Molecular basis of cryptorchidism-induced infertility

Changes in characteristics of spermatogonial stem cells in response to heat stress in stallions

Spermatogonial stem cells (SSCs) are essential for the maintenance of male fertility and survival of species. Environmental conditions, notably heat stress, have been identified as important causes of male infertility and have a negative impact on SSCs. Animals with cryptorchid testes (CT) are optimal models for the study of long-term heat stress-related changes in germ cells. The effect of heat stress on germ cells differs depending on the spermatogenesis stage. Thus, verifying whether the specific phase of spermatogenesis is dependent or independent of heat stress in stallions is important. We evaluated the heat stress-related response of SSCs by comparing the relative abundance of mRNA transcripts and expression patterns of the undifferentiated embryonic cell transcription factor 1 (UTF-1) and deleted in azoospermia-like (DAZL) in the seminiferous tubules of CT and normal testes (NT) of stallions using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), immunofluorescence, and western blotting. We also analyzed the relative abundance of mRNA of different proliferative markers, including minichromosome maintenance 2 (MCM2), marker of proliferation Ki-67 (MKI-67), and proliferating cell nuclear antigen (PCNA). Testicular tissues from four Thoroughbred unilateral cryptorchid postpubertal stallions were used in this study during the breeding season. The relative abundance of the mRNA transcripts of UTF-1 and MCM2 was significantly upregulated in the CT group than that of those in the NT group. In contrast, the relative abundance of the mRNA transcripts of DAZL was significantly downregulated in the CT group than that of those in the NT group. Western blot quantification showed that the relative intensity of UTF-1 protein bands was significantly higher, while that of DAZL protein bands was significantly lower in the CT group than in the NT group. Immunofluorescence studies showed that the number of germ cells immunostained with UTF-1 was significantly higher while immunostained with DAZL was significantly lower in the CT group than that in the NT group. The higher expression level of UTF-1 in the CT group shows that undifferentiated SSCs are not affected by long-term exposure to heat stress. These results also indicate that germ cells after differentiation phase are directly affected by heat-stress conditions, such as cryptorchidism, in stallions.

Expression pattern of germ cell markers in cryptorchid stallion testes

Cryptorchidism affects spermatogenesis and testis development, often resulting in stallion subfertility/infertility. This study aims to identify the specific germ cells impacted by cryptorchism in stallions. In a previous study, we found that PGP9.5 and VASA are molecular markers expressed in different germ cells within stallions. Herein, we assessed the heat stress-induced response of spermatogonial stem cells (SSCs) in the seminiferous tubules (ST) of cryptorchid stallion testes (CST) and normal stallion testes (NST). This goal was accomplished by comparing PGP9.5 and VASA expression patterns through reverse transcription quantitative PCR and immunofluorescence assays. We also compared the cross-sectional ST area between groups. Six post-pubertal Thoroughbred unilateral cryptorchid stallions were used. The relative abundance of the mRNA transcripts of PGP9.5 and VASA was significantly upregulated in the NST group than in the CST group. Additionally, the cross-sectional ST area and localization of PGP9.5 and VASA in germ cells were significantly higher in the NST group than in the CST group. Regarding Leydig cells, PGP9.5 staining was observed in both groups. Spermatogonia, primary spermatocytes and secondary spermatocytes were immunostained with VASA in the NST group, while immunostaining was only observed in spermatogonia in the CST group. These results indicate long-term exposure to heat stress conditions, such as cryptorchidism, directly impacts germ cell proliferation and differentiation, leading to impaired spermatogenesis and compromised fertility in stallions.

Inhibition of Autophagy in Heat-Stressed Sperm of Adult Mice: A Possible Role of Catsper1, 2 Channel Proteins

Objective

Various phenomena guarantee gamete maturation and formation at all stages of evolution, one of which is autophagy playing a critical role in the final morphology of gametes, particularly sperms. Autophagy is influenced by oxidative stress, disturbances of calcium homeostasis, and hyperthermia conditions. The current study aimed to assess the autophagy-related proteins along with the activity of sperm calcium channel (CatSper) proteins following the induction of heat stress (HS).

Methods

The study sample includes two groups of adult mice: sham and HS groups. In the HS group, the right testis was transferred to the abdominal cavity for 120 hours and then returned to the scrotum where it remained for 7 days. After 7 days, the testis and epididymis were removed to conduct real-time, immunohistochemical studies, sperm parameter evaluation, and seminiferous tubule assessment. In this study, the expression and distribution of autophagy proteins were measured. Plus, CatSper1 and CatSper2 were evaluated as proteins of calcium channels.

Results

The results of the present study demonstrated that the expression intensity of autophagy indices in seminiferous tubules decreased significantly after HS induction, which was associated with a decrease in the distribution of CatSper proteins in the sperms. HS led to morphological changes in sperm, reduced motility and viability of sperm, and decreased spermatogenesis indices.

Conclusion

In this study, following heat stress, the decrease in CatSper protein distribution may lead to the structural disorder of CatSper channels, which could strongly affect autophagic activity. Also, disruption of spermatogenesis and sperm parameters may be the consequence of decreased autophagy activity.

Transcriptomic Analysis of Testicular Gene Expression in a Dog Model of Experimentally Induced Cryptorchidism

Cryptorchidism, a condition in which testes fail to descend from the abdomen into the scrotum, is a risk factor for infertility and germ cell cancer. Normally, tight junctions between adjacent Sertoli cells in the testes form a blood–testes barrier that regulates spermatogenesis; however, the effect of cryptorchidism on tight junctions is not well-understood. We established a model of heat-induced testicular damage in dogs using surgical cryptorchidism. We sequenced RNA to investigate whether certain transcripts are expressed at higher rates in heat-damaged versus normally descended testes. Claudins, cell adhesion molecules, were relatively highly expressed in cryptorchid testes: claudins 2, 3, 5, 11, and 18 were significantly increased in cryptorchid testes and reduced by orchiopexy. SOX9-positive Sertoli cells were present in the seminiferous tubules in both cryptorchid and control testes. Using real-time PCR and Western blot analysis to compare Sertoli cells cultured at 34 °C and 37 °C, we found that Sertoli cell claudins 2, 3, 5, 11, and 18 were significantly increased at 37 °C; however, accumulation was higher in the G0/G1 phase in Sertoli cells cultured at 34 °C. These results indicate that testicular hyperthermia caused by cryptorchidism affects claudin expression, regulated germ cell death, and the proliferation of Sertoli cells.

Comparative transcriptome analysis of experimental cryptorchidism: Of mice and cynomolgus monkeys

In most mammalian species, the testis descends from the abdomen into the scrotum during fetal or neonatal life. The failure of testicular descent, a pathological condition known as cryptorchidism, has long been the subject of scientific interest in a wide range of fields, including medicine, developmental biology and evolutionary biology. In this study, we analyzed global gene expression changes associated with experimental cryptorchidism in mice by using RNA-seq. A total of 453 differentially expressed genes were identified, of which 236 genes were up-regulated and 217 genes were down-regulated. Gene ontology, pathway and gene network analysis highlighted the activation of inflammatory response in experimental cryptorchidism. By examining the promoter regions of differentially expressed genes, we identified 12 causal transcription factors. In addition, we also induced experimental cryptorchidism in two cynomolgus monkeys and performed RNA-seq. A cross-species comparison was performed at the gene expression level. Our study provides a valuable resource for further understanding molecular mechanisms of cryptorchidism in mammals.

Cyclophosphamide suppresses spermatogenesis in the testis of mice through downregulation of miR-34b and miR-34c

Cyclophosphamide (CP) is commonly used as an anticancer agent but has been associated with high toxicity in several organs, including the testes. In this study, we aimed to evaluate the effects of CP-induced testicular toxicity, using glial cell line-derived neurotrophic factor (GDNF), occludin and transforming growth factor beta 3 (TGF-β3) primary antibodies, and miR-34b and miR-34c expressions. Eighteen young Balb/c male mice were divided into three groups. The control group received no treatment. The mice of CP group were injected 100 mg kg^-1  day^-1 CP for 5 days, and the same amount of saline was injected in the sham group. The animals were sacrificed 24 hr after the last injection. Immunohistochemical analysis of testicular tissues showed a decrease in both spermatogenic germ cell count and also GDNF, occludin expressions, but an increase in TGF-β3 expression in the CP group compared to the others group. The expressions of miR-34b and miR-34c were examined by qPCR technique, a significant decrease was observed in tissue samples in the CP-treated group. The expression of GDNF, occludin and TGF-β3 plays an important role in testicular injury caused by CP, and the decrease in the expression of miR-34b/c in tissue samples may be an important marker for the detection of testicular damage.

Ameliorating effects of curcumin-loaded superparamagnetic iron oxide nanoparticles (SPIONs) on the mouse testis exposed to the transient hyperthermia: A molecular and stereological study

BACKGROUND

Testicular hyperthermia can have negative effects on male fertility. Despite reported therapeutic benefits of curcumin, several factors often limit its application such as low water solubility and instable structure. Curcumin-loaded superparamagnetic iron oxide nanoparticles (SPIONs) were designed to solve its limitation of use. In the present study, we evaluated the effect of curcumin-loaded SPIONs on transient testicular hyperthermia in mouse.

MATERIALS AND METHOD

A total of 18 adult male NMRI mice were divided into three groups (n = 6): I. Controls (Cont), II. Scrotal hyperthermia (Hyp), III. Scrotal hyperthermia + curcumin-loaded iron particles (240 μL) (Hyp + Cur). After seventy days, the animals were sacrificed and used for further molecular and stereological evaluations.

RESULTS

Sperm count, motility and viability significantly decreased in group hyp as compared to cont group. Furthermore, Sperm DNA fragmentation and cell apoptosis in testes increased remarkably in group hyp, compared with group cont. Stereological study showed a reduction in number of spermatogenic and Leydig cells, as well as reduced weight and volume of testes in hyp group. Degenerative appearance of testes exposed to hyperthermia was also observed. In addition, higher mRNA expression of inflammatory cytokines (IL1-α, IL6, and TNF-α) was detected in group hyp compared to cont group. However, curcumin-loaded SPIONs alleviated all of the pathologic changes in the Hyp + Cur group compared to the hyp group.

CONCLUSION

Here, we used nanoparticle form of curcumin in testicular hyperthermia model and showed its ameliorating effects on testes damages caused by heat stress, which can be an appropriate method to overcome the problems that limit curcumin application in cases with increased intra testicular temperature.

Timing of pubertal development in boys born with cryptorchidism and hypospadias: a nationwide cohort study

Pubertal development may be altered in boys with cryptorchidism and hypospadias, but existing knowledge is inconsistent. Therefore, we investigated the association between cryptorchidism and hypospadias and pubertal development in a large cohort study. Boys in the Puberty Cohort, a cohort nested within the Danish National Birth Cohort, were included in this study. Information on cryptorchidism and hypospadias was retrieved from the Danish National Patient Register. From 11 years until 18 years or full pubertal development, information on physical markers of pubertal development was provided biannually, including Tanner stages, axillary hair, acne, voice break, and first ejaculation. In multivariate regression models for interval censored data, the mean (95% confidence intervals [CIs]) differences in months in obtaining the pubertal markers between boys with and without the anomalies were estimated. Among 7698 boys, 196 (2.5%) had cryptorchidism and 60 (0.8%) had hypospadias. Boys with hypospadias experienced first ejaculation and voice break 7.7 (95% CI: 2.5-13.0) months and 4.5 (95% CI: 0.3-8.7) months later than boys without hypospadias. The age at attaining the Tanner stages for gonadal and pubic hair growth was also higher, though not statistically significant. Pubertal development seemed unaffected in boys with mild as well as severe cryptorchidism. In conclusion, hypospadias may be associated with delayed pubertal development, but pubertal development seems unaffected by cryptorchidism. The relation between hypospadias and later pubertal development may be due to the underlying shared in utero risk or genetic factors.

Retinoic acid: A potential therapeutic agent for cryptorchidism infertility based on investigation of flutamide-induced cryptorchid rats in vivo and in vitro

Cryptorchidism is a common disorder in children and may cause infertility in adults. The BTB is essential for maintaining the microenvironment necessary for normal spermatogenesis. This study investigated whether retinoic acid (RA) may regulate the proteins that are essential for integrity of the BTB in cryptorchidism. Female Sprague-Dawley rats were administrated flutamide during late pregnancy to induce a model of cryptorchidism in male offspring. The concentrations of RA and BTB tight and gap junction protein levels were significantly lower in untreated cryptorchid pups compared with normal pups, but almost normal in cryptorchid pups given RA. Studies in vitro corroborated these findings. The sperm quality of RA-treated model pups was better compared with the untreated model. RA treatment may have therapeutic potential to restore retinoic acid and proteins associated with integrity of the BTB in cryptorchid testis.

Environmental Toxins and Male Fertility

PURPOSE OF REVIEW

Global industrialization has increased population exposure to environmental toxins. A global decline in sperm quality over the last few decades raises questions about the adverse impact of environmental toxins on male reproductive health.

RECENT FINDINGS

Multiple animal- and human-based studies on exposure to environmental toxins suggest a negative impact on semen quality, in terms of sperm concentration, motility, and/or morphology. These toxins may exert estrogenic and/or anti-androgenic effects, which in turn alter the hypothalamic-pituitary-gonadal axis (HPGA), induce sperm DNA damage, or cause sperm epigenetic changes. This chapter will discuss the most recent literature about the most common environmental toxins and their impact on spermatogenesis and its consequences on male fertility. Understanding the presence and underlying mechanism of these toxins will help us preserve the integrity of the male reproduction system and formulate better regulations against their indiscriminate use.

Effect of local scrotal heating on the expression of tight junction-associated molecule Occludin in boar testes

The aim of this study was to determine whether local scrotal heating (42°C, for 1 hr) had an effect on the expression of tight junction (TJ)-associated molecule Occludin in boar testes. Adult boars (Landrace, n = 6) were used and randomly divided into two groups (n = 3 each). Three boars were given local scrotal exposure to 42°C for approximately 1 h with a home-made electric blanket of controlled temperature as local scrotal heating group, the other three boars received no heat treatment and were left at standard room temperature as control group. After 6 hr, all boars were castrated and the testes were harvested. qRT-PCR, Western blotting and immunohistochemistry were used to explore the expression and localization of Occludin. qRT-PCR and Western blotting showed that the protein and mRNA levels of Occludin significantly decreased in local scrotal heating group as compared to the control. Furthermore, immunoreactivity staining of Occludin was localized at the sites of the blood-testis barrier (BTB) and formed an almost consecutive and strong immunoreactivity strand in the control, while Occludin was limited to Sertoli cells (SCs) and no obvious immunoreactivity strand was present in local scrotal heating group. These data indicated that local scrotal heating decreased the expression of TJ-associated molecule Occludin, which may be involved in heat-induced spermatogenesis damage.

Next-generation sequencing-based microRNA profiling of mice testis subjected to transient heat stress

This study aimed to investigate the role of microRNA (miRNA) in heat stress-induced spermatogenic impairment. Testes from 15 adult ICR mice subjected to testicular hyperthermia at 43°C for 30 min and from 15 control mice were collected and pooled into 3 samples. Isolated RNA from these samples was subjected to small RNA high-throughput sequencing, and differentially expressed miRNAs were identified and validated using RT-PCR. The identified miRNAs were further subjected to Gene Ontology and KEGG analyses, which revealed significant enrichment for pathways potentially involved in heat stress-induced spermatogenic impairment. Additionally, a correlation analysis of the relative levels of validated miRNAs with germ cell apoptosis was performed. Of the 11 miRNAs identified as differentially expressed, 8 were validated as consistent with sequencing data. Further analyses suggested that the target genes of those miRNAs were involved in various pathways (e.g., ribosomal, HIF-1, MAPK) that may be critical to heat stress-induced testicular damage. Some identified miRNAs, including miR-449a-3p, miR-92a-1-5p, miR-423-3p, and miR-128-3p, correlated closely with germ cell apoptosis. The study results reveal a detailed miRNA profile of heat stress-induced testicular damage and highlight new and potentially important candidate targets in the process of male infertility.

Association between RNA-binding protein Ptbp2 and germ cell injury in an experimentally-induced unilateral cryptorchidism murine model

RNA binding protein polypyrimidine tract binding protein 2 (Ptbp2) as a key alternative splicing regulator for male germ cell development is well established. However, its expression levels and role in cryptorchidism testes tissues has not been explored. Additionally, the molecular mechanism of heat stress impacts the correct proliferation and differentiation of germ cells is unclear. To investigate whether changes in Ptbp2 expression are correlated with heat stress-induced germ cell injury in testicular tissue, we used a murine model of intraperitoneal cryptorchidism with surgical operation. Here we present compelling evidence that germ cells are severely damaged in mice with unilateral cryptorchidism, with non-obstructive azoospermia. And the Ptbp2 and Pgk2 mRNA levels were significantly decreased in parallel, leading us to conclude that the negative correlation between Ptbp2 levels and germ cell injury in unilateral cryptorchidism murine model. We hypothesize that Ptbp2 is susceptible to heat stress and its disruption has resulted in stability decline of germ cell transcripts Pgk2 mRNA, which consequently lead to germ cell injury in cryptorchidism testes. Thus, we confirm that Ptbp2 is an essential factor in heat stress-induced sperm cell injury and non-obstructive azoospermia.

Isobaric tags for relative and absolute quantification-based proteomic analysis of testis biopsies in rhesus monkeys treated with transient scrotal hyperthermia

This study aimed to examine the cellular and molecular events that occur in rhesus monkey testes after scrotal hyperthermia. Eight male adult rhesus monkeys were subjected to scrotal hyperthermia at 43°C for 30 min daily for 6 consecutive days. Sperm concentration, reproductive hormones, and testis histology were examined before hyperthermia (day 0), and at 8, 15, 30, 45, 60, 75, and 90 days after the initiation of hyperthermia. iTRAQ-based proteomic analysis was conducted on testicular tissues collected on days 0, 8, and 60 to identify differentially expressed proteins at the early and recovery stages of testicular damage. The sperm concentration was significantly decreased at days 30 and 45 after treatment (p < 0.01) and recovered to baseline at day 60. When compared with day 0, 101 and 24 differentially expressed proteins were identified at days 8 and 60 after heat treatment, respectively. The molecular functions of the differentially expressed proteins at day 8 were mainly nucleic acid binding, unfolded protein binding, nucleotide binding, and nucleoside phosphate binding. Spliceosome was enriched as the most significant pathway at day 8. CIRBP, PSIP1, Sam68, and Decorin were validated and found to be consistent with the proteomic data, indicating the reliability of the proteomic profiles identified in this study. In summary, we suggest that the proteins identified in this study may play important roles in heat-induced spermatogenic impairment. Some of these proteins, such as CIRBP, PSIP1, Sam68, and Decorin, may be early molecular targets responsible for spermatogenesis suppression induced by heat treatment.

Effect of transient scrotal hyperthermia on sperm parameters, seminal plasma biochemical markers, and oxidative stress in men

In this experimental prospective study, we aimed to analyze the effect of transient scrotal hyperthermia on the male reproductive organs, from the perspective of sperm parameters, semen plasma biochemical markers, and oxidative stress, to evaluate whether different frequencies of heat exposure cause different degrees of damage to spermatogenesis. Two groups of volunteers (10 per group) received testicular warming in a 43°C water bath 10 times, for 30 min each time: group 1: 10 consecutive days; group 2: once every 3 days. Sperm parameters, epididymis and accessory sex gland function, semen plasma oxidative stress and serum sex hormones were tested before treatment and in the 16-week recovery period after treatment. At last, we found an obvious reversible decrease in sperm concentration (P = 0.005 for Group 1 and P= 0.008 for Group 2 when the minimums were compared with baseline levels, the same below), motility (P = 0.009 and 0.021, respectively), the hypoosmotic swelling test score (P = 0.007 and 0.008, respectively), total acrosin activity (P = 0.018 and 0.009, respectively), and an increase in the seminal plasma malondialdehyde concentration (P = 0.005 and 0.017, respectively). The decrease of sperm concentration was greater for Group 2 than for Group 1 (P = 0.031). We concluded that transient scrotal hyperthermia seriously, but reversibly, negatively affected the spermatogenesis, oxidative stress may be involved in this process. In addition, intermittent heat exposure more seriously suppresses the spermatogenesis compared to consecutive heat exposure. This may be indicative for clinical infertility etiology analysis and the design of contraceptive methods based on heat stress.

Expression of Phosphodiesterase 4B cAMP-Specific Gene in Subjects With Cryptorchidism and Down's Syndrome

Cryptorchidism represents a risk factor for infertility and germ cell testicular neoplasia. An increased rate of cryptorchidism has been reported in subjects with Down's syndrome. Cyclic nucleotide phosphodiesterases (PDEs) are important messengers that regulate and mediate a number of cellular responses to extracellular signals, such as neurotransmitters and hormones. PDE4B, cAMP-specific (PDE4B) gene which maps to chromosome 1p31.3 appears to be involved in schizophrenia, chronic psychiatric illness, learning, memory, and mood disturbances. Expression of PDE4 enzymes have been studied in testes of cryptorchid rats. Expression of PDE4B protein examination showed marked degenerative changes in the epithelial lining of the seminiferous tubules. These findings led us to evaluate PDE4 mRNA expression in leukocytes of peripheral blood of five men with DS and cryptorchidism and eleven subjects with DS without cryptorchidism compared with healthy men (controls) by quantitative Real Time PCR (qRT-PCR). This study showed that the PDE4B gene was downexpressed in men with DS and cryptorchidism compared to normal controls and DS without cryptorchidism. A lower expression of the PDE4B gene may be involved in the neurological abnormalities in subjects with Down's syndrome. Moreover, PDE4B gene may be involved in the testicular abnormalities of men with DS and cryptorchidism.

Causes, effects and molecular mechanisms of testicular heat stress

The process of spermatogenesis is temperature-dependent and occurs optimally at temperatures slightly lower than that of the body. Adequate thermoregulation is imperative to maintain testicular temperatures at levels lower than that of the body core. Raised testicular temperature has a detrimental effect on mammalian spermatogenesis and the resultant spermatozoa. Therefore, thermoregulatory failure leading to heat stress can compromise sperm quality and increase the risk of infertility. In this paper, several different types of external and internal factors that may contribute towards testicular heat stress are reviewed. The effects of heat stress on the process of spermatogenesis, the resultant epididymal spermatozoa and on germ cells, and the consequent changes in the testis are elaborated upon. We also discuss the molecular response of germ cells to heat exposure and the possible mechanisms involved in heat-induced germ cell damage, including apoptosis, DNA damage and autophagy. Further, the intrinsic and extrinsic pathways that are involved in the intricate mechanism of germ cell apoptosis are explained. Ultimately, these complex mechanisms of apoptosis lead to germ cell death.

SPAG5 mRNA is over-expressed in peripheral blood leukocytes of patients with Down's syndrome and cryptorchidism

Men with Down's syndrome (DS) have an increased risk of cryptorchidism, but the mechanisms causing its onset are not clear. Cryptorchidism causes a primary testiculopathy responsible for infertility. SPAG5 mRNA is predominantly expressed in testis in pachytene spermatocytes. This observation prompted us to evaluate the expression of SPAG5 gene in five DS men with cryptorchidism and five normal healthy men (controls) by quantitative real-time PCR in peripheral blood leukocytes. We found that SPAG5 is over expressed in the five men with DS and cryptorchidism compared with five age- and sex-matched normal controls. This finding suggests that the increased expression of this gene may play a pathogenic role durin testicular development in subjects with DS and cryptorchidism.

Expression of STRBP mRNA in patients with cryptorchidism and Down's syndrome

The most frequent defect of the male urogenital tract at birth is cryptorchidism. Cryptorchidism causes primitive testicular pathology responsible for infertility. Men with Down's syndrome (DS) have an increased risk of cryptorchidism. The spermatid perinuclear RNA-binding protein (STRBP) gene codifies a microtubule-associated RNA-binding protein and it is highly expressed in the testis as well as in the brain. At both levels, this gene seems to play a relevant role in the regular development of these organs. These observations prompted us to evaluate the expression of STRBP mRNA in 5 DS men with cryptorchidism and 5 normal healthy men (controls) by quantitative Real Time PCR in peripheral blood leukocytes. We found a decreased expression of the STRBP gene in men with DS and cryptorchidism compared with controls. This finding suggests that the impaired expression of this gene in DS may play a pathogenetic role in the altered brain and testicular development in subjects with DS and cryptorchidism.

Spermatogenesis in cryptorchidism

Cryptorchidism or undescended testis is the most frequent congenital abnormality in newborn boys. The process of testicular descent to the scrotum is controlled by hormones produced in Leydig cells, insulin-like3, and androgens. Variation in genetic and environmental factors might affect testicular descent. A failure of spermatogenesis and germ cell apoptosis resulting in infertility as well as an increased risk of neoplastic transformation of germ cell are the direct consequences of cryptorchidism in adulthood.