FSH for the Treatment of Male Infertility

E. Two livebirths achieved in cases of hypergonadotropic hypogonadism nonobstructive azoospermia, treated with GnRH agonist and gonadotrophins: a case series and review of the literature

Non-obstructive azoospermia (NOA) is the most severe form of male factor infertility. It results form from either primary or secondary testicular failure. Here, we report cases of two patients with NOA due to maturation arrest and increased serum FSH, treated with GnRH agonist and gonadotrophins. The two NOA patients underwent a pharmacological treatment consisting of pituitary desensibilization using a GnRH agonist and testicular stimulation using menotropin. Testicular stimulation started one month after the beginning of GnRH agonist treatment. The female partner underwent controlled ovarian stimulation (COS) followed by intracytoplasmic sperm injection (ICSI). On the third day of the cycle, menotropin daily doses was administered. When at least one follicle ≥14 mm was visualized, pituitary blockage was performed using GnRH antagonist ganirelix. When three or more follicles attained a mean diameter of ≥17 mm, triptorelin acetate was administered to trigger final follicular maturation. Oocyte retrieval was performed 35 hours later. After treatment, male partner blood levels of the FSH, LH, decreased and total testosterone were increased. Spermatozoa was observed after semen collection in both cases. After COS, oocytes were retrieved and ICSI was performed. Embryos were biopsied for preimplantation genetic testing (PGT) and those considered euploidy were transferred resulting in positive implantation, ongoing pregnancy, and livebirth on both cases. In this report we present a successful strategy for hypergonadotropic hypogonadism AOA men, as an alternative approach to the surgical testicular sperm recovery. Nevertheless, prospective randomized trials are needed to confirm our findings.

Mechanistic Insights into Bisphenol A-Mediated Male Infertility: Potential Role of Panax Ginseng Extract

Male infertility is identified by the inability of a man to successfully impregnate his fertile female partner, even following a year of regular unprotected sexual intercourse. About half of all infertility cases are attributed to what is known as "male factor" infertility. The escalating prevalence of male infertility in the contemporary era across the globe can be largely attributed to environmental pollution, which is the common etiological factor due to the ubiquitous presence of the environmental contaminants. Bisphenol A is recognized as an endocrine-disrupting chemical that has adverse effects on both male and female reproductive systems. On the other hand, numerous studies have demonstrated that Panax ginseng possessed the potential to improve male infertility parameters; promote spermatogenesis, recover the quality and motility of sperm and enhance testicular functions as it acted as a natural androgen supplement. The objective of this review is to offer a summary of the findings obtained from the current research data on the insult of bisphenol A (BPA) on male infertility and its supposed mode of action, as well as shed light on the potent ameliorative role of Panax ginseng extract, with a special focus on the mechanism behind its action. This review delivers a clear understanding of BPA mechanism of action on male infertility and the presumed risks deriving from its exposure. Also, this review provides evidence for the functional role of Panax ginseng extract in restoring male fertility.

APHRODITE criteria: addressing male patients with hypogonadism and/or infertility owing to altered idiopathic testicular function

RESEARCH QUESTION

Can a novel classification system of the infertile male - 'APHRODITE' (Addressing male Patients with Hypogonadism and/or infeRtility Owing to altereD, Idiopathic TEsticular function) - stratify different subgroups of male infertility to help scientists to design clinical trials on the hormonal treatment of male infertility, and clinicians to counsel and treat the endocrinological imbalances in men and, ultimately, increase the chances of natural and assisted conception?

DESIGN

A collaboration between andrologists, reproductive urologists and gynaecologists, with specialization in reproductive medicine and expertise in male infertility, led to the development of the APHRODITE criteria through an iterative consensus process based on clinical patient descriptions and the results of routine laboratory tests, including semen analysis and hormonal testing.

RESULTS

Five patient groups were delineated according to the APHRODITE criteria; (1) Hypogonadotrophic hypogonadism (acquired and congenital); (2) Idiopathic male infertility with lowered semen analysis parameters, normal serum FSH and normal serum total testosterone concentrations; (3) A hypogonadal state with lowered semen analysis parameters, normal FSH and reduced total testosterone concentrations; (4) Lowered semen analysis parameters, elevated FSH concentrations and reduced or normal total testosterone concentrations; and (5) Unexplained male infertility in the context of unexplained couple infertility.

CONCLUSION

The APHRODITE criteria offer a novel and standardized patient stratification system for male infertility independent of aetiology and/or altered spermatogenesis, facilitating communication among clinicians, researchers and patients to improve reproductive outcomes following hormonal therapy. APHRODITE is proposed as a basis for future trials of the hormonal treatment of male infertility.

EGF-driven EGFR/miR-27b-3p/FOXO1 promotes rat FSH synthesis and secretion

The adenopituitary secretes follicle-stimulating hormone (FSH), which plays a crucial role in regulating the growth, development, and reproductive functions of organisms. Investigating the process of FSH synthesis and secretion can offer valuable insights into potential areas of focus for reproductive research. Epidermal growth factor (EGF) is a significant paracrine/autocrine factor within the body, and studies have demonstrated its ability to stimulate FSH secretion in animals. However, the precise mechanisms that regulate this action are still poorly understood. In this research, in vivo and in vitro experiments showed that the activation of epidermal growth factor receptor (EGFR) by EGF induces the upregulation of miR-27b-3p and that miR-27b-3p targets and inhibits Foxo1 mRNA expression, resulting in increased FSH synthesis and secretion. In summary, this study elucidates the precise molecular mechanism through which EGF governs the synthesis and secretion of FSH via the EGFR/miR-27b-3p/FOXO1 pathway.

Early Pharmacologic Approaches to Avert Anabolic Steroid-induced Male Infertility: A Narrative Review

PURPOSE

To review the impact of testosterone and other androgenic-anabolic steroids (AASs) on male fertility, exploring potential drugs that can be used to preserve or restore male fertility upon AAS use or prior contact.

METHODS

A review was performed to provide a unifying clinical link between drugs used to preserve or restore male fertility (ie, clomiphene citrate, human chorionic gonadotropin, selective estrogen receptor modulators, recombinant luteinizing and follicle-stimulating hormones, and human menopausal gonadotrophin) in the context of AAS-induced infertility and related aspects.

FINDINGS

Human chorionic gonadotropin (125-500 IU every other day), clomiphene citrate (12.5-50 mg/d), recombinant luteinizing hormone (125-500 IU every other day), recombinant follicle-stimulating hormone (75-150 IU 1-3×/wk), and human menopausal gonadotrophin (75-150 IU 1-3×/wk) are promising early pharmacologic approaches to avert AAS-induced male infertility. Additionally, a full partner assessment is crucial to the success of a couple planning to have children. The partner's age and gynecopathies must be considered. Egg or sperm cryopreservation can also be alternatives for future fertility. Reinforcing AAS cessation is imperative to achieving better success in misusers.

IMPLICATIONS

The exponential increase in AAS misuse raises concerns about the impact on male fertility. This review suggests that gonadotropin analogs and selective androgen receptor modulators (clomiphene citrate) are viable approaches to early preserve or restore fertility in men on AAS use or with previous contact. However, proper standardization of doses and combinations is required and hence physicians should also be aware of patients' and partners' fertility.

Sperm Concentration Improvement May Be a Parameter Predicting Efficacy of FSH Therapy of Male Idiopathic Infertility

Testis stimulation with follicle-stimulating hormone (FSH) is one of the empirical treatments proposed for male idiopathic infertility, although reliable markers to predict its efficacy are still lacking. This study aimed to identify parameters able to predict FSH efficacy in terms of pregnancy achievement. A real-world study was conducted, enrolling idiopathic infertile men treated with FSH 150IU three times weekly. Patients were treated until pregnancy achievement or for a maximum of two years and two visits were considered: V0 (baseline) and V1 (end of FSH treatment). Primary endpoints were the V1-V0 percentage change in sperm concentration, total sperm count, and total motile sperm number. In total, 48 pregnancies were recorded (27.7%) among 173 men (age 37.9 ± 6.2 years). All three endpoints increased after FSH administration, and only the V1-V0 percentage of sperm concentration significantly predicted pregnancy (p = 0.007). A V1-V0 sperm concentration of 30.8% predicted pregnancy, and the sperm concentration V1-V0 percentage (Y) required to obtain a pregnancy was predicted according to its baseline values (x): Y = 9.8433x2 - 203.67x + 958.29. A higher number of pregnancies was reached in men with baseline sperm concentration below 7.3 million/mL. Thus, the percentage of sperm concentration increasing after FSH administration could predict the treatment efficacy in terms of pregnancy. At the dosage used, the efficacy was significantly higher in patients with a starting sperm concentration < 7.3 mill/mL. Mathematical analyses identified a function able to predict the sperm concentration increase required to obtain a pregnancy in relation to the baseline sperm number.

Extra-Gonadal and Non-Canonical Effects of FSH in Males

Recombinant follicle-stimulating hormone (FSH) is commonly used for the treatment of female infertility and is increasingly being used in males as well, as recommended by notable guidelines. FSH is composed of an α subunit, shared with other hormones, and a β subunit, which confers specificity of biological action by interacting with its surface receptor (FSHR), predominantly located in granulosa and Sertoli cells. However, FSHRs also exist in extra-gonadal tissues, indicating potential effects beyond male fertility. Emerging evidence suggests that FSH may have extra-gonadal effects, including on bone metabolism, where it appears to stimulate bone resorption by binding to specific receptors on osteoclasts. Additionally, higher FSH levels have been associated with worse metabolic and cardiovascular outcomes, suggesting a possible impact on the cardiovascular system. FSH has also been implicated in immune response modulation, as FSHRs are expressed on immune cells and may influence inflammatory response. Furthermore, there is growing interest in the role of FSH in prostate cancer progression. This paper aims to provide a comprehensive analysis of the literature on the extra-gonadal effects of FSH in men, with a focus on the often-conflicting results reported in this field. Despite the contradictory findings, the potential for future development in this area is substantial, and further research is needed to elucidate the mechanisms underlying these effects and their clinical implications.

Allosteric modulation of gonadotropin receptors

Gonadotropins regulate reproductive functions by binding to G protein-coupled receptors (FSHR and LHCGR) expressed in the gonads. They activate multiple, cell-specific signalling pathways, consisting of ligand-dependent intracellular events. Signalling cascades may be modulated by synthetic compounds which bind allosteric sites of FSHR and LHCGR or by membrane receptor interactions. Despite the hormone binding to the orthosteric site, allosteric ligands, and receptor heteromerizations may reshape intracellular signalling pattern. These molecules act as positive, negative, or neutral allosteric modulators, as well as non-competitive or inverse agonist ligands, providing a set of new compounds of a different nature and with unique pharmacological characteristics. Gonadotropin receptor allosteric modulation is gathering increasing interest from the scientific community and may be potentially exploited for clinical purposes. This review summarizes the current knowledge on gonadotropin receptor allosteric modulation and their potential, clinical use.

Follicle-stimulating hormone effectiveness in male idiopathic infertility: What happens in daily practice?

OBJECTIVES

To assess the effectiveness of follicle-stimulating hormone (FSH) administration in male idiopathic infertility in a clinical setting.

METHODS

A retrospective real-world study was carried out, including all consecutive FSH-treated infertile men attending the Andrology Unit of Modena (Italy) from June 2015 to May 2022. Medical history, physical and andrological examinations, hormonal and seminal parameters, therapeutic management and pregnancy data were collected. The primary endpoint was the number of pregnancies obtained after FSH administration, whereas semen parameters change was the secondary outcome.

RESULTS

A total of 194 of 362 (53.6%) infertile men, eligible according to the Italian Health System regulations, were treated with FSH (mean age 37.9 ± 6.1 years). Following FSH administration (mean therapy duration 9.1 ± 7.1 months), 43 pregnancies were recorded (27.6%), of which 22 occurred naturally and 21 after assisted reproduction. A significant increase in sperm concentration (9.9 ± 12.2 vs. 18.9 ± 38.9 million/mL, p = 0.045) was detected after treatment, together with a significant increase in normozoospermia (from 1.0% to 5.1%, p = .044) and a reduction in azoospermia rate (from 9.8% to 7%, p = 0.044). Dividing the cohort in FSH-responders and non-responders, in terms of pregnancy achieved, higher sperm concentrations (15.7 ± 26.6 vs. 22.2 ± 25.7 million/mL, p = 0.033) and progressive sperm motility (18.0 ± 18.2 vs. 27.3 ± 11.3, p = 0.044) were found in pregnancy group.

CONCLUSION

Our experience suggests that FSH, empirically administered to men with idiopathic infertility, leads to pregnancy in one out of four patients and increases sperm concentration. Although the expected limits because of a real-world data study, the number of FSH-treated patients required to achieve one pregnancy seems to be lower in clinical setting if compared to previously published data.

Disruptions in Hypothalamic-Pituitary-Gonadal Axis Development and Their IgG Modulation after Prenatal Systemic Inflammation in Male Rats

The development of the neuroendocrine system, including the hypothalamic-pituitary-gonadal (HPG) axis, is sensitive to environmental impacts during critical developmental periods. Maternal immune system activation by bacterial or viral infection may be one of the negative impacts. This study focused on the effect of systemic inflammation induced by lipopolysaccharides (LPS E. coli) on the HPG axis development in male rat offspring, corrected by the anti-inflammatory action of polyclonal IgG and monoclonal anti-interleukin (IL)-6 receptor antibodies (IL-6RmAbs). A single LPS exposure on the 12th embryonic day (ED) led to a decrease in the number of afferent synaptic inputs on gonadotropin-releasing, hormone-producing neurons in adult male offspring. LPS exposure on ED18 did not lead to such disruptions. Moreover, after the LPS injections on ED12, circulating follicle-stimulating hormone and sex steroid levels were reduced, and the gonadal structure was disrupted. A prenatal IL-6R blockade with IL-6RmAbs and polyclonal IgG reduced the negative effects of inflammation on fetal HPG axis development. Overall, the data obtained confirm the morphogenetic effect of inflammation on fetal HPG development and IL-6 involvement in these processes.

Male infertility and gonadotropin treatment: What can we learn from real-world data?

Gonadotropin therapy to treat specific male infertility disorders associated with hypogonadotropic hypogonadism is evidence-based and effective in restoring spermatogenesis and fertility. In contrast, its use to improve fertility in men with idiopathic oligozoospermia or nonobstructive azoospermia remains controversial, despite being widely practiced. The existence of two major inter-related pathways for spermatogenesis, including FSH and intratesticular testosterone, provides a rationale for empiric hormone stimulation therapy in both eugonadal and hypogonadal males with idiopathic oligozoospermia or nonobstructive azoospermia. Real-world data (RWD) on gonadotropin stimulating for these patient subsets, mainly using human chorionic gonadotropin and follicle-stimulating hormone, accumulated gradually, showing a positive therapeutic effect in some patients, translated by increased sperm production, sperm quality, and sperm retrieval rates. Although more evidence is needed, current insights from RWD research indicate that selected male infertility patients might be managed more effectively using gonadotropin therapy, with potential gains for all parties involved.

Male factor infertility and assisted reproductive technologies: indications, minimum access criteria and outcomes

BACKGROUND

Infertility, which is defined as the inability to conceive after at least 12 months of regular unprotected sexual intercourses, affects about 15-20% of couples worldwide and a male factor is involved in about half of the cases. The development of assisted reproductive technology (ART) made it possible to conceive also to individuals affected from severe oligospermia or azoospermia. However, the impact of the male factor on embryo development, implantation, prevalence of chromosomal abnormalities, genetic and epigenetic alterations, and clinical and obstetric outcomes is still controversial.

PURPOSE

This narrative review examines the indications, minimum access criteria, and outcomes by individual ART technique in relation to the male factor.

Real-world evidence analysis of the follicle-stimulating hormone use in male idiopathic infertility

Male idiopathic infertility remains a therapeutic challenge in the couple infertility management. In this setting, an empirical treatment with follicle-stimulating hormone (FSH) is allowed, although not recommended. Twenty-one clinical trials and four meta-analyses highlighted an overall increased pregnancy rate in case of FSH administration, but the indiscriminate FSH prescription is still unsupported by clinical evidence in idiopathic infertility. This context could represent an example in which real-world data (RWD) could add useful information. From a nationwide clinical practice survey performed in Italy, emerged the clinicians' attitude to prescribe FSH in the case of impaired semen with a significant improvement of semen parameters, identifying FSH treatment as a therapeutic card in the real-life management. Although more robust data are still needed to optimize FSH treatment in male idiopathic infertility, RWD should be included in the body of evidence considered in healthcare decision-making.

MicroRNA-targeting in male infertility: Sperm microRNA-19a/b-3p and its spermatogenesis related transcripts content in men with oligoasthenozoospermia

Objective: To elucidate and validate the potential regulatory function of miR-19a/b-3p and its spermatogenesis-related transcripts content in sperm samples collected from men with oligoasthenozoospermia.

Methods: Men presenting at an infertility clinic were enrolled. MicroRNA (miRNA) and target genes evaluation were carried out using in silico prediction analysis, Reverse transcription-quantitative PCR (RT-qPCR) validation, and Western blot confirmation.

Results: The expression levels of miRNA-19a/b-3p were significantly up-regulated and 51 target genes were significantly down-regulated in oligoasthenozoospermic men compared with age-matched normozoospermic men as determined by RT-qPCR. Correlation analysis highlighted that sperm count, motility, and morphology were negatively correlated with miRNA-19a/b-3p and positively correlated with the lower expression level of 51 significantly identified target genes. Furthermore, an inverse correlation between higher expression levels of miRNA-19a/b-3p and lower expression levels of 51 target genes was observed. Consistent with the results of the RT-qPCR, reduced expression levels of STK33 and DNAI1 protein levels were identified in an independent cohort of sperm samples collected from men with oligoasthenozoospermia.

Conclusion: Findings suggest that the higher expression of miRNA-19a/b-3p or the lower expression of target genes are associated with oligoasthenozoospermia and male infertility, probably through influencing basic semen parameters. This study lay the groundwork for future studies focused on investigating therapies for male infertility.

Treatment of congenital hypogonadotropic hypogonadism in male patients

Congenital hypogonadotropic hypogonadism (CHH) is characterized by complete or partial failure of pubertal development because of inadequate secretion of gonadotropic hormones. CHH consists of hypogonadotropic hypogonadism with anosmia or hyposmia, Kallmann syndrome, and the normosmic variation normosmic idiopathic hypogonadotropic hypogonadism. CHH is one of the few treatable diseases of male infertility, although men with primary testicular dysfunction have irreversibly diminished spermatogenic capacity. The approach to CHH treatment is determined by goals such as developing virilization or inducing fertility. This review focuses on the current knowledge of therapeutic modalities for inducing puberty and fertility in men with CHH.

Follicle-stimulating hormone signaling in Sertoli cells: a licence to the early stages of spermatogenesis

Follicle-stimulating hormone signaling is essential for the initiation and early stages of spermatogenesis. Follicle-stimulating hormone receptor is exclusively expressed in Sertoli cells. As the only type of somatic cell in the seminiferous tubule, Sertoli cells regulate spermatogenesis not only by controlling their own number and function but also through paracrine actions to nourish germ cells surrounded by Sertoli cells. After follicle-stimulating hormone binds to its receptor and activates the follicle-stimulating hormone signaling pathway, follicle-stimulating hormone signaling will establish a normal Sertoli cell number and promote their differentiation. Spermatogonia pool maintenance, spermatogonia differentiation and their entry into meiosis are also positively regulated by follicle-stimulating hormone signaling. In addition, follicle-stimulating hormone signaling regulates germ cell survival and limits their apoptosis. Our review summarizes the aforementioned functions of follicle-stimulating hormone signaling in Sertoli cells. We also describe the clinical potential of follicle-stimulating hormone treatment in male patients with infertility. Furthermore, our review may be helpful for developing better therapies for treating patients with dysfunctional follicle-stimulating hormone signaling in Sertoli cells.

Evaluation of selected semen parameters and biomarkers of male infertility - preliminary study

Background: Because the etiopathogenesis of male infertility is multifactorial our study was designed to clarify the relationship between standard semen parameters, testicular volume, levels of reproductive hormones and the fragmentation of sperm nuclear DNA (SDF). Methods: Patients (n = 130) were clustered as subjects: 1) with an abnormal volume (utrasonography) of at least one testis (<12 mL) or with a normal volume of testes and 2) with abnormal levels of at least one of the reproductive hormones (FSH, LH, PRL, TSH, total T - electrochemiluminescence method) or with normal hormonal profiles and 3) with high level of SDF (>30%), moderate (>15-30%) or low (≤15%) (sperm chromatin dispersion test). Results: In subjects with a decreased testicular volume and in subjects with abnormal levels of reproductive hormones, decreased basic semen parameters were found. Participants with abnormal testicular volume had a higher percentage of SDF and a higher level of FSH (Mann-Whitney U test). In turn, men with a high level of SDF had lower testicular volume and conventional sperm parameters than men with a low level of SDF (Kruskal-Wallis test). Conclusions: We showed that spermatogenesis disorders coexisted with decreased testicular volume and increased FSH levels. The disorders of spermatogenesis were manifested by reduced basic sperm characteristics and a high level of sperm nuclear DNA damage.

Regulation of antral follicular growth by an interplay between gonadotropins and their receptors

Knowledge of the growth and maturation of human antral follicles is based mainly on concepts and deductions from clinical observations and animal models. To date, new experimental approaches and in vitro data contributed to a deep comprehension of gonadotropin receptors' functioning and may provide new insights into the mechanisms regulating still unclear physiological events. Among these, the production of androgen in the absence of proper LH levels, the programming of follicular atresia and dominance are some of the most intriguing. Starting from evolutionary issues at the basis of the gonadotropin receptor signal specificity, we draw a new hypothesis explaining the molecular mechanisms of the antral follicular growth, based on the modulation of endocrine signals by receptor-receptor interactions. The "heteromer hypothesis" explains how opposite death and life signals are delivered by gonadotropin receptors and other membrane partners, mediating steroidogenesis, apoptotic events, and the maturation of the dominant follicle.

"Seminal testosterone", rising viewpoint of local spermatogenesis in nonobstructive azoospermia: One center long-term bidirectional cohort study

OBJECTIVE

Reproductive hormones are a traditional good method to evaluate spermatogenesis but might not accurately represent local spermatogenesis. To find a more accurate method, seminal reproductive hormones were studied.

METHODS

A bidirectional cohort study was performed. A total of 126 infertile men from 2018 to 2019 were retrospectively analyzed. They were divided into nonobstructive azoospermia (NOA), oligozoospermia (OLZ) and normal (NOR) groups. A prospective study was conducted on patients in the NOA and OLZ groups for 2 years. Microscopic testicular sperm extraction was performed for NOA patients, who were divided into a focal spermatogenesis group (FS) and an idiopathic azoospermia group (IA). Drug treatment was for OLZ patients, who were divided into a valid group (VA) and an invalid group (IN). The differences in sperm parameters and reproductive hormones were compared. ANOSIM analysis was used between and within groups. Pearson correlation analysis, CO inertia analysis and Proctor's analysis were for relationships. ROC curve for the specificity and sensitivity. Time series analysis was for the trends between hormones and time.

RESULTS

The b-FSH, b-LH, s-T and ΔT in the NOA group were significantly higher than those in the OLZ and NOR groups. However, the s-FSH, s-E₂, s-P, ΔFSH, ΔLH, ΔP and ΔE₂ were lower. Thirty-one NOA patients underwent MTSE, of whom 12 had sperm (FS) and 19 had no sperm (IA). The s-FSH and s-E₂ of the FS group were higher than those of the IA group. Twenty-six OLZ patients completed 30 days of treatment, of which 11 had an improved sperm count (VA) and 15 had no (IN). The ΔT of the VA group was higher than that of the IN group. After follow-up for 2 years, 18 patients' results showed that b-FSH, b-LH and s-T were different over time, with delays of 19, 3 and -19 days. SC is closely related to pH, s-FSH, s-LH, s-E₂, s-P, s-T, b-FSH, b-LH, ΔFSH, ΔLH, ΔP, ΔE₂ and ΔT. There were complex common trends and relationships between different kinds of hormones. s-FSH, s-LH, s-E₂, s-P, s-T, b-FSH and b-LH were useful to judge spermatogenesis, of which s-T, b-FSH and b-LH were more sensitive. If s-T, b-FSH and b-LH reached 64.4, 9.4 and 4.7, respectively, their prediction performance was the strongest.

CONCLUSION

Seminal testosterone is sensitive for judging local spermatogenesis in nonobstructive azoospermia patients, which may be the direction of local spermatogenesis in nonobstructive azoospermia.

CLINICAL TRIAL REGISTRATION

http://www.chictr.org.cn/index.aspx, identifier ChiCTR2200060463.

Bacteria and cells as alternative nano-carriers for biomedical applications

INTRODUCTION

Nano-based systems have received a lot of attention owing to their particular properties and, hence, have been proposed for a wide variety of biomedical applications. These nanosystems could be potentially employed for diagnosis and therapy of different medical issues. Although these nanomaterials are designed for specific tasks, interactions, and transformations when administered to the human body affect their performance and behavior. In this regard, bacteria and other cells have been presented as alternative nanocarriers. These microorganisms can be genetically modified and customized for a more specific therapeutic action and, in combination with nanomaterials, can lead to bio-hybrids with a unique potential for biomedical purposes.

AREAS COVERED

Literature regarding bacteria and cells employed in combination with nanomaterials for biomedical applications is revised and discussed in this review. The potential as well as the limitations of these novel bio-hybrid systems are evaluated. Several examples are presented to show the performance of these alternative nanocarriers.

EXPERT OPINION

Bio-hybrid systems have shown their potential as alternative nanocarriers as they contribute to better performance than traditional nano-based systems. Nevertheless, their limitations must be studied, and advantages and drawbacks assessed before their application to medicine.

Purification Process of a Recombinant Human Follicle Stimulating Hormone Biosimilar (Primapur®) to Yield a Pharmaceutical Product with High Batch-to-Batch Consistency

Recombinant human follicle stimulating hormone (r-hFSH) is widely used for infertility treatment and is subject to the development of biosimilars. There are different purification strategies that can yield r-hFSH of pharmaceutical quality from Chinese hamster ovary cell culture broth. We developed a purification process for r-hFSH centered on immunoaffinity chromatography with single-domain recombinant camelid antibodies. The resulting downstream process is simple and devoid of ultrafiltration operations. Studies on chromatography resin resource and ligand leakage showed that the immunoaffinity matrix employed was suitable for industrial use and stable for at least 40 full chromatography cycles, and the leaked single-domain antibody ligand was completely removed by subsequent purification steps. All chromatography resins employed withstood the same 40 cycles of use without significant changes in separation efficiency and product binding capacity. The resulting industrial purification process yielded batches of r-hFSH with consistent levels of purity and bioactivity.

Bacterial Infections Affect Male Fertility: A Focus on the Oxidative Stress-Autophagy Axis

Numerous factors trigger male infertility, including lifestyle, the environment, health, medical resources and pathogenic microorganism infections. Bacterial infections of the male reproductive system can cause various reproductive diseases. Several male reproductive organs, such as the testicles, have unique immune functions that protect the germ cells from damage. In the reproductive system, immune cells can recognize the pathogen-associated molecular patterns carried by pathogenic microorganisms and activate the host's innate immune response. Furthermore, bacterial infections can lead to oxidative stress through multiple signaling pathways. Many studies have revealed that oxidative stress serves dual functions: moderate oxidative stress can help clear the invaders and maintain sperm motility, but excessive oxidative stress will induce host damage. Additionally, oxidative stress is always accompanied by autophagy which can also help maintain host homeostasis. Male reproductive system homeostasis disequilibrium can cause inflammation of the genitourinary system, influence spermatogenesis, and even lead to infertility. Here, we focus on the effect of oxidative stress and autophagy on bacterial infection in the male reproductive system, and we also explore the crosslink between oxidative stress and autophagy during this process.

An overview of FSH-FSHR biology and explaining the existing conundrums

FSH was first identified in 1930 and is central to mammalian reproduction. It is indeed intriguing that despite being researched upon for about 90 years, there is still so much more to learn about FSH-FSHR biology. The purpose of this review is to provide an overview of current understanding of FSH-FSHR biology, to review published data on biological and clinical relevance of reported mutations, polymorphisms and alternately spliced isoforms of FSHR. Tissue-resident stem/progenitor cells in multiple adult tissues including ovaries, testes and uterus express FSHR and this observation results in a paradigm shift in the field. The results suggest a direct action of FSH on the stem cells in addition to their well-studied action on Granulosa and Sertoli cells in the ovaries and testes respectively. Present review further addresses various concerns raised in recent times by the scientific community regarding extragonadal expression of FSHR, especially in cancers affecting multiple organs. Similar population of primitive and pluripotent tissue-resident stem cells expressing FSHR exist in multiple adult tissues including bone marrow and reproductive tissues and help maintain homeostasis throughout life. Any dysfunction of these stem cells results in various pathologies and they also most likely get transformed into cancer stem cells and initiate cancer. This explains why multiple solid as well as liquid tumors express OCT-4 and FSHR. More research efforts need to be focused on alternately spliced FSHR isoforms.

Long-term exposure to environmental levels of phenanthrene disrupts spermatogenesis in male mice

Phenanthrene (Phe) is a tricyclic polycyclic aromatic hydrocarbon with high bioavailability under natural exposure. However, there are few studies on the reproductive toxicity of Phe in mammals. In this study, male Kunming mice were gavaged once every two days with Phe (5, 50, and 500 ng/kg) for 28 weeks. The accumulation levels of Phe in the testis were dose-dependently increased. Histopathological staining showed that Phe exposure reduced the number of spermatogonia, sperm and Sertoli cells. The percentage of testicular apoptotic cells was significantly increased, which was further verified by the upregulated BAX protein. The expression of the GDNF/PI3K/AKT signaling pathway was downregulated, which might suppress the self-renewal and differentiation of spermatogonial stem cells. Meanwhile, Phe exposure inhibited the expression of Sertoli cell markers (Fshr, WT1, Sox9) and the Leydig cell marker Cyp11a1, indicating damage to the function of Sertoli cells and Leydig cells. Serum estrogen and testicular estrogen receptor alpha were significantly upregulated, while androgen receptor expression was downregulated. These alterations might be responsible for impaired spermatogenesis. This study provides new insights for evaluating the reproductive toxicity and potential mechanisms of Phe in mammals.

PTPN5 promotes follicle-stimulating hormone secretion through regulating intracellular calcium homeostasis

Protein tyrosine phosphatase non-receptor type 5 (PTPN5), also called striatal-enriched protein tyrosine phosphatase (STEP), is highly expressed in neurons of the basal ganglia, hippocampus, cortex, and related structures, also in the pituitary. Gonadotropins are the key regulator of the reproduction in mammals. In this study, PTPN5 is detected to express in murine pituitary in a developmental manner. Moreover, the expression of PTPN5 in the pituitary is heavily reduced after ovary removal. Follicle-stimulating hormone (FSH) secretion in gonadotropes is regulated by PTPN5 via binding GnRH to GnRH-R. Two parallel signaling pathways, Gs-protein kinase A (PKA)-PTPN5 and Gq-phospholipases C (PLC)-p38 MAPK-PTPN5, cooperatively regulate GnRH-induced FSH secretion. We also show that influx of Ca²⁺ activates the Ca²⁺ -dependent phosphatase calcineurin, leading to the phosphorylation and activation of PTPN5. The intracellular release of Ca²⁺ is reduced via TC2153. In conclusion, blocking or knocking out of PTPN5 reduces the release of FSH in whole pituitary. Mechanically, PTPN5 regulates gonadotropes' function through regulating intracellular calcium homeostasis.

Severe male factor in in vitro fertilization: definition, prevalence, and treatment. An update

Infertility affects 10%-15% of couples worldwide. Of all infertility cases, 20%-70% are due to male factors. In the past, men with severe male factor (SMF) were considered sterile. Nevertheless, the development of intracytoplasmic sperm injection (ICSI) drastically modified this scenario. The advances in assisted reproductive technology (ART), specifically regarding surgical sperm retrieval procedures, allowed the efficacious treatment of these conditions. Yet, before undergoing ICSI, male factor infertility requires careful evaluation of clinical and lifestyle behavior together with medical treatment. Epidemiologically speaking, women whose male partner is azoospermic tend to be younger and with a better ovarian reserve. These couples, in fact, are proposed ART earlier in their life, and for this reason, their ovarian response after stimulation is generally good. Furthermore, in younger couples, azoospermia can be partially compensated by the efficient ovarian response, resulting in an acceptable fertility rate following in vitro fertilization (IVF) techniques. Conversely, when azoospermia is associated with a reduced ovarian reserve and/or advanced maternal age, the treatment becomes more challenging, with a consequent reduction in IVF outcomes. Nonetheless, azoospermia seems to impair neither the euploidy rate at the blastocyst stage nor the implantation of euploid blastocysts. Based on the current knowledge, the assessment of male infertility factors should involve: (1) evaluation - to diagnose and quantify seminologic alterations; (2) potentiality - to determine the real possibilities to improve sperm parameters and/or retrieve spermatozoa; (3) time - to consider the available "treatment window", based on maternal age and ovarian reserve. This review represents an update of the definition, prevalence, causes, and treatment of SMF in a modern ART clinic.

Altered Biology of Testicular VSELs and SSCs by Neonatal Endocrine Disruption Results in Defective Spermatogenesis, Reduced Fertility and Tumor Initiation in Adult Mice

Reproductive health of men has declined in recent past with reduced sperm count and increased incidence of infertility and testicular cancers mainly attributed to endocrine disruption in early life. Present study aims to evaluate whether testicular stem cells including very small embryonic-like stem cells (VSELs) and spermatogonial stem cells (SSCs) get affected by endocrine disruption and result in pathologies in adult life. Effect of treatment on mice pups with estradiol (20 μg on days 5-7) and diethylstilbestrol (DES, 2 μg on days 1-5) was studied on VSELs, SSCs and spermatogonial cells in adult life. Treatment affected spermatogenesis, tubules in Stage VIII & sperm count were reduced along with reduction of meiotic (4n) cells and markers (Prohibitin, Scp3, Protamine). Enumeration of VSELs by flow cytometry (2-6 μm, 7AAD-, LIN-CD45-SCA-1+) and qRT-PCR using specific transcripts for VSELs (Oct-4a, Sox-2, Nanog, Stella, Fragilis), SSCs (tOct-4, Gfra-1, Gpr-125) and early germ cells (Mvh, Dazl) showed several-fold increase but transition from c-Kit negative to c-Kit positive spermatogonial cells was blocked on D100 after treatment. Transcripts specific for apoptosis (Bcl2, Bax) remained unaffected but tumor suppressor (p53) and epigenetic regulator (NP95) transcripts showed marked disruption. 9 of 10 mice exposed to DES showed tumor-like changes. To conclude, endocrine disruption resulted in a tilt towards excessive self-renewal of VSELs (leading to testicular cancer after DES treatment) and blocked differentiation (reduced numbers of c-Kit positive cells, meiosis, sperm count and fertility). Understanding the underlying basis for infertility and cancer initiation from endogenous stem cells through murine modelling will hopefully improve human therapies in future.

GnRH-Related Neurohormones in the Fruit Fly Drosophila melanogaster

Genomic and phylogenetic analyses of various invertebrate phyla revealed the existence of genes that are evolutionarily related to the vertebrate’s decapeptide gonadotropin-releasing hormone (GnRH) and the GnRH receptor genes. Upon the characterization of these gene products, encoding peptides and putative receptors, GnRH-related peptides and their G-protein coupled receptors have been identified. These include the adipokinetic hormone (AKH) and corazonin (CRZ) in insects and their cognate receptors that pair to form bioactive signaling systems, which network with additional neurotransmitters/hormones (e.g., octopamine and ecdysone). Multiple studies in the past 30 years have identified many aspects of the biology of these peptides that are similar in size to GnRH and function as neurohormones. This review briefly describes the main activities of these two neurohormones and their receptors in the fruit fly Drosophila melanogaster. The similarities and differences between Drosophila AKH/CRZ and mammalian GnRH signaling systems are discussed. Of note, while GnRH has a key role in reproduction, AKH and CRZ show pleiotropic activities in the adult fly, primarily in metabolism and stress responses. From a protein evolution standpoint, the GnRH/AKH/CRZ family nicely demonstrates the developmental process of neuropeptide signaling systems emerging from a putative common ancestor and leading to divergent activities in distal phyla.

Recent advances in understanding gonadotropin signaling

Gonadotropins are glycoprotein sex hormones regulating development and reproduction and bind to specific G protein–coupled receptors expressed in the gonads. Their effects on multiple signaling cascades and intracellular events have recently been characterized using novel technological and scientific tools. The impact of allosteric modulators on gonadotropin signaling, the role of sugars linked to the hormone backbone, the detection of endosomal compartments supporting signaling modules, and the dissection of different effects mediated by these molecules are areas that have advanced significantly in the last decade. The classic view providing the exclusive activation of the cAMP/protein kinase A (PKA) and the steroidogenic pathway by these hormones has been expanded with the addition of novel signaling cascades as determined by high-resolution imaging techniques. These new findings provided new potential therapeutic applications. Despite these improvements, unanswered issues of gonadotropin physiology, such as the intrinsic pro-apoptotic potential to these hormones, the existence of receptors assembled as heteromers, and their expression in extragonadal tissues, remain to be studied. Elucidating these issues is a challenge for future research.

The Impact of Estrogen and Estrogen-Like Molecules in Neurogenesis and Neurodegeneration: Beneficial or Harmful?

Estrogens and estrogen-like molecules can modify the biology of several cell types. Estrogen receptors alpha (ERα) and beta (ERβ) belong to the so-called classical family of estrogen receptors, while the G protein-coupled estrogen receptor 1 (GPER-1) represents a non-classical estrogen receptor mainly located in the plasma membrane. As estrogen receptors are ubiquitously distributed, they can modulate cell proliferation, differentiation, and survival in several tissues and organs, including the central nervous system (CNS). Estrogens can exert neuroprotective roles by acting as anti-oxidants, promoting DNA repair, inducing the expression of growth factors, and modulating cerebral blood flow. Additionally, estrogen-dependent signaling pathways are involved in regulating the balance between proliferation and differentiation of neural stem/progenitor cells (NSPCs), thus influencing neurogenic processes. Since several estrogen-based therapies are used nowadays and estrogen-like molecules, including phytoestrogens and xenoestrogens, are omnipresent in our environment, estrogen-dependent changes in cell biology and tissue homeostasis have gained attention in human health and disease. This article provides a comprehensive literature review on the current knowledge of estrogen and estrogen-like molecules and their impact on cell survival and neurodegeneration, as well as their role in NSPCs proliferation/differentiation balance and neurogenesis.

Role of FSH and FSH receptor on HUVECs migration

Follicle-stimulating hormone (FSH) is a pituitary glycoprotein that regulates follicle maturation through its binding to follicle-stimulating hormone receptor (FSHR). Endothelial cells express FSHR, but its exact role in endothelial cells remains unclear. Here we show that FSHR expression was detectable in human umbilical vein endothelial cells (HUVECs). FSH stimulation promoted HUVECs migration but not proliferation. Because FSHR is a GPCR, FSH treatment triggers the activation of cAMP-PKA signaling pathways, and the JAK-STAT, PI3K-AKT, and JNK-MAPK pathways. RNAi of FSHR dramatically attenuated the activation effect of FSH on HUVECs migration, as well as the related signaling pathways. Treatment of FSH in HUVECs also transcriptionally upregulated the expression of VAV3 and LAMA2, suppression either of VAV3 or LAMA2 by RNAi attenuated the FSH's effect on HUVECs migration. All of these results indicated a functional role of FSH in the regulation of endothelial cells.