Fig. 1

Rimonabant treatment normalizes mtCB1R overexpression and boosts mtPKA signaling in the RTT mouse brain. After 4 or 7 days of systemic treatment with the CB1 cannabinoid receptor (CB1R) inverse agonist rimonabant (Rim, 0.3 mg/kg) or vehicle (Veh), and precisely 4 h after the last injection, Mecp2-308 heterozygous female mice (RTT) and wild-type (Wt) controls were sacrificed and the brain tissue was sampled to assess the CB1R and protein kinase A (PKA) activity in isolated brain mitochondria. (A) Treatment with Rim normalizes the levels of CB1R expressed at the mitochondrial membranes (mtCB1R) that are increased in the brain of RTT mice compared to Wt controls. Immunoblots were assembled to show examples from 1 animal from each experimental group. Protein loading was assessed by glyceraldehyde 3-phosphate dehydrogenase (GAPDH) antibody for homogenate (hom) and cytochrome oxidase subunit 1 (COX1) for mitochondrial fractions (mit). (B) The effects of Rim on mtCB1R expression were replicated after a longer 7-day treatment schedule. Two observations were removed from the mtCB1R data after 7 days of treatment as they significantly exceeded the group’s distribution. (C) Rim boosts the activation of the mtCB1R-target PKA in the RTT mouse brain mitochondria (mtPKA). A single observation was removed from the mtPKA data as it was significantly outside the group average. N = 3–6. The histograms are mean ± SEM and represent the arbitrary densitometric units expressed as a percentage of the values of Wt and Veh. * p < 0.05, ** p < 0.01, two-way ANOVA followed by Tukey’s post-hoc test or Kruskal-wallist test followed by Dunn’s post-hoc test