PRSS50 is a testis protease responsible for proper sperm tail formation and function.

Multiple morphological abnormalities of the sperm flagella (MMAF) are a major cause of asthenoteratozoospermia. We have identified protease serine 50 (PRSS50) as having a crucial role in sperm development, because Prss50-null mice presented with impaired fertility and sperm tail abnormalities. PRSS50 could also be involved in centrosome function because these mice showed a threefold increase in acephalic sperm (head-tail junction defect), sperm with multiple heads (spermatid division defect) and sperm with multiple tails, including novel two conjoined sperm (complete or partial parts of several flagellum on the same plasma membrane). Our data support that, in the testis, as in tumorigenesis, PRSS50 activates NFκB target genes, such as the centromere protein leucine-rich repeats and WD repeat domain-containing protein 1 (LRWD1), which is required for heterochromatin maintenance. Prss50-null testes have increased IκκB, and reduced LRWD1 and histone expression. Low levels of de-repressed histone markers, such as H3K9me3, in the Prss50-null mouse testis may cause increases in post-meiosis proteins, such as AKAP4, affecting sperm formation. We provide important insights into the complex mechanisms of sperm development, the importance of testis proteases in fertility and a novel mechanism for MMAF.

E2F1 regulates testicular descent and controls spermatogenesis by influencing WNT4 signaling.

Cryptorchidism is the most common urologic birth defect in men and is a predisposing factor of male infertility and testicular cancer, yet the etiology remains largely unknown. E2F1 microdeletions and microduplications contribute to cryptorchidism, infertility and testicular tumors. Although E2f1 deletion or overexpression in mice causes spermatogenic failure, the mechanism by which E2f1 influences testicular function is unknown. This investigation revealed that E2f1-null mice develop cryptorchidism with severe gubernacular defects and progressive loss of germ cells resulting in infertility and, in rare cases, testicular tumors. It was hypothesized that germ cell depletion resulted from an increase in WNT4 levels. To test this hypothesis, the phenotype of a double-null mouse model lacking both Wnt4 and E2f1 in germ cells was analyzed. Double-null mice are fertile. This finding indicates that germ cell maintenance is dependent on E2f1 repression of Wnt4, supporting a role for Wnt4 in germ cell survival. In the future, modulation of WNT4 expression in men with cryptorchidism and spermatogenic failure due to E2F1 copy number variations may provide a novel approach to improve their spermatogenesis and perhaps their fertility potential after orchidopexy.

Variants in ALX4 and their association with genitourinary defects.

BACKGROUND: Genitourinary anomalies occur in approximately 1% of humans, but in most cases, the cause is unknown. Aristaless-like homeobox 4 (ALX4) is an important homeodomain transcription factor. ALX4 mutations in humans and mouse have been associated with craniofacial defects and genitourinary anomalies such as cryptorchidism and epispadias. OBJECTIVES: To investigate the presence and the functional impact of ALX4 variants in patients with genitourinary defects. MATERIALS AND METHODS: Two separate patient cohorts were analyzed. One includes clinical exome-sequencing (ES) data from 7500 individuals. The other includes 52 ALX4 Sanger-sequenced individuals with bladder exstrophy-epispadias complex (BEEC). Dual luciferase assays were conducted to investigate the functional transcriptional impact of ALX4 variants in HeLa cells and HEK293 cells. RESULTS: A total of 41 distinct ALX4 heterozygous missense variants were identified in the ES cohort with 15 variants present as recurrent in multiple patients. p.G369E and p.L373F were the only two present in individuals with genitourinary defects. A p.L373F heterozygous variant was also identified in one of the 52 individuals in the BEEC cohort. p.L373F and p.G369E were tested in vitro as both are considered damaging by MutationTaster, although only p.G369E was considered damaging by PolyPhen-2. p.L373F did not alter transcriptional activity in HeLa and HEK293 cells. p.G369E caused a significant 3.4- and 1.8-fold decrease in transcriptional activities relative to wild-type ALX4 in HEK293 and HeLa cells, respectively. DISCUSSION AND CONCLUSIONS: Our study supports the idea that transcription factors like ALX4 could influence the normal development of the GU tract in humans as demonstrated in mouse models as ALX4 variant p.G369E (predicted pathogenic by multiple databases) affects ALX4 function in vitro. Variant p.L373F (predicted pathogenic by only MutationTaster) did not affect ALX4 function in vitro. Exon-sequence information and mouse genetics provide important insights into the complex mechanisms driving genitourinary defects allowing the association of transcriptional defects with congenital disorders.

Testosterone versus clomiphene citrate in managing symptoms of hypogonadism in men.

INTRODUCTION: Both clomiphene citrate (CC) and testosterone supplementation therapy (TST) are effective treatments for men with hypogonadism. We sought to compare changes in symptoms and treatment efficacy in hypogonadal men before and after receiving CC and TST. PATIENTS AND METHODS: 52 men who received TST and 23 men who received CC for symptomatic hypogonadism were prospectively followed for change in hormone levels and symptoms after treatment. These men were also compared to eugonadal men who were not on CC or TST during the same period. Comparisons were made between baseline and posttreatment hormone levels and symptoms. Symptoms were evaluated using the androgen deficiency in aging male (ADAM) and quantitative ADAM (qADAM) questionnaires. RESULTS: Serum total testosterone increased from pretreatment levels in all men (P < 0.05), regardless of therapy type (TST: 281-541 ng/dL, CC: 235.5-438 ng/dL). Men taking TST reported fewer ADAM symptoms after treatment (5-2, P < 0.05). Similarly, men taking CC reported fewer ADAM symptoms after treatment (3.5-1.5, P < 0.05). Conversely, eugonadal men had similar T levels (352 vs. 364 ng/dL) and hypogonadal symptoms (1.5 vs. 1.4) before and after follow-up. When we evaluated individual symptoms, men treated with TST showed significant increases in qADAM scores in libido, erectile function, and sports performance. However, among the men who received CC, qADAM subscore for libido was lower following treatment (3.75-3.2, P = 0.04), indicating that CC could have an adverse effect on libido in hypogonadal men. CONCLUSIONS: Both TST and CC are effective medications in treating hypogonadism; however, our study indicates that TST is more effective in raising serum testosterone levels and improving hypogonadal symptoms. CC remains a viable treatment modality for hypogonadal men but its adverse effect on libido warrant further study.

Association of Free Testosterone With Hypogonadal Symptoms in Men With Near-normal Total Testosterone Levels.

OBJECTIVE: To investigate the association between hypogonadal symptoms and free testosterone (FT) levels in men with near-normal total testosterone (T) levels (250-350 ng/dL) and to determine whether a discriminatory threshold for FT exists below which hypogonadal symptoms become more prevalent. METHODS: We reviewed the charts of 3167 men who presented to an outpatient men's health clinic. Two hundred thirty-one men had symptoms of "low testosterone" and serum testosterone levels between 250 and 350 ng/dL. We evaluated hypogonadal symptoms using the Androgen Deficiency in the Adult Male (ADAM) and quantitative ADAM (qADAM) questionnaires. Serum levels of T and sex hormone-binding globulin were collected on the same day that men completed their questionnaires. We used linear regression to determine whether a threshold of FT exists for hypogonadal symptoms. We performed univariate and multivariable analyses to evaluate factors that predicted a low FT level. RESULTS: The median age was 43.5 years, and the median testosterone and FT levels were 303 ng/dL and 6.3 ng/dL, respectively. Prevalence and severity of hypogonadal symptoms (ADAM and qADAM) were similar between men with low (<6.4 ng/mL) and normal FT levels. There was an association between age and 3 of the 10 hypogonadal symptoms (decreased enjoyment in life, sadness, and deterioration of work performance) with a low FT on a univariate analysis. Only younger age was positively associated with FT on multivariable analysis. CONCLUSION: We did not observe a relationship between hypogonadal symptoms and FT in men with near-normal testosterone levels. Symptom-specific FT thresholds could not be defined, as age remains an important confounder.

Hypogonadism and renal failure: An update.

The prevalence of both hypogonadism and renal failure is increasing. Hypogonadism in men with renal failure carries with it significant morbidity, including anemia and premature cardiovascular disease. It remains unclear whether testosterone therapy can affect the morbidity and mortality associated with renal failure. As such, in this review, we sought to evaluate the current literature addressing hypogonadism and testosterone replacement, specifically in men with renal failure. The articles chosen for this review were selected by performing a broad search using Pubmed, Embase and Scopus including the terms hypogonadism and renal failure from 1990 to the present. This review is based on both primary sources as well as review articles. Hypogonadism in renal failure has a multifactorial etiology, including co-morbid conditions such as diabetes, hypertension, old age and obesity. Renal failure can lead to decreased luteinizing hormone production and decreased prolactin clearance that could impair testosterone production. Given the increasing prevalence of hypogonadism and the potential morbidity associated with hypogonadism in men with renal failure, careful evaluation of serum testosterone would be valuable. Testosterone replacement therapy should be considered in men with symptomatic hypogonadism and renal failure, and may ameliorate some of the morbidity associated with renal failure. Patients with all stages of renal disease are at an increased risk of hypogonadism that could be associated with significant morbidity. Testosterone replacement therapy may reduce some of the morbidity of renal failure, although it carries risk.

Genomic and genetic variation in E2F transcription factor-1 in men with nonobstructive azoospermia.

OBJECTIVE: To identify gene dosage changes associated with nonobstructive azoospermia (NOA) using array comparative genomic hybridization (aCGH). DESIGN: Prospective study. SETTING: Medical school. PATIENT(S): One hundred ten men with NOA and 78 fertile controls. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The study has four distinct analytic components: aCGH, a molecular karyotype that detects copy number variations (CNVs); Taqman CNV assays to validate CNVs; mutation identification by Sanger sequencing; and histological analyses of testicular tissues. RESULT(S): A microduplication at 20q11.22 encompassing E2F transcription factor-1 (E2F1) was identified in one of eight men with NOA analyzed using aCGH. CNVs were confirmed and in an additional 102 men with NOA screened using Taqman CNV assays, for a total of 110 NOA men analyzed for CNVs in E2F1. Eight of 110 (7.3%) NOA men had microduplications or microdeletions of E2F1 that were absent in fertile controls. CONCLUSION(S): E2F1 microduplications or microdeletions are present in men with NOA (7.3%). Duplications or deletions of E2F1 occur very rarely in the general population (0.011%), but E2F1 gene dosage changes, previously reported only in cancers, are present in a subset of NOA men. These results recapitulate the infertility phenotype seen in mice lacking or overexpressing E2f1.

Effect of testosterone supplementation on symptoms in men with hypogonadism.

Testosterone supplementation regimens are efficacious for improving both hypogonadal symptoms and serum total testosterone levels. Younger men appear to respond better to symptom improvement following testosterone therapy.

Hypogonadal symptoms in young men are associated with a serum total testosterone threshold of 400 ng/dL.

OBJECTIVE: To investigate the association between hypogonadal symptoms and serum total testosterone (TT) levels in young men (aged <40 years), in an attempt to determine whether there exists a clear-cut discriminatory threshold of TT below which hypogonadal symptoms become more prevalent. PATIENTS AND METHODS: We retrospectively reviewed the charts of 352 men who presented to an outpatient Men's Health Clinic with chief complaint of 'low testosterone'. Sexual, psychological and physical symptoms were evaluated using the Androgen deficiency in Aging Male (ADAM) questionnaire. Serum levels of TT were collected on the same day that men completed their ADAM questionnaires. We subsequently performed univariate (t-test, chi-square) and multivariate analyses (ordinal logistic regression) to evaluate factors that predicted a low TT level. RESULTS: The probability of hypogonadal symptoms increased at a serum TT level of 400 ng/dL. A cluster of symptoms: two psychological ('decreased energy', 'sadness'), and three physical ('decreased strength and endurance', 'decreased ability to play sports', and 'deterioration in work performance') were most strongly associated with serum TT levels of <400 ng/dL. On multivariable analysis, only 'lack of energy' predicted a TT level of <400 ng/dL. CONCLUSIONS: Hypogonadal symptoms in men aged <40 years can be associated with a TT level of <400 ng/dL. Of the hypogonadal symptoms evaluated with the ADAM questionnaire, 'lack of energy' appears to be the most important symptom that predicts a TT level of <400 ng/dL.

Hypogonadal symptoms are associated with different serum testosterone thresholds in middle-aged and elderly men.

OBJECTIVE: To determine the association between hypogonadal symptoms and total serum testosterone levels in middle-aged and elderly men (aged > 40 years), and to identify whether there exists a clear-cut discriminatory threshold of total testosterone below which the probability of hypogonadal symptoms increases. METHODS: We retrospectively reviewed the charts of 360 men who presented to an outpatient men's health clinic with a chief complaint of low testosterone. Sexual, psychological, and physical symptoms were evaluated using the androgen deficiency in the aging male (ADAM) questionnaire. Serum levels of total testosterone were collected on the same day on which men completed their ADAM questionnaires. We performed the univariate (t test, chi-square, and binary logistic regression) and multivariate analyses (binary logistic regression) to evaluate the total testosterone threshold and the symptoms that predicted a low-testosterone level. RESULTS: A cluster of symptoms: 1 sexual (decreased libido), 1 psychological (decreased energy), and 3 physical (decreased strength or endurance, decreased ability to play sports, and falling asleep after dinner) were most associated with total serum testosterone levels of ≤ 300 ng/dL. The threshold testosterone serum levels that were associated with an increased prevalence of these hypogonadal symptoms ranged from 320 to 375 ng/dL. On multivariate analysis, age, but not symptoms on the ADAM questionnaire, predicted a total testosterone level of < 300 ng/dL. CONCLUSION: A distinct constellation of hypogonadal symptoms exists at various serum testosterone levels. Consequently, identification of the thresholds for specific symptom management will be critical in establishing patient-centered treatment algorithms.

Management of erectile dysfunction in the hypogonadal man: a case-based review.

Erectile dysfunction (ED) has emerged as an important marker of cardiovascular and overall health, independent of other known conventional risk factors. ED often precedes coronary artery disease in half of affected subjects, and could indicate the presence of cardiovascular pathology. The pathophysiology and role of androgens in sexual function are described, along with the relevant literature on the effects of aging in erectile and gonadal function. The concept of testosterone supplementation (TST) in men with ED is reviewed. The authors utilize clinical vignettes to discuss the appropriate management of two clinical cases of men at different life stages who have ED in the setting of hypogonadism and propose a treatment algorithm. In patients of all ages, proper identification of the underlying pathophysiology of decreased libido and erectile function is paramount in choosing between the use of TST, phosphodiesterase type 5 inhibitors, or both, in the management of these disorders.

Genitourinary defects associated with genomic deletions in 2p15 encompassing OTX1.

Normal development of the genitourinary (GU) tract is a complex process that frequently goes awry. In male children the most frequent congenital GU anomalies are cryptorchidism (1-4%), hypospadias (1%) and micropenis (0.35%). Bladder exstrophy and epispadias complex (BEEC) (1∶47000) occurs less frequently but significantly impacts patients' lives. Array comparative genomic hybridization (aCGH) identified seven individuals with overlapping deletions in the 2p15 region (66.0 kb-5.6 Mb). Six of these patients have GU defects, while the remaining patient has no GU defect. These deletions encompass the transcription factor OTX1. Subjects 2-7 had large de novo CNVs (2.39-6.31 Mb) and exhibited features similar to those associated with the 2p15p16.1 and 2p15p14 microdeletion syndromes, including developmental delay, short stature, and variable GU defects. Subject-1 with BEEC had the smallest deletion (66 kb), which deleted only one copy of OTX1. Otx1-null mice have seizures, prepubescent transient growth retardation and gonadal defects. Two subjects have short stature, two have seizures, and six have GU defects, mainly affecting the external genitalia. The presence of GU defects in six patients in our cohort and eight of thirteen patients reported with deletions within 2p14p16.1 (two with deletion of OTX1) suggest that genes in 2p15 are important for GU development. Genitalia defects in these patients could result from the effect of OTX1 on pituitary hormone secretion or on the regulation of SHH signaling, which is crucial for development of the bladder and genitalia.