Accumulating evidence indicates that neurotrophic factor-like substances involved in the induction of neurotrophic factor synthesis may aid in the treatment of neurological disorders, such as Alzheimer's disease. Yokukansan (YKS), a traditional Kampo medicine, has been used for the treatment of anxiety and mood disorders. In the present study, we aimed to identify the signaling pathways associated with YKS-mediated enhancement of nerve growth factor (NGF)-induced neurite extension in rat pheochromocytoma (PC12) cells. Akt and extracellular-regulated kinase 1/2 (ERK1/2) phosphorylation levels were assessed by western blot analysis, in the presence of YKS and following the treatment with TrkA inhibitor, K252a. YKS treatment (NGF+YKS 0.5 group) enhanced NGF-induced neurite outgrowth and phosphorylation/activation of Akt and ERK1/2 in PC12 cells. Moreover, YKS-induced effects were inhibited by the treatment with the TrkA receptor antagonist K252a (NGF+YKS 0.5+K252a group); no significant difference in neurite outgrowth was observed between K252a-treated (NGF+YKS 0.5+K252a group) and NGF-K252a-treated cells (NGF+K252a group). However, neurite outgrowth in K252a-treated cells (NGF+K252a and NGF+YKS 0.5+K252a group) reached only one-third of the level in NGF-treated cells (NGF group). NGF-mediated Akt phosphorylation increased by YKS was also inhibited by K252a treatment (NGF+YKS 0.5+K252a group), but no significant difference in ERK1/2 phosphorylation was observed between NGF-YKS-K252a- and NGF-treated cells (NGF group). Our results indicate that YKS treatment enhanced NGF-induced neurite outgrowth via induction of Akt and ERK1/2 phosphorylation, following the binding of NGF to the TrkA receptor. These findings may be useful in the development of novel therapeutic strategies for the treatment of Alzheimer's disease.

中文翻译：

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汉方药Yokukansan（YKS）增强了PC12细胞中神经生长因子（NGF）诱导的神经突增生。

越来越多的证据表明，与神经营养因子合成诱导有关的类神经营养因子物质可能有助于治疗神经系统疾病，例如阿尔茨海默氏病。传统的汉方药物“四海山”（Yokukansan，YKS）已用于治疗焦虑症和情绪障碍。在本研究中，我们旨在确定与YKS介导的大鼠嗜铬细胞瘤（PC12）细胞中神经生长因子（NGF）诱导的神经突延伸相关的信号传导途径。在YKS存在下和用TrkA抑制剂K252a处理后，通过蛋白质印迹分析评估了Akt和细胞外调节的激酶1/2（ERK1 / 2）磷酸化水平。YKS处理（NGF + YKS 0.5组）增强了PC12细胞中NGF诱导的神经突增生以及Akt和ERK1 / 2的磷酸化/激活。此外，用TrkA受体拮抗剂K252a（NGF + YKS 0.5 + K252a组）治疗可抑制YKS诱导的作用。在经K252a处理的细胞（NGF + YKS 0.5 + K252a组）和经过NGF-K252a处理的细胞（NGF + K252a组）之间，未观察到神经突生长的显着差异。但是，在经过K252a处理的细胞（NGF + K252a和NGF + YKS 0.5 + K252a组）中神经突生长仅达到经过NGF处理的细胞（NGF组）中神经突的生长。K252a处理（NGF + YKS 0.5 + K252a组）也抑制了由YKS增加的NGF介导的Akt磷酸化（NGF + YKS 0.5 + K252a组），但在NGF-YKS-K252a处理的细胞和NGF处理的细胞（NGF组）之间未观察到ERK1 / 2磷酸化的显着差异。 ）。我们的结果表明，YKS治疗通过诱导Akt和ERK1 / 2磷酸化增强NGF诱导的神经突增生，NGF与TrkA受体结合后。这些发现可能在开发新的治疗阿尔茨海默氏病的治疗策略中有用。