Germ Cells In Testis Research Articles

Ultrastructural Characterization of Testis in Non-descript Goat (Capra hircus)

Background: The proposed experiment was aimed at locating the spermatogonial stem cell niches inside the testis and to characterise the development of germ cells of testis in the non- descript goats at the different stages of pre and post natal life, which could be useful in selecting the goats for breeding at appropriate time and for other interventions related to reproductive developments in the goats. Methods: The present study was conducted on the testes of non-descript goats divided into three groups, viz. neonatal (within 1 month), prepubertal (from 1-18 months) and pubertal (above 18 months) with 10 healthy animals in each group. The collected samples of testis were processed for scanning electron microscopic study and subsequently, the samples were viewed and the photographs were taken in the facility available at Central Instrumentation Facility (CIF), OUAT, Bhubaneswar. Result: The present study revealed that the testis was surrounded by the tunica albuginea, a thin capsule of connective tissue, from which thin septum originated and extended into the inside of the organ. Among these septa, the seminiferous tubules were found. The seminiferous epithelium consisted of spermatogonial cells at different stages of development separated from each other by interstitial connective tissue. The interstitium was made up of randomly arranged collagen bundles. The intertubular vascular connective tissue contained Leydig cells mainly at wider locations where they were bounded by more than two seminiferous tubules. The mediastinal rete testis area contained many cavities of many intercommunicating channels supported by connective tissue pillars. The present study helped in developing a baseline data on the ultrastructural characteristics of seminiferous epithelium, rete restis, peritubular cells, Lyedig cells and other components of testis in non-descript goat at different post natal stages under study. The appearance of seprmatogonial cell lineage at the various post natal stages in non-descript goat would help in accessing the reproductive status of the animal.

Stage-specific expression of Toll-like receptors in the seminiferous epithelium of mouse testis

Genes encoding Toll-like receptors (TLRs) are expressed by germ cells in the mouse testis. Nevertheless, the expression of TLRs by germ cells has only been demonstrated for TLR-3, TLR-9, and TLR-11. Furthermore, the expression of each TLR in relation to the stage of spermatogenesis remains uncertain. We aimed in the present study to examine the expression pattern of all TLRs in germ cells throughout the cycle of seminiferous epithelium in the adult mouse testis. Immunohistochemistry was used to evaluate the expression of TLRs. Results of the present study reveal the expression of TLRs by specific populations of germ cells. Expression of TLRs, except for TLR-7, at endosomal compartments, acrosomes, and/or residual bodies was another interesting and novel finding of the present study. We further demonstrate that the expression of TLR-1, -2, -3, -4, -5, -7, -11, -12, and -13 follows a distinct spatiotemporal pattern throughout the cycle of seminiferous epithelium. While TLR-1, -3, -5, -11, and -12 are expressed in all stages, TLR-4 is expressed only in early and middle stages of spermatogenic cycle. On the other hand, TLR-2, -7, and -13 are expressed only in early stage of spermatogenic cycle. Evidence demonstrating the expression of TLRs in a stage specific manner throughout spermatogenesis strengthen the hypothesis that the expression of various TLRs by germ cells is a developmentally regulated process. However, if TLRs play a role in the regulation of proliferation, growth, maturation, and differentiation of germ cells throughout the cycle of the seminiferous epithelium warrants further investigations.

The Odad3 Gene Is Necessary for Spermatozoa Development and Male Fertility in Mice.

Odad3 gene loss-of-function mutation leads to Primary Ciliary Dyskinesia (PCD), a disease caused by motile cilia dysfunction. Previously, we demonstrated that knockout of the Odad3 gene in mice replicates several features of PCD, such as hydrocephalus, defects in left-right body symmetry, and male infertility, with a complete absence of sperm in the reproductive tract. The majority of Odad3 knockout animals die before sexual maturation due to severe hydrocephalus and failure to thrive, which precludes fertility studies. Here, we performed the expression analysis of the Odad3 gene during gonad development and in adult testes. We showed that Odad3 starts its expression during the first wave of spermatogenesis, specifically at the meiotic stage, and that its expression is restricted to the germ cells in the adult testes, suggesting that Odad3 plays a role in spermatozoa formation. Subsequently, we conditionally deleted the Odad3 gene in adult males and demonstrated that even partial ablation of the Odad3 gene leads to asthenoteratozoospermia with multiple morphological abnormalities of sperm flagella (MMAF) in mice. The analysis of the seminiferous tubules in Odad3-deficient mice revealed defects in spermatogenesis with accumulation of seminiferous tubules at the spermiogenesis and spermiation phases. Furthermore, analysis of fertility in heterozygous Odad3+/- knockout mice revealed a reduction in sperm count and motility as well as abnormal sperm morphology. Additionally, Odad3+/- males exhibited a shorter fertile lifespan. Overall, these results suggest the important role of Odad3 and Odad3 gene dosage in male fertility. These findings may have an impact on the genetic and fertility counseling practice of PCD patients carrying Odad3 loss-of-function mutations.

AZIN2 is associated with apoptosis of germ cells in undescended testis

Undescended testis (UDT), known as cryptorchidism (CRY), is a common congenital disorder in which one or both testicles do not descend normally into the scrotum. A unilateral UDT model was established by inducing UDT in mice through surgery. The results showed that the testis in the UDT model group was abnormal; the lumen of the seminiferous tubule was atrophic; apoptosis, necrosis and shedding were observed in many of the germ cells; the level of sex hormones was abnormal; and mature sperm was reduced. Subsequently, transcriptome sequencing was conducted on the testicular tissue of UDT model mice. Through analysis and verification of differential genes, AZIN2 was identified as playing a key role in the decline in male fertility caused by cryptorchidism. AZIN2 expression and spermine content was down-regulated in the testis of the UDT group. We then used a combination of hypoxanthine and xanthine to create a GC-1 cell damage model. In this model, AZIN2 expression and spermine content was down-regulated. When si-Azin2 transfected GC-1 cells, cell viability and proliferation were decreased. However, in the GC-1 cell damage model transfected with Azin2 over-expressed plasmid, AZIN2 expression and spermine content was up-regulated, reversing the cell damage caused by hypoxanthine and xanthine, and restoring the proliferation ability of GC-1 cells. These results indicate that in UDT, down-regulated AZIN2 expression is a factor in testicular damage. This discussion of the connection between AZIN2 and germ cells has important clinical significance as it provides an important reference for the diagnosis and treatment of cryptorchidism.

Commentary: The fate of germ cells in cryptorchid testis.

Commentary: The fate of germ cells in cryptorchid testis.

The fate of germ cells in cryptorchid testis.

Cryptorchidism in males constitutes a notable risk factor for both infertility and testicular cancer. Infertility in adulthood is closely linked to the germ cell status in childhood. Furthermore, the significance of germ cell status is important as more than 95% of all reported testicular malignancies are germ cell tumors. The review aims to elucidate the pathogenesis of germ cells in cryptorchid testes concerning their association with infertility and testicular malignancies. Impaired germ cell numbers are evident in cryptorchid testes even during antenatal and neonatal stages. In cryptorchidism there is a rapid decline in germ cell number within the first year of life, partially attributed to physiologic gonocyte apoptosis. Additionally, germ cells fail to differentiate normally during mini-puberty leading to reduced germ cell proliferation and delayed clearance of gonocytes from the seminiferous epithelium. Absence of germ cells in testicular biopsies occurs already 10 months of age and germ cell deterioration progressively worsens with approximately 50% of persisting cryptorchid testes lacking germ cells during puberty. The deficient germ cell maturation and proliferation leads to later infertility. Elevated temperature in the cryptorchid testes and also hormonal deficiency contribute to this phenomenon. Germ cell neoplasia in situ (GCNIS) originating during fetal development may manifest in rare cases associated with disorders of sexual development, chromosomal abnormalities in boys, specific syndromes, and teratomas that include cryptorchidism. In adults, the presence of GCNIS predominantly represents a new histology pattern before invasive germ cell cancer is demonstrated and is neither congenital nor related to abnormal gonocyte transformation.

Molecular mechanisms of cellular dysfunction in testes from men with non-obstructive azoospermia.

Male factor infertility affects 50% of infertile couples worldwide; the most severe form, non-obstructive azoospermia (NOA), affects 10-15% of infertile males. Treatment for individuals with NOA is limited to microsurgical sperm extraction paired with in vitro fertilization intracytoplasmic sperm injection. Unfortunately, spermatozoa are only retrieved in ~50% of patients, resulting in live birth rates of 21-46%. Regenerative therapies could provide a solution; however, understanding the cell-type-specific mechanisms of cellular dysfunction is a fundamental necessity to develop precision medicine strategies that could overcome these abnormalities and promote regeneration of spermatogenesis. A number of mechanisms of cellular dysfunction have been elucidated in NOA testicular cells. These mechanisms include abnormalities in both somatic cells and germ cells in NOA testes, such as somatic cell immaturity, aberrant growth factor signalling, increased inflammation, increased apoptosis and abnormal extracellular matrix regulation. Future cell-type-specific investigations in identifying modulators of cellular transcription and translation will be key to understanding upstream dysregulation, and these studies will require development of in vitro models to functionally interrogate spermatogenic niche dysfunction in both somatic and germ cells.

Oncofertility: technical challenges in immature testicular tissue banking

The gonadotoxicity of cancer therapy ranges from severe to mild effects on spermatogenesis, structural, functional, and genetic integrity of spermatozoa. However, these effects are even more pronounced in prepubertal males due to the susceptibility of the prepubertal testis to cytotoxic therapy. The proliferating germ cells in the prepubertal testis are mitotic in nature, thereby becoming a target for anticancer agents. Immature testicular tissue (ITT) cryopreservation is offered as the only fertility preservation (FP) strategy for prepubertal males facing gonadotoxic risk, though it is still experimental in nature. Multiple cryopreservation protocols have been developed to ensure safe and efficacious storage of the tissue and to enable maximum recovery of germ cells during thawing. The thawed tissue can then be used for fertility restoration by either in vitro spermatogenesis or transplantation to reinitiate spermatogenesis and thereby result in the production of mature spermatozoa. However, there are many challenges to overcome to successfully offer this procedure as an established one. This mini-review gives an overview of the progress in ITT cryopreservation and fertility restoration procedures, along with the other challenges.

Rhox8 homeobox gene ablation leads to rete testis abnormality and male subfertility in mice†.

The reproductive homeobox X-linked (Rhox) genes encode transcription factors that are expressed selectively in reproductive tissues including the testis, epididymis, ovary, and placenta. While many Rhox genes are expressed in germ cells in the mouse testis, only Rhox8 is expressed exclusively in the Sertoli cells during embryonic and postnatal development, suggesting a possible role of Rhox8 in embryonic gonad development. Previously, Sertoli cell-specific knockdown of RHOX8 resulted in male subfertility due to germ cell defects. However, this knockdown model was limited in examining the functions of Rhox8 as RHOX8 knockdown occurred only postnatally, and there was still residual RHOX8 in the testis. In this study, we generated new Rhox8 knockout (KO) mice using the CRISPR/Cas9 system. Sex determination and fetal testis development were apparently normal in mutant mice. Fertility analysis showed a low fecundity in Rhox8 KO adult males, with disrupted spermatogenic cycles, increased germ cell apoptosis, and reduced sperm count and motility. Interestingly, Rhox8 KO testes showed an increase in testis size with dilated seminiferous tubules and rete testis, which might be affected by efferent duct (ED) Rhox8 ablation dysregulating the expression of metabolism and transport genes in the EDs. Taken together, the data presented in this study suggest that Rhox8 in the Sertoli cells is not essential for sex determination and embryonic testis differentiation but has an important role in complete spermatogenesis and optimal male fertility.

Study of spermatogenic and Sertoli cells in the Hu sheep testes at different developmental stages.

Spermatogenesis is a highly organized process by which undifferentiated spermatogonia self-renew and differentiate into spermatocytes and spermatids. The entire developmental process from spermatogonia to sperm occurs within the seminiferous tubules. Spermatogenesis is supported by the close interaction of germ cells with Sertoli cells. In this study, testicular tissues were collected from Hu sheep at 8 timepoints after birth: 0, 30, 90, 180, 270, 360, 540, and 720 days. Immunofluorescence staining and histological analysis were used to explore the development of male germ cells and Sertoli cells in the Hu sheep testes at these timepoints. The changes in seminiferous tubule diameter and male germ cells in the Hu sheep testes at these different developmental stages were analyzed. Then, specific molecular markers were used to study the proliferation and differentiation of spermatogonia, the timepoint of spermatocyte appearance, and the maturation and proliferation of Sertoli cells in the seminiferous tubules. Finally, the formation of the blood-testes barrier was studied using antibodies against the main components of the blood-testes barrier, β-catenin, and ZO-1. These findings not only increased the understanding of the development of the Hu sheep testes, but also laid a solid theoretical foundation for Hu sheep breeding.

C9orf131 and C10orf120 are not essential for male fertility in humans or mice.

Male infertility affects approximately 7% of childbearing couples and is a major health issue. Although nearly 50% idiopathic infertile men are assumed to have a genetic basis, the underlying causes remain largely unknown in most infertility cases. Here, we report two rare homozygous variants in two previously uncharacterized genes, C9orf131 and C10orf120, identified in two unrelated men with asthenozoospermia. Both genes were predominantly expressed in the testes. Furthermore, C9orf131 and C10orf120 knockout mice were successfully generated using the CRISPR-Cas9 technology. However, both C9orf131-/- and C10orf120-/- adult male mice were fertile, with testis-to-body weight ratios comparable to those of wild-type mice. No overt differences were found between wild-type, C9orf131-/-, and C10orf120-/- mice regarding testicular/epididymal tissue morphology, sperm count, sperm motility, or sperm morphology. Moreover, TUNEL assays indicated that the number of apoptotic germ cells in testes was not significantly different between the three groups. In summary, these findings suggest that C9orf131 and C10orf120 are redundant genes in male infertility.

A single N-terminal amino acid determines the distinct roles of histones H3 and H3.3 in the Drosophila male germline stem cell lineage.

Adult stem cells undergo asymmetric cell divisions to produce 2 daughter cells with distinct cell fates: one capable of self-renewal and the other committed for differentiation. Misregulation of this delicate balance can lead to cancer and tissue degeneration. During asymmetric division of Drosophila male germline stem cells (GSCs), preexisting (old) and newly synthesized histone H3 are differentially segregated, whereas old and new histone variant H3.3 are more equally inherited. However, what underlies these distinct inheritance patterns remains unknown. Here, we report that the N-terminal tails of H3 and H3.3 are critical for their inheritance patterns, as well as GSC maintenance and proper differentiation. H3 and H3.3 differ at the 31st position in their N-termini with Alanine for H3 and Serine for H3.3. By swapping these 2 amino acids, we generated 2 mutant histones (i.e., H3A31S and H3.3S31A). Upon expressing them in the early-stage germline, we identified opposing phenotypes: overpopulation of early-stage germ cells in the H3A31S-expressing testes and significant germ cell loss in testes expressing the H3.3S31A. Asymmetric H3 inheritance is disrupted in the H3A31S-expressing GSCs, due to misincorporation of old histones between sister chromatids during DNA replication. Furthermore, H3.3S31A mutation accelerates old histone turnover in the GSCs. Finally, using a modified Chromatin Immunocleavage assay on early-stage germ cells, we found that H3A31S has enhanced occupancy at promoters and transcription starting sites compared with H3, while H3.3S31A is more enriched at transcriptionally silent intergenic regions compared to H3.3. Overall, these results suggest that the 31st amino acids for both H3 and H3.3 are critical for their proper genomic occupancy and function. Together, our findings indicate a critical role for the different amino acid composition of the N-terminal tails between H3 and H3.3 in an endogenous stem cell lineage and provide insights into the importance of proper histone inheritance in specifying cell fates and regulating cellular differentiation.

Loss of Dead end1 induces testicular teratomas from primordial germ cells that failed to undergo sexual differentiation in embryonic testes

Spontaneous testicular teratomas (STTs) are tumours comprising a diverse array of cell and tissue types, which are derived from pluripotent stem-like cells called embryonal carcinoma cells (ECCs). Although mouse ECCs originate from primordial germ cells (PGCs) in embryonic testes, the molecular basis underlying ECC development remains unclear. This study shows that the conditional deletion of mouse Dead end1 (Dnd1) from migrating PGCs leads to STT development. In Dnd1-conditional knockout (Dnd1-cKO) embryos, PGCs colonise the embryonic testes but fail to undergo sexual differentiation; subsequently, ECCs develop from a portion of the PGCs. Transcriptomic analyses reveal that PGCs not only fail to undergo sexual differentiation but are also prone to transformation into ECCs by upregulating the expression of marker genes for primed pluripotency in the testes of Dnd1-cKO embryos. Thus, our results clarify the role of Dnd1 in developing STTs and developmental process of ECC from PGC, providing novel insights into pathogenic mechanisms of STTs.

Research progress in effects of MAGE-A family on gastric cancer.

Gastric cancer (GC) is one of the most common malignant tumors worldwide, and most of the patients are diagnosed at the advanced stage. Most of the treating options are comprehensive treatment, in which immunotherapy plays more and more important role. Melanoma antigen-associated gene-A (MAGE-A) family is a kind of cancer testis antigens. Except in germ cells of testis and trophoblast cells of placenta, MAGE-A family is highly expressed in cancerous tissues and participates in a variety of biological processes, such as cancer cell proliferation, differentiation and metastasis. In addition, cancer testis antigen also possesses good immunogenicity, which can induce humoral and cellular immune responses, is a good target for immunotherapy, and has good application value in the diagnosis, treatment and prognosis of GC. A variety of targeted therapeutic drugs based on MAGE-A are in phase I or II clinical trials, it has good safety and potential clinical application value. With the continuous progress of clinical trials and basic research on MAGE-A targets in GC, it is expected to provide a theoretical basis for clinical transformation and immunotherapy of MAGE-A in the future.

What are Sertoli cells? Historical, methodological, and functional aspects.

Sertoli cells are somatic cells that are in close contact with germ cells in the mammalian testes. They have multiple functions and fulfill key roles for the development and proper maturation of spermatogenic cells into functional spermatozoa. One of their most important properties is to release trophic factors and supply nutrients to germ cells. But they are also involved in the regulation of the immune system in testis, and provide an immunologically privileged environment for developing germ cells. Because they are so essential for reproductive cells, their alterations can have detrimental consequences for fertility. Many environmental factors and exposures such as high caloric diet, toxins, and pollutants are thought to compromise Sertoli cells physiology. This review describes the discovery of Sertoli cells and the methods used for their study, summarizes their major properties and functions, and describes their dysfunctions in pathologies, particularly associated with environmental stressors.

The Divergent and Conserved Expression Profile of Turtle Nanog Gene Comparing with Fish and Mammals.

Simple SummaryChinese soft-shell turtle (Pelidiscus sinensis) is a widely farmed aquatic reptile in China. It has of high nutritional, pharmaceutical, and economic value, but wild Chinese soft-shell turtle has been faced with an extreme decline of populations. Thus, it is of great significance to study the germ cells biology and develop the techniques for turtle breeding and genetic resource preserving. Nanog is a homeodomain-containing transcription factor, and it plays a vital role in maintaining the pluripotency of embryonic stem cells; there is a lack of reporting on the Nanog gene in reptile. In this study, the cDNA sequence and promoter of a Nanog gene was identified in P. sinensis, designed as PsNanog. PsNanog gene products were mainly expressed in gonads and were especially rich in ovary. Particularly, PsNanog mRNA and protein was exclusively expressed in germ cells in ovary and testis. Collectively, this is the first report on the gene structure and expression of Nanog in turtle, which may lay a foundation for further functional analysis of the Nanog in turtle, even in the reptiles. Further, PsNanog probably has the conserved and divergent function in regulating cell pluripotency and germ cell development in turtle, compared with other species, including teleosts and mammals.Nanog is a homeodomain-containing transcription factor, and it plays a vital role in maintaining the pluripotency of embryonic stem cells. Nanog’s function has been well studied in many species. However, there is lack of reporting on the Nanog gene in reptile. Here, we identified a 1032 bp cDNA sequence of a Nanog gene in Pelidiscus sinensis, known as PsNanog. PsNanog has a highly conserved HD domain and shares a high identity with that of Chelonia mydas and the lowest identity with Oryzias latipes. Similarly, PsNanog presented a tight cluster with C. mydas Nanog, but was far from those of teleosts. Additionally, we cloned a length of 1870 bp PsNanog promoter. Dual luciferase assay showed that the DNA fragment of −1560 to +1 exhibited a high promoter activity. The RT-PCR and RT-qPCR results showed that PsNanog was predominantly expressed in ovary, and then in testis. The in situ hybridization and immunohistochemical analysis showed that PsNanog was expressed in the early primary oocytes and the cytoplasm of the cortical region of stage VIII oocytes in ovary, and distributed in most stages of germ cells in testis. Collectively, the results imply that PsNanog probably has the conserved function in regulating germ cell development across phyla and is also a pluripotent cell gene and expressed in germ cells, which is similar to that in teleosts and mammals.

Dosage Compensation of the X Chromosome during Sheep Testis Development Revealed by Single-Cell RNA Sequencing.

Simple SummaryMale and female mammals carry the same complement of autosomes but differ with respect to their sex chromosomes: females carry XX chromosomes and males carry XY chromosomes. The evolutionary loss of genes from the Y chromosome led to a disparity in the dosage of X chromosomes versus autosomal genes, with males becoming monosomic for X-linked gene products. An imbalance in gene expression may have detrimental consequences. In males, X-linked genes need to be upregulated to levels equal to those of females, which is called dosage compensation. The existence of dosage compensation in germ cells is controversial. In testis, dosage compensation is thought to cease during meiosis. Some studies showed that the X chromosome is inactivated during meiosis and premature transcriptional inactivation of the X and Y chromosome during mid-spermatogenesis is essential for fertility. However, some studies failed to find support for male germline X inactivation. Using single-cell RNA seq data, in this study, we presented a comprehensive transcriptional map of sheep testes at different developmental stages and found that germ cell types in sheep testes show X-chromosome expression similar to that in the autosomes. The dosage compensation of germ cells at different stages was analyzed. MSL complex members are expressed in female flies and orthologs exist in many species, where dosage compensation mechanisms are absent or fundamentally different. This suggests that the MSL complex members also function outside of the dosage compensation machinery. Studies have shown that MSL complex can regulate mammalian X inactivation and activation.Dosage compensation is a mechanism first proposed by Susumu Ohno, whereby X inactivation balances X gene output between males (XY) and females (XX), while X upregulation balances X genes with autosomal gene output. These mechanisms have been actively studied in Drosophila and mice, but research regarding them lags behind in domestic species. It is unclear how the X chromosome is regulated in the sheep male germline. To address this, using single-cell RNA sequencing, we analyzed testes in three important developmental stages of sheep. We observed that the total RNA per cell from X and autosomes peaked in SSCs and spermatogonia and was then reduced in early spermatocytes. Furthermore, we counted the detected reads per gene in each cell type for X and autosomes. In cells experiencing dose compensation, close proximity to MSL (male-specific lethal), which is regulated the active X chromosome and was observed. Our results suggest that there is no dose compensation in the pre-meiotic germ cells of sheep testes and, in addition, MSL1 and MSL2 are expressed in early germ cells and involved in regulating mammalian X-chromosome inactivation and activation.

Commentary on to “Clinicopathologic predictors of outcomes in children with stage I testicular germ cell tumors: A pooled post hoc analysis of trials from the Children's Oncology Group”

I commend the authors for studying clinical stage I testis germ cell tumor (TGCT) to identify predictors for relapse during surveillance and I appreciate the challenges that come with analyzing clinical management of a relatively rare disease [ [1] Singla N. Wong J. Singla S. Krailo M. Huang L. Shaikh F. et al. Clinicopathologic predictors of outcomes in children with Stage I testicular germ cell tumors: a pooled post hoc analysis of trials from the Children's Oncology Group. J Pediatr Urol. 2022; (In press https:://doi.org/10.1016/j.jpurol.2022.04.022) Google Scholar ]. Nonetheless, potential biases should be considered when interpreting the results. The authors analyzed multiple data points (age and pT stage at diagnosis, tumor markers and pathology specimen characteristics) to determine which, if any, affect risk of relapse, development of secondary malignant neoplasm or death during surveillance. Surveillance protocols were not the same for all patients, which the authors acknowledged is a potential selection bias. Of the data points analyzed, only age and AFP level were available for all 106 patients. Tumor pT stage was unknown in 27 percent, beta-HCG unknown in 46 percent and histology unknown in 25 percent of the study population. The authors explained the incidences of unknown, stating that in order to maintain statistical integrity they reported “unknown” unless the full complement of pathologic variables was available. But missing data for a large proportion of a study population could bias results, regardless of the reason for the data missing. Response to commentary re: Clinicopathologic predictors of outcomes in children with stage I testicular germ cell tumors: A pooled post hoc analysis of trials from the Children's oncology groupJournal of Pediatric UrologyPreviewPediatric and adolescent patients with testicular germ cell tumors (TGCT) are a particularly challenging population to study given the relatively uncommon incidence of TGCT in children. Unlike in adults, there are no reliable prognostic features to individualize risk of relapse among children with low-stage TGCT. Given this pressing clinical need, herein we leveraged data from three prospective cooperative trials to identify clinicopathologic features predictive for relapse in children with stage I TGCT. Full-Text PDF

Germline FOXJ2 overexpression causes male infertility via aberrant autophagy activation by LAMP2A upregulation

Spermatogenesis is a complex biological process that produces haploid spermatozoa and requires precise regulation by many tissue-specific factors. In this study, we explored the role and mechanism of Fork head box J2 (FOXJ2, which is highly expressed in spermatocytes) in the regulation of spermatogenesis using a germline-specific conditional Foxj2 knock-in mouse model (Stra8-Cre; Foxj2tg/tg mouse). Foxj2 overexpression in mouse testes led to spermatogenesis failure, which started at the initiation of meiosis, and resulted in male infertility. Lysosomes and autophagy-related genes were upregulated in Stra8-cre; Foxj2tg/tg mouse testes and the number of autolysosomes in the spermatocytes in Stra8-cre; Foxj2tg/tg mice was increased. Chromatin immunoprecipitation-PCR and Dual-luciferase reporter assays showed that Lamp2 (encoding lysosome‐associated membrane protein‐2) was a target of FOXJ2. Foxj2 overexpression increased the expression levels of Lamp2a and Hsc70 (70-kDa cytoplasmic heat shock protein) in the Stra8-cre; Foxj2tg/tg mouse testes. Our results suggested that Foxj2 overexpression in the germ cells of mouse testes affects chaperone-mediated autophagy by upregulating LAMP2A, leading to spermatogenesis failure at the initiation of meiosis, thus resulting in male infertility. Our findings provide a new insight into the function of FOXJ2 in spermatogenesis and the significance of autophagy regulation in spermatogenesis.

LIN28 Family in Testis: Control of Cell Renewal, Maturation, Fertility and Aging.

Male reproductive development starts early in the embryogenesis with somatic and germ cell differentiation in the testis. The LIN28 family of RNA-binding proteins promoting pluripotency has two members—LIN28A and LIN28B. Their function in the testis has been investigated but many questions about their exact role based on the expression patterns remain unclear. LIN28 expression is detected in the gonocytes and the migrating, mitotically active germ cells of the fetal testis. Postnatal expression of LIN28 A and B showed differential expression, with LIN28A expressed in the undifferentiated spermatogonia and LIN28B in the elongating spermatids and Leydig cells. LIN28 interferes with many signaling pathways, leading to cell proliferation, and it is involved in important testicular physiological processes, such as cell renewal, maturation, fertility, and aging. In addition, aberrant LIN28 expression is associated with testicular cancer and testicular disorders, such as hypogonadotropic hypogonadism and Klinefelter’s syndrome. This comprehensive review encompasses current knowledge of the function of LIN28 paralogs in testis and other tissues and cells because many studies suggest LIN28AB as a promising target for developing novel therapeutic agents.