The CB1/VR1 agonist arvanil induces apoptosis through an FADD/caspase-8-dependent pathway.
1. Arvanil (N-arachidonoylvanillamine), a nonpungent capsaicin-anandamide hybrid molecule, has been shown to exert biological activities through VR1/CB1-dependent and -independent pathways. We have found that arvanil induces dose-dependent apoptosis in the lymphoid Jurkat T-cell line, but not in peripheral blood T lymphocytes. Apoptosis was assessed by DNA fragmentation through cell cycle and TUNEL analyses. 2. Arvanil-induced apoptosis was initiated independently of any specific phase of the cell cycle, and it was inhibited by specific caspase-8 and -3 inhibitors and by the activation of protein kinase C. In addition, kinetic analysis by Western blots and fluorimetry showed that arvanil rapidly activates caspase-8, -7 and -3, and induces PARP cleavage. 3. The arvanil-mediated apoptotic response was greatly inhibited in the Jurkat-FADDDN cell line, which constitutively expresses a negative dominant form of the adapter molecule Fas-associated death domain (FADD). This cell line does not undergo apoptosis in response to Fas (CD95) stimulation. 4. Using a cytofluorimetric approach, we have found that arvanil induced the production of reactive oxygen species (ROS) in both Jurkat-FADD+ and Jurkat-FADDDN cell lines. However, ROS accumulation only plays a residual role in arvanil-induced apoptosis. 5. These results demonstrate that arvanil-induced apoptosis is essentially mediated through a mechanism that is typical of type II cells, and implicates the death-inducing signalling complex and the activation of caspase-8. This arvanil-apoptotic activity is TRPV1 and CB-independent, and can be of importance for the development of potential anti-inflammatory and antitumoral drugs.
Sancho
Rocio
R
Departamento de Biología Celular, Fisiología e Inmunología, Universidad de Córdoba, Facultad de Medicina, Avda. de Menendez Pidal s/n, Córdoba 14004, Spain.
de la Vega
Laureano
L
Appendino
Giovanni
G
Di Marzo
Vincenzo
V
Macho
Antonio
A
Munoz
Eduardo
E
D048868:Adaptor Proteins, Signal Transducing; D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D002211:Capsaicin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D002352:Carrier Proteins / Q000378:metabolism*; D053181:Caspase 8; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism*; D002478:Cells, Cultured; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D053938:DNA Fragmentation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D053222:Fas Ligand Protein; D053200:Fas-Associated Death Domain Protein; D006801:Humans; D020287:In Situ Nick-End Labeling; D019169:Jurkat Cells; D008562:Membrane Glycoproteins / Q000235:genetics; D008954:Models, Biological; D017382:Reactive Oxygen Species / Q000378:metabolism; D043884:Receptor, Cannabinoid, CB1 / Q000819:agonists / Q000502:physiology; D011955:Receptors, Drug / Q000819:agonists / Q000502:physiology; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000187:drug effects; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; C505533:FADD protein, human; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D053200:Fas-Associated Death Domain Protein; D008562:Membrane Glycoproteins; D017382:Reactive Oxygen Species; D043884:Receptor, Cannabinoid, CB1; D011955:Receptors, Drug; C121153:arvanil; C505530:CASP8 protein, human; D053181:Caspase 8; D020169:Caspases; D002211:Capsaicin