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Tea Polyphenols Protect Against Methylmercury-Induced Cell Injury in Rat Primary Cultured Astrocytes, Involvement of Oxidative Stress and Glutamate Uptake/Metabolism Disorders

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Abstract

Methylmercury (MeHg) is an extremely dangerous environmental contaminant, accumulating preferentially in CNS and causing a series of cytotoxic effects. However, the precise mechanisms are still incompletely understood. The current study explored the mechanisms that contribute to MeHg-induced cell injury focusing on the oxidative stress and Glu uptake/metabolism disorders in rat primary cultured astrocytes. Moreover, the neuroprotective effects of tea polyphenols (TP), a natural antioxidant, against MeHg cytotoxicity were also investigated. Astrocytes were exposed to 0, 2.5, 5, 10, and 20 μM MeHgCl for 6–30 h, or pretreated with 50, 100, 200, and 400 μM TP for 1–12 h; cell viability and LDH release were then determined. For further experiments, 50, 100, and 200 μM of TP pretreatment for 6 h followed by 10 μM MeHgCl for 24 h were performed for the examination of the responses of astrocytes, specifically addressing NPSH levels, ROS generation, ATPase activity, the expressions of Nrf2 pathway as well as Glu metabolism enzyme GS and Glu transporters (GLAST and GLT-1). Exposure of MeHg resulted in damages of astrocytes, which were shown by a loss of cell viability, and supported by high levels of LDH release, morphological changes, apoptosis rates, and NPSH depletion. In addition, astrocytes were sensitive to MeHg-mediated oxidative stress, a finding that is consistent with ROS overproduction; Nrf2 as well as its downstream genes HO-1 and γ-GCSh were markedly upregulated. Moreover, MeHg significantly inhibited GS activity, as well as expressions of GS, GLAST, and GLT-1. On the contrary, pretreatment with TP presented a concentration-dependent prevention against MeHg-mediated cytotoxic effects of astrocytes. In conclusion, the findings clearly indicated that MeHg aggravated oxidative stress and Glu uptake/metabolism dysfunction in astrocytes. TP possesses some abilities to prevent MeHg cytotoxicity through its antioxidative properties.

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References

  1. Bridges CC, Zalups RK (2010) Transport of inorganic mercury and methylmercury in target tissues and organs. J Toxicol Environ Health B Crit Rev 13(5):385–410. doi:10.1080/10937401003673750

    Article  CAS  PubMed  Google Scholar 

  2. Aschner M, Syversen T, Souza DO, Rocha JB, Farina M (2007) Involvement of glutamate and reactive oxygen species in methylmercury neurotoxicity. Braz J Med Biol Res 40(3):285–291. doi:10.1590/S0100-879X2007000300001

    Article  CAS  PubMed  Google Scholar 

  3. Yin Z, Milatovic D, Aschner JL, Syversen T, Rocha JB, Souza DO, Sidoryk M, Albrecht J, Aschner M (2007) Methylmercury induces oxidative injury, alterations in permeability and glutamine transport in cultured astrocytes. Brain Res 1131(1):1–10. doi:10.1016/j.brainres.2006.10.070

    Article  CAS  PubMed  Google Scholar 

  4. Yin Z, Lee E, Ni M, Jiang H, Milatovic D, Rongzhu L, Farina M, Rocha JB, Aschner M (2011) Methylmercury-induced alterations in astrocyte functions are attenuated by ebselen. Neurotoxicology 32(3):291–299. doi:10.1016/j.neuro.2011.01.004

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  5. Ceccatelli S, Dare E, Moors M (2010) Methylmercury-induced neurotoxicity and apoptosis. Chem Biol Interact 188(2):301–308. doi:10.1016/j.cbi.2010.04.007

    Article  CAS  PubMed  Google Scholar 

  6. Franco JL, Braga HC, Stringari J, Missau FC, Posser T, Mendes BG, Leal RB, Santos AR, Dafre AL, Pizzolatti MG, Farina M (2007) Mercurial-induced hydrogen peroxide generation in mouse brain mitochondria: protective effects of quercetin. Chem Res Toxicol 20(12):1919–1926. doi:10.1021/tx7002323

    Article  CAS  PubMed  Google Scholar 

  7. Franco JL, Posser T, Dunkley PR, Dickson PW, Mattos JJ, Martins R, Bainy AC, Marques MR, Dafre AL, Farina M (2009) Methylmercury neurotoxicity is associated with inhibition of the antioxidant enzyme glutathione peroxidase. Free Radic Biol Med 47(4):449–457. doi:10.1016/j.freeradbiomed.2009.05.013

    Article  CAS  PubMed  Google Scholar 

  8. Farina M, Aschner M, Rocha JB (2011) Oxidative stress in MeHg-induced neurotoxicity. Toxicol Appl Pharmacol 256(3):405–417. doi:10.1016/j.taap.2011.05.001

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  9. Farina M, Rocha JB, Aschner M (2011) Mechanisms of methylmercury-induced neurotoxicity: evidence from experimental studies. Life Sci 89(15–16):555–563. doi:10.1016/j.lfs.2011.05.019

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  10. Branco V, Canario J, Holmgren A, Carvalho C (2011) Inhibition of the thioredoxin system in the brain and liver of zebra–seabreams exposed to waterborne methylmercury. Toxicol Appl Pharmacol 251(2):95–103. doi:10.1016/j.taap.2010.12.005

    Article  CAS  PubMed  Google Scholar 

  11. Razafimanjato H, Garmy N, Guo XJ, Varini K, Di Scala C, Di Pasquale E, Taieb N, Maresca M (2010) The food-associated fungal neurotoxin ochratoxin A inhibits the absorption of glutamate by astrocytes through a decrease in cell surface expression of the excitatory amino-acid transporters GLAST and GLT-1. Neurotoxicology 31(5):475–484. doi:10.1016/j.neuro.2010.06.003

    Article  CAS  PubMed  Google Scholar 

  12. Bak LK, Schousboe A, Waagepetersen HS (2006) The glutamate/GABA-glutamine cycle: aspects of transport, neurotransmitter homeostasis and ammonia transfer. J Neurochem 98(3):641–653. doi:10.1111/j.1471-4159.2006.03913.x

    Article  CAS  PubMed  Google Scholar 

  13. Shanker G, Syversen T, Aschner JL, Aschner M (2005) Modulatory effect of glutathione status and antioxidants on methylmercury-induced free radical formation in primary cultures of cerebral astrocytes. Brain Res Mol Brain Res 137(1–2):11–22. doi:10.1016/j.molbrainres.2005.02.006

    Article  CAS  PubMed  Google Scholar 

  14. Allen JW, Shanker G, Aschner M (2001) Methylmercury inhibits the in vitro uptake of the glutathione precursor, cystine, in astrocytes, but not in neurons. Brain Res 894(1):131–140. doi:10.1016/S0006-8993(01)01988-6

    Article  CAS  PubMed  Google Scholar 

  15. Allen JW, Mutkus LA, Aschner M (2001) Methylmercury-mediated inhibition of 3 H-d-aspartate transport in cultured astrocytes is reversed by the antioxidant catalase. Brain Res 902(1):92–100. doi:10.1016/S0006-8993(01)02375-7

    Article  CAS  PubMed  Google Scholar 

  16. do Nascimento JL, Oliveira KR, Crespo-Lopez ME, Macchi BM, Maues LA, Pinheiro C, Silveira LC, Herculano AM (2008) Methylmercury neurotoxicity and antioxidant defenses. Indian J Med Res 128(4):373–382

    PubMed  Google Scholar 

  17. Wang L, Jiang H, Yin Z, Aschner M, Cai J (2009) Methylmercury toxicity and Nrf2-dependent detoxification in astrocytes. Toxicol Sci 107(1):135–143. doi:10.1093/toxsci/kfn201

    Article  CAS  PubMed  Google Scholar 

  18. Cao XH, Zhao SS, Liu DY, Wang Z, Niu LL, Hou LH, Wang CL (2011) ROS-Ca (2+) is associated with mitochondria permeability transition pore involved in surfactin-induced MCF-7 cells apoptosis. Chem Biol Interact 190(1):16–27. doi:10.1016/j.cbi.2011.01.010

    Article  CAS  PubMed  Google Scholar 

  19. Ni M, Li X, Yin Z, Sidoryk-Wegrzynowicz M, Jiang H, Farina M, Rocha JB, Syversen T, Aschner M (2011) Comparative study on the response of rat primary astrocytes and microglia to methylmercury toxicity. Glia 59(5):810–820. doi:10.1002/glia.21153

    Article  PubMed  PubMed Central  Google Scholar 

  20. Kensler TW, Wakabayashi N (2010) Nrf2: friend or foe for chemoprevention? Carcinogenesis 31(1):90–99. doi:10.1093/carcin/bgp231

    Article  CAS  PubMed  Google Scholar 

  21. Hwang GW (2012) Role of intracellular defense factors against methylmercury toxicity. Biol Pharm Bull 35(11):1881–1884. doi:10.1248/bpb.b212019

    Article  CAS  PubMed  Google Scholar 

  22. Toyama T, Sumi D, Shinkai Y, Yasutake A, Taguchi K, Tong KI, Yamamoto M, Kumagai Y (2007) Cytoprotective role of Nrf2/Keap1 system in methylmercury toxicity. Biochem Biophys Res Commun 363(3):645–650. doi:10.1016/j.bbrc.2007.09.017

    Article  CAS  PubMed  Google Scholar 

  23. Toyama T, Shinkai Y, Yasutake A, Uchida K, Yamamoto M, Kumagai Y (2011) Isothiocyanates reduce mercury accumulation via an Nrf2-dependent mechanism during exposure of mice to methylmercury. Environ Health Perspect 119(8):1117–1122. doi:10.1289/ehp.1003123

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  24. Ni M, Li X, Yin Z, Jiang H, Sidoryk-Wegrzynowicz M, Milatovic D, Cai J, Aschner M (2010) Methylmercury induces acute oxidative stress, altering Nrf2 protein level in primary microglial cells. Toxicol Sci 116(2):590–603. doi:10.1093/toxsci/kfq126

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  25. Kaur P, Aschner M, Syversen T (2007) Role of glutathione in determining the differential sensitivity between the cortical and cerebellar regions towards mercury-induced oxidative stress. Toxicology 230(2–3):164–177. doi:10.1016/j.tox.2006.11.058

    Article  CAS  PubMed  Google Scholar 

  26. Wormser U, Brodsky B, Milatovic D, Finkelstein Y, Farina M, Rocha JB, Aschner M (2012) Protective effect of a novel peptide against methylmercury-induced toxicity in rat primary astrocytes. Neurotoxicology 33(4):763–768. doi:10.1016/j.neuro.2011.12.004

    Article  CAS  PubMed  Google Scholar 

  27. Rush T, Liu X, Nowakowski AB, Petering DH, Lobner D (2012) Glutathione-mediated neuroprotection against methylmercury neurotoxicity in cortical culture is dependent on MRP1. Neurotoxicology 33(3):476–481. doi:10.1016/j.neuro.2012.03.004

    Article  CAS  PubMed  Google Scholar 

  28. Johnson R, Bryant S, Huntley AL (2012) Green tea and green tea catechin extracts: an overview of the clinical evidence. Maturitas 73(4):280–287. doi:10.1016/j.maturitas.2012.08.008

    Article  CAS  PubMed  Google Scholar 

  29. Bornhoeft J, Castaneda D, Nemoseck T, Wang P, Henning SM, Hong MY (2012) The protective effects of green tea polyphenols: lipid profile, inflammation, and antioxidant capacity in rats fed an atherogenic diet and dextran sodium sulfate. J Med Food 15(8):726–732. doi:10.1089/jmf.2011.0258

    Article  CAS  PubMed  Google Scholar 

  30. Narotzki B, Reznick AZ, Navot-Mintzer D, Dagan B, Levy Y (2013) Green tea and vitamin E enhance exercise-induced benefits in body composition, glucose homeostasis, and antioxidant status in elderly men and women. J Am Coll Nutr 32(1):31–40. doi:10.1080/07315724.2013.767661

    Article  CAS  PubMed  Google Scholar 

  31. Christian H, Brian J, Shelby N (2008) Antioxidant effects of green tea and its polyphenols on bladder cells. Life Sci 83(1–2):12–18. doi:10.1016/j.lfs.2008.04.010

    Google Scholar 

  32. Cavet ME, Harrington KL, Vollmer TR, Ward KW, Zhang JZ (2011) Anti-inflammatory and anti-oxidative effects of the green tea polyphenol epigallocatechin gallate in human corneal epithelial cells. Mol Vis 17:533–542

    CAS  PubMed  PubMed Central  Google Scholar 

  33. Forester SC, Lambert JD (2011) The role of antioxidant versus pro-oxidant effects of green tea polyphenols in cancer prevention. Mol Nutr Food Res 55(6):844–854. doi:10.1002/mnfr.201000641

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  34. Yang CS, Lambert JD, Sang S (2009) Antioxidative and anti-carcinogenic activities of tea polyphenols. Arch Toxicol 83(1):11–21. doi:10.1007/s00204-008-0372-0

    Article  CAS  PubMed  Google Scholar 

  35. Liu W, Xu Z, Deng Y, Xu B, Yang H, Wei Y, Feng S (2014) Excitotoxicity and oxidative damages induced by methylmercury in rat cerebral cortex and the protective effects of tea polyphenols. Environ Toxicol 29(3):269–283. doi:10.1002/tox.21755

    Article  CAS  PubMed  Google Scholar 

  36. Na HK, Surh YJ (2008) Modulation of Nrf2-mediated antioxidant and detoxifying enzyme induction by the green tea polyphenol EGCG. Food Chem Toxicol 46(4):1271–1278. doi:10.1016/j.fct.2007.10.006

    Article  CAS  PubMed  Google Scholar 

  37. Wu TY, Khor TO, Saw CL, Loh SC, Chen AI, Lim SS, Park JH, Cai L, Kong AN (2011) Anti-inflammatory/anti-oxidative stress activities and differential regulation of Nrf2-mediated genes by non-polar fractions of tea Chrysanthemum zawadskii and licorice Glycyrrhiza uralensis. AAPS J 13(1):1–13. doi:10.1208/s12248-010-9239-4

    Article  PubMed  Google Scholar 

  38. Zhao F, Liao Y, Jin Y, Li G, Lv X, Sun G (2012) Effects of arsenite on glutamate metabolism in primary cultured astrocytes. Toxicol In Vitro 26(1):24–31. doi:10.1016/j.tiv.2011.10.003

    Article  CAS  PubMed  Google Scholar 

  39. Xu B, Xu ZF, Deng Y (2009) Effect of manganese exposure on intracellular Ca2+ homeostasis and expression of NMDA receptor subunits in primary culturedneurons. Neurotoxicology 30(6):941–949. doi:10.1016/j.neuro.2009.07.011

    Article  CAS  PubMed  Google Scholar 

  40. Brumatti G, Sheridan C, Martin SJ (2008) Expression and purification of recombinant annexin V for the detection of membrane alterations on apoptotic cells. Methods 44(3):235–240. doi:10.1016/j.ymeth.2007.11.010

    Article  CAS  PubMed  Google Scholar 

  41. Ahamed M, Akhtar MJ, Siddiqui MA, Ahmad J, Musarrat J, Al-Khedhairy AA, AlSalhi MS, Alrokayan SA (2011) Oxidative stress mediated apoptosis induced by nickel ferrite nanoparticles in cultured A549 cells. Toxicology 283(2–3):101–108. doi:10.1016/j.tox.2011.02.010

    Article  CAS  PubMed  Google Scholar 

  42. Lowry OH, Rosebrough NJ, Farr AL, Randall RJ (1951) Protein measurement with the Folin phenol reagent. J Biol Chem 193(1):265–275

    CAS  PubMed  Google Scholar 

  43. Cheng WW, Lin ZQ, Wei BF, Zeng Q, Han B, Wei CX, Fan XJ, Hu CL, Liu LH, Huang JH, Yang X, Xi ZG (2011) Single-walled carbon nanotube induction of rat aortic endothelial cell apoptosis: reactive oxygen species are involved in the mitochondrial pathway. Int J Biochem Cell Biol 43(4):564–572. doi:10.1016/j.biocel.2010.12.013

    Article  CAS  PubMed  Google Scholar 

  44. Ratnakumari L, Audet R, Qureshi IA, Butterworth RF (1995) Na+, K(+)-ATPase activities are increased in brain in both congenital and acquired hyperammonemic syndromes. Neurosci Lett 197(2):89–92. doi:10.1016/0304-3940(95)11906-D

    Article  CAS  PubMed  Google Scholar 

  45. Renis M, Cardile V, Russo A, Campisi A, Collova F (1998) Glutamine synthetase activity and HSP70 levels in cultured rat astrocytes: effect of 1-octadecyl-2-methyl-rac-glycero-3-phosphocholine. Brain Res 783(1):143–150. doi:10.1016/S0006-8993(97)01321-8

    Article  CAS  PubMed  Google Scholar 

  46. Guerguerian AM, Brambrink AM, Traystman RJ, Huganir RL, Martin LJ (2002) Altered expression and phosphorylation of N-methyl-D-aspartate receptors in piglet striatum after hypoxiaischemia. Brain Res 104(1):66–80. doi:10.1016/S0169-328X(02)00285-1

    Article  CAS  Google Scholar 

  47. Bellum S, Thuett KA, Bawa B, Abbott LC (2013) The effect of methylmercury exposure on behavior and cerebellar granule cell physiology in aged mice. J Appl Toxicol 33(9):959–969. doi:10.1002/jat.2786

    Article  CAS  PubMed  Google Scholar 

  48. Aschner M (2012) Considerations on methylmercury (MeHg) treatments in in vitro studies. Neurotoxicology 33(3):512–513. doi:10.1016/j.neuro.2012.05.002

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  49. Noguchi Y, Shinozaki Y, Fujishita K, Shibata K, Imura Y, Morizawa Y, Gachet C, Koizumi S (2013) Astrocytes protect neurons against methylmercury via ATP/P2Y(1) receptor-mediated pathways in astrocytes. PLoS One 8(2):e57898. doi:10.1371/journal.pone.0057898

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  50. Sokolowski K, Falluel-Morel A, Zhou X, DiCicco-Bloom E (2011) Methylmercury (MeHg) elicits mitochondrial-dependent apoptosis in developing hippocampus and acts at low exposures. Neurotoxicology 32(5):535–544. doi:10.1016/j.neuro.2011.06.003

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  51. Roos DH, Puntel RL, Farina M, Aschner M, Bohrer D, Rocha JB, de Vargas Barbosa NB (2011) Modulation of methylmercury uptake by methionine: prevention of mitochondrial dysfunction in rat liver slices by a mimicry mechanism. Toxicol Appl Pharmacol 252(1):28–35. doi:10.1016/j.taap.2011.01.010

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  52. Lu TH, Hsieh SY, Yen CC, Wu HC, Chen KL, Hung DZ, Chen CH, Wu CC, Su YC, Chen YW, Liu SH, Huang CF (2011) Involvement of oxidative stress-mediated ERK1/2 and p38 activation regulated mitochondria-dependent apoptotic signals in methylmercury-induced neuronal cell injury. Toxicol Lett 204(1):71–80. doi:10.1016/j.toxlet.2011.04.013

    Article  CAS  PubMed  Google Scholar 

  53. Glaser V, Leipnitz G, Straliotto MR, Oliveira J, dos Santos VV, Wannmacher CM, de Bem AF, Rocha JB, Farina M, Latini A (2010) Oxidative stress-mediated inhibition of brain creatine kinase activity by methylmercury. Neurotoxicology 31(5):454–460. doi:10.1016/j.neuro.2010.05.012

    Article  CAS  PubMed  Google Scholar 

  54. Lee JH, Khor TO, Shu L, Su ZY, Fuentes F, Kong AN (2013) Dietary phytochemicals and cancer prevention: Nrf2 signaling, epigenetics, and cell death mechanisms in blocking cancer initiation and progression. Pharmacol Ther 137(2):153–171. doi:10.1016/j.pharmthera.2012.09.008

    Article  CAS  PubMed  Google Scholar 

  55. Kanner BI (2006) Structure and function of sodium-coupled GABA and glutamate transporters. J Membr Biol 213(2):89–100. doi:10.1007/s00232-006-0877-5

    Article  CAS  PubMed  Google Scholar 

  56. Swamy M, Salleh MJ, Sirajudeen KN, Yusof WR, Chandran G (2010) Nitric oxide (no), citrulline - no cycle enzymes, glutamine synthetase and oxidative stress in anoxia (hypobaric hypoxia) and reperfusion in rat brain. Int J Med Sci 7(3):147–154. doi:10.7150/ijms.7.147

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  57. Liu W, Xu Z, Yang T, Deng Y, Xu B, Feng S, Li Y (2014) The protective role of tea polyphenols against methylmercury-induced neurotoxic effects in rat cerebral cortex via inhibition of oxidative stress. Free Radic Res 48(8):849–863. doi:10.3109/10715762.2014.916039

    Article  CAS  PubMed  Google Scholar 

  58. Rah DK, Han DW, Baek HS, Hyon SH, Park BY, Park JC (2007) Protection of rabbit kidney fromischemia/reperfusion injury by green tea polyphenol pretreatment. Arch Pharm Res 30(11):1447–1454. doi:10.1007/BF02977370

    Article  CAS  PubMed  Google Scholar 

  59. Erikson KM, Dorman DC, Lash LH, Aschner M (2008) Duration of airborne-manganese exposure in rhesus monkeys is associated with brain regional changes in biomarkers of neurotoxicity. Neurotoxicology 29(3):377–385. doi:10.1016/j.neuro.2007.12.007

    Article  CAS  PubMed  Google Scholar 

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Acknowledgments

This study was supported by grants from the National Natural Science Foundation of China (No. 81172631).

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The authors declare that there is no conflict of interest.

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  1. Department of Environmental Health, School of Public Health, China Medical University, Shenyang, 110122, Liaoning province, China

    Wei Liu, Zhaofa Xu, Tianyao Yang, Yu Deng, Bin Xu & Shu Feng

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  1. Wei Liu
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Liu, W., Xu, Z., Yang, T. et al. Tea Polyphenols Protect Against Methylmercury-Induced Cell Injury in Rat Primary Cultured Astrocytes, Involvement of Oxidative Stress and Glutamate Uptake/Metabolism Disorders. Mol Neurobiol 53, 2995–3009 (2016). https://doi.org/10.1007/s12035-015-9161-y

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