Organic Matter Decomposition in River Ecosystems: Microbial Interactions Influenced by Total Nitrogen and Temperature in River Water.

Microbes contribute to the organic matter decomposition (OMD) in river ecosystems. This study considers two aspects of OMD in river ecosystems which have not been examined in scientific studies previously, and these are the microbial interactions in OMD and the influence of environmental factors on microbial interactions. Cotton strip (CS), as a substitute for organic matter, was introduced to Luanhe River Basin in China. The results of CS assay, microbial sequencing, and redundancy analysis (RDA) showed that CS selectively enriched bacterial and fungal groups related to cellulose decomposition, achieving cotton strip decomposition (CSD). Bacterial phylum Proteobacteria and fungal phyla Rozellomycota and Ascomycota were the dominant groups associated with CSD. Network analysis and Mantel test results indicated that bacteria and fungi on CS cooperatively formed an interaction network to achieve the CSD. In the network, modules 2 and 4 were significantly positively associated with CSD, which were considered as the key modules in this study. The key modules were mainly composed of phyla Proteobacteria and Ascomycota, indicating that microbes in key modules were the effective decomposers of CS. Although keystone taxa were not directly associated with CSD, they may regulate the genera in key modules to achieve the CSD, since some keystone taxa were linked with the microbial genera associated with CSD in the key modules. Total nitrogen (TN) and temperature in water were the dominant environmental factors positively influenced CSD. The key modules 2 and 4 were positively influenced by water temperature and TN in water, respectively, and two keystone taxa were positively associated with TN. This profoundly revealed that water temperature and TN influenced the OMD through acting on the keystone taxa and key modules in microbial interactions. The research findings help us to understand the microbial interactions influenced by environmental factors in OMD in river ecosystems.

Isoginkgetin-loaded reactive oxygen species scavenging nanoparticles ameliorate intervertebral disc degeneration via enhancing autophagy in nucleus pulposus cells.

Excessive reactive oxygen species (ROS) in nucleus pulposus cells (NPCs) promote extracellular matrix (ECM) degradation and cellular inflammatory responses by activating a variety of cellular pathways, ultimately inducing cell apoptosis and leading to the development of low back pain. Here, we designed and fabricated an isoginkgetin-loaded ROS-responsive delivery system (IGK@SeNP) based on diselenide block copolymers. Successfully encapsulated IGK was released intelligently and rapidly in a microenvironment with high ROS levels in degenerative disc. Controlled-release IGK not only efficiently scavenged ROS from the intervertebral disc together with diselenide block copolymers but also effectively enhanced autophagy in NPCs to inhibit ECM degradation and cell apoptosis, and showed significant therapeutic effects in the rat intervertebral disc degeneration (IDD) model. Overall, the synergistic effects of IGK@SeNP in ROS scavenging and autophagy enhancement endowed it with an attractive therapeutic strategy for IDD treatment.

The effects of pre-dialysis blood pressure targets on prognosis and health-related quality of life in haemodialysis patients.

OBJECTIVE: The aim of the study is to investigate the effects of pre-dialysis blood pressure targets on health-related quality of life and prognosis and to determine the optimal target for pre-dialysis blood pressure in haemodialysis patients. METHODS: A total of 58 haemodialysis patients undergoing dialysis for more than 3 months were enrolled in the study from 1 January 2018 to 31 December 2018. The subjects were divided into two groups according to their pre-dialysis blood pressure: a standard target group (pre-dialysis systolic blood pressure of 110-140 mm Hg) and a relaxed target group (pre-dialysis systolic blood pressure of 155-165 mm Hg). The Quality Metrics SF-36 survey instrument was used to assess health-related quality of life in the study participants. In addition, general clinical data and biochemical indicators including heart rate, respiration rate, blood pressure and ultrafiltration volume and rate during dialysis were observed and recorded. Patients were followed-up for 12 months, and prognostic data were recorded. Death was regarded as the endpoint. RESULTS: Scores on the SF-36 in the standard target group were significantly higher than those in the relaxed target group, with the exception of the role-emotional (RE) and mental health (MH) dimensions. At the end of the study, the number of mortality events in the relaxed target group was higher than in the standard target group. There were no other significant differences between the two groups. CONCLUSION: The scores from the health-related quality of life survey were higher in standard target group, but no differences in mortality risk between the two groups were observed.

Randomized Double-Blinded Comparison of Intermittent Boluses Phenylephrine and Norepinephrine for the Treatment of Postspinal Hypotension in Patients with Severe Pre-Eclampsia During Cesarean Section.

Background: Norepinephrine has fewer negative effects on heart rate (HR) and cardiac output (CO) for treating postspinal hypotension (PSH) compared with phenylephrine during cesarean section. However, it remains unclear whether fetuses from patients with severe pre-eclampsia could benefit from the superiority of CO. The objective of this study was to compare the safety and efficacy of intermittent intravenous boluses of phenylephrine and norepinephrine used in equipotent doses for treating postspinal hypotension in patients with severe pre-eclampsia during cesarean section. Methods: A total of 80 patients with severe pre-eclampsia who developed PSH predelivery during cesarean section were included. Eligible patients were randomized at a 1:1 ratio to receive either phenylephrine or norepinephrine for treating PSH. The primary outcome was umbilical arterial pH. Secondary outcomes included other umbilical cord blood gas values, Apgar scores at 1 and 5 min, changes in hemodynamic parameters including CO, mean arterial pressure (MAP), HR, stroke volume (SV), and systemic vascular resistance (SVR), the number of vasopressor boluses required, and the incidence of bradycardia, hypertension, nausea, vomiting, and dizziness. Results: No significant difference was observed in umbilical arterial pH between the phenylephrine and norepinephrine groups (7.303±0.38 vs 7.303±0.44, respectively; P=0.978). Compared with the phenylephrine group, the overall CO (P=0.009) and HR (P=0.015) were greater in the norepinephrine group. The median [IQR] total number of vasopressor boluses required was comparable between the two groups (2 [1 to 3] and 2 [1 to 3], respectively; P=0.942). No significant difference was found in Apgar scores or the incidence of maternal complications between groups. Conclusion: A 60 µg bolus of phenylephrine and a 4.5 µg bolus of norepinephrine showed similar neonatal outcomes assessed by umbilical arterial pH and were equally effective when treating PSH during cesarean section in patients with severe pre-eclampsia. Norepinephrine provided a higher maternal CO and a lower incidence of bradycardia.

Insight into the plant-associated bacterial interactions: Role for plant arsenic extraction and carbon fixation.

This study investigated the interactions between rhizosphere and endosphere bacteria during phytoextraction and how the interactions affect arsenic (As) extraction and carbon (C) fixation of plants. Pot experiments, high-throughput sequencing, metabonomics, and network analysis were integrated. Results showed that positive correlations dominated the interconnections within modules (>95 %), among modules (100 %), and among keystone taxa (>72 %) in the bacterial networks of plant rhizosphere, root endosphere, and shoot endosphere. This confirmed that cooperative interactions occurred between bacteria in the rhizosphere and endosphere during phytoextraction. Modules and keystone taxa positively correlating with plant As extraction and C fixation were identified, indicating that modules and keystone taxa promoted plant As extraction and C fixation simultaneously. This is mainly because modules and keystone taxa in plant rhizosphere, root endosphere, and shoot endosphere carried arsenate reduction and C fixation genes. Meanwhile, they up-regulated the significant metabolites related to plant As tolerance. Additionally, shoot C fixation increased peroxidase activity and biomass thereby facilitating plant As extraction was confirmed. This study revealed the mechanisms of plant-associated bacterial interactions contributing to plant As extraction and C fixation. More importantly, this study provided a new angle of view that phytoextraction can be applied to achieve multiple environmental goals, such as simultaneous soil remediation and C neutrality.

Effects of freeze-thaw dynamics and microplastics on the distribution of antibiotic resistance genes in soil aggregates.

This is the first study investigating the effects of freeze-thaw (FT) and microplastics (MPs) on the distribution of antibiotic resistance genes (ARGs) in soil aggregates (i.e., soil basic constituent and functional unit) via microcosm experiments. The results showed that FT significantly increased the total relative abundance of target ARGs in different aggregates due to the increase in intI1 and ARG host bacteria. However, polyethylene MPs (PE-MPs) hindered the increase in ARG abundance caused by FT. The host bacteria carrying ARGs and intI1 varied with aggregate size, and the highest number of hosts was observed in micro-aggregates (<0.25 mm). FT and MPs altered host bacteria abundance by affecting aggregate physicochemical properties and bacterial community and enhanced multiple antibiotic resistance via vertical gene transfer. Although the dominant factors affecting ARGs varied with aggregate size, intI1 was a co-dominant factor in various-sized aggregates. Furthermore, other than ARGs, FT, PE-MPs, and their integration promoted the proliferation of human pathogenic bacteria in aggregates. These findings suggested that FT and its integration with MPs significantly affected ARG distribution in soil aggregates. They amplified antibiotic resistance environmental risks, contributing to a profound understanding of soil antibiotic resistance in the boreal region.

Transfer of antibiotic resistance genes from soil to wheat: Role of host bacteria, impact on seed-derived bacteria, and affecting factors.

The transfer of antibiotic resistance genes (ARGs) from soils to plants is poorly understood, especially the role of host bacteria in soils and its impact on seed-derived bacteria. Wheat (Triticum aestivum L.) was thus used to fill the gap by conducting pot experiments, with target ARGs and bacterial community analyzed. Results showed that the relative abundances of target ARGs gradually decreased during transfer of ARGs from the rhizosphere soil to root and shoot. Host bacteria in the rhizosphere soil were the primary source of ARGs in wheat. The 38, 21, and 19 potential host bacterial genera of target ARGs and intI1 in the rhizosphere soil, root, and shoot were identified, respectively, and they mainly belonged to phylum Proteobacteria. The abundance of ARGs carried by pathogenic Corynebacterium was reduced in sequence. During transfer of ARGs from the rhizosphere soil to root and shoot, some seed-derived bacteria and pathogenic Acinetobacter obtained ARGs through horizontal gene transfer and became potential host bacteria. Furthermore, total organic carbon, available nitrogen of the rhizosphere soil, water use efficiency, vapor pressure deficit, and superoxide dismutase of plants were identified as the key factors affecting potential host bacteria transfer in soils to wheat. This work provides important insights into transfer of ARGs and deepens our understanding of potential health risks of ARGs from soils to plants.

Comparative dose-response study of intrathecal hyperbaric ropivacaine for cesarean delivery in preterm singleton versus twin pregnancies.

INTRODUCTION: Previously, we demonstrated that patients with full-term singletons and preterm twins require similar dose of intrathecal hyperbaric ropivacaine. However, these findings may be attributable to enrolled patients with preterm twin pregnancies. In this study, we aimed to determine the intrathecal dose requirements of hyperbaric ropivacaine for twins and singletons at equal gestational ages. METHODS: We enrolled 75 patients with preterm singletons and 75 patients with preterm twins scheduled for cesarean delivery under combined spinal-epidural anesthesia in this two-arm parallel, randomized, double-blind, dose-response study. Patients with singletons and twins were randomly assigned to receive one of five different doses of hyperbaric ropivacaine: 10, 12, 14, 16, or 18 mg. A probit regression model was used to determine the dose effective in 50% of patients (ED50) and dose effective in 90% of patients (ED90) values. The relative median potency was calculated to compare the ED50 between patients with twins and singletons. RESULTS: Intrathecal ropivacaine ED50 and ED90 (with 95% CI) in patients with preterm singletons were 9.9 (7.2 to 11.5) mg and 16.8 (14.5 to 22.9) mg, respectively. In patients with preterm twins, these values were 9.2 (95% CI 6.4 to 10.8) mg and 15.6 (95% CI 13.6 to 20.6) mg. Between patients with preterm twins and preterm singletons, the relative potency (ED50 ratios) was 0.933 (95% CI 0.72 to 1.15). CONCLUSIONS: During preterm gestation, intrathecal hyperbaric ropivacaine dose requirements for scheduled cesarean delivery were not different between patients with twins and singletons. TRIAL REGISTRATION NUMBER: ChiCTR2100051382.

Identification of a chemotherapy-associated gene signature for a risk model of prognosis in gastric adenocarcinoma through bioinformatics analysis.

Background: Over the past few years, the overall survival rate of patients with gastric adenocarcinoma who have received different chemotherapy regimens has increased. However, not all gastric cancer patients who receive chemotherapy have a longer survival. We need better predictive biomarkers. This study is to construct a new risk model of chemotherapy-associated genes in gastric adenocarcinoma (GA) for prognostication. Methods: RNA-seq data and clinical information of GSE26901 (containing 44 chemotherapy samples and 65 patients without chemotherapy) in Gene Expression Omnibus (GEO) and stomach adenocarcinoma (STAD, containing 360 cancer tissue samples and 50 paired normal tissue samples) in The Cancer Genome Atlas (TCGA) were selected for screening differentially expressed genes (DEGs). Multivariate Cox regression was conducted to screen prognosis-associated genes and its link to patients' prognosis were screened by least absolute shrinkage and selection operator (LASSO) regression analysis. Based on the key genes, a risk scoring equation for the prognosis model was established, and constructed survival prognosis model. The model was tested for predictive ability through training set (TCGA datasets) and validation set (GSE84437). The correlations of the risk score with clinical pathological features, immune score and drug sensitivity score were evaluated. Results: In total, 179 overlapping genes were obtained by screening DEGs. Univariate Cox analysis revealed 36 prognosis-related genes, and LASSO regression analysis revealed 8 key genes (KCNJ2, GATA5, CLDN1, SERPINE1, FCER2, PMEPA1, TMEM37 and CRTAC1). Kaplan-Meier (K-M) analysis uncovered a relatively short overall survival time in the high-risk group. The model was verified to possess favourable predictive ability. In addition, the nomogram model were demonstrated good predictability with area under the curve (AUC) for 1-5 years in training set were 0.78, 0.78, 0.76, 0.79 and 0.81. The high-risk group was less likely to get benefits from immunotherapy and less sensitive to cisplatin. Conclusions: According to the results of our training set and validation set, the risk model based on the eight chemotherapy-related gene signatures predicting prognosis has certain predictive accuracy in predicting the survival of GA patients which can be a promising prognostic parameter for GA. However, its efficacy remains to be proved in clinical practice.

Analysis of the influence paths of land use and landscape pattern on organic matter decomposition in river ecosystems: Focusing on microbial groups.

Organic matter decomposition (OMD) is one of the important river ecosystem functions. Changes in land use and landscape pattern (LULP) have a serious influence on the OMD in neighboring river ecosystems. However, there is limited information on the influence paths of LULP on organic matter decomposition in river ecosystems. In this study, cotton strip (CS) as a substitute for investigating OMD, was introduced to the delineated catchments in Luanhe River Basin in China, meanwhile combining with remote sensing interpretation, water quality analysis, microbial sequencing, and redundancy analysis (RDA) to identify the dominant LULP metrics, water quality parameters, and microbial groups controlling the OMD. Then the structural equation models (SEMs) were used to connect these dominant controlling factors to track the influence paths of LULP on OMD in river ecosystems. RDA results indicated that construction land (CON), farmland (FAR) and landscape shape index (LSI) in LULP, total nitrogen (TN), chemical oxygen demand (COD) and pH in water quality, bacterial phyla Planctomycetes and Firmicutes, as well as fungal phyla Chytridiomycota and Basidiomycota were the dominant factors controlling the OMD (quantified by tensile strength loss (TSL) and respiration (RES)). These four microbial phyla contributed significantly to OMD. SEMs further proposed three paths to explain the mechanism of LULP influencing on OMD, which were CON - TN - Firmicutes - TSL, CON - TN - Chytridiomycota - RES, and FAR - COD - Chytridiomycota - TSL. CON promoted OMD mainly through enhancing TN content in river water to increase Firmicutes and Chytridiomycota. FAR increased Chytridiomycota by decreasing COD in river water, promoting OMD. These results will deepen our understanding of the influence of LULP on river ecosystem functions and provide valuable information for policymakers and managers to carry out watershed land planning and river management in the future.

Comparative Dose-Response Study of Phenylephrine Bolus for the Treatment of the First Episode of Spinal Anesthesia-Induced Hypotension for Cesarean Delivery in Severe Preeclamptic versus Normotensive Parturients.

Background: It is well-known that severe preeclamptic parturients have less vasopressor requirements than normotensive parturients; however, the exact dose difference is poorly documented. This study aimed to determine and compare the ED50 and ED90 of a single bolus phenylephrine for the treatment of spinal anesthesia-induced hypotension in parturients with severe preeclampsia and parturients with normotension. Methods: Seventy-five parturients with severe preeclampsia scheduled for cesarean delivery under combined spinal-epidural anesthesia were enrolled and randomly allocated to receive a single bolus of phenylephrine at five different doses (40, 50, 60, 70, and 80 µg), whereas 75 parturients with normotension were randomized to receive a single bolus of phenylephrine at five different doses (70, 80, 90, 100, and 110 µg) for the treatment of the first episode of hypotension. Phenylephrine dose values were log-transformed, the proportions of the successful interventions at each dose were converted to probits, and regression analysis was performed. Results: The ED50 and ED90 (95% CI) of bolus phenylephrine were 72.1 (61.7 to 79.9) µg and 107 (95.9-128.6) µg in parturients with normotension. The ED50 and ED90 values in parturients with severe preeclampsia were 47.6 (41.3-52.7) µg and 70.7 (62.9-86.7) µg. The relative median potency was 1.51 (1.16-2.61). Conclusion: Under this study conditions, severe preeclamptic parturients required a 34% reduction of ED50 of phenylephrine dose compared with normotensive parturients.

COX-2-related tumor immune microenvironment in non-small cell lung cancer: a novel signature to predict hot and cold tumor.

Background: At present, non-small cell lung cancer (NSCLC) remains a great threat to the health of people worldwide. Immune checkpoint inhibitors (ICIs) have shown positive results in the treatment of advanced NSCLC. However, the treatment response of ICIs is not stable and unpredictable. We used a bioinformatics analysis to determine a novel signature to diagnose the hot and cold tumor in NSCLC which may guide the programmed cell death protein 1/programmed cell death 1 ligand 1 (PD-1/PD-L1) therapeutic strategy. Methods: The RNA-seq dataset and clinical data of 485 lung adenocarcinoma (LUAD) and 473 lung squamous cell carcinoma (LUSC) samples from The Cancer Genome Atlas (TCGA) database. Tumor infiltrating immune cells was calculated by CIBERSORT algorithm and ConsensusClusterPlus was used to classify the hot and cold tumor. Least absolute shrinkage and selection operator (LASSO) regression, Support Vector Machine (SVM) and Gaussian Mixture Model (GMM) were performed to determine the diagnostic area under curve (AUC) of novel signature of ICIs treatment. Overall survival (OS) analysis was based on the Kaplan-Meier statistical method. Results: In this study, we found that the expression of PD-1/PD-L1 is associated with COX2 (PTGS2) expression. We identified novel signatures [STMN3, KIRREL1, SH2D3C, VCL, PDCD1, CD274, PTGS2, combined diagnostic (AUC) =0.838], in order to diagnose the hot and cold tumor subtype to indicate the treatment response of PD-1/PD-L1 inhibitor in NSCLC. Furthermore, we found that in hot tumor subtype, high PDCD1 expression group had worse OS than low PDCD1 expression group (P=0.047); high SH2D3C expression group had worse OS than low SH2D3C expression group either (P=0.003). SH2D3C was correlated to PD-1 expression in NSCLC samples (R=0.49, P<0.001). We speculated that SH2D3C likely plays a crucial role in PD-1-related immunotherapy in NSCLC patients. Pathway enrichment showed that the focal adhesion (P=0.005) and actin cytoskeleton (P=0.022) pathways were associated with OS. Conclusions: This study aimed to identify the classification of hot and cold tumors, and develop a novel signature to predict the ICI treatments response for PD-1/PD-L1 high expression NSCLC patients.

Comparative study on the manually-controlled variable-rate versus fixed-rate infusion of norepinephrine for preventing hypotension during spinal anesthesia for cesarean delivery.

STUDY OBJECTIVE: Previous studies have shown that prophylactic norepinephrine infusion is superior to intermittent bolus administration in preventing post-spinal hypotension. Nevertheless, it is still controversial whether manually-controlled variable-rate infusion is more effective than fixed-rate infusion. The purpose of the present study was to compare the efficacy of variable-rate infusion and fixed-rate infusion of norepinephrine for prophylaxis against maternal hypotension and maintaining hemodynamic stability during spinal anesthesia for cesarean delivery to determine more effective mode for clinical practice. DESIGN: A prospective randomized, controlled study. SETTING: Operating room, Women's Hospital, Zhejiang University School of Medicine. PATIENTS: A total of 161 parturients scheduled for elective cesarean delivery with spinal anesthesia were randomized into Group F (fixed-rate infusion) and Group V (variable-rate infusion). INTERVENTIONS: Parturients received prophylactic norepinephrine infusion concurrent with the intrathecal injection at rate started at 0.05 µg/kg/min. In Group F, norepinephrine was administered continuously at a fixed (on-off) rate, and a bolus of norepinephrine 5 µg or 10 µg was given when systolic blood pressure (SBP) decreased by 20% or more of baseline. In Group V, manually adjusted norepinephrine infusion within the range 0-0.14 µg/kg/min, according to SBP at 1-min intervals until delivery, aim to maintain values close to the baseline. MEASUREMENTS: During the study period, the incidence of maternal hypotension, hemodynamic performance, the number of physician interventions, reactive hypertension, bradycardia, nausea, vomiting, norepinephrine cumulative dose (before delivery), and neonatal outcomes were recorded. MAIN RESULTS: The incidence of maternal hypotension was significantly lower in Group V than that in Group F (9% versus 30%) (P < 0.001). No significant difference was found in the serial changes in SBP and heart rate (HR) for the first 15 min. Group V showed higher frequency of physician interventions compared with the Group F (P < 0.001). The incidence of hypertension, severe hypotension, nausea, vomiting, bradycardia, norepinephrine cumulative dose, and neonatal outcome were comparable between the two groups. CONCLUSION: When norepinephrine was infused at an initial dose of 0.05 µg/kg/min for preventing hypotension during spinal anesthesia for cesarean delivery, due to technical limitations of inadequate dose design in this study, neither a variable-rate infusion (need more physician intervention) nor a fixed-rate infusion regimen (experience more transient hypotension) was optimal. However, in terms of clinical importance, how to prevent the parturients from experiencing more incidence of hypotension might be a greater concern for anesthesiologists.

Effect of systematic nursing on the stress response and recovery of gastrointestinal function in patients undergoing laparoscopic cholecystectomy.

OBJECTIVE: To explore the effect of systematic nursing on the stress response and recovery of gastrointestinal function in patients undergoing laparoscopic cholecystectomy. METHODS: A retrospective study was conducted among 102 patients with gallbladder system disease. They were divided into an observation group (n=51, perioperative systematic care) and a control group (n=51, perioperative conventional care) according to a random number table. The clinical indicators, postoperative recovery of gastrointestinal function, and patients' stress response, psychological status and quality of life before and after intervention were compared between the two groups. RESULTS: Compared with the control group, the time to get out of bed for the first time after operation, the recovery time of bowel sounds, and the time of first gas/defecation after operation in the observation group were significantly earlier (all P<0.01), and the hospital stay was significantly shorter (P<0.001). Compared with 12 hours before operation, the serum adrenaline and cortisol levels of the two groups were significantly higher at 48 hours after operation, and the levels in the observation group were lower than the control group (all P<0.001). Compared with 1 day before the operation, the scores of Hamilton Anxiety Scale (HAMA) and Hamilton Depression Scale (HAMD) in both groups were reduced when they were discharged from the hospital, and the scores in the observation group were lower than that of the control group (all P<0.01). Three months after the operation, the scores of Generic Quality of Life Inventory-74 (GQOLI-74) in the two groups increased in all dimensions, and the scores in the observation group were higher than the control group (all P<0.05). CONCLUSION: Systematic care during the perioperative period of laparoscopic cholecystectomy can alleviate the degree of stress, promote the recovery of postoperative gastrointestinal function, relieve the level of anxiety and depression, and improve the quality of life of patients after discharge from the hospital.

Identification of estrogen receptor target genes involved in gonadal feminization caused by estrogen in Xenopus laevis.

Estrogens and estrogenic endocrine disrupting chemicals can cause gonadal feminization in some vertebrates mainly through estrogen receptor (ER), but the underlying molecular mechanisms are unclear. The present study aimed to identify ER target genes involved in estrogen-caused gonadal feminization in Xenopus laevis. Based on our recent transcriptomic data that 10 nM 17ß-estradiol (E2) altered gene transcription in feminizing gonads of male X. laevis at NF stages 48, 50, and 52, we searched estrogen response element (ERE) using the Dragon ERE Finder software in the promoter region of all the E2-regulated genes. As a result, 163 genes containing ERE sequence were identified as predicted ER target genes at NF stage 50 (on the 14th day postfertilization), a crucial stage for gonadal feminization. Then, some of these predicted ER target genes were further investigated, mainly including the genes that were suggested to be involved in E2-caused gonadal feminization and genes being dramatically up or down-regulated by E2. Fifteen genes were demonstrated to be responsive to E2, in turn ER antagonist blocked the E2-regulated transcription. Finally, we identified 10 genes that can bind to ERα by a chromatin immunoprecipitation-qPCR. Taken together, we identified the 10 genes that contain predicted ERE sequences, are responsive to estrogen and ER antagonist, and have ability to bind to ER as ER target genes, including pglyrp2, apoa1, fgb, tdo2, ca6, nags, cpb2, tmprss6, nudc, zwilch. Our results could help to improve the understanding of the molecular mechanisms for gonadal feminization caused by estrogenic endocrine disrupting chemicals in X. laevis, and even in other species.

PepCyber:P~PEP: a database of human protein protein interactions mediated by phosphoprotein-binding domains.

Phosphoprotein-binding domains (PPBDs) mediate many important cellular and molecular processes. Ten PPBDs have been known to exist in the human proteome, namely, 14-3-3, BRCT, C2, FHA, MH2, PBD, PTB, SH2, WD-40 and WW. PepCyber:P approximately PEP is a newly constructed database specialized in documenting human PPBD-containing proteins and PPBD-mediated interactions. Our motivation is to provide the research community with a rich information source emphasizing the reported, experimentally validated data for specific PPBD-PPEP interactions. This information is not only useful for designing, comparing and validating the relevant experiments, but it also serves as a knowledge-base for computationally constructing systems signaling pathways and networks. PepCyber:P approximately PEP is accessible through the URL, http://www.pepcyber.org/PPEP/. The current release of the database contains 7044 PPBD-mediated interactions involving 337 PPBD-containing proteins and 1123 substrate proteins.

Transcriptomic analysis identifies early cellular and molecular events by which estrogen disrupts testis differentiation and causes feminization in Xenopus laevis.

Extensive studies have shown that estrogenic endocrine-disrupting chemicals (EDCs) can disrupt testis differentiation and even cause feminization in vertebrates. However, little is known about the mechanisms by which estrogenic EDCs disrupt testis differentiation. Here, we employed Xenopus laevis, a model amphibian species sensitive to estrogenic EDCs, to explore the molecular and cellular events by which 17ß-estradiol (E2) disrupts testis differentiation and causes feminization. Following waterborne exposure to E2 from stage 45/46, genetically male X. laevis were confirmed to undergo testis differentiation inhibition and ovary differentiation activation at stages 52 and 53, ultimately displaying gonadal feminization at stage 66. Using a time-course RNA sequencing approach, we then identified thousands of differentially expressed transcripts (DETs) in genetically male gonad-mesonephros complexes at stages 48, 50 and 52 (the window for testis differentiation) between E2 treatment and the control. Enrichment analysis suggests alterations in cell proliferation, extracellular matrix, and cell motility following E2 exposure. Further verification by multiple methods demonstrated that E2 inhibited cell proliferation, disrupted extracellular matrix, and altered cell motility in the genetically male gonads compared with controls, implying that these events together contributed to testis differentiation disruptions and feminization in X. laevis. This study for the first time uncovered some of the early molecular and cellular events by which estrogen disrupts testicular differentiation and causes feminization in X. laevis. These new findings improve our understanding of the mechanisms by which estrogenic EDCs disrupt testicular differentiation in vertebrates.

Transcriptional changes caused by estrogenic endocrine disrupting chemicals in gonad-mesonephros complexes of genetic male Xenopus laevis: Multiple biomarkers for early detection of testis differentiation disruption.

Our recent study revealed some early molecular and cellular events in which 17ß-estradiol (E2) disrupted testis differentiation and resulted in feminization in Xenopus laevis (the African clawed frog), an ideal species for studying reproductive endocrine disruption by estrogenic endocrine disrupting chemicals (EDCs). On this basis, we aimed to develop multiple biomarkers for early detection of testis differentiation disruption by estrogenic EDCs in X. laevis. Tadpoles at stage 45/46 were exposed to four known estrogenic EDCs with different estrogenic activities, including E2, diethylstilbestrol (DES), mestranol (MES) and 4-n-nonyphenol (NP). At stage 53, gonadal morphological and histological changes as well as altered sex-dimorphic gene expression in gonad-mesonephros complexes (GMCs) showed that these estrogenic EDCs disrupted testis differentiation and caused feminization to different degrees. Then we measured transcriptional changes of 48 candidate genes, which are believed to be associated with E2-induced testis differentiation alterations, in GMCs at stage 50. As a result, 19 genes were found to be transcriptionally altered by all test chemicals and proposed as promising biomarkers for early detection of testis differentiation disruption by estrogenic EDCs. Finally, all biomarker responses were integrated as integrated biomarker response (IBR) index to characterize testis differentiation disruption by these estrogenic EDCs in X. laevis. Compared with the methods used in previous studies, the multiple biomarker test using X. laevis at early developmental stages largely shortens the exposure duration, thereby achieving the goal of rapid detection. Certainly, the biomarker test needs further validations in the future study.

Isoflurane cerebral preconditioning in a spontaneous hypertension rat model is associated with sphingosine kinases.

BACKGROUND: Isoflurane preconditioning could reduce different kinds of brain injury via sphingosine kinase (SPK). Both sphingosine kinase 1 and sphingosine kinase 2 play important roles in brain protection. However, the effects of isoflurane preconditioning on SPK expression in hypertension have not been investigated before. OBJECTIVES: To verify whether the neuroprotective effects of the anesthetic isoflurane after an ischemic injury are altered in hypertension and to identify its possible mechanisms involving SPK. MATERIAL AND METHODS: Wistar rats (control) and spontaneous hypertension rats (SHR) were exposed to isoflurane preconditioning before transient middle cerebral artery occlusion. The infarct volumes of cortical and subcortical brain areas were measured. The expression levels of SPK1 and SPK2 were measured before and after isoflurane preconditioning. RESULTS: In the SHR group, isoflurane preconditioning significantly reduced only the infarct volumes of the subcortical brain (p < 0.05), not of the cortical brain. After 3 h of isoflurane exposure and preconditioning, SPK2 levels in the SHR group increased in the cortical brain (p < 0.05), but not in the subcortical brain area, Unlike in the control group, isoflurane exposure and preconditioning could significantly increase SPK2 levels in both cortical and subcortical brain area. CONCLUSIONS: The brain protection effects induced by isoflurane preconditioning after an ischemic injury are mainly mediated by the SPK2 isoform and are somewhat impaired in hypertension. Attention should be paid to ischemic injury patients with hypertension.

2,2',4,4'-tetrabromodipheny ether (BDE-47) disrupts gonadal development of the Africa clawed frog (Xenopus laevis).

Previous studies have shown that BDE-47, one of the most abundant polybrominated diphenyl ethers (PBDEs) congeners, has a weak estrogenic activity, but it has remained unclear whether BDE-47 disrupts gonadal development and causes male-to-female sex reversal in lower vertebrates, with limited and controversial data. The present study aimed to determine the effects of BDE-47 on gonadal development in Xenopus laevis, a model amphibian species for studying adverse effects of estrogenic chemicals on reproductive development. X. laevis at stage 45/46 were exposed to BDE-47 (0.5, 5, 50 nM) in semi-static system, with 1 nM 17ß-estradiol (E2) as the positive control. When reaching stage 53, tadpoles were examined for gonadal morphology, histology and sex-dimorphic gene expression. The phenotypic sex (gonadal morphology and histology) of each BDE-47-treated tadpole matched its genetic sex, showing no sex-reversal, whereas one half of genetic males treated with E2 displayed ovarian-like features. However, some genetic males (26%) in the 50 nM BDE-47 treatment group were found to contain more germ cells clumping together in the medulla, along with an increasing tendency of the gonad length/kidney length ratio in males, resembling feminizing outcomes of E2. These observations seem to suggest that BDE-47 exerted weak feminizing effects. However, BDE-47 induced increases in expression of both female-biased genes and male-biased genes in two sexes, which disagrees with feminizing outcomes, suggesting complicated effects of BDE-47 on gonadal development. Taken together, all results demonstrate that nanomolar BDE-47 disrupted gonadal development and exerted weak feminizing effects, but not resulted in male-to-female sex reversal in X. laevis.