A diagnostic germ cell score for immature testicular tissue at risk of germ cell loss

Klinefelter Syndrome (KS) is the most common genetic cause of infertility in men. Degeneration of the testicular tissue starts in utero and accelerates at puberty with hyalinisation of seminiferous tubules, spermatogonia apoptosis and germ cell maturation arrest. Therefore, fertility preservation in young KS boys has been proposed, although this measure is still debated due to insufficient knowledge of the pathophysiology of the disease. To better understand the underlying mechanisms of testicular failure and germ cell loss, we analysed functional and morphological alterations in the somatic compartment of KS testis, i.e., Sertoli cells, including the blood–testis barrier (BTB) and Leydig cells (LC). We compared three populations: 35 KS 47,XXY non-mosaic patients, 28 Sertoli-cell-only (SCO) syndrome patients and 9 patients with normal spermatogenesis. In KS patients the expression of BTB proteins connexin-43 and claudin-11 assessed with a semi-quantitative scoring system appeared significantly reduced with a disorganised pattern. A significant reduction in seminiferous tubules expressing androgen receptors (AR) was observed in KS compared to normal spermatogenesis controls. INSL3 expression, a marker of LC maturation, was also significantly reduced in KS compared to patients with normal spermatogenesis or SCO. Hence, the somatic compartment impairment in KS could be involved in degeneration of seminiferous tubules.

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Cisplatin and carboplatin result in similar gonadotoxicity in immature human testis with implications for fertility preservation in childhood cancer

BMC Medicine ◽

10.1186/s12916-020-01844-y ◽

2020 ◽

Vol 18 (1) ◽

Author(s):

Melissa D. Tharmalingam ◽

Gabriele Matilionyte ◽

William H. B. Wallace ◽

Jan-Bernd Stukenborg ◽

Kirsi Jahnukainen ◽

...

Keyword(s):

Germ Cell ◽

Childhood Cancer ◽

Cell Loss ◽

Testicular Tissue ◽

Cell Number ◽

Human Testis ◽

Cell Populations ◽

Similar Degree ◽

Future Fertility ◽

The Impact

Abstract Background Clinical studies indicate chemotherapy agents used in childhood cancer treatment regimens may impact future fertility. However, effects of individual agents on prepubertal human testis, necessary to identify later risk, have not been determined. The study aimed to investigate the impact of cisplatin, commonly used in childhood cancer, on immature (foetal and prepubertal) human testicular tissues. Comparison was made with carboplatin, which is used as an alternative to cisplatin in order to reduce toxicity in healthy tissues. Methods We developed an organotypic culture system combined with xenografting to determine the effect of clinically-relevant exposure to platinum-based chemotherapeutics on human testis. Human foetal and prepubertal testicular tissues were cultured and exposed to cisplatin, carboplatin or vehicle for 24 h, followed by 24–240 h in culture or long-term xenografting. Survival, proliferation and apoptosis of prepubertal germ stem cell populations (gonocytes and spermatogonia), critical for sperm production in adulthood, were quantified. Results Cisplatin exposure resulted in a significant reduction in the total number of germ cells (− 44%, p < 0.0001) in human foetal testis, which involved an initial loss of gonocytes followed by a significant reduction in spermatogonia. This coincided with a reduction (− 70%, p < 0.05) in germ cell proliferation. Cisplatin exposure resulted in similar effects on total germ cell number (including spermatogonial stem cells) in prepubertal human testicular tissues, demonstrating direct relevance to childhood cancer patients. Xenografting of cisplatin-exposed human foetal testicular tissue demonstrated that germ cell loss (− 42%, p < 0.01) persisted at 12 weeks. Comparison between exposures to human-relevant concentrations of cisplatin and carboplatin revealed a very similar degree of germ cell loss at 240 h post-exposure. Conclusions This is the first demonstration of direct effects of chemotherapy exposure on germ cell populations in human foetal and prepubertal testis, demonstrating platinum-induced loss of all germ cell populations, and similar effects of cisplatin or carboplatin. Furthermore, these experimental approaches can be used to determine the effects of established and novel cancer therapies on the developing testis that will inform fertility counselling and development of strategies to preserve fertility in children with cancer.

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Faculty Opinions recommendation of When does germ cell loss and fibrosis occur in patients with Klinefelter syndrome?

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.733094219.793555183 ◽

2019 ◽

Author(s):

Robert Oates

Keyword(s):

Germ Cell ◽

Klinefelter Syndrome ◽

Cell Loss

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Drosophila CG2469 Encodes a Homolog of Human CTR9 and Is Essential for Development

G3 Genes|Genome|Genetics ◽

10.1534/g3.116.035196 ◽

2016 ◽

Vol 6 (12) ◽

pp. 3849-3857 ◽

Cited By ~ 5

Author(s):

Dhananjay Chaturvedi ◽

Mayu Inaba ◽

Shane Scoggin ◽

Michael Buszczak

Keyword(s):

Germ Cell ◽

Sequence Similarity ◽

Cell Loss ◽

Germline Stem Cell ◽

Cell Nuclei ◽

Transcriptional Initiation ◽

Histone Locus Bodies ◽

Paf1 Complex ◽

Histone Locus ◽

Drosophila Cells

Abstract Conserved from yeast to humans, the Paf1 complex participates in a number of diverse processes including transcriptional initiation and polyadenylation. This complex typically includes five proteins: Paf1, Rtf1, Cdc73, Leo1, and Ctr9. Previous efforts identified clear Drosophila homologs of Paf1, Rtf1, and Cdc73 based on sequence similarity. Further work showed that these proteins help to regulate gene expression and are required for viability. To date, a Drosophila homolog of Ctr9 has remained uncharacterized. Here, we show that the gene CG2469 encodes a functional Drosophila Ctr9 homolog. Both human and Drosophila Ctr9 localize to the nuclei of Drosophila cells and appear enriched in histone locus bodies. RNAi knockdown of Drosophila Ctr9 results in a germline stem cell loss phenotype marked by defects in the morphology of germ cell nuclei. A molecular null mutation of Drosophila Ctr9 results in lethality and a human cDNA CTR9 transgene rescues this phenotype. Clonal analysis in the ovary using this null allele reveals that loss of Drosophila Ctr9 results in a reduction of global levels of histone H3 trimethylation of lysine 4 (H3K4me3), but does not compromise the maintenance of stem cells in ovaries. Given the differences between the null mutant and RNAi knockdown phenotypes, the germ cell defects caused by RNAi likely result from the combined loss of Drosophila Ctr9 and other unidentified genes. These data provide further evidence that the function of this Paf1 complex component is conserved across species.

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Prognostic Value of Apoptosis-Inducing Factor (AIF) in Germ Cell Tumors

Cancers ◽

10.3390/cancers13040776 ◽

2021 ◽

Vol 13 (4) ◽

pp. 776

Author(s):

Katarina Letkovska ◽

Pavel Babal ◽

Zuzana Cierna ◽

Silvia Schmidtova ◽

Veronika Liskova ◽

...

Keyword(s):

Germ Cell ◽

Nuclear Translocation ◽

Malignant Tumors ◽

Expression Patterns ◽

Germ Cell Tumors ◽

Testicular Tissue ◽

Testicular Germ Cell ◽

Visceral Metastases ◽

Apoptosis Inducing Factor ◽

Clinicopathological Variables

Apoptosis is a strictly regulated process essential for preservation of tissue homeostasis. This study aimed to evaluate expression of apoptosis inducing factor (AIF) in testicular germ cell tumors (GCTs) and to correlate expression patterns with clinicopathological variables. Formalin-fixed and paraffin-embedded specimens of non-neoplastic testicular tissue and GCTs obtained from 216 patients were included in the study. AIF expression was detected by immunohistochemistry, scored by the multiplicative quickscore method (QS). Normal testicular tissue exhibits higher cytoplasmic granular expression of AIF compared to GCTs (mean QS = 12.77 vs. 4.80, p < 0.0001). Among invasive GCTs, mean QS was the highest in embryonal carcinoma, yolk sac tumor and seminoma, lower in teratoma and the lowest in choriocarcinoma. No nuclear translocation of AIF was observed. Nonpulmonary visceral metastases were associated with lower AIF expression. Metastatic GCTs patients with high AIF expression had better overall survival compared to patients with low AIF expression (HR = 0.26, 95% CI 0.11–0.62, p = 0.048). We observed significantly lower AIF expression in GCTs compared to normal testicular tissue, which is an uncommon finding in malignant tumors. AIF downregulation might represent one of the mechanisms of inhibition of apoptosis and promotion of cell survival in GCTs.

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Modification of spermatozoa quality in mature small ruminants

Reproduction Fertility and Development ◽

10.1071/rd11902 ◽

2012 ◽

Vol 24 (1) ◽

pp. 13 ◽

Cited By ~ 6

Author(s):

G. B. Martin ◽

T. Jorre de St Jorre ◽

F. A. Al Mohsen ◽

I. A. Malecki

Keyword(s):

Large Body ◽

Small Ruminants ◽

Cell Loss ◽

Testicular Tissue ◽

The Other ◽

Sperm Production ◽

Testicular Mass ◽

Other Hand ◽

Sperm Survival ◽

Sperm Output

This review is based largely, but not entirely, on the assumption that gamete quality is directly linked to sperm output and thus testicular mass, an approach made necessary by the absence of a large body of data on factors that affect gamete quality in ruminants. On the other hand, there is a change in the efficiency of sperm production per gram of testicular tissue when the testis is growing or shrinking, a clear indicator of changes in the rates of cell loss during the process of spermatogenesis, probably through apoptosis. We therefore postulate that the spermatozoa that do survive when the testis is shrinking are of a lower quality than those that are produced when the testis is growing and the rate of sperm survival is increasing. In adult small ruminants in particular, testicular mass and sperm production are highly labile and can be manipulated by management of photoperiod (melatonin), nutrition, genetics and behaviour (‘mating pressure’). Importantly, these factors do not act independently of each other – rather, the outcomes in terms of sperm production are dictated by interactions. It therefore seems likely that spermatozoa quality will be affected by these same factors, but definitive answers await detailed studies.

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