Analysis of the Reversible Impact of the Chemodrug Busulfan on Mouse Testes.

Laura Thirouard,Claude Beaudoin,Angélique De Haze,Françoise Caira,Manon Garcia,Hélène Holota,David H Volle,Jean-Paul Saru,Mélusine Monrose

doi:10.3390/cells10092403

Abstract

Spermatogenesis is a process within the testis that leads to the production of spermatozoa. It is based on a population of spermatogonial stem cells, which have the capacity to self-renew and to differentiate throughout life to ensure the functions of reproduction are maintained. Male fertility disorders are responsible for half of the cases of infertility in couples worldwide. It is well known that cancer treatments are associated with reversible or irreversible fertility disorders. Busulfan (Bu) is an alkylating agent that significantly inhibits spermatogenesis. The present study relied on a combination of in vivo and in vitro approaches as well as RNAseq analysis to characterize the effects of Bu, in which mouse testes were used as a model. An in silico analysis revealed that many of the Bu-modulated genes are potentially regulated by the SIN3 Transcription Regulator Family Member A (SIN3A) and E2F Transcription Factor (E2F) families of transcription factors. The results demonstrate that the deregulated genes function in processes related to the cell cycle, DNA repair, and cell death mechanisms, including the Tumor Protein 53 (TP53) pathway. This reinforces the role of the TP53 signaling pathway as a major player in Bu effects. In addition, Bu altered the patterns of mRNA accumulation for various genes in undifferentiated spermatogonia. This work provides significant insight into the kinetics and impacts of busulfan, which could pave the way for developing strategies to minimize the impact of chemodrugs and, thus, could lead to germ cell lineage regeneration following anticancer treatments.

Highlights

Spermatogenesis is the process of spermatozoa production
High doses of chemotherapy may lead to complete depletion of the seminiferous tubules, resulting in permanent sterility
(15 mg/kg), our results show that, after busulfan exposure, there was no impact of busulfan on body weight at 4 and 8 weeks compared with vehicle-treated animals (Figure 1A)

Summary

Introduction

Spermatogenesis is the process of spermatozoa production. Spermatogenesis takes place in the testicles beginning at puberty and is constantly maintained throughout life. The duration of spermatogenesis is 35 days in mice and 74 days in humans, and the process is subdivided into several stages, each with a defined duration. The maintenance of spermatogenesis requires spermatogonial stem cells, which self-renew throughout life. These spermatogonial stem cells (SSCs) enter a process of proliferation and differentiation before meiosis is initiated and they become spermatozoa, which are released into the lumen of seminiferous tubules. For 60% of men with fertility problems, the defects correspond to an alteration in the production of spermatozoa by the testicle [3]

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Conclusion