Araya Juan A, Ramírez Alejandra E, Figueroa-Aroca Daniela, Sotes Gastón J, Pérez Claudia, Becerra Jose, Saez-Orellana Francisco, Guzmán Leonardo, Aguayo Luis G, Fuentealba Jorge
Laboratorio de Screening de Compuestos Neuroactivos, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile.
Laboratorio de Química de Productos Naturales, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile.
J Alzheimers Dis. 2014;42(1):143-55. doi: 10.3233/JAD-132045.
Alzheimer's disease (AD) is a progressive and neurodegenerative disorder and one of the current therapies involves strengthening the cholinergic tone in central synapses. Neuroprotective properties for nicotine have been described in AD, through its actions on nicotinic receptors and the further activation of the PI3K/Akt/Bcl-2 survival pathway. We have tested a quinolizidine alkaloid extract (TM0112) obtained from Teline monspessulanna (L.) K. Koch seeds to evaluate its action on nicotinic acetylcholine receptor (nAChR) in a neuronal AD model. Our data show that PC-12 cells pretreated with amyloid-β (Aβ) peptide for 24 h in presence of TM0112 modified Aβ-reduction on cellular viability (Aβ = 80 ± 3%; +TM0112 = 113 ± 4%, n = 15). In addition, this effect was blocked with atropine, MLA, and α-BTX (+TM0112+atropine = 87 ± 4%; +TM0112+MLA = 86 ± 4%; +TM0112+α-BTX = 92 ± 3%). Furthermore, similar protective effects were observed in rat cortical neurons (Aβ = 63 ± 6%; +TM0112 = 114 ± 8%), but not in HEK293T cells (Aβ = 61.4 ± 6.1%; +TM0112 = 62.8 ± 5.2) that do not express α7 nAChR. Moreover, the frequency of synaptic activity in the neuronal network (Aβ = 51.6 ± 16.9%; +TM0112 = 210.8 ± 47.9%, n > 10), as well as the intracellular Ca2+ transients were recovered by TM0112 (Aβ = 61.4 ± 6.9%; +TM0112 = 112.0 ± 5.7%; n = 3) in rat hippocampal neurons. TM0112 increased P-Akt, up to 250% with respect to control, and elevated Bcl-2/Bax percentage (Aβ = 61.0 ± 8.2%; +TM0112 = 105.4 ± 19.5%, n = 4), suggesting a coupling between nAChR activation and an intracellular neuroprotective pathway. Our results suggest that TM0112 could be a new potential source for anti-AD drugs.
阿尔茨海默病（AD）是一种进行性神经退行性疾病，目前的治疗方法之一是增强中枢突触中的胆碱能张力。尼古丁对AD具有神经保护作用，这是通过其对烟碱受体的作用以及PI3K/Akt/Bcl-2生存途径的进一步激活来实现的。我们测试了从蒙氏岩黄芪（Teline monspessulanna (L.) K. Koch）种子中提取的喹嗪类生物碱提取物（TM0112），以评估其在神经元AD模型中对烟碱型乙酰胆碱受体（nAChR）的作用。我们的数据表明，在存在TM0112的情况下，用淀粉样β蛋白（Aβ）肽预处理24小时的PC-12细胞，其细胞活力的Aβ降低得到改善（Aβ = 80 ± 3%；+TM0112 = 113 ± 4%，n = 15）。此外，阿托品、甲基牛扁亭（MLA）和α-银环蛇毒素可阻断这种作用（+TM0112+阿托品 = 87 ± 4%；+TM0112+MLA = 86 ± 4%；+TM0112+α-银环蛇毒素 = 92 ± 3%）。此外，在大鼠皮质神经元中也观察到了类似的保护作用（Aβ = 63 ± 6%；+TM0112 = 114 ± 8%），但在不表达α7 nAChR的HEK293T细胞中未观察到（Aβ = 61.4 ± 6.1%；+TM0112 = 62.8 ± 5.2）。此外，TM0112恢复了神经元网络中的突触活动频率（Aβ = 51.6 ± 16.9%；+TM0112 = 210.8 ± 47.9%，n > 10），以及大鼠海马神经元中的细胞内Ca2+瞬变（Aβ = 61.4 ± 6.9%；+TM0112 = 112.0 ± 5.7%；n = 3）。TM0112使磷酸化Akt增加，相对于对照组增加了250%，并提高了Bcl-2/Bax百分比（Aβ = 61.0 ± 8.2%；+TM0112 = 105.4 ± 19.5%，n = 4），表明nAChR激活与细胞内神经保护途径之间存在耦合。我们的结果表明，TM0112可能是抗AD药物的一个新的潜在来源。
