RESUMEN
Ischemia-reperfusion (IR) is one of the significant medical problems in China. Triphenyltetrazolium chloride (TTC) staining is used to detect the status of the infarct size, and real-time PCR and western blotting are used to detect expressions of genes. TUNEL assay has been used to detect apoptosis. Using a tree shrew myocardial IR model, we found that in the reperfusion period, resina draconis (RD) treatment reduced the infarct size by TTC staining, and significantly enhanced the superoxide dismutase expression and down-regulated the malondialdehyde concentration in a dose-dependent manner. In hearts showing IR, Bax was increased and Bcl-2 was reduced, and RD treatment inhibited the IR-induced Bax expression and up-regulated the IR suppressed level of Bcl-2. TUNEL assay showed that IR induced the apoptosis of myocardial cells, and RD treatment suppressed the IR-induced apoptosis. CHOP and GRP78 were also upregulated in IR hearts, and RD treatment could significantly attenuate the CHOP and GRP78 levels compared with IR group. We further found that IR decreased the miR-423-3p expression and upregulated its target gene ERK both in mRNA and protein levels, and RD treatment upregulated miR-423-3p expression and downregulated ERK expression compared with the IR group. Importantly, miR-423-3p mimics inhibited IR increased ERK, CHOP and GRP78 expressions, and enhanced IR decreased Bcl-2 expression, and inhibited the IR-induced apoptosis of myocardial cells. The findings of this study suggest that RD treatment inhibited the endoplasmic reticulum induced apoptosis of myocardial cells via regulating miR-423-3p/ERK signaling pathway in a tree shrew myocardial IR model.
Asunto(s)
Cardiotónicos/farmacología , Dracaena/química , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Daño por Reperfusión Miocárdica/tratamiento farmacológico , Miocitos Cardíacos/efectos de los fármacos , Resinas de Plantas/farmacología , Animales , Apoptosis/efectos de los fármacos , Apoptosis/genética , Cardiotónicos/aislamiento & purificación , Modelos Animales de Enfermedad , Retículo Endoplásmico/efectos de los fármacos , Retículo Endoplásmico/genética , Retículo Endoplásmico/metabolismo , Estrés del Retículo Endoplásmico/efectos de los fármacos , Regulación de la Expresión Génica , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Masculino , Malondialdehído/antagonistas & inhibidores , Malondialdehído/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/genética , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Daño por Reperfusión Miocárdica/genética , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/patología , Miocardio/metabolismo , Miocardio/patología , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Resinas de Plantas/aislamiento & purificación , Superóxido Dismutasa/genética , Superóxido Dismutasa/metabolismo , Factor de Transcripción CHOP/genética , Factor de Transcripción CHOP/metabolismo , Tupaiidae , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismo , Proteína Letal Asociada a bcl/genética , Proteína Letal Asociada a bcl/metabolismoRESUMEN
OBJECTIVE: To establish an ex vivo model of myocardial ischemia reperfusion in tree shrews. METHODS: The Langendorff ex vivo heart perfusion system was used to establish the myocardial ischemia reperfusion model in tree shrews with different irrigation and reperfusion time settings. Alanine aminotransferase (ALT), aspartate transaminase (AST) and lactic dehydrogenase (LDH) levels were measured by enzyme-labeled immunosorbent assay, creatine kinase MB (CK-MB) was detected using immunosuppression method, and malondialdehyde was measured with thiobarbital staining method; the infarct size was measured using 2, 3, 5-triphenyltrazoliumchloride (TTC) method. RESULTS: Ischemia for 30 min and reperfusion for 30 and 60 min caused more significant increase in CK-MB and LDH levels in the perfusion fluid and also in the levels of ALT, CK-MB and AST in the myocardial tissue compared with other experimental settings (P<0.05), but these parameters were comparable between the former two settings (P>0.05). The mean heart rate in 30-min ischemia with 60-min reperfusion group was obviously lower than that in continuous reperfusion group, 15-min ischemia with 30-min reperfusion group and 30-min ischemia with 30-min reperfusion group (P<0.05), and the heart rate was similar between the latter 3 groups (P>0.05). ECG analysis showed that the mean heart rate in 30-min ischemia with 30-min reperfusion group was closer to the physiological heart rate of tree shrews. CONCLUSION: We successfully established an ex vivo myocardial ischemia reperfusion model using tree shrews, and ischemia for 30 min followed by reperfusion for 30 min is the optimal experimental setting.
