Induction of brain-derived neurotrophic factor in plaque-associated glial cells of aged APP23 transgenic mice.
Brain-derived neurotrophic factor (BDNF) is a versatile neurotrophic factor that has been implicated in cell survival, cell differentiation, axonal growth, and activity-dependent synaptic plasticity. Changes in BDNF expression have also been reported during the course of several neurological disorders, including Alzheimer's disease (AD). The role of BDNF in AD, however, has remained elusive. To learn more about this neurotrophic factor, we investigated BDNF expression in brain of amyloid precursor protein overexpressing mice (APP23 transgenic mice). In situ hybridization revealed BDNF mRNA signals associated with amyloid plaques. Laser microdissection in combination with quantitative RT-PCR demonstrated a sixfold increase of BDNF mRNA in the immediate plaque vicinity, a threefold increase in a tissue ring surrounding the plaque, and control levels in interplaque areas comparable with those measured in age-matched nontransgenic mice. Double immunofluorescence localized BDNF to microglial cells and astrocytes surrounding the plaque. Cortical BDNF protein levels were quantified by ELISA demonstrating a >10-fold increase compared with age-matched controls. This upregulation of BDNF protein significantly correlated with the beta-amyloid load in the transgenic animals. Taken together, our data demonstrate a plaque-associated upregulation of BDNF in APP23 transgenic mice and implicate this neurotrophin in the regulation of inflammatory and axonal growth processes in the plaque vicinity.
Burbach
Guido J
GJ
Institute of Clinical Neuroanatomy, J. W. Goethe University, D-60590 Frankfurt, Germany.
Hellweg
Rainer
R
Haas
Carola A
CA
Del Turco
Domenico
D
Deicke
Uwe
U
Abramowski
Dorothee
D
Jucker
Mathias
M
Staufenbiel
Matthias
M
Deller
Thomas
T
D000367:Age Factors; D000544:Alzheimer Disease / Q000378:metabolism* / Q000473:pathology; D016229:Amyloid beta-Peptides / Q000378:metabolism; D016564:Amyloid beta-Protein Precursor / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000096:biosynthesis* / Q000235:genetics; D004195:Disease Models, Animal; D005625:Frontal Lobe / Q000378:metabolism / Q000473:pathology; D017403:In Situ Hybridization; D051379:Mice; D008822:Mice, Transgenic; D009457:Neuroglia / Q000378:metabolism* / Q000473:pathology; D010446:Peptide Fragments / Q000378:metabolism; D058225:Plaque, Amyloid / Q000378:metabolism* / Q000473:pathology; D017729:Presynaptic Terminals / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism
D016229:Amyloid beta-Peptides; D016564:Amyloid beta-Protein Precursor; D019208:Brain-Derived Neurotrophic Factor; D010446:Peptide Fragments; D012333:RNA, Messenger; C078592:amyloid beta-protein (1-40); C075222:amyloid beta-protein (1-42)