Huang Yu-Yin, Peng Chi-Hsien, Yang Yi-Ping, Wu Chih-Chiau, Hsu Wen-Ming, Wang Hsiao-Jung, Chan Kwok-Han, Chou Yi-Pen, Chen Shih-Jen, Chang Yuh-Lih
Department of Anesthesiology, Taipei Veterans General Hospital and National Yang-Ming University, Taiwan.
J Pharmacol Sci. 2007 May;104(1):61-72. doi: 10.1254/jphs.fp0061255.
Desipramine (DP) is a tricyclic antidepressant used for treating depression and numerous other psychiatric disorders. Recent studies have shown that DP can promote neurogenesis and improve the survival rate of hippocampal neurons. However, whether DP induces neuroprotection or promotes the differentiation of neural stem cells (NSCs) needs to be elucidated. In this study, we cultured NSCs derived from the hippocampal tissues of adult rats as an in vitro model to evaluate the modulation effect of DP on NSCs. First, we demonstrated that the expression of Bcl-2 mRNA and nestin in 2 microM DP-treated NSCs were up-regulated and detected by real-time reverse transcriptase polymerase chain reaction (RT-PCR). The results of Western blotting and immunofluorescent study confirmed that Bcl-2 protein expression was significantly increased in Day 3 DP-treated NSCs. Using the Bcl-2 small interfering RNA (siRNA) method, our results further showed that DP protects the lipopolysaccharide (LPS)-induced apoptosis in NSCs, in part by activating the expression of Bcl-2. Furthermore, DP treatment significantly inhibited the induction of proinflammatory factor interleukin (IL)-1beta, IL-6, and tumor necrosis factor-alpha in the culture medium of LPS-treated NSCs mediated by Bcl-2 modulation. The results of high performance liquid chromatography coupled to electrochemical detection further confirmed that DP significantly increased the functional production of serotonin (26+/-3.5 microM, DP-treated 96 h) and noradrenaline (50+/-8.9 microM, DP-treated 96 h) in NSCs through activation of the MAPK/ERK pathway and partially mediated by Bcl-2. In conclusion, the present results indicate that DP can increase neuroprotection ability by inhibiting the LPS-induced inflammatory process in NSCs via the modulation of Bcl-2 expression, as confirmed by the siRNA method.
地昔帕明（DP）是一种三环类抗抑郁药，用于治疗抑郁症和许多其他精神疾病。最近的研究表明，DP可以促进神经发生并提高海马神经元的存活率。然而，DP是诱导神经保护还是促进神经干细胞（NSC）的分化尚需阐明。在本研究中，我们培养了源自成年大鼠海马组织的NSC作为体外模型，以评估DP对NSC的调节作用。首先，我们通过实时逆转录聚合酶链反应（RT-PCR）证明，在2 microM DP处理的NSC中，Bcl-2 mRNA和巢蛋白的表达上调。蛋白质印迹和免疫荧光研究结果证实，在第3天DP处理的NSC中，Bcl-2蛋白表达显著增加。使用Bcl-2小干扰RNA（siRNA）方法，我们的结果进一步表明，DP部分通过激活Bcl-2的表达来保护脂多糖（LPS）诱导的NSC凋亡。此外，DP处理显著抑制了由Bcl-2调节介导的LPS处理的NSC培养基中促炎因子白细胞介素（IL）-1β、IL-6和肿瘤坏死因子-α的诱导。高效液相色谱-电化学检测结果进一步证实，DP通过激活MAPK/ERK途径并部分由Bcl-2介导，显著增加了NSC中5-羟色胺（26±3.5 microM，DP处理96小时）和去甲肾上腺素（50±8.9 microM，DP处理96小时）的功能性产生。总之，本研究结果表明，如siRNA方法所证实，DP可通过调节Bcl-2表达来抑制LPS诱导的NSC炎症过程，从而提高神经保护能力。
