Glycogen synthase kinase-3beta is associated with Parkinson's disease

We immunohistochemically examined the expression of glycogen synthase kinase-3beta (GSK-3beta) in the brains of Parkinson's disease (PD) patients. GSK-3beta was localized in punctate structures in the cytosol of subsets of neurons in the midbrain and upper pons. GSK-3beta was also localized in Lewy bodies (LBs) as was phosphorylated GSK-3beta (Ser9) (pGSK-3beta (Ser9)). Both GSK-3beta and pGSK-3beta (Ser9) were localized specifically in the halo of LBs. The core of LBs was negative for GSK-3beta, while pGSK-3beta (Ser9) was present in only a small number of LB cores. Cortical LBs were positive for pGSK-3beta (Ser9) but not for GSK-3beta. Neither GSK-3beta nor pGSK-3beta (Ser9) was present in glial cytoplasmic inclusions (GCIs) in the brains of multiple system atrophy (MSA) patients. Our results suggest that GSK-3beta plays a role in the pathogenesis of PD but not in that of MSA.     

Decreased level of the cell cycle regulator p27 and increased level of its ubiquitin ligase Skp2 in endometrial carcinoma but not in normal secretory or in hyperstimulated endometrium

p27 is a cyclin-dependent kinase (CDK) inhibitor whose specific late G(1) destruction allows progression of the cell across the G(1)/S boundary. The protein is ubiquitinated by S-phase kinase-interacting protein-2 (Skp2) following its specific phosphorylation, and is subsequently degraded by the 26s proteasome. There is a direct relationship between low level of p27 and rapid proliferation occurring in several benign states and in many malignancies. In the glandular cells of the normal endometrium, the level of p27 is exceedingly low during the proliferative phase, whereas it is markedly increased during the secretory phase. The expression of p27 in endometrial carcinoma is very low but has been found to increase following treatment with progesterone. However, estrogen exposure is considered as a major risk factor in developing endometrial cancer. The implications of the high dose of estrogen and progesterone induced during IVF treatment are still unknown. We have examined the expression of p27 and Skp2 as well as of Ki67 proliferation marker by using endometrial extracts and cells from normal endometrium, from ovarian hyperstimulated patients, and from endometrial carcinoma patients. The expression of p27, Skp2 and Ki67 was found to be similar in both normal secretory endometrium and endometrium from ovarian hyperstimulated patients. In striking contrast, p27 is significantly lower while Skp2 and Ki67 are significantly higher in the endometrial carcinoma and in endometrium from the proliferative phase compared with their normal secretory counterpart tissue.     

Immunohistochemical analysis of estrogen receptor alpha, estrogen receptor beta and progesterone receptor in normal human endometrium

The endometrium expresses estrogen (ER) and progesterone receptors (PR), which are involved in autocrine and paracrine regulation processes in response to estrogen and progesterone. The aim of the present study was to evaluate immunohistochemical distribution patterns of estrogen receptor alpha (ER alpha), estrogen receptor beta (ER beta) and PR in normal human endometrial tissue with the use of monoclonal antibodies. Human endometria were obtained from 17 premenopausal patients undergoing surgery for non-malignant diseases and were classified to be in proliferative, early secretory and late secretory phases by histological and anamnestical means. Distribution patterns of the steroid receptors were evaluated using the IRS-score and the Mann-Whitney rank-sum test was used to compare the means. Correlation was assessed with the Spearman factor and linear regression analysis. ER alpha and PR expression decreased significantly (p<0.05) in glandular epithelium from the proliferative to the late secretory phase. ER beta expression showed a similar significant decrease (p<0.05), although staining intensity was lower than that of ER alpha. A significant correlation between expression of all three steroid receptors was observed (p<0.001). Distribution patterns of ER alpha, ER beta and PR in normal human endometrium showed a cyclic variation during the menstrual cycle. A significant correlation between expression of ER alpha, ER beta and PR was also demonstrated using regression analysis, indicating dependence of expression of these three steroid receptors. The present study shows the presence of steroid receptors in human endometrial epithelium, indicating that these cells respond to estrogen and progesterone and thus playing a significant role in endometrial physiology.     

Menstrual-like breakdown and apoptosis in human endometrial explants

BACKGROUND: Apoptosis occurs in late secretory and menstrual human endometrium and is thought to play an important role in endometrial physiology. Menstrual-like breakdown has been observed in vitro in endometrial explants. The purpose of this study was to assess the role of apoptosis in menstrual-like breakdown in human endometrial explants. METHODS: Human endometrial tissue was obtained during the mid-secretory phase and cultured with or without estrogen and progesterone. The occurrence of breakdown was assessed by histology. Apoptosis was determined by gel electrophoresis for the detection of DNA fragmentation and by immunohistochemistry using the M30 CytoDEATH and anti-cleaved caspase-3 (CASP3) antibodies for the detection of caspase activity. Expression of BCL2 and BAX was quantified using real-time PCR analysis. RESULTS: Apoptosis occurred in human endometrial explants at all time-points studied. Cleaved CASP3 and M30 antigen expression increased in all explants, suggesting the involvement of CASP3 in the apoptosis. Low BCL2:BAX ratios were observed in all samples when compared with pre-culture controls. Estradiol and progesterone supplementation of the culture media reduced or eliminated menstrual-like breakdown but did not affect the degree of apoptosis observed. CONCLUSIONS: The apoptosis observed in endometrium during the late secretory phase and menstrual phase does not appear to be mechanistically related to the tissue breakdown but rather may be involved in the impending remodelling that occurs in the endometrium in the transition from secretory to proliferative phase following the menses.     

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.     

血管内皮生长因子在子宫内膜异位症发病中的作用

目的探讨血管内皮生长因子(vascularendothelialgrowthfactor,VEGF)在子宫内膜异位症(endometriosis,EM)发病中的作用。方法应用免疫组织化学方法并结合图像分析技术。结果正常子宫内膜和EM在位内膜腺上皮细胞的VEGF随月经周期呈现规律性变化,分泌期腺上皮VEGF蛋白表达量显著高于增殖期(P<0.05)。在增殖期,EM在位子宫内膜腺上皮VEGF的表达与正常子宫内膜相比无明显差别,但在分泌期,EM在位子宫内膜腺上皮细胞中VEGF的表达强度明显高于正常子宫内膜(P<0.01)。EM在位内膜腺上皮的VEGF含量显著高于同组卵巢子宫内膜异位囊肿的异位腺上皮(P<0.01)。结论表明VEGF的表达异常与EM的发病有关。     

Membrane-type matrix metalloproteinases and vascularization in human endometrium during the menstrual cycle

Endometrial angiogenesis is essential for a vascularized receptive endometrium. Previously, we described that membrane type-3 metalloproteinase (MT3-MMP) is associated with endometrial angiogenesis in vitro. The association of MT-MMPs with endometrial angiogenesis in vivo is unknown. Therefore, this study analysed the presence of MT-MMPs in human endometrium and their correlation with neovascularization. RNA/protein expressions of the six MT-MMPs were determined in cultured endometrial cells. Vascularization parameters and MT-MMP expressions in vivo were evaluated by immunohistochemistry in serial endometrium sections. MT1-, MT2-, MT3- and MT4-MMP antigens were expressed in cultured endometrial endothelial cells. MT2-, MT3- and MT4-MMP were expressed by endothelium during the proliferative and secretory phase. Strikingly, these phases showed elevated vascularization, elevated total vascular surface in proliferative phases, elevated number of vessels in proliferative/late secretory phases and increased luminal surface in the proliferative phases. All MT-MMP antigens were expressed in various endometrial cell types in vivo, with decreased levels during the early secretory phase. In conclusion, all MT-MMPs are expressed in endometrium in a cycle-dependent pattern. The vascular expression of MT2-, MT3- and MT4-MMP correlated with angiogenic episodes of the cycle. Since MT2- and MT3-MMP are known to regulate tube formation, these findings support earlier in vitro data on the role of MT3-MMP in endometrial angiogenesis. Additionally, MT2-MMP appears to be associated with endometrial neovascularization also.     

Telomerase activity in the human endometrium throughout the menstrual cycle

In a total of 41 endometrial tissue samples, the relationship between telomerase activity and proliferating cell nuclear antigen (PCNA) labelling index was studied. In samples of endometrium from the proliferative phase of the menstrual cycle, telomerase activity was found in 15 out of 17 cases (88%). Two samples from the early proliferative phase showed negative telomerase activity and a low PCNA labelling index. However, three out of 16 samples of early secretory phase endometrium showed telomerase activity and a PCNA labelling index. In mid- to late secretory phase endometrium, in menopausal endometrium and in decidualized endometrium induced by progesterone neither telomerase activity nor PCNA labelling was found. These results suggest that telomerase activity of the endometrium may be correlated with the proliferative potential of the epithelial cells and that its activity may be regulated by oestrogen.      

Expression of cystic fibrosis transmembrane conductance regulator in human endometrium

BACKGROUND: As a cAMP-regulated Cl- channel, cystic fibrosis transmembrane conductance regulator (CFTR) plays a critical role in the active secretion of electrolytes and fluid in epithelial cells. Women with CFTR gene mutations are less fertile, generally assumed to be due to cervical factors. However, there is little known about CFTR protein expression in human endometrium and its possible roles in reproduction. METHODS AND RESULTS: CFTR protein and mRNA levels in human endometrium were analysed using immunohistochemical and in situ hybridization methods, respectively. Significant expression of CFTR protein was only seen in the glandular cells from late proliferative to all secretory phases, consistent with western blot analysis. High levels of CFTR mRNA were present only around the ovulatory period. In cultured glandular cells, the production of CFTR protein and mRNA was stimulated by estradiol and inhibited by progesterone. A forskolin-activated Cl- current in endometrial epithelial cells with a linear I-V relationship was detected by the whole-cell patch-clamp technique. CONCLUSIONS: (i) CFTR mRNA and protein were localized in human endometrial epithelial cells and the amounts varied in a cyclic manner; (ii) CFTR expression in cultured glandular cells was up- and downregulated by estradiol and progesterone, respectively; and (iii) CFTR in human endometrium functions as a cAMP-activated Cl- channel.     

Immunohistochemical characterization of proliferation, oestrogen receptor and progesterone receptor expression in endometriosis: comparison of eutopic and ectopic endometrium with normal cycling endometrium

Recent studies examining oestrogen and progesterone receptorstatus and the proliferative activity of endo-metriotic lesionshave produced conflicting reports. This study aimed to clarifythe receptor status and proliferative activity of eutopic andectopic endometrium from women with endometriosis and endometriumfrom normal women. Progesterone and oestrogen receptor expressionand proliferative activity were studied in eutopic and ectopicendometrium from 30 women with endometriosis and in endometriumfrom 30 normal cycling women using microwave-pretreated paraffin-embeddedsections stained with an avidin-biotin peroxidase technique.Progesterone and oestrogen receptor expression in the controlendo-metrium did not differ from that of eutopic endometriumfrom women with endometriosis. Oestrogen receptor expressionin ectopic endometrium increased from the proliferative to thelate secretory phase. Epithelial progesterone receptor expressiondecreased during the cycle. Oestrogen receptor expression inboth epithelium and stroma of ectopic endometrium was significantlyhigher than in eutopic endometrium throughout the cycle. Incontrast, stromal progesterone receptor expression tended tobe reduced in ectopic endometrium compared with eutopic tissue.Epithelial progesterone receptor expression was increased inectopic endometrium but only in the late secretory phase. Althoughproliferative activity in the epithelium of control and eutopicendometrium was reduced from the proliferative to the late secretoryphase, stromal activity did not vary. The proliferative activityin ectopic endometrium remained low and constant throughoutthe cycle. In the proliferative and early secretory phases,the proliferative activity of eutopic endometrium was increasedcompared with ectopic endometrium, but in the late secretoryphase, levels were comparable. These findings challenge previousreports which have suggested that oestrogen receptors are reducedin ectopic tissue. This may have clinical implications for thedevelopment of novel treatments for endometriosis.     

Expression of interleukin-8 receptors in endometriosis

BACKGROUND: Although the etiology of endometriosis is not well understood, chemokines and their receptors are believed to play a role in its pathogenesis. Therefore, we aimed to investigate the expression and localization of interleukin-8 (IL-8) receptors CXCR1 and CXCR2 in eutopic and ectopic endometrial tissues of women with endometriosis, and in endometrium of women without endometriosis. METHODS: Ectopic (n = 27) and homologous eutopic endometrium (n = 25) from women with endometriosis and endometrium from women without endometriosis (n = 27) were used for immunohistochemical analysis of CXCR1 and CXCR2. RESULTS: In normal endometrium, epithelial CXCR1 and CXCR2 immunostaining intensities were similar in the proliferative and secretory phase. Stromal CXCR1 expression was less then epithelial expression and did not show cyclical difference. No stromal CXCR2 expression was observed. In eutopic endometrium of women with endometriosis compared to endometrium of women without endometriosis, there was a significant increase in both proliferative and secretory phases for epithelial CXCR2 expression, and in proliferative phase for CXCR1 expression (P < 0.05). Both receptor immunoreactivities were significantly increased in the epithelial cells of ectopic endometrial tissues compared to that of normal endometrium (P < 0.05). CONCLUSIONS: These findings suggest that IL-8 and its receptors may be involved in the pathogenesis of endometriosis.     

Immunocytochemical study of progesterone receptors in the human endometrium during the menstrual cycle

Specific mouse monoclonal antibody (alpha PR6) against progesterone receptor was used with an avidin biotin complex technique to localize progesterone receptors in frozen sections of 26 normal cyclic human endometria. Progesterone receptor was detected in the nuclei of epithelial and stromal cells in both the functionalis and basalis layers. In the functionalis, the receptor content increased from the early to the late proliferative phase in both cell components. It remained high in the early secretory phase and decreased in the mid- and late secretory phases, comparatively more rapidly in the epithelium than in the stroma. In the latter, the predecidual cell nuclei were receptor-positive. The menstrual phase endometrium lacked receptors. The basalis was rich in progesterone receptors during the proliferative, early and midsecretory phases in both components and receptor-free during the late secretory and menstrual phases of the cycle. Myometrial smooth muscle cell nuclei contained progesterone receptors, whereas they were absent in endometrial and myometrial vessels. Overall, the epithelial progesterone receptor content seemed to correlate with the endometrial tissue levels of estradiol, possibly reflecting its estrogen sensitivity, whereas the stromal progesterone receptor content during the secretory phase at least, in part, may be constitutively synthetized.     

Immunohistochemical detection of hepatocyte nuclear factor 1beta in ovarian and endometrial clear-cell adenocarcinomas and nonneoplastic endometrium

Recent studies have noted specific expression of hepatocyte nuclear factor (HNF) 1beta in ovarian clear-cell adenocarcinoma (CCA). In this study, we aimed to determine whether HNF-1beta can be a specific marker of CCA in both the ovary and the endometrium and to assess the pathological significance of HNF-1beta expression in CCAs. We examined HNF-1beta expression immunohistochemically in 186 ovarian carcinomas, including 40 CCAs; 33 endometrial carcinomas, including 5 CCAs; 22 endometria at different stages of the menstrual cycle (5 in the proliferative, 12 in the secretory, and 5 in the menstrual phases); and 7 gestational endometria. The incidence of HNF-1beta immunoreactivity differed significantly between CCAs and other histology in both the ovary (100% in the former versus 2% in the latter) and the endometrium (100% in the former versus 0% in the latter) (P < .0001 each). In nonneoplastic endometrium, 25% or more immunoreactive cells were confined to the mid-to-late secretory phase of the menstrual cycle and gestational endometrium. HNF-1beta would be an excellent marker for distinguishing CCAs from other lesions in both the ovary and the endometrium. HNF-1beta expression seems to be associated with physiopathological cytoplasmic glycogen accumulation in these organs.     

P-glycoprotein expression is increased in human secretory and gestational endometrium.

To determine the expression, distribution, and intracellular localization of the multi-drug resistance gene product P-glycoprotein (Pgp) in the human menstrual cycle and in early gestational endometrium, we retrospectively studied 36 endometrial samples utilizing 3 murine monoclonal antibodies (MAbs), MAb C219, MAb C494, and MAb JSB-1, which recognize spatially distinct cytoplasmic epitopes of Pgp. Formalin-fixed, paraffin-embedded endometrial samples obtained from 36 women of reproductive age with normal menstrual cycles were assigned morphologic menstrual dates: proliferative (N = 10), secretory (N = 19), menstrual (N = 1), and gestational endometrium (N = 6). The cellular localization, staining intensity, and percentage of Pgp immunoreactive cells varied with the phase of the menstrual cycle. Early proliferative endometria revealed no Pgp immunoreactivity for all three MAbs. Mid-proliferative endometria showed weak immunostaining in less than 15% of the glandular epithelia. Late proliferative endometria showed a strong apical paranuclear/Golgi staining pattern. Early secretory endometria showed strong luminal membranous, subnuclear vacuolar membranous, and supranuclear vacuolar membranous immunostaining to all 3 MAbs in greater than 80% of the glandular epithelia. Apical paranuclear/Golgi and membranous staining were present in nonvacuolated mid-secretory glands. Immunoreactivity diminished in the late secretory phase with mild to moderate staining in less than 35% of the endometrial glands. Menstrual endometria showed weak, focal staining. All gestational endometria showed marked cytoplasmic, membranous, and apical/Golgi immunostaining both in the hypersecretory (Arias-Stella) endometrial glands as well as in the decidua. In general, the intensity of MAb C494 immunostaining was weaker than that of MAb C219 or JSB-1. These results suggest the following: Pgp expression parallels that of nuclear progesterone receptor expression in the normal human endometrial cycle and early gestational endometrium; Pgp expression corresponds to rising plasma and tissue levels of progesterone as well as to morphologic changes in the endometrial glandular epithelium associated with the marked development of the secretory apparatus; Pgp expression is hormonally regulated and may be involved in uteroplacental transport of substrates important in the implantation process and in early embryo-endometrial interactions; and Pgp may be involved in the transport of progesterone across the uterine epithelium during pregnancy.     

Hormonal regulation and localization of estrogen, progestin and androgen receptors in the endometrium of nonhuman primates: effects of progesterone receptor antagonists

This article reviews the effects of estradiol (E(2)), progesterone (P) and P receptor antagonists (PA) on the rhesus macaque endometrium. Ovariectomized macaques can be treated with implants of estradiol (E(2)) and P to induce precisely controlled, artificial menstrual cycles. During these cycles, treatment with E(2) alone induces an artificial proliferative phase marked by extensive endometrial epithelial cell proliferation and increased expression of stromal and epithelial estrogen receptor (ER) and P receptor (PR). Androgen receptor (AR) is also upregulated by E(2) but is expressed only by the endometrial stroma. Progesterone acts on the E(2) primed endometrium to induce secretory differentiation and causes suppression of epithelial and stromal ER, epithelial PR, and stromal AR in the functionalis zone. However, epithelial ER and PR are retained in the basalis zone during the secretory phase. When potent P antagonists (PA) are administered acutely at the end of an E(2) + P induced cycle, menses typically ensues similar to P withdrawal at the end of the menstrual cycle. When PAs are administered chronically there is significant blockage of all P- dependent effects including upregulation of ER, PR and AR and suppression of glandular secretory function. However, chronic PA administration also inhibits estrogen-dependent endometrial cell proliferation and growth. This endometrial antiproliferative effect is the basis of the clinical use of PA to control various diseases such as endometriosis.     

Decidualization and maintenance of a functional prostaglandin system in human endometrial cell lines following transformation with SV40 large T antigen

Prostaglandins (PGs) are key regulators of reproductive function and associated pathologies. We have established stable endometrial stromal and epithelial cell lines with SV40 large T antigen (TAG) as a model to study PG action in the human endometrium. Two clones for each cell type were selected for rapid growth, PG production and response to interleukin-1beta (IL-1beta). The resulting stromal (HIESC) and epithelial (HIEEC) cells retain their characteristics for at least 40 population doublings (PDs). The selected clones express progesterone (PR) and estrogen receptor-alpha (ER-alpha) at both mRNA and protein levels. By contrast, with the existing known human endometrial cell lines Ishikawa and KLE, HIESC and HIEEC increase their production of PGF2alpha and PGE2 and cyclooxygenase (COX)-2 protein expression in response to IL-1beta. The latter cells also express the main biosynthetic enzymes involved in PG production, cytosolic phospholipase A2 (PLA2), COX-1 and COX-2, PGF synthase and PGE synthase and the corresponding EP2, EP3, EP4 and FP receptors. The selective COX-2 inhibitor NS-398 completely inhibits the increased production of PGs induced by IL-1beta in both cell types, whereas dexamethasone (DEX) exerts a stronger inhibition in HIESC than in HIEEC. The latter observation may be related to the higher expression of COX-1 measured in HIEEC. On the basis of the present characterization and previous determination of corresponding primary cell cultures, HIESC and HIEEC appear appropriate to study the contribution of PGs in the regulation of human endometrium function and associated pathologies.     

Secretory endometrium highly expresses urocortin messenger RNA and peptide: possible role in the decidualization process

BACKGROUND: Urocortin (UCN) gene expression and synthesis have been reported in epithelial and stromal cells of the human endometrium. In this study we evaluated (i) UCN messenger RNA (mRNA) expression and peptide production in uterine specimens collected throughout the endometrial cycle, (ii) UCN secretion after decidualization of cultured human endometrial stromal cells (HESCs) and (iii) the effect of UCN on endometrial decidualization. METHODS: HESCs were isolated from samples of human endometrium collected from healthy patients with normal menstrual cycle and cultured in presence of cAMP, 17-beta-estradiol (E(2)) + medroxyprogesterone acetate (MPA) and UCN. UCN levels were measured in endometrial extracts by an enzyme immunoassay, and changes of endometrial UCN mRNA expression were measured by RT-PCR analysis. RESULTS: UCN peptide concentrations and mRNA expression were highest in the secretory phase of the menstrual cycle (P < 0.001, late secretory versus early and late proliferative phase) and higher in the late than the early secretory phase (P < 0.01). After decidualization of HESC with cAMP or E(2) + MPA, UCN levels rose in parallel with prolactin concentrations by days 6 (P < 0.01, for all). Finally, the addition of UCN to HESCs, with or without E(2) + MPA, induced the release of prolactin. CONCLUSIONS: The evidence that (i) UCN is highly expressed in the secretory phase of the endometrial cycle; (ii) cAMP and E(2) + MPA modulate secretion of UCN and (iii) UCN induces HESCs decidualization together suggest a possible role for UCN in endometrial physiology.