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Introduction: Labour and delivery are processes associated with inflammation within intrauterine and cervical tissues. The mechanisms that induce labour-associated changes and, in particular, the role of microRNAs (miRNAs) remain to be elucidated. MiRNAs are small non-coding RNAs that repress gene expression via mRNA degradation and translational repression. Let-7 miRNAs are negatively regulated by RNA-binding protein, Lin28, and both function downstream of NF-kappa B signalling. In non-gestational tissues, let-7 and Lin28 reportedy function as negative and positive regulators of IL-6 expression. We hypothesised that labour-associated inflammation involves the downregulation of let-7 miRNAs and upregulation of Lin28 expression. Aim: To determine the expression of Lin28 protein and let-7 miRNA in human gestational tissue obtained before and after labour. Method: Gestational tissues were collected from women at term by Caesarean section with and without labour and following normal vaginal delivery (n = 6 per group). Protein and RNA was extracted and Lin28 and let-7 miRNA expression was measured by Western blotting and real-time PCR. Results: The data obtained established that let-7 miRNA and Lin28 display tissue-specific expression: Lin28 was strongly expressed in the placenta and choriodecidua, but not measurable in amnion; and let-7b and -7c expression were significantly lower in choriodecidua compare to placenta and amnion, whereas the amnion expressed less let-7d and -7f than other tissues. Conclusion: While the expression of Lin28 protein and let-7 miRNA did not vary significantly with labour onset and delivery, changes in their bioactivity and impact on nuclear signalling pathways in human gestational tissues remain to be established. (C) 2013 Elsevier Ltd. All rights reserved.

Free to read at publisher's site. BACKGROUND AND PURPOSE Inflammation of the extraplacental membranes plays a key role in the pathogenesis of preterm labour. The aim of this study was to screen a number of commercially available small molecule nuclear factor-kappa B inhibitors to identify candidates suitable for clinical evaluation as anti-inflammatory agents for the prevention of preterm birth. EXPERIMENTAL APPROACH Nine inhibitors were evaluated across a range of concentrations for their ability to inhibit lipopolysaccharide (LPS)-stimulated cytokine production in primary term choriodecidual cells in culture without affecting cell viability. Expression of 112 inflammation- and apoptosis-related genes was evaluated using boutique oligonucleotide arrays. KEY RESULTS Two IKK beta inhibitors were found to be highly effective and non-toxic inhibitors of choriodecidual cytokine production: parthenolide and [5-(p-fluorophenyl)-2-ureido] thiophene-3-carboxamide (TPCA-1). Both compounds also inhibited LPS-stimulated nuclear translocation of p65/RelA. Expression of 38 genes on the arrays (34%) was significantly (P < 0.05) inhibited by TPCA-1 or parthenolide. Of the 14 genes significantly stimulated by LPS, all were inhibited by TPCA-1 and 12 were inhibited by parthenolide. Overall, gene expression was more robustly inhibited by TPCA-1 than parthenolide; however, expression of two genes was only inhibited by parthenolide. Neither compound significantly altered the expression profile of anti-apoptosis genes on the arrays. CONCLUSIONS AND IMPLICATIONS These studies provide evidence that pharmacological inhibition of IKK beta activity holds promise as a potential strategy for the prevention and/or treatment of inflammation-driven preterm birth. TPCA-1 appeared the most promising compound among those tested in this study. Different inhibitors may have subtly different effect profiles despite having similar modes of action.

The key molecular regulatory mechanisms that govern and coordinate the molecular alterations that underpin the process of human labour remain incompletely understood although enhanced intrauterine prostaglandin production is known to be requisite. We have advanced the hypothesis that epigenetic regulation of key enzymes may occur in intrauterine tissues during pregnancy to prevent inadvertent activation of this powerful initiating signal by dampening responses to premature activation by agents such as cytokines. Our studies have shown that responsiveness of amnion, a key intrauterine tissue, to interleukin-1 beta is abrogated by inhibition of histone deacetylation, whereas PGDH amounts were increased basally. The findings do integrate well with others concerning progesterone (inhibitory) actions such that a decrease in the level of histone acetylation in human gestational tissues near term might herald a coordinated series of events that all result in a positive drive for labour at term or preterm.

Context: Myostatin is a member of the TGF- superfamily and is primarily known for its ability to inhibit muscle growth. It also has actions on glucose metabolism. We hypothesized that it may act as a paracrine regulator of glucose uptake in the placenta, potentially contributing to fetal and placental growth. Objectives: The objective of this study was to determine whether myostatin is present in and formed by the human placenta and to evaluate its effects on glucose uptake. Materials and Methods: Myostatin protein and mRNA were measured using Western immunoblotting and real-time PCR, respectively. Glucose uptake was assessed by uptake of radiolabeled deoxyglucose in vitro. Placental tissues were obtained at term ( n = 8), preterm ( n = 8; 24 - 34 wk), and early in pregnancy ( n = 6; 9 - 13 wk). Results: Human placentas were shown to express myostatin protein, with a significantly lower expression in term samples compared with samples collected in preterm samples. Human placentas express myostatin mRNA throughout gestation, which does not change. Myostatin treatment of human term placental explants resulted in an increase in deoxyglucose uptake compared with controls. Conclusions: Myostatin is synthesized, released, and acts within the human placenta. It contributes to placental glucose homeostasis and may be a therapeutic target in diseases ranging from placental insufficiency to diabetes in pregnancy.

OBJECTIVE: Our objective was to identify the novel or differential expression of growth or development associated genes in the human gestational membranes that might play roles in pregnancy or in term or preterm parturition. STUDY DESIGN: Complementary DNA arrays were probed with [alpha(33)P]dCTP-labeled-complementary DNA that was prepared from the RNA of reflected amnion and choriodecidua that represent term not-in-labor, term spontaneous labor, and preterm labor with and without chorioamnionitis (n = 4 per group). Differential expression (term not-in-labor vs term spontaneous labor or preterm labor with chorioamnionitis vs preterm labor without chorioamnionitis) was evaluated by Wilcoxon tests. RESULTS: All 16 amnion samples expressed angiogenic factors (endothelin-2 and -3, vascular endothelial growth factor, and vascular endothelial growth factor-B) and neurotrophic factors (ephrin-A2, ephrin receptors-A2, -B1, -B3, -B4, and -B5, neuropilin-2, p75/nerve growth factor receptor and semaphorin-F). In both amnion and choriodecidua, the expression of vascular endothelial growth factor and the angiopoietin receptor, Tie-2, were greater with term spontaneous labor than with term not-in-labor (P <.05); increased VEGF receptor-2 (flk-1) expression was observed in term spontaneous labor choriodecidua (P <.05) but not amnion. Ephrin-A1 expression increased with term spontaneous labor in both tissues (P <.05). Semaphorin-F expression decreased with preterm labor with chorioamnionitis in choriodecidua (P <.05), although the trend was not significant in amnion (P =. 1). CONCLUSION: Neurotrophic and angiogenic factor genes are expressed in amnion and choriodecidual membranes. Several of the genes exhibit differential expression with labor at term or in association with infection preterm, which suggests roles in or associated with these processes.

Prostaglandin H synthase-2 (PGHS-II) specific inhibitors have been proposed as a potential treatment in the prevention of preterm birth. We examined the efficacy of PGHS inhibitors on basal and cytokine-stimulated prostaglandin (PG) production by the amnion-like WISH cell line. WISH cells were treated with interleukin (IL)-1beta and tumour necrosis factor (TNF)-alpha in the presence or absence of indomethacin, etodolac, 5,5-dimethy-3-(3-fluorophenyl)-4-(4-methlysulphonyl) phenyl-2 (5H)furanone (DFU) or nimesulide (1.6-1000 nM) for 16 h. PG production was then measured using radioimmunoassay. Nimesulide and DFU were the most selective non-steroidal anti-inflammatory drugs (NSAIDs) of IL-beta-stimulated PG production in these studies with an a IC50basal/IC50stimulated ratio of, respectively, 142.2 and 113.8, followed by etodolac (25.3) and indomethacin (2.2). Similar results were obtained when cells were stimulated with TNF-alpha. The results of this study suggest that PGHS-II-selective NSAIDs may be effective in the prevention of cytokine-driven amnion PG production associated with preterm labour. (C) 2002 Elsevier Science Ltd. All rights reserved.

Objective: To test the effect of selective and non-selective inhibitors of prostaglandin H synthase-2 (PGHS-II) on basal and cytokine-stimulated prostaglandin (PG) production by the immortalized human myometrial cell line, UTLRp16. Study Design: UTLRp16 cells were treated with interleukin (IL)-1beta (0.1, 1, 10 ng/ml) and tumor necrosis factor (TNF)-alpha (1, 3, 10 ng/ml) in the presence or absence of indomethacin, etodolac, 5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulponyl) phenyl-2 (5H)-furanone (DFU) or nimesulide for 16 h (1.6-1000 nM). PG production was then measured by radioimmunoassay. Results: IL-1beta and TNF-alpha both stimulated production of PGE(2) and 6-keto-PGF(1alpha) in a concentration-dependent manner. DFU showed the most PGHS-II selectivity with IL-beta-stimulated PG production, with a IC50basal/IC50stimulated ratio of 177.8, followed by nimesulide (122.5). etodolac (23.5) and indomethacin (2.7). DFU was not as selective in TNF-alpha stimulated cells ratio (99.5). Conclusion: PGHS-II-selective inhibitors may be effective in the prevention of cytokine-driven myometrial PG production associated with preterm labor. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.