Molecular and Cellular Biochemistry

, Volume 444, Issue 1–2, pp 149–160 | Cite as

Alpha-synuclein aggregation, Ubiquitin proteasome system impairment, and l-Dopa response in zinc-induced Parkinsonism: resemblance to sporadic Parkinson’s disease

  • Vinod Kumar
  • Deepali Singh
  • Brajesh Kumar Singh
  • Shweta Singh
  • Namrata Mittra
  • Rakesh Roshan Jha
  • Devendra Kumar Patel
  • Chetna Singh


Alpha-synuclein (α-synuclein) aggregation and impairment of the Ubiquitin proteasome system (UPS) are implicated in Parkinson’s disease (PD) pathogenesis. While zinc (Zn) induces dopaminergic neurodegeneration resulting in PD phenotype, its effect on protein aggregation and UPS has not yet been deciphered. The current study investigated the role of α-synuclein aggregation and UPS in Zn-induced Parkinsonism. Additionally, levodopa (l-Dopa) response was assessed in Zn-induced Parkinsonian model to establish its closeness with idiopathic PD. Male Wistar rats were treated with zinc sulfate (Zn; 20 mg/kg; i.p.) twice weekly for 12 weeks along with respective controls. In few subsets, animals were subsequently treated with l-Dopa for 21 consecutive days following Zn exposure. A significant increase in total and free Zn content was observed in the substantia nigra of the brain of exposed groups. Zn treatment caused neurobehavioral anomalies, striatal dopamine decline, and dopaminergic neuronal cell loss accompanied with a marked increase in α-synuclein expression/aggregation and Ubiquitin-conjugated protein levels in the exposed groups. Zn exposure substantially reduced UPS-associated trypsin-like, chymotrypsin-like, and caspase-like activities along with the expression of SUG1 and β-5 subunits of UPS in the nigrostriatal tissues of exposed groups. l-Dopa treatment rescued from Zn-induced neurobehavioral deficits and restored dopamine levels towards normalcy; however, Zn-induced dopaminergic neuronal loss, reduction in tyrosine hydroxylase expression, and increase in oxidative stress were unaffected. The results suggest that Zn caused UPS impairment, resulting in α-synuclein aggregation subsequently leading to dopaminergic neurodegeneration, and that Zn-induced Parkinsonism exhibited positive l-Dopa response similar to sporadic PD.


Zinc α-Synuclein aggregation Ubiquitin proteasome system Parkinson’s disease l-Dopa 



The authors sincerely thank the Department of Biotechnology (DBT), New Delhi, India; the Department of Science and Technology (DST), New Delhi, India, and University Grants Commission (UGC), New Delhi, India for providing research fellowship to Vinod Kumar, Namrata Mittra, and Brajesh Kumar Singh/Deepali Singh, respectively. The financial aid provided to Chetna Singh through CSIR-network program “Neurodegenerative Diseases: Causes and Corrections” (miND; BSC0115) is sincerely acknowledged. The CSIR-IITR communication number of this article is 3499.

Compliance with ethical standards

Conflicts of interest

The authors declare no conflicts of interest.

Ethical approval

This study was approved by the Institutional Animal Ethics Committee. The experiments were performed as per the guidelines of the Committee for the Purpose of Control and Supervision of Experiments on Animals (CPCSEA) throughout the study.


  1. 1.
    Dawson TM, Dawson VL (2003) Rare genetic mutations shed light on the pathogenesis of Parkinson disease. J Clin Invest 111:145–151CrossRefPubMedPubMedCentralGoogle Scholar
  2. 2.
    Migliore L, Coppede F (2009) Genetics, environmental factors and the emerging role of epigenetics in neurodegenerative diseases. Mutat Res 667:82–97CrossRefPubMedGoogle Scholar
  3. 3.
    Wirdefeldt K, Adami HO, Cole P, Trichopoulos D, Mandel J (2011) Epidemiology and etiology of Parkinson’s disease: a review of the evidence. Eur J Epidemiol 26(Suppl 1):S1–S58CrossRefPubMedGoogle Scholar
  4. 4.
    Dexter DT, Wells FR, Lees AJ, Agid F, Agid Y, Jenner P, Marsden CD (1989) Increased nigral iron content and alterations in other metal ions occurring in brain in Parkinson’s disease. J Neurochem 52:1830–1836CrossRefPubMedGoogle Scholar
  5. 5.
    Kumar A, Singh BK, Ahmad I, Shukla S, Patel DK, Srivastava G, Kumar V, Pandey HP, Singh C (2012) Involvement of NADPH oxidase and glutathione in zinc-induced dopaminergic neurodegeneration in rats: similarity with paraquat neurotoxicity. Brain Res 1438:48–64CrossRefPubMedGoogle Scholar
  6. 6.
    Kumar V, Singh BK, Chauhan AK, Singh D, Patel DK, Singh C (2016) Minocycline rescues from zinc-induced nigrostriatal dopaminergic neurodegeneration: biochemical and molecular interventions. Mol Neurobiol 53:2761–2777CrossRefPubMedGoogle Scholar
  7. 7.
    Singh BK, Kumar A, Ahmad I, Kumar V, Patel DK, Jain SK, Singh C (2011) Oxidative stress in zinc-induced dopaminergic neurodegeneration: implications of superoxide dismutase and heme oxygenase-1. Free Radic Res 45:1207–1222CrossRefPubMedGoogle Scholar
  8. 8.
    Spillantini MG, Crowther RA, Jakes R, Hasegawa M, Goedert M (1998) Alpha-synuclein in filamentous inclusions of Lewy bodies from Parkinson’s disease and dementia with Lewy bodies. Proc Natl Acad Sci USA 95:6469–6473CrossRefPubMedPubMedCentralGoogle Scholar
  9. 9.
    Xu L, Pu J (2016) Alpha-synuclein in Parkinson’s disease: from pathogenetic dysfunction to potential clinical application. Parkinson’s Disease 2016:1720621PubMedPubMedCentralGoogle Scholar
  10. 10.
    Stefanis L (2012) Alpha-synuclein in Parkinson’s disease. Cold Spring Harb Perspect Med 2:a009399CrossRefPubMedPubMedCentralGoogle Scholar
  11. 11.
    Blesa J, Phani S, Jackson-Lewis V, Przedborski S (2012) Classic and new models of Parkinson’s disease. J Biomed Biotechnol 2012:845618CrossRefPubMedPubMedCentralGoogle Scholar
  12. 12.
    Javed H, Kamal MA, Ojha S (2016) An overview on the role of alpha-synuclein in experimental models of Parkinson’s disease from pathogenesis to therapeutics. CNS Neurol Disord Drug Targets 15:1240–1252CrossRefPubMedGoogle Scholar
  13. 13.
    Yamada M, Iwatsubo T, Mizuno Y, Mochizuki H (2004) Overexpression of alpha-synuclein in rat substantia nigra results in loss of dopaminergic neurons, phosphorylation of alpha-synuclein and activation of caspase-9: resemblance to pathogenetic changes in Parkinson’s disease. J Neurochem 91:451–461CrossRefPubMedGoogle Scholar
  14. 14.
    Lee VM, Trojanowski JQ (2006) Mechanisms of Parkinson’s disease linked to pathological alpha-synuclein: new targets for drug discovery. Neuron 52:33–38CrossRefPubMedGoogle Scholar
  15. 15.
    Moore DJ, Dawson VL, Dawson TM (2003) Role for the ubiquitin-proteasome system in Parkinson’s disease and other neurodegenerative brain amyloidoses. Neuromolecular Med 4:95–108CrossRefPubMedGoogle Scholar
  16. 16.
    Vilchez D, Saez I, Dillin A (2014) The role of protein clearance mechanisms in organismal ageing and age-related diseases. Nat Commun 5:5659CrossRefPubMedGoogle Scholar
  17. 17.
    McNaught KS, Belizaire R, Isacson O, Jenner P, Olanow CW (2003) Altered proteasomal function in sporadic Parkinson’s disease. Exp Neurol 179:38–46CrossRefPubMedGoogle Scholar
  18. 18.
    Zheng C, Geetha T, Babu JR (2014) Failure of ubiquitin proteasome system: risk for neurodegenerative diseases. Neurodegener Dis 14:161–175CrossRefPubMedGoogle Scholar
  19. 19.
    McNaught KS, Jenner P (2001) Proteasomal function is impaired in substantia nigra in Parkinson’s disease. Neurosci Lett 297:191–194CrossRefPubMedGoogle Scholar
  20. 20.
    Sherman NY, Goldberg AL (2001) Cellular defenses against unfolded proteins: a cell biologist thinks about neurodegenerative diseases. Neuron 29:15–32CrossRefPubMedGoogle Scholar
  21. 21.
    Wang XF, Li S, Chou AP, Bronstein JM (2006) Inhibitory effects of pesticides on proteasome activity: implication in Parkinson’s disease. Neurobiol Dis 23:198–205CrossRefPubMedGoogle Scholar
  22. 22.
    Betarbet R, Sherer TB, Greenamyre JT (2005) Ubiquitin-proteasome system and Parkinson’s diseases. Exp Neurol 191:S17–S27CrossRefGoogle Scholar
  23. 23.
    Fornai F, Schluter OM, Lenzi P, Gesi M, Ruffoli R, Ferrucci M, Lazzeri G, Busceti CL, Pontarelli F, Battaglia G, Pellegrini A, Nicoletti F, Ruggieri S, Paparelli A, Sudhof TC (2005) Parkinson-like syndrome induced by continuous MPTP infusion: convergent roles of the ubiquitin-proteasome system and alpha-synuclein. Proc Natl Acad Sci USA 102:3413–3418CrossRefPubMedPubMedCentralGoogle Scholar
  24. 24.
    Yang W, Tiffany-Castiglioni E (2007) The bipyridyl herbicide paraquat induces proteasome dysfunction in human neuroblastoma SH-SY5Y cells. J Toxicol Environ Health A 70:1849–1857CrossRefPubMedGoogle Scholar
  25. 25.
    Izumi Y, Yamamoto N, Matsushima S, Yamamoto T, Takada-Takatori Y, Akaike A, Kume T (2015) Compensatory role of the Nrf2-ARE pathway against paraquat toxicity: relevance of 26S proteasome activity. J Pharmacol Sci 129:150–159CrossRefPubMedGoogle Scholar
  26. 26.
    Kwakye GF, McMinimy RA, Aschner M (2017) Disease-toxicant interactions in Parkinson’s disease neuropathology. Neurochem Res 42:1772–1786CrossRefPubMedGoogle Scholar
  27. 27.
    Agrawal S, Singh A, Tripathi P, Mishra M, Singh MP, Singh MP (2015) Cypermethrin-induced nigrostriatal dopaminergic neurodegeneration alters the mitochondrial function: a proteomics study. Mol Neurbiol 51:448–465CrossRefGoogle Scholar
  28. 28.
    Kumar A, Ahmad I, Shukla S, Singh BK, Patel DK, Pandey HP, Singh C (2010) Effect of zinc and paraquat co-exposure on neurodegeneration: modulation of oxidative stress and expression of metallothioneins, toxicant responsive and transporter genes in rats. Free Radic Res 44:950–965CrossRefPubMedGoogle Scholar
  29. 29.
    Tripathi P, Singh A, Bala L, Patel DK, Singh MP (2017) Ibuprofen protects from cypermethrin-induced changes in the striatal dendritic length and spine density. Mol Neurobiol. CrossRefPubMedGoogle Scholar
  30. 30.
    Yang W, Chen L, Ding Y, Zhuang X, Kang UJ (2007) Paraquat induces dopaminergic dysfunction and proteasome impairment in DJ-1 deficient mice. Hum Mol Genet 16:2900–2910CrossRefPubMedGoogle Scholar
  31. 31.
    Lowry OH, Rosebrough NJ, Farr AL, Randall RJ (1951) Protein measurement with the Folin phenol reagent. J Biol Chem 193:265–275PubMedGoogle Scholar
  32. 32.
    Chauhan AK, Mittra N, Kumar V, Patel DK, Singh C (2016) Inflammation and B-cell lymphoma-2 associated X protein regulate zinc-induced apoptotic degeneration of rat nigrostriatal dopaminergic neurons. Mol Neurobiol 53:5782–5795CrossRefPubMedGoogle Scholar
  33. 33.
    Gu Z, Nakamura T, Yao D, Shi ZQ, Lipton SA (2005) Nitrosative and oxidative stress links dysfunctional ubiquitination to Parkinson’s disease. Cell Death Differ 12:1202–1204CrossRefPubMedGoogle Scholar
  34. 34.
    Kim TD, Paik SR, Yang CH, Kim J (2000) Structural changes in alpha-synuclein affect its chaperone-like activity in vitro. Protein Sci 9:2489–2496CrossRefPubMedPubMedCentralGoogle Scholar
  35. 35.
    Agrawal S, Dixit A, Singh A, Tripathi P, Singh D, Patel DK, Singh M.P (2015) Cyclosporin A and MnTMPyP alleviate α-synuclein expression and aggregation in cypermethrin-induced Parkinsonism. Mol Neurobiol 52:1619–1628CrossRefPubMedGoogle Scholar
  36. 36.
    Snyder H, Mensah K, Theisler C, Lee J, Matouschek A, Wolozin B (2003) Aggregated and monomeric alpha-synuclein bind to the S6′ proteasomal protein and inhibit proteasomal function. J Biol Chem 278:11753–11759CrossRefPubMedGoogle Scholar
  37. 37.
    Sawada H, Kohno R, Kihara T, Izumi Y, Sakka N, Ibi M, Nakanishi M, Nakamizo T, Yamakawa K, Shibasaki H, Yamamoto N, Akaike A, Inden M, Kitamura Y, Taniguchi T, Shimohama S (2004) Proteasome mediates dopaminergic neuronal degeneration and its inhibition causes alpha-synuclein inclusions. J Biol Chem 279:10710–10719CrossRefPubMedGoogle Scholar
  38. 38.
    Chen M, Chen Q, Cheng XW, Lu TJ, Jia JM, Zhang C, Xiong ZQ (2009) Zn2 + mediates ischemia-induced impairment of the Ubiquitin-proteasome system in the rat hippocampus. J Neurochem 111:1094–1103CrossRefPubMedGoogle Scholar
  39. 39.
    Katzenschlager R, Lees AJ (2002) Treatment of Parkinson’s disease: levodopa as the first choice. J Neurol 249(Suppl 2):II19–I24PubMedGoogle Scholar
  40. 40.
    Huot P, Johnston TH, Koprich JB, Fox SH, Brotchie JM (2012) l-DOPA pharmacokinetics in the MPTP-lesioned macaque model of Parkinson’s disease. Neuropharmacology 63:829–836CrossRefPubMedGoogle Scholar
  41. 41.
    Camp DM, Loeffler DA, LeWitt PA (2000) l-DOPA does not enhance hydroxyl radical formation in the nigrostriatal dopamine system of rats with a unilateral 6-hydroxydopamine lesion. J Neurochem 74:1229–1240CrossRefPubMedGoogle Scholar
  42. 42.
    Datla KP, Blunt SB, Dexter DT (2001) Chronic l-DOPA administration is not toxic to the remaining dopaminergic nigrostriatal neurons, but instead may promote their functional recovery, in rats with partial 6-OHDA or FeCl(3) nigrostriatal lesions. Mov Disord 16:424–434CrossRefPubMedGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2017

Authors and Affiliations

  • Vinod Kumar
    • 1
    • 2
  • Deepali Singh
    • 1
    • 2
  • Brajesh Kumar Singh
    • 1
  • Shweta Singh
    • 1
  • Namrata Mittra
    • 1
    • 2
  • Rakesh Roshan Jha
    • 3
  • Devendra Kumar Patel
    • 3
  • Chetna Singh
    • 1
    • 2
  1. 1.Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment GroupCSIR-Indian Institute of Toxicology Research (CSIR-IITR)LucknowIndia
  2. 2.Academy of Scientific and Innovative ResearchLucknowIndia
  3. 3.Analytical Chemistry Laboratory, Regulatory Toxicology GroupCSIR-Indian Institute of Toxicology Research (CSIR-IITR)LucknowIndia

Personalised recommendations