Aberrant DNA methylation at imprinted genes in testicular sperm retrieved from men with obstructive azoospermia and undergoing vasectomy reversal

Male factor infertility has been associated with abnormal DNA methylation at imprinted genes. Little information is available on the status of imprinting in the sperm of men with azoospermia, including the association between aberrant imprinting and obstructive azoospermia (OA) or non-OA (NOA). Analysis of DNA methylation at imprinted genes in the sperm of men undergoing vasectomy reversal would aid determination of whether aberrant imprinting is associated with obstruction. Testicular sperm was retrieved from testicular biopsies obtained from men with azoospermia (N=18), including OA (N=10), NOA (N=5), and unknown pathology (N=3), and from men undergoing vasectomy reversal (N=17). Sperm was also obtained from proven fertile men (N=9). DNA methylation was investigated at multiple CpG sites within the differentially methylated regions (DMRs) of three imprinted genes,H19,IG-GTL2andMEST, using bisulphite sequencing. Unique clones representative of single cells were analyzed. We found a significant decrease in DNA methylation at theH19DMR in testicular sperm of azoospermic men compared with proven fertile men. The decrease was also significant between OA and proven fertile men, and between men undergoing vasectomy reversal and proven fertile men, suggesting that aberrant DNA methylation may be associated with obstruction. Changes in DNA methylation atIG-GTL2andMESTDMRs among groups were not significant. Our data suggest that imprinting abnormalities may be associated with obstruction and may occur in response to changes in testicular environment and not only spermatogenesis failure, as previously reported. Methylation at theH19DMR was particularly prone to modification in testicular sperm.

Download Full-text

Exposure to organophospate contaminants is associated with aberrant DNA methylation at imprinted genes in sperm: results of the TIEGER study.

ISEE Conference Abstracts ◽

10.1289/isee.2016.3647 ◽

2016 ◽

Vol 2016 (1) ◽

Author(s):

Adelheid Soubry* ◽

Craig M Butt ◽

Steffen Fieuws ◽

Cathrine Hoyo ◽

Stephanie Romanus ◽

...

Keyword(s):

Dna Methylation ◽

Imprinted Genes ◽

Aberrant Dna Methylation

Download Full-text

Human exposure to flame-retardants is associated with aberrant DNA methylation at imprinted genes in sperm

Environmental Epigenetics ◽

10.1093/eep/dvx003 ◽

2017 ◽

Vol 3 (1) ◽

Cited By ~ 21

Author(s):

Adelheid Soubry ◽

Cathrine Hoyo ◽

Craig M. Butt ◽

Steffen Fieuws ◽

Thomas M. Price ◽

...

Keyword(s):

Dna Methylation ◽

Human Exposure ◽

Flame Retardants ◽

Imprinted Genes ◽

Aberrant Dna Methylation

Download Full-text

Whole-genome methylation analysis of testicular germ cells from cryptozoospermic men points to recurrent and functionally relevant DNA methylation changes

Clinical Epigenetics ◽

10.1186/s13148-021-01144-z ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Sara Di Persio ◽

Elsa Leitão ◽

Marius Wöste ◽

Tobias Tekath ◽

Jann-Frederik Cremers ◽

...

Keyword(s):

Dna Methylation ◽

Germ Cells ◽

Regulatory Elements ◽

Obstructive Azoospermia ◽

Whole Genome ◽

Genome Methylation ◽

Genome Level ◽

Aberrant Dna Methylation ◽

Almost All ◽

Distal Regulatory Elements

Abstract Background Several studies have reported an association between male infertility and aberrant sperm DNA methylation patterns, in particular in imprinted genes. In a recent investigation based on whole methylome and deep bisulfite sequencing, we have not found any evidence for such an association, but have demonstrated that somatic DNA contamination and genetic variation confound methylation studies in sperm of severely oligozoospermic men. To find out whether testicular germ cells (TGCs) of such patients might carry aberrant DNA methylation, we compared the TGC methylomes of four men with cryptozoospermia (CZ) and four men with obstructive azoospermia, who had normal spermatogenesis and served as controls (CTR). Results There was no difference in DNA methylation at the whole genome level or at imprinted regions between CZ and CTR samples. However, using stringent filters to identify group-specific methylation differences, we detected 271 differentially methylated regions (DMRs), 238 of which were hypermethylated in CZ (binominal test, p < 2.2 × 10–16). The DMRs were enriched for distal regulatory elements (p = 1.0 × 10–6) and associated with 132 genes, 61 of which are differentially expressed at various stages of spermatogenesis. Almost all of the 67 DMRs associated with the 61 genes (94%) are hypermethylated in CZ (63/67, p = 1.107 × 10–14). As judged by single-cell RNA sequencing, 13 DMR-associated genes, which are mainly expressed during meiosis and spermiogenesis, show a significantly different pattern of expression in CZ patients. In four of these genes, the promoter is hypermethylated in CZ men, which correlates with a lower expression level in these patients. In the other nine genes, eight of which downregulated in CZ, germ cell-specific enhancers may be affected. Conclusions We found that impaired spermatogenesis is associated with DNA methylation changes in testicular germ cells at functionally relevant regions of the genome. We hypothesize that the described DNA methylation changes may reflect or contribute to premature abortion of spermatogenesis and therefore not appear in the mature, motile sperm.

Download Full-text

MICROSCOPIC TESTICULAR SPERM EXTRACTION

The Professional Medical Journal ◽

10.29309/tpmj/2018.25.02.439 ◽

2018 ◽

Vol 25 (02) ◽

pp. 180-184

Author(s):

Maher Saleh Moazin ◽

Muhammad Tahir Bashir Malik ◽

Muhammad Aslam ◽

Naif Aldaham ◽

Muhammad Yahya Alrawi

Keyword(s):

Chromosomal Abnormalities ◽

Testicular Sperm Extraction ◽

Obstructive Azoospermia ◽

Testicular Sperm ◽

Male Factor ◽

Sperm Retrieval ◽

Retrieval Rate ◽

Medical City ◽

Infertile Couples ◽

Small Hematoma

Azoospermia, the complete absence of sperms in the ejaculate is found in 1% ofnormal males and 10-15% of infertile couples. Surgical sperm retrieval (SSR) and use of spermsfor ICSI/IVF offers an opportunity of parenting to the male factor infertile couples. Micro-TESEgives higher surgical sperms retrieval rates in those patients in whom the chances of spermretrieval otherwise are very low. Objectives: To evaluate the outcome of Microscopic TesticularSperm Extraction (Micro-TESE) in different patients groups of non-obstructive azoospermia,in terms of testicular volume, histopathology, hormones levels as well as cytogenetic variants.Study Design: Retrospectively reviewed. Setting: Urology Division, King Fahd Medical City,Riyadh in collaboration with King Abdullah Reproductive Medical Unit (RMU). Period: January2011 to January 2016. Material & Methods: Fifty-four patients of primary and secondary infertilityage range of 29 to 65 years who had undergone Microscopic Testicular Sperm Extraction(Micro-TESE). Outcome measures: Finding of sperm in testicular specimen extracted bymicroscopic testicular dissection. Results: Out of 54 patients, hormonal abnormalities werefound in 45% patients and 65% had low volume testes. Abnormal histology was found in 23%patients and 9% had chromosomal abnormalities. Overall sperm retrieval rate in all groups was33%. Sperm retrieval rate was 34 % in patients with small volume testes (<15ml), 42% patientswith abnormal hormones (FSH), 33% patients with abnormal histology and 38% in patientswith chromosomal abnormalities. Minor complications (small hematoma and orchalgia) wereobserved in two (3.7%) patients. Conclusion: Micro-TESE is a valid option for sperm retrieval inpatients in which probability of sperm retrieval is otherwise very low.

Download Full-text