Exposure to diisononyl phthalate induced an increase in blood pressure through activation of the ACE/ AT1R axis and inhibition of NO production

A narrative review of phthalates: From environmental release to kidney injury

Plastic products play an indispensable role in human daily lives, largely due to their low cost and unrivaled convenience. Phthalates (PAEs) are the most significant plastic additives due to their distinctive properties and are extensively utilized and produced in large quantities. Nevertheless, given their inability to form covalent bonds with plastics, these compounds are prone to leaching from plastic surfaces. As a result, the use of plastics in various industries has become a major source of PAEs in the environment, leading to increased risks to humans. The kidneys, which play a central role in the excretion of PAEs, are considered one of the primary target organs for PAEs accumulation and toxicity. A growing body of evidence supports an association between exposure to PAEs and adverse effects on the kidney. In environments, PAEs are often exposed simultaneously with other contaminants that may directly or indirectly modify the toxic effects of PAEs. This review focuses on the adverse effects of PAEs exposure on the kidney and their mechanisms of action, as well as the interactions between PAEs and other contaminants on the kidney. This review underscores the necessity for future toxicological studies to prioritize the mechanisms of renal injury caused by co-exposure to PAEs and other pollutants. The employment of advanced technologies, including network toxicology and molecular docking techniques, is imperative to enhance comprehension of the potential toxicity associated with co-exposures.

Exposure to phthalates and replacements during pregnancy in association with gestational blood pressure and hypertensive disorders of pregnancy

Exposure to endocrine-disrupting chemicals such as phthalates may increase risk of hypertensive disorders of pregnancy (HDP). Prior studies lack investigation of chemical mixtures, phthalate replacements, or key periods of susceptibility including early pregnancy. In the present study, we used a longitudinal approach to evaluate gestational exposure to phthalates and replacements, as both single-pollutants and mixtures, in association with blood pressure and diagnosis of preeclampsia or any HDP. The Human Placenta and Phthalates prospective pregnancy cohort includes 291 participants recruited from two U.S. clinics. Urinary metabolites of ten phthalates and replacements were quantified at up to 8 time points per individual and averaged to create early (12-15 weeks) and overall (12-38 weeks) pregnancy exposure biomarkers. We collected data on gestational blood pressure (mean = 6.2 measures per participant) and diagnosis of preeclampsia (n = 26 cases) or any HDP (n = 44 cases). Linear mixed effects models estimated associations between exposure biomarkers and repeated blood pressure measures. We estimated exposure biomarker associations with preeclampsia and HDP using Cox proportional hazards or logistic regression models, respectively. Quantile g-computation was used to estimate joint effects of a phthalate or replacement mixture with each outcome. Early pregnancy exposure biomarkers demonstrated greater associations with adverse outcomes compared to overall pregnancy. A one-interquartile range increase in early pregnancy di-isononyl phthalate metabolites (ƩDiNP) was associated with a 1.13 mmHg (95 % confidence interval [CI]: 0.25, 2.37) and 0.90 mmHg (CI: 0.16, 1.65) increase in systolic and diastolic blood pressure, respectively. We also found positive but nonsignificant associations of early pregnancy mono-3-carboxypropyl phthalate, di-2-ethylhexyl terephthalate metabolites, and the high molecular weight phthalate mixture with blood pressure. Early pregnancy ƩDiNP was furthermore associated with increased odds of HDP (odds ratio: 1.37, CI: 1.03, 1.82), but not preeclampsia. In sum, early gestational exposure to DiNP and other high molecular weight phthalates may contribute to HDP.

Diisononyl phthalate down-regulates the expression of antioxidant genes NFE2L2, TXN, and TXNRD2, while diethyl-hexyl terephthalate up-regulates their expression including SOD-1

Phthalates, widely utilised as plasticisers to enhance the flexibility of rigid materials like polyvinyl chloride, are known for their endocrine-disrupting properties and cytotoxic effects.This study investigated the impact of Diisononyl phthalate (DINP) and Diethyl-hexyl terephthalate (DEHT) on human endothelial cells (EA.hy926).The assessment focused on cell viability, reactive oxygen species (ROS) production, and the antioxidant-responsive genes expression (NFE2L2, SOD1, TXN, and TXNRD2) following exposure to varying 1, 10, and 100 µg/mL of DINP or DEHT.Cell viability was determined using MTT and lactate dehydrogenase (LDH) release assays. ROS were measured using the DCFDA assay.Gene expression analysis was conducted via qRT-PCR after 48 h of exposure. Results revealed that DINP 100 µg/mL significantly reduced cell viability at 11 and 17% at 48 and 72 h, respectively, whereas increased LDH release by 69% at 48 h. ROS levels also rose by 19-30%, accompanied by down-regulation of NFE2L2, TXN, and TXNRD2.Conversely, DEHT had no adverse effect on cell viability or LDH levels but elevated ROS production (11-14%) and induced up-regulation of antioxidant genes, including SOD1.The findings indicate that DINP exposure could negatively affect the cellular antioxidant response, whereas DEHT leads to up-regulation of antioxidant genes without detrimental effects on viability.

Toxic Effects of Exposure to Phthalates on Cardiac Injury Biomarkers: Evidence from NHANES 1999-2004

Background: Humans are consistently and increasingly exposed to phthalate products, but the effect of the combined exposure to phthalates on myocardial injury remains largely unexplored. The present study aimed to explore the effect of the combined exposure to phthalates on myocardial injury. Methods: A total of 1237 male adults (aged ≥20) without coronary artery disease (CAD) from the National Health and Nutrition Examination Survey (NHANES) in 1999-2004 were included in the current study. Multiple linear regression, Bayesian kernel machine regression (BKMR), and a weighted quantile sum (WQS) model were employed to examine the associations of urinary phthalate metabolites with two cardiac injury biomarkers, including troponin T (TNT) and troponin I, using four highly sensitive assays (Abbott, Chicago, IL, USA; Siemens, Erlangen, Germany; and Ortho, Raritan, NJ, USA) (TNIA, TNIS, TNIO). Results: According to the linear regression analysis, mono-(3-carboxypropyl) phthalate (MCPP, a metabolite of di-n-octyl phthalate) was found to be positively associated with serum TNT; a positive association was found between mono-isobutyl phthalate (MiBP, a metabolite of di-isobutyl phthalate) and TNIA, as well as MiBP and TNIS. Mono-benzyl phthalate (MBzP, a metabolite of butyl benzyl phthalate) and MCPP were positively associated with serum TNIO. The BKMR analyses showed a positive overall relationship of serum TNT, TNIA, TNIS, and TNIO with increased concentrations of phthalate metabolites. The WQS model showed MCPP and MBzP were the top two contributors to being an increased risk for elevated TNT levels. MCPP and mono-ethyl phthalate (MEP, a metabolite of diethyl phthalate) were identified as the leading contributors to increased TNIA and TNIS. MCPP and MBzP were the dominant contributors to elevated TNIO. Conclusions: As a combined mixture, phthalate metabolites were positively associated with serum TNT and TNI among adults without CAD, indicating the potential toxic effect of phthalate exposure on cardiac injury.

Formaldehyde causes an increase in blood pressure by activating ACE/AT1R axis

Previous studies suggest some link between formaldehyde exposure and harmful cardiovascular effects. But whether exposure to formaldehyde can cause blood pressure to rise, and if so, what the underlying mechanism is, remains unclear. In this study, C57BL/6 male mice were exposed to 0.1, 0.5, 2.5 mg/m³ of gaseous formaldehyde for 4 h daily over a three-week period. The systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP) and heart rate (HR) of the mice were measured by tail-cuff plethysmography, and any histopathological changes in the target organs of hypertension were investigated. The results showed that exposure to formaldehyde did cause a significant increase in blood pressure and heart rate, and resulted in varying degrees of damage to the heart, aortic vessels and kidneys. To explore the underlying mechanism, a specific inhibitor of angiotensin converting enzyme (ACE) was used to block the ACE/AT1R axis. We observed the levels of ACE and angiotensin II type 1 receptor (AT1R), as well as the bradykinin (BK) in cardiac cytoplasm. The data suggest that exposure to formaldehyde induced an increase in the expression of ACE and AT1R, and decreased the levels of BK. Strikingly, treatment with 5 mg/kg/d ACE inhibitor can attenuate the increase in blood pressure and the pathological changes caused by formaldehyde exposure. This result has improved our understanding of whether, and how, formaldehyde exposure affects the development of hypertension.

Phthalate promotes atherosclerosis through interacting with long-non coding RNA and induces macrophage foam cell formation and vascular smooth muscle damage

BACKGROUND

Phthalates are commonly used in variety of plastic products. Previously it has been revealed that di (2-ethylhexyl) phthalate (DEHP), as the most common member of the class of phthalates, may disturb cholesterol homeostasis and deregulate the inflammatory response, and leading to accelerate the atherosclerosis process. In this regard, the aim of the current study is to explore the underlying mechanism of DEHP-induced atherosclerosis through the increasing of foam cell formation and Vascular Smooth Muscle Cells (VSMCs) damage via the interaction of long-non coding RNA (GAS5) and miR-145-5p.

METHODS

ApoE^-/- mice were used to evaluate the in vivo study. RAW264.7 and VSMCs were used to evaluate the effect of DEHP on formation of foam cell, cell proliferation, and cell damage in vitro. Animals were treated with DEHP (5% w/w of food) orally and cells were treated with medium containing of 100 μM DEHP; qRT-PCR, Western blotting, flowcytometry, IHC, oil red O, BODIPY, and autophagic vacuoles assay were used to evaluate the effect of DEHP on formation of atherosclerosis.

RESULTS

DEHP significantly accelerated the formation of atherosclerosis in mice and alter the lipid profile in mice. In addition, after treating VSMCs with DEHP, GAS5 was significantly up-regulated and miR-145-5p was down-regulated. In VSMCs treated with DEHP, we observed that GAS5 could be used as the competing endogenous RNA (ceRNA) of miR-145-5p to regulate the proliferation and apoptosis of VSMCs; and the expression of GAS5 was correlated with the expression of miR-145-5p. DEHP increased the ox-LDL uptake by macrophage and increasing the formation of foam cells. Besides, GAS5 knocking down reversed the effect of DEHP on foam cell formation and ox-LDL uptake.

CONCLUSION

DEHP could accelerate the atherosclerosis process through increasing VSMCs damage and formation of macrophage foam cell by increasing lipid uptake though down regulating lncRNA GAS5 and altering in regulation of miR-145-5p.

Effects of DEHP, DEHT and DINP Alone or in a Mixture on Cell Viability and Mitochondrial Metabolism of Endothelial Cells In Vitro

Plasticizers are chemicals in high demand, used in a wide range of commercial products. Human are exposed through multiple pathways, from numerous sources, to multiple plasticizers. This is a matter of concern, as it may contribute to adverse health effects. The vascular system carries plasticizers throughout the body and therefore can interact with the endothelium. The aim of the study was to evaluate the in vitro toxicity on endothelial cells by considering the individual and the mixture effects of bis-(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP) or bis-(2-ethylhexyl) terephthalate (DEHT). In this study, their cytotoxicity on HMEC-1 cells was evaluated on cell function (viability, cell counting, total glutathione and intracellular adenosines) and mitochondrial function (mitochondrial respiration). Results showed cellular physiological perturbations induced with all the condition tested, excepted for DEHT. Plasticizers induced a cytotoxicity by targeting mitochondrial respiration, depleting mitochondrial ATP production and increasing glycolytic metabolism. Additionally, delayed effects were observed between the cellular and the mitochondrial parameters. These results suggest that endothelial cells could go through a metabolic adaptation to face plasticizer-induced cellular stress, to effectively maintain their cellular processes. This study provides additional information on the adverse effects of plasticizers on endothelial cells.

Air Pollution Health Impact Monitoring and Health Risk Assessment Technology and Its Application - China, 2006-2019

Air pollution is a significant risk factor contributing to the burden of disease in China. Health risk assessment and management are important to reduce the impact of air pollution on public health. To help formulate standardized health risk assessment techniques, a series of studies were conducted from 2006 to 2019. Through systematic review, study of molecular mechanisms, epidemiological investigation, and health effect monitoring, the overall project established a monitoring and evaluation indicator system, a comprehensive information platform, software for automatic data cleaning, and standardized health risk assessment techniques. Technical specifications have been issued by the National Health Commission for promoting health risk assessments across China. This paper introduces the project, the research approach, its main research accomplishments, innovations, and public health significance, and describes directions for further research.

Association of urine phthalate metabolites, bisphenol A levels and serum electrolytes with 24-h blood pressure profile in adolescents

BACKGROUND

Among the possible causes of hypertension in adolescence, electrolyte imbalances and environmental pollutants are drawing increasing attention. We aimed to examine the relationship between bisphenol A (BPA), phthalate metabolites, and serum electrolytes and blood pressure.

METHODS

Eighty-six participants aged 12-15 years were included in the study. Body mass index (BMI), office blood pressure and 24-h ambulatory blood pressure measurements (ABPM), and carotid intima-media thickness were determined. Blood samples were taken for hemogram, renal function tests, and serum electrolytes. Free- and total-BPA and phthalate metabolites were analyzed from urine samples.

RESULTS

Of the participants, 34 were evaluated as normal blood pressure profile, 33 as white-coat hypertension (WCHT), and 19 as ABPM-hypertension. Adolescents in ABPM- hypertension groups had higher BMI-standard deviation score (SDS), leucocyte, platelet count; but lower serum chloride, compared to the normal blood pressure profile group. The percentage of adolescents with detectable urinary mono-benzyl phthalate (MBzP) was higher in ABPM-hypertension (42.1%) and WCHT groups (33.3%), compared to the normal blood pressure profile group (5.9%, p = 0.004). Associations between MBzP and ABPM- hypertension and WCHT were remained after confounding factor adjustment. Adolescents with detectable MBzP levels had also higher "albumin-corrected calcium" and lower serum phosphate and "albumin-corrected calcium x phosphate product" compared to others. Adolescents with detectable urinary MBzP levels had higher blood pressure profiles in some 24-h (mean arterial pressure-SDS, systolic blood pressure-SDS), daytime (systolic blood pressure-SDS), and night-time (mean arterial pressure-SDS, systolic blood pressure-SDS, and diastolic blood pressure-SDS) measurements, compared to others. WCHT was found to be associated negatively with monomethyl phthalate and the sum of dibutyl phthalate metabolites and ABPM-HT with MCPP. There was no significant association between blood pressure profiles and free- and total-BPA status.

CONCLUSION

MBzP was associated with adverse blood pressure profiles in adolescence. Additive follow-up studies are necessary for cause-effect relations.

Maternal Phthalates Exposure and Blood Pressure during and after Pregnancy in the PROGRESS Study

BACKGROUND

Phthalate exposure is ubiquitous and may affect biological pathways related to regulators of blood pressure. Given the profound changes in vasculature during pregnancy, pregnant women may be particularly susceptible to the potential effects of phthalates on blood pressure.

OBJECTIVES

We examined associations of phthalate exposure during pregnancy with maternal blood pressure trajectories from mid-pregnancy through 72 months postpartum.

METHODS

Women with singleton pregnancies delivering a live birth in Mexico City were enrolled during the second trimester (n=892). Spot urine samples from the second and third trimesters were analyzed for 15 phthalate metabolites. Blood pressure and covariate data were collected over nine visits through 72 months postpartum. We used linear, logistic, and linear mixed models; latent class growth models (LCGMs); and Bayesian kernel machine regression to estimate the relationship of urinary phthalate biomarkers with maternal blood pressure.

RESULTS

As a joint mixture, phthalate biomarker concentrations during pregnancy were associated with higher blood pressure rise during mid-to-late gestation. With respect to individual biomarkers, second trimester concentrations of monobenzyl phthalate (MBzP) and di(2-ethylhexyl) phthalate biomarkers (ΣDEHP) were associated with higher third trimester blood pressure. Two trajectory classes were identified by LCGM, characterized by increasing blood pressure through 72 months postpartum ("increase-increase") or decreased blood pressure through 18 months postpartum with a gradual increase thereafter ("decrease-increase"). Increasing exposure to phthalate mixtures during pregnancy was associated with higher odds of being in the increase-increase class. Similar associations were observed for mono-2-ethyl-5-carboxypentyl terephthalate (MECPTP) and dibutyl phthalate (ΣDBP) biomarkers. When specific time periods were examined, we observed specific temporal relationships were observed for ΣDEHP, MECPTP, MBzP, and ΣDBP.

DISCUSSION

In our cohort of pregnant women from Mexico City, exposure to phthalates and phthalate biomarkers was associated with higher blood pressure during late pregnancy, as well as with long-term changes in blood pressure trajectories. https://doi.org/10.1289/EHP8562.

Exposure evaluation of diisononyl phthalate in the adults of Drosophila melanogaster: Potential risks in fertility, lifespan, behavior, and modes of action

Diisononyl phthalate (DINP) as a phthalate plasticizer is widely used in daily life and production, which shows endocrine disruption effects and has several adverse effects on the normal physiological function. Here, the effects of DINP (0.1%, 0.2%, 0.5%, and 1.0%) (v/v) on the fertility, lifespan, climbing behavior, anti-starvation ability of Drosophila melanogaster and the potential modes of action were investigated. The results showed that DINP impaired fertility in a dose-dependent manner and smaller ovarian volume, lower hatching rate, and fewer offspring was observed at higher concentrations. The effect of DINP on the lifespan showed gender-specific, and mortality was increased after exposure above 0.2% DINP. The climbing ability increased at 0.1% DINP compared with the vehicle group, while it manifested a dose-dependent decrease at higher concentrations. The anti-starvation ability exhibited hormesis after short-term culture and reduced as culture time extending. By measuring the redox status (catalase (CAT) and reactive oxygen species (ROS)) of adult flies after two exposure methods, it was found that DINP induced redox instability, which may explain the above effects at the molecular level. This study provides data to support a comprehensive analysis of DINP potential toxicity and to guide its rational use and management better.

The effects of the phthalate DiNP on reproduction†

Di-isononyl phthalate (DiNP) is a high molecular weight, general purpose, plasticizer used primarily in the manufacture of polymers and consumer products. It can be metabolized rapidly and does not bioaccumulate. The primary metabolite of DiNP is monoisononyl-phthalate (MiNP) and the secondary metabolites include three oxidative derivatives of DiNP, which have been identified mainly in urine: mono-oxoisononyl phthalate (MOINP or oxo-MiNP), mono-carboxyisooctyl phthalate (MCIOP, MCOP or cx-MiNP), and mono-hydroxyisononyl phthalate (MHINP or OH-MiNP). The secondary metabolites are very sensitive biomarkers of DiNP exposure while primary metabolites are not. As the usage of DiNP worldwide increases, studies evaluating its potential reproductive toxicity are becoming more prevalent in the literature. In studies on female animals, the researchers found that the exposure to DiNP appears to induce negative effects on ovarian function and fertility in animal models. Whether or not DiNP has direct effects on the uterus is still controversial, and the effects on human reproduction require much more research. Studies on males indicate that DiNP exposure has disruptive effects on male reproduction and fertility. Occupational studies also indicate that the exposure to DiNP might induce negative effects on male reproduction, but larger cohort studies are needed to confirm this. This review presents an overview of the literature regarding the reproductive effects of exposure to DiNP.

Phthalate exposure linked to high blood pressure in Chinese children

BACKGROUND

Exposure to phthalate esters may be linked to the risk of high blood pressure (HBP), but limited evidence is available in Chinese children.

OBJECTIVE

To investigate the associations between nine phthalate metabolites (mPAEs) and systolic/diastolic BP, pulse pressure (PP), mean arterial pressure (MAP), and the risk of HBP.

METHODS

In this cross-sectional study, a total of 1044 primary school children (6-8 years old) were enrolled from Shenzhen, China, between 2016 and 2017. Nine mPAEs were analyzed from urine using ultra-performance liquid chromatography and tandem mass spectrometry. A multivariable linear regression model was used to explore the associations between phthalate exposure and systolic/diastolic BP, PP, and MAP. A binary logistic regression model was used to examine the associations between phthalate exposure and the risk of HBP.

RESULTS

Monomethyl phthalate (MMP) concentrations were significantly higher in HBP children than normal BP children. MMP, monoisobutyl phthalate (MiBP), monobutyl phthalate (MnBP), mono(5-carboxy-2-ethylpentyl) phthalate, mono-[(2-carboxy methyl)hexyl] phthalate (MCMHP), the sum of four short-chain mPAEs (∑LMW), and the sum of all nine mPAEs (∑₉mPAEs) were significantly positively associated with increases in systolic BP z-score, while only MMP was significantly positively associated with diastolic BP z-score. MMP, MiBP, MnBP, MCMHP, ∑LMW, and ∑₉mPAEs were significantly associated with increases in PP, while MMP and MnBP were significantly associated with increases in MAP. MMP was significantly associated with the risk of HBP, with an odds ratio of 1.87 (95% CI: 1.23, 2.85).

CONCLUSIONS

The present study suggests that dimethyl phthalate exposure increases the risk of HBP. And some types of phthalates are associated with elevations in systolic/diastolic BP z scores, PP, and MAP in Chinese children.

Phthalates Implications in the Cardiovascular System

Today’s sedentary lifestyle and eating habits have been implicated as some of the causes of the increased incidence of several diseases, including cancer and cardiovascular diseases. However, environmental pollutants have also been identified as another possible cause for this increase in recent decades. The constant human exposure to plastics has been raising attention regarding human health, particularly when it comes to phthalates. These are plasticizers used in the manufacture of industrial and consumer products, such as PVC (Polyvinyl Chloride) plastics and personal care products, with endocrine-disrupting properties, as they can bind molecular targets in the body and interfere with hormonal function. Since these compounds are not covalently bound to the plastic, they are easily released into the environment during their manufacture, use, or disposal, leading to increased human exposure and enhancing health risks. In fact, some studies have related phthalate exposure with cardiovascular health, having already shown a positive association with the development of hypertension and atherosclerosis in adults and some cardiometabolic risk factors in children and adolescents. Therefore, the main purpose of this review is to present and relate the most recent studies concerning the implications of phthalates effects on the cardiovascular system.