A form of cell death with some features resembling apoptosis in the amitochondrial unicellular organism Trichomonas vaginalis.
One of hallmarks of apoptosis is the degradation and concomitant compaction of chromatin. It is assumed that caspases and caspase-independent pathways are rate limiting for the development of nuclear apoptosis. The caspase-independent pathway involves apoptosis-inducing factor (AIF) and leads to DNA fragmentation and peripheral chromatin condensation. Both pathways are the result of activation of death signals that the mitochondrion receives, integrates, and responds to with the release of various molecules (e.g., cytochrome c and AIF). In fact, both pathways have in common the final point of the DNA fragmentation and the mitochondrial origin of molecules that initiate the apoptotic events. Here, we examine the question of whether apoptosis or apoptotic-like processes exist in a unicellular organism that lacks mitochondria. We herein show that a form of cell death with some features resembling apoptosis is indeed present in Trichomonas vaginalis. Characterization of morphological aspects implicated in this event together with the preliminary biochemical data provided may lead to new insight about the evolutionary relationships between the different forms of programmed cell death identified so far.
Chose
Olivier
O
Laboratoire Génie Enzymatique et Cellulaire, UMR CNRS 6022, Université de Technologie de Compiègne, 60205 Compiègne cedex, France.
Noël
Christophe
C
Gerbod
Delphine
D
Brenner
Catherine
C
Viscogliosi
Eric
E
Roseto
Alberto
A
D000818:Animals; D017209:Apoptosis; D051033:Apoptosis Inducing Factor; D002352:Carrier Proteins / Q000378:metabolism; D016923:Cell Death; D002467:Cell Nucleus / Q000648:ultrastructure; D053938:DNA Fragmentation; D005420:Flavoproteins / Q000032:analysis; D008565:Membrane Proteins / Q000032:analysis; D008928:Mitochondria / Q000502:physiology; D009707:Nucleosomes / Q000648:ultrastructure; D010718:Phosphatidylserines / Q000032:analysis; D015800:Protozoan Proteins; D014246:Trichomonas vaginalis / Q000737:chemistry / Q000166:cytology* / Q000648:ultrastructure
D051033:Apoptosis Inducing Factor; D002352:Carrier Proteins; D005420:Flavoproteins; C405950:Hmp31 protein, Trichomonas vaginalis; D008565:Membrane Proteins; D009707:Nucleosomes; D010718:Phosphatidylserines; D015800:Protozoan Proteins