Cannabinoid receptor agonist WIN-55,212-2 protects differentiated PC12 cells from organophosphorus- induced apoptosis

Cannabinoid neuroprotection is usually greater in vivo than in neuronal cell culture systems. To the authors' knowledge, a good in vitro culture model for the neuroprotective effects of cannabinoids does not exist. Therefore, a 3-dimensional (3D) culture system was developed to investigate the neuroprotective effects of the cannabinoid receptor agonist WIN-55,212-2 on apoptosis of differentiated PC12 cells, caused by the organophosphorus compounds paraoxon and diazinon. Cells pretreated with WIN-55,212-2 were exposed to a proapoptotic concentration of paraoxon and diazinon. TUNEL was used to detect apoptosis, and neurite length was assessed by morphometry. Both paraoxon and diazinon induced apoptosis, although the latter was more potent. WIN-55,212-2 also protected cells from neurite retraction and DNA fragmentation induced by the OPs. The results suggest that WIN-55,212-2 protects PC12 cells cultured under 3D conditions from organophosphorus-induced apoptosis. This 3D culture system may prove to be a useful tool for investigating the neuroprotective effects of cannabinoids.