mTOR/P70S6K promotes spermatogonia proliferation and spermatogenesis in Sprague Dawley rats

Quercetin induces ferroptosis by inactivating mTOR/S6KP70 pathway in oral squamous cell carcinoma

Although recent studies increasingly suggest the potential anti-cancer effect of quercetin, the exact underlying mechanism remains poorly demonstrated in oral squamous cell carcinoma (oSCC). Therefore, our research explored the impacts of quercetin on the ferroptosis and mTOR/S6KP70 axis in oSCC cell lines. After treating oSCC cells with quercetin or indicated compounds and transfection with SLC7A11- or S6KP70-overexpressing plasmid, cell viability was detected by CCK-8 assay. The level of ferroptosis in oSCC cells was assessed by measuring ROS and GSH levels. The activation of mTOR/S6KP70 axis was assessed by Western blotting. Quercetin promoted ferroptosis in an mTOR/S6KP70-dependent manner to inhibit tumor growth in oSCC cells. Mechanistically, we revealed that quercetin induced lipid peroxidation and reduced GSH levels by repressing SLC7A11 expression in oSCC cells. Specifically, the effects of quercetin on ferroptosis and mTOR and S6KP70 phosphorylation were partially blocked by both mTOR agonist and S6KP70 overexpression. Moreover, mTOR inhibitor promoted ferroptosis in quercetin-treated oSCC cells. Our findings showed that ferroptosis may be a new anti-tumor mechanism of quercetin. Additionally, we identified that quercetin can target mTOR/S6KP70 cascade to inhibit the growth of oSCC cells.

Bazi Bushen alleviates reproductive aging in aged male mice

Bazi Bushen (BZBS), a traditional Chinese medicine (TCM), has demonstrated therapeutic efficacy in testicular dysfunction within D-galactose and NaNO2 mouse models. This study aimed to ascertain if BZBS could also mitigate the decline in testicular function associated with natural aging. Therefore, male aged mice were employed to evaluate the preventive effects of BZBS on male reproductive aging. This was achieved by assessing sex hormone production, testicular histomorphology, and spermatogenesis. Relative to the untreated aged control group, BZBS administration elevated the levels of sex hormones and spermatocyte populations and preserved normal testicular structure in aged mice. Notably, spermatogenesis was maintained. Further analyses, including malondialdehyde (MDA) assays and real-time PCR, indicated that BZBS diminished testicular oxidative stress and the inflammatory burden. Corroborating these findings, mice treated with BZBS exhibited reductions in the populations of senescent and apoptotic cells within the seminiferous tubules, suggesting alleviated cellular damage. In contrast, we observed that rapamycin, a drug known for its longevity benefits, induced excessive testicular apoptosis and did not decrease lipid peroxidation. Collectively, our results highlight BZBS's promising clinical potential in counteracting male reproductive aging, underlining its mechanisms of action.

Diabetes-induced male infertility: potential mechanisms and treatment options

Male infertility is a physiological phenomenon in which a man is unable to impregnate a fertile woman during a 12-month period of continuous, unprotected sexual intercourse. A growing body of clinical and epidemiological evidence indicates that the increasing incidence of male reproductive problems, especially infertility, shows a very similar trend to the incidence of diabetes within the same age range. In addition, a large number of previous in vivo and in vitro experiments have also suggested that the complex pathophysiological changes caused by diabetes may induce male infertility in multiple aspects, including hypothalamic-pituitary-gonadal axis dysfunction, spermatogenesis and maturation disorders, testicular interstitial cell damage erectile dysfunction. Based on the above related mechanisms, a large number of studies have focused on the potential therapeutic association between diabetes progression and infertility in patients with diabetes and infertility, providing important clues for the treatment of this population. In this paper, we summarized the research results of the effects of diabetes on male reproductive function in recent 5 years, elaborated the potential pathophysiological mechanisms of male infertility induced by diabetes, and reviewed and prospected the therapeutic measures.

High-fructose consumption suppresses insulin signaling pathway accompanied by activation of macrophage and apoptotic markers in rat testis

Dietary high-fructose may cause metabolic disturbances; however, its effect on the reproductive system is little understood. The insulin signaling pathway is critical in testicular development, maintenance of microcirculation and spermatogenesis. Therefore, in this study, we aimed to investigate the impact of dietary high-fructose on insulin signaling pathway as well as macrophage and apoptotic markers in testicular tissue of rats. Fructose was administered to male Wistar rats as a 20% solution in drinking water for fifteen-week. Gene expression of ir-β, irs-1, irs-2, pi3k, akt, mtor, and enos in the testicular samples was determined by real-time PCR. Protein expression of IR, IRS-1, IRS-2, PI3K, Akt, phospho-Akt (p-Akt), mTOR, eNOS, phospho-eNOS (p-eNOS), and GLUT5 was established by analysis of Western Blot. Testicular expression of occludin, CD163, CD68, caspase-8, and caspase-3 was analyzed by using immunohistochemical assay. Testicular level of fructose was measured by colorimetric method. Dietary high-fructose decreased mRNA expressions of irs-1, irs-2, pi3k, and mtor in the testicular tissue of rats. Also, this dietary intervention impaired protein expressions of IR, IRS-1, IRS-2, PI3K, p-Akt, mTOR, eNOS, and p-eNOS as well as p-Akt/Akt and p-eNOS/eNOS ratios in the testis of rats. However, a high-fructose diet increased the expression of CD163, CD68, caspase-8 and caspase-3, but decreased that of occludin, in the testicular tissue of rats. The high-fructose consumption in rats suppresses testicular insulin signaling but activates macrophages-related factors and apoptotic markers. These changes induced by dietary fructose could be related to male reproductive dysfunction.

Genotypic and Allelic Prevalence of the TGF- Β1 +869 C/T SNP and Their Relationship to Seminogram in Infertile Males

Background

The influence of cytokine in the reproductive system is becoming increasingly important. The polymorphisms of the transforming growth factor-β1 (TGF-β1) gene are involved in male infertility. This study aimed to demonstrate the association between TGF-β1 and infertility and to investigate its impact on semen quality.

Methods

In this case-control study, serum TGF-β1 concentration was measured in 144 patients diagnosed with infertility and 40 fertile males by enzyme-linked immunosorbent assay (ELISA). The tetra-amplification refractory mutation system-PCR (T-ARMS-PCR) analysis was performed to detect the genotyping of the TGF-β1 (+869 C/T) (rs1800470) SNPs gene.

Results

Serum concentration of TGF-β1 was less in infertile males compared to fertile ones. The detected and more effective genotypes and alleles of TGF-β1 gene polymorphic on male infertility were, in normozoospermic group, CT genotype, probability (p)= 0.45, relative risk (RR)= 1.56, confidence intervals (CI): 0.58-4.22, and T allele (p= 0.46, RR= 1.32, CI: 0.65-2.69), in oligozoospermic and azoospermic groups, CC genotype (p= 0.32, RR= 1.58, CI: 0.73-3.41), (p= 0.013, RR= 3.50, CI: 1.40-8.73), and allele C (p= 0.44, RR= 1.32, CI: 0.73-2.38), (p= 0.06, RR= 2.14, CI: 1.02-4.50), respectively. The recessive model (TT+CT) showed increased risk among normozoospermic group (p=0.44, RR=1.67, CI:0.60-4.62). The serum concentration of TGF-β1 with CT and TT genotypes was less than that of CC genotype. TGF-β1 C/T genotype correlated with low sperm number, high immotile sperm, and high abnormal sperm morphology.

Conclusions

Our study revealed that the TGF-β1(rs1800470) gene polymorphisms are associated negatively with semen quality.

Acylated ghrelin suppresses doxorubicin-induced testicular damage and improves sperm parameters in rats via activation of Nrf2 and mammalian target of rapamycin

Background

Exogenous administration of acylated ghrelin (AG) afforded reproductive protective effect in several animal models but not in those treated with doxorubicin (DOX). This study evaluated the protective effect of AG against DOX-induced testicular damage and impairment in sperm parameters in rats and examined the potential mechanisms of action.

Materials and Methods

Adult male rats were divided into five groups (n = 8/each) as control, control + AG (40 nmol/kg/day; subcutaneous), DOX (10 mg/kg/day 1; intraperitoneal [i.p.]), DOX + AG, and DOX + AG + brusatol (an Nrf2 inhibitor) (2 mg/kg/every 3 days; i.p.). The treatment regimen continued for 65 days.

Results

AG prevented testicular damage and apoptosis; increased sperm count, motility, and viability; and reduced the number of abnormal sperms. It also increased their circulatory levels of AG, des-acylated ghrelin (DAG), and AG/DAG ratio and the testicular mRNA levels of ghrelin and growth hormone secretagogue receptor 1a Concomitantly, AG increased serum and testicular testosterone levels, reduced serum levels of the follicle-stimulating hormone and luteinizing hormone, and upregulated the testicular protein levels of the steroidogenic acute regulatory protein and 3β-hydroxysteroid dehydrogenase in DOX-treated rats. In the testes of the control and DOX-treated rats, AG increased the phosphorylation of mammalian target of rapamycin and stimulated the levels of glutathione and superoxide dismutase, as well as the nuclear activation of Nrf2. All these effects were completely prevented by co-treatment with brusatol.

Conclusion

AG replacement therapy could be a novel strategy to prevent reproductive toxicity in cancer patients.

Role of Macroautophagy in Mammalian Male Reproductive Physiology

Physiologically, autophagy is an evolutionarily conserved and self-degradative process in cells. Autophagy carries out normal physiological roles throughout mammalian life. Accumulating evidence shows autophagy as a mechanism for cellular growth, development, differentiation, survival, and homeostasis. In male reproductive systems, normal spermatogenesis and steroidogenesis need a balance between degradation and energy supply to preserve cellular metabolic homeostasis. The main process of autophagy includes the formation and maturation of the phagophore, autophagosome, and autolysosome. Autophagy is controlled by a group of autophagy-related genes that form the core machinery of autophagy. Three types of autophagy mechanisms have been discovered in mammalian cells: macroautophagy, microautophagy, and chaperone-mediated autophagy. Autophagy is classified as non-selective or selective. Non-selective macroautophagy randomly engulfs the cytoplasmic components in autophagosomes that are degraded by lysosomal enzymes. While selective macroautophagy precisely identifies and degrades a specific element, current findings have shown the novel functional roles of autophagy in male reproduction. It has been recognized that dysfunction in the autophagy process can be associated with male infertility. Overall, this review provides an overview of the cellular and molecular basics of autophagy and summarizes the latest findings on the key role of autophagy in mammalian male reproductive physiology.

The role of stimulator of interferon genes-mediated AMPK/mTOR/P70S6K autophagy pathway in cyfluthrin-induced testicular injury

Cyfluthrin is widely used in the field of sanitary pest control by its wide insecticidal spectrum, high efficiency and low toxicity, low residue, and good biodegradability. But, as a double-edged sword, a large amount of cyfluthrin remains are still in the environment. The residual cyfluthrin is absorbed into the food chain through vegetation and then poses a risk to soil organisms and human health. Several studies have suggested that cyfluthrin is one of the main factors causing testicular damage, but the mechanism remains unclear. In this study, we established in vivo and in vitro models of testicular injury in rats and GC-2 cells exposed to cyfluthrin to explore whether stimulator of interferon genes (STING) gene mediates the regulation of AMPK/mTOR/p70S6K autophagy pathway, which lays a foundation for further study of the mechanism of testicular injury induced by cyfluthrin. The results showed that the activity of super oxide dismutase in testis decreased and the activity of malonic dialdehyde increased with the increase of concentration in vivo and in vitro. At the same time, the levels of mitochondrial damage and inflammation in the testis also increased, which further activated autophagy. In this process, the increased level of inflammation is related to the increased expression of STING gene, and AMPK/mTOR/p70S6K autophagy pathway is also involved. To sum up, cyfluthrin has certain reproductive toxicity, and long-term exposure can induce testicular cell damage. STING gene can participate in cyfluthrin-induced testicular injury through AMPK/mTOR/P70S6K autophagy pathway.

The traditional Chinese medicine Qiangjing tablet prevents blood-testis barrier injury induced by CdCl2 through the PI3K/Akt/Rictor signaling pathway

OBJECTIVE

Environmental contaminants such as cadmium (Cd) may have a deleterious impact on sperm and reduce male fertility by compromising the blood-testis barrier (BTB). Hence, the effects of the traditional Chinese medicine Qiangjing tablet (QJP) on sperm quality and BTB alterations induced by Cd in mouse testes were examined.

METHODS

Adult KM mice challenged with Cd chloride were examined, QJP was administered to mice as an oral drug by gavage, and the experiments lasted 2 weeks. Testicular and epididymal weights, sperm quality, anti-sperm antibodies (AsAb), hormone levels, and histology were evaluated. Changes in the levels of N-cadherin, occludin, ZO-1, claudin-11, F-actin, and β-tubulin and their mRNAs were evaluated. The effects of QJP on the PI3K/Akt/Rictor pathway were evaluated.

RESULTS

CdCl₂ decreased reproductive organ weight, sperm quality, and testosterone (T) levels; increased AsAb, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) levels; induced structural damage in testicles with BTB disruption; increased BTB permeability; and decreased N-cadherin, occludin, ZO-1, claudin-11, F-actin, and β-tubulin expression. After treatment, QJP blocked the effects of Cd on reproductive organ weight, sperm quality, and T; mitigated germinal epithelium compartment alterations; decreased AsAb, FSH, and LH levels; and preserved BTB ultrastructure and function. In addition, QJP induced increases in N-cadherin, occludin, ZO-1, claudin-11, F-actin, and β-tubulin levels and the expression of their mRNAs through the PI3K/Akt/Rictor pathway. After the application of JRAB2011, the levels of a specific mTORC2 suppressor, Rictor, and the BTB-protective effect of QJP were greatly reduced.

CONCLUSIONS

We demonstrated the effect of QJP against Cd-induced damage to the BTB, and the results indicate that QJP may play a significant role in opposing the effects of Cd through the PI3K/Akt/Rictor pathway.

Both selenium deficiency and excess impair male reproductive system via inducing oxidative stress-activated PI3K/AKT-mediated apoptosis and cell proliferation signaling in testis of mice

Selenium (Se) deficiency or excess impairs testicular development and spermatogenesis, while the underlying mechanisms in this regard remain unclear. This study was designed to explore the molecular biology of Se deficiency or excess in spermatogenesis in mice. Three-week-old male mice (n = 10 mice/diet) were fed with Se-deficient diet (SeD, 0.02 mg Se/kg), adequate-Se diet (SeA, 0.2 mg Se/kg), or excess-Se diet (SeE, 2.0 mg Se/kg) for 5 months. Compared with SeA, SeD reduced (P < 0.05) the body weight (10.4%) and sperm density (84.3%) but increased (P < 0.05) sperm deformity (32.8%); SeE decreased (P < 0.05) the sperm density (78.5%) and sperm motility (35.9%) of the mice. Meanwhile, both SeD and SeE increased (P < 0.05) serum FSH concentrations (10.4-25.6%) and induced testicular damage in mice in comparison with the SeA. Compared with SeA, SeD increased (P < 0.05) the 8-OHdG concentration by 25.5%; SeE increased (P < 0.05) both MDA and 8-OHdG concentrations by 118.8-180.3% in testis. Furthermore, transcriptome analysis showed that there 1325 and 858 transcripts were altered (P < 0.05) in the testis by SeD and SeE, respectively, compared with SeA. KEGG pathway analysis revealed that these differentially expressed genes were mainly enriched in the PI3K-AKT signaling pathway, which is regulated by oxidative stress. Moreover, western blotting analysis revealed that SeD and SeE dysregulated PI3K-AKT-mediated apoptosis and cell proliferation signaling, including upregulating (P < 0.05) caspase 3, cleaved-caspase 3, BCL-2 and (or) P53 and downregulating (P < 0.05) PI3K, p-AKT, p-mTOR, 4E-BP1, p-4E-BP1 and (or) p-p70S6K in the testis of mice compared with SeA. Additionally, compared with SeA, both SeD and SeE increased (P < 0.05) GPX3 and SELENOO; SeD decreased (P < 0.05) GPX1, TXRND3 and SELENOW, but SeE increased (P < 0.05) production of three selenoproteins in the testis. Conclusively, both Se deficiency and excess impairs male reproductive system in mice, potentially with the induction of oxidative stress and activation of PI3K/AKT-mediated apoptosis and cell proliferation signaling in the testis.

Bone marrow mesenchymal stem cells repair hexavalent chromium-induced testicular injury by regulating autophagy and ferroptosis mediated by the AKT/mTOR pathway in rats

There is no ideal therapy for testicular damage induced by Cr(VI); however, bone marrow mesenchymal stem cells (BMSCs) transplantation may be a promising therapy. A Cr(VI) solution was administered to rats by intraperitoneal injection for 30 days, then BMSCs from donor rats were transplanted. Two weeks later, decreased activity and appetite, along with other pathological changes, were improved in the BMSCs group. The location of BMSCs in damaged testes was observed via laser confocal microscopy. Chromium content in the Cr(VI) and BMSCs groups significantly increased compared with that in the control group, but there was no significant difference between the two groups, as revealed by atomic absorption spectrometry. The ferrous iron and the total iron content of testes in the BMSCs group were significantly lower than those in the Cr(VI) group, as observed by Lillie staining and a tissue iron assay kit. Western blotting and immunohistochemical analyses revealed that the expression of Beclin 1, LC3B, 4-hydroxynonenal, and transferrin receptor 1 was decreased in the BMSCs group, compared with the Cr(VI) group. The expression of glutathione peroxidase 4 (GPX4), SLC7A11, p-AKT, mammalian target of rapamycin (mTOR), and p-mTOR in the BMSCs group was higher than that in the Cr(VI) group. Taken together, we propose that BMSCs repair Cr(VI)-damaged testes by alleviating ferroptosis and downregulating autophagy-associated proteins through the upregulation of AKT and mTOR phosphorylation.

Carob extract induces spermatogenesis in an infertile mouse model via upregulation of Prm1, Plzf, Bcl-6b, Dazl, Ngn3, Stra8, and Smc1b

ETHNOPHARMACOLOGICAL RELEVANCE

Ethnopharmacological studies for drug discovery from natural compounds play an important role for developing current therapeutical platforms. Plants are a group of natural sources which have been served as the basis in the treatment of many diseases for centuries. In this regard, Ceratonia siliqua (carob) is one of the herbal medicine which is traditionally used for male infertility treatments. But so far the main mechanisms for effects of carob are unknown. Here, we intend to investigate the ability of carob extract to induce spermatogenesis in an azoospermia mouse model and determine the mechanisms that underlie its function.

AIM OF THE STUDY

This is a pre-clinical animal model study to evaluate the effect of carob extract in spermatogenesis recovery.

METHODS

We established an infertile mouse model with the intent to examine the ability of carob extract as a potential herbal medicine for restoration of male fertility. Sperm parameters, as well as gene expression dynamics and levels of spermatogenesis hormones, were evaluated 35 days after carob administration.

RESULTS

Significant enhanced sperm parameters (P < 0.05) showed that the carob extract could induce spermatogenesis in the infertile mouse model. Our data suggested an anti-apototic and inducer role in the expressions of cell cycle regulating genes. Carob extract improved the spermatogenesis niche by considerable affecting Sertoli and Leydig cells (P < 0.05). The carob-treated mice were fertile and contributed to healthy offspring that matured. Our data confirmed that this extract triggered the hormonal system, the spermatogenesis-related gene expression network, and signaling pathways to induce and promote sperm production with notable level (P < 0.05). We found that the aqueous extract consisted of a polar and mainly well water-soluble substance. Carob extract might upregulate spermatogenesis hormones via its amino acid components, which were detected in the extract by liquid chromatography-mass spectrometry (LC-MS).

CONCLUSION

Our results strongly suggest that carob extract might be a promising future treatment option for male infertility. This finding could pave the way for clinical trials in infertile men. This is the first study that has provided reliable, strong pre-clinical evidence for carob extract as an effective candidate for fertility recovery in cancer-related azoospermia.

mTOR (Mammalian Target of Rapamycin): Hitting the Bull's Eye for Enhancing Neurogenesis After Cerebral Ischemia?

Ischemic stroke remains a leading cause of morbidity and disability around the world. The sequelae of serious neurological damage are irreversible due to body's own limited repair capacity. However, endogenous neurogenesis induced by cerebral ischemia plays a critical role in the repair and regeneration of impaired neural cells after ischemic brain injury. mTOR (mammalian target of rapamycin) kinase has been suggested to regulate neural stem cells ability to self-renew and differentiate into proliferative daughter cells, thus leading to improved cell growth, proliferation, and survival. In this review, we summarized the current evidence to support that mTOR signaling pathways may enhance neurogenesis, angiogenesis, and synaptic plasticity following cerebral ischemia, which could highlight the potential of mTOR to be a viable therapeutic target for the treatment of ischemic brain injury.

Hexokinase inhibitor 2-deoxyglucose coordinates citrullination of vimentin and apoptosis of fibroblast-like synoviocytes by inhibiting HK2 /mTORC1-induced autophagy

High hexokinase 2 (HK2) expression is associated with aberrant activation of fibroblast-like synoviocytes (FLSs) in rheumatoid arthritis (RA). However, the mechanism by which this occurs has not been fully elucidated. To investigate the role of HK2 and its underlying mechanism, adjuvant arthritis (AA) rats were treated with the HK2 inhibitor, 2-deoxyglucose (2-DG). In conjunction with HK2 knockdown experiments in FLSs, we evaluated the effect of HK2 on the citrullination of vimentin (cVIM), autophagy and apoptosis-associated protein expression, including that of cVIM, LC3, p62, Beclin1, Bax, Bcl2, and caspase 3. We further investigated the interaction of HK2 with downstream mTORC1 signaling effectors. Correlation analysis revealed that 2-DG treatment and HK2 knockdown upregulated the expression levels of caspase3, Bax, and p62 and downregulated the expression levels of LC3, Bcl2, and Beclin1, as well as decreasing vimentin citrullination. Furthermore, interactions between HK2 and mTOR decreased, coinciding with mTORC1 pathway activation. These findings suggest that the regulation of apoptosis and cVIM by HK2/mTORC1-dependent autophagy involves the inhibition of aberrant FLSs activation in the rat model of arthritis.

Autophagy: A Double-Edged Sword in Male Reproduction

Autophagy, an evolutionarily conserved cell reprogramming mechanism, exists in all eukaryotic organisms. It is a fundamental and vital degradation/recycling pathway that removes undesirable components, such as cytoplasmic organelles, misfolded proteins, viruses, and intracellular bacteria, to provide energy and essential materials for organisms. The success of male reproduction depends on healthy testes, which are mainly composed of seminiferous tubules and mesenchyme. Seminiferous tubules are composed of Sertoli cells (SCs) and various germ cells, and the main functional part of mesenchyme are Leydig cells (LCs). In recent years, a large amount of evidence has confirmed that autophagy is active in many cellular events associated with the testes. Autophagy is not only important for testicular spermatogenesis, but is also an essential regulatory mechanism for the ectoplasmic specialization (ES) integrity of SCs, as well as for the normal function of the blood-testes barrier (BTB). At the same time, it is active in LCs and is crucial for steroid production and for maintaining testosterone levels. In this review, we expanded upon the narration regarding the composition of the testes; summarized the regulation and molecular mechanism of autophagy in SCs, germ cells, and LCs; and concluded the roles of autophagy in the process of spermatogenesis and testicular endocrinology. Through integrating the latest summaries and advances, we discuss how the role of autophagy is a double-edged sword in the testes and may provide insight for future studies and explorations on autophagy in male reproduction.

Exploring the pharmacological mechanism of Shengjing capsule on male infertility by a network pharmacology approach

Background

Shengjing capsule (SJC) is a traditional Chinese medicine (TCM) and has gained widespread clinical application for the treatment of male infertility (MI). However, the pharmacological mechanism of SJC against MI remains vague to date.

Method

The active ingredients of SJC and their targets were identified from the database, and MI-related genes were retrieved from several databases. Protein–protein interaction (PPI) data were obtained to construct the PPI networks. The candidate targets of SJC against MI were identified through topological analysis of the PPI network. Functional enrichment analysis of candidate targets was performed, and the key target genes were identified from the gene-pathway network.

Results

We identified 154 active ingredients and 314 human targets of SJC, as well as 564 MI-related genes. Eight pharmacological network diagrams illustrating the interactions among herbs, active ingredients, targets, and pathways, were constructed. The four dominating network maps included a compound-target network of SJC, a compound-anti-MI targets network, a candidate targets PPI network, a pathway-gene network, and a drug-key compounds-hub targets-pathways network. Systematic analysis indicated that the targets of SJC in the treatment of MI mainly involved RPS6, MAPK1, MAPK3, MDM2, and DDX5. Pathway enrichment analysis showed that SJC had the potential to impact multiple biological pathways, such as cancer-related pathways, viral/bacterial infection-related pathways, and signal transduction-related pathways.

Conclusion

Our results preliminarily revealed the pharmacological basis and molecular mechanism SJC in treating MI, but further experimental research is required to verify these findings.

F1 Male Sterility in Cattle-Yak Examined through Changes in Testis Tissue and Transcriptome Profiles

Simple Summary

Cattle-yak, a crossbreed of cattle and yak, has evident heterosis but F1 male cattle-yak is unable to generate sperm and is sterile, which limits the fixation of heterosis. This study analyzed the differences in testicular tissue development between four-year-old yak and cattle-yak from the perspective of histomorphological changes and sequenced the testicular tissue of the two using RNA-seq technology, examining the differential gene expression related to spermatogenesis and apoptosis. These findings offer a theoretical explanation for the sterility in F1 male cattle-yak that can help yak hybridization.

Abstract

Male-derived sterility in cattle-yaks, a hybrid deriving from yak and cattle, is a challenging problem. This study compared and analyzed the histomorphological differences in testis between sexually mature yak and cattle-yak, and examined the transcriptome differences employing RNA-seq. The study found that yak seminiferous tubules contained spermatogenic cells at all levels, while cattle-yak seminiferous tubules had reduced spermatogonia (SPG) and primary spermatocyte (Pri-SPC), fewer secondary spermatocytes (Sec-SPC), an absence of round spermatids (R-ST) and sperms (S), and possessed large vacuoles. All of these conditions could have significantly reduced the volume and weight of cattle-yak testis compared to that of yak. RNA-seq analysis identified 8473 differentially expressed genes (DEGs; 3580 upregulated and 4893 downregulated). GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment evaluations for DEGs found their relation mostly to spermatogenesis and apoptosis. Among the DEGs, spermatogonia stem cell (SSCs) marker genes (Gfra1, CD9, SOHLH1, SALL4, ID4, and FOXO1) and genes involved in apoptosis (Fas, caspase3, caspase6, caspase7, caspase8, CTSK, CTSB and CTSC) were significantly upregulated, while differentiation spermatogenic cell marker genes (Ccna1, PIWIL1, TNP1, and TXNDC2) and meiosis-related genes (TEX14, TEX15, MEIOB, STAG3 and M1AP) were significantly downregulated in cattle-yak. Furthermore, the alternative splicing events in cattle-yak were substantially decreased than in yak, suggesting that the lack of protein subtypes could be another reason for spermatogenic arrest in cattle-yak testis.

The Mechanism and Experimental Validation of Forsythoside A in the Treatment of Male Infertility Were Analyzed Based on Network Pharmacology and Molecular Docking

Chinese medicine extracts are currently the hotspot of new drug research and development. Herein, we report the mechanism of action of the traditional Chinese medicine extract Forsythiaside A in the treatment of male infertility and experimental verification. We first obtained 95 intersection genes between the target protein of Forsythiaside A and the target genes of male infertility and screened 13 key genes. In molecular docking, Forsythiaside A can each have a higher total docking score with 12 key genes and have a better combination. These 95 intersection genes are mainly related to biological processes such as response to peptide hormone, response to oxidative stress, and participation in the oxidative stress of the forkhead box O (FoxO) signaling pathway. Therefore, we use ornidazole to induce an experimental model of oligoasthenospermia in rats and use different concentrations of Forsythiaside A to intervene. We proved that the semen quality and superoxide dismutase (SOD) activities of model group rats were significantly lower than those of the blank group, and semen quality and SOD activities of the low-dose group and high-dose group were significantly higher than those of the model group. The malondialdehyde (MDA) level of model group rats was significantly higher than that of blank group, while the MDA levels of the low-dose group and high-dose group were significantly lower than that of the model group. Forsythoside A is a potential drug substance for male infertility and improves the semen quality, MDA levels, and SOD activities of rats with oligoasthenospermia.

S6K1 acts through FOXO to regulate juvenile hormone biosynthesis in the red flour beetle, Tribolium castaneum

As the downstream effector of the target of rapamycin complex 1 (TORC1) signaling pathway, the ribosomal protein S6 kinase (S6K) is an important regulator of insect reproduction, however, the underlying mechanism remains obscure. In this study, a S6K gene, named TcS6K1, was isolated from the red flour beetle, Tribolium castaneum. Analysis of temporal and spatial expression patterns revealed that TcS6K1 is expressed at the highest level in the one-day-old first instar larvae and head of 7-day-old females, respectively. RNAi-mediated knockdown of TcS6K1 in either female or male adults decreased the number of eggs laid, with a concomitant reduction of mRNA levelsof vitellogenin genes, TcVg1 and TcVg2, two male accessory gland secretory proteins, as well as the juvenile hormone (JH) biosynthesis-related gene, farnesol dehydrogenase (TcFDH). While the mRNA and protein levels of the transcription factor forkhead box O (TcFOXO) were not affected, suppression of TcS6K1 expression promoted TcFOXO nuclear translocation to exert its transcriptional action. Further RNAi and EMSA analysis revealed that TcFOXO negatively regulated the expression of TcFDH. These results indicate that S6K might regulate beetles' reproduction through FOXO/JH signaling pathway.

Effects of Bisphenol A on reproductive toxicity and gut microbiota dysbiosis in male rats

Bisphenol A (BPA) is an environmental endocrine disruptor. Recent studies have shown an association between decreased spermatogenesis and gut microbiota alteration. However, the potential associations and mechanisms of BPA exposure on spermatogenesis, hormone production, and gut microbiota remain unknown. This study aims to investigate BPA-induced male reproductive toxicity and the potential link with gut microbiota dysbiosis. Male Sprague Dawley rats were exposed to BPA at different doses by oral gavage for thirty consecutive days. The extent of testicular damage was evaluated by basic parameters of body weight and hematoxylin-eosin (H&E) staining. Next, we determined the mRNA levels and protein levels of apoptosis, histone-related factors, and mammalian target of rapamycin (mTOR) pathway in testes. Finally, 16 S rDNA sequencing was used to analyze gut microbiota composition after BPA exposure. BPA exposure damaged testicular histology, significantly decreased sperm count, and increased sperm abnormalities. In addition, BPA exposure caused oxidative stress and cell apoptosis in testes. The levels of histone (H2A, H3) were significantly increased, while ubiquitin histone H2A (ub-H2A) and ubiquitin histone H2B (ub-H2B) were markedly reduced. Furthermore, BPA activated the PI3K and AKT expression, but the protein expressions of mTOR and 4EBP1 in testes were inhibited significantly. Additionally, the relative abundance of class Gammaproteobacteria, and order Betaproteobacteriales was significantly higher when treated with a high dose of BPA compared to the control group, which was negatively correlated with testosterone level. This study highlights the relationship between BPA-induced reproductive toxicity and gut microbiota disorder and provides new insights into the prevention and treatment of BPA-induced reproductive damage.

RNF144B stimulates the proliferation and inhibits the apoptosis of human spermatogonial stem cells via the FCER2/NOTCH2/HES1 pathway and its abnormality is associated with azoospermia

Studies on gene regulation and signaling transduction pathways of human spermatogonial stem cells (SSCs) are of the utmost significance for unveiling molecular mechanisms underlying human spermatogenesis and gene therapy of male infertility. We have demonstrated, for the first time, that RNF144B stimulated cell proliferation and inhibited the apoptosis of human SSCs. The target of RNF144B was identified as FCER2 by RNA sequencing. We revealed that RNF144B interacted with FCER2 by immunoprecipitation. Consistently, overexpression of FCER2 reversed the phenotype of proliferation and apoptosis of human SSCs caused by RNF144B knockdown. Interestingly, FCER2 pulled down N2ICD (NOTCH2 intracellular domain), while N2ICD could bind to FCER2 in human SSCs. The levels of NOTCH2, FCER2, HES1, and HEY1 were reduced by RNF144B siRNA in human SSCs. Significantly, RNF144B was expressed at a lower level in nonobstructive azoospermia (NOA) patients than in the obstructive azoospermia (OA) patients with normal spermatogenesis, and 52 patients with heterozygous mutations of RNF144B were detected in 1,000 NOA patients. These results implicate that RNF144B promotes the proliferation of human SSCs and suppresses their apoptosis via the FCER2/NOTCH2/HES1 pathway and that the abnormality of RNF144B is associated with spermatogenesis failure. This study thus provides novel molecular mechanisms regulating the fate determinations of human SSCs, and it offers new biomarkers for the diagnosis and treatment of male infertility.

Low-dose rapamycin prevents Ang-II-induced toxicity in Leydig cells and testicular dysfunction in hypertensive SHR model

Hypertension is a common chronic cardiovascular disease reported among both men and women. Hypertension in males affects the testis and reproduction function; however, the pathogenesis is poorly understood. Rapamycin has been reported to have a variety of beneficial pharmacological effects; however, high-doses rapamycin does have side effects such as immunosuppression. The present study investigates whether low-dose rapamycin can reduce the damage caused by hypertension to the testis of spontaneously hypertensive rats (SHRs) and further examines molecular mechanism of low-dose rapamycin in preventing testicular toxicity induced by angiotensin II (Ang II). Low rapamycin dose restores the testicle size, histological alterations, 3β-hydroxysteroid dehydrogenase (3β-HSD) expression, and prevents apoptosis in SHR rats. Ang II downregulates angiotensin-converting enzyme-2 (ACE2) expression through AT1R, p-ERK, and MAS receptor in LC-540 Leydig cells in a dose-dependent manner. Low doses of rapamycin effectively upregulate steroidogenic enzymes, steroidogenic acute regulatory protein and 3β-HSD expression in Leydig cells. Rapamycin upregulates ACE2 expression through p-PKAc and p-PI3k in Ang II-treated cells. Further, rapamycin curbs mitochondrial superoxide generation and depleted mitochondrial membrane potential induced by Ang II through activation of Nrf2-mediated Gpx4 and superoxide dismutase 2 expression. Our results revealed the involvement of ACE2, AT1R, AT2R, PKAc, and oxidative stress in Ang-II-induced testicular toxicity, suggesting low-dose rapamycin could be a potential therapeutic candidate to attenuate testicular toxicity.

The Mechanism of Heat Stress Resistance During Spermatogenesis in Turpan Black Sheep

Heat stress can affect the reproductive function of livestock and cause harm to animal production, which can seriously damage the economic interests of livestock producers. Therefore, it is important to explore the effect of heat stress on reproductive function to improve livestock production. In this study, the experimental animals Turpan black sheep and Suffolk sheep were selected as controls, each with 10 sheep, and the reproductive physiological performance was measured in Turpan, China from April to August when there was no heat stress to strong heat stress. The results showed that the sperm density, vitality, and kinematic parameters of Suffolk sheep were significantly lower than that in Turpan black sheep (p < 0.01) after heat stress, while the sperm acrosome malfunctions and DNA damage were significantly higher in Suffolk sheep (p < 0.01). In addition, the endogenous levels of reproductive hormones and oxidative stress indicators in the blood of Turpan black sheep were stable before and after heat stress treatment, while Suffolk sheep showed different degrees of fluctuations. There was no significant difference in testicular histomorphology between the two after heat stress treatment. However, Suffolk sheep showed a significantly decreased number of spermatocytes after heat stress treatment (p < 0.05). It was found that during meiosis, the proportion of cells in the meiotic zygotene stage of Suffolk sheep was significantly higher than that of Turpan black sheep. To investigate the mechanism of normal spermatogenesis in Turpan black sheep under heat stress, we performed RNA-Seq analysis on the testis. The results showed that there were 3,559 differential genes in Turpan black sheep before and after heat stress, with 2,118 up-regulated genes and 1,441 down-regulated genes. The enrichment analysis of GO and KEGG showed that the differential genes are mainly involved in cellular component organization or biogenesis, cell cycle process, mitotic cell cycle process, meiotic cell cycle process, double-strand break repair and Rap1 signaling pathway, Ras signaling pathway, Cell cycle, signaling pathways regulating pluripotency of stem cells Oocyte meiosis. Genes related to spermatogenesis, SYCP2, TDRD9, BRDT, CEP120, BRCA1, etc. were significantly up-regulated in Turpan black sheep after heat stress. In summary, our results showed that the up-regulation of genes involved in spermatogenesis protects the normal production of sperm in Turpan black sheep under HS, thereby achieving normal reproductive function.Our research systematically elucidated the mechanism of heat stress resistance during spermatogenesis in Turpan black sheep and provided potential possibilities for the subsequent breeding of new heat-resistant breeds.

Long-Term Wi-Fi Exposure From Pre-Pubertal to Adult Age on the Spermatogonia Proliferation and Protective Effects of Edible Bird’s Nest Supplementation

Children are vulnerable to the radiofrequency radiation (RFR) emitted by Wi-Fi devices. Nevertheless, the severity of the Wi-Fi effect on their reproductive development has been sparsely available. Therefore, this study was conducted to evaluate the Wi-Fi exposure on spermatogonia proliferation in the testis. This study also incorporated an approach to attenuate the effect of Wi-Fi by giving concurrent edible bird’s nest (EBN) supplementation. It was predicted that Wi-Fi exposure reduces spermatogonia proliferation while EBN supplementation protects against it. A total of 30 (N = 30) 3-week-old Sprague Dawley weanlings were divided equally into five groups; Control, Control EBN, Wi-Fi, Sham Wi-Fi, and Wi-Fi + EBN. 2.45 GHz Wi-Fi exposure and 250 mg/kg EBN supplementation were conducted for 14 weeks. Findings showed that the Wi-Fi group had decreased in spermatogonia mitosis status. However, the mRNA and protein expression of c-Kit-SCF showed no significant decrease. Instead, the reproductive hormone showed a reduction in FSH and LH serum levels. Of these, LH serum level was decreased significantly in the Wi-Fi group. Otherwise, supplementing the Wi-Fi + EBN group with 250 mg/kg EBN resulted in a significant increase in spermatogonia mitotic status. Even though EBN supplementation improved c-Kit-SCF mRNA and protein expression, the effects were insignificant. The improvement of spermatogonia mitosis appeared to be associated with a significant increase in blood FSH levels following EBN supplementation. In conclusion, the long-term Wi-Fi exposure from pre-pubertal to adult age reduces spermatogonia proliferation in the testis. On the other hand, EBN supplementation protects spermatogonia proliferation against Wi-Fi exposure.

Comparative transcriptomic analysis reveals reproductive impairments caused by PCBs and OH-PCBs through the dysregulation of ER and AR signaling

Reports have highlighted the presence of PCBs and their metabolites, OH-PCBs, in human serum as well as their endocrine-disrupting effects on reproductive function through direct interactions with the androgen receptor (AR) and estrogen receptor (ER). However, the molecular mechanisms directly linking the actions of PCBs and OH-PCBs on the AR and ER to induce reproductive impairment remain poorly understood. In this study, we characterized the cellular response to PCBs and OH-PCBs acting on AR and ER transactivation at the transcriptome level coupled with bioinformatics analysis to identify the downstream pathways of androgen and estrogen signaling that leads to reproductive dysfunction. We first confirmed the agonistic and antagonistic effects of several PCBs and OH-PCBs on AR- and ER-mediated reporter gene activity using the androgen-responsive LNCaP and estrogen-responsive MCF-7 cell lines, respectively. Anti-estrogenic activity was not detected among the tested compounds; however, we found that in addition to anti-androgenic and estrogenic activity, PCB 28 and PCB 138 exhibited androgenic activity, while most of the tested OH-PCBs showed a synergistic effect on DHT-mediated transactivation of the AR. Bioinformatics analysis of transcriptome profiles from selected PCBs and OH-PCBs revealed various pathways that were dysregulated depending on their agonistic, antagonistic, or synergistic effects. The OH-PCBs with estrogenic activity affected pathways including vitamin metabolism and calcium transport. Other notable dysregulated pathways include cholesterol transport in response to androgenic PCBs, thyroid hormone metabolism in response to anti-androgenic PCBs, and antioxidant pathways in response to androgen-synergistic OH-PCBs. Our results demonstrate that PCBs and OH-PCBs directly alter specific pathways through androgen- or estrogen-mediated signaling, thereby providing additional insights into the mechanisms by which these compounds cause reproductive dysfunction.

Autophagy: a multifaceted player in the fate of sperm

BACKGROUND

Autophagy is an intracellular catabolic process of degrading and recycling proteins and organelles to modulate various physiological and pathological events, including cell differentiation and development. Emerging data indicate that autophagy is closely associated with male reproduction, especially the biosynthetic and catabolic processes of sperm. Throughout the fate of sperm, a series of highly specialized cellular events occur, involving pre-testicular, testicular and post-testicular events. Nonetheless, the most fundamental question of whether autophagy plays a protective or harmful role in male reproduction, especially in sperm, remains unclear.

OBJECTIVE AND RATIONALE

We summarize the functional roles of autophagy in the pre-testicular (hypothalamic–pituitary–testis (HPG) axis), testicular (spermatocytogenesis, spermatidogenesis, spermiogenesis, spermiation) and post-testicular (sperm maturation and fertilization) processes according to the timeline of sperm fate. Additionally, critical mechanisms of the action and clinical impacts of autophagy on sperm are identified, laying the foundation for the treatment of male infertility.

SEARCH METHODS

In this narrative review, the PubMed database was used to search peer-reviewed publications for summarizing the functional roles of autophagy in the fate of sperm using the following terms: ‘autophagy’, ‘sperm’, ‘hypothalamic–pituitary–testis axis’, ‘spermatogenesis’, ‘spermatocytogenesis’, ‘spermatidogenesis’, ‘spermiogenesis’, ‘spermiation’, ‘sperm maturation’, ‘fertilization’, ‘capacitation’ and ‘acrosome’ in combination with autophagy-related proteins. We also performed a bibliographic search for the clinical impact of the autophagy process using the keywords of autophagy inhibitors such as ‘bafilomycin A1’, ‘chloroquine’, ‘hydroxychloroquine’, ‘3-Methyl Adenine (3-MA)’, ‘lucanthone’, ‘wortmannin’ and autophagy activators such as ‘rapamycin’, ‘perifosine’, ‘metformin’ in combination with ‘disease’, ‘treatment’, ‘therapy’, ‘male infertility’ and equivalent terms. In addition, reference lists of primary and review articles were reviewed for additional relevant publications. All relevant publications until August 2021 were critically evaluated and discussed on the basis of relevance, quality and timelines.

OUTCOMES

(i) In pre-testicular processes, autophagy-related genes are involved in the regulation of the HPG axis; and (ii) in testicular processes, mTORC1, the main gate to autophagy, is crucial for spermatogonia stem cell (SCCs) proliferation, differentiation, meiotic progression, inactivation of sex chromosomes and spermiogenesis. During spermatidogenesis, autophagy maintains haploid round spermatid chromatoid body homeostasis for differentiation. During spermiogenesis, autophagy participates in acrosome biogenesis, flagella assembly, head shaping and the removal of cytoplasm from elongating spermatid. After spermatogenesis, through PDLIM1, autophagy orchestrates apical ectoplasmic specialization and basal ectoplasmic specialization to handle cytoskeleton assembly, governing spermatid movement and release during spermiation. In post-testicular processes, there is no direct evidence that autophagy participates in the process of capacitation. However, autophagy modulates the acrosome reaction, paternal mitochondria elimination and clearance of membranous organelles during fertilization.

WIDER IMPLICATIONS

Deciphering the roles of autophagy in the entire fate of sperm will provide valuable insights into therapies for diseases, especially male infertility.

Long Noncoding RNAs: Recent Insights into Their Role in Male Infertility and Their Potential as Biomarkers and Therapeutic Targets

Long noncoding RNAs (lncRNAs) are composed of nucleotides located in the nucleus and cytoplasm; these are transcribed by RNA polymerase II and are greater than 200 nt in length. LncRNAs fulfill important functions in a variety of biological processes, including genome imprinting, cell differentiation, apoptosis, stem cell pluripotency, X chromosome inactivation and nuclear transport. As high throughput sequencing technology develops, a substantial number of lncRNAs have been found to be related to a variety of biological processes, such as development of the testes, maintaining the self-renewal and differentiation of spermatogonial stem cells, and regulating spermatocyte meiosis. These indicate that lncRNAs can be used as biomarkers and potential therapeutic targets for male infertility. However, only a few comprehensive reviews have described the role of lncRNAs in male reproduction. In this paper, we summarize recent findings relating to the role of lncRNAs in spermatogenesis, their potential as biomarkers for male infertility and the relationship between reproductive arrest and transgenerational effects. Finally, we suggest specific targets for the treatment of male infertility from the perspective of lncRNAs.

In vivo and in vitro protective effects of the Wuzi Yanzong pill against experimental spermatogenesis disorder by promoting germ cell proliferation and suppressing apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Wuzi Yanzong pill (WZYZP) is a classical traditional Chinese medicine (TCM) formula originated from the Tang dynasty. WZYZP has a long history of use for reinforcing kidney and alleviating male infertility in China.

AIM OF THE STUDY

The effect of WZYZP on male infertility and the mechanism underlying this effect was not clarified clearly. Therefore, this study aimed to investigate the protective effect of WZYZP in experimental spermatogenesis disorder via in vivo and in vitro studies, to promote the use of this formula for the treatment of spermatogenesis disorder.

MATERIAL AND METHODS

Male SD rats were exposed to tripterygium glycosides to induce experimental spermatogenesis disorder, and WZYZP was subsequently administrated at different dosages for treatment. Sperm counts, sperm motility, and serum hormone levels were detected. HE staining and TUNEL staining were performed to evaluate the pathological lesions and apoptosis of testes, respectively. Next, germ cells were isolated from spermatogenesis disorder-model rats and treated with WZYZP- containing serum at different concentrations. CCK-8 assay and flow cytometry assay were performed to detect cell proliferation and apoptosis. Immunofluorescence assay, qRT-PCR and Western blotting analyses were performed to detect the expression of Beclin 1, LC3 and TGF-β-PI3k/AKT-mTOR pathway - related factors, including TGF-β, PI3K, AKT, mTOR, 4 EBP-1 and p70S6K.

RESULTS

In vivo experiments showed that WZYZP protected against spermatogenesis disorder in model rats by improving sperm count and motility, as well as restoring serum hormone levels. HE and TUNEL staining demonstrated that the pathological injuries and cell apoptosis in testes of the model rats were alleviated by WZYZP treatment. Moreover, in vitro experiments of germ cells isolated from spermatogenesis disorder-model rats showed that WZYZP treatment increased the cell proliferation, inhibited cell apoptosis and autophagy. qRT-PCR and Western blotting assay results showed that this protective effect was associated with the regulation of the TGF-β/PI3K/AKT/mTOR signaling pathway. The expression levels of p-PI3K/PI3K, p-AKT/AKT, p-mTOR/mTOR, 4 EBP-1 and p70S6K were increased, while TGF-β was inhibited in the WZYZP treated groups.

CONCLUSION

The results showed that WZYZP could protect against experimental spermatogenesis disorder by increasing the germ cell proliferation and inhibiting their apoptosis. Our support the clinical use of this formula for the management of spermatogenesis disorder.

Hallmarks of Testicular Aging: The Challenge of Anti-Inflammatory and Antioxidant Therapies Using Natural and/or Pharmacological Compounds to Improve the Physiopathological Status of the Aged Male Gonad

The evolutionary theory of aging supports a trade-off relationship between reproduction and aging. Aging of the male reproductive system primarily affects the testes, leading to a decrease in the levels of sexual hormones, alterations in sperm quality and production, and a decline in fertility that does not necessarily involve a complete cessation of spermatogenesis. Inflammation, oxidation, and apoptosis are events considered as predictors of pathogenesis and the development of age-related diseases that are frequently observed in aged testes. Although the molecular mechanisms are still poorly understood, accumulating evidence points toward pro-inflammatory molecules and reactive oxygen species as primary contributing factors for testicular aging. However, the real impact of aging-related testicular alterations on fertility, reproductive health, and life span is far from being fully revealed. This work discusses the current knowledge on the impact of aging in the testis, particularly of aging-related dysregulated inflammation and oxidative damage on the functioning of its different cell populations. More interestingly, this review covers the potential benefits of anti-aging interventions and therapies using either pharmacological compounds (such as non-selective non-steroidal anti-inflammatory medication) or more natural alternatives (such as various nutraceuticals or even probiotics) that exhibit anti-inflammatory, antioxidant, and anti-apoptotic properties. Some of these are currently being investigated or are already in clinical use to delay or prevent testicular aging.

Network Pharmacology-Based Strategy to Investigate Pharmacological Mechanisms of the Drug Pair Astragalus-Angelica for Treatment of Male Infertility

Background

The traditional Chinese medicines Astragalus and Angelica are often combined to treat male infertility, but the specific therapeutic mechanism is not clear. Therefore, this study applies a network pharmacology approach to investigate the possible mechanism of action of the drug pair Astragalus-Angelica (PAA) in the treatment of male infertility.

Methods

Relevant targets for PAA treatment of male infertility are obtained through databases. Protein-protein interactions (PPIs) are constructed through STRING database and screen core targets, and an enrichment analysis is conducted through the Metascape platform. Finally, molecular docking experiments were carried out to evaluate the affinity between the target protein and the ligand of PAA.

Results

The active ingredients of 112 PAA, 980 corresponding targets, and 374 effective targets of PAA for the treatment of male infertility were obtained, which are related to PI3K-Akt signaling pathway, HIF-1 signaling pathway, AGE-RAGE signaling pathway, IL-17 signaling pathway, and thyroid hormone signaling pathway.

Conclusion

In this study, using a network pharmacology method, we preliminarily analyzed the effective components and action targets of the PAA. We also explored the possible mechanism of action of PAA in treating male infertility. They also lay a foundation for expanding the clinical application of PAA and provide new ideas and directions for further research on the mechanisms of action of the PAA and its components for male infertility treatment.

Wuzi-Yanzong prescription alleviates spermatogenesis disorder induced by heat stress dependent on Akt, NF-κB signaling pathway

Akt and nuclear factor kappa B (NF-κB) signaling pathways are involved in germ cell apoptosis and inflammation after testicular heat stress (THS). We observed that after THS induced by the exposure of rat testes to 43 °C for 20 min, their weight decreased, the fraction of apoptotic testicular germ cells significantly increased, and the proliferation of germ cells was inhibited. In addition, THS lowered serum testosterone (T) level, whereas the levels of follicle stimulating hormone and luteinizing hormone were not significantly changed. The ultrastructure of the seminiferous tubules became abnormal after THS, the structure of the blood-testis barrier (BTB) became loose, and the Sertoli cells showed a trend of differentiation. The level of phosphorylated Akt was reduced, whereas the amount of phosphorylated NF-κB p65 was augmented by THS. Wuzi-Yanzong (WZYZ), a classic Chinese medicine prescription for the treatment of male reproductive dysfunctions, alleviated the changes induced by THS. In order to determine the mechanism of action of WZYZ, we investigated how this preparation modulated the levels of T, androgen receptor (AR), erythropoietin (EPO), EPO receptor, and Tyro-3, Axl, and Mer (TAM) family of tyrosine kinase receptors. We found that WZYZ activated the Akt pathway, inhibited the Toll-like receptor/MyD88/NF-κB pathway, and repaired the structure of BTB by regulating the levels of T, AR, TAM receptors, and EPO. In conclusion, these results suggest that WZYZ activates the Akt pathway and inhibits the NF-κB pathway by acting on the upstream regulators, thereby improving spermatogenesis deficit induced by THS.

MiR-181a Promotes Spermatogenesis by Targeting the S6K1 Pathway

Approximately 15% of couples suffer from infertility worldwide, and male factors contribute to about 30% of total sterility cases. However, there is little progress in treatments due to the obscured understanding of underlying mechanisms. Recently microRNAs have emerged as a key player in the process of spermatogenesis. Expression profiling of miR-181a was carried out in murine testes and spermatocyte culture system. In vitro cellular and biochemical assays were used to examine the effect of miR-181a and identify its target S6K1, as well as elucidate the function with chemical inhibitor of S6K1. Human testis samples analysis was employed to validate the findings. miR-181a level was upregulated during mouse spermatogenesis and knockdown of miR-181a attenuated the cell proliferation and G1/S arrest and increased the level of S6K1, which was identified as a downstream target of miR-181a. Overexpression of S6K1 also led to growth arrest of spermatocytes while inhibitor of S6K1 rescued the miR-181a knockdown-mediated cell proliferation defect. In human testis samples of azoospermia patients, low level of miR-181a was correlated with defects in the spermatogenic process. miR-181a is identified as a new regulator and high level of miR-181a contributes to spermatogenesis via targeting S6K1.

Rictor/mTORC2 is involved in endometrial receptivity by regulating epithelial remodeling

Successful embryo implantation requires well-functioning endometrial luminal epithelial cells to establish uterine receptivity. Inadequate uterine receptivity is responsible for approximately two thirds of implantation failures in humans. However, the regulatory mechanism governing this functional process remains largely unexplored. A previous study revealed that the expression of Rictor, the main member of mTORC2, in mouse epithelial cells is increased on the fourth day of gestation (D4). Here, we provide the first report of the involvement of Rictor in the regulation of endometrial receptivity. Rictor was conditionally ablated in the mouse endometrium using a progesterone receptor cre (PRcre ) mouse model. Loss of Rictor altered polarity remodeling and the Na+ channel protein of endometrial cells by mediating Rac-1/PAK1(pPAK1)/ERM(pERM) and Sgk1/pSgk1 signaling, respectively, ultimately resulting in impaired fertility. In the endometrium of women with infertility, the expression of Rictor was changed, along with the morphological transformation and Na+ channel protein of epithelial cells. Our findings demonstrate that Rictor is crucial for the establishment of uterine receptivity in both mice and humans. The present study may help improve the molecular regulatory network of endometrial receptivity and provide new diagnostic and treatment strategies for infertility.

Arginine promotes testicular development in boars through nitric oxide and putrescine

The present work aimed to explore the influence and underlying mechanisms involving arginine in testicular development in boars. To this end, thirty 30-day-old male Duroc piglets (7.00 ± 0.30 kg) were randomly sorted into two groups, maintained on either a basal diet (CON, n = 15) or a diet supplemented with 0.8% arginine (ARG, n = 15). Blood and testicular samples were collected during the experimental period to analyse amino acid composition and arginine metabolite levels. The results showed that dietary supplementation with arginine increased number of spermatogonia and height of the seminiferous epithelium (p < 0.05). Sperm density, total number and effective number of sperm of the boars in the ARG group increased significantly compared with those in the CON group (p < 0.05). Although arginine supplementation did not affect plasma amino acid levels, testicular arginine levels in 150-day-old boars exhibited a significant increase (p < 0.05). The level of serum nitric oxide (NO) and activity of nitric oxide synthase (NOS) also increased in 150-day-old boars in the ARG group (p < 0.05). Interestingly, dietary supplementation with arginine increased testicular levels of putrescine in 150-day-old boars (p < 0.05). These results indicated that arginine supplementation increased serum NO levels and testicular arginine and putrescine abundance, thereby improving testicular development and semen quality in boars.

Roles of Stra8 and Tcerg1l in retinoic acid induced spermatogonial differentiation in mouse†

Retinoic acid (RA) induces spermatogonial differentiation, but the mechanism by which it operates remains largely unknown. We developed a germ cell culture assay system to study genes involved in spermatogonial differentiation triggered by RA. Stimulated by RA 8 (Stra8), a RA-inducible gene, is indispensable for meiosis initiation, and its deletion results in a complete block of spermatogenesis at the pre-leptotene/zygotene stage. To interrogate the role of Stra8 in RA mediated differentiation of spermatogonia, we derived germ cell cultures from the neonatal testis of both wild type and Stra8 knock-out mice. We provide the first evidence that Stra8 plays a crucial role in modulating the responsiveness of undifferentiated spermatogonia to RA and facilitates transition to a differentiated state. Stra8-mediated differentiation is achieved through the downregulation of a large portfolio of genes and pathways, most notably including genes involved in the spermatogonial stem cell self-renewal process. We also report here for the first time the role of transcription elongation regulator-1 like (Tcerg1l) as a downstream effector of RA-induced spermatogonial differentiation.

Mechanisms of doxorubicin-mediated reproductive toxicity - A review

The anticancer drug doxorubicin has been associated with several adverse side-effects including reproductive toxicity in both genders. The current review has complied the mechanisms of doxorubicin induced reproductive toxicity. The articles cited in the review were searched using Google Scholar, PubMed, Scopus, Science Direct. Doxorubicin treatment has been found to cause a decrease in testicular mass along with histopathological deformities, oligospermia and abnormalities in sperm morphology. Apart from severely affecting the normal physiological role of both Leydig cells and Sertoli cells, doxorubicin also causes chromosome abnormalities and affects DNA methylase enzyme. Testicular lipid metabolism has been found to be negatively affected by doxorubicin treatment resulting in altered profile of sphingolipids glycerophospholipids and neutral lipids. Dysregulation of 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β- hydroxysteroid dehydrogenase (17β-HSD) are strongly linked to testicular exposure to doxorubicin. Further, oxidative stress along with endoplasmic reticulum stress are also found to aggravate the male reproductive functioning in doxorubicin treated conditions. Several antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase (GPx) are downregulated by doxorubicin. It also disturbs the hormones of the hypothalamic-pituitary-gonadal (HPG)-axis including testosterone, luteinizing hormone, follicle stimulating hormone etc. In females, the drug disturbs folliculogenesis and oogenesis leading to failure of ovulation and uterine cycle. In rodent model the drug shortens pro-estrous and estrous phases. It was also found that doxorubicin causes mitochondrial dysfunction in oocytes with impaired calcium signaling along with ER stress. The goal of the present review is to comprehends various pathways due to which doxorubicin treatment promotes toxicity in male and female reproductive system.

Rimklb mutation causes male infertility in mice

Rimklb is a mammalian homologue of the E. coli enzyme RimK, which catalyzes addition of glutamic acid to the ribosomal protein S6. To date, no previous studies have shown any physiological role for Rimklb in mammals. In this study, using Western blotting, we found that Rimklb is distributed and expressed in mouse testis and heart. Rimklb was subsequently localized to the testicular Leydig cells using immunohistochemistry with an anti-Rimklb antibody. We generated a Rimklb mutant mouse in which a three-base deletion results in deletion of Ala 29 and substitution of Leu 30 with Val, which we named the Rimklb^{A29del, L30V} mutant mouse. Rimklb^{A29del, L30V} mutant mice show a decrease in testicular size and weight, and in vitro fertilization demonstrates complete male infertility. Furthermore, we found that a key factor in the mammalian target of the rapamycin/ribosomal protein S6 transcriptional pathway is hyperphosphorylated in the seminiferous tubules of the mutant testis. We conclude that Rimklb has important roles that include spermatogenesis in seminiferous tubules. In summary, male Rimklb^{A29del, L30V} mice are infertile.

Analysis of lncRNA Expression Profile during the Formation of Male Germ Cells in Chickens

Simple Summary

The differentiation of germ cells plays an important role in sex differentiation in poultry. Therefore, it is necessary for us to explore the potential regulators in the process of germ cell development. In this study, RNA-seq was used to detect the expression profile of long non-coding RNAs (lncRNAs) in chicken embryonic stem cells (ESCs), primordial germ cells (PGCs) and spermatogonial stem cells (SSCs). The results showed that a total of 296, 280 and 357 differentially expressed lncRNAs (DELs) were screened in ESCs vs. PGCs, ESCs vs. SSCs and PGCs vs. SSCs, respectively. Functional analysis of the target genes of DELs showed that autophagy, Wnt/β-catenin, TGF-β, Notch and ErbB signaling pathways were involved in the differentiation process of male germ cells and, moreover, XLOC_612026, XLOC_612029, XLOC_240662, XLOC_362463, XLOC_023952, XLOC_674549, XLOC_160716, ALDBGALG0000001810, ALDBGALG0000002986, XLOC_657380674549, XLOC_022100 and XLOC_657380 were predicted to be the key lncRNAs in this process. Our findings could not only supply scientific data for constructing the gene regulatory network of germ cell development, but also provide new ideas for further optimizing the induction efficiency of germ cells in vitro.

Abstract

Germ cells have an irreplaceable role in transmitting genetic information from one generation to the next, and also play an important role in sex differentiation in poultry, while little is known about epigenetic factors that regulate germ cell differentiation. In this study, RNA-seq was used to detect the expression profiles of long non-coding RNAs (lncRNAs) during the differentiation of chicken embryonic stem cells (ESCs) into spermatogonial stem cells (SSCs). The results showed that a total of 296, 280 and 357 differentially expressed lncRNAs (DELs) were screened in ESCs vs. PGCs, ESCs vs. SSCs and PGCs vs. SSCs, respectively. Gene Ontology (GO) and KEGG enrichment analysis showed that DELs in the three cell groups were mainly enriched in autophagy, Wnt/β-catenin, TGF-β, Notch and ErbB and signaling pathways. The co-expression network of 37 candidate DELs and their target genes enriched in the biological function of germ cell development showed that XLOC_612026, XLOC_612029, XLOC_240662, XLOC_362463, XLOC_023952, XLOC_674549, XLOC_160716, ALDBGALG0000001810, ALDBGALG0000002986, XLOC_657380674549, XLOC_022100 and XLOC_657380 were the key lncRNAs in the process of male germ cell formation and, moreover, the function of these DELs may be related to the interaction of their target genes. Our findings preliminarily excavated the key lncRNAs and signaling pathways in the process of male chicken germ cell formation, which could be helpful to construct the gene regulatory network of germ cell development, and also provide new ideas for further optimizing the induction efficiency of germ cells in vitro.

The rapamycin analog Everolimus reversibly impairs male germ cell differentiation and fertility in the mouse†

Sirolimus, also known as rapamycin, and its closely related rapamycin analog (rapalog) Everolimus inhibit "mammalian target of rapamycin complex 1" (mTORC1), whose activity is required for spermatogenesis. Everolimus is Food and Drug Administration approved for treating human patients to slow growth of aggressive cancers and preventing organ transplant rejection. Here, we test the hypothesis that rapalog inhibition of mTORC1 activity has a negative, but reversible, impact upon spermatogenesis. Juvenile (P20) or adult (P>60) mice received daily injections of sirolimus or Everolimus for 30 days, and tissues were examined at completion of treatment or following a recovery period. Rapalog treatments reduced body and testis weights, testis weight/body weight ratios, cauda epididymal sperm counts, and seminal vesicle weights in animals of both ages. Following rapalog treatment, numbers of differentiating spermatogonia were reduced, with concomitant increases in the ratio of undifferentiated spermatogonia to total number of remaining germ cells. To determine if even low doses of Everolimus can inhibit spermatogenesis, an additional group of adult mice received a dose of Everolimus ∼6-fold lower than a human clinical dose used to treat cancer. In these animals, only testis weights, testis weight/body weight ratios, and tubule diameters were reduced. Return to control values following a recovery period was variable for each of the measured parameters and was duration and dose dependent. Together, these data indicate rapalogs exerted a dose-dependent restriction on overall growth of juvenile and adult mice and negative impact upon spermatogenesis that were largely reversed; following treatment cessation, males from all treatment groups were able to sire offspring.

Transcriptome profiling of porcine testis tissue reveals genes related to sperm hyperactive motility

BACKGROUND

Sperm hyperactive motility has previously been shown to influence litter size in pigs, but little is known about the underlying biological mechanisms. The aim of this study was to use RNA sequencing to investigate gene expression differences in testis tissue from Landrace and Duroc boars with high and low levels of sperm hyperactive motility. Boars with divergent phenotypes were selected based on their sperm hyperactivity values at the day of ejaculation (day 0) (contrasts (i) and (ii) for Landrace and Duroc, respectively) and on their change in hyperactivity between day 0 and after 96 h liquid storage at 18 °C (contrast (iii)).

RESULTS

RNA sequencing was used to measure gene expression in testis. In Landrace boars, 3219 genes were differentially expressed for contrast (i), whereas 102 genes were differentially expressed for contrast (iii). Forty-one differentially expressed genes were identified in both contrasts, suggesting a functional role of these genes in hyperactivity regardless of storage. Zinc finger DNLZ was the most up-regulated gene in contrasts (i) and (iii), whereas the most significant differentially expressed gene for the two contrasts were ADP ribosylation factor ARFGAP1 and solute carrier SLC40A1, respectively. For Duroc (contrast (ii)), the clustering of boars based on their gene expression data did not reflect their difference in sperm hyperactivity phenotypes. No results were therefore obtained for this breed. A case-control analysis of variants identified in the Landrace RNA sequencing data showed that SNPs in NEU3, CHRDL2 and HMCN1 might be important for sperm hyperactivity.

CONCLUSIONS

Differentially expressed genes were identified in Landrace boars with high and low levels of sperm hyperactivity at the day of ejaculate collection and high and low change in hyperactivity after 96 h of sperm storage. The results point towards important candidate genes, biochemical pathways and sequence variants underlying sperm hyperactivity in pigs.

Proteomic analysis reveals key proteins involved in arginine promotion of testicular development in boars

In order to study the effect of l-arginine on testicular development in boars and its underlying mechanism, thirty 30-day-old Duroc boars (7.0 ± 0.3 kg) were randomly allocated to either a basal diet (CON, n = 15) or a 0.8% arginine diet (ARG, n = 15). Blood samples were collected and weight measurements were done regularly to every pig during the experimental period. Testes were collected for histological and proteomic analysis from 150-day-old boars. Results showed that dietary supplementation with arginine significantly increased testicular weight, the number of spermatogonia, and the height of the seminiferous epithelium (P < 0.05). The serum levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH) were also significantly increased in the ARG group (P < 0.05). A total of 154 differentially expressed proteins (DEPs) were identified, 76 of them were upregulated and 78 were downregulated. Mainly enriched metabolic pathways were the mTOR and Wnt signaling pathways. Functional annotation suggested that 18 DEPs were related to male reproduction. Western blotting results further validated the results from proteomics. This study may provide new insights into the molecular mechanisms by which arginine promotes male testicular development.

Autophagy Induced by ROS Aggravates Testis Oxidative Damage in Diabetes via Breaking the Feedforward Loop Linking p62 and Nrf2

Testicular dysfunction due to hyperglycemia is the main cause of infertility in diabetic men. Over the years, in order to solve this growing problem, a lot of research has been done and a variety of treatments have been created, but so far, there is no safe, effective, and practical method to prevent male infertility caused by diabetes. In this review, we emphasize the male infertility mechanism caused by diabetes from the effects of oxidative stress and autophagy on the function of testes via the PI3K/Akt/mTOR signaling pathway, and we highlight that oxidative stress-induced autophagy breaks the feedforward loop linking Nrf2 and p62 and promotes oxidative damage in diabetic testes.

The dynamics and regulation of microfilament during spermatogenesis

Spermatogenesis is a highly complex physiological process which contains spermatogonia proliferation, spermatocyte meiosis and spermatid morphogenesis. In the past decade, actin binding proteins and signaling pathways which are critical for regulating the actin cytoskeleton in testis had been found. In this review, we summarized 5 actin-binding proteins that have been proven to play important roles in the seminiferous epithelium. Lack of them perturbs spermatids polarity and the transport of spermatids. The loss of Arp2/3 complex, Formin1, Eps8, Palladin and Plastin3 cause sperm release failure suggesting their irreplaceable role in spermatogenesis. Actin regulation relies on multiple signal pathways. The PI3K/Akt signaling pathway positively regulate the mTOR pathway to promote actin reorganization in seminiferous epithelium. Conversely, TSC1/TSC2 complex, the upstream of mTOR, is activated by the LKB1/AMPK pathway to inhibit cell proliferation, differentiation and migration. The increasing researches focus on the function of actin binding proteins (ABPs), however, their collaborative regulation of actin patterns and potential regulatory signaling networks remains unclear. We reviewed ABPs that play important roles in mammalian spermatogenesis and signal pathways involved in the regulation of microfilaments. We suggest that more relevant studies should be performed in the future.

Natural Plant Extract Berbamine Is a Potent Inhibitor of Cell Growth and Survival of Human Tenon's Fibroblasts

INTRODUCTION

Post-trabeculectomy scarring due to excessive proliferation of human Tenon's fibroblasts (HTFs) often led to operation failure. Developing a new anti-fibrosis drug with high efficacy to inhibit HTF cell growth will greatly improve the effectiveness of trabeculectomy.

OBJECTIVE

This study aims to investigate the effect of berbamine (BBM) treatment on the cell growth and survival of HTFs.

METHODS

Cultured human fetal Tenon's fibroblasts (HFTFs) were treated with or without different concentrations of BBM. Cell morphology was observed with a phase contrast microscope. A CCK-8 method and Ki67 immunofluorescence were used to determine cell viability and cell proliferation. A scratch test was used to study cell migration. Flow cytometry and TUNEL staining were performed to detect cell apoptosis. The expression of BAX/BCL-2, ERK, and AKT/mTOR pathway components was determined by Western blotting.

RESULTS

BBM treatment disrupted HFTF normal morphology and inhibited its cell growth in a dose-dependent manner. Ki67 immunofluorescence and scratch assay showed BBM suppressed HFTF cell proliferation and migration. Importantly, BBM dose-dependently increased the BAX/BCL-2 ratio and induced apoptosis in HFTF cells. Western blotting showed BBM significantly inhibited the ERK and AKT/mTOR pathway, and PTEN inhibition ameliorated the inhibitory effect of BBM on cell viability and survival in HFTFs.

CONCLUSIONS

BBM potently inhibits the cell growth and survival of HTFs through AKT/mTOR and has the potential to serve as an anti-fibrosis drug after trabeculectomy.

Some of the Factors Involved in Male Infertility: A Prospective Review

Infertility is defined as the inability of couples to have a baby after one year of regular unprotected intercourse, affecting 10 to 15% of couples. According to the latest WHO statistics, approximately 50-80 million people worldwide sufer from infertility, and male factors are responsible for approximately 20-30% of all infertility cases. The diagnosis of infertility in men is mainly based on semen analysis. The main parameters of semen include: concentration, appearance and motility of sperm. Causes of infertility in men include a variety of things including hormonal disorders, physical problems, lifestyle problems, psychological issues, sex problems, chromosomal abnormalities and single-gene defects. Despite numerous efforts by researchers to identify the underlying causes of male infertility, about 70% of cases remain unknown. These statistics show a lack of understanding of the mechanisms involved in male infertility. This article focuses on the histology of testicular tissue samples, the male reproductive structure, factors affecting male infertility, strategies available to find genes involved in infertility, existing therapeutic methods for male infertility, and sperm recovery in infertile men.

ZEA-induced autophagy in TM4 cells was mediated by the release of Ca2+ activates CaMKKβ-AMPK signaling pathway in the endoplasmic reticulum

Zearalenone (ZEA) is a prevalent non-steroidal estrogenic mycotoxin produced mainly by Fusarium contamination. Our previous study showed that ZEA induces the autophagy of Sertoli cells (SCs). However, the underlying mechanisms are still unknown. Several studies have indicated that the increasing level of cytoplasmic Ca²⁺ could induce autophagy through CaMKKβ and AMPK pathways. Thus in order to investigate the potential mechanism underlying ZEA-induced autophagy, the activity of calmodulin-dependent kinase kinase β(CaMKKβ)and AMP-activated protein kinase (AMPK) signaling pathway in ZEA-infected TM4 cells was studied. In the present study, ZEA activated the CaMKKβ and AMPK signaling pathways. The AMPK inhibitor and activator significantly inhibited and stimulated the effect of ZEA on AMPK, the transformation from LC3I to LC3II, and the distribution of LC3 dots. In addition, cytosolic calcium (Ca²⁺) was increased gradually with the concentration of ZEA. After treatment of ZEA-infected cells with 1, 2-bis (2-aminophenoxy) ethane-N, N, N', N'- tetraacetic acid- tetraac etoxymethyl ester (BAPTA-AM) and 2-aminoethyl diphenylborinate (2-APB), the intracellular concentration of Ca²⁺ reduced significantly. Also, the activities of CaMKKβ and AMPK and subsequent autophagy decreased. Moreover, the antioxidant NAC significantly decreased activities of AMPK and autophagy -related protein. Therefore, it can be speculated that ROS- mediated ER-stress induced by ZEA activates AMPK via Ca²⁺-CaMKKβ leading to autophagy in TM4 cells.

New insights into the role of mTORC1 in male fertility in zebrafish

Mechanistic target of rapamycin complex 1 (mTORC1) plays crucial roles in male fertility. In mammals, deregulation of mTORC1 led to disordered spermatogonia proliferation and spermatogenesis, which eventually caused infertility in males. However, its roles in male fertility of non-mammalian species remain unclarified. In the present study, it was found that treatment of rapamycin, an mTORC1 inhibitor, resulted in infertility with decreased milt production and sperm motility in zebrafish. However, it is surprising to find that spermatogenesis was normal in these fish. All types of germ cells were found and the proliferation of spermatogonia and spermatocyte were normal. These results suggested that maturation of sperm may be impaired in males treated with rapamycin. Increased apoptosis was found surrounding the lumen containing spermatozoa, implicating a loss of Sertoli cells in testes treated with rapamycin. Moreover, LH/hCG mediated up-regulation of steroidogenic genes was abolished. The expression of npr and ar induced by LH/hCG was also blocked, which further suppressed the signaling of progestin and androgen. Collectively, mTORC1 maintains male fertility via different mechanisms in fish and mammals. mTORC1 is dispensable for spermatogenesis in zebrafish, but possibly supports the maintenance of Sertoli cells and mediates the signaling of hormones, which are crucial for sperm maturation.

Testicular expression of long non-coding RNAs is affected by curative GnRHa treatment of cryptorchidism

Background

Cryptorchidism is a frequent endocrinopathy in boys that has been associated with an increased risk of developing testicular cancer and infertility. The condition is curable by combined surgery and hormonal treatment during early pre-pubertal stages using gonadotropin releasing hormone agonist (GnRHa). However, whether the treatment also alters the expression of testicular long non-coding RNAs (lncRNAs) is unknown. To gain insight into the effect of GnRHa on testicular lncRNA levels, we re-analyzed an expression dataset generated from testicular biopsies obtained during orchidopexy for bilateral cryptorchidism.

Results

We identified EGFR-AS1, Linc-ROR, LINC00221, LINC00261, LINC00282, LINC00293, LINC00303, LINC00898, LINC00994, LINC01121, LINC01553, and MTOR-AS1 as potentially relevant for the stimulation of cell proliferation mediated by GnRHa based on their direct or indirect association with rapidly dividing cells in normal and pathological tissues. Surgery alone failed to alter the expression of these transcripts.

Conclusion

Given that lncRNAs can cooperate with chromatin-modifying enzymes to promote epigenetic regulation of genes, GnRHa treatment may act as a surrogate for mini-puberty by triggering the differentiation of Ad spermatogonia via lncRNA-mediated epigenetic effects. Our work provides additional molecular evidence that infertility and azoospermia in cryptorchidism, resulting from defective mini-puberty cannot be cured with successful orchidopexy alone.

Bioinformatic identification of key genes and molecular pathways in the spermatogenic process of cryptorchidism

This study aims to determine key genes and pathways that could play important roles in the spermatogenic process of patients with cryptorchidism. The gene expression profile data of GSE25518 was obtained from the Gene Expression Omnibus (GEO) database. Microarray data were analyzed using BRB-Array Tools to identify differentially expressed genes (DEGs) between high azoospermia risk (HAZR) patients and controls. In addition, other analytical methods were deployed, including hierarchical clustering analysis, class comparison between patients with HAZR and the normal control group, gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and the construction of a protein–protein interaction (PPI) network. In total, 1015 upregulated genes and 1650 downregulated genes were identified. GO and KEGG analysis revealed enrichment in terms of changes in the endoplasmic reticulum cellular component and the endoplasmic reticulum protein synthetic process in the HAZR group. Furthermore, the arachidonic acid pathway and mTOR pathway were also identified as important pathways, while RICTOR and GPX8 were indentified as key genes involved in the spermatogenic process of patients with cryptorchidism. In present study, we found that changes in the synthesis of endoplasmic reticulum proteins, arachidonic acid and the mTOR pathway are important in the incidence and spermatogenic process of cryptorchidism. GPX8 and RICTOR were also identified as key genes associated with cryptorchidism. Collectively, these data may provide novel clues with which to explore the precise etiology and mechanism underlying cryptorchidism and cryptorchidism-induced human infertility.