Search

Neurotransmission and cognitive dysfunctions have been linked to old age disorders including Alzheimer’s disease (AD). Aluminium is a known neurotoxic metal, whereas d-galactose (d-gal) has been established as a senescence agent. WIN55,212-2 (WIN), is a potent cannabinoid agonist which partially restores neurogenesis in aged rats. The current study aimed to explore the therapeutic potentials of WIN on Aluminium chloride (AlCl3) and d-gal-induced rat models with cognitive dysfunction. Healthy male albino Wistar rats weighing between 200–250 g were injected with d-gal 60 mg/kg intra peritoneally (i.p), while AlCl3 (200 mg/kg) was orally administered once daily for 10 consecutive weeks. Subsequently, from weeks 8–11 rats were co-administered with WIN (0.5, 1 and 2 mg/kg/day) and donepezil 1 mg/kg. The cognitive functions of the rats were assessed with a Morris water maze (MWM). Furthermore, oxidative stress biomarkers; malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) and neurogenesis markers: Nestin and glial fibrillary acidic protein (GFAP) were also evaluated, as well as the histology of the hippocampus. The results revealed that rats exposed to AlCl3 and d-gal alone showed cognitive impairments and marked neuronal loss (p < 0.05) in their hippocampal conus ammonis 1 (CA1). Additionally, a significant decrease in the expressions of GFAP and Nestin was also observed, including increased levels of MDA and decreased levels of SOD and GSH. However, administration of WIN irrespective of the doses given reversed the cognitive impairments and the associated biochemical derangements. As there were increases in the levels SOD, GSH, Nestin and GFAP (p < 0.05), while a significant decrease in the levels of MDA was observed, besides attenuation of the aberrant cytoarchitecture of the rat’s hippocampi. The biochemical profiles of the WIN-treated rats were normal. Thus, these findings offer possible scientific evidence of WIN being an effective candidate in the treatment of AD-related cognitive deficits.

Background Epidemiological studies recognize cannabis intake as a risk factor for schizophrenia, yet the majority of adolescents who use marijuana do not develop psychosis. Similarly, the abuse of synthetic cannabinoids poses a risk for psychosis. For these reasons, it is imperative to understand the effects of adolescent cannabinoid exposure in susceptible individuals. Methods We recently developed a novel rodent model of schizophrenia susceptibility, the F2 methylazoxymethanol acetate rat, where only a proportion (~40%) of rats display a schizophrenia-like phenotype. Using this model, we examined the effects of adolescent synthetic cannabinoid exposure (0.2 mg/kg WIN55, 212-2, i.p.) or adolescent endocannabinoid upregulation (0.3 mg/kg URB597, i.p.) on dopamine neuron activity and amphetamine sensitivity in adulthood. Results Adolescent synthetic cannabinoid exposure significantly increased the proportion of susceptible rats displaying a schizophrenia-like hyperdopaminergic phenotype after puberty without producing any observable alterations in control rats. Furthermore, this acquired phenotype appears to correspond with alterations in parvalbumin interneuron function within the hippocampus. Endocannabinoid upregulation during adolescence also increased the proportion of susceptible rats developing an increase in dopamine neuron activity; however, it did not alter the behavioral response to amphetamine, further emphasizing differences between exogenous and endogenous cannabinoids. Conclusions Taken together, these studies provide experimental evidence that adolescent synthetic cannabinoid exposure may contribute to psychosis in susceptible individuals.

Early-life stress induces an abnormal brain development and increases the risk of psychiatric diseases, including depression, anxiety and substance use disorders. We have developed a reliable model for maternal neglect, named maternal separation with early weaning (MSEW) in CD1 mice. In the present study, we evaluated the long-term effects on anxiety-like behaviours, nociception as well as the Iba1-positive microglial cells in this model in comparison to standard nest (SN) mice. Moreover, we investigated whether MSEW alters the cannabinoid agonist WIN55,212-2 effects regarding reward, spatial and emotional memories, tolerance to different cannabinoid responses, and physical dependence. Adult male offspring of MSEW group showed impaired responses on spatial and emotional memories after a repeated WIN55,212-2 treatment. These behavioural impairments were associated with an increase in basolateral amygdala and hippocampal CB1-expressing fibres and higher number of CB1-containing cells in cerebellum. Additionally, MSEW promotes a higher number of Iba1-positive microglial cells in basolateral amygdala and cerebellum. As for the cannabinoid-induced effects, rearing conditions did not influence the rewarding effects of WIN55,212-2 in the conditioned place preference paradigm. However, MSEW mice showed a delay in the development of tolerance to the cannabinoid effects. Moreover, CB1-positive fibres were reduced in limbic areas in MSEW mice after cannabinoid withdrawal precipitated with the CB1 antagonist SR141617A. These findings support that early-life stress promotes behavioural and molecular changes in the sensitivity to cannabinoids, which are mediated by alterations in CB1 signalling in limbic areas and it induces an increased Iba1-microglial marker which could interfere in emotional memories formation. This study was supported by the Ministerio de Economia y Competitividad (grant number SAF2016-75966-R-FEDER and PID2019-104077RB-100), Ministerio de Sanidad (Retic-ISCIII, RD16/017/010 and Plan Nacional sobre Drogas 2018/007). L.A.Z received a FPI grant (BES-2017-080066) from Ministerio de Economia y Competitividad. A.G-B received a FI-AGAUR grant from the Generalitat de Catalunya (2019FI_B0081). A.C-Z received CONACYT grant (276577) from the Mexican government.

Triple-negative breast cancer (TNBC) is a highly heterogeneous disease with poor prognosis and inadequate therapeutic outcome. This contribution reports the use of a cannabinoid derivative, WIN55,212-2 (WIN) on the growth of TNBC in a 4T1 syngeneic mouse model. To reduce the well-known psychoactive side effects of cannabinoids, we prepared a nanomicellar formulation of WIN (SMA-WIN). In vivo biodistribution, in silico ADME predictions, anticancer activity, and psychoactive effect of WIN and SMA-WIN studies suggest that SMA-WIN formulation can reduce to greater extent tumor growth with milder psychoactive side effects when compared to free drug. Finally, the effects of WIN and SMA-WIN in combination with doxorubicin (Doxo), an established chemotherapeutic agent for the treatment of TNBC, were investigated in vitro and in vivo. SMA-WIN in combination with Doxo showed therapeutic efficacy and was able to reduce the tumor volume of TNBC murine model drastically. Moreover, SMA-WIN, while favoring drug tumor accumulation, minimized the adverse psychoactive effects that have impeded the use of this agent in the clinic. To our knowledge, this is the first report for the assessment of cannabinoid nanoparticles in vivo for the treatment of TNBC and its enhanced anticancer effect at low doses with Doxo. These findings suggest a new therapeutic strategy in the management of TNBC.

Highlights • We identified a highly conserved enhancer in the CB1 gene that contains a SNP associated with substance abuse in humans. • CRISPR genome editing to delete this enhancer caused a reduction of CB1 gene expression in hippocampus. • Deletion of this enhancer reduced alcohol intake, cannabinoid response and altered anxiety-like behaviour. • These studies provide an important platform for the future exploration of cannabinoid pharmacogenetics., The cannabinoid-1 receptor (CB1) plays a critical role in a number of biological processes including nutrient intake, addiction and anxiety-related behaviour. Numerous studies have shown that expression of the gene encoding CB1 (CNR1) is highly dynamic with changes in the tissue specific expression of CNR1 associated with brain homeostasis and disease progression. However, little is known of the mechanisms regulating this dynamic expression. To gain a better understanding of the genomic mechanisms modulating the expression of CNR1 in health and disease we characterised the role of a highly conserved regulatory sequence (ECR1) in CNR1 intron 2 that contained a polymorphism in linkage disequilibrium with disease associated SNPs. We used CRISPR/CAS9 technology to disrupt ECR1 within the mouse genome. Disruption of ECR1 significantly reduced CNR1 expression in the hippocampus but not in the hypothalamus. These mice also displayed an altered sex-specific anxiety-related behavioural profile (open field test), reduced ethanol intake and a reduced hypothermic response following CB1 agonism. However, no significant changes in feeding patterns were detected. These data suggest that, whilst not all of the expression of CNR1 is modulated by ECR1, this highly conserved enhancer is required for appropriate physiological responses to a number of stimuli. The combination of comparative genomics and CRISPR/CAS9 disruption used in our study to determine the functional effects of genetic and epigenetic changes on the activity of tissue-specific regulatory elements at the CNR1 locus represent an important first step in gaining a mechanistic understanding of cannabinoid regulatory pharmacogenetics.

Obsessive–compulsive disorder (OCD) is a common psychiatric disorder characterized by the occurrence of obsessions and compulsions. Glutamatergic abnormalities have been related to the pathophysiology of OCD. Cannabinoids inhibit glutamate release in the central nervous system, but the involvement of drugs targeting the endocannabinoid system has not yet been tested in animal models of repetitive behavior. Thus, the aim of the present study was to verify the effects of the CB1 receptor agonist WIN55,212-2, the inhibitor of anandamide uptake AM404 and the anandamide hydrolysis inhibitor URB597, on compulsive-associate behavior in male C57BL/6J mice submitted to the marble burying test (MBT), an animal model used for anti-compulsive drug screening. WIN55,212-2 (1 and 3mg/kg), AM404 (1 and 3mg/kg) and URB597 (0.1, 0.3 and 1mg/kg) induced a significant decrease in the number of buried marbles compared to controls. Pretreatment with the CB1 receptor antagonist, AM251, prevented both WIN55,212-2 and URB597 effects. These results suggest a potential role for drugs acting on the cannabinoid system in modulating compulsive behavior.

The cannabinoid CB1 receptor (CB1) is one of the most abundant G protein-coupled receptors in the brain, but little is known about the mechanisms that modulate CB1 receptor signaling. Here, we show that inhibition or null mutation of the epsilon isozyme of protein kinase C (PKCepsilon) selectively enhances behavioral responses to the CB1 agonist WIN55,212-2 in mice, but not to the structurally unrelated CB1 agonist CP55,940. Binding affinity for [(3)H] WIN55,212-2 was increased in brain membranes from PKCepsilon(-/-) mice compared with PKCepsilon(+/+) mice. There was no difference in binding of the inverse agonist [(3)H] SR141716A. In addition, repeated administration of WIN55,212-2 produced greater analgesic and thermal tolerance in PKCvarepsilon(-/-) mice compared with PKCepsilon(+/+)mice. These results indicate that PKCvarepsilon selectively regulates behavioral sensitivity, CB1 receptor binding and tolerance to WIN55,212-2.

RATIONALE: Pathological impulsivity is a prominent feature in several psychiatric disorders, but detailed understanding of the specific neuronal processes underlying impulsive behavior is as yet lacking.OBJECTIVES: As recent findings have suggested involvement of the brain cannabinoid system in impulsivity, the present study aimed at further elucidating the role of cannabinoid CB(1) receptor activation in distinct measures of impulsive behavior.MATERIALS AND METHODS: The effects of the selective cannabinoid CB(1) receptor antagonist, rimonabant (SR141716A) and agonist WIN55,212-2 were tested in various measures of impulsive behavior, namely, inhibitory control in a five-choice serial reaction time task (5-CSRTT), impulsive choice in a delayed reward paradigm, and response inhibition in a stop-signal paradigm.RESULTS: In the 5-CSRTT, SR141716A dose-dependently improved inhibitory control by decreasing the number of premature responses. Furthermore, SR141716A slightly improved attentional function, increased correct response latency, but did not affect other parameters. The CB(1) receptor agonist WIN55,212-2 did not change inhibitory control in the 5-CSRTT and only increased response latencies and errors of omissions. Coadministration of WIN55,212-2 prevented the effects of SR141716A on inhibitory control in the 5-CSRTT. Impulsive choice and response inhibition were not affected by SR141716A at any dose, whereas WIN55,212-2 slightly impaired response inhibition but did not change impulsive choice.CONCLUSIONS: The present data suggest that particularly the endocannabinoid system seems involved in some measures of impulsivity and provides further evidence for the existence of distinct forms of impulsivity that can be pharmacologically dissociated.