Ischemic postconditioning attenuates the inflammatory response in ischemia/reperfusion myocardium by upregulating miR499 and inhibiting TLR2 activation.
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.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Daño por Reperfusión Miocárdica
/
Regulación hacia Arriba
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MicroARNs
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Receptor Toll-Like 2
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Poscondicionamiento Isquémico
Límite:
Animals
Idioma:
En
Revista:
Mol Med Rep
Año:
2020
Tipo del documento:
Article
Pais de publicación:
Grecia