Preparation and immunogenicity of tag-free recombinant human eppin.

Human epididymal protease inhibitor (eppin) may be effective as a male contraceptive vaccine. In a number of studies, eppin with an engineered His(6)-tag has been produced using prokaryotic expression systems. For production of pharmaceutical-grade proteins for human use, however, the His(6)-tag must be removed.

Variants of the EPPIN gene affect the risk of idiopathic male infertility in the Han-Chinese population.

Background: It has been identified that human epididymal protease inhibitor (EPPIN) plays a critical role in sperm function and male fertility. The aim of this study was to determine whether variants of the EPPIN gene are risk factors for idiopathic male infertility.

Methods: All subjects, including 473 idiopathic infertile men and 198 fertile controls, underwent complete historical and physical examinations.

Variants in the Eppin gene show association with semen quality in Han-Chinese population.

The human epididymal protease inhibitor (Eppin) gene is specifically expressed in testis and epididymis and is important in male reproduction. However, to date, there is no report on variants of this gene, particularly in relation to male fertility. To investigate the association between Eppin genetic variants and semen quality, variant genotyping and semen analysis was performed in 473 males with definite idiopathic infertility by polymerase chain reaction-restriction fragment length polymorphism and computer-assisted semen analysis.

Localization of epididymal protease inhibitor in adult rat and its transcription profile in testis during postnatal development.

To investigate the expression pattern of rat Eppin (epididymal protease inhibitor; official symbol Spinlw1), we detected mRNA transcripts and subsequent protein translation of Eppin in several sorts of tissues by RT-PCR and western blotting. Then immunohistochemistry was performed for more detailed observation. The testicular transcription level was monitored by real-time PCR throughout postnatal development.

The effect of anti-eppin antibodies on ionophore A23187-induced calcium influx and acrosome reaction of human spermatozoa.

Background: Before a spermatozoon can fertilize an oocyte it must undergo a cascade of biochemical and physiological changes that facilitate its binding and penetration into the oocyte. Epididymal protease inhibitor (eppin) has been found to play a critical role in male fertility through an immunological approach.

Methods: In this study, we used an anti-eppin antibody to clarify the effect of eppin on human sperm functions during fertilization.

Relationship between urinary metabolites of polycyclic aromatic hydrocarbons and thyroid hormone levels in Chinese non-occupational exposure adult males.

Polycyclic aromatic hydrocarbons (PAH) are ubiquitous global pollutants. Limited studies suggested that PAH may interfere with thyroid function in animals, but little is known about humans. A population of 480 Chinese males was recruited.

[Correlation between ERp57 and pregnancy of intrauterine insemination].

Objective: To investigate the association between the pregnancy rate of intrauterine insemination (IUI) and the ERp57 expression level in donor sperm.

Methods: Forty-two sperm samples were divided into 3 groups according to the pregnancy rate: Group A (n = 16, pregnancy rate = 0), B (n = 13, pregnancy rate 10%-20%) and C (n = 13, pregnancy rate > or = 20%). The optical density (OD) was normalized to the beta-tubulin band for the evaluation of the ERp57 level.