Elsevier

Urology

Volume 83, Issue 2, February 2014, Pages 324-330
Urology

Infertility
B7-H3 Promoted Sperm Motility in Humans

https://doi.org/10.1016/j.urology.2013.07.078Get rights and content

Objective

To determine whether seminal B7-H3 levels are correlated to semen parameters and affect human sperm functions.

Methods

A total of 83 healthy donors of proven fertility (aged 22-37 years) and 176 infertile men (aged 21-38 years) were recruited. Computer-assisted semen analysis and enzyme-linked immunosorbent assay were used to assess the correlations between seminal B7-H3 levels and semen parameters. Flow cytometry and fluorescence microscopy were used to detect the putative receptor for B7-H3. Computer-assisted semen analysis and FITC-conjugated pisum sativum agglutinin staining were performed for assessing sperm motility, capacitation, and acrosome reaction (AR) after incubation with various concentrations of B7-H3 for 0-4 hours in vitro.

Results

Seminal B7-H3 level was significantly higher in the healthy donors than that in the infertile men (P <.05), and closely associated with sperm concentrations and progressive motility (all P <.05), but not the other parameters examined (all P >.05). A putative receptor for B7-H3 was detected on the surface of sperm, with no significant differences in expression between the healthy donors and infertile men (P >.05). Seminal B7-H3 promoted sperm progressive motility in a time- and dose-dependent manner in vitro, although having no significant influence on sperm capacitation and AR.

Conclusion

B7-H3 showed a favorable effect on human sperm motility, without affecting sperm capacitation and AR.

Section snippets

Reagents

Human B7-H3 Ig and B7-H3 were obtained from R&D Systems, Minneapolis, MN. Fluorescein Labeling Kit-NH2, used for B7-H3Ig labeling, was purchased from Dojindo Molecular Technologies (Kumamoto, JP). Biggers-Whittem-Whittingham (BWW) medium, Hoechst 33258, Ionophore (A23187), and FITC-conjugated Pisum sativum agglutinin (PSA-FITC) were acquired from Sigma (St. Louis, FR). All other chemicals were purchased from Sigma, unless otherwise indicated.

Study Patients and Sample Preparation

Semen samples were obtained from 83 healthy donors

Patient Demographics

Ages and semen parameters, such as sperm concentration, motility, and normal morphologic features of the healthy donors and infertile patients are presented in Table 1. No statistical differences in age were found between the groups.

B7-H3 Levels in Serum and Seminal Plasma

Serum B7-H3 levels in the healthy donors and infertile men were determined as 4.53 ± 1.12 and 4.49 ± 1.92 ng/mL, respectively, with no significant differences between the 2 groups (P = .962). However, B7-H3 in seminal plasma was significantly higher in the healthy

Comment

Prostatic secretion, the major component of seminal plasma, provides an optimal environment for sperm acquiring fertilizing potential.1 A previous study by our group demonstrated that the EPS B7-H3 levels in the healthy men are significantly higher than those in the chronic prostatitis patients.10 Although the relationship between chronic prostatitis and fertility has been debated for many years,28 the issue of whether B7-H3 contributes to sperm fertilizing ability remains an interesting

Conclusion

The present study demonstrated that seminal B7-H3 promoted sperm progressive motility in a time- and dose-dependent manner in vitro. Moreover, B7-H3 might function in a novel manner in addition to its role as an immunoregulatory protein. However, the data are still preliminary, although they are interesting. Further studies are essential for clarifying underlying molecular mechanisms for actions of B7-H3.

Acknowledgments

We thank Prof. Zhice Xu, Perinatal Biology Center, The First Affiliated Hospital of Soochow University, for his assistance in this work, Prof. Feng Guo, Central Lab, The First Affiliated Hospital of Soochow University, for her assistance in fluorescence microscopy analysis, Dr. Yiping Li, Institute of Pediatrics of Children's Hospital of Soochow University for his assistance in flow cytometry analysis.

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  • All authors contributed equally.

    Financial Disclosure: The authors declare that they have no relevant financial interests.

    Funding Support: This work was supported by the National Natural Science Foundation of China (81072085, 81272839, 81300537), the Key Discipline of Medicine of Jiangsu Province (XK 201151), Jiangsu Province's Outstanding Medical Academic Leader program (LJ201138), and the Key Laboratory Foundation of Suzhou (SZS201001, SZS0702).

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