Effects of highly purified follicle-stimulating hormone on sperm DNA damage in men with male idiopathic subfertility: a pilot study

Unraveling the harmful effect of oxidative stress on male fertility: A mechanistic insight

Male infertility is a widely debated issue that affects males globally. There are several mechanisms involved. Oxidative stress is accepted to be the main contributing factor, with sperm quality and quantity affected by the overproduction of free radicals. Excess reactive oxygen species (ROS) cannot be controlled by the antioxidant system and, thus, potentially impact male fertility and hamper sperm quality parameters. Mitochondria are the driving force of sperm motility; irregularities in their function may lead to apoptosis, alterations to signaling pathway function, and, ultimately, compromised fertility. Moreover, it has been observed that the prevalence of inflammation may arrest sperm function and the production of cytokines triggered by the overproduction of ROS. Further, oxidative stress interacts with seminal plasma proteomes that influence male fertility. Enhanced ROS production disturbs the cellular constituents, particularly DNA, and sperms are unable to impregnate the ovum. Here, we review the latest information to better understand the relationship between oxidative stress and male infertility, the role of mitochondria, the cellular response, inflammation and fertility, and the interaction of seminal plasma proteomes with oxidative stress, as well as highlight the influence of oxidative stress on hormones; collectively, all of these factors are assumed to be important for the regulation of male infertility. This article may help improve our understanding of male infertility and the strategies to prevent it.

Endocrinopathies and Male Infertility

Male infertility is approaching a concerning prevalence worldwide, and inflicts various impacts on the affected couple. The hormonal assessment is a vital component of male fertility evaluation as endocrine disorders are markedly reversible causatives of male infertility. Precise hormonal regulations are prerequisites to maintain normal male fertility parameters. The core male reproductive event, spermatogenesis, entails adequate testosterone concentration, which is produced via steroidogenesis in the Leydig cells. Physiological levels of both the gonadotropins are needed to achieve normal testicular functions. The hypothalamus-derived gonadotropin-releasing hormone (GnRH) is considered the supreme inducer of the gonadotropins and thereby the subsequent endocrine reproductive events. This hypothalamic–pituitary–gonadal (HPG) axis may be modulated by the thyroidal or adrenal axis and numerous other reproductive and nonreproductive hormones. Disruption of this fine hormonal balance and their crosstalk leads to a spectrum of endocrinopathies, inducing subfertility or infertility in men. This review article will discuss the most essential endocrinopathies associated with male factor infertility to aid precise understanding of the endocrine disruptions-mediated male infertility to encourage further research to reveal the detailed etiology of male infertility and perhaps to develop more customized therapies for endocrinopathy-induced male infertility.

FSH dosage effect on conventional sperm parameters: a meta-analysis of randomized controlled studies

Follicle-stimulating hormone (FSH) represents a therapeutic option in normogonadotropic patients with idiopathic oligozoospermia. The aim of this review was to evaluate the possible dose- and drug-dependent efficacy of FSH treatment on conventional sperm parameters. We performed a comprehensive systematic review via a meta-analysis of all available randomized controlled trials, in which FSH administration was compared with placebo or no treatment when administered to normogonadotropic patients with idiopathic oligozoospermia. Of the 971 articles that were retrieved, 5 were finally included, including a total of 372 patients and 294 controls. Overall, FSH treatment was effective in ameliorating the sperm concentration, total count, progressive motility, but not normal forms. On the basis of the weekly dosage, the studies were classified into those using low (175–262.5 IU per week), intermediate (350–525 IU per week), and high (700–1050 IU per week) doses. At low doses, FSH improved only sperm motility. At intermediate doses, FSH ameliorated sperm concentration and morphology. Total sperm count and progressive motility showed a trend toward the increase. At high doses, FSH increased sperm concentration, total sperm count, and progressive motility. Sperm morphology showed a trend toward the increase. Finally, both highly purified FSH (hpFSH) and recombinant human FSH (rhFSH) improved sperm concentration, total sperm count, progressive motility, but not morphology. No different efficacy was observed between these two preparations. This meta-analysis provides evidence in favor of high FSH doses. The FSH efficacy was not related to the preparation type (recombinant vs highly purified). Further studies are needed to evaluate the effectiveness of long-standing treatment regimes.

Follicle-Stimulating Hormone Treatment and Male Idiopathic Infertility: Effects on Sperm Parameters and Oxidative Stress Indices according to FSHR c. 2039 A/G and c. -29 G/A Genotypes

Scientific evidence shows that the administration of follicle-stimulating hormone (FSH) to infertile patients with normal serum FSH concentrations improves sperm parameters in oligozoospermic men. The aim of this study was to evaluate the effects of highly purified urofollitropin (hpFSH) on conventional and bio-functional sperm parameters and on oxidative stress indices in patients with idiopathic infertility. We also evaluated the response to hpFSH on these parameters in relationship to FSHR c. 2039 A/G and FSHR c. -29 G/A genotypes. A prospective longitudinal study was conducted on 42 patients with idiopathic male infertility, 23 of whom underwent to FSHR c. 2039 A/G and FSHR c. -29 G/A genotyping. Each patient was asked to collect two semen samples before and after administration of 150 IU hpFSH three times a week for 16 weeks. Patients were divided into responders or non-responders based on whether their total sperm count had at least doubled or was less than double at the end of treatment, respectively. Responders showed a significantly higher semen volume, sperm concentration, spermatids, and leukocytes. Non-responders had a significant decrease of the percentage of spermatozoa in early apoptosis after hpFSH administration. Oxidative stress indexes did not differ significantly after FSH administration in both groups. Conventional and bio-functional sperm parameters did not differ in patients with FSHR c. 2039 GG and AA genotypes, and FSHR c. -29 GG genotype both before and after FSH administration. The FSHR c. 2039 and FSHR -29 G/A genotypes and allelic distribution did not differ between responders and non-responders. FSH showed to be capable of ameliorating sperm parameters in about half patients treated, therefore it may be helpful in patients with idiopathic infertility.

Reactive oxygen species and male reproductive hormones

Reports of the increasing incidence of male infertility paired with decreasing semen quality have triggered studies on the effects of lifestyle and environmental factors on the male reproductive potential. There are numerous exogenous and endogenous factors that are able to induce excessive production of reactive oxygen species (ROS) beyond that of cellular antioxidant capacity, thus causing oxidative stress. In turn, oxidative stress negatively affects male reproductive functions and may induce infertility either directly or indirectly by affecting the hypothalamus-pituitary-gonadal (HPG) axis and/or disrupting its crosstalk with other hormonal axes. This review discusses the important exogenous and endogenous factors leading to the generation of ROS in different parts of the male reproductive tract. It also highlights the negative impact of oxidative stress on the regulation and cross-talk between the reproductive hormones. It further describes the mechanism of ROS-induced derangement of male reproductive hormonal profiles that could ultimately lead to male infertility. An understanding of the disruptive effects of ROS on male reproductive hormones would encourage further investigations directed towards the prevention of ROS-mediated hormonal imbalances, which in turn could help in the management of male infertility.

Effects of FSH on Sperm DNA Fragmentation: Review of Clinical Studies and Possible Mechanisms of Action

Sperm DNA fragmentation (sDF) is an important reproductive problem, associated to an increased time-to-pregnancy and a reduced success rate in natural and in vitro fertilization. sDF may virtually originate at any time of sperm's life: in the testis, in the epididymis, during transit in the ejaculatory ducts and even following ejaculation. Studies demonstrate that an apoptotic pathway, mainly occurring in the testis, and oxidative stress, likely acting in the male genital tract, are responsible for provoking the DNA strand breaks present in ejaculated spermatozoa. Although several pharmacological anti-oxidants tools have been used to reduce sDF, the efficacy of this type of therapies is questioned. Clearly, anti-apoptotic agents cannot be used because of the ubiquitous role of the apoptotic process in the body. A notable exception is represented by Follicle-stimulating hormone (FSH), which regulates testis development and function and has been demonstrated to exert anti-apoptotic actions on germ cells. Here, we review the existing clinical studies evaluating the effect of FSH administration on sDF and discuss the possible mechanisms through which the hormone may reduce sDF levels in infertile subjects. Although there is evidence for a beneficial effect of the hormone on sDF, further studies with clear and univocal patient inclusion criteria, including sDF cut-off levels and considering the use of a pharmacogenetic approach for patients selection are warranted to draw firm conclusions.

New insights in sperm biology: How benchside results in the search for molecular markers may help understand male infertility

The male factor is responsible for about 40% of couple infertility cases and such percentage is expected to increase in the future because of several likely factors including the presence of endocrine disruptors in the environment, changes in lifestyle habits and advanced couple aging. How such factors affect male fertility status, however, should be clarified. Most studies on male fertility status have focused on parameters analyzed using a spermiogram test, the primary diagnostic tool in the routine assessment of male infertility, which is, however, poorly predictive of both natural and medically assisted conception. For these reasons it is mandatory for the scientific community to identify new molecular markers to incorporate into the existing diagnostic tests of male fertility. Ideally, such markers would be detected in mature spermatozoa to avoid invasive procedures for the patient. This review summarizes the recent advancements in benchside approaches that appear most promising for the development of new diagnostic sperm fertility tests, or identification of therapeutic targets, and, illustrates their advantages and limits.

Reduced Seminal Concentration of CD45pos Cells after Follicle-Stimulating Hormone Treatment in Selected Patients with Idiopathic Oligoasthenoteratozoospermia

The present study evaluated the conventional sperm parameters and the seminal concentration of CD45pos cells (pan-leukocyte marker) of infertile patients with idiopathic oligoasthenoteratozoospermia (OAT). The patients were arbitrarily divided into three groups treated with recombinant follicle-stimulating hormone FSH: α (Group A = 20 patients), recombinant FSH- β (Group B = 20 patients), and highly purified human FSH (Group C = 14 patients). All treated groups achieved a similar improvement of the main sperm parameters (density, progressive motility, and morphology), but only the increase in the percentage of spermatozoa with normal morphology was significant compared to the baseline in all three examined groups. Moreover, all groups had a significant reduction of the seminal concentration of CD45pos cells and of the percentage of immature germ cells. Before and after the treatment, the concentration of CD45pos cells showed a positive linear correlation with the percentage of immature germ cells and a negative correlation with the percentage of spermatozoa with regular morphology. These results demonstrate that treatment with FSH is effective in patients with idiopathic OAT and that there are no significant differences between the different preparations. The novelty of this study is in the significant reduction of the concentration of CD45pos cells observed after the treatment.

Follicle-stimulating hormone treatment in normogonadotropic infertile men

Several empirical treatments have been proposed to treat idiopathic infertility in men, including follicle-stimulating hormone (FSH). FSH administration is effective in patients with hypogonadotropic hypogonadism, which suggests it might be useful in patients with oligozoospermia who have normal FSH levels. Indeed, many studies have evaluated the efficacy of FSH administration in these patients, several of which have shown improvements in sperm parameters. By contrast, other studies have not reported any significant effect of FSH administration on conventional sperm parameters, although some of have reported the normalization of spermatozoon ultrastructural morphology, as well as reductions in DNA fragmentation, production of reactive oxygen species and aneuploidy. Contemporary studies suggest that the response to FSH treatment in oligozoospermic patients might, at least partially, reflect polymorphisms of the FSH receptor gene. Thus, FSH administration in oligozoospermic men with normal serum FSH levels might be efficacious only in selected patients. For this reason, additional studies are needed to determine the predictive factors and clinical conditions that can be used to identify patients who could benefit from FSH treatment.