Expression data of testis biopsies obtained from men with spermatogenic impairment
ABSTRACT: Testicular biopsies were extracted surgically from men presenting with different states of spermatogenic impairments. The biopsies were scored histologically according to the Johnsen score system and microarrray technology was applied in order to correlate the gene expression pattern with the morphological categorization. Keywords: disease state analysis Overall design: Testicular biopsies were extracted surgically and fixed in RNAlater. Total RNA was extracted by GITC-method and post-purified using RNeasy columns. Arrays were hybridized overnight with 10 ug of Biotin-11-UTP-labeled cRNA, stringency washed and stained with Cy5-Streptavidin.
INSTRUMENT(S): GE Healthcare/Amersham Biosciences CodeLink™ UniSet Human 20K I Bioarray
Project description:We investigated testicular biopsies from 28 men which presented with full spermatogenesis (Johnsen Score 10, 12 samples), arrest at the spermatid stage (Johnsen Score 8, 6 samples), arrest at spermatocyte stage (Johnsen Score 5, 5 samples) and Sertoli-cell-only syndrom (Johnsen Score 2, 5 samples). Testicular biopsies were obtained by the "sandwich" method and conserved in RNALater (Ambion) during surgery. Keywords: spermatogenesis germ cell differentiation Keywords: disease state analysis Overall design: Total RNA was extracted from the biopsies by desintegration in RNAPure (Biozym) and post-cleanup with RNEasy columns (Qiagen). 2 ug of total RNA were labeled with the Amersham Codelink Expression Kit according to the manufacturers protocol, obtaining 40-80 ug of Biotin-labeled cRNA. 10 ug of fragmented cRNA were hybridized for 16h to Human 20K Codelink microarrays (Amersham), washed and stained with Cy5-Streptavidin according to manufacturers protocols and scanned with an Affymetrix 428 Array Scanner at gain 70. Spots were quantified by Codelink Expression software v4.0.
Project description:Mature sperm cells can be found in testicular specimens extracted from azoospermic men with non-mosaic Klinefelter syndrome (KS). The present study evaluates the expression of various known molecular markers of spermatogenesis in a population of men with KS and assesses the ability of those markers to predict spermatogenesis.Two groups of men with non-obstructive azoospermia who underwent testicular sperm-retrieval procedures were included in the study: 31 had non-mosaic KS (KS group) and 91 had normal karyotype (NK group). Each group was subdivided into mixed atrophy (containing some mature sperm cells) or Sertoli cell only syndrome according to testicular histology and cytology observations. Semi-quantitative histological morphometric analysis (interstitial hyperplasia and hyalinization, tubules with cells and abnormal thickness of the basement membrane) and expression of spermatogenetic markers (DAZ, RBM, BOLL, and CDY1) were evaluated and compared among those subgroups.Clear differences in the histological morphometry and spermatogenetic marker expression were noted between the KS and NK groups. There was a significant difference in the expression of spermatogenetic markers between the subgroups of the NK group (as expected), while no difference could be discerned between the two subgroups in the KS group.We conclude that molecular spermatogenetic markers have a pattern of expression in men with KS that is distinctively different from that of men with NK, and that it precludes and limits their use for predicting spermatogenesis in the former. It is suggested that this difference might be due to the specific highly abnormal histological morphometric parameters in KS specimens.
Project description:Previous studies, including our own, have reported that spermatozoa isolated from the testis have remarkably higher occurrence of aneuploidy once isolated from azoospermic men. This notion, however, did not translate into a lower pregnancy rate nor a greater proportion of miscarriages. Indeed, ICSI offspring generated from surgically retrieved gametes did not suffer from increased karyotypic aneuploidy than children generated from ejaculated specimens. In recent years, aneuploidy assessments on a larger number of cells and utilizing more chromosome probes have reported a progressive decrease in chromosomal aberrations in spermatozoa directly retrieved from the seminiferous tubules. In light of the availability of more accurate molecular genetic techniques, we have decided to challenge the notion that sampling epididymal and testicular tissues yields spermatozoa with higher incidence of aneuploidy than those retrieved in the ejaculate. In a retrospective manner, we have carried out an analysis by FISH with 9 chromosome probes on at least 1000 cells from the ejaculates of 87 consenting men and the specimens of 6 azoospermic men, while spermatozoa of fertile donors were used as control. Aneuploidy by FISH yielded 0.9% for the donor control but rose in the study group to 3.6% in the ejaculated, 1.2% for the epididymal, and 1.1% for testicular spermatozoa. There were no differences in autosomal or gonosomal disomies, nor nullisomies. In this group, once the specimens of these men were used for ICSI, ejaculated spermatozoa yielded a 22% clinical pregnancy rate that resulted in 62.5% pregnancy loss. The surgically retrieved specimens yielded a 50% clinical pregnancy rate that progressed to term. To confirm our findings, in a prospective analysis, DNA sequencing was carried out on the ejaculates and surgical samples of 22 men with various spermatogenic characteristics. In this comparison, the findings were similar with actually a higher incidence of aneuploidy in the ejaculated spermatozoa (n = 16) compared to those surgically retrieved (n = 6) (P<0.0001). For this group, the clinical pregnancy rate for the ejaculated specimens was 47.2% with 29.4% pregnancy loss, while the surgically retrieved yielded a 50% clinical pregnancy rate, all progressing to term. A subsequent prospective combined assessment on ejaculated and surgically retrieved spermatozoa by FISH and NGS was performed on non-azoospermic men with high DNA fragmentation in their ejaculate. The assessment by FISH evidenced 2.8% chromosomal defects in the ejaculated and 1.2% in testicular biopsies while by NGS became 8.4% and 1.3% (P = 0.02), respectively. Interestingly, we evidenced a pregnancy rate of 0% with ejaculated while 100% with the testicular spermatozoa in this latter group. This indicates that improved techniques for assessing sperm aneuploidy on a wider number of cells disproves earlier reports and corroborates the safe utilization of testicular spermatozoa with a positive impact on chances of pregnancy.
Project description:A thorough understanding of the events during mammalian spermatogenesis requires studying specific molecular signatures of individual testicular cell populations as well as their interaction in co-cultures. However, most purification techniques to isolate specific testicular cell populations are time-consuming, require large numbers of animals, and/or are only able to isolate a few cell types. Here we describe a cost-effective and timesaving approach that uses a single protocol to enrich multiple testicular cell populations (Sertoli, Leydig, and several spermatogenic cell populations) from as few as one mouse. Our protocol combines rigorous enzymatic digestion of seminiferous tubules with counter-current centrifugal elutriation, yielding specific testicular cell populations with >80%-95% purity.
Project description:The spermatogenic cycle describes the periodic development of germ cells in the testicular tissue. The temporal-spatial dynamics of the cycle highlight the unique, complex, and interdependent interaction between germ and somatic cells, and are the key to continual sperm production. Although understanding the spermatogenic cycle has important clinical relevance for male fertility and contraception, there are a number of experimental obstacles. For example, the lengthy process cannot be visualized through dynamic imaging, and the precise action of germ cells that leads to the emergence of testicular morphology remains uncharacterized. Here, we report an agent-based model that simulates the mouse spermatogenic cycle on a cross-section of the seminiferous tubule over a time scale of hours to years, while considering feedback regulation, mitotic and meiotic division, differentiation, apoptosis, and movement. The computer model is able to elaborate the germ cell dynamics in a time-lapse movie format, allowing us to trace individual cells as they change state and location. More importantly, the model provides mechanistic understanding of the fundamentals of male fertility, namely how testicular morphology and sperm production are achieved. By manipulating cellular behaviors either individually or collectively in silico, the model predicts causal events for the altered arrangement of germ cells upon genetic or environmental perturbations. This in silico platform can serve as an interactive tool to perform long-term simulation and to identify optimal approaches for infertility treatment and contraceptive development.
Project description:Peroxisomes are involved in the degradation of very long-chain fatty acids (VLCFAs) by ?-oxidation. Besides neurological defects, peroxisomal dysfunction can also lead to testicular abnormalities. However, underlying alterations in the testes due to a peroxisomal defect are not well characterized yet. To maintain all metabolic functions, peroxisomes require an import machinery for the transport of matrix proteins. One component of this translocation machinery is PEX13. Its inactivation leads to a peroxisomal biogenesis defect. We have established a germ cell-specific KO of Pex13 to study the function of peroxisomes during spermatogenesis in mice. Exon 2 of floxed Pex13 was specifically excised in germ cells prior to meiosis by using a transgenic mouse strain carrying a STRA8 inducible Cre recombinase. Germ cell differentiation was interrupted at the round spermatid stage in Pex13 KO mice with formation of multinucleated giant cells (MNCs) and loss of mature spermatids. Due to a different cellular content in the germinal epithelium of Pex13 KO testes compared to control, whole testes biopsies were used for the analyses. Thus, differences in lipid composition and gene expression are only shown for whole testicular tissue but cannot be limited to single cells. Gas chromatography revealed an increase of shorter fatty acids and a decrease of n-6 docosapentaenoic acid (C22:5n-6) and n-3 docosahexaenoic acid (C22:6n-3), the main components of sperm plasma membranes. Representative genes of the metabolite transport and peroxisomal ?-oxidation were strongly down-regulated. In addition, structural components of the blood-testis barrier (BTB) were altered. To conclude, defects in the peroxisomal compartment interfere with normal spermatogenesis.
Project description:Infertility is a growing concern in developed societies. Two extreme phenotypes of male infertility are non-obstructive azoospermia (NOA) and severe oligospermia (SO), which are characterized by severe spermatogenic failure (SpF). We designed a genetic association study comprising 725 Iberian infertile men as a consequence of SpF and 1058 unaffected controls to evaluate whether five single-nucleotide polymorphisms (SNPs), previously associated with reduced fertility in Hutterites, are also involved in the genetic susceptibility to idiopathic SpF and specific clinical entities. A significant difference in the allele frequencies of <i>USP8</i>-rs7174015 was observed under the recessive model between the NOA group and both the control group (<i>p</i> = 0.0226, OR = 1.33) and the SO group (<i>p</i> = 0.0048, OR = 1.78). Other genetic associations for <i>EPSTI1</i>-rs12870438 and <i>PSAT1</i>-rs7867029 with SO and between <i>TUSC1</i>-rs10966811 and testicular sperm extraction (TESE) success in the context of NOA were observed. In silico analysis of functional annotations demonstrated cis-eQTL effects of such SNPs likely due to the modification of binding motif sites for relevant transcription factors of the spermatogenic process. The findings reported here shed light on the molecular mechanisms leading to severe phenotypes of idiopathic male infertility, and may help to better understand the contribution of the common genetic variation to the development of these conditions.
Project description:Perturbations in the vitamin A metabolism pathway could be a significant cause of male infertility, as well as a target toward the development of a male contraceptive, necessitating the need for a better understanding of how testicular retinoic acid (RA) concentrations are regulated. Quantitative analyses have recently demonstrated that RA is present in a pulsatile manner along testis tubules. However, it is unclear if the aldehyde dehydrogenase (ALDH) enzymes, which are responsible for RA synthesis, contribute to the regulation of these RA concentration gradients. Previous studies have alluded to fluctuations in ALDH enzymes across the spermatogenic cycle, but these inferences have been based primarily on qualitative transcript localization experiments. Here, we show via various quantitative methods that the three well-known ALDH enzymes (ALDH1A1, ALDH1A2, and ALDH1A3), and an ALDH enzyme previously unreported in the murine testis (ALDH8A1), are not expressed in a stage-specific manner in the adult testis, but do fluctuate throughout juvenile development in perfect agreement with the first appearance of each advancing germ cell type. We also show, via treatments with a known ALDH inhibitor, that lowered testicular RA levels result in an increase in blood-testis barrier permeability, meiotic recombination, and meiotic defects. Taken together, these data further our understanding of the complex regulatory actions of RA on various spermatogenic events and, in contrast with previous studies, also suggest that the ALDH enzymes are not responsible for regulating the recently measured RA pulse.
Project description:The objective of this systemic review was to evaluate the benefit of repairing clinical varicocele in infertile men with nonobstructive azoospermia (NOA). The surgically obtained sperm retrieval rate (SRR) and pregnancy rates following assisted reproductive technology (ART) with the use of retrieved testicular sperm were the primary outcomes. The secondary outcomes included the presence of viable sperm in postoperative ejaculate to avoid the testicular sperm retrieval and pregnancy rates (both assisted and unassisted) using postoperative ejaculated sperm. An electronic search to collect the data was performed using the MEDLINE and EMBASE databases until April 2015. Eighteen studies were included in this systematic review and accounted for 468 patients who were diagnosed with NOA and varicocele. These patients were subjected to either surgical varicocele repair or percutaneous embolization. Three controlled studies evaluating sperm retrieval outcomes indicated that in patients who underwent varicocelectomy, SRR increased compared to those without varicocele repair (OR: 2.65; 95% CI: 1.69-4.14; P< 0.001). Although pregnancy rates with the use of testicular sperm favored the varicocelectomy group, results were not statistically significant (clinical pregnancy rate OR: 2.07; 95% CI: 0.92-4.65; P= 0.08; live birth rate OR: 2.19; 95% CI: 0.99-4.83; P= 0.05). The remaining fifteen studies reported postoperative semen analysis results. In 43.9% of the patients (range: 20.8%-55.0%), sperm were found in postoperative ejaculates. Pregnancy rates for unassisted and assisted (after IVF/ICSI) were 13.6% and 18.9% in the group of men with sperm in postoperative ejaculates, respectively. Our findings indicate that varicocelectomy in patients with NOA and clinical varicocele is associated with improved SRR. In addition, approximately 44% of the treated men will have enough sperm in the ejaculate to avoid sperm retrieval. Limited data on pregnancy outcomes with both postoperative ejaculated sperm and harvested testicular sperm preclude any firm conclusion with regard to the possible increased fertility potential in treated individuals. In conclusion, the results of our study indicate that infertile men with NOA and clinical varicocele benefit from varicocelectomy. ?Given the low/moderate quality of evidence available, it is advisable that doctors discuss with their patients with NOA the risks and benefits of varicocele repair.
Project description:Prior studies have demonstrated that combined treatment of testosterone with a progestin induces a more rapid and greater suppression of spermatogenesis than testosterone treatment alone. We hypothesized that the suppressive effects of the combination of testosterone undecanoate (TU) injections plus oral levonorgestrel (LNG) on spermatogenesis may be mediated through a greater perturbation of testicular gene expression than TU alone. To test this hypothesis, we performed open testicular biopsy on 12 different adult healthy subjects: 1) four healthy men as controls; 2) four men 2 wk after TU treatment; and 3) four men 2 wk after TU + LNG administration. RNA isolated from biopsies was used for DNA microarray using the Affymetrix Human Genome U133 Plus 2.0 oligonucleotide microarrays. Gene expression with >or=2-fold changes (P < 0.05) compared with control was analyzed using the National Institutes of Health Database for Annotation, Visualization, and Integrated Discovery 2008 resource. The TU treatment altered the gene expression in 109 transcripts, whereas TU + LNG altered the gene expression in 207 transcripts compared with control. Both TU and TU + LNG administration suppressed gene expression of insulin-like 3; cytochrome P450, family 17, subfamily A1 in Leydig cells; and inhibin alpha in Sertoli cells; they increased proapoptotic transcripts BCL2-like 14, insulin-like growth factor-binding protein 3; and they decreased X-linked inhibitor of apoptosis protein. In comparison with TU treatment alone, TU + LNG treatment upregulated insulin-like 6 and relaxin 1, and downregulated RNA-binding protein transcripts. We conclude that TU + LNG administration induces more changes in testicular gene expression than TU alone. This exploratory study provided a novel and valuable database to study the mechanisms of action of hormonal regulation of spermatogenesis in men and identified testicular-specific molecules that may serve as potential targets for male contraceptive development.