Cannabidiol (CBD), a non-psychotomimetic constituent of Cannabis sativa, has been recently approved for epileptic syndromes often associated with Autism spectrum disorder (ASD). However, the putative efficacy and mechanism of action of CBD in patients suffering from ASD and related comorbidities remain debated, especially because of the complex pharmacology of CBD. We used pharmacological, immunohistochemical and biochemical approaches to investigate the effects and mechanisms of action of CBD in the recently validated Fmr1-Δexon 8 rat model of ASD, that is also a model of Fragile X Syndrome (FXS), the leading monogenic cause of autism. CBD rescued the cognitive deficits displayed by juvenile Fmr1-Δexon 8 animals, without inducing tolerance after repeated administration. Blockade of CA1 hippocampal GPR55 receptors prevented the beneficial effect of both CBD and the fatty acid amide hydrolase (FAAH) inhibitor URB597 in the short-term recognition memory deficits displayed by Fmr1-Δexon 8 rats. Thus, CBD may exert its beneficial effects through CA1 hippocampal GPR55 receptors. Docking analysis further confirmed that the mechanism of action of CBD might involve competition for brain fatty acid binding proteins (FABPs) that deliver anandamide and related bioactive lipids to their catabolic enzyme FAAH. These findings demonstrate that CBD reduced cognitive deficits in a rat model of FXS and provide initial mechanistic insights into its therapeutic potential in neurodevelopmental disorders.
- Klíčová slova
- Cannabidiol, Cognitive performance, Fatty acid amide hydrolase, Fragile X syndrome, GPR55 receptors,
- MeSH
- hipokampální oblast CA1 účinky léků metabolismus MeSH
- hipokampus * účinky léků metabolismus MeSH
- kanabidiol * farmakologie terapeutické užití MeSH
- krysa rodu Rattus MeSH
- modely nemocí na zvířatech * MeSH
- paměť účinky léků MeSH
- protein FMRP metabolismus genetika MeSH
- receptory kanabinoidní * metabolismus MeSH
- receptory spřažené s G-proteiny metabolismus MeSH
- rozpoznávání (psychologie) * účinky léků MeSH
- simulace molekulového dockingu MeSH
- syndrom fragilního X * farmakoterapie metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- Fmr1 protein, rat MeSH Prohlížeč
- GPR55 protein, rat MeSH Prohlížeč
- kanabidiol * MeSH
- protein FMRP MeSH
- receptory kanabinoidní * MeSH
- receptory spřažené s G-proteiny MeSH
Fragile X syndrome (FXS) is an inherited form of intellectual disability caused by the loss of the mRNA-binding fragile X mental retardation protein (FMRP). FXS is characterized by neuronal hyperexcitability and behavioral defects, however the mechanisms underlying these critical dysfunctions remain unclear. Here, using male Fmr1 knockout mouse model of FXS, we identify abnormal extracellular potassium homeostasis, along with impaired potassium channel Kir4.1 expression and function in astrocytes. Further, we reveal that Kir4.1 mRNA is a binding target of FMRP. Finally, we show that the deficit in astroglial Kir4.1 underlies neuronal hyperexcitability and several behavioral defects in Fmr1 knockout mice. Viral delivery of Kir4.1 channels specifically to hippocampal astrocytes from Fmr1 knockout mice indeed rescues normal astrocyte potassium uptake, neuronal excitability, and cognitive and social performance. Our findings uncover an important role for astrocyte dysfunction in the pathophysiology of FXS, and identify Kir4.1 channel as a potential therapeutic target for FXS.
- MeSH
- astrocyty * metabolismus MeSH
- chování zvířat MeSH
- draslík metabolismus MeSH
- draslíkové kanály dovnitř usměrňující * metabolismus genetika MeSH
- hipokampus metabolismus MeSH
- kanál KCNJ10 MeSH
- messenger RNA metabolismus genetika MeSH
- modely nemocí na zvířatech MeSH
- myši inbrední C57BL MeSH
- myši knockoutované MeSH
- myši MeSH
- neurony * metabolismus fyziologie MeSH
- protein FMRP * metabolismus genetika MeSH
- syndrom fragilního X * metabolismus genetika patofyziologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Názvy látek
- draslík MeSH
- draslíkové kanály dovnitř usměrňující * MeSH
- Fmr1 protein, mouse MeSH Prohlížeč
- kanál KCNJ10 MeSH
- messenger RNA MeSH
- protein FMRP * MeSH
Fragile X syndrome (FXS) is the most frequently inherited form of intellectual disability and prevalent single-gene cause of autism. A priority of FXS research is to determine the molecular mechanisms underlying the cognitive and social functioning impairments in humans and the FXS mouse model. Glutamate ionotropic alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors (AMPARs) mediate a majority of fast excitatory neurotransmission in the central nervous system and are critically important for nearly all aspects of brain function, including neuronal development, synaptic plasticity, and learning and memory. Both preclinical and clinical studies have indicated that expression, trafficking, and functions of AMPARs are altered and result in altered synapse development and plasticity, cognitive impairment, and poor mental health in FXS. In this review, we discuss the contribution of AMPARs to disorders of FXS by highlighting recent research advances with a specific focus on change in AMPARs expression, trafficking, and dependent synaptic plasticity. Since changes in synaptic strength underlie the basis of learning, development, and disease, we suggest that the current knowledge base of AMPARs has reached a unique point to permit a comprehensive re-evaluation of their roles in FXS.
- MeSH
- AMPA receptory genetika metabolismus MeSH
- lidé MeSH
- mentální retardace genetika metabolismus MeSH
- mutace fyziologie MeSH
- neuroplasticita fyziologie MeSH
- syndrom fragilního X genetika metabolismus MeSH
- transport proteinů fyziologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- AMPA receptory MeSH
