Preferential Extracellular Generation of the Active Parkinsonian Toxin MPP+ by Transporter-Independent Export of the Intermediate MPDP+

Abstract Aims: 1-Methyl-4-phenyl-tetrahydropyridine (MPTP) is among the most widely used neurotoxins for inducing experimental parkinsonism. MPTP causes parkinsonian symptoms in mice, primates, and humans by killing a subpopulation of dopaminergic neurons. Extrapolations of data obtained using MPTP-based parkinsonism models to human disease are common; however, the precise mechanism by which MPTP is converted into its active neurotoxic metabolite, 1-methyl-4-phenyl-pyridinium (MPP+), has not been fully elucidated. In this study, we aimed to address two unanswered questions related to MPTP toxicology: (1) Why are MPTP-converting astrocytes largely spared from toxicity? (2) How does MPP+ reach the extracellular space? Results: In MPTP-treated astrocytes, we discovered that the membrane-impermeable MPP+, which is generally assumed to be formed inside astrocytes, is almost exclusively detected outside of these cells. Instead of a transporter-mediated export, we found that the intermediate, 1-methyl-4-phenyl-2,3-dihydropyridinium (MPDP+), and/or its uncharged conjugate base passively diffused across cell membranes and that MPP+ was formed predominately by the extracellular oxidation of MPDP+ into MPP+. This nonenzymatic extracellular conversion of MPDP+ was promoted by O2, a more alkaline pH, and dopamine autoxidation products. Innovation and Conclusion: Our data indicate that MPTP metabolism is compartmentalized between intracellular and extracellular environments, explain the absence of toxicity in MPTP-converting astrocytes, and provide a rationale for the preferential formation of MPP+ in the extracellular space. The mechanism of transporter-independent extracellular MPP+ formation described here indicates that extracellular genesis of MPP+ from MPDP is a necessary prerequisite for the selective uptake of this toxin by catecholaminergic neurons. Antioxid. Redox Signal. 23, 1001–1016.

[1]  J. Langston,et al.  Biotransformation of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine in primary cultures of mouse astrocytes. , 1991, The Journal of pharmacology and experimental therapeutics.

[2]  O. H. Viveros,et al.  Subcellular compartmentalization of 1-methyl-4-phenylpyridinium with catecholamines in adrenal medullary chromaffin vesicles may explain the lack of toxicity to adrenal chromaffin cells. , 1987, Proceedings of the National Academy of Sciences of the United States of America.

[3]  F. Guengerich,et al.  Metabolism of 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine by Mitochondrion-targeted Cytochrome P450 2D6 , 2012, The Journal of Biological Chemistry.

[4]  J. Langston,et al.  Iron‐mediated bioactivation of 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) in glial cultures , 1995, Glia.

[5]  Tanja Waldmann,et al.  Rapid, complete and large‐scale generation of post‐mitotic neurons from the human LUHMES cell line , 2011, Journal of neurochemistry.

[6]  T. Yoshikawa,et al.  Predominant role of plasma membrane monoamine transporters in monoamine transport in 1321N1, a human astrocytoma‐derived cell line , 2014, Journal of neurochemistry.

[7]  Katrin Marcus,et al.  Identification of L-ferritin in Neuromelanin Granules of the Human Substantia Nigra , 2009, Molecular & Cellular Proteomics.

[8]  S. Snyder,et al.  Parkinsonism-inducing neurotoxin, N-methyl-4-phenyl-1,2,3,6 -tetrahydropyridine: uptake of the metabolite N-methyl-4-phenylpyridine by dopamine neurons explains selective toxicity. , 1985, Proceedings of the National Academy of Sciences of the United States of America.

[9]  R. Duvoisin,et al.  Protection against the dopaminergic neurotoxicity of 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine by monoamine oxidase inhibitors , 1984, Nature.

[10]  DuhamelAlain,et al.  Targeting chelatable iron as a therapeutic modality in Parkinson's disease. , 2014 .

[11]  W. Dauer,et al.  Parkinson's Disease Mechanisms and Models , 2003, Neuron.

[12]  A. Barzilai,et al.  The molecular mechanisms of dopamine toxicity. , 2003, Advances in neurology.

[13]  L. Greene,et al.  Neuromelanin biosynthesis is driven by excess cytosolic catecholamines not accumulated by synaptic vesicles. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[14]  N. Castagnoli,et al.  Potential bioactivation pathways for the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). , 1985, Life sciences.

[15]  Dmitri B Papkovsky,et al.  Assessment of cellular oxygen gradients with a panel of phosphorescent oxygen-sensitive probes. , 2012, Analytical chemistry.

[16]  L. Peterson,et al.  Studies on the molecular mechanism of bioactivation of the selective nigrostriatal toxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. , 1985, Drug metabolism and disposition: the biological fate of chemicals.

[17]  P. Langguth,et al.  Caki-1 Cells as a Model System for the Interaction of Renally Secreted Drugs with OCT3 , 2008, Nephron Physiology.

[18]  K. Perry,et al.  Tissue concentrations of MPTP and MPP+ in relation to catecholamine depletion after the oral or subcutaneous administration of MPTP to mice. , 1989, Life sciences.

[19]  J. Javitch,et al.  Paraquat neurotoxicity is mediated by the dopamine transporter and organic cation transporter-3 , 2011, Proceedings of the National Academy of Sciences.

[20]  J. Langston,et al.  Chronic Parkinsonism in humans due to a product of meperidine-analog synthesis. , 1983, Science.

[21]  M. Leist,et al.  Requirement of a dopaminergic neuronal phenotype for toxicity of low concentrations of 1-methyl-4-phenylpyridinium to human cells. , 2009, Toxicology and applied pharmacology.

[22]  J. Blesa,et al.  Animal Models of Parkinson’s Disease , 2021, The Hidden Life of the Basal Ganglia.

[23]  P. Sonsalla,et al.  Studies on species sensitivity to the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Part 1: Systemic administration. , 1994, The Journal of pharmacology and experimental therapeutics.

[24]  H. Liou,et al.  Cellular localization of the organic cation transporters, OCT1 and OCT2, in brain microvessel endothelial cells and its implication for MPTP transport across the blood‐brain barrier and MPTP‐induced dopaminergic toxicity in rodents , 2010, Journal of neurochemistry.

[25]  L. Tremblay,et al.  Experimental Models of Parkinson’s Disease , 2002, Annales pharmaceutiques francaises.

[26]  Dietmar Schomburg,et al.  MetaboliteDetector: comprehensive analysis tool for targeted and nontargeted GC/MS based metabolome analysis. , 2009, Analytical chemistry.

[27]  R. Ramsay,et al.  Energy-dependent uptake of N-methyl-4-phenylpyridinium, the neurotoxic metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, by mitochondria. , 1986, The Journal of biological chemistry.

[28]  Daniel Weindl,et al.  Complexity of dopamine metabolism , 2013, Cell Communication and Signaling.

[29]  J. Langston,et al.  Pargyline prevents MPTP-induced parkinsonism in primates. , 1984, Science.

[30]  D. Sulzer,et al.  Neuromelanin of the Human Substantia Nigra: An Update , 2013, Neurotoxicity Research.

[31]  J. Pedraza-Chaverri,et al.  Quinolinic Acid: An Endogenous Neurotoxin with Multiple Targets , 2013, Oxidative medicine and cellular longevity.

[32]  W. Nicklas,et al.  Inhibition of NADH-linked oxidation in brain mitochondria by 1-methyl-4-phenyl-pyridine, a metabolite of the neurotoxin, 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine. , 1985, Life sciences.

[33]  R. Ramsay,et al.  Energy-driven uptake of N-methyl-4-phenylpyridine by brain mitochondria mediates the neurotoxicity of MPTP. , 1986, Life sciences.

[34]  E. Neafsey,et al.  Differential Cytotoxicities of N‐Methyl‐β‐Carbolinium Analogues of MPP+ in PC12 Cells: Insights into Potential Neurotoxicants in Parkinson's Disease , 1994, Journal of neurochemistry.

[35]  Can Ince,et al.  Mitochondrial PO2 measured by delayed fluorescence of endogenous protoporphyrin IX , 2006, Nature Methods.

[36]  G. Le Douaron,et al.  MALDI Mass Spectrometry Imaging of 1-Methyl-4-phenylpyridinium (MPP+) in Mouse Brain , 2013, Neurotoxicity Research.

[37]  S. Snyder,et al.  NORMAL MPTP BINDING IN PARKINSONIAN SUBSTANTIA NIGRA: EVIDENCE FOR EXTRANEURONAL TOXIN CONVERSION IN HUMAN BRAIN , 1985, The Lancet.

[38]  J. Langston,et al.  Production and disposition of 1‐methyl‐4‐phenylpyridinium in primary cultures of mouse astrocytes , 1992, Glia.

[39]  A. Henn,et al.  Characterization of mouse cell line IMA 2.1 as a potential model system to study astrocyte functions. , 2012, ALTEX.

[40]  R. Mayer,et al.  The vectorial orientation of human monoamine oxidase in the mitochondrial outer membrane. , 1979, The Biochemical journal.

[41]  K. Chiba,et al.  Metabolism of the neurotoxic tertiary amine, MPTP, by brain monoamine oxidase. , 1984, Biochemical and biophysical research communications.

[42]  D. P. Jones.  Intracellular diffusion gradients of O2 and ATP. , 1986, The American journal of physiology.

[43]  N. Castagnoli,et al.  The formation of reactive intermediates in the MAO-catalyzed oxidation of the nigrostriatal toxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). , 1988, Toxicology.

[44]  Subramanian Rajagopalan,et al.  Genetic or Pharmacological Iron Chelation Prevents MPTP-Induced Neurotoxicity In Vivo A Novel Therapy for Parkinson's Disease , 2003, Neuron.

[45]  B. Kalyanaraman,et al.  1‐Methyl‐4‐phenylpyridinium accumulates in cerebellar granule neurons via organic cation transporter 3 , 2003, Journal of neurochemistry.

[46]  N. Ballatori,et al.  The organic cation transporter-3 is a pivotal modulator of neurodegeneration in the nigrostriatal dopaminergic pathway , 2009, Proceedings of the National Academy of Sciences.

[47]  M. Leist,et al.  Neuroprotection by Minocycline Caused by Direct and Specific Scavenging of Peroxynitrite* , 2010, The Journal of Biological Chemistry.

[48]  B. Kalyanaraman,et al.  Mechanism of oxidation of 1-methyl-4-phenyl-2,3-dihydropyridinium (MPDP+). , 1987, Biochemical and biophysical research communications.

[49]  C. Marsden,et al.  INCREASED NIGRAL IRON CONTENT IN POSTMORTEM PARKINSONIAN BRAIN , 1987, The Lancet.

[50]  E. Takahashi,et al.  Impact of diffusional oxygen transport on oxidative metabolism in the heart. , 1998, The Japanese journal of physiology.

[51]  R. Palmiter,et al.  Mitochondrial complex I inhibition is not required for dopaminergic neuron death induced by rotenone, MPP+, or paraquat , 2008, Proceedings of the National Academy of Sciences.