Expression and regulation of interleukin-8 in human fallopian tubal cells

Glucocorticoid-induced reversal of interleukin-1β-stimulated inflammatory gene expression in human oviductal cells

Studies indicate that high-grade serous ovarian carcinoma (HGSOC), the most common epithelial ovarian carcinoma histotype, originates from the fallopian tube epithelium (FTE). Risk factors for this cancer include reproductive parameters associated with lifetime ovulatory events. Ovulation is an acute inflammatory process during which the FTE is exposed to follicular fluid containing both pro- and anti-inflammatory molecules, such as interleukin-1 (IL1), tumor necrosis factor (TNF), and cortisol. Repeated exposure to inflammatory cytokines may contribute to transforming events in the FTE, with glucocorticoids exerting a protective effect. The global response of FTE cells to inflammatory cytokines or glucocorticoids has not been investigated. To examine the response of FTE cells and the ability of glucocorticoids to oppose this response, an immortalized human FTE cell line, OE-E6/E7, was treated with IL1β, dexamethasone (DEX), IL1β and DEX, or vehicle and genome-wide gene expression profiling was performed. IL1β altered the expression of 47 genes of which 17 were reversed by DEX. DEX treatment alone altered the expression of 590 genes, whereas combined DEX and IL1β treatment altered the expression of 784 genes. Network and pathway enrichment analysis indicated that many genes altered by DEX are involved in cytokine, chemokine, and cell cycle signaling, including NFκΒ target genes and interacting proteins. Quantitative real time RT-PCR studies validated the gene array data for IL8, IL23A, PI3 and TACC2 in OE-E6/E7 cells. Consistent with the array data, Western blot analysis showed increased levels of PTGS2 protein induced by IL1β that was blocked by DEX. A parallel experiment using primary cultured human FTE cells indicated similar effects on PTGS2, IL8, IL23A, PI3 and TACC2 transcripts. These findings support the hypothesis that pro-inflammatory signaling is induced in FTE cells by inflammatory mediators and raises the possibility that dysregulation of glucocorticoid signaling could contribute to increased risk for HGSOC.

Chemokines in the pathogenesis of endometriosis and infertility

Endometriosis is a chronic benign disease that affects women of reproductive age causing abdominal pain and infertility. Its pathogenesis remains obscure despite all the research conducted over the past 100 years. However, there is a consensus among the specialists that the basis of its pathophysiology would be multifactorial. Many publications have demonstrated that chemokines are somehow associated with the development of endometriosis and infertility. In this study, we reviewed all PubMed literature using MeSH terms "chemokines" and "endometriosis" as well as "chemokines" and "female infertility" to establish what we know and what we do not yet know about this relationship.

Increased expression of the von Hippel-Lindau gene in the implantation site of human tubal pregnancy

The objective of this study was to investigate the expression of the von Hippel-Lindau (VHL) gene in tissues of human fallopian tube and tubal pregnancy. Twenty patients undergoing salpingectomy for tubal pregnancy were recruited into the study group. Tissues of tubal pregnancy were separated into both the implantation and non-implantation sites as the implantation group and the non-implantation group, respectively. Samples of ampullary fallopian tube during mid-secretory phase were collected from twenty patients with benign uterine disease as the control group. Immunohistochemistry, real-time reverse transcription polymerase chain reaction, and Western blotting analysis were performed to detect expressions of VHL mRNA and protein. The results showed that VHL immunostaining appeared in the cytoplasm of tubal epithelial cells. Expression of VHL mRNA in the implantation group was higher than that in the non-implantation group or the control group (P < 0.01). Intensity of VHL protein in the implantation group was increased compared with that in the non-implantation group (P < 0.05) or in the control group (P < 0.01). There was no difference on expressions of VHL mRNA and protein between the non-implantation group and the control group (P > 0.05). In conclusion, VHL mRNA and protein are present in human tubal tissues. The VHL gene expression is increased in the implantation site of tubal pregnancy, and locally elevated expression of the VHL gene might be associated with human tubal pregnancy.

Leukemia inhibitory factor (LIF) is immunohistochemically localized in tubal ectopic pregnancy

Leukemia inhibitory factor (LIF) is essential for implantation of the embryo in the endometrium. It is not clear whether the blastocyst requires expression of LIF for implantation into tissues other than endometrium. Immunohistochemical localization of LIF was performed in the fallopian tube of 20 women with ectopic pregnancies, 7 women with normal pregnancies and 20 healthy non-pregnant women. Fallopian tubes were evaluated from specimens taken during tubal ligation in normal pregnancies and non-pregnant fertile women or at operation for tubal surgery in ectopic pregnancies. Biopsies were assayed by immunohistochemistry. Semi-quantitative immunohistochemical reaction scores (IRS) were used for immunohistochemical analyses. Immunolabeling of LIF was detected in the surface epithelium and stroma of fallopian tubes in all subjects. IRS score in the epithelium and stroma of non-pregnant women and women with intrauterine pregnancy were similar (p>0.05). However, women with ectopic pregnancy had significantly increased labeling of LIF compared to others (p<0.05). Immunohistochemical labeling of LIF in the fallopian tube was found to be increased in ectopic pregnancies compared to non-pregnant and healthy pregnant controls. This may indicate a role of LIF in the ectopic implantation of embryos.

Human oviductal stromal fibroblasts, but not oviductal epithelial cells, express Toll-like receptor 4: the site-specific mucosal immunity of the human fallopian tube against bacterial infection

PROBLEM

To evaluate the site-specific immunoregulatory mechanisms against bacterial infection in the human fallopian tubes.

METHOD OF STUDY

We investigated the effects of lipopolysaccharide (LPS) on the production of CXC chemokines by cultured oviductal epithelial cells (OEC) and oviductal stromal fibroblasts (OSF). The expression of Toll-like receptor (TLR) 4 and CD14 protein in OEC and OSF were evaluated. The phosphorylation of the inhibitor kappaB-alpha (IkappaB-alpha) protein after LPS stimulation was also examined.

RESULTS

Lipopolysaccharide stimulated the secretion of granulocyte chemotactic protein-2, growth-regulated oncogene-alpha, and epithelial neutrophil activating peptide-78 by OSF, but not by OEC. The phosphorylation of the IkappaB-alpha protein was not detected in OEC after stimulation by LPS, whereas IkappaB-alpha phosphorylation was observed in OSF after stimulation by LPS. The expression of the TLR4 protein and mRNA was detected only in OSF but not in OEC. The expression of CD14 was not detected in either OEC or OSF.

CONCLUSION

These results suggest that epithelial cells and fibroblasts in the human fallopian tube have evolved a unique, site-specific mechanism for recognizing Gram-negative pathogens. The lack of TLR4 in OEC may be important for avoiding a state of unnecessary inflammation that could disrupt the epithelial barrier and cause irreversible tubal scarring.

Interleukin-1beta regulates vascular endothelial growth factor and soluble fms-like tyrosine kinase-1 secretion by human oviductal epithelial cells and stromal fibroblasts

The aim of the present study was to evaluate the effects of interleukin (IL)-1beta on the production of vascular endothelial growth factor (VEGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) in the human fallopian tube. Human oviductal epithelial cells (OECs) and oviductal stromal fibroblasts (OSFs) were isolated from ten premenopausal patients. The secretion of VEGF and sFlt-1 by cultured OECs and OSFs in response to IL-1beta and IL-1 receptor antagonist (IL-1RA) was measured using an enzyme-linked immunosorbent assay. The secretion of VEGF and sFlt-1 was detected in cultured OECs and OSFs under untreated conditions; secretion of these angiogenic modulators was significantly stimulated with IL-1beta administration in these cells. IL-1beta-induced production of VEGF and sFlt-1 by these cells was significantly inhibited by the addition of IL-1RA. The present findings suggest that IL-1beta in the local environment may stimulate oviductal vascular permeability by inducing the production of VEGF by oviductal cells via both autocrine and paracrine mechanisms. Simultaneous upregulation of sFlt-1 secretion by these cells after IL-1beta stimulation may prevent an excessive upregulation of vascular permeability. The modulation of the ratio of VEGF and sFlt-1 in the fallopian tube may contribute to the normal and pathological processes of oviductal fluid secretion by regulating oviductal vascular permeability during the menstrual cycle and during the peri-implantation period.

Tuba uterina leukemia inhibitory factor concentration does not increase in tubal pregnancy: A preliminary study

The aim of the present study was to compare the levels of leukemia inhibitory factor (LIF) in the tubal ampullary region in normal and ectopic pregnancies and assess possible causative role of LIF in ectopic pregnancy. Although there was a tendency of increase in LIF concentrations in the ectopic pregnancy group, we were not able to determine a statistically significant difference between the two groups.