Effects of multiple doses of cyclophosphamide on mouse testes: accessing the germ cells lost, and the functional damage of stem cells

Nme8 is essential for protection against chemotherapy drug cisplatin-induced male reproductive toxicity in mice

Cisplatin (CP), a chemotherapy drug commonly used in cancers treatment, causes serious reproductive toxicity. With younger cancer patients and increasing survival rates, it is important to preserve their reproductive capacity. NME8 is highly expressed in testis and contains thioredoxin and NDPK domains, suggesting it may be a target against the CP-induced reproductive toxicity. We deleted exons 6-7 of the Nme8 in mice based on human mutation sites and observed impaired transcript splicing. In mice, Nme8 was not essential for spermatogenesis, possibly due to functional compensation by its paralog, Nme5. Nme8 expression was elevated and translocated to the nucleus in response to two weeks of CP treatment. Under CP treatment, Nme8 deficiency further impaired antioxidant capacity, induced lipid peroxidation and increased ROS level, and failed to activate autophagy, resulting in aggravated DNA damage in testes and sperm. Consequently, the proliferation and differentiation of spermatogonia and the meiosis of spermatocyte were almost completely halted, and sperm motility was impaired. Our research indicates that NME8 protects against CP-induced testis and sperm damage. This may provide new insights into the physiological functions of the Nme family and potential targets for preserving fertility in young male cancer patients.

The protection afforded by kefir against cyclophosphamide induced testicular toxicity in rats by oxidant antioxidant and histopathological evaluations

Cyclophosphamide (CTX) is the most commonly used effective alkylating drug in cancer treatment, but its use is restricted because its toxic side effect causes testicular toxicity. CTX disrupts the tissue redox and antioxidant balance and the resulting tissue damage causes oxidative stress. In our study based on this problem, kefir against CTX-induced oxidative stress and testicular toxicity were investigated. Rats were divided into 6 groups: control, 150 mg/kg CTX, 5 and 10 mg/kg kefir, 5 and 10 mg/kg kefir + 150 CTX. While the fermented kefirs were mixed and given to the rats for 12 days, CTX was given as a single dose on the 12th day of the experiment. Testis was scored according to spermatid density, giant cell formation, cells shed into tubules, maturation disorder, and atrophy. According to our biochemical findings, the high levels of total oxidant status (TOS), and the low levels of total antioxidant status (TAS) in the CTX group, which are oxidative stress markers, indicate the toxic effect of CTX, while the decrease in TOS levels and the increase in TAS levels in the kefir groups indicate the protective effect of kefir. In the CTX-administered group, tubules with impaired maturation and no spermatids were observed in the transverse section of the testicle, while in the kefir groups, the presence of near-normal tubule structures and tubule lumens despite CTX showed the protective effect of kefir. In our study, it was observed that kefir had a protective and curative effect on CTX-induced toxicity and oxidative stress and could be a strong protector.

Restoration of fertility in nonablated recipient mice after spermatogonial stem cell transplantation

Spermatogonial stem cell (SSC) transplantation is a valuable tool for studying stem cell-niche interaction. However, the conventional approach requires the removal of endogenous SSCs, causing damage to the niche. Here we introduce WIN18,446, an ALDH1A2 inhibitor, to enhance SSC colonization in nonablated recipients. Pre-transplantation treatment with WIN18,446 induced abnormal claudin protein expression, which comprises the blood-testis barrier and impedes SSC colonization. Consequently, WIN18,446 increased colonization efficiency by 4.6-fold compared with untreated host. WIN18,446-treated testes remained small despite the cessation of WIN18,446, suggesting its irreversible effect. Offspring were born by microinsemination using donor-derived sperm. While WIN18,446 was lethal to busulfan-treated mice, cyclophosphamide- or radiation-treated animals survived after WIN18,446 treatment. Although WIN18,446 is not applicable to humans due to toxicity, similar ALDH1A2 inhibitors may be useful for SSC transplantation into nonablated testes, shedding light on the role of retinoid metabolism on SSC-niche interactions and advancing SSC research in animal models and humans.

Therapeutic potential of bone marrow mesenchymal stem cells in cyclophosphamide-induced infertility

Cancer is a deadly disease characterized by abnormal cell proliferation. Chemotherapy is one technique of cancer treatment. Cyclophosphamide (CYP) is the most powerful chemotherapy medication, yet it has serious adverse effects. It is an antimitotic medicine that regulates cell proliferation and primarily targets quickly dividing cells, and it has been related to varying levels of infertility in humans. In the current study, we assessed the biochemical, histological, and microscopic evaluations of testicular damage following cyclophosphamide administration. Further, we have explored the potential protective impact of mesenchymal stem cell (MSCs) transplantation. The biochemical results revealed that administration of cyclophosphamide increased serum concentrations of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), while it decreased serum concentrations of free testosterone hormone (TH), testicular follicle-stimulating hormone, luteinizing hormone, and free testosterone hormone concentrations, testicular total antioxidant capacity (TAC), and testicular activity of superoxide dismutase (SOD) enzyme. The histology and sperm examinations revealed that cyclophosphamide induced destruction to the architectures of several tissues in the testes, which drastically reduced the Johnsen score as well as the spermatogenesis process. Surprisingly, transplantation of mesenchymal stem cell after cyclophosphamide administration altered the deterioration effect of cyclophosphamide injury on the testicular tissues, as demonstrated by biochemical and histological analysis. Our results indicated alleviation of serum and testicular sex hormones, as well as testicular oxidative stress markers (total antioxidant capacity and superoxide dismutase activity), and nearly restored the normal appearance of the testicular tissues, Johnsen score, and spermatogenesis process. In conclusion, our work emphasizes the protective pharmacological use of mesenchymal stem cell to mitigate the effects of cyclophosphamide on testicular tissues that impair the spermatogenesis process following chemotherapy. These findings indicate that transferring mesenchymal stem cell to chemotherapy patients could significantly improve spermatogenesis.

Optimization of Testicular Fixation-Embedding Techniques for Improved Evaluation of Mammalian Spermatogonial Morphology and Function

Numerous methods have been successfully used to evaluate mammalian spermatogonial biology However, the conventional light microscopy assays present a challenge in precisely identifying spermatogonial phenotypes, which can result in discrepancies between molecular and morphological findings. Such precise association could lead to a more robust interpretation of spermatogonial activity in steady-state spermatogenesis, which may facilitate the translation from basic research to clinical applications. In this chapter, we present two histological processing methods that enable a comprehensive analysis of spermatogonial morphology and function, involving fixation of mammalian testicular tissue in glutaraldehyde and embedding in plastic resin. These techniques have proven to be effective in light microscopy studies.

Models and Methods for Evaluating Regeneration of Spermatogenesis After Cytotoxic Treatments

Cytotoxic exposure, predominantly during radiation and/or chemotherapy treatment for cancer, interferes with fertility in men. While moderate doses cause temporary azoospermia allowing eventual recovery of spermatogenesis, higher doses of sterilizing agents can cause permanent sterility by killing the spermatogonial stem cells (SSCs). In this chapter, the methods involved in the following aspects of cytotoxic regeneration are described: (i) designing rodent and non-human primate models for regeneration of spermatogenesis after cytotoxic treatment by radiation and chemotherapy; (ii) analysis of SSCs with respect to the impact of the cytotoxic treatment, including analysis of spermatogonial clones, scoring the testicular section to analyze the extent of spermatogenic recovery, preparation of testicular and epididymal sperm, and collection of semen in non-human primates for sperm analysis; and (iii) preparation and delivery of a GnRH antagonist and steroids for enhancement or induction of spermatogonial differentiation, leading to the regeneration of spermatogenesis, largely applicable in the rat model.

The protective effect of C-phycocyanin in male mouse reproductive system

C-phycocyanin from Spirulina platensis has pharmacological effects such as anti-oxidation, anti-cancer, anti-inflammatory and anti-atherosclerosis activities as well as liver and kidney protection. However, there is little research on C-phycocyanin applied in the field of reproductive medicine, and it is therefore the focus of the current study. In this study, a GC-1 spg cell model and male mouse reproductive injury model were constructed by TNF α + Smac mimetic + zVAD-fmk (TSZ) and cyclophosphamide (Cy), respectively. It has been proved that C-phycocyanin can increase cell viability and reduce cell death in GC-1 spg cells induced by TSZ. C-phycocyanin could protect the reproductive system of male mice from cyclophosphamide, improve spermatogenesis, sperm quality and fertility, increase the release of testosterone, stabilize the feedback regulation mechanism, and ensure the spermatogenic ability of mice. It could also improve the ability of anti-oxidation. In addition, C-phycocyanin could play a protective role by down-regulating RIPK1, RIPK3, and p-MLKL to inhibit the necroptotic signaling pathway. These results suggest that C-phycocyanin could protect GC-1 spg cells and the reproductive system of male mice from TSZ and cyclophosphamide, and the protective mechanism may be achieved by inhibiting the signal pathway of necroptosis. Therefore, C-phycocyanin could serve as a promising reproductive system protective agent. C-phycocyanin may enter public life as a health product in the future.

A Short Review on Growth and Endocrine Long-term Complications in Children and Adolescents with β-Thalassemia Major: Conventional Treatment versus Hematopoietic Stem Cell Transplantation

The conventional treatment of β-thalassemia (β-TM) patients is based on the correction of anemia through regular blood transfusions and iron chelation therapy. However, allogeneic hematopoietic stem cell transplantation (HSCT) remains the only currently available technique that has curative potential. Variable frequency and severity of long-term growth and endocrine changes after conventional treatment as well as after HSCT have been reported by different centers. The goal of this mini-review is to summarize and update knowledge about long-term growth and endocrine changes after HSCT in patients with β-TM in comparison to those occurring in β-TM patients on conventional treatment. Regular surveillance, early diagnosis, treatment, and follow-up in a multi-disciplinary specialized setting are suggested to optimize the patient's quality of life (www.actabiomedica.it).

Phycobiliproteins Ameliorate Gonadal Toxicity in Male Mice Treated with Cyclophosphamide

Cyclophosphamide (CP)-which is used to treat autoimmune diseases and cancer-is related to gonadotoxicity attributed to oxidative stress. As phycobiliproteins (PBPs) are strong antioxidants that are unexplored as protective agents against male gonadotoxicity, our work aimed to investigate the effects of PBP crude extract on testicular damage and sperm parameter alterations caused by CP in mice. Three doses of PBP (50, 100, and 200 mg/kg) were tested in the experimental groups (n = 8 per group), administered concomitantly with 100 mg/kg CP. After 42 days receiving PBP daily and CP weekly, body and relative testicular weights, serum testosterone levels, testicular lipoperoxidation and antioxidant enzyme activity levels, and testicular histology and sperm parameter alterations were assessed. The results showed that PBP crude extract at 200 mg/kg prevented testosterone serum reduction, body weight loss, lipoperoxidation and enzyme activity increments, and sperm parameter alterations and partially ameliorated relative testicular weight reductions and histological damage in CP-treated mice. In conclusion, we showed that PBP crude extract (200 mg/kg) mitigated oxidative damage in the testes and ameliorated alterations in sperm parameters in mice treated with CP (100 mg/kg); therefore, PBP extract could be considered as a potential protective agent against CP toxicity.

Protective and therapeutic effect of hydrogen sulfide on hemorrhagic cystitis and testis dysfunction induced with cyclophosphamide

Backround/aim

Cyclophosphamide (CP) is a drug used for treatment of many malignant diseases. However, it can cause serious side effects such as hemorrhagic cystitis and male infertility. Hydrogen sulfide (H2S) is a gaseous mediator and is suggested to have antioxidant, antiinflammatory, and antiapoptotic effects. In this study, dose-dependent effects of H2S donor sodium hydrosulfide (NaHS) on cyclophosphamide-induced hemorrhagic cystitis and testicular dysfunction were investigated in rats.

Material and methods

Rats were divided into 5 groups (n = 8): control, CP, NaHS25 μmol/kg, NaHS50 μmol/kg, and NaHS100 μmol/ kg. After treatment for 7 days intraperitoneally (ip), a single ip dose of CP 200 mg/kg was given on the 8th day. Then, treatment was continued for 7 days. In bladder and testicular tissues, IL 6, IL 10, cGMP, NO, H2S, FSH, LH, and testosterone levels were measured by ELISA. Histopathological examination with H&E staining, as well as immunohistochemical staining for acrolein in bladder and caspase-3 and APAF-1 in testis were performed.

Results

NaHS prevented the increased IL 6 and IL 10 values induced by CP as well as prevented the decrease in cGMP values associated with CP. There was no significant change in FSH values, but the LH value, which increased with CP, decreased with 25, 50, and 100 μmol/kg NaHS. In contrast, testosterone decreased in the CP group and increased in the treatment groups. NaHS was effective in many biochemical and histopathological parameters at 25 and 50 μmol/kg doses, and this effect decreased at 100 μmol/kg dose.

Conclusion

H2S has a protective and therapeutic effect on hemorrhagic cystitis and testicular dysfunction induced by cyclophosphamide. It can be suggested that H2S is a promising molecule in facilitating cancer treatment.

Involvement of Cytokines and Hormones in the Development of Spermatogenesis In Vitro from Spermatogonial Cells of Cyclophosphamide-Treated Immature Mice

Aggressive chemotherapy treatment may lead to male infertility. Prepubertal boys do not produce sperm at this age, however, they have spermatogonial stem cells in their testes. Here, we examined the effect of intraperitoneal injection of cyclophosphamide (CP) on the capacity of immature mice (IM) to develop spermatogenesis in vivo and in vitro [using methylcellulose culture system (MCS)]. Our results show a significant decrease in testicular weight, total number of testicular cells, and the number of Sertoli, peritubular, premeiotic, and meiotic/post-meiotic cells, but an increase in the percentages of damaged seminiferous tubules in CP-treated IM compared to control. The functionality of Sertoli cells was significantly affected. The addition of testosterone to isolated cells from seminiferous tubules of CP-treated IM significantly increased the percentages of premeiotic (CD9-positive cells) and meiotic/post-meiotic cells (ACROSIN-positive cells) developed in MCS compared to control. The addition of FSH did not affect developed cells in MCS compared to control, but in combination with testosterone, it significantly decreased the percentages of CD9-positive cells and ACROSIN-positive cells. The addition of IL-1 did not affect developed cells in MCS compared to control, but in combination with testosterone, it significantly increased the percentages of VASA-positive cells and BOULE-positive cells compared to IL-1 or testosterone. Addition of TNF significantly increased only CD9-positive cells in MCS compared to control, but in combination with testosterone, it significantly decreased ACROSIN-positive cells compared to testosterone. Our results show a significant impairment of spermatogenesis in the testes of CP-treated IM, and that spermatogonial cells from these mice proliferate and differentiate to meiotic/post-meiotic cells under in vitro culture conditions.

Identification of abnormal protein expressions associated with mouse spermatogenesis induced by cyclophosphamide

Cyclophosphamide (CP) is a clinical anticancer drug that can cause male reproductive abnormalities, but the underlying mechanisms for this remain unknown. The present study aimed to explore the potential toxicity induced by CP in spermatogenesis events of germ cell proliferation, meiosis, and blood-testis barrier integrity at the molecular level. CP-treated mice showed significantly reduced serum testosterone levels, sperm motility and concentration. The results of immunohistochemistry and Western blot showed that CP reduced the proliferation of germ cells (PCNA, PLZF) and increased germ cell apoptosis (Bax and TUNEL-positive cells) in CP-treated mice testes. The expression of meiotic related proteins (SYCP3, REC8, MLH1) decreased significantly in the fourth week after administration, and the expression of blood-testis barrier related proteins (β-catenin, ZO-1) and sperm quality-associated proteins (PGK2, HSPA4) decreased significantly in the first week after administration. CP leads to the apoptosis of male germ cells, inhibits the proliferation of germ cells, and affects meiosis and the blood-testis barrier, resulting in the decline of sperm quality. This study provides information to further the study of molecular mechanism and protective strategy of CP influence.

Chemotherapy induced damage to spermatogonial stem cells in prepubertal mouse in vitro impairs long-term spermatogenesis

Chemotherapy can affect testis development of young boys with cancer, reducing the chances of fatherhood in adulthood. Studies using experimental models are needed to determine the damage caused by individual chemotherapy drugs in order to predict the risk of infertility and direct patients towards appropriate fertility preservation options. Here, we investigated the individual role of two drugs, cisplatin and doxorubicin, using an in vitro culture model of prepubertal (postnatal day 5) mouse testis that supports induction and maintenance of full spermatogenesis. Twenty-four hour exposure with either drug at clinically-relevant doses (0.25, 0.5 or 0.75 μg/mL for cisplatin, or 0.01, 0.03 or 0.05 μg/mL for doxorubicin), induced an acute significant loss of spermatogonial stem cells (SSCs; PLZF+), proliferating SSCs (PLZF+BrdU+), total germ cells (MVH+), and spermatocytes (SCP3+) one week after chemotherapy exposure. By the time of the first (Week 4) and second (Week 8) waves of spermatogenesis, there was no longer any effect on SSC or proliferating SSC numbers in drug-exposed testis compared to untreated tissue: however, the populations of total germ cells and spermatocytes were still lower in the higher-dose cisplatin treated groups, along with a reduced frequency of round and elongated spermatids in both cisplatin- and doxorubicin-treated testis fragments. Overall, this study details a direct impairment of germ cell development following acute chemotherapy-induced damage during the prepubertal phase, most likely due to an effect on SSCs, using an in vitro culture system that successfully recapitulates key events of mouse spermatogenesis.

GDF-15 Neutralization Alleviates Platinum-Based Chemotherapy-Induced Emesis, Anorexia, and Weight Loss in Mice and Nonhuman Primates

Platinum-based cancer therapy is restricted by dose-limiting side effects and is associated with elevation of growth differentiation factor 15 (GDF-15). But whether this elevation contributes to such side effects has been unclear. Here, we explored the effects of GDF-15 blockade on platinum-based chemotherapy-induced emesis, anorexia, and weight loss in mice and/or nonhuman primate models. We found that circulating GDF-15 is higher in subjects with cancer receiving platinum-based chemotherapy and is positively associated with weight loss in colorectal cancer (NCT00609622). Further, chemotherapy agents associated with high clinical emetic score induce circulating GDF-15 and weight loss in mice. Platinum-based treatment-induced anorexia and weight loss are attenuated in GDF-15 knockout mice, while GDF-15 neutralization with the monoclonal antibody mAB1 improves survival. In nonhuman primates, mAB1 treatment attenuates anorexia and emesis. These results suggest that GDF-15 neutralization is a potential therapeutic approach to alleviate chemotherapy-induced side effects and improve the quality of life.

Approaches and Technologies in Male Fertility Preservation

Male fertility preservation is required when treatment with an aggressive chemo-/-radiotherapy, which may lead to irreversible sterility. Due to new and efficient protocols of cancer treatments, surviving rates are more than 80%. Thus, these patients are looking forward to family life and fathering their own biological children after treatments. Whereas adult men can cryopreserve their sperm for future use in assistance reproductive technologies (ART), this is not an option in prepubertal boys who cannot produce sperm at this age. In this review, we summarize the different technologies for male fertility preservation with emphasize on prepubertal, which have already been examined and/or demonstrated in vivo and/or in vitro using animal models and, in some cases, using human tissues. We discuss the limitation of these technologies for use in human fertility preservation. This update review can assist physicians and patients who are scheduled for aggressive chemo-/radiotherapy, specifically prepubertal males and their parents who need to know about the risks of the treatment on their future fertility and the possible present option of fertility preservation.

A male germ cell assay and supporting somatic cells: its application for the detection of phase specificity of genotoxins in vitro

Male germ stem cells are responsible for transmission of genetic information to the next generation. Some chemicals exert a negative impact on male germ cells, either directly, or indirectly affecting them through their action on somatic cells. Ultimately, these effects might inhibit fertility, and may exhibit negative consequences on future offspring. Genotoxic anticancer agents may interact with DNA in germ cells potentially leading to a heritable germline mutation. Experimental information in support of this theory has not always been reproducible and suitable in vivo studies remain limited. Thus, alternative male germ cell tests, which are now able to detect phase specificity of such agents, might be used by regulatory agencies to help evaluate the potential risk of mutation. However, there is an urgent need for such approaches for identification of male reproductive genotoxins since this area has until recently been dependent on in vivo studies. Many factors drive alternative approaches, including the (1) commitment to the principles of the 3R's (Replacement, Reduction, and Refinement), (2) time-consuming nature and high cost of animal experiments, and (3) new opportunities presented by new molecular analytical assays. There is as yet currently no apparent appropriate model of full mammalian spermatogenesis in vitro, under the REACH initiative, where new tests introduced to assess genotoxicity and mutagenicity need to avoid unnecessary testing on animals. Accordingly, a battery of tests used in conjunction with the high throughput STAPUT gravity sedimentation was recently developed for purification of male germ cells to investigate genotoxicity for phase specificity in germ cells. This system might be valuable for the examination of phases previously only available in mammals with large-scale studies of germ cell genotoxicity in vivo. The aim of this review was to focus on this alternative approach and its applications as well as on chemicals of known in vivo phase specificities used during this test system development.

Comparison effects of olive leaf extract and oleuropein compounds on male reproductive function in cyclophosphamide exposed mice

Spermatogenesis is a complicated process in which sperm is susceptible to various chemotherapy drugs such as cyclophosphamide (CP). As olive leaf extract (OLE) and its active ingredient, oleuropein, have variousantioxidant, anti-apoptotic, and anti-inflammatory properties the aim of the present study was to investigate the effects of OLE and oleuropein on male reproductive function focusing antioxidative effects and histological modifications in the testes of CP-exposed mice. In order to do this, 80 NMRI male mice were divided into eight groups including control group, group received CP, group received OLE, group received oleuropein, group received OLE following CP exposure, group received oleuropein following CP exposure, group received OLE plus oleuropein and group received OLE plus oleuropein following CP exposure. In all groups CP (single dose of 100 mg/kg (, OLE (100 mg/kg for consequence 28 days) and oleuropein (100 mg/kg for consequence 28 days) were injected intraperitoneally. Moreover, testis histology, sperm parameters and serum levels of LH, FSH, MDA and antioxidant capacity were investigated. Results showed that CP caused oxidative state and abnormal changes in sperms and testes. Besides, treatments with oleuropein and OLE led to mitigate the harmful effects of CP on the male reproductive system. In conclusion, our findings showed that olive's compounds can diminish the hazardous effects of CP on spermatogenesis in mice.

Cytotoxic effects, inflammatory response and apoptosis induction of cyclophosphamide in the peripheral blood leukocyte of blunt snout bream (Megalobrama amblycephala)

The present study was aimed to evaluate the effects of the cyclophosphamide (CY) exposure (Control, 0.032, 0.32, 1.0, 1.6 and 3.2 mg/mL) on the damage in the peripheral blood leukocytes of blunt snout bream for 24 h, which including cell viability, apoptosis, lactate dehydrogenase (LDH) release, mitochondrial membrane potential (Δѱm), ROS, antioxidant enzyme activity and the relative mRNA levels of apoptosis. Results showed that cell viability and Δѱm effects of CY were greatly reduced, and occurred in a dose-dependent manner. CY exposure (0.32-3.2 mg/mL) significantly increased the LDH release and induced apoptosis accompanied by ΔΨm disruption and ROS generation compared to the control. The cellular ROS was significantly increased with increase of CY level from 0.032 mg/mL to 1 mg/mL and the plateau occurred at 0.32 mg/mL. Additionally CY exposure led to oxidative stress as evidenced by significantly the decrease of SOD and CAT and increase of MDA concentration after treating cells with 3.2 mg/mL of CY. Besides, the relative mRNA levels of caspase-3 in the dose of 0.032, 0.32 mg/mL CY, caspase-9 and interleukins-1β (IL-1β) in the dose of 0.32 mg/mL CY, tumor necrosis factor-alpha (TNF-α) in the dose of 0.032 mg/mL CY significantly higher than that of the control. In conclusion, 0.32-3.2 mg/mL CY could lead to cytotoxic effect, inflammatory response and induce the apoptosis of the peripheral blood leukocyte of Megalobrama amblycephala.

Depletion of endogenous germ cells in striped catfish Pangasianodon hypophthalmus (Sauvage, 1878) by heat-chemical treatments

Germ cell (GC) transplantation (GCT) is a proven powerful reproductive technique to enhance the production efficiency of domesticated animals and aid to the recovery of endangered germ lines. In mammals, several methods have been adopted for the eradication of GCs such as treatment with cytotoxic drugs, irradiation, cold ischaemia and hyperthermic treatment. Some of these methods have also been tried in fishes, and conditions for sterilization of gonads have been established. Here, we report the production of GC-depleted male striped catfish Pangasianodon hypophthalmus in 12 weeks by the combination of heat and chemical treatments. The cytotoxic drug busulphan (40 mg/kg) was intraperitoneally injected into the animals at 2-week intervals (six doses in total) and maintained in water at 38°C between weeks 1 and 12. The effectiveness of the treatment was assessed using gonadal index and histology. At the end of 12 weeks, very severe gonadal degeneration was observed in fish treated with the heat-chemical combination, and 100% of sampled fish (n = 5) were found devoid of endogenous GCs. On contrary, high temperature alone caused minor gonadal degeneration. Results obtained in this study suggest that endogenous GCs of large-bodied fish such as P. hypophthalmus can also be sterilized by heat and chemical treatments within a considerably short period.

Chemotherapy drugs cyclophosphamide, cisplatin and doxorubicin induce germ cell loss in an in vitro model of the prepubertal testis

Long term survival rates for childhood cancers is steadily increasing, however cancer survivors can experience fertility problems as a consequence of chemotherapy treatment. This is particularly problematic for young boys, for whom no fertility preservation treatment is yet established. Here, we have determined the effects on prepubertal mouse testis of three commonly used chemotherapy drugs; cyclophosphamide (using its active metabolite phosphoramide mustard), cisplatin and doxorubicin, exposing testicular fragments to a clinically relevant range of concentrations in vitro. All three drugs induced a specific and highly significant loss of germ cells, including spermatogonial stem cells. In contrast, there was no significant effect on somatic cells, for either Sertoli or interstitial cells. Time course analysis of cleaved Caspase-3 expression showed a significant increase in apoptosis eight hours prior to a detectable decrease in germ cell numbers following exposure to phosphoramide mustard or cisplatin, although this pattern was not seen following doxorubicin-exposure. Moreover, analysis of DNA damage at 16 h showed increased γH2AX expression in response to all three drugs. Overall, results show that cisplatin, doxorubicin and cyclophosphamide all specifically induce loss of germ cells, including of spermatogonial stem cells, in the prepubertal mouse testis at concentrations relevant to human therapeutic exposures.

A systematic investigation of the maximum tolerated dose of cytotoxic chemotherapy with and without supportive care in mice

Background

Cytotoxic chemotherapeutics form the cornerstone of systemic treatment of many cancers. Patients are dosed at maximum tolerated dose (MTD), which is carefully determined in phase I studies. In contrast, in murine studies, dosages are often based on customary practice or small pilot studies, which often are not well documented. Consequently, research groups need to replicate experiments, resulting in an excess use of animals and highly variable dosages across the literature. In addition, while patients often receive supportive treatments in order to allow dose escalation, mice do not. These issues could affect experimental results and hence clinical translation.

Methods

To address this, we determined the single-dose MTD in BALB/c and C57BL/6 mice for a range of chemotherapeutics covering the canonical classes, with clinical score and weight as endpoints.

Results

We found that there was some variation in MTDs between strains and the tolerability of repeated cycles of chemotherapy at MTD was drug-dependent. We also demonstrate that dexamethasone reduces chemotherapy-induced weight loss in mice.

Conclusion

These data form a resource for future studies using chemotherapy in mice, increasing comparability between studies, reducing the number of mice needed for dose optimisation experiments and potentially improving translation to the clinic.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3677-7) contains supplementary material, which is available to authorized users.

Doxorubicin and vincristine affect undifferentiated rat spermatogonia

Anticancer drugs, such as alkylating agents, can affect male fertility by targeting the DNA of proliferative spermatogonial stem cells (SSC). Therefore, to reduce such side effects, other chemotherapeutics are used. However, less is known about their potential genotoxicity on SSC. Moreover, DNA repair mechanisms in SSC are poorly understood. To model treatments deprived of alkylating agents that are commonly used in cancer treatment, we tested the impact of exposure to doxorubicin and vincristine, alone or in combination (MIX), on a rat spermatogonial cell line with SSC characteristics (GC-6spg). Vincristine alone induced a cell cycle arrest and cell death without genotoxic impact. On the other hand, doxorubicin and the MIX induced a dose-dependent cell death. More importantly, doxorubicin and the MIX induced DNA breaks, measured by the COMET assay, at a non-cytotoxic dose. To elucidate which DNA repair pathway is activated in spermatogonia after exposure to doxorubicin, we screened the expression of 75 genes implicated in DNA repair. Interestingly, all were expressed constitutively in GC-6spg, suggesting great potential to respond to genotoxic stress. Doxorubicin treatments affected the expression of 16 genes (>1.5 fold change;P < 0.05) involved in cell cycle, base/nucleotide excision repair, homologous recombination and non-homologous end joining (NHEJ). The significant increase in CDKN1A and XRCC1 suggest a cell cycle arrest and implies an alternative NHEJ pathway in response to doxorubicin-induced DNA breaks. Together, our results support the idea that undifferentiated spermatogonia have the ability to respond to DNA injury from chemotherapeutic compounds and escape DNA break accumulation.

Testicular parameters and spermatogenesis in different birthweight boars

The present study investigated the effect of birthweight on testicular development and spermatogenesis in boars. Twenty-four pairs of littermate boars were selected: one piglet with the highest birthweight (HW) and the other with the lowest birthweight (LW) within the litter. Two subsets of 12 pairs of male littermates from each birthweight group were obtained after selection: one subset was orchiectomised at 8 days and the other at 8 months of age. HW boars had higher body and testicular weights at both ages (P < 0.05). Testosterone concentrations and the relative expression of 17α-hydroxylase in the testis were similar between birthweight groups. Birthweight affected somatic and germ cell numbers in the neonatal testis, which were higher in HW boars (P < 0.05). Moreover, a significant reduction in the number of pachytene spermatocytes and round spermatids was observed in LW boars (P < 0.05) at 8 months of age, which caused a decrease in the total number of elongated spermatids and daily sperm production (P < 0.05). Hence, HW boars have the potential to produce more spermatozoa and consequently more semen doses per ejaculate, and would be very valuable to an industry that relies on AI.

Ethanolic extract of Moringa oleifera Lam. leaves protect the pre-pubertal spermatogonial cells from cyclophosphamide-induced damage

ETHNOPHARMACOLOGICAL RELEVANCE

Moringa oleifera Lam. is widely cultivated in Asian and African countries for its medicinal and dietary significance. The leaves are highly nutritious and are known to possess various biological activities.

MATERIALS AND METHODS

Pre-pubertal Swiss albino male mice were injected with single dose of cyclophosphamide (CP, 200mg/kg body weight) or ethanolic extract of Moringa oleifera leaves (MOE, 100mg/kg body weight) intraperitoneally. In combination group, MOE was administered 24h prior to CP injection.

RESULTS

CP induced a significant decrease in testicular weight (p<0.01) and depletion of germ cells (p<0.001) and higher level of DNA damage (p<0.001) compared to control. The expression of P53, Bax, Cytochrome C (Cyt C) was increased while there was a decrease in the expression of Bcl2, c-Kit and Oct4. Administration of MOE 24h prior to CP treatment ameliorated the depletion (p<0.001), DNA damage (p<0.001) and apoptosis (p<0.01) of germ cells induced by CP. The mitigating effect of MOE appears to be mediated by up-regulating the expression of c-Kit and Oct4 transcripts in P53-independent manner.

CONCLUSION

MOE protects the spermatogonial cells from CP-induced damage by modulating the apoptotic response elicited by CP and therefore can be considered as an efficient method of male fertility preservation.

Leydig cells contribute to the inhibition of spermatogonial differentiation after irradiation of the rat

Irradiation with 6 Gy produces a complete block of spermatogonial differentiation in LBNF1 rats that would be permanent without treatment. Subsequent suppression of gonadotropins and testosterone (T) restores differentiation to the spermatocyte stage; however, this process requires 6 weeks. We evaluated the role of Leydig cells (LCs) in maintenance of the block in spermatogonial differentiation after exposure to radiation by specifically eliminating functional LCs with ethane dimethane sulfonate (EDS). EDS (but not another alkylating agent), given at 10 weeks after irradiation, induced spermatogonial differentiation in 24% of seminiferous tubules 2 weeks later. However, differentiation became blocked again at 4 weeks as LCs recovered. When EDS was followed by treatment with GnRH antagonist and flutamide, sustained spermatogonial differentiation was induced in >70% of tubules within 2 weeks. When EDS was followed by GnRH antagonist plus exogenous T, which also inhibits LC recovery but restores follicle stimulating hormone (FSH) levels, the spermatogonial differentiation was again rapid but transient. These results confirm that the factors that block spermatogonial differentiation are indirectly regulated by T, and probably FSH, and that adult and possibly immature LCs contribute to the production of such inhibitory factors. We tested whether insulin-like 3 (INSL3), a LC-produced protein whose expression correlated with the block in spermatogonial differentiation, was indeed responsible for the block by injecting synthetic INSL3 into the testes and knocking down its expression in vivo with siRNA. Neither treatment had any effect on spermatogonial differentiation. The Leydig cell products that contribute to the inhibition of spermatogonial differentiation in irradiated rats remain to be elucidated.

The Potent Humanin Analogue (HNG) Protects Germ Cells and Leucocytes While Enhancing Chemotherapy-Induced Suppression of Cancer Metastases in Male Mice

Humanin is a peptide that is cytoprotective against stresses in many cell types. We investigated whether a potent humanin analogue S14G-humanin (HNG) would protect against chemotherapy-induced damage to normal cells without interfering with the chemotherapy-induced suppression of cancer cells. Young adult male mice were inoculated iv with murine melanoma cells. After 1 week, cancer-bearing mice were randomized to receive either: no treatment, daily ip injection of HNG, a single ip injection of cyclophosphamide (CP), or CP+HNG and killed at the end of 3 weeks. HNG rescued the CP-induced suppression of leucocytes and protected germ cell from CP-induced apoptosis. Lung metastases were suppressed by HNG or CP alone, and further suppressed by CP+HNG treatment. Plasma IGF-1 levels were suppressed by HNG with or without CP treatment. To investigate whether HNG maintains its protective effects on spermatogonial stem cells, sperm output, and peripheral leucocytes after repeated doses of CP, normal adult male mice received: no treatment, daily sc injection of HNG, 6 ip injections of CP at 5-day intervals, and the same regimens of CP+HNG and killed at the end of 4 weeks of treatment. Cauda epididymal sperm counts were elevated by HNG and suppressed by CP. HNG rescued the CP-induced suppression of spermatogonial stem cells, sperm count and peripheral leucocytes. We conclude that HNG 1) protects CP-induced loss of male germ cells and leucocytes, 2) enhances CP-induced suppression of cancer metastases, and 3) acts as a caloric-restriction mimetic by suppressing IGF-1 levels. Our findings suggest that humanin analogues may be promising adjuvants to chemotherapy.

Zn(II)-curcumin protects against oxidative stress, deleterious changes in sperm parameters and histological alterations in a male mouse model of cyclophosphamide-induced reproductive damage

The poor bioavailability and stability of curcumin limit its clinical application. A novel Zn(II)-curcumin complex was synthesized and its effects against cyclophosphamide (CP)-induced reproductive damage were compared with curcumin. Oral administration of Zn(II)-curcumin significantly prevented CP-induced elevation of malondialdehyde (MDA) level and reductions in superoxide dismutase (SOD) activity and glutathione (GSH) content in mouse testis. Zn(II)-curcumin significantly ameliorated CP-induced reductions in body and reproductive organs weights. Zn(II)-curcumin dose-dependently ameliorated CP-induced reproductive system impairments, by improving sperm parameters (sperm count, viability, motility) and reducing serum testosterone and histological alterations. Compared to curcumin at the same dose, Zn(II)-curcumin more effectively alleviated CP-induced reproductive injury, leading to a reduced severity of testicular pathologic changes, lower MDA level, elevated SOD activity and GSH content, and increased sperm parameters and serum testosterone. These results suggest Zn(II)-curcumin more effectively protects against CP-induced reproductive damage than curcumin alone due to a synergistic reduction in oxidative stress.

Fetal cyclophosphamide exposure induces testicular cancer and reduced spermatogenesis and ovarian follicle numbers in mice

Exposure to radiation during fetal development induces testicular germ cell tumors (TGCT) and reduces spermatogenesis in mice. However, whether DNA damaging chemotherapeutic agents elicit these effects in mice remains unclear. Among such agents, cyclophosphamide (CP) is currently used to treat breast cancer in pregnant women, and the effects of fetal exposure to this drug manifested in the offspring must be better understood to offer such patients suitable counseling. The present study was designed to determine whether fetal exposure to CP induces testicular cancer and/or gonadal toxicity in 129 and in 129.MOLF congenic (L1) mice. Exposure to CP on embryonic days 10.5 and 11.5 dramatically increased TGCT incidence to 28% in offspring of 129 mice (control value, 2%) and to 80% in the male offspring of L1 (control value 33%). These increases are similar to those observed in both lines of mice by radiation. In utero exposure to CP also significantly reduced testis weights at 4 weeks of age to ∼70% of control and induced atrophic seminiferous tubules in ∼30% of the testes. When the in utero CP-exposed 129 mice reached adulthood, there were significant reductions in testicular and epididymal sperm counts to 62% and 70%, respectively, of controls. In female offspring, CP caused the loss of 77% of primordial follicles and increased follicle growth activation. The results indicate that i) DNA damage is a common mechanism leading to induction of testicular cancer, ii) increased induction of testis cancer by external agents is proportional to the spontaneous incidence due to inherent genetic susceptibility, and iii) children exposed to radiation or DNA damaging chemotherapeutic agents in utero may have increased risks of developing testis cancer and having reduced spermatogenic potential or diminished reproductive lifespan.

Effects of tadalafil on hemorrhagic cystitis and testicular dysfunction induced by cyclophosphamide in rats

INTRODUCTION

The protective and/or therapeutic potential of tadalafil (TDL) on cyclophosphamide (CP)-induced hemorrhagic cystitis (HC) and testicular dysfunction in rats was evaluated.

MATERIALS AND METHODS

The animals except from the control group were divided into four groups and treated with saline, or 1, 5 or 10 mg/kg TDL orally (CP, TDL1, TDL5 and TDL10 groups, respectively) before and after CP injection. Body and organ weights, sperm count, cGMP, nitric oxide (NO), IL-6 and IL-10 levels in serum and bladder tissue, and serum testosterone (T), LH and FSH levels were determined. The histological analysis of bladder and testis was performed and the number of apoptotic cells was determined.

RESULTS AND CONCLUSION

The CP group had decreased cGMP and NO levels in the bladder, serum T level (p < 0.05) and sperm count (p < 0.001) and higher IL-6 levels in serum and bladder (p < 0.01). Treatment with TDL resulted in increased cGMP (p < 0.001), NO (p < 0.05) and serum T (p < 0.05) levels. Histological analysis of the CP group showed severe HC in bladder and testicular damage. TDL-treated animals showed a dose-dependent improvement in all of these histological impairments. In conclusion, a selective inhibitor of phosphodiesterase-5 enzyme, TDL, showed a protective and/or therapeutic effect on CP-induced HC and testicular dysfunction in rats.

Effects of pharmaceutical medications on male fertility

The number of couples seeking consultation for infertility problems has steadily increased over the past decade, affecting 10%-15% of the sexually active population. Abnormal semen production, a male factor infertility (MFI), is thought to be the cause of up to 50% of all infertilities in developed countries. There are potentially many different causes of male infertility, including hormonal, anatomical, and secondary to exposure to exogenous substances. In many cases of MFI, a definitive cause for abnormalities is never identified. Recently, the research community has given greater attention to identifying causes of MFI ranging from genetic Y chromosome microdeletions to mechanisms of environmental damage on sperm production. Still evolving, is a clear understanding of how many pharmaceutical medications may cause MFI, which is often treatable and reversible. In this review we will outline the data regarding various pharmaceutical medications that have been investigated as possible causes of MFI.