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The testis is a reservoir for viruses that can cause persistent infection and adversely affect male reproductive health, an observation commonly attributed to deficiencies in inducible antiviral defence mechanisms. In this study, we demonstrate that interferon-epsilon (IFNε), a type I interferon initially discovered in female reproductive epithelia, is constitutively expressed by meiotic and post-meiotic spermatogenic cells, Leydig cells and macrophages in mouse testes. A similar distribution pattern was observed in human testes. Mice lacking IFNɛ were more susceptible to Zika virus-induced inflammation and damage of the testis and epididymis compared to wild-type mice. Exogenous IFNε treatment reduced the viral infection burden in cultured human testicular cells by inducing interferon-stimulated gene expression, and reducing inflammatory gene expression and cell damage. Treatment was more effective when administered prior to infection. These data indicate a critical role for constitutively-expressed IFNɛ in limiting viral infection and inflammatory damage in the male reproductive tract.

Male germ cells share a common origin across animal species, therefore they likely retain a conserved genetic program that defines their cellular identity. However, the unique evolutionary dynamics of male germ cells coupled with their widespread leaky transcription pose significant obstacles to the identification of the core spermatogenic program. Through network analysis of the spermatocyte transcriptome of vertebrate and invertebrate species, we describe the conserved evolutionary origin of metazoan male germ cells at the molecular level. We estimate the average functional requirement of a metazoan male germ cell to correspond to the expression of approximately 10,000 protein-coding genes, a third of which defines a genetic scaffold of deeply conserved genes that has been retained throughout evolution. Such scaffold contains a set of 79 functional associations between 104 gene expression regulators that represent a core component of the conserved genetic program of metazoan spermatogenesis. By genetically interfering with the acquisition and maintenance of male germ cell identity, we uncover 161 previously unknown spermatogenesis genes and three new potential genetic causes of human infertility. These findings emphasize the importance of evolutionary history on human reproductive disease and establish a cross-species analytical pipeline that can be repurposed to other cell types and pathologies.

IntroductionAzoospermia, characterized by an absence of sperm in the ejaculate, represents the most severe form of male infertility. While surgical sperm retrieval in obstructive azoospermia (OA) is successful in the majority of cases, patients with non-obstructive azoospermia (NOA) show retrieval rates of only about 50% and thus frequently have unnecessary surgery. Surgical intervention could be avoided if patients without preserved spermatogenesis are identified preoperatively. This prospective study aimed to discover biomarkers in seminal plasma that could be employed for a non-invasive differential diagnosis of OA/NOA in order to rationalize surgery recommendations and improve success rates.MethodsAll patients signed written informed consent, underwent comprehensive andrological evaluation, received human genetics to exclude relevant pathologies, and patients with azoospermia underwent surgical sperm retrieval. Using label-free LC-MS/MS, we compared the proteomes of seminal plasma samples from fertile men (healthy controls (HC), n=8) and infertile men diagnosed with 1) OA (n=7), 2) NOA with successful sperm retrieval (mixed testicular atrophy (MTA), n=8), and 3) NOA without sperm retrieval (Sertoli cell-only phenotype (SCO), n=7). Relative abundance changes of two candidate markers of sperm retrieval, HSPA2 and LDHC, were confirmed by Western Blot.ResultsWe found the protein expression levels of 42 proteins to be significantly down-regulated (p ≤ 0.05) in seminal plasma from SCO NOA patients relative to HC whereas only one protein was down-regulated in seminal plasma from MTA patients. Analysis of tissue and cell expression suggested that the testis-specific proteins LDHC, PGK2, DPEP3, and germ-cell enriched heat-shock proteins HSPA2 and HSPA4L are promising biomarkers of spermatogenic function. Western blotting revealed a significantly lower abundance of LDHC and HSPA2 in the seminal plasma of men with NOA (SCO and MTA) compared to controls.DiscussionThe results indicate that certain testis-specific proteins when measured in seminal plasma, could serve as indicators of the presence of sperm in the testis and predict the success of sperm retrieval. Used in conjunction with conventional clinical assessments, these proteomic biomarkers may assist in the non-invasive diagnosis of idiopathic male infertility.

Abstract Purpose Sperm morphology and motility are major contributors to male‐factor infertility, with many genes predicted to be involved. This study aimed to elucidate differentially expressed transcripts in human testis tissues of normal and abnormal spermatogenesis that could reveal new genes that may regulate sperm morphology and function. Methods Human testis biopsies were collected from men with well‐characterized phenotypes of normal spermatogenesis, spermatid arrest, and Sertoli cell‐only phenotype, and transcriptional differences were quantified by RNA‐sequencing (RNA‐Seq). Differentially expressed genes (DEGs) were filtered based on predominant expression in spermatids and gene functional annotations relevant to sperm morphology and motility. Selected 10 DEGs were validated by qRT‐PCR and the localization of two proteins was determined in testis biopsies. Results The analysis revealed 6 genes (SPATA31E1, TEKT3, SLC9C1, PDE4A, CFAP47, and TNC) that are excellent candidates for novel genes enriched in developing human sperm. The immunohistochemical localization of two proteins, ORAI1 and SPATA31E1, in testis biopsies, verified that both are expressed in developing human germ cells, with SPATA31E1 enriched in late spermatocytes and spermatids. Conclusion This study identified human germ cell‐enriched genes that could play functional roles in spermiogenesis and could thus be important in the development of morphologically normal, motile sperm.

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) has a high prevalence of up to 15% and accounts for 90–95% of prostatitis diagnoses, and yet its etiopathogenesis and link to prostate cancer (PCa) are still unclear. Here, we investigated microRNAs in exosomes isolated from blood and post‐prostatic‐massage urine of CP/CPPS type IIIb patients and healthy men. THP‐1 monocytes (human leukemia monocytic cell line) were treated with exosomes and subjected to mRNA arrays “Cancer Inflammation and Immunity Crosstalk” and “Transcription Factors.” Using The Cancer Genome Atlas, the expression of CP/CPPS‐associated microRNAs was analyzed in PCa and normal prostate tissue. In silico functional studies were carried out to explore the disease ontology of CP/CPPS. In CP/CPPS, urine exosomes exhibited significant upregulation of eight PCa‐specific microRNAs (e.g., hsa‐miR‐501, hsa‐miR‐20a, and hsa‐miR‐106), whose target genes were significantly enriched for GO terms, hallmark gene sets, and pathways specific for carcinogenesis. In THP‐1 monocytes, CP/CPPS‐derived urine exosomes induced upregulation of PCa‐associated proinflammatory genes (e.g., CCR2 and TLR2) and proto‐oncogene transcription factors (e.g., MYB and JUNB). In contrast, CP/CPPS‐derived blood exosomes exhibited molecular properties similar to those of healthy men. Thus, CP/CPPS exhibits molecular changes that constitute a risk for PCa and should be considered in the development of PCa biomarkers and cancer screening programs.

Résumé Contexte Chez les hommes infertiles qui présentent une azoospermie non obstructive (NOA), le citrate de clomifène a été proposé comme pré-traitement avant la chirurgie pour extraction testiculaire de spermatozoïdes (TESE), surtout quand la testostérone sérique est basse. Présentation du cas Nous rendons compte, ici, d’un patient azoospermique de 33 ans avec antécédent de traitements répétés par TESE « frais » et par citrate de clomifène (50 mg/jour sur 6 mois) avant de subir une biopsie testiculaire bilatérale assistée microscopiquement. L’étude histologique et immunohistochimique a révélé un arrêt hétérogène de la spermatogénèse au stade de spermatogonies ou de spermatocytes primaires, avec des foyers de spermatogenèse préservée jusqu’au stade de spermatides allongées dans le testicule droit. Dans le testicule gauche, la majorité des tubules (>70%) ne présentaient ni lumière tubulaire ni épithélium séminifère régulier mais un grand nombre de cellules spermatogonies-like. Ces cellules se sont avérées être des spermatogonies normalement différenciées (positives pour l’antigène 4 associé au mélanome (MAGEA4), négatives pour la phosphatase alcaline placentaire (PlAP)) avec une activité proliférative accrue (positives pour l’antigène nucléaire de prolifération cellulaire (PCNA)) et un taux un peu plus élevé de cellules apoptotiques. Comparée à celle d’un tissu témoin avec spermatogenèse normale, l’expression des récepteurs aux hormones sexuelles, récepteur aux androgènes (AR), récepteur aux estrogènes (ER) alpha et récepteur 1 à la protéine G couplée aux estrogènes (GPER1), n’était pas modifiée dans les échantillons du patient. Les cellules de Sertoli semblaient matures (positives à la vimentine, négatives cytokératine 18), tandis que l’expression de la protéine 1 de la zone occludens (ZO-1), de la claudine 11, et de la connexine 43 était absente ou délocalisée dans les tubules présentant une abondance de spermatogonies. Conclusion Ces résultats suggèrent que la formation de la barrière hémato-testiculaire est perturbée dans les tubules affectés. À notre connaissance, il s’agit de la première observation d’une prolifération excessive et non maligne de spermatogonies chez un patient avec NOA. Bien que les mécanismes moléculaires sous-jacents restent à élucider, nous supposons que cette pathologie inhabituelle a été déclenchée par le traitement au citrate de clomifène à haute dose précédant la biopsie testiculaire.

Metabolic syndrome (MetS), which is associated with chronic inflammation, predisposes males to hypogonadism and subfertility. The underlying mechanism of these pathologies remains poorly understood. Homozygous leptin-resistant obese db/db mice are characterized by small testes, low testicular testosterone, and a reduced number of Leydig cells. Here we report that IL-1β, CCL2 (also known as MCP-1), and corticosterone concentrations were increased in the testes of db/db mice relative to those in WT controls. Cultured murine and human Leydig cells responded to cytokine stress with increased CCL2 release and apoptotic signals. Chemical inhibition of CCL2 rescued Leydig cell function in vitro and in db/db mice. Consistently, we found that Ccl2-deficient mice fed with a high-energy diet were protected from testicular dysfunction compared with similarly fed WT mice. Finally, a cohort of infertile men with a history of MetS showed that reduction of CCL2 plasma levels could be achieved by weight loss and was clearly associated with recovery from hypogonadism. Taken together, we conclude that CCL2-mediated chronic inflammation is, to a large extent, responsible for the subfertility in MetS by causing damage to Leydig cells.

Steroid sulfatase (STS) deficiency is the underlying cause of the skin condition known as recessive X-linked ichthyosis (RXLI). RXLI patients show scales on their skin caused by high concentrations of cholesterol sulfate (CS), as they are not capable of releasing the sulfate group from its structure to obtain free cholesterol. CS has been reported, so far, as the sole sulfated steroid with increased concentrations in the blood of RXLI patients. A non-targeted LC-MS approach in negative mode detection (LC-MS precursor ion scan mode) was applied to serum samples of 12 RXLI patients and 19 healthy males. We found that CS was not the only sulfated compound consistently elevated in RXLI patients, because a group of compounds with a m/z of 481 was found in high concentrations too. Further LC-MS/MS demonstrated that the main contributor to the m/z 481 signal in RXLI serum is 27-hydroxycholesterol-3-sulfate (27OHC3S). Accordingly, a new method for 27OHC3S quantification in the context of RXLI has been developed and validated. Other hydroxycholesterol sulfate compounds were elevated as well in RXLI patients.

Germline development in vivo is dependent on the environment formed by somatic cells and the differentiation cues they provide; hence, the impact of local factors is highly relevant to the production of sperm. Knowledge of how somatic and germline cells interact is central to achieving biomedical goals relating to restoring, preserving or restricting fertility in humans. This review discusses the growing understanding of how cytokines contribute to testicular function and maintenance of male reproductive health, and to the pathologies associated with their abnormal activity in this organ. Here we consider both cytokines that signal through JAKs and are regulated by SOCS, and those utilizing other pathways, such as the MAP kinases and SMADs. The importance of cytokines in the establishment and maintenance of the testis as an immune-privilege site are described. Current research relating to the involvement of immune cells in testis development and disease is highlighted. This includes new data relating to testicular cancer which reinforce the understanding that tumorigenic cells shape their microenvironment through cytokine actions. Clinical implications in pathologies relating to local inflammation and to immunotherapies are discussed.