title: Up-regulation of microRNA-135a protects against myocardial ischemia/reperfusion injury by decreasing TXNIP expression in diabetic mice.
abstract: OBJECTIVE
  The heart in diabetic state is sensitive to myocardial ischemia reperfusion (mI/R) injury. In the present study, we investigated the potential mechanisms of modulating mI/R injury in diabetic state.
  
  
  METHODS
  Diabetic db/db mice and control non-diabetic mice were administrated with mI/R injury or sham operation. Mouse atrial-derived cardiac cell line HL-1 subjected to hypoxia-reoxygenation (H/R) was used as in vitro model of I/R injury to the heart.
  
  
  RESULTS
  Compared with normal mice, mI/R elevated the levels of myocardial infarct size, apoptosis and TXNIP expression (in mRNA and protein) in diabetic mice. Myocardial miR-135a expression level was reduced in diabetic mice regardless of mI/R treatment or not. MiR-135a overexpression protected myocardial cells from mI/R injury in diabetic mice. In vitro, high glucose incubation contributed to a significant down-regulation of miR-135a and up-regulation of TXNIP in cells with or without H/R treatment. Luciferase reporter assay showed that TXNIP was a target gene of miR-135a. MiR-135a overexpression protected HL-1 cells from H/R injury in high glucose condition, while this effect was reversed by up-regulated TXNIP.
  
  
  CONCLUSIONS
  miR-135a protects against mI/R injury by decreasing TXNIP expression in diabetic state.
authors.affiliation: Department of Cardiology, Anhui Provincial Hospital Affiliated to Anhui Medical University Hefei 230001, China.
authors.forename: Hong-Jun
authors.initials: HJ
authors.lastname: Zhu
authors.affiliation: Department of Gerontology, Yijishan Hospital of Wannan Medical College Wuhu 241001, China.
authors.forename: De-Guo
authors.initials: DG
authors.lastname: Wang
authors.affiliation: Department of Cardiology, Anhui Provincial Hospital Affiliated to Anhui Medical University Hefei 230001, China.
authors.forename: Ji
authors.initials: J
authors.lastname: Yan
authors.affiliation: Department of Cardiology, Anhui Provincial Hospital Affiliated to Anhui Medical University Hefei 230001, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Xu
keywords: Myocardial ischemia/reperfusion injury; TXNIP; diabetes; miR-135a; myocardial infarction