Role of mitochondria in apoptosis

In  living  cells,  especially  eukaryotes,  mitochondria  involvement  appears  to  be  important in  the  general  status  of  every  aspect  of  life.  Apoptosis  as  a  programmed  cell  death  is  mandatory to  all  life  process  thus,  mitochondria  might  be  describe  as  organelles  that  serves  as  a  gatekeeper to  trap  a  variety  of  proapototic  protein  and  prevent  the  functions  of  this  proteins  in  the  cytosol. The  release  of  this  protein  into  the  cytosol  induces  apoptosis,  because  mitochondria  has  been implicated as a  major  control center  regulating and inducing apoptosis  this induction of  apoptosis leads  to  the  growth  of  various  new  cells,cells  turnover  and  tissue  homeostasis,  embryogenesis, induction  and  maintenance  of  immune  tolerance,  development  of  the  nervous  system  and endocrine-dependent  tissue  atrophy  (Fadok,  2000).  Apoptosis  has  many  distinctive  features  that give  away  its  presence  to  a  trained  eye,  however,  the  apoptotic  bodies  are  ultimately  swallowed by  neighbouring  cells  or  macrophages  (Savill  &  Fadok,  2000).  Although  the  exact  speed  of  the process  depends  on  the  cell  type,  in  most  case  the  whole  episode  is  over  within  a  few  hours (Wyllie,  1997,  Cummings  et  al.,  1997).  Morphological  changes  of  the  apoptotic  cells,  including condensation  of  chromatin  and  cytoplasm,  fragmentation  of  the  cell  and  apoptotic  body formation, can be  detected by  using light microscopy  (Daugas   et al.,  2000).