Abstract
Introduction: The accumulation of amyloid-β peptide (Aβ) decreases cerebral blood flow in elderly people with Alzheimer’s disease (AD) and is believed to be the initiator of this disorder. As a traditional Chinese medicine, Yangxue Qingnao (YXQN) improves cerebral insufficiency and attenuates cognitive impairment, showing potential against AD. But whether YXQN has the ability to block Aβ self-aggregation is rarely reported.
Objective: Here, we investigate the effects of YXQN on Aβ accumulation and its mediated cytotoxicity using a range of biochemical, biophysical, and cell-based approaches. Methods: Thioflavin T assay, transmission electron microscope, and 1H NMR experiments were used to investigate the effects of YXQN on Aβ fibrogenesis and aggregation. Far-UV CD spectra were acquired to assess the alteration of YXQN on the conformation of the amyloid protein. Three short Aβ42 peptides (AA 1-16, AA 17-33 and AA 28-42) were designed to analyse the Aβ42 epitope to which YXQN components bind. The effect of YXQN on Aβ-induced cytotoxicity was investigated through SH-SY5Y cell viability assay. Results: We provide evidence showing that YXQN clearly reduces Aβ42 fibrillogenesis and alters its β-sheet conformation, indicating the inhibition of primary nucleation of amyloid protein. Using the different Aβ short peptides, residues 17-33 were identified as the target epitope for YXNQ components interacting with Aβ42. Furthermore, in the SH-SY5Y cell injury model, our data show that high-dose YXQN attenuates amyloid-induced cytotoxicity approximately 60% and effectively ameliorates cell distortion in morphology. Conclusion: Based on these results, YXQN exerts a neuroprotective effect by inhibiting Aβ42 toxic aggregation, which has the potential to combat AD.Keywords: Aβ42 aggregation, YXQN, Aβ-induced cytotoxicity, Alzheimer's disease, fibrogenesis, aggregation.
[http://dx.doi.org/10.1016/j.jalz.2018.02.001]
[http://dx.doi.org/10.1371/journal.pone.0085885] [PMID: 24465766]
[http://dx.doi.org/10.1101/cshperspect.a006338] [PMID: 22762015]
[http://dx.doi.org/10.1523/JNEUROSCI.5825-09.2010] [PMID: 20371804]
[http://dx.doi.org/10.1038/416535a] [PMID: 11932745]
[http://dx.doi.org/10.1016/j.jalz.2011.03.003] [PMID: 21514248]
[http://dx.doi.org/10.1073/pnas.0913046107] [PMID: 20351246]
[http://dx.doi.org/10.1126/science.1566067] [PMID: 1566067]
[http://dx.doi.org/10.1126/sciadv.1501244] [PMID: 26933687]
[http://dx.doi.org/10.1007/s13311-013-0192-7] [PMID: 23670234]
[http://dx.doi.org/10.1021/ja107552s] [PMID: 21062056]
[http://dx.doi.org/10.1016/j.compbiolchem.2018.10.015] [PMID: 30445338]
[http://dx.doi.org/10.7554/eLife.00857] [PMID: 23878726]
[http://dx.doi.org/10.1016/j.ebiom.2017.09.004] [PMID: 28923680]
[http://dx.doi.org/10.1073/pnas.1206433109] [PMID: 22814377]
[http://dx.doi.org/10.1002/cmdc.201100585] [PMID: 22323134]
[http://dx.doi.org/10.1126/scitranslmed.3002254] [PMID: 21613622]
[http://dx.doi.org/10.1038/s41467-018-03755-2] [PMID: 29610518]
[http://dx.doi.org/10.1515/bc.2010.089] [PMID: 20731541]
[http://dx.doi.org/10.1074/jbc.M404751200] [PMID: 15590663]
[http://dx.doi.org/10.1021/np010039x] [PMID: 12350137]
[http://dx.doi.org/10.1002/ana.24188] [PMID: 24853080]
[http://dx.doi.org/10.2174/187152709787847315] [PMID: 19355930]
[http://dx.doi.org/10.1038/ncomms11934] [PMID: 27327500]
[http://dx.doi.org/10.1126/science.aav9518] [PMID: 31221773]
[http://dx.doi.org/10.1177/0271678X16671146] [PMID: 27780904]
[http://dx.doi.org/10.1074/jbc.M608856200] [PMID: 17303576]
[http://dx.doi.org/10.1073/pnas.0606298103] [PMID: 17121991]
[http://dx.doi.org/10.1007/s11655-011-0643-0] [PMID: 21390580]
[http://dx.doi.org/10.1007/BF02835743] [PMID: 15975302]
[PMID: 15143727]
[http://dx.doi.org/10.1111/j.1479-8301.2012.00423.x] [PMID: 23551409]
[http://dx.doi.org/10.3389/fnagi.2017.00157] [PMID: 28603494]
[http://dx.doi.org/10.1002/pro.5560020312] [PMID: 8453378]
[http://dx.doi.org/10.1039/C6SC04797A] [PMID: 28970886]
[http://dx.doi.org/10.1074/jbc.M116.764092] [PMID: 28154182]
[http://dx.doi.org/10.1021/acschemneuro.6b00006] [PMID: 26835536]
[http://dx.doi.org/10.1002/jbio.201100023] [PMID: 21702084]
[http://dx.doi.org/10.1073/pnas.0506723102] [PMID: 16293696]
[http://dx.doi.org/10.1073/pnas.0706522104] [PMID: 18025469]
[http://dx.doi.org/10.1021/bi701427q] [PMID: 17979302]
[http://dx.doi.org/10.1126/science.1105850] [PMID: 15653506]
[http://dx.doi.org/10.1073/pnas.1615613114] [PMID: 28011763]
[http://dx.doi.org/10.1038/srep07992] [PMID: 25613018]
[http://dx.doi.org/10.1097/NEN.0b013e3182345e46] [PMID: 22002425]
[PMID: 29178159]
[http://dx.doi.org/10.1039/C6CC07803F] [PMID: 28067349]
[http://dx.doi.org/10.1002/cbic.201402430] [PMID: 25262917]
[http://dx.doi.org/10.1021/jm040773o] [PMID: 15293994]
[http://dx.doi.org/10.1021/bi961598j] [PMID: 8973180]
[http://dx.doi.org/10.1007/s10571-013-0006-9] [PMID: 24263411]
[http://dx.doi.org/10.1155/2015/161020] [PMID: 26583091]
[http://dx.doi.org/10.3233/JAD-2012-111979] [PMID: 22430532]
[http://dx.doi.org/10.1016/j.neuroscience.2017.05.005] [PMID: 28504198]
[http://dx.doi.org/10.1016/j.bbrc.2016.12.166] [PMID: 28034755]
[http://dx.doi.org/10.1002/anie.201405109] [PMID: 24931598]
[http://dx.doi.org/10.1038/s41467-019-11183-z] [PMID: 31350392]
[http://dx.doi.org/10.1074/jbc.M117.806109] [PMID: 29282295]
[PMID: 29878728]
[http://dx.doi.org/10.1016/j.cbi.2019.06.020] [PMID: 31194956]
[http://dx.doi.org/10.1016/j.bmcl.2017.09.051] [PMID: 28988761]
[http://dx.doi.org/10.1016/j.bmc.2017.05.041] [PMID: 28559058]
[http://dx.doi.org/10.1039/C4SC01531B] [PMID: 25383163]