title: Epigenetic regulation of motor neuron cell death through DNA methylation.
abstract: DNA methylation is an epigenetic mechanism for gene silencing engaged by DNA methyltransferase (Dnmt)-catalyzed methyl group transfer to cytosine residues in gene-regulatory regions. It is unknown whether aberrant DNA methylation can cause neurodegeneration. We tested the hypothesis that Dnmts can mediate neuronal cell death. Enforced expression of Dnmt3a induced degeneration of cultured NSC34 cells. During apoptosis of NSC34 cells induced by camptothecin, levels of Dnmt1 and Dnmt3a increased fivefold and twofold, respectively, and 5-methylcytosine accumulated in nuclei. Truncation mutation of the Dnmt3a catalytic domain and Dnmt3a RNAi blocked apoptosis of cultured neurons. Inhibition of Dnmt catalytic activity with RG108 and procainamide protected cultured neurons from excessive DNA methylation and apoptosis. In vivo, Dnmt1 and Dnmt3a are expressed differentially during mouse brain and spinal cord maturation and in adulthood when Dnmt3a is abundant in synapses and mitochondria. Dnmt1 and Dnmt3a are expressed in motor neurons of adult mouse spinal cord, and, during their apoptosis induced by sciatic nerve avulsion, nuclear and cytoplasmic 5-methylcytosine immunoreactivity, Dnmt3a protein levels and Dnmt enzyme activity increased preapoptotically. Inhibition of Dnmts with RG108 blocked completely the increase in 5-methycytosine and the apoptosis of motor neurons in mice. In human amyotrophic lateral sclerosis (ALS), motor neurons showed changes in Dnmt1, Dnmt3a, and 5-methylcytosine similar to experimental models. Thus, motor neurons can engage epigenetic mechanisms to drive apoptosis, involving Dnmt upregulation and increased DNA methylation. These cellular mechanisms could be relevant to human ALS pathobiology and disease treatment.
authors.affiliation: Division of Neuropathology, Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2196, USA.
authors.forename: Barry A
authors.initials: BA
authors.lastname: Chestnut
authors.forename: Qing
authors.initials: Q
authors.lastname: Chang
authors.forename: Ann
authors.initials: A
authors.lastname: Price
authors.forename: Catherine
authors.initials: C
authors.lastname: Lesuisse
authors.forename: Margaret
authors.initials: M
authors.lastname: Wong
authors.forename: Lee J
authors.initials: LJ
authors.lastname: Martin
mesh_terms: D044503:5-Methylcytosine / Q000031:analogs & derivatives; D000367:Age Factors; D053829:Amyloid Precursor Protein Secretases / Q000235:genetics / Q000378:metabolism; D000690:Amyotrophic Lateral Sclerosis / Q000473:pathology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics*; D016282:Aspartic Acid Endopeptidases / Q000235:genetics / Q000378:metabolism; D002166:Camptothecin / Q000494:pharmacology; D053148:Caspase 3 / Q000378:metabolism; D002461:Cell Line, Transformed; D002490:Central Nervous System / Q000254:growth & development / Q000378:metabolism; D003596:Cytosine / Q000031:analogs & derivatives / Q000378:metabolism; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics; D019175:DNA Methylation / Q000235:genetics*; D000090205:DNA Methyltransferase 3A; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology; D057890:Epigenomics / Q000379:methods*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D051379:Mice; D008822:Mice, Transgenic; D009046:Motor Neurons / Q000502:physiology*; D009154:Mutation / Q000235:genetics; D010797:Phthalimides; D011422:Propionates / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D020426:Sciatic Neuropathy / Q000378:metabolism / Q000473:pathology; D013482:Superoxide Dismutase / Q000378:metabolism; D014162:Transfection; D014364:Tryptophan / Q000031:analogs & derivatives; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics*; D000099156:Superoxide Dismutase 2
chemical_list: D044503:5-Methylcytosine; D053829:Amyloid Precursor Protein Secretases; D016282:Aspartic Acid Endopeptidases; D002166:Camptothecin; D053148:Caspase 3; D003596:Cytosine; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases; D000090205:DNA Methyltransferase 3A; D004791:Enzyme Inhibitors; D049452:Green Fluorescent Proteins; D007211:Indoles; D010797:Phthalimides; D011422:Propionates; D034741:RNA, Small Interfering; D013482:Superoxide Dismutase; D014364:Tryptophan; D000099156:Superoxide Dismutase 2; C000717967:DNMT3A protein, human; C000715535:Dnmt3a protein, mouse; C503639:RG108; C011865:5-hydroxymethylcytosine; C000619380:DNMT1 protein, human; C000619381:Dnmt1 protein, mouse; C509282:Bace1 protein, mouse
references.citation: J Neuropathol Exp Neurol. 1999 May;58(5):459-71
references.pmid: 10331434
references.citation: Annu Rev Biophys Biomol Struct. 1995;24:293-318
references.pmid: 7663118
references.citation: Mol Neurodegener. 2009 Jul 20;4:31
references.pmid: 19619317
references.citation: Nature. 2007 Sep 13;449(7159):248-51
references.pmid: 17713477
references.citation: J Neurotrauma. 2002 Jul;19(7):815-28
references.pmid: 12184852
references.citation: J Neurosci Res. 2005 Mar 15;79(6):734-46
references.pmid: 15672446
references.citation: Pharmaceuticals (Basel). 2010;3(4):839-915
references.pmid: 21258649
references.citation: EMBO J. 1998 Sep 1;17(17):4905-8
references.pmid: 9724627
references.citation: Cancer Res. 2005 Jul 15;65(14):6305-11
references.pmid: 16024632
references.citation: Nat Neurosci. 2010 Apr;13(4):423-30
references.pmid: 20228804
references.citation: Ann Neurol. 2009 Sep;66(3):378-89
references.pmid: 19551849
references.citation: J Biol Chem. 2003 Feb 14;278(7):4806-12
references.pmid: 12473678
references.citation: Amyotroph Lateral Scler. 2009 Oct-Dec;10(5-6):418-29
references.pmid: 19922134
references.citation: J Biochem. 2000 Aug;128(2):315-21
references.pmid: 10920268
references.citation: J Comp Neurol. 2007 Jan 1;500(1):20-46
references.pmid: 17099894
references.citation: Cell. 2002 Aug 9;110(3):385-97
references.pmid: 12176325
references.citation: J Neurocytol. 1996 Dec;25(12):821-8
references.pmid: 9023727
references.citation: Curr Top Microbiol Immunol. 2006;301:45-66
references.pmid: 16570845
references.citation: Oncogene. 2001 May 28;20(24):3139-55
references.pmid: 11420731
references.citation: J Neurosci. 1996 Feb 1;16(3):939-45
references.pmid: 8558262
references.citation: Science. 2001 Aug 10;293(5532):1068-70
references.pmid: 11498573
references.citation: J Cereb Blood Flow Metab. 2002 Aug;22(8):935-50
references.pmid: 12172379
references.citation: Gene. 1999 Aug 5;236(1):87-95
references.pmid: 10433969
references.citation: Brain Res Bull. 1998 Jul 1;46(4):281-309
references.pmid: 9671259
references.citation: Expert Opin Investig Drugs. 2009 May;18(5):573-84
references.pmid: 19388875
references.citation: J Neurochem. 2003 Apr;85(1):234-47
references.pmid: 12641745
references.citation: J Neurobiol. 2002 Feb 15;50(3):181-97
references.pmid: 11810634
references.citation: Am J Pathol. 2009 Feb;174(2):574-85
references.pmid: 19116365
references.citation: Proteomics. 2005 Feb;5(2):566-71
references.pmid: 15627964
references.citation: Neuroreport. 2001 Dec 4;12(17):3763-6
references.pmid: 11726790
references.citation: Cell. 1995 Jan 13;80(1):155-65
references.pmid: 7813012
references.citation: Cancer Sci. 2006 Jun;97(6):453-8
references.pmid: 16734722
references.citation: J Biol Chem. 1999 Nov 12;274(46):33002-10
references.pmid: 10551868
references.citation: J Neurosci. 2005 Jul 6;25(27):6449-59
references.pmid: 16000635
references.citation: Glia. 2010 Feb;58(3):277-86
references.pmid: 19672971
references.citation: Cell. 1999 Oct 29;99(3):247-57
references.pmid: 10555141
references.citation: Nat Neurosci. 2010 Sep;13(9):1137-43
references.pmid: 20729844
references.citation: J Neurosci. 2008 Jan 9;28(2):395-406
references.pmid: 18184782
references.citation: J Biol Chem. 2005 Dec 9;280(49):40749-56
references.pmid: 16230360
references.citation: Science. 2003 Oct 31;302(5646):890-3
references.pmid: 14593184
references.citation: Biochemistry (Mosc). 2005 May;70(5):533-49
references.pmid: 15948707
references.citation: Hum Mol Genet. 2009 Jan 15;18(2):304-17
references.pmid: 18971205
references.citation: Nucleic Acids Res. 2005 Nov 27;33(20):e176
references.pmid: 16314307
references.citation: Nucleic Acids Res. 1984 Jun 25;12(12):4811-24
references.pmid: 6330684
references.citation: Amyotroph Lateral Scler. 2007 Apr;8(2):83-6
references.pmid: 17453634
references.citation: Differentiation. 1994 Apr;56(1-2):39-44
references.pmid: 8026645
references.citation: Neurobiol Dis. 2000 Dec;7(6 Pt B):613-22
references.pmid: 11114260
references.citation: Ann Neurol. 2011 May;69(5):743-58
references.pmid: 21520238
references.citation: J Neurotrauma. 2006 Dec;23(12):1794-801
references.pmid: 17184189
references.citation: Electrophoresis. 2006 Jul;27(14):2844-5
references.pmid: 16688701
references.citation: Cell. 2006 Sep 22;126(6):1189-201
references.pmid: 16949657
references.citation: J Neurosci. 2000 May 1;20(9):3175-81
references.pmid: 10777781
references.citation: Chromosoma. 2010 Feb;119(1):35-40
references.pmid: 19730874
references.citation: Neuron. 2007 Mar 15;53(6):857-69
references.pmid: 17359920
references.citation: Toxicol Pathol. 2011 Jan;39(1):220-33
references.pmid: 21378209
references.citation: J Biol Chem. 2006 Jun 9;281(23):15763-73
references.pmid: 16606618
references.citation: Hum Mol Genet. 2010 Jun 1;19(11):2284-302
references.pmid: 20223753
references.citation: J Neurosci. 2011 Feb 23;31(8):2815-27
references.pmid: 21414903
references.citation: J Mol Biol. 1987 Jul 20;196(2):261-82
references.pmid: 3656447
references.citation: Neuromolecular Med. 2002;2(1):47-60
references.pmid: 12230304
references.citation: Hum Mol Genet. 2000 Oct;9(16):2395-402
references.pmid: 11005794
references.citation: J Biol Chem. 1983 Aug 10;258(15):9078-85
references.pmid: 6307991
references.citation: Toxicol Lett. 2007 Jan 10;168(1):83-7
references.pmid: 17156946
references.citation: Proc Natl Acad Sci U S A. 2011 Mar 1;108(9):3630-5
references.pmid: 21321201
references.citation: Cereb Cortex. 2009 Jun;19(6):1273-93
references.pmid: 18820287
references.citation: J Clin Invest. 2010 May;120(5):1603-16
references.pmid: 20424322
references.citation: Mol Cell Biol. 2002 May;22(9):3157-73
references.pmid: 11940673
references.citation: J Neurobiol. 1999 Aug;40(2):185-201
references.pmid: 10413449
references.citation: Hum Mol Genet. 2000 Mar 1;9(4):597-604
references.pmid: 10699183
references.citation: Genes Dev. 2002 Jan 1;16(1):6-21
references.pmid: 11782440
references.citation: Dev Dyn. 1992 Jul;194(3):209-21
references.pmid: 1467557
references.citation: Exp Neurol. 2009 Aug;218(2):333-46
references.pmid: 19272377
references.citation: J Cereb Blood Flow Metab. 2000 Jan;20(1):153-67
references.pmid: 10616804