title: [MicroRNA-21 protects cardiomyocytes from tumor necrosis factor-α induced apoptosis in vitro via modulating PTEN/AKT/FOXO3a pathway].
abstract: OBJECTIVE
  To explore the effect of microRNA-21 on tumor necrosis factor (TNF)-α induced cardiomyocytes apoptosis and the association with PTEN/AKT/FOXO3a signaling pathway.
  
  
  METHODS
  Neonatal cardiomyocytes were isolated and cultured in vitro. Cardiomyocytes apoptosis was induced by TNF-α (10 ng/ml for 24 h) and examined by the cardiomyocytes apoptotic index. Eukaryotic expression vector for lenti-microRNA-21 was established and then transferred into the cardiomyocytes. MicroRNA-21 and PTEN mRNA were examined by qRT-PCR. Intracellular signal molecules, such as the expression of PTEN, phosphorylated PTEN, AKT, phosphorylated AKT (pAKTser473, pAKTThr308), FOXO3a, phosphorylated FOXO3a and FasL were detected by Western blot.
  
  
  RESULTS
  MicroRNA-21 reduced TNF-α induced cardiomyocytes apoptosis [(23.42 ± 1.98)% vs. (78.37 ± 2.03)%, P < 0.05]. TNF-α downregulated the expression of microRNA-21 and upregulated the mRNA and protein expressions of PTEN. Phosphorylation of PTEN, AKT and FOXO3a was enhanced in cardiomyocytes transfected with lenti-microRNA-21 (P < 0.05). TNF-α also significantly activated the phosphorylation of PTEN, AKT and FOXO3a (P < 0.05). Compared with cardiomyocytes treated with TNF-α (10 ng/ml), the phosphorylation of PTEN, AKT and FOXO3a as well as expression of pPTEN, pAKTser473, pFOXO3a and FasL were significantly suppressed in cardiomyocytes treated with lenti-microRNA-21 and TNF-α (P < 0.05). Total AKT and FOXO3a were similar among all groups (P > 0.05).
  
  
  CONCLUSIONS
  MicroRNA-21 could protect cardiomyocytes from TNF-α- induced apoptosis through PTEN/AKT/FOXO3a pathway, which might serve as a new therapy option for various cardiovascular diseases in the future.
authors.affiliation: Department of Cardiology, First Affiliated Hospital of Nanchang University, Medical College of Nanchang University, Nanchang 330006, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Tang
authors.forename: Meng-hong
authors.initials: MH
authors.lastname: Wang
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects; D002478:Cells, Cultured; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors / Q000378:metabolism; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000473:pathology; D051059:PTEN Phosphohydrolase / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: C499515:FOXO3 protein, rat; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors; D035683:MicroRNAs; D014409:Tumor Necrosis Factor-alpha; C546082:mirn21 microRNA, rat; D051057:Proto-Oncogene Proteins c-akt; D051059:PTEN Phosphohydrolase; C487216:Pten protein, rat