The association of serum trans-nonachlor levels with atherosclerosis

Reduced bioenergetics and mitochondrial fragmentation in human primary cytotrophoblasts induced by an EGFR-targeting chemical mixture

Exposures to complex environmental chemical mixtures during pregnancy reach and target the feto-placental unit. This study investigates the influence of environmental chemical mixtures on placental bioenergetics. Recognizing the essential role of the epidermal growth factor receptor (EGFR) in placental development and its role in stimulating glycolysis and mitochondrial respiration in trophoblast cells, we explored the effects of chemicals known to disrupt EGFR signaling on cellular energy production. Human primary cytotrophoblasts (hCTBs) and a first-trimester extravillous trophoblast cell line (HTR-8/SVneo) were exposed to a mixture of EGFR-interfering chemicals, including atrazine, bisphenol S, niclosamide, PCB-126, PCB-153, and trans-nonachlor. An RNA sequencing approach revealed that the mixture altered the transcriptional signature of genes involved in cellular energetics. Next, the impact of the mixture on cellular bioenergetics was evaluated using a combination of mitochondrial and glycolytic stress tests, ATP production, glucose consumption, lactate synthesis, and super-resolution imaging. The chemical mixture did not alter basal oxygen consumption but diminished the maximum respiratory capacity in a dose-dependent manner, indicating a disruption of mitochondrial function. The respiratory capacity and ATP production were increased by EGF, while the Chem-Mix reduced both EGF- and non-EGF-mediated oxygen consumption rate in hCTBs. A similar pattern was observed in the glycolytic medium acidification, with EGF increasing the acidification, and the Chem-Mix blocking EGF-induced glycolytic acidification. Furthermore, direct stochastic optical reconstruction microscopy (dSTORM) imaging demonstrated that the Chem-Mix led to a reduction of the mitochondrial network architecture, with findings supported by a decrease in the abundance of OPA1, a mitochondrial membrane GTPase involved in mitochondrial fusion. In conclusion, we demonstrated that a mixture of EGFR-disrupting chemicals alters mitochondrial remodeling, resulting in disturbed cellular bioenergetics, reducing the capacity of human cytotrophoblast cells to generate energy. Future studies should investigate the mechanism by which mitochondrial dynamics are disrupted and the pathological significance of these findings.

Blood Levels of Organochlorine Contaminants Mixtures and Cardiovascular Disease

Importance

Cardiovascular toxic effects derived from high exposures to individual organochlorine compounds are well documented. However, there is no evidence on low but continuous exposure to combined organochlorine compounds in the general population.

Objective

To evaluate the association of combined exposure to several organochlorine compounds, including organochlorine pesticides and polychlorinated biphenyls, with incident cardiovascular disease (CVD) in the general population.

Design, Setting, and Participants

This prospective nested case-control study included data from 2 cohorts: the Swedish Mammography Cohort-Clinical (SMC-C) and the Cohort of 60-Year-Olds (60YO), with matched case-control pairs based on age, sex, and sample date. Baseline blood sampling occurred from November 2003 to September 2009 (SMC-C) and from August 1997 to March 1999 (60YO), with follow-up through December 2017 (SMC-C) and December 2014 (60YO). Participants with myocardial infarction or ischemic stroke were matched with controls for composite CVD evaluation. Data were analyzed from September 2020 to May 2023.

Exposures

A total of 25 organochlorine compounds were measured in blood at baseline by gas chromatography-triple quadrupole mass spectrometry. For 7 compounds, more than 75% of the samples were lower than the limit of detection and not included.

Main Outcomes and Measures

Incident cases of primary myocardial infarction and ischemic stroke were ascertained via linkage to the National Patient Register (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes I21 and I63). The quantile-based g-computation method was used to estimate the association between the combined exposure to several organochlorine compounds and composite CVD.

Results

Of 1528 included participants, 1024 (67.0%) were female, and the mean (SD) age was 72 (7.0) years in the SMC-C and 61 (0.1) years in the 60YO. The odds ratio of composite CVD was 1.71 (95% CI, 1.11-2.64) per 1-quartile increment of total organochlorine compounds mixture. Organochlorinated pesticides were the largest contributors, and β-hexachlorocyclohexane and transnonachlor had the highest impact. Most of the outcome was not explained by disturbances in the main cardiometabolic risk factors, ie, high body mass index, hypertension, lipid alteration, or diabetes.

Conclusions and Relevance

In this prospective nested case-control study, participants with higher exposures to organochlorines had an increased probability of experiencing a cardiovascular event, the major cause of death worldwide. Measures may be required to reduce these exposures.

Increased risk of atherosclerosis associated with pesticide exposure in rural areas in Korea

Atherosclerosis is a progressive inflammation in systemic vessels, and pesticide exposure has been emerging as its risk factor. This cross-sectional study investigated the association between pesticide exposure and the risk of atherosclerosis in a rural population in Korea using carotid intima-media thickness (CIMT). This study used dataset from the baseline survey of the Korea Farmers Cohort Study between November 2005 and January 2008, and the final analysis included 477 participants. Well-structured questionnaires were used to estimate pesticide exposure. CIMT ≥ 0.9 mm was established for carotid atherosclerosis. Multiple logistic regression analyses were undertaken to evaluate the association between pesticide exposure and atherosclerosis, adjusting demographic and health-related confounders. Even after adjustments, the increased risk of atherosclerosis was significantly associated with pesticide exposure, such as a lifetime history of farming (odds ratio [OR] 3.25 95% confidence interval [CI] 1.51–6.98), a history of using pesticide (OR 3.42 95% CI 1.63–7.16), using pesticide 10 times or more annually (OR 2.55 95% CI 1.21–5.39), and higher cumulative exposure index level (OR 3.63 95% CI 1.65–7.97). Further prospective studies are required to elucidate effects of pesticide exposure on the risk of atherosclerosis.

Associations between persistent organic pollutants and metabolic syndrome in morbidly obese individuals

BACKGROUND AND AIMS

Persons with "metabolically healthy" obesity may develop cardiometabolic complications at a lower rate than equally obese persons with evident metabolic syndrome. Even morbidly obese individuals vary in risk profile. Persistent organic pollutants (POPs) are widespread environmental chemicals that impair metabolic homeostasis. We explored whether prevalence of metabolic syndrome in morbidly obese individuals is associated with serum concentrations of POPs.

METHODS AND RESULTS

A cross-sectional study among 161 men and 270 women with BMI >35 kg/m² and comorbidity, or >40 kg/m². Circulating concentrations of 15 POPs were stratified by number of metabolic syndrome components. In multiple logistic regression analysis odds ratios between top quartile POPs and metabolic risk factors versus POPs below the top quartile were calculated adjusting for age, gender, body mass index, smoking status, alcohol consumption and cholesterol concentrations. Age-adjusted concentrations of trans-nonachlor and dioxin-like and non-dioxin-like polychlorinated biphenyls (PCBs) increased with number of metabolic syndrome components in both genders (p < 0.001), while the organochlorine pesticides HCB, β-HCH and p,p'DDE increased only in women (p < 0.008). Organochlorine pesticides in the top quartile were associated with metabolic syndrome as were dioxin-like and non-dioxin-like PCBs (OR 2.3 [95% CI 1.3-4.0]; OR 2.5 [95% CI 1.3-4.8] and 2.0 [95% CI 1.1-3.8], respectively). Organochlorine pesticides were associated with HDL cholesterol and glucose (OR = 2.0 [95% CI = 1.1-3.4]; 2.4 [95% CI = 1.4-4.0], respectively). Dioxin-like PCBs were associated with diastolic blood pressure, glucose and homeostatic model assessment-insulin resistance index (OR = 2.0 [95% CI = 1.1-3.6], 2.1 [95% CI = 1.2-3.6] and 2.1 [95% CI = 1.0-4.3], respectively).

CONCLUSION

In subjects with morbid obesity, metabolic syndrome was related to circulating levels of organochlorine pesticides and PCBs suggesting that these compounds aggravate clinically relevant complications of obesity.

Determinants of increasing serum POPs in a population at high risk for cardiovascular disease. Results from the PREDIMED-CANARIAS study

Persistent organic pollutants (POPs) are well-known ubiquitous environmental chemicals which have been related to adverse health outcomes, including cardiovascular disease (CVD). The purpose of this study was to evaluate POPs burden, and its determinants, in a population at high risk of suffering CVD enrolled in the PREDIMED Study (Spanish acronym for PREvention by means of MEDiterranean Diet). This cohort was formed by 343 participants (55-80 y.o.), which were selected for a preventive nutritional intervention for CVD based on the Mediterranean Diet. Relevant information on demographic, behavioral, dietary, and socioeconomic characteristics was obtained from each participant through a specific questionnaire, and their anthropometric and clinical measurements were recorded. In addition, the levels of 35 POPs were determined in serum samples taken before the beginning of the nutritional intervention. All the samples showed detectable levels of, at least, one POP, being DDT-derivatives and marker-PCBs the most frequently detected compounds. Our results showed that people at high risk for CVD showed a higher level of contamination by POPs as compared to other studies done in cohorts of Western people at no special risk of CVD. Although educational level seems to be a relevant determinant for POPs burden in our population, the main determining factor seems to be the diet. Thus, while the intake of food of animal origin was significantly associated with levels of PCBs, especially in men, the intake of vegetal-origin food was positively related to levels of organochlorine pesticides, indicating a different dietary source for these two groups of chemicals. Our results showing that subjects at high risk for cardiovascular disease present elevated POPs burden might have a relevant public health impact given the generalized and difficult to avoid exposure to POPs and the elevated worldwide frequency of the CVD.