Project description:Spermatogenesis is a complex multi-step process involving intricate interactions between different cell types in the male testis. Disruption of these interactions results in infertility. Combination of shotgun tissue proteomics with MALDI imaging mass spectrometry is markedly potent in revealing topological maps of molecular processes within tissues. Here, we use a combinatorial approach on a characterized mouse model of hormone induced male infertility to uncover misregulated pathways. Comparative testicular proteome of wildtype and mice overexpressing human P450 aromatase (AROM+) with pathologically increased estrogen levels unravels gross dysregulation of spermatogenesis and emergence of pro-inflammatory pathways in AROM+ testis. In situ MS allowed us to localize misregulated proteins/peptides to defined regions within the testis. Results suggest that infertility is associated with substantial loss of proteomic heterogeneity, which define distinct stages of seminiferous tubuli in healthy animals. Importantly, considerable loss of mitochondrial factors, proteins associated with late stages of spermatogenesis and steroidogenic factors characterise AROM+ mice. Thus, the novel proteomic approach pinpoints in unprecedented ways the disruption of normal processes in testis and provides a signature for male infertility.
Project description:Infertility is a problem that affects around 15% of couples. In 40-50% of these couples male infertility is involved. The cause of male infertility is still poorly diagnosed and treated. One of the entities of male infertility is disturbed spermatogenesis, which can lead to nonobstructive azoospermia (NOA), with no sperm cells in the ejaculate. The whole genome sequencing (WGS) allow us to identify novel rare variants in potentially NOA-associated genes. One of them was ESX1 gene. The aim of the study was to activate the ESX1 gene using CRISPRa technology in testicular seminoma cells - TCam2. In this study we achieved the successful activation of ESX1 gene in genetically modified TCam-2 cells using CRISPRa system, in which the expression level of ESX1 gene was significantly higher compared to WT cells and negative control with non-targeted sgRNA (p<0.01). These results were successfully confirmed at protein level by using Western blotting and immunofluorescence. Using RNA-seq analysis we determined the genes that were potentially regulated by ESX1 gene. Such genes associated with proliferation and apoptosis process: CCND1, KDR, WNT11, LGALS3, LINC00662, PDE1C, RPS6KA5, FGF4, NANOG, L1TD1, which were differently expressed in cells with ESX1 gene activation in comparison to the controls (p<0.05).
Project description:Male factor infertility affects about 7% of men in the general population and it can be related to a number of different etiologic factors, including genetic anomalies. Both sex chromosomes are enriched in genes prevalently or exclusively expressed in the testis. Nevertheless only the Y chromosome-linked Copy Number Variants (CNVs) and Y-linked genes have been demonstrated as important contributors to impaired sperm production in humans Data on the potential role of X-linked gene products in spermatogenesis derives mainly from model organisms. X-linked genes seem to be expressed both in pre-meiotic and post-meiotic germ cells in the mouse testis and interestingly those expressed in the post-meiotic cells belong to multicopy gene families. The apparent paucity of X-linked factors in male infertility is most likely related to the scarcity of studies, which focused only on a total of seven genes. No pathogenic mutations causing infertility have, thus far, been described in these genes, with the exception of AR gene In order to advance in the understanding of the role of X-linked CNVs and genes in male infertility, we applied an innovative approach based on high resolution X chromosome specific CGH array. Given that such a detailed analysis of the X chromosome has not been published so far and the testicular function of subjects included in the Genomic Variant Database is unknown (except for 24 X-linked CNVs reported in the recent paper by Tuttelmann), our is the first study providing a detailed analysis of X-linked losses and gains in several hundreds of subjects with known sperm parameters.
Project description:Klinefelter syndrome (KS), also known as 47,XXY, is characterized by a distinct set of physiological abnormalities, commonly including infertility. The molecular basis for Klinefelter-related infertility is still unclear, largely due to the cellular complexity of the testis and the intricate endocrine and paracrine signaling that regulates spermatogenesis. Here, we demonstrate an analysis framework for dissecting human testis pathology that uses comparative analysis of single-cell RNA-sequencing data from the biopsies of 13 human donors. By comparing donors from a range of ages and forms of infertility, we generate gene expression signatures that characterize normal testicular function and distinguish clinically distinct forms of male infertility. Unexpectedly, we identified a subpopulation of Sertoli cells within multiple cases of KS that lack transcription from the XIST locus, with the consequence of increased X-linked gene expression compared to all other KS cell populations. By systematic assessment of known signaling pathways, we identify 72 pathways potentially active in testis, dozens of which appear upregulated in KS. Altogether our data support a model of pathogenic changes in interstitial cells cascading from loss of X-inactivation in pubertal Sertoli cells, and nominate testicular GNRH1 as a dosage-sensitive factor secreted by Sertoli cells that may contribute to the process. Our findings demonstrate the value of comparative patient analysis in mapping genetic mechanisms of disease, and identify an epigenetic phenomenon in KS Sertoli cells that may prove important for understanding causes of infertility and sex chromosome evolution.
Project description:Male factor infertility is increasing and recognized as playing a key role in reproductive health and disease. The current primary diagnostic approach is to assess sperm quality associated with reduced sperm number and motility, which has been historically of limited success in separating fertile from infertile males. The current study was designed to develop a molecular analysis to identify male infertility using genome wide alterations in sperm DNA methylation. A signature of differential DNA methylation regions (DMRs) was identified to be associated with male infertility patients. A promising therapeutic treatment of male infertility is the use of follicle stimulating hormone (FSH) analogs which improved sperm numbers and motility in a sub-population of infertility patients. The current study also identified genome-wide DMRs that were associated with the patients that were responsive to FSH therapy versus those that were non-responsive.