Novel Genes of the Male Reproductive System: Potential Roles in Male Reproduction and as Non-hormonal Male Contraceptive Targets.

The development of novel non-hormonal male contraceptives represents a pivotal frontier in reproductive health, driven by the need for safe, effective, and reversible contraceptive methods. This comprehensive review explores the genetic underpinnings of male fertility, emphasizing the crucial roles of specific genes and structural variants (SVs) identified through advanced sequencing technologies such as long-read sequencing (LRS). LRS has revolutionized the detection of structural variants and complex genomic regions, offering unprecedented precision and resolution over traditional next-generation sequencing (NGS). Key genetic targets, including those implicated in spermatogenesis and sperm motility, are highlighted, showcasing their potential as non-hormonal contraceptive targets. The review delves into the systematic identification and validation of male reproductive tract-specific genes, utilizing advanced transcriptomics and genomics studies with validation using novel knockout mouse models. We discuss the innovative application of small molecule inhibitors, developed through platforms like DNA-encoded chemistry technology (DEC-Tec), which have shown significant promise in preclinical models. Notable examples include inhibitors targeting serine/threonine kinase 33 (STK33), soluble adenylyl cyclase (sAC), cyclin-dependent kinase 2 (CDK2), and bromodomain testis associated (BRDT), each demonstrating nanomolar affinity and potential for reversible and specific inhibition of male fertility. This review also honors the contributions of Dr. David L. Garbers whose foundational work has paved the way for these advancements. The integration of genomic, proteomic, and chemical biology approaches, supported by interdisciplinary collaboration, is poised to transform male contraceptive development. Future perspectives emphasize the need for continued innovation and rigorous testing to bring these novel contraceptives from the laboratory to clinical application, promising a new era of male reproductive health management.

Safe Sex and the Debate over Condoms on Campus in the 1980s: Sperm Busters at Harvard and Protection Connection at the University of Texas at Austin.

During the 1980s, college students in the United States helped to destigmatize the distribution and use of condoms. They shifted their aims from preventing unwanted pregnancy to stopping the spread of sexually transmitted infections including the newly identified acquired immunodeficiency syndrome (AIDS). Two student-led initiatives to deliver condoms after hours at Harvard University in Cambridge, Massachusetts and the University of Texas at Austin show regional and temporal differences in sexual mores as awareness of AIDS increased. These male students adopted a non-pharmaceutical intervention to prevent pregnancy and disease in the context of increased marketing of Trojan® brand condoms. Interviews with co-founders reveal how the students grappled with backlash from family members and campus administrators less enthusiastic about their popularization of condoms. Co-founders described how media attention affected their college experiences and how condom companies changed campus culture. Overall, large non-pharmaceutical companies such as Trojan® and small condom-resellers such as those at Harvard and the University of Texas at Austin reshaped cultural norms around safe sex as awareness of AIDS grew between 1985 and 1987.

Novel progestogenic androgens for male contraception: design, synthesis, and activity of C7 α-substituted testosterone†.

Male contraceptive development has included use of testosterone (T) with or without a progestin or the use of a single molecule such as progestogenic androgens (PA) for suppression of testicular T production. Expanding upon the vast amount of data accumulated from nortestosterone (NT), NT analogs, and their prodrugs, a new series of PA, the C7 methyl, and ethyl α-substituted T analogs 7α-Methyltestosterone (7α-MT) and 7α-Ethyltestosterone (7α-ET), respectively, were hypothesized and designed to have superior androgenic and progestogenic activities when compared with parent T. Results from androgen receptor and progesterone receptor competitive binding and transcriptional activation assays showed favorable activities for these T analogs. Additionally, 7α-MT and 7α-ET were shown to be active substrates for aromatase in vitro, mitigating a potential negative impact on bone mineral density with long-term use. In conjunction with this observation, the diminished metabolism of these T analogs by 5α-reductase may reduce potential concerns for prostatic growth. In the Hershberger in vivo rat bioassay, 7α-MT and 7α-ET showed superior androgenic and anabolic activities as compared with T. These C7 α-substituted T analogs also showed clear progestogenic activity in the McPhail bioassay which evaluated endometrial glandular arborization in a rabbit model. The discovery of aromatizable molecules with reduced metabolism by 5α-reductase that have androgenic, anabolic, and progestogenic properties indicates that the core and/or prodrugs of 7α-MT and 7α-ET are promising molecules for further development as male contraceptive PAs.

Resumption of Spermatogenesis and Fertility Post Withdrawal of Hydroxyurea Treatment.

Hydroxyurea (HU), a drug for treating cancers of the blood and the management of sickle cell anemia, induces hypogonadism in males. However, the impact of HU on testicular architecture and function, as well as its effects on the resumption of male fertility following treatment withdrawal, remain poorly understood. We used adult male mice to determine whether HU-induced hypogonadism is reversible. Fertility indices of mice treated with HU daily for ~1 sperm cycle (2 months) were compared with those of their control counterparts. All indices of fertility were significantly reduced among mice treated with HU compared to controls. Interestingly, significant improvements in fertility indices were apparent after a 4-month withdrawal from HU treatment (testis weight: month 1 post-HU withdrawal (M1): HU, 0.09 ± 0.01 vs. control, 0.33 ± 0.03; M4: HU, 0.26 ± 0.03 vs. control, 0.37 ± 0.04 g); sperm motility (M1: HU,12 vs. 59; M4: HU, 45 vs. control, 61%; sperm density (M1: HU, 1.3 ± 0.3 vs. control, 15.7 ± 0.9; M4: HU, 8.1 ± 2.5 vs. control, 16.8 ± 1.9 million). Further, circulating testosterone increased in the 4th month following HU withdrawal and was comparable to that of controls. When a mating experiment was conducted, recovering males sired viable offspring with untreated females albeit at a lower rate than control males (p < 0.05); therefore, qualifying HU as a potential candidate for male contraception.

Single or repeated immunization against GnRH fails to completely abolish spermatogenesis in dwarf bucks (Capra hircus).

In both captive wildlife and production animals is important to develop strategies for population control. Immunization against GnRH is an easy and inexpensive immunocastration method that reduces the concentration of testosterone and decreases sperm quality. However, its effectiveness depends on the species and repetition of the treatment. This study aimed to compare the effectiveness of a single treatment (initial immunization plus a booster with Improvac) vs repeated treatment (six doses of Improvac) to inhibit testicular function and maintain the contraceptive status during long periods in bucks. Three Dwarf bucks (Capra hircus) received two doses of Improvac, the first on Week 0, and the booster 4 weeks later (single immunization, group SI) while three Dwarf bucks received one dose of Improvac every 6 months during 3 consecutive years (repeated immunization, group RI). The other three Dwarf bucks remained untreated (control bucks, group CON). Bucks from RI had a greater decrease in scrotal circumference, testosterone concentration, male odor intensity, and sperm quality than SI bucks. However, there were no differences between SI and CON bucks in any of the variables studied. Overall, repeated treatment of Improvac decreased the testicular function of Dwarf bucks, although did not produce complete infertility. However, the repetition of the treatment produced more intensive negative effects, indicating that the strength of the effects of Improvac is rapidly lost in bucks.

[Recommendations of the Committee of Andrology and Sexual Medicine of the AFU concerning the management of Vasectomy]. / Recommandations du Comité d'Andrologie et de Médecine Sexuelle de l'AFU concernant la prise en charge de la vasectomie.

OBJECTIVES: To answer the main clinical questions asked by practitioners and men consulting for a vasectomy request. METHOD: The CPR method was used. The clinical questions were formulated according to the PICO methodology. A Pubmed literature search for the period 1984-2021 identified 508 references, of which 79 were selected and analyzed with the GRADE grid. RECOMMENDATIONS: Vasectomy is a permanent, potentially reversible contraception. It is a safe procedure. A second vasectomy is necessary in only 1 % of cases. Surgical complications (hematoma, infection, pain, etc.) are rare. The frequency of prolonged scrotal pain after vasectomy is about 5 %, and less than 2 % describe a negative impact of this pain on their quality of life. Vasectomy does not have negative consequences on sexuality. The only contraindication to vasectomy is the minor patient. Patients at increased risk of remorse are single, divorced or separated men under the age of 30. Sperm storage may be particularly appropriate for them. Whatever the reason, the law allows the surgeon to refuse to perform the vasectomy. He must inform the patient of this at the first consultation. The choice of the type of anesthesia is left to the discretion of the surgeon and the patient. It must be decided during the preoperative consultation. Local anesthesia should be considered first. General anesthesia should be particularly considered in cases of anxiety or intense sensitivity of the patient to palpation of the vas deferens, difficulty palpating the vas deferens, or a history of scrotal surgery that would make the procedure more complex. Concerning the vasectomy technique, 2 points seem to improve the efficiency of the vasectomy: coagulation of the deferential mucosa and interposition of fascia. Leaving the proximal end of the vas deferens free seems to reduce the risk of post-vasectomy syndrome without increasing the risk of failure or complications. No-scalpel vasectomy is associated with a lower risk of postoperative complications than conventional vasectomy. Regarding follow-up, it is recommended to perform a spermogram at 3 months post-vasectomy and after 30 ejaculations. If there are still a few non-motile spermatozoa at 3 months, it is recommended that a check-up be performed at 6 months post-vasectomy. In case of motile spermatozoa or more than 100,000 immobile spermatozoa/mL at 6 months (defining failure), a new vasectomy should be considered. Contraception must be maintained until the effectiveness of the vasectomy is confirmed.

Male Hormonal Contraception.

The economic and public health burdens of unplanned pregnancies are evident globally. Since the introduction of the condom >300 years ago, assumptions about male willingness to participate in contraception, as well as concerns about failure rates and side effects, have stagnated the development of additional reversible male contraceptives. However, changing attitudes and recent research advances have generated renewed interest in developing reversible male contraceptives. To achieve effective and reversible suppression of spermatogenesis, male hormonal contraception relies on suppression of testicular testosterone and sperm production using an androgen-progestin combination. While these may be associated with side effects-changes in libido, weight, hematocrit, and cholesterol-recently, novel androgens and progestins have shown promise for a "male pill" with reduced side effects. Here we summarize landmark studies in male contraceptive development, showcase the most recent advances, and look into the future of this field, which has the potential to greatly impact global public health.

Catalyzing momentum in male contraceptive development†.

Globally, nearly half of all pregnancies are unplanned. Male contraceptives offer the potential to decrease unintended pregnancy and introduce contraceptive equity, but decades of research have yet to bring a novel product to market. New funding avenues from the philanthropic sector seek to stimulate research in male contraceptives through investments, grants, and support for trainees alongside other programs that encourage product development and ultimately commercialization. This Forum outlines the purpose of and funding opportunities provided by Male Contraceptive Initiative, a funding agency and non-profit focused on the advancement of non-hormonal, reversible contraceptive technologies for those who produce sperm.

The P2X1 receptor as a therapeutic target.

Within the family of purinergic receptors, the P2X1 receptor is a ligand-gated ion channel that plays a role in urogenital, immune and cardiovascular function. Specifically, the P2X1 receptor has been implicated in controlling smooth muscle contractions of the vas deferens and therefore has emerged as an exciting drug target for male contraception. In addition, the P2X1 receptor contributes to smooth muscle contractions of the bladder and is a target to treat bladder dysfunction. Finally, platelets and neutrophils have populations of P2X1 receptors that could be targeted for thrombosis and inflammatory conditions. Drugs that specifically target the P2X1 receptor have been challenging to develop, and only recently have small molecule antagonists of the P2X1 receptor been available. However, these ligands need further biological validation for appropriate selectivity and drug-like properties before they will be suitable for use in preclinical models of disease. Although the atomic structure of the P2X1 receptor has yet to be determined, the recent discovery of several other P2X receptor structures and improvements in the field of structural biology suggests that this is now a distinct possibility. Such efforts may significantly improve drug discovery efforts at the P2X1 receptor.

The novel BRDT inhibitor NHWD870 shows potential as a male contraceptive in mice.

Small molecule inhibitors of the bromodomain and extraterminal domain (BET) family proteins have emerged as promising options not only for the treatment of multiple cancers but also for disturbing the process of sperm maturation with potential for use as viable contraceptive targets. In this study, we find that the BET family inhibitor NHWD870 and BRDT can bind well in vitro through bioinformatics software prediction and protein binding inhibition experiments. NHWD870 can produce a good contraceptive effect through animal experiments in vivo, and the fertility can be restored to normal after drug withdrawal. Transcriptomics and proteomics results suggest that NHWD870 affects pathways related to spermatogenesis and maturation, further contributing to the male infertility phenotype. Our results show that NHWD870 can induce a complete and reversible contraceptive effect in mice, which is stronger than that of JQ1 and its synthesized derivatives. This study is expected to eventually lead to clinical trials.

Magnetic Testis Targeting and Magnetic Hyperthermia for Noninvasive, Controllable Male Contraception via Intravenous Administration.

Mild testicular hyperthermia by the photothermal effect of gold nanorods could realize controllable male contraception. However, associated limitations, such as testicular administration and infrared laser inflicting severe pain, and the nondegradability of nanoparticles potentially causing toxicity, have restricted further clinical application. Inspired by the excellent physicochemical properties of iron oxide nanoparticles (IONPs), and the finding that testicular injection of PEG-coated IONPs with a diameter of 50 nm (PEG@Fe3O4-50) following an alternating magnetic field (AMF) could achieve controllable male contraception; here we propose a noninvasive, targeting approach for male contraception via intravenous administration. The magnetic properties and testes targeting of IONPs were proven to be greatly affected by their surface chemistry and particle size. After systemic administration, citric acid stabilized IONPs with size of 100 nm (CA@Fe3O4-100) were found to be the best ideal thermoagent for realizing the noninvasive contraception. This study offers new strategies for male contraception.

Knowledge, professional attitudes, and training among health professionals regarding male contraceptive methods.

OBJECTIVES: Health professionals are at the forefront of information and acceptability regarding contraceptive methods, however only one study evaluated their knowledge of male contraception (MC) including hormonal MC (HMC) and thermal MC (TMC). Our objective was to evaluate the knowledge, professional attitudes, and training of French practitioners regarding the management of couple contraception by male contraception (MC). STUDY DESIGN: We designed a descriptive, cross-sectional, multicentre study in 2,396 French practitioners belonging to national or regional institutions involved in contraception. We solicited practitioners by e-mail to complete an anonymous questionnaire; we analysed their knowledge, professional attitudes, and training regarding the management of couple contraception by MC. RESULTS: The overall participation rate was 18% (427/2,396). Condoms, withdrawal, and vasectomy were known by 98%, 89%, and 76% of the population, respectively. Hormonal MC and Thermal (TMC) were known by 10% and 24% of the population, respectively. Fifty-five percent of the population never or infrequently offered MC during a couple's contraceptive request consultation. Only 14% of the population had ever participated in training on MC; 96% wanted to be better trained on MC, and 87% expressed a willingness to participate in training on the subject. CONCLUSIONS: Health professionals involved in contraception have unsatisfactory knowledge about MC methods based on spermatogenesis inhibition and are eager to have more information about them. To advance the acceptability and dissemination of MC methods, it seems imperative to enhance research in the field and to provide health professionals with an adapted training programme.

Male contraception: What do women think?

INTRODUCTION: Women currently bear the most responsibility in contraception, with a wide choice of methods, while only a few existing male contraceptives are available. However, it has been shown that men are willing to get involved in birth control and to control their own fertility. Our research was focused on female population and a survey was carried out to explore women's perceptions of male contraception. METHODS: An observational quantitative cross-sectional study using a self-administered-questionnaire was carried out between November 2019 and February 2020. All women aged from 16-years-old to menopause completing the questionnaire were included. Descriptive statistical analyses were conducted, qualitative variables were expressed as counts and frequency. RESULTS: In total, 379 interpretable completed questionnaires were included. Among the women, 69.7% were in favour of letting men deal with contraception, without referring to a specific method. After having been made aware of the medical information concerning existing male contraceptives and those in development, the proportion of women in favour dropped to 46.7%. The most acceptable method for a majority of women was the male pill, which is still being developed. The majority (78.4%) of the women in our survey felt insufficiently informed about male contraception. DISCUSSION: In our study, women seemed to want to share contraceptive responsibility with men, but the lack of information and of acceptable contraception methods available remained an obstacle. Although larger-scale studies are needed to confirm these results, the development of a wider range of male contraception methods seems to be what both men and women have long been expecting.

Still no pill for men? Double standards & demarcating values in biomedical research.

Double standards are widespread throughout biomedicine, especially in research on reproductive health. One of the clearest cases of double standards involves the feminine gendering of reproductive responsibility for contraception and the continued lack of highly effective, reversible methods for cisgender men. While the biomedical establishment accepts diversity and inclusion as important social values for clinical trials, their continued use of inequitable standards undermines their ability to challenge unfair social hierarchies by developing male contraception. Thus, the gender/sex bias present in contraceptive research raises the "New Demarcation Problem": If we accept that values can and will play important roles in science, how can we nevertheless distinguish positive influences of values from more corrosive bias? I argue that biomedical researchers ought to aim their clinical trials at equity and utilize methodologies that actually achieve that aim. More specifically, I contend that we can avoid the problem of double standards by gender/sex in contraceptive research by utilizing more equitable standards. My demarcation strategy captures dynamic interplay between values and their effects, with direct policy implications for institutions conducting, funding, and evaluating clinical trials. For male contraceptive trials, this involves shifting risk assessment from an individual model to a shared model for sexual partners.

Dissecting EPPIN protease inhibitor domains in sperm motility and fertilizing ability: repercussions for male contraceptive development.

EPPIN (epididymal protease inhibitor) is a mammalian conserved sperm-binding protein displaying an N-terminal WFDC (whey-acidic protein four-disulfide core) and a C-terminal Kunitz protease inhibitor domains. EPPIN plays a key role in regulating sperm motility after ejaculation via interaction with the seminal plasma protein SEMG1 (semenogelin-1). EPPIN ligands targeting the SEMG1 binding site in the Kunitz domain are under development as male contraceptive drugs. Nevertheless, the relative contributions of EPPIN WFDC and Kunitz domains to sperm function remain obscure. Here, we evaluated the effects of antibodies targeting specific epitopes in EPPIN's WFDC (Q20E antibody, Gln20-Glu39 epitope) and Kunitz (S21C and F21C antibodies, Ser103-Cys123 and Phe90-C110 epitopes, respectively) domains on mouse sperm motility and fertilizing ability. Computer-assisted sperm analysis showed that sperm co-incubation with S21C antibody (but not F21C antibody) lowered progressive and hyperactivated motilities and impaired kinematic parameters describing progressive (straight-line velocity; VSL, average path velocity; VAP and straightness; STR) and vigorous sperm movements (curvilinear velocity; VCL, amplitude of lateral head movement; ALH, and linearity; LIN) compared with control. Conversely, Q20E antibody-induced milder inhibition of progressive motility and kinematic parameters (VAP, VCL and ALH). Sperm co-incubation with S21C or Q20E antibodies affected in vitro fertilization as revealed by reduced cleavage rates, albeit without changes in capacitation-induced tyrosine phosphorylation. In conclusion, we show that targeting specific epitopes in EPPIN Kunitz and WFDC domains inhibits sperm motility and capacitation-associated events, which decrease their fertilizing ability; nevertheless, similar observations in vivo remain to be demonstrated. Simultaneously targeting residues in S21C and Q20E epitopes is a promising approach for the rational design of EPPIN-based ligands with spermostatic activity.

Promising results in development of male contraception.

Nowadays, conscious planning of the family is very important for many people. The possibility of using protective measures against unplanned pregnancy is a great comfort. Most forms of contraceptives are intended for women, although their use can be ruled out in various health conditions. Scientists have been trying to develop a different type of method for men for many years. More and more research is being done and there have been promising results. It is hoped that soon both genders will have a similar range of contraceptive options to enable responsible family planning.

How mammals pack their sperm: a variant matter.

Producing competent gametes is essential for transmitting genetic information throughout generations. Spermatogenesis is a unique example of rearrangements of genome packaging to ensure fertilization. After meiosis, spermatids undergo drastic morphological changes, perhaps the most dramatic ones occurring in their nuclei, including the transition into a protamine-packaged genome. In this issue of Genes & Development, Montellier and colleagues (pp. 1680-1692) shed new light on the molecular mechanisms regulating this transition by ascribing for the first time a function to a histone variant, TH2B, in the regulation of this process.

Chromatin-to-nucleoprotamine transition is controlled by the histone H2B variant TH2B.

The conversion of male germ cell chromatin to a nucleoprotamine structure is fundamental to the life cycle, yet the underlying molecular details remain obscure. Here we show that an essential step is the genome-wide incorporation of TH2B, a histone H2B variant of hitherto unknown function. Using mouse models in which TH2B is depleted or C-terminally modified, we show that TH2B directs the final transformation of dissociating nucleosomes into protamine-packed structures. Depletion of TH2B induces compensatory mechanisms that permit histone removal by up-regulating H2B and programming nucleosome instability through targeted histone modifications, including lysine crotonylation and arginine methylation. Furthermore, after fertilization, TH2B reassembles onto the male genome during protamine-to-histone exchange. Thus, TH2B is a unique histone variant that plays a key role in the histone-to-protamine packing of the male genome and guides genome-wide chromatin transitions that both precede and follow transmission of the male genome to the egg.

Ricinus communis-linn (castor plant), male contraceptives and reproductive health of women.

The medicinal use of castor plant is extensive. Castor oil is most commonly used as a laxative, and the leaves and seeds have been used to augment labour, promote lactation and to treat syphilis and leprosy. Its use for contraception is an ancient practice among the Rukuba women of Plateau State in Nigeria, who would chew 2-3 seeds for contraceptive coverage of one year. The acute and chronic spermatogenic effect of the minor seed variety of ricinus communis-linn is hereby reported. Thirty male rats weighing 200-250g were grouped (n = 5) and treated with the n-hexane extract of the seeds, each made up to 1ml with physiological saline, and given as a single dose, intraperitoneally. Control groups had 1 ml physiological saline. Semen was collected 72 h and 6 weeks after treatment and analyzed within one hour of collection. The seed extract suppressed spermatogenesis and sperm motility up to six weeks after treatment. But semen parameters reverted to normal values in the 7 weeks of treatment, showing primary spermatocytes and spermatids in the seminiferous tubules. Our results showed ricinus communis-linn to be a potent but reversible anti-spermatogenic agent with significant anti-motility properties. Moreover, being of plant origin, it is readily available and affordable. We hereby present ricinus communis-linn as a possible male contraceptive agent that can relieve women of their reproductive burden globally.

Optimization of lead compounds into on-demand, nonhormonal contraceptives: leveraging a public-private drug discovery institute collaboration†.

Efforts to develop new male or female nonhormonal, orally available contraceptives assume that to be effective and safe, targets must be (1) essential for fertility; (2) amenable to targeting by small-molecule inhibitors; and (3) restricted to the germline. In this perspective, we question the third assumption and propose that despite its wide expression, soluble adenylyl cyclase (sAC: ADCY10), which is essential for male fertility, is a valid target. We hypothesize that an acute-acting sAC inhibitor may provide orally available, on-demand, nonhormonal contraception for men without adverse, mechanism-based effects. To test this concept, we describe a collaboration between academia and the unique capabilities of a public-private drug discovery institute.