[Uncoupling protein 2 combats oxidative damage to human sperm].
OBJECTIVE
Germ cells are much more susceptible to oxidative stress than somatic cells. Accumulating evidence indicates that uncoupling protein 2 (UCP2) prevents the apoptosis of multiple types of cells induced by reactive oxygen species (ROS). The present study aimed to evaluate the protective effect of uncoupling protein 2 (UCP2) against oxidative damage to human sperm.


METHODS
Semen parameters were obtained from 97 semen samples by computer assisted sperm analysis (CASA), and the samples, based on the percentage of grade a + b sperm, allotted to Groups I (n = 25, grade a + b sperm > 50%), II (n = 24, grade a + b sperm 25%-50%), III (n = 24, grade a + b sperm 10-25%) and IV (n = 24, grade a + b sperm < 10%). The expressions of sperm UCP2 mRNA was detected by RT-PCR, and the malonaldehyde (MDA) content in ROS was determined in the sperm suspension.


RESULTS
The expressions of UCP2 mRNA in sperm were 1.51 +/- 0.24, 1.28 +/- 0.15, 1.17 +/- 0.20 and 0.69 +/- 0.18, and the MDA contents were (14.66 +/- 2.55), (16.00 +/- 2.09), (17.44 +/- 1.40) and (21.20 +/- 3.50) nmol/10(8) sperm in Groups I, II, III and lV, respectively. There was a significant negative correlation between the expression of UCP2 mRNA and the content of MDA (r = -0.633, P < 0.01), the former obviously reduced while the latter remarkably increased in the groups of lower sperm motility (P < 0.01).


CONCLUSIONS
UCP2 plays an important protective role against oxidative stress damage to human sperm by diminishing ROS production.
Fu
Zhi-Hong
ZH
Department of Reproductive Healthcare, Shenzhen Maternity and Child Healthcare Hospital, Shenzhen, Guangdong 518000, China. fzhlxylxw@yahoo.com.cn
Zhou
Yong-Hong
YH
Zhu
Wen-Jie
WJ
Chen
Xiu-Min
XM
Li
Xue-Mei
XM
Tan
Zhen
Z
D000328:Adult; D006801:Humans; D007473:Ion Channels / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D024101:Mitochondrial Proteins / Q000378:metabolism*; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013076:Sperm Count; D013081:Sperm Motility; D013094:Spermatozoa / Q000378:metabolism*; D000071246:Uncoupling Protein 2
D007473:Ion Channels; D024101:Mitochondrial Proteins; D017382:Reactive Oxygen Species; C000604389:UCP2 protein, human; D000071246:Uncoupling Protein 2