N6-methyladenosine dynamics in placental development and trophoblast functions, and its potential role in placental diseases.

N6-methyladenosine (m6A) is the most abundant modification controlling RNA metabolism and cellular functions, but its roles in placental development are still poorly understood. Here, we characterized the synchronization of m6A modifications and placental functions by mapping the m6A methylome in human placentas (n = 3, each trimester), revealing that the dynamic patterns of m6A were associated with gene expression homeostasis and different biological pathways in placental development. Then, we generated trophoblast-specific knockout mice of Wtap, a critical component of methyltransferase complex, and demonstrated that Wtap was essential for trophoblast proliferation, placentation and perinatal growth. Further in vitro experiments which includes cell viability assays and series molecular binding assays demonstrated that WTAP-m6A-IGF2BP3 axis regulated the RNA stability and translation of Anillin (ANLN) and VEGFA, promoting trophoblast proliferation and secretion. Dysregulation of this regulatory axis was observed in placentas from pregnancies with fetal growth restriction (FGR) or preeclampsia, revealing the pathogenic effects of imbalanced m6A modifications. Therefore, our findings provide novel insights into the functions and regulatory mechanisms of m6A modifications in placental development and placental-related gestational diseases.

Extra villous trophoblast-derived PDL1 can ameliorate macrophage inflammation and promote immune adaptation associated with preeclampsia.

INTRODUCTION: Severe preeclampsia (sPE) is a systemic syndrome that may originate from chronic inflammation. Maintaining maternal-fetal hemostasis by the co-inhibitory molecule programmed death ligand 1 (PDL1) can be favorable for ameliorating inflammation from immune cells. Apart from programmed death 1 (PD1) expression, decidual macrophages (dMs) produce inflammatory cytokines, in response to cells which express PDL1. However, strong evidence is lacking regarding whether the PDL1/PD1 interaction between trophoblasts and decidual macrophages affects inflammation during sPE development. METHODS: To determine whether the trophoblast-macrophage crosstalk via the PDL1/PD1 axis modulates the inflammatory response in sPE-like conditions, at first, maternal-fetal tissues from sPE and normal patients were collected, and the PDL1/PD1 distribution was analyzed by Western blot, immunohistochemistry/ immunofluorescence and flow cytometry. Next, a coculture system was established and flow cytometry was used to identify how PDL1 was involved in macrophage-related inflammation under hypoxic stress. Transcriptional analysis was performed to clarify the inflammation-associated pathway induced by the PDL1/PD1 interaction. Finally, the Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME) mouse model was used to examine the effect of PDL1 on macrophage-related inflammation by measuring PE-like symptoms. RESULTS: In maternal-fetal tissue from sPE patients, placental extravillous trophoblasts (EVTs) and dMs had a surprisingly increase of PDL1 and PD1 expression, respectively, accompanied by a higher percentage of CD68 +CD86 + dMs. In vitro experiments showed that trophoblast-derived PDL1 under hypoxia interacted with PD1 on CD14 +CD80 +macrophages, leading to suppression of inflammation through the TNFα-p38/NFκB pathway. Accordingly, the PE-like mouse model showed a reversal of PE-like symptoms and a reduced F4/80 + CD86 + macrophage percentage in the uterus in response to recombinant PDL1 protein administration, indicating the protective effect of PDL1. DISCUSSION: Our results initially explained an immunological adaptation of trophoblasts under placental hypoxia, although this protection was insufficient. Our findings suggest the possible capacity of modulating PDL1 expression as a potential therapeutic strategy to target the inflammatory response in sPE.

N6-methyladenosine modifications in maternal-fetal crosstalk and gestational diseases.

As a medium among pregnant women, environment and fetus, placenta owns powerful and delicate epigenetic processes to regulate gene expression and maintain cellular homeostasis. N6-methyladenosine (m6A) is the most prevalent modification that determines the fate of RNA, and its dynamic reversibility indicates that m6A may serve as a sensitive responder to environmental stimuli. Emerging evidence suggests that m6A modifications play an essential role in placental development and maternal-fetal crosstalk, and are closely related to gestational diseases. Herein, we summarized the latest techniques for m6A sequencing and highlighted current advances of m6A modifications in maternal-fetal crosstalk and the underlying mechanisms in gestational diseases. Therefore, proper m6A modifications are important in placental development, but its disturbance mainly caused by various environmental factors can lead to abnormal placentation and function with possible consequences of gestational diseases, fetal growth and disease susceptibility in adulthood.

IL-27 deficiency inhibits proliferation and invasion of trophoblasts via the SFRP2/Wnt/ß-catenin pathway in fetal growth restriction.

Background: Fetal growth restriction (FGR) is characterized by restricted fetal growth and dysregulated placental development. The etiology and pathogenesis still remain elusive. IL-27 shows multiple roles in regulating various biological processes, however, how IL-27 involves in placentation in FGR pregnancy hasn't been demonstrated. Methods: The levels of IL-27 and IL-27RA in FGR and normal placentae were determined by immunohistochemistry, western blot and RT-PCR. HTR-8/SVneo cells and Il27ra-/- murine models have been adopted to evaluate the effects of IL-27 on the bio-functions of trophoblast cells. GO enrichment and GSEA analysis were performed to explore the underlying mechanism. Findings: IL-27 and IL-27RA was lowly expressed in FGR placentae and administration of IL-27 on HTR-8/SVneo could promote its proliferation, migration and invasion. Comparing with wildtypes, Il27ra-/- embryos were smaller and lighter, and the placentae from which were poorly developed. In mechanism, the molecules of canonical Wnt/ß-catenin pathway (CCND1, CMYC, SOX9) were downregulated in Il27ra-/- placentae. In contrast, the expression of SFRP2 (negative regulator of Wnt) was increased. Overexpression of SFRP2 in vitro could impair trophoblast migration and invasion capacity. Interpretation: IL-27/IL-27RA negatively regulates SFRP2 to activate Wnt/ß-catenin, and thus promotes migration and invasion of trophoblasts during pregnancy. However, IL-27 deficiency may contribute to the development of FGR by restricting the Wnt activity.

Syringin exerts anti-inflammatory and antioxidant effects by regulating SIRT1 signaling in rat and cell models of acute myocardial infarction.

INTRODUCTION: This study aimed to investigate the role of syringin in improving heart function during myocardial ischemia/reperfusion (I/R) and to determine whether the sirtuin 1/peroxisome proliferator-activated receptor gamma coactivator 1 alpha (SIRT1/PGC-1α) pathway contributes to this cardioprotective effect in vivo and in vitro. METHODS: H9c2 cells were incubated with H2 O2 for 12 h. The effect of syringin was assessed by measuring cell viability; the apoptotic rate; Keap1/NRF2/HO-1 activation; and the levels of proinflammatory cytokines, oxidative products, and antioxidative enzymes. In addition, SIRT1 was silenced via short hairpin RNA (shRNA)-SIRT1 transfection to evaluate its involvement in syringin-mediated protection. Syringin rescued cells from H2 O2 -induced reductions in viability, antioxidative enzyme levels, and NRF2/HO-1 activation; likewise, syringin inhibited apoptosis, inflammation, and oxidative stress. We also created a rat model of I/R by ligating the left anterior descending coronary artery for 30 min, followed by reperfusion for 12 min. Syringin was then intraperitoneally injected, and the effect on infarct size and cardiac function was examined after 7 days. NRF2/HO-1 activity and the levels of myocardial proinflammatory cytokines, oxidative products, and antioxidative enzymes were measured. RESULTS: In comparison to the untreated I/R group, the syringin treatment group exhibited improved cardiac function and reduced cardiac lesion and infarct size. Syringin administration also markedly reduced the levels of proinflammatory cytokines and reactive oxygen species and promoted antioxidative enzyme expression and NRF2/HO-1 pathway activation. CONCLUSIONS: Syringin may serve a protective role in animal and cell models of I/R by improving cardiac function, inhibiting the inflammatory response, and activating the antioxidative response.

Spironolactone Inhibits Cardiomyocyte Hypertrophy by Regulating the Ca2+/Calcineurin/p-NFATc3 Pathway.

This study aimed to investigate the protective effect and molecular mechanism of spironolactone in isoproterenol-induced cardiomyocyte hypertrophy. In this study, primary cardiomyocytes were extracted from the heart of neonatal rats. After stable culture, they were processed with isoproterenol alone or isoproterenol (10 µM) combined with different doses (low dose of 10 µM and high dose of 50 µM), and the cellular activity was determined by MTT experiment. The volume of cells was measured with an inverted microscope and CIAS-1000 cell image analysis system. The mRNA expression levels of ANP and BNP in cells were explored by RT-qPCR. The levels of ANP and BNP proteins and NFATc3 phosphorylation in the nucleus were detected by western blot. The extracellular Ca2+ concentration and CaN activity were measured by colorimetry with the kit. Isoproterenol significantly enlarged the volume of cardiomyocytes (p < 0.001), upregulated mRNA and expression levels of ANP and BNP proteins (p < 0.001), increased extracellular Ca2+ concentration and CaN activity (p < 0.001), and upregulated NFATc3 phosphorylation in the nucleus (p < 0.001). The volume of cells treated with isoproterenol combined with different doses of spironolactone significantly decreased compared with those treated with isoproterenol alone (p < 0.001). mRNA and expression levels of ANP and BNP proteins downregulated significantly (p < 0.001). The extracellular Ca2+ (p < 0.01) concentration and CaN activity (p < 0.001) decreased significantly, and NFATc3 phosphorylation in the nucleus downregulated significantly (p < 0.001). There was no significant difference in cell volume (p=0.999), ANP and BNP mRNA (p=0.695), expression levels of proteins, CaN activity (0.154), and NFATc3 phosphorylation in the nucleus between the cells treated with isoproterenol combined with high-dose spironolactone and those in the control group. In conclusion, spironolactone can reverse isoproterenol-induced cardiomyocyte hypertrophy by inhibiting the Ca2+/CaN/NFATc3 pathway.

Prognostic value of prealbumin, N-terminal pro-B-type natriuretic peptide, heart type fatty acid binding protein, and cardiac troponin I in elderly patients for heart failure and poor outcomes.

OBJECTIVES: This study aimed to investigate the prognostic value of serum prealbumin, N-terminal pro-B-type natriuretic peptide (NT-proBNP), heart type fatty acid binding protein (hFABP), and cardiac troponin I (cTnI) for heart failure and cardiac death in elderly patients. METHODS: We studied 426 consecutive patients with New York Heart Association classes I to IV who were recruited between February 2014 and 2018. Cardiac mortality was the primary end point. Receiver operator characteristic curves were created to analyze predictive values. RESULTS: When prealbumin, NT-proBNP, hFABP, and cTnI were combined, the areas under the receiver operator characteristic curve reached 0.930 and 0.903 for heart failure and cardiac death, respectively. Prealbumin, NT-proBNP, hFABP, and cTnI levels changed differently during therapy in patients in different prognosis groups. These parameters improved in patients who did not develop major adverse cardiovascular events (MACEs), but were unchanged or deteriorated in patients with MACEs. Multivariate Cox regression analysis showed that these parameters were significant independent risk factors for MACEs and cardiac death. CONCLUSIONS: Our study shows that serum prealbumin, NT-proBNP, hFABP, and cTnI levels are significant prognostic factors for elderly patients with poor cardiac function. These parameters are more accurate for prognosis when used together.

An Experimental Study of Dynamic Compression Performance of Self-Compacting Concrete.

To investigate the dynamic performance of self-compacting concrete (SCC), the dynamic uniaxial compression tests at eight different loading strain rates were performed on the ordinary concrete and SCC cubic specimens. Based on the tests, the compression failure patterns and stress-strain curves of both kinds of concrete were obtained. The results show that SCC performs more brittle than ordinary concrete by showing the diagonal crack failure pattern of SCC at a high strain rate. Besides, with the increase of loading strain rate, the peak compressive stress of SCC is slightly lower than that of ordinary concrete, but the increase of elastic modulus is slightly higher than that of ordinary concrete. The peak compressive strains of the two kinds of concrete are discrete under the influence of loading strain rate, thus putting forward the relation equation for the loading strain rate and peak compressive stress increase coefficient of the two kinds of concrete. Besides, based on the theory of elastic-plastic damage and considering the dynamic extension of damage, the dynamic constitutive relation with good applicability between ordinary concrete and SCC was established.

Study on Properties Prediction and Braiding Optimization of Axial Braided Carbon/Carbon Composite.

It is well established that the microstructure has significant effects on the properties of axial braided C/C composites. In this study, a method coupling the homogenization method and finite element method (FEM) was proposed to predict the relationship between the microstructure characteristics and macroscopic properties. Based on the representative volume element (RVE) model, the periodic displacement boundary condition was introduced to predict the equivalent elastic properties of the RVE and component of C/C composite material, and the coefficient of thermal expansion (CTE) of the material was predicted by the energy prediction method. The predicted results were in good agreement with experimental results. By predicting the thermal and mechanical properties of the materials with different braiding spacing and fiber rod diameter, the variation of the properties with braiding spacing and fiber rod diameter was obtained. The research methods and results in this paper could provide important references for the optimization and rational application of composite materials.

LINC00511 promotes proliferation and invasion by sponging miR-515-5p in gastric cancer.

BACKGROUND: Long non-coding RNAs (lncRNAs) are known to be involved in tumorigenesis. The functions of LINC00511 in gastric cancer are poorly understood. METHODS: Quantitative RT-PCR was performed to investigate the levels of LINC00511 in gastric cancer tissues and cell lines. CCK-8, flow cytometry, wound-healing and Transwell assays were performed to examine cellular functions. The underlying regulatory mechanisms of LINC00511 in gastric cancer progression were determined using luciferase reporter and RIP assays. RESULTS: LINC00511 levels were significantly higher in gastric cancer tissues and cell lines than in normal samples. The high expression of LINC00511 in gastric cancer patient samples positively correlated with advanced clinical characters and poor prognosis. Depleting LINC00511 reduced tumor cell proliferation, migration and invasion, slowed tumor growth, and accelerated cell apoptosis. Our mechanistic study results indicated that LINC00511 promotes gastric cancer progression in a miR-515-5p-dependent manner. CONCLUSION: We established that LINC00511 may contribute to the proliferation and invasion of gastric cancer cells by modulating miR-515-5p, indicating that LINC00511 may be a potential molecular target for the development of anti-cancer drugs.

LINC00528 regulates myocardial infarction by targeting the miR-143-3p/COX-2 axis.

This study is aimed to explore the roles of LINC00528 in myocardial infarction (MI) progression. Quantitative real-time PCR showed that the expression of LINC00528 and COX-2 was upregulated while miR-143-3p expression was down-regulated in post-MI cells. In function assays, LINC00528 suppression promoted post-MI cells proliferation and reduced cell apoptosis in vitro. In mechanism, LINC00528 interacted with miR-143-3p in post-MI cells. COX-2 served as a target of miR-143-3p in post-MI cells. Besides, LINC00528 inhibition on COX-2 expression and post-MI cells progression could be partially abolished by miR-143-3p inhibitors. Therefore, our findings suggested that LINC00528 exerted its regulatory roles in MI via the miR-143-3p/COX-2 axis, which provided a potential therapeutic target for MI patients treatment.