Autor(es):
Xapelli, Sara Alves ; Agasse, Fabienne ; Sardà-Arroyo, Laura ; Bernardino, Liliana ; Santos, Tiago ; Ribeiro, Filipa F. ; Valero, Jorge ; Bragança, José ; Schitine, Clarissa ; de Melo Reis, Ricardo A ; Sebastião, Ana M. ; Malva, João O.
Data: 2013
Identificador Persistente: https://hdl.handle.net/10316/109774
Origem: Estudo Geral - Universidade de Coimbra
Assunto(s): Animals; Arachidonic Acids; Basic Helix-Loop-Helix Transcription Factors; Cell Differentiation; Cell Proliferation; Cells, Cultured; Cerebral Ventricles; GABAergic Neurons; Gene Expression Regulation; Immunohistochemistry; Mice; Mice, Inbred C57BL; Multipotent Stem Cells; Nerve Tissue Proteins; Neurites; Neurons; Receptor, Cannabinoid, CB1; Stem Cells; Neurogenesis
Descrição
The endocannabinoid system has been implicated in the modulation of adult neurogenesis. Here, we describe the effect of type 1 cannabinoid receptor (CB1R) activation on self-renewal, proliferation and neuronal differentiation in mouse neonatal subventricular zone (SVZ) stem/progenitor cell cultures. Expression of CB1R was detected in SVZ-derived immature cells (Nestin-positive), neurons and astrocytes. Stimulation of the CB1R by (R)-(+)-Methanandamide (R-m-AEA) increased self-renewal of SVZ cells, as assessed by counting the number of secondary neurospheres and the number of Sox2+/+ cell pairs, an effect blocked by Notch pathway inhibition. Moreover, R-m-AEA treatment for 48 h, increased proliferation as assessed by BrdU incorporation assay, an effect mediated by activation of MAPK-ERK and AKT pathways. Surprisingly, stimulation of CB1R by R-m-AEA also promoted neuronal differentiation (without affecting glial differentiation), at 7 days, as shown by counting the number of NeuN-positive neurons in the cultures. Moreover, by monitoring intracellular calcium concentrations ([Ca(2+)]i) in single cells following KCl and histamine stimuli, a method that allows the functional evaluation of neuronal differentiation, we observed an increase in neuronal-like cells. This proneurogenic effect was blocked when SVZ cells were co-incubated with R-m-AEA and the CB1R antagonist AM 251, for 7 days, thus indicating that this effect involves CB1R activation. In accordance with an effect on neuronal differentiation and maturation, R-m-AEA also increased neurite growth, as evaluated by quantifying and measuring the number of MAP2-positive processes. Taken together, these results demonstrate that CB1R activation induces proliferation, self-renewal and neuronal differentiation from mouse neonatal SVZ cell cultures.
