Project description:Mammalian spermatozoa acquire their fertilizing ability during epididymal transit. Gene expression patterns along the epididymis are established by specific transcription factor networks that coordinate region-specific functions. The epididymis is usually divided into 3 segments: caput, corpus, and cauda. The human epididymis anatomy does not allow clear distinction between these three segments. To determine to which extent gene expression is segmented along the human epididymis, transcriptome profiling was performed on 8 distinct epididymal regions from 3 donors. Microarray analysis was performed on a Gene Chip Human Clariom S (Affymetrix®) array representing 337 100 transcriptional variants encoded by 20 800 genes. Proximal segments 1 to 3 were distinguishable from the distal epididymal segments (4 to 8) as shown by unsupervised Principal Component Analysis. Transcripts from each segment with differentially expressed genes (DEGs) > 2-fold change and FDR < 0.05 were clustered in relation to their intensity profiles. While no DEGs were detected between segments 1–3 corresponding to the efferent ducts, 1140 DEGs were detected between efferent ducts (1–3) and the epididymis (4–8), 400 between caput (4–6) vs. corpus/cauda (7–8) and none between corpus (7) and cauda (8). Gene Ontology annotation revealed that up-regulated DEGs in the efferent ducts (1–3) were predominantly related to cilium assembly/movement and cell differentiation. The biological process terms 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). In conclusion, 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. Taken together, analysis of the human epididymal transcriptome reveals a limited DEG profile.

Project description:BACKGROUND: The molecular mechanisms resulting in the establishment of regionalized gene expression in the human epididymis involve numerous and complex regulatory elements that have not yet been fully elucidated. Interestingly, more than 200 microRNAs (miRNAs) have been identified in the human epididymis that could be involved in the regulation of mRNA stability and post-transcriptionnal expression in this organ. METHODS: Using a global miRNA microarray approach, we investigated the correlation between the miRNA signature and the gene expression profile found in three distinct regions (caput, corpus and cauda) of human epididymides from 3 donors. In silico prediction of transcript miRNA targets was performed in silico using TargetScan and Miranda software’s. To experimentally verify some of these data, FHCE1 immortalized epididymal cell lines were cotransfected with mimics microRNAs and plasmid constructs containing the 3’UTR of target genes downstream of the luciferase gene. RESULTS: We identified 35 miRNAs differentially expressed between the different segments of the epididymis (fold change > 2, P < 0.01). Among these miRNAs, miR-890, miR-892a, miR-892b, miR-891a, miR-891b belonging to the same cluster located on the X chromosome and specifically expressed in epididymal tissues, are significantly more expressed in the corpus and cauda regions compared to the caput. Interestingly, a strong negative correlation (r= -0,89, P <0.001) was found between the pattern of expression of miR-892b and its potential mRNA target Esrrg (Estrogen Related Receptor Gamma), with miR-145 and Cldn10 mRNA (r= -0,92, P<0.001) and with miR-145 and Cftr mRNA (r= -0,69, P<0.05). We confirmed that miR-145 and miR-892b inhibit the expression of the luciferase reporter via Cldn10 and Esrrg 3’ UTRs respectively, whereas miR-145 does not affect the expression of luciferase after its co-transfection with the plasmid containing the Cftr 3’UTR. CONCLUSION: Overall, our study shows that the expression of miRNAs is segmented along the different regions of the human epididymal duct and correlates with the pattern of target gene expression in these regions. Therefore, epididymal miRNAs may be in charge of the maintenance of gene expression profile in the epididymis that dictate segment-specific secretion of proteins and establish physiological compartments that directly or indirectly affect sperm maturation and fertility. Normal human epididymides from three donors of 26–50 years of age, were collected and dissected into 3 anatomical regions (caput, corpus and cauda).A cross-comparison between the miRNA signature found in different segments was performed using GeneChip miRNA Array 1.0 (Affimetrix, Santa Clara, CA).

Project description:BACKGROUND: The molecular mechanisms resulting in the establishment of regionalized gene expression in the human epididymis involve numerous and complex regulatory elements that have not yet been fully elucidated. Interestingly, more than 200 microRNAs (miRNAs) have been identified in the human epididymis that could be involved in the regulation of mRNA stability and post-transcriptionnal expression in this organ. METHODS: Using a global miRNA microarray approach, we investigated the correlation between the miRNA signature and the gene expression profile found in three distinct regions (caput, corpus and cauda) of human epididymides from 3 donors. In silico prediction of transcript miRNA targets was performed in silico using TargetScan and Miranda software’s. To experimentally verify some of these data, FHCE1 immortalized epididymal cell lines were cotransfected with mimics microRNAs and plasmid constructs containing the 3’UTR of target genes downstream of the luciferase gene. RESULTS: We identified 35 miRNAs differentially expressed between the different segments of the epididymis (fold change > 2, P < 0.01). Among these miRNAs, miR-890, miR-892a, miR-892b, miR-891a, miR-891b belonging to the same cluster located on the X chromosome and specifically expressed in epididymal tissues, are significantly more expressed in the corpus and cauda regions compared to the caput. Interestingly, a strong negative correlation (r= -0,89, P <0.001) was found between the pattern of expression of miR-892b and its potential mRNA target Esrrg (Estrogen Related Receptor Gamma), with miR-145 and Cldn10 mRNA (r= -0,92, P<0.001) and with miR-145 and Cftr mRNA (r= -0,69, P<0.05). We confirmed that miR-145 and miR-892b inhibit the expression of the luciferase reporter via Cldn10 and Esrrg 3’ UTRs respectively, whereas miR-145 does not affect the expression of luciferase after its co-transfection with the plasmid containing the Cftr 3’UTR. CONCLUSION: Overall, our study shows that the expression of miRNAs is segmented along the different regions of the human epididymal duct and correlates with the pattern of target gene expression in these regions. Therefore, epididymal miRNAs may be in charge of the maintenance of gene expression profile in the epididymis that dictate segment-specific secretion of proteins and establish physiological compartments that directly or indirectly affect sperm maturation and fertility.

Dataset Information

Next Generation Sequencing Facilitates Quantitative Analysis of Wild Type, Mst1/2 dKO and Mst1/2; Yap tKO Initial segments of Epididymis Transcriptomes

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