Abstract
Oxidative stress has been associated with neuronal loss in neurodegenerative diseases and during age-associated cognitive decline. Flavonoids have been proposed to play a useful role in protecting the central nervous system against oxidative and excitotoxic stress, although the mechanism of action is unknown. Using oxidized low-density lipoprotein (oxLDL) as the oxidative insult we investigated the mechanism of neurotoxicity and attempted to identify possible sites of action of two of the most potent protective flavonoids, epicatechin and kaempferol, in cultured primary neurons. Using cultured striatal neurons and selective phosphospecific antibodies we addressed the potential role of extracellular signal-regulated kinases 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK). OxLDL stimulated a Ca(2+)-dependent activation of both ERK1/2 and JNK that was strongly inhibited by pre-treatment with low micromolar concentrations of epicatechin. Neurotoxicity induced by oxLDL, however, was neither reduced nor enhanced by inhibiting ERK1/2 activation with mitogen-activated protein kinase kinase (MEK) inhibitors, suggesting that this cascade is unlikely to be involved in either oxLDL toxicity or the protective effects of flavonoids. oxLDL caused a sustained activation of JNK that resulted in the phosphorylation of the transcription factor c-Jun, which was abolished in neurons pre-treated with flavonoids. Furthermore, oxLDL induced the cleavage of procaspase-3 and increased caspase-3-like protease activity in neurons, an effect which was strongly inhibited by pre-exposure to either epicatechin or kaempferol. In addition, a caspase-3 inhibitor reduced oxLDL-induced neuronal death, implicating an apoptotic mechanism. A major in vivo metabolite of epicatechin, 3'-O-methyl-epicatechin was as effective as epicatechin in protecting neurons. Thus dietary flavonoids might have potential as protective agents against neuronal apoptosis through selective actions within stress-activated cellular responses, including protein kinase signalling cascades.
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- Abe K., Saito H. Amyloid beta neurotoxicity not mediated by the mitogen-activated protein kinase cascade in cultured rat hippocampal and cortical neurons. Neurosci Lett. 2000 Sep 29;292(1):1–4. doi: 10.1016/s0304-3940(00)01415-4. [DOI] [PubMed] [Google Scholar]
- Alexi T., Borlongan C. V., Faull R. L., Williams C. E., Clark R. G., Gluckman P. D., Hughes P. E. Neuroprotective strategies for basal ganglia degeneration: Parkinson's and Huntington's diseases. Prog Neurobiol. 2000 Apr;60(5):409–470. doi: 10.1016/s0301-0082(99)00032-5. [DOI] [PubMed] [Google Scholar]
- Anderson C. N., Tolkovsky A. M. A role for MAPK/ERK in sympathetic neuron survival: protection against a p53-dependent, JNK-independent induction of apoptosis by cytosine arabinoside. J Neurosci. 1999 Jan 15;19(2):664–673. doi: 10.1523/JNEUROSCI.19-02-00664.1999. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bastianetto S., Zheng W. H., Quirion R. The Ginkgo biloba extract (EGb 761) protects and rescues hippocampal cells against nitric oxide-induced toxicity: involvement of its flavonoid constituents and protein kinase C. J Neurochem. 2000 Jun;74(6):2268–2277. doi: 10.1046/j.1471-4159.2000.0742268.x. [DOI] [PubMed] [Google Scholar]
- Behl C. Alzheimer's disease and oxidative stress: implications for novel therapeutic approaches. Prog Neurobiol. 1999 Feb;57(3):301–323. doi: 10.1016/s0301-0082(98)00055-0. [DOI] [PubMed] [Google Scholar]
- Behrens A., Sibilia M., Wagner E. F. Amino-terminal phosphorylation of c-Jun regulates stress-induced apoptosis and cellular proliferation. Nat Genet. 1999 Mar;21(3):326–329. doi: 10.1038/6854. [DOI] [PubMed] [Google Scholar]
- Bhat N. R., Zhang P. Hydrogen peroxide activation of multiple mitogen-activated protein kinases in an oligodendrocyte cell line: role of extracellular signal-regulated kinase in hydrogen peroxide-induced cell death. J Neurochem. 1999 Jan;72(1):112–119. doi: 10.1046/j.1471-4159.1999.0720112.x. [DOI] [PubMed] [Google Scholar]
- Bickford P. C., Gould T., Briederick L., Chadman K., Pollock A., Young D., Shukitt-Hale B., Joseph J. Antioxidant-rich diets improve cerebellar physiology and motor learning in aged rats. Brain Res. 2000 Jun 2;866(1-2):211–217. doi: 10.1016/s0006-8993(00)02280-0. [DOI] [PubMed] [Google Scholar]
- Bonni A., Brunet A., West A. E., Datta S. R., Takasu M. A., Greenberg M. E. Cell survival promoted by the Ras-MAPK signaling pathway by transcription-dependent and -independent mechanisms. Science. 1999 Nov 12;286(5443):1358–1362. doi: 10.1126/science.286.5443.1358. [DOI] [PubMed] [Google Scholar]
- Camandola S., Poli G., Mattson M. P. The lipid peroxidation product 4-hydroxy-2,3-nonenal increases AP-1-binding activity through caspase activation in neurons. J Neurochem. 2000 Jan;74(1):159–168. doi: 10.1046/j.1471-4159.2000.0740159.x. [DOI] [PubMed] [Google Scholar]
- Cantuti-Castelvetri I., Shukitt-Hale B., Joseph J. A. Neurobehavioral aspects of antioxidants in aging. Int J Dev Neurosci. 2000 Jul-Aug;18(4-5):367–381. doi: 10.1016/s0736-5748(00)00008-3. [DOI] [PubMed] [Google Scholar]
- Castagne V., Gautschi M., Lefevre K., Posada A., Clarke P. G. Relationships between neuronal death and the cellular redox status. Focus on the developing nervous system. Prog Neurobiol. 1999 Nov;59(4):397–423. doi: 10.1016/s0301-0082(99)00012-x. [DOI] [PubMed] [Google Scholar]
- Chung B. H., Wilkinson T., Geer J. C., Segrest J. P. Preparative and quantitative isolation of plasma lipoproteins: rapid, single discontinuous density gradient ultracentrifugation in a vertical rotor. J Lipid Res. 1980 Mar;21(3):284–291. [PubMed] [Google Scholar]
- Cockle S. M., Kimber S., Hindmarch I. The effects of Ginkgo biloba extract (LI 1370) supplementation on activities of daily living in free living older volunteers: a questionnaire survey. Hum Psychopharmacol. 2000 Jun;15(4):227–235. doi: 10.1002/1099-1077(200006)15:4<227::AID-HUP208>3.0.CO;2-M. [DOI] [PubMed] [Google Scholar]
- Coyle J. T., Puttfarcken P. Oxidative stress, glutamate, and neurodegenerative disorders. Science. 1993 Oct 29;262(5134):689–695. doi: 10.1126/science.7901908. [DOI] [PubMed] [Google Scholar]
- Davis R. J. Signal transduction by the JNK group of MAP kinases. Cell. 2000 Oct 13;103(2):239–252. doi: 10.1016/s0092-8674(00)00116-1. [DOI] [PubMed] [Google Scholar]
- Halliwell B. Reactive oxygen species and the central nervous system. J Neurochem. 1992 Nov;59(5):1609–1623. doi: 10.1111/j.1471-4159.1992.tb10990.x. [DOI] [PubMed] [Google Scholar]
- Herdegen T., Skene P., Bähr M. The c-Jun transcription factor--bipotential mediator of neuronal death, survival and regeneration. Trends Neurosci. 1997 May;20(5):227–231. doi: 10.1016/s0166-2236(96)01000-4. [DOI] [PubMed] [Google Scholar]
- Inanami O., Watanabe Y., Syuto B., Nakano M., Tsuji M., Kuwabara M. Oral administration of (-)catechin protects against ischemia-reperfusion-induced neuronal death in the gerbil. Free Radic Res. 1998 Oct;29(4):359–365. doi: 10.1080/10715769800300401. [DOI] [PubMed] [Google Scholar]
- Jiang Z. Y., Hunt J. V., Wolff S. P. Ferrous ion oxidation in the presence of xylenol orange for detection of lipid hydroperoxide in low density lipoprotein. Anal Biochem. 1992 May 1;202(2):384–389. doi: 10.1016/0003-2697(92)90122-n. [DOI] [PubMed] [Google Scholar]
- Joseph J. A., Shukitt-Hale B., Denisova N. A., Bielinski D., Martin A., McEwen J. J., Bickford P. C. Reversals of age-related declines in neuronal signal transduction, cognitive, and motor behavioral deficits with blueberry, spinach, or strawberry dietary supplementation. J Neurosci. 1999 Sep 15;19(18):8114–8121. doi: 10.1523/JNEUROSCI.19-18-08114.1999. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Joseph J. A., Shukitt-Hale B., Denisova N. A., Prior R. L., Cao G., Martin A., Taglialatela G., Bickford P. C. Long-term dietary strawberry, spinach, or vitamin E supplementation retards the onset of age-related neuronal signal-transduction and cognitive behavioral deficits. J Neurosci. 1998 Oct 1;18(19):8047–8055. doi: 10.1523/JNEUROSCI.18-19-08047.1998. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Keller J. N., Hanni K. B., Markesbery W. R. Oxidized low-density lipoprotein induces neuronal death: implications for calcium, reactive oxygen species, and caspases. J Neurochem. 1999 Jun;72(6):2601–2609. doi: 10.1046/j.1471-4159.1999.0722601.x. [DOI] [PubMed] [Google Scholar]
- Kong A. N., Yu R., Chen C., Mandlekar S., Primiano T. Signal transduction events elicited by natural products: role of MAPK and caspase pathways in homeostatic response and induction of apoptosis. Arch Pharm Res. 2000 Feb;23(1):1–16. doi: 10.1007/BF02976458. [DOI] [PubMed] [Google Scholar]
- Kruman I., Bruce-Keller A. J., Bredesen D., Waeg G., Mattson M. P. Evidence that 4-hydroxynonenal mediates oxidative stress-induced neuronal apoptosis. J Neurosci. 1997 Jul 1;17(13):5089–5100. doi: 10.1523/JNEUROSCI.17-13-05089.1997. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kuhnle G., Spencer J. P., Schroeter H., Shenoy B., Debnam E. S., Srai S. K., Rice-Evans C., Hahn U. Epicatechin and catechin are O-methylated and glucuronidated in the small intestine. Biochem Biophys Res Commun. 2000 Oct 22;277(2):507–512. doi: 10.1006/bbrc.2000.3701. [DOI] [PubMed] [Google Scholar]
- Luo Y., Umegaki H., Wang X., Abe R., Roth G. S. Dopamine induces apoptosis through an oxidation-involved SAPK/JNK activation pathway. J Biol Chem. 1998 Feb 6;273(6):3756–3764. doi: 10.1074/jbc.273.6.3756. [DOI] [PubMed] [Google Scholar]
- Markwell M. A., Haas S. M., Tolbert N. E., Bieber L. L. Protein determination in membrane and lipoprotein samples: manual and automated procedures. Methods Enzymol. 1981;72:296–303. doi: 10.1016/s0076-6879(81)72018-4. [DOI] [PubMed] [Google Scholar]
- Maroney A. C., Finn J. P., Bozyczko-Coyne D., O'Kane T. M., Neff N. T., Tolkovsky A. M., Park D. S., Yan C. Y., Troy C. M., Greene L. A. CEP-1347 (KT7515), an inhibitor of JNK activation, rescues sympathetic neurons and neuronally differentiated PC12 cells from death evoked by three distinct insults. J Neurochem. 1999 Nov;73(5):1901–1912. [PubMed] [Google Scholar]
- Mielke K., Herdegen T. JNK and p38 stresskinases--degenerative effectors of signal-transduction-cascades in the nervous system. Prog Neurobiol. 2000 May;61(1):45–60. doi: 10.1016/s0301-0082(99)00042-8. [DOI] [PubMed] [Google Scholar]
- Murray B., Alessandrini A., Cole A. J., Yee A. G., Furshpan E. J. Inhibition of the p44/42 MAP kinase pathway protects hippocampal neurons in a cell-culture model of seizure activity. Proc Natl Acad Sci U S A. 1998 Sep 29;95(20):11975–11980. doi: 10.1073/pnas.95.20.11975. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Perkinton M. S., Sihra T. S., Williams R. J. Ca(2+)-permeable AMPA receptors induce phosphorylation of cAMP response element-binding protein through a phosphatidylinositol 3-kinase-dependent stimulation of the mitogen-activated protein kinase signaling cascade in neurons. J Neurosci. 1999 Jul 15;19(14):5861–5874. doi: 10.1523/JNEUROSCI.19-14-05861.1999. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Perry G., Roder H., Nunomura A., Takeda A., Friedlich A. L., Zhu X., Raina A. K., Holbrook N., Siedlak S. L., Harris P. L. Activation of neuronal extracellular receptor kinase (ERK) in Alzheimer disease links oxidative stress to abnormal phosphorylation. Neuroreport. 1999 Aug 2;10(11):2411–2415. doi: 10.1097/00001756-199908020-00035. [DOI] [PubMed] [Google Scholar]
- Pryor W. A., Castle L. Chemical methods for the detection of lipid hydroperoxides. Methods Enzymol. 1984;105:293–299. doi: 10.1016/s0076-6879(84)05037-0. [DOI] [PubMed] [Google Scholar]
- Pulverer B. J., Kyriakis J. M., Avruch J., Nikolakaki E., Woodgett J. R. Phosphorylation of c-jun mediated by MAP kinases. Nature. 1991 Oct 17;353(6345):670–674. doi: 10.1038/353670a0. [DOI] [PubMed] [Google Scholar]
- Rice-Evans C. A., Miller N. J., Paganga G. Structure-antioxidant activity relationships of flavonoids and phenolic acids. Free Radic Biol Med. 1996;20(7):933–956. doi: 10.1016/0891-5849(95)02227-9. [DOI] [PubMed] [Google Scholar]
- Samanta S., Perkinton M. S., Morgan M., Williams R. J. Hydrogen peroxide enhances signal-responsive arachidonic acid release from neurons: role of mitogen-activated protein kinase. J Neurochem. 1998 May;70(5):2082–2090. doi: 10.1046/j.1471-4159.1998.70052082.x. [DOI] [PubMed] [Google Scholar]
- Satoh T., Nakatsuka D., Watanabe Y., Nagata I., Kikuchi H., Namura S. Neuroprotection by MAPK/ERK kinase inhibition with U0126 against oxidative stress in a mouse neuronal cell line and rat primary cultured cortical neurons. Neurosci Lett. 2000 Jul 14;288(2):163–166. doi: 10.1016/s0304-3940(00)01229-5. [DOI] [PubMed] [Google Scholar]
- Schroeter H., Williams R. J., Matin R., Iversen L., Rice-Evans C. A. Phenolic antioxidants attenuate neuronal cell death following uptake of oxidized low-density lipoprotein. Free Radic Biol Med. 2000 Dec 15;29(12):1222–1233. doi: 10.1016/s0891-5849(00)00415-9. [DOI] [PubMed] [Google Scholar]
- Skaper S. D., Floreani M., Negro A., Facci L., Giusti P. Neurotrophins rescue cerebellar granule neurons from oxidative stress-mediated apoptotic death: selective involvement of phosphatidylinositol 3-kinase and the mitogen-activated protein kinase pathway. J Neurochem. 1998 May;70(5):1859–1868. doi: 10.1046/j.1471-4159.1998.70051859.x. [DOI] [PubMed] [Google Scholar]
- Soh Y., Jeong K. S., Lee I. J., Bae M. A., Kim Y. C., Song B. J. Selective activation of the c-Jun N-terminal protein kinase pathway during 4-hydroxynonenal-induced apoptosis of PC12 cells. Mol Pharmacol. 2000 Sep;58(3):535–541. doi: 10.1124/mol.58.3.535. [DOI] [PubMed] [Google Scholar]
- Stanciu M., Wang Y., Kentor R., Burke N., Watkins S., Kress G., Reynolds I., Klann E., Angiolieri M. R., Johnson J. W. Persistent activation of ERK contributes to glutamate-induced oxidative toxicity in a neuronal cell line and primary cortical neuron cultures. J Biol Chem. 2000 Apr 21;275(16):12200–12206. doi: 10.1074/jbc.275.16.12200. [DOI] [PubMed] [Google Scholar]
- Sugawa M., Ikeda S., Kushima Y., Takashima Y., Cynshi O. Oxidized low density lipoprotein caused CNS neuron cell death. Brain Res. 1997 Jun 27;761(1):165–172. doi: 10.1016/s0006-8993(97)00468-x. [DOI] [PubMed] [Google Scholar]
- Sun G. Y., Xia J., Draczynska-Lusiak B., Simonyi A., Sun A. Y. Grape polyphenols protect neurodegenerative changes induced by chronic ethanol administration. Neuroreport. 1999 Jan 18;10(1):93–96. doi: 10.1097/00001756-199901180-00018. [DOI] [PubMed] [Google Scholar]
- Tournier C., Hess P., Yang D. D., Xu J., Turner T. K., Nimnual A., Bar-Sagi D., Jones S. N., Flavell R. A., Davis R. J. Requirement of JNK for stress-induced activation of the cytochrome c-mediated death pathway. Science. 2000 May 5;288(5467):870–874. doi: 10.1126/science.288.5467.870. [DOI] [PubMed] [Google Scholar]
- Wang H., Joseph J. A. Quantifying cellular oxidative stress by dichlorofluorescein assay using microplate reader. Free Radic Biol Med. 1999 Sep;27(5-6):612–616. doi: 10.1016/s0891-5849(99)00107-0. [DOI] [PubMed] [Google Scholar]
- Xia Z., Dickens M., Raingeaud J., Davis R. J., Greenberg M. E. Opposing effects of ERK and JNK-p38 MAP kinases on apoptosis. Science. 1995 Nov 24;270(5240):1326–1331. doi: 10.1126/science.270.5240.1326. [DOI] [PubMed] [Google Scholar]
- Yuan J., Yankner B. A. Apoptosis in the nervous system. Nature. 2000 Oct 12;407(6805):802–809. doi: 10.1038/35037739. [DOI] [PubMed] [Google Scholar]
- Zhang Y., Dawson V. L., Dawson T. M. Oxidative stress and genetics in the pathogenesis of Parkinson's disease. Neurobiol Dis. 2000 Aug;7(4):240–250. doi: 10.1006/nbdi.2000.0319. [DOI] [PubMed] [Google Scholar]