Involvement of mu-calpain in human sperm capacitation for fertilization

PROBLEM: The distribution and physiological role of calpains in human sperm were investigated. METHOD OF STUDY: Semen collected manually from healthy donors was liquefied then centrifuged by percoll gradient centrifugation. After exposure to different concentrations of Ca2+ ionophore A23187, the samples were used for immunostaining sodium dodecyl sulfate polyacrylamide gel electrophoresis, and western blot analysis. It was speculated from the results of the study using calpain-specific inhibitors that calpain contributes to the sperm motility and acrosome reaction. RESULTS: With the anti-pro mu-calpain antibody, sperm were immunostained, whereas all were negative for anti-pro mu-calpain antibody binding. Stained sperm were classified into four types according to the staining pattern: acrosome type, equatorial segment type, whole head type, and neck and tail segments type. Western blot analysis of sperm homogenate revealed a single 80-kDa band using the anti-pro mu-calpain antibody, its dose-dependent reduction with Ca2+ ionophore A23187 suggesting activation by this treatment. In the presence of membrane permeable calpain inhibitors, sperm motility and acrosome reaction were significantly suppressed. CONCLUSION: These results indicate that mu-calpain may play pivotal roles in the process of fertilization of human sperm.     

Functional characterization of prostaglandin transporter and terminal prostaglandin synthases during decidualization of human endometrial stromal cells

BACKGROUND: Decidualization of endometrial stromal cells is essential for successful implantation and pregnancy. Prostaglandins (PG) have been shown to be required for the initiation and maintenance of decidualization in animal models. The transport of PG across the plasma membrane is mediated by carriers such as prostaglandin transporter (PGT). Our recent data have shown the expression of human PGT (hPGT) in the endometrium during the menstrual cycle. The objective of the present study was to characterize hPGT in decidualized stromal cells. METHODS AND RESULTS: Human endometrial stromal cells were treated with a combination of cAMP and medroxyprogesterone acetate to induce decidualization. Decidualization was confirmed by morphological differentiation and increased secretion of prolactin. A large increase in hPGT mRNA level, as measured by real-time PCR analysis, was observed in decidual cells compared with control. Similarly, a 2-fold up-regulation of hPGT and 3-12-fold increase in PG biosynthetic enzymes were obtained at the protein level. Decidual cells exhibited a higher isotopic PGE2 uptake and greater intracellular PG levels than control. CONCLUSIONS: The higher uptake of PG by decidual cells is highly likely to be mediated via hPGT. PGT is a newly identified regulator of PG action at the cellular level and likely contributes to the regulation of PG action in female reproductive processes.     

Progesterone induces the fibulin-1 expression in human endometrial stromal cells

BACKGROUND: By using microarray analysis with human endometrial stromal cells (ESCs), we previously reported that the mRNA for fibulin-1, an extracellular matrix as well as a plasma glycoprotein, is up-regulated by progesterone. In the present study, we tried to clarify the spatial and temporal regulation mechanism of fibulin-1 in the human endometrium. METHODS AND RESULTS: Quantitative analysis with real-time PCR experiments on human endometrial tissues showed significantly higher fibulin-1 mRNA expressions in secretory phase endometria than in proliferative phase. Immunohistochemical studies revealed that the fibulin-1 protein is expressed in the glandular epithelium in proliferative phase endometria, and that expression switched to the stroma in secretory phase endometria. In culture experiments with ESCs, a significant increase of fibulin-1 mRNA expression was observed in cells treated with 6 alpha-methyl-17 alpha-hydroxy-progesterone acetate (MPA) or 8 bromoadenosine 3':5'-cyclic monophosphate (8-Br-cAMP). MPA stimulated the fibulin-1 mRNA expression in a dose-dependent manner, and a progesterone antagonist, RU-486, inhibited the stimulatory effect almost completely. By contrast, beta-estradiol alone did not increase the fibulin-1 mRNA expression. CONCLUSIONS: These results suggest that fiblin-1 is an important molecule that mediates progesterone action in human ESC differentiation towards implantation.     

Uterus and endometrium: Inhibition of human endometrial stromal cell proliferation by interleukin 6

We investigated the ability of interleukin 6 (IL-6) to modulatehuman endometrial stromal cell growth in vitro Stromal cellproliferation in response to treatment with varying concentrationsof IL-6 was determined. Endometrial tissue was obtained from10 normally cycling women during the secretory phase of theirmenstrual cycle. Treatment with IL-6 resulted in a dose- andcell-density-dependent inhibition of endometrial stromal cellproliferation in vitro. The maximal inhibition was observedwith 200 pg/ml of IL-6 and at a concentration of 10⁵ cells/well.During in-vitro culture, stromal cells produced low amountsof IL-6 and demonstrated the presence of IL-6 receptor. Thesedata demonstrate that IL-6 acts as a growth-regulatory signalfor human endometrial stromal cells. We postulate that IL-6may contribute to the maintenance of homeostasis in normal endometriumand that perturbation of IL-6 mediated responses may play arole in disorders of the endometrium such as endometrial cancerand endometriosis.     

Insulin-like growth factor-binding proteins produced by Vero cells, human oviductal cells and human endometrial cells, and the role of insulin-like growth factor-binding protein-3 in mouse embryo co-culture systems

Co-culturing embryos on helper cells can mimic the in-vivo environment,thereby enhancing embryo development in vitro. Insulin-likegrowth factors (IGF) and their binding proteins (IGFBP) alsoenhance embryo development To investigate the kinds of IGFBPproduced by various cell monolayers and the effects of IGFBP-3on mouse embryo co-culture systems, 2-cell ICR mouse embryoswere cultured in either human tubal fluid medium alone or inthe presence of Vero cells, human oviductal cells or endometrialcells. The helper cells were analysed immunohisto-chemicallyto investigate the types of IGFBP produced by various cell monolayers.The concentrations of IGF-I and IGFBP-3 in media obtained fromthe culture of embryos alone, cells alone or cells plus embryoswere determined by radioimmunoassays. On day 7, more blastocystshatched in the co-culture groups (73% in the Vero cell group,76% in the endometrial cell group and 74% in the oviductal cellgroup) than in the control group (43%) (P < 0.0001). Theresults of immunohistochemistry revealed that (i) all threecell groups produced a lot of IGFBP-1, -2 and -3, but only alittle of IGFBP-4 and -5; and (ii) IGFBP-1, -2 and -3 were presentin blastocysts in either the presence or absence of helper cells.The IGF-I secreted by cell monolayers or embryos was undetectable(detection limit 0.83 ug/1). The IGFBP-3 concentrations in mediaobtained from co-cultured embryos and cells were significantlyhigher than in media without embryos (median values in oviductalcell culture medium, 165 versus 127 µg/1, P = 0.04; medianvalues in endometrial cell culture medium, 277.5 versus 183.5µg/1, P = 0.0002; median values in Vero cell culture medium,219 versus 120 µg/1, P = 0.011). Although IGFBP-3 concentrationin the medium that contained embryos alone was undetectableby radioimmuno-assay (detection limit 1.1 µg/1), immunohistochemistrydemonstrated the presence of IGFBP-3 in the embryos. Co-culturein systems in which there was an increased production of IGFBP-3led to an improved development of mouse embryos. IGFBP can improvethe binding of IGF to cell surface receptors of target tissue,and thus enhance the effect of limited IGF concentrations inpromoting embryo development in a co-culture system. We concludethat Vero cells, human endometrial cells and oviductal cellsproduce IGFBP-1, -2, -3, -4 and -5. IGFBP-3 may play a rolein embryotrophic potential by either regulating the action ofIGF or directly enhancing embryo development     

Caspase cascade of Fas-mediated apoptosis in human normal endometrium and endometrial carcinoma cells

Human endometrial epithelial cells undergo apoptosis immediately before the menstrual period. Apoptotic signalling was analysed using human endometrial tissue and a human endometrial carcinoma cell line (HHUA). Activity levels of caspase-3, -8, and -9 were elevated in human endometrium during the late secretory phase and in HHUA cells incubated with an anti-Fas monoclonal antibody (mAb). Fas-mediated apoptosis of HHUA cells was blocked by prior exposure to inhibitors of caspase-9, -8 and -3. In HHUA cells treated with anti-Fas mAb, a release of cytochrome c was detected in the cytosolic fraction, in addition a full-length Bid was degraded. Full-length FLIP(L) (p55) was degraded during apoptosis, and p29 (regarded as the product of p55 cleavage) appeared instead of FLIP(L). In normal human endometrial tissue, Bid degradation was also observed in a cyclic manner with a peak during the early secretory phase of the menstrual cycle. Furthermore, the release of cytochrome c was seen in the early secretory phase. However, expression of FLIP(S) was only observed during the menstrual cycle in normal endometrial tissue. We concluded that the main apoptotic signalling in both normal human endometrial tissue and HHUA cells exposed to anti-Fas mAb is the mitochondrial pathway via Bid degradation. Although the function of FLIP is still unknown on normal endometrial tissue, it may be regulated by FLIP(L) expression on HHUA cells derived from human endometrial carcinoma.     

Molecular interactions during pregnancy: A mouse monoclonal antibody, S2n8, detects a 140 kDa protein on the surface of human endometrial stromal cells and decidual cells

We developed a mouse monoclonal antibody, S2n8, by immunizingmice i.p. with human decidual cells collected in the first trimesterof pregnancy. By indirect immunofluorescence staining of frozensections, S2n8 was found to react with decidual cells and endometrialstromal cells throughout the menstrual cycle, but not with endometrialglandular cells or with the endometrial surface epithelium.Judging from the fluorescence intensity, the antigen expressionon stromal cells was weak in the proliferative phase, and becamestronger in the secretory phase. Decidual cells in the firsttrimester of pregnancy and decidual cells at term showed strongexpression of this antigen. Indirect immunofluorescence stainingof enzymatically dispersed decidual tissue revealed that theS2n8 antigen was expressed on the decidual cell surface. Flowcytometric analysis of 12 freshly prepared stromal cell-enrichedcell suspensions showed that 74.8–94.2% (mean ±SD 86.1 ± 6.6%) of the cells carried the antigen. Theexpression of S2n8 antigen on cultured stromal cells was enhancedby the addition of oestradiol and/or progesterone. The antigenicmolecule was purified by immunoaffinity chromatography fromdecidua collected in the first trimester of pregnancy, and themolecular weight was estimated to be 140 kDa. These findingsindicate that the S2n8 antigen is a useful cell surface markerfor stromal cells/decidual cells and is associated with theirdifferentiation.     

Expression of a secretory product by microvillous and ciliated cells of the human endometrial epithelium in vivo and in vitro

A monoclonal antibody which identifies a component of post-ovulatoryendometrial secretions is now shown to be expressed within thecytoplasm and on the cell surface of both microvillous and ciliatedepithelial cells. A glandular explantatlon model was developedin order to study the ‘carry over’ of this secretionto the regenerative phase endometriwn. A loss of cytoplasmicantigen was observed in vitro. However, it was retained on thecell surface in a fashion consistent with its expression atthe time of explantation. Mosaicism of expression of this secretorycomponent occurs throughout the secretory-phase and is particularlypronounced at the time of transition from proliferative to secretoryphase. It is conduded that both ciliated and microvillous epithelialcells produce a post-ovulatory secretory component which maybe retained on the cell surface in the absence of hormonal stimulation.     

Roles of p38 and c-jun in the differentiation, proliferation and immortalization of normal human endometrial cells

BACKGROUND: It has been reported that p38 and c-jun operateas mediators of cell proliferation and differentiation. Therefore,by studying the roles of c-jun and p38 in the proliferationand differentiation of normal human endometrial cells, we canbetter understand the mechanism of these processes in endometrialcells. METHODS: Separation of glandular and stromal componentswas based on a modification of the work of Satyaswaroop et al.To confirm the purification of the endometrial cells and theexpression of the transfected SV40 large T antigen, immunocytochemicalanalysis and western blot analysis were performed. RESULTS:There were polygonal shapes in the stromal cells in the earlypassage 1–2, while the aged endometrial stromal cellswere spindle shaped. To investigate passage-dependent molecularevents in endometrial cells, the c-jun and pp38 levels wereexamined. Both c-jun and pp38 were significantly reduced withcellular aging and passages. To understand the role of c-jun,endometrial stromal cells were treated with SP600125 which isa specific inhibitor of c-jun. SP600125 induced morphologicalchanges of young endometrial stromal cells with polygonal shape;the young cells appeared as aged endometrial cells with spindleshape. In addition, an immortalized endometrial cell line wasestablished and shown to express activated c-jun, similiar tonormal endometrial cells. CONCLUSIONS: These results suggestthat the modulation of p38 and c-jun may play an important rolein the differentiation and proliferation of human endometrialcells.     

Argyrophil cells in normal endometrial glands

Summary Normal endometrium from one hundred normal cases were examined histologically, using sections stained with the Grimelius method. Endocrine cells were demonstrated in 4 cases. Immunohistochemically, these cells were positive for anti-serotonin and anti-somatostatin antisera. Argyrophil granules were also observed in supranuclear or subnuclear regions of glandular cells in 17 cases, and argyrophilia was present in the apical region including the brush borders or microvilli of glandular cells in 6 cases. In these latter 23 cases argyrophilia seemed to be nonspecific, having no relation to endocrine type secretory granules, judging from the electronmicroscopic observations on the silver-impregnated sections. The presence of endocrine cells and the pattern of argyrophilia in glandular cells were similar to those found previously in endometrial glandular adenocarcinomas with argyrophil cells. This is the first report on the occurrence of endocrine cells in normal endometrial glands.     

Induction of human sperm capacitation and protein tyrosine phosphorylation by endometrial cells and interleukin-6

In order to become fully competent at fertilizing the oocyte, spermatozoa must undergo the maturational process of capacitation during their journey in the female reproductive tract. Endometrial cells secrete an array of growth factors that can affect spermatozoa. Among these factors, it has been previously demonstrated that interleukin-6 (IL-6) affects the fertilizing capacity of human spermatozoa. As the expression of this cytokine varies throughout the menstrual cycle and increases during the periovulatory period, the involvement of IL-6 in human sperm capacitation was investigated, with emphasis on the signal transduction cascade triggered by this agent in sperm cells. Spermatozoa were treated with recombinant human IL-6. Protein phosphotyrosine content and localization of the phosphotyrosine containing proteins were evaluated by western blot and indirect immunofluorescence, respectively, using a monoclonal anti-phosphotyrosine antibody. The acrosomal status was evaluated on IL-6 treated spermatozoa before or after challenge with the ionophore A23187 according to the fluorescent pattern observed upon binding to the Pisum sativum agglutinin conjugated to fluorescein isothiocyanate. In the present study, it is shown that, as for endometrial cell-conditioned media, IL-6 induces human sperm capacitation. The IL-6 effects most likely occur through binding to its receptor, IL-6Ralpha, whose presence in the sperm is also reported in this study. As for the IL-6 receptor, this is the first report on the presence of the tyrosine kinase JAK1 in the spermatozoa. Moreover, this kinase becomes phosphorylated on tyrosine residues upon sperm treatment with recombinant IL-6, which suggests its activation by the cytokine. Taken together, our results demonstrate that the IL-6 intracellular signalling machinery is present in human spermatozoa and might be involved in the acquisition of sperm fertilizing ability, also known as the capacitation process.     

Clinical relevance of benign endometrial cells in postmenopausal women

Our objective was to determine if the finding of benign endometrial cells on a Papanicolaou (Pap) smear of a postmenopausal woman is associated with endometrial/uterine pathology, independent of symptomatology and hormone replacement therapy (HRT) status. The medical records of 146 postmenopausal patients who had a Pap smear showing normal-appearing endometrial cells between January 9, 1997 and January 12, 2000 were reviewed. Uterine pathology for each patient was determined by reviewing the results of endometrial sampling (endometrial biopsy or dilatation and curettage), hysterectomy, or pelvic sonogram, which were performed within 24 mo of the cytologic smear. The results were then correlated with clinical symptomatology and HRT status of each patient at the time the cytologic smear was obtained. Of the 146 Pap smears coded with "endometrial cells in a postmenopausal woman," 50 were excluded due to prior hysterectomy, perimenopausal status, and absence of further follow-up. Of the remaining 96 women, 27 (28%) had benign pathologic findings including polyps, leiomyomata, and simple hyperplasia without atypia, whereas 11 (12%) had significant pathologic findings including hyperplasia with atypia, adenocarcinoma, mixed Mullerian tumor, and leiomyosarcoma. Of the 11 patients with significant pathology, only one patient did not have abnormal vaginal bleeding but instead had a 30-wk-size irregular uterus on examination, and only 2 patients received hormone replacement therapy. In conclusion, Reporting endometrial cells on Pap smears in postmenopausal women did not lead to the diagnosis of any cases of significant pathology that would have gone unsuspected clinically. Moreover, HRT status did not affect the incidence of normal endometrial cells on Pap smears in postmenopausal women, nor did it aid in distinguishing which postmenopausal women had endometrial/uterine pathology. This calls into question the usefulness of the current Bethesda guideline to report "benign endometrial cells in a postmenopausal woman."     

Tryptase-positive mast cells and CD8-positive T cells in human endometrial cancer

In this study, we correlated the number of tryptase-reactive mast cells with the number of CD8-positive T cells in human endometrial adenocarcinoma biopsy specimens by means of immunohistochemical techniques. Results have shown that CD8-positive T cell counts correlate to tryptase-positive mast cell counts and that these parameters increase in accordance with the tumor progression of human endometrial carcinoma. These data suggest that inhibition of inflammation or manipulation of inflammatory resolution pathways may be a new therapeutic approach for the treatment of endometrial adenocarcinoma.     

NEDD9在子宫内膜样腺癌中的表达及意义

目的 探讨NEDD9(neural precursor cell expressed developmentally down-regulated9)在子宫内膜样腺癌中的表达及意义。方法 应用免疫组化方法检测NEDD9在50例子宫内膜样腺癌和30例子宫内膜单纯性增生组织中的表达,并检测雌激素受体(ER)、孕激素受体(PR)在子宫内膜样腺癌的表达。结果 NEDD9在子宫内膜样腺癌中的表达高于在子宫内膜单纯性增生组织中的表达(p=0.226);在子宫内膜样腺癌中,NEDD9的高表达与肌层浸润≥1/2、FIGO分期III期和ER阴性表达相关(p=0.012,p=0.041及p=0.039)。结论 NEDD9促进子宫内膜样腺癌的侵袭,并与其ER表达状态负相关。     

低氧对人脐带间充质干细胞生物学特性及增殖的影响简

目的探讨低氧培养条件对人脐带间充质干细胞（hUC-MSCs）的生长和增殖的影响。方法采用人脐带酶消化法分离培养hUC-MSCs,分别将细胞置人体积分数20％、10％、3％0,条件下培养,通过细胞成脂、成骨分化诱导及流式细胞仪检测其表面标志物.鉴定hUC-MSCs：绘制细胞生长曲线,用流式细胞仪检测细胞周期及凋亡情况。结果低氧条件培养hUC-MSCs具有成脂、成骨等多项分化的潜能：流式细胞仪检测呈CD105、CD73、CD90、CD44、HLA-ABC高表达,CDl06、CD29、CD45、CD34、HLA-DR低表达;体积分数3％O2培养组与正常体积分数20％O2培养组及体积分数10％0,培养组相比（各组倍增时间分别为17.2h、20.8h、18.9h）,细胞增殖速度加快（P〈0.05）;G0/G1期细胞减少（各组G0／G1期细胞数分别为77.11％±3.89％、83.92％±5.59％、80.19％±5.16％）,S期细胞增多（S期细胞数分别为15.73％±2.56％、10.91％±1.86％、13.31％-4-2.31％）,增殖指数升高（P〈0.05）;细胞凋亡率降低（流式细胞仪检测各组凋亡率分别为13.41％±1.39％、20.83％±1.81％、19.11％±2.44％）（P〈0.05）。结论体积分数3％O：持续培养可促进hUC-MSCs的增殖.减少细胞凋亡。     

Dipeptidyl peptidase IV as a differentiation marker of the human endometrial glandular cells.

To investigate the involvement of membrane-bound peptidases in the human endometrial function, we examined the expression of dipeptidyl peptidase (DPP) IV and its enzyme activity. Immunohistological studies revealed that DPP IV was detected on human endometrial glandular cells and endometrial surface epithelium, but not on endometrial stromal cells or decidual cells in the first trimester of pregnancy. DPP IV expression on glandular cells and surface epithelium was weak in the proliferative phase, began to increase gradually in the early secretory phase, and was strong in mid-to late secretory phase and in the first trimester of pregnancy. DPP IV enzyme activity was detected histochemically in glandular cells and surface epithelium in the mid-secretory phase, and became stronger in the late secretory phase, but was rarely detected in the proliferative phase and early secretory phase. During the first trimester of pregnancy DPP IV enzyme activity in glandular cells and surface epithelium was slightly weaker than in the late secretory phase. Endometrial stromal cells and decidual cells, however, had no detectable DPP IV enzyme activity at any time throughout the menstrual cycle or during the first trimester of pregnancy. These findings indicate that DPP IV is a differentiation marker for glandular cells and surface epithelium and that active DPP IV is present in both areas during the peri-implantation period and thereafter.     

酶消化结合差时贴壁的方法体外分离培养人子宫内膜细胞

目的探讨酶消化结合差时贴壁培养的方法对人子宫内膜细胞进行体外培养的培养效果,以寻找一种简单高效的人子宫内膜细胞体外分离培养的方法。方法采用胶原酶消化结合差时贴壁的方法,对人正常子宫内膜细胞进行体外分离培养,并传代、冻存及复苏。光镜下观察其培养效果,通过免疫荧光法对腺上皮细胞及间质细胞进行鉴定,并分析其纯度。结果共培养人子宫内膜38份,成功培养35份,培养成功率92％,冻存后成功复苏率达97％;子宫内膜腺上皮细胞和间质细胞分别经角蛋白单抗和波形蛋白单抗免疫荧光显色为阳性,腺上皮细胞和间质细胞原代纯度均达90％以上。结论酶消化结合差时贴壁的培养方法,操作简单、培养成功率高、污染机会少、省时、维持细胞活性好,是子宫内膜细胞体外分离培养的简单高效方法。