miR-199-5p regulates spermiogenesis at the posttranscriptional level via targeting Tekt1 in allotriploid crucian carp

Brief biology and pathophysiology of Tekt bundles

Tektins, a family of microtubule-stabilizing proteins, are critical for cilia and flagella assembly in mammals. They maintain doublet microtubule stability and ciliary/flagellar motility. Loss of Tekt1-5 causes microtubule instability, impaired motility, and diseases like infertility, retinal degeneration, Mainzer-Saldino syndrome, and diabetic nephropathy. Pathophysiological stimuli regulate Tektin expression through transcriptional, posttranscriptional, translational, and posttranslational modifications. This review summarizes the latest findings on Tektin functions and their role in diseases.

Fatty acid metabolism-related signature suggests an oncogenic role of TEKT1 in endometrial cancer

OBJECTIVE

The study aims to construct a prognostic signature to detect the molecular interaction between the fatty acid metabolism and the progression of endometrial cancer.

MATERIALS AND METHODS

A total of 309 fatty acid metabolism relative genes were analyzed in the endometrial cancer cohort from The Cancer Genome Atlas. Dataset GSE216872 was applied for external validation. The R program was chosen to detect the expression of FAMRGs and execute GO/KEGG analysis. Considering the clinical information and pathological features, a prognostic gene signature was constructed using LASSO Cox regression analysis. According to FAM risk score, endometrial cancer patients were divided into high and low FAM-risk score groups. By differential expression analysis and cytoscape, TEKT1 was identified as the hub gene. Functional enrichments explored the biological process TEKT1 participated. Cellular proliferation, clone formation, migration, invasion, cycle, and apoptosis were assessed to detect the effect of TEKT1 in endometrial cancer. Co-immunoprecipitation and Western blot were performed to determine the mechanism of TEKT1.

RESULTS

A prognostic signature based on 10 FAMRGs (ACACB, PTGIS, BMPR1B, DHCR24, FAAH, GPX1, GPX4, INMT, PON3, PPT2) was generated using Lasso Cox hazards regression analysis in TCGA. TEKT1 was identified as the gene related to fatty acid metabolism. Next, we demonstrated that TEKT1 was highly expressed in endometrial cancer tissues in CPTAC and was mainly involved in the cell cycle and biosynthesis of unsaturated fatty acids. Ex-vivo experiments revealed that TEKT1 promoted proliferation, migration, and invasiveness while inhibiting apoptosis. Further experiments demonstrated that TEKT1 might promote fatty acid synthesis by binding to AMPK-γ for ACC and FASN downregulation.

CONCLUSION

A reliable predictive signature based on genes related to fatty acid metabolism in endometrial cancer was conducted, wherein TEKT1 was mainly implicated as the primary gene of interest. TEKT1 showed affinity to AMPK-γ and probably promoted FA synthesis in endometrial cancer.

Identification of potential candidate miRNAs related to semen quality in seminal plasma extracellular vesicles and sperms of male duck (Anas Platyrhynchos)

Semen quality is an important indicator that can directly affect fertility. In mammals, miRNAs in seminal plasma extracellular vesicles (SPEVs) and sperms can regulate semen quality. However, relevant regulatory mechanism in duck sperms remains largely unclear. In this study, duck SPEVs were isolated and characterized by transmission electron microscopy (TEM), western blot (WB), and nanoparticle tracking analysis (NTA). To identify the important molecules affecting semen quality, we analysed the miRNA expression in sperms and SPEVs of male ducks in high semen quality group ((DHS, DHSE) and low semen quality group (DLS, DLSE). We identified 94 differentially expressed (DE) miRNAs in the comparison of DHS vs. DLS, and 21 DE miRNAs in DHSE vs. DLSE. Target genes of SPEVs DE miRNAs were enriched in ErbB signaling pathway, glycometabolism, and ECM-receptor interaction pathways (P < 0.05), while the target genes of sperm DE miRNAs were enriched in ribosome (P < 0.05). The miRNA-target-pathway interaction network analyses indicated that 5 DE miRNAs (miR-34c-5p, miR-34b-3p, miR-449a, miR-31-5p, and miR-128-1-5p) targeted the largest number of target genes enriched in MAPK, Wnt and calcium signaling pathways, of which FZD9 and ANAPC11 were involved in multiple biological processes related to sperm functions, indicating their regulatory effects on sperm quality. The comparison of DE miRNAs of SPEVs and sperms found that mir-31-5p and novel-273 could potentially serve as biomarkers for semen quality detection. Our findings enhance the insight into the crucial role of SPEV and sperm miRNAs in regulating semen quality and provide a new perspective for subsequent studies.

Environmentally relevant estrogens impaired spermatogenesis and sexual behaviors in male and female zebrafish

Environmental estrogens (EEs) are found extensively in natural waters and negatively affect fish reproduction. Research on the reproductive toxicity of EEs mixtures in fish at environmentally relevant concentrations is scarce. In this study, adult male zebrafish were exposed for 60 days to EES (a mixture of EEs), EE2-low (5.55 ng/L, with an estrogenic potency equal to EES), and EE2-high (11.1 ng/L). After exposure, the expression levels of vtg1, vtg3, and esr1 in the livers in EES-treated fish remained unaltered, whereas they were significantly increased in EE2-treated fish. Both EE2-high and EES exposures notably reduced the gonad somatic index and sperm count. A disrupted spermatogenesis was also observed in the testes of EE2-high- and EES-exposed fish, along with an alteration in the expression of genes associated with spermatogonial proliferation (pcna, nanog), cell cycle transition (cyclinb1, cyclind1), and meiosis (aldh1a2, cyp26a1, sycp3). Both EE2 and EES significantly lowered plasma 11-ketotestosterone levels in males, likely by inhibiting the expression level of genes for its synthesis (scc, cyp17a1 and cyp11b2), and increased 17β-estradiol (E2) levels, possibly through upregulating the expression of cyp19a1a. A significant increase in tnfrsf1a expression and the tnfrsf1a/tnfrsf1b ratio in EE2-high and EES-treated males also suggests increased apoptosis via the extrinsic pathway. Further investigation showed that both EE2-high and EES diminished the sexual behavior of male fish, accompanied with reduced E2 levels in the brain and the expression of genes in the kisspeptin/gonadotropin-releasing hormone system. Interestingly, the sexual behavior of unexposed females paired with treated males was also reduced, indicating a synergistic effect. This study suggests that EES have a more severe impact on reproduction than EE2-low, and EEs could interfere not only with spermatogenesis in fish, but also with the sexual behaviors of both exposed males and their female partners, thereby leading to a more significant disruption in fish reproduction.

Discovery of a novel miRNA involved in the regulation of male infertility in zebrafish

Azoospermia and asthenospermia are common manifestations of male infertility, but it needs further studies to understand the intrinsic regulation mechanism. As a popular model organism, zebrafish is often used to assess reproductive complications. In this study, by analyzing miRNA transcriptome of the mature triploid zebrafish testis afflicted with spermatogenic dysfunctions, leading to the identification of 36 miRNAs that are differentially expressed in comparison with diploid, which are predicted to target 2737 genes. Subsequent functional annotation of these genes pinpointed two miRNAs might association with spermatogenesis. Inhibitory experiments showed that NC_007115.7.7_998413 inhibited conducts a substantial decline in sperm density, and conducted lower embryo fertilization rate than control. And putative target genes qRT-PCR evaluation showed that spata2 was significant down-regulate upon inhibited NC_007115.7.7_998413. In summary, this research positions newly identified miRNA NC_007115.7.998413 as a regulatory factor in male zebrafish reproductive development, enhancing our comprehension of the molecular regulated pathways involved in spermatogenesis.

MicroRNAs in spermatogenesis dysfunction and male infertility: clinical phenotypes, mechanisms and potential diagnostic biomarkers

Infertility affects approximately 10-15% of couples worldwide who are attempting to conceive, with male infertility accounting for 50% of infertility cases. Male infertility is related to various factors such as hormone imbalance, urogenital diseases, environmental factors, and genetic factors. Owing to its relationship with genetic factors, male infertility cannot be diagnosed through routine examination in most cases, and is clinically called 'idiopathic male infertility.' Recent studies have provided evidence that microRNAs (miRNAs) are expressed in a cell-or stage-specific manner during spermatogenesis. This review focuses on the role of miRNAs in male infertility and spermatogenesis. Data were collected from published studies that investigated the effects of miRNAs on spermatogenesis, sperm quality and quantity, fertilization, embryo development, and assisted reproductive technology (ART) outcomes. Based on the findings of these studies, we summarize the targets of miRNAs and the resulting functional effects that occur due to changes in miRNA expression at various stages of spermatogenesis, including undifferentiated and differentiating spermatogonia, spermatocytes, spermatids, and Sertoli cells (SCs). In addition, we discuss potential markers for diagnosing male infertility and predicting the varicocele grade, surgical outcomes, ART outcomes, and sperm retrieval rates in patients with non-obstructive azoospermia (NOA).

Alternative signal pathways underly fertilization and egg activation in a fish with contrasting modes of spawning

BACKGROUND

The processes of fertilization and egg activation are vital for early embryogenesis. However, while the mechanisms associated with key events during these processes differ among species and modes of spawning, the signal pathways underlying these processes are opaque for many fishes, including economically important species.

RESULTS

We investigated phenotypic traits, ultrastructure and protein expression levels in the eggs of the topmouth culter (Culter alburnus), a protected and economically important freshwater fish that exhibits two spawning modes, producing semi-buoyant eggs and adhesive eggs. Unfertilized eggs of C. alburnus were examined, as well as eggs at fertilization and 30 min post fertilization. Our results showed that in semi-buoyant eggs, energy metabolism was activated at fertilization, followed by elevated protein expression of cytoskeleton and extracellular matrix (ECM)-receptor interactions that resulted in rapid egg swelling; a recognized adaptation for lotic habitats. In contrast, in adhesive eggs fertilization initiated the process of sperm-egg fusion and blocking of polyspermy, followed by enhanced protein expression of lipid metabolism and the formation of egg envelope adhesion and hardening, which are adaptive in lentic habitats.

CONCLUSION

Our findings indicate that alternative signal pathways differ between modes of spawning and timing during the key processes of fertilization and egg activation, providing new insights into the molecular mechanisms involved in adaptive early embryonic development in teleost fishes.

Glucocorticoid exposure modifies the miRNA profile of sperm in the guinea pig: Implications for intergenerational transmission

Approximately 1%-3% of the adult population are treated with synthetic glucocorticoids (sGCs) for a variety of conditions. Studies have demonstrated that adversities experienced by males prior to conception may lead to abnormal neuroendocrine function and behaviors in offspring and that epigenetic factors including microRNA (miRNA) within sperm may be responsible for driving these effects. However, it remains unclear where in the epididymis sperm miRNA changes are occurring. Here, we hypothesized that sGC exposure will alter the miRNA profile of sperm in the epididymis in a region-specific manner. Adult male guinea pigs were exposed to regular drinking water (Ctrl) or water with the sGC dexamethasone (Dex; 3mg/kg) (n = 6/group) every other day for 48 days. Sperms were collected from epididymal seminal fluid in the caput and cauda regions of the epididymis and total RNA was extracted. miRNAs were assessed by miRNA 4.0 microarray; data were processed by TAC 4.0.1 and R. miRNA analysis revealed one miRNA in the caput that was significantly decreased by Dex in sperm. In the cauda, 31 miRNAs were reduced in sperm following Dex-exposure. The findings of this study demonstrate that Dex-exposure influences miRNA profile of sperm in the cauda but not the caput of the epididymis. This suggests that glucocorticoids target the epididymis to modify sperm miRNA and do not modify the miRNA content during spermiation in the testes.

Plasticizer DEHP exposure in early pregnancy affects the endometrial decidualization in mice through reducing lncRNA RP24-315D19.10 expression

OBJECTIVES

To explore the effect of exposure to di (2-ethyl) hexyl phthalate (DEHP) in early pregnancy on endometrial decidualization in mice and its relation with lncRNA RP24-315D19.10.

METHODS

Early pregnancy mice were exposed to DEHP (1000 mg·kg－1·d－1) to construct the model. The uterus was collected on day 6 of pregnancy to detect its effect on decidualization by HE staining and immunofluorescence. A decidualization induction model of mouse endometrial stromal cells exposed to DEHP (0.1, 0.5, 2.5, 12.5, 62.5 μmol/L) was constructed. The changes of cell morphology were observed by light microscopy and phalloidin staining, and the expression of decidual reaction related molecular markers were detected by immunofluorescence, realtime RT-PCR and Western blotting. The expression of RP24-315D19.10 in decidua tissue and cells was detected by realtime RT-PCR. Cellular localization of RP24-315D19.10 was determined by lncLocator database and RNA FISH. AnnoLnc2 database was used to predict miRNAs bound to RP24-315D19.10.

RESULTS

The number of embryo implantation sites, uterine weight and uterine area were significantly lower in the DEHP exposed group than those in the control group, and the expression of the decidual reaction related molecular markers matrix metalloprotein 9 and homeobox A10 in the DEHP exposure group were also significantly lower than those in the control group (all P<0.05). With the increase of DEHP concentration, the expression of dtprp in decidua cells was gradually decreased. 2.5 μmol/L DEHP exposed stromal cells failed to be fully decidualized in vitro, andphalloidin staining showed abnormal cytoskeleton morphology. The expression levels of homeobox A10, bone morphogenetic protein 2 and proliferating cell nuclear antigen in the DEHP exposure group were significantly lower than those in the control group (all P<0.05). The expression of RP24-315D19.10 in DEHP exposed decidua tissue and cells was significantly reduced (both P<0.05). RP24-315D19.10 is mainly localized in the cytoplasm and RP24-315D19.10 might bind to 45 miRNAs, among them, miR-138-5p, miR-155-5p, miR-183-5p and miR-223-3p were associated with endometrial decidualization.

CONCLUSIONS

DEHP exposure in early pregnancy may impair endometrial decidualization, and the damage may be associated with the down-regulation of RP24-315D19.10.