Ginsenoside Rg1 (Rg1), a saponin extracted from Panax ginseng, has been well documented to be effective against ischemic/reperfusion (I/R) neuronal injury. However, the underlying mechanisms remain obscure. In the present study, we investigated the roles of Nrf2 and miR-144 in the protective effects of Rg1 against I/R-induced neuronal injury. In OGD/R-treated PC12 cells, Rg1 (0.01-1 μmol/L) dose-dependently attenuated the cell injury accompanied by prolonging nuclear accumulation of Nrf2, enhancing the transcriptional activity of Nrf2, as well as promoting the expression of ARE-target genes. The activation of the Nrf2/ARE pathway by Rg1 was independent of disassociation with Keap1, but resulted from post-translational regulations. Knockdown of Nrf2 abolished all the protective changes of Rg1 in OGD/R-treated PC12 cells. Furthermore, Rg1 treatment significantly decreased the expression of miR-144, which downregulated Nrf2 production by targeting its 3'-untranlated region after OGD/R. Knockdown of Nrf2 had no effect on the expression of miR-144, suggesting that miR-144 was an upstream regulator of Nrf2. We revealed that there was a direct binding between Nrf2 and miR-144 in PC12 cells. Application of anti-miR-144 occluded the activation of the Nrf2/ARE pathway by Rg1 in OGD/R-treated PC12 cells. In tMCAO rats, administration of Rg1 (20 mg/kg) significantly alleviated ischemic injury, and activated Nrf2/ARE pathway. The protective effects of Rg1 were abolished by injecting of AAV-HIF-miR-144-shRNA into the predicted ischemic penumbra. In conclusion, our results demonstrate that Rg1 alleviates oxidative stress after I/R through inhibiting miR-144 activity and subsequently promoting the Nrf2/ARE pathway at the post-translational level.

中文翻译：

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人参皂苷Rg1通过miR-144 / Nrf2 / ARE途径防止缺血/再灌注引起的神经元损伤。

人参皂苷Rg1（Rg1）是一种从人参提取的皂苷，已被充分证明对缺血/再灌注（I / R）神经元损伤有效。但是，基本机制仍然不清楚。在本研究中，我们调查了Nrf2和miR-144在Rg1对I / R诱导的神经元损伤的保护作用中的作用。在OGD / R处理的PC12细胞中，Rg1（0.01-1μmol/ L）剂量依赖性地减轻细胞损伤，同时延长Nrf2的核积累，增强Nrf2的转录活性，并促进ARE靶标的表达基因。Rg1对Nrf2 / ARE途径的激活与与Keap1的解离无关，但由翻译后调控引起。击倒Nrf2消除了OGD / R处理的PC12细胞中Rg1的所有保护性变化。此外，Rg1处理显着降低了miR-144的表达，miR-144通过靶向OGD / R后其3'-未分支区域而下调了Nrf2的产生。敲低Nrf2对miR-144的表达没有影响，表明miR-144是Nrf2的上游调节子。我们揭示了PC12细胞中Nrf2和miR-144之间存在直接结合。在OGD / R处理的PC12细胞中，抗​​miR-144的应用阻断了Rg1对Nrf2 / ARE途径的激活。在tMCAO大鼠中，给予Rg1（20 mg / kg）可以显着减轻缺血性损伤，并激活Nrf2 / ARE途径。通过将AAV-HIF-miR-144-shRNA注入预测的局部缺血半影中，可以消除Rg1的保护作用。综上所述，