Portal de Periódicos da CAPES

Hypericin‐induced photosensitization of HeLa cells leads to apoptosis or necrosis

1998; Wiley; Volume: 440; Issue: 1-2 Linguagem: Inglês

10.1016/s0014-5793(98)01416-1

1873-3468

Annelies Vantieghem, Zerihun Assefa, Peter Vandenabeele, Wim Declercq, Stéphane Courtois, Jackie R. Vandenheede, Wilfried Merlevede, Peter de Witte, Patrizia Agostinis,

Ocular Infections and Treatments

Here we report that photoactivated hypericin can induce either apoptosis or necrosis in HeLa cells. Under apoptotic conditions the cleavage of poly(ADP‐ribose) polymerase (PARP) into the 85‐kDa product is blocked by the caspase inhibitors benzyloxycarbonyl‐Val‐Ala‐Asp‐fluoromethylketone (z‐VAD‐fmk) and benzyloxycarbonyl‐Asp‐Glu‐Val‐Asp‐fluoromethylketone (z‐DEVD‐fmk). Both inhibitors protect cells from apoptosis but cannot prevent hypericin‐induced necrosis. Conversely, HeLa cells overexpressing the viral cytokine response modifier A (CrmA), which inhibits caspase‐1 and ‐8, still undergo hypericin‐induced apoptosis and necrosis. Evidence is provided for the release of mitochondrial cytochrome c in the cytosol and for procaspase‐3 activation in the hypericin‐induced cell killing.