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Sriram S, Macedo T, Mavinkurve‐Groothuis A, van de Wetering M, Looijenga LHJ. Alkylating agents-induced gonadotoxicity in prepubertal males: Insights on the clinical and preclinical front. Clin Transl Sci 2024; 17:e13866. [PMID: 38965809 PMCID: PMC11224131 DOI: 10.1111/cts.13866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/26/2024] [Accepted: 06/06/2024] [Indexed: 07/06/2024] Open
Abstract
Rising cure rates in pediatric cancer patients warrants an increased attention toward the long-term consequences of the diagnosis and treatment in survivors. Chemotherapeutic agents can be gonadotoxic, rendering them at risk for infertility post-survival. While semen cryopreservation is an option that can be provided for most (post)pubertal boys before treatment, this is unfortunately not an option prepubertal in age, simply due to the lack of spermatogenesis. Over the last couple of years, studies have thus focused on better understanding the testis niche in response to various chemotherapeutic agents that are commonly administered and their direct and indirect impact on the germ cell populations. These are generally compounds that have a high risk of infertility and have been classified into risk categories in curated fertility guidelines. However, with it comes the lack of evidence and the challenge of using informative models and conditions most reflective of the physiological scenario, in short, the appropriate study designs for clinically relevant outcomes. Besides, the exact mechanism(s) of action for many of these "risk" compounds as well as other agents is unclear. Understanding their behavior and effect on the testis niche will pave the way for incorporating new strategies to ultimately combat infertility. Of the various drug classes, alkylating agents pose the highest risk of gonadotoxicity as per previously established studies as well as risk stratification guidelines. Therefore, this review will summarize the findings in the field of male fertility concerning gonadotoxicity of akylating agents as a result of chemotherapy exposure.
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Affiliation(s)
- Sruthi Sriram
- Princess Máxima Center for Pediatric OncologyUtrechtThe Netherlands
| | - Tiago Macedo
- Princess Máxima Center for Pediatric OncologyUtrechtThe Netherlands
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Fraser B, Wilkins A, Whiting S, Liang M, Rebourcet D, Nixon B, Aitken RJ. Development of peptides for targeting cell ablation agents concurrently to the Sertoli and Leydig cell populations of the testes: An approach to non-surgical sterilization. PLoS One 2024; 19:e0292198. [PMID: 38574116 PMCID: PMC10994420 DOI: 10.1371/journal.pone.0292198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 12/28/2023] [Indexed: 04/06/2024] Open
Abstract
The surgical sterilization of cats and dogs has been used to prevent their unwanted breeding for decades. However, this is an expensive and invasive procedure, and often impractical in wider contexts, for example the control of feral populations. A sterilization agent that could be administered in a single injection, would not only eliminate the risks imposed by surgery but also be a much more cost-effective solution to this worldwide problem. In this study, we sought to develop a targeting peptide that would selectively bind to Leydig cells of the testes. Subsequently, after covalently attaching a cell ablation agent, Auristatin, to this peptide we aimed to apply this conjugated product (LH2Auristatin) to adult male mice in vivo, both alone and together with a previously developed Sertoli cell targeting peptide (FSH2Menadione). The application of LH2Auristatin alone resulted in an increase in sperm DNA damage, reduced mean testes weights and mean seminiferous tubule size, along with extensive germ cell apoptosis and a reduction in litter sizes. Together with FSH2Menadione there was also an increase in embryo resorptions. These promising results were observed in around a third of all treated animals. Given this variability, we discuss how these reagents might be modified in order to increase target cell ablation and improve their efficacy as sterilization agents.
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Affiliation(s)
- Barbara Fraser
- Priority Research Centre for Reproductive Science, University of Newcastle, Callaghan, NSW, Australia
- Pregnancy and Reproduction Program, Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
- College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW, Australia
| | - Alex Wilkins
- Priority Research Centre for Reproductive Science, University of Newcastle, Callaghan, NSW, Australia
- Pregnancy and Reproduction Program, Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
- College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW, Australia
| | - Sara Whiting
- Priority Research Centre for Reproductive Science, University of Newcastle, Callaghan, NSW, Australia
- Pregnancy and Reproduction Program, Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
- College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW, Australia
| | - Mingtao Liang
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW, Australia
- College of Health, Medicine and Wellbeing, University of Newcastle, Callaghan, NSW, Australia
| | - Diane Rebourcet
- Priority Research Centre for Reproductive Science, University of Newcastle, Callaghan, NSW, Australia
- Pregnancy and Reproduction Program, Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
- College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW, Australia
| | - Brett Nixon
- Priority Research Centre for Reproductive Science, University of Newcastle, Callaghan, NSW, Australia
- Pregnancy and Reproduction Program, Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
- College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW, Australia
| | - Robert John Aitken
- Priority Research Centre for Reproductive Science, University of Newcastle, Callaghan, NSW, Australia
- Pregnancy and Reproduction Program, Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
- College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW, Australia
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Fraser BA, Wilkins AL, De Iuliis GN, Rebourcet D, Nixon B, Aitken RJ. Development of a model for studying the developmental consequences of oxidative sperm DNA damage by targeting redox-cycling naphthoquinones to the Sertoli cell population. Free Radic Biol Med 2023; 206:50-62. [PMID: 37356777 DOI: 10.1016/j.freeradbiomed.2023.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/07/2023] [Accepted: 06/12/2023] [Indexed: 06/27/2023]
Abstract
Oxidative stress can be induced in the testes by a wide range of factors, including scrotal hyperthermia, varicocele, environmental toxicants, obesity and infection. The clinical consequences of such stress include the induction of genetic damage in the male germ line which may, in turn, have serious implications for the health and wellbeing of the progeny. In order to confirm the transgenerational impact of oxidative stress in the testes, we sought to develop an animal model in which this process could be analysed. Our primary approach to this problem was to induce Sertoli cells (robust, terminally differentiated, tissue-specific testicular cells whose radioresistance indicates significant resistance to oxidative stress) to generate high levels of reactive oxygen species (ROS) within the testes. To achieve this aim, six follicle-stimulating hormone (FSH) peptides were developed and compared for selective targeting to Sertoli cells both in vitro and in vivo. Menadione, a redox-cycling agent, was then conjugated to the most promising FSH candidate using a linker that had been optimised to enable maximum production of ROS in the targeted cells. A TM4 Sertoli cell line co-incubated with the FSH-menadione conjugate in vitro exhibited significantly higher levels of mitochondrial ROS generation (10-fold), lipid peroxidation (2-fold) and oxidative DNA damage (2-fold) than the vehicle control. Additionally, in a proof-of-concept study, ten weeks after a single injection of the FSH-menadione conjugate in vivo, injected male mice were found to exhibit a 1.6 fold increase in DNA double strand breaks and 13-fold increase in oxidative DNA damage to their spermatozoa while still retaining their ability to initiate a pregnancy. We suggest this model could now be used to study the influence of chronic oxidative stress on testicular function with emphasis on the impact of DNA damage in the male germ line on the mutational profile and health of future generations.
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Affiliation(s)
- Barbara Anne Fraser
- Priority Research Centre for Reproductive Science, The University of Newcastle, Callaghan, NSW, 2308, Australia; Pregnancy and Reproduction Program, Hunter Medical Research Institute, Kookaburra Cct, New Lambton Heights, NSW, 2305, Australia; College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW, 2308, Australia.
| | - Alexandra Louise Wilkins
- Priority Research Centre for Reproductive Science, The University of Newcastle, Callaghan, NSW, 2308, Australia; Pregnancy and Reproduction Program, Hunter Medical Research Institute, Kookaburra Cct, New Lambton Heights, NSW, 2305, Australia; College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Geoffry Nunzio De Iuliis
- Priority Research Centre for Reproductive Science, The University of Newcastle, Callaghan, NSW, 2308, Australia; Pregnancy and Reproduction Program, Hunter Medical Research Institute, Kookaburra Cct, New Lambton Heights, NSW, 2305, Australia; College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Diane Rebourcet
- Priority Research Centre for Reproductive Science, The University of Newcastle, Callaghan, NSW, 2308, Australia; Pregnancy and Reproduction Program, Hunter Medical Research Institute, Kookaburra Cct, New Lambton Heights, NSW, 2305, Australia; College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Brett Nixon
- Priority Research Centre for Reproductive Science, The University of Newcastle, Callaghan, NSW, 2308, Australia; Pregnancy and Reproduction Program, Hunter Medical Research Institute, Kookaburra Cct, New Lambton Heights, NSW, 2305, Australia; College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Robert John Aitken
- Priority Research Centre for Reproductive Science, The University of Newcastle, Callaghan, NSW, 2308, Australia; Pregnancy and Reproduction Program, Hunter Medical Research Institute, Kookaburra Cct, New Lambton Heights, NSW, 2305, Australia; College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW, 2308, Australia
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Panghal A, Sahu C, Singla S, Jena G. Juvenile exposure and adult risk assessment with single versus repeated exposure of melphalan in the germ cells of male SD rat: Deciphering the molecular mechanisms. Reprod Toxicol 2022; 113:71-84. [PMID: 35961530 DOI: 10.1016/j.reprotox.2022.08.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 08/04/2022] [Accepted: 08/08/2022] [Indexed: 10/15/2022]
Abstract
Melphalan significantly contributes to the increase in childhood cancer survival rate. It acts as a gonadotoxic agent and leads to testes damage, dysbalance in gonadal hormones, and impairment in the germ cell proliferation. Therefore, it might be a potent threat to male fertility in individuals who have undergone melphalan treatment during childhood cancer. However, the molecular mechanisms of melphalan-induced gonadal damage are not yet fully explored and they need to be investigated to determine the benefit-risk profile. In the present study, juvenile male SD rats were subjected to single and intermittent cycles of melphalan exposure in a dose-dependent (0.375, 0.75 and 1.5 mg/kg) manner. Methods of end-points evaluations were quantification of micronuclei formation in peripheral blood, sperm count, sperm motility and head morphology, sperm and testicular DNA damage, histological studies in testes, oxidative/nitrosative stress parameters. A single cycle of exposure at high dose (1.5 mg/kg) produced significant effect on micronuclei formation only after the first week of exposure, whereas failed to produce significant effect at the end of the sixth week. Intermittent cycles of exposure at the dose of 1.5 mg/kg produced significant alterations in all the parameters (micronuclei in peripheral blood, testes and epididymides weight and length, MDA, GSH and nitrite levels, sperm count and motility, sperm head morphology, testicular and sperm DNA damage, protein expression in testes and histological parameters). So, time of exposure as well as the amount of exposure (total dosage administered) is critical in determining the magnitude of the damage in germ cell risk assessment.
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Affiliation(s)
- Archna Panghal
- Facility for Risk Assessment and Intervention Studies, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, S.A.S Nagar, Punjab 160062, India.
| | - Chittaranjan Sahu
- Facility for Risk Assessment and Intervention Studies, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, S.A.S Nagar, Punjab 160062, India.
| | - Shivani Singla
- Facility for Risk Assessment and Intervention Studies, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, S.A.S Nagar, Punjab 160062, India.
| | - Gopabandhu Jena
- Facility for Risk Assessment and Intervention Studies, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, S.A.S Nagar, Punjab 160062, India.
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Sagaradze G, Monakova A, Basalova N, Popov V, Balabanyan V, Efimenko A. Regenerative medicine for male infertility: A focus on stem cell niche injury models. Biomed J 2022; 45:607-614. [PMID: 35123107 PMCID: PMC9486244 DOI: 10.1016/j.bj.2022.01.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 10/19/2021] [Accepted: 01/27/2022] [Indexed: 02/08/2023] Open
Abstract
Stem and progenitor cells located within stem cell niches maintain the renewal and regeneration of tissues and organs throughout the life of an adult organism. Stem cell niche component dysfunction might alter the activity of stem cells and ultimately lead to the development of difficult-to-treat chronic or acute disorders. Of note, some cases of idiopathic male infertility, a highly prevalent diagnosis with no specific treatment options, might be associated with a spermatogonial stem cell(SSC) niche disturbance. To overcome this disease entity, approaches aiming at launching the regeneration of an altered stem cell niche are worth considering. Particularly, mesenchymal stromal cells (MSCs) or their secretome might fulfill this task due to their promising contribution in recovering injured stem cell niches. However, the successful application of MSC-based treatment is limited by the uncovered mechanisms of action of MSCs and their secretome. Specific animal models should be developed or adapted to reveal the role of MSCs and their secretome in a stem cell niche recovery. In this review, in a bid to consider MSCs and their secretome as a therapeutic regenerative approach for idiopathic male infertility we focus on the rationale of SSC niche injury modeling.
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Affiliation(s)
- Georgy Sagaradze
- Institute for Regenerative Medicine, Medical Research and Education Center, Lomonosov Moscow State University, Moscow, Russia
| | - Anna Monakova
- Faculty of Medicine, Lomonosov Moscow State University, Moscow, Russia
| | - Nataliya Basalova
- Institute for Regenerative Medicine, Medical Research and Education Center, Lomonosov Moscow State University, Moscow, Russia; Faculty of Medicine, Lomonosov Moscow State University, Moscow, Russia
| | - Vladimir Popov
- Institute for Regenerative Medicine, Medical Research and Education Center, Lomonosov Moscow State University, Moscow, Russia; Faculty of Medicine, Lomonosov Moscow State University, Moscow, Russia
| | - Vadim Balabanyan
- Institute for Regenerative Medicine, Medical Research and Education Center, Lomonosov Moscow State University, Moscow, Russia
| | - Anastasia Efimenko
- Institute for Regenerative Medicine, Medical Research and Education Center, Lomonosov Moscow State University, Moscow, Russia; Faculty of Medicine, Lomonosov Moscow State University, Moscow, Russia.
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Wyns C, Kanbar M, Giudice MG, Poels J. Fertility preservation for prepubertal boys: lessons learned from the past and update on remaining challenges towards clinical translation. Hum Reprod Update 2020; 27:433-459. [PMID: 33326572 DOI: 10.1093/humupd/dmaa050] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 09/25/2020] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Childhood cancer incidence and survivorship are both on the rise. However, many lifesaving treatments threaten the prepubertal testis. Cryopreservation of immature testicular tissue (ITT), containing spermatogonial stem cells (SSCs), as a fertility preservation (FP) option for this population is increasingly proposed worldwide. Recent achievements notably the birth of non-human primate (NHP) progeny using sperm developed in frozen-thawed ITT autografts has given proof of principle of the reproductive potential of banked ITT. Outlining the current state of the art on FP for prepubertal boys is crucial as some of the boys who have cryopreserved ITT since the early 2000s are now in their reproductive age and are already seeking answers with regards to their fertility. OBJECTIVE AND RATIONALE In the light of past decade achievements and observations, this review aims to provide insight into relevant questions for clinicians involved in FP programmes. Have the indications for FP for prepubertal boys changed over time? What is key for patient counselling and ITT sampling based on the latest achievements in animals and research performed with human ITT? How far are we from clinical application of methods to restore reproductive capacity with cryostored ITT? SEARCH METHODS An extensive search for articles published in English or French since January 2010 to June 2020 using keywords relevant to the topic of FP for prepubertal boys was made in the MEDLINE database through PubMed. Original articles on fertility preservation with emphasis on those involving prepubertal testicular tissue, as well as comprehensive and systematic reviews were included. Papers with redundancy of information or with an absence of a relevant link for future clinical application were excluded. Papers on alternative sources of stem cells besides SSCs were excluded. OUTCOMES Preliminary follow-up data indicate that around 27% of boys who have undergone testicular sampling as an FP measure have proved azoospermic and must therefore solely rely on their cryostored ITT to ensure biologic parenthood. Auto-transplantation of ITT appears to be the first technique that could enter pilot clinical trials but should be restricted to tissue free of malignant cells. While in vitro spermatogenesis circumvents the risk linked to cancer cell contamination and has led to offspring in mice, complete spermatogenesis has not been achieved with human ITT. However, generation of haploid germ cells paves the way to further studies aimed at completing the final maturation of germ cells and increasing the efficiency of the processes. WIDER IMPLICATIONS Despite all the research done to date, FP for prepubertal boys remains a relatively young field and is often challenging to healthcare providers, patients and parents. As cryopreservation of ITT is now likely to expand further, it is important not only to acknowledge some of the research questions raised on the topic, e.g. the epigenetic and genetic integrity of gametes derived from strategies to restore fertility with banked ITT but also to provide healthcare professionals worldwide with updated knowledge to launch proper multicollaborative care pathways in the field and address clinical issues that will come-up when aiming for the child's best interest.
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Affiliation(s)
- Christine Wyns
- Andrology lab, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain, Brussels, Belgium.,Department of Gynecology-Andrology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Marc Kanbar
- Andrology lab, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain, Brussels, Belgium.,Department of Gynecology-Andrology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Maria Grazia Giudice
- Andrology lab, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain, Brussels, Belgium.,Department of Gynecology-Andrology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Jonathan Poels
- Andrology lab, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain, Brussels, Belgium.,Department of Gynecology-Andrology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
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Hall SE, Nixon B, Aitken RJ. Non-surgical sterilisation methods may offer a sustainable solution to feral horse (Equus caballus) overpopulation. Reprod Fertil Dev 2017; 29:1655-1666. [DOI: 10.1071/rd16200] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 09/09/2016] [Indexed: 11/23/2022] Open
Abstract
Feral horses are a significant pest species in many parts of the world, contributing to land erosion, weed dispersal and the loss of native flora and fauna. There is an urgent need to modify feral horse management strategies to achieve public acceptance and long-term population control. One way to achieve this is by using non-surgical methods of sterilisation, which are suitable in the context of this mobile and long-lived species. In this review we consider the benefits of implementing novel mechanisms designed to elicit a state of permanent sterility (including redox cycling to generate oxidative stress in the gonad, random peptide phage display to target non-renewable germ cells and the generation of autoantibodies against proteins essential for conception via covalent modification) compared with that of traditional immunocontraceptive approaches. The need for a better understanding of mare folliculogenesis and conception factors, including maternal recognition of pregnancy, is also reviewed because they hold considerable potential in providing a non-surgical mechanism for sterilisation. In conclusion, the authors contend that non-surgical measures that are single shot and irreversible may provide a sustainable and effective strategy for feral horse control.
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Swegen A, Aitken RJ. Prospects for immunocontraception in feral horse population control: exploring novel targets for an equine fertility vaccine. Reprod Fertil Dev 2016; 28:853-863. [DOI: 10.1071/rd14280] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 10/11/2014] [Indexed: 12/12/2022] Open
Abstract
Feral horses populate vast land areas and often induce significant ecological and economic damage throughout the landscape. Non-lethal population control methods are considered favourable in light of animal welfare, social and ethical considerations; however, no single effective, safe and species-specific contraceptive agent is currently available for use in free-ranging wild and feral horses. This review explores aspects of equine reproductive physiology that may provide avenues for the development of specific and long-lasting immunocontraceptive vaccines and some of the novel strategies that may be employed to facilitate appropriate antigen discovery in future research. Potential antigen targets pertaining to spermatozoa, the ovary and oocyte, as well as the early conceptus and its associated factors, are reviewed in the context of their suitability for immunocontraceptive vaccine development.
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Chen H, Mruk DD, Xia W, Bonanomi M, Silvestrini B, Cheng CY. Effective Delivery of Male Contraceptives Behind the Blood-Testis Barrier (BTB) - Lesson from Adjudin. Curr Med Chem 2016; 23:701-13. [PMID: 26758796 PMCID: PMC4845722 DOI: 10.2174/0929867323666160112122724] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 12/18/2014] [Accepted: 01/11/2016] [Indexed: 12/15/2022]
Abstract
The blood-testis barrier (BTB) is one of the tightest blood-tissue barriers in the mammalian body. It divides the seminiferous epithelium of the seminiferous tubule, the functional unit of the testis, where spermatogenesis takes place, into the basal and the adluminal (apical) compartments. Functionally, the BTB provides a unique microenvironment for meiosis I/II and post-meiotic spermatid development which take place exclusively in the apical compartment, away from the host immune system, and it contributes to the immune privilege status of testis. However, the BTB also poses major obstacles in developing male contraceptives (e.g., adjudin) that exert their effects on germ cells in the apical compartment, such as by disrupting spermatid adhesion to the Sertoli cell, causing germ cell exfoliation from the testis. Besides the tight junction (TJ) between adjacent Sertoli cells at the BTB that restricts the entry of contraceptives from the microvessels in the interstitium to the adluminal compartment, drug transporters, such as P-glycoprotein and multidrug resistance-associated protein 1 (MRP1), are also present that actively pump drugs out of the testis, limiting drug bioavailability. Recent advances in drug formulations, such as drug particle micronization (<50 μm) and co-grinding of drug particles with ß-cyclodextrin have improved bioavailability of contraceptives via considerable increase in solubility. Herein, we discuss development in drug formulations using adjudin as an example. We also put emphasis on the possible use of nanotechnology to deliver adjudin to the apical compartment with multidrug magnetic mesoporous silica nanoparticles. These advances in technology will significantly enhance our ability to develop effective non-hormonal male contraceptives for men.
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Affiliation(s)
| | | | | | | | | | - Chuen-Yan Cheng
- Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave, New York 10065, USA..
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