Low levels of human β-defensin 1 (DEFB1) in sperm may explain some of the common causes of male infertility, according to findings published in Science Translational Medicine (2014;6:249ra108).
Ruiying Diao, of the First Affiliated Hospital of Shenzhen University in China, and colleagues studied sperm and DEFB1 levels in men diagnosed with infertility caused by asthenozoospermia or leukocytospermia.
The researchers found low levels of DEFB1 in sperm from men with infertility caused by either asthenozoospermia or leukocytospermia, both of which are associated with reduced motility and reduced bactericidal activity in sperm. The same defects in sperm were observed when there was interference with DEFB1 function.
Treatment with recombinant DEFB1 markedly restores DEFB1 expression, bactericidal activity, sperm quality, and egg-penetrating ability in sperm from men with asthenozoospermia or leukocytospermia, the authors noted.