Potential roles of Alzheimer precursor protein A4 and beta-amyloid in survival and function of aged spinal motor neurons after axonal injury.
To study the potential role of Alzheimer precursor protein A4 (APP) and beta-amyloid (A/beta) on aging motor neuron survival, expression of APP, A/beta, and choline acetyltransferase (ChaT) were investigated in aged rats after either distal axotomy or root avulsion injury. Approximately 45% in number of total aged spinal motor neuron were normally APP-positive. A/beta-positive neurites were observed normally in the spinal ventral horn of aged rats. After distal axotomy, without apparent neurodegeneration such as cell loss and decreased ChaT-immunoreactivity, increased levels of APP expression were observed in the spinal cords of aged rats post-injury. In contrast, after avulsion, expression of APP and A/beta were downregulated in the spinal ventral horn of aged rats, and marked loss of spinal motor neurons and downregulated ChaT expression were observed. Our data indicate that APP and A/beta might play beneficial roles in neuronal survival of aged spinal motor neurons after axonal injury.
Xie
Yuanyun
Y
Department of Anatomy, Faculty of Medicine, University of Hong Kong, Hong Kong, People's Republic of China.
Yao
Zhibin
Z
Chai
Hong
H
Wong
Wai-Man
WM
Wu
Wutian
W
D000375:Aging / Q000473:pathology*; D016229:Amyloid beta-Peptides / Q000494:pharmacology*; D016564:Amyloid beta-Protein Precursor / Q000494:pharmacology*; D000818:Animals; D019771:Axotomy / Q000379:methods; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D004195:Disease Models, Animal; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D009046:Motor Neurons / Q000187:drug effects* / Q000473:pathology; D011843:Radiculopathy / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000378:metabolism / Q000473:pathology; D013124:Spinal Injuries / Q000473:pathology*; D013997:Time Factors
D016229:Amyloid beta-Peptides; D016564:Amyloid beta-Protein Precursor; D002795:Choline O-Acetyltransferase