Oxidative stress and the induction of cyclooxygenase enzymes and apoptosis in the murine placenta

Cross-Sectional Associations between Prenatal Per- and Poly-Fluoroalkyl Substances and Bioactive Lipids in Three Environmental Influences on Child Health Outcomes (ECHO) Cohorts

Prenatal per- and poly-fluoroalkyl substances (PFAS) exposure may influence gestational outcomes through bioactive lipids─metabolic and inflammation pathway indicators. We estimated associations between prenatal PFAS exposure and bioactive lipids, measuring 12 serum PFAS and 50 plasma bioactive lipids in 414 pregnant women (median 17.4 weeks' gestation) from three Environmental influences on Child Health Outcomes Program cohorts. Pairwise association estimates across cohorts were obtained through linear mixed models and meta-analysis, adjusting the former for false discovery rates. Associations between the PFAS mixture and bioactive lipids were estimated using quantile g-computation. Pairwise analyses revealed bioactive lipid levels associated with PFDeA, PFNA, PFOA, and PFUdA (p < 0.05) across three enzymatic pathways (cyclooxygenase, cytochrome p450, lipoxygenase) in at least one combined cohort analysis, and PFOA and PFUdA (q < 0.2) in one linear mixed model. The strongest signature revealed doubling in PFOA corresponding with PGD2 (cyclooxygenase pathway; +24.3%, 95% CI: 7.3-43.9%) in the combined cohort. Mixture analysis revealed nine positive associations across all pathways with the PFAS mixture, the strongest signature indicating a quartile increase in the PFAS mixture associated with PGD2 (+34%, 95% CI: 8-66%), primarily driven by PFOS. Bioactive lipids emerged as prenatal PFAS exposure biomarkers, deepening insights into PFAS' influence on pregnancy outcomes.

Maternal nano-titanium dioxide inhalation exposure alters placental cyclooxygenase and oxidant balance in a sexually dimorphic manner

The placenta plays a critical role in nutrient-waste exchange between the maternal and fetal circulation, and thus impacts fetal growth and development. We have previously shown that nano-titanium dioxide (nano-TiO2) inhalation exposure during gestation decreased fetal female pup and placenta mass [1], which persists in the following generation [2]. In utero exposed females, once mated, their offspring's placentas had increased capacity for H2O2 production. Generation of oxidants such as hydrogen peroxide (H2O2), have been shown to impact cyclooxygenase activity, specifically metabolites such as prostacyclin (PGI2) or thromboxane (TXA2). Therefore, we hypothesized that maternal nano-TiO2 inhalation exposure during gestation results in alterations in placental production of prostacyclin and thromboxane mediated by enhanced H2O2 production in a sexually dimorphic manner. Pregnant Sprague-Dawley rats were exposed to nano-TiO2 aerosols or filtered air (sham--control) from gestational day (GD) 10-19. Dams were euthanized on GD 20, and fetal serum and placental tissue were collected based on fetal sex. Fetal placental zones (junctional zone (JZ) and labyrinth zone (LZ)) were assessed for xanthine oxidoreductase (XOR) activity, H2O2, and catalase activity, as well as 6-keto-PGF1α and TXB2 levels. Nano-TiO2 exposed fetal female LZ demonstrated significantly greater XOR activity compared to exposed males. Exposed fetal female LZ also demonstrated significantly diminished catalase activity compared to sham-control females. Exposed fetal female LZ had significantly increased abundance of 6-keto-PGF1α compared to sham-control females and increased TXB2 compared to exposed males. In the aggregate these data indicate that maternal nano-TiO2 inhalation exposure has a greater impact on redox homeostasis and PGI2/TXA2 balance in the fetal female LZ. Future studies need to address if treatment with an XO inhibitor during gestation can prevent diminished fetal female growth during maternal nano-TiO2 inhalation exposure.

Endocrine-disrupting compounds and their impact on human placental function: evidence from placenta organ-on-chip studies

The effects of endocrine-disrupting compounds (EDCs) on the placenta, a critical gestational organ for xenobiotic protection, are well reported; however, models to determine the role of EDCs in placental disruption are limited. An advanced 2nd-trimester human placenta organ-on-chip model (2TPLA-OOC) was developed and validated, with six representative cells of the maternal and the fetal interface interconnected with microchannels. Various EDCs (150 ng mL-1 each of bisphenol A, bisphenol S, and polybrominated diphenyl ethers-47 and -99) were gradually propagated across the chip for 72 hours, and their various effects were determined. Cigarette smoke extract (CSE), an environmental risk factor, was used as a positive control. EDCs produced overall oxidative stress in the placental/decidual cells, induced cell-specific endocrine effects, caused limited (<10%) apoptosis/necrosis in trophoblasts and mesenchymal cells, induced localized inflammation but an overall anti-inflammatory shift, did not change immune cell migration from stroma to decidua, and did not affect placental nutrient transport. Overall, (1) the humanized 2TPLA-OOC recreated the placental organ and generated data distinct from the trophoblast and other cells studied in isolation, and (2) at doses associated with adverse pregnancies, EDCs produced limited and localized insults, and the whole organ compensated for the exposure.

Melatonin-mediated actions and circadian functions that improve implantation, fetal health and pregnancy outcome

This review summarizes data related to the potential importance of the ubiquitously functioning antioxidant, melatonin, in resisting oxidative stress and protecting against common pathophysiological disorders that accompany implantation, gestation and fetal development. Melatonin from the maternal pineal gland, but also trophoblasts in the placenta, perhaps in the mitochondria, produce this molecule as a hedge against impairment of the uteroplacental unit. We also discuss the role of circadian disruption on reproductive disorders of pregnancy. The common disorders of pregnancy, i.e., stillborn fetus, recurrent fetal loss, preeclampsia, fetal growth retardation, premature delivery, and fetal teratology are all conditions in which elevated oxidative stress plays a role and experimental supplementation with melatonin has been shown to reduce the frequency or severity of these conditions. Moreover, circadian disruption often occurs during pregnancy and has a negative impact on fetal health; conversely, melatonin has circadian rhythm synchronizing actions to overcome the consequences of chronodisruption which often appear postnatally. In view of the extensive findings supporting the ability of melatonin, an endogenously-produced and non-toxic molecule, to protect against experimental placental, fetal, and maternal pathologies, it should be given serious consideration as a supplement to forestall the disorders of pregnancy. Until recently, the collective idea was that melatonin supplements should be avoided during pregnancy. The data summarized herein suggests otherwise. The current findings coupled with the evidence, published elsewhere, showing that melatonin is highly protective of the fertilized oocyte from oxidative damage argues in favor of its use for improving pregnancy outcome generally.

Cross-sectional associations between prenatal maternal per- and poly-fluoroalkyl substances and bioactive lipids in three Environmental influences on Child Health Outcomes (ECHO) cohorts

Background

Per- and poly-fluoroalkyl substances (PFAS) exposure can occur through ingestion of contaminated food and water, and inhalation of indoor air contaminated with these chemicals from consumer and industrial products. Prenatal PFAS exposures may confer risk for pregnancy-related outcomes such as hypertensive and metabolic disorders, preterm birth, and impaired fetal development through intermediate metabolic and inflammation pathways.

Objective

Estimate associations between maternal pregnancy PFAS exposure (individually and as a mixture) and bioactive lipids.

Methods

Our study included pregnant women in the Environmental influences on Child Health Outcomes Program: Chemicals in our Bodies cohort (CiOB, n=73), Illinois Kids Developmental Study (IKIDS, n=287), and the ECHO-PROTECT cohort (n=54). We measured twelve PFAS in serum and 50 plasma bioactive lipids (parent fatty acids and eicosanoids derived from cytochrome p450, lipoxygenase, and cyclooxygenase) during pregnancy (median 17 gestational weeks). Pairwise associations across cohorts were estimated using linear mixed models and meta-analysis. Associations between the PFAS mixture and individual bioactive lipids were estimated using quantile g-computation.

Results

PFDeA, PFOA, and PFUdA were associated (p<0.05) with changes in bioactive lipid levels in all three enzymatic pathways (cyclooxygenase [n=6 signatures]; cytochrome p450 [n=5 signatures]; lipoxygenase [n=7 signatures]) in at least one combined cohort analysis. The strongest signature indicated that a doubling in PFOA corresponded with a 24.3% increase (95% CI [7.3%, 43.9%]) in PGD2 (cyclooxygenase pathway) in the combined cohort. In the mixtures analysis, we observed nine positive signals across all pathways associated with the PFAS mixture. The strongest signature indicated that a quartile increase in the PFAS mixture was associated with a 34% increase in PGD2 (95% CI [8%, 66%]), with PFOS contributing most to the increase.

Conclusions

Bioactive lipids were revealed as biomarkers of PFAS exposure and could provide mechanistic insights into PFAS' influence on pregnancy outcomes, informing more precise risk estimation and prevention strategies.

Epigenetic mechanism of Gtl2-miRNAs causes the primitive sheep characteristics found in purebred Merino sheep

BACKGROUND

It is not uncommon for some individuals to retain certain primitive characteristics even after domestication or long-term intensive selection. Wild ancestors or original varieties of animals typically possess strong adaptability to environmental preservation, a trait that is often lacking in highly artificially selected populations. In the case of the Merino population, a world-renowned fine wool sheep breed, a phenotype with primitive coarse wool characteristic has re-emerged. It is currently unclear whether this characteristic is detrimental to the production of fine wool or whether it is linked to the adaptability of sheep. The underlying genetic/epigenetic mechanisms behind this trait are also poorly understood.

RESULTS

This study identified lambs with an ancestral-like coarse (ALC) wool type that emerged during the purebred breeding of Merino fine wool sheep. The presence of this primitive sheep characteristic resulted in better environmental adaptability in lambs, as well as improved fine wool yield in adulthood. Reciprocal cross experiments revealed that the ALC phenotype exhibited maternal genetic characteristics. Transcriptomic SNP analysis indicated that the ALC phenotype was localized to the imprinted Gtl2-miRNAs locus, and a significant correlation was found between the ALC wool type and a newly identified short Interstitial Telomeric Sequences (s-ITSs) at this locus. We further confirmed that a novel 38-nt small RNA transcribed from these s-ITSs, in combination with the previously reported 22-nt small RNAs cluster from the Gtl2-miRNAs locus, synergistically inhibited PI3K/AKT/Metabolic/Oxidative stress and subsequent apoptotic pathways in wool follicle stem cells, resulting in the ALC wool type. The necessity of Gtl2-miRNAs in controlling primary hair follicle morphogenesis, as well as the wool follicle type for ALC wool lambs, was verified using intergenic differentially methylated region-knockout mice.

CONCLUSION

The ALC wool type of Merino sheep, which does not reduce wool quality but increases yield and adaptability, is regulated by epigenetic mechanisms in the imprinted Gtl2-miRNAs region on sheep chromosome 18, with the maternally expressed imprinted gene responsible for the ALC phenotype. This study highlights the significance of epigenetic regulation during embryonic and juvenile stages and emphasizes the advantages of early adaptation breeding for maternal parents in enhancing the overall performance of their offspring.

Flip a coin: cell senescence at the maternal-fetal interface†

During pregnancy, cell senescence at the maternal-fetal interface is required for maternal well-being, placental development, and fetal growth. However, recent reports have shown that aberrant cell senescence is associated with multiple pregnancy-associated abnormalities, such as preeclampsia, fetal growth restrictions, recurrent pregnancy loss, and preterm birth. Therefore, the role and impact of cell senescence during pregnancy requires further comprehension. In this review, we discuss the principal role of cell senescence at the maternal-fetal interface, emphasizing its "bright side" during decidualization, placentation, and parturition. In addition, we highlight the impact of its deregulation and how this "dark side" promotes pregnancy-associated abnormalities. Furthermore, we discuss novel and less invasive therapeutic practices associated with the modulation of cell senescence during pregnancy.

Maternal hypothyroidism and its effect on placental histopathology in singleton live births resulting from in vitro fertilization treatment

We aimed to examine the impact of maternal hypothyroidism on placental pathology and perinatal outcomes in singleton live births resulting from IVF, using medical records of IVF births between 2009 and 2017 at a tertiary hospital. The primary outcomes included anatomical, inflammation, vascular malperfusion, and villous maturation placental features. Secondary outcomes included foetal, maternal, perinatal, and delivery complications. There were 1,057 live births, of which 103 (9.7%) and 954 (90.3%) were in the study and control groups, respectively. Patients in the study group were more likely to have diabetes mellitus, polycystic ovarian syndrome, gestational diabetes mellitus, and non-reassuring foetal heart rate (NRFHR) tracing during delivery. After adjustment for potential confounding factors, hypothyroidism was significantly associated with the bilobed placenta (aOR 4.1; 95% CI 1.2-14.3), retroplacental haematoma (aOR 2.4; 95% CI 1.2-4.9), decidual arteriopathy (aOR 2.0; 95% CI 1.2-4.1) and subchorionic thrombi (aOR 2.4; 95% CI 1.3-5.0). Additionally, there was a statistically significant relationship with NRFHR tracing. The incidence of acute chorioamnionitis and severe foetal inflammatory response was higher in the study group. In conclusion, the placental histopathology patterns of singleton IVF live births show that maternal hypothyroidism has a significant impact on adverse perinatal outcomes.

Interactions of N-Mannich Bases of Pyrrolo[3,4-c]pyrrole with Artificial Models of Cell Membranes and Plasma Proteins, Evaluation of Anti-Inflammatory and Antioxidant Activity

Despite the widespread and easy access to NSAIDs, effective and safe treatment of various inflammatory disorders is still a serious challenge because of the severe adverse effects distinctive to these drugs. The Mannich base derivatives of pyrrolo[3,4-c]pyrrole are potent, preferential COX-2 inhibitors with a COX-2/COX-1 inhibitory ratio better than meloxicam. Therefore, we chose the six most promising molecules and subjected them to further in-depth research. The current study presents the extensive biological, spectroscopic and in silico evaluation of the activity and physicochemical properties of pyrrolo[3,4-c]pyrrole derivatives. Aware of the advantages of dual COX-LOX inhibition, we investigated the 15-LOX inhibitory activity of these molecules. We also examined their antioxidant effect in several in vitro experiments in a protection and regeneration model. Furthermore, we defined how studied compounds interact with artificial models of cell membranes, which is extremely important for drugs administered orally with an intracellular target. The interactions and binding mode of the derivatives with the most abundant plasma proteins-human serum albumin and alpha-1-acid glycoprotein-are also described. Finally, we used computational techniques to evaluate their pharmacokinetic properties. According to the obtained results, we can state that pyrrolo[3,4-c]pyrrole derivatives are promising anti-inflammatory and antioxidant agents with potentially good membrane permeability.

The Role of Autophagy in the Female Reproduction System: For Beginners to Experts in This Field

Autophagy is a fundamental process involved in regulating cellular homeostasis. Autophagy has been classically discovered as a cellular process that degrades cytoplasmic components non-selectively to produce energy. Over the past few decades, this process has been shown to work in energy production, as well as in the reduction of excessive proteins, damaged organelles, and membrane trafficking. It contributes to many human diseases, such as neurodegenerative diseases, carcinogenesis, diabetes mellitus, development, longevity, and reproduction. In this review, we provide important information for interpreting results related to autophagic experiments and present the role of autophagy in this field.

New N-Substituted-1,2,4-triazole Derivatives of Pyrrolo[3,4-d]pyridazinone with Significant Anti-Inflammatory Activity-Design, Synthesis and Complementary In Vitro, Computational and Spectroscopic Studies

Regarding that the chronic use of commonly available non-steroidal and anti-inflammatory drugs (NSAIDs) is often restricted by their adverse effects, there is still a current need to search for and develop new, safe and effective anti-inflammatory agents. As a continuation of our previous work, we designed and synthesized a series of 18 novel N-substituted-1,2,4-triazole-based derivatives of pyrrolo[3,4-d]pyridazinone 4a-c-9a-c. The target compounds were afforded via a convenient way of synthesis, with good yields. The executed cell viability assay revealed that molecules 4a-7a, 9a, 4b-7b, 4c-7c do not exert a cytotoxic effect and were qualified for further investigations. According to the performed in vitro test, compounds 4a-7a, 9a, 4b, 7b, 4c show significant cyclooxygenase-2 (COX-2) inhibitory activity and a promising COX-2/COX-1 selectivity ratio. These findings are supported by a molecular docking study which demonstrates that new derivatives take position in the active site of COX-2 very similar to Meloxicam. Moreover, in the carried out in vitro evaluation within cells, the title molecules increase the viability of cells pre-incubated with the pro-inflammatory lipopolysaccharide and reduce the level of reactive oxygen and nitrogen species (RONS) in induced oxidative stress. The spectroscopic and molecular modeling study discloses that new compounds bind favorably to site II(m) of bovine serum albumin. Finally, we have also performed some in silico pharmacokinetic and drug-likeness predictions. Taking all of the results into consideration, the molecules belonging to series a (4a-7a, 9a) show the most promising biological profile.

Cell death mechanisms and their roles in pregnancy related disorders

Autophagy and apoptosis are catabolic pathways essential for homeostasis. They play a crucial role for normal placental and fetal development. These cell death mechanisms are exaggerated in placental disorders such as preeclampsia, intrauterine growth restriction (IUGR) and gestational diabetes mellitus (GDM). Apoptosis is widely studied, highly controlled and regulated whereas; autophagy is an orderly degradation and recycling of the cellular components. Cellular senescence may be initiated by a variety of stimuli, including hypoxia, oxidative stress, reduction in survival signals and nutrition deprivation. Apoptosis is regulated by two types of pathways intrinsic and extrinsic. Extrinsic pathway is initiated by apoptosis inducing cells such as macrophages, natural killer cells whereas; intrinsic pathway is initiated in response to DNA damage, cell injury and lack of oxygen. In autophagy, the cell or organelles undergo lysosomal degradation. Placental apoptosis increases as the gestation progresses while autophagy plays a role in trophoblast differentiation and invasion. In pregnancy disorders like preeclampsia and IUGR, proapoptotic markers such as caspase 3, 8, BAX are higher and antiapoptotic markers like Bcl-2 are lower. In GDM, apoptotic markers are reduced resulting in increased placental mass and fetal macrosomia. Apoptosis in the pathological pregnancies is also influenced by the reduced levels of micronutrients and long chain polyunsaturated fatty acids resulting in disturbed placental biology. This chapter describes the role of various key molecular events involved in cellular senescence and the various factors influencing them. This will help identify future therapeutic strategies for better management of these processes.

α-Solanine Causes Cellular Dysfunction of Human Trophoblast Cells via Apoptosis and Autophagy

The trophoblast, an embryonic tissue, exerts a crucial role in the processes of implantation and placentation. Toxins in food can cause malfunction of trophoblasts, resulting in apoptosis, oxidative stress, and abnormal angiogenesis. α-solanine, a steroidal glycoalkaloid, has antitumor properties on several cancer cells. However, its effect on human trophoblasts has not been elucidated. In this study, human extravillous trophoblast HTR-8/SVneo cells were exposed to α-solanine. Cellular functions including proliferation, migration, invasion, tube formation, and apoptosis were assessed. To monitor autophagic flux, trophoblasts were transfected with a mCherry-GFP-LC3B vector using lentiviral transduction, and expression of autophagy-related biomarkers including Beclin 1, Atgl3, and microtubule-associated protein 1 light chain-3 (MAP1-LC3) were detected. The results show that application of 20 μM α-solanine or above inhibited the cell viability, migration, invasion, and tube formation of the human trophoblast. Cell cycle was arrested at S and G2/M phases in response to 30 μM α-solanine. α-solanine induced apoptosis of HTR-8/SVneo cells and triggered autophagy by increasing the autophagic gene expression and stimulating the formation of autophagosome and autophagic flux. In conclusion, α-solanine can impair the functions of human trophoblast cells via activation of cell apoptosis and autophagy.

Design, Synthesis and Comprehensive Investigations of Pyrrolo[3,4-d]pyridazinone-Based 1,3,4-Oxadiazole as New Class of Selective COX-2 Inhibitors

The long-term use of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) in treatment of different chronic inflammatory disorders is strongly restricted by their serious gastrointestinal adverse effects. Therefore, there is still an urgent need to search for new, safe, and efficient anti-inflammatory agents. Previously, we have reported the Mannich base-type derivatives of pyrrolo[3,4-d]pyridazinone which strongly inhibit cyclooxygenase, have better affinity to COX-2 isoenzyme and exert promising anti-oxidant activity. These findings encouraged us to perform further optimization of that structure. Herein, we present the design, synthesis, molecular docking, spectroscopic, and biological studies of novel pyrrolo[3,4-d]pyridazinone derivatives bearing 4-aryl-1-(1-oxoethyl)piperazine pharmacophore 5a,b-6a,b. The new compounds were obtained via convenient, efficient, one-pot synthesis. According to in vitro evaluations, novel molecules exert no cytotoxicity and act as selective COX-2 inhibitors. These findings stay in good correlation with molecular modeling results, which additionally showed that investigated compounds take a position in the active site of COX-2 very similar to Meloxicam. Moreover, all derivatives reduce the increased level of reactive oxygen and nitrogen species and prevent DNA strand breaks caused by oxidative stress. Finally, performed spectroscopic and molecular docking studies demonstrated that new compound interactions with bovine serum albumin (BSA) are moderate, formation of complexes is in one-to-one ratio, and binding site II (subdomain IIIA) is favorable.

Cyclooxygenase 2 as a Marker of Early Pregnancy Loss in Cytomegalovirus Infection

Background. Increased expression of cyclooxygenase 2 in the placenta plays a significant role in the formation of placental disorders in the pathological course of pregnancy. It was shown that a high level of expression of cyclooxygenase 2 leads to excessive synthesis of prostaglandins, which stimulate the contractile activity of the uterine myometrium and trigger the abortion mechanism. An analysis of modern literature has shown a lack of data proving the involvement of cyclooxygenase 2 in the pathogenesis of early miscarriages in cytomegalovirus infection. Objective. To establish the pathogenetic role of cyclooxygenase 2 in early pregnancy in the course of miscarriage during exacerbation of cytomegalovirus infection. Materials and methods. The study included 86 women with a gestational age of 8–12 weeks, of which 46 women with spontaneous abortion (O03) and exacerbation of cytomegalovirus infection (main group) and 40 women with medical abortion (O04) without cytomegalovirus infection (control group). The material for the study was peripheral blood serum, urine, homogenate of the villous chorion of the placental tissue. The content of cyclooxygenase 2, the level of IgM and IgG antibodies to cytomegalovirus, low-type IgG antibodies to cytomegalovirus (avidity index) were analyzed by enzyme-linked immunosorbent assay; the content of arachidonic acid – by capillary gas-liquid chromatography. Results. During the study, women of the main group found an increase in the concentration of arachidonic acid by 59 % (p < 0.001) and the activity of the lipolytic enzyme cyclooxygenase 2 – by 58 % (p < 0.001) in the placenta villous chorion homogenate. Conclusion. With an exacerbation of cytomegalovirus infection in the homogenate of the villous placenta chorion of pregnant women with spontaneous abortion, an increase in the content of arachidonic acid and the level of cyclooxygenase 2 is observed. An increased level of cyclooxygenase 2 indicates the development of pregnancy complications and can be used as a non-specific marker predictor of pregnancy termination during exacerbation of cytosis.

Stereological study of the placental structure in abortion-prone mice model (CBA/J×DBA/2J)

Recurrent spontaneous abortion (RSA) is an important reproductive health issue defined as the loss of two or more consecutive pregnancies before the 20th week of gestation, affecting 2-5% of couples. This study aimed to evaluate the volume, number of cells, and length of the vessels in the placenta in normal and abortion-prone (AP) pregnant mice on gestational day (gd) 13.5. Fetal and placental tissues of female CBA/J mated DBA/2J (AP group) and BALB/c (normal pregnant group) were collected and prepared for stereological assessments on gd13.5. The volumes of the placenta and its main layers decidua basalis (Db), junctional zone (Jz), and labyrinth zone (Lz) were investigated. The number of spongiotrophoblast cells, glycogen cells, giant cells, trophoblast cells, lymphocytes, and neutrophils were estimated as well. The AP group showed a reduction in the volume of the placenta (48.7%) and its components. Moreover, the number of spongiotrophoblast cells (66.7%), glycogen cells (76.2%), giant cells (73.3%), and trophoblast cells (81.4%) was decreased in AP compared to normal pregnant (NP) mice. Also, in AP group recognized a 10-fold increase in the number of lymphocytes and a four-fold increase in the number of neutrophils in comparison to the NP group (p < 0.05). Activation of different immune cell types might induce systemic inflammation at the feto-maternal interface, resulting in impaired placenta formation and abortion.

Placental development and function in trisomy 21 and mouse models of Down syndrome: Clues for studying mechanisms underlying atypical development

Down syndrome (DS) is the most common genetic disorder leading to developmental disability. The phenotypes associated with DS are complex and vary between affected individuals. Placental abnormalities in DS include differences in cytotrophoblast fusion that affect subsequent conversion to syncytiotrophoblast, atypical oxidative stress/antioxidant balance, and increased expression of genes that are also upregulated in the brains of individuals with Alzheimer's disease. Placentas in DS are prematurely senescent, showing atypical evidence of mineralization. Fetuses with DS are especially susceptible to adverse obstetric outcomes, including early in utero demise, stillbirth and growth restriction, all of which are related to placental function. The placenta, therefore, may provide key insights towards understanding the phenotypic variability observed in individuals with DS and aid in identifying biomarkers that can be used to evaluate phenotypic severity and prenatal treatments in real time. To address these issues, many different mouse models of DS have been generated to identify the mechanisms underlying developmental changes in many organ systems. Little is known, however, regarding placental development in the currently available mouse models of DS. Based upon the relative paucity of data on placental development in preclinical mouse models of DS, we recommend that future evaluation of new and existing models routinely include histologic and functional assessments of the placenta. In this paper we summarize studies performed in the placentas of both humans and mouse models with DS, highlighting gaps in knowledge and suggesting directions for future research.

Anti-inflammatory effects of mesenchymal stem cell-derived exosomal microRNA-146a-5p and microRNA-548e-5p on human trophoblast cells

Human umbilical cord mesenchymal stem cells (MSCs) have been reported to improve the migration and invasion of trophoblast cells; however, little is known about whether MSC-derived exosomes and exosomal miRNAs can regulate trophoblast cell properties. In this study, we investigated whether exosomal miRNAs from amniotic fluid-derived MSC (AF-MSC) could regulate the inflammatory response of the human trophoblast cell line HTR8/SVneo. We verified the anti-inflammatory effects of AF-MSCs on lipopolysaccharide (LPS)-induced inflammatory trophoblast cells and found that miR-146a-5p and miR-548e-5p in the AF-MSC–derived exosomes regulate nuclear factor κB, AKT and mitogen-activated protein kinase protein phosphorylation. Furthermore, we found that the transfection of human trophoblast cells with miR-146a-5p and miR-548e-5p inhibitors reduced trophoblast migration (P &lt; 0.05 vs control) and the expression of proliferating cell nuclear antigen, a protein essential for cell proliferation (P &lt; 0.01 vs control). In particular, the miR-548e-5p inhibitor induced apoptosis, while tumor necrosis factor receptor–associated factor 6, a predicted target of miR-146a-5p and miR-548e-5p, was involved in the regulation of oxidative stress in the human trophoblast cells. In a mouse model of LPS-induced preterm birth (PB), miR-146a-5p expression was found to be relatively low in the group in which the effect of AF-MSCs was insignificant. However, this study is limited in that the changes in the expression of some genes in response to AF-MSCs differ between the cell line and mouse model. Collectively, these data show that exosomal miR-146a-5p and miR-548e-5p from AF-MSCs have anti-inflammatory effects on human trophoblast cells and may be novel targets for treating inflammatory diseases and associated problems that occur during pregnancy, such as PB.

Conditional loss of ERK1 and ERK2 results in abnormal placentation and delayed parturition in the mouse

Extracellular-signal-regulated kinases (ERK) 1 and 2 regulate many aspects of the hypothalamic-pituitary-gonadal axis. We sought to understand the role of ERK1/2 signaling in cells expressing a Cre allele regulated by the endogenous GnRHR promoter (GRIC-ERKdko). Adult female GRIC-ERKdko mice were hypogonadotropic and anovulatory. Gonadotropin administration and mating led to pregnancy in one-third of the ERKdko females. Litters from ERKdko females and pup weights were reduced coincident with delayed parturition and 100% neonatal mortality. Based on this, we examined Cre expression in implantation sites as a potential mechanism. GnRHR mRNA levels at e10.5 and e12.5 were comparable to pituitary levels from adult female mice at proestrus and GnRHR mRNA in decidua was enriched compared to whole implantation site. In vivo studies confirmed recombination in decidua, and GRIC-ERKdko placentas showed reduced ERK2 expression. Histopathology revealed abnormalities in placental architecture in the GRIC-ERKdko animals. Regions of apoptosis at the decidual/uterine interface at e18.5 were observed in control animals but apoptotic tone in these regions was reduced in ERKdko animals. These studies support a potential model of ERK-dependent signaling within the implantation site leading to loss of placental architecture and mis-regulation of apoptotic events at parturition occurring coincident with prolonged gestation and neonatal mortality.

Exploring the druggable space around the Fanconi anemia pathway using machine learning and mechanistic models

BACKGROUND

In spite of the abundance of genomic data, predictive models that describe phenotypes as a function of gene expression or mutations are difficult to obtain because they are affected by the curse of dimensionality, given the disbalance between samples and candidate genes. And this is especially dramatic in scenarios in which the availability of samples is difficult, such as the case of rare diseases.

RESULTS

The application of multi-output regression machine learning methodologies to predict the potential effect of external proteins over the signaling circuits that trigger Fanconi anemia related cell functionalities, inferred with a mechanistic model, allowed us to detect over 20 potential therapeutic targets.

CONCLUSIONS

The use of artificial intelligence methods for the prediction of potentially causal relationships between proteins of interest and cell activities related with disease-related phenotypes opens promising avenues for the systematic search of new targets in rare diseases.

Maternal vitamin D deficiency increases the thromboxane/prostacyclin ratio through alterations in the one-carbon cycle in Wistar rats

This study aims to test the hypothesis that vitamin D deficiency can influence long-chain polyunsaturated fatty acid metabolism through alterations in the one-carbon cycle. Wistar rats (n = 8 per group) were given either a control (1,000 IU D3/kg diet) or a vitamin D deficient (VDD) (0 IU D3/kg diet) diet from pre-pregnancy to delivery. On day 20 of gestation, pregnant female rats were delivered by C-section to collect placenta and blood. VDD group demonstrated high serum parathyroid hormone, low serum phosphate, low plasma folate, higher plasma homocysteine, and higher plasma malondialdehyde levels (P < 0.05 for all) as compared to control. Lower protein levels of placental cystathionine-β-synthase enzyme (P < 0.05) were observed in the VDD group as compared to control. VDD group demonstrated higher placental mRNA levels of the enzymes phospholipase A₂ and cyclooxygenase-2 (P < 0.05 for both) as compared to control. Protein levels of the enzymes phospholipase A₂ and cyclooxygenase-2 were lower (P < 0.05 for both) in the VDD group as compared to the control group. The ratio of thromboxane B₂ and 6-keto prostaglandin F_1α in serum was higher (P < 0.05) in the VDD group as compared to control; although the serum levels of 6-keto prostaglandin F_1α and thromboxane B₂ were similar in both the groups. Our findings suggest that increased oxidative stress due to maternal vitamin D deficiency results in the imbalance between the vasoconstrictor (thromboxane B₂ ) and vasodilator (6-keto prostaglandin F_1α ) eicosanoids, which may lead to endothelial dysfunction and poor pregnancy outcome. © 2019 BioFactors, 45 (4):548-555, 2019.

Epigenetically dysregulated genes and pathways implicated in the pathogenesis of non-syndromic high myopia

Myopia, commonly referred to as nearsightedness, is one of the most common causes of visual disability throughout the world. It affects more people worldwide than any other chronic visual impairment condition. Although the prevalence varies among various ethnic groups, the incidence of myopia is increasing in all populations across globe. Thus, it is considered a pressing public health problem. Both genetics and environment play a role in development of myopia. To elucidate the epigenetic mechanism(s) underlying the pathophysiology of high-myopia, we conducted methylation profiling in 18 cases and 18 matched controls (aged 4–12 years), using Illumina MethylationEPIC BeadChips array. The degree of myopia was variable among subjects, ranging from −6 to −15D. We identified 1541 hypermethylated CpGs, representing 1745 genes (2.0-fold or higher) (false discovery rate (FDR) p ≤ 0.05), multiple CpGs were p < 5 × 10⁻⁸ with a receiver operating characteristic area under the curve (ROC-AUC) ≥ 0.75 in high-myopia subjects compared to controls. Among these, 48 CpGs had excellent correlation (AUC ≥ 0.90). Herein, we present the first genome-wide DNA methylation analysis in a unique high-myopia cohort, showing extensive and discrete methylation changes relative to controls. The genes we identified hold significant potential as targets for novel therapeutic intervention either alone, or in combination.

Maternal one carbon metabolism through increased oxidative stress and disturbed angiogenesis can influence placental apoptosis in preeclampsia

Adequate maternal nutrition is critical for a healthy pregnancy outcome and poor maternal nutrition is known to be associated with pregnancy complications like preeclampsia. We have earlier demonstrated that there is an imbalance in the levels of micronutrients (folate and vitamin B₁₂) along with low levels of long chain polyunsaturated fatty acids (LCPUFA) and high homocysteine levels in women with preeclampsia. Homocysteine is known to be involved in the formation of free radicals leading to increased oxidative stress. Higher oxidative stress has been shown to be associated with increased apoptotic markers in the placenta. Preeclampsia is of placental origin and is associated with increased oxidative stress, disturbed angiogenesis and placental apoptosis. The process of angiogenesis is important for placental and fetal development and various angiogenic growth factors inhibit apoptosis by inactivation of proapoptotic proteins through a series of cellular signalling pathways. We propose that an altered one carbon cycle resulting in increased oxidative stress and impaired angiogenesis will contribute to increased placental apoptosis leading to preeclampsia. Understanding the association of one carbon cycle components and the possible mechanisms through which they regulate apoptosis will provide clues for reducing risk of pregnancy complications.

Immunological Tolerance, Pregnancy, and Preeclampsia: The Roles of Semen Microbes and the Father

Although it is widely considered, in many cases, to involve two separable stages (poor placentation followed by oxidative stress/inflammation), the precise originating causes of preeclampsia (PE) remain elusive. We have previously brought together some of the considerable evidence that a (dormant) microbial component is commonly a significant part of its etiology. However, apart from recognizing, consistent with this view, that the many inflammatory markers of PE are also increased in infection, we had little to say about immunity, whether innate or adaptive. In addition, we focused on the gut, oral and female urinary tract microbiomes as the main sources of the infection. We here marshall further evidence for an infectious component in PE, focusing on the immunological tolerance characteristic of pregnancy, and the well-established fact that increased exposure to the father's semen assists this immunological tolerance. As well as these benefits, however, semen is not sterile, microbial tolerance mechanisms may exist, and we also review the evidence that semen may be responsible for inoculating the developing conceptus (and maybe the placenta) with microbes, not all of which are benign. It is suggested that when they are not, this may be a significant cause of PE. A variety of epidemiological and other evidence is entirely consistent with this, not least correlations between semen infection, infertility and PE. Our view also leads to a series of other, testable predictions. Overall, we argue for a significant paternal role in the development of PE through microbial infection of the mother via insemination.

Lipopolysaccharide (LPS)-mediated priming of toll-like receptor 4 enhances oxidant-induced prostaglandin E2 biosynthesis in primary murine macrophages

Agonists and pseudo-agonists for toll-like receptor 4 (TLR4) are common in our environment. Thus, human exposure to these agents may result in "priming or sensitization" of TLR4. A body of evidence suggests that LPS-mediated sensitization of TLR4 can increase the magnitude of responses to exogenous agents in multiple tissues. We have previously shown that reactive oxygen and nitrogen species (RONS) stimulate TLR4. There is no evidence that LPS-primed TLR4 can influence the magnitude of responses to oxidants from either endogenous or exogenous sources. In the present study, we directly tested the hypothesis that LPS-primed TLR4 will sensitize primary murine peritoneal macrophages (pM) to oxidant-mediated prostaglandin E2 (PGE₂) production. We used potassium peroxychromate (PPC) and potassium peroxynitrite (PPN) as direct in vitro sources of exogenous RONS. Our results showed that a direct treatment with PPC or PPN alone as sources of exogenous oxidants had a limited effect on PGE₂ biosynthesis. In contrast, pM sensitized by prior incubation with LPS-EK, a TLR4-specific agonist, followed by oxidant stimulation exhibited increased transcriptional and translational expression of cyclooxygenase-2 (COX-2) with enhanced PGE₂ biosynthesis/production only in pM derived from TLR4-WT mice but not in TLR4-KO mice. Thus, we have shown a critical role for LPS-primed TLR4 in oxidant-induced inflammatory phenotypes that have the potential to initiate, propagate and maintain many human diseases.

CD39 and CD73 activity are protective in a mouse model of antiphospholipid antibody-induced miscarriages

OBJECTIVE

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder of young adults associated with devastating pregnancy complications (recurrent miscarriages, preeclampsia and low birth weight) and vascular complications including thrombosis. The key components implicated in pathogenesis of APS are the complement cascade and tissue factor (TF) activity causing inflammation and coagulation. Purinergic signalling involving catabolism of ATP to adenosine by cell-surface enzymes CD39 and CD73 has anti-inflammatory and anti-thrombotic effects. We studied whether activities of CD39 and CD73 are important in preventing the development of miscarriages in APS.

METHODS

We studied frequency of miscarriages and decidual pathology following passive transfer of human aPL-ab to pregnant wildtype mice, and mice deficient in CD39 and CD73, and also transgenic mice exhibiting 2-3X higher CD39 activity.

RESULTS

aPL-ab infusion in pregnant CD39-or CD73-knockout mice triggers an increase in miscarriages, associated with increased TF expression and complement deposition as well as elevated oxidative stress and pro-inflammatory TNF-α and IL-10 expression within the placental decidua. In contrast, aPL-ab induced miscarriages are prevented in mice over-expressing CD39, with reduced decidual TF expression and C3d deposition, diminished lipid peroxidation (4-hydroxynonenal or 4-HNE positive lipid adducts), and reduced TNF-α expression.

CONCLUSION

We demonstrate a protective role for CD39 in APS and provide rationale for both the development of endothelial cell-targeted soluble CD39 as a novel therapeutic for APS and analysis of perturbations in the purinergic pathway to explain human disease.

Selective Targeting of a Novel Vasodilator to the Uterine Vasculature to Treat Impaired Uteroplacental Perfusion in Pregnancy

Fetal growth restriction (FGR) in pregnancy is commonly caused by impaired uteroplacental blood flow. Vasodilators enhance uteroplacental perfusion and fetal growth in humans and animal models; however, detrimental maternal and fetal side effects have been reported. We hypothesised that targeted uteroplacental delivery of a vasodilator would enhance drug efficacy and reduce the risks associated with drug administration in pregnancy. Phage screening identified novel peptides that selectively accumulated in the uteroplacental vasculature of pregnant mice. Following intravenous injection, the synthetic peptide CNKGLRNK selectively bound to the endothelium of the uterine spiral arteries and placental labyrinth in vivo; CNKGLRNK-decorated liposomes also selectively bound to these regions. The nitric oxide donor 2-[[4-[(nitrooxy)methyl]benzoyl]thio]-benzoic acid methyl ester (SE175) induced significant relaxation of mouse uterine arteries and human placental arteries in vitro; thus, SE175 was encapsulated into these targeted liposomes and administered to healthy pregnant C57BL/6J mice or endothelial nitric oxide synthase knockout (eNOS-/-) mice, which exhibit impaired uteroplacental blood flow and FGR. Liposomes containing SE175 (0.44mg/kg) or PBS were administered on embryonic (E) days 11.5, 13.5, 15.5 and 17.5; fetal and placental weights were recorded at term and compared to mice injected with free PBS or SE175. Targeted uteroplacental delivery of SE175 had no effect on fetal weight in C57BL/6J mice, but significantly increased fetal weight and mean spiral artery diameter, and decreased placental weight, indicative of improved placental efficiency, in eNOS-/- mice; free SE175 had no effect on fetal weight or spiral artery diameter. Targeted, but not free SE175 also significantly reduced placental expression of 4-hydroxynonenal, cyclooxygenase-1 and cyclooxygenase-2, indicating a reduction in placental oxidative stress. These data suggest that exploiting vascular targeting peptides to selectively deliver SE175 to the uteroplacental vasculature may represent a novel treatment for FGR resulting from impaired uteroplacental perfusion.

Co-localization of microsomal prostaglandin E synthase-1 with cyclooxygenase-1 in layer II of murine placental syncytiotrophoblasts

The placenta is an organ that secretes prostaglandin (PG) E₂ into the fetal-placental circulation to regulate both vascular tone and remodeling of the fetal ductus arteriosus. Placental PGE₂ synthesis might be mediated by microsomal PGE synthase-1 (mPGES-1), in addition to cyclooxygenase (COX) isoforms. Thus, the purpose of this study is to clarify the temporal and spatial expression patterns of mPGES-1, together with COX-1 and COX-2, in murine placenta. We found that mPGES-1 and COX-1 protein levels continuously increased in the placental labyrinth from gestational day (GD) 13.5 to GD19.5, becoming higher than in the decidua or the junctional zone by GD17.5. The PGE₂ level at GD17.5 was also highest in the labyrinth. Immunofluorescence stainings for mPGES-1 and COX-1 in the labyrinth at GD17.5 overlapped and were located on the fetal side of the signals for connexin 26, which forms gap junctions between maternal-facing (SynT-I) and fetal-facing (SynT-II) syncytiotrophoblast layers, and on the maternal side of the signals for glucose transporter 1 on the basal plasma membrane of SynT-II. On the other hand, the signals for COX-2 did not overlap with those for mPGES-1. These results indicate that COX-1 and mPGES-1 are co-localized in murine placental SynT-II, facing the fetal-placental circulation. Therefore, SynT-II could contribute to placental synthesis of PGE₂ for release into the fetal-placental circulation.

Maternal diabetes impairs oxidative and inflammatory response in murine placenta

Placenta is the major exchange surface between mother and fetus and plays a pivotal role in fetal development. A better understanding of the mechanisms by which diabetes alters placental function may allow better management of diabetes pregnancies. In this study, we attempt to investigate the effect of diabetic milieu with and without malformation on placental function. In order to investigate the impact of diabetic pregnancy on oxidative stress, endothelial and vascular functions of placental tissue, we mated diabetic and non-diabetic female rats with normal male rats. At gestational day 17, we terminated pregnancy, assessed fetuses for malformations and isolated placenta for measurement of various parameters of placental function. Our results show that maternal diabetes induced a state of oxidative stress in placenta, which disrupts normal signaling, activating apoptosis, as well as perturbing endothelial and vascular placental functions. The coalescence of these insults on various levels of placental function could contribute to the pleiotropic nature of diabetes-induced placental stress.

Blastomere removal from cleavage-stage mouse embryos alters placental function, which is associated with placental oxidative stress and inflammation

Blastomere biopsy is an essential technique in preimplantation genetic diagnosis (PGD), a screening test that can detect genetic abnormalities of embryos before their transfer into uterus. Our results showed that the weights of fetuses derived from biopsied embryos were lower than that of non-biopsied counterparts at E12.5, E15.5, and E18.5. The ratio of fetal/placental (F/P) weights in the biopsied group was significantly lower than that in the non-biopsied group at E18.5. At E18.5, the mRNAs for selected glucose transporters, system A amino acid transporters, system L amino acid transporters, and imprinted genes were downregulated in the placentae of biopsied group, and the GLUT1 and CAT3 protein levels were decreased too. More apoptotic cells were detected by TUNEL in the placentae of biopsied group. Placentae from biopsied embryos exhibited lower levels of SOD and GSH. Furthermore, the concentration of MDA increased in the placentae from biopsied group. The levels of IL1B, IL6, and TNFA also significantly increased in the placentae of biopsied group. This study suggested that placental function may be sensitive to blastomere biopsy procedures, and placental oxidative stress and inflammation associated with blastomere biopsy may be critical factors of abnormal placental function and further influence the fetal development.

Mitochondrial - Endoplasmic reticulum interactions in the trophoblast: Stress and senescence

Placental stress has been implicated in the pathophysiology of complications of pregnancy, including growth restriction and pre-eclampsia. Initially, attention focused on oxidative stress, but recently mitochondrial and endoplasmic reticulum stress have been identified. Complex molecular interactions exist among these different forms of stress, making it unlikely that any occurs in isolation. In part, this is due to close physiological connections between the two organelles principally involved, mitochondria and the endoplasmic reticulum (ER), mediated through Ca²⁺ signalling. Here, we review the involvement of the mitochondria-ER unit in the generation of stress within the trophoblast, and consider consequences for obstetric outcome. Mild stress may induce adaptive responses, including upregulation of antioxidant defences and autophagy, while moderate levels may affect stem cell behaviour and reduce cell proliferation, contributing to the growth-restricted phenotype. High levels of stress can stimulate release of pro-inflammatory cytokines and anti-angiogenic factors, increasing the risk of pre-eclampsia. In addition, chronic stress may promote senescence of the trophoblast, which in other cell types leads to a pro-inflammatory senescence-associated secretory phenotype. Evidence from rodents suggests that a degree of trophoblastic stress develops with increasing gestational age in normal pregnancies. The increase in maternal concentrations of soluble fms-like tyrosine kinase-1 (sFlt-1) and reduction in placental growth factor (PlGF) suggest the same may occur in the human, starting around 30 weeks of pregnancy. Placental malperfusion, or co-existing maternal conditions, such as diabetes, will exacerbate that stress. Amelioration of trophoblastic stress should remain a research priority, but will be difficult due to the complexity of the molecular pathways involved.

Intrauterine trophoblast migration: A comparative view of humans and rodents

Trophoblast migration and invasion through the decidua and maternal uterine spiral arteries are crucial events in placentation. During this process, invasive trophoblast replace vascular endothelial cells as the uterine arteries are remodeled to form more permissive vessels that facilitate adequate blood flow to the growing fetus. Placentation failures resulting from either extensive or shallow trophoblastic invasion can cause pregnancy complications such as preeclampsia, intrauterine growth restriction, placenta creta, gestational trophoblastic disease and even maternal or fetal death. Consequently, the use of experimental animal models such as rats and mice has led to great progress in recent years with regards to the identification of mechanisms and factors that control trophoblast migration kinetics. This review aims to perform a comparative analysis of placentation and the mechanisms and factors that coordinate intrauterine trophoblast migration in humans, rats and mice under physiological and pathological conditions.

Role of nuclear factor kappa beta, tumor necrosis factor α, and cyclooxygenase-2 in preterm labor

Background: The pathway of tumor necrosis factor alpha (TNFα), nuclear factor kappa beta (NF-κB), and cyclooxygenase-2 (COX-2) activation in releasing prostaglandins is suggested to be crucial for initiating labor in the pathogenesis of preterm labor. The aim of the study was to know whether there were mean differences of NF-κB, TNFα, and COX-2 expressions between preterm and term labor and also to know the correlation among them in preterm labor.Methods: A case-control study was performed from May 2013 to February 2014 in Arifin Achmad Hospital, Pekanbaru. There were 30 subjects with preterm labor as cases and 30 with normal labor as controls. All subjects had singleton gestation with maximum parity was three, age limit of 35 year-old, and spontaneous labor in both groups. Placental tissue was collected from all subjects and evaluated with hematoxylin eosin staining. The expressions of TNFα, NF-κB, and COX-2 in the tissue were assessed with immunohistochemical staining by counting the percentage of smeared cells by two experts. The expressions of TNFα, NF-κB, and COX-2 between case and control were compared using t-test and the correlation was analyzed with Pearson correlation coefficient.Results: Mean (SD) of expressions of TNFα (93.05% [12.68] vs 49.11% [27.33]), NF-κB (42.46% [27.29] vs 13.66% [17.77]), and COX-2 (88.75% [10.86] vs 46% [30.36]) were significantly higher in the preterm labor compared to term labor (p = 0.001). There was significant correlation between TNFα and NF-κB expression (r = 0.385; p = 0.036) and no correlation was found between NF-κB and COX-2 (p = 0.982) in preterm labor.Conclusion: High expressions of TNFα, NF-κB, and COX-2 in preterm labor showed to contribute in the onset of preterm labor. High TNFα may suggest that infection was a leading cause of preterm labor. This is supported with an increase in NF-κB activation will increase COX-2 and subsequently prostaglandins that result in premature labor.

Aspirin inhibits expression of sFLT1 from human cytotrophoblasts induced by hypoxia, via cyclo-oxygenase 1

INTRODUCTION

Elevated circulating soluble FLT1 (sFLT1) levels seen in preeclampsia may play a role in its development. Aspirin is recommended for prevention of preeclampsia. We hypothesized that aspirin may inhibit the production of sFlt1.

METHODS

Placentas from women with and without preeclampsia were collected. Primary cytotrophoblasts (CTBs) were cultured from normal placentas and treated with aspirin, sc-560, a COX1 inhibitor or celecoxib, a COX2 inhibitor. The expression of sFLT1, FLT1, COX1 and COX2 was studied. The effect of aspirin on sFlt1 expression was also studied in HEK293 cells and in HTR-8/SVNeo cells.

RESULTS

The expression of sFLT1 was increased in preeclamptic placentas compared to control placentas and the expression and release of sFLT1 increased in CTBs exposed to 2% O2 compared to controls. Aspirin at 3 and 12 mM concentration reduced the expression and release of sFLT1 in CTBs. Aspirin also inhibited sFlt1 expression from HTR-8/SVNeo and HEK293 cells. Sc-560, but not celecoxib, reduced sFLT1 expression and release from CTBs. Aspirin and sc-560 also reduced hypoxia-induced FLT1 mRNA expression and inhibited COX1 mRNA in CTBs.

DISCUSSION

This study confirms that sFLT1 expression is increased in preeclamptic placentas and in CTBs exposed to hypoxia. Aspirin inhibits the production sFLT1 in CTBs and in HTR-8/SVNeo. Sc-560 recapitulated the effects of aspirin on sFLT1 expression and release in CTBs suggesting that the aspirin effect may be mediated via inhibition of COX1. The study increases our understanding of the mechanisms regulating sFlt1 expression and provides a plausible explanation for the effect of aspirin to prevent preeclampsia.

Endoplasmic reticulum stress is induced in the human placenta during labour

Placental endoplasmic reticulum (ER) stress has been postulated in the pathophysiology of pre-eclampsia (PE) and intrauterine growth restriction (IUGR), but its activation remains elusive. Oxidative stress induced by ischaemia/hypoxia-reoxygenation activates ER stress in vitro. Here, we explored whether exposure to labour represents an in vivo model for the study of acute placental ER stress. ER stress markers, GRP78, P-eIF2α and XBP-1, were significantly higher in laboured placentas than in Caesarean-delivered controls localised mainly in the syncytiotrophoblast. The similarities to changes observed in PE/IUGR placentas suggest exposure to labour can be used to investigate induction of ER stress in pathological placentas.

Role of lectin-like oxidized low density lipoprotein-1 in fetoplacental vascular dysfunction in preeclampsia

The bioavailability of nitric oxide (NO) represents a key marker in vascular health. A decrease in NO induces a pathological condition denominated endothelial dysfunction, syndrome observed in different pathologies, such as obesity, diabetes, kidney disease, cardiovascular disease, and preeclampsia (PE). PE is one of the major risks for maternal death and fetal loss. Recent studies suggest that the placenta of pregnant women with PE express high levels of lectin-like oxidized LDL receptor-1 (LOX-1), which induces endothelial dysfunction by increasing reactive oxygen species (ROS) and decreasing intracellular NO. Besides LOX-1 activation induces changes in migration and apoptosis of syncytiotrophoblast cells. However, the role of this receptor in placental tissue is still unknown. In this review we will describes the physiological roles of LOX-1 in normal placenta development and the potential involvement of this receptor in the pathophysiology of PE.

Paraoxonase 2 protein is spatially expressed in the human placenta and selectively reduced in labour

Humans parturition involves interaction of hormonal, neurological, mechanical stretch and inflammatory pathways and the placenta plays a crucial role. The paraoxonases (PONs 1-3) protect against oxidative damage and lipid peroxidation, modulation of endoplasmic reticulum stress and regulation of apoptosis. Nothing is known about the role of PON2 in the placenta and labour. Since PON2 plays a role in oxidative stress and inflammation, both features of labour, we hypothesised that placental PON2 expression would alter during labour. PON2 was examined in placentas obtained from women who delivered by cesarean section and were not in labour and compared to the equivalent zone of placentas obtained from women who delivered vaginally following an uncomplicated labour. Samples were obtained from 12 sites within each placenta: 4 equally spaced apart pieces were sampled from the inner, middle and outer placental regions. PON2 expression was investigated by Western blotting and real time PCR. Two PON2 forms, one at 62 kDa and one at 43 kDa were found in all samples. No difference in protein expression of either isoform was found between the three sites in either the labour or non-labour group. At the middle site there was a highly significant decrease in PON2 expression in the labour group when compared to the non-labour group for both the 62 kDa form (p = 0.02) and the 43 kDa form (p = 0.006). No spatial differences were found within placentas at the mRNA level in either labour or non-labour. There was, paradoxically, an increase in PON2 mRNA in the labour group at the middle site only. This is the first report to describe changes in PON2 in the placenta in labour. The physiological and pathological significance of these remains to be elucidated but since PON2 is anti-inflammatory further studies are warranted to understand its role.

The expression of thioredoxin-1 in preterm delivery placenta

Preterm delivery (PTD) is the leading cause of infant mortality and morbidity. However, the mechanism at the molecular level is still unknown. Placental inflammatory response and oxidative stress are associated with PTD. Thioredoxin-1 (TRX-1) regulates oxidative stress, inflammation, and the activities of transcription factors.

OBJECTIVES

The objective was to detect in placental tissues the expressions of TRX-1 and the TRX-1-related molecules: tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), thioredoxin-1-binding protein-2 (TBP-2), hypoxia inducible transcription factor 1α (HIF-1α), and forkhead box protein O3A (FoxO3A).

METHODS

PTD was defined as gestation of <37 weeks and term delivery (TD) as ≥37 weeks. The expressions of TRX-1 and TRX-1-related molecules were examined in placental tissues by real-time polymerase chain rection and western blot.

RESULTS

The expressions of TRX-1, TNF-α, COX-2, HIF-1α, and FoxO3A in the placenta of PTD were significantly higher as compared with TD, but no difference was observed in TBP-2 expression.

DISCUSSION

These results indicate that TRX-1 may be adaptively induced by the effects of inflammation and oxidative stress, suggesting protective roles for TRX-1 against these effects in the placenta of PTD.

NADPH oxidase as an important source of reactive oxygen species at the mouse maternal-fetal interface: putative biological roles

Oxygen derivatives that comprise the large family of reactive oxygen species (ROS) are actively involved in placental biology. They are generated at the maternal-fetal interface at the level of decidual, trophoblast and mesenchymal components. In normal conditions, ROS produced in low concentrations participate in different functions as signalling molecules, regulating activation of redox-sensitive transcription factors and protein kinases involved in cell survival, proliferation and apoptosis, hence much of cell functioning. Physiological ROS generation is also associated with such defence mechanisms as phagocytosis and microbiocidal activities. In mice, particularly but not exclusively, trophoblast cells phagocytose intensively during implantation and post-implantation periods and express enzymic machinery to address a ROS-producing response to changes in the environment. The cells directly associated with ROS production are trophoblast giant cells, which mediate each and every relationship with the maternal organism. In this review, the production of ROS by the implanting mouse trophoblast is discussed, focusing on NADPH oxidase expression, regulatory mechanisms and similarities with NOX2 from phagocytes. Some of the current controversies are assessed by attempting to integrate data from studies in human trophoblast and mouse models.

Fetal growth restriction in hypothyroidism is associated with changes in proliferative activity, apoptosis and vascularisation of the placenta

The objective of this study was to evaluate fetal weight, histomorphometric changes and proliferative activity, apoptosis and angiogenesis of the placenta in rats with hypothyroidism. Thirty-six adult female rats were divided into two groups with 18 animals each: control and hypothyroidism. Hypothyroidism was induced by daily administration of propylthiouracil (1 mg/animal). The administration began five days before becoming pregnant and the animals were sacrificed at 14 or 19 days of gestation. The control group received a placebo. The number and weight of fetuses and the rate of fetal death was determined, as well as the morphometric characteristics, the immunohistochemical expression of cell division control protein 47 (CDC)-47 and vascular endothelial growth factor (VEGF) and the number of apoptotic cells in the placental disk. The data were analysed by Mann–Whitney U test. Hypothyroidism reduced the weight of fetuses and of the uterus and placenta (P < 0.05), altered the thickness of the placental labyrinth and spongiotrophoblast (P < 0.05), increased the population of glycogen cells in the spongiotrophoblast (P < 0.05), interfered with the vascular development of the placental labyrinth and decreased VEGF expression (P < 0.05), reduced the expression of CDC-47 and cellularity and increased the apoptotic rate in the placental disk (P < 0.05). We conclude that hypothyroidism affects fetal weight by altering the proliferative activity, apoptosis and vascularisation of the placenta.

Placental inflammation and oxidative stress in the mouse model of assisted reproduction

Higher rates of low birth weight and prematurity are observed in pregnancies generated with assisted reproduction technologies (ART). Both conditions have been associated with placental inflammation and oxidative stress. Since placental and fetal levels of progesterone, a major anti-inflammatory steroid, are decreased in murine ART, we investigated placental inflammation and oxidative stress in this model as potential mediators of negative birth outcomes. After generating mouse pregnancies by in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) we evaluated the antioxidant defense network and major inflammatory cytokines in maternal, placental and fetal tissues. Additionally, placentas were analyzed for total lipid levels, fibrosis, apoptosis, reactive oxygen species and integrity of intracellular nucleotides. Placentas from ART contained significantly less lipids, with greater levels of apoptosis and degraded nucleotides. Placentas from ICSI pregnancies had lower activities of superoxide dismutase (SOD), thioredoxin reductase (TrxR), xanthine oxidase (XO), catalase, glutathione-S-transferase (GST) glutathione peroxidase, and glutathione reductase (GR). Furthermore, GR, GST and SOD were also lower in fetal livers from ICSI pregnancies. Placentas from IVF pregnancies had decreased levels of SOD, TrxR and XO only. In placentas from both ICSI and IVF pregnancies IL-6 levels were significantly increased. These data suggest that ART is associated with placental inflammation (IL-6), oxidative stress and apoptosis but not fibrosis or remodeling. These effects are markedly greater with the ICSI technique. Since ICSI is ubiquitous, oxidative stress and placental inflammation associated with this method may be a critical factor in negative birth outcomes such as prematurity and low birth weight.

Chronic treatment with vitamin D lowers arterial blood pressure and reduces endothelium-dependent contractions in the aorta of the spontaneously hypertensive rat

Vitamin D has cardiovascular protective effects besides regulating calcium homeostasis. To examine the chronic in vivo effect of a physiological dose of 1,25-dihydroxyvitamin D(3) on the occurrence of endothelium-dependent contractions, spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) were treated with the vitamin D derivative for 6 wk. The serum 1,25-dihydroxyvitamin D(3) level of both treated WKY and SHR was significantly higher than in untreated rats while the mean arterial blood pressure of the treated SHR was significantly lower than that of control SHR. Aortic rings with or without endothelium were studied in conventional organ chambers for isometric force measurement. Confocal microscopy was used to measure the cytosolic free calcium concentration (with the fluorescent dye fluo 4) and reactive oxygen species (ROS; with dichlorodihydrofluorescein diacetate). Reverse transcription PCR and Western blotting were used to determine the mRNA and protein expression level of cyclooxygenase-1 (COX-1), prostacyclin synthase, and thromboxane synthase. The endothelium-dependent concentration-contraction curves to both acetylcholine- and A-23187-induced contractions were shifted to the right in aortas from treated SHR but not from treated WKY. The chronic treatment normalized the relaxations of contracted preparations to acetylcholine. There were no significant differences in the increases in cytosolic free calcium concentration evoked by acetylcholine and A-23187 between control and treated groups. The endothelial ROS level was higher in SHR than WKY aortas and reduced by the chronic treatment. The gene and protein expression studies indicated that the overexpression of COX-1 observed in SHR aorta was reduced by the chronic treatment. These results demonstrate that chronic treatment with 1,25-dihydroxyvitamin D(3) modulates vascular tone and this modulation is accompanied by a lowered blood pressure, reduced expression of COX-1 mRNA and protein, and reduced ROS level in SHR. The reduction in endothelium-dependent contractions does not involve the surge in endothelial cytosolic calcium concentration that initiates the contractions.

Iron behaving badly: inappropriate iron chelation as a major contributor to the aetiology of vascular and other progressive inflammatory and degenerative diseases

BACKGROUND

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular 'reactive oxygen species' (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation.

REVIEW

We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation).The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible.This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, since in some circumstances (especially the presence of poorly liganded iron) molecules that are nominally antioxidants can actually act as pro-oxidants. The reduction of redox stress thus requires suitable levels of both antioxidants and effective iron chelators. Some polyphenolic antioxidants may serve both roles.Understanding the exact speciation and liganding of iron in all its states is thus crucial to separating its various pro- and anti-inflammatory activities. Redox stress, innate immunity and pro- (and some anti-)inflammatory cytokines are linked in particular via signalling pathways involving NF-kappaB and p38, with the oxidative roles of iron here seemingly involved upstream of the IkappaB kinase (IKK) reaction. In a number of cases it is possible to identify mechanisms by which ROSs and poorly liganded iron act synergistically and autocatalytically, leading to 'runaway' reactions that are hard to control unless one tackles multiple sites of action simultaneously. Some molecules such as statins and erythropoietin, not traditionally associated with anti-inflammatory activity, do indeed have 'pleiotropic' anti-inflammatory effects that may be of benefit here.

CONCLUSION

Overall we argue, by synthesising a widely dispersed literature, that the role of poorly liganded iron has been rather underappreciated in the past, and that in combination with peroxide and superoxide its activity underpins the behaviour of a great many physiological processes that degrade over time. Understanding these requires an integrative, systems-level approach that may lead to novel therapeutic targets.

Human milk enhances antioxidant defenses against hydroxyl radical aggression in preterm infants

BACKGROUND

Preterm infants endowed with an immature antioxidant defense system are prone to oxidative stress. Hydroxyl radicals are very aggressive reactive oxygen species that lack specific antioxidants. These radicals cannot be measured directly, but oxidation byproducts of DNA or phenylalanine in urine are reliable markers of their activity. Human milk has a higher antioxidant capacity than formula.

OBJECTIVE

We hypothesized that oxidative stress associated with prematurity could be diminished by feeding human milk.

DESIGN

We recruited a cohort of stable preterm infants who lacked perinatal conditions associated with oxidative stress; were not receiving prooxidant or antioxidant drugs, vitamins, or minerals before recruitment; and were fed exclusively human milk (HM group) or preterm formula (PTF group). Collected urine was analyzed for oxidative bases of DNA [8-hydroxy-2'-deoxyguanosine (8-oxodG)/2'-deoxyguanosine (2dG) ratio] and oxidative derivatives of phenylalanine [ortho-tyrosine (o-Tyr)/Phe ratio] by HPLC coupled to tandem mass spectrometry. Healthy term newborn infants served as control subjects.

RESULTS

Both preterm groups eliminated greater amounts of metabolites than did the control group. However, the PTF group eliminated significantly (P < 0.02) higher amounts of 8-oxodG (8-oxodG/2dG ratio: 10.46 +/- 3.26) than did the HM group (8-oxodG/2dG ratio: 9.05 +/- 2.19) and significantly (P < 0.01) higher amounts of o-Tyr (o-Tyr/Phe ratio: 14.90 +/- 3.75) than did the HM group (o-Tyr/Phe ratio: 12.53 +/- 3.49). When data were lumped together independently of the type of feeding received, a significant correlation was established between the 8-oxodG/2dG and o-Tyr/Phe ratios in urine, dependent on gestational age and birth weight.

CONCLUSION

Prematurity is associated with protracted oxidative stress, and human milk is partially protective.

Chemopreventive agents induce oxidative stress in cancer cells leading to COX-2 overexpression and COX-2-independent cell death

Chemopreventive agents generate oxidative stress, which culminates in cell death and may be part of a general mechanism of chemoprevention. The redox-responsive cyclooxygenase (COX)-2, overexpressed during carcinogenesis, has been a target for cancer prevention. To assess the potential link between chemopreventive agents, oxidative stress and COX-2, we studied the chemopreventive sulindac and nitric oxide-donating aspirin (NO-ASA). Both generated oxidative stress and induced COX-2 in various cell lines, more prominently in dying cells. Two antioxidants and an inhibitor of NADPH oxidase abrogated the induction of COX-2 and cell death. Exogenous xanthine/xanthine oxidase, which produce O(2)(-)., had the same effect. Inhibition of caspases and cox-2 knockdown showed that COX-2 did not participate in reactive oxygen species (ROS) generation or cell death induction in response to NO-ASA. Our results support three potentially useful ideas: (i) the concept that ROS are a critical component of the action of chemopreventive agents; (ii) the notion that COX-2 may not be an ideal target for chemoprevention and (iii) the possibility that COX-2 may be overexpressed in cancer cells due to their state of oxidative stress. It is conceivable that, if further substantiated, these findings may inform the rational design of chemotherapeutic strategies, in particular the choice of agents in combination approaches.

Overexpression of thioredoxin-1 reduces oxidative stress in the placenta of transgenic mice and promotes fetal growth via glucose metabolism

Oxidative stress occurs where there is an imbalance between the production and scavenging of free radicals. Pregnancy per se is a state of oxidative stress due to the increased metabolic activity of placental mitochondria and reduced scavenging ability of antioxidant systems. Overproduction of reactive oxygen species may be associated with impaired fetal growth. However, the physiological influence of antioxidant systems on fetal growth is not well understood. In this study we assessed the effects of antioxidant systems on fetal growth using human thioredoxin (hTRX)-1 overexpressing transgenic (Tg) mice. Tg or C57BL/6 [wild-type (WT)] male mice were mated with WT female mice, and dams were killed to obtain the fetuses and placentas on gestational d 15. Tg fetuses were significantly heavier than WT fetuses, whereas placental weight did not differ significantly between the two groups. Immunohistochemically, hTRX-1 was localized to the nuclei of labyrinthine trophoblasts in Tg mice. In addition, placental expression of 8-hydroxy-2'-deoxyguanosine, which reflects DNA damage caused by oxidative stress, was reduced in Tg mice compared with WT mice. Placental expression of glucose transporter-1 mRNA and protein was significantly higher in Tg mice than WT mice, whereas no significant differences were observed for glucose transporter-3, IGF, and IGF-binding protein mRNA expression. These results suggest that placental and/or systemic antioxidant systems can influence fetal growth. In particular, increased hTRX-1 activity and the resulting modified placental redox state may play an important role in fetal growth by increasing the availability of glucose.