Age-related motor neuron degeneration in DNA repair-deficient Ercc1 mice.
Degeneration of motor neurons contributes to senescence-associated loss of muscle function and underlies human neurodegenerative conditions such as amyotrophic lateral sclerosis and spinal muscular atrophy. The identification of genetic factors contributing to motor neuron vulnerability and degenerative phenotypes in vivo are therefore important for our understanding of the neuromuscular system in health and disease. Here, we analyzed neurodegenerative abnormalities in the spinal cord of progeroid Ercc1(Delta/-) mice that are impaired in several DNA repair systems, i.e. nucleotide excision repair, interstrand crosslink repair, and double strand break repair. Ercc1(Delta/-) mice develop age-dependent motor abnormalities, and have a shortened life span of 6-7 months. Pathologically, Ercc1(Delta/-) mice develop widespread astrocytosis and microgliosis, and motor neuron loss and denervation of skeletal muscle fibers. Degenerating motor neurons in many occasions expressed genotoxic-responsive transcription factors p53 or ATF3, and in addition, displayed a range of Golgi apparatus abnormalities. Furthermore, Ercc1(Delta/-) motor neurons developed perikaryal and axonal intermediate filament abnormalities reminiscent of cytoskeletal pathology observed in aging spinal cord. Our findings support the notion that accumulation of DNA damage and genotoxic stress may contribute to neuronal aging and motor neuron vulnerability in human neuromuscular disorders.
de Waard
Monique C
MC
Department of Genetics, Erasmus Medical Centre, Rotterdam, The Netherlands.
van der Pluijm
Ingrid
I
Zuiderveen Borgesius
Nils
N
Comley
Laura H
LH
Haasdijk
Elize D
ED
Rijksen
Yvonne
Y
Ridwan
Yanto
Y
Zondag
Gerben
G
Hoeijmakers
Jan H J
JH
Elgersma
Ype
Y
Gillingwater
Thomas H
TH
Jaarsma
Dick
D
D051700:Activating Transcription Factor 3; D000375:Aging / Q000473:pathology*; D000818:Animals; D001835:Body Weight / Q000235:genetics; D002038:Bungarotoxins / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000172:deficiency*; D004720:Endonucleases / Q000172:deficiency*; D037502:Galectin 3 / Q000378:metabolism; D005786:Gene Expression Regulation / Q000235:genetics; D005911:Gliosis / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009046:Motor Neurons / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D053580:Muscle Strength / Q000235:genetics; D009410:Nerve Degeneration / Q000235:genetics* / Q000503:physiopathology*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D016900:Neurofilament Proteins / Q000378:metabolism; D009469:Neuromuscular Junction / Q000378:metabolism / Q000473:pathology; D011930:Reaction Time / Q000235:genetics; D016622:Silver Staining / Q000379:methods; D013116:Spinal Cord / Q000473:pathology*
D051700:Activating Transcription Factor 3; C103002:Atf3 protein, mouse; D002038:Bungarotoxins; D004268:DNA-Binding Proteins; D037502:Galectin 3; D009419:Nerve Tissue Proteins; D016900:Neurofilament Proteins; C061195:neurofilament protein M; D004720:Endonucleases; C499360:Ercc1 protein, mouse