title: Quantitative study of caspase-3 activity in semen and after swim-up preparation in relation to sperm quality.
abstract: BACKGROUND
  There are no studies relating the apoptotic marker caspase-3 in human sperm to different degrees of abnormal sperm concentration, morphology and rapid progressive motility.
  
  
  METHODS
  Semen from 67 males with abnormal semen analyses (n = 61) and normozoospermia (n = 6) were used. In each case, sperm from the neat semen (semen fraction) and after gradient centrifugation and swim-up (swim-up fraction) were incubated with a caspase-3 profluorogenic substrate. Caspase-3 activity was quantified in 119 850 sperm, 67 488 from semen and 52 362 from swim-up fractions. Logistic regression was used to estimate odds ratio (with 99% confidence intervals) for the presence of caspase-3-positive sperm.
  
  
  RESULTS
  In semen fractions, no relationship was found between abnormal semen analysis subgroups and sperm caspase-3 activity. On the contrary, a significantly increased number of sperm with caspase-3 activity was found in the swim-up fractions from samples with poor sperm morphology. When analysis was restricted to single semen analysis defects, a significant increase of caspase-3-positive sperm was found in the semen fractions of cases with asthenozoospermia, and in the swim-up fractions of cases with teratozoospermia.
  
  
  CONCLUSIONS
  Sperm caspase-3 activity seems to be associated with teratozoospermia and asthenozoospermia, thus suggesting that nuclear, mitochondrial and cytoskeletal abnormalities induce caspase-3 activation during spermiogenesis or sperm maturation.
authors.affiliation: Department of Genetics, Faculty of Medicine, University of Porto, Portugal.
authors.forename: Carolina
authors.initials: C
authors.lastname: Almeida
authors.forename: Margarida F
authors.initials: MF
authors.lastname: Cardoso
authors.forename: Mário
authors.initials: M
authors.lastname: Sousa
authors.forename: Paulo
authors.initials: P
authors.lastname: Viana
authors.forename: Ana
authors.initials: A
authors.lastname: Gonçalves
authors.forename: Joaquina
authors.initials: J
authors.lastname: Silva
authors.forename: Alberto
authors.initials: A
authors.lastname: Barros
mesh_terms: D000328:Adult; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism*; D006801:Humans; D007248:Infertility, Male / Q000201:enzymology; D008297:Male; D008875:Middle Aged; D009845:Oligospermia / Q000201:enzymology / Q000473:pathology; D012044:Regression Analysis; D012661:Semen / Q000201:enzymology*; D013094:Spermatozoa / Q000473:pathology / Q000502:physiology*
chemical_list: C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases