Prevalence of cysts in seminal tract and abnormal semen parameters in patients with 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.

Wall Tension and Tubular Resistance in Kidney Cystic Conditions

The progressive formation of single or multiple cysts accompanies several renal diseases. Specifically, (i) genetic forms, such as adult dominant polycystic kidney disease (ADPKD), and (ii) acquired cystic kidney disease (ACKD) are probably the most frequent forms of cystic diseases. Adult dominant polycystic kidney disease (ADPKD) is a genetic disorder characterized by multiple kidney cysts and systemic alterations. The genes responsible for the condition are known, and a large amount of literature focuses on the molecular description of the mechanism. The present manuscript shows that a multiscale approach that considers supramolecular physical phenomena captures the characteristics of both ADPKD and acquired cystic kidney disease (ACKD) from the pathogenetic and therapeutical point of view, potentially suggesting future treatments. We first review the hypothesis of cystogenesis in ADPKD and then focus on ACKD, showing that they share essential pathogenetic features, which can be explained by a localized obstruction of a tubule and/or an alteration of the tubular wall tension. The consequent tubular aneurysms (cysts) follow Laplace's law. Reviewing the public databases, we show that ADPKD genes are widely expressed in various organs, and these proteins interact with the extracellular matrix, thus potentially modifying wall tension. At the kidney and liver level, the authors suggest that altered cell polarity/secretion/proliferation produce tubular regions of high resistance to the urine/bile flow. The increased intratubular pressure upstream increases the difference between the inside (Pi) and the outside (Pe) of the tubules (∆P) and is counterbalanced by lower wall tension by a factor depending on the radius. The latter is a function of tubule length. In adult dominant polycystic kidney disease (ADPKD), a minimal reduction in the wall tension may lead to a dilatation in the tubular segments along the nephron over the years. The initial increase in the tubule radius would then facilitate the progressive expansion of the cysts. In this regard, tubular cell proliferation may be, at least partially, a consequence of the progressive cysts' expansion. This theory is discussed in view of other diseases with reduced wall tension and with cysts and the therapeutic effects of vaptans, somatostatin, SGLT2 inhibitors, and potentially other therapeutic targets.

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.

Rapidly Progressing to ESRD in an Individual with Coexisting ADPKD and Masked Klinefelter and Gitelman Syndromes

Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenetic hereditary renal disease, promoting end-stage renal disease (ESRD). Klinefelter syndrome (KS) is a consequence of an extra copy of the X chromosome in males. Main symptoms in KS include hypogonadism, tall stature, azoospermia, and a risk of cardiovascular diseases, among others. Gitelman syndrome (GS) is an autosomal recessive disorder caused by SLC12A3 variants, and is associated with hypokalemia, hypomagnesemia, hypocalciuria, normal or low blood pressure, and salt loss. The three disorders have distinct and well-delineated clinical, biochemical, and genetic findings. We here report a male patient with ADPKD who developed early chronic renal failure leading to ESRD, presenting with an intracranial aneurysm and infertility. NGS identified two de novo PKD1 variants, one known (likely pathogenic), and a previously unreported variant of uncertain significance, together with two SLC12A3 pathogenic variants. In addition, cytogenetic analysis showed a 47, XXY karyotype. We investigated the putative impact of this rare association by analyzing possible clinical, biochemical, and/or genetic interactions and by comparing the evolution of renal size and function in the proband with three age-matched ADPKD (by variants in PKD1) cohorts. We hypothesize that the coexistence of these three genetic disorders may act as modifiers with possible synergistic actions that could lead, in our patient, to a rapid ADPKD progression.

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.

Genetic underpinnings of asthenozoospermia

Asthenozoospermia (AZS), defined by reduced motility or absent sperm motility, is one of the main causes of male infertility. This condition may be divided into isolated AZS in the absence of other symptoms and syndromic AZS, which is characterized by several concurrent clinical symptoms. Sperm motility depends on fully functional flagellum, energy availability, and the crosstalk of several signaling pathways; therefore, mutations in genes involved in flagellar assembly and motile regulation can cause AZS. Thus, it is crucial to understand the genetic causes and mechanisms contributing to AZS. In this review, we summarize the current knowledge about the particular genes and mechanisms involved in intact flagellum, energy availability, and signaling transduction that could cause human AZS and discuss the respective gene defects known to be responsible for these abnormalities. Additionally, we discuss intracytoplasmic sperm injection outcomes and offspring health where available in these cases.

Reproduction Function in Male Patients With Bardet Biedl Syndrome

PURPOSE

Bardet-Biedl syndrome (BBS) is a ciliopathy with a wide spectrum of symptoms due to primary cilia dysfunction, including genitourinary developmental anomalies as well as impaired reproduction, particularly in males. Primary cilia are known to be required at the following steps of reproduction function: (i) genitourinary organogenesis, (ii) in fetal firing of hypothalamo-pituitary axe, (iii) sperm flagellum structure, and (iv) first zygotic mitosis conducted by proximal sperm centriole. BBS phenotype is not fully understood.

METHODS

This study explored all steps of reproduction in 11 French male patients with identified BBS mutations.

RESULTS

BBS patients frequently presented with genitourinary malformations, such as cryptorchidism (5/11), short scrotum (5/8), and micropenis (5/8), but unexpectedly, with normal testis size (7/8). Ultrasonography highlighted epididymal cysts or agenesis of one seminal vesicle in some cases. Sexual hormones levels were normal in all patients except one. Sperm numeration was normal in 8 out of the 10 obtained samples. Five to 45% of sperm presented a progressive motility. Electron microscopy analysis of spermatozoa did not reveal any homogeneous abnormality. Moreover, a psychological approach pointed to a decreased self-confidence linked to blindness and obesity explaining why so few BBS patients express a child wish.

CONCLUSIONS

Primary cilia dysfunction in BBS impacts the embryology of the male genital tract, especially epididymis, penis, and scrotum through an insufficient fetal androgen production. However, in adults, sperm structure does not seem to be impacted. These results should be confirmed in a greater BBS patient cohort, focusing on fertility.

Factors influencing the clinical outcome of preimplantation genetic testing for polycystic kidney disease

STUDY QUESTION

What are the factors influencing the success rate for couples undergoing preimplantation genetic testing (PGT) for polycystic kidney disease (PKD)?

SUMMARY ANSWER

In our study cohort, the live birth delivery rate is significantly associated with female age while the male infertility accompanying autosomal dominant PKD (ADPKD) does not substantially affect the clinical outcome.

WHAT IS KNOWN ALREADY

While women with ADPKD have no specific fertility problems, male ADPKD patients may present with reproductive system abnormalities and infertility.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study involves 91 PGT cycles for PKD for 43 couples (33 couples for PKD1, 2 couples for PKD2 and 8 couples for autosomal recessive PKD (ARPKD)) from January 2005 until December 2016 with follow-up of transfers until end of 2017.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Sixteen single-cell clinical tests for PKD based on multiplex PCR of short tandem repeat markers, with or without a specific mutation were developed and applied for diagnosis of 584 Day 3 cleavage stage embryos. In 18 couples, the male partner was affected with ADPKD (=Group A) and 12 of them had a documented infertility status. Group A underwent 52 cycles to oocyte retrieval. For 18 other couples, the female partner was affected with ADPKD (=Group B) and four male partners from this group had a documented history of infertility. This group underwent 31 cycles to OR.

MAIN RESULTS AND THE ROLE OF CHANCE

Genetic analysis resulted in 545 embryos (93.3%) with a diagnosis, of which 215 (36.8%) were genetically transferable. Transfer of 74 embryos in 53 fresh cycles and of 34 cryopreserved embryos in 33 frozen-warmed embryo transfer cycles resulted in a live birth delivery rate of 38.4% per transfer with 31 singleton live births, two twin live births and one ongoing pregnancy. The observed cumulative delivery rate was 57.8% per couple after five treatment cycles. Thirty cryopreserved embryos still remain available for transfer. The clinical pregnancy rate per transfer (fresh + frozen; 45.9% in group A versus 60.0% in group B, P < 0.05) and the live birth delivery rate per transfer (fresh + frozen; 27.0% in group A versus 42.9% in group B, P < 0.05) was significantly lower for couples with the male partner affected with ADPKD compared with couples with the female partner affected with ADPKD. However, a multivariate logistic regression analysis showed that only female age was associated with live birth delivery rate (odds ratio = 0.87; 95% CI: 0.77-0.99; P = 0.032).

LIMITATIONS, REASONS FOR CAUTION

This study is based on retrospective data from a single centre with Day 3 one-cell and two-cell biopsy. Further analysis of a larger cohort of PKD patients undergoing PGT is required to determine the impact of male infertility associated with ADPKD on the cumulative results.

WIDER IMPLICATIONS OF THE FINDINGS

Knowledge about factors affecting the clinical outcome after PGT can be a valuable tool for physicians to counsel PKD patients about their reproductive options. Males affected with ADPKD who suffer from infertility should be advised to seek treatment in time to improve their chances of conceiving a child.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was obtained. There are no competing interests to declare.

TRIAL REGISTRATION NUMBER

Not applicable.

Combined Preimplantation Genetic Testing for Autosomal Dominant Polycystic Kidney Disease: Consequences for Embryos Available for Transfer

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease and presents with genetic and clinical heterogeneity. ADPKD can also manifest extra-renally, and seminal cysts have been associated with male infertility in some cases. ADPKD-linked male infertility, along with female age, have been proposed as factors that may influence the clinical outcomes of preimplantation genetic testing (PGT) for monogenic disorders (PGT-M). Large PGT for aneuploidy assessment (PGT-A) studies link embryo aneuploidy to increasing female age; other studies suggest that embryo aneuploidy is also linked to severe male-factor infertility. We aimed to assess the number of aneuploid embryos and the number of cycles with transferable embryos in ADPKD patients after combined-PGT. The combined-PGT protocol, involving PGT-M by PCR and PGT-A by next-generation sequencing, was performed in single trophectoderm biopsies from 289 embryos in 83 PGT cycles. Transferable embryos were obtained in 69.9% of cycles. The number of aneuploid embryos and cycles with transferable embryos did not differ when the male or female had the ADPKD mutation. However, a significantly higher proportion of aneuploid embryos was found in the advanced maternal age (AMA) group, but not in the male factor (MF) group, when compared to non-AMA and non-MF groups, respectively. Additionally, no significant differences in the percentage of cycles with transferable embryos were found in any of the groups. Our results indicate that AMA couples among ADPKD patients have an increased risk of aneuploid embryos, but ADPKD-linked male infertility does not promote an increased aneuploidy rate.

MRI findings of obstructive azoospermia: lesions in and out of pelvic cavity

Obstructive azoospermia (OA) is caused by excurrent duct obstruction, which can occur anywhere along the course of the male reproductive tract and is classically characterized by normal spermatogenesis. To be familiar with the imaging anatomy of normal and abnormal male genital ducts is essential to the diagnosis of OA. In some circumstances, OA can also be related to some specific syndromes; thus, making an accurate diagnosis may require an integral view of the whole abdomen and pelvis. MR is a great complementary imaging modality either for the detection of obstructive factors, especially for characterization of those indeterminate features on ultrasound, or for the identification of specific syndromes related to OA. In this article, a series of patients with OA caused by different kinds of lesions in and out of the pelvic cavity (abdomen) shown on MR imaging were included, and some cases of specific syndromes related to OA were also reviewed.

Mass Spectrometry-Based Analysis of TRPP2 Phosphorylation

Differential phosphorylation of proteins is a key regulatory mechanism in biology. Immunoprecipitation-coupled mass spectrometry facilitates the targeted analysis of transient receptor ion potential channel polycystin-2 (TRPP2) phosphorylation. However, empirical testing is required to optimize experimental conditions for immunoprecipitation and mass spectrometry. Here, we present a detailed workflow for the reliable analysis of endogenous TRPP2 phosphorylation in differentiated renal epithelial cells.

Clinical characteristics of individual organ system disease in non-motile ciliopathies

Non-motile ciliopathies (disorders of the primary cilia) include autosomal dominant and recessive polycystic kidney diseases, nephronophthisis, as well as multisystem disorders Joubert, Bardet-Biedl, Alström, Meckel-Gruber, oral-facial-digital syndromes, and Jeune chondrodysplasia and other skeletal ciliopathies. Chronic progressive disease of the kidneys, liver, and retina are common features in non-motile ciliopathies. Some ciliopathies also manifest neurological, skeletal, olfactory and auditory defects. Obesity and type 2 diabetes mellitus are characteristic features of Bardet-Biedl and Alström syndromes. Overlapping clinical features and molecular heterogeneity of these ciliopathies render their diagnoses challenging. In this review, we describe the clinical characteristics of individual organ disease for each ciliopathy and provide natural history data on kidney, liver, retinal disease progression and central nervous system function.

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.

A novel frameshift PKD1 mutation in a Chinese patient with autosomal dominant polycystic kidney disease and azoospermia: A case report

Autosomal dominant polycystic kidney disease (ADPKD) is primarily caused by mutations in polycystin 1, transient receptor potential channel interacting (PKD1) and PKD2, and characterized by numerous cysts in various organs, primarily the kidneys and liver. The present case report is on a 33-year-old Chinese male patient who suffered from abdominal pain and hypertension, and presented with long-term infertility. Laboratory tests indicated that the patient had a normal renal function, while abdominal computed tomography demonstrated that the patient had enlarged kidneys with a volume of 1,127.21 cm³. In a semen analysis, no sperm was detected, while a subsequent testicular biopsy analysis demonstrated numerous mature sperms with progressive motility which suggests that the cysts of the epididymis and the dilated seminal vesicles may have obstructed the ejaculation of semen. Genetic testing identified that a novel missense mutation (c.9053delT) that was responsible for the disease. ADPKD has various disease severities, which depend on whether there is a PKD1 or PKD2 mutation and whether the mutation impairs the function of the polycystin protein. Therefore, genetic testing is important for the clinical diagnosis and prognosis of ADPKD patients, as well as prenatal diagnosis.

Novel mutations of PKD genes in Chinese patients suffering from autosomal dominant polycystic kidney disease and seeking assisted reproduction

Background

Autosomal dominant polycystic kidney disease (ADPKD), the commonest inherited kidney disease, is generally caused by heterozygous mutations in PKD1, PKD2, or GANAB (PKD3).

Methods

We performed mutational analyses of PKD genes to identify causative mutations. A set of 90 unrelated families with ADPKD were subjected to mutational analyses of PKD genes. Genes were analysed using long-range PCR (LR-PCR), direct PCR sequencing, followed by multiplex ligation-dependent probe amplification (MLPA) or screening of GANAB for some patients. Semen quality was assessed for 46 male patients, and the correlation between mutations and male infertility was analysed.

Results

A total of 76 mutations, including 38 novel mutations, were identified in 77 families, comprising 72 mutations in PKD1 and 4 in PKD2, with a positive detection rate of 85.6%. No pathogenic mutations of GANAB were detected. Thirty-seven patients had low semen quality and were likely to be infertile. No association was detected between PKD1 mutation type and semen quality. However, male patients carrying a pathogenic mutation in the Ig-like repeat domain of PKD1 had a high risk of infertility.

Conclusion

Our study identified a group of novel mutations in PKD genes, which enrich the PKD mutation spectrum and might help clinicians to make precise diagnoses, thereby allowing better family planning and genetic counselling. Men with ADPKD accompanied by infertility should consider intracytoplasmic sperm injection combined with preimplantation genetic diagnosis to achieve paternity and obtain healthy progeny.

Electronic supplementary material

The online version of this article (10.1186/s12881-018-0693-7) contains supplementary material, which is available to authorized users.

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.

The spectrum of renal involvement in male patients with infertility related to excretory-system abnormalities: phenotypes, genotypes, and genetic counseling

BACKGROUND

While reproductive technologies are increasingly used worldwide, epidemiologic, clinical and genetic data regarding infertile men with combined genital tract and renal abnormalities remain scarce, preventing adequate genetic counseling.

METHODS

In a cohort-based study, we assessed the prevalence (1995-2014) and the clinical characteristics of renal disorders in infertile males with genital tract malformation. In a subset of 34 patients, we performed a detailed phenotype analysis of renal and genital tract disorders.

RESULTS

Among the 180 patients with congenital uni- or bilateral absence of vas deferens (CU/BAVD), 45 (25 %) had a renal malformation. We also identified 14 infertile men with combined seminal vesicle (SV) and renal malformation but no CU/BAVD. Among the 34 patients with detailed clinical description, renal disease was unknown before the assessment of the infertility in 27 (79.4 %), and 7 (20.6 %) had chronic renal failure. Four main renal phenotypes were observed: solitary kidney (47 %); autosomal-dominant polycystic kidney disease (ADPKD, 0.6 %); uni- or bilateral hypoplastic kidneys (20.6 %); and a complex renal phenotype associated with a mutation of the HNF1B gene (5.8 %). Absence of SV and azoospermia were significantly associated with the presence of a solitary kidney, while dilatation of SV and necroasthenozoospermia were suggestive of ADPKD.

CONCLUSION

A dominantly inherited renal disease (ADPKD or HNF1B-related nephropathy) is frequent in males with infertility and combined renal and genital tract abnormalities (26 %). A systematic renal screening should be proposed in infertile males with CU/BAVD or SV disorders.

Targeted rescue of a polycystic kidney disease mutation by lysosomal inhibition

Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenic cause of end-stage renal disease. The molecular pathogenesis of ADPKD is not completely known, and there is no approved therapy. To date, there is limited knowledge concerning the molecular consequences of specific disease-causing mutations. Here we show that the ADPKD missense variant TRPP2(D511V) greatly reduces TRPP2 protein stability, and that TRPP2(D511V) function can be rescued in vivo by small molecules targeting the TRPP2 degradation pathway. Expression of the TRPP2(D511V) protein was significantly reduced compared to wild-type TRPP2. Inhibition of lysosomal degradation of TRPP2(D511V) by the US Food and Drug Administration (FDA)-approved drug chloroquine strongly increased TRPP2 protein levels in vitro. The validation of these results in vivo requires appropriate animal models. However, there are currently no mouse models harboring human PKD2 missense mutations, and screening for chemical rescue of patient mutations in rodent models is time-consuming and expensive. Therefore, we developed a Drosophila melanogaster model expressing the ortholog of TRPP2(D511V) to test chemical rescue of mutant TRPP2 in vivo. Notably, chloroquine was sufficient to improve the phenotype of flies expressing mutant TRPP2. Thus, this proof-of-concept study highlights the potential of directed therapeutic approaches for ADPKD, and provides a rapid-throughput experimental model to screen PKD2 patient mutations and small molecules in vivo.

Identification of an NPHP1 deletion causing adult form of nephronophthisis

AIMS

Nephronophthisis (NPHP) is an autosomal recessive cystic disease of the kidney with main characteristic features of polyuria/polydipsia, mild or absent proteinuria, interstitial fibrosis, and tubular cysts. NPHP is responsible for 5-10 % of inheritable end-stage renal disease (ESRD) cases. We investigated the clinical features and genetic cause of NPHP in a Persian family with three siblings affected by tubulointerstitial nephropathy reaching ESRD in adulthood.

METHODS

Uromodulin (UMOD), known to be involved in adult medullary cystic kidney disease, and nephronophthisis 1 (NPHP1) were investigated in the genomic DNA of the probands using DNA sequencing, multiplex ligation-dependent probe amplification (MLPA) analysis and molecular karyotyping.

RESULTS

No mutation was detected in UMOD. Copy number variation analysis of the NPHP1 gene using the commercially available MLPA kit identified a recurrent large homozygous deletion encompassing all NPHP1 exons. The parents were heterozygous for this deletion. Whole genome array-CGH analysis confirmed a homozygous deletion on chromosome 2q13, NPHP1 site, and revealed that the size of the copy number loss was approximately 102 Kbp.

CONCLUSION

This is the first report of determination of an NPHP1 deletion size using routine diagnostic methods. The results of this study expand the knowledge about the genotype-phenotype correlations in NPHP1, and have implications for genetic counseling and family planning advice for other affected families. This is the first molecular analysis of NPHP1 in an Iranian kindred.

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.

Stimulation of human damaged sperm motility with hydrogen molecule

Background

Sperm motility is a critical factor in male fertility. Low motility can be caused by a variety factors including abnormal spermatogenesis, oxidative damage, or depletion of intracellular ATP. Recent findings indicate that hydrogen molecule (H₂) selectively reduces toxic reactive oxygen species. In this study, we investigated the effects of H₂ on human sperm motility in vitro.

Methods

Experimentally damaged sperm suspensions from patients left at room temperature for > 5 days or frozen immediately after ejaculation were used. After exposure with H₂, their forward motility was measured with a counting chamber. A time-lapse movie was recorded to analyze sperm swimming speed. Mitochondria were stained with a membrane potential-sensitive dye.

Results

H₂ treatment significantly improved the rate of forward motility, whereas treatment with nitrogen gas did not. While treatment for 30 min was sufficient to improve motility, it did not affect sperm swimming speed. After 24 h, retreatment with H₂ increased the motility again. H₂ treatment also increased mitochondrial membrane potential. Forward motility of low motile frozen-thawed sperm from patients significantly improved with cleavage medium containing H₂.

Conclusions

Our results illustrated that H₂ treatment stimulates low sperm motility. H₂ is a new promising tool for male infertility treatments.

Spanish guidelines for the management of autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is the most frequent cause of genetic renal disease and accounts for 6-10% of patients on renal replacement therapy (RRT). Very few prospective, randomized trials or clinical studies address the diagnosis and management of this relatively frequent disorder. No clinical guidelines are available to date. This is a consensus statement presenting the recommendations of the Spanish Working Group on Inherited Kidney Diseases, which were agreed to following a literature search and discussions. Levels of evidence found were C and D according to the Centre for Evidence-Based Medicine (University of Oxford). The recommendations relate to, among other topics, the use of imaging and genetic diagnosis, management of hypertension, pain, cyst infections and bleeding, extra-renal involvement including polycystic liver disease and cranial aneurysms, management of chronic kidney disease (CKD) and RRT and management of children with ADPKD. Recommendations on specific ADPKD therapies are not provided since no drug has regulatory approval for this indication.

Lesions of the Seminal Vesicles and their MRI Characteristics

Over the past few decades, MRI of the prostate has made great strides in improving cancer detection and is being embraced by more clinicians each day. This article aims to review the imaging characteristics of common and uncommon, but consequential lesions involving the seminal vesicles (SV), as seen predominantly on MRI. Many of these findings are seen incidentally during imaging of the prostate. Anatomy and embryology of the SV will be described which will help illustrate the associations of abnormalities seen. Congenital, infectious, neoplastic, and tumor mimics will be explored in detail, with discussion on clinical presentation and treatment strategies.

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.

Renal transplantation in autosomal dominant polycystic kidney disease

In patients with autosomal dominant polycystic kidney disease (ADPKD) evaluated for kidney transplantation, issues related to native nephrectomy, cystic liver involvement, screening for intracranial aneurysms and living-related kidney donation deserve special consideration. Prophylactic native nephrectomy is restricted to patients with a history of cyst infection or recurrent haemorrhage or to those in whom space must be made to implant the graft. Patients with liver involvement require pretransplant imaging. Selection of patients for pretransplant screening of intracranial aneurysms should follow the general recommendations for patients with ADPKD. In living related-donor candidates aged <30 years and at-risk of ADPKD, molecular genetic testing should be carried out when ultrasonography and MRI findings are normal or equivocal. After kidney transplantation, patient and graft survival rates are excellent and the volume of native kidneys decreases. However, liver cysts continue to grow and treatment with a somatostatin analogue should be considered in patients with massive cyst involvement. Cerebrovascular events have a marginal effect on post-transplant morbidity and mortality. An increased risk of new-onset diabetes mellitus and nonmelanoma skin cancers has been reported, but several studies have challenged these findings. Finally, no data currently support the preferential use of mammalian target of rapamycin inhibitors as immunosuppressive agents in transplant recipients with ADPKD.

Polycystic liver disease: an overview of pathogenesis, clinical manifestations and management

Polycystic liver disease (PLD) is the result of embryonic ductal plate malformation of the intrahepatic biliary tree. The phenotype consists of numerous cysts spread throughout the liver parenchyma. Cystic bile duct malformations originating from the peripheral biliary tree are called Von Meyenburg complexes (VMC). In these patients embryonic remnants develop into small hepatic cysts and usually remain silent during life. Symptomatic PLD occurs mainly in the context of isolated polycystic liver disease (PCLD) and autosomal dominant polycystic kidney disease (ADPKD). In advanced stages, PCLD and ADPKD patients have massively enlarged livers which cause a spectrum of clinical features and complications. Major complaints include abdominal pain, abdominal distension and atypical symptoms because of voluminous cysts resulting in compression of adjacent tissue or failure of the affected organ. Renal failure due to polycystic kidneys and non-renal extra-hepatic features are common in ADPKD in contrast to VMC and PCLD. In general, liver function remains prolonged preserved in PLD. Ultrasonography is the first instrument to assess liver phenotype. Indeed, PCLD and ADPKD diagnostic criteria rely on detection of hepatorenal cystogenesis, and secondly a positive family history compatible with an autosomal dominant inheritance pattern. Ambiguous imaging or screening may be assisted by genetic counseling and molecular diagnostics. Screening mutations of the genes causing PCLD (PRKCSH and SEC63) or ADPKD (PKD1 and PKD2) confirm the clinical diagnosis. Genetic studies showed that accumulation of somatic hits in cyst epithelium determine the rate-limiting step for cyst formation. Management of adult PLD is based on liver phenotype, severity of clinical features and quality of life. Conservative treatment is recommended for the majority of PLD patients. The primary aim is to halt cyst growth to allow abdominal decompression and ameliorate symptoms. Invasive procedures are required in a selective patient group with advanced PCLD, ADPKD or liver failure. Pharmacological therapy by somatostatin analogues lead to beneficial outcome of PLD in terms of symptom relief and liver volume reduction.

Case study: polycystic livers in a transgenic mouse line

Three mice (2 male, 1 female; age, 5 to 16 mo) from a mouse line transgenic for keratin 14 (K14)-driven LacZ expression and on an outbred Crl:CD1(ICR) background, were identified as having distended abdomens and livers that were diffusely enlarged by numerous cysts (diameter, 0.1 to 2.0 cm). Histopathology revealed hepatic cysts lined by biliary type epithelium and mild chronic inflammation, and confirmed the absence of parasites. Among 21 related mice, 5 additional affected mice were identified via laparotomy. Breeding of these 5 mice (after 5 mo of age) did not result in any offspring; the K14 mice with polycystic livers failed to reproduce. Affected male mice had degenerative testicular lesions, and their sperm was immotile. Nonpolycystic K14 control male mice bred well, had no testicular lesions, and had appropriate sperm motility. Genetic analysis did not identify an association of this phenotype with the transgene or insertion site.

Extra-renal manifestations of autosomal dominant polycystic kidney disease (ADPKD): considerations for routine screening and management

Autosomal-dominant polycystic kidney disease (ADPKD) is a systemic disease, marked by progressive increase of bilateral renal cysts, resulting in chronic kidney disease (CKD) and often leading to end-stage renal disease (ESRD). Apart from renal cysts, patients often have extra-renal disease, involving the liver, heart and vasculature. Other less common but equally important extra-renal manifestations of ADPKD include diverticular disease, hernias, male infertility and pain. Extra-renal disease burden is often asymptomatic, but may result in increased morbidity and mortality. If the disease burden is significant, screening may prove beneficial. We review the rationale for current screening recommendations and propose some guidelines for screening and management of 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.

Diagnosis and management of polycystic liver disease

Polycystic liver disease (PLD) is arbitrarily defined as a liver that contains >20 cysts. The condition is associated with two genetically distinct diseases: as a primary phenotype in isolated polycystic liver disease (PCLD) and as an extrarenal manifestation in autosomal dominant polycystic kidney disease (ADPKD). Processes involved in hepatic cystogenesis include ductal plate malformation with concomitant abnormal fluid secretion, altered cell-matrix interaction and cholangiocyte hyperproliferation. PLD is usually a benign disease, but can cause debilitating abdominal symptoms in some patients. The main risk factors for growth of liver cysts are female sex, exogenous oestrogen use and multiple pregnancies. Ultrasonography is very useful for achieving a correct diagnosis of a polycystic liver and to differentiate between ADPKD and PCLD. Current radiological and surgical therapies for symptomatic patients include aspiration-sclerotherapy, fenestration, segmental hepatic resection and liver transplantation. Medical therapies that interact with regulatory mechanisms controlling expansion and growth of liver cysts are under investigation. Somatostatin analogues are promising; several clinical trials have shown that these drugs can reduce the volume of polycystic livers. The purpose of this Review is to provide an update on the diagnosis and management of PLD with a focus on literature published in the past 4 years.

Microarray analysis of microRNA expression patterns in the semen of infertile men with semen abnormalities

MicroRNAs (miRNAs) play a crucial role in tissue development and the pathology of many diseases, however, the effects and roles of miRNAs in the development of semen abnormalities in infertile males have not yet been investigated. In this study, we analyzed and compared the miRNA expression profiles of abnormal semen from 86 infertile males with normal semen from 86 healthy males using an miRNA microarray. In total, 52 miRNAs were differentially expressed between the abnormal semen of infertile males and the normal semen of healthy males. The differential expression of selected miRNAs was validated by real time qRT-PCR and northern blotting: miR-574-5p, miR-297, miR-122, miR-1275, miR-373, miR-185 and miR-193b were upregulated (fold change>1.5, p<0.001) and miR-100, miR-512-3p, miR-16, miR-19b, miR-23b and miR-26a were downregulated (fold change<0.667, p<0.001) in the semen of infertile males with semen abnormalities. In conclusion, this study provides new insights into specific miRNAs that are associated with semen abnormalities in infertile males.

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.

Seminal vesicle cysts causing pelvic pain: importance of computed tomography

A seminal vesicle cyst is a rare etiology of pelvic pain. However, its rarity may result in oversight or misinterpretation if the radiologist or emergency physician is unfamiliar with this entity. Seminal vesicle cysts may cause pelvic pain because of mass effect, infection, internal hemorrhage, or urinary and bladder obstruction. Because seminal vesicle cysts rarely result in physical examination findings or laboratory abnormalities, pelvic computed tomography plays a pivotal role in their diagnosis and in evaluating patients with pelvic pain. Recognition of the imaging findings of seminal vesicle cysts is necessary to allow prompt, accurate diagnosis. Therefore, emergency physicians and radiologists interpreting examinations from the emergency department should be familiar with these imaging findings because seminal vesicle cysts may be the etiology of pelvic pain and the patient may benefit from urologic consultation and cyst aspiration or resection. The purposes of this article are to provide examples of pelvic pain caused by seminal vesicle cysts, illustrate the key imaging findings on computed tomography, and briefly review the literature.

Educational paper: ciliopathies

Cilia are antenna-like organelles found on the surface of most cells. They transduce molecular signals and facilitate interactions between cells and their environment. Ciliary dysfunction has been shown to underlie a broad range of overlapping, clinically and genetically heterogeneous phenotypes, collectively termed ciliopathies. Literally, all organs can be affected. Frequent cilia-related manifestations are (poly)cystic kidney disease, retinal degeneration, situs inversus, cardiac defects, polydactyly, other skeletal abnormalities, and defects of the central and peripheral nervous system, occurring either isolated or as part of syndromes. Characterization of ciliopathies and the decisive role of primary cilia in signal transduction and cell division provides novel insights into tumorigenesis, mental retardation, and other common causes of morbidity and mortality, including diabetes mellitus and obesity. New technologies ("Next generation sequencing/NGS") have considerably improved genetic research and diagnostics by allowing simultaneous investigation of all disease genes at reduced costs and lower turn-around times. This is undoubtedly a result of the dynamic development in the field of human genetics and deserves increased attention in genetic counselling and the management of affected families.

Polycystic diseases in visceral organs

Primary cilia are nonmotile, microtubule-based, antenna-like organelles projecting from the apical surface of most mammalian cells. Elegant studies have established the importance of ciliary structure and function in signal transduction and the sensory roles of cilia in maintaining healthy cellular state. In particular, dysfunctional cilia have been implicated in a large number of diseases mainly characterized by the presence of fluid-filled cysts in various organs. Aside from polycystic kidney disease (PKD), however, the roles of cilia in polycystic liver disease (PLD), polycystic pancreas disease (PPD), and polycystic ovarian syndrome (PCOS) are still very vague. In addition, although gender and sex hormones are known to regulate cyst formation, their roles in regulating physiological functions of cilia need to be further explored.

Sperm status regulates sexual attraction in Caenorhabditis elegans

Mating behavior of animals is regulated by the sensory stimuli provided by the other sex. Sexually receptive females emit mating signals that can be inhibited by male ejaculate. The genetic mechanisms controlling the release of mating signals and encoding behavioral responses remain enigmatic. Here we present evidence of a Caenorhabditis elegans hermaphrodite-derived cue that stimulates male mating-response behavior and is dynamically regulated by her reproductive status. Wild-type males preferentially mated with older hermaphrodites. Increased sex appeal of older hermaphrodites was potent enough to stimulate robust response from mating-deficient pkd-2 and lov-1 polycystin mutant males. This enhanced response of pkd-2 males toward older hermaphrodites was independent of short-chain ascaroside pheromones, but was contingent on the absence of active sperm in the hermaphrodites. The improved pkd-2 male response toward spermless hermaphrodites was blocked by prior insemination or by genetic ablation of the ceh-18-dependent sperm-sensing pathway of the hermaphrodite somatic gonad. Our work suggests an interaction between sperm and the soma that has a negative but reversible effect on a hermaphrodite-derived mating cue that regulates male mating response, a phenomenon to date attributed to gonochoristic species only.

Pseudodominant inheritance of nephronophthisis caused by a homozygous NPHP1 deletion

Nephronophthisis (NPHP) is an autosomal recessive kidney disease characterized by tubular basement membrane disruption, interstitial infiltration, and tubular cysts. NPHP leads to end-stage renal failure (ESRD) in the first three decades of life and is the most frequent genetic cause of chronic renal failure in children and young adults. Extrarenal manifestations are known, such as retinitis pigmentosa, brainstem and cerebellar anomalies, liver fibrosis, and ocular motor apraxia type Cogan. We report on a Turkish family with clinical signs of nephronophthisis. The phenotype occurred in two generations and therefore seemed to be inherited in an autosomal dominant pattern. Nevertheless, a deletion analysis of the NPHP1 gene on chromosome 2 was performed and showed a homozygous deletion. Analysis of the family pedigree indicated no obvious consanguinity in the last three generations. However, haplotype analysis demonstrated homozygosity on chromosome 2 indicating a common ancestor to the parents of all affected individuals. NPHP1 deletion analysis should always be considered in patients with apparently dominant nephronophthisis. Furthermore, three out of four patients developed ESRD between 27 and 43 years of age, which may be influenced by yet unknown modifier genes.

Congenital fibrocystic liver diseases

Fibrocystic diseases affecting the liver and often also other organs like the kidneys are a clinically and genetically heterogeneous group of disorders that may present in utero or remain clinically silent into late adulthood. During recent years, substantial progress has been made in unravelling the aetiology with primary cilia playing a central pathogenic role in many if not all of these diseases. The fibrocystogenic process shares some common features including proliferation and dilatation of epithelial bile ducts with concomitant abnormal apoptosis, fluid secretion and extracellular matrix deposition. In this review, we summarise clinical and diagnostic aspects, mechanisms of hepatic cystogenesis, and recent knowledge on potential therapies for these conditions.

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).

Autosomal dominant polycystic kidney disease: the last 3 years

Autosomal dominant polycystic kidney disease is the most prevalent, potentially lethal monogenic disorder. It has large inter- and intra-familial variability explained to a large extent by its genetic heterogeneity and modifier genes. An increased understanding of its underlying genetic, molecular, and cellular mechanisms and a better appreciation of its progression and systemic manifestations have laid out the foundation for the development of clinical trials and potentially effective therapies. The purpose of this review is to update the core of knowledge in this area with recent publications that have appeared during 2006-2009.

Male infertility associated with adult dominant polycystic kidney disease: a case series

INTRODUCTION

Although described earlier, the association of male infertility with adult dominant polycystic kidney disease (ADPKD) is quite rare and unfamiliar to some of the multidisciplinary team members caring for affected men.

MATERIALS AND METHODS

Infertile men diagnosed to have ADPKD were evaluated by clinical characteristics including testis volume, as well as serum hormone levels, semen analysis, and transrectal ultrasonography (TRUS) because of low volume ejaculate.

RESULTS

Semen analysis revealed low-normal volume, normal pH, and azoospermia/virtual azoospermia. Serum hormones were within the normal range. Transrectal ultrasonography demonstrated cystic dilatation of the seminal vesicles in all three men.

CONCLUSION

Patients should be referred for andrological evaluation of a presentation similar to obstructive azoospermia. Their potential to achieve paternity by surgical sperm retrieval combined with assisted reproductive technology is another example of cooperation between andrologists and gynecologists.