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Molecular Neurobiology

, Volume 54, Issue 8, pp 5815–5828 | Cite as

Neuroprotection Through Rapamycin-Induced Activation of Autophagy and PI3K/Akt1/mTOR/CREB Signaling Against Amyloid-β-Induced Oxidative Stress, Synaptic/Neurotransmission Dysfunction, and Neurodegeneration in Adult Rats

  • Abhishek Kumar Singh
  • Mahendra Pratap Kashyap
  • Vinay Kumar Tripathi
  • Sandeep Singh
  • Geetika Garg
  • Syed Ibrahim RizviEmail author
Article

Abstract

Autophagy is a catabolic process involved in the continuous removal of toxic protein aggregates and cellular organelles to maintain the homeostasis and functional integrity of cells. The mechanistic understanding of autophagy mediated neuroprotection during the development of neurodegenerative disorders remains elusive. Here, we investigated the potential role of rapamycin-induced activation of autophagy and PI3K/Akt1/mTOR/CREB pathway(s) in the neuroprotection of amyloid-beta (Aβ1-42)-insulted hippocampal neurons in rat model of Alzheimer’s disease (AD) like phenotypes. A single intra-hippocampal injection of Aβ1-42 impaired redox balance and markedly induced synaptic dysfunction, neurotransmission dysfunction, and cognitive deficit, and suppressed pro-survival signaling in the adult rats. Rapamycin administration caused a significant reduction of mTOR complex 1 phosphorylation at Ser2481 and a significant increase in levels of autophagy markers such as microtubule-associated protein-1 light chain-3 (LC3), beclin-1, sequestosome-1/p62, unc-51-like kinase 1 (ULK1). In addition, rapamycin induced the activation of autophagy that further activated p-PI3K, p-Akt1 (Ser473), and p-CREB (Ser183) expression in Aβ1-42-treated rats. The activated autophagy markedly reversed Aβ1-42-induced impaired redox homeostasis by decreasing the levels of prooxidants—ROS generation, intracellular Ca2+ flux and LPO, and increasing the levels of antioxidants—SOD, catalase, and GSH. The activated autophagy also provided significant neuroprotection against Aβ1-42-induced synaptic dysfunction by increasing the expression of synapsin-I, synaptophysin, and PSD95; and neurotransmission dysfunction by increasing the levels of CHRM2, DAD2 receptor, NMDA receptor, and AMPA receptor; and ultimately improved cognitive ability in rats. Wortmannin administration significantly reduced the expression of autophagy markers, p-PI3K, p-Akt1, and p-CREB, as well as the autophagy mediated neuroprotective effect. Our study demonstrate that autophagy can be an integrated part of pro-survival (PI3K/Akt1/mTOR/CREB) signaling and autophagic activation restores the oxidative defense mechanism(s), neurodegenerative damages, and maintains the integrity of synapse and neurotransmission in rat model of AD.

Keywords

Amyloid-beta Autophagy Cognitive deficits Neurodegeneration Neuroprotection Rapamycin Synaptic dysfunction Wortmannin 

Notes

Acknowledgments

Dr. D. S. Kothari Post-Doctoral Fellowship scheme of the University Grant Commission, New Delhi, India, is acknowledged for providing financial support (F.4-2/2006(BSR)/BL/14-15/0326) and fellowship to Dr. A. K. Singh. The Department of Biochemistry, University of Allahabad is a recipient of the FIST grant from the DST SERB, Government of India.

Compliance with Ethical Standards

Conflict of Interest

The authors declare that they have no conflict of interest.

References

  1. 1.
    Sanchez PE, Zhu L, Verret L et al (2012) Levetiracetam suppresses neuronal network dysfunction and reverses synaptic and cognitive deficits in an Alzheimer’s disease model. Proc Natl Acad Sci 109:E2895–E2903CrossRefPubMedPubMedCentralGoogle Scholar
  2. 2.
    Martínez E, Navarro A, Ordóñez C et al (2013) Oxidative stress induces apolipoprotein D overexpression in hippocampus during aging and Alzheimer’s disease. J Alzheimers Dis JAD 36:129–144PubMedGoogle Scholar
  3. 3.
    Melov S, Adlard PA, Morten K et al (2007) Mitochondrial oxidative stress causes hyperphosphorylation of tau. PLoS One 2:e536CrossRefPubMedPubMedCentralGoogle Scholar
  4. 4.
    Chen Y, Wei G, Nie H et al (2014) β-Asarone prevents autophagy and synaptic loss by reducing ROCK expression in a senescence-accelerated prone 8 mice. Brain Res 1552:41–54CrossRefPubMedGoogle Scholar
  5. 5.
    Trepanier CH, Jackson MF, MacDonald JF (2012) Regulation of NMDA receptors by the tyrosine kinase Fyn: regulation of NMDA receptors. FEBS J 279:12–19CrossRefPubMedGoogle Scholar
  6. 6.
    Palop JJ, Chin J, Roberson ED et al (2007) Aberrant excitatory neuronal activity and compensatory remodeling of inhibitory hippocampal circuits in mouse models of Alzheimer’s disease. Neuron 55:697–711CrossRefPubMedGoogle Scholar
  7. 7.
    Alberdi E, Sánchez-Gómez MV, Cavaliere F et al (2010) Amyloid β oligomers induce Ca2+ dysregulation and neuronal death through activation of ionotropic glutamate receptors. Cell Calcium 47:264–272CrossRefPubMedGoogle Scholar
  8. 8.
    Mizushima N, Komatsu M (2011) Autophagy: renovation of cells and tissues. Cell 147:728–741CrossRefPubMedGoogle Scholar
  9. 9.
    Cuervo AM, Bergamini E, Brunk UT et al (2005) Autophagy and aging: the importance of maintaining “clean” cells. Autophagy 1:131–140CrossRefPubMedGoogle Scholar
  10. 10.
    Ling D, Salvaterra PM (2009) A central role for autophagy in Alzheimer-type neurodegeneration. Autophagy 5:738–740CrossRefPubMedGoogle Scholar
  11. 11.
    Wong E, Cuervo AM (2010) Autophagy gone awry in neurodegenerative diseases. Nat Neurosci 13:805–811CrossRefPubMedPubMedCentralGoogle Scholar
  12. 12.
    Nixon RA, Wegiel J, Kumar A et al (2005) Extensive involvement of autophagy in Alzheimer disease: an immuno-electron microscopy study. J Neuropathol Exp Neurol 64:113–122CrossRefPubMedGoogle Scholar
  13. 13.
    Yu WH, Cuervo AM, Kumar A et al (2005) Macroautophagy—a novel Beta-amyloid peptide-generating pathway activated in Alzheimer’s disease. J Cell Biol 171:87–98CrossRefPubMedPubMedCentralGoogle Scholar
  14. 14.
    Zhang J, Zhang Y, Li J et al (2012) Autophagosomes accumulation is associated with β-amyloid deposits and secondary damage in the thalamus after focal cortical infarction in hypertensive rats: autophagy and β-amyloid after cortical infarction. J Neurochem 120:564–573CrossRefPubMedGoogle Scholar
  15. 15.
    Kim J, Kundu M, Viollet B, Guan KL (2011) AMPK and mTOR regulate autophagy through direct phosphorylation of Ulk1. Nat Cell Biol 13:132–141CrossRefPubMedPubMedCentralGoogle Scholar
  16. 16.
    Sarkar S (2013) Regulation of autophagy by mTOR-dependent and mTOR-independent pathways: autophagy dysfunction in neurodegenerative diseases and therapeutic application of autophagy enhancers. Biochem Soc Trans 41:1103–1130CrossRefPubMedGoogle Scholar
  17. 17.
    Kim DH, Sarbassov DD, Ali SM et al (2002) mTOR interacts with raptor to form a nutrient-sensitive complex that signals to the cell growth machinery. Cell 110:163–175CrossRefPubMedGoogle Scholar
  18. 18.
    Schmelzle T, Hall MN (2000) TOR, a central controller of cell growth. Cell 103:253–262CrossRefPubMedGoogle Scholar
  19. 19.
    Wouters BG, Koritzinsky M (2008) Hypoxia signalling through mTOR and the unfolded protein response in cancer. Nat Rev Cancer 8:851–864CrossRefPubMedGoogle Scholar
  20. 20.
    Berger Z, Ravikumar B, Menzies FM et al (2006) Rapamycin alleviates toxicity of different aggregate-prone proteins. Hum Mol Genet 15:433–442CrossRefPubMedGoogle Scholar
  21. 21.
    Nixon RA (2006) Autophagy in neurodegenerative disease: friend, foe or turncoat? Trends Neurosci 29:528–535CrossRefPubMedGoogle Scholar
  22. 22.
    Bagheri M, Joghataei MT, Mohseni S, Roghani M (2011) Genistein ameliorates learning and memory deficits in amyloid β(1–40) rat model of Alzheimer’s disease. Neurobiol Learn Mem 95:270–276CrossRefPubMedGoogle Scholar
  23. 23.
    Chauhan A, Sharma U, Jagannathan NR et al (2011) Rapamycin protects against middle cerebral artery occlusion induced focal cerebral ischemia in rats. Behav Brain Res 225:603–609CrossRefPubMedGoogle Scholar
  24. 24.
    Xu JT, Tu HY, Xin WJ et al (2007) Activation of phosphatidylinositol 3-kinase and protein kinase B/Akt in dorsal root ganglia and spinal cord contributes to the neuropathic pain induced by spinal nerve ligation in rats. Exp Neurol 206:269–279CrossRefPubMedGoogle Scholar
  25. 25.
    Lowry OH, Rosebrough NJ, Farr AL, Randall RJ (1951) Protein measurement with the Folin phenol reagent. J Biol Chem 193:265–275PubMedGoogle Scholar
  26. 26.
    Wang H, Joseph JA (1999) Quantifying cellular oxidative stress by dichlorofluorescein assay using microplate reader. Free Radic Biol Med 27:612–616CrossRefPubMedGoogle Scholar
  27. 27.
    Lipton SA, Rosenberg PA (1994) Excitatory amino acids as a final common pathway for neurologic disorders. N Engl J Med 330:613–622CrossRefPubMedGoogle Scholar
  28. 28.
    Ohkawa H, Ohishi N, Yagi K (1979) Assay for lipid peroxides in animal tissues by thiobarbituric acid reaction. Anal Biochem 95:351–358CrossRefPubMedGoogle Scholar
  29. 29.
    Kakkar P, Das B, Viswanathan PN (1984) A modified spectrophotometric assay of superoxide dismutase. Indian J Biochem Biophys 21:130–132PubMedGoogle Scholar
  30. 30.
    Hong IS, Lee H-Y, Kim HP (2014) Anti-oxidative effects of rooibos tea (Aspalathus linearis) on immobilization-induced oxidative stress in rat brain. PLoS One 9:e87061CrossRefPubMedPubMedCentralGoogle Scholar
  31. 31.
    Hissin PJ, Hilf R (1976) A fluorometric method for determination of oxidized and reduced glutathione in tissues. Anal Biochem 74:214–226CrossRefPubMedGoogle Scholar
  32. 32.
    Kashyap MP, Singh AK, Yadav DK et al (2015) 4-Hydroxy-trans-2-nonenal (4-HNE) induces neuronal SH-SY5Y cell death via hampering ATP binding at kinase domain of Akt1. Arch Toxicol 89:243–258CrossRefPubMedGoogle Scholar
  33. 33.
    Ellman GL, Courtney KD, Andres V, Feather-Stone RM (1961) A new and rapid colorimetric determination of acetylcholinesterase activity. Biochem Pharmacol 7:88–95CrossRefPubMedGoogle Scholar
  34. 34.
    Seth PK, Alleva FR, Balazs T (1982) Alteration of high-affinity binding sites of neurotransmitter receptors in rats after neonatal exposure to streptomycin. Neurotoxicology 3:13–19PubMedGoogle Scholar
  35. 35.
    Moreira EG, Vassilieff I, Vassilieff VS (2001) Developmental lead exposure: behavioral alterations in the short and long term. Neurotoxicol Teratol 23:489–495CrossRefPubMedGoogle Scholar
  36. 36.
    Ali T, Yoon GH, Shah SA et al (2015) Osmotin attenuates amyloid beta-induced memory impairment, tau phosphorylation and neurodegeneration in the mouse hippocampus. Sci Rep 5:11708CrossRefPubMedPubMedCentralGoogle Scholar
  37. 37.
    Brouillette J, Caillierez R, Zommer N et al (2012) Neurotoxicity and memory deficits induced by soluble low-molecular-weight amyloid-1-42 oligomers are revealed in vivo by using a novel animal model. J Neurosci 32:7852–7861CrossRefPubMedGoogle Scholar
  38. 38.
    Flynn JM, Melov S (2013) SOD2 in mitochondrial dysfunction and neurodegeneration. Free Radic Biol Med 62:4–12CrossRefPubMedGoogle Scholar
  39. 39.
    Mattson MP, Magnus T (2006) Ageing and neuronal vulnerability. Nat Rev Neurosci 7:278–294CrossRefPubMedPubMedCentralGoogle Scholar
  40. 40.
    Yao J, Du H, Yan S et al (2011) Inhibition of amyloid-beta (Abeta) peptide-binding alcohol dehydrogenase-Abeta interaction reduces a accumulation and improves mitochondrial function in a mouse model of Alzheimer’s disease. J Neurosci 31:2313–2320CrossRefPubMedPubMedCentralGoogle Scholar
  41. 41.
    Sheehan JP, Swerdlow RH, Miller SW et al (1997) Calcium homeostasis and reactive oxygen species production in cells transformed by mitochondria from individuals with sporadic Alzheimer’s disease. J Neurosci 17:4612–4622PubMedGoogle Scholar
  42. 42.
    Damme M, Suntio T, Saftig P, Eskelinen E-L (2015) Autophagy in neuronal cells: general principles and physiological and pathological functions. Acta Neuropathol (Berl) 129:337–362CrossRefGoogle Scholar
  43. 43.
    Li L, Zhang X, Le W (2010) Autophagy dysfunction in Alzheimer’s disease. Neurodegener Dis 7:265–271PubMedGoogle Scholar
  44. 44.
    Efeyan A, Comb WC, Sabatini DM (2015) Nutrient-sensing mechanisms and pathways. Nature 517:302–310CrossRefPubMedPubMedCentralGoogle Scholar
  45. 45.
    Sarbassov DD, Guertin DA, Ali SM, Sabatini DM (2005) Phosphorylation and regulation of Akt/PKB by the rictor-mTOR complex. Science 307:1098–1101CrossRefPubMedGoogle Scholar
  46. 46.
    Abada A, Elazar Z (2014) Getting ready for building: signaling and autophagosome biogenesis. EMBO Rep 15:839–852CrossRefPubMedPubMedCentralGoogle Scholar
  47. 47.
    Zou J, Yue F, Jiang X et al (2013) Mitochondrion-associated protein LRPPRC suppresses the initiation of basal levels of autophagy via enhancing Bcl-2 stability. Biochem J 454:447–457CrossRefPubMedPubMedCentralGoogle Scholar
  48. 48.
    Mizushima N (2007) Autophagy: process and function. Genes Dev 21:2861–2873CrossRefPubMedGoogle Scholar
  49. 49.
    Jaeger PA, Pickford F, Sun CH et al (2010) Regulation of amyloid precursor protein processing by the Beclin 1 complex. PLoS One 5:e11102CrossRefPubMedPubMedCentralGoogle Scholar
  50. 50.
    Gibson SB (2013) Investigating the Role of Reactive Oxygen Species in Regulating Autophagy. In: Methods Enzymol. Elsevier, pp 217–235Google Scholar
  51. 51.
    Salminen A, Kaarniranta K, Haapasalo A et al (2012) Emerging role of p62/sequestosome-1 in the pathogenesis of Alzheimer’s disease. Prog Neurobiol 96:87–95CrossRefPubMedGoogle Scholar
  52. 52.
    Kitagishi Y, Nakanishi A, Ogura Y, Matsuda S (2014) Dietary regulation of PI3K/AKT/GSK-3β pathway in Alzheimer’s disease. Alzheimers Res Ther 6:35CrossRefPubMedPubMedCentralGoogle Scholar
  53. 53.
    Tong L, Thornton PL, Balazs R, Cotman CW (2001) Beta-amyloid-(1-42) impairs activity-dependent cAMP-response element-binding protein signaling in neurons at concentrations in which cell survival is not compromised. J Biol Chem 276:17301–17306CrossRefPubMedGoogle Scholar
  54. 54.
    Silva AJ, Kogan JH, Frankland PW, Kida S (1998) CREB and memory. Annu Rev Neurosci 21:127–148CrossRefPubMedGoogle Scholar
  55. 55.
    Pugazhenthi S, Wang M, Pham S et al (2011) Downregulation of CREB expression in Alzheimer’s brain and in Aβ-treated rat hippocampal neurons. Mol Neurodegener 6:60CrossRefPubMedPubMedCentralGoogle Scholar
  56. 56.
    O’Reilly KE, Rojo F, She QB et al (2006) mTOR inhibition induces upstream receptor tyrosine kinase signaling and activates Akt. Cancer Res 66:1500–1508CrossRefPubMedPubMedCentralGoogle Scholar
  57. 57.
    Palop JJ, Mucke L (2010) Amyloid-β–induced neuronal dysfunction in Alzheimer’s disease: from synapses toward neural networks. Nat Neurosci 13:812–818CrossRefPubMedPubMedCentralGoogle Scholar
  58. 58.
    Shen W, Ganetzky B (2009) Autophagy promotes synapse development in Drosophila. J Cell Biol 187:71–79CrossRefPubMedPubMedCentralGoogle Scholar
  59. 59.
    Yang DS, Stavrides P, Saito M et al (2014) Defective macroautophagic turnover of brain lipids in the TgCRND8 Alzheimer mouse model: prevention by correcting lysosomal proteolytic deficits. Brain 137:3300–3318CrossRefPubMedPubMedCentralGoogle Scholar
  60. 60.
    Collingridge GL, Isaac JTR, Wang YT (2004) Receptor trafficking and synaptic plasticity. Nat Rev Neurosci 5:952–962CrossRefPubMedGoogle Scholar
  61. 61.
    Kar S, Slowikowski SPM, Westaway D, Mount HTJ (2004) Interactions between beta-amyloid and central cholinergic neurons: implications for Alzheimer’s disease. J Psychiatry Neurosci JPN 29:427–441PubMedGoogle Scholar
  62. 62.
    Attems J, Quass M, Jellinger KA (2007) Tau and alpha-synuclein brainstem pathology in Alzheimer disease: relation with extrapyramidal signs. Acta Neuropathol (Berl) 113:53–62CrossRefGoogle Scholar
  63. 63.
    Beaulieu JM, Gainetdinov RR (2011) The physiology, signaling, and pharmacology of dopamine receptors. Pharmacol Rev 63:182–217CrossRefPubMedGoogle Scholar
  64. 64.
    Chang KT, Berg DK (2001) Voltage-gated channels block nicotinic regulation of CREB phosphorylation and gene expression in neurons. Neuron 32:855–865CrossRefPubMedGoogle Scholar
  65. 65.
    Nair VD, Sealfon SC (2003) Agonist-specific transactivation of phosphoinositide 3-kinase signaling pathway mediated by the dopamine D2 receptor. J Biol Chem 278:47053–47061CrossRefPubMedGoogle Scholar
  66. 66.
    Janssen WGM, Vissavajjhala P, Andrews G et al (2005) Cellular and synaptic distribution of NR2A and NR2B in macaque monkey and rat hippocampus as visualized with subunit-specific monoclonal antibodies. Exp Neurol 191(Suppl 1):S28–S44CrossRefPubMedGoogle Scholar
  67. 67.
    Mishizen-Eberz AJ, Rissman RA, Carter TL et al (2004) Biochemical and molecular studies of NMDA receptor subunits NR1/2 A/2B in hippocampal subregions throughout progression of Alzheimer’s disease pathology. Neurobiol Dis 15:80–92CrossRefPubMedGoogle Scholar
  68. 68.
    Paula-Lima AC, Brito-Moreira J, Ferreira ST (2013) Deregulation of excitatory neurotransmission underlying synapse failure in Alzheimer’s disease. J Neurochem 126:191–202CrossRefPubMedGoogle Scholar
  69. 69.
    Hardingham GE, Bading H (2010) Synaptic versus extrasynaptic NMDA receptor signalling: implications for neurodegenerative disorders. Nat Rev Neurosci 11:682–696CrossRefPubMedPubMedCentralGoogle Scholar
  70. 70.
    Wang Q, Zengin A, Ying W et al (2008) Chronic treatment with simvastatin upregulates muscarinic M1/4 receptor binding in the rat brain. Neuroscience 154:1100–1106CrossRefPubMedGoogle Scholar
  71. 71.
    Francis PT, Palmer AM, Snape M, Wilcock GK (1999) The cholinergic hypothesis of Alzheimer’s disease: a review of progress. J Neurol Neurosurg Psychiatry 66:137–147CrossRefPubMedPubMedCentralGoogle Scholar
  72. 72.
    Matsuda S, Miura E, Matsuda K et al (2008) Accumulation of AMPA receptors in autophagosomes in neuronal axons lacking adaptor protein AP-4. Neuron 57:730–745CrossRefPubMedGoogle Scholar
  73. 73.
    Morrison JH, Baxter MG (2014) Synaptic health. JAMA Psychiatry 71:835CrossRefPubMedGoogle Scholar
  74. 74.
    Spilman P, Podlutskaya N, Hart MJ et al (2010) Inhibition of mTOR by rapamycin abolishes cognitive deficits and reduces amyloid-β levels in a mouse model of Alzheimer’s disease. PLoS One 5:e9979CrossRefPubMedPubMedCentralGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  • Abhishek Kumar Singh
    • 1
  • Mahendra Pratap Kashyap
    • 2
  • Vinay Kumar Tripathi
    • 3
  • Sandeep Singh
    • 1
  • Geetika Garg
    • 1
  • Syed Ibrahim Rizvi
    • 1
    Email author
  1. 1.Department of BiochemistryUniversity of AllahabadAllahabadIndia
  2. 2.Department of UrologyUniversity of Pittsburgh School of MedicinePittsburghUSA
  3. 3.Department of Animal Science and BiotechnologyChonbuk National UniversityJeonjuRepublic of Korea

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