Prevalence of epididymal, seminal vesicle, prostate, and testicular cysts in autosomal dominant polycystic kidney disease

Secondary infertility due to necrospermia in men with autosomal-dominant polycystic kidney disease: a report of two cases

Autosomal-dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease characterized by the formation of numerous cysts in organs other than the kidneys. Although female patients with ADPKD do not have direct fertility problems, infertility in male patients may arise following the formation of cystic lesions in the lower seminal tract, which impair the function of spermatozoa. Generally, the treatment strategy for necrospermia depends on the severity of sperm viability, and intracytoplasmic sperm injection may be offered to patients with necrospermia. We report two cases of secondary infertility in men with ADPKD. These men experienced an inability to reproduce naturally after the previous birth of a child, suggesting a progressive deterioration of semen quality. Semen analysis showed necrospermia in both patients, and transrectal ultrasound revealed marked dilatation of the seminal vesicles bilaterally. The main cause of secondary infertility in male patients with ADPKD is sperm death resulting from progressive dilatation of seminal vesicles. Further research is needed on the appropriate follow-up schedule for men with ADPKD who desire to reproduce naturally.

Novel underlying genetic markers for asthenozoospermia due to abnormal spermatogenesis and reproductive organ inflammation

Asthenozoospermia, a male fertility disorder, has a complex and multifactorial etiology. Moreover, the effectiveness of different treatments for asthenozoospermia remains uncertain. Hence, by using bioinformatics techniques, the present study aimed to determine the underlying genetic markers and pathogenetic mechanisms associated with asthenozoospermia due to abnormal spermatogenesis and inflammation of the reproductive tract. GSE160749 dataset was downloaded from the Gene Expression Omnibus database, and the data were filtered to obtain 1336 differentially expressed genes (DEGs) associated with asthenozoospermia. These DEGs were intersected with the epithelial mesenchymal transition datasets to yield 61 candidate DEGs. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed, and the results revealed that these candidate DEGs were significantly enriched in the enzyme-linked receptor pathway and the thyroid hormone pathway. A protein-protein interaction network was constructed to identify the key genes of asthenozoospermia. A total of five key genes were identified, among which SOX9 was significantly upregulated, while HSPA4, SMAD2, HIF1A and GSK3B were significantly downregulated. These findings were validated by conducting reverse transcription-quantitative PCR for clinical semen samples. To determine the underlying molecular mechanisms, a regulatory network of transcription factors and miRNA-mRNA interactions was predicted. The expression levels of HSPA4, SMAD2 and GSK3B were positively associated with several related etiological genes of asthenozoospermia. In total, five key genes were closely associated with the level and type of immune cells; higher levels of activated B cells and CD8 T cells were observed in asthenozoospermia. Thus, the findings of the present study may provide clues to determine the underlying novel diagnostic genetic markers and treatment strategies for asthenozoospermia.

Hedgehog signaling regulates Wolffian duct development through the primary cilium†

Primary cilia play pivotal roles in embryonic patterning and organogenesis through transduction of the Hedgehog signaling pathway (Hh). Although mutations in Hh morphogens impair the development of the gonads and trigger male infertility, the contribution of Hh and primary cilia in the development of male reproductive ductules, including the epididymis, remains unknown. From a Pax2Cre; IFT88fl/fl knock-out mouse model, we found that primary cilia deletion is associated with imbalanced Hh signaling and morphometric changes in the Wolffian duct (WD), the embryonic precursor of the epididymis. Similar effects were observed following pharmacological blockade of primary cilia formation and Hh modulation on WD organotypic cultures. The expression of genes involved in extracellular matrix, mesenchymal-epithelial transition, canonical Hh and WD development was significantly altered after treatments. Altogether, we identified the primary cilia-dependent Hh signaling as a master regulator of genes involved in WD development. This provides new insights regarding the etiology of sexual differentiation and male infertility issues.

Sperm morphological abnormalities in autosomal dominant polycystic kidney disease are associated with the Hippo signaling pathway via PC1

Background

Autosomal dominant polycystic kidney disease (ADPKD) is a hereditary kidney disorder mostly caused by mutations in PKD1 or PKD2 genes. Here, we report thirteen ADPKD males with infertility and investigated the sperm morphological defects associated with PC1 disruption.

Methods

Targeted next-generation sequencing was performed to detect PKD1 variants in patients. Sperm morphology was observed by immunostaining and transmission electron microscopy, and the sperm motility was assessed using the computer-assisted sperm analysis system. The Hippo signaling pathway was analyzed with by quantitative reverse transcription polymerase chain reaction (qPCR) and western blotting in vitro.

Results

The ADPKD patients were infertile and their sperm tails showed morphological abnormalities, including coiled flagella, absent central microtubules, and irregular peripheral doublets. In addition, the length of sperm flagella was shorter in patients than in controls of in in. In vitro, ciliogenesis was impaired in Pkd1-depleted mouse kidney tubule cells. The absence of PC1 resulted in a reduction of MST1 and LATS1, leading to nuclear accumulation of YAP/TAZ and consequently increased transcription of Aurka. which might promote HDAC6-mediated ciliary disassembly.

Conclusion

Our results suggest the dysregulated Hippo signaling significantly contributes to ciliary abnormalities in and may be associated with flagellar defects in spermatozoa from ADPKD patients.

Recurrent haematospermia: an unusual presentation of autosomal dominant polycystic kidney disease

Haematospermia, even though alarming, is usually benign and self-limiting, especially in a sexually active male. Nevertheless recurrent, refractory or painful haematospermia is troublesome and warrants thorough evaluation. In this context, we describe a rare case of recurrent haematospermia whereby evaluation revealed haemorrhage in seminal vesicle cysts and consequently established the aetiology of autosomal dominant polycystic kidney disease.

Genetic testing, ultrasonography and preimplantation genetic testing of men with autosomal dominant polycystic kidney disease in Hunan, China

The present study identified novel mutations in polycystic kidney disease (PKD) genes in China, determined the prevalence of cysts in the genital tract and accessory gonad in autosomal dominant PKD (ADPKD) patients, correlated these genes with ADPKD and male infertility and investigated whether male infertility associated with ADPKD affected the clinical outcomes in a preimplantation genetic testing (PGT) cycle cohort. This study was a cross-sectional study. Twenty-four unrelated men with ADPKD recruited from the Reproductive and Genetic Hospital of CITIC-Xiangya in China were investigated between January 2019 and December 2020. A total of 24 variations were identified in 22 patients, including 23, 1 and 0 variations in PKD1, PKD2 and GANAB, respectively. Genital tract and accessory gonadal cysts were significant dependent variables for male infertility. A diagnosis was made in 87.04% (94/108) and 51.85% (56/108) of the embryos for ADPKD and PGT-A respectively. Clinical pregnancy reached 72.73% per embryo transfer and 84.21% per patient. We identified a group of novel mutations in PKD genes, which enriches the PKD mutation spectrum. Although genital tract and accessory gonadal cysts greatly influence the fertility of men with ADPKD, they have minimal clinical consequences on pregnancy by intracytoplasmic sperm injection (ICSI) and PGT.

Epididymal cyst in children

The terms "epididymal cyst" and "spermatocele" are commonly used to describe the same entity, but, conversely, they are slightly different. Epididymal cyst is a benign mass, and it is more common than previously thought in prepubertal age. Pathogenic mechanisms for epididymal cyst have not been fully clarified yet, even if epididymal cysts have been reported in association with other malformations of the urinary tract or complex syndromes. Epididymal cyst is easily characterized and differentiated from spermatocele using ultrasound imaging. Conservative management constitutes the treatment of choice in the majority of cases, and surgery is recommended only in selected cases. Conclusion: To date, a review on epididymal cyst in childhood is lacking in the literature. Herein, an overview of knowledge about epididymal cyst in children has been carried out with particular attention to differential diagnosis, proper management, and practice guidelines for caregivers of children who may present with an epididymal cyst. What is Known: • Epididymal cyst is a benign sac in the testicles which is usually asymptomatic. • Epididymal cyst is easily diagnosed by ultrasound scans, and it is considered a self-limiting disease in the majority of cases. What is New: • Insight on differential diagnosis between epididymal cyst and spermatocele. • Valuable knowledge on the best management strategy for epididymal cyst and on practice guidelines for parents of children presenting with epididymal cyst.

Primary cilia: biosensors of the male reproductive tract

BACKGROUND

The primary cilium is a microtubule-based organelle that extends transiently from the apical cell surface to act as a sensory antenna. Initially viewed as a cellular appendage of obscure significance, the primary cilium is now acknowledged as a key coordinator of signaling pathways during development and in tissue homeostasis.

OBJECTIVES

The aim of this review was to present the structure and function of this overlooked organelle,with an emphasis on its epididymal context and contribution to male infertility issues.

MATERIALS AND METHODS

A systematic review has been performed in order to include main references relevant to the aforementioned topic.

RESULTS

Increasing evidence demonstrates that primary cilia dysfunctions are associated with impaired male reproductive system development and male infertility issues.

DISCUSSION

While a large amount of data exists regarding the role of primary cilia in most organs and tissues, few studies investigated the contribution of these organelles to male reproductive tract development and homeostasis.

CONCLUSION

Functional studies of primary cilia constitute an emergent and exciting new area in reproductive biology research.

Prostatic cyst in autosomal dominant polycystic kidney disease: unusual association

Prostate cyst, as an extrarenal manifestation in patients with autosomal dominant polycystic kidney disease, although infrequent, nevertheless goes beyond tenuous concomitance and may rarely contribute to recurrent urinary tract infection or outflow obstruction and mostly remains asymptomatic. In this context, we report a case of incidentally detected, an asymptomatic prostatic cyst in a patient of autosomal dominant polycystic kidney disease.

Relationship of Seminal Megavesicles, Prostate Median Cysts, and Genotype in Autosomal Dominant Polycystic Kidney Disease

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD) can involve prostate and seminal vesicles but the potential interrelationship of these findings and associations with PKD gene mutation locus and type is unknown.

PURPOSE

To determine the interrelationship of seminal megavesicles (seminal vesicles with lumen diameter > 10mm) and prostatic cysts in ADPKD and to determine whether there are associations with PKD gene mutations.

STUDY TYPE

Retrospective, case control.

POPULATION

Male ADPKD subjects (n = 92) with mutations in PKD1 (n = 71; 77%) or PKD2 (n = 21; 23%), and age/gender-matched controls without ADPKD (n = 92).

FIELD STRENGTH/SEQUENCE

1.5T, axial/coronal T₂ -weighted MR images.

ASSESSMENT

Reviewers blinded to genotype independently measured seminal vesicle lumen diameter and prevalence of cysts in prostate, kidney, and liver.

STATISTICAL TESTS

Nonparametric tests for group comparisons and univariate and multivariable logistic regression analyses to identify associations of megavesicles and prostate median cysts with mutations and renal/hepatic cyst burden.

RESULTS

Seminal megavesicles were found in 23 of 92 ADPKD (25%) subjects with PKD1 (22/71, 31%) or PKD2 (n = 1/21, 5%) mutations, but in only two control subjects (P < 0.0001). Prostate median cysts were found in 17/92 (18%) ADPKD subjects, compared with only 6/92 (7%) controls (P = 0.01), and were correlated with seminal vesicle diameters (ρ = 0.24, P = 0.02). Nonmedian prostate cyst prevalence was identical between ADPKD and controls (7/92, 8%). After adjusting for age, estimated glomerular filtration rate, and height-adjusted total kidney volume, ADPKD subjects with megavesicles were 10 times more likely to have a PKD1 than a PKD2 mutation. Among PKD1 subjects, seminal megavesicles occurred more frequently with nontruncating mutations with less severe kidney involvement.

DATA CONCLUSION

ADPKD is associated with prostate median cysts near ejaculatory ducts. These cysts correlate with seminal megavesicles (dilated to >10 mm) which predict a 10-fold greater likelihood of PKD1 vs. PKD2 mutation. Cysts elsewhere in the prostate are not related to ADPKD.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:894-903.

MR Imaging of the Prostate Gland

This article discusses MR imaging of the normal prostate and of disease conditions of the prostate including prostatitis, cystic lesions, amyloidosis, calculi, hematospermia, benign prostatic hyperplasia, and malignancy.

Intraparenchymal Epididymal Cyst (IEC) 4 cm in Diameter in a 15-Year Old Male Patient; a Case Report and Review of the Literature

Intraparenchymal epididymal cysts (IECs) are benign cystic formations of the epididymis of unknown pathogenesis, which typically appear in adolescence or adulthood. In patients older than 14 years old their prevalence is doubled. After systematic and thorough research of the current literature, we did not find another case report of intraparenchymal epididymal cyst with similar dimensions. The male patient, 15 years old, visited our outpatient department complaining of pain in the right hemiscrotum. Diagnosis of IEC was confirmed after the conduction of ultrasound examination. Patient underwent surgical exploration of the right hemiscrotum. Resection of the IEC followed. Postoperative course was uneventful, with recession of the symptoms. In our opinion, IECs should be surgically removed, either when they are symptomatic or when they are asymptomatic, but of a diameter greater than 1 cm and without regression tendency.

Seminal megavesicle in autosomal dominant polycystic kidney disease

Retrospective analysis of 99 male autosomal dominant polycystic kidney disease (ADPKD) patients compared to an age-matched control population showed seminal vesicle ectasia >10 mm (megavesicle) in 23% (23/99) of ADPKD patients that was not present in any controls (P<.0001). Median (range) seminal vesicle convoluted tubule diameter in ADPKD patients was 4.2 (1.7-30) mm compared to 3.1 (1.7-6.8) mm in controls (P<.0001). Discrete cysts were identified in four ADPKD patients but in none of the control population (P=.12). Seminal megavesicles may explain the infertility sometimes observed in male ADPKD patients.

Disruption of estrogen receptor signaling and similar pathways in the efferent ductules and initial segment of the epididymis

Seminiferous tubular atrophy may involve indirectly the disruption of estrogen receptor-α (ESR1) function in efferent ductules of the testis. ESR1 helps to maintain fluid resorption by the ductal epithelium and the inhibition or stimulation of this activity in rodent species will lead to fluid accumulation in the lumen. If not resolved, the abnormal buildup of fluid in the head of the epididymis and efferent ductules becomes a serious problem for the testis, as it leads to an increase in testis weight, tubular dilation and seminiferous epithelial degeneration, as well as testicular atrophy. The same sequence of pathogenesis occurs if the efferent ductule lumen becomes occluded. This review provides an introduction to the role of estrogen in the male reproductive tract but focuses on the various overlapping mechanisms that could induce efferent ductule dysfunction and fluid backpressure histopathology. Although efferent ductules are difficult to find, their inclusion in routine histological evaluations is recommended, as morphological images of these delicate tubules may be essential for understanding the mechanism of testicular injury, especially if dilations are observed in the rete testis and/or seminiferous tubules.

Signature Lesion:

The rete testis and efferent ductules can appear dilated, as if the lumens were greatly expanded with excess fluid or the accumulation of sperm. Because the efferent ductules resorb most of the fluid arriving from the rete testis lumen, one of two mechanisms is likely to be involved: a) reduced fluid uptake, which has been caused by the disruption in estrogen receptor signaling or associated pathways; or b) an increased rate of fluid resorption, which results in luminal occlusion. Both mechanisms can lead to a temporary increase in testicular weight, tubular dilation and atrophy of the seminiferous tubules.

Novel roles of Pkd2 in male reproductive system development

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common inherited genetic diseases, caused by mutations in PKD1 and/ or PKD2. Infertility and reproductive tract abnormalities in male ADPKD patients are very common and have higher incidence than in the general population. In this work, we reveal novel roles of Pkd2 for male reproductive system development. Disruption of Pkd2 caused dilation of mesonephric tubules/efferent ducts, failure of epididymal coiling, and defective testicular development. Deletion of Pkd2 in the epithelia alone was sufficient to cause reproductive tract defects seen in Pkd2(-/-) mice, suggesting that epithelial Pkd2 plays a pivotal role for development and maintenance of the male reproductive tract. In the testis, Pkd2 also plays a role in interstitial tissue and testicular cord development. In-depth analysis of epithelial-specific knockout mice revealed that Pkd2 is critical to maintain cellular phenotype and developmental signaling in the male reproductive system. Taken together, our data for the first time reveal novel roles for Pkd2 in male reproductive system development and provide new insights in male reproductive system abnormality and infertility in ADPKD patients.

Pkd1 is required for male reproductive tract development

Reproductive tract abnormalities and male infertility have higher incidence in ADPKD patients than in general populations. In this work, we reveal that Pkd1, whose mutations account for 85% of ADPKD cases, is essential for male reproductive tract development. Disruption of Pkd1 caused multiple organ defects in the murine male reproductive tract. The earliest visible defect in the Pkd1(-/-) reproductive tract was cystic dilation of the efferent ducts, which are derivatives of the mesonephric tubules. Epididymis development was delayed or arrested in the Pkd1(-/-) mice. No sign of epithelial coiling was seen in the null mutants. Disruption of Pkd1 in epithelium alone using the Pax2-cre mice was sufficient to cause efferent duct dilation and coiling defect in the epididymis, suggesting that Pkd1 is critical for epithelium development and maintenance in male reproductive tract. In-depth analysis showed that Pkd1 is required to maintain tubulin cytoskeleton and important for Tgf-β/Bmp signal transduction in epithelium of male reproductive tract. Altogether, our results for the first time provide direct evidence for developmental roles of Pkd1 in the male reproductive tract and provide new insights in reproductive tract abnormalities and infertility in ADPKD patients.

Male infertility and adult polycystic kidney disease--revisited: case report and current literature review

Adult polycystic kidney disease (APKD) is one of the most common inherited disorders affecting one in 800-1000 live births. Extra-renal manifestation of APKD is not uncommon. Cysts involving the male and female reproductive system have been reported. However, fertility is affected only in male subjects. Among cysts involving the reproductive system, seminal vesicle cysts have been reported to be the most common. The effect of seminal vesicle cysts on male fertility has been controversial. Current literature reports that majority of men remain fertile. However, uraemia and its implications on fertility and abnormal semen parameters in men with seminal vesicle cysts must be taken into consideration. We herein present two patients with APKD with contrasting semen parameters and also review the current literature.

Cystic dysplasia of the epididymis: a disorder of mesonephric differentiation associated with renal maldevelopment

The occurrence of congenital epididymal malformations with a cystic component has not been fully characterized. Most epididymal cysts occur later in life and are likely acquired. In addition, congenital malformations of the male excretory system are extremely uncommon in fetuses and neonates, and epididymal dysplastic changes have not been reported in these cases. In this study, we report 20 cases (including 19 fetal/neonatal autopsies and one surgical specimen from an older child) showing the same spectrum of histological findings in the epididymis, characterized by cystic ductal dilation with dysplastic ducts of variable diameters and irregular shapes, with ill-defined walls. Efferent ductules also showed dysplastic features. In addition, 18 cases had either renal and/or urinary tract anomalies, including renal dysplasia (eight), pelvicaliceal dilation (eight), renal agenesis (four) and hypoplasia (one), ureteral agenesis (two) and hypoplasia (one), urethra and bladder agenesis (two), prostate agenesis (two), and autosomal recessive polycystic renal disease (two). Our observations led to the recognition of a peculiar, not previously described congenital lesion of the epididymis, and we propose the term cystic dysplasia of the epididymis for this anomaly. Similar to what is observed in other male genital system anomalies (including malformations of the rete testis, vas deferens, and seminal vesicles), most lesions occurred in association with renal and/or urinary tract malformations, suggesting a spectrum of congenital malformations. The shared embryological origin of these structures may explain their simultaneous occurrence, possibly related to disrupted mesonephric duct development.

Extrarenal manifestations of autosomal dominant polycystic kidney disease

Although asymptomatic in most patients, extrarenal manifestations of ADPKD may become more clinically relevant with the increasing life expectancy of affected patients. They mainly encompass cysts in other organs than the kidney (liver: 94%, seminal vesicle: 40%, pancreas: 9%, arachnoid membrane: 8%, and spinal meningeal, 2%) and connective tissue abnormalities (mitral valve prolapse: 25%, intracranial aneurysms: 8%, and abdominal hernia: 10%). Their recognition may spare the patient from other, useless investigations (eg, when an arachnoid cyst is incidentally found) or lead to the implementation of prophylactic or therapeutic measures (eg, screening, sometimes followed by the treatment of an asymptomatic intracranial aneurysm in at-risk patients, or, in the presence of a severe polycystic liver disease, avoidance from estrogens and treatment aimed to slow cyst growth).

Treatment of autosomal dominant polycystic kidney disease (ADPKD): the new horizon for children with ADPKD

Polycystic kidney disease (PKD) is the most common inherited renal disorder. Patients with PKD remain clinically asymptomatic for decades, while significant anatomic and physiologic systemic changes take place. Sequencing of the responsible genes and identification of their protein products have significantly expanded our understanding of the pathophysiology of PKD. The molecular basis for cystogenesis is being unraveled, leading to new targets for therapy and giving hope to millions of people suffering from PKD. This has direct implications for children with PKD with regard to screening for the disease and identification of high-risk individuals. In this article we provide a review of the clinical manifestations in children with autosomal dominant polycystic kidney disease (ADPKD), the genetic and molecular basis for the disease, and a concise review of potential therapies being evaluated.

Prevalence of cysts in seminal tract and abnormal semen parameters in patients with autosomal dominant polycystic kidney disease

BACKGROUND AND OBJECTIVES

Autosomal dominant polycystic kidney disease is a systemic disorder with a wide range of extrarenal involvement. The scope of this study was to analyze the prevalence of seminal cysts and to correlate these findings with the sperm parameters in patients with autosomal dominant polycystic kidney disease.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A prospective study enrolled 30 adult men with autosomal dominant polycystic kidney disease. Of these 30 patients, 22 agreed to provide a semen sample for analysis, and 28 of 30 agreed to undergo an ultrasound rectal examination. Data obtained from the semen tests and from the ultrasound study were compared.

RESULTS

Cysts in the seminal tract were present in 10 (43.47%) of 28 individuals. Twenty of 22 patients showed abnormal semen parameters, with asthenozoospermia as the most common finding. No correlation between ultrasound findings and sperm abnormalities was observed.

CONCLUSIONS

The presence of cysts in the seminal tract is remarkably high (43.47%); however, this finding does not correlate with sperm abnormalities, which are also a frequent finding, especially asthenozoospermia. This semen abnormality is probably related to the abnormal function of polycystins. More attention should be paid to reproductive aspects in the initial evaluation of patients with autosomal dominant polycystic kidney disease before their ability to conceive is further impaired by uremia.

Hematospermia: imaging findings

Hematospermia is an anxiety provoking but otherwise generally benign and self-limited condition that is infrequently associated with significant underlying pathology, and is most often considered to be idiopathic in nature. Management with routine clinical evaluation, watchful waiting, and reassurance generally suffice without further diagnostic workup or treatment. Noninvasive imaging may play an important role in the diagnostic workup of men with hematospermia, particularly in those who are >40 years old, have other associated symptoms or signs of disease, or have persistence of hematospermia. Many entities may be encountered in association with hematospermia at imaging, and specific therapeutic interventions may be used if certain treatable underlying pathologies are coincidentally detected. In this comprehensive review, we discuss the potential etiologies, diagnostic workup, imaging techniques, relevant male pelvic anatomy, imaging appearance of specific associated pathologies, and treatment for hematospermia.

Clinical Laboratory Evaluation of Male Subfertility

Male subfertility is a common problem with a complex etiology, requiring a complete andrological work-up for proper diagnosis. The male reproductive tract is controlled by a well-balanced hormonal system, in which hypothalamic (GnRH), pituitary (LH, FSH) and testicular hormones (androgens, inhibin B) participate. Any disturbance of this hormonal system may therefore lead to testicular dysfunction and interfere with the spermatogenesis process. In addition, also other components along the ductal system, such as epididymis, prostate and seminal vesicles, that improve sperm fertility by contributing their secretions to the semen, might function inadequately and thus fail to enhance the fertilizing capacity of the sperm cells. External factors (heat, chemicals, life style) and anatomical abnormalities (varicocele) were shown to have a negative influence on male fertility. In a number of patients genetic defects can be identified as the cause of their infertility. Laboratory tests are available to assess hormone concentrations, semen composition, accessory gland function and sperm cell function. Conventional semen analysis includes the determination of sperm concentration, semen volume, sperm motility (qualitative and quantitative), sperm morphology, sperm cell vitality, pH, leucocytes and antibodies. The usefulness of the determination of these parameters as predictor of fertility appears to be rather limited, however. Therefore, alternative tests, some based on more functional aspects (sperm penetration, capacitation, acrosome reaction), have been developed. Furthermore, there is an increasing attention for the assessment of DNA integrity, for instance by the flowcytometer-based Sperm Chromation Structure Assay (SCSA), as an additional or alternative parameter of sperm quality. It is likely and desirable that further assays with better predictive value are being developed in the near future.

Polycystins and mechanosensation in renal and nodal cilia

The external surfaces of the human body, as well as its internal organs, constantly experience different kinds of mechanical stimulations. For example, tubular epithelial cells of the kidney are continuously exposed to a variety of mechanical forces, such as fluid flow shear stress within the lumen of th nephron. The majority of epithelial cells along the nephron, except intercalated cells, possess a primary cilium, an organelle projecting from the cell's apical surface into the luminal space. Despite its discovery over 100 years ago, the primary cilium's function continued to elude researchers for many decades. However, recent studies indicate that renal cilia have a sensory function. Studies on polycystic kidney disease (PKD) have identified many of the molecular players, which should help solve the mystery of how the renal cilium senses fluid flow. In this review, we will summarize the recent breakthroughs in PKD research and discuss the role(s) of the polycystin signaling complex in mediating mechanosensory function by the primary cilium of renal epithelium as well as of the embryonic node.

Polycystin-1L2 is a novel G-protein-binding protein

Mutations in genes encoding polycystin-1 (PC1) and polycystin-2 cause autosomal dominant polycystic kidney disease. The polycystin protein family is composed of Ca2+-permeable pore-forming subunits and receptor-like integral membrane proteins. Here we describe a novel member of the polycystin-1-like subfamily, polycystin-1L2 (PC1L2), encoded by PKD1L2, which has various alternative splicing forms with two translation initiation sites. PC1L2 short form starts in exon 12 of the long form. The longest open reading frame of PKD1L2 short form, determined from human testis cDNA, encodes a 1775-amino-acid protein and 32 exons, whereas the long form is predicted to encode a 2460-residue protein. Both forms have a small receptor for egg jelly domain, a G-protein-coupled receptor proteolytic site, an LH2/PLAT, and 11 putative transmembrane domains, as well as a number of rhodopsin-like G-protein-coupled receptor signatures. RT-PCR analysis shows that the short form, but not the long form, of human PKD1L2 is expressed in the developing and adult heart and kidney. Furthermore, by GST pull-down assay we observed that PC1L2 and polycystin-1L1 are able to bind to specific G-protein subunits. We also show that PC1 C-terminal cytosolic domain binds to Galpha12, Galphas, and Galphai1, while it weakly interacts with Galphai2. Our results indicate that both PC1-like molecules may act as G-protein-coupled receptors.

Psoriatic arthritis associated with adult polycystic kidney disease, seminal vesicle, and epididymal cysts

Patients with seminal vesicle and epididymal cysts are mostly asymptomatic. To date, only one patient presenting with bloody ejaculate and acute scrotum has been reported. Different extrarenal manifestations and the association of adult polycystic kidney disease (APKD) with some connective tissue diseases are known. We report on a 60-year-old male patient with bloody ejaculate and acute scrotum who had been diagnosed as having APKD 1 year earlier and whose past medical history revealed inflammatory low back pain, psoriasis, and the diagnosis of psoriatic arthritis. Cultures of urine and ejaculate were sterile, and the patient's renal functions were normal. Ultrasound showed epididymal and seminal vesicle cysts in addition to hepatic and renal cysts. Our case is the first in which psoriatic arthritis accompanied APKD, seminal vesicle cysts, and epididymal cysts. We also review other APKD cases that have accompanied seminal vesicle cysts.

Recent advances in the cell biology of polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is a significant familial disorder, crossing multiple ethnicities as well as organ systems. The goal of understanding and, ultimately, curing ADPKD has fostered collaborative efforts among many laboratories, mustered on by the opportunity to probe fundamental cellular biology. Here we review what is known about ADPKD including well-accepted data such as the identification of the causative genes and the fact that PKD1 and PKD2 act in the same pathway, fairly well-accepted concepts such as the "two-hit hypothesis," and somewhat confusing information regarding polycystin-1 and -2 localization and protein interactions. Special attention is paid to the recently discovered role of the cilium in polycystic kidney disease and the model it suggests. Studying ADPKD is important, not only as an evaluation of a multisystem disorder that spans a lifetime, but as a testament to the achievements of modern biology and medicine.