Pharmacologic reversal of neurogenic and neuroplastic abnormalities and cognitive impairments without affecting Aβ and tau pathologies in 3xTg-AD mice

• Published in: Acta neuropathologica 2010-11, Vol.120 (5), p.605-621
• Main Authors: Blanchard, Julie, Wanka, Lukas, Tung, Yunn-Chyn, Cárdenas-Aguayo, María del Carmen, LaFerla, Frank M., Iqbal, Khalid, Grundke-Iqbal, Inge
• Format: Article
• Language: English
• Subjects: Alzheimer Disease - metabolism; Alzheimer Disease - pathology; Alzheimer Disease - prevention & control; Alzheimer's disease; Amino acids; Amyloid beta-Peptides - metabolism; Animal models; Animals; beta -Amyloid; Blotting, Western; Brain; Brain - drug effects; Brain - metabolism; Brain - pathology; Chromatography, High Pressure Liquid; Ciliary neurotrophic factor; Ciliary Neurotrophic Factor - chemistry; Cognition Disorders - metabolism; Cognition Disorders - pathology; Cognition Disorders - prevention & control; Cognitive ability; Cortex; Dentate gyrus; Disease Models, Animal; Hippocampus; Immunohistochemistry; Maze Learning - drug effects; Medicine; Medicine & Public Health; Memory - drug effects; Mice; Mice, Transgenic; Neurodegenerative diseases; Neurofibrillary tangles; Neurofibrillary Tangles - drug effects; Neurofibrillary Tangles - metabolism; Neurofibrillary Tangles - pathology; Neurogenesis; Neurogenesis - drug effects; Neuronal Plasticity - drug effects; Neuroprotective Agents - pharmacology; Neurosciences; Original Paper; Pathology; Peptides - chemical synthesis; Plaque, Amyloid - drug therapy; Plaque, Amyloid - metabolism; Plaque, Amyloid - pathology; Plaques; Plasticity; Plasticity (neural); Protein Structure, Secondary; Tau protein; tau Proteins - metabolism; Transgenic mice
• ISSN: 0001-6322; 1432-0533
• DOI: 10.1007/s00401-010-0734-6

In addition to the occurrence of numerous neurofibrillary tangles and Aβ plaques, neurogenesis and neuronal plasticity are markedly altered in Alzheimer disease (AD). Although the most popular therapeutic approach has been to inhibit neurodegeneration, another is to promote neurogenesis and neuronal plasticity by utilizing the regenerative capacity of the brain. Here we show that, in a transgenic mouse model of AD, 3xTg-AD mice, there was a marked deficit in neurogenesis and neuroplasticity, which occured before the formation of any neurofibrillary tangles or Aβ plaques and was associated with cognitive impairment. Furthermore, peripheral administration of Peptide 6, an 11-mer, which makes an active region of ciliary neurotrophic factor (CNTF, amino acid residues 146–156), restored cognition by enhancing neurogenesis and neuronal plasticity in these mice. Although this treatment had no detectable effect on Aβ and tau pathologies in 9-month animals, it enhanced neurogenesis in dentate gyrus, reduced ectopic birth in the granular cell layer, and increased neuronal plasticity in the hippocampus and cerebral cortex. These findings, for the first time, demonstrate the possibility of therapeutic treatment of AD and related disorders by peripheral administration of a peptide corresponding to a biologically active region of CNTF.