Low-dose aspirin can downregulate progesterone resistance and increase the expression of LIF in endometriosis during the implantation window.

AIM: Study the effect of low-dose aspirin on the endometrial receptivity in endometriosis rat models. MATERIALS AND METHODS: This study is to explore the expressions of progesterone receptor and LIF among three groups of endometriosis rat models: control group (n = 12), EMs group (n = 15), and aspirin group (n = 17). The expressions of progesterone receptor (PR), PRA, PRB, and leukemia inhibitory factor receptor (LIFR) in eutopic endometrium were determined using immunohistochemistry technology, western blot, and qRT-PCR. The levels of LIF in eutopic endometrium and serum were detected by western blot, qRT-PCR, and ELISA. RESULTS: The expressions of PR, PRA, and PRB protein were significantly increased in the eutopic endometrium after low-dose aspirin treatment, and the level of PRB mRNA was also increased while the ratio of PRA/PRB mRNA was decreased in the eutopic endometrium. The levels of LIF in eutopic endometrium and serum were increased compared with the untreated endometriosis rats. However, the expression of LIFR was not statistically different among the three groups. CONCLUSIONS: The results suggest that the low-dose aspirin treatment could downregulate progesterone resistance and increase the expression of LIF of endometriosis rats during the implantation window, which could improve endometrial receptivity and enhance the pregnant rate of endometriosis. It may provide a potential treatment method for endometriosis-related infertility.

Leukemia Inhibitory Factor: A Potential Biomarker and Therapeutic Target in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive, treatment-resistant cancer. Five-year survival rate is about 9%, one of the lowest among all solid tumors. Such a poor outcome is partly due to the limited knowledge of tumor biology, and the resulting lack of effective treatment options and robust predictive biomarkers. The leukemia inhibitory factor (LIF) has recently emerged as a potential biomarker and therapeutic target for PDAC. Accumulating evidence has suggested that LIF plays a role in supporting cancer evolution as a regulator of cell differentiation, renewal and survival. Interestingly, it can be detected in the serum of PDAC patients at higher concentrations than healthy individuals, this supporting its potential value as diagnostic biomarker. Furthermore, preliminary data indicate that testing for LIF serum concentration or tissue expression may help with treatment response monitoring and prognostication. Finally, studies in PDAC mouse models have also shown that LIF may be a valuable therapeutic target, and first-in-human clinical trial is currently ongoing. This article aims to review the available data on the role of LIF in PDAC promotion, and to discuss the evidence supporting its potential role as a biomarker and target of effective anti-cancer therapy in this setting.

LIF in embryo culture medium is a predictive marker for clinical pregnancy following IVF-ET of patients with fallopian tube obstruction.

Leukemia inhibitory factor (LIF) has played a vital role in a series of reproductive events, including follicle growth, embryo growth and differentiation. However, it is unclear whether the level of LIF in embryo culture medium can be used as a marker for clinical pregnancy. In this study, we aimed to investigate whether LIF level in embryo culture medium can act as a predictive marker for pregnancy outcome of in vitro fertilization-embryo transfer (IVF-ET) in infertile women due to tubal problems. A total of 208 infertile women due to tubal problems underwent IVF-ET treatment. The women were divided into two groups according to whether they were clinically pregnant. The level of LIF in the embryo culture medium was measured, and the correlation between LIF level and embryo quality and clinical pregnancy outcome was analyzed. The embryo culture medium was collected on the day of blastocyst transplantation. Compared to non-pregnant group, LIF level in the embryo culture medium on the day of blastocyst transplantation was significantly higher in the pregnant group. LIF level in the embryo culture medium may be used as a non-invasive auxiliary biomarker for predictive clinical pregnancy in infertile women with tubal problems that using single blastocyst transfer method.

Cigarette smoke exposure reduces leukemia inhibitory factor levels during respiratory syncytial viral infection.

Background: Viral infections are considered a major driving factor of chronic obstructive pulmonary disease (COPD) exacerbations and thus contribute to disease morbidity and mortality. Respiratory syncytial virus (RSV) is a frequently detected pathogen in the respiratory tract of COPD patients during an exacerbation. We previously demonstrated in a murine model that leukemia inhibitory factor (LIF) expression was increased in the lungs during RSV infection. Subduing LIF signaling in this model enhanced lung injury and airway hypersensitivity. In this study, we investigated lung LIF levels in COPD patient samples to determine the impact of disease status and cigarette smoke exposure on LIF expression. Materials and methods: Bronchoalveolar lavage fluid (BALF) was obtained from healthy never smokers, smokers, and COPD patients, by written informed consent. Human bronchial epithelial (HBE) cells were isolated from healthy never smokers and COPD patients, grown at the air-liquid interface and infected with RSV or stimulated with polyinosinic:polycytidylic acid (poly (i:c)). Mice were exposed to cigarette smoke daily for 6 months and were subsequently infected with RSV. LIF expression was profiled in all samples. Results: In human BALF, LIF protein was significantly reduced in both smokers and COPD patients compared to healthy never smokers. HBE cells isolated from COPD patients produced less LIF compared to never smokers during RSV infection or poly (i:c) stimulation. Animals exposed to cigarette smoke had reduced lung levels of LIF and its corresponding receptor, LIFR. Smoke-exposed animals had reduced LIF expression during RSV infection. Two possible factors for reduced LIF levels were increased LIF mRNA instability in COPD epithelia and proteolytic degradation of LIF protein by serine proteases. Conclusions: Cigarette smoke is an important modulator for LIF expression in the lungs. Loss of LIF expression in COPD could contribute to a higher degree of lung injury during virus-associated exacerbations.

Immunohistochemical and ultrastructural analysis of the effect of omega-3 on embryonic implantation in an experimental mouse model.

OBJECTIVE: Implantation is the first step to a healthy pregnancy. Omega-3 supplementation is common to use during pregnancy, for its antioxidant and membrane stabilising effect. In this study we have aimed to study the effect of Omega-3 supplementation on implantation in a mouse model by immunohistochemical methods and electron microscopic evaluation. MATERIALS AND METHODS: Mice were randomized into three groups to receive standard food, Omega-3 400 mg/kg and Omega-3 1000 mg/kg one menstrual cycle before mating. Mice were sacrificed on third day of estimated implantation and uterine horns were evaluated immunohistochemically for staining of Laminin and Leukemia Inhibitory Factor (LIF) and ultrastructural morphology. RESULTS: Laminin and LIF immunoreactivity were increased signifcantly in the high dose group when compared to the control and low-dose groups in lumen epithelium basal membrane, gland epithelium basal membrane and endometrial stroma. Electron-microscopic evaluation showed a decrease in epithelial height and microvilli loss in the high dose groups. CONCLUSION: Omega-3 supplementation increased implantation markers Laminin and LIF and decreased epithelial height and microvilli thus seems to prepare the endometrium for a favorable environment of implantation.

LIF and LIF­R expression in the endometrium of fertile and infertile women: A prospective observational case­control study.

The aim of the present study was to determine the expression of leukemia inhibitory factor (LIF) and LIF receptor (LIF­R) in the endometrium of fertile and infertile women during the implantation window. A prospective study was conducted between March 2013 and March 2015 at Iakentro, Infertility Treatment Center (Thessaloniki, Greece) and the 3rd Department of Obstetrics and Gynecology, Aristotle University of Thessaloniki (Thessaloniki, Greece). The patient group consisted of women diagnosed with infertility, whereas the control group consisted of women who had delivered at least one live newborn (fertile women). An endometrial biopsy was obtained using a Pipelle on day 7 or 8 post­ovulation, and the expression of LIF and LIF­R was assessed by immunohistochemistry in epithelial and stromal cells. Primary outcomes included positive cellular percentage, staining intensity and H­score. P<0.05 was considered to indicate a statistically significant difference. Overall, 45 women were included in the present analysis (15 fertile women and 30 infertile women). Mean age was 32.8±6.0 years for the fertile group, and 37.6±3.7 for the infertile group. LIF and LIF­R expression was significantly reduced in the epithelial cells of infertile women (P=0.05 and P=0.006, respectively). However, no significant differences were detected with regards to the expression of LIF in stromal cells (P=0.95). In addition, LIF­R expression was relatively higher in the stromal cells of the fertile group; however, the difference did not reach statistical significance (P=0.10). In conclusion, endometrial expression of LIF and LIF­R is significantly reduced in the epithelial cells of infertile women. Expression patterns of LIF­R in stromal cells require further research in order to achieve definitive results.

Expression of leukemia inhibitory factor in the rat retina following acute ocular hypertension.

The aim of the present study was to investigate the expression of leukemia inhibitory factor (LIF) and its downstream signaling pathways in the rat retina following acute ocular hypertension. The intraocular pressure of the rats was elevated to 110 mmHg for 1 h by infusing the anterior chamber with normal saline. The retinal tissues were obtained 12 h, 24 h, and 2, 3 and 7 days after termination of the ocular hypertension. Hematoxylin and eosin and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were performed to assess the morphological changes and the apoptosis of retinal cells, respectively. Quantification of the retinal ganglion cells (RGCs) was performed using fluorogold retrograde (FG) staining. The expression levels of LIF, LIF receptor (LIFR), signal transducers and activators of transcription 3 (STAT3), phosphorylated STAT3 (P­STAT3), Akt, phosphorylated­Akt (P­Akt), extracellular signal­regulated kinase (ERK) and phosphorylated ERK (P­ERK) were determined at different time­points following acute ocular hypertension using western blot analysis. Reverse transcription­quantitative polymerase chain reaction was performned to detect the mRNA expression levels of LIF and LIFR. The results revealed that 12 h, 24 h, 2, 3 and 7 days after reperfusion, the thickness of the inner nuclear layer and the inner plexiform layer was decreased, with a significant reduction in the number of RGCs, as determined using TUNEL and FG staining. The expression levels of LIF and LIFR were increased following acute ocular hypertension. At 12 h post­retinal reperfusion, the expression levels of P­STAT3 and P­Akt were significantly upregulated, while the expression of P­ERK was decreased. The changes in the expression levels of LIF and LIFR suggested that LIF may be important in the process of degeneration/protection following retinal ischemia induced by acute ocular hypertension, via activation of the Janus kinase/STAT and Akt signaling pathways.

Identification of novel proteins differentially expressed in pluripotent embryonic stem cells and differentiated cells.

Mammalian pluripotent stem cells possess properties of self-renewal and pluripotency. These abilities are maintained by the strict regulation of pluripotent stem cell-specific transcription factor network and unique properties of chromatin in the stem cells. Although these major signaling pathways robustly control the characteristics of stem cells, other regulatory factors, such as metabolic pathways, are also known to modulate stem cell proliferation and differentiation. In this study, we fractionated protein samples from mouse embryonic stem (ES) cells cultured with or without the leukemia inhibitory factor (LIF). Protein expression was quantified by 2-dimensional differential gel electrophoresis (2D-DIGE). In total, 44 proteins were identified as being differentially expressed in the pluripotent stem cells and the differentiated cells. Surprisingly, half of the identified proteins were the proteins localized in mitochondria, which supply cellular energy and regulate cell cycle, development, and cell death. Some of these identified proteins are involved in the metabolic function and the regulation of pluripotency. Further analysis of the identified proteins could provide new information for the manipulation of pluripotency in ES cells.

Correlations of leukemia inhibitory factor and macrophage migration inhibitory factor with endometrial carcinoma.

OBJECTIVE: To investigate the correlations of leukemia inhibitory factor (LIF) and macrophage migration inhibitory factor (MIF) with endometrial carcinoma. MATERIALS AND METHODS: The study included 113 endometrial specimens from the Fourth Affiliated Hospital of Harbin Medical University, collected from May 2006 to October 2008, classified into normal endometrium, simple hyperplasia, complex hyperplasia, atypical hyperplasia, and endometrial carcinoma. The LIF and MIF expression of all 113 specimens was detected with immunohistochemistrical (IHC) method. RESULTS: The MIF expression in hyperplastic endometrium and endometrial carcinoma increased significantly as compared with that in normal endometrium (p < 0.05 and p < 0.001, respectively), and its expression in endometrial carcinoma was also remarkably higher than that in hyperplastic endometrium (p < 0.001). The expressions of LIF in atypical hyperplasia and endometrial carcinoma were also significantly higher than that in the normal endometrium (p < 0.05), but it is not obviously higher in simple hyperplasia and complex hyperplasia than in the normal endometrium (p > 0.05). Furthermore, the expression of LIF showed no statistical difference between hyperplastic endometrium and endometrial carcinoma. CONCLUSION: It could be speculated that MIF may be correlated with the occurrence of endometrial carcinoma. However, whether LIF also has a correlation with the occurrence of endometrial carcinoma still cannot be presumed.

Interleukin-6 Family of Cytokines in Crevicular Fluid of Renal Transplant Recipients With and Without Cyclosporine A-Induced Gingival Overgrowth.

BACKGROUND: Interleukin (IL)-6 family of cytokines, including IL-6, oncostatin M (OSM), leukemia inhibitory factor (LIF), and IL-11, have fibrogenic features. The current study determines gingival crevicular fluid (GCF) levels of fibrosis-related IL-6-type cytokines in cyclosporine A (CsA)-induced gingival overgrowth (GO). METHODS: Eighty non-smokers were included (40 CsA-medicated renal transplant patients with GO [GO+; n = 20] or without GO [GO-; n = 20], 20 individuals with gingivitis, and 20 healthy participants). Probing depth and plaque, papilla bleeding, and hyperplastic index scores were recorded. GCF samples were obtained from the mesio-buccal aspects of two teeth. GCF IL-6, IL-1ß, OSM, LIF, and IL-11 levels were analyzed by enzyme-linked immunosorbent assay. RESULTS: The GO+ and GO- groups had higher IL-6 total amounts than the healthy group (P <0.008). IL-1ß total amounts in the GO+ group were significantly higher than in both the healthy and GO- groups (P <0.008). OSM total amount was elevated in the GO+ and GO- groups compared with both the gingivitis and healthy groups (P <0.008). All groups had similar LIF and IL-11 total amounts (P >0.008). Moderate positive correlations were detected among IL-6, IL-1ß, OSM, and IL-11 total amount in GCF and clinical parameters (P <0.05). CONCLUSIONS: IL-6 and OSM increases in GCF as a result of CsA usage or an immunosuppressed state irrespective of the severity of inflammation and the presence of GO. The IL-6 family of cytokines might not be directly involved in biologic mechanisms associated with CsA-induced GO. Lack of an association between assessed IL-6 cytokines and CsA-induced GO might indicate distinct effects of these cytokines on fibrotic changes of different tissues.

Aberrant expression of leukemia inhibitory factor receptor (LIFR) and leukemia inhibitory factor (LIF) is associated with tubal pregnancy occurrence.

BACKGROUND/AIM: Tubal pregnancy is a major cause of maternal death in the first trimester and exploration of its underlying molecular mechanism is of great importance. This study aimed to explore the association of tubal pregnancy with leukemia inhibitory factor (LIF) and leukemia inhibitory factor receptor (LIFR) expression in oviduct tissues. MATERIALS AND METHODS: Immunohistochemistry was performed to probe the differential expression of LIF and LIFR in oviduct tissues among a control group (including NP group, n = 11; and IP group, n = 12), tubal pregnancy group (Ect-N group, n = 31; and Ect-A group, n = 40), and chronically inflamed group (including Inf-S group, n = 11; and Inf-P group, n = 9), followed by semiquantitative analysis. RESULTS: Semiquantitative immunohistochemical analysis demonstrated that there was no significant difference in LIF expression in either the epithelial or stromal cells of oviduct tissues between the tubal pregnancy group and the control group (P < 0.05). However, LIF expression was remarkably elevated in the Inf-S and Inf-P group compared to the other groups (P < 0.05). In the epithelial cells of the fallopian tubes, LIFR expression was highest in the chronically inflamed group, followed by the tubal pregnancy group, outnumbering the control group (P < 0.05). More interestingly, an opposite expression trend of LIFR was observed in the stromal cells of the fallopian tubes among these groups (P <0.05). CONCLUSION: Aberratn expression of LIF and LIFR might be associated with the occurrence of tubal pregnancy.

[Expression of endogenous leukemia inhibitory factor in neonatal rats with periventricular leukomalacia].

OBJECTIVE: To study the changes of endogenous leukemia inhibitory factor (LIF) in neonatal rats with periventricular leukomalacia (PVL). METHODS: A PVL model of 3-day-old Wistar rats was prepared by left carotid artery ligation followed by 6% oxygen for 4 hours. The rats were sacrificed at 1, 3, 7, 14 and 28 days of hypoxia ischemia (HI), and the brain tissues were sampled. Real-Time PCR and Western blot methods were applied to analyze the expression of LIF mRNA and protein. Double staining immunofluorescence was used to detect the co-expression of LIF and GFAP. RESULTS: At 1, 3 and 7 days of HI, LIF protein level in the PVL group was higher than in the control group (P<0.01). In the PVL group, the LIF protein level on the third day after HI reached a peak and was higher than the other time points (P<0.01). The change of LIF mRNA expression showed the same tendency with LIF protein. The double staining immunofluorescence showed a co-expression of LIF and GFAP. CONCLUSIONS: LIF mRNA and LIF protein expression in astrocytes show a trend of initial increase followed by steady decline in neonatal rats with PVL, suggesting that endogenous LIF may participate in the repair of PVL.

Tissue levels of leukemia inhibitory factor vary by osteoarthritis grade.

The objective of this study was to observe the expression of leukemia inhibitory factor (LIF) in animals and in different clinical grades of patient osteoarthritic tissues. Thirty-five rabbits were used in a Colombo model of experimental osteoarthritis (OA). Five rabbits each were sacrificed on postoperative days 3, 7, 14, 28, 42, 56, and 84. Immunohistochemistry analysis for LIF expression and distribution in the cartilage and synovium of animals was performed at these times. Sixty-seven samples of human articular tissue were obtained from patients with different grades of OA according to symptoms and radiographic inspection. The mRNA expression of LIF was determined by reverse transcription polymerase chain reaction, and LIF protein was determined by enzyme-linked immunosorbent assay (ELISA). The results showed a slight expression of LIF in normal cartilage tissue but less in synovium tissue; however, the expression of LIF was marked in synovial lining cells and superficial and middle-layer cartilage in animal OA (P<.05). Leukemia inhibitory factor mRNA was expressed at the highest level in moderate degrading subchondral bone, and LIF was expressed at the highest level in seriously degrading articular cartilage tissue. These results were similar to those found with ELISA. This study suggests that LIF in OA articular tissues varies by clinical symptoms and grade. It plays an important role in the pathogenesis of OA.

Puerarin, a selective oestrogen receptor modulator, disrupts pregnancy in rats at pre-implantation stage.

The tubers of Pueraria tuberosa have folkloric repute as emmenagogue. The n-BuOH fraction of the ethanolic extract of tubers exhibits significant antifertility activity in laboratory animals. The present investigation explored the active principle(s) of the tuber extract with reference to contragestive effects in rats and probed the possible mechanism of action. Bioactivity-guided fractionation identified puerarin as the major constituent that exerted pregnancy-terminating effects. Oral administration of puerarin at ≥300  mg/kg per day for days (D) 1-2 post-coitus resulted in complete implantation failure. Serum oestradiol levels during D2-D5 and progesterone (P(4)) level on D5 remained unaffected, but the endometrial expression of oestrogen receptor α (ERα) and ERß was adversely modulated that disrupted the implantation-specific characteristic endometrial oestrogenic milieu. The eventual consequence was loss of endometrial receptivity characterised by down-regulation of the uterine expression of P(4) receptor (PR) and attenuation of endometrial expression of leukaemia inhibitory factor, vascular endothelial growth factor and cyclo-oxygenase-2, the three important signalling molecules involved in the process of implantation. Light microscopic examination of the embryos demonstrated no untoward effect of puerarin on the development of embryos until D4, but D5 blastocysts underwent gross morphological distortion. The findings taken together are interpreted to suggest that puerarin adversely impacts the uterine expression of ER and PR that disrupts the implantation-conducive uterine milieu and prevents implantation. In conclusion, puerarin may be envisaged as a prospective molecule that merits further exploration for the development of non-steroidal post-coital contraceptive for women.

Gingival crevicular fluid and plasma acute-phase cytokine levels in different periodontal diseases.

BACKGROUND: The aim of the present study is to investigate gingival crevicular fluid (GCF) and plasma acute-phase cytokines, interleukin-1ß (IL-1ß), interleukin-6 (IL-6), interleukin-11 (IL-11), oncostatin M (OSM), and leukemia inhibitory factor (LIF) levels in patients with different periodontal diseases. METHODS: Eighty individuals were included in this study; 20 with chronic periodontitis (CP), 20 with generalized aggressive periodontitis (GAgP), 20 with gingivitis, and 20 classified as healthy (H). Probing depth, clinical attachment level, plaque index, and papilla bleeding index were recorded. Plasma and GCF IL-1ß, IL-6, IL-11, OSM, and LIF levels were analyzed by enzyme-linked immunosorbent assay. RESULTS: CP and GAgP groups had significantly higher GCF IL-1ß, IL-6, and IL-11 levels when compared with the H group (P <0.05). Conversely, GCF LIF levels of the CP and GAgP groups were lower than those of the H group (P <0.05). GCF OSM levels did not differ significantly among study groups. Plasma levels of all the cytokines studied were not significantly different among the study groups. CONCLUSIONS: Based on the present data, elevated IL-1ß, IL-6, and IL-11 GCF levels, but not plasma levels, are suggested as reliable inflammatory biomarkers in periodontal diseases. Decreased LIF levels in diseased groups might reflect the possible beneficial effects of LIF in the modulation of inflammatory response in gingiva.

Effects of leukemia inhibitory factor on proliferation and odontoblastic differentiation of human dental pulp cells.

INTRODUCTION: The purpose of this study was to determine whether the leukemia inhibitory factor (LIF) is expressed in human dental tissue and exerts its effect on proliferation and odontoblastic differentiation of the dental pulp cells (DPCs). METHODS: An immunohistochemical assay was used to detect the expression of LIF and leukemia inhibitory factor receptor (LIFR) in the human dental pulp. The proliferation of DPCs was examined by culturing human primary DPCs in the presence of LIF with different doses or the neutralizing antibody to LIF. Western blot was performed to assay the phosphorylation of Janus kinase 2 (Jak2) and signal transducer and activator of transcription 3 (Stat3) in the presence or absence of LIF and/or AG 490, a specific inhibitor of Jak2. The odontoblastic differentiation of DPCs was determined using the alkaline phosphatase (ALP) activity assay, quantification of bone sialoprotein (BSP) and dentin sialophosphoprotein (DSPP) gene expression, and mineralization nodule formation. RESULTS: LIF and LIFR were present in the odontoblasts and DPCs. LIF induced proliferation of DPCs, which was inhibited by the LIF neutralizing antibody and AG 490. LIF induced phosphorylation of Jak2 and Stat3 but not in the presence of the AG490. ALP activity of DPCs, in the absence or presence of mineralization induction medium, was inhibited by LIF. Furthermore, the mineralization nodule formation and the expression of BSP and DSPP were inhibited by LIF. This inhibition on differentiation was attenuated by the AG490. CONCLUSIONS: LIF and LIFR are expressed in the human dental pulp. LIF promotes the proliferation of DPCs, and the odontoblastic differentiation is inhibited via the Jak2-Stat3 signaling pathway.

Expression of endometrial protein markers in infertile women and the association with subsequent in vitro fertilization outcome.

Endometrial biopsies were performed during the luteal phase just before an IVF cycle in 104 infertile women, and immunohistochemical staining was performed to investigate expression patterns of hCG-LH receptor, leukemia-inhibitory factor, macrophage colony-stimulating factor, HOXA-10, vascular endothelial growth factor A, and their relation to subsequent IVF pregnancy. Only glandular expression of vascular endothelial growth factor A in early luteal endometrium was significantly higher in the pregnant group compared with the nonpregnant group (6.0 ± 3.9 vs. 2.9 ± 3.4) and thus could be a predicting marker for subsequent IVF pregnancy.

Expression of leukemia inhibitory factor and leukemia inhibitory factor receptor in the canine pituitary gland and corticotrope adenomas.

Leukemia inhibitory factor (LIF) is a pleiotropic cytokine of the IL-6 family that activates the hypothalamic-pituitary-adrenal axis and promotes corticotrope cell differentiation during development. The aim of this study was to investigate the expression of LIF and its receptor (LIFR) in the canine pituitary gland and in corticotrope adenomas, and to perform a mutation analysis of LIFR. Using immunohistochemistry, immunofluorescence, and quantitative expression analysis, LIF and LIFR expression were studied in pituitary glands of control dogs and in specimens of corticotrope adenoma tissue collected through hypophysectomy in dogs with pituitary-dependent hypercortisolism (PDH, Cushing's disease). Using sequence analysis, cDNA was screened for mutations in the LIFR. In the control pituitary tissues and corticotrope adenomas, there was a low magnitude of LIF expression. The LIFR, however, was highly expressed and co-localized with ACTH(1-24) expression. Cytoplasmatic immunoreactivity of LIFR was preserved in corticotrope adenomas and adjacent nontumorous cells of pars intermedia. No mutation was found on mutation analysis of the complete LIFR cDNA. Surprisingly, nuclear to perinuclear immunoreactivity for LIFR was present in nontumorous pituitary cells of the pars distalis in 10 of 12 tissue specimens from PDH dogs. These data show that LIFR is highly co-expressed with adrenocorticotropic hormone (ACTH) and alpha-melanocyte-stimulating hormone (alpha-MSH) in the canine pituitary gland and in corticotrope adenomas. Nuclear immunoreactivity for LIFR in nontumorous cells of the pars distalis may indicate the presence of a corticotrope adenoma.

Evaluation of immune inhibitory cytokine profiles in epithelial ovarian carcinoma.

OBJECTIVE: The aim of this study was to detect expression of different cytokines in epithelial ovarian carcinoma (EOC) cells and normal ovarian surface epithelial (OSE) cells in vitro and the levels of those with elevated expression in the EOC patients, and to analyze the contribution of cytokine profiles to tumor immune deficiency. MATERIALS AND METHODS: Cytokine antibody array was used to detect cytokine profiles in two cell lines of EOC (SKOV3 and CaoV3), primarily cultured EOC and OSE cells. The levels of leukemia inhibitory factor (LIF), interleukin-10 (IL-10), IL-4, and transforming growth factor-beta1 (TGF-beta1) in peritoneal fluids and sera in the patients with EOC and benign gynecological tumors were detected by enzyme-linked immunosorbent assay. RESULTS: The levels of LIF, IL-10, and IL-4 were detected two times higher in the culture supernatants of the EOC cell lines than those in OSE cells by cytokine antibody array. Both LIF and IL-10 levels were more increased in ascites of EOC patients than in those in benign gynecological tumor patients (P < 0.05). The level of IL-4 was not detectable in any samples of ascites or sera. No difference of TGF-beta1 value was detected between patients with EOC and benign gynecological tumors. CONCLUSION: Epithelium ovarian carcinoma cells can produce more LIF, IL-10 and IL-4 than OSE cells, and contribute to the elevated levels of those cytokines in EOC patients, which probably participates in the development of immune deficiency in the peritoneal cavity of EOC patients.

Prokineticin 1 mediates fetal-maternal dialogue regulating endometrial leukemia inhibitory factor.

Implantation requires communication between a receptive endometrium and a healthy blastocyst. This maternal-embryonic crosstalk involves local mediators within the uterine microenvironment. We demonstrate that a secreted protein, prokineticin 1 (PROK1), is expressed in the receptive endometrium and during early pregnancy. PROK1 induces expression of leukemia inhibitory factor (LIF) in endometrial epithelial cells and first trimester decidua via a Gq-Ca(2+)-cSrc-mitogen-activated protein kinase kinase-mediated pathway. We show that human embryonic chorionic gonadotropin (hCG) induces sequential mRNA expression of PROK1 and LIF in an in vivo baboon model, in human endometrial epithelial cells, and in first-trimester decidua. We have used micro RNA constructs targeted to PROK1 to demonstrate that hCG-mediated LIF expression in the endometrium is dependent on prior induction of PROK1. Dual immunohistochemical analysis colocalized expression of the luteinizing hormone/chorionic gonadotropin receptor, PROK1, PROKR1, and LIF to the glandular epithelial cells of the first trimester decidual tissue. PROK1 enhances adhesion of trophoblast cells to fibronectin and laminin matrices, which are mediated predominantly via LIF induction. These data describe a novel signaling pathway mediating maternal-embryonic crosstalk, in which embryonic hCG via endometrial PROK1 may play a pivotal role in enhancing receptivity and maintaining early pregnancy.