Epididymis cell atlas in a patient with a sex development disorder and a novel NR5A1 gene mutation

This study aims to characterize the cell atlas of the epididymis derived from a 46,XY disorders of sex development (DSD) patient with a novel heterozygous mutation of the nuclear receptor subfamily 5 group A member 1 (NR5A1) gene. Next-generation sequencing found a heterozygous c.124C>G mutation in NR5A1 that resulted in a p.Q42E missense mutation in the conserved DNA-binding domain of NR5A1. The patient demonstrated feminization of external genitalia and Tanner stage 1 breast development. The surgical procedure revealed a morphologically normal epididymis and vas deferens but a dysplastic testis. Microfluidic-based single-cell RNA sequencing (scRNA-seq) analysis found that the fibroblast cells were significantly increased (approximately 46.5%), whereas the number of main epididymal epithelial cells (approximately 9.2%), such as principal cells and basal cells, was dramatically decreased. Bioinformatics analysis of cell-cell communications and gene regulatory networks at the single-cell level inferred that epididymal epithelial cell loss and fibroblast occupation are associated with the epithelial-to-mesenchymal transition (EMT) process. The present study provides a cell atlas of the epididymis of a patient with 46,XY DSD and serves as an important resource for understanding the pathophysiology of DSD.

Differential gene expression profiles of human efferent ducts and proximal epididymis

BACKGROUND

Gene expression patterns along the epididymis are established by specific transcription factor networks that coordinate region-specific functions. In rodents, the epididymis can be divided in up to 19 segments. Based on gross anatomy, the human epididymis is divided into caput, corpus, and cauda segments together with efferent ducts that occupy the proximal part of this organ.

OBJECTIVES

To determine to which extent gene expression pattern is segmented along the efferent ducts and the proximal region of the epididymis in men of reproductive age.

MATERIALS AND METHODS

Epididymal transcriptome profiling was performed on eight distinct regions from three donors. Microarray analysis was performed on a gene-chip microarray. Differentially expressed genes (DEGs)>2-fold change (P < .05) were clustered in relation to their intensity profiles. Overrepresented biological functions from gene ontology were searched using DAVID 6.8. Expression profiles were validated by qRT-PCR quantification of selected genes.

RESULTS

There were no DEGs among segments 1-3 of efferent ducts region neither among segments 4-6 of the caput epididymis. 1058 DEGs were identified between efferent ducts and the epididymis, whereas 444 and 846 DEGs distinguished the caput from the corpus (section 7) and cauda (section 8) epididymis, respectively. A total of 131 DEGs were detected between corpus (7) and cauda (8) transcriptomes. Up-regulated DEGs in the efferent ducts were predominantly related to cilium assembly/movement and cell differentiation. Fertilization, defense, and immune responses were associated with caput epididymis (4-6), while spermatogenesis and protein binding were found all along the epididymis (4-8).

DISCUSSION

The proximal human epididymis is exclusively occupied by efferent ducts with a distinct DEG profile compared with the downstream epididymal segments. Moreover, gene expression profiling revealed two regions in the human epididymis: the caput and the distal corpus/cauda region.

CONCLUSIONS

Human epididymal transcriptome reveals limited DEGs, and efferent ducts have a distinct DEGs profile.

Region-specific microRNA signatures in the human epididymis

The epithelium of the human epididymis maintains an appropriate luminal environment for sperm maturation that is essential for male fertility. Regional expression of small noncoding RNAs such as microRNAs contributes to segment-specific gene expression and differentiated functions. MicroRNA profiles were reported in human epididymal tissues but not specifically in the epithelial cells derived from those regions. Here, we reveal miRNA signatures of primary cultures of caput, corpus, and cauda epididymis epithelial cells and of the tissues from which they were derived. We identify 324 epithelial cell-derived microRNAs and 259 tissue-derived microRNAs in the epididymis, some of which displayed regionalized expression patterns in cells and/or tissues. Caput cell-enriched miRNAs included miR-573 and miR-155. Cauda cell-enriched miRNAs included miR-1204 and miR-770. Next, we determined the gene ontology pathways associated with in silico predicted target genes of the differentially expressed miRNAs. The effect of androgen receptor stimulation on miRNA expression was also investigated. These data show novel epithelial cell-derived miRNAs that may regulate the expression of important gene networks that are responsible for the regionalized gene expression and function of the epididymis.