Aβ peptide secretion is reduced by Radix Polygalae‑induced autophagy via activation of the AMPK/mTOR pathway

Zhao,Huan; Wang,Zhi‑Cheng; Wang,Kui‑Feng; Chen,Xiao‑Yu

doi:10.3892/mmr.2015.3781

Aβ peptide secretion is reduced by Radix Polygalae‑induced autophagy via activation of the AMPK/mTOR pathway

Authors:
- Huan Zhao
- Zhi‑Cheng Wang
- Kui‑Feng Wang
- Xiao‑Yu Chen
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Affiliations: Department of Histology and Embryology, Anhui Medical University, Hefei, Anhui 230032, P.R. China, Department of Laboratorial Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200071, P.R. China, Shanghai Genhouse Technology Co., Ltd., Shanghai 201203, P.R. China
Published online on: May 13, 2015 https://doi.org/10.3892/mmr.2015.3781
Pages: 2771-2776

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Abstract

Radix Polygalae is a traditional Chinese medicine that has been used as a sedative and to improve memory for a number of years. The impact of Radix Polygalae in patients with Alzheimer's disease has been investigated. However the mechanisms underlying its effects remain unclear. In the current study, the toxicity of various doses (100, 40, 20, 10, 5 and 0 µg/ml) of Radix Polygalae was measured in the human neuroblastoma cell line (SH‑SY5Y) using an MTT assay. Changes in amyloid β (Aβ) levels in the supernatant of Chinese hamster ovary (CHO) cells overexpressing β‑amyloid pro‑protein (APP) and BACE1 (CHO‑APP/BACE1), were detected using an ELISA assay. In order to confirm that the Aβ reduction was associated with autophagy, the autophagy marker protein, light chain 3 (LC3), was measured by western blot analysis and autophagosomes were assessed using MDC staining. In addition, the mechanism underlying the autophagy induced by Radix Polygalae was analyzed using western blotting to measure the protein expression of mammalian target of rapamycin (mTOR), p70s6k, Raptor, protein kinase B and adenosine monophosphate‑activated protein kinase (AMPK), in addition to the phosphorylated forms of these proteins. The results demonstrated no significant toxicity of Radix Polygalae in SH‑SY5Y cells, at a dose of 100 µg/ml. The secretion of Aβ was markedly reduced following treatment with Radix Polygalae, and this reduction occurred in a dose‑dependent manner. The autophagy levels were shown to be enhanced in the drug treatment group, using fluorescence microscopy. In addition, levels of LC3Ⅱ/LC3Ⅰ, the marker protein of autophagy, were also increased. The results of the current study suggest that Radix Polygalae may aid in the elimination of the Aβ peptide, via the induction of autophagy, by the AMPK/mTOR signaling pathway. These results may provide a basis for further kin vivo investigation.

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1	Feng Y and Wang X: Antioxidant therapies for Alzheimer’s disease. Oxid Med Cell Longev. 2012:4729322012. View Article : Google Scholar
2	Huang Y and Mucke L: Alzheimer mechanisms and therapeutic strategies. Cell. 148:1204–1222. 2012. View Article : Google Scholar : PubMed/NCBI
3	Bondareff W: Age-related changes in brain extracellular space affect processing of amyloid-β peptides in Alzheimer’s disease. J Alzheimers Dis. 35:1–6. 2013.
4	Shi TY, Zhao DQ, Wang HB, et al: A new chiral pyrrolyl α-nitronyl nitroxide radical attenuates β-amyloid deposition and rescues memory deficits in a mouse model of Alzheimer disease. Neurotherapeutics. 10:340–353. 2013. View Article : Google Scholar :
5	Cappai R and White AR: Amyloid β. Int J Biochem Cell Biol. 31:885–889. 1999. View Article : Google Scholar : PubMed/NCBI
6	Cavallucci V, D’Amelio M and Cecconi F: Aβ toxicity in Alzheimer’s disease. Mol Neurobiol. 45:366–378. 2012. View Article : Google Scholar : PubMed/NCBI
7	Sanchez-Varo R, Trujillo-Estrada L, Sanchez-Mejias E, et al: Abnormal accumulation of autophagic vesicles correlates with axonal and synaptic pathology in young Alzheimer’s mice hippocampus. Acta Neuropathol. 123:53–70. 2012. View Article : Google Scholar :
8	Zhu Z, Li C, Wang X, Yang Z, Chen J, Hu L, Jiang H and Shen X: 2,2′,4′-trihydroxychalcone from Glycyrrhiza glabra as a new specific BACE1 inhibitor efficiently ameliorates memory impairment in mice. J Neurochem. 114:374–385. 2010. View Article : Google Scholar : PubMed/NCBI
9	Arsikin K, Kravic-Stevovic T, Jovanovic M, Ristic B, Tovilovic G, Zogovic N, Bumbasirevic V, Trajkovic V and Harhaji-Trajkovic L: Autophagy-dependent and -independent involvement of AMP-activated protein kinase in 6-hydroxydopamine toxicity to SH-SY5Y neuroblastoma cells. Biochim Biophys Acta. 1822:1826–1836. 2012. View Article : Google Scholar : PubMed/NCBI
10	Tung YT, Wang BJ, Hu MK, Hsu WM, Lee H, Huang WP and Liao YF: Autophagy: a double-edged sword in Alzheimer’s disease. J Biosci. 37:157–165. 2012. View Article : Google Scholar : PubMed/NCBI
11	Periyasamy-Thandavan S, Jiang M, Schoenlein P and Dong Z: Autophagy: Molecular machinery, regulation and implications for renal pathophysiology. Am J Physiol Renal Physiol. 297:F244–F256. 2009. View Article : Google Scholar : PubMed/NCBI
12	Cheung ZH and Ip NY: Autophagy deregulation in neurode-generative diseases-recent advances and future perspectives. J Neurochem. 118:317–325. 2011. View Article : Google Scholar : PubMed/NCBI
13	Kaushik S and Cuervo AM: Autophagy as a cell-repair mechanism: Activation of chaperone-mediated autophagy during oxidative stress. Mol Aspects Med. 27:444–454. 2006. View Article : Google Scholar : PubMed/NCBI
14	Majumder S, Richardson A, Strong R and Oddo S: Inducing autophagy by rapamycin before, but not after, the formation of plaques and tangles ameliorates cognitive deficits. PLoS One. 6:e254162011. View Article : Google Scholar : PubMed/NCBI
15	Chong ZZ, Shang YC, Zhang L, Wang S and Maiese K: Mammalian target of rapamycin: Hitting the bull’s-eye for neurological disorders. Oxid Med Cell Longev. 3:374–391. 2010. View Article : Google Scholar
16	Wu X, Kihara T, Akaike A, Niidome T and Sugimoto H: PI3K/Akt/mTOR signaling regulates glutamate transporter 1 in astrocytes. Biochem Biophys Res Commun. 393:514–518. 2010. View Article : Google Scholar : PubMed/NCBI
17	Klionsky DJ, Meijer AJ, Codogno P, Neufeld TP and Scott RC: Autophagy and p70S6 kinase. Autophagy. 1:59–61. 2005. View Article : Google Scholar
18	Din FV, Valanciute A, Houde VP, Zibrova D, Green KA, Sakamoto K, Alessi DR and Dunlop MG: Aspirin inhibits mTOR signaling, activates AMP-activated protein kinase, and induces autophagy in colorectal cancer cells. Gastroenterology. 142:1504–15.e3. 2012. View Article : Google Scholar : PubMed/NCBI
19	Saiki S, Sasazawa Y, Imamichi Y, et al: Caffeine induces apoptosis by enhancement of autophagy via PI3K/Akt/mTOR/p70S6K inhibition. Autophagy. 7:176–187. 2011. View Article : Google Scholar :
20	Lin Z, Gu J, Xiu J, Mi T, Dong J and Tiwari JK: Traditional chinese medicine for senile dementia. Evid Based Complement Alternat Med. 2012:6926212012. View Article : Google Scholar
21	Lee HJ, Ban JY, Koh SB, Seong NS, Song KS, Bae KW and Seong YH: Polygalae radix extract protects cultured rat granule cells against damage induced by NMDA. Am J Chin Med. 32:599–610. 2004. View Article : Google Scholar : PubMed/NCBI
22	Park CH, Choi SH, Koo JW, Seo JH, Kim HS, Jeong SJ and Suh YH: Novel cognitive improving and neuroprotective activities of Polygala tenuifolia Willdenow extract, BT-11. J Neurosci Res. 70:484–492. 2002. View Article : Google Scholar : PubMed/NCBI
23	Lv J, Jia H, Jiang Y, Ruan Y, Liu Z, Yue W, Beyreuther K, Tu P and Zhang D: Tenuifolin, an extract derived from tenuigenin, inhibits amyloid-β secretion in vitro. Acta Physiol (Oxf). 196:419–425. 2009. View Article : Google Scholar
24	Melo MC, Gadelha DN, Oliveira TK and Brandt CT: Alcohol extract of Schinu sterebinthifolius raddi (anacardiaceae) as a local antimicrobial agent in severe autogenously fecal peritonitis in rats. Acta Cir Bras. 29(Suppl 1): 52–56. 2014. View Article : Google Scholar : PubMed/NCBI
25	Munafó DB and Colombo MI: A novel assay to study autophagy: Regulation of autophagosome vacuole size by amino acid deprivation. J Cell Sci. 114:3619–36291. 2001.PubMed/NCBI
26	Hung SY, Huang WP, Liou HC and Fu WM: Autophagy protects neuron from Abeta-induced cytotoxicity. Autophagy. 5:502–510. 2009. View Article : Google Scholar : PubMed/NCBI
27	Cai Z, Yan LJ, Li K, Quazi SH and Zhao B: Roles of AMP-activated protein kinase in Alzheimer’s disease. Neuromolecular Med. 14:1–14. 2012. View Article : Google Scholar : PubMed/NCBI
28	Arbel M and Solomon B: Immunotherapy for Alzheimer’s disease: Attacking amyloid beta from the inside. Trends Immunol. 28:511–513. 2007. View Article : Google Scholar : PubMed/NCBI
29	Jeon S, Bose S, Hur J, Jun K, Kim YK, Cho KS and Koo BS: A modified formulation of Chinese traditional medicine improves memory impairment and reduces Aβ level in the Tg-APPswe/PS1dE9 mouse model of Alzheimer’s disease. J Ethnopharmacol. 137:783–789. 2011. View Article : Google Scholar : PubMed/NCBI
30	Lai AY and McLaurin J: Inhibition of amyloid-beta peptide aggregation rescues the autophagic deficits in the TgCRND8 mouse model of Alzheimer disease. Biochim Biophys Acta. 1822:1629–1637. 2012. View Article : Google Scholar : PubMed/NCBI
31	Eisenberg D and Jucker M: The amyloid state of proteins in human diseases. Cell. 148:1188–1203. 2012. View Article : Google Scholar : PubMed/NCBI
32	Gao J, Inagaki Y, Li X, Kokudo N and Tang W: Research progress on natural products from traditional Chinese medicine in treatment of Alzheimer’s disease. Drug Discov Ther. 7:46–57. 2013.PubMed/NCBI
33	Meraz-Ríos MA, Toral-Rios D, Franco-Bocanegra D, Villeda-Hernández J and Campos-Peña V: Inflammatory process in Alzheimer’s Disease. Front Integr Neurosci. 7:592013. View Article : Google Scholar
34	Cuchillo-Ibáñez I, Balmaceda V, Botella-López A, Rabano A, Avila J and Sáez-Valero J: Beta-amyloid impairs reelin signaling. PLoS One. 8:e722972013. View Article : Google Scholar : PubMed/NCBI
35	Tokutake T, Kasuga K, Yajima R, Sekine Y, Tezuka T, Nishizawa M and Ikeuchi T: Hyperphosphorylation of Tau induced by naturally secreted amyloid-β at nanomolar concentrations is modulated by insulin-dependent Akt-GSK3β signaling pathway. J Biol Chem. 287:35222–35233. 2012. View Article : Google Scholar : PubMed/NCBI
36	Spilman P, Podlutskaya N, Hart MJ, Debnath J, Gorostiza O, Bredesen D, Richardson A, Strong R and Galvan V: Inhibition of mTOR by rapamycin abolishes cognitive deficits and reduces amyloid-beta levels in a mouse model of Alzheimer’s disease. PLoS One. 5:e99792010. View Article : Google Scholar
37	Lafay-Chebassier C, Paccalin M, Page G, Barc-Pain S, Perault-Pochat MC, Gil R, Pradier L and Hugon J: mTOR/p70S6k signalling alteration by Ab exposure as well as in APP-PS1 transgenic models and in patients with Alzheimer’s disease. J Neurochem. 94:215–225. 2005. View Article : Google Scholar : PubMed/NCBI
38	Lee JW, Park S, Takahashi Y and Wang HG: The association of AMPK with ULK1 regulates autophagy. PLoS One. 5:e153942010. View Article : Google Scholar : PubMed/NCBI