Project description:BACKGROUND: Vasectomized men who wish for restoration of fertility commonly face problems to conceive despite high surgical success rates of vasovasostomy, a surgery routinely used to retrieve duct patency. In human, vasectomy has consequences on the epididymal transcriptome and is responsible for non-reversible changes that affect the biochemical parameters and functions of ejaculated sperm in vasovasotomized men. Since microRNAs (miRNAs) are key regulators of post-transcriptional gene expression, we explored the consequences of vasectomy on miRNA pattern in the human epididymis and determined the repercussion and reversibility of these changes in seminal microvesicles (SMVs) from semen of vasovasostomized men. METHOD: miRNA signatures from a unique set of human epididymal segments (caput, corpus, cauda) provided by controls and vasectomized donors as well as miRNA content of SMVs isolated from semen of normal, vasectomized and vasovasostomized donors were determined by using high-throughput microarray technology. Epididymal miRNA signature was correlated with gene expression profiles by employing an integrated genomic approach. RESULTS: While the segmented pattern of miRNA expression was maintained along the human epididymis following vasectomy, the array of miRNAs from each anatomical region significantly differed between normal and vasectomized donors. Greatest changes were observed in cauda epididymidis and were negatively correlated with transcription factors. Vasectomy also impacted expression of miRNAs found in SMVs from normal donors, including miRNAs of epididymal origin contained in epididymosomes. Among seminal miRNAs sequelae, 52 were reversible according to miRNA expression level following duct patency retrieval. In contrast, 66 of miRNAs found in SMVs were not retrieved in SMVs after vasovasostomy. CONCLUSION: We showed that vasectomy has a substantial impact on the miRNA signature of the epididymis and SMVs, and that vasovasostomy does not restore all molecular players found in normal fertile individuals. According to the critical role played by miRNAs in the control of male fertility, we believe that miRNA sequelae occurring upstream and downstream of the vasectomy site may be in part responsible for the reduced fertility outcome reported after surgically successful vasectomy reversal. Human epididymides from 3 control (26, 47 and 50 years old. GEO accession number GSE35522) and 3 vasectomized donors (45, 47 and 48 years old), were collected and dissected into 3 anatomical regions (caput, corpus and cauda). Seminal microvesicles (SMVs) were isolated from the semen of normal (pool of 3 donnors), vasectomized (pool of 3 donnors) and vasovasostomized donors (pool of 5 donnors). A cross-comparison between the miRNA signature found in different segments and seminal vesicles was performed using GeneChip miRNA Array 2.0 (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. 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.

Project description:Study question: Can region-specific transcriptional profiling of the epididymis from fertile and sub-fertile bulls predict the aetiology of fertility/subfertility in males? Summary answer:The highly regulated gene expression along the bovine epididymis is affected by the fertility status of bulls used for artificial insemination. What is known already: In mammals, sperm maturation and storage occur in the epididymis. Each epididymal segment has his own transcriptomic signature that modulates the intraluminal composition that governs sequential modifications of the maturing male gamete. Main results and the role of chance: Hierarchical clustering and Principal Component Analysis revealed a clear separation between caput, corpus and cauda epididymides. Some transcripts characterize a particular anatomical segment, whereas others are expressed in two out of three epididymal segments. GO analysis allowed deduction of specific functions played by each epididymal segment. The transcriptional profiles between fertile vs. sub-fertile conditions clustered most closely in the corpus and cauda segments, whereas the profiles in the caput segment were distinct between fertile and sub-fertile bulls. Of the differently expressed genes, ten (including AKAP4, SMCP, SPATA3, TCP11, ODF1, CTCFL, SPATA18, ADAM28, SORD and FAM161A) were found to exert functions related to reproductive systems and 5 genes (including DEAD, CYST11, DEFB119, DEFB124 and MX1) were found to be associated with the defence response. Limitations, reasons for caution: Further work is required to correlate these modulations of epididymal functions with sperm fertilizing ability in order to understand the aetiology of certain cases of idiopathic infertility in livestock and men. Wider implications of the findings: As fertility can be quantified in bulls used for artificial insemination, this species is a unique model to aid in the understanding of male fertility/subfertility in man.Our data provide a molecular characterization that will facilitate advances in understanding the involvement of epididymalphysiology in sub/infertility aetiology.

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.

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MicroRNA signature is altered in both human epididymis and seminal microvesicles following vasectomy.

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