title: On the origin, evolution, and nature of programmed cell death: a timeline of four billion years.
abstract: Programmed cell death is a genetically regulated process of cell suicide that is central to the development, homeostasis and integrity of multicellular organisms. Conversely, the dysregulation of mechanisms controlling cell suicide plays a role in the pathogenesis of a wide range of diseases. While great progress has been achieved in the unveiling of the molecular mechanisms of programmed cell death, a new level of complexity, with important therapeutic implications, has begun to emerge, suggesting (i) that several different self-destruction pathways may exist and operate in parallel in our cells, and (ii) that molecular effectors of cell suicide may also perform other functions unrelated to cell death induction and crucial to cell survival. In this review, I will argue that this new level of complexity, implying that there may be no such thing as a 'bona fide' genetic death program in our cells, might be better understood when considered in an evolutionary context. And a new view of the regulated cell suicide pathways emerges when one attempts to ask the question of when and how they may have become selected during evolution, at the level of ancestral single-celled organisms.
authors.affiliation: EMI-U 9922 INSERM/Université Paris 7, IFR 02, Hôpital Bichat-Claude Bernard, AP-HP, 46 rue Henri Huchard, 75877 Paris cedex 18, France. ants@club-internet.fr
authors.forename: J C
authors.initials: JC
authors.lastname: Ameisen
mesh_terms: D000818:Animals; D017209:Apoptosis; D005075:Biological Evolution; D029742:Caenorhabditis elegans Proteins; D020169:Caspases / Q000502:physiology; D056890:Eukaryota / Q000166:cytology / Q000502:physiology; D005057:Eukaryotic Cells / Q000502:physiology; D018398:Homeodomain Proteins / Q000502:physiology; D006801:Humans; D008928:Mitochondria / Q000235:genetics / Q000502:physiology; D010802:Phylogeny; D018521:Plant Physiological Phenomena; D013995:Time
chemical_list: D029742:Caenorhabditis elegans Proteins; D018398:Homeodomain Proteins; C064658:RAG-1 protein; D020169:Caspases; C089223:ced-3 protein, C elegans