Zika Virus Causes Testis Damage and Leads to Male Infertility in Mice.

Zika virus (ZIKV) persists in the semen of male patients, a first for flavivirus infection. Here, we demonstrate that ZIKV can induce inflammation in the testis and epididymidis, but not in the prostate or seminal vesicle, and can lead to damaged testes after 60 days post-infection in mice. ZIKV induces innate immune responses in Leydig, Sertoli, and epididymal epithelial cells, resulting in the production of pro-inflammatory cytokines/chemokines. However, ZIKV does not induce a rapid and abundant cytokine production in peritubular cell and spermatogonia, suggesting that these cells are vulnerable for ZIKV infection and could be the potential repositories for ZIKV. Our study demonstrates a correlation between ZIKV and testis infection/damage and suggests that ZIKV infection, under certain circumstances, can eventually lead to male infertility.

Correlation between viral infections in male semen and infertility: a literature review.

Infertility affects approximately one-sixth of couples globally, with the incidence of male infertility steadily increasing. However, our understanding of the impact of viral infections on fertility remains limited. This review consolidates findings from previous studies, outlining 40 viruses identified in human semen and summarizing their key characteristics, modes of transmission, and their effects on both the reproductive and endocrine systems. Furthermore, it elucidates potential pathogenic mechanisms and treatment prospects of viruses strongly associated with male infertility. This synthesis will enhance our comprehension of how viral infections influence male reproductive health, offering valuable insights for future research as well as the diagnosis and treatment of infectious infertility.

Association between post-COVID-19 conditions and male semen quality in Japan: A descriptive investigation.

Some reports suggest that coronavirus disease 2019 (COVID-19) may affect male reproductive function. There is also concern in Japan that COVID-19 may contribute to the pre-existing decline in male fertility; however, no studies have investigated the effects of COVID-19 on male reproductive function. In this study, we aimed to analyze the semen quality of men who had recovered from COVID-19. Male patients who had recovered from COVID-19 between February 2020 and September 2021 were recruited for this study. Participants were sent a semen collection kit; they were asked to collect semen at home and deliver it to a laboratory at Osaka University. We used these samples to analyze sperm concentration, total sperm count, and semen volume. In total, 125 participants were included in this study. The median age of all patients was 46 years (interquartile range (IQR): 38-52 years). The severity of COVID-19 was mild in 80 patients; 19 were moderate I, 22 were moderate II, and four were severe. The median semen volume was 2.5 mL (IQR: 1.8-3.1), the median sperm concentration was 98.9 million/mL (IQR: 43.8-162.2), and the median total sperm count was 212.1 million (IQR: 89.7-368.2). In a previous study in Japan, the median sperm count in adult men was reported to be 201 million. Participants in our study did not have lower sperm counts than this, despite their older age. Our results suggest that the long-term effects of COVID-19 on spermatogenesis are minimal.

Activation of PTH1R alleviates epididymitis and orchitis through Gq and ß-arrestin-1 pathways.

Inflammation in the epididymis and testis contributes significantly to male infertility. Alternative therapeutic avenues treating epididymitis and orchitis are expected since current therapies using antibiotics have limitations associated to side effects and are commonly ineffective for inflammation due to nonbacterial causes. Here, we demonstrated that type 1 parathyroid hormone receptor (PTH1R) and its endogenous agonists, parathyroid hormone (PTH) and PTH-related protein (PTHrP), were mainly expressed in the Leydig cells of testis as well as epididymal epithelial cells. Screening the secretin family G protein-coupled receptor identified that PTH1R in the epididymis and testis was down-regulated in mumps virus (MuV)- or lipopolysaccharide (LPS)-induced inflammation. Remarkably, activation of PTH1R by abaloparatide (ABL), a Food and Drug Administration-approved treatment for postmenopausal osteoporosis, alleviated MuV- or LPS-induced inflammatory responses in both testis and epididymis and significantly improved sperm functions in both mouse model and human samples. The anti-inflammatory effects of ABL were shown to be regulated mainly through the Gq and ß-arrestin-1 pathway downstream of PTH1R as supported by the application of ABL in Gnaq± and Arrb1-/- mouse models. Taken together, our results identified an important immunoregulatory role for PTH1R signaling in the epididymis and testis. Targeting to PTH1R might have a therapeutic effect for the treatment of epididymitis and orchitis or other inflammatory disease in the male reproductive system.

ORF8 protein of SARS-CoV-2 reduces male fertility in mice.

As one of the most rapidly evolving proteins of the genus Betacoronavirus, open reading frames (ORF8's) function and potential pathological consequence in vivo are still obscure. In this study, we show that the secretion of ORF8 is dependent on its N-terminal signal peptide sequence and can be inhibited by reactive oxygen species scavenger and endoplasmic reticulum-Golgi transportation inhibitor in cultured cells. To trace the effect of its possible in vivo secretion, we examined the plasma samples of coronavirus disease 2019 (COVID-19) convalescent patients and found that the patients aged from 40 to 60 had higher antibody titers than those under 40. To explore ORF8's in vivo function, we administered the mice with ORF8 via tail-vein injection to simulate the circulating ORF8 in the patient. Although no apparent difference in body weight, food intake, and vitality was detected between vehicle- and ORF8-treated mice, the latter displayed morphological abnormalities of testes and epididymides, as indicated by the loss of the central ductal lumen accompanied by a decreased fertility in 5-week-old male mice. Furthermore, the analysis of gene expression in the testes between vehicle- and ORF8-treated mice identified a decreased expression of Col1a1, the loss of which is known to be associated with mice's infertility. Although whether our observation in mice could be translated to humans remains unclear, our study provides a potential mouse model that can be used to investigate the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on the human reproductive system.

The other side of COVID-19 pandemic: Effects on male fertility.

The outbreak of novel coronavirus disease 2019 (COVID-19) has become a major pandemic threat worldwide. According to the existing clinical data, this virus not only causes respiratory diseases and affects the lungs but also induces histopathological or functional changes in various organs like the testis and also the male genital tract. The renin-angiotensin system (RAS), also ACE 2 and TMPRSS2 play an important role in the cellular entry for SARS-CoV-2. Because the male genital system presents high ACE 2 expression, the importance of this pathway increases in COVID-19 cases. As the COVID-19 pandemic has affected the male genital system in direct or indirect ways and showed a negative impact on male reproduction, this paper focuses on the possible mechanisms underlying the damage caused by COVID-19 to the testis and also other components of the male genital tract.

Evaluating the impact of COVID-19 on male reproduction.

Invasion or damage of the male reproductive system is one of the reported outcomes of viral infection. Current studies have documented that SARS-CoV-2, which causes COVID-19, can damage the male reproductive system in large part by inflammatory damage caused by a cytokine storm. However, whether SARS-CoV-2 can infect the human testis directly and enter semen is controversial. Other adverse effects of SARS-CoV-2 on male reproduction are also of concern and require comprehensive evaluation. Here, we analyze the invasiveness of SARS-CoV-2 in the testis and examine reported mechanisms by which SARS-CoV-2 interferes with male reproduction. Long-term implications of SARS-CoV-2 infection on male reproduction are also discussed. It should be emphasized that although COVID-19 may induce testicular damage, a substantial decrease in male reproductive capacity awaits clinical evidence. We propose that there is an urgent need to track male COVID-19 patients during their recovery. The development of suitable experimental models, including human reproductive organoids, will be valuable to further investigate the viral impact on reproduction for current and future pandemics.

COVID-19 and male reproductive function: a prospective, longitudinal cohort study.

The existing evidence suggests that the human reproductive system may be potentially vulnerable to COVID-19 infection. However, little is known about the virus-host interaction of COVID-19 in sperm cells. We are the first to address the connection between changes in multiple seminal biomarkers and reproductive function in male patients recovering from COVID-19. In a prospective longitudinal cohort study, seminal ACE2 activity, markers of inflammation and oxidative stress, apoptotic variables, and semen quality parameters were evaluated at 10-day intervals for a maximum follow-up time of 60 days among male patients with laboratory-confirmed COVID-19 (n = 84) and healthy controls (CON; n = 105). At the baseline and the subsequent follow-ups, the COVID-19 group revealed significantly higher levels of seminal plasma ACE2 enzymatic activity, IL-1ß, IL-6, IL-8, IL-10, TGF-ß, TNF-α, IFN-α, IFN-γ, ROS, caspase-8, caspase-9, and caspase-3 activity as well as lower levels of SOD activity than those in the CON group (P < 0.05). These perturbations tended to persist over time and were correlated with significant impairments in semen volume, progressive motility, sperm morphology, sperm concentration, and the number of spermatozoa. We provide the direct experimental evidence that the male reproductive system could be targeted and damaged by the COVID-19 infection. These findings go beyond our current understanding of the disease, suggesting that the reproductive function of the patients recovering from the disease should be precisely followed and evaluated to detect and avoid more serious reproductive problems in the future, as they may develop a transient state of male subfertility like those with oligoasthenoteratozoospermia.

Does COVID-19 Worsen the Semen Parameters? Early Results of a Tertiary Healthcare Center.

INTRODUCTION: The coronavirus disease 2019 (COVID-19) is a global pandemic which may affect multiple organs and systems including testes and disrupt the gonadal functions. The current study aimed to evaluate the effect of COVID-19 on the semen parameters and sex-related hormone levels in infertile men. METHODS: The study included 21 patients who were evaluated in Ankara City Hospital, Andrology Clinic, for male infertility and have had the diagnosis of COVID-19. All the patients were evaluated in terms of semen parameters. The follicle-stimulating hormone, luteinizing hormone, and testosterone (T) levels were also evaluated in 8 of the patients. The results were presented through 2 dependent group analyses, based on the data of the patients collected before and after the diagnosis of COVID-19. RESULTS: None of the patients needed to be hospitalized at any time through the course of COVID-19. There was a significant decrease in semen volume, percentage of total motility, percentage of progressive motility, and normal sperm morphology after COVID-19 (3 [1-8] vs. 2.5 [1.5-5], p = 0.005; 48.6 ± 22.1 vs. 34.7 ± 20.7, p = 0.001; 35.1 ± 21.7 vs. 21.8 ± 15.9, p < 0.001; 6 [3-24] vs. 5 [3-18], p = 0.015; respectively). There was also a significant decline in T level of the patients after the diagnosis of COVID-19 (350.1 ± 115.5 vs. 289.8 ± 103.3, p = 0.009). CONCLUSION: COVID-19 may have unfavorable effects on the gonadal functions and may lead to further deterioration of the semen parameters in infertile men, which should be considered through the evaluation for infertility.

Investigation of SARS-CoV-2 in semen samples and the effects of COVID-19 on male sexual health by using semen analysis and serum male hormone profile: A cross-sectional, pilot study.

The study investigated whether there is a male reproductive system coronavirus disease-2019 (COVID-19) phenomenon. Thirty participants who met the inclusion criteria were enrolled in the study between April and May 2020. The participants were assigned in one of the three groups including COVID-19 patients before and after treatment, and controls. Presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within the semen samples was investigated. Additionally, participant's demographics, semen parameters and serum sex hormone levels were compared between the groups. SARS-CoV-2 was not detected within the semen samples. Sperm morphology and serum sex hormone levels were significantly different between the groups. In the post hoc analysis, sperm morphology was significantly lower in the COVID-19 patients. Patients before treatment had significantly lower serum FSH, LH and T levels than controls. However, patients after treatment had similar serum FSH, LH and T levels with controls and patients before treatment. In our opinion, COVID-19 and its treatment had no specific deteriorative effect on male sexual health at a short-time period. In the patients before treatment, decreased serum of T, FSH and LH levels was consistent with acute patient stress due to COVID-19. Similarly, it seems that decreased sperm morphology was associated with the acute fever.

Review of COVID-19 and male genital tract.

COVID-19 pandemic leads to health challenges globally, and its diverse aspects need to be uncovered. Multi-organ injuries have been reported by describing potential SARS-CoV-2 entrance routes: ACE2 and TMPRSS2. Since these cell surface receptors' expression has been disclosed within the male reproductive system, its susceptibility to being infected by SARS-CoV-2 has been summarised through this literature review. Expression of ACE2 and TMPRSS2 at RNA or protein level has been reported across various investigations indicates that the male genitalia potentially is vulnerable to SARS-CoV-2 infection. Presence of SARS-CoV-2 within semen samples and following direct viral damage, secondary inflammatory response causing orchitis or testicular discomfort and finally the amount of viral load leading testicular damage and immune response activation are among probable underlying mechanisms. Therefore, genital examination and laboratory tests should be considered to address the male reproductive tract complications and fertility issues.

Potential mechanisms of SARS-CoV-2 action on male gonadal function and fertility: Current status and future prospects.

The novel coronavirus was recognised in December 2019 and caught humanity off guard. The virus employs the angiotensin-converting enzyme 2 (ACE2) receptor for entry into human cells. ACE2 is expressed on different organs, which is raising concern as to whether these organs can be infected by the virus or not. The testis appears to be an organ enriched with levels of ACE2, while the possible mechanisms of involvement of the male reproductive system by SARS-CoV-2 are not fully elucidated. The major focus of the present studies is on the short-term complications of the coronavirus and gains importance on studying the long-term effects, including the possible effects of the virus on the male reproductive system. The aim of this review was to provide new insights into different possible mechanisms of involvement of male gonads with SARS-CoV-2 including investigating the ACE2 axis in testis, hormonal alterations in patients with COVID-19, possible formation of anti-sperm antibodies (ASA) and subsequently immunological infertility as a complication of SARS-CoV-2 infection. Finally, we suggest measuring the sperm DNA fragmentation index (DFI) as a determiner of male fertility impairment in patients with COVID-19 along with other options such as sex-related hormones and semen analysis. Invasion of SARS-CoV-2 to the spermatogonia, Leydig cells and Sertoli cells can lead to sex hormonal alteration and impaired gonadal function. Once infected, changes in ACE2 signalling pathways followed by oxidative stress and inflammation could cause spermatogenesis failure, abnormal sperm motility, DNA fragmentation and male infertility.

The probable destructive mechanisms behind COVID-19 on male reproduction system and fertility.

PURPOSE: The present study aims to summarize the current understanding of probable mechanisms and claims of adverse effects of SARS-CoV-2 on male fertility potential. METHODS: Our search was including original articles, reviews, guidelines, letters to the editor, comments on guidelines, and editorials, regarding the male reproductive system. We used the words SARS-CoV-2, coronavirus, severe acute respiratory syndrome coronavirus 2, "2019 ncov," testis, sperm, male factor infertility, fertility treatment, semen, assisted reproductive technology (ART), sexual transmission, and ACE2. RESULTS: Data showed coronavirus affects men more than women because of more expression of 2019 nCoV receptors (ACE2 and TMPRSS2) in testicular cells. Also, "Bioinformatics Analysis" suggests that sperm production may be damaged, since "Pseudo Time Analysis" has shown disruption in spermatogenesis. "Gene Ontology" (GO) showed an increase in viral reproduction and a decrease in sperm production-related terms. Recently, SARS-COV-2 mRNA and protein were detected in the semen of patients that had recovered from SARS-CoV-2 infection. Therefore, the probable disruption of blood-testis barrier (BTB) in febrile diseases is suspected in the acute phase of the disease enabling viral entry into the testes. Not only is spermatogenesis disturbed, but also disturbs gonadotropin, androgens, and testosterone secretion during SARS-CoV-2 infection. No sexual transmission has been reported yet; however, detection of the virus in semen still makes the sexual transmission an open question. CONCLUSION: There is a concern that male fertility may be disturbed after the SARS-CoV-2 infection. Therefore, follow-up of the reproductive functions and male fertility may be necessary in recovered cases, especially in aged men.

The ACE2 expression in Sertoli cells and germ cells may cause male reproductive disorder after SARS-CoV-2 infection.

The serious coronavirus disease-2019 (COVID-19) was first reported in December 2019 in Wuhan, China. COVID-19 is an infectious disease caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). Angiotensin converting enzyme 2(ACE2) is the cellular receptor for SARS-CoV-2. Considering the critical roles of testicular cells for the transmission of genetic information between generations, we analyzed single-cell RNA-sequencing (scRNA-seq) data of adult human testis. The mRNA expression of ACE2 was expressed in both germ cells and somatic cells. Moreover, the positive rate of ACE2 in testes of infertile men was higher than normal, which indicates that SARS-CoV-2 may cause reproductive disorders through pathway activated by ACE2 and the men with reproductive disorder may easily to be infected by SARS-CoV-2. The expression level of ACE2 was related to the age, and the mid-aged with higher positive rate than young men testicular cells. Taken together, this research provides a biological background of the potential route for infection of SARS-CoV-2 and may enable rapid deciphering male-related reproductive disorders induced by COVID-19.

Is there an impact of the COVID-19 pandemic on male fertility? The ACE2 connection.

The viral pandemic of the coronavirus disease 2019 (COVID-19), generated by a novel mutated severe acute respiratory syndrome coronavirus (SARS-CoV-2), has become a serious worldwide public health emergency, evolving exponentially. While the main organ targeted in this disease is the lungs, other vital organs, such as the heart and kidney, may be implicated. The main host receptor of the SARS-CoV-2 is angiotensin converting enzyme 2 (ACE2), a major component of the renin-angiotensin-aldosterone system (RAAS). The ACE2 is also involved in testicular male regulation of steroidogenesis and spermatogenesis. As the SARS-CoV-2 may have the potential to infect the testis via ACE2 and adversely affect male reproductive system, it is essential to commence with targeted studies to learn from the current pandemic, with the possibility of preemptive intervention, depending on the findings and time course of the continuing pandemic.

Impact of human papillomavirus infection in semen on sperm progressive motility in infertile men: a systematic review and meta-analysis.

BACKGROUND: Human papillomavirus (HPV) has been considered as one of the most common sexually transmitted viruses that may be linked to unexplained infertility in men. The possible mechanisms underlying correlation between HPV infection and infertility could be related to the altered sperm parameters. Current studies have investigated the effect of HPV seminal infection on sperm quality in infertile men, but have shown inconsistent results. METHODS: We systematically searched PubMed, Embase, Web of Science and CNKI for studies that examined the association between HPV seminal infection and sperm progressive motility. Data were pooled using a random-effects model. Outcomes were the sperm progressive motility rate. Results are expressed as standardised mean difference (SMD) with 95% confidence interval (CI). Heterogeneity was evaluated by the I-square (I2) statistic. RESULTS: Ten studies were identified, including 616 infertile patients with HPV seminal infection and 2029 infertile controls without HPV seminal infection. Our meta-analysis results indicated that sperm progressive motility was significantly reduced in HPV-infected semen samples compared with non-infected groups [SMD:-0.88, 95% CI:-1.17 ~ - 0.59]. There existed statistical heterogeneity (I2 value: 86%) and the subgroup analysis suggested that study region might be the causes of heterogeneity. CONCLUSIONS: HPV semen infection could significantly reduce sperm progressive motility in infertile individuals. There were some limitations in the study such as the differences in age, sample sizes and the number of HPV genotypes detected. Further evidences are needed to better elucidate the relationship between HPV seminal infection and sperm quality.

Mumps virus infection disrupts blood-testis barrier through the induction of TNF-α in Sertoli cells.

Mumps virus (MuV) has high tropism to the testis and may lead to male infertility. Sertoli cells are the major targets of MuV infection. However, the mechanisms by which MuV infection impairs male fertility and Sertoli cell function remain unclear. The present study elucidated the effect of MuV infection on the blood-testis barrier (BTB). The transepithelial electrical resistance of MuV-infected mouse Sertoli cells was monitored, and the expression of major proteins of the BTB was examined. We demonstrated that MuV infection disrupted the BTB by reducing the levels of occludin and zonula occludens 1. Sertoli cells derived from Tlr2-/- and Tnfa-/- mice were analyzed for mediating MuV-induced impairment. TLR2-mediated TNF-α production by Sertoli cells in response to MuV infection impaired BTB integrity. MuV-impaired BTB was not observed in Tlr2-/- and Tnfa-/- Sertoli cells. Moreover, an inhibitor of TNF-α, pomalidomide, prevents the disruption of BTB in response to MuV infection. FITC-labeled biotin tracing assay confirmed that BTB permeability and spermatogenesis were transiently impaired by MuV infection in vivo. These findings suggest that the disruption of the BTB could be one of the mechanisms underlying MuV-impaired male fertility, in which TNF-α could play a critical role.-Wu, H., Jiang, X., Gao, Y., Liu, W., Wang, F., Gong, M., Chen, R., Yu, X., Zhang, W., Gao, B., Song, C., Han, D. Mumps virus infection disrupts blood-testis barrier through the induction of TNF-α in Sertoli cells.

Could COVID-19 have an impact on male fertility?

The pandemic caused by Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to several hypotheses of functional alteration of different organs. The direct influence of this virus on the male urogenital organs is still to be evaluated. However some hypotheses can already be made, especially in the andrological field, for the biological similarity of the SARS-CoV and SARS-CoV2. As well as SARS-CoV, SARS CoV-2 uses the 'Angiotensin Converting Enzyme-2' (ACE2) as a receptor to enter human cells. It was found that ACE2, Angiotensin (1-7) and its MAS receptors are present, over in the lung, also in the testicles, in particular in Leydig and Sertoli cells. A first hypothesis is that the virus could enter the testicle and lead to alterations in testicular functionality. A second hypothesis is that the binding of the virus to the ACE2 receptor, could cause an excess of ACE2 and give rise to a typical inflammatory response. The inflammatory cells could interfere with the function of Leydig and Sertoli cells. Both hypotheses should be evaluated and confirmed, in order to possibly monitor fertility in patients COVID-19+.

Impact of COVID-19 and other viruses on reproductive health.

Male infertility is linked to some viral infections including human papillomavirus (HPV), herpes simplex viruses (HSV) and human immunodeficiency viruses (HIVs). Almost nothing is known about severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) effect on fertility. The possible risk factors of coronavirus disease 2019 (COVID-19) infection on fertility comes from the abundance of angiotensin-Converting Enzyme-2 (ACE2), receptor entry of the virus, on testes, a reduction in important sex hormone ratios and COVID-19-associated fever. Recent studies have shown a gender difference for COVID-19 rates and comorbidity. In this review, we will discuss the potential effect of COVID-19 on male fertility and talk about what needs to be done by the scientific community to tackle our limited understanding of the disease. On the other side, we will focus on what is known so far about the risk of COVID-19 on pregnancy, neonatal health and the vertical transfer of the virus between mothers and their neonates. Finally, because reproduction is a human right and infertility is considered a health disease, we will discuss how assisted reproductive clinics can cope with the pandemic and what guidelines they should follow to minimise the risk of viral transmission.

Could SARS-CoV-2 affect male fertility?

We performed this systematic review to evaluate the possibility of an impact of SARS-CoV-2 infection on male fertility. SARS-CoV-2 enters the cells with the help of ACE2; therefore, testicular expression of ACE2 was analysed from transcriptome sequencing studies and our unpublished data. Literature suggested that SARS-CoV-1 (2002-2004 SARS) had a significant adverse impact on testicular architecture, suggesting a high possibility of the impact of SARS-CoV-2 as well. Out of two studies on semen samples from COVID-19 affected patients, one reported the presence of SARS-CoV-2 in the semen samples while the other denied it, raising conflict about its presence in the semen samples and the possibility of sexual transmission. Our transcriptome sequencing studies on rat testicular germ cells showed ACE expression in rat testicular germ cells. We also found ACE2 expression in transcriptome sequencing data for human spermatozoa, corroborating its presence in the testicular germ cells. Transcriptome sequencing data from literature search revealed ACE2 expression in the germ, Sertoli and Leydig cells. The presence of ACE2 on almost all testicular cells and the report of a significant impact of previous SARS coronavirus on testes suggest that SARS-CoV-2 is highly likely to affect testicular tissue, semen parameters and male fertility.