Germacrone is an anti-inflammatory ingredient in the Chinese medicine zedoary turmeric. The purpose of this study was to explore the protective mechanism of germacrone against PC12 cells injury caused by oxygen-glucose deprivation/reperfusion (OGD/R). OGD/R injury model of PC12 cells was established by using OGD/R (2 h/24 h). The cell viability was assessed by MTT assay and LDH release. The ultrastructure of cells was observed by transmission electron microscopy (TEM). The expression of autophagy related proteins in cells was determined by Western Blot. The results of ultrastructural observation showed that PC12 cells damaged by OGD/R showed typical autophagy characteristics. In addition, OGD/R observably up-regulated the expression of autophagy related proteins: the class III type phosphoinositide 3-kinase (PI3K III), light chain 3(LC3), and Beclin-1 in PC12 cells, and inhibited the expression of the class I type phosphoinositide 3-kinase (PI3K I), Protein kinase B (Akt), the mammalian target of rapamycin (mTOR), and B-cell lymphoma 2(Bcl-2) proteins. Furthermore, germacrone increased the cell viability of OGD/R-damaged PC12 cells by down-regulating the expression of LC3 protein in cells in a concentration-dependent manner. More importantly, germacrone significantly inhibited the expression of PI3K III, LC3, and Beclin-1 in OGD/R-injured PC12 cells, and up-regulated the expressionof PI3K I, Akt, mTOR, and Bcl-2 proteins in cells, and this inhibited or up-regulated effect was reversed by PI3K I inhibitor (ZSTK474). The above results indicated that germacrone could inhibit the autophagy effect in OGD/R injury model of PC12 cells, the mechanism of inhibition was regulated by PI3K III/Beclin-1/Bcl-2 and PI3K I/Akt/mTOR pathways, thereby improving the cell viability of PC12 cells and playing a neuroprotective role, which provided a new drug for the treatment of OGD/R.

中文翻译：

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Germacrone可通过抑制PC12细胞中的自噬过程来防止氧葡萄糖剥夺/再灌注损伤。

Germacrone是中药姜黄中的消炎成分。这项研究的目的是探讨胚芽酮对氧-葡萄糖剥夺/再灌注（OGD / R）引起的PC12细胞损伤的保护机制。用OGD / R（2 h / 24 h）建立PC12细胞的OGD / R损伤模型。通过MTT测定和LDH释放评估细胞活力。通过透射电子显微镜（TEM）观察细胞的超微结构。通过Western Blot确定细胞中自噬相关蛋白的表达。超微结构观察结果表明，OGD / R损伤的PC12细胞具有典型的自噬特性。此外，OGD / R明显上调自噬相关蛋白的表达：III类磷酸肌醇3激酶（PI3K III），轻链3（LC3），和Beclin-1在PC12细胞中，并抑制I类磷酸肌醇3激酶（PI3K I），蛋白激酶B（Akt），雷帕霉素的哺乳动物靶标（mTOR）和B细胞淋巴瘤2（Bcl）的表达-2）蛋白。此外，胚芽酮通过以浓度依赖性方式下调细胞中LC3蛋白的表达来增加OGD / R损伤的PC12细胞的细胞活力。更重要的是，胚芽酮显着抑制OGD / R损伤的PC12细胞中PI3K III，LC3和Beclin-1的表达，并上调细胞中PI3K I，Akt，mTOR和Bcl-2蛋白的表达，因此PI3K I抑制剂（ZSTK474）可以逆转抑制或上调的抑制作用。以上结果表明胚芽酮可以抑制PC12细胞OGD / R损伤模型的自噬作用，