Distinct kinetic mechanisms of H3K4 methylation catalyzed by MLL3 and MLL4 core complexes.

The methyltransferases MLL3 and MLL4 primarily catalyze the monomethylation of histone H3 lysine 4 (H3K4) on enhancers to regulate cell-type-specific gene expression and cell fate transition. MLL3 and MLL4 share almost identical binding partners and biochemical activities, but perform specific and nonredundant functions. The features and functions that distinguish MLL3 and MLL4 remain elusive. Here, we characterize the kinetic mechanisms of MLL3 and MLL4 ternary complexes containing the catalytic SET domain from MLL3 or MLL4 (MLL3SET or MLL4SET), the SPRY domain of ASH2L (ASH2LSPRY), and a short fragment of RBBP5 (RBBP5AS-ABM) to search for possible explanations. Steady-state kinetic analyses and inhibition studies reveal that the MLL3 complex catalyzes methylation in a random sequential bi-bi mechanism. In contrast, the MLL4 complex adopts an ordered sequential bi-bi mechanism, in which the cofactor S-adenosylmethionine (AdoMet) binds to the enzyme prior to the H3 peptide, and the methylated H3 peptide dissociates from the enzyme before S-adenosylhomocysteine (AdoHcy) detaches after methylation. Substrate-binding assays using fluorescence polarization (FP) confirm that AdoMet binding is a prerequisite for H3 binding for the MLL4 complex but not for the MLL3 complex. Molecular dynamic simulations reveal that the binding of AdoMet exclusively induces conformational constraints on the AdoMet-binding groove and the H3 substrate-binding pocket of MLL4, therefore stabilizing a specific active conformation to ease entry of the substrate H3. The distinct kinetic mechanisms and conformational plasticities provide important insights into the differential functions of MLL3 and MLL4 and may also guide the development of selective inhibitors targeting MLL3 or MLL4.

Gender differences in UV-induced skin inflammation, skin carcinogenesis and systemic damage.

Ultraviolet (UV) radiation-induced chronic inflammation contributes to all stages of skin tumor development. In addition, gender plays an important role in inflammatory diseases or cancer. In this study, histopathology changes, hematology, oxidative stress and inflammatory response were used to evaluate sex differences in UV-induced chronic inflammation-associated cancer development. The results showed that the male and female mice had photoaging damage at the 9th week. However, skin tumors only appeared in male mice at 31st week. Furthermore, UV increased ROS production, p65, p-p65, IL-6 and TNF-α protein expressions in skin, and these factors elevated more in male mouse model. Hematology results showed that the parameters of blood systemic inflammation were changed in different degrees in model groups, while the pathological results showed inflammatory cell infiltration in the internal organs of both model groups in varying degrees. These results indicate that there are gender differences in UV-induced skin inflammation, carcinogenesis and systemic damage. Moreover, male mice are more sensitive to UV irradiation, which may be responsible to greater oxidative stress and inflammatory damage.

The Effect of BML-111 in Preeclampsia Rat Model Induced by the Low Dose of Cadmium Chloride.

Aim This article determines the optimal time and dose of cadmium chloride (CdCl 2 ) injected to pregnant rat to establish experimental preeclampsia (PE) model. In addition, the therapeutic potential of BML-111, a lipoxin A4 analogue, in the CdCl 2 -induced PE model was also evaluated. Methods Peritoneal injection of two dose of CdCl 2 for successive 6 days was tested in the pregnant rats starting from various gestational days (GDs). During this process, the systolic blood pressure and the body weight of pregnant rats and neonatal rats were monitored. The pathological changes of the placenta and kidney were evaluated by hematoxylin and eosin staining. The phosphorylation of extracellular signal-regulated kinase 1/2 and signal transducer and activator of transcription 3 in the placentas was detected by Western blot, and the messenger ribonucleic acid expression of interleukin (IL)-6, tumor necrosis factor-α, and IL-10 in the placentas were detected by real-time polymerase chain reaction. BML-111 at the dose of 1 mg/kg/day was peritoneally injected into the rat after establishing the PE model to test its therapeutic potential. Results In the present study, we successfully established the PE model in pregnant rats by intraperitoneally injection of CdCl 2 at the dose of 0.125 mg/kg/day from GD 9 to 14. We recapitulated multiple features of clinical PE in CdCl 2 -induced rat, including high blood pressure, renal dysfunction, and inflammatory response in placenta. Furthermore, treatment with BML-111 significantly relieved multiple features in our PE rat model. Conclusions BML-111 has a potential therapeutic effect in pregnant rats with CdCl 2 -induced PE, which appears to be mediated through inhibition of inflammatory processes in the placenta.

Lipoxin A4 interferes with embryo implantation via suppression of epithelial-mesenchymal transition.

PROBLEM: To test whether lipoxin A4 (LXA4) interferes with embryo implantation via suppression of epithelial-mesenchymal transition (EMT). METHOD OF STUDY: We developed a mouse model of LXA4 blocking embryo implantation and detected the indicators of EMT to confirm that LXA4 inhibits EMT might be a mechanism of interfering with the embryo implantation. We detected integrin-linked kinase (ILK), N-formylpeptide receptor 2 (FPR2), vascular endothelial growth factor, matrix metalloproteinases (MMPs), Akt, GSK3ß, NF-ĸB, twist, vimentin, fibronectin, and ß-catenin mRNA expression using reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time RT-PCR; localized protein expression using immunohistochemistry and Western blotting assay; MMPs activity assay by gelatin zymography; and the status of implantation in pregnant animals assessed by pontamine blue reaction test. RESULTS: Preimplantation administration of LXA4 resulted in implantation failure. LXA4 has a time- and dose-dependent effect on embryo implantation. Day 0.5 after fertilization is the most effective time to use LXA4 to block embryo implantation. (a) LXA4 reduced endometrial stroma edema; (b) LXA4 inhibited the activity of MMP9 and significantly upregulated the expression of ß-catenin, and downregulated the expression of vimentin, fibronectin, twist, NF-κB, Akt, and Gsk-3ß in the endometrium and TEV-1 cells; (c) LXA4 upregulated the expression of FPR2, and downregulated the expression of ILK; FPR2-overexpressing had an inhibitory effect on ILK in TEV-1 cells. CONCLUSION: LXA4 inhibits EMT which attenuates ILK action by enhancing FPR2; therefore, this might be a mechanism of interfering with embryo implantation.

Progesterone attenuates hypertension and autoantibody levels to the angiotensin II type 1 receptor in response to elevated cadmium during pregnancy.

INTRODUCTION: Preeclampsia is associated with the presence of pathogenic angiotensin-receptor-activating autoantibodies. Cadmium is an increasingly prevalent environmental pollutant that can mimic oestrogens, which may enhance immunoglobulin production. Progesterone exerts opposite effects to oestrogen. METHODS: We measured the levels of cadmium and progesterone in preeclamptic patients and controls. Pregnant rats exposed to cadmium (0.125 mg/kg body weight) from gestational day 9-12 were treated with/without progesterone (3 mg/kg) beginning from gestational day 9 to delivery. We analysed the main features of preeclampsia and circulating level of the angiotensin II type 1 receptor agonistic autoantibody. We also measured the expression of activation-induced cytosine deaminase in B cells. RESULTS: There were higher cadmium levels and lower progesterone levels in the blood of preeclamptic women than in the blood of those with a healthy pregnancy. Based on this finding, a rat model of preeclampsia was established by intraperitoneally administrating low-dose cadmium on gestational days 9-12. Rats were then treated with/without progesterone. Key features of preeclampsia, including hypertension, proteinuria and placental abnormalities, appeared in pregnant rats after cadmium injection and improved after treatment with progesterone. Cadmium increased immunoglobulin production, mainly angiotensin II type 1-receptor-agonistic autoantibodies, by increasing the expression of activation-induced cytosine deaminase in B cells; progesterone exerted an opposite effect. CONCLUSION: Cadmium induced immune abnormalities that may be a key pathogenic contributor to preeclampsia. Progesterone supplementation to correct hormonal imbalance may be a viable strategy for preeclampsia management.

Superparamagnetic iron oxide nanoparticles modified with dimyristoylphosphatidylcholine and their distribution in the brain after injection in the rat substantia nigra.

The subcellular distributions of nanoparticles in the brain are important for their biological application. We synthesized and characterized the superparamagnetic iron oxide nanoparticles (SPIONs) modified with poly (ethylene glycol) (PEG) and polyethylenimine (PEI) (PEG/PEI-SPIONs), and with dimyristoylphosphatidylcholine (DMPC) (DMPC-SPIONs). The nanoparticles were unilaterally injected into the left substantia nigra of rat brains. The distributions of the nanoparticles in the left brains of the rats were examined by ICP-OES (inductively coupled plasma optical emission spectrometer) and TEM (transmission electron microscopy) at 24h after the injection. Iron was found in the olfactory bulb, temporal lobe, frontal cortex, thalamus and brain stem at 24h after the injection of DMPC-SPIONs and PEG/PEI-SPIONs. In the rat substantia nigra, most DMPC-SPIONs were distributed in and on the myelin sheath around axons or on cell membranes, some were in cells. As a comparison, less iron was found in the rat brains at 24h after the injection of PEG/PEI-SPIONs. Our experiments suggest DMPC modification on SPIONs be a safe and effective method for increasing SPIONs distribution on the cell membranes. This work is encouraging for further study on using DMPC-SPIONs for efficient drug delivery or for deep brain stimulation of neurons in a magnetic field.

Superparamagnetic iron oxide nanoparticles conjugated with folic acid for dual target-specific drug delivery and MRI in cancer theranostics.

Monodispersed SPIONs (superparamagnetic iron oxide nanoparticles) co-coated with PEG and PEI polymers were prepared by an improved polyol method. To accomplish cancer-specific targeting properties, FA (folic acid) was then modified on the SPIONs via EDC/NHS method (FA-SPIONs). Doxorubicin (DOX) as an example anticancer drug was loaded within FA-SPIONs (DOX@FA-SPIONs), the DOX release rate of DOX@FA-SPIONs was much high in low pH PBS. The SPIONs, FA-SPIONs and DOX@FA-SPIONs with mean hydrodynamic diameters of 23, 40 and 67nm, respectively, performed excellent colloidal stability in PBS. Confocal laser scanning microscope (CLSM) study implicates that the DOX@FA-SPIONs target MCF-7 cells efficiently through the FA receptor-mediated endocytosis. DOX@FA-SPIONs were tested in nude mice with xenograft MCF-7 breast tumor though tail intravenous injection and were found inhibiting tumor growth more efficiently. The application of a magnetic field (MF) greatly improved the growth inhibiting efficiencies of DOX@FA-SPIONs on MCF-7 cells in vitro and on xenograft MCF-7 breast tumor of nude mice in vivo. The aggregation of SPIONs in tumor was monitored by magnetic resonance imaging (MRI) as the DOX@FA-SPIONs exhibited high r2 relaxivity (81.77mM-1S-1). Histology on liver, Lung, kidney and heart in mice showed no significant toxicity of DOX@FA-SPIONs on mice organs after 35-day treatment. The FA-SPIONs are a high efficient drug delivery nanoplatform for advanced cancer theranostics.

Cadmium-induced immune abnormality is a key pathogenic event in human and rat models of preeclampsia.

With increased industrial development, cadmium is an increasingly important environmental pollutant. Studies have identified various adverse effects of cadmium on human beings. However, the relationships between cadmium pollution and the pathogenesis of preeclampsia remain elusive. The objective of this study is to explore the effects of cadmium on immune system among preeclamptic patients and rats. The results showed that the cadmium levels in the peripheral blood of preeclamptic patients were significantly higher than those observed in normal pregnancy. Based on it, a novel rat model of preeclampsia was established by the intraperitoneal administration of cadmium chloride (CdCl2) (0.125 mg of Cd/kg body weight) on gestational days 9-14. Key features of preeclampsia, including hypertension, proteinuria, placental abnormalities and small foetal size, appeared in pregnant rats after the administration of low-dose of CdCl2. Cadmium increased immunoglobulin production, mainly angiotensin II type 1-receptor-agonistic autoantibodies (AT1-AA), by increasing the expression of activation-induced cytosine deaminase (AID) in B cells. AID is critical for the maturation of antibody and autoantibody responses. In addition, angiotensin II type 1-receptor-agonistic autoantibody, which emerged recently as a potential pathogenic contributor to PE, was responsible for the deposition of complement component 5 (C5) in kidneys of pregnant rats via angiotensin II type 1 receptor (AT1R) activation. C5a is a fragment of C5 that is released during C5 activation. Selectively interfering with C5a signalling by a complement C5a receptor-specific antagonist significantly attenuated hypertension and proteinuria in Cd-injected pregnant rats. Our results suggest that cadmium induces immune abnormalities that may be a key pathogenic contributor to preeclampsia and provide new insights into treatment strategies of preeclampsia.

Glioma-targeted superparamagnetic iron oxide nanoparticles as drug-carrying vehicles for theranostic effects.

Multifunctional nanoparticles capable of the specific delivery of therapeutics to diseased cells and the real-time imaging of these sites have the potential to improve cancer treatment through personalized therapy. In this study, we have proposed a multifunctional nanoparticle that integrate magnetic targeting, drug-carrier functionality and real-time MRI imaging capabilities in one platform for the theranostic treatment of tumors. The multifunctional nanoparticle was designed with a superparamagnetic iron oxide core and a multifunctional shell composed of PEG/PEI/polysorbate 80 (Ps 80) and was used to encapsulate DOX. DOX-loaded multifunctional nanoparticles (DOX@Ps 80-SPIONs) with a Dh of 58.0 nm, a zeta potential of 28.0 mV, and a drug loading content of 29.3% presented superior superparamagnetic properties with a saturation magnetization (Ms) of 24.1 emu g(-1). The cellular uptake of DOX@Ps 80-SPIONs by C6 cells under a magnetic field was significantly enhanced over that of free DOX in solution, resulting in stronger in vitro cytotoxicity. The real-time therapeutic outcome of DOX@Ps 80-SPIONs was easily monitored by MRI. Furthermore, the negative contrast enhancement effect of the nanoparticles was confirmed in glioma-bearing rats. Prussian blue staining and ex vivo DOX fluorescence assays showed that the magnetic Ps 80-SPIONs and encapsulated DOX were delivered to gliomas by imposing external magnetic fields, indicating effective magnetic targeting. Due to magnetic targeting and Ps 80-mediated endocytosis, DOX@Ps 80-SPIONs in the presence of a magnetic field led to the complete suppression of glioma growth in vivo at 28 days after treatment. The therapeutic mechanism of DOX@Ps 80-SPIONs acted by inducing apoptosis through the caspase-3 pathway. Finally, DOX@Ps 80-SPIONs' safety at therapeutic dosage was verified using pathological HE assays of the heart, liver, spleen, lung and kidney. Multifunctional SPIONs could be used as potential carriers for the theranostic treatment of CNS diseases.

Superparamagnetic Iron Oxide Nanoparticles Modified with Tween 80 Pass through the Intact Blood-Brain Barrier in Rats under Magnetic Field.

The methods for the delivery of theranostic agents across the blood-brain barrier (BBB) are highly required. Superparamagnetic iron oxide nanoparticles (SPIONs) coated with PEG (poly(ethylene glycol)), PEI (poly(ethylene imine)), and Tween 80 (polysorbate 80) (Tween-SPIONs) were prepared. We demonstrate the effective passage of tail-vein-injected Tween-SPIONs across normal BBB in rats under an external magnetic field (EMF). The quantitative analyses show significant accumulation of SPIONs in the cortex near the magnet, with progressively lower accumulation in brain tissues far from the magnet. A transmission electron microscopy picture of an ultrathin section of the rat brain displays Tween-SPIONs crossing the BBB. The comparative study confirms that both the Tween-80 modification and EMF play crucial roles in the effective passage of SPIONs across the intact BBB. However, the magnetic force alone cannot drag the SPIONs coated with PEI/PEG polymers through the BBB. The results indicate the Tween-SPIONs cross the BBB via an active penetration facilitated by EMF. This work is encouraging for further study on the delivery of drug or diagnostic agents into the parenchyma of the brain for dealing with neurological disorders by using Tween-SPIONs carriers under EMF.

Glucocorticoid exposure in early placentation induces preeclampsia in rats via interfering trophoblast development.

In pregnancy, placenta can be exposed to glucocorticoids (GCs) via several ways, which may disturb placentation and adversely affect pregnancy. Preeclampsia (PE) is thought to be attributed, in part, to impaired trophoblast development. The purpose of the present study was to confirm that GC exposure in early placentation could lead to PE in rats, with the mechanisms involving dysregulated trophoblast development. In the study, pregnant rats were administered with 2.5mg/kg Dex subcutaneously once per day from gestational day 7 to 13. Maternal systolic blood pressure and urinary albumin were increased, while both fetus and placenta were restricted after GC exposure relative to the control group. GC exposure also contributed to placental abnormalities and renal impairment. Moreover, placental oxidative damage was increased along with placental hypoxia-inducible factor 1-alpha (HIF1A) overexpression after GC treatment. Mechanically, GC induced PE in rat partially through inhibiting trophoblast proliferation, migration, invasion and epithelial-mesenchymal transition (EMT), which involved phospho-extracellular signal regulated kinase (p-ERK) downregulation. Furthermore, GC receptor was required for the inhibition of GC on trophoblast proliferation, migration, invasion and EMT in vitro. These findings suggest that GC exposure in early placentation could contribute to PE in pregnant rats, with the mechanisms involving inhibition of trophoblast proliferation, migration, invasion and EMT by GC.

Increased Oxidative DNA Damage in Placenta Contributes to Cadmium-Induced Preeclamptic Conditions in Rat.

To explore the possible mechanisms of cadmium (Cd)-induced preeclamptic conditions in rats. In the present study, we introduced the in vivo model of preeclampsia by giving intraperitoneal injections of cadmium chloride (CdCl2) to pregnant rats from gestational day (GD) 4 to 19. Maternal body weights were recorded on GD 0, 14, and 20, while their systolic blood pressures (SBPs) monitored on GD 3, 11, and 18. On GD 20, rats were sacrificed and the specimens were collected. The morphological changes of placenta and kidney tissues of pregnant rats were examined by hematoxylin and eosin staining assay. Blood Cd level was detected by inductively coupled plasma mass spectrometry. Total antioxidant capacity (TAC) was evaluated using FRAP method and total nitrite (NOx) was detected with Griess reagent. Antioxidative factors and DNA damage/repair biomarkers were measured by real-time qPCR, western blot or immunohistochemistry study. The current results showed that CdCl2-treated pregnant rats developed preeclampsia (PE)-like manifestations, such as hypertension, albuminuria, with decreased TAC and increased blood Cd level, and pro-oxidative/antioxidative or DNA damage/repair biomarkers. Our study demonstrated that increased oxidative DNA damage in placenta could contribute to Cd-induced preeclamptic conditions in rat.

Dual-color labeled anti-mucin 1 antibody for imaging of ovarian cancer: A preliminary animal study.

To investigate the feasibility of the anti-mucin 1 (anti-MUC1/CD227) antibody in the fluorescent imaging of ovarian cancer, the CD227 antibody and a control IgG antibody were labeled with a near-infrared dye [Cy5.5-N-hydroxysuccinimide (NHS)] and a green dye (fluorescein-NHS). In vivo fluorescence images were obtained at 4, 12 and 36 h after injection of the probes into OVCAR3 tumor-bearing mice. The tumor to background ratios were calculated for both probes. Ex vivo fluorescence images were obtained following sacrifice at 36 h. After conjugation to Cy5.5 and fluorescein, the dual-color labeled CD227 probe (Ab-FL-Cy5.5) could be visualized by both green and near-infrared fluorescence. Uptake by the tumors was higher for the Ab-FL-Cy5.5 than for the IgG-Cy5.5 probe. All tumors could be visualized by in vivo imaging with an acceptable tumor to background ratio. Ex vivo studies demonstrated the advantages of using green fluorescence imaging to guide the resection of tumor tissues. These preliminary data indicate that the Ab-FL-Cy5.5 probe is promising for further tumor imaging applications and clinical translation.

Intestinal dysbiosis: an emerging cause of pregnancy complications?

The gut microbiota is intimately involved in numerous aspects of normal human physiology, including nutrition and metabolism, immunomodulation and behavior and stress response. Intestinal dysbiosis can be a contributing cause of many diseases, altering the function of both near and far organ systems. During pregnancy, the maternal body undergoes dramatic physiological changes to support the growth of fetus-placenta, while intestinal dysbiosis may directly or indirectly disturb the remodeling of physiological balance, leading to maternal maladaptation. Thus, intestinal dysbiosis, i.e., altered composition or metabolism of microbiota may adversely affect pregnancy outcome and lead to pregnancy complications via disrupting maternal adaptation. Indeed, pregnant women with potential maladaptations are at high risk of developing pregnancy disorders, which is increasingly observed in clinical cases. Here we discuss the hypothesis that intestinal dysbiosis may induce pregnancy complications via affecting maternal adaptation and the possible mechanistic pathways.

Preeclampsia induced by cadmium in rats is related to abnormal local glucocorticoid synthesis in placenta.

BACKGROUND: Cadmium (Cd) is a major environmental pollutant that causes multiple adverse health effects in humans and animals. In this study, we investigated Cd-mediated toxic effects in rats during pregnancy and endocrine intervention in the placenta. METHODS: We exposed pregnant rats to intraperitoneal Cd (CdCl2) at various doses (0, 0.25, and 0.5 mg/kg BW/day) from days 5 to 19 of pregnancy and evaluated the maternal-placental-fetal parameters linked to preeclampsia. We measured the corticosterone level in rat serum and placental tissue by sensitive ELISA and also analyzed the expression of glucocorticoid synthesis enzymes in the placenta. RESULTS: Key features of preeclampsia (PE), including hypertension, proteinuria, glomerular endotheliosis, placental abnormalities and small fetal size, appeared in pregnant rats after injection with 0.5 mg/kg BW/day Cd. The placental corticosterone production and maternal and fetal plasma corticosterone levels were increased in rats treated with 0.5 mg/kg BW/day Cd (P <0.01). The expression of 21-hydroxylase (CYP21) and 11beta-hydroxylase (CYP11B1), enzymes essential for corticosteroid synthesis, were increased in Cd-exposed placenta (P <0.01). 11beta-hydroxysteroid dehydrogenase (11beta-HSD2), a dominant negative regulator of local glucocorticoid levels, was decreased in Cd-exposed placenta (P <0.01). CONCLUSIONS: Our study demonstrates for the first time that changes in placental glucocorticoid synthesis induced by Cd exposure during pregnancy could contribute to preeclamptic conditions in rats.

Preeclampsia is associated with a deficiency of lipoxin A4, an endogenous anti-inflammatory mediator.

OBJECTIVE: To test whether lipoxin A4 (LXA4) deficiency results in preeclampsia. DESIGN: Prospective experimental study. SETTING: Patient and animal research facilities. ANIMAL(S): Sprague-Dawley rats. INTERVENTION(S): We measured LXA4 and its biosynthetic enzymes, blocked the LXA4 signaling pathway, treated experimental rats with preeclampsia with LXA4, and detected inflammatory factors, FPR2/ALX, and 11ß-HSD2 to systematically test whether lack of LXA4 results in preeclampsia. MAIN OUTCOME MEASURE(S): We measured serum levels of LXA4 and inflammatory factors using enzyme-linked immunosorbent assay; detected LXA4 biosynthetic enzymes, inflammatory factors, FPR2/ALX, and 11ß-HSD2 mRNA expression using reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time RT-PCR; and localized protein expression using immunohistochemistry. RESULT(S): FPR2/ALX and LXA4 and its biosynthetic enzymes were found to be decreased in women with preeclampsia. Replenishing LXA4 improved the symptoms of lipopolysaccharide-induced rats with preeclampsia, while blocking LXA4 signaling resulted in preeclampsia. LXA4 significantly reduced interleukin-6 (IL-6), tumor necrosis factor-α, and IFN-γ but increased IL-10, LXA4 up-regulated 11ß-HSD2. CONCLUSION(S): A deficiency of LXA4 may result in preeclampsia, which might be ascribed to a reduction in inflammation response, oxidative stress, and regulation of 11ß-HSD2.

Lipoxin A4: The double-edge sword in mice pregnancy.

PROBLEM: To evaluate the role for LXA4 in the pregnancy. METHOD OF STUDY: We detected the changes of LXA4 and LXA4 biosynthetic enzymes in the mice's pregnancy, blocked LXA4 signaling pathway, managed LXA4 level, and treated LPS-induced mouse abortion model to systematically determine how LXA4 impact pregnancy. RESULTS: The concentrations of LXA4 in serum and uterus were lowest on Days 4.5 of pregnancy and in labor as compared to Day 12.5 of pregnancy (270.2 ± 33.2, 277.5 ± 23.7 versus 457.1 ± 40.9 pg/mL). Inhibition of the LXA4 signaling pathway did not affect pregnancy during the peri-implantation period of pregnancy, but induced abortion when administered after implantation of blastocysts. High levels of LXA4 interfered with implantation, but protected mice from aborting in response to LPS. CONCLUSION: LXA4 might be involved in the process of pregnancy, and LXA4 might act as the double-edge sword in pregnancy: the anti-implantation effect in the stage of peri-implantation and the anti-abortion affect after blastocyst implantation.

Glucocorticoids sensitize rat placental inflammatory responses via inhibiting lipoxin A4 biosynthesis.

Inflammation dysregulation in placenta is implicated in the pathogenesis of numerous pregnancy complications. Glucocorticoids (GCs), universally considered anti-inflammatory, can also exert proinflammatory actions under some conditions, whereas whether and how GCs promote placental inflammation have not been intensively investigated. In this paper we report the opposing regulation of rat placental inflammation by synthetic GC dexamethasone (Dex). When Dex was subcutaneously injected 1 h after we administered an intraperitoneal lipopolysaccharide (LPS) challenge, neutrophil infiltration and proinflammatory Il1b, Il6, and Tnfa expression in rat placenta were significantly reduced. In contrast, Dex pretreatment for 24 h potentiated rat placental proinflammatory response to LPS and delayed inflammation resolution, which involved MAPKs and NF-kappaB activation. Mechanically, Dex pretreatment promoted 5-lipoxygenase (ALOX5) activation and increased leukotriene B4 production, whereas it inhibited the anti-inflammatory and proresolving lipid mediator lipoxin A4 (LXA4) biosynthesis in rat placenta via downregulating ALOX15 and ALOX15B expression. Moreover, LXA4 supplementation dampened Dex-potentiated placental inflammation and suppressed Dex-mediated ALOX5 activation in vivo and in vitro. Taken together, these findings suggest that GCs exposure could promote placental inflammation initiation and delay resolution via disrupting LXA4 biosynthesis.

Fasting plasma glucose at 24-28 weeks to screen for gestational diabetes mellitus: new evidence from China.

OBJECTIVE: To evaluate the usefulness of a fasting plasma glucose (FPG) at 24-28 weeks' gestation to screen for gestational diabetes mellitus (GDM). RESEARCH DESIGN AND METHODS: The medical records and results of a 75-g 2-h oral glucose tolerance test (OGTT) of 24,854 pregnant women without known pre-GDM attending prenatal clinics in 15 hospitals in China were examined. RESULTS: FPG cutoff value of 5.1 mmol/L identified 3,149 (12.1%) pregnant women with GDM. FPG cutoff value of 4.4 mmol/L ruled out GDM in 15,369 (38.2%) women. With use of this cutoff point, 12.2% of patients with mild GDM will be missed. The positive predictive value is 0.322, and the negative predictive value is 0.928. CONCLUSIONS: FPG at 24-28 weeks' gestation could be used as a screening test to identify GDM patients in low-resource regions. Women with an FPG between ≥4.4 and ≤5.0 mmol/L would require a 75-g OGTT to diagnose GDM. This would help to avoid approximately one-half (50.3%) of the formal 75-g OGTTs in China.

Treatment of Lipoxin A(4) and its analogue on low-dose endotoxin induced preeclampsia in rat and possible mechanisms.

Preeclampsia (PE) is known to represent an exaggerated maternal inflammatory response to pregnancy. Lipoxin A(4) (LXA(4)), considered as an endogenous stop signal in inflammation, has been extensively studied pre clinically for its inflammatory pro-resolving effects. Thus, in the current study, we tested the effect of BML-111 (synthetic analogue of LXA(4)) on experimental PE rats induced by low-dose endotoxin (LPS) and of LXA(4) on human extravillous trophoblast cell line (TEV-1). In vivo experiment results showed that systolic blood pressure, 24 h-urinary albumin excretion, serum TNF-α and IL-8 levels and morphologic damage of placenta and kidney caused by LPS were all effectively alleviated by BML-111. LXA(4) also inhibited LPS-triggered apoptosis, activation of NF-κB, TNF-α and IL-8 mRNA and protein expression in TEV-1 cells. At the same time, BML-111 protected the cells from LPS-reduced proliferation. The current study demonstrated for the first time that LXA(4) could alleviate the symptoms of PE in endotoxin exposed rats.