Project description:This study investigates the transcriptomic landscape of human gonadal tissues from individuals with Differences of Sex Development (DSD). Bulk RNA sequencing was performed on dysgenetic testes, testes, ovaries, and ovotestes obtained from pediatric and adult patients with 46,XY and 46,XX DSD phenotypes.
Project description:In a rare subtype of XX Disorder of Sex Development (DSD), individuals are negative for SRY, the testis determining factor on the Y chromosome, yet develop testes or ovotestes, and both of these phenotypes occur in the same family. This is a naturally occurring disorder in humans (Homo sapiens) and dogs (C. familiaris), and phenotypes in the canine XX DSD model are strikingly similar to those in this type of human XX DSD. The purposes of this study were to identify 1) a variant associated with XX DSD in the canine model and 2) gene expression alterations in canine embryonic gonads that could be informative to causation. Using a genome wide association study (GWAS) and whole genome sequencing (WGS), we identified a variant on C. familiaris autosome 9 (CFA9) that is significantly associated with XX DSD in the canine model and in affected purebred dogs. This is the first marker and candidate causative variant identified for inherited canine XX DSD. It lies within the canine ortholog for the human disorder (OMIM 278850), which resides on 17q24, upstream of SOX9. Gene expression studies (RNA-seq and PRO-seq) in embryonic gonads at risk of XX DSD from the canine model identified significant RSPO1 downregulation in comparison to XX controls, without significant upregulation of SOX9 or other known testis pathway genes. A novel mechanism is proposed in which the canine XX DSD variant acts upstream of RSPO1 to induce epigenomic gonadal mosaicism.
Project description:Reproductive development is a complex process orchestrated by precise gene expression and cellular interactions. Disruption to this process can result in Differences of Sex Development (DSDs) which occur in approximately 1-2% of live births. We have previously developed a protocol to differentiate human induced pluripotent stem cells (hiPSCs) into testis-like organoids as a model to study the molecular mechanisms underlying reproductive development and DSD. Here, we performed bulk and single-cell RNA sequencing on testis-like organoids to investigate their transcriptional landscape. Transcriptomic analysis revealed six cell clusters expressing markers associated with bipotential, early Sertoli, and testicular interstitial cells. To address the limited emergence of mature cell types, we generated a doxycycline-inducible NR5A1/SF1 hiPSC line, which successfully triggered the expression of Leydig cell markers upon overexpression. Our findings provide a comprehensive transcriptional profile of hiPSC-derived testis-like organoids, offering insights into human fetal gonadal development and a novel disease modelling system for DSDs.
Project description:Reproductive development is a complex process orchestrated by precise gene expression and cellular interactions. Disruption to this process can result in Differences of Sex Development (DSDs) which occur in approximately 1-2% of live births. We have previously developed a protocol to differentiate human induced pluripotent stem cells (hiPSCs) into testis-like organoids as a model to study the molecular mechanisms underlying reproductive development and DSD. Here, we performed bulk and single-cell RNA sequencing on testis-like organoids to investigate their transcriptional landscape. Transcriptomic analysis revealed six cell clusters expressing markers associated with bipotential, early Sertoli, and testicular interstitial cells. To address the limited emergence of mature cell types, we generated a doxycycline-inducible NR5A1/SF1 hiPSC line, which successfully triggered the expression of Leydig cell markers upon overexpression. Our findings provide a comprehensive transcriptional profile of hiPSC-derived testis-like organoids, offering insights into human fetal gonadal development and a novel disease modelling system for DSDs.
Project description:Remarkable progress has been achieved in understanding the mechanisms controlling sex determination, yet the cause for many Disorders of Sexual Development remains unknown. Of particular interest is a rare XX DSD subtype in which individuals are negative for SRY, the testis determining factor on the Y chromosome, yet develop testes or ovotestes, and both phenotypes occur in the same family. This is a naturally occurring disorder in humans and dogs (Canis lupus familiaris), and phenotypes in the canine XX DSD model are strikingly similar to those in this type of human XX DSD. The purposes of this study were to identify 1) a variant associated with XX DSD in the canine model and 2) gene expression alterations in canine embryonic gonads that could be informative to causation. Using a genome wide association study (GWAS) and whole genome sequencing (WGS), we identified a variant on Canis familiaris autosome 9 (CFA9) that is significantly associated with XX DSD in the canine model and in affected purebred dogs. This is the first marker and candidate mutation identified for inherited canine XX DSD, and it lies within the canine ortholog for the human disorder (OMIM 278850). Inheritance of the variant indicates that XX DSD is a complex trait in which breed genetic background affects penetrance. Furthermore, the homozygous variant genotype is associated with embryonic lethality in at least one breed. Gene expression studies (RNA-seq and PRO-seq) in embryonic gonads at risk of XX DSD from the canine model identified significant RSPO1 downregulation without significant upregulation of SOX9 or other known testis pathway genes. A novel mechanism is proposed in which the canine XX DSD mutation acts upstream of RSPO1 to induce epigenomic gonadal mosaicism.
Project description:<p>The Gabriella Miller Kids First Pediatric Research Program (Kids First) is a trans-NIH effort initiated in response to the 2014 Gabriella Miller Kids First Research Act and supported by the NIH Common Fund. This program focuses on gene discovery in pediatric cancers and structural birth defects and the development of the Gabriella Miller Kids First Pediatric Data Resource (Kids First Data Resource). Both childhood cancers and structural birth defects are critical and costly conditions associated with substantial morbidity and mortality. Elucidating the underlying genetic etiology of these diseases has the potential to profoundly improve preventative measures, diagnostics, and therapeutic interventions.</p> <p>Whole Genome Sequence (WGS) and phenotypic data from this study are accessible through dbGaP and <a href="https://kidsfirstdrc.org/">kidsfirstdrc.org</a>, where other Kids First datasets can also be accessed. Disorders/Differences of Sex Development (DSD) are congenital conditions in which development of chromosomal, gonadal, or anatomic sex is atypical. DSD are chronic medical conditions collectively affecting ~1% of the population, frequently requiring life-long care by multiple specialists, and carrying a significant public health burden. Some are associated with life-threatening events, such as adrenal crises in Congenital Adrenal Hyperplasia (CAH). DSD are also associated with increased infertility, cancer, gender dysphoria risks, psychosocial distress and pervasive challenges to health-related quality of life (HRQoL) for patients and families. DSD are broadly classified into three categories: sex chromosome DSD, 46,XY DSD and 46,XX DSD, and further classified according to the type of gonad found in the patient (ovary, testis, ovotestis). </p> <p>We were able to increase significantly the diagnostic success for DSD using Whole Exome Sequencing (WES), with the identification of disease-causing and likely pathogenic variants in a third of a cohort of 46,XY patients. We have therefore proposed a shift in the diagnostic approach to DSD to use next-gen sequencing as a first-line clinical test, which could lead to faster and more accurate diagnosis, and orient further clinical management, limiting unnecessary, costly, and often invasive endocrine testing and imaging. However many remain unexplained (over half of the XY cases, a significant minority of XX cases, including most ovotesticular DSD, and most syndromic cases). In addition, the very large phenotypic variability in cases with known variants in the same gene is unexplained. </p> <p>We here propose to use Whole-Genome Sequencing (WGS), which dramatically improves upon exome sequencing, covering both coding and non-coding parts of the genome more uniformly, as an approach to not only improve diagnostic yield, but also to identify novel genes and regulatory elements involved in DSD.</p>
Project description:The ability to transmit genetic information through generations depends on preservation of genome integrity. Genetic abnormalities affect cell differentiation, causing tissue specification defects and cancer. We addressed genomic instability in individuals with Differences of Sex Development (DSD), characterized by gonadal dysgenesis, sex reversal, infertility, high susceptibility for different types of cancer, especially Germ Cell Tumors (GCT), and in men with testicular GCTs. We analyzed the whole proteome of leukocytes and confirmed it with immunoblotting and quantitative PCR analysis. Additional data from tissue biopsies strengthen our observations in peripheral blood. In particular, the analysis of leukocytes and dysgenic gonads uncovered DNA damage phenotypes, supported by changes in DNA damage response mechanisms: altered autophagy and innate immune response, suppressed TP53-dependent DNA repair.
Project description:Differences of Sex Development (DSD) are a set of conditions where development of chromosomal, gonadal, or anatomical sex is atypical. With overlapping phenotypes and multiple genes involved, poor diagnostic yields are achieved for many of these conditions. The current DSD diagnostic regimen can be augmented by investigating transcriptome/proteome in vivo, but it is hampered by the unavailability of affected gonadal tissue at the relevant developmental stage. We try to mitigate this limitation by reprogramming readily available skin tissue-derived dermal fibroblasts into Sertoli cells (SC), which could then be deployed for different diagnostic strategies. SCs form the target cell type of choice because they act like an organizing center of embryonic gonadal development and many DSD arise when these developmental processes go awry. Methods: We employed a computational predictive algorithm for cell conversions called Mogrify to predict the transcription factors (TFs) required for direct reprogramming of human dermal fibroblasts into SCs. We established trans-differentiation culture conditions where stable transgenic expression of these TFs was achieved in 46, XY adult dermal fibroblasts using lentiviral vectors. The resulting Sertoli like cells (SLCs) were validated for SC phenotype using several approaches. Results: SLCs exhibited Sertoli-like morphological and cellular properties as revealed by morphometry and xCelligence cell behavior assays. They also showed Sertoli-specific expression of molecular markers such as SOX9, PTGDS, BMP4, or DMRT1 as revealed by IF imaging, RNAseq and qPCR. The SLC transcriptome shared about two thirds of its differentially expressed genes with a human adult SC transcriptome and expressed markers typical of embryonic SCs. Notably, SLCs lacked expression of most markers of other gonadal cell types such as Leydig, germ, peritubular myoid or granulosa cells. Conclusions: The trans-differentiation method was applied to a variety of commercially available 46, XY fibroblasts derived from patients with DSD and to a 46, XX cell line. The DSD SLCs displayed altered levels of trans-differentiation in comparison to normal 46, XY-derived SLCs, thus showcasing the robustness of this new trans-differentiation model.