Metformin increases the ovulatory rate and pregnancy rate from clomiphene citrate in patients with polycystic ovary syndrome who are resistant to clomiphene citrate alone.

OBJECTIVE: To determine whether metformin treatment increases the ovulation and pregnancy rates in response to clomiphene citrate (CC) in women who are resistant to CC alone. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: Multicenter environment. PATIENT(S): Anovulatory women with the polycystic ovary syndrome (PCOS) who were resistant to CC. INTERVENTION(S): Participants received placebo or metformin, 500 mg three times daily, for 7 weeks. Information on reproductive steroids, gonadotropins, and oral glucose tolerance testing was obtained at baseline and after treatment. Metformin or placebo was continued and CC treatment was begun at 50 mg daily for 5 days. Serum P level > or =4 ng/mL was considered to indicate ovulation. With ovulation, the daily CC dose was not changed, but with anovulation it was increased by 50 mg for the next cycle. Patients completed the study when they had had six ovulatory cycles, became pregnant, or experienced anovulation while receiving 150 mg of CC. MAIN OUTCOME MEASURE(S): Ovulation and pregnancy rates. RESULT(S): In the metformin and placebo groups, 9 of 12 participants (75%) and 4 of 15 participants (27%) ovulated, and 6 of 11 participants (55%) and 1 of 14 participants (7%) conceived, respectively. Comparisons between the groups were significant. CONCLUSION(S): In anovulatory women with PCOS who are resistant to CC, metformin use significantly increased the ovulation rate and pregnancy rate from CC treatment.

Increased circulating lipid peroxides in severe preeclampsia activate NF-kappaB and upregulate ICAM-1 in vascular endothelial cells.

Preeclampsia is a systemic disease of pregnancy characterized by maternal hypertension, proteinuria, and edema. These clinical pathological findings may be attributed to abnormalities in vascular endothelial activation secondary to increased oxidative stress. To test the hypothesis that increased circulating lipid peroxides in preeclamptic women activate vascular endothelial cells, we determined NF-kappaB transcriptional activity and ICAM-1 expression in human umbilical vein endothelial cells (HUVEC) cultured with plasma from women with severe preeclampsia (preeclamptic plasma, N = 12) or plasma from normal pregnancies (normal plasma, N = 12). Preeclamptic women had increased circulating lipid peroxides compared with normal pregnant women, as demonstrated by a 4.5-fold higher concentration of plasma malondialdehyde (PkB luciferase reporter construct transfected into HUVEC, preeclamptic plasma was found to up-regulate HUVEC NF-kappaB activity by 2.5-fold when compared with normal plasma (PkB activation in response to preeclamptic-plasma by 77% (PkB activation and ICAM-1 expression on HUVEC, which can be inhibited by vitamin E and N-acetyl-cysteine.

Cytokines in implantation.

Implantation is a process that involves development, attachment and invasion of the blastocyst into the endometrium. Successful implantation requires appropriate communication between the embryo and maternal endometrium. There is evidence to suggest that cytokines produced by the maternal endometrium and the developing embryo play a crucial role in this signalling process. Although numerous cytokine-receptor pairs are expressed by the maternal endometrium and the embryo during implantation, functional knowledge of these cytokines is limited. Compelling data demonstrating a functional role for cytokines in implantation comes from studies using specific cytokine and cytokine receptor knockout mice. There are limited similar data for human implantation, but clinical correlative data and studies using in vitro models indicate that cytokines may have an important functional role in this process. Cytokines that appear to have a functional role in mammalian implantation include leukaemia inhibitory factor, interleukin 1, hepatocyte growth factor, stem cell factor, macrophage colony-stimulating factor and insulin-like growth factors. As implantation failure is a significant cause of natural and in vitro fertilization pregnancy failure, a better understanding of the functional role of these cytokine-receptor pairs is important for improving the diagnosis and treatment of infertility.

Hepatocyte growth factor stimulates trophoblast invasion: a potential mechanism for abnormal placentation in preeclampsia.

Hepatocyte growth factor (HGF) is a cytokine that is produced in the placental villous core and acts in a paracrine manner on trophoblasts that express the HGF receptor Met. Because HGF stimulates the invasion of many epithelial cell types, villous core HGF could regulate placental trophoblast invasion. As preeclampsia is characterized by inadequate trophoblast invasion, we investigated the hypothesis that decreased placental HGF production is a mechanism for inadequate trophoblast invasion in this disease. Placental villous explant HGF production over 24 h was 25% lower in patients with preeclampsia (n = 5; 7.29 +/- 0.8 ng/mL) than in normal patients (n = 5; 9.76 +/- 0.5 ng/mL; P < 0.05). The human first trimester trophoblast cell line (ED27) used in subsequent invasion studies was found to express c-met messenger ribonucleic acid by RT-PCR and Met protein by Western analysis, and underwent phosphorylation of tyrosine residues on Met with HGF exposure. A Boyden chamber invasion assay using collagen type I showed that HGF caused a specific dose-response increase in trophoblast invasion first seen at 10 ng/mL (2.2-fold increase; P < 0.05). The stimulation of trophoblast invasion by HGF may in part be due to the 2-fold induction of 92-kDa collagenase as determined by zymogram analysis of the trophoblast-conditioned medium. These studies suggest that HGF has an important role in placental trophoblast invasion through the activation of Met and the subsequent induction of 92-kDa collagenase in these cells. In addition, decreased placental production of HGF in preeclampsia provides a potential mechanism for the lack of trophoblast invasion that is seen in this pregnancy disorder.

Placental Fas ligand expression is a mechanism for maternal immune tolerance to the fetus.

Fas ligand (FasL) is a peptide that plays an important immunoregulatory role in limiting the host immune response. Several studies have shown that the expression of FasL in the anterior chamber of the eye and the testis allows these tissues to be immunoprivileged sites. Immunotolerance is achieved by binding of FasL to its receptor (Fas) on activated immune cells, which results in cell apoptosis. To determine whether FasL has a role in maternal immune tolerance to the fetus, we looked for the expression of FasL in the human placenta. Immunoperoxidase staining localized FasL to both syncytiotrophoblast and cytotrophoblast in placental villi and chorionic extravillous trophoblast. Western analysis demonstrated FasL in placental villi and a human first-trimester trophoblast cell line (ED27). In contrast, Fas was colocalized to CD45 (leukocyte common antigen) positive cells found in maternal decidua. When isolated peripheral blood lymphocytes were induced to express Fas with phytohemagglutinin (PHA) and interleukin-2 (IL-2) and then cocultured with trophoblast, 30% of the lymphocytes underwent apoptosis, as determined by the in situ death (TUNEL) assay. Neutralizing antibodies to FasL inhibited apoptosis by 40% in these studies. In contrast, activated lymphocytes cocultured with non-FasL-expressing fibroblasts or unactivated non-Fas-expressing lymphocytes cocultured with ED27 trophoblast showed little evidence of apoptosis. These findings suggest that FasL expressed by fetal trophoblast cells can induce apoptosis in activated lymphocytes there by providing a mechanism for maternal immune tolerance to the fetus.

Hepatocyte growth factor (HGF) induces invasion of endometrial carcinoma cell lines in vitro.

OBJECTIVES: The overall goal of this study was to investigate the role of the hepatocyte growth factor (HGF)/Met pathway in the pathophysiology of invasive endometrial carcinoma. Our objectives were (1) to examine expression of HGF and Met in surgical endometrial carcinoma specimens and endometrial carcinoma cell lines, and (2) to determine if HGF would stimulate invasion of endometrial carcinoma cell lines in vitro. METHODS: Using RT-PCR and Western immunoblotting, endometrial carcinoma specimens and the endometrial carcinoma cell lines KLE, HEC-1A, HEC-1B, and RL-95 were examined for expression of HGF and Met. A Boyden chamber invasion assay using collagen type I coated 8-microm porous membranes was then used to determine if HGF would stimulate cell invasion. Last, we assessed the capacity of endometrial stromal cells, isolated from normal human endometrium, to produce HGF as determined by an enzyme-linked immunosorbent assay and to stimulate invasion of the KLE cell line. RESULTS: All of the endometrial carcinoma tissue samples were found to express Met mRNA, and two of four samples expressed HGF mRNA. However, the endometrial carcinoma cell lines expressed only Met and not HGF mRNA. Both the endometrial carcinoma tissue specimens and the endometrial carcinoma cell lines expressed the 140-kDa Met protein. HGF induced the invasion of the KLE and HEC-1A cells through the collagen-coated membranes in a dose-dependent fashion. The optimal concentration of HGF was between 10 and 100 ng/ml. HGF (10 ng/ml) stimulated KLE invasion 1.8-fold (P < 0.05) and HEC-1A invasion 6.5-fold (P < 0.05). During exposure to endometrial stromal cell conditioned medium containing HGF as determined by ELISA, invasion of the KLE cell line was stimulated 2.5-fold (P < 0.05). CONCLUSION: These results demonstrate that HGF stimulates the invasion of endometrial carcinoma cells in vitro. Since endometrial adenocarcinoma specimens express Met, these findings suggest that the HGF/Met pathway may play a role in the invasive progression of endometrial carcinoma.

Characteristics of luteinizing hormone secretion in younger versus older premenopausal women.

OBJECTIVES: The objectives of this study were to document specific attributes of pulsatile luteinizing hormone secretion in middle-aged women before discernible alterations in their menstrual cycles and to compare the results to corresponding data obtained in younger women. STUDY DESIGN: After documenting normal cycle length, biphasic basal body temperatures, and normal midluteal progesterone in younger and middle-aged women during an initial cycle, daily blood samples and samples withdrawn at 10-minute intervals for 8 hours during the midfollicular phase were obtained during a subsequent cycle. RESULTS: Assessment of luteinizing hormone pulses with the pulse detection algorithm Cluster demonstrated a prolonged interpulse interval and increased pulse width in the older women. Assessment of luteinizing hormone secretory bursts and half-life with the deconvolution analysis procedure demonstrated a prolonged interburst interval and half-life in the older women. Appraisal of approximate entropy revealed greater orderliness of luteinizing hormone release in the older women. CONCLUSIONS: Middle-aged women exhibit alterations in hypothalamic-pituitary function that may account in part for age-related changes in reproductive potential.

The differential expression of hepatocyte growth factor and met in human placenta.

Met is the tyrosine kinase receptor for the ligand hepatocyte growth factor (HGF). Met/HGF plays an important role in epithelial cell proliferation, migration, and morphogenesis. HGF also plays a crucial role in placental development in the mouse. To determine whether HGF potentially has a similar role in human placental development, the production and localization of Met and HGF were determined in early second trimester and term placentas. Reverse transcription-PCR using specific primers demonstrated the expression of Met and HGF messenger ribonucleic acid in placental villi. HGF production was determined by enzyme-linked immunosorbent assay. HGF production over 48 h by second trimester placental villous explants in culture (810 pg/mg total protein x h) was 2.1-fold greater than that in term placental villous explants (380 pg/mg total protein x h; P < 0.01). Isolated trophoblast did not produce HGF, whereas isolated villous core tissues and villous core mesenchymal cells did produce HGF. Interleukin-1 beta treatment of placental villi or coculture of villous core mesenchymal cells with isolated trophoblast cells did not stimulate HGF production. Using immunohistochemistry, HGF localized to the villous core compartment with no localization to the trophoblast. In contrast, Met localized mainly to cytotrophoblast. These findings suggest that HGF produced by the villous core may act in a paracrine fashion to regulate trophoblast development or function through the HGF receptor, Met.

Reproductive immunology update: the 52nd annual meeting of the American Society of Reproductive Medicine.

The American Society of Reproductive Medicine meeting (formerly the American Fertility Society) was held in Boston, Massachusetts, USA, on November 2-6, 1996. Numerous abstracts concerning original research in reproductive immunology were presented at the meeting. In addition, seminars and round table discussions were held on the topics of hormonal immunocontraception, immunologic testing in reproduction, antiphospholipid syndrome, endometriosis, and immunologic infertility.

The expression of interleukin-1 alpha, interleukin-1 beta, and interleukin-1 receptor type I mRNA during preimplantation mouse development.

Interleukin-1 (IL-1) plays an important role in implantation of the early embryo since blockade of the IL-1 receptor prevents implantation in the mouse. Whether IL-1 blockade during implantation has a direct effect on the embryo or only the uterus is unknown since reliable data are not available concerning the expression of IL-1 or IL-1 receptor on the preimplantation embryo. Because of the significant role for IL-1 in implantation, we investigated the potential for an embryonic-maternal IL-1 signaling mechanism during mouse preimplantation embryo development. Reverse transcriptase-polymerase chain reaction (RT-PCR) was performed for IL-1 alpha, IL-1 beta and IL-1 receptor type I (IL-1R) on mRNA isolated from mouse preimplantation embryos and uteri collected between the 2-cell to blastocyst stage. Preimplantation embryos have the capability to produce IL-1 beta after the 4-cell stage of development since IL-1 beta mRNA was detected from the 4-cell to blastocyst stage but not at the 2-cell stage. Unlike IL-1 beta, IL-1 alpha was not expressed in preimplantation embryos. It is unlikely that IL-1 has a direct effect on the preimplantation embryo since IL-1R mRNA was not expressed in preimplantation embryos. In contrast, IL-1 could have a direct effect on the uterus since IL-1R mRNA was found to be expressed in uteri at all developmental time points. Our findings suggest that there is a potential embryonic-maternal IL-1 signaling mechanism through the expression of IL-1 beta by the preimplantation embryo and the expression of IL-1R in the uterus.

Interleukin-1 beta and tumor necrosis factor-alpha stimulate granulocyte colony-stimulating factor production by placental villous core mesenchymal cells.

OBJECTIVE: To test the hypothesis that interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) regulate granulocyte colony-stimulating factor (G-CSF) production by human placental villous core mesenchymal cells. METHODS: Villous core mesenchymal cells were isolated from placentas at 14-20 weeks' gestation and cultured in vitro. Cells were treated with IL-1 beta or TNF-alpha in dose-response and time-course studies. We measured G-CSF mRNA expression by Northern blot analysis and G-CSF protein production by enzyme-linked immunosorbent assay of the conditioned media. RESULTS: Unstimulated mesenchymal cells expressed negligible G-CSF. Steady-state G-CSF mRNA expression was maximal 3-6 hours after IL-1 beta treatment and 6-18 hours after TNF-alpha treatment. Each cytokine induced G-CSF protein production in dose-and time-dependent manners, with IL-1 beta more potent than TNF-alpha. The G-CSF mRNA expression and G-CSF protein production induced by the combination of both cytokines exceeded that induced by either cytokine alone. CONCLUSIONS: Interleukin-1 beta and TNF-alpha stimulate G-CSF production by placental villous core mesenchymal cells in vitro. These results identify a potential mechanism by which villous core mesenchymal cells mediate, in part, the placental response to these two cytokines.

The expression of stem cell factor and its receptor, c-kit in human endometrium and placental tissues during pregnancy.

Stem cell factor (SCF) and its receptor Kit regulate the proliferation and survival of early hematopoietic cell types as well as germ cells and melanocytes. As SCF augments the effects of several hematopoietic growth factors that are produced in reproductive tissues during pregnancy and also plays an important role in cell migration, proliferation, and survival, we studied the expression and localization of this receptor/ligand in human endometrial and placental tissues. Kit was detected by Western blot analysis in early decidual and placental tissues (8-19 weeks gestation) and in term placenta. Immunohistochemistry localized Kit mainly in trophoblast and to a lesser extent in scattered cells in the placental villous core and decidual stroma. Ribonuclease protection assay showed that SCF messenger ribonucleic acid (mRNA) expression increased 3-fold in decidua from early pregnancy compared to proliferative and secretory endometrium (P < 0.05). Placental tissues expressed 4- to 8-fold higher levels of SCF mRNA compared to decidus (P < 0.05). Isolated placental villous core expressed 7-fold higher levels of SCF mRNA than did trophoblast (P < 0.05). Thus, SCF and its receptor Kit are expressed in human endometrium and placental tissues during pregnancy, and the pattern of receptor/ligand expression suggests that endometrial and placental villous core SCF may have a paracrine effect on trophoblast through the receptor Kit.

Preeclampsia is associated with decreased placental interleukin-6 production.

OBJECTIVE: The etiology of preeclampsia is poorly understood, but may involve abnormal fetal-maternal immunologic interactions. Interleukin-6 (IL-6) is a multifunctional immunologic cytokine that is normally produced by the placenta during pregnancy. Recent studies have shown that amniotic fluid IL-6 is decreased in pregnancies complicated by preeclampsia. Consequently, this study was designed to test the hypothesis that placental IL-6 production is decreased in preeclampsia. METHODS: Placental explants from normal (N = 6) and preeclamptic (N = 6) pregnancies were cultured in vitro, and the media were sampled at 0, 2, 6, 16, 28, and 48 hours. Production rates of IL-6 were measured by enzyme-linked immunosorbent assay, and relative IL-6 mRNA expression was measured by Northern and dot blot analyses. RESULTS: Production rates of IL-6 were 2.3-fold lower in preeclamptic placentas than in normal placentas, at 146 pg/microgram/hour versus 341 pg/microgram/hour (P < .05). However, relative steady-state IL-6 mRNA expression was identical in preeclamptic and normal placentas. CONCLUSIONS: Placental IL-6 production is decreased in preeclampsia. The decrease in placental IL-6 production and secretion in preeclampsia is regulated by a post-transcriptional mechanism.

Coculture cells that express leukemia inhibitory factor (LIF) enhance mouse blastocyst development in vitro.

PURPOSE: Leukemia inhibitory factor is a cytokine that plays an important role in implantation and enhances mouse preimplantation embryo development in vitro. Since leukemia inhibitory factor enhances early embryo development, we tested the hypothesis that coculture cells that express leukemia inhibitory factor would enhance mouse blastocyst development in vitro. In this study, Northern analysis for leukemia inhibitory factor was performed on total RNA extracted from Vero cells, human embryonic fibroblasts, and human placental fibroblasts. METHODS: Two-cell mouse embryos were cultured to blastocyst in Ham's F-10 with 15% human cord serum (control) or with the coculture cells. Northern analysis demonstrated expression of LIF mRNA in Vero cells and embryonic fibroblasts but not in placental fibroblasts. Development to blastocyst was significantly enhanced in two-cell embryos cultured with Vero cells (86%, 140/163) and embryonic fibroblasts (83%, 118/142) when compared to controls (71%, 67/94, P < 0.05) or placental fibroblasts (71%, 95/134), P < 0.05). CONCLUSION: These data suggest that coculture cells that express leukemia inhibitory factor may be superior to nonleukemia inhibitory factor expressing cells for early preimplantation embryo development.

Role for the stem cell factor/KIT complex in Schwann cell neoplasia and mast cell proliferation associated with neurofibromatosis.

Schwann cells are the primary cell type in the disfiguring lesions associated with neurofibromatosis type 1 (NF-1). These lesions also contain abnormally high numbers of mast cells, a cell type which develops in response to stem cell factor. We report here that neonatal and adult rat and human Schwann cells, as well as a transfected rat Schwann cell line and a human Schwannoma line derived from an NF-1 patient, all produced stem cell factor mRNA and protein. In coculture experiments, surface expression of stem cell factor by neonatal rat Schwann cells was profoundly downregulated by contact with dorsal root ganglion neurites. The receptor for stem cell factor, KIT, was not expressed in normal Schwann cells but was expressed in the human Schwannoma line, suggesting that aberrant KIT expression may form an autocrine loop in certain Schwann cell neoplasias.

Interleukin-1 beta stimulates interleukin-6 production in placental villous core mesenchymal cells.

Interleukin-6 (IL-6) is a pleiotropic mediator of immune function and a growth factor for a variety of hematopoietic cell types. Because IL-1 beta is known to induce IL-6 production in nonplacental mesenchymal cells and is locally produced by maternal decidua, this study was designed to determine whether IL-1 beta could regulate IL-6 production by second trimester placental villous core mesenchymal cells (VCMC) in vitro. VCMC were prepared for culture by enzymatic digestion of placentas (14-20 weeks gestation; n = 7). Immunohistochemistry performed on the confluent cells demonstrated that more than 95% of the cells had a fibroblast-like morphology and were vimentin positive, less than 5% were leukocyte common antigen (CA-45) positive, and no trophoblast contamination was demonstrated by the lack of cytokeratin staining. In dose-response experiments, a specific dose-response induction of IL-6 mRNA expression and IL-6-immunoreactive protein production by IL-1 beta was demonstrated; this was first seen at 100 pg/ml IL-1 beta [455 +/- 191 ng/ml (+/- SEM); controls, 42 +/- 16 ng/ml; P < 0.05]. In time-course studies, the addition of 10 ng/ml IL-1 beta significantly increased IL-6 production rates; this was first seen at 8 h of culture and increased in a linear fashion up to 48 h. At 48 h of culture, IL-6 levels were 17 times higher in treated VCMC (861 +/- 179 ng/ml) compared to those in nontreated VCMC (51 +/- 14 ng/ml). In summary, IL-1 beta stimulates VCMC IL-6 production in a specific dose- and time-dependent manner. From these results, we conclude that VCMC are an important source of IL-6 in second trimester placenta and that production of placental IL-6 be may regulated by decidual IL-1 beta.

Differential mRNA expression and production of interleukin-6 in placental trophoblast and villous core compartments.

PROBLEM: Interleukin-6 (IL-6) is a pleiotropic protein that functions as an immunoregulatory peptide, growth factor, and endocrine hormone. IL-6 has been shown to be produced in whole placental tissue and isolated trophoblast (TC). In addition, the villous core (VC) compartment of the placenta contains cell types (fibroblasts, macrophages) capable of IL-6 production. Consequently, the present study was designed to determine the relative contribution of the TC and VC compartments to placental IL-6 production. METHOD: The VC and TC compartments from term pregnancies were separated using CR-Dispase digestion and Percoll density gradient centrifugation. The VC, TC, and whole placental tissues were cultured in Dulbecco's modified Eagle's medium over a 28-h period. Relative IL-6 mRNA expression was determined by dot blot analysis and secreted IL-6 protein was determined by enzyme-linked immunosorbent assays. RESULTS: All three tissues demonstrated linear production of IL-6 protein over the culture period. At 28 h, whole placental tissue produced the most IL-6 (5.1 ng +/- 0.8 ng/microgram/protein) followed by TC (4.0 ng +/- 1.3 ng/micrograms) and VC (0.55 ng +/- 0.24 ng/microgram). Although production rates of IL-6 were 8.4-fold higher in TC compared to VC (P < .05), steady-state IL-6 mRNA expression was 3.5-fold higher in freshly isolated VC compared to TC (P < .0001) and 13-fold higher in VC compared to TC (P < .01) after 24 h in culture. CONCLUSIONS: These results demonstrate that: (1) the placenta can produce large quantities of immunoreactive IL-6 in vitro, (2) TC produce significantly more IL-6 than VC although both compartments contribute to placental IL-6 production, (3) placental IL-6 production and secretion are probably posttranscriptionally regulated since steady-state IL-6 mRNA expression in VC and TC compartments did not correlate with IL-6 production.

Identification of the fetal liver cytochrome CYP3A7 in human endometrium and placenta.

Placenta and endometrium carry out steroidogenic biotransformation reactions such as 6-beta-hydroxylation of cortisol, a reaction characteristic of the dominant family of cytochromes P450 in human liver, CYP3A. To investigate the possible role in these extrahepatic tissues of the CYP3A microsomal hemoproteins, we analyzed placental and endometrial microsomes on Western blots developed with an anti-human CYP3A antibody. We found an immunoreactive 51,500 D protein that migrated between CYP3A3 (HLp) and CYP3A5 (HLp2) identical with CYP3A7 (HFLa). CYP3A7, a form found prominently in human fetal liver microsomes, was first isolated as a liver 16-alpha-dehydroepiandrosterone-sulfate hydroxylase. Northern blot analysis of total RNA isolated from placenta or from endometrium demonstrated a single band that cross-hybridized with a CYP3A7 cDNA. Amplification of the same RNA samples with the use of primers specific for CYP3A7, produced a 552-bp segment that had the predicted size and the same DNA sequence as does liver CYP3A7 cDNA. Hybridizable endometrial CYP3A7 mRNA was detected more frequently (six of seven samples) and in higher amounts (approximately 12-fold higher) in pregnant compared with nonpregnant women (4 of 12 samples). In addition, during the secretory phase of the menstrual cycle CYP3A7 expression was sixfold higher than in the one sample from the proliferative phase that had detectable CYP3A7 mRNA. Moreover, the amounts of placental and endometrial CYP3A7 mRNA and protein increased substantially from the first to the second trimester of pregnancy. We conclude that placenta and endometrium express the same P450 as is found in fetal liver. These tissues represent a previously unrecognized and quantitatively important site for 6-beta-hydroxylation and 16-alpha-hydroxylation of specific steroid precursors, possibly for protection of the fetus from the toxic effects of endogenous steroids and foreign substrates.

Interleukin-1 beta stimulates colony-stimulating factor-1 production in human term placenta.

The human placenta produces hematopoietic growth factors including colony stimulating factor-1 (CSF-1). We have previously demonstrated Interleukin-1 beta (IL-1 beta) production by decidualized endometrium during pregnancy. Since IL-1 beta stimulates CSF-1 production in a variety of mesenchymal cell types including second trimester villous core mesenchymal cells, the present study was designed to determine if IL-1 beta could also regulate CSF-1 production in term placental explants in vitro. Placental villous explants from normal term placentas (n = 5) were cultured with or without recombinant human IL-1 beta. A dose response relationship between increased added IL-1 beta and increased CSF-1 production as measured by enzyme-linked immunosorbent assay was observed with 1 ng/mL IL-1 beta being the lowest dose to significantly increase CSF-1 production (P < 0.01). In time course experiments, 10 ng/mL maximally induced CSF-1 messenger RNA expression 2.7 fold (P < 0.005) compared to controls at 8 h of culture as determined by dot blot analysis. Production rates of CSF-1 were linear up to 24 h at which time IL-1 beta (10 ng/mL)-treated samples had 1.7-fold higher levels of CSF-1 in the media than nontreated controls (8.38 ng/gm tissue vs. 4.94 ng/gm tissue, P < 0.01). These results demonstrate that IL-1 beta can regulate placental CSF-1 production in vitro and suggest that maternal decidual IL-1 beta may regulate placental CSF-1 production in vivo.

Alterations in the postovariectomy increases in gonadotropin secretion in middle-aged persistent-estrous rats: correlation with pituitary gonadotropin subunit gene expression.

This study compared the changes in pituitary and serum levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) at various times following ovariectomy (OVX) between young cyclic and middle-aged persistent-estrous (PE) rats and related these to the relative gene expression of the pituitary gonadotropin subunits. In intact animals, both pituitary and serum levels of LH were similar between these two age groups, while the LH beta mRNA expression was significantly (p < 0.05) greater in young rats. Following OVX in young rats, the serum LH levels markedly increased (p < 0.05) beginning on day 7 and reaching a maximum fourfold increase by day 9. In contrast, the post-OVX increases in serum LH in middle-aged females were significantly delayed. OVX significantly (p < 0.05) increased pituitary LH contents of young rats by day 5, but had no effect on LH contents in middle-aged females until day 30 post-OVX. These changes were associated with increases in LH beta mRNA expression in both young and middle-aged females, but the levels were significantly (p < 0.05) lower in middle-aged females. Both pituitary and serum levels of FSH were significantly (p < 0.05) higher in middle-aged PE than in young rats prior to OVX, while the FSH beta mRNA expression was similar in both age groups. Following OVX in young rats, serum FSH levels rapidly increased (p < 0.05) on day 3 and attained tenfold higher values by day 30.(ABSTRACT TRUNCATED AT 250 WORDS)