阿茲海默症(AD)是最常見的神經退化性疾病之一，導致記憶和其他認知上功能的障礙。目前的研究認為是β類澱粉蛋白斑塊(Aβ)的累積和神經元纖維的糾結，這兩個因素與突觸的損壞及神經死亡有關。又在阿茲海默症中Aβ會誘導不正常的麩胺酸神經傳遞，進而過度刺激突觸上的麩胺酸受體如AMPAR, NMDAR, Kainate receptor和mGluR1/ 3/5，最後導致細胞產生興奮性毒性而使神經元死亡。美金剛(Memantine)，為N-甲基-D-天冬氨酸(NMDA)受體拮抗劑，已被使用於治療中度至重度阿茲海默病人，更深化了這項觀點。我們研究旨在篩選能改善Aβ誘導病理性神經傳遞之中草藥。利用出生後1-3天小鼠腦中分離培養初級皮質神經元，以免疫螢光染色及西方點墨法觀察之後具有如vGLUT1/ 2, AMPAR, NMDAR, PSD95, type III tubulin等麩胺酸神經元和神經元連結的特殊標記。又將這些神經與一種對膜電位改變敏感稱之為DiBAC4(3)的藥劑處理，經過β類澱粉蛋白胺基酸1-42的寡聚形式刺激後，發現可以偵測到這些神經元去極化的現象。利用這個平台，我們在16種中草藥單方的萃取物中發現6種能有效地減緩Aβ誘導的異常去極化現象，暫時命名其中兩種中草藥為P1029和P1033。我們進一步在這單方中找到有效的純物質，暫時命名為P1033-BE，且找出其對初級培養神經細胞存活率的IC50濃度，再利用麩胺酸接受器的致效劑與抑制劑後，我們更發現P1033-BE可能透過NMDAR及AMPAR來降低Aβ所誘導的神經不正常去及化現象，目前P1033-BE對Aβ在分子機制上如訊息傳導路徑分子的機制研究正在進行中。此研究期望最終能使P1033-BE成為臨床上治療阿茲海默患者的藥物。

Alzheimer’s disease (AD), one of the most common neurodegenerative diseases, leads to memory impairment and other cognitive problems. The two pathological hallmarks of AD are accumulation of β-amyloid (Aβ) plaques and neurofibrillary tangles, by which they associate with synapse loss and neuronal death. Recent studies have indicated that Aβ-induced glutamate neurotransmission may play a crucial role in AD. A rise in glutamate could result in over-stimulating synaptic glutamate receptors such as AMPAR, NMDAR, Kainate receptor, and mGluR1/3/5, and subsequently cause neuronal cell death. The clinical use of memantine, an uncompetitive N-methyl-D-aspartate (NMDA) antagonist, strengthens this opinion. In this study, we screened Chinese herbal medicines/herbal extracts for ameliorating the Aβ-induced pathophysiological neurotransmission. We established the primary culture of cortical neurons isolated from postnatal 1-3 days mice. These neurons have been characterized by markers of glutamatergic neurons and neuronal networks such as vGLUT1/2, AMPAR, NMDAR, PSD95, type III tubulin. After stimulating by oligomeric forms of Aβ 1-42, these neurons depolarize, indicating by a slow response voltage sensitive dye DiBAC4(3). Utilizing this platform, we found 6 out of 16 herbal extracts which are effective to alleviate Aβ-induced abnormal depolarization and temporarily named two of them P1029 and P1033. We also eventually found a pure compound, P1033-BE, is capable to block Aβ-induced abnormal depolarization. Using agonists and antagonists of glutamatergic receptors, we dissect that the effect of P1033-BE could mediate through NMDAR and AMPAR. The molecular mechanisms of this effective pure compound on which pathways are being explored. Hopefully, we will make this ultimately become clinical drugs to treat AD patients.

Berchtold NC, Cotman CW (1998) Evolution in the conceptualization of dementia and Alzheimer's disease: Greco-Roman period to the 1960s. Neurobiol Aging 19:173-189.
Blanchard BJ, Chen A, Rozeboom LM, Stafford KA, Weigele P, Ingram VM (2004) Efficient reversal of Alzheimer's disease fibril formation and elimination of neurotoxicity by a small molecule. Proc Natl Acad Sci U S A 101:14326-14332.
Blurton-Jones M, Laferla FM (2006) Pathways by which Abeta facilitates tau pathology. Curr Alzheimer Res 3:437-448.
Brewer GJ, Torricelli JR (2007) Isolation and culture of adult neurons and neurospheres. Nat Protoc 2:1490-1498.
Butterfield DA, Pocernich CB (2003) The glutamatergic system and Alzheimer's disease: therapeutic implications. CNS Drugs 17:641-652.
Chen X, Yan SD (2006) Mitochondrial Abeta: a potential cause of metabolic dysfunction in Alzheimer's disease. IUBMB life 58:686-694.
Crimins JL, Pooler A, Polydoro M, Luebke JI, Spires-Jones TL (2013) The intersection of amyloid beta and tau in glutamatergic synaptic dysfunction and collapse in Alzheimer's disease. Ageing Res Rev 12:757-763.
De Felice FG, Velasco PT, Lambert MP, Viola K, Fernandez SJ, Ferreira ST, Klein WL (2007) Abeta oligomers induce neuronal oxidative stress through an N-methyl-D-aspartate receptor-dependent mechanism that is blocked by the Alzheimer drug memantine. J Biol Chem 282:11590-11601.
Dineley KT, Bell KA, Bui D, Sweatt JD (2002) beta -Amyloid peptide activates alpha 7 nicotinic acetylcholine receptors expressed in Xenopus oocytes. J Biol Chem 277:25056-25061.
Esposito Z, Belli L, Toniolo S, Sancesario G, Bianconi C, Martorana A (2013) Amyloid beta, glutamate, excitotoxicity in Alzheimer's disease: are we on the right track? CNS Neurosci Ther 19:549-555.
Fa M, Orozco IJ, Francis YI, Saeed F, Gong Y, Arancio O (2010) Preparation of oligomeric beta-amyloid 1-42 and induction of synaptic plasticity impairment on hippocampal slices. J Vis Exp.
Fong S, Shoemaker M, Cadaoas J, Lo A, Liao W, Tagliaferri M, Cohen I, Shtivelman E (2008) Molecular mechanisms underlying selective cytotoxic activity of BZL101, an extract of Scutellaria barbata, towards breast cancer cells. Cancer Biol Ther 7:577-586.
Forstl H, Kurz A (1999) Clinical features of Alzheimer's disease. Eur Arch Psychiatry Clin Neurosci 249:288-290.
Fremeau RT, Jr., Troyer MD, Pahner I, Nygaard GO, Tran CH, Reimer RJ, Bellocchio EE, Fortin D, Storm-Mathisen J, Edwards RH (2001) The expression of vesicular glutamate transporters defines two classes of excitatory synapse. Neuron 31:247-260.
Goedert M, Klug A, Crowther RA (2006) Tau protein, the paired helical filament and Alzheimer's disease. J Alzheimers Dis 9:195-207.
Harvey RJ, Skelton-Robinson M, Rossor MN (2003) The prevalence and causes of dementia in people under the age of 65 years. J Neurol Neurosurg Psychiatry 74:1206-1209.
Hong H, Liu GQ (2006) Scutellarin protects PC12 cells from oxidative stress-induced apoptosis. J Asian Nat Prod Res 8:471-479.
Jarrett JT, Berger EP, Lansbury PT, Jr. (1993) The carboxy terminus of the beta amyloid protein is critical for the seeding of amyloid formation: implications for the pathogenesis of Alzheimer's disease. Biochemistry 32:4693-4697.
Kawahara M (2010) Neurotoxicity of beta-amyloid protein: oligomerization, channel formation, and calcium dyshomeostasis. Curr Pharm Des 16:2779-2789.
Kim TI, Lee YK, Park SG, Choi IS, Ban JO, Park HK, Nam SY, Yun YW, Han SB, Oh KW, Hong JT (2009) l-Theanine, an amino acid in green tea, attenuates beta-amyloid-induced cognitive dysfunction and neurotoxicity: reduction in oxidative damage and inactivation of ERK/p38 kinase and NF-kappaB pathways. Free Radic Biol Med 47:1601-1610.
Kuperstein F, Yavin E (2002) ERK activation and nuclear translocation in amyloid-beta peptide- and iron-stressed neuronal cell cultures. Eur J Neurosci 16:44-54.
Magdesian MH, Carvalho MM, Mendes FA, Saraiva LM, Juliano MA, Juliano L, Garcia-Abreu J, Ferreira ST (2008) Amyloid-beta binds to the extracellular cysteine-rich domain of Frizzled and inhibits Wnt/beta-catenin signaling. J Biol Chem 283:9359-9368.
Mattson MP (2004) Pathways towards and away from Alzheimer's disease. Nature 430:631-639.
Murphy MP, LeVine H, 3rd (2010) Alzheimer's disease and the amyloid-beta peptide. J Alzheimers Dis 19:311-323.
Necula M, Kayed R, Milton S, Glabe CG (2007) Small molecule inhibitors of aggregation indicate that amyloid beta oligomerization and fibrillization pathways are independent and distinct. J Biol Chem 282:10311-10324.
Ono K, Condron MM, Teplow DB (2009) Structure-neurotoxicity relationships of amyloid beta-protein oligomers. Proc Natl Acad Sci U S A 106:14745-14750.
Plasek J, Sigler K (1996) Slow fluorescent indicators of membrane potential: a survey of different approaches to probe response analysis. J Photochem Photobiol B 33:101-124.
Querfurth HW, LaFerla FM (2010) Alzheimer's disease. N Engl J Med 362:329-344.
Reisberg B, Doody R, Stoffler A, Schmitt F, Ferris S, Mobius HJ (2003) Memantine in moderate-to-severe Alzheimer's disease. N Engl J Med 348:1333-1341.
Revett TJ, Baker GB, Jhamandas J, Kar S (2013) Glutamate system, amyloid ss peptides and tau protein: functional interrelationships and relevance to Alzheimer disease pathology. J Psychiatry Neurosci 38:6-23.
Sakono M, Zako T (2010) Amyloid oligomers: formation and toxicity of Aβ oligomers. FEBS J 277:1348-1358.
Scheuner D, Eckman C, Jensen M, Song X, Citron M, Suzuki N, Bird TD, Hardy J, Hutton M, Kukull W, Larson E, Levy-Lahad E, Viitanen M, Peskind E, Poorkaj P, Schellenberg G, Tanzi R, Wasco W, Lannfelt L, Selkoe D, Younkin S (1996) Secreted amyloid beta-protein similar to that in the senile plaques of Alzheimer's disease is increased in vivo by the presenilin 1 and 2 and APP mutations linked to familial Alzheimer's disease. Nature medicine 2:864-870.
Selkoe DJ, Schenk D (2003) Alzheimer's disease: molecular understanding predicts amyloid-based therapeutics. Annu Rev Pharmacol Toxicol 43:545-584.
Shang YZ, Qin BW, Cheng JJ, Miao H (2006) Prevention of oxidative injury by flavonoids from stems and leaves of Scutellaria baicalensis Georgi in PC12 cells. Phytother Res 20:53-57.
Shankar GM, Bloodgood BL, Townsend M, Walsh DM, Selkoe DJ, Sabatini BL (2007) Natural oligomers of the Alzheimer amyloid-beta protein induce reversible synapse loss by modulating an NMDA-type glutamate receptor-dependent signaling pathway. The Journal of neuroscience : the official journal of the Society for Neuroscience 27:2866-2875.
Sokolow S, Luu SH, Nandy K, Miller CA, Vinters HV, Poon WW, Gylys KH (2012) Preferential accumulation of amyloid-beta in presynaptic glutamatergic terminals (VGluT1 and VGluT2) in Alzheimer's disease cortex. Neurobiol Dis 45:381-387.
Subramaniam S, Unsicker K (2010) ERK and cell death: ERK1/2 in neuronal death. The FEBS J 277:22-29.
Troy CM, Rabacchi SA, Xu Z, Maroney AC, Connors TJ, Shelanski ML, Greene LA (2001) beta-Amyloid-induced neuronal apoptosis requires c-Jun N-terminal kinase activation. J Neurochem 77:157-164.
Tsumoto T (1990) Excitatory amino acid transmitters and their receptors in neural circuits of the cerebral neocortex. Neurosci Res 9:79-102.
Tu S, Okamoto S, Lipton SA, Xu H (2014) Oligomeric Abeta-induced synaptic dysfunction in Alzheimer's disease. Mol Neurodegener 9:48.
Valincius G, Heinrich F, Budvytyte R, Vanderah DJ, McGillivray DJ, Sokolov Y, Hall JE, Losche M (2008) Soluble amyloid beta-oligomers affect dielectric membrane properties by bilayer insertion and domain formation: implications for cell toxicity. Biophys J 95:4845-4861.
Whitcomb DJ, Hogg EL, Regan P, Piers T, Narayan P, Whitehead G, Winters BL, Kim DH, Kim E, St George-Hyslop P, Klenerman D, Collingridge GL, Jo J, Cho K (2015) Intracellular oligomeric amyloid-beta rapidly regulates GluA1 subunit of AMPA receptor in the hippocampus. Sci Rep 5:10934.
Wischik CM, Novak M, Thogersen HC, Edwards PC, Runswick MJ, Jakes R, Walker JE, Milstein C, Roth M, Klug A (1988) Isolation of a fragment of tau derived from the core of the paired helical filament of Alzheimer disease. Proc Natl Acad Sci U S A 85:4506-4510.
Yao M, Nguyen TV, Pike CJ (2005) Beta-amyloid-induced neuronal apoptosis involves c-Jun N-terminal kinase-dependent downregulation of Bcl-w. J Neurosci 25:1149-1158.
Yeh YC, Chen HY, Yang SH, Lin YH, Chiu JH, Lin YH, Chen JL (2014) Hedyotis diffusa combined with scutellaria barbata are the core treatment of Chinese herbal medicine used for breast cancer patients: a population-based study. Evid Based Complement Alternat Med 2014:202378.