Altered expression of the CB1 cannabinoid receptor in the triple transgenic mouse model of Alzheimer's disease.
The endocannabinoid system has gained much attention as a new potential pharmacotherapeutic target in various neurodegenerative diseases, including Alzheimer's disease (AD). However, the association between CB1 alterations and the development of AD neuropathology is unclear and often contradictory. In this study, brain CB1 mRNA and CB1 protein levels were analyzed in 3 × Tg-AD mice and compared to wild-type littermates at 2, 6 and 12 months of age, using in-situ hybridization and immunohistochemistry, respectively. Semiquantitative analysis of CB1 expression focused on the prefrontal cortex (PFC), prelimbic cortex, dorsal hippocampus (DH), basolateral amygdala complex (BLA), and ventral hippocampus (VH), all areas with high CB1 densities that are strongly affected by neuropathology in 3 × Tg-AD mice. At 2 months of age, there was no change in CB1 mRNA and protein levels in 3 × Tg-AD mice compared to Non-Tg mice in all brain areas analyzed. However, at 6 and 12 months of age, CB1 mRNA levels were significantly higher in PFC, DH, and BLA, and lower in VH in 3 × Tg-AD mice compared to wild-type littermates. CB1 immunohistochemistry revealed that CB1 protein expression was unchanged in 3 × Tg-AD at 2 and 6 months of age, while a significant decrease in CB1 receptor immunoreactivity was detected in the BLA and DH of 12-month-old 3 × Tg-AD mice, with no sign of alteration in other brain areas. The altered CB1 levels appear, rather, to be age-and/or pathology-dependent, indicating an involvement of the endocannabinoid system in AD pathology and supporting the ECS as a potential novel therapeutic target for treatment of AD.
Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy.
Gaurav
G
Bedse
Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy.
Adele
A
Romano
Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy.
Silvia
S
Cianci
Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy.
Angelo M
AM
Lavecchia
Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy.
Pace
P
Lorenzo
School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, UK.
Maurice R
MR
Elphick
Department of Neurobiology and Behaviour, University of California, Irvine, CA, USA.
Frank M
FM
Laferla
Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy.
Gianluigi
G
Vendemiale
Department of Biochemical Sciences, Istituto Pasteur-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome, Italy.
Caterina
C
Grillo
Department of Biochemical Sciences, Istituto Pasteur-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome, Italy.
Fabio
F
Altieri
Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy.
Tommaso
T
Cassano
Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy.
Silvana
S
Gaetani
D000367:Age Factors; D000544:Alzheimer Disease / Q000235:genetics / Q000473:pathology*; D016564:Amyloid beta-Protein Precursor / Q000235:genetics; D000704:Analysis of Variance; D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism*; D004195:Disease Models, Animal; D005786:Gene Expression Regulation / Q000235:genetics*; D006801:Humans; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009154:Mutation / Q000235:genetics; D053764:Presenilin-1 / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D043884:Receptor, Cannabinoid, CB1 / Q000235:genetics / Q000378:metabolism*; D016875:tau Proteins / Q000235:genetics
D016564:Amyloid beta-Protein Precursor; C508853:PSEN1 protein, human; D053764:Presenilin-1; D012333:RNA, Messenger; D043884:Receptor, Cannabinoid, CB1; D016875:tau Proteins
3 × Tg-AD mice; Alzheimer's disease; CB1 mRNA; CB1 receptor; basolateral amygdala complex; endocannabinoid system; hippocampus; prefrontal cortex