MicroRNAs (miRNAs) are a class of non-coding single-stranded RNA molecules, about 22 nucleotides in length, and highly conserved in evolution. They participate in a variety of important biological processes, including the development, differentiation, and apoptosis of eukaryotes. Recent studies have discovered that miRNAs play important roles in the development of primordial germ cells, spermatogenesis, and the process of fertilization.
Animals ; Male ; Mice ; MicroRNAs ; metabolism ; Spermatozoa ; metabolism

We have yet to develop a fundamental understanding of the molecular complexities of human spermatozoa. This encompasses the unique packaging and structure of the sperm genome along with their paternally derived RNAs in preparation for their delivery to the egg. The diversity of these transcripts is vast, including several anti-sense molecules resembling known regulatory micro-RNAs. The field is still grasping with its delivery to the oocyte at fertilization and possible significance. It remains tempting to analogize them to maternally-derived transcripts active in early embryo patterning. Irrespective of their role in the embryo, their use as a means to assess male factor infertility is promising.
DNA ; genetics ; metabolism ; Humans ; Male ; RNA, Messenger ; genetics ; Spermatozoa ; metabolism

OBJECTIVETo investigate the expression of carbonic anhydrase II (CA2) in human testes and spermatozoa, and to compare the expressions of CA2 in ejaculated spermatozoa between normozoospermic and asthenozoospermic men.

METHODSThe localization of CA2 in human testes was observed by immunohistochemistry, and that in human sperm by immunofluorescence. Western blot was used to detect the expression of CA2 in the semen samples obtained from 16 normozoospermic and 16 asthenozoospermic volunteers.

RESULTSThe CA2 protein was shown to be localized in the tail of elongating spermatids by immunohistochemistry and in the flagellum of human sperm by immunofluorescence. Western blot revealed an obviously increased expression of CA2 in the spermatozoa of asthenozoospermic patients, with statistically significant difference from the normozoospermic group (1.84 +/- 0.32 vs 1.41 +/- 0.26, P < 0.05).

CONCLUSIONThe CA2 protein is expressed in the spermatogenic stage of elongating spermatids in human testes and localized in the sperm tail. The expression of CA2 is significantly increased in the spermatozoa of asthenozoospermic men, which might be responsible for low sperm motility.

Asthenozoospermia ; metabolism ; Carbonic Anhydrase II ; metabolism ; Humans ; Male ; Sperm Motility ; Spermatozoa ; metabolism ; Testis ; metabolism

Heat shock protein (HSP) is a group of evolutionarily highly conserved cell chaperone proteins involved in the processes of molecular chaperone, cytoprotection, anti-apoptosis and immunoregulation. Recent studies found that HSP is also involved in spermatogenesis, sperm capacitation and fertilization, which play a significant role in male reproduction. Therefore, further studies on the action mechanisms of HSP in male infertility may offer a new insight into the management of the problem.
Heat-Shock Proteins ; metabolism ; Humans ; Infertility, Male ; metabolism ; Male ; Spermatozoa ; metabolism

OBJECTIVETo analyze the quality characteristics of human spermatozoa with hyaluronic acid (HA) receptors and search for a new indicator for the assessment of sperm quality.

METHODSUsing sperm-HA binding assay with HA-coated slides, we determined the binding rate of motile sperm with HA receptors and analyzed its correlation with routine semen parameters, sperm membrane function, sperm fertilizing function and diminished/arrested sperm maturation.

RESULTSThe motile sperm with HA binding sites in the acrosomal region showed significantly higher acrosomal integrity ([95.4 +/- 3.9]%) and mitochondrial membrane potential (MMP) ([97.8 +/- 2.1]%) than those in the initial semen ([68.8 +/- 6.2]% and [72.8 +/- 7.4]%) (P < 0.01). The sperm-HA binding scores were correlated mildly with many routine semen parameters (r = 0.195-0.268, P < 0.05), positively with the acrosome reaction level after ionophore challenge (r = 0.666, P < 0.01) and normal sperm morphology (r = 0.417, P < 0.01), and negatively with sperm nucleoprotein immaturation (r = -0.266, P < 0.01), DNA fragmentation (r = -0. 308, P < 0.01) and excessive residual cytoplasm (r = -0.218, P < 0.05).

CONCLUSIONSperm with HA receptors in the acrosomal region exhibit significant advantages in plasma membrane structure, fertilizing potential and maturation. The sperm-HA binding assay, which is based on a relationship between sperm receptors for zona pellucida and HA, is likely to become a new independent indicator for assessing the multiple qualities of spermatozoa.

Acrosome ; metabolism ; Humans ; Hyaluronan Receptors ; metabolism ; Hyaluronic Acid ; Male ; Spermatozoa ; cytology ; metabolism ; physiology

OBJECTIVETo compare the expressions of ODF1 (outer dense fiber of the sperm tail 1) in ejaculated spermatozoa from normozoospermic and asthenozoospermic men with low sperm motility.

METHODSSemen analyses were performed on the semen samples obtained from normozoospermic (n=20) and asthenozoospermic (n=20) volunteers according to the WHO criteria. To rule out the contamination of germ cells and leucocytes, the human ejaculated spermatozoa were purified by a discontinuous Percoll density gradient centrifugation. RT-PCR and Western blot were used to detect the expressions of ODF1 in the spermatozoa from the two groups.

RESULTSRT-PCR showed that the expression of ODF1 mRNA was significantly lower in the spermatozoa from the asthenozoospermic patients than in those from the normozoospermic men (1.35 +/- 0.25 vs. 2.79 +/- 0.28, P < 0.05). Western blot confirmed the results from RT-PCR and revealed an obviously decreased expression of ODF1 in the spermatozoa of the asthenozoospermic patients, with statistically significant difference from the normozoospermic group (1.44 +/- 0.26 vs. 3.64 +/- 0.34, P < 0.05).

CONCLUSIONThe expression of ODF1 was significantly decreased in the ejaculated spermatozoa of asthenozoospermic men, which might be responsible for low sperm motility.

Asthenozoospermia ; metabolism ; Heat-Shock Proteins ; metabolism ; Humans ; Male ; Sperm Motility ; Spermatozoa ; metabolism

There are over 200 secretive proteins in the epididymis. Spermatozoa are generally considered to become mature and full-functional after interacting with secretive proteins in the epididymis. This review is aimed at summarizing some aspects of the biochemical, molecular and functional characterization of some new proteins recently detected in human epididymis, and is expected to contribute to further researches on the mechanism of epididymal reproduction and contraception.
Epididymis ; secretion ; Humans ; Male ; Proteins ; metabolism ; Spermatozoa ; metabolism ; Sugar Alcohol Dehydrogenases ; metabolism

Osteopontin (OPN) is an extracellular matrix protein with multifunctions, expressed in various tissues and body fluids, involved in various physiological and pathological processes. It is also detected in the reproductive tract of both males and females, and participates in the implantation, development and differentiation of embryos. Recent studies have indicated that OPN is closely related with male fertility and may affect sperm quality and fertilization. An insight into the functions of OPN may help to explain the mechanisms of male infertility and improve the success rate of assisted reproductive technology.
Animals ; Fertility ; Genitalia, Male ; metabolism ; Humans ; Male ; Mammals ; Osteopontin ; metabolism ; Spermatozoa ; metabolism

OBJECTIVETo investigate the role of the cation channel of sperm 1 (CatSper1) protein in the pathogenesis of idiopathic asthenozoospermia.

METHODSSperm samples from patients with idiopathic asthenozoospermia were separated by Percoll discontinuous density gradients, and the distribution and expression of the CatSper1 protein were determined by immunocytochemistry. Western blotting was used to detect the different expressions of CatSper1 in the ejaculated sperm from the normal control, mild asthenozoospermia, moderate asthenozoospermia and severe asthenozoospermia groups, followed by statistical analyses.

RESULTSThe expression of CatSper1, located in the principle piece of the sperm tail, was reduced significantly in the samples from the idiopathic asthenozoospermia patients as compared with the normal controls (t = 2.188, P = 0.042). The relative contents of the CatSper1 protein in the sperm of the control, mild asthenozoospermia, moderate asthenozoospermia and severe asthenozoospermia groups were 0.806 +/- 0.266, 0.669 +/- 0.207, 0.505 +/- 0.214 and 0.295 +/- 0.162, respectively, significantly decreased in the asthenozoospermia patients in comparison with the normal controls (P <0.05). There was a positive correlation between the percentage of progressively motile sperm and the relative content of the CatSper1 protein (r = 0.633, P = 0.000).

CONCLUSIONThe decreased or abnormal expression of the CatSper1 protein may be a factor involved in the pathogenesis of idiopathic asthenozoospermia.

Adult ; Asthenozoospermia ; metabolism ; Calcium Channels ; metabolism ; Case-Control Studies ; Humans ; Male ; Spermatozoa ; metabolism ; Young Adult

OBJECTIVETo investigate the role of the SEPT4 protein in the pathogenesis of idiopathic asthenozoospermia.

METHODSSamples of ejaculated sperm from idiopathic asthenozoospermia patients and normozoospermic men were separated and purified by Percoll discontinuous density gradients, the distribution and expression of SEPT4 in the sperm samples were determined by immunocytochemistry, and the expressions of SEPT4 mRNA and SEPT4 protein were detected by RT-PCR and Western blot.

RESULTSImmunocytochemistry showed that the expression of SEPT4, located in the annulus, was significantly reduced in the sperm of the idiopathic asthenozoospermia patients (t = 3.452, P < 0.01). RT-PCR revealed that the expression of SEPT4 mRNA was significantly lower in the sperm of the idiopathic asthenozoospermia patients than in those of the normozoospermic men (t = 3.521, P < 0.05). Western blot confirmed the results of RT-PCR (t = 5.872, P < 0.05).

CONCLUSIONThe expression of SEPT4 is significantly decreased in the ejaculated sperm of idiopathic asthenozoospermia patients, which might be one of the causes of idiopathic asthenozoospermia.

Adult ; Asthenozoospermia ; metabolism ; Case-Control Studies ; Humans ; Male ; Septins ; metabolism ; Sperm Motility ; Spermatozoa ; metabolism ; Young Adult