Does prohibitin expression regulate sperm mitochondrial membrane potential, sperm motility, and male fertility?
Prohibitin (PHB) is a highly conserved major sperm mitochondrial membrane protein whose absence in somatic cells is associated with mitochondrial membrane depolarization and increased generation of reactive oxygen species (ROS). Our recent findings suggest that high levels of oxidants in human semen may contribute to male infertility and that sperm motility could be the earliest and most sensitive indicator of oxidative damage. Based on PHB's roles in mitochondrial sub-compartmentalization and respiratory chain assembly, we examine sperm PHB expression and mitochondrial membrane potential (MITO) in infertile men with poor sperm motility (asthenospermia, A) and/or low sperm concentrations (oligoasthenospermia, OA). Here, we demonstrate that MITO is significantly lower in sperm from A and OA subjects than in normospermic (N) subjects; the decrease is more severe for OA than for A subjects. PHB expression is also significantly lower in sperm from A and OA subjects. Significantly positive correlations are found among PHB expression, MITO, and sperm motility in normospermic, asthenospermic, and oligoasthenospermic subjects. Collectively, our observations lead to the hypothesis that PHB expression is an indicator of sperm quality in infertile men, and that it regulates sperm motility via an alteration in MITO and increased ROS levels.
Department of Anatomy, Histology and Embryology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China.
Mei-Jiao
MJ
Wang
Jia-Xian
JX
Ou
Guo-Wu
GW
Chen
Jun-Ping
JP
Wu
Hui-Juan
HJ
Shi
Wai-Sum
WS
O
Patricia A
PA
Martin-DeLeon
Hong
H
Chen
D000328:Adult; D006801:Humans; D007248:Infertility, Male / Q000378:metabolism*; D008297:Male; D053078:Membrane Potential, Mitochondrial; D008928:Mitochondria / Q000378:metabolism; D000091402:Prohibitins; D017382:Reactive Oxygen Species / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D013081:Sperm Motility; D018709:Statistics, Nonparametric
C000717328:PHB protein, human; D000091402:Prohibitins; D017382:Reactive Oxygen Species; D012097:Repressor Proteins