7):840-50. doi: 10.1161/CIRCULATIONAHA.112.094524. Epub 2012 Jul 18.

Abstract

Background: Cardiac interstitial fibrosis is a major cause of the deteriorated performance of the heart in patients with chronic myocardial infarction. MicroRNAs (miRs) have recently been proven to be a novel class of regulators of cardiovascular diseases, including those associated with cardiac fibrosis. This study aimed to explore the role of miR-101 in cardiac fibrosis and the underlying mechanisms.

Methods and results: Four weeks after coronary artery ligation of rats, the expression of miR-101a and miR-101b (miR-101a/b) in the peri-infarct area was decreased. Treatment of cultured rat neonatal cardiac fibroblasts with angiotensin II also suppressed the expression of miR-101a/b. Forced expression of miR-101a/b suppressed the proliferation and collagen production in rat neonatal cardiac fibroblasts, as revealed by cell counting, MTT assay, and quantitative reverse transcription-polymerase chain reaction. The effect was abrogated by cotransfection with AMO-101a/b, the antisense inhibitors of miR-101a/b. c-Fos was found to be a target of miR-101a because overexpression of miR-101a decreased the protein and mRNA levels of c-Fos and its downstream protein transforming growth factor-β1. Silencing c-Fos by siRNA mimicked the antifibrotic action of miR-101a, whereas forced expression of c-Fos protein canceled the effect of miR-101a in cultured cardiac fibroblasts. Strikingly, echocardiography and hemodynamic measurements indicated remarkable improvement of the cardiac performance 4 weeks after adenovirus-mediated overexpression of miR-101a in rats with chronic myocardial infarction. Furthermore, the interstitial fibrosis was alleviated and the expression of c-Fos and transforming growth factor-β1 was inhibited.

Conclusion: Overexpression of miR-101a can mitigate interstitial fibrosis and the deterioration of cardiac performance in postinfarct rats, indicating the therapeutic potential of miR-101a for cardiac disease associated with fibrosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiotensin II / pharmacology
  • Animals
  • Animals, Newborn
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Chronic Disease
  • Collagen / biosynthesis
  • Compliance / drug effects
  • Compliance / physiology
  • Echocardiography
  • Fibroblasts / metabolism
  • Fibrosis
  • Gene Silencing
  • Hemodynamics
  • Male
  • Mice
  • Mice, Inbred C57BL
  • MicroRNAs / genetics
  • MicroRNAs / therapeutic use*
  • Myocardial Infarction / drug therapy*
  • Myocardium / pathology*
  • Proto-Oncogene Proteins c-fos / biosynthesis
  • Proto-Oncogene Proteins c-fos / physiology*
  • Rats
  • Rats, Sprague-Dawley
  • Transforming Growth Factor beta1 / physiology*
  • Treatment Outcome
  • Vasoconstrictor Agents / pharmacology
  • Ventricular Dysfunction, Left / drug therapy*

Substances

  • Fosb protein, rat
  • MIRN101 microRNA, rat
  • MicroRNAs
  • Proto-Oncogene Proteins c-fos
  • Transforming Growth Factor beta1
  • Vasoconstrictor Agents
  • Angiotensin II
  • Collagen