中国神经再生研究(英文版)

中国神经再生研究(英文版) ›› 2016, Vol. 11 ›› Issue (2): 319-325.doi: 10.4103/1673-5374.177741

• 原著:退行性病与再生 • 上一篇    下一篇

人参皂苷Rg1 对抗神经退变：诱导海马神经元突起生长

  

  • 收稿日期:2015-03-10 出版日期:2016-02-15 发布日期:2016-02-15

Ginsenoside Rg1 protects against neurodegeneration by inducing neurite outgrowth in cultured hippocampal neurons

Liang Huang, Li-feng Liu, Juan Liu, Ling Dou, Ge-ying Wang, Xiao-qing Liu, Qiong-lan Yuan   

  1. Department of Neurology, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, China
  • Received:2015-03-10 Online:2016-02-15 Published:2016-02-15
  • Contact: Qiong-lan Yuan, Ph.D.,yqiongl@tongji.edu.cn.

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摘要：

人参皂苷Rg1有抗衰老和抗神经退变作用，但其具体机制尚不完全清楚。为探讨此问题，实验将新生大鼠海马神经元培养24h后，加入人参皂苷Rg1合并或不合并Akt或MAPK信号通路抑制剂干预24h。进行生长相关蛋白43免疫组化染色，评估神经突起生长情况。将海马神经元暴露于淀粉样β蛋白25-35共30min后，加入人参皂苷Rg1合并或不合并Akt或MEK信号通路抑制剂干预48h，以Hoechst 33258染色评估神经元存活情况。同时应用western blot检测Erk1/2和Akt磷酸化水平。人参皂苷Rg1诱导培养的海马神经元突起生长，但这种作用被Akt和MEK抑制剂API-2和PD98059抑制，但不受p-38MAPK和JNK抑制剂SP600125和SB203580的影响。与这种作用一致的是，人参皂苷Rg1上调Erk1/2和Akt磷酸化水平，且该作用可被PD98059 和API-2逆转。Rg1明显抑制淀粉样β蛋白25-35诱导的海马神经元凋亡，该作用受API-2和PD98059抑制，但不受SP600125和SB203580影响。Rg1明显逆转淀粉样β蛋白25-35诱导的Akt和Erk1/2磷酸化水平的下降，但API-2抵消了该作用。这些实验结果表明，Rg1诱导海马神经元突起生长，拮抗淀粉样β蛋白25-35诱导的神经元损害，作用途径为激活了Akt 和Erk1/2通路。

关键词: 神经再生, 人参皂苷Rg1, 神经突生长, 淀粉样β蛋白25-35, Akt 和 MAPK信号通路, 海马神经元, 凋亡, 生长相关蛋白43, Hoechst33258染色, PD98059, API-2

Abstract:

Ginsenoside Rg1 (Rg1) has anti-aging and anti-neurodegenerative effects. However, the mechanisms underlying these actions remain unclear. The aim of the present study was to determine whether Rg1 affects hippocampal survival and neurite outgrowth in vitro after exposure to amyloid-beta peptide fragment 25–35 (Aβ25–35), and to explore whether the extracellular signal-regulated kinase (ERK) and Akt signaling pathways are involved in these biological processes. We cultured hippocampal neurons from newborn rats for 24 hours, then added Rg1 to the medium for another 24 hours, with or without pharmacological inhibitors of the mitogen-activated protein kinase (MAPK) family or Akt signaling pathways for a further 24 hours. We then immunostained the neurons for growth associated protein-43, and measured neurite length. In a separate experiment, we exposed cultured hippocampal neurons to Aβ25–35 for 30 minutes, before adding Rg1 for 48 hours, with or without Akt or MAPK inhibitors, and assessed neuronal survival using Hoechst 33258 staining, and phosphorylation of ERK1/2 and Akt by western blot analysis. Rg1 induced neurite outgrowth, and this effect was blocked by API-2 (Akt inhibitor) and PD98059 (MAPK/ERK kinase inhibitor), but not by SP600125 or SB203580 (inhibitors of c-Jun N-terminal kinase and p38 MAPK, respectively). Consistent with this effect, Rg1 upregulated the phosphorylation of Akt and ERK1/2; these effects were reversed by API-2 and PD98059, respectively. In addition, Rg1 significantly reversed Aβ25–35-induced apoptosis; this effect was blocked by API-2 and PD98059, but not by SP600125 or SB203580. Finally, Rg1 significantly reversed the Aβ25–35-induced decrease in Akt and ERK1/2 phosphorylation, but API-2 prevented this reversal. Our results indicate that Rg1 enhances neurite outgrowth and protects against Aβ25–35-induced damage, and that its mechanism may involve the activation of Akt and ERK1/2 signaling.

Key words: nerve regeneration, ginsenoside Rg1, neurite outgrowth, Aβ25–35, hippocampal neurons, Akt, MAPK, apoptosis, growth associated protein-43, Hoechst 33258 staining, PD98059, API-2, neural regeneration