Sertoli Cell-only Syndrome Patients Research Articles

MALDI Imaging Mass Spectrometry Reveals Lipid Alterations in Physiological and Sertoli Cell-Only Syndrome Human Testicular Tissue Sections

Azoospermia, the absence of sperm cells in semen, affects around 15% of infertile males. Sertoli cell-only syndrome (SCOS) is the most common pathological lesion in the background of non-obstructive azoospermia and is characterised by the complete absence of germinal epithelium, with Sertoli cells exclusively present in the seminiferous tubules. Studies have shown a correlation between successful spermatogenesis and male fertility with lipid composition of spermatozoa, semen, seminal plasma or testis. The aim of this research was to discover the correlation between the Johnsen scoring system and phospholipid expressions in testicular cryosections of SCOS patients. MALDI imaging mass spectrometry is used to determine spatial distributions of molecular species, such as phospholipids. Phosphatidylcholines (PCs), phosphatidylethanolamines (PEs) and sphingomyelins (SMs) are the most abundant phospholipids in mammalian cells and testis. SMs, the structural components of plasma membranes, are crucial for spermatogenesis and sperm function. Plasmalogens, are unique PCs in testis with strong antioxidative properties. This study, using imaging mass spectrometry, demonstrates the local distribution of phospholipids, particularly SMs, PCs, plasmalogens and PEs in human testicular samples with SCOS for the first time. This study found a strong relationship between the Johnsen scoring system and phospholipid expression levels in human testicular tissues. Future findings could enable routine diagnostic techniques during microTESE procedures for successful sperm extraction.

Identification of PDCL2 as a candidate marker in Sertoli cell-only syndrome by chromatin immunoprecipitation-sequencing and bioinformatics analysis.

Sertoli cell-only syndrome (SCOS) or germ cell aplasia is one of the most serious histopathological subtypes within the scope of non-obstructive azoospermia (NOA). Understanding the molecular mechanism of SCOS and identifying new non-invasive markers for clinical application is crucial to guide proper sperm procurement and avoid unnecessary interventions. This study sought to identify the differentially expressed genes (DEGs) of SCOS by using gene sequencing identity and verify the key marker genes to provide basic data for subsequent research on SCOS. A total of 50 testicular samples were collected in this study from 25 patients with SCOS and 25 patients with normal spermatogenesis. In total, 5 pairs of testis samples were used for the RNA-sequencing (RNA-seq). We identified the DEGs between the SCOS and normal spermatogenesis patients and conducted a Gene Ontology (GO) analysis and a Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. The expression of the main target gene phosducin-like 2 (PDCL2) was examined by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC). In total, 3,133 upregulated DEGs and 1,406 downregulated DEGs were identified by the RNA-seq. The highly enriched processes involved in spermatogenesis included the mitotic cell cycle, cell cycle, and oocyte maturation. The expression of PDCL2 was verified as a downregulation marker in SCOS by qRT-PCR and IHC. This study identified the DEGs of SCOS, and the bioinformatics analysis results identified the potential target key genes and pathways for SCOS. PDCL2 is a key gene involved in SCOS and may serve as a non-invasive downregulation marker of SCOS.

Gene panel analysis of literature-based infertility genes in Sertoli cell-only syndrome patients

Sertoli cell-only syndrome (SCOS) is a condition of male infertility characterized by a total absence of spermatogenic cells in nearly all seminiferous tubules. Apart from well-established genetic changes such as Klinefelter syndrome, CFTR variants, and Y-chromosome microdeletions, several hundred candidate genes were reported as associated with male infertility. We selected 92 evidence-based genes associated with infertility and investigated data from whole-exome sequencing in 6 individuals with clinically diagnosed SCOS. Eight heterozygous variants passed our filtering criteria, including population frequency ≤ 0.1% and high functional impact indicated by Sift, Polyphen, and CADD scores. Out of them, we considered only variants with putative autosomal dominant effects on infertility that were subsequently validated by Sanger sequencing. This filtering pipeline has led to the final likely causative variants detected in CHD7 and SCYP3 genes that potentially explain SCOS in two of our patients. Our discoveries suggest that gene panel testing of patients with SCOS could improve the diagnostic outcome; however, assembling a gene panel consisting of only genuine causative genes is crucial.

Sertoli cell-only syndrome: advances, challenges, and perspectives in genetics and mechanisms.

Male infertility can be caused by quantitative and/or qualitative abnormalities in spermatogenesis, which affects men's physical and mental health. Sertoli cell-only syndrome (SCOS) is the most severe histological phenotype of male infertility characterized by the depletion of germ cells with only Sertoli cells remaining in the seminiferous tubules. Most SCOS cases cannot be explained by the already known genetic causes including karyotype abnormalities and microdeletions of the Y chromosome. With the development of sequencing technology, studies on screening new genetic causes for SCOS are growing in recent years. Directly sequencing of target genes in sporadic cases and whole-exome sequencing applied in familial cases have identified several genes associated with SCOS. Analyses of the testicular transcriptome, proteome, and epigenetics in SCOS patients provide explanations regarding the molecular mechanisms of SCOS. In this review, we discuss the possible relationship between defective germline development and SCOS based on mouse models with SCO phenotype. We also summarize the advances and challenges in the exploration of genetic causes and mechanisms of SCOS. Knowing the genetic factors of SCOS offers a better understanding of SCO and human spermatogenesis, and it also has practical significance for improving diagnosis, making appropriate medical decisions, and genetic counseling. For therapeutic implications, SCOS research, along with the achievements in stem cell technologies and gene therapy, build the foundation to develop novel therapies for SCOS patients to produce functional spermatozoa, giving them hope to father children.

Pathological findings in infertile men

To define the pathological findings in a series of infertile men, and to investigate their relationship with their medical records and hormonal assessment. Retrospective, observational study in which we included all infertile men with a diagnosis of azoospermia who underwent testicular diagnostic biopsy. In our center, this process is performed systematically to all men with azoospermia. We collected patient history, findings on physical examination and hormonal levels. Pathological study analyzed the presence of all cellular maturation stages, the proportion of Sertoli, germ and Leydig cells, the size of the lumen of the seminiferous tubules, the thickening of the basement membrane, the presence of hyalinization and CIS. We identified 71 samples, with a mean age of 34.9 years (SD 6.38). The histological analysis showed 54.9% (39) of Sertoli cell only syndrome (SCO), 26.9% (19) sclerosis, 21.1% (15) hypospermatogenesis, 15.5% (11) conserved spermatogenesis, 14.1% (10) germ cell maturation arrest and 7 % (5) Leydig cell hyperplasia. Of them, 32.2% (22) were mixed pattern. Mean testosterone was 16 ng/dL (SD 7.31), LH 9.18 IU/L (SD 5.67), and FSH 17.49 IU/L (SD 12). FSH was higher (18.90 vs 9.35, p=0.02) in those with abnormal histology (52) in contrast to those with normal histology (9). Higher levels of FSH were found in SCO patients (20.87 vs 12.95), being the sclerosis group the one with the highest mean FSH (26.79 vs 16.09, p=0.01). Also, significant higher LH levels in those men with abnormal histology (9.87 vs 5.29, p=0.02) was found, although when analyzing for different histologic diagnosis, no significant differences were observed. In our series, the most frequent pattern in biopsies is SCO 54,9% (39). We observed significantly elevated levels of FSH and LH in the abnormal histology group, which is consistent with what has been previously described in the literature. We do not have any conflict of interest.

Y-chromosome genes associated with sertoli cell-only syndrome identified by array comparative genome hybridization

BackgroundThe precise contribution of each chromosome gene or gene family in achieving male fertility is still the subject of debate. Most studies have examined male populations with heterogeneous causes of infertility, and have therefore reached controversial or uncertain conclusions. This study uses Y-chromosome array-based comparative genomic hybridization (aCGH) to examine a population of males with a uniform sertoli cell-only syndrome (SCOS) infertility phenotype. MethodsInitial analysis of gene copy number variations in 8 SCOS patients, with determination of the log-ratio of probe signal intensity against a DNA reference, was performed using the Y-chromosome NimbleGen aCGH. To confirm the role of candidate genes, real-time quantitative RT-PCR was used to compare 19 patients who had SCOS non-obstructive azoospermia with 15 patients who had obstructive azoospermia but normal spermatogenesis. ResultsOur initial aCGH experiments identified CDY1a and CDY1b double deletions in all 8 patients who had total germ cell depletion. However, 5 patients had DAZ1/2 and DAZ3/4 deletions, 1 patient had a DAZ2 and DAZ3/4 deletion, and 2 patients had no DAZ1/2 or DAZ3/4 deletions. Examination of testicular mRNA expression in another 19 patients with SCOS indicated all patients had no detectable levels of CDY1. ConclusionsOur findings indicate that CDY1 deletion in SCOS patients, and analysis of the expression of DAZ and CDY1 genes using aCGH and quantitative RT-PCR, may be useful to predict the presence of mature spermatozoa.

Identification of genomic imbalances (CNVs as well as LOH) in sertoli cell only syndrome cases through cytoscan microarray.

Sertoli cell only syndrome (SCOS) is characterized by complete absence of germ cells in seminiferous tubules of testis. SCOS is multifactorial but genetic factors play a major role in pathogenesis of the disorder with idiopathic origin. Genetic factors majorly include sex chromosomal aneuploidy and Yq Microdeletion. But a large number of cases are still idiopathic. The study aimed to evaluate the genomic imbalances (CNVs and LOH) in idiopathic SCOS patients. The study is based on 28 apparent idiopathic SCOS cases and 10 controls. Molecular cytogenetic techniques viz., FISH, STS-Multiplex PCR and Affymetrix cytoscan microarray (750K) were used. The microarray screened whole genomic imbalances in DNA from peripheral blood of 25 cases (excluded Klinefelter syndrome patients) and testicular FNAC sample of 2 cases. High FSH and low Inhibin B were observed in cases as compared to control controls groups. Four cases of sex chromosomal abnormality (i.e., three non-mosaic 47, XXY males and one non-mosaic 46, XX male) as well as four cases of Yq microdeletion (i.e., three cases with AZFc deletion and one case with complete AZFa, b and c deletion) were identified. Microarray detected unbalanced translocation of two segments of Y-chromosome i.e., Yp11.31-p11.2 (~4.o mb region, involving SRY) and Yp11.2 (~2.5 mb region) on X-chromosome in XX male. Also, loss of segment on same X-chromosome involving PAR1 region was identified. We have identified both autosomal and sex chromosomal CNVs (recurrent as well as private) involving candidate genes like SYCE1, ZFPM2, SRPK1, DAZ1, BPY2, HSFY1, VCY1 etc. All these CNVs are possibly associated with SCOS pathogenesis. CNVs identified in cases were already reported as pathogenic variant in clinical database DECIPHER. Microarray also detected many LOH (all autosomal, >3.0 mb size) that covered genes with spermatogenesis related function. The mechanism of action of LOH in pathogenesis of SCOS still remains unravelled. CNVs and LOH related to spermatogenesis identified from two different sample types (blood vs. testicular tissue) were discordant. This study should be extended for larger cohort of patients.

Sertoli cell-only syndrome: etiology and clinical management.

Almost 50% of infertility cases are due to male factors, and spermatogenesis failure is one of the most severe forms of male infertility. Sertoli cell-only syndrome (SCOS) also known as germ cell aplasia is characterized by azoospermia in which the seminiferous tubules of testicular biopsy are lined only with Sertoli cells. The definitive diagnosis of SCOS is by diagnostic testicular biopsy. Although SCOS may be a result of Klinefelter syndrome, most of the SCOS men have a normal karyotype. Along with genetic aberrations, signaling pathways and endocrine processes might be major factors in the development of SCOS. Sperm retrieval and intracytoplasmic sperm injection (ICSI) are available treatments for SCOS. However, some SCOS patients do not have therapeutic options to help them having a biological child. This review aims to summarize our present knowledge about SCOS and to highlight the importance of future researches in the diagnosis and treatment of this disorder.

Testicular steroid sulfatase overexpression is associated with Leydig cell dysfunction in primary spermatogenic failure.

Decreased testosterone (T) to LH ratio and increased 17β-estradiol (E2) serum concentrations represent a common finding among patients with severe spermatogenic failure, suggesting a concurrent Leydig cell steroidogenic dysfunction. Aromatase overexpression has been associated with increased serum and intratesticular E2 in these patients. However, it is unknown whether the sulfatase pathway contributes to the increased availability of active estrogens in patients with primary spermatogenic failure. To assess estrogen sulfotransferase (SULT1E1) and steroid sulfatase (STS) mRNA abundance in testicular tissue of patients with Sertoli cell-only syndrome (SCOS) and normal tissues, its association with serum and intratesticular hormone levels, and to explore the mRNA and protein testicular localization of both enzymes. Testicular tissues of 23 subjects with SCOS (cases) and 22 patients with obstructive azoospermia and normal spermatogenesis (controls) were obtained after biopsy. SULT1E1 and STS transcripts accumulation was quantified by RT-qPCR. For mRNA and protein localization, we performed RT-qPCR in Leydig cell clusters and seminiferous tubules isolated by laser-capture microdissection and immunofluorescence in testicular tissues. Serum and intratesticular hormones were measured by immunoradiometric assays. SULT1E1 mRNA accumulation was similar in both groups. The amount of STS mRNA was higher in cases (p=0.007) and inversely correlated with T/LH ratio (r=-0.402; p=0.02). Also, a near significant correlation was observed with intratesticular E2 (r=0.329, p=0.057), in agreement with higher intratesticular E2 in cases (p<0.001). Strong STS immunoreaction was localized in the wall of small blood vessels but not in Leydig cells. Both SULT1E1 and STS mRNA abundance was similar in Leydig cell clusters and the tubular compartment, except for lower SUTL1E1 mRNA in the seminiferous tubules of SCOS patients (p=0.001). Our results suggest that an unbalance of the STS/SULT1E1 pathway contributes to the testicular hyperestrogenic microenvironment in patients with primary spermatogenic failure and Leydig cell dysfunction.

Fam9B was associated with human spermatogenesis and male-specific sterility

Spermatogenesis is the process of gamete formation, which includes mitosis in spermatogonia, meiosis in spermatocytes, and spermiogenesis. A key event is the formation of the synaptonemal complex (SC). Mutations of genes encoding SC components (such as SYCP3，synaptonemal complex protein 3) lead to infertility or subfertility due to germ cell death. Fam9B mapped on the human chromosome X (Xp22.3) was more similar to SYCP3 in their amino acid sequences and expressed in human testis. However, the expression and precise underlying mechanisms of Fam9B have not been clearly in testes during the spermatogenesis and infertility. And Fam9B mutation associated with sterility? This study was an analysis of azoospermia, sertoli cell only syndrome (SCOS) and proven fertile patients, including 162 patients diagnosed with azoospermia, 65 patients diagnosed with SCOS and 10 proven fertile patients at the Reproductive Medical Center of Peking University Third Hospital between January 2015 and January 2019. Fam9B was cloned, expressed and identified. Genome DNA sequencing analysis, RT-PCR, Western-blot, Immunohistochemistry and immunocytochemistry were performed. Fam9B was analyzed with blood and testicular biopsy samples from azoospermia patients by genome DNA sequencing analysis. These likely mutations were further screened in SCOS patients and in men proven to be fertile. And Fam9B was cloned, expressed and identified with testicular samples using RT-PCR, western blot, Immunohistochemistry and immunocytochemistry. The concentration of testosterone in azoospermia and SCOS patients were determined, and their relativity was studied by statistic methods. Fam9B mRNAs and protein were detected in human testis, and Fam9B was expressed at different level in patients of azoospermia, SCOS and normal groups. Immunohistochemical staining showed that Fam9B was expressed in the nucleus of primary spermatocyte in fertile persons. Moreover, Fam9B was more similar to SYCP3 expression pattern and located on the SC during the leptotene and diplotene spermatocytes. Furthermore, genome DNA sequencing analysis revealed three fam9b deletion patients and five patients of point mutation in fam9b gene. Spermatogenesis of these three patients was arrested at spermatocytes and accompanied by germ cells lost. Interesting, testosterone concentrations levels of these three patients were decreased compared with controls (P < 0.01) . Fam9B may be a SC related protein participated in human normal spermatogenesis. And mutations of fam9b may be risk of spermatocytes arrest and male-specific sterility.

Disordered APC/C-mediated cell cycle progression and IGF1/PI3K/AKT signalling are the potential basis of Sertoli cell-only syndrome.

The cause of Sertoli cell-only syndrome (SCOS), a condition in which only Sertoli cells line the seminiferous tubules in the testis, is unknown. Three microarray data sets were downloaded from public databases and were used to compare SCOS and control group. A total of 291 genes differentially expressed (Log2 |FC|≥1 and adjusted p value<0.05) in SCOS patients. Further 238 genes were significantly downregulated, and 53 genes were significantly upregulated. To identify the hub genes in the differentially expressed genes, we constructed a protein-protein interaction network, and CCNB1, CCNA2, AURKA, KIF11, CCNB2, CDC6, PRC1, NCAPG, KIF2C and PLK4 were screened from the network for the downregulated genes. Since the upregulated genes could not form a network, we concentrated on the genes with a higher fold change, and CPA3, NFIB, LONRF2, LYVE1, ATP8B4, IGF1, ITPR1 and PLAT were identified as the top 50% fold change genes in any of the three microarray data sets. Among downregulated hub genes, CDC6, CCNA2, CCNB1 and CCNB2 were involved in APC/C-mediated cell cycle progression. Among key upregulated genes, IGF1 was involved in the PI3K/AKT pathway, while the other genes have not been reported in Sertoli or Leydig cells. In conclusion, SCOS appears to be caused by disordered APC/C-mediated cell cycle progression and PI3K/AKT signalling.

Fibroblast growth factor-5 promotes spermatogonial stem cell proliferation via ERK and AKT activation

BackgroundSertoli cells are the most important somatic cells contributing to the microenvironment (named niche) for spermatogonial stem cells (SSCs). They produce amounts of crucial growth factors and structure proteins that play essential roles in the complex processes of male SSCs survival, proliferation, and differentiation. It has been suggested that Sertoli cell abnormalities could result in spermatogenesis failure, eventually causing azoospermia in humans. However, to the end, the gene expression characteristics and protein functions of human Sertoli cells remained unknown. In this study, we aimed to evaluate the effect of fibroblast growth factor-5 (FGF5), a novel growth factor downregulated in Sertoli cells from Sertoli cell-only syndrome (SCOS) patients compared to Sertoli cells from obstructive azoospermia (OA) patients, on SSCs.MethodsWe compared the transcriptome between Sertoli cell from SCOS and OA patients. Then, we evaluated the expression of FGF5, a growth factor which is downregulated in SCOS Sertoli cells, in human primary cultured Sertoli cells and testicular tissue. Also, the proliferation effect of FGF5 in mice SSCs was detected using EDU assay and CCK-8 assay. To investigate the mechanism of FGF5, Phospho Explorer Array was performed. And the results were verified using Western blot assay.ResultsUsing RNA-Seq, we found 308 differentially expressed genes (DEGs) between Sertoli cells from SCOS and OA patients. We noted and verified that the expression of fibroblast growth factor-5 (FGF5) was higher in Sertoli cells of OA patients than that of SCOS patients at both transcriptional and translational levels. Proliferation assays showed that rFGF5 enhanced the proliferation of mouse SSCs line C18-4 in a time- and dose-dependent manner. Moreover, we demonstrated that ERK and AKT were activated and the expression of Cyclin A2 and Cyclin E1 was enhanced by rFGF5.ConclusionThe distinct RNA profiles between Sertoli cells from SCOS and OA patients were identified using RNA-Seq. Also, FGF5, a growth factor that downregulated in SCOS Sertoli cells, could promote SSCs proliferation via ERK and AKT activation.

Identification of Premeiotic, Meiotic, and Postmeiotic Cells in Testicular Biopsies Without Sperm from Sertoli Cell-Only Syndrome Patients.

Sertoli cell-only syndrome (SCOS) affects about 26.3–57.8% of azoospermic men, with their seminiferous tubules containing only Sertoli cells. Recently, it was reported that testicular biopsies from nonobstructive azoospermic (NOA) patients contained germ cells, and that sperm could be found in the tubules of 20% of SCOS patients using testicular sperm extraction technology. Since the patients without sperm in their testicular biopsies do not have therapy to help them to father a biological child, in vitro maturation of spermatogonial stem cells (SSCs) isolated from their testis is a new approach for possible future infertility treatment. Recently, the induction of human and mice SSCs proliferation and differentiation was demonstrated using different culture systems. Our group reported the induction of spermatogonial cell proliferation and differentiation to meiotic and postmeiotic stages in mice, rhesus monkeys, and prepubertal boys with cancer using 3D agar and methylcellulose (MCS) culture systems. The aim of the study was to identify the type of spermatogenic cells present in biopsies without sperm from SCOS patients, and to examine the possibility of inducing spermatogenesis from isolated spermatogonial cells of these biopsies in vitro using 3D MCS. We used nine biopsies without sperm from SCOS patients, and the presence of spermatogenic markers was evaluated by PCR and specific immunofluorescence staining analyses. Isolated testicular cells were cultured in MCS in the presence of StemPro enriched media with different growth factors and the development of colonies/clusters was examined microscopically. We examined the presence of cells from the different stages of spermatogenesis before and after culture in MCS for 3–7 weeks. Our results indicated that these biopsies showed the presence of premeiotic markers (two to seven markers/biopsy), meiotic markers (of nine biopsies, cAMP responsive element modulator-1 (CREM-1) was detected in five, lactate dehydrogenase (LDH) in five, and BOULE in three) and postmeiotic markers (protamine was detected in six biopsies and acrosin in three). In addition, we were able to induce the development of meiotic and/or postmeiotic stages from spermatogonial cells isolated from three biopsies. Thus, our study shows for the first time the presence of meiotic and/or postmeiotic cells in biopsies without the sperm of SCOS patients. Isolated cells from some of these biopsies could be induced to meiotic and/or postmeiotic stages under in vitro culture conditions.

Deficient LRRC8A-dependent volume-regulated anion channel activity is associated with male infertility in mice.

Ion channel-controlled cell volume regulation is of fundamental significance to the physiological function of sperm. In addition to volume regulation, LRRC8A-dependent volume-regulated anion channel (VRAC) activity is involved in cell cycle progression, insulin signaling, and cisplatin resistance. Nevertheless, the contribution of LRRC8A and its dependent VRAC activity in the germ cell lineage remain unknown. By utilizing a spontaneous Lrrc8a mouse mutation (c.1325delTG, p.F443*) and genetically engineered mouse models, we demonstrate that LRRC8A-dependent VRAC activity is essential for male germ cell development and fertility. Lrrc8a-null male germ cells undergo progressive degeneration independent of the apoptotic pathway during postnatal testicular development. Lrrc8a-deficient mouse sperm exhibit multiple morphological abnormalities of the flagella (MMAF), a feature commonly observed in the sperm of infertile human patients. Importantly, we identified a human patient with a rare LRRC8A hypomorphic mutation (c.1634G>A, p.Arg545His) possibly linked to Sertoli cell-only syndrome (SCOS), a male sterility disorder characterized by the loss of germ cells. Thus, LRRC8A is a critical factor required for germ cell development and volume regulation in the mouse, and it might serve as a novel diagnostic and therapeutic target for SCOS patients.

445 Relevance of testicular histopathology on prediction of sperm retrieval rates after a conventional bilateral multiple TESE in case of non-obstructive azoospermia (NOA) and obstructive-azoospermia (OA)

To establish the relevance of testicular histopathology (TH) on sperm retrieval (SR) after testicular sperm extraction (TESE) in patients with non-obstructive azoospermia (NOA) and in obstructive azoospermia (OA) patients, already underwent a previous failure testicular fine needle aspiration (TEFNA). We evaluated a total of 82 azoospermic men, underwent TESE, referring to our Centre between January 2008 and March 2017. A general and genital physical examination, scrotal and trans-rectal ultrasound, semen analysis, hormone measurements, including follicle stimulating hormone (FSH), luteinizing hormone (LH) and total testosterone (TT) were collected. Successful sperm retrieval (SSR) was obtained in 36 men of total (43.9%).(Table 1) SSR was 29.5% in NOA patients, while OA men, underwent a previous failure TEFNA, had SR in 86% of cases. Mean LH was 6.55 IU/L, TT 4.70 ng/ml, testicular volume (TV) right 13.7 ml and TV left 13.6 ml. FSH mean was 13.45 IU/L in patients with negative SR and 8.18 IU/L in men with SSR. According to histology, 20.7% had Normal Spermatogenesis (NS), 35.3% Hypospermatogenesis (H), 35.3% Maturation Arrest (MA) and 8.5% Sertoli-Cell-Only-Syndrome (SCOS). SSR was 88.2% in patients with NS, 24.1% in the MA group and 48.27% in patients with Hypospermatogenesis, while negative SR was reported in SCOS patients. 2 patients with NS and unsuccessful SR, underwent a second TESE, of whom one had SR and cryopreservation.

Relevance of testicular histopathology on prediction of sperm retrieval rates in case of non-obstructive and obstructive azoospermia.

The aim of our research was to establish the relevance of testicular histopathology on sperm retrieval after testicular sperm extraction in patients with non-obstructive azoospermia and in patients with obstructive azoospermia, who already underwent a previous failure testicular fine needle aspiration. We evaluated a total of 82 azoospermic men, underwent testicular sperm extraction, referring to the Assisted Reproductive Technology Centre of the University of Florence, Italy between January 2008 and March 2017. A general and genital physical examination, scrotal and trans-rectal ultrasound, semen analysis, hormone measurements, including follicle-stimulating hormone, luteinizing hormone and total testosterone, were collected. Successful sperm retrieval was obtained in 36 men of total (43.9%). Successful sperm retrieval was 29.5% in non-obstructive azoospermia patients, while men with obstructive azoospermia, who, underwent a previous failure testicular fine needle aspiration, had sperm retrieval in 86% of cases. Mean luteinizing hormone was 6.55 IU/L, total testosterone 4.70 ng/mL, right testicular volume 13.7 mL and left testicular volume 13.6 mL. Mean Follicle-stimulating hormone was 13.45 IU/L in patients with negative sperm retrieval and 8.18 IU/L in men with successful sperm retrieval. According to histology, 20.7% had normal spermatogenesis, 35.3% hypospermatogenesis, 35.3% maturation arrest and 8.5% Sertoli cell-only syndrome. Successful sperm retrieval was 88.2% in patients with normal spermatogenesis, 24.1% in the maturation arrest group and 48.27% in patients with hypospermatogenesis, while negative sperm retrieval was reported in Sertoli cell-only syndrome patients. Seven cases with maturation arrest showed a successful sperm retrieval. Testicular histopathology after testicular sperm extraction offers important information on prediction of sperm retrieval and can guide the surgeon in choosing the more suitable therapeutic practice.

Leydig cell dysfunction is associated with post-transcriptional deregulation of CYP17A1 in men with Sertoli cell-only syndrome.

Is the expression of steroidogenic enzyme 17α-Hydroxylase/17,20-Lyase (CYP17A1) down-regulated in Leydig cells (LCs) of men with spermatogenic failure and compensated impairment of LC function, i.e. a low testosterone to LH (T/LH) ratio? Although the transcriptional expression of CYP17A1 is increased, its protein expression is decreased, in isolated LCs of men with spermatogenic failure and reduced serum T/LH. Primary spermatogenic defects have been associated with functional and morphological abnormalities of LCs, characterized by decreased serum testosterone (T) levels, decreased T/LH, increased 17β-estradiol (E2) and E2/T ratio, and larger clusters of LCs (LC hyperplasia). CYP17A1 is a key enzyme in the testosterone pathway and has been implicated in the steroidogenic lesion produced by E2 stimulation. We studied 18 azoospermic patients with Sertoli cell-only syndrome (SCOS) and signs of LC dysfunction (cases) and 10 obstructive azoospermic/oligozoospermic men with normal spermatogenesis (controls). The SCOS patients were sub-grouped into 9 cases with T/LH <2 and 9 cases with T/LH ≥2. All of the men underwent testicular biopsy for sperm retrieval at the Reproductive Unit of a University Hospital. The transcriptional expression of CYP17A1 and SF-1 (steroidogenic factor 1) was quantified by SYBR®Green-based qPCR in LCs isolated by laser capture microdissection (LCM), and relative expression to the control pool was assessed. CYP17A1 protein expression was semi-quantified by indirect immunofluorescence (IFI) using Image-Pro Plus v7.0 (Media Cybernetics) in testicular tissue. FSH and LH serum concentrations, and serum and intratesticular T (ITT) and E2 (ITE2) were measured by IRMA and RIA, respectively. Relative CYP17A1 mRNA expression was increased in cases with T/LH <2 compared to cases with T/LH ≥2, by a mean of 3.3-fold (P = 0.002). No corresponding increase in protein expression was found; in fact, CYP17A1 immunostaining intensity assessed by the Integrated Optical Density (IOD) parameter was lower in the cases with T/LH <2 compared to controls (P = 0.008). Relative SF-1 mRNA expression was similar in both case subgroups. CYP17A1 mRNA expression correlated with ITE2 and intratesticular E2/T (r = 0.536; P = 0.026 and r = 0.542; P = 0.016, respectively), while an inverse association was observed for ITE2 and protein level expression (r = -0.421; P = 0.05). Not applicable. We should interpret the results of the semi-quantification of immunofluorescent staining by Image-Pro Plus software with caution, because it is a semi-quantitative method that may have certain difficulties regarding the disposition of protein in the cells. However, it is not influenced by variations in the number of cells that express the protein, as could be the case of western blot analysis in testicular tissue. Dysfunctional LCs of men with SCOS show post-transcriptional deregulation of CYP17A1, with increased mRNA and decreased protein expression, which may be modulated by increased ITE2 levels. In addition, transcriptional expression of CYP17A1 was not associated with changes in SF-1 mRNA expression. This work was supported by the National Fund for Scientific and Technological Development (FONDECYT) of Chile to A.C. [grant number 1120176]. The authors declare no conflict of interest.

Quantitative proteomic analysis of human testis reveals system-wide molecular and cellular pathways associated with non-obstructive azoospermia

Male infertility accounts for half of the infertility problems experienced by couples. Azoospermia, having no measurable level of sperm in seminal fluid, is one of the known conditions resulting in male infertility. In order to elucidate the complex molecular mechanisms causing male azoospermia, label-free quantitative shotgun proteomics was carried out on testicular tissue specimens from patients with obstructive azoospermia and non-obstructive azoospermia, including maturation arrest (MA) and Sertoli cell only syndrome (SCOS). The abundance of 520 proteins was significantly changed across three groups of samples. We were able to identify several functional biological pathways enriched in azoospermia samples and confirm selected differentially abundant proteins, using multiple histological methods. The results revealed that cell cycle and proteolysis, and RNA splicing were the most significant biological processes impaired by the substantial suppression of proteins related to the aforementioned categories in SCOS tissues. In the MA patient testes, generation of precursor metabolites and energy as well as oxidation-reduction were the most significantly altered processes. Novel candidate proteins identified in this study include key transcription factors, many of which have not previously been shown to be associated with azoospermia. Our findings can provide substantial insights into the molecular regulation of spermatogenesis and human reproduction. SignificanceThe obtained data showed a drastic suppression of proteins involved in spliceosome, cell cycle and proteasome proteins, as well as energy and metabolic production in Sertoli cell only syndrome testis tissue, and to a lesser extent in maturation arrest samples. Moreover, we identified new transcription factors that are highly down-regulated in SCOS and MA patients, thus helping to understand the molecular complexity of spermatogenesis in male infertility. Our findings provide novel candidate protein targets associated with SCOS or MA azoospermia.

MP70-11 EVIDENCE OF SPERMATOGONIAL STEM CELL PRESENCE IN MEN WITH SERTOLI CELL-ONLY SYNDROME

INTRODUCTION AND OBJECTIVES: Sertoli cell-only syndrome (SCOS) is one of the most severe forms of male factor infertility and is classically thought to be devoid of germ cells. However, evidence from microsurgical testicular sperm extractions (TESE) on patients with SCOS has revealed the presence of rare focal areas of spermatogenesis, thereby suggesting the presence of spermatogonial stem cells (SSC) in at least some patients with SCOS. We hypothesize that SSCs are present in most patients with SCOS and that it is abnormal differentiation of the SSC into spermatogonia (SPG) A and/or B that leads to SCOS. METHODS: Testicular samples were obtained from 5 men with pure SCOS on biopsy during TESE and from 5 cadaveric men with normal spermatogenesis. Specimens were assessed for mRNA markers of SSC, SPG A, and SPG B by RNA sequencing. Immunofluorescence was then used to visualize SSCs and SPG A in the testicular samples. Finally, flow cytometry using known markers for SSC (SSEA4) and SPG A (GFRa1) was used to provide quantitative evidence of cellular presence in testicular samples. RESULTS: On RNA sequencing, mRNA markers for SSC and SPG A are expressed in similar numbers in men with normal spermatogenesis and in those with SCOS. On the other hand, there was a dramatic overexpression of mRNA markers for differentiated cells, such as spermatocytes, in men with normal spermatogenesis (Table 1). Immunofluorescence showed increased expression of GFRa1 in the testes of men with SCOS when compared to the testes of men with normal spermatogenesis. Flow cytometry analysis of four testicular samples from men with SCOS and four samples from those with normal spermatogenesis showed a similar number of SSEA4+ cells (0.11%), but a nearly four-fold increase in the number of GFRa1+ cells in men with SCOS compared to those with normal spermatogenesis (0.7% versus 0.18%, respectively). CONCLUSIONS: These findings suggest that SSCs are present in patients with SCOS in similar numbers as in those with normal spermatogenesis. However, there is a surprising accumulation of SPG in SCOS patients. Rather than differentiating and proceeding down the spermatogenesis pathway, the SSCs proliferate, but remain undifferentiated. The azoospermia seen in men with SCOS appears to be secondary to a defect in SSC differentiation and entry into meiosis. Source of Funding: The project was supported by The Frederick J. and Theresa Dow Wallace Fund of the New York Community Trust. This project was also supported by grant number T32HS00066 from the Agency for Healthcare Research and Quality. The content is solely the responsibility of the authors and does not necessarily represent the official views of the Agency for Healthcare Research and Quality.

MiRNA-133b promotes the proliferation of human Sertoli cells through targeting GLI3.

Sertoli cells play critical roles in regulating spermatogenesis and they can be reprogrammed to the cells of other lineages, highlighting that they have significant applications in reproductive and regenerative medicine. The fate determinations of Sertoli cells are regulated precisely by epigenetic factors. However, the expression, roles, and targets of microRNA (miRNA) in human Sertoli cells remain unknown. Here we have for the first time revealed that 174 miRNAs were distinctly expressed in human Sertoli cells between Sertoli-cell-only syndrome (SCOS) patients and obstructive azoospermia (OA) patients with normal spermatogenesis using miRNA microarrays and real time PCR, suggesting that these miRNAs may be associated with the pathogenesis of SCOS. MiR-133b is upregulated in Sertoli cells of SCOS patients compared to OA patients. Proliferation assays with miRNA mimics and inhibitors showed that miR-133b enhanced the proliferation of human Sertoli cells. Moreover, we demonstrated that GLI3 was a direct target of miR-133b and the expression of Cyclin B1 and Cyclin D1 was enhanced by miR-133b mimics but decreased by its inhibitors. Gene silencing of GLI3 using RNA inference stimulated the growth of human Sertoli cells. Collectively, miR-133b promoted the proliferation of human Sertoli cells by targeting GLI3. This study thus sheds novel insights into epigenetic regulation of human Sertoli cells and the etiology of azoospermia and offers new targets for treating male infertility