The autophagosomal-lysosomal compartment in programmed cell death

In the last decade a tremendous progress has been achieved in understanding the control of apoptosis by survival and death factors as well as the mole cular mechanisms of preparation and execution of the cell's suicide, Howeve r, accumulating evidence suggests that programmed cell death (PCD) is not c onfined to apoptosis but that cells use different pathways for active self destruction as reflected by different morphology: condensation prominent, t ype I or apoptosis; autophagy prominent, type II; etc. Autophagic PCD appea rs to be a phylogenetically old phenomenon, it may occur in physiological a nd disease states. Recently, distinct biochemical and molecular features ha ve been be assigned to this type of PCD. However, autophagic and apoptotic PCD should not be considered as mutually exclusive phenomena, Rather, they appear to reflect a high degree of flexibility in a cell's response to chan ges of environmental conditions, both physiological or pathological, Furthe rmore, recent data suggest that diverse or relatively unspecific signals su ch as photodamage or lysosomotropic agents may be mediatd by lysosomal cyst eine proteases (cathepsins) to caspases and thus, apoptosis, The present pa per reviews morphological, functional and biochemical/molecular data sugges ting the participation of the autophagosomal-lysosomal compartment in progr ammed cell death.