Ultrastructural examination of testicular tissues and evaluation of ZO-1 protein levels obtained from azoospermic cases

Abstract

Spermatogenesis is a process that involves cellular and biochemical processes. The purpose of this study is to understand the role of tight junctions in spermatogenesis by evaluating Zonula occludens-1 (ZO-1) protein levels of cells from the testicular sperm extraction (TESE) biopsies in patients with azoospermia The study included 40 infertile men with azoospermia. They were divided into two groups, as spermatozoa positive (n=20) and spermatozoa negative (n=20). Testis tissues were examined morphologically, immunohistochemically and ultrastructurally by using transmission electron microscopy (TEM). The structure of seminiferous tubules were deteriorated, degenerated and hyalinized in spermatozoa negative group. ZO-1 expression level was normal in blood-testis barrier of spermatozoa positive group in comparing to lateral surfaces of sertoli cells spermatozoa negative group. The ultrastructural results were also supported with light microscopy findings. These findings suggest that decrease of the ZO-1 protein expression level in Sertoli cells might be one of the factors involved in the impairment of spermatogenesis in spermatozoa negative group. Therefore, we suggest that tight junctions may have crucial roles in spermatogenesis.

Keywords

• TESE
• Azoospermia
• Tight juntion proteins ZO-1
• Male ınfertılıty

References

1. Chen, W., Hu, J., Zhang, Z., Chen, L., Xie, H., Dong, N., Chen Y., Zuguo Liu, Z., 2012. Localization and expression of Zonula Occludins-1 in the rabbit corneal epithelium following exposure to benzal konium chloride. PLoS ONE. 7(7): e40893.
2. Chiquoine, A.D.,1964. Observations on the early events of cadmium necrosis of the testis. AnatRec. 149:23–35.
3. Garg, V., Gard, S.P., 2011. Role of nitric oxide in male infertility. J Indian Acad. Forensic Med. 33(1). 65-68.
4. Gao, Y., Mruk, D., Chen, H., Lui, W.Y., Lee, W.M., Cheng, C.Y., 2017.Regulation of the blood-testis barrier by a local axis in the testis: role of laminin α2 in the basement membrane. FASEB J.31(2):584-597.
5. Hikim, A. P., Lue, Y., Yamamoto, C. M., Vera, Y., Rodriguez, S., Yen, P. H., Soeng, K., Wang, C., Swerdloff, R.S., 2003. Key apoptotic pathways for heat-induced programmed germ cell death in the testis. Endocrinology. 144, 3167–3175.
6. Jiang, X.H.,Bukhari, I., Zheng, W., Yin, S., Wang, Z., Cooke H.J., Shi, Q.H., 2014.Blood-testis barrier and spermatogenesis: lessons from genetically-modified mice.Asian J. Androl.16(4):572-80.
7. Kang Z., Qiao N., Liu G., Chen H., Tang Z., Ying Li Y., 2017. Copper-induced apoptosis and autophagy through oxidative stress-mediated mitochondrial dysfunction in male germ cells. Toxicol In Vitro. 61:104639.
8. Kumar, N., Singh, A.K., 2015. Trends of male factor infertility, an important cause of infertility: A review of literature. J. Hum.Reprod Sci. 8(4):191-6.

9. Lee, N.P., Cheng, C.Y., 2008. Nitric oxide and cyclic nucleotides: Their roles ınjunction dynamics and spermatogenesis. Adv. Exp. Med. Biol.636:172-85.
10. Lee, N.P.Y., Cheng, C.Y., 2003. Regulation of sertoli cell tight junction in the rat testis viathe nitric oxide synthase/soluble guanylate cyclase/cGMP/Protein Kinase G signaling pathway: an in vitro study. Endocrinology.144:3114-3129.
11. Nieschlag, E., Behre, H., Nieschlag, S., Van, Ahlen H. 2011. Male reproductive health and dysfunction. Internistische Praxis. Andrology. 51: 751.
12. Rumbold, A.R., Sevoyan, A., Oswald, T.K., Fernandez R.C., Davies, M.J., Moore, V.M., 2019. Impact of male factor infertility on offspring health and development. FertilSteril. 111(6):1047-1053.
13. Sapanidou, V., Taitzoglou, I., Tsakmakidis, I.,Kourtzelis, I., Fletouris, D., Theodoridis, A., Zervos, I., Tsantarliotou, M., 2015. Antioxidant effect of crocin on bovine sperm quality and in vitro fertilization. Theriogenology. 84(8):1273-82.
14. Skakkebaek, N.E., Rajpert De Meyts, E., Main, K.M., 2001. Testicular dysgenesis syndrome: an increasingly common developmental disorder with environmental aspects. Hum.Reprod 16: 972−8.
15. Sun,H.,Yang, B., Zhu, C., Liu, R., Wang, H., Li, W., 2013. Presence of metastasis-associated protein 1 in Sertoli cells is required for propercontact between sertoli cells and adjacent germ cells.Urology.81(1):66-73.
16. Vlajkovic, S., Cukuranovic, R., Bjelakovic, M.R., Stefanovic. V. 2012. Possible Therapeutic Use of Spermatogonial Stem Cells in the Treatment of Male Infertility: A Brief Overview. ScientificWorldJournal. 8.
17. Yan Cheng,C.,Dolores, D.M, 2012.The Blood-Testis Barrier and Its Implications for Male Contraception. PharmacolRev. 64(1): 16–64.
18. WHO.,2010. World Health organization laboratory manual for the examination and the processing of human semen. 5 th ed;pp161.