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During mammalian pregnancy, the circulating concentration of cortisol (in rodents, corticosterone) in the mother is much higher than that in the fetus. Since the placenta is the only barrier, apart from the uterus, between the mother and her fetus, this gradient in cortisol concentrations suggests that there is a placental barrier preventing maternal cortisol from crossing into the fetus. The intracellular enzyme 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) is an ideal candidate for this barrier because it interconverts cortisol and corticosterone to their inactive metabolites cortisone and 11-dehydrocorticosterone. Indeed, 11 beta-HSD enzyme is expressed in the placenta of humans and a range of other animal species. Moreover, it is well positioned to serve as the barrier since it is localized to the syncytiotrophoblast, the site of maternal-fetal exchange. Given that fetal exposure to excessive amounts of glucocorticoids leads to intrauterine growth retardation, it has been hypothesized that the physiological significance of this placental 11 beta-HSD barrier is to protect the fetus from adverse effects of maternal glucocorticoids.
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Transforming growth factor β (TGFβ) superfamily signaling is essential for female reproduction. Dysregulation of the TGFβ signaling pathway can cause reproductive diseases. SMA and MAD (mothers against decapentaplegic) (SMAD) proteins are downstream signaling transducers of the TGFβ superfamily. SMAD7 is an inhibitory SMAD that regulates TGFβ signaling in vitro. However, the function of SMAD7 in the ovary remains poorly defined. To determine the signaling preference and potential role of SMAD7 in the ovary, we herein examined the expression, regulation, and function of SMAD7 in mouse granulosa cells. We showed that SMAD7 was expressed in granulosa cells and subject to regulation by intraovarian growth factors from the TGFβ superfamily. TGFB1 (TGFβ1), bone morphogenetic protein 4, and oocyte-derived growth differentiation factor 9 (GDF9) were capable of inducing Smad7 expression, suggesting a modulatory role of SMAD7 in a negative feedback loop. Using a small interfering RNA approach, we further demonstrated that SMAD7 was a negative regulator of TGFB1. Moreover, we revealed a link between SMAD7 and GDF9-mediated oocyte paracrine signaling, an essential component of oocyte–granulosa cell communication and folliculogenesis. Collectively, our results suggest that SMAD7 may function during follicular development via preferentially antagonizing and/or fine-tuning essential TGFβ superfamily signaling, which is involved in the regulation of oocyte–somatic cell interaction and granulosa cell function.
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Summary. Gossypol acetic acid was administered orally (30, 60, 90 and 120 mg/kg/day) on Days 1–5 post coitum to mature female rats. At autopsy on Day 10, pregnancy in most treated animals (6/7 and 6/8) was blocked at high doses (90 and 120 mg/kg/day respectively). As the daily dose decreased to 60 mg/kg/day half (4/8) were not pregnant. However, at a lower dose (30 mg/kg/day), or at a single dose of 200 mg/kg at Day 1 p.c., pregnancy was not blocked. The concentrations of progesterone in the serum of these females were significantly decreased except at the low dose. The numbers of implantation sites in the treated females that did remain pregnant were similar to those in control females except at the dose of 120 mg/kg/day. Gossypol did not retard the development of the preimplantation embryo or cavitation. The Pontamine Blue test revealed that the drug did not interfere with the initiation of implantation. We suggest that gossypol has an antifertility effect in the female rat because it is luteolytic and disrupts post-implantation development.
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Search for other papers by P. N. Srivastava in
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Summary.
High concentrations of α-chlorohydrin were found to inhibit hyaluronidase, β-glucuronidase, and aryl sulphatases in bull and rabbit spermatozoa, but not acrosin and neuraminidase. Preincubation of the enzyme and α-chlorohydrin was essential to achieve the maximum inhibition which was irreversible.
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Search for other papers by P. N. SRIVASTAVA in
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Summary.
Ram sperm acrosomes were disrupted by Hyamine and Triton treatment and extracts were initially fractionated with a Sephadex G-100 column at pH 3·5. Acrosin, a proteolytic enzyme, was completely separated from hyaluronidase by this step. Highly active hyaluronidase, specific activity of 1320 units/mg protein (38,280 National Formulary units/mg protein), was obtained by DEAE chromatography but two minor contaminants were present. The partially purified enzyme had an optimum at pH 4·3. The enzyme showed no activity at pH 3·0 and only 10% of its activity at pH 8·0. Heparin and chondroitin sulphate B inhibited 50% of its activity. The molecular weight was estimated to be 62,000 by sodium dodecyl sulphate gel electrophoresis.
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Search for other papers by Caiyun Yang in
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Although the process of gamete formation in plants has many unique features, much has been learnt from the comparative analysis between plants and other eukaryotic systems. Plants have a number of factors that have made them desirable for the analysis of gamete development; these include late germline specification, the non-lethality of mutations affecting gamete development and the large size of their chromosomes. The availability of the fully annotated Arabidopsis genome and comparative analysis using yeast, animal and E. coli has led to the identification and functional characterisation of many genes with roles in gamete development, principally those associated with meiosis, recombination and DNA repair. The advantages that plants give with the use of mutant screens to identify genes associated with gamete formation have also provided access to genes that are difficult to characterise by alternative routes. This has yielded novel information regarding the processes of gamete formation in higher plants. The times may now be changing with the advantages that plants provide serving to advance knowledge of gamete formation in other eukaryotic systems.
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Abnormal sperm parameters such as oligospermia, asthenospermia, and teratozoospermia result in male factor infertility. Previous studies have shown that mitochondria play an important role in human spermatozoa motility. But the related pathogenesis is far from elucidated. The aim of this study was to investigate the association between gene associated with retinoid-interferon-induced mortality 19 (GRIM19) and asthenospermia. In this study, Grim19 knockout model (Grim19+/− mouse) was created through genome engineering. We showed that compared with WT mice, the sperm count and motility of Grim19+/− mice were significantly reduced. Grim19 may contribute to sperm count and vitality by influencing the mitochondrial membrane potential, intracellular reactive oxygen species production, and increasing cell apoptosis. The spermatogenic cells of all levels in the lumen of the seminiferous tubules were sparsely arranged, and the intercellular space became larger in the testis tissue of Grim19+/− mice. The serum testosterone concentration is significantly reduced in Grim19+/− mice. The expression of steroid synthesis-related proteins STAR, CYP11A1, and HSD3B was decreased in Grim19+/− mice. To further confirm whether changes in testosterone biosynthesis were due to Grim19 downregulation, we validated this result using Leydig cells and TM3 cells. We also found that Notch signaling pathway was involved in Grim19-mediated testosterone synthesis to some extent. In conclusion, we revealed a mechanism underlying Grim19 mediated spermatozoa motility and suggested that Grim19 affected the synthesis of testosterone and steroid hormones in male mouse partly through regulating Notch signal pathways.
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Search for other papers by Yang Yang in
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The epithelial-to-mesenchymal transition may play a role in adenomyosis. GRIM19 expression is downregulated in adenomyotic lesions, and the effects of this downregulation in adenomyosis remain relatively unclear. In this study, we aimed to explore whether aberrant GRIM19 expression is associated with the epithelial-to-mesenchymal transition in adenomyosis and found that the expression of both GRIM19 and WT1 was low, and epithelial-to-mesenchymal transition, which included significant changes in CDH1, CDH2 and KRT8 expression, occurred in adenomyotic lesions, as confirmed by Western blotting and quantitative real-time PCR. We provided novel insights into WT1 expression in adenomyosis, revealing that WT1 expression was increased in the endometrial glands of adenomyotic lesions by immunohistochemistry. In vitro, knockdown of GRIM19 expression by small interfering RNA (siRNA) promoted the proliferation, migration and invasion of Ishikawa cells, as measured by Cell Counting Kit-8, wound healing assay and Transwell assays. Western blotting and quantitative real-time PCR confirmed that WT1 expression increased and epithelial-to-mesenchymal transition was induced, including the upregulation of CDH2 and downregulation of CDH1 and KRT8after transfecting the GRIM19 siRNA to Ishikawa cells. Furthermore, Wt1 expression was upregulated and epithelial-to-mesenchymal transition was observed, including downregulation of Cdh1 and Krt8 in Grim19 gene-knockdown mice. Upregulation of Wt1 expression in the endometrial glands of Grim19 knockdown mice was also verified by immunohistochemistry. Taken together, these results reveal that low expression of GRIM19 in adenomyosis may upregulate WT1 expression and induce epithelial-to-mesenchymal transition in the endometria, providing new insights into the pathogenesis of adenomyosis.
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Search for other papers by Shi Yang in
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Search for other papers by Yang Liu in
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State Key Laboratory of Oncogenes and Related Genes, Department of Urology, Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai Key Laboratory of Reproductive Medicine, Stem Cell Research Center, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 1630 Dongfang Road, Shanghai 200127, China
State Key Laboratory of Oncogenes and Related Genes, Department of Urology, Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai Key Laboratory of Reproductive Medicine, Stem Cell Research Center, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 1630 Dongfang Road, Shanghai 200127, China
State Key Laboratory of Oncogenes and Related Genes, Department of Urology, Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai Key Laboratory of Reproductive Medicine, Stem Cell Research Center, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 1630 Dongfang Road, Shanghai 200127, China
Search for other papers by Zuping He in
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Infertility is a major and largely incurable disease caused by disruption and loss of germ cells. It affects 10–15% of couples, and male factor accounts for half of the cases. To obtain human male germ cells ‘especially functional spermatids’ is essential for treating male infertility. Currently, much progress has been made on generating male germ cells, including spermatogonia, spermatocytes, and spermatids, from various types of stem cells. These germ cells can also be used in investigation of the pathology of male infertility. In this review, we focused on advances on obtaining male differentiated germ cells from different kinds of stem cells, with an emphasis on the embryonic stem (ES) cells, the induced pluripotent stem (iPS) cells, and spermatogonial stem cells (SSCs). We illustrated the generation of male differentiated germ cells from ES cells, iPS cells and SSCs, and we summarized the phenotype for these stem cells, spermatocytes and spermatids. Moreover, we address the differentiation potentials of ES cells, iPS cells and SSCs. We also highlight the advantages, disadvantages and concerns on derivation of the differentiated male germ cells from several types of stem cells. The ability of generating mature and functional male gametes from stem cells could enable us to understand the precise etiology of male infertility and offer an invaluable source of autologous male gametes for treating male infertility of azoospermia patients.
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As the distal part of the crustacean male reproductive tract, terminal ampullae play important roles in sperm development and storage of mature spermatophores. In the present study, the novel gene terminal ampullae peptide (TAP) was cloned from terminal ampullae of the prawn, Macrobrachium rosenbergii. The cDNA sequence consists of 768 nucleotides, with an open-reading frame of 264 nucleotides which encodes a putative 88-amino acid precursor protein with a 17-amino acid residue signal peptide. Western blotting and immunohistochemical analysis revealed that TAP was distributed on terminal ampullae and sperm, and its expression was related to gonad development. To elucidate the functional role of TAP in vivo, we disrupted the TAP gene by RNA interference (RNAi) and evaluated the effect on fertility and several sperm parameters. Although there was no difference in fertility between RNAi-induced prawns and controls, RNAi treatment decreased the sperm gelatinolytic activity and blocked proteolytic activity on the vitelline coat. These data provide evidence that TAP participates in regulating sperm proteolytic activity, and performs a crucial role in sperm maturation and degradation of the vitelline coat during fertilization.
