RÉSUMÉ
The endocannabinoid (eCB) system, via the cannabinoid CB1 receptor, regulates neurodevelopment by controlling neural progenitor proliferation and neurogenesis. CB1 receptor signalling in vivo drives corticofugal deep layer projection neuron development through the regulation of BCL11B and SATB2 transcription factors. Here, we investigated the role of eCB signalling in mouse pluripotent embryonic stem cell-derived neuronal differentiation. Characterization of the eCB system revealed increased expression of eCB-metabolizing enzymes, eCB ligands and CB1 receptors during neuronal differentiation. CB1 receptor knockdown inhibited neuronal differentiation of deep layer neurons and increased upper layer neuron generation, and this phenotype was rescued by CB1 re-expression. Pharmacological regulation with CB1 receptor agonists or elevation of eCB tone with a monoacylglycerol lipase inhibitor promoted neuronal differentiation of deep layer neurons at the expense of upper layer neurons. Patch-clamp analyses revealed that enhancing cannabinoid signalling facilitated neuronal differentiation and functionality. Noteworthy, incubation with CB1 receptor agonists during human iPSC-derived cerebral organoid formation also promoted the expansion of BCL11B+ neurons. These findings unveil a cell-autonomous role of eCB signalling that, via the CB1 receptor, promotes mouse and human deep layer cortical neuron development.
Sujet(s)
Différenciation cellulaire/génétique , Protéines de liaison aux séquences d'ADN MAR/génétique , Neurones/métabolisme , Récepteur cannabinoïde de type CB1/génétique , Protéines de répression/génétique , Facteurs de transcription/génétique , Protéines suppresseurs de tumeurs/génétique , Animaux , Prolifération cellulaire/effets des médicaments et des substances chimiques , Cervelet/croissance et développement , Développement embryonnaire/génétique , Endocannabinoïdes/agonistes , Endocannabinoïdes/génétique , Endocannabinoïdes/métabolisme , Régulation de l'expression des gènes au cours du développement/génétique , Humains , Cellules souches pluripotentes induites/effets des médicaments et des substances chimiques , Souris , Cellules souches neurales/cytologie , Cellules souches neurales/métabolisme , Neurogenèse/effets des médicaments et des substances chimiques , Organoïdes/croissance et développement , Transduction du signal/génétiqueRÉSUMÉ
Hepatitis E virus (HEV), as a hepatotropic virus, is supposed to exclusively infect the liver and only cause hepatitis. However, a broad range of extrahepatic manifestations (in particular, idiopathic neurological disorders) have been recently reported in association with its infection. In this study, we have demonstrated that various human neural cell lines (embryonic stem cell-derived neural lineage cells) induced pluripotent stem cell-derived human neurons and primary mouse neurons are highly susceptible to HEV infection. Treatment with interferon-α or ribavirin, the off-label antiviral drugs for chronic hepatitis E, exerted potent antiviral activities against HEV infection in neural cells. More importantly, in mice and monkey peripherally inoculated with HEV particles, viral RNA and protein were detected in brain tissues. Finally, patients with HEV-associated neurological disorders shed the virus into cerebrospinal fluid, indicating a direct infection of their nervous system. Thus, HEV is neurotropic in vitro, and in mice, monkeys, and possibly humans. These results challenge the dogma of HEV as a pure hepatotropic virus and suggest that HEV infection should be considered in the differential diagnosis of idiopathic neurological disorders.