Hepatitis B Virus S Protein Enhances Sperm Apoptosis and Reduces Sperm Fertilizing Capacity In Vitro

Abstract

ObjectiveStudying the impact of Hepatitis B virus S protein (HBs) on early apoptotic events in human spermatozoa and sperm fertilizing capacity.Methodology/Principal FindingsSpermatozoa were exposed to HBs (0, 25, 50, 100 µg/ml) for 3 h, and then fluo-4 AM calcium assay, Calcein/Co2+ assay, protein extraction and ELISA, ADP/ATP ratio assay, sperm motility and hyperactivation and sperm-zona pellucida (ZP) binding and ZP-induced acrosome reaction (ZPIAR) tests were performed. The results showed that in the spermatozoa, with increasing concentration of HBs, (1) average cytosolic free Ca2+ concentration ([Ca2+]i) rose; (2) fluorescence intensity of Cal-AM declined; (3) average levels of cytochrome c decreased in mitochondrial fraction and increased in cytosolic fraction; (4) ADP/ATP ratios rose; (5) average rates of total motility and mean hyperactivation declined; (6) average rate of ZPIAR declined. In the above groups the effects of HBs exhibited dose dependency. However, there was no significant difference in the number of sperms bound to ZP between the control and all test groups.ConclusionHBs could induce early events in the apoptotic cascade in human spermatozoa, such as elevation of [Ca2+]i, opening of mitochondrial permeability transition pore (MPTP), release of cytochrome c (cyt c) and increase of ADP/ATP ratio, but exerted a negative impact on sperm fertilizing capacity.

Transcription and regulation of hepatitis B virus genes in host sperm cells

“…Development of the human embryo begins with the fusion of sperm and egg, and sperm quality can affect embryogenesis from a very early stage. 46 Our previous studies demonstrated that the HBV S protein can cause a series of apoptotic events resulting in reduced sperm motility, loss of sperm membrane integrity, sperm dysfunction, decreased fertility, and sperm death; 47 48 49 HBV infection can induce various chromosomal aberrations in sperm, including aneuploidy, acentric fragment and deletion, ring chromosome, triradial, dicentric chromosomes and pulverization. 8 Nonetheless, sperm with these chromosomal aberrations can achieve normal fertilization and introduce these aberrations into the embryo, which may increase the risk of abortion, stillbirth, or birth defects.…”

Melatonin improves cryopreservation of ram sperm by inhibiting mitochondrial permeability transition pore opening

“…The release of Cyt c from mitochondria was detected to evaluate the change of mitochondrial membrane permeability induced by MPTP opening. The concentration of mitochondria Cyt c was analysed as described (Huang et al, 2013…”

“…The mPTP opening assay was performed via an established calcein cobalt loading procedure by incubating cells with calcein acetoxymethyl ester (calcein-AM), as described (Huang et al, 2013). Calcein is a fluorescent dye of 1 kDa; the calcein quenching method is a highly selective in situ indicator of sustained mPTP opening in mammals.…”

Swim‐up as a strategy for isolation of spermatozoa without viral incorporation in men with chronic hepatitis B: A pilot study

“…HBV, infertility, spermatozoa, swim-up Hepatitis B is primarily a liver disease, but HBV may also affect male fertility (Garolla et al, 2013). Some studies have shown that HBV affects sperm parameters adversely, resulting in reduced overall motility, reduced mean sperm motility, lower viability and a reduced normal morphology compared to controls (Gimenes et al, 2014;Huang et al, 2013;Lorusso et al, 2010;Zhou et al, 2011). In patients with cHB higher proportions of apoptotic, necrotic and immature sperm cells were observed (Gimenes et al, 2014;Moretti, Federico, Giannerini, & Collodel, 2008;Zhou et al, 2011), as well as an increased frequency of sperm aneuploidy, with chromosome aberrations and DNA-fragmentation, leading to problems in spermatogenesis (Garolla et al, 2013).…”