title: Activation pattern of caspases in human spermatozoa.
abstract: OBJECTIVE
  We investigated the activation of caspases 8, 9, 1, and 3 in human ejaculated spermatozoa to study main pathways of apoptosis. Potential functional impact of this phenomenon and possible activation mechanisms were examined by [1] subjecting cells to freezing and thawing, and [2] testing the dependence of caspase activity on membrane integrity.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Andrology Center Leipzig (European Academy of Andrology).
  
  
  METHODS
  Ten healthy volunteers, 40 semen samples.
  
  
  METHODS
  Sperm populations were separated by annexin V magnetic activated cell sorting (MACS) according to externalized phosphatidylserine.
  
  
  METHODS
  Active caspases 8, 9, 1, and 3 were examined in human ejaculated spermatozoa before and after cryopreservation.
  
  
  RESULTS
  The active caspases were localized in the postacrosomal region (caspases 8, 1, and 3) or in the midpiece (caspase 9). Cryopreservation led to a significant increase in the number of cells showing activation of all caspases. The MACS separation resulted in a significant depletion of sperm positive for activated caspases within the externalized phosphatidylserine-negative fraction.
  
  
  CONCLUSIONS
  Caspases 8, 9, 1, and 3, representing the main pathways of apoptosis, are present in human spermatozoa and can become activated, particularly after freezing and thawing, and are associated with changes in the outer cell membrane. Spermatozoa showing these changes and caspase activation can be efficiently removed from semen samples by the annexin V MACS technique.
authors.affiliation: Department of Dermatology/Andrology Unit, University of Leipzig, Leipzig, Germany. paau@medizin.uni-leipzig.de
authors.forename: Uwe
authors.initials: U
authors.lastname: Paasch
authors.forename: Sonja
authors.initials: S
authors.lastname: Grunewald
authors.forename: Ashok
authors.initials: A
authors.lastname: Agarwal
authors.forename: Hans-Jürgen
authors.initials: HJ
authors.lastname: Glandera
mesh_terms: D017304:Annexin A5; D020170:Caspase 1 / Q000378:metabolism; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism*; D002462:Cell Membrane / Q000473:pathology; D002469:Cell Separation; D015925:Cryopreservation; D004789:Enzyme Activation; D006801:Humans; D008280:Magnetics; D008297:Male; D008954:Models, Biological; D010718:Phosphatidylserines / Q000378:metabolism; D012016:Reference Values; D013094:Spermatozoa / Q000201:enzymology* / Q000473:pathology; D014018:Tissue Distribution
chemical_list: D017304:Annexin A5; D010718:Phosphatidylserines; C505407:CASP3 protein, human; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases; D020170:Caspase 1