A distinct death mechanism is induced by 1-methyl-4-phenylpyridinium or by 6-hydroxydopamine in cultured rat cortical neurons: Degradation and dephosphorylation of tau

Baek Soo Han, Jai Sung Noh, Byoung Joo Gwag, Young J. Oh

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We examined whether the well-known neurotoxins 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenylpyridinium ion (MPP+) recruit distinct cell death mechanisms using primary cultured neurons derived from day 16 embryonic rat cortices. Electron microscopy revealed that cell death induced by both 6-OHDA and MPP+ was typified by a condensation of chromatin while prominent mitochondrial swelling was observed only in those cells treated with MPP+. Co-treatment of cells with a pan-caspase inhibitor, Z-VAD-fmk, attenuated 6-OHDA-induced chromatin condensation and neuronal death. Co-treatment with such antioxidants as N-acetylcysteine or Mn-TBAP also suppressed 6-OHDA-induced cell death. None of these treatments attenuated MPP+-induced cell death although caspase inhibition abolished MPP+-induced chromatin condensation. Interestingly, in these paradigms of cell death, the N-terminus of tau was specifically cleaved and the levels of phosphorylated tau were markedly decreased following 6-OHDA treatment. By contrast, the C-terminus of tau was cleaved in MPP+-induced cell death while the levels of phosphorylated tau remained largely unaltered. Taken together, our results indicate that distinct cellular mechanisms appear to underlie neurotoxin-induced cortical neuronal cell death.

Original languageEnglish
Pages (from-to)99-102
Number of pages4
JournalNeuroscience Letters
Issue number2
Publication statusPublished - 2003 May 1


All Science Journal Classification (ASJC) codes

  • Neuroscience(all)

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