Effect of n-3 polyunsaturated fatty acids on ischemic heart disease and cardiometabolic risk factors: a two-sample Mendelian randomization study.

BACKGROUND: The cardioprotective ability of n-3 polyunsaturated fatty acids (PUFAs) is controversial. Most studies suggest a specific role for PUFAs in cardioprotection from ischemic heart disease (IHD). However, few studies have used genetic biomarkers of n-3 PUFAs to examine their potential relationships with IHD. This study aimed to use Mendelian randomization to evaluate whether genetically-predicted n-3 PUFAs affect IHD and cardiometabolic risk factors (CRFs). METHODS: Genetic variants strongly (p < 5 × 10-8) and independently (r2 > 0.1) associated with n-3 PUFAs were derived from the CHARGE Consortium (including 8,866 subjects of European ancestry) and were used as instrumental variables (IVs) for evaluating the effect of n-3 PUFAs, including α-linolenic acid (ALA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA). Data on the associations between the IVs and IHD, myocardial infarction, and CRFs (including diabetes, lipids, blood pressure, body mass index, and waist-to-hip ratio (WHR)) were obtained from the UK Biobank SOFT CAD GWAS with the CARDIoGRAMplusC4D 1000 Genomes-based GWAS (113,937 IHD cases and 339,115 controls), the Myocardial Infarction Genetics and CARDIoGRAM Exome consortia (42,335 MI cases and 78,240 controls), the DIAbetes Genetics Replication And Meta-analysis consortium (26,676 diabetes mellitus cases and 132,532 controls), the Global Lipids Genetics Consortium (n = 196,475), the International Consortium for Blood Pressure (n = 69,395), and the meta-analysis of GWAS for body fat distribution in the UK Biobank and Genetic Investigation of Anthropometric Traits (n = 694,649). RESULTS: Genetically-predicted higher ALA was associated with lower risk of IHD, type 2 diabetes (T2D), and lower serum lipids. The effect size per 0.05-unit increase (about 1 standard deviation) in plasma ALA level) was - 1.173 (95% confidence interval - 2.214 to - 0.133) for IHD. DPA and EPA had no association with IHD but were associated with a higher risk of T2D, higher levels of lipids or WHR. DHA had no association with IHD or CRFs. CONCLUSIONS: Our study suggests a benefit of ALA for IHD and its main risk factors. DHA, DPA, and EPA had no association with IHD but were partly associated with increasing cardiometabolic risk factors.

Genetic and epigenetic associations of ANRIL with coronary artery disease and risk factors.

BACKGROUND: Both DNA genotype and methylation of antisense non-coding RNA in the INK4 locus (ANRIL) have been robustly associated with coronary artery disease (CAD), but the interdependent mechanisms of genotype and methylation remain unclear. METHODS: Eighteen tag single nucleotide polymorphisms (SNPs) of ANRIL were genotyped in a matched case-control study (cases 503 and controls 503). DNA methylation of ANRIL and the INK4/ARF locus (p14ARF, p15INK4b and p16INK4a) was measured using pyrosequencing in the same set of samples (cases 100 and controls 100). RESULTS: Polymorphisms of ANRIL (rs1004638, rs1333048 and rs1333050) were significantly associated with CAD (p < 0.05). The incidence of CAD, multi-vessel disease, and modified Gensini scores demonstrated a strong, direct association with ANRIL gene dosage (p < 0.05). There was no significant association between ANRIL polymorphisms and myocardial infarction/acute coronary syndrome (MI/ACS) (p > 0.05). Methylation levels of ANRIL were similar between the two studied groups (p > 0.05), but were different in the rs1004638 genotype, with AA and AT genotype having a higher level of ANRIL methylation (pos4, p = 0.006; pos8, p = 0.019). Further Spearman analyses indicated that methylation levels of ANRIL were positively associated with systolic blood pressure (pos6, r = 0.248, p = 0.013), diastolic blood pressure (pos3, r = 0.213, p = 0.034; pos6, r = 0.220, p = 0.028), and triglyceride (pos4, r = 0.253, p = 0.013), and negatively associated with high-density lipoprotein cholesterol (pos2, r = - 0.243, p = 0.017). Additionally, we identified 12 transcription factor binding sites (TFBS) within the methylated ANRIL region, and functional annotation indicated these TFBS were associated with basal transcription. Methylation at the INK4/ARF locus was not associated with ANRIL genotype. CONCLUSIONS: These results indicate that ANRIL genotype (tag SNPs rs1004638, rs1333048 and rs1333050) mainly affects coronary atherosclerosis, but not MI/ACS. There may be allele-related DNA methylation and allele-related binding of transcription factors within the ANRIL promoter.

Optimal blood pressure control for patients after thoracic endovascular aortic repair of type B aortic dissection.

BACKGROUND: Guidelines recommend tight systolic blood pressure (SBP) control for favorable outcomes of type B aortic dissection (BAD) but are still limited by the optimal cut-off value of SBP. The purpose of this study was to evaluate the optimal cut-off value of SBP in BAD patients after thoracic endovascular aortic repair (TEVAR). METHODS: From January 2011 to April 2017, 269 consecutive patients with BAD after TEVAR were included in the study. All patients were followed up according to a strict follow-up protocol. Cox regression analysis was used to examine the association between SBP at discharge and 90-day aortic related adverse events (ARAE). RESULTS: All 269 patients completed 90 days of follow-up, and the unadjusted ARAE-free rates at 90-day was 95.1 ± 1.3%. The cut-off value of SBP at discharge identified by receiver operator curve was 130 mmHg for 90-day ARAE. In multivariable models, binary SBP at discharge was significant associated with 90-day ARAE (HR 3.780; 95% CI 1.236-11.556; p = 0.020). Hybrid operation (OR 2.046; 95%CI 1.015-4.122; p = 0.045) and insertion of ≥2 stents (OR 2.950; 95%CI 1.172-7.426; p = 0.022) were demonstrated to be independently associated with poor SBP control (SBP > 130 mmHg) using Logistic analysis. CONCLUSIONS: The optimal cut-off value of SBP at discharge was 130 mmHg which can be used to predict short-term ARAE. Blood pressure in patients with hybrid operation and ≥ 2 stents should be given more focus.

Hypertension and hypertensive left ventricular hypertrophy are associated with ACE2 genetic polymorphism.

AIMS: Renin-angiotensin system modulates cardiac structure independent of blood pressure. The present study aimed at investigating whether single nucleotide polymorphism (SNP) and haplotype of angiotensin converting enzyme 2 (ACE2) could influence blood pressure and the susceptibility to hypertensive left ventricular hypertrophy (LVH). SUBJECTS AND METHODS: A total of 647 patients (347 females and 300 males) with newly diagnosed mild to moderate essential hypertension were enrolled in a blood pressure matched, case-control study. Four ACE2 tagSNPs (rs2074192, rs4646176, rs4646155 and rs2106809) were genotyped and major haplotypes consisting of these four SNPs were reconstructed for all subjects. KEY FINDINGS: In females, minor alleles of ACE2 rs2074192 and rs2106809 respectively conferred a 2.1 and 2.0 fold risk for LVH. ACE2 haplotype TCGT increased the risk for LVH while another haplotype CCGC decreased the risk in females. The covariates-adjusted mean left ventricular mass index was 11% greater in TCGT haplotype carriers than in noncarriers in women. In females, the covariates-adjusted mean systolic blood pressure was 3.4 mm Hg lower in CCGC haplotype carriers than in noncarriers. In males, the covariates-adjusted mean systolic blood pressure was 2.4 mm Hg lower in CCGC haplotype carriers than in noncarriers. SIGNIFICANCE: ACE2 tagSNPs rs2074192 and rs2106809 as well as major haplotypes CCGC and TCGT may serve as novel risk markers for LVH in hypertensive patients.

Integrative analysis of competing endogenous RNA networks reveals the functional lncRNAs in heart failure.

Heart failure has become one of the top causes of death worldwide. It is increasing evidence that lncRNAs play important roles in the pathology processes of multiple cardiovascular diseases. Additionally, lncRNAs can function as ceRNAs by sponging miRNAs to affect the expression level of mRNAs, implicating in numerous biological processes. However, the functional roles and regulatory mechanisms of lncRNAs in heart failure are still unclear. In our study, we constructed a heart failure-related lncRNA-mRNA network by integrating probe re-annotation pipeline and miRNA-target interactions. Firstly, some lncRNAs that had the central topological features were found in the heart failure-related lncRNA-mRNA network. Then, the lncRNA-associated functional modules were identified from the network, using bidirectional hierarchical clustering. Some lncRNAs that involved in modules were demonstrated to be enriched in many heart failure-related pathways. To investigate the role of lncRNA-associated ceRNA crosstalks in certain disease or physiological status, we further identified the lncRNA-associated dysregulated ceRNA interactions. And we also performed a random walk algorithm to identify more heart failure-related lncRNAs. All these lncRNAs were verified to show a strong diagnosis power for heart failure. These results will help us to understand the mechanism of lncRNAs in heart failure and provide novel lncRNAs as candidate diagnostic biomarkers or potential therapeutic targets.

Association of Female Reproductive Factors with Hypertension, Diabetes and LQTc in Chinese Women.

The association of female reproductive factors (FRFs) with cardiovascular risk factors among different population was variable and inconsistent. The objective of this study was to examine the association between FRFs and hypertension, type 2 diabetes mellitus (DM), and long heart-rate-corrected QT interval (LQTc) in Chinese post-menopausal women (Post-MW). A total of 8046 Post-MW from the China Chaoshan Biobank Cohort Study were included for analysis. Logistic regression and general linear regression models were used to estimate the association between FRFs and hypertension, DM, and LQTc. Compared with women with 0 or 1 live birth, increasing risk of hypertension (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.16-1.96), DM (OR, 1.65; 95% CI, 1.22-2.22), and LQTc (OR, 1.45; 95% CI, 1.01-2.09) were observed in women who had five or more live births. Further analysis demonstrated that the association between parity and hypertension, DM, and LQTc was mediated by lifestyle and dyslipidemia. Women with more live births had increased body mass index and waist circumstance, and were inclined to consume more salty food, animal fat, and alcohol, but less meat, vegetable, fish, plant oil, and tea, compared with that had fewer live births (all P < 0.05).

Prevalence, awareness, treatment, and control of hypertension among residents in Guangdong Province, China, 2004 to 2007.

BACKGROUND: As a result of the large variation in geographic, demographic, and socioeconomic characteristics in different regions of China, the prevalence and treatment of hypertension in different regions differ widely. However, little is known about the recent trends of hypertension in Guangdong Province in southern China. We assessed the trends in prevalence, awareness, treatment, and control of hypertension in Guangdong Province between 2004 and 2007. METHODS AND RESULTS: The Guangdong Provincial Chronic Disease Risk Factor Surveillance, modeled on the national Chronic Disease Risk Factor Surveillance, was conducted every 3 years beginning in 2004 with a representative sample of Guangdong Province residents ≥18 years of age. Data from the Guangdong Provincial Chronic Disease Risk Factor Surveillance I (2004; n=7633) and II (2007; n=6447) were used to describe the trends in the prevalence of hypertension among Guangdong Province adults. Hypertension outcomes were examined with interview and examination data. From 2004 to 2007, the age-standardized prevalence rate of hypertension in Guangdong Province residents increased from 12.2% to 15.4% (P<0.001), with the largest increases among rural women (from 9.3% to 19.1%; P<0.001). Among hypertensive people, there was no improvement in awareness and treatment between 2004 and 2007; the control rates decreased from 7.1% in 2004 to 4.5% in 2007 (P<0.01). CONCLUSIONS: One in 7 Guangdong Province adults is hypertensive, but only one quarter are aware of the condition. About 22% of hypertensive patients receive treatment, and few have their hypertension effectively controlled. Hypertension has become a major public health problem in southern China. Comprehensive public health measures need to be taken to decrease the incidence of hypertension and to prevent the progression of hypertension to cardiovascular disease.

Relationship between intracellular Ca²âº and ROS during fluoride-induced injury in SH-SY5Y cells.

The mechanisms underlying the neurotoxicology of endemic fluorosis still remain obscure. To explore lactate dehydrogenase (LDH) leakage, intracellular Ca²âº concentration ([Ca²âº]i ) and reactive oxygen species (ROS) production induced by fluoride, human neuroblastoma (SH-SY5Y) cells were incubated with sodium fluoride (NaF, 20, 40, 80 mg/L) for 24 h, with 40 mg/L NaF for 3, 6, 12, 18, 24 h, and N-acetyl-L-cysteine (NAC), ethyleneglycol-bis-(ß-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA), 1,2-bis(O-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetra(acetoxymethyl) ester (BAPTA-AM) alone or combined with fluoride (40 mg/L) respectively for 12 h in vitro. The results showed that the LDH levels in the 40 and 80 mg/L fluoride-treated groups were significantly higher than that of the control group (in the test level of 0.05, the difference were statistical significance). [Ca²âº]i and ROS reached a peak at 3 h and 12 h respectively after exposure to 40 mg/L fluoride. Fluoride coincubated with NAC (antioxidant) dramatically decreased ROS and LDH levels compared with the fluoride only group (in the test level of 0.05, the difference were statistical significance). However, fluoride-induced increase in [Ca²âº]i was not affected by NAC. BAPTA-AM (intracellular calcium chelator) markedly lowered fluoride-induced increase of [Ca²âº]i , ROS and LDH levels while EGTA (extracellular calcium chelator) have no effects on them. These results indicate that fluoride-related Ca²âº release from the site of intracellular calcium storage causes the elevation of ROS contributing to the cytotoxicity in SH-SY5Y cells.

The effect of c-Fos demethylation on sodium fluoride-induced apoptosis in L-02 cells.

To investigate the effects of sodium fluoride (NaF) on apoptosis, c-Fos mRNA and protein expression levels, and methylation status as well as Dnmt1, Dnmt3a, and Dnmt3b mRNA expression levels in human embryo hepatocyte (L-02) which were exposed to different concentrations of NaF (0, 20, 40, and 80 mg/l) for 24 h in vitro. Results showed that the percentage of apoptosis and c-Fos mRNA and protein expression levels in 40 and 80 mg/l NaF-treated groups were higher than those in the control group (P<0.05). Further, Dnmt1 mRNA expression level was significantly decreased in the 80 mg/l NaF-treated groups compared to the control group (P<0.05); Dnmt3a and Dnmt3b mRNA expression levels were significantly decreased in 40 and 80 mg/l NaF-treated groups compared to the control group (P<0.05). c-Fos methylation levels, according to the bisulfite sequencing results, were decreased in 20, 40, and 80 mg/l NaF-treated groups against the control group. These results suggest that NaF could induce apoptosis and upregulate mRNA and protein expression level of c-Fos as well as decrease mRNA expression levels of Dnmt1, Dnmt3a, and Dnmt3b in L-02 cells. The decrease in c-Fos methylation levels might be involved in the early phase of apoptosis induced by NaF in L-02 cells.

A local outbreak of dengue caused by an imported case in Dongguan China.

BACKGROUND: Dengue, a mosquito-borne febrile viral disease, is found in tropical and sub-tropical regions around the world. Since the first occurrence of dengue was confirmed in Guangdong, China in 1978, dengue outbreaks have been reported sequentially in different provinces in South China transmitted by peridomestic Ae. albopictus mosquitoes, diplaying Ae. aegypti, a fully domestic vector that transmits dengue worldwide. Rapid and uncontrolled urbanization is a characteristic change in developing countries, which impacts greatly on vector habitat, human lifestyle and transmission dynamics on dengue epidemics. In September 2010, an outbreak of dengue was detected in Dongguan, a city in Guangdong province characterized by its fast urbanization. An investigation was initiated to identify the cause, to describe the epidemical characteristics of the outbreak, and to implement control measures to stop the outbreak. This is the first report of dengue outbreak in Dongguan, even though dengue cases were documented before in this city. METHODS: Epidemiological data were obtained from local Center of Disease Control and prevention (CDC). Laboratory tests such as real-time Reverse Transcription Polymerase Chain Reaction (RT-PCR), the virus cDNA sequencing, and Enzyme-Linked immunosorbent assay (ELISA) were employed to identify the virus infection and molecular phylogenetic analysis was performed with MEGA5. The febrile cases were reported every day by the fever surveillance system. Vector control measures including insecticidal fogging and elimination of habitats of Ae. albopictus were used to control the dengue outbreak. RESULTS: The epidemiological studies results showed that this dengue outbreak was initiated by an imported case from Southeast Asia. The outbreak was characterized by 31 cases reported with an attack rate of 50.63 out of a population of 100,000. Ae. albopictus was the only vector species responsible for the outbreak. The virus cDNA sequencing analysis showed that the virus responsible for the outbreak was Dengue Virus serotype-1 (DENV-1). CONCLUSIONS: Several characterized points of urbanization contributed to this outbreak of dengue in Dongguan: the residents are highly concentrated; the residents' life habits helped to form the habitats of Ae. albopictus and contributed to the high Breteau Index; the self-constructed houses lacks of mosquito prevention facilities. This report has reaffirmed the importance of a surveillance system for infectious diseases control and aroused the awareness of an imported case causing the epidemic of an infectious disease in urbanized region.

Effects of the Fas/Fas-L pathway on fluoride-induced apoptosis in SH-SY5Y cells.

The mechanisms underlying fluoride-induced apoptosis in neurons still remain unknown. To investigate apoptosis, caspase-3 activity, and mRNA expression of Fas, Fas-L, and caspases (-3 and -8) induced by fluoride, human neuroblastoma (SH-SY5Y) cells were incubated with 0, 20, 40, and 80 mg/L sodium fluoride (NaF) for 24 h in vitro. The data show that cell viability in the 40 and 80 mg/L fluoride groups were significantly lower than that of the control group. The percentages of apoptosis in the 40 and 80 mg/L fluoride groups were markedly higher than those in the control group, and they increased with the increase in fluoride concentration. The activity of caspase-3 and mRNA expression levels for Fas, Fas-L, and caspases (-3 and -8) in the 40 and 80 mg/L fluoride groups were significantly higher than those in the control group. An agonistic anti-Fas monoclonal antibody (CH-11) significantly augmented apoptosis induction by fluoride, showing a synergistic effect, while a Fas-blocking antibody (ZB4) partly inhibited fluoride-induced apoptosis of SH-SY5Y cells. The results indicate that fluoride exposure could induce apoptosis in SH-SY5Y cells, and the Fas/Fas-L signaling pathway may play an important role in the process.

[Prevalence regarding weight misperception and related influencing factors among residents in Guangdong province].

OBJECTIVE: To explore the prevalence of weight misperception and related influencing factors among adult residents in Guangdong province so as to provide information for prevention and control on weight misperception. METHODS: A multi-stage stratified random sampling method was used to select the sample. Forty-two streets/villages were selected from 21 counties/districts through randomly sampling. Four communities were then chosen from every selected town or district, followed by 40 families chosen from every village or community. Questionnaire was used to collect data on weight perception and its related risk factors. SPSS 16.0 was used for data analysis. RESULTS: There were 6625 respondents participating in the study. Out of them, 50.2% participants misperceived their weight status, among which 35.9% of them underestimated while 14.3% overestimated their weights. Females aged 15 - 24 were more likely to overestimate weights than males in the same age group (38.6% vs. 18.5%), while males were more likely to underestimate weights than females (25.8% vs. 8.5%). The prevalence of underestimation on weights increased with the increase of age in both males and females but the prevalence of overestimation on weights decreased. Data from multivariate results from logistic analysis showed that rural residents, males, being elderly, residents with low education level, manual occupations (agriculture, forestry, animal husbandry and fishery), low family income and with anxiety were the major risk factors on underestimation of weight. However, factors as being urban residents, females, adolescents, minority and never having received weight measurement etc. were the major risk factors of overestimated on weight. CONCLUSION: Misperceptions of weight status in Guangdong province exhibited a high prevalence with complicated influencing factors, calling for more psychological research to be carried out to prevent and reduce the misperceptions on weight status.

Cytogenotoxicity induced by PBDE-47 combined with PCB153 treatment in SH-SY5Y cells.

Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are important recalcitrant halogenated compounds that have been regarded as major environmental pollutants. Recently, their concurrent appearance in the environment and humans and their structural and toxicological profile similarities have sparked interest in the potential toxicologic consequences of their coexposure. The aim of the current study was to evaluate the cytogenotoxic effects induced by 2,2',4,4'-tetrabromodiphenyl ether (PBDE-47) combined with 2,2',4,4',5,5'-hexachlorobiphenyl (PCB153) treatment in human neuroblastoma cells (SH-SY5Y) in vitro. SH-SY5Y cells were exposed to different concentrations of PBDE-47 (0, 2, 4, 8 µM) with or without PCB153 (5 µM) for 24 h. Thereafter, the cell viability, DNA damage, chromosomal abnormalities, and DNA-protein crosslinks (DPC) were determined. The results show that PBDE-47 and PCB153 alone and in combination induce DNA damage, with an increase in the frequency of micronuclei (MN) and DPC formation with increasing PBDE-47 concentration. In cells coexposed to PBDE-47 and PCB153, the cell viability significantly decreased while the MN frequency, DNA damage and DPC formation were all obviously increased compared to those of cells treated with the corresponding concentrations of PBDE-47 or PCB153 alone. Factorial analysis suggests that there were interactions between PBDE-47 and PCB153. The results imply that PBDE-47 interacts with PCB153 to inhibit cell viability and induce DNA damage, DPC formation, and chromosome abnormalities.

Mechanism of the neurotoxic effect of PBDE-47 and interaction of PBDE-47 and PCB153 in enhancing toxicity in SH-SY5Y cells.

Polybrominated diphenyl ethers (PBDEs) are used in large quantities as flame-retardant additives, especially in electrical appliances and textiles. Because of their structural similarity, PBDEs are thought to have toxicities similar to those of polychlorinated biphenyls (PCBs), which are well-known persistent compounds. Both 2,2',4,4'-tetrabromodiphenyl ether (PBDE-47) and 2,2',4,4',5, 5'-hexachlorobiphenyl (PCB153) can coexist in the environment and human tissues as dominant congeners of PBDEs and PCBs, respectively. To explore the mechanisms of the neurotoxic effect of PBDE-47 and the interaction in combination with PCB153, cell viability, lactate dehydrogenase (LDH) leakage, intracellular Ca2+ concentration ([Ca2+]i), apoptosis and expression levels of death associated protein kinase (DAPK), caspase3, caspase12 and cytochrome c mRNA and proteins were measured in SH-SY5Y cells treated with PBDE-47 (0, 1, 5, 10 micromol/L) and/or PCB153 (5 micromol/L) for 24 h. Compared to controls, the cell viabilities were clearly decreased (P<0.05), and LDH leakage, [Ca2+]i and apoptosis were significantly increased (P<0.05). Furthermore, expression levels of DAPK and caspase3 mRNA, caspase12, as well as cytochrome c mRNA and proteins were markedly increased (P<0.05), while pro-caspase3 proteins were significantly decreased (P<0.05). A positive correlation between [Ca2+]i and percentage of apoptotic cells (r=0.86, P<0.05) and an interaction between PBDE-47 and PCB153 (P<0.05) were observed. We conclude that PBDE-47 can induce SH-SY5Y cell apoptosis via three classic apoptosis pathways and interact with PCB153 to enhance neurotoxicity.

Influence of PCB153 on oxidative DNA damage and DNA repair-related gene expression induced by PBDE-47 in human neuroblastoma cells in vitro.

We studied the relationship between 2,2,4,4-tetrabromodiphenyl ether (PBDE-47) and oxidative DNA damage as well as the mode of interaction between PBDE-47 and 2,2,4,4,5,5-hexachlorobiphenyl (PCB153) by incubating SH-SY5Y cells in four doses of PBDE-47 (0, 1, 5, 10 microM) and/or 5 microM PCB153 and 100 microM NAC (N-acetylcysteine) for 24 h. Results showed that reactive oxygen species (ROS) production in the 5 microM PBDE-47 + PCB153 and 10 microM PBDE-47 + PCB153 groups were significantly higher than that of the control group (p < 0.05). DNA strand breakage and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels were significantly increased in the 10 microM PBDE-47, 5 microM PBDE-47 + PCB153, and 10 microM PBDE-47 + PCB153 groups compared with the control (p < 0.05). Furthermore, ROS formation and DNA strand breakage were dramatically increased in the 5 microM PBDE-47 + PCB153 and 10 microM PBDE-47 + PCB153 groups compared with the corresponding PBDE-47 only group and the PCB153 group (p< 0.05). The level of 8-OHdG was significantly increased in the 10 microM PBDE-47 + PCB153 group compared with the corresponding PBDE-47 only group and the PCB153 group (p < 0.05). The PBDE-47 group coincubated with NAC decreased the ROS level and ameliorated PBDE-47-mediated DNA damage. The mRNA expression levels of X-ray repair cross-complementing gene 1 (Xrcc1) were significantly decreased in the 10 microM PBDE-47, 5 microM PBDE-47 + PCB153, and 10 microM PBDE-47 + PCB153 groups, whereas X-ray repair cross-complementing gene 3 (Xrcc3) were significantly increased in the 10 microM PBDE-47 and 10 microM PBDE-47 + PCB153 groups compared with the control (p < 0.05). The PBDE-47 groups coincubated with NAC, however, considerably increased Xrcc1 while decreasing Xrcc3 mRNA expression (p < 0.05). These results indicate that PBDE-47 induced oxidative DNA damage and that PBDE-47 combined with PCB153 may increase such effects in SH-SY5Y cells in vitro. Furthermore, our results suggest that oxidative stress is responsible for DNA damage induced by PBDE-47.

[Effects of PCB153 on DNA damage and DNA repair-related genes expressions induced by PBDE-47 in human neuroblastoma cells in vitro].

OBJECTIVE: To explore the effects of PCB153 on DNA damage and DNA repair-related gene expressions induced by PBDE-47 in SH-SY5Y cells. METHODS: SH-SY5Y cells were incubated with different concentrations of 1,5 and 10 micromol/L PBDE-47 or/and 5 micromol/L PCB153 and antioxidant n-acetyl cysteine (NAC 100 micromol/L) for 24h in vitro, percentage of DNA in the tail, olive tail moment, the mRNA expression levels of XRCC1 and XRCC3 were measured respectively. RESULTS: PBDE-47 increased percentage of DNA in the tail and olive tail moment significantly at doses of 5 micromol/L and above in a concentration-dependent manner compared to the control (P < 0.05). The percentage of DNA in the tail and olive tail moment were significantly higher in cells treated by 5 micromol/L PBDE-47 + 5 micromol/L PCB153 and 10 micromol/L PBDE-47 + 5 micromol/L PCB153 groups compared to the corresponding doses of PBDE-47 groups or PCB153 group (P < 0.05). The percentage of DNA in the tail and olive tail moment of cells treated by the groups added NAC were obviously lower than that of their corresponding groups not added it (P < 0.05). The interactive action was observed between PBDE-47 and PCB153 at concentrations of 10 micromol/L PBDE-47 (F = 23.74, P < 0.01). Significant decreased XRCC1 mRNA expression were observed at 10 micromol/L PBDE-47, 5 micromol/L PBDE-47 + 5 micromol/L PCB153, and 10 micromol/L PBDE-47 + 5 micromol/L PCB153 groups while significant increased XRCC3 mRNA expression were observed at 10 micromol/L PBDE-47 and 10 micromol/L PBDE-47 + 5 micromol/L PCB153 compared to the control group (P < 0.05). XRCC1 mRNA expression in cells treated by 100 micromol/L NAC + 10 micromol/L PBDE-47 + 5 micromol/L PCB153 group was significantly higher than that in 10 micromol/L PBDE-47 + 5 micromol/L PCB153 group (P < 0.05). XRCC3 mRNA expression in cells treated by PBDE-47 antioxidant groups were significantly lower than that in their corresponding non-antioxidant groups (P < 0.05). Correlation analysis showed there was a negative relationship between DNA damage and XRCC1 mRNA expression while a positive relationship between DNA damage and XRCC3 mRNA expression (r1 = 0.74, r2 = 0.76, P < 0.05). CONCLUSION: PBDE-47 can induce DNA damage, PBDE-47 combined with PCB153 may increase the effects on DNA damage in SH-SY5Y cells in vitro, oxidative stress may play a important role in DNA damage induced by PBDE-47.

[Cyto-genotoxicity induced by 2, 2', 4, 4'-tetrabromodiphenyl ethers combined with 2, 2', 4, 4', 5-hexachlorobiphenyl treatment in SH-SY5Y cells].

OBJECTIVE: To investigate the cyto-genotoxicity of 2, 2', 4, 4'-tetrabromodiphenyl ethers (PBDE-47) combined with 2, 2', 4, 4', 5-hexachlorobiphenyl (PCB153) treatment in SH-SY5Y cells. METHODS: Exponentially growing SH-SY5Y cells were exposed to different concentrations of PBDE-47 or/and PCB153 for 24 h in vitro. Cell viability, DNA damage, chromosome abnormalities, and DNA-protein crosslinks (DPC) were measured using MTT, comet assay, cytokinesis-block micronucleus (CBMN) test, and SDS-KCl assay respectively. RESULTS: Compared to the each single PBDE-47 groups, the nuclear division index (NDI) was significantly lower (P < 0.05) and the frequencies of micronuclei (MNI), percentage of DNA in the tail, Olive tail moment and DPC were significantly increased (P < 0.05) in the PBDE-47 combined with PCB153 groups. There was a statistical decrease in cell viability in groups of 4 micromol/L PBDE-47 and above combined with PCB153 than that in contrast to the same dose of PBDE-47 group or PCB153 alone (P < 0.05). Significant increase was found in MNI frequency and DPC in 2 micromol/L PBDE-47 and above combined with PCB153 than those in the single PCB153 group (P < 0.05). In the groups of 4 micromol/L PBDE-47 and above combined with PCB153, the cell NDI were significantly lower than that of the single PCB153 group (P < 0.05). Compared to the single PCB153 group, the percentage of DNA in the tail and Olive tail moment was significantly increased in the 8 micromol/L PBDE-47 combined with 5 micromol/L PCB153. Factorial analysis showed that interactions between PBDE-47 and PCB153 existed in inhibiting cell viability, inducing DNA damage, MNI, and DPC formation (P < 0.01), and possessing synergistic effects. CONCLUSION: Some dose of PBDE-47 combined with PCB153 can inhibit cell viability, induce DNA damage, DPC formation, and chromosome abnormalities. The pattern of the combined effect is synergistic in cyto-genotoxicity.

PBDE-47-induced oxidative stress, DNA damage and apoptosis in primary cultured rat hippocampal neurons.

2,2',4,4'-Tetrabromodiphenyl ether (PBDE-47) causes developmental neurotoxicity in animal studies, but the mechanism remains poorly understood. This paper investigates the mechanism by studying the effects of oxidative stress, DNA damage, and apoptosis induced by PBDE-47 in cultured primary rat hippocampal neurons at different PBDE-47-concentrations (0, 2.06, 20.6, and 41.2 microM). The results showed that reactive oxygen species (ROS) level, percentage of apoptosis, malondialdehyde (MDA) content, the glutathione peroxidase (GSH-Px) level and the lactic dehydrogenase (LDH) leakage rate were affected by exposure of cells to 41.2 microM PDBE-47 (P<0.05), but not to the lower concentrations tested (20.6 and 2.06 microM). Reduced glutathione (GSH), superoxide dismutase (SOD), and increased DNA damage (tested by a comet assay) were affected at all concentrations tested in a dose-related manner (P<0.05). These results suggested that PBDE-47 could induce oxidative stress, DNA damage, and apoptosis in primary rat hippocampal neurons. Whether or not this concentration response pattern indicates that ROS leads to DNA damage and/or apoptosis must be confirmed with further experiments.

Effects of PBDE-47 on cytotoxicity and genotoxicity in human neuroblastoma cells in vitro.

Polybrominated diphenyl ethers (PBDEs) are an important class of flame retardants. Because of their detection in human breast milk and structural similarity to polychlorinated biphenyls (PCBs), concern has been raised about their potential toxicity, particularly neurotoxic effects in newborns and children. The aim of the current study was to evaluate the cytotoxic and genotoxic effects of 2,2',4,4'-tetrabromodiphenyl ether (PBDE-47) in human neuroblastoma (SH-SY5Y) cells in vitro. SH-SY5Y cells were incubated with different concentrations of PBDE-47 (1, 2, 4, 8 microg/ml) for 24 h, and a set of bioassays were conducted to measure: cell viability, cell proliferation (nuclear division index, NDI), lactate dehydrogenase (LDH) leakage, reactive oxygen species (ROS) formation, cell apoptosis, and DNA breakage and cytogenetic damage. The data showed that PBDE-47 inhibited cell viability, increased LDH leakage, and induced cell apoptosis. All significant effects were observed at concentrations of 4 microg/ml and above (P<0.05). After 24 h exposure, a concentration-dependent increase in ROS formation was observed, and there were obviously increase in comparison to the control at concentrations as low as 2 microg/ml PBDE-47. Log-transformed Olive Tail Moment (OTM) were significantly increased compared with the control at various PBDE-47 concentrations (P<0.05), while a significant increase in the percentage of DNA in the tail was only observed at 8 microg/ml PBDE-47 (P<0.05). PBDE-47 caused a concentration-dependent decrease in NDI, and concentration-dependent increases in chromosome abnormalities as measured by total Micronuclei (MNi)/1000 binucleate cells (BNCs), micronucleated binucleate cells (MNBNCs)/1000 BNCs, and nucleoplasmic bridges (NPBs)/1000 BNCs. The results indicate that PBDE-47 is cytotoxic and genotoxic in SH-SY5Y cells in vitro.

Effects of fluoride on the expression of NCAM, oxidative stress, and apoptosis in primary cultured hippocampal neurons.

The mechanisms underlying the neurotoxicity of endemic fluorosis still remain unknown. To investigate the expression level of neural cell adhesion molecules (NCAM), oxidative stress, and apoptosis induced by fluoride, the primary rat hippocampal neurons were incubated with 20, 40, and 80 mg/l sodium fluoride for 24 h in vitro. The results showed that the cell survival rate in the 80 mg/l fluoride-treated group was significantly lower than that of the control group. Forty and 80 mg/l of fluoride induced significantly increased lactate dehydrogenase release, intracellular reactive oxygen species, and the percentage of apoptosis. Compared with control group, the malondialdehyde levels were significantly elevated while glutathione levels and glutathione peroxidase activities were decreased in all fluoride-treated groups, accompanied by the markedly reduced superoxide dismutase activity in 80 mg/l fluoride-treated group. With respect to NCAM mRNA expression levels, a significant dose-dependent decrease was observed in 40 and 80 mg/l fluoride-treated groups against the control group. In addition, as compared to the control group, the protein expression levels of NCAM-180 in 40 and 80 mg/l fluoride-treated groups, NCAM-140 in all fluoride-treated groups, and NCAM-120 in the 80 mg/l fluoride-treated group were significantly decreased. Our study herein suggested that fluoride could cause oxidative stress, apoptosis, and decreased mRNA and protein expression levels of NCAM in rat hippocampal neurons, contributing to the neurotoxicity induced by fluoride.