Association of serum levels of 4-tertiary-octylphenol with cardiovascular risk factors and carotid intima-media thickness in adolescents and young adults

Examining a decade-long trend in exposure to per- and polyfluoroalkyl substances and their correlation with lipid profiles: Insights from a prospective cohort study on the young Taiwanese population

Per- and polyfluoroalkyl substances (PFAS) are artificial chemicals extensively utilized in everyday products, and numerous cross-sectional epidemiological studies consistently link PFAS exposure with lipid profiles across diverse populations and age groups. In longitudinal studies, the findings also indicate a positive correlation between PFAS and lipid profiles; however, this association remains unexplored in adolescents and young adults. Notably, previous research has predominantly focused on conventional lipid biomarkers, with limited exploration of the relationship between PFAS and diverse lipoprotein subfractions. Furthermore, there is a lack of comprehensive investigation into the temporal trends in PFAS concentrations in Taiwan. To address this research gap, we conducted a prospective study following 592 adolescents and young adults (12-30 years old at enrollment) from the YOung TAiwanese Cohort (YOTA) over a duration of 10 years. During the follow-up period, we measured 11 types of PFAS and various lipid profile biomarkers (low-density lipoprotein cholesterol (LDL-C), small dense LDL-C (sdLDL-C), low-density lipoprotein triglyceride (LDL-TG), high-density lipoprotein cholesterol (HDL-C), HDL3-C, lipoprotein(a), triglyceride). Our results revealed a general decline in PFAS concentrations in the study population. Regarding the correlation between the average levels (averaged across the initial and second tracking periods) of PFAS and lipid profiles (during the second tracking period), we observed positive correlations with total cholesterol and LDL-C for perfluorononanoic acid (PFNA), perfluoroundecanoic acid (PFUdA), perfluorododecanoic acid (PFDoA), N-methylperfluorooctane sulfonamide acetic acid (N-MeFOSAA), and the sum of PFAS (sum of the 11 kinds of PFAS). Additionally, average levels of PFUdA, N-MeFOSAA, and the sum of PFAS exhibited positive associations with sdLDL-C. This study unveiled an overall decrease in PFAS concentrations and underscores a potential link between PFAS exposure and adverse changes in lipid profiles among young populations, emphasizing the need for further exploration into the mechanisms of PFAS on lipid metabolism and atherosclerosis.

Associations of prenatal and concurrent exposure to phenols mixture with anthropometric measures and blood pressure during childhood: A time-varying mixture approach

BACKGROUND

Environmental phenols were recognized as endocrine disrupting chemicals (EDCs). However, their impact on childhood anthropometric measures and blood pressure (BP) is still inconclusive. Limited studies have simultaneously considered prenatal and childhood exposures in analyzing mixtures of phenols.

OBJECTIVE

We investigated the relationships between combined prenatal and childhood exposures (two periodic exposures) to phenol mixtures and anthropometric measure and BP, to further identify the vulnerable periods of phenol exposure and to explore the important individual contribution of each phenol.

METHODS

We analyzed 434 mother-child dyads from the Sheyang Mini Birth Cohort Study (SMBCS). The urinary concentrations of 11 phenolic compounds were measured using gas chromatography tandem mass spectrometry. Generalized linear regression models (GLMs) and hierarchical Bayesian Kernel Machine Regression (hBKMR) were used to examine the effects of individual phenolic compounds at each period and of two periodic exposures.

RESULTS

In the single-chemical analysis, prenatal or childhood exposure to specific phenols, especially Benzopheone-3 (BP3), 4-tert-Octylphenol (4-tOP), and Benzyl paraben (BePB) were associated with BMI z-scores (BAZ), Waist-to-height ratio (WHtR), and BP. In the hBKMR models, two periodic exposures to phenol mixtures had a U-shaped association with WHtR, primarily driven by childhood BePB exposure. Moreover, among the phenol mixtures analysis, childhood 4-tOP exposure was identified as the primary contributor to the positive association with diastolic BP. Concurrent exposure to phenol mixtures resulted in greater susceptibility.

CONCLUSIONS

We found that prenatal and childhood exposure to phenol mixtures might influence childhood obesity and elevate blood pressure levels. Concurrent exposure to 4-tOP may be the primary driver of the positive associations with BP.

Examining the impact of polyfluoroalkyl substance exposure on erythrocyte profiles and its related nutrients: Insights from a prospective study on young Taiwanese

Per- and polyfluoroalkyl substances (PFAS) constitute a group of synthetic chemicals extensively utilized across various commonplace products. PFAS are known to have various toxic effects on human health. The relationship between PFAS exposure and erythrocytes has been a subject of interest in epidemiological research, but so far, only limited cross-sectional studies have investigated. Additionally, the role of erythrocyte related nutrition indicators on PFAS-induced changes in erythrograms has not been explored. To fill these knowledge gaps, we launched a longitudinal study over a decade, tracking 502 adolescents and young adults aged 12 to 30 from the YOung TAiwanese Cohort (YOTA). Our analysis encompassed 11 types of plasma PFAS, as well as erythrograms and serum levels of ferritin, transferrin saturation, vitamin B12, and folate. Our examination unveiled positive associations between specific average levels of PFAS compounds, including linear perfluorooctanoic acid (PFOA), branched perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS), and transferrin saturation. Furthermore, linear PFOA and both linear and branched PFOS were negatively correlated with vitamin B12 levels. Specifically, we observed that the average linear PFOA demonstrated positive correlations with mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH), while average PFNA also exhibited positive associations with hemoglobin (Hb) and hematocrit (Hct) in a multiple linear regression model. Subsequent analysis revealed noteworthy interactions between vitamin B12 and PFNA, as well as folate and PFNA, in the context of their impact on Hb, Hct, and PFNA relationships. Additionally, an interaction with transferrin saturation was identified in the correlation between Hct and PFNA. These findings suggest a plausible link between PFAS exposure and erythrograms among young populations, underscoring the potential involvement of iron status, vitamin B12, and folate in this association. Further studies are imperative to elucidate the precise effects of PFAS on erythrocyte in human subjects.

Association of alkylphenols exposure with serum liver function markers in pregnant women in Guangxi, China

The liver toxicity of alkylphenols (APs) has been demonstrated in animal studies. However, relevant epidemiological evidence is still lacking in humans, especially during pregnancy. We obtained the levels of biochemical indicators of liver function in early (<13 weeks, mean gestation=9.80±1.96 weeks) and late (≥32 weeks, mean gestation = 37.23±2.45 weeks) pregnancies from 219 pregnant women in the Guangxi Zhuang birth cohort from 2015-2017. We also examined the serum levels of APs in these pregnant women in early pregnancy. The present study aimed to investigate the correlations between the exposure of pregnant women to APs and their serum liver function indices. The results of the generalized linear model (GLM) in this study revealed that nonylphenol (NP) was positively correlated with total bilirubin (TBIL) (P=0.04) in early pregnancy, and 4-n-nonylphenol (4-N-NP) was negatively correlated with glutamyl transferase (GGT) (P=0.012). In late pregnancy, NP was positively associated with TBIL (P=0.002), and 4-tert-octylphenol (4-T-OP) was positively correlated with alanine aminotransferase (ALT) (P=0.02). Restricted cubic spline (RCS) results revealed doseresponse relationships between NP and TBIL (Poverall=0.011) and between 4-N-NP and GGT (Poverall=0.007) in early pregnancy. In late pregnancy, there were doseresponse relationships between NP and TBIL (Poverall=0.001) and between 4-T-OP and ALT (Poverall=0.033). There was also a doseresponse relationship between NP volume and GGT with an inverted 'U' shape (Poverall=0.041, Pnonlinear=0.012). Bayesian kernel machine regression modeling (BKMR) revealed that TBIL increased significantly (P<0.05) with increasing levels of coexposure to APs in both early and late pregnancy. Overall, exposure to APs during pregnancy affects maternal liver function to varying degrees. The present study provides new epidemiological evidence that exposure to alkylphenols in pregnant women interferes with liver function.

Exposure Profile and Characteristics of Parabens and Alkylphenols in Plasma among Rural Adults in Central China

Parabens and alkylphenols pose serious hazards to human health, yet there are few studies on their exposure profiles and health risks in rural Chinese populations. In this study, 804 participants were selected from the Henan Rural Cohort in mid-eastern China. The plasma levels of parabens (methylparaben, ethylparaben, propylparaben, butylparaben (BuP)) and alkylphenols (4-tert-butylphenol (4-t-BP), 4-tert-octylphenol (4-t-OP)) were analyzed via liquid chromatography-tandem mass spectrometry. Linear regression models were used to investigate factors that may influence pollutant exposure levels. The correlation between contaminants was assessed using Spearman's correlation. The human contaminant intake was estimated using the estimated daily intake (EDI). The health risk was assessed using the hazard quotient (HQ). The detection frequency of four parabens and two alkylphenols exceeded 75%, with median concentrations of 0.444, 0.067, 0.078, 0.053, 8.810, and 6.401 ng/mL, respectively. Significant correlations were observed between parabens, as well as between 4-t-BP and 4-t-OP. Regarding gender, paraben concentrations were higher in women than in men, except for BuP. The EDI for pollutants except 4-t-OP was lower than their respective tolerable/acceptable daily intake. In total, 85.70% of participants had 4-t-OP HQ > 1. A widespread exposure to parabens and alkylphenols among the rural population was found. The high health risks of alkylphenol exposure indicate that alkylphenols should be used with caution.

The Association between 4-Tertiary-Octylphenol, Apoptotic Microparticles, and Carotid Intima-Media Thickness in a Young Taiwanese Population

As one of the most common alkylphenols, 4-tertiary-octylphenol (4-tOP) is commonly used in many consumer products. Our previous epidemiological study revealed a negative correlation between serum 4-tOP levels and carotid intima-media thickness (CIMT), which serves as a biomarker of arteriosclerosis. We aimed to explore the role of apoptotic microparticles, markers of vascular endothelial cell function, in the 4-tOP and CIMT connection. To investigate this, we enrolled 886 Taiwanese adolescents and young adults (aged 12-30 years) and examined the relationships among serum 4-tOP levels, apoptotic microparticles (CD31+/CD42a-, CD31+/CD42a+), and CIMT. Our results showed negative associations among serum 4-tOP levels, both apoptotic microparticles, and CIMT in multiple linear regression analysis. The odds ratios for CIMT (≥75th percentile) and the natural logarithm of 4-tOP were highest when both CD31+/CD42a- and CD31+/CD42a+ were greater than the 50th percentile. Conversely, the odds ratios were lowest when both CD31+/CD42a- and CD31+/CD42a+ were less than the 50th percentile. In the structural equation model, we demonstrated that serum 4-tOP levels were negatively correlated with CIMT and indirectly and negatively correlated with CIMT through both apoptotic microparticles. In conclusion, our study reported the inverse association between 4-tOP apoptotic microparticles and CIMT in a young Taiwanese population. Further experimental studies are needed to clarify these associations.

Recent Advances in the Synthesis, Characterization, and Application of Carbon Nanomaterials for the Removal of Endocrine-Disrupting Chemicals: A Review

The large-scale production and frequent use of endocrine-disrupting chemicals (EDCs) have led to the continuous release and wide distribution of these pollutions in the natural environment. At low levels, EDC exposure may cause metabolic disorders, sexual development, and reproductive disorders in aquatic animals and humans. Adsorption treatment, particularly using nanocomposites, may represent a promising and sustainable method for EDC removal from wastewater. EDCs could be effectively removed from wastewater using various carbon-based nanomaterials, such as carbon nanofiber, carbon nanotubes, graphene, magnetic carbon nanomaterials, carbon membranes, carbon dots, carbon sponges, etc. Important applications of carbon nanocomposites for the removal of different kinds of EDCs and the theory of adsorption are discussed, as well as recent advances in carbon nanocomposite synthesis technology and characterization technology. Furthermore, the factors affecting the use of carbon nanocomposites and comparisons with other adsorbents for EDC removal are reviewed. This review is significant because it helps to promote the development of nanocomposites for the decontamination of wastewater.

Research Advances in the Analysis of Estrogenic Endocrine Disrupting Compounds in Milk and Dairy Products

Milk and dairy products are sources of exposure to estrogenic endocrine disrupting compounds (e-EDCs). Estrogenic disruptors can accumulate in organisms through the food chain and may negatively affect ecosystems and organisms even at low concentrations. Therefore, the analysis of e-EDCs in dairy products is of practical significance. Continuous efforts have been made to establish effective methods to detect e-EDCs, using convenient sample pretreatments and simple steps. This review aims to summarize the recently reported pretreatment methods for estrogenic disruptors, such as solid-phase extraction (SPE) and liquid phase microextraction (LPME), determination methods including gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS), Raman spectroscopy, and biosensors, to provide a reliable theoretical basis and operational method for e-EDC analysis in the future.

Global DNA methylation mediates the association between serum perfluorooctane sulfonate and carotid intima-media thickness in young and middle-aged Taiwanese populations

PURPOSE

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals used in the manufacture of many everyday products. Previous reports have shown PFAS exposure may contribute to cardiovascular diseases (CVD). Recent studies have also identified a critical role for DNA methylation, a model of epigenetic regulation, in the pathogenesis of CVD. Additionally, PFAS has been shown to affect DNA methylation. Our previous study reported the positive association between serum perfluorooctane sulfonate (PFOS) levels and mean carotid intima-media thickness (CIMT), a biomarker of arteriosclerosis, in a cohort composed of adolescent and young adult Taiwanese. However, the contribution of DNA methylation in the mechanism of PFOS-induced arteriosclerosis has never been explored in previous literature.

APPROACH AND RESULTS

In this cross-sectional study, we included 1425 young and middle-aged Taiwanese individuals (12-63 years) to investigate the correlation between serum PFOS levels, 5mdC/dG (a global DNA methylation marker) and the mean CIMT. We showed that the positive association between serum PFOS levels, 5mdC/dG, and mean CIMT. The regression coefficients of mean CIMT with a one-unit increase in ln-PFOS concentration were higher when the levels of 5mdC/dG were above the 50th percentile in the multiple regression analysis. In the structural equation model (SEM), the results showed that serum PFOS levels were directly correlated with mean CIMT and indirectly correlated with CIMT through 5mdC/dG.

CONCLUSIONS

Our results showed that PFOS exposure has direct associations on arteriosclerosis and indirect direct associations on arteriosclerosis through DNA methylation. The results suggest that DNA methylation might regulate the relationship between PFOS and arteriosclerosis in the study subjects. Additional works are required to understand the causal inference between PFOS, DNA methylation, and arteriosclerosis.

Association between serum per- and polyfluoroalkyl substances and thrombograms in young and middle-aged Taiwanese populations

PURPOSE

Per- and polyfluoroalkyl substances (PFAS) are a class of man-made chemicals used in many products. Recent in vitro and epidemiological reports have found that PFAS exposure can modify the function of platelets. Platelet size has been shown to affect platelet activity, and thrombograms are a simple method of indirect assessment of platelet function. However, there has been no large-scale research investigating the association between PFAS levels and complete thrombograms in humans.

APPROACH AND RESULTS

In the current cross-sectional study, we enrolled 1779 Taiwanese subjects (aged between 12 and 63 years) to study the associations between serum PFAS concentrations and thrombograms. There were 1175 men and 604 women with a mean age of 34.5 years. When all four PFAS were fitted by the multiple linear models at the same time, platelet counts decreased significantly with increasing quartiles of perfluorooctanoate acid (PFOA) and perfluorooctane sulfonate (PFOS), while platelet distribution width (PDW), mean platelet volume (MPV), and platelet-large cell ratio (PLCR) also increased significantly with increasing quartiles of PFOS. The mean platelet count was the lowest (264.02 k/µL [95% CI 256.00-272.04]; P < 0.001) when both PFOA and PFOS concentrations were above the 50th percentile.

CONCLUSIONS

We report that serum PFAS levels were correlated with thrombograms. If the association is etiologic, PFOA/PFOS may decrease the number of platelets, while PFOS may also increase the variation and the average size of platelets in the subjects of the study. Interestingly, PFOA and PFOS may have synergistic effects on the decrease in platelet counts. Further research is needed to study the effect of PFAS on platelets in humans.

Global DNA methylation mediates the association between urine mono-2-ethylhexyl phthalate and serum apoptotic microparticles in a young Taiwanese population

Di-(2-ethylhexyl) phthalate (DEHP) has been used as a plasticizer for decades. Recent research evidence has revealed that environmental factors can alter vascular endothelial cell function through DNA methylation. However, no previous in vitro/vivo study has explored the role of DNA methylation in DEHP exposure and vascular endothelial cell function. In the present study, we enrolled 793 subjects aged 12 to 30 years from a young Taiwanese cohort to investigate the association between mono-2-ethylhexyl phthalate (MEHP) (urine DEHP metabolite), 5mdC/dG (global DNA methylation marker), CD31⁺/CD42a^-, CD31⁺/CD42a⁺, and CD14 (apoptotic microparticles of vascular cells). In multiple regression analyses, the levels of mono-2-ethylhexyl phthalate (MEHP) were positively associated with 5mdC/dG and all three apoptotic microparticles. In addition, the regression coefficients between MEHP and the three types of apoptotic microparticles were higher when the 5mdC/dG levels were higher than the 50th percentile. In the structural equation model (SEM), we found that MEHP had a direct correlation with CD31⁺/CD42a^- and an indirect association with CD31⁺/CD42a^- through the effect of 5mdC/dG. Moreover, MEHP only had a direct association with CD31⁺/CD42a⁺ and an indirect association with CD14. In conclusion, the results show that global DNA methylation mediates the relationship between MEHP and apoptotic microparticles. These findings indicate that DNA methylation may play a role in the pathogenesis of DEHP-induced endothelial cell apoptosis in humans. Further studies are needed to clarify the causal inference.

Association between the total plasma isomers of per- and polyfluoroalkyl substances and erythrograms in young and middle-aged Taiwanese populations

PURPOSE

Per- and polyfluoroalkyl substances (PFAS) are human-made chemicals used in daily use products. Recent studies have shown that different perfluorooctanoic acid (PFOA) and/or perfluorooctane sulfonate (PFOS) isomers may have different biological effects. In vitro studies have also reported that PFAS exposure can alter the structure of hemoglobin (Hb). In epidemiology, however, few studies have investigated the relationship between PFAS exposure and erythrocytes. Additionally, the correlation between PFOA/PFOS isomers and full erythrograms has never been explored.

APPROACH AND RESULTS

In cohorts comprising young and middle-aged Taiwanese populations, we enrolled 1483 participants (aged between 12 and 63 years) to analyze the correlations between the plasma levels of PFOA/PFOS isomers and whole-blood erythrograms. The study comprised 868 men and 615 women with a mean age of 31.2 years. When all PFOA/PFOS isomers were entered into the multiple linear regression model, the linear PFOA (L-PFOA) levels were positively correlated with the Hb, hematocrit (HCT), mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) levels while the branched PFOS (B-PFOS) levels were positively associated with the Hb, HCT, and mean corpuscular hemoglobin concentration (MCHC). The mean value of Hb was the highest (14.66 mg/dL (95% CI =14.52-14.80); P for trend <0.001) when both the L-PFOA and B-PFOS levels were above the 50th percentile.

CONCLUSIONS

The results imply that PFOA/PFOS isomers may increase the weight and volume of Hb/RBC and that L-PFOA/B-PFOS may have an additive effect on the Hb levels. However, it is also possible PFAS detected at a higher concentration may due to its binding to higher levels of Hb. Further studies are needed to investigate the effects of PFOA/PFOS isomers on RBCs in humans.

Zinc status is independently related to the bone mineral density, fracture risk assessment tool result, and bone fracture history: Results from a U.S. nationally representative survey

PURPOSE

Previous reports have identified the important role of zinc in bone health. Although the risk of zinc deficiency is still a concern in the U.S., there has never been an in-depth study of the association between zinc status and bone health in a sample representing the country.

METHODS

We included 2,895 subjects (aged ≥ 40 years) from National Health and Nutrition Examination Survey (NHANES) 2013-2014 to explore the relationship among three biomarkers of zinc (serum, food, and total intake), the bone mineral density (BMD) of the total spine and femur, the FRAX® scores, and the previous history of bone fractures.

RESULTS

We showed a one-unit increase in the ln-serum zinc level was associated with an increase in the total spine BMD (ß = 0.068; S.E. = 0.028; P =  0.030) and total femur BMD (ß = 0.061; S.E. = 0.017; P =  0.003), while a one-unit increase in the ln-food zinc intake amount was correlated with an increase in the total femur BMD in the participants (ß = 0.023; S.E. = 0.009; P =  0.021). The ln-total zinc intake amount was correlated with an increase in the total femur BMD in women (ß = 0.016; S.E. = 0.007; P =  0.041). We also found food zinc intake was negatively correlated with the FRAX® score, while increased levels of all three zinc biomarkers were associated with a decreased incidence of previous bone fractures.

CONCLUSIONS

In this representative survey of American adults above 40 years old, higher zinc status was associated with higher total spine and femoral BMD, lower FRAX® scores, and lower incidence of previous fractures. If this finding is causal, increased zinc intake remains an important issue for Americans.

Associations of urinary phenolic environmental estrogens exposure with blood glucose levels and gestational diabetes mellitus in Chinese pregnant women

BACKGROUND

Endocrine-disrupting chemicals (EDCs) are considered to be related to diabetes, but studies of the association between phenolic EDCs and gestational diabetes mellitus (GDM) are limited.

OBJECTIVES

To assess associations of maternal urinary bisphenol A (BPA), nonylphenol (NP), and 2-tert-octylphenol (2-t-OP) with GDM occurrence.

METHODS

A cross-sectional study was performed among 390 Chinese women at 24-28 weeks of gestation. GDM was diagnosed with a 2-h 75-g oral glucose tolerance test (OGTT). BPA, NP, and 2-t-OP concentrations were determined in urine samples. Linear and logistic regression tests evaluated associations of BPA, NP, and 2-t-OP with blood glucose levels and GDM prevalence.

RESULTS

The 2-t-OP concentrations in GDM patients were significantly higher than in non-GDM women with median values of 2.23 μg/g Cr and 1.79 μg/g Cr, respectively. No significant difference was observed in BPA and NP. Urinary 2-t-OP was positively associated with blood glucose levels after adjustment for several confounding factors and urinary BPA and NP. Higher 2-t-OP levels were associated with higher odds of GDM (OR: 5.78; 95% CI: 2.04, 16.37), whereas higher NP levels were associated with lower odds (OR: 0.22; 95% CI: 0.05, 0.85) in the adjusted models. In addition, compared to the first quartile of 2-t-OP, the adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) for GDM in the second, third, and fourth quartiles were 2.81 (1.23, 6.42), 3.01 (1.30, 6.93), and 5.49 (2.24, 13.46), respectively.

CONCLUSION

Our study indicates that, for the first time to our knowledge, exposure to 2-t-OP is associated with a higher risk of GDM. However, higher NP exposure is associated with lower GDM risk. Further studies are necessary to affirm the associations of 2-t-OP and NP with GDM, and to elucidate the causality of these findings.

The association between urine di-(2-ethylhexyl) phthalate metabolites, global DNA methylation, and subclinical atherosclerosis in a young Taiwanese population

Di-(2-ethylhexyl) phthalate (DEHP) has been utilized in many products for years. DEHP exposure has been linked to cardiovascular diseases (CVD) and its risk factors. Recent evidence has found a crucial role for epigenetics, including DNA methylation, in CVD. Moreover, DEHP exposure has proved to alter DNA methylation in epidemiological studies. However, the interplay between DEHP exposure, global DNA methylation, and atherosclerosis has never been reported. In this current study, we enrolled 793 participants (12-30 years) from a Taiwanese population to investigate the association between concentrations of DEHP metabolites, 5mdC/dG (global DNA methylation marker) and the carotid intima-media thickness (CIMT). The results showed urine mono-2-ethylhexyl phthalate (MEHP) level was positively correlated with 5mdC/dG and CIMT, respectively. In logistic regression models, the odds ratios (OR) of thicker CIMT (greater than 75^th percentile) with one unit increase in ln-MEHP level was higher when levels of 5mdC/dG were above 50%. In structural equation model, the result showed urine MEHP levels are directly associated with CIMT. Moreover, MEHP had an indirect association with CIMT through the 5mdC/dG after adjusting other confounding effects. In the current study, urine DEHP metabolite levels were positively correlated with 5mdC/dG, and CIMT. Our results showed DEHP had a direct and indirect association with CIMT through the 5mdC/dG. The finding implies that DNA methylation may mediate the association between DEHP exposures and subclinical atherosclerosis in this young population. Future effort is needed to elucidate the causal relationship between DEHP exposure, DNA methylation and CVD.

Effects of octylphenol exposure on the lipid metabolism and microbiome of the intestinal tract of Rana chensinensis tadpole by RNAseq and 16s amplicon sequencing

Octylphenol (OP) is a widely distributed endocrine disrupting chemical (EDC), and can be commonly found in various and diverse environmental media. Previous studies have reported that OP exposure could cause many adverse effects on aquatic animals. However, knowledge concerning the impact of OP on lipid metabolism in amphibians was still limited. In our study, Rana chensinensis tadpoles were exposed to different OP concentrations (0, 10^-8, 10^-7 and 10^-6 mol/L) from the Gosner stage (Gs) 25-38. The RNA-seq analysis of tadpole intestines was explored by RNA-seq, and six differentially expressed genes (DEGs) related to the fat digestion and absorption were validated by RT-qPCR. Moreover, we used 16s amplicon sequencing to evaluate effects of OP on intestinal microbiome in tadpoles, further determining the variations of lipid metabolism. Our results revealed that OP exposure influenced gene expression levels related to fat digestion and absorption and led to alteration of structure and composition of intestinal microbiome. At the phylum level, the Firmicutes/Bacteroidetes ratio was gradually decreased in OP exposure groups, which disrupted lipid metabolism. According to the results of intestinal microbial functional prediction, OP exposure interfered with metabolic function and increased risk of disease. These data provide us with powerful resources to assess the effects of OP on lipid metabolism by integrating RNAseq and 16s amplicon sequencing analysis of intestinal tract and intestinal microbiome.