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Ischemic postconditioning attenuates the inflammatory response in ischemia/reperfusion myocardium by upregulating miR­499 and inhibiting TLR2 activation.
Zhang, Xin-Yue; Huang, Zheng; Li, Qing-Jie; Zhong, Guo-Qiang; Meng, Jian-Jun; Wang, Dong-Xiao; Tu, Rong-Hui.
Afiliación
  • Zhang XY; Department of Cardiology, First Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.
  • Huang Z; Department of Cardiology, First Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.
  • Li QJ; Department of Cardiology, Second Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.
  • Zhong GQ; Department of Cardiology, First Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.
  • Meng JJ; Department of Geriatric Health Care Center, First Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.
  • Wang DX; Department of Cardiology, First Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.
  • Tu RH; Guangxi Key Laboratory of Precision Medicine in Cardio­Cerebrovascular Diseases Control and Prevention, Nanning, Guangxi 530021, P.R. China.
Mol Med Rep ; 22(1): 209-218, 2020 07.
Article en En | MEDLINE | ID: mdl-32377693
Toll-like receptor 2 (TLR2)-mediated myocardial inflammation serves an important role in promoting myocardial ischemic/reperfusion (I/R) injury. Previous studies have shown that miR­499 is critical for cardioprotection after ischemic postconditioning (IPostC). Therefore, the present study evaluated the protective effect of IPostC on the myocardium by inhibiting TLR2, and also assessed the involvement of microRNA (miR)­499. Rat hearts were subjected to 30 min of ischemia and 2 h of reperfusion. The IPostC was 3 cycles of 30 sec of reperfusion and 30 sec of re­occlusion prior to reperfusion. In total, 90 rats were randomly divided into six groups (n=15 per group): Sham; I/R; IPostC; miR­499 negative control adeno­associated virus (AAV) vectors + IPostC; miR­499 inhibitor AAV vectors + IPostC; and miR­499 mimic AAV vectors + IPostC. It was identified that IPostC significantly decreased the I/R­induced cardiomyocyte apoptotic index (29.4±2.03% in IPostC vs. 42.64±2.27% in I/R; P<0.05) and myocardial infarct size (48.53±2.49% in IPostC vs. 66.52±3.1% in I/R; P<0.05). Moreover, these beneficial effects were accompanied by increased miR­499 expression levels (as demonstrated by reverse transcription­quantitative PCR) in the myocardial tissue and decreased TLR2, protein kinase C (PKC), interleukin (IL)­1ß and IL­6 expression levels (as demonstrated by western blotting and ELISA) in the myocardium and serum. The results indicated that IPostC + miR­499 mimics significantly inhibited inflammation and the PKC signaling pathway and enhanced the anti­inflammatory and anti­apoptotic effects of IPostC. However, IPostC + miR­499 inhibitors had the opposite effect. Therefore, it was speculated that IPostC may have a miR­499­dependent cardioprotective effect. The present results suggested that miR­499 may be involved in IPostC­mediated ischemic cardioprotection, which may occur via local and systemic TLR2 inhibition, subsequent inhibition of the PKC signaling pathway and a decrease in inflammatory cytokine release, including IL­1ß and IL­6. Moreover, these effects will ultimately lead to a decrease in the myocardial apoptotic index and myocardial infarct size via the induction of the anti­apoptotic protein Bcl­2, and inhibition of the pro­apoptotic protein Bax in myocardium.
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Daño por Reperfusión Miocárdica / Regulación hacia Arriba / MicroARNs / Receptor Toll-Like 2 / Poscondicionamiento Isquémico Límite: Animals Idioma: En Revista: Mol Med Rep Año: 2020 Tipo del documento: Article Pais de publicación: Grecia

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Daño por Reperfusión Miocárdica / Regulación hacia Arriba / MicroARNs / Receptor Toll-Like 2 / Poscondicionamiento Isquémico Límite: Animals Idioma: En Revista: Mol Med Rep Año: 2020 Tipo del documento: Article Pais de publicación: Grecia