Nickel nanoparticles exert cytotoxic effects on trophoblast HTR-8/SVneo cells possibly via Nrf2/MAPK/caspase 3 pathway.

Nickel nanoparticles are widely used in the industry and may affect the reproductive system. The potential molecular mechanism of exposing the first-trimester trophoblast cell line (HTR-8/SVneo) to nickel nanoparticles remains unclear. Hence, the aim of this study was to investigate the in vitro cytotoxicity of Ni NPs on HTR-8/SVneo cells. HTR-8/SVneo cells were subjected to various concentrations (0, 2.5, 5, 7.5, 10, and 12.5 µg/cm2) of Ni NPs. The toxicity of the Ni NPs was evaluated in HTR-8/SVneo cells by measuring cell viability. The underlying mechanism of nickel nanoparticles toxicity to HTR-8/SVneo cells was determined by measuring the content of intracellular reactive oxygen species, mitochondrial membrane potential, and the rate of cell apoptosis and cell cycle, by measuring adenosine triphosphate levels, intracellular lipid peroxidation malondialdehyde, total superoxide dismutase, and CuZn/Mn-SOD activities, and by determining proteins related to Nrf2, MAPK, and Cytochrome c. Our results showed that the nickel nanoparticles treatment reduced the viability of HTR-8/SVneo cells, while it increased their oxidative stress and lowered their mitochondrial respiratory capacity. Additionally, the nickel nanoparticles treatment induced cell S-phase arrest and apoptosis. These molecular events may be linked to the oxidative stress-Nrf2 pathway/MAPK/Caspase 3 cascade. Thus, nickel nanoparticles exert cytotoxic effects on HTR-8/SVneo cells, which could affect the function of the placenta in human.

ROS generation is involved in titanium dioxide nanoparticle-induced AP-1 activation through p38 MAPK and ERK pathways in JB6 cells.

Titanium dioxide (TiO2 ) is generally regarded as a nontoxic and nongenotoxic white mineral, which is mainly applied in the manufacture of paper, paint, plastic, sunscreen lotion and other products. Recently, TiO2 nanoparticles (TiO2 NPs) have been demonstrated to cause chronic inflammation and lung tumor formation in rats, which may be associated with the particle size of TiO2 . Considering the important role of activator protein-1 (AP-1) in regulating multiple genes involved in the cell proliferation and inflammation and the induction of neoplastic transformation, we aimed to evaluate the potency of TiO2 NPs (≤ 20 nm) on the activation of AP-1 signaling pathway and the generation of reactive oxygen species (ROS) in a mouse epidermal cell line, JB6 cells. MTT, electron spin resonance (ESR), AP-1 luciferase activity assay in vitro and in vivo, and Western blotting assay were used to clarify this problem. Our results indicated that TiO2 NPs dose-dependently caused the hydroxyl radical (·OH) generation and sequentially increased the AP-1 activity in JB6 cells. Using AP-1-luciferase reporter transgenic mice models, an obvious increased AP-1 activity was detected in dermal tissue after exposure to TiO2 NPs for 24 h. Interestingly, TiO2 NPs increased the AP-1 activity via stimulating the expression of mitogen-activated protein kinases (MAPKs) family members, including extracellular signal-regulated protein kinases (ERKs), p38 kinase, and C-Jun N-terminal kinases (JNKs). Of note, the AP-1 activation induced by TiO2 NPs could be blocked by specific inhibitors (SB203580, PD98059, and SP 600125, respectively) that inhibit ERKs and p38 kinase but not JNKs. These findings indicate that ROS generation is involved in TiO2 NPs-induced AP-1 activation mediated by MAPKs signal pathway.

Designing a general method for predicting the regulatory relationships between long noncoding RNAs and protein-coding genes based on multi-omics characteristics.

MOTIVATION: Long noncoding RNA (lncRNA) has been verified to interact with other biomolecules especially protein-coding genes (PCGs), thus playing essential regulatory roles in life activities and disease development. However, the inner mechanisms of most lncRNA-PCG relationships are still unclear. Our study investigated the characteristics of true lncRNA-PCG relationships and constructed a novel predictor with machine learning algorithms. RESULTS: We obtained the 307 true lncRNA-PCG pairs from database and found that there are significant differences in multiple characteristics between true and random lncRNA-PCG sets. Besides, 3-fold cross-validation and prediction results on independent test sets show the great AUC values of LR, SVM and RF, among which RF has the best performance with average AUC 0.818 for cross-validation, 0.823 and 0.853 for two independent test sets, respectively. In case study, some candidate lncRNA-PCG relationships in colorectal cancer were found and HOTAIR-COMP interaction was specially exemplified. The proportion of the reported pairs in the predicted positive results was significantly higher than that in negative results (P < 0.05). SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Genome-wide identification of the essential protein-coding genes and long non-coding RNAs for human pan-cancer.

MOTIVATION: Genome-scale CRISPR/Cas9 system has been a democratized gene editing technique and widely used to investigate gene functions in some biological processes and diseases especially cancers. Aiming to characterize gene aberrations and assess their effects on cancer, we designed a pipeline to identify the essential genes for pan-cancer. METHODS: CRISPR screening data were used to identify the essential genes that were collected from published data and integrated by Robust Rank Aggregation algorithm. Then, hypergeometrics test and random walks with restart (RWR) were used to predict additional essential genes on broader scale. Finally, the expression status and potential roles of these genes were explored based on TCGA portal and regulatory network analysis. RESULTS: We collected 926 samples from 10 CRISPR-based screening studies involving 33 different types of cancer to identify cancer-essential genes, which consists of 799 protein-coding genes (PCGs) and 97 long non-coding RNAs (lncRNAs). Then, we constructed a 'bi-colored' network with both PCGs and lncRNAs and applied it to predict additional essential genes including 495 PCGs and 280 lncRNAs on a broader scale using hypergeometrics test and RWR. After obtaining all essential genes, we further investigated their potential roles in cancer and found that essential genes have higher and more stable expression levels, and are associated with multiple cancer-associated biological processes and survival time. The regulatory network analysis detected two intriguing modules of essential genes participating in the regulation of cell cycle and ribosome biogenesis in cancer. AVAILABILITY AND IMPLEMENTATION: . SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Microarray Profiling of Circular RNA Identifies hsa_circ_0126991 as a Potential Risk Factor for Essential Hypertension.

Essential hypertension (EH), a major cause of cardiovascular diseases, is an important public health issue. However, the molecular mechanisms involved in EH remain unknown. Circular RNA (circRNA) is a novel promising biomarker for the disease. The purpose of the present study was to determine the expression of circRNAs in the blood of EH patients and to evaluate the performance of circRNA for early diagnosis of EH. A total of 178 subjects were recruited in the case-control study. Initial screening was done by using the Agilent human circRNA microarray followed by qRT-PCR validation. Finally, miRNAs were combined with circRNAs to create a new early prediction model for EH. The expression level of hsa_circ_0126991 in EH patients was significantly higher in comparison with healthy controls (p < 0.0001). Using the interaction of miR-10a-5p in combination with hsa_circ_0126991 led to a sensitivity of 0.708, a specificity of 0.764, and combined area under the curve of 0.774 (95% CI: 0.705-0.843) for early diagnosis of EH. In summary, the present study uncovered a novel perspective that hyperexpression of hsa_circ_0126991 is correlated with the risk of EH and may serve as a stable biomarker for early diagnosis of EH.

Mechanistic insight, diagnosis, and treatment of ammonia-induced hepatic encephalopathy.

Hepatic encephalopathy is a neuropsychological syndrome due to biochemical disturbance of brain function in advanced liver disease patients. Diagnosis and treatment of the condition is very demanding and has negative toll on finances with increased healthcare utilization. The pathophysiology is not completely understood; however, there is evidence that ammonia plays an important role in the etiology. Conventional methods of solely relying on blood ammonia level to diagnose hepatic encephalopathy did not help much; likewise, the use of lactulose alone in treating hepatic encephalopathy has also been discouraged. This paper analyzed the current knowledge regarding the mechanism of how ammonia disrupts the normal brain function as well as the use of latest diagnosing tools including those under development to evaluate the neuropsychiatric state of patients and their quality of life. The efficacies of lactulose and rifaximin combination for short-term and long-term treatment in addition to nutritional interventions and other drugs undergoing clinical trials were also reviewed.

Up-regulation of circular RNA hsa_circ_0037909 promotes essential hypertension.

AIMS: Essential hypertension (EH) is a high prevalence disease facing a public health challenge. People were little known about the genetics of diagnosing the cause of EH. Circular RNAs that have a continuous cycle of covalent closure, without affected by RNA exonuclease, and are more stable and hard to degrade may involve into the molecule regulation mechanism of EH as an important biomedical. METHODS: qRT-PCR was used to analyze circRNAs in total volume of human blood and the induced human aortic endothelial cells (HAECs) and human umbilical vein endothelial cells (HUVECs). Our case-control study was involved with 48 pairs of case controls with sex and age (±3 years) match. We conducted t test, Pearson's χ2 test, and receiver operating characteristics (ROC) curve analysis for the corresponding analysis. RESULTS: The expression level of hsa_circ_0037909 in EH patients was significantly higher than that in the healthy controls (P = 0.007), and the expression level of hsa-miR-637 in EH patients was significantly lower in than that in the healthy controls (P = 0.039); the same result appears in the HAECs and HUVECs. Hsa-miR-637 (adjusted P = 0.018), hsa_circ_0037909 (adjusted P = 0.005), HDL (adjusted P = 0.024), and serum creatinine (adjusted P = 0.014) were brought into the model which performed logistic regression analysis. The combination of two RNAs was excellent (P < 0.001) through ROC curve analysis. Hsa_circ_0037909 was significantly positively correlated with serum creatinine (P < 0.001) and low-density lipoprotein (LDL) (P = 0.017). CONCLUSIONS: Our findings suggested that the combination of hsa_circ_0037911 and hsa-miR-637 may be a significant important biomarker for early diagnosis of EH. Hsa_circ_0037909 may affect serum creatinine or LDL leading to the formation of EH.

Serine hydroxymethyltransferase 1 promoter hypermethylation increases the risk of essential hypertension.

BACKGROUND: Serine hydroxymethyltransferase 1 (SHMT1) is an enzyme involved in folic acid metabolism and is known to contribute to the development of hypertension. We evaluated the relationship between SHMT1 promoter methylation and essential hypertension (EH). METHODS: Quantitative methylation-specific polymerase chain reaction was used to measure the SHMT1 promoter methylation level in 241 EH patients and 288 age- and gender-matched healthy individuals. The diagnostic value of SHMT1 promoter hypermethylation was analyzed using a receiver operating characteristic (ROC) curve. The Gene Expression Omnibus (GEO) database and dual-luciferase reporter assay were used to validate our findings. RESULTS: Compared with the control group, significant differences in SHMT1 promoter methylation were found in both EH and hyperhomocysteinemia groups (P < 0.001 and P = 0.029, respectively). The area under the curve of the diagnosis of SHMT1 promoter hypermethylation for EH was 0.808, with a sensitivity and specificity of 73.9% and 77.8%, respectively. The risk of SHMT1 promoter hypermethylation was significantly higher in the >65-year group than in the ≤65-year group (odds ratio = 3.925; 95% confidence interval = 2.141-7.196). In addition, GEO database analysis showed that 5-aza-deoxycytidine increased gene expression in several carotid endothelial cell lines. A dual-luciferase reporter assay revealed that the target sequence in the SHMT1 promoter upregulated gene expression. CONCLUSION: Our findings indicate that SHMT1 promoter hypermethylation increases the risk of EH and may be a promising biomarker for EH.

Chemical composition database establishment and metabolite profiling analysis of Yangyin qingfei decoction.

The chemical fingerprinting and metabolite profile in a rat plasma sample after intragastric administration of Yangyin qingfei decoction (YYQFD, 14 g/kg) were investigated. First, YYQFD was analyzed by UPLC/Q-TOF MS to establish the chemical composition database by comparing their retention behavior, accurate molecular mass and MS2 data with those of references or known compounds in the literature. In this database, 100 chemical constituents with information on retention time, molecular mass, molecular formula, MS2 data and compound name were identified, which can provide compound information for further metabolite profiling studies. Furthermore, 64 compounds including 37 prototypes and 27 metabolites were detected in the dosed rat plasma sample, and the metabolic pathways of YYQFD were hydrolyzation, hydroxylation, dehydrogenation, glucuronidation, glucosylation, sulfation and mixed modes. Among the five component herbs in the YYQFD, Glycyrrhizae Radix et Rhizome and Fritillariae Thunbergii bulbs were actively metabolized, contributing 16 and 7 metabolites, respectively. It is suggested that chemical characterization and metabolite profiling studies are valuable to elucidate the material basis of herbal preparations.

Impact of ambient PM2.5 on adverse birth outcome and potential molecular mechanism.

PM2.5 (particulate matter ≤2.5 µm in aerodynamic diameter) refers to atmospheric particulate matter (PM) with an aerodynamic diameter of equal and less than 2.5 µm that tends to be suspended for long periods of time and travel over long distances in both outdoor and indoor atmospheres. PM2.5, along with the toxic compounds attached on it, may cause a wide range of disorders. The fetus is considered to be highly susceptible to a variety of toxicants including atmospheric pollutants such as PM2.5 through prenatal exposure. To better understand the relationship between maternal exposure to PM2.5 and adverse birth outcomes for reproduction and fetus development, we studied the published data on this issue including case-control studies, cohort studies and meta-analyses studies, and summarized the basic impact of ambient particulate matter on adverse birth outcomes. Research evidence indicates that PM2.5 has a potential to induce low birth weight (LBW), preterm birth (PTB), and stillbirth. A further in-depth analysis shows that oxidative stress, DNA methylation, mitochondrial DNA (mtDNA) content alteration, and endocrine disruptions may all play an important role in PM2.5 induced adverse effects to pregnant women and fetuses. In addition, PM2.5 exposure can cause male reproductive toxicity, leading to associated adverse pregnancy outcomes.

The regulatory network analysis of long noncoding RNAs in human colorectal cancer.

Colorectal cancer (CRC) is among one of the most prevalent and lethiferous diseases worldwide. Long noncoding RNAs (lncRNAs) are commonly accepted to function as a key regulatory factor in human cancer, but the potential regulatory mechanisms of CRC-associated lncRNA are largely obscure. Here, we integrated several expression profiles to obtain 55 differentially expressed (DE) lncRNAs. We first detected lncRNA interactions with transcription factors, microRNAs, mRNAs, and RNA-binding proteins to construct a regulatory network and then create functional enrichment analyses for them using bioinformatics approaches. We found the upregulated genes in the regulatory network are enriched in cell cycle and DNA damage response, while the downregulated genes are enriched in cell differentiation, cellular response, and cell signaling. We then employed module-based methods to mine several intriguing modules from the overall network, which helps to classify the functions of genes more specifically. Next, we confirmed the validity of our network by comparisons with a randomized network using computational method. Finally, we attempted to annotate lncRNA functions based on the regulatory network, which indicated its potential application. Our study of the lncRNA regulatory network provided significant clues to unveil lncRNAs potential regulatory mechanisms in CRC and laid a foundation for further experimental investigation.

A Dual pH/Magnetic Responsive Nanocarrier Based on PEGylated Fe3O4 Nanoparticles for Doxorubicin Delivery.

Cancer chemotherapy has limitations such as nonselective distribution of drugs, detrimental side effects on normal tissues; here we reported a smart pH and magnetic sensitive drug delivery system (DDS) based on PEGylated Fe3O4 superparamagnetic nanoparticles. The citric-coated Fe3O4 (CIO) nanoparticles were firstly synthesized and further functionalized by biocompatible poly(ethylene glycol) bis(carboxymethyl ether) (COOH-PEG-COOH), thus PEGylated CIO (GCIO) nanoparticles were obtained. Doxorubicin (DOX) was conjugated as a model drug to the nanoparticles via hydrazone bond. The roughly sphere GCIO nanoparticles were comparatively strong magnetism with high drug loading capability (~89%) in relatively uniform size. Drug release study revealed that the GCIO-DOX performed pH-responsive drug-release properties. MTT assay demonstrated that GCIO nanoparticles possessed low cytotoxicity and good physiological stability. Further, cell viability results indicated that the GCIO-DOX showed effective cytotoxicity only a bit lower than free DOX. All obtained data indicated that the combined pH-responsive and magnetic multifunction drug delivery system can has excellent potential applications in cancer therapy.

Potential applications and human biosafety of nanomaterials used in nanomedicine.

With the rapid development of nanotechnology, potential applications of nanomaterials in medicine have been widely researched in recent years. Nanomaterials themselves can be used as image agents or therapeutic drugs, and for drug and gene delivery, biological devices, nanoelectronic biosensors or molecular nanotechnology. As the composition, morphology, chemical properties, implant sites as well as potential applications become more and more complex, human biosafety of nanomaterials for clinical use has become a major concern. If nanoparticles accumulate in the human body or interact with the body molecules or chemical components, health risks may also occur. Accordingly, the unique chemical and physical properties, potential applications in medical fields, as well as human biosafety in clinical trials are reviewed in this study. Finally, this article tries to give some suggestions for future work in nanomedicine research. Copyright © 2017 John Wiley & Sons, Ltd.

Hypomethylation of the Interferon γ Gene as a Potential Risk Factor for Essential Hypertension: A Case-Control Study.

Essential hypertension (EH) is a multifactorial disease. Interferon-γ (IFN-γ) plays an important role in the onset of EH through cytokine-mediated systemic inflammatory responses. We aimed to determine whether the methylation status of the IFN-γ gene (IFNG) promoter is involved in the pathogenesis of EH. Six copies of CpG dinucleotides are distributed between 3,203 bp and 3,121 bp upstream from the transcription initiation site of IFNG, termed CpG1 to CpG6 in the 5'-to-3' direction. We recruited 96 patients with EH and 96 sex- and age-matched healthy subjects as controls. Using bisulfate pyrosequencing datasets, we analyzed the methylation status of the six CpG sites and thus found that CpG5 was consistently methylated in all of the 96 EH patients and 96 control subjects. Among the remaining five CpG sites, there was no significant difference in the methylation levels of CpG4 and CpG6 between the two groups. By contrast, CpG1 (P = 0.003) and CpG3 (P = 5.87 × 10-7) were highly methylated among the EH subjects compared with the controls, whereas CpG2 (P = 1.24 × 10-12) was significantly less methylated in among EH subjects. The methylation levels of CpG2 were still lower after adjustment with logistic regression (adjusted P = 0.032). The CpG2 methylation level was an effective marker of EH (area under curve = 0.384; P = 1.40 × 10-15). The present study shows that hypomethylation of the IFNG promoter is significantly related to the risk of EH, providing new insights into the pathogenesis of EH.

In vitro evaluation of the toxicity and underlying molecular mechanisms of Janus Fe3 O4 -TiO2 nanoparticles in human liver cells.

Recent studies show that Janus Fe3 O4 -TiO2 nanoparticles (NPs) have potential applications as a multifunctional agent of magnetic resonance imaging (MRI) and photodynamic therapy (PDT) for the diagnosis and therapy of cancer. However, little work has been done on their biological effects. To evaluate the toxicity and underlying molecular mechanisms of Janus Fe3 O4 -TiO2 nanoparticles, an in vitro study using a human liver cell line HL-7702 cells was conducted. For comparison, the Janus Fe3 O4 -TiO2 NPs parent material TiO2 NPs was also evaluated. Results showed that both Fe3 O4 -TiO2 NPs and TiO2 NPs decreased cell viability and ATP levels when applied in treatment, but increased malonaldehyde (MDA) and reactive oxygen species (ROS) generation. Mitochondria JC-1 staining assay showed that mitochondrial membrane permeability injury occurred in both NPs treated cells. Cell viability analysis showed that TiO2 NPs induced slightly higher cytotoxicity than Fe3 O4 -TiO2 NPs in HL7702 cells. Western blotting indicated that both TiO2 NPs and Fe3 O4 -TiO2 NPs could induce apoptosis, inflammation, and carcinogenesis related signal protein alterations. Comparatively, Fe3 O4 -TiO2 NPs induced higher signal protein expressions than TiO2 NPs under a high treatment dose. However, under a low dose (6.25 µg/cm2 ), neither NPs had any significant toxicity on HL7702 cells. In addition, our results suggest both Fe3 O4 -TiO2 NPs and TiO2 NPs could induce oxidative stress and have a potential carcinogenetic effect in vitro. Further studies are needed to elaborate the detailed mechanisms of toxicity induced by a high dose of Fe3 O4 -TiO2 NPs.

Dual action of peroxisome proliferator-activated receptor alpha in perfluorodecanoic acid-induced hepatotoxicity.

Perfluorodecanoic acid (PFDA) is widely used in production of many daily necessities based on their surface properties and stability. It was assigned as a Persistent Organic Pollutant in 2009 and became a public concern partly because of its potential for activation of the peroxisome proliferator-activated receptor alpha (PPARα). In this study, wild-type and Ppara-null mice were administered PFDA (80 mg/kg). Blood and liver tissues were collected and subjected to systemic toxicological and mechanistic analysis. UPLC-ESI-QTOFMS-based metabolomics was used to explore the contributing components of the serum metabolome that led to variation between wild-type and Pparα-null mice. Bile acid homeostasis was disrupted, and slight hepatocyte injury in wild-type mice accompanied by adaptive regulation of bile acid synthesis and transport was observed. The serum metabolome in wild-type clustered differently from that in Pparα-null, featured by sharp increases in bile acid components. Differential toxicokinetic tendency was supported by regulation of UDP-glucuronosyltransferases dependent on PPARα, but it did not contribute to the hepatotoxic responses. Increase in Il-10 and activation of the JNK pathway indicated inflammation was induced by disruption of bile acid homeostasis in wild-type mice. Inhibition of p-p65 dependent on PPARα activation by PFDA stopped the inflammatory cascade, as indicated by negative response of Il-6, Tnf-α, and STAT3 signaling. These data suggest disruptive and protective role of PPARα in hepatic responses induced by PFDA.

Analytical Techniques and Pharmacokinetics of Gastrodia elata Blume and Its Constituents.

Gastrodia elata Blume (G. elata), commonly called Tianma in Chinese, is an important and notable traditional Chinese medicine (TCM), which has been used in China as an anticonvulsant, analgesic, sedative, anti-asthma, anti-immune drug since ancient times. The aim of this review is to provide an overview of the abundant efforts of scientists in developing analytical techniques and performing pharmacokinetic studies of G. elata and its constituents, including sample pretreatment methods, analytical techniques, absorption, distribution, metabolism, excretion (ADME) and influence factors to its pharmacokinetics. Based on the reported pharmacokinetic property data of G. elata and its constituents, it is hoped that more studies will focus on the development of rapid and sensitive analytical techniques, discovering new therapeutic uses and understanding the specific in vivo mechanisms of action of G. elata and its constituents from the pharmacokinetic viewpoint in the near future. The present review discusses analytical techniques and pharmacokinetics of G. elata and its constituents reported from 1985 onwards.

Combined toxicity of heavy metal mixtures in liver cells.

With rapid industrialization, China is now facing great challenges in heavy metal contamination in the environment. Human exposure to heavy metals through air, water and food commonly involves a mixture consisting of multiple heavy metals. In this study, eight common heavy metals (Pb, Cd, Hg, Cu, Zn, Mn, Cr, Ni) that cause environmental contamination were selected to investigate the combined toxicity of different heavy metal mixtures in HL7702 cells. Toxicity (24 h LC50 ) of each individual metal on the cells ranked Hg > Cr = Cd > Cu > Zn > Ni > Mn > Pb; toxicity of the different mixtures ranked: M5 > M3PbHgCd > M5+Mn > M5+Cu > M2CdNi > M4A > M8-Mn > M8 > M5+Zn > M4B > M8-Cr > M8-Zn > M8-Cu > M8-Pb > M8-Cd > M8-Hg > M8-Ni > M3PbHgNi > M3CuZnMn. The cytotoxicity data of individual metals were successfully used to build the additive models of two- to eight-component metal mixtures. The comparison between additive model and combination model or partly additive model was useful to evaluate the combined effects in mixture. Synergistic, antagonistic or additive effects of the toxicity were observed in different mixtures. These results suggest that the combined effects should be considered in the risk assessment of heavy metal co-exposure, and more comprehensive investigations on the combined effects of different heavy metal mixtures are needed in the future. Copyright © 2016 John Wiley & Sons, Ltd.

Tributyltin induces disruption of microfilament in HL7702 cells via MAPK-mediated hyperphosphorylation of VASP.

Tributyltin (TBT) has been widely used for various industrial purposes, and it has toxic effects on multiple organs and tissues. Previous studies have found that TBT could induce cytoskeletal disruption, especially of the actin filaments. However, the underlying mechanisms remain unclear. The aim of the present study was to determine whether TBT could induce microfilament disruption using HL7702 cells and then to assess for the total levels of various microfilament-associated proteins; finally, the involvement of the MAPK pathway was investigated. The results showed that after TBT treatment, F-actin began to depolymerize and lost its characteristic filamentous structure. The protein levels of Ezrin and Cofilin remained unchanged, the actin-related protein (ARP) 2/3 levels decreased slightly, and the vasodilator-stimulated phosphoprotein (VASP) decreased dramatically. However, the phosphorylation levels of VASP increased 2.5-fold, and the ratio of phosphorylated-VASP/unphosphorylated-VASP increased 31-fold. The mitogen-activated protein kinases (MAPKs) ERK and JNK were discovered to be activated. Inhibition of ERK and JNK not only largely diminished the TBT-induced hyperphosphorylation of VASP but also recovered the cellular morphology and rescued the cells from death. In summary, this study demonstrates that TBT-induced disruption of actin filaments is caused by the hyperphosphorylation of VASP through MAPK pathways. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1530-1538, 2016.

Homocysteine, Ischemic Stroke, and Coronary Heart Disease in Hypertensive Patients: A Population-Based, Prospective Cohort Study.

BACKGROUND AND PURPOSE: Total homocysteine level (tHcy) is a risk factor of ischemic stroke (IS) and coronary heart disease. However, the results are conflicting and mainly focused on healthy individuals in developed countries. METHODS: A prospective, population-based cohort study was conducted among 5935 participants from 60 communities in the city of Shenzhen, China. A Cox regression analysis was applied to evaluate the contribution of tHcy to the risk of IS and coronary heart disease. The effect of folic acid supplementation on tHcy levels was also evaluated among 501 patients with essential hypertension, who received an average of 2.5 years of folic acid supplementation. RESULTS: After adjustment for confounding factors, the hazard ratios (95% confidence intervals) of IS caused by hyperhomocysteinemia were 2.18 (1.65-2.89), 2.40 (1.56-3.67), and 2.73 (1.83-4.08) in the total, male, and female participants, respectively. Compared with normal levels of tHcy (<15 µmol/L), the hazard ratios (95% confidence intervals) for IS in the highest tHcy category (≥30 µmol/L) were 4.96 (3.03-8.12), 6.11 (3.44-10.85), and 1.84 (0.52-6.46) in the total, males, and females participants, respectively. However, we did not observe a significant relationship between tHcy and the risk of coronary heart disease. The 2.5 years of folic acid supplementation reduced tHcy levels by 6.7 µmol/L (27.92%) in patients with essential hypertension. CONCLUSIONS: Hyperhomocysteinemia in Chinese hypertensive patients is significantly associated with IS risk but not coronary heart disease susceptibility, and folic acid supplementation can efficiently reduce tHcy levels.