RESUMEN
We have previously shown that in HeLa cells treated with a variety of agents there is an increase in cell surface peptidase (CSP) activity in those cells undergoing apoptosis. The increase in CSP activity observed in UVB-irradiated cells undergoing apoptosis was unaffected when the cultures were treated with the aminopeptidase inhibitor bestatin, and matrix metalloprotease inhibitor BB3103, but greatly enhanced when treated with the caspase 3 inhibitor-DEVD, and reduced in the presence of the poly(ADP-ribose) polymerase (PARP) inhibitor-3-aminobenzamide (3AB). Neither 3AB nor DEVD had an effect on the gross morphology of the apoptotic cells observed under electron microscopy, nor did they have an effect on phosphatidylserine eversion on the cell membrane, or that of PARP cleavage. All the agents except for DEVD had no effect on the level of caspase 3 activity in the cells. The results suggest that other caspases may cleave PARP in these cells. Both 3AB and DEVD treatment reduced the level of actin cleavage seen in the apoptotic cells. The increase in CSP activity observed in cells undergoing UVB-induced apoptosis appears to involve PARP but not caspase 3.
Asunto(s)
Apoptosis/efectos de la radiación , Caspasa 3/metabolismo , Membrana Celular/enzimología , Rayos Ultravioleta , Actinas/metabolismo , Anexina A5/metabolismo , Apoptosis/efectos de los fármacos , Forma de la Célula/efectos de los fármacos , Forma de la Célula/efectos de la radiación , Citometría de Flujo , Células HeLa , Humanos , Microscopía Electrónica , Poli(ADP-Ribosa) Polimerasas/metabolismo , Inhibidores de Proteasas/farmacología , Coloración y EtiquetadoRESUMEN
The NF-κB signalling pathway plays an important role in controlling cellular immune responses, inflammation and apoptosis. In multiple sclerosis (MS), there is evidence of dysregulation of NF-κB signalling in patients with a relapsing-remitting disease course, but thus far there is little information on whether it is also dysregulated in patients with progressive disease. We hypothesised that patients with progressive MS would have more activation of NF-κB than relapsing-remitting MS patients. Using several different methods, we showed that there was more nuclear translocation of p65 in cells from progressive MS patients, particularly in T cells and monocytes. In addition, the amount of p65 translocated to the nucleus in cells of patients with progressive MS was not increased upon non-specific activation of the cells with the mitogen Con A. These results suggest that NF-κB dysregulation occurs in patients with progressive MS patients, as well as those with relapsing-remitting MS.