Adolescence is a sensitive period for acrylamide-induced sex hormone disruption: Evidence from NHANES populations and experimental mice.

Acrylamide (AA) is widely contaminated in environment and diet. However, the association of AA and sex hormones has rarely been investigated, especially in adolescents, a period of particular susceptibility to sex hormone disruption. In this study, survey-weighted multivariate linear regression models were conducted to determine the association between AA Hb biomarkers [HbAA and glycidamide (HbGA)] and sex hormones [total testosterone (TT) and estradiol (E2)] in a total of 3268 subjects from National Health and Nutrition Examination Survey (NHANES) 2013-2016 waves. Additionally, adult and pubertal mice were treated with AA to assess the effect of AA on sex hormones and to explore the potential mechanisms. Among all the subjects, significant negative patterns for HbGA and sex hormones were identified only in youths (6-19 years old), with the lowest ß being - 0.53 (95% CI: -0.80 to -0.26) for TT in males and - 0.58 (95% CI: -0.93 to -0.23) for E2 in females. Stratified analysis further revealed significant negative associations between HbGA and sex hormones in adolescents, with the lowest ß being - 0.58 (95% CI: -1.02 to -0.14) for TT in males and - 0.54 (95% CI: -1.03 to -0.04) for E2 in females, while there were no significant differences between children or late adolescents. In mice, the levels of TT and E2 were dramatically reduced in AA-treated pubertal mice but not in adult mice. AA disturbed the expression of genes in the hypothalamic-pituitary-gonadal (HPG) axis, induced apoptosis of hypothalamus-produced gonadotropin-releasing hormone (GnRH) neurons in the hypothalamus and reduced serum and hypothalamic GnRH levels in pubertal mice. Our study indicates AA could reduce TT and E2 levels by injuring GnRH neurons and disrupting the HPG axis in puberty, which manifested as severe endocrine disruption on adolescents. Our findings reinforce the idea that adolescence is a vulnerable stage in AA-induced sex hormone disruption.

Hydroxytyrosol and Oleuropein Inhibit Migration and Invasion via Induction of Autophagy in ER-Positive Breast Cancer Cell Lines (MCF7 and T47D).

Hydroxytyrosol (HT) and oleuropein (OL), the most abundant of the phenolic compounds in olives, have anticancer properties against breast cancer (BC). However, little attention has been paid to the mechanism of HT or OL in BC cells. The objective of this study was to identify the underlying molecular mechanisms of these compounds. ER-positive BC MCF7 and T47D cells were treated with HT and OL in combination with hepatocyte growth factor (HGF), rapamycin (Rapa, an agonist of autophagy) or 3-methyladenine (3-MA, an inhibitor of autophagy). Cell viability, metastasis capability and autophagy-related proteins were evaluated by wound healing assays, Transwell assays and Western blot. HT and OL reduced the cell viability of MCF-7 and T47D cells in a dose-dependent manner. Both cells were more sensitive to HT than OL. In addition, Rapa significantly inhibited HGF-induced migration and invasion, indicating that metastases of both BC cells could be inhibited by suppression of autophagy. Moreover, HT and OL significantly blocked HGF- or 3-MA-induced cell migration and invasion by reversing LC3II/LC3I and Beclin-1 downregulation and p62 upregulation. These findings revealed that HT and OL could suppress migration and invasion by activating autophagy in ER-positive BC cells, which might be a promising therapeutic strategy.

Difenoconazole induces cardiovascular toxicity through oxidative stress-mediated apoptosis in early life stages of zebrafish (Danio rerio).

Difenoconazole (DIF), a common broad-spectrum triazole fungicide, is associated with an increased risk of cardiovascular diseases. Unfortunately, little attention has been paid to the mechanisms underlying this association. In this study, zebrafish embryos were exposed to DIF (0, 0.3, 0.6 and 1.2 mg/L) from 4 to 96 h post fertilization (hpf) and cardiovascular toxicity was evaluated. Our results showed that DIF decreased hatching rate, survival rate and heart rate, with increased malformation rate. Cardiovascular deformities are the most prominent, including pericardial edema, abnormal cardiac structure and disrupted vascular pattern in two transgenic zebrafish models (myl7:egfp and fli1:egfp). DIF exacerbated oxidative stress by via accumulation of reactive oxygen species (ROS) and inhibition of antioxidant enzyme. Cardiovascular apoptosis was triggered through increased expression of p53, bcl-2, bax and caspase 9, while DIF suppressed the transcription of key genes involved in calcium signaling and cardiac muscle contraction. These adverse outcomes were restored by the antioxidant N-acetyl-L-cysteine (NAC), indicating that oxidative stress played a crucial role in DIF-induced cardiovascular toxicity caused by apoptosis and inhibition of cardiac muscle contraction. Taken together, this study revealed the key role of oxidative stress in DIF-induced cardiovascular toxicity and provided novel insights into strategies to mitigate its toxicity.

Fenvalerate induces oxidative hepatic lesions through an overload of intracellular calcium triggered by the ERK/IKK/NF-κB pathway.

Fenvalerate (FEN), a mainstream pyrethroid pesticide, was initially recommended as a low-toxicity agent for controlling agricultural and domestic pests. Despite the widespread use of FEN worldwide, little data are available on FEN-induced hepatic lesions and molecular mechanisms. In the present study, we first performed an occupational cross-sectional study on FEN factory workers and found that the levels of serum alanine aminotransferase (ALT) and total antioxidant capacity increased, whereas malondialdehyde decreased in laborers in the working areas where the levels of airborne FEN were much higher compared with the office area. The results were then confirmed by animal experiments that abnormal hepatic histology, increased ALT level, and compromised hepatic oxidative capability were observed in rats exposed to a high concentration of FEN. Furthermore, the bioinformatics analysis of gene microarray in rat liver tissue showed that FEN significantly changed the expressions of genes related to the regulation of intracellular calcium ion homeostasis and the calcium signal pathway. Finally, the functional experiments in Buffalo rat liver (BRL) cells demonstrated that FEN first activated ERK MAPK, followed by IKK and NF-κB, which triggered the transcription of genes responsible for accelerating an overload of intracellular calcium ions, prompted reactive oxygen species generation in the mitochondria, and finally, induced hepatic cellular apoptosis. The calcium signaling pathway and in particular, an overload of intracellular calcium play a critical role in this pathophysiological process via the ERK/IKK/NF-κB pathway. Our study furthers the understanding of the mechanism of FEN-induced hepatic injuries and may have implications in the prevention and control of liver diseases induced by environmental pesticides.-Qiu, L.-L., Wang, C., Yao, S., Li, N., Hu, Y., Yu, Y., Xia, R., Zhu, J., Ji, M., Zhang, Z., Wang S.-L. Fenvalerate induces oxidative hepatic lesions through an overload of intracellular calcium triggered by the ERK/IKK/NF-κB pathway.

Identification of 5-hydroxymethylfurfural in cigarette smoke extract as a new substrate metabolically activated by human cytochrome P450 2A13.

Cytochrome P450 2A13 (CYP2A13) is an extrahepatic enzyme mainly expressed in the human respiratory system and is reported to mediate tobacco-specific N-nitrosamines (TSNA) metabolism in cigarette smoke. This study aimed to identify other new substrates of CYP2A13 in cigarette smoke and their corresponding respiratory toxicity. Following separation by HPLC, GC-MS/MS, NMR and cytotoxicity assays in BEAS-2B cells stably expressing CYP2A13 (B-2A13), 5-Hydroxymethylfurfural (5-HMF) was screened and identified in the 4-5 min section of cigarette smoke extract (CSE). In vitro metabolism results showed that CYP2A13 mediated the fast clearance of 5-HMF and formed the metabolite 5-HMF acid (5-HMFA). CSE 5-HMF (CSE-5-HMF) showed cytotoxicity similar to that of standard 5-HMF in B-2A13 and B-2A5 cells, which was inhibited by 8-methoxypsoralen (8-MOP), a CYP enzyme inhibitor. Mouse CYP2A5, a homologous CYP enzyme to CYP2A13, shares many substrates with CYP2A13 in cigarette smoke. Thus, CYP2A5-/- mice were generated to explore the role of CYP2A5 in 5-HMF bioactivation. Compared with CYP2A5-/- mice, WT mice showed serious histological lung and nasal olfactory mucosa damage, as well as increased inflammatory cells and elevated TNF-α and IL-6 levels in bronchoalveolar lavage fluid. Besides, nasal microsomes undertook fast 5-HMFA formation in WT mice than that in CYP2A5-/- mice, which could be inhibited by 8-MOP. This study is the first to identify 5-HMF as a new toxic substrate of human CYP2A13 in cigarette smoke, it may play a potential role in cigarette smoke-induced respiratory injuries.

High-fat diet aggravates 2,2',4,4'-tetrabromodiphenyl ether-inhibited testosterone production via DAX-1 in Leydig cells in rats.

Growing evidence has revealed that a high-fat diet (HFD) could lead to disorders of glycolipid metabolism and insulin-resistant states, and HFDs have been associated with the inhibition of testicular steroidogenesis. Our previous study demonstrated that 2,2',4,4'-tetrabromodiphenyl ether (BDE47) could increase the risk of diabetes in humans and reduce testosterone production in rats. However, whether the HFD affects BDE47-inhibited testosterone production by elevating insulin levels and inducing related pathways remains unknown. In male rats treated with BDE47 by gavage for 12 weeks, the HFD significantly increased the BDE47 content of the liver and testis and increased the weight of the adipose tissue; increased macrovesicular steatosis in the liver and the levels of triglycerides, fasting glucose and insulin; further aggravated the disruption of the seminiferous epithelium; and lowered the level of testosterone, resulting in fewer sperm in the epididymis. Of note, the HFD enhanced BDE47-induced DAX-1 expression and decreased the expression levels of StAR and 3ß-HSD in the testicular interstitial compartments in rats. In isolated primary Leydig cells from rats, BDE47 or insulin increased DAX-1 expression, decreased the expression of StAR and 3ß-HSD, and reduced testosterone production, which was nearly reversed by knocking down DAX-1. These results indicated that the HFD aggravates BDE47-inhibited testosterone production through hyperinsulinemia, and the accumulation of testicular BDE47 that induces the up-regulation of DAX-1 and the subsequent down-regulation of steroidogenic proteins, i.e., StAR and 3ß-HSD, in Leydig cells.

Artesunate Suppresses the Growth of Prostatic Cancer Cells through Inhibiting Androgen Receptor.

Prostatic cancer (PCa) is a leading cause of cancer related death in males and is often regarded as a kind of androgen-sensitive cancer. Artesunate (ART), a semi-synthetic derivative of the Chinese herb Artemisia annua, is such an anti-cancer agent. However, the effects and mechanism of ART on PCa cells remains unclear. The study aims to elaborate the mechanism of the involvement of androgen receptor (AR) in anti-prostatic cancer (PCa) of artesunate (ART). PCa cells 22rvl were used in vivo and in vitro, and the viability and apoptosis were conducted using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay, respectively. Ectopic expressions of AR and DNA methyltransferase (DNMT) were detected in cells in overexpression or interference of AR or DNMT3b. ART dose-dependently suppressed tumor growth, inhibited cell viability, enhanced apoptosis, decreased AR expression, and increased the expression and the catalytic activity of DNMT3b in 22rv1 cells either in transplanted mice or in vitro. Furthermore, AR downregulated DNMT3b expression, and overexpression of AR or interference of DNMT3b could reverse ART-induced cytotoxicity and apoptosis in 22rvl cells, whereas overexpression of DNMT3b could not change the effect profiles of ART on the cells. The results indicated that ART suppressed tumor growth of prostatic cancer cells through AR-DNMT3b pathway, underlying ART will allow for the utilization of this Chinese therapeutic agent for the potential treatment of prostate cancer.

miR-138-1* regulates aflatoxin B1-induced malignant transformation of BEAS-2B cells by targeting PDK1.

Environmental carcinogens-induced lung cancer and potential mechanisms have attracted widespread attention. Currently, microRNAs (miRNAs) have been recognized as key players in development of cancer, among which guide strand of miRNA has been well documented rather than its passenger strand (miRNA*). Our previous study showed that treatment of 0.1 nM AFB1 for 50 passages could induce malignant transformation of immortalized human bronchial epithelial cells stably expressing CYP2A13 (P50 B-2A13 cells). However, the role of miRNAs in this carcinogenic proceeding is still unclear. In present study, 36 upregulated and 27 downregulated miRNAs in P50 B-2A13 cells were first identified by miRNA microarray, and miR-138-1* was selected as a candidate miRNA by RT-qPCR and pilot experiments. Functional studies revealed that miR-138-1* could inhibit proliferation, colony formation, migration and invasion of P50 B-2A13 cells. Further, target analysis and dual-luciferase reporter gene assay identified that miR-138-1(*) was consequentially paired with 3'-UTR of 3-phosphoinositide-dependent protein kinase-1 (PDK1) and decreased the luciferase activity. miR-138-1* could decrease the expressions of PDK1 and its downstream proteins in PI3K/PDK/Akt pathway but not vice versa, indicating that miR-138-1* might affect AFB1-induced malignant transformation through targeting PDK1. As predicted, interference of PDK1 showed the similar effects to miR-138-1* in the proliferation, colony formation, migration and invasion of P50 B-2A13 cells. Our study demonstrated that miR-138-1* played a critical role in AFB-induced malignant transformation of B-2A13 cells by targeting PDK1. Still, the study provides a novel insight into the roles of miRNA* during carcinogenesis, particularly airborne carcinogens-induced lung cancer.

Cytochrome P450 2A13 mediates the neoplastic transformation of human bronchial epithelial cells at a low concentration of aflatoxin B1.

Cytochrome P450 2A13 (CYP2A13), mainly expressed in human respiratory tract, is highly efficient in the metabolic activation of aflatoxin (AF) B1 (AFB1) and is assumed to play a role in human lung tumorigenesis in airborne AFB1 exposure. To validate the assumption, we exposed human bronchial epithelial (BEAS-2B) cells stably expressing CYP2A13 (B-2A13), CYP1A2 (B-1A2) and CYP2A6 (B-2A6) to 0.1-10 nM AFB1 for 30-50 passages. B-2A13 cells showed increased sensitivity to 0.1 nM AFB1-induced neoplastic transformation and the formation of tumors in nude mice were observed at passage 30 (P30) while it occurred at P50 B-1A2 cells. B-2A6, similar to vector control, showed no neoplastic transformation in this condition. Additionally, AFB1-DNA adducts and 8-OHdG significantly increased in transformed P40 B-2A13, in parallel with the upregulation of p-ATR, p-BRCA1, Mre11, Rad50 and Rad51. However, the apoptosis of P40 cells was near normal, while the expression of Bax, C-Caspase 3 and C-PARP increased passage-dependently. Inhibition of ATR (ATR siRNA or NU6027) reversely increased the apoptosis of P40 B-2A13 cells in parallel with the upregulation of Bax, C-Caspase 3 and C-PARP, suggesting that ATR plays an important role in maintaining cell survival via antiapoptosis. Additionally, activation of ATR was necessary to neoplastic transformation since blockage of ATR in P40 cells inhibited DNA damage repair response and anchorage-independent growth. Our data demonstrated that CYP2A13 played a critical role in AFB1-induced neoplastic transformation. ATR-mediated the dysfunction of apoptosis and DNA damage repair might be involved. These results help establish a linkage between airborne AFB1 and human respiratory carcinoma.

Prediction of molecular-specific mutagenic alerts and related mechanisms of chemicals by a convolutional neural network (CNN) model based on SMILES split.

Structural alerts (SAs) are essential to identify chemicals for toxicity evaluation and health risk assessment. We constructed a novel SMILES split-based deep learning model (SSDL) that was trained and verified with 5850 chemicals from the ISSSTY database and 384 external test chemicals from published papers. The training accuracy was above 0.90 and the evaluation metrics (precision, recall and F1-score) all reached 0.78 or above on both internal and external test chemicals. In this model, the molecular-specific fragment importance of chemicals was first quantified independently. Then, the SA identification method based on the importance of these fragments was statistically analyzed and verified with the ISSSTY test and external test chemicals containing one of 28 typical SAs, and most of the performances were better than that of expert rules. Furthermore, a mutagenicity mechanism prediction method was developed using 237 chemicals with four known mutagenic mechanisms based on molecular similarity calibrated by the SSDL method and fragment importance, which significantly improved accuracy in three mechanisms and had comparable accuracy in the other one compared to traditional methods. Overall, the SSDL model quantifying fragment toxicity within molecules would be a novel potentially powerful tool in the determination and visualization of molecular-specific SAs and the prediction of mutagenicity mechanisms for environmental or industrial compounds and drugs.

Cytochrome P450 2A13 enhances the sensitivity of human bronchial epithelial cells to aflatoxin B1-induced DNA damage.

Cytochrome P450 2A13 (CYP2A13) mainly expresses in human respiratory system and mediates the metabolic activation of aflatoxin B1 (AFB1). Our previous study suggested that CYP2A13 could increase the cytotoxic and apoptotic effects of AFB1 in immortalized human bronchial epithelial cells (BEAS-2B). However, the role of CYP2A13 in AFB1-induced DNA damage is unclear. Using BEAS-2B cells that stably express CYP2A13 (B-2A13), CYP1A2 (B-1A2), and CYP2A6 (B-2A6), we compared their effects in AFB1-induced DNA adducts, DNA damage, and cell cycle changes. BEAS-2B cells that were transfected with vector (B-vector) were used as a control. The results showed that AFB1 (5-80 nM) dose- and time-dependently induced DNA damage in B-2A13 cells. AFB1 at 10 and 80nM significantly augmented this effect in B-2A13 and B-1A2 cells, respectively. B-2A6 cells showed no obvious DNA damage, similar to B-vector cells and the vehicle control. Similarly, compared with B-vector, B-1A2 or B-2A6 cells, B-2A13 cells showed more sensitivity in AFB1-induced γH2AX expression, DNA adduct 8-hydroxy-deoxyguanosine formation, and S-phase cell-cycle arrest. Furthermore, AFB1 activated the proteins related to DNA damage responses, such as ATM, ATR, Chk2, p53, BRCA1, and H2AX, rather than the proteins related to DNA repair. These effects could be almost completely inhibited by 100 µM nicotine (a substrate of CYP2A13) or 1 µM 8-methoxypsoralen (8-MOP; an inhibitor of CYP enzyme). Collectively, these findings suggest that CYP2A13 plays an important role in low-concentration AFB1-induced DNA damage, possibly linking environmental airborne AFB1 to genetic injury in human respiratory system.

Cytochrome P450 2A13 is an efficient enzyme in metabolic activation of aflatoxin G1 in human bronchial epithelial cells.

Cytochrome P450 2A13 (CYP2A13) is an extrahepatic enzyme that mainly expresses in human respiratory system, and it is reported to mediate the metabolic activation of aflatoxin B1. Due to the structural similarity, AFG1 is predicted to be metabolized by CYP2A13. However, the role of CYP2A13 in metabolic activation of AFG1 is unclear. In present study, human bronchial epithelial cells that stably express CYP2A13 (B-2A13) were used to conduct the effects of AFG1 on cytotoxicity, apoptosis, DNA damages, and their response protein expression. Low concentrations of AFG1 induced significant cytotoxicity and apoptosis, which was consistent with the increased expressions of pro-apoptotic proteins, such as C-PARP and C-caspase-3. In addition, AFG1 increased 8-OHdG and γH2AX in the nuclies and induced S phase arrest and DNA damage in B-2A13 cells, and the proteins related to DNA damage responses, such as ATM, ATR, Chk2, p53, BRCA1, and γH2AX, were activated. All the above effects were inhibited by nicotine (a substrate of CYP2A13) or 8-MOP (an inhibitor of CYP enzymes), confirming that CYP2A13 mediated the AFG1-induced cytotoxicity and DNA damages. Collectively, our findings first demonstrate that CYP2A13 might be an efficient enzyme in metabolic activation of AFG1 and helps provide a new insight into adverse effects of AFG1 in human respiratory system.

Mechanism of BDE209-induced impaired glucose homeostasis based on gene microarray analysis of adult rat liver.

Several persistent organic pollutants are reported to be potentially associated with the risk of human diabetes that has become rapidly epidemic in China currently. 2,2',3,3',4,4',5,5',6,6'-decabromodiphenyl ether (BDE209) is commercially most important both in the production and in the use of polybrominated diphenyl ethers (PBDEs). It might bioaccumulate in wildlife and human and is the only PBDEs mixture still used today. In the present study, male adult rats treated with BDE209 (0, 0.05, 1, and 20 mg/kg) for 8 weeks were used to explore the effects of BDE209 on glucose homeostasis and possible mechanisms; 0.05 mg/kg of BDE209 induced dose-related hyperglycemia. Then, we performed the full-genome gene expression microarrays, gene ontology analysis, and pathway analysis in this group and control. BDE209 induced 1,257 liver gene transcript changes, and 18 canonical pathways were significantly enriched. Four of them were involved in immune diseases, including autoimmune thyroid disease, graft-versus-host disease, allograft rejection, and type I diabetes mellitus (T1MD), which was confirmed by the decrease in serum insulin. Subsequently, gene act network and gene co-expression network found that some MHC molecules and TNF-α were involved in T1DM pathway, which was then confirmed by the increase in serum TNF-α. Additionally, reduced glutathione and superoxide dismutase in plasma indicated that oxidative damage might partly contribute to BDE209-induced hyperglycemia. The results of this study provide some new experimental evidence that the exposure to high levels of BDE209 may contribute to the onset of diabetes in human populations. Further work needs to be done to confirm this link.

Different effects of androgen on the expression of Fut1, Fut2, Fut4 and Fut9 in male mouse reproductive tract.

The α-(1,2) fucosyltransferases (Fut1 and Fut2) and α-(1,3) fucosyltransferases (Fut4, Fut9) are responsible for the synthesis of Lewis X (LeX) and Lewis Y (LeY) conjugated to glycoproteins. We recently reported that these fucosyltransferases were differentially expressed in the reproductive tract of male mouse. Here, we studied the effect of androgen on fucosyltransferase expression through the use of mouse castration models. We found that Fut1 mRNA and Fut4 mRNA were upregulated, while Fut2 mRNA and Fut9 mRNA were downregulated by androgen in the caput epididymis. However, in the vas deferens and prostate, only Fut4 mRNA and Fut2 mRNA were respectively upregulated following exposure to androgen. In the seminal vesicle, all fucosyltransferases, with the exception of Fut9, were upregulated. We identified the androgen receptor binding sites (ARBSs) of Fut2, Fut4 and Fut9 in the caput epididymis. Luciferase assay for these ARBSs is able to provide an indication as to why Fut4 and Fut9 are differently expressed and regulated by androgen, although they catalyze the same α-(1,3) fucose linkage. Our study showed that androgen could differentially regulate the expression of these fucosyltransferases and provided an insight into the characteristic distribution of each fucosyltransferase responsible for LeX/LeY biosynthesis in the male reproductive tract.

Butyl benzyl phthalate as a key component of phthalate ester in relation to cognitive impairment in NHANES elderly individuals and experimental mice.

Phthalates are a group of neurotoxicants with cognitive-disrupting potentials. Given the structural diversity of phthalates, the corresponding neurotoxicity is dramatically altered. To identify the potential contributions of different phthalates on the process of cognitive impairment, data of 836 elders from the NHANES 2011-2014 cycles were used. Survey-weighted logistic regression and principal component analysis-weighted quantile sum regression (PCA-WQSR) models were applied to estimate the independent and combined associations of 11 urinary phthalate metabolites with cognitive deficit (assessed by 4 tests: Immediate Recall (IR), Delayed Recall (DR), Animal Fluency (AF), and Digit Symbol Substitution Test (DSST)) and to identify the potential phthalate with high weight. Laboratory mice were further used to examine the effect of phthalates on cognitive function and to explore the potential mechanisms. In logistic regression models, MBzP was the only metabolite positively correlated with four tests, with ORs of 2.53 (quartile 3 (Q3)), 2.26 (Q3), 2.89 (Q4) and 2.45 (Q2), 2.82 (Q4) for IR, DR, AF, and DSST respectively. In PCA-WQSR co-exposure models, low-molecular-weight (LMW) phthalates were the only PC positively linked to DSST deficit (OR: 1.93), which was further validated in WQSR analysis (WQS OR7-phthalates: 1.56 and WQS OR8-phthalates: 1.55); consistent with the results of logistic regression, MBzP was the dominant phthalate. In mice, butyl benzyl phthalate (BBP), the parent phthalate of MBzP, dose-dependently reduced cognitive function and disrupted hippocampal neurons. Additionally, the hippocampal transcriptome analysis identified 431 differential expression genes, among which most were involved in inhibiting the neuroactive ligand-receptor interaction pathway and activating the cytokine-cytokine receptor interaction pathway. Our study indicates the critical role of BBP in the association of phthalates and cognitive deficits among elderly individuals, which might be speculated that BBP could disrupt hippocampal neurons, activate neuroinflammation, and inhibit neuroactive receptors. Our findings provide new insight into the cognitive-disrupting potential of BBP.

A novel approach to predict the comprehensive EROD potency: Mechanism-based curve fitting of CYP1A1 activity by PAHs.

Cytochrome P450 1A1 (CYP1A1) plays critical roles in polycyclic aromatic hydrocarbon (PAH) toxicity, including DNA adduction and ROS generation. Therefore, CYP1A1 activity quantified by the 7-ethoxyresorufin-O-deethylase (EROD) assay (named EROD potency) has been considered a typical biomarker of PAH exposure and toxicity. The EROD dose-response curve always presents a biphasic style, increasing at low concentrations and decreasing at high concentrations of PAHs, but relative effect potency (REP) commonly used in PAH risk assessment is only involved in the increasing phase. In this study, a full bell-shaped EROD curve fitting formula Eq. (1) was obtained by considering both CYP1A1 mRNA induction and enzyme inhibition to completely assess the EROD potency of PAHs. Correspondingly, in silico models of QSAR and docking methods successfully predicted the full EROD curves of PAHs, and the structure-activity relationship indicated that PAHs with heavy molecular weight and large diameter showed stronger EROD potency. Further EROD potency with predicted curve parameters (EC50,ind and area index) was confirmed by the reported REP (R2 = 0.697-0.977) and experimental data from human and mouse cells (R2 = 0.700-0.804). This study provides a novel curve fitting for the EROD dose-response relationship and a prediction model for PAH EROD potency.

Endo-TLIF versus MIS-TLIF in 1-segment lumbar spondylolisthesis: A prospective randomized pilot study.

OBJECTIVE: To evaluate the curative efficacy by comparing perioperative characteristics and 1.5-year observational outcomes in 1-segment lumbar spondylolisthesis between traditional minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and optimized Endoscopic TLIF techniques. METHODS: The study was a single-center, randomized controlled trial comparing two different treatment approaches for 1-segment lumbar spondylolisthesis. 102 patients treated by MIS-TLIF (48 cases) or Endo-TLIF (54 cases) were included from March 2018 to April 2019. Perioperative parameters and clinical outcomes were evaluated. Degree of slip were measured, and fusion rates were determined at 18 months after surgery. RESULTS: The Endo-TLIF group had similar return to work time and rate. Blood loss, left bed time, analgesic ratio were significantly less in Endo-TLIF group. The Endo-TLIF group had a significantly longer operative time. Significant postoperative reduction in %slip was showed in both groups. The VAS and ODI improved significantly in both groups after surgery. Significant decreases in low-back pain in Endo-TLIF group were found at postoperative day 1 and 3 months. The fusion rate in the two groups was similar. CONCLUSION: Endo-TLIF surgery with a C-shaped working tube and a visualization system may be regarded as an efficient alternative surgery for 1-segment lumbar spondylolisthesis. It is a safe and minimally invasive way to perform this surgery and has shown satisfactory clinical outcomes. TRIAL REGISTRATION: ChiCTR1800015197, 13 March 2018. TRIAL REGISTRY: Chinese Clinical Trial Registry. Registered 13 March 2018. http://www.chictr.org.cn/showproj.aspx?proj=25865.

The Ganglioside Monosialotetrahexosylganglioside Protects Auditory Hair Cells Against Neomycin-Induced Cytotoxicity Through Mitochondrial Antioxidation: An in vitro Study.

Neomycin is a common ototoxic aminoglycoside antibiotic that causes sensory hearing disorders worldwide, and monosialotetrahexosylganglioside (GM1) is reported to have antioxidant effects that protect various cells. However, little is known about the effect of GM1 on neomycin-induced hair cell (HC) ototoxic damage and related mechanism. In this study, cochlear HC-like HEI-OC-1 cells along with whole-organ explant cultures were used to establish an in vitro neomycin-induced HC damage model, and then the apoptosis rate, the balance of oxidative and antioxidant gene expression, reactive oxygen species (ROS) levels and mitochondrial membrane potential (MMP) were measured. GM1 could maintain the balance of oxidative and antioxidant gene expression, inhibit the accumulation of ROS and proapoptotic gene expression, promoted antioxidant gene expression, and reduce apoptosis after neomycin exposure in HEI-OC-1 cells and cultured cochlear HCs. These results suggested that GM1 could reduce ROS aggregation, maintain mitochondrial function, and improve HC viability in the presence of neomycin, possibly through mitochondrial antioxidation. Hence, GM1 may have potential clinical value in protecting against aminoglycoside-induced HC injury.

Bioaccumulation of BDE47 in testes by TiO2 nanoparticles aggravates the reproductive impairment of male zebrafish by disrupting intercellular junctions.

This study attempts to explore the potential impact of titanium dioxide nanoparticles (n-TiO2) on bioconcentration and reproductive impairments of male zebrafish in the presence of 2,2',4,4'-tetrabromodiphenyl ether (BDE47), the congener of PBDEs predominant in environment and most abundant in biosamples. n-TiO2 nanoparticles strongly adsorbed BDE47 to form BDE47/TiO2 complex, which was taken up into the testes of zebrafish, and increased the tissue burdens of both BDE47 and n-TiO2. Correspondingly, no observed toxic dose of n-TiO2 (100 µg/L) was found to aggravate the abnormal histological morphology of the testes and the decrease in egg production, gonadosomatic index, sexual hormone levels and related gene expression in zebrafish in the presence of BDE47 at 5 or 50 µg/L. In addition, n-TiO2 exacerbated the destruction resulting from the ultrastructural disassembly of intercellular connectivity of germ cells in zebrafish and the decrease in transepithelial electrical resistance in TM4 cells induced by BDE47. Furthermore, n-TiO2 enhanced BDE47 to initially activate p-JNK MAPK signaling pathway and subsequently triggered the downregulation of junction proteins (i.e., ZO-1, Connexin-43 and N-cadherin), leading to impaired cell-cell junctions in vivo and in vitro. Our results demonstrated that n-TiO2 should act as a carrier to facilitate the accumulation of BDE47 in zebrafish testes and result in a synergistic effect on BDE47-induced adverse reproductive outcomes via disruption of intercellular connectivity of zebrafish testes. This study is beneficial in providing a scientific basis for improving the health risk assessment of environmental pollutants, particularly those that coexist with nanoparticle contamination in realistic environments.

Mutagenicity risk prediction of PAH and derivative mixtures by in silico simulations oriented from CYP compound I-mediated metabolic activation.

PAHs and their derivatives are the main sources of mutagenicity and carcinogenicity in airborne particular matter and cause serious public health and environmental problems. Risk assessment is challenging due to the mixed nature and deficiency of toxicity data of most PAHs and their derivatives. Cytochrome P450 enzymes (CYPs) play important roles in PAH-induced carcinogenicity via metabolic activation, and CYP conformations with compound I structures strongly influence metabolic sites and metabolite species. In this study, complexes of BaP with CYP1A1, CYP1B1 or CYP2C19 compound I were successfully simulated by QM/MM methods and verified by metabolic clearance, and the mutagenicity of chemicals was then predicted by the BaP-7,8-epoxide-related metabolic conformation fitness (MCF) approach, which was validated by Ames tests, showing satisfying accuracy (R2 = 0.46-0.66). Furthermore, a prediction model of the mutagenicity risk of PAH and derivative mixtures was established based on the relative potential factor (RPF) approach and the RPF calculated from the mathematical relationship between the minimum MCF (MCFmin) and RPF, which was successfully validated by the mutagenesis of PAH and derivative mixture mimic-simulating PM2.5 samples collected in eastern China. This study provides fast reliable tools for assessing risk of the complex components of environmental PAHs and their derivatives.