Cytochrome c oxidase IV isoform 1 (COX4-1) regulates the proliferation, migration and invasion of trophoblast cells via modulating mitochondrial function.

INTRODUCTION: Spontaneous miscarriage is a common complication of early pregnancy. Previous studies have shown that mitochondrial function plays an important role in establishment of a successful pregnancy. Cytochrome c oxidase subunit 4 isoform 1 (COX4I1), a component of electron transport chain complex Ⅳ, is required for coupling the rate of ATP production to energetic requirements. However, there is very limited research on its role in trophoblast biology and how its dysfunction may contribute to spontaneous miscarriage. METHODS: Placental villi (7-10 weeks gestational age) collected from either induced termination of pregnancy or after spontaneous miscarriage were examined for expression of COX4I1. COX4I1 was knocked down by siRNA transfection of primary isolates of EVT cells. Real-time cell analysis (RTCA) and 5-Ethynyl-2'-deoxyuridine (EdU) were used to detect changes in proliferation ability after COX4I1 knockdown of EVT cells. Migration and invasion indices were determined by RTCA. Mitochondrial morphology was observed via MitoTracker staining. Oxidative phosphorylation, ATP production, and glycolysis in COX4I1-deficient cells and controls were assessed by a cellular energy metabolism analyzer (Seahorse). RESULTS: In placental villous tissue, COX4I1 expression was significantly decreased in the spontaneous miscarriage group. Knockdown of COX4I1 inhibited EVT cell proliferation, increased the migration and invasion ability and mitochondrial fusion of EVT cells. Mitochondrial respiration and glycolysis were impaired in COX4I1-deficient EVT cells. Knockdown of MMP1 could rescue the increased migration and invasion induced by COX4I1 silencing. DISCUSSION: Low expression of COX4I1 leads to mitochondrial dysfunction in EVT, resulting in altered trophoblast function, and ultimately to pregnancy loss.

Interleukin-1 beta signals through the ERK signalling pathway to modulate human placental trophoblast migration and invasion in the first trimester of pregnancy.

INTRODUCTION: Interleukin-1 beta (IL-1ß) can promote cell migration, invasion and metastasis in various cancer cells. The mechanism of its role in human trophoblast has not been fully investigated. Therefore, we aimed to investigate the expression level of IL-1ß in first trimester decidua and placenta and its potential role in regulation of extravillous trophoblast cell (EVT) invasion and migration. METHODS: First trimester placenta and decidua were collected to study the expression levels of IL-1ß and its receptors by immunohistochemical staining. Primary isolates of first trimester EVT or the HTR-8/SVneo trophoblast like cell line were used to assess migration and invasion. Matrix metalloproteinase levels were assessed by gelatin zymography and ELISA. The phosphorylation profile of signaling pathway proteins was detected with the Proteome Profiler Human Phospho-Kinase Array Kit. Differentially expressed proteins in cells was detected and verified by Western Blot. RESULTS: IL-1ß, its receptors and antagonist are expressed in first trimester placenta and decidua, exogenous IL-1ß stimulates trophoblast cell outgrowth, migration and invasion through the ERK signaling pathway. IL-1ß was significantly increased in the placenta at 6-7 weeks gestation compared with 8-9 weeks gestation (P < 0.0001). Transwell and RTCA assays indicated that IL-1ß stimulates the invasion and migration of EVT. In addition, IL-1ß promoted the phosphorylation of ERK 1/2. It also promoted the expression of MMP2 and MMP9 in EVT as demonstrated by gelatin zymography assay and enzyme linked immunosorbent assay. DISCUSSION: This study demonstrated IL-1ß expression in placenta and decidua, and that it regulates EVT invasion and migration.

The Role of DNMT1 and C/EBPα in the Regulation of CYP11A1 Expression During Syncytialization of Human Placental Trophoblasts.

Progesterone synthesized in the placenta is essential for pregnancy maintenance. CYP11A1 is a key enzyme in progesterone synthesis, and its expression increases greatly during trophoblast syncytialization. However, the underlying mechanism remains elusive. Here, we demonstrated that passive demethylation of CYP11A1 promoter accounted for the upregulation of CYP11A1 expression during syncytialization with the participation of the transcription factor C/EBPα. We found that the methylation rate of a CpG locus in the CYP11A1 promoter was significantly reduced along with decreased DNA methyltransferase 1 (DNMT1) expression and its enrichment at the CYP11A1 promoter during syncytialization. DNMT1 overexpression not only increased the methylation of this CpG locus in the CYP11A1 promoter, but also decreased CYP11A1 expression and progesterone production. In silico analysis disclosed multiple C/EBPα binding sites in both CYP11A1 and DNMT1 promoters. C/EBPα expression and its enrichments at both the DNMT1 and CYP11A1 promoters were significantly increased during syncytialization. Knocking-down C/EBPα expression increased DNMT1 while it decreased CYP11A1 expression during syncytialization. Conclusively, C/EBPα plays a dual role in the regulation of CYP11A1 during syncytialization. C/EBPα not only drives CYP11A1 expression directly, but also indirectly through downregulation of DNMT1, which leads to decreased methylation in the CpG locus of the CYP11A1 promoter, resulting in increased progesterone production during syncytialization.

EGCG attenuated acute myocardial infarction by inhibiting ferroptosis via miR-450b-5p/ACSL4 axis.

BACKGROUND: Epigallocatechin gallate (EGCG) has multiple biological effects such as anti-tumor multiple drug resistance, antioxidation and anti-inflammatory properties. Ferroptosis is the main driving factor of ischemic heart injury, thus inhibiting ferroptosis may prove to be an effective treatment strategy for cardiovascular diseases. However, the role of EGCG on ferroptosis in ischemic myocardium and underlying mechanisms remain uncertain. PURPOSE: This study was aimed to investigate the effects and potential mechanisms of EGCG on myocardial ischemic-induced ferroptosis both in vitro and in vivo. METHODS: Cardiomyocyte hypoxia model and mouse acute myocardial infarction (AMI) model were established in vitro and in vivo. MiR-450b-5p and ACSL4 silencing or overexpression plasmids were transfected, with or without EGCG pretreatment. Cell viability was determined by the CCK-8 assay. Hematoxylin and eosin (HE) staining and transmission electron microscopy (TEM) were used to evaluate the morphologic alterations. TTC staining was used to observe the infarction area, and echocardiography was adopted to appraise the heart function. Using flow cytometry, the presence of reactive oxygen species (ROS) was assessed. The content of cardiac troponin I (cTn I), glutathione (GSH), malondialdehyde (MDA), divalent iron ions (Fe2+) and superoxide dismutase (SOD) were detected using reagent kits. A luciferase activity assay was performed to assess the binding ability of miR-450b-5p to ACSL4. Expressions of related genes and proteins were measured by RT-qPCR and western blotting respectively. RESULTS: EGCG attenuated AMI-induced ferroptosis and improved myocardial ischemia injury, which was associated with reducing iron deposition and cTn I, inhibition of lipid peroxidation, decreasing TFR1 and ACSL4, and upregulating SLC7A11, FTH1 and GPX4. Meanwhile, EGCG pretreatment increased miR-450b-5p expression in ischemic myocardium. Further researches discovered that knockdown of miR-450b-5p partially compromised EGCG-generated protective effect in hypoxia HL-1 cells, while combination with miR-450b-5p mimic could strengthen the potency of EGCG on ischemic myocardium. The dual-luciferase test demonstrated that miR-450b-5p has binding to ACSL4. Furthermore, silencing of ACSL4 synergistically increased the cardioprotective effect of EGCG. More significantly, EGCG treatment regulated the ferroptosis-related proteins expression via miR-450b-5p/ACSL4 axis. CONCLUSION: In summary, the present study evidently demonstrated that EGCG attenuates myocardial ischemia injury by targeting ferroptosis. Our work revealed the role of miR-450b-5p/ACSL4 axis in AMI for the first time. Further, it also elucidated the molecular mechanisms of EGCG on inhibiting ferroptosis greatly depend on the miR-450b-5p/ACSL4 axis, suggesting that EGCG may act as a novel anti-ferroptosis agent and exert a therapeutic role in AMI.

Extravillous trophoblast cell-derived exosomes induce vascular smooth muscle cell apoptosis via a mechanism associated with miR-143-3p.

The remodeling of uterine spiral arteries is a complex process requiring the dynamic action of various cell types. During early pregnancy, extravillous trophoblast (EVT) cells differentiate and invade the vascular wall, replacing the vascular smooth muscle cells (VSMCs). Several in vitro studies have shown that EVT cells play an important role in promoting VSMC apoptosis, however, the mechanism underlying this process is not fully understood. In this study, we demonstrated that EVT-conditioned media and EVT-derived exosomes could induce VSMC apoptosis. Through data mining and experimental verification, it was demonstrated that the EVT exosome miR-143-3p induced VSMC apoptosis in both VSMCs and a chorionic plate artery (CPA) model. Furthermore, FAS ligand was also expressed on the EVT exosomes and may play a co-ordinated role in apoptosis induction. These data clearly demonstrated that VSMC apoptosis is mediated by EVT-derived exosomes and their cargo of miR-143-3p as well as their cell surface presentation of FASL. This finding increases our understanding of the molecular mechanisms underlying the regulation of VSMC apoptosis during spiral artery remodeling.

Knockdown of heat shock protein family D member 1 (HSPD1) promotes proliferation and migration of ovarian cancer cells via disrupting the stability of mitochondrial 3-oxoacyl-ACP synthase (OXSM).

BACKGROUND: Heat shock protein 60 (HSP60) is essential for the folding and assembly of newly imported proteins to the mitochondria. HSP60 is overexpressed in most types of cancer, but its association with ovarian cancer is still in dispute. SKOV3 and OVCAR3 were used as experimental models after comparing the expression level of mitochondrial HSP60 in a normal human ovarian epithelial cell line and four ovarian cancer cell lines. RESULTS: Low HSPD1 (Heat Shock Protein Family D (HSP60) Member 1) expression was associated with unfavorable prognosis in ovarian cancer patients. Knockdown of HSPD1 significantly promoted the proliferation and migration of ovarian cancer cells. The differentially expressed proteins after HSPD1 knockdown were enriched in the lipoic acid (LA) biosynthesis and metabolism pathway, in which mitochondrial 3-oxoacyl-ACP synthase (OXSM) was the most downregulated protein and responsible for lipoic acid synthesis. HSP60 interacted with OXSM and overexpression of OXSM or LA treatment could reverse proliferation promotion mediated by HSPD1 knockdown. CONCLUSIONS: HSP60 interacted with OXSM and maintained its stability. Knockdown of HSPD1 could promote the proliferation and migration of SKOV3 and OVCAR3 via lowering the protein level of OXSM and LA synthesis.

Amnion-derived serum amyloid A1 participates in sterile inflammation of fetal membranes at parturition.

OBJECTIVES: Sterile inflammation of fetal membranes is an indispensable event of normal parturition. However, triggers of sterile inflammation are not fully resolved. Serum amyloid A1 (SAA1) is an acute phase protein produced primarily by the liver. Fetal membranes can also synthesize SAA1 but its functions are not well defined. Given the role of SAA1 in the acute phase response to inflammation, we postulated that SAA1 synthesized in the fetal membranes may be a trigger of local inflammation at parturition. METHODS: The changes of SAA1 abundance in parturition were studied in the amnion of human fetal membranes. The role of SAA1 in chemokine expression and leukocyte chemotaxis was examined in cultured human amnion tissue explants as well as primary human amnion fibroblasts. The effects of SAA1 on monocytes, macrophages and dendritic cells were investigated in cells derived from a human leukemia monocytic cell line (THP-1). RESULTS: SAA1 synthesis increased significantly in human amnion at parturition. SAA1 evoked multiple chemotaxis pathways in human amnion fibroblasts along with upregulation of a series of chemokines via both toll-like receptor 4 (TLR4) and formyl peptide receptor 2 (FPR2). Moreover, SAA1-conditioned medium of cultured amnion fibroblasts was capable of chemoattracting virtually all types of mononuclear leukocytes, particularly monocytes and dendritic cells, which reconciled with the chemotactic activity of conditioned medium of cultured amnion tissue explants collected from spontaneous labor. Furthermore, SAA1 could induce the expression of genes associated with inflammation and extracellular matrix remodeling in monocytes, macrophages and dendritic cells derived from THP-1. CONCLUSIONS: SAA1 is a trigger of sterile inflammation of the fetal membranes at parturition.

Ezrin accelerates breast cancer liver metastasis through promoting furin-like convertase-mediated cleavage of Notch1.

BACKGROUND: Ezrin, known as a crosslinker between the plasma membrane and actin cytoskeleton, is closely associated with breast cancer (BC) progression. Here, we explored a novel role of ezrin in breast cancer liver metastasis (BCLM). METHODS: The clinical relevance of ezrin was evaluated using in silico tools and confirmed in BC specimens. The effect of ezrin on proliferation, migration and invasion was examined in vitro and in vivo using murine primary liver-metastatic breast cancer cells (mLM). The molecular mechanism involved in ezrin-mediated activation of the Notch1 signaling pathway was elucidated using in vitro models. RESULTS: Data-mining demonstrated that ezrin mRNA and protein expression is up-regulated in breast cancer cohorts and has prognostic significance. Ezrin overexpression promotes cell proliferation, migration and invasion in vitro and in vivo. Hairy and enhancer of split-1 (Hes1) is one of the most significantly enriched candidates of differentially expressed genes in ezrin overexpression and control mLM cells. Ezrin can positively regulate Hes1 mRNA and protein expression, and their coexpression was associated with poor prognosis in BC patients. Ezrin promoted BC cell proliferation in a Hes1-dependent manner without directly interacting with Hes1. The functional link between ezrin and Hes1 is dependent on Notch1 activation through promotion of furin-like convertase cleavage. CONCLUSION: Our results demonstrated that ezrin drives BCLM through activation of the Notch signaling pathway via furin-like convertase. These findings provide a better understanding of the mechanism of ezrin in breast cancer progression, with the goal of discovering a novel target for the treatment of BCLM in the future.

Role of EZH2-mediated H3K27me3 in placental ADAM12-S expression: implications for fetoplacental growth.

BACKGROUND: Enhancer of zeste homolog 2 (EZH2)-mediated histone 3 lysine 27 trimethylation (H3K27me3) is a transcription silencing mark, which is indispensable for cell lineage specification at the early blastocyst stage. This epigenetic repression is maintained in placental cytotrophoblasts but is lifted when cytotrophoblasts differentiate into syncytiotrophoblasts. However, the physiological impact of this lift remains elusive. Here, we investigated whether lifting EZH2-mediated H3K27me3 during syncytialization upregulates the expression of a short secretory isoform of a disintegrin and metalloprotease 12 (ADAM12-S), a well-recognized placenta-derived protease that cleaves insulin-like growth factor binding protein 3 to increase insulin-like growth factor (IGF) bioavailability for the stimulation of fetoplacental growth. The transcription factor and the upstream signal involved were also explored. METHODS: Human placenta tissue and cultured primary human placental cytotrophoblasts were utilized to investigate the role of EZH2-mediated H3K27me3 in ADAM12-S expression and the associated transcription factor and upstream signal during syncytialization. A mouse model was used to examine whether inhibition of EZH2-mediated H3K27me3 regulates placental ADAM12-S expression and fetoplacental growth. RESULTS: EZH2 and ADAM12 are distributed primarily in villous cytotrophoblasts and syncytiotrophoblasts, respectively. Increased ADAM12-S expression, decreased EZH2 expression, and decreased EZH2/H3K27me3 enrichment at the ADAM12 promoter were observed during syncytialization. Knock-down of EZH2 further increased ADAM12-S expression in trophoblasts. Syncytialization was also accompanied by increased STAT5B expression and phosphorylation as well as its enrichment at the ADAM12 promoter. Knock-down of STAT5B attenuated ADAM12-S expression during syncytialization. Epidermal growth factor (EGF) was capable of inducing ADAM12-S expression via stimulation of STAT5B expression and phosphorylation during syncytialization. Mouse studies revealed that administration of an EZH2 inhibitor significantly increased ADAM12-S levels in maternal blood and fetoplacental weights along with decreased H3K27me3 abundance and increased ADAM12-S expression in the placenta. CONCLUSIONS: Lifting EZH2-mediated H3K27me3 increases ADAM12-S expression during syncytialization with the participation of EGF-activated STAT5B, which may lead to elevation of ADAM12-S level in maternal blood resulting in increased IGF bioavailability for the stimulation of fetoplacental growth in pregnancy. Our studies suggest that the role of EZH2-mediated H3K27me3 may switch from cell lineage specification at the early blastocyst stage to regulation of fetoplacental growth in later gestation.

Is there a place for Traditional Chinese Medicine (TCM) in the treatment of recurrent pregnancy loss?

Recurrent pregnancy loss (RPL) impacts a couple's quality of life, mental health and constitutes a large economic burden for care. Traditional Chinese Medicine (TCM) is an integrated systematic medical practice with wide clinical applications that has been predominantly used throughout Asian countries for over 2000 years. However, the efficacy of TCM in the treatment of RPL remains unclear due not only to a lack of experimental evidence, but also a lack of comprehensive summarized conclusions. Therefore, the current manuscript reviews recent relevant publications of the clinical use of TCM in RPL and illustrates its potential mechanisms. All publications (in both Chinese and English), especially randomized controlled trials (RCTs), on the use of TCM in RPL for the last ten years and research on its mechanisms were included. This review also describes our understanding of the problems and challenges in the modernization of TCM research.

De novo Synthesis of SAA1 in the Placenta Participates in Parturition.

Serum amyloid A1 (SAA1) is an acute phase protein produced mainly by the liver to participate in immunomodulation in both sterile and non-sterile inflammation. However, non-hepatic tissues can also synthesize SAA1. It remains to be determined whether SAA1 synthesized locally in the placenta participates in parturition via eliciting inflammatory reactions. In this study, we investigated this issue by using human placenta and a mouse model. We found that SAA1 mRNA and protein were present in human placental villous trophoblasts, which was increased upon syncytialization as well as treatments with lipopolysaccharides (LPS), tumor necrosis factor-α (TNF-α), and cortisol. Moreover, significant increases in SAA1 abundance were observed in the placental tissue or in the maternal blood in spontaneous deliveries without infection at term and in preterm birth with histological chorioamnionitis. Serum amyloid A1 treatment significantly increased parturition-pertinent inflammatory gene expression including interleukin-1ß (IL-1ß), IL-8, TNF-α, and cyclooxygenase-2 (COX-2), along with increased PGF2α production in syncytiotrophoblasts. Mouse study showed that SAA1 was present in the placental junctional zone and yolk sac membrane, which was increased following intraperitoneal administration of LPS. Intraperitoneal injection of SAA1 not only induced preterm birth but also increased the abundance of IL-1ß, TNF-α, and COX-2 in the mouse placenta. Conclusively, SAA1 can be synthesized in the human placenta, which is increased upon trophoblast syncytialization. Parturition is accompanied with increased SAA1 abundance in the placenta. Serum amyloid A1 may participate in parturition in the presence and absence of infection by inducing the expression of inflammatory genes in the placenta.

Exosomes Derived From Epigallocatechin Gallate-Treated Cardiomyocytes Attenuated Acute Myocardial Infarction by Modulating MicroRNA-30a.

BACKGROUND: Ischemia-derived exosomes can restrict excessive autophagy by transferring microRNA-30a (miR30a) to cells. Reports have confirmed that epigallocatechin gallate (EGCG) alleviates acute myocardial infarction (AMI) by regulating autophagy; however, research evaluating the communication with cardiomyocytes and exosomes is lacking. This study aimed to explore whether exosomes derived from EGCG-treated cardiomyocytes mitigated AMI by adjusting miR30a to inactivate apoptosis and autophagy. METHODS: Exosomes were extracted from cardiomyocytes, cultured either in control or AMI condition, with or without EGCG pretreatment. The exosome characteristics were analyzed by nanoparticle tracking analyses and transmission electron microscopy. The change in miR30a in cells and exosomes was demonstrated by qRT-PCR. H9c2 or stable miR30a knockdown (miR30aKD) cell lines were incubated with exosomes derived from EGCG-treated cardiomyocytes in vitro or in vivo. The effect of EGCG and exosomes on I/R-induced cardiomyocyte apoptosis and autophagy was assessed. RESULTS: EGCG improved the activity of cardiomyocytes, and increased average diameter, concentration, miR30a mRNA level, and specific protein expression in AMI-derived exosomes produced by cardiomyocytes. Moreover, the coincubation of AMI cells with EGCG or exosomes derived from EGCG-treated cardiomyocytes attenuated cardiomyocyte apoptosis and autophagy. CONCLUSIONS: The findings showed that EGCG upregulates miR30a, which was efficiently transferred via exosomes between cardiomyocytes, thereby contributing to the suppression of apoptosis and autophagy. By focusing on the cardiomyocyte microenvironment, we identified a new target of EGCG alleviating AMI by regulating apoptosis and autophagy.

MicroRNA-384-5p/Beclin-1 As Potential Indicators For Epigallocatechin Gallate Against Cardiomyocytes Ischemia Reperfusion Injury By Inhibiting Autophagy Via PI3K/Akt Pathway.

BACKGROUND/AIMS: Epigallocatechin gallate (EGCG) has established protective actions against myocardial ischemia/reperfusion (I/R) injury by regulating autophagy. However, little is known about the mechanisms of EGCG in posttranscriptional regulation in the process of cardioprotection. Here we studied whether microRNAs play a role in EGCG-induced cardioprotection. METHODS: The myocardial I/R injury in vitro and in vivo model were made, with or without EGCG pretreatment. The upregulation and silencing of microRNA-384-5p (miR-384) and Beclin-1 in H9c2 cell lines were established. Rats were transfected with miR-384 specific shRNA. Dual-luciferase reporter gene assay was conducted to verify the relationship between miR-384 and Beclin-1. TTC staining was performed to analyze the area of myocardial infarct size. Cell viability was monitored by cell counting kit-8 (CCK-8). The release of cardiac troponin-I (cTnI) was examined by ELISA. The levels of autophagy-related genes or proteins expression were evaluated by qRT-PCR or Western blotting. Autophagosomes of myocardial cells were detected by transmission electron microscopy and laser scanning confocal microscope. RESULTS: I/R increased both autophagosomes and autolysosomes, thereby increasing autophagic flux both in vitro and in vivo. Pretreatment with EGCG attenuated I/R-induced autophagic flux expression, accompanied by an increase in cell viability and a decrease in the size of myocardial infarction. MiR-384 expression was down-regulated in H9c2 cell lines when subjected to I/R, while this suppression could be reversed by EGCG pretreatment. The dual-luciferase assay verified that Beclin-1 was a target of miR-384. Both overexpression of miR-384 and knocking down of Beclin-1 significantly inhibited I/R-induced autophagy, accompanied by the activation of PI3K/Akt pathway, thus enhanced the protective effect of EGCG. However, these functions were abrogated by the PI3K inhibitor, LY294002. CONCLUSION: We confirmed that EGCG has a protective role in microRNA-384-mediated autophagy by targeting Beclin-1 via activating the PI3K/Akt signaling pathway. Our results unveiled a novel role of EGCG in myocardial protection, involving posttranscriptional regulation with miRNA-384.

Activation of prostaglandin EP4 receptor attenuates the induction of cyclooxygenase-2 expression by EP2 receptor activation in human amnion fibroblasts: implications for parturition.

Human amnion fibroblasts produce abundant prostaglandin E2 (PGE2), which plays a crucial role in parturition by stimulating not only myometrial contraction and cervical ripening but also the expression of the rate-limiting enzyme in PGE2 synthesis-namely, cyclooxygenase-2 (COX-2). This feed-forward induction of COX-2 expression by PGE2 is mediated via its receptors coupled with the cAMP and PKA pathway and subsequent phosphorylation of the transcription factors cAMP-response element binding protein (CREB) and signal transducer and activator of transcription 3 (STAT3). Although prostaglandin E receptor (EP)-2 and EP4 for PGE2 are coupled with activation of the cAMP and PKA pathway, the exact roles of these 2 receptors in the regulation of COX-2 expression in amnion fibroblasts remain to be determined. Here, we clarify this issue by employing human amnion tissue and fibroblasts with the long-term objective of specific targeting of prostaglandin synthesis in prevention of preterm birth. We find that an EP2 agonist caused long-lasting increases in CREB phosphorylation and COX-2 expression, whereas an EP4 agonist induced only transient increases in CREB phosphorylation and COX-2 expression in amnion fibroblasts. Moreover, only EP2 stimulation increased STAT3 phosphorylation, whereas only EP4 stimulation increased PI3K activity. EP4 antagonist or inhibition of PI3K enhanced the induction of CREB and STAT3 phosphorylation and COX-2 expression by PGE2 or EP2 stimulation, which was attenuated by EP4 overexpression. Of interest, PGE2 and cortisol, both well-demonstrated stimulants of COX-2 expression in amnion fibroblasts, increased EP2 but decreased EP4 receptor expression. Furthermore, increased EP2 but decreased EP4 abundance were observed in amnion tissue at parturition. We conclude that EP2 and EP4 receptors play different roles in the regulation of COX-2 expression in human amnion fibroblasts. EP2 is the dominant PGE2 receptor mediating the induction of COX-2 at parturition, which can be attenuated by simultaneous activation of PI3K coupled to the EP4 receptor.-Lu, J.-W., Wang, W.-S., Zhou, Q., Gan, X.-W., Myatt, L., Sun, K. Activation of prostaglandin EP4 receptor attenuates the induction of cyclooxygenase-2 expression by EP2 receptor activation in human amnion fibroblasts: implications for parturition.

Effects of pyrite and bornite on bioleaching of two different types of chalcopyrite in the presence of Leptospirillum ferriphilum.

The effects of pyrite and bornite on bioleaching of two different chalcopyrite samples by Leptospirillum ferriphilum were studied for the first time. Results showed that bioleaching behaviors of the two chalcopyrite samples were extremely different. Bornite decreased the redox potential (ORP) and maintained it at an appropriate range (380-480 mV vs. Ag/AgCl) to promote chalcopyrite (A) dissolution, but caused the redox potential out of the optimum range and inhibited chalcopyrite (B) dissolution. Large amount of pyrite decreased the redox potential and maintained it at an optimum range to promote chalcopyrite (A) dissolution, while increased the redox potential and kept it at appropriate range for a longer period of time to enhance the dissolution rate of chalcopyrite (B). Chalcopyrite (B) had significantly higher values of conductivity and oxidation-reduction rate when compared with those of chalcopyrite (A). The work is potentially useful in interpreting the inconsistence of the researches of chalcopyrite hydrometallurgy.