title: Cannabinoid control of brain bioenergetics: Exploring the subcellular localization of the CB1 receptor.
abstract: Brain mitochondrial activity is centrally involved in the central control of energy balance. When studying mitochondrial functions in the brain, however, discrepant results might be obtained, depending on the experimental approaches. For instance, immunostaining experiments and biochemical isolation of organelles expose investigators to risks of false positive and/or false negative results. As an example, the functional presence of cannabinoid type 1 (CB1) receptors on brain mitochondrial membranes (mtCB1) was recently reported and rapidly challenged, claiming that the original observation was likely due to artifact results. Here, we addressed this issue by directly comparing the procedures used in the two studies. Our results show that the use of appropriate controls and quantifications allows detecting mtCB1 receptor with CB1 receptor antibodies, and that, if mitochondrial fractions are enriched and purified, CB1 receptor agonists reliably decrease respiration in brain mitochondria. These data further underline the importance of adapted experimental procedures to study brain mitochondrial functions.
authors.affiliation: INSERM U862, NeuroCentre Magendie, 33077 Bordeaux, France ; University of Bordeaux, 33077 Bordeaux, France.
authors.forename: Etienne
authors.initials: E
authors.lastname: Hebert-Chatelain
authors.affiliation: Department of Neurosciences, Faculty of Medicine and Dentistry, University of the Basque Country UPV/EHU, 48940 Leioa, Spain.
authors.forename: Leire
authors.initials: L
authors.lastname: Reguero
authors.affiliation: Department of Neurosciences, Faculty of Medicine and Dentistry, University of the Basque Country UPV/EHU, 48940 Leioa, Spain.
authors.forename: Nagore
authors.initials: N
authors.lastname: Puente
authors.affiliation: Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.
authors.forename: Beat
authors.initials: B
authors.lastname: Lutz
authors.affiliation: INSERM U862, NeuroCentre Magendie, 33077 Bordeaux, France ; University of Bordeaux, 33077 Bordeaux, France.
authors.forename: Francis
authors.initials: F
authors.lastname: Chaouloff
authors.affiliation: University of Bordeaux, 33077 Bordeaux, France ; Laboratoire Maladies Rares: Génétique et Métabolisme, 33077 Bordeaux, France.
authors.forename: Rodrigue
authors.initials: R
authors.lastname: Rossignol
authors.affiliation: INSERM U862, NeuroCentre Magendie, 33077 Bordeaux, France ; University of Bordeaux, 33077 Bordeaux, France.
authors.forename: Pier-Vincenzo
authors.initials: PV
authors.lastname: Piazza
authors.affiliation: INSERM U862, NeuroCentre Magendie, 33077 Bordeaux, France ; University of Bordeaux, 33077 Bordeaux, France.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Benard
authors.affiliation: Department of Neurosciences, Faculty of Medicine and Dentistry, University of the Basque Country UPV/EHU, 48940 Leioa, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Grandes
authors.affiliation: INSERM U862, NeuroCentre Magendie, 33077 Bordeaux, France ; University of Bordeaux, 33077 Bordeaux, France.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Marsicano
keywords: BSA, bovine serum albumin; Brain bioenergetics; CB1 receptor; CB1, cannabinoid type 1 receptor; DAB–Ni, Ni-intensified 3,3ʹ-diaminobenzidine–4HCl; DMSO, dimethyl sulfoxide; KO, knock-out; LDHa, lactate dehydrogenase a; SDHA, succinate dehydrogenase a; Slp2, stomatin-like protein 2; WIN, WIN55,212-2; WT, wild-type; antibodies; electron microscopy; mitochondria; organelle purification