Shikonin exerts an anti-leukemia effect against FLT3-ITD mutated acute myeloid leukemia cells via targeting FLT3 tyrosine kinase and its downstream pathways.

INTRODUCTION: Acute myeloid leukemia (AML) with internal tandem duplication (ITD) mutations in Fms-like tyrosine kinase 3 (FLT3) has an unfavorable prognosis. Recently, using newly emerging inhibitors of FLT3 has led to improved outcomes of patients with FLT3-ITD mutations. However, drug resistance and relapse continue to be significant challenges in the treatment of patients with FLT3-ITD mutations. This study aimed to evaluate the anti-leukemic effects of shikonin (SHK) and its mechanisms of action against AML cells with FLT3-ITD mutations in vitro and in vivo. METHODS: The CCK-8 assay was used to analyze cell viability, and flow cytometry was used to detect cell apoptosis and differentiation. Western blotting and real-time polymerase chain reaction (RT-PCR) were used to examine the expression of certain proteins and genes. Leukemia mouse model was created to evaluate the anti-leukemia effect of SHK against FLT3-ITD mutated leukemia in vivo. RESULTS: After screening a series of leukemia cell lines, those with FLT3-ITD mutations were found to be more sensitive to SHK in terms of proliferation inhibition and apoptosis induction than those without FLT3-ITD mutations. SHK suppresses the expression and phosphorylation of FLT3 receptors and their downstream molecules. Inhibition of the NF-κB/miR-155 pathway is an important mechanism through which SHK kills FLT3-AML cells. Moreover, a low concentration of SHK promotes the differentiation of AML cells with FLT3-ITD mutations. Finally, SHK could significantly inhibit the growth of MV4-11 cells in leukemia bearing mice. CONCLUSION: The findings of this study indicate that SHK is a promising drug for the treatment of FLT3-ITD mutated AML.

No-touch endoscopic full-thickness resection technique for gastric gastrointestinal stromal tumors.

BACKGROUND : There remain concerns regarding the technical feasibility of endoscopic resection for large gastrointestinal stromal tumors (GISTs), mainly relating to the risk of tumor rupture and the adequacy of the resection margins. This study aimed to evaluate the feasibility and therapeutic outcomes of the newly developed no-touch endoscopic full-thickness resection (NT-EFTR) technique for GISTs. METHODS : In this retrospective study, 92 patients with gastric GISTs undergoing NT-EFTR were included. Clinicopathological, endoscopic, and follow-up data were collected and analyzed. RESULTS : The median tumor size was 2.5 cm and en bloc resection was achieved in all patients with negative surgical margins. The median time of the NT-EFTR procedure was 59.5 minutes. Large tumors (> 3.0 cm), extraluminal tumor growth pattern, and large gastric defects were significant contributors to long operative times. Patients were discharged within 4 days postoperatively. During follow-up, all patients were free from local recurrence and distant metastasis. CONCLUSIONS : NT-EFTR was a feasible method for the resection of gastric GISTs and can be expected to achieve complete radical resection. Large tumors with extraluminal growth and large gastric defects impact procedural difficulty.

Measurable residual disease detected by flow cytometry independently predicts prognoses of NPM1-mutated acute myeloid leukemia.

Acute myeloid leukemia (AML) with NPM1 mutation is a distinct genetic entity with favorable outcomes. Nevertheless, emerging evidence suggests that NPM1-mutated AML is still a highly heterogeneous disorder. In this study, 266 patients with AML with NPM1 mutations were retrospectively analyzed to evaluate the associations between variant allele frequency (VAF) of NPM1 mutations, co-mutated genes, measurable residual disease (MRD), and patient outcomes. Multiparameter flow cytometry (MFC) and real-time quantitative polymerase chain reaction (RT-PCR) were used for monitoring MRD. Ultimately, 106 patients were included in the long-term follow-up period. Patients with high NPM1 VAF (≥ 42.43%) had poorer 2-year relapse-free survival (RFS) (55.7% vs. 70.2%, P = 0.017) and overall survival (OS) (63.7% vs. 82.0%, P = 0.027) than those with low VAF. DNMT3A mutations negatively influenced the outcomes of patients with NPM1 mutations. Patients with high DNMT3A VAF or NPM1/DNMT3A/FLT3-ITD triple mutations had shorter RFS and significantly lower OS than that in controls. After two cycles of chemotherapy, patients with positive MFC MRD results had lower RFS (MRD+ vs. MRD-:44.9% vs. 67.6%, P = 0.007) and OS (61.5% vs. 76.6%, P = 0.011) than those without positive MFC MRD results. In multivariate analysis, high NPM1 VAF (hazard ratio [HR] = 2.045; P = 0.034) and positive MRD after two cycles of chemotherapy (HR = 3.289; P = 0.003) were independent risk factors for RFS; MRD positivity after two cycles of chemotherapy (HR = 3.293; P = 0.008) independently predicted the OS of the patients. These results indicate that VAF of both NPM1 gene itself or certain co-occurring gene pre-treatment and MRD post-treatment are potential markers for restratifying the prognoses of patients AML having NPM1 mutations.

PD-L1 negatively regulates antifungal immunity by inhibiting neutrophil release from bone marrow.

Programmed death ligand 1 (PD-L1) has been shown to be inducibly expressed on neutrophils to suppress host immunity during polymicrobial sepsis, virus and parasite infections. However, the role of PD-L1 on neutrophil-mediated antifungal immunity remains wholly unknown. Here, we show that the expression of PD-L1 on murine and human neutrophils was upregulated upon the engagement of C-type lectin receptor Dectin-1 with its ligand ß-glucans, exposed on fungal pathogen Candida albicans yeast. Moreover, ß-glucan stimulation induced PD-L1 translocation into nucleus to regulate the production of chemokines CXCL1 and CXCL2, which control neutrophil mobilization. Importantly, C. albicans infection-induced expression of PD-L1 leads to neutrophil accumulation in bone marrow, through mediating their autocrine secretion of CXCL1/2. Furthermore, neutrophil-specific deficiency of PD-L1 impaired CXCL1/2 secretion, which promoted neutrophil migration from bone marrow into the peripheral circulation, thereby conferring host resistance to C. albicans infection. Finally, either PD-L1 blockade or pharmacological inhibition of PD-L1 expression significantly increased neutrophil release from bone marrow to enhance host antifungal immunity. Our data together indicate that activation of Dectin-1/PD-L1 cascade by ß-glucans inhibits neutrophil release from bone marrow reserve, contributing to the negative regulation of antifungal innate immunity, which functions as a potent immunotherapeutic target against life-threatening fungi infections.

ETV5 overexpression promotes progression of esophageal squamous cell carcinoma by upregulating SKA1 and TRPV2.

Esophageal squamous cell carcinoma (ESCC) is notorious for the rapid progression especially early tumor metastasis due to the unclear mechanism. Recently, ETV5 attracts much attention for its potential role as an oncogenic transcription factor involved in multiple cancers. However, no one reported the mechanism behind the association between ETV5 expression and esophageal squamous cell carcinoma progression. In this study, we found that ETV5 was upregulated in ESCC both from online database and our ESCC tissues and ETV5 was associated with tumor staging and prognosis. Knockdown of ETV5 or its downstream genes SKA1 and TRPV2 significantly suppress ESCC cells migration and invasion, respectively. Additionally, in vivo study showed knockdown of ETV5 inhibited tumor metastasis. Further experiments unveiled ETV5 could transcriptionally upregulate the expression of SKA1 and TRPV2 and further activate MMPs in ESCC progression. In conclusion, ETV5 was associated with ESCC tumor staging and ESCC prognosis clinically. ETV5 promoted metastasis of ESCC by activating MMPs through augmenting the transcription of SKA1 and TRPV2. ETV5 was likely to be a novel oncogene and therapeutic target in ESCC.

Blood glucose mediated the effects of cognitive function impairment related to aluminum exposure in Chinese aluminum smelting workers.

OBJECT: To explore the effects of occupational aluminum exposure on workers' cognitive function and blood glucose concentration, and to analyze whether blood glucose concentration can mediate the cognitive changes caused by aluminum. METHOD: Our study recruited 375 workers from an aluminum factory in northern China. We collected the fasting elbow venous blood of the workers, measured their fasting blood glucose concentration (FBG), and used ICP-MS to determine plasma aluminum concentration (P-Al) as an indicator of internal exposure. The Montreal Cognitive Assessment (MoCA), was used to assess the cognitive function of workers. Generalized linear model was used to analyze the association of P-Al with cognitive function and blood glucose concentration, and the restricted cubic spline model was used to fit the dose-response relationship. We also conducted a mediation effect analysis. RESULT: We observed the dose-response relationship, that is, as the P-Al increased, sum of MoCA, visuospatial/executive, naming, language, and abstraction scores decreased, and the blood glucose concentration increased. For every e-fold increase in P-Al, sum of MoCA, visuospatial/executive, naming, language, and abstraction scores decreased by 0.328 points, 0.120 points, 0.059 points, 0.060 points, and 0.083 points, respectively, and FBG rose by 0.109 mmol/L. FBG has a significant mediating effect between P-Al and sum of MoCA (P for mediator=0.042), and it could explain 10.7% of the effect of cognitive level related to P-Al. CONCLUSION: Occupational aluminum exposure negatively affected the cognitive function of workers and positively affected FBG. FBG may partially explain the impact of occupational aluminum exposure on workers' cognitive function.

Hypoxic ucMSC-secreted exosomal miR-125b promotes endothelial cell survival and migration during wound healing by targeting TP53INP1.

A hypoxic microenvironment is a common feature of skin wounds. Our previous study demonstrated that three-dimensional coculture of umbilical cord-derived mesenchymal stem cells (ucMSCs) and endothelial cells facilitates cell communication and host integration in skin tissue engineering. Here, we aimed to identify the mechanism by which ucMSCs affect endothelial cells under hypoxic conditions after skin injury. We demonstrate that hypoxia enhances the exosome-mediated paracrine function of ucMSCs, which increases endothelial cell proliferation and migration. In a mouse full-thickness skin injury model, ucMSC-derived exosomes can be taken up by endothelial cells and accelerate wound healing. Hypoxic exosomes lead to a better outcome than normoxic exosomes by promoting proliferation and inhibiting apoptosis. Mechanistically, microRNA-125b (miR-125b) transcription is induced by hypoxia in ucMSCs. After being packaged into hypoxic exosomes and transported to endothelial cells, miR-125b targets and suppresses the expression of tumor protein p53 inducible nuclear protein 1 (TP53INP1) and alleviates hypoxia-induced cell apoptosis. Inhibition of miR-125b-TP53INP1 interaction attenuates the protective effect of hypoxic exosomes. Moreover, artificial agomiR-125b can accelerate wound healing in vivo. Our findings reveal communication between ucMSCs and endothelial cells via exosomal miR-125b/TP53INP1 signaling in the hypoxic microenvironment and present hypoxic exosomes as a promising therapeutic strategy to enhance cutaneous repair.

Longitudinal study of the effects of occupational aluminium exposure on workers' cognition.

OBJECTIVE: To explore the effects of occupational aluminium(Al) exposure on workers' cognition through a longitudinal study. METHODS: The study population consisted of 276 workers in an Al factory. In 2014, we used inductively coupled plasma mass spectrometry (ICP-MS) to determine the plasma aluminium (P-Al) concentration of the workers, and a combined questionnaire to test the workers' cognitive function. Followed-up in 2016, the workers were tested again for cognitive function. Generalized linear regression was used to assess the association between P-Al concentration and cognitive scores, and multivariable logistic regression was used to assess the risk of cognitive decline caused by Al exposure. RESULTS: Generalized linear regression results showed that a non-significant association was found between the P-Al concentration and cognitive test scores (P > 0.05) in 2014. Two years later, each 10-fold increase in P-Al concentration was inversely associated with the score of Mini-Mental state examination (MMSE) (ß: -0.53, 95% CI: -0.86, -0.20) and Fuld object memory evaluation (FOME) (ß: -0.93, 95% CI: -1.62, -0.24). Each 10-fold increase in P-Al concentration was inversely associated with MMSE2016-2014 (ß: -0.38, 95% CI: -0.74, -0.01) and FOME2016-2014 (ß: -1.20, 95% CI: -1.95, -0.45). There was a statistically significant difference in the average annual rate of change of MMSE and FOME with the tertile of P-Al concentration increase (P < 0.05). The multivariable logistic regression results showed that as the P-Al concentration increased, the risk of a FOME score decline increased (Ptrend = 0.009). CONCLUSIONS: Continuous occupational Al exposure can damage workers' overall cognitive ability, especially episodic memory function.

Cross-sectional study based on occupational aluminium exposure population.

To evaluate the different characteristics of cognitive impairment caused by occupational aluminium exposure at different ages, we surveyed 1660 workers in Shanxi Aluminium Plant, China, and assessed their cognitive function and plasma aluminium concentration. In multiple linear regression, the scores of the digit-span test (DST) and digit-span backward test (DSBT) were negatively correlated with plasma aluminium concentration when concentration reached 34.52 µg/L in younger group (＜40 years), while in the middle-aged group (≥40 years) only found when concentration reached 42.25 µg/L (ß<0, P < 0.05). In logistic regression, when plasma aluminum concentration reached 42.25µg/L, odds ratios (95 % confidence interval) were 1.695 (1.062-2.705) and 3.270 (1.615-6.620) for DST, 7.644 (3.846-15.192) and 15.308 (4.180-56.059) for DSBT in middle-aged group and younger group, respectively. These results showed that aluminium exposures were associated with cognitive impairment among aluminium-exposed workers, particularly for young workers who were more susceptible.

ADP-ribosylation factors improve biomass yield and salinity tolerance in transgenic switchgrass (Panicum virgatum L.).

KEY MESSAGE: PvArf regulate proline biosynthesis by physically interacting with PvP5CS1 to improve salt tolerance in switchgrass. The genetic factors that contribute to stress resiliency are yet to be determined. Here, we identified three ADP-ribosylation factors, PvArf1, PvArf-B1C, and PvArf-related, which contribute to salinity tolerance in transgenic switchgrass (Panicum virgatum L.). Switchgrass overexpressing each of these genes produced approximately twofold more biomass than wild type (WT) under normal growth conditions. Transgenic plants accumulated modestly higher levels of proline under normal conditions, but this level was significantly increased under salt stress providing better protection to transgenic plants compared to WT. We found that PvArf genes induce proline biosynthesis genes under salt stress to positively regulate proline accumulation, and further demonstrated that PvArf physically interact with PvP5CS1. Moreover, the transcript levels of two key ROS-scavenging enzyme genes were significantly increased in the transgenic plants compared to WT, leading to reduced H2O2 accumulation under salt stress conditions. PvArf genes also protect cells against stress-induced changes in Na+ and K+ ion concentrations. Our findings uncover that ADP-ribosylation factors are key determinants of biomass yield in switchgrass, and play pivotal roles in salinity tolerance by regulating genes involved in proline biosynthesis.

Change in Functional Brain Activation Patterns Induced by Olfactory Stimulation in Multiple Sclerosis.

BACKGROUND: Olfactory disorder is one of the commonly appearing symptoms in diseases like Parkinson's disease (PD) and Alzheimer's disease (AD). However, reports of olfactory changes in multiple sclerosis (MS) are scarce and usually ignored or seldom recognized by clinicians. The majority of current research is based on subjective answers obtained by smelling odorants. OBJECTIVE: To gain better insights into the central brain regions involved in the olfactory process. We measured preliminary contrast assessment characteristics of brain activation in MS patients and healthy controls using functional magnetic resonance imaging (fMRI) under an odor stimulation task. METHODS: Olfactory event-related fMRI was used to assess the olfactory network neuronal activity during passively inhaled volatile gases of lavender and rose solutions alternately in 18 MS patients and 20 healthy sex- and age-matched adults. Spearman correlation analysis was conducted between the lesions in central and olfactory-induced activated brain regions. RESULTS: We observed significant reductions in the number of activated brain areas compared with healthy controls in MS patients under a standard activation mode; the right insula, right amygdala, right inferior frontal gyrus, right frontal middle gyrus, and left supramarginal gyrus were activated in MS patients (t = 2.04, P < 0.05). Meanwhile, the intensity of the activated olfactory brain network revealed attenuation. The Spearman correlation analysis indicated the distribution and number of demyelination lesions, exerting a little impact on major activation of brain regions during olfactory stimulation (r = -0.524, P = 0.054). CONCLUSION: This study establishes that olfaction-related brain regions were altered in patients with MS confirmed by fMRI. The finding refreshes the awareness that olfactory disturbance involved just in structural pathology like olfactory bulbs and tracts or olfactory sulcus, which reportedly is responsible for the deficits.

miR-210 Participates in Hepatic Ischemia Reperfusion Injury by Forming a Negative Feedback Loop With SMAD4.

BACKGROUND AND AIMS: Hepatic ischemia-reperfusion (IR) injury is a major complication of liver transplantation, resection, and hemorrhagic shock. Hypoxia is a key pathological event associated with IR injury. MicroRNA-210 (miR-210) has been characterized as a micromanager of hypoxia pathway. However, its function and mechanism in hepatic IR injury is unknown. APPROACH AND RESULTS: In this study, we found miR-210 was induced in liver tissues from patients subjected to IR-related surgeries. In a murine model of hepatic IR, the level of miR-210 was increased in hepatocytes but not in nonparenchymal cells. miR-210 deficiency remarkably alleviated liver injury, cell inflammatory responses, and cell death in a mouse hepatic IR model. In vitro, inhibition of miR-210 decreased hypoxia/reoxygenation (HR)-induced cell apoptosis of primary hepatocytes and LO2 cells, whereas overexpression of miR-210 increased cells apoptosis during HR. Mechanistically, miR-210 directly suppressed mothers against decapentaplegic homolog 4 (SMAD4) expression under normoxia and hypoxia condition by directly binding to the 3' UTR of SMAD4. The pro-apoptotic effect of miR-210 was alleviated by SMAD4, whereas short hairpin SMAD4 abrogated the anti-apoptotic role of miR-210 inhibition in primary hepatocytes. Further studies demonstrated that hypoxia-induced SMAD4 transported into nucleus, in which SMAD4 directly bound to the promoter of miR-210 and transcriptionally induced miR-210, thus forming a negative feedback loop with miR-210. CONCLUSIONS: Our study implicates a crucial role of miR-210-SMAD4 interaction in hepatic IR-induced cell death and provides a promising therapeutic approach for liver IR injury.

Proline Biosynthesis Enzyme Genes Confer Salt Tolerance to Switchgrass (Panicum virgatum L.) in Cooperation With Polyamines Metabolism.

Understanding the regulation of proline metabolism necessitates the suppression of two Δ1-pyrroline-5-carboxylate synthetase enzyme (P5CS) genes performed in switchgrass (Panicum virgatum L.). The results reveal that overexpressing PvP5CS1 and PvP5CS2 increased salt tolerance. Additionally, transcript levels of spermidine (Spd) and spermine (Spm) synthesis and metabolism related genes were upregulated in PvP5CS OE-transgenic plants and downregulated in the PvP5CS RNAi transformants. According to salt stress assay and the measurement of transcript levels of Polyamines (PAs) metabolism-related genes, P5CS enzyme may not only be the key regulator of proline biosynthesis in switchgrass, but it may also indirectly affect the entire subset of pathway for ornithine to proline or to putrescine (Put). Furthermore, application of proline prompted expression levels of Spd and Spm synthesis and metabolism-related genes in both PvP5CS-RNAi and WT plants, but transcript levels were even lower in PvP5CS-RNAi compared to WT plants under salt stress condition. These results suggested that exogenous proline could accelerate polyamines metabolisms under salt stress. Nevertheless, the enzymes involved in this process and the potential functions remain poorly understood. Thus, the aim of this study is to reveal how proline functions with PAs metabolism under salt stress in switchgrass.

Sex-specific difference in placental inflammatory transcriptional biomarkers of maternal phthalate exposure: a prospective cohort study.

Previous epidemiologic research has shown that phthalate exposure in pregnant women is related to birth outcomes in a sex-specific manner. These outcomes may be mediated by placental inflammation, which is the proposed biological mechanism. This is the first study to address the relationship between phthalate exposure and gene expression in placental inflammation in a sex-specific manner. We performed quantitative PCR to measure placental inflammatory mRNAs (CRP, TNF-α, IL-1ß, IL-6, IL-10, MCP-1, IL-8, CD68, and CD206) in 2469 placentae that were sampled at birth. We estimated the associations between mRNA and urinary phthalate monoesters using multiple linear regression models. Mono-n-butyl phthalate (MBP) was correlated with higher IL-1ß, IL-6, and CRP expression in placentae of male fetuses and with higher IL-6, CRP, MCP-1, IL-8, IL-10, and CD68 expression in placentae of female fetuses. Mono benzyl phthalate (MBzP) increased the expression of TNF-α, MCP-1, and CD68 only in placentae of male fetuses. Mono (2-ethyl-5-oxohexyl) phthalate (MEOHP) was negatively correlated with CRP, MCP-1, and CD68 in placentae of female fetuses. Maternal phthalate exposure was associated with inflammatory variations in placental tissues. The associations were stronger in placentae of male than of female fetuses. Compared with the other metabolites, MBP plays a strong role in these associations. The placenta is worth being further investigated as a potential mediator of maternal exposure-induced disease risk in children.

Urinary concentrations of phthalate metabolites during gestation and intrahepatic cholestasis of pregnancy: a population-based birth cohort study.

Phthalates, a class of widely used endocrine-disrupting chemicals (EDCs), are toxic to various organ systems in animals and humans. Intrahepatic cholestasis of pregnancy (ICP) is a reversible liver dysfunction causing cholestasis in late pregnancy. Evidence on the associations between exposure to phthalates and ICP is still lacking. In the present study, we investigated the relationships between urinary concentrations of phthalate metabolites and the risk of ICP in a Chinese population-based birth cohort. Pregnant women participated in the Ma'anshan Birth Cohort (MABC) study in China. Seven phthalate metabolites were detected in a urine sample in early pregnancy. Chemical concentrations were grouped by quartiles, and associations with outcomes were examined using logistic regression with adjustment for urine creatinine, race, education, poverty status, smoking status, alcohol consumption, maternal age, prepregnancy body mass index (BMI), parity, twin pregnancy, and pregnancy-related liver complications. Of 3474 women recruited into the Ma'anshan Birth Cohort, 2760 met the inclusion criteria and contributed to further analysis and biomonitoring data. Elevated odds ratios (ORs) of ICP were observed in the highest quartiles of monomethyl phthalate (MMP) exposure (OR = 1.59, 95% confidence intervals (CI) = 1.01-2.51) and monobutyl phthalate (MBP) exposure (OR = 1.82, 95% CI = 1.16-2.85) in the adjusted analyses. Our findings add to the evidence that supports the role of maternal phthalate exposure in the first trimester of gestation as a risk factor for ICP.

Proline improves switchgrass growth and development by reduced lignin biosynthesis.

Transgenic switchgrass overexpressing Lolium perenne L. delta1-pyrroline 5-carboxylate synthase (LpP5CS) in group I (TG4 and TG6 line) and group II (TG1 and TG2 line) had significant P5CS and ProDH enzyme activities, with group I plants (TG4 and TG6) having higher P5CS and lower ProDH enzyme activity, while group II plants had higher ProDH and lower P5CS enzyme activity. We found group II transgenic plants showed stunted growth, and the changed proline content in overexpressing transgenic plants may influence the growth and development in switchgrass. RNA-seq analysis showed that KEGG enrichment included phenylpropanoid biosynthesis pathway among group I, group II and WT plants, and the expression levels of genes related to lignin biosynthesis were significantly up-regulated in group II. We also found that lignin content in group II transgenic plants was higher than that in group I and WT plants, suggesting that increased lignin content may suppress switchgrass growth and development. This study uncover that proline can appropriately reduce lignin biosynthesis to improve switchgrass growth and development. Therefore, appropriate reduction in lignin content and increase in biomass are important for bioenergy crop to lower processing costs for biomass fermentation-derived fuels.

Overexpression of the Lolium perenne L. delta1-pyrroline 5-carboxylate synthase (LpP5CS) gene results in morphological alterations and salinity tolerance in switchgrass (Panicum virgatum L.).

In plants, Δ1-pyrroline- 5-carboxylate synthase (P5CS) is the rate-limiting enzyme in proline biosynthesis. In this study, we introduced the LpP5CS (Lolium perenne L.) gene into switchgrass by Agrobacterium-mediated transformation. The transgenic lines (TG) were classified into two groups based on their phenotypes and proline levels. The group I lines (TG4 and TG6) had relatively high proline levels and improved biomass yield. The group II lines (TG1 and TG2) showed low proline levels, severely delayed flowering, stunted growth and reduced biomass yield. Additionally, we used RNA-seq analysis to detect the most significant molecular changes, and we analyzed differentially expressed genes, such as flowering-related and CYP450 family genes. Moreover, the biomass yield, physiological parameters, and expression levels of reactive oxygen species scavenger-related genes under salt stress all indicated that the group I plants exhibited significantly increased salt tolerance compared with that of the control plants, in contrast to the group II plants. Thus, genetic improvement of switchgrass by overexpressing LpP5CS to increase proline levels is feasible for increasing plant stress tolerance.

Overexpression of gene encoding the key enzyme involved in proline-biosynthesis (PuP5CS) to improve salt tolerance in switchgrass (Panicum virgatum L.).

KEY MESSAGE: Genetic improvement through overexpressing PuP5CS in switchgrass is feasible for enhancing plant salt stress tolerance. Switchgrass (Panicum virgatum L.) has developed into a dedicated bioenergy crop. To improve the biomass production of switchgrass grown on different types of soil, abiotic stress tolerance traits are considered for its genetic improvement. Proline accumulation is a widespread response when plants are subjected to abiotic stresses such as drought, cold and salinity. In plants, P5CS gene encodes the key regulatory enzyme that plays a crucial role in proline biosynthesis. Here, we introduced the PuP5CS gene (from Puccinellia chinampoensis) into switchgrass by Agrobacterium-mediated transformation. Transgenic lines overexpressing the PuP5CS gene showed phenotypic advantages, in leaf width, internode diameter, internode length, tiller numbers and precocious flowering under normal conditions, and the transgenic lines displayed better regenerative capacity in forming more tillers after harvest. Moreover, the PuP5CS gene enhanced the salt tolerance of transgenic switchgrass by altering a wide range of physiological responses. In accordance with the physiological results, histological analysis of cross sections through the leaf blade showed that the areas of bulliform cells and bundle sheath cells were significantly increased in PuP5CS-overexpressing leaves. The expression levels of ROS scavenging-associated genes in transgenic plants were higher than in control plants under salt stress. The results show that genetic improvement through overexpressing PuP5CS in switchgrass is feasible for enhancing plant stress tolerance.

Effects of the phthalate exposure during three gestation periods on birth weight and their gender differences: A birth cohort study in China.

Phthalate has been widely used as a type of plasticiser in various consuming products in daily life. Recent studies have suggested that prenatal phthalate exposure may have adverse effects on fetal development. We aimed to identify the effects of in utero phthalate exposure on birth weight (BW). We evaluated a birth cohort comprising 3474 pregnant women and their single infants; 3103, 2975 and 2838 urine samples were collected in the first, second and third trimesters, respectively. Phthalate metabolites included monomethyl phthalate (MMP), monoethyl phthalate (MEP), mono-n-butyl phthalate (MBP), monobenzyl phthalate (MBzP), mono-(2-ethylhexyl) phthalate (MEHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEHHP), and mono-(2-ethyl-5-hydroxylhexyl) phthalate (MEOHP), which were analysed in the urine by using high performance liquid chromatography-tandem mass spectrometry. Mixed linear model was used in the statistical analysis. Generally, MMP and MEP exposure during pregnancy was associated with decreased birth weight of infants (MMP, ß=-12.192, p=0.009; MEP, ß=-11.876, p=0.014). Hierarchical analysis found that MMP and MEOHP exposure was associated with decreased infants' birth weight only in low birth weight groups (MMP, ß=-42.538, p=0.005; MEOHP, ß=-63.224, p=0.008); MEHP and MEHHP exposure was associated with decreased infants' birth weight in both low birth weight group (MEHP, ß=-42.348, p=0.035; MEHHP, ß=-50.485, p=0.006) and high birth weight group (MEHP, ß=-16.580, p=0.034; MEHHP, ß=-18.009, p=0.040), MBP and MEHP exposure were associated with increased infants' birth weight in male NBW group (MBP, ß=10.438, p=0.039; MEHP, ß=13.223, p=0.017). Moreover, the effect has sex difference. The reduction of birth weight associated with MEHP and MEOHP exposure was stronger in male infants, while MMP and MEP exposure was more significant in female infants.

Prenatal phthalate exposure and placental size and shape at birth: A birth cohort study.

OBJECTIVE: There is concern over the potential placental effects of prenatal phthalate exposure, and the potential adverse effects of prenatal phthalate exposure require further study; however, few data are available in humans. We investigated the associations between phthalate exposure in each trimester and both placental size and shape at birth. METHODS: We measured the urinary concentrations of phthalate metabolites among 2725 pregnant women in the Ma'anshan Birth Cohort. Before collecting urine samples from each of the three trimesters, the pregnant women were interviewed via questionnaires. Placental information was obtained from hospital records. We estimated the sex-specific associations between urinary phthalate concentrations in each trimester and both placental size and shape at birth using adjusted multiple regression. A linear mixed model was used for the repeated measures analysis with subject-specific random intercepts and slopes for gestational age at sample collection to test the effect of phthalate levels on placental size and shape and to estimate the effect sizes. RESULTS: Overall, placental breadth increased by 0.148cm (95% CI: 0.078, 0.218) with each 1 ln-concentration increase in MBP in the first trimester. The difference between placental length and breadth (length-breadth) decreased by 0.086cm (95% CI: -0.159, -0.012) and 0.149cm (95% CI: -0.221, -0.076) with each 1 ln-concentration increase in MMP and MBP, respectively, in the first trimester. In the second trimester, placental thickness increased by 0.017cm (95% CI: 0.006, 0.027), 0.020cm (95% CI: 0.004, 0.036), 0.028cm (95% CI: 0.007, 0.048), and 0.035cm (95% CI: 0.018, 0.053) with each 1 ln-concentration increase in MMP, MBP, MEOHP, and MEHHP, respectively. In the third trimester, placental thickness increased by 0.037cm (95% CI: 0.019, 0.056) and 0.019cm (95% CI: 0, 0.037) with each 1 ln-concentration increase in MBP and MEHP, respectively. Multiple linear regression for each offspring sex indicated that prenatal phthalate exposure increased placental thickness in both the first and second trimesters in males, whereas the corresponding relationship was close to null in females. Linear mixed models (LMMs) yielded similar results. CONCLUSION: Our results suggest the presence of associations between prenatal phthalate exposure and placental size and shape. Exposure to certain phthalates may cause the placenta to become thicker and more circular. Associations appeared stronger for the subsample representing male offspring than those for the subsample representing female offspring. Given the few studies on this topic, additional research is warranted.