RESUMO
Here are reported the antiproliferative effects of the cannabinoid agonist WIN upon human melanoma cells expressing mRNA and protein for both CB1 and CB2 receptors. While WIN exerted antimitogenic effects, selective CB1 or CB2 agonists were unable to reproduce such effects and selective CB1 and CB2 antagonists did not inhibit WIN-induced cell death. Cells treated with WIN, preincubated with the lipid raft disruptor methylcyclodestrin, were rescued from death. WIN induced activation of caspases and phosphorylation of ERK that were attenuated in cultures treated with methylcyclodestrin. Membrane lipid raft complex-mediated antimitogenic effect of WIN in melanoma could represents a potential targets for a melanoma treatment.
Assuntos
Benzoxazinas/farmacologia , Canabinoides/farmacologia , Melanoma/tratamento farmacológico , Microdomínios da Membrana/efeitos dos fármacos , Morfolinas/farmacologia , Naftalenos/farmacologia , Receptor CB1 de Canabinoide/agonistas , Receptor CB2 de Canabinoide/agonistas , Apoptose/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular , Humanos , Melanoma/metabolismo , Melanoma/patologia , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Nerve growth factor (NGF) is a pleiotropic member of the neurotrophin family. Beside its neuronal effects, NGF plays a role in various processes, including angiogenesis. Mast cells release NGF and are among elements contributing to angiogenesis, a process regulated by arrays of factors, including the inhibitory cannabinoids. The possible inhibitory role of cannabinoids on mast cell-related NGF mitogenic effect on endothelial cells was then investigated. Human mastocytic cells HMC-1, challenged with PMA to yield release of NGF, were preincubated with the endocannabinoid PEA. Then, conditioned media were added to HUVEC cultures. PMA-activated HMC-1 cells released substantial amounts of NGF, whereas PEA inhibited PMA-induced NGF release. HUVEC proliferation increased after treatment with media from activated HMC-1 cells, while was reduced with media from HMC-1 cells treated with PEA. To characterize receptors mediating such effects of PEA, RT-PCR and western blot analysis were performed on HMC-1 cells. None of the two cannabinoid CB1 and CB2 receptors was expressed by HMC-1 cells, which on the other hand expressed the orphan receptor GPR55. PEA was ineffective in inhibiting NGF release from HMC-1 cells treated with PMA and transfected with positive GPR55 RNAi, whereas it induced significant reduction of NGF in cells transfected with the corresponding negative control RNAi. Results indicate that NGF released from inflammatory mast cells induces angiogenesis. Cannabinoids attenuate such pro-angiogenic effects of NGF. Finally, cannabinoids could be considered for antiangiogenic treatment in disorders characterized by prominent inflammation.
Assuntos
Moduladores de Receptores de Canabinoides/farmacologia , Endocanabinoides , Mastócitos/metabolismo , Mastócitos/patologia , Fator de Crescimento Neural/antagonistas & inibidores , Fator de Crescimento Neural/metabolismo , Linhagem Celular Tumoral , Células Cultivadas , Relação Dose-Resposta a Droga , Humanos , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Mastócitos/efeitos dos fármacos , Receptores de Canabinoides , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Acetato de Tetradecanoilforbol/toxicidadeRESUMO
Spinal cord injury (SCI) is a major cause of disability, its clinical outcome depending mostly on the extent of damage in which proapoptotic cytokines have a crucial function. In particular, the inducers of apoptosis belonging to TNF receptor superfamily and their respective ligands are upregulated after SCI. In this study, the function of the proapoptotic cytokine tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in SCI-induced damage was investigated in the mouse. SCI resulted in severe trauma, characterized by prominent inflammation-related damage and apoptosis. Immunostaining for TRAIL and its receptor DR5 was found in the white and gray matter of the perilesional area, as also confirmed by western blotting experiments. Immunoneutralization of TRAIL resulted in improved functional recovery, reduced apoptotic cell number, modulation of molecules involved in the inflammatory response (FasL, TNF-alpha, IL-1beta, and MPO), and the corresponding signaling (caspase-8 and -3 activation, JNK phosphorylation, Bax, and Bcl-2 expression). As glucocorticoid-induced TNF receptor superfamily-related protein (GITR) activated by its ligand (GITRL) contributes to SCI-related inflammation, interactions between TRAIL and GITRL were investigated. SCI was associated with upregulated GITR and GITRL expression, a phenomenon prevented by anti-TRAIL treatment. Moreover, the expression of both TRAIL and DR5 was reduced in tissues from mice lacking the GITR gene (GITR(-/-)) in comparison with wild-type mice suggesting that TRAIL- and GITRL-activated pathways synergise in the development of SCI-related inflammatory damage. Characterization of new targets within such molecular systems may constitute a platform for innovative treatment of SCI.