Institute of Basic Medical Sciences, Guangzhou Higher Education Mega Center, Guangdong Pharmaceutical University, 280 Wai Huan Dong Road, Guangzhou 510006, China.
Neurochem Res. 2012 Dec;37(12):2787-94. doi: 10.1007/s11064-012-0872-4. Epub 2012 Sep 5.
Protein kinase C (PKC) signaling pathway is recognized as an important molecular mechanism of Alzheimer's disease (AD) in the regulation of neuronal plasticity and survival. Genistein, the most active molecule of soy isoflavones, exerts neuroprotective roles in AD. However, the detailed mechanism has not been fully understood yet. The present study aimed to investigate whether the neuroprotective effects of genistein against amyloid β (Aβ)-induced toxicity in cultured rat pheochromocytoma (PC12) cells is involved in PKC signaling pathway. PC12 cells were pretreated with genistein for 2 h following incubation with Aβ(25-35) for additional 24 h. Cell viability was assessed by MTT. Hoechst33342/PI staining was applied to determine the apoptotic cells. PKC activity, intracellular calcium level and caspase-3 activity were analyzed by assay kits. The results showed that pretreatment with genistein significantly increased cell viability and PKC activity, decreased the levels of intracellular calcium, attenuated Hoechst/PI staining and blocked caspase-3 activity in Aβ(25-35)-treated PC12 cells. Pretreatment of Myr, a general PKC inhibitor, significantly attenuated the neuroprotective effect of genistein against Aβ(25-35)-treated PC12 cells. The present study indicates that PKC signaling pathway is involved in the neuroprotective action of genistein against Aβ(25-35)-induced toxicity in PC12 cells.
蛋白激酶 C（PKC）信号通路被认为是调节神经元可塑性和存活的阿尔茨海默病（AD）的重要分子机制。大豆异黄酮中最活跃的分子染料木黄酮在 AD 中发挥神经保护作用。然而，其详细的机制尚未完全了解。本研究旨在探讨染料木黄酮对培养的大鼠嗜铬细胞瘤（PC12）细胞中淀粉样β（Aβ）诱导的毒性的神经保护作用是否涉及 PKC 信号通路。PC12 细胞先用染料木黄酮预处理 2 h，然后再用 Aβ（25-35）孵育 24 h。通过 MTT 评估细胞活力。采用 Hoechst33342/PI 染色法检测凋亡细胞。通过试剂盒分析 PKC 活性、细胞内钙水平和 caspase-3 活性。结果表明，染料木黄酮预处理可显著提高细胞活力和 PKC 活性，降低细胞内钙水平，减轻 Hoechst/PI 染色，并阻断 Aβ（25-35）处理的 PC12 细胞中 caspase-3 的活性。PKC 的通用抑制剂 Myr 预处理可显著减弱染料木黄酮对 Aβ（25-35）处理的 PC12 细胞的神经保护作用。本研究表明，PKC 信号通路参与了染料木黄酮对 Aβ（25-35）诱导的 PC12 细胞毒性的神经保护作用。
