Arsenic, blood pressure, and hypertension in the Strong Heart Family Study

NBR1-mediated autophagic degradation of caspase 8 protects vascular endothelial cells against arsenite-induced apoptotic cell death

Vascular endothelial cells play a critical role in maintaining the health of blood vessels, but dysfunction can lead to cardiovascular diseases. The impact of arsenite exposure on cardiovascular health is a significant concern due to its potential adverse effects. This study aims to explore how NBR1-mediated autophagy in vascular endothelial cells can protect against oxidative stress and apoptosis induced by arsenite. Initially, our observations revealed that arsenite exposure increased oxidative stress and triggered apoptotic cell death in human umbilical vein endothelial cells (HUVECs). However, treatment with the apoptosis inhibitor Z-VAD-FMK notably reduced arsenite-induced apoptosis. Additionally, arsenite activated the autophagy pathway and enhanced autophagic flux in HUVECs. Interestingly, inhibition of autophagy exacerbated arsenite-induced apoptotic cell death. Our findings also demonstrated the importance of autophagy receptor NBR1 in arsenite-induced cytotoxicity, as it facilitated the recruitment of caspase 8 to autophagosomes for degradation. The protective effect of NBR1 against arsenite-induced apoptosis was compromised when autophagy was inhibited using pharmacological inhibitors or through genetic knockdown of essential autophagy genes. Conversely, overexpression of NBR1 facilitated caspase 8 degradation and reduced apoptotic cell death in arsenite-treated HUVECs. In conclusion, our study highlights the vital role of NBR1-mediated autophagic degradation of caspase 8 in safeguarding vascular endothelial cells from arsenite-induced oxidative stress and apoptotic cell death. Targeting this pathway could offer a promising therapeutic approach to mitigate cardiovascular diseases associated with arsenite exposure.

Metals on the Menu-Analyzing the Presence, Importance, and Consequences

Metals are integral components of the natural environment, and their presence in the food supply is inevitable and complex. While essential metals such as sodium, potassium, magnesium, calcium, iron, zinc, and copper are crucial for various physiological functions and must be consumed through the diet, others, like lead, mercury, and cadmium, are toxic even at low concentrations and pose serious health risks. This study comprehensively analyzes the presence, importance, and consequences of metals in the food chain. We explore the pathways through which metals enter the food supply, their distribution across different food types, and the associated health implications. By examining current regulatory standards for maximum allowable levels of various metals, we highlight the importance of ensuring food safety and protecting public health. Furthermore, this research underscores the need for continuous monitoring and management of metal content in food, especially as global agricultural and food production practices evolve. Our findings aim to inform dietary recommendations, food fortification strategies, and regulatory policies, ultimately contributing to safer and more nutritionally balanced diets.

Arsenic Exposure-Related Hypertension in Bangladesh and Reduced Circulating Nitric Oxide Bioavailability

BACKGROUND

Hypertension is a major cause of death worldwide. Although arsenic exposure has been associated with the risk of hypertension, this association appears nonuniform due to inconsistent results from studies conducted in different populations. Moreover, hypertension is a complex condition with multiple underlying mechanisms and factors. One factor is impaired production and bioavailability of vascular nitric oxide (NO). However, the implications of the effects of arsenic exposure on circulating NO and its association with hypertension in humans are largely unknown.

OBJECTIVE

We investigated the dose-response relationship between arsenic exposure and hypertension with vascular NO levels as a potential mediator of arsenic-related hypertension in individuals exposed to a broad range of arsenic.

METHODS

A total of 828 participants were recruited from low- and high-arsenic exposure areas in Bangladesh. Participants' drinking water, hair, and nail arsenic concentrations were measured by inductively coupled plasma mass spectroscopy. Hypertension was defined as a systolic blood pressure (SBP) value of ≥ 140 and a diastolic (DBP) value of ≥ 90  mmHg . Serum NO levels reflected by total serum nitrite concentrations were measured by immunoassay. A formal causal mediation analysis was used to assess NO as a mediator of the association between arsenic level and hypertension.

RESULTS

Increasing concentrations of arsenic measured in drinking water, hair, and nails were associated with the increasing levels of SBP and DBP. The odds of hypertension were dose-dependently increased by arsenic even in participants exposed to relatively low to moderate levels (10 - 50 μ g / L ) of water arsenic [odds ratios (ORs) and 95% confidence intervals (CIs): 2.87 (95% CI: 1.28, 6.44), 2.67 (95% CI: 1.27, 5.60), and 5.04 (95% CI: 2.71, 9.35) for the 10 - 50 μ g / L , 50.01 - 150 μ g / L , and > 150 μ g / L groups, respectively]. Causal mediation analysis showed a significant mediating effect of NO on arsenic-related SBP, DBP, and hypertension.

CONCLUSION

Increasing exposure to arsenic was associated with increasing odds of hypertension. The association was mediated through the reduction of vascular NO bioavailability, suggesting that impaired NO bioavailability was a plausible underlying mechanism of arsenic-induced hypertension in this Bangladeshi population. https://doi.org/10.1289/EHP13018.

Update of the risk assessment of inorganic arsenic in food

The European Commission asked EFSA to update its 2009 risk assessment on arsenic in food carrying out a hazard assessment of inorganic arsenic (iAs) and using the revised exposure assessment issued by EFSA in 2021. Epidemiological studies show that the chronic intake of iAs via diet and/or drinking water is associated with increased risk of several adverse outcomes including cancers of the skin, bladder and lung. The CONTAM Panel used the benchmark dose lower confidence limit based on a benchmark response (BMR) of 5% (relative increase of the background incidence after adjustment for confounders, BMDL05) of 0.06 μg iAs/kg bw per day obtained from a study on skin cancer as a Reference Point (RP). Inorganic As is a genotoxic carcinogen with additional epigenetic effects and the CONTAM Panel applied a margin of exposure (MOE) approach for the risk characterisation. In adults, the MOEs are low (range between 2 and 0.4 for mean consumers and between 0.9 and 0.2 at the 95th percentile exposure, respectively) and as such raise a health concern despite the uncertainties.

Interactions of arsenic exposure, arsenic metabolism with red blood cell folate on the risk of hypertension: NHANES 2007-2016

PURPOSE

Arsenic exposure was associated with hypertension, and arsenic metabolism might be influenced by folate concentrations. Thus, this study aimed to explore the interaction between arsenic exposure and metabolism with folate concentrations on hypertension.

METHODS

We studied 6643 adults aged 20 years and older who participated in the National Health and Nutrition Examination Survey from 2007 through 2016. Urinary total arsenic (UTAs), the percentage of urinary dimethylarsinic acid (DMA%), serum and red blood cell (RBC) folate were collected. Logistic regression and restricted cubic spline (RCS) analyses were performed to determine the association and dose-response relationship. Interaction analyses were conducted on both additive and multiplicative scales.

RESULTS

UTAs (median: 7.05 μg/L) was positively associated with hypertension risk, and the adjusted OR was 1.44 (95% CI: 1.06-1.95) when comparing the third with the lowest quartile. And participants with the highest quintile of RBC folate had increased hypertension risk than those with the lowest quintile (adjusted OR = 1.43, 95% CI: 1.06-1.94). Significant additive interaction was observed between excessive RBC folate with high UTAs (AP = 0.323, 95% CI: 0.083-0.564) and low DMA% (AP = 0.381, 95% CI: 0.119-0.643) on hypertension risk.

CONCLUSION

Our results suggested significant interactions between high UTAs and low DMA% with excessive RBC folate on hypertension risk.

Potential Roles of Metals in the Pathogenesis of Pulmonary and Systemic Hypertension

Pulmonary and systemic hypertension (PH, SH) are characterized by vasoconstriction and vascular remodeling resulting in increased vascular resistance and pulmonary/aortic artery pressures. The chronic stress leads to inflammation, oxidative stress, and infiltration by immune cells. Roles of metals in these diseases, particularly PH are largely unknown. This review first discusses the pathophysiology of PH including vascular oxidative stress, inflammation, and remodeling in PH; mitochondrial dysfunction and metabolic changes in PH; ion channel and its alterations in the pathogenesis of PH as well as PH-associated right ventricular (RV) remodeling and dysfunctions. This review then summarizes metal general features and essentiality for the cardiovascular system and effects of metals on systemic blood pressure. Lastly, this review explores non-essential and essential metals and potential roles of their dyshomeostasis in PH and RV dysfunction. Although it remains early to conclude the role of metals in the pathogenesis of PH, emerging direct and indirect evidence implicates the possible contributions of metal-mediated toxicities in the development of PH. Future research should focus on comprehensive clinical metallomics study in PH patients; mechanistic evaluations to elucidate roles of various metals in PH animal models; and novel therapy clinical trials targeting metals. These important discoveries will significantly advance our understandings of this rare yet fatal disease, PH.

Association between Heavy Metals, Metalloids and Metabolic Syndrome: New Insights and Approaches

Metabolic syndrome (MetS) is an important public health issue that affects millions of people around the world and is growing to pandemic-like proportions. This syndrome is defined by the World Health Organization (WHO) as a pathologic condition characterized by abdominal obesity, insulin resistance, hypertension, and hyperlipidemia. Moreover, the etiology of MetS is multifactorial, involving many environmental factors, including toxicant exposures. Several studies have associated MetS with heavy metals exposure, which is the focus of this review. Environmental and/or occupational exposure to heavy metals are a major risk, contributing to the development of chronic diseases. Of particular note, toxic metals such as mercury, lead, and cadmium may contribute to the development of MetS by altering oxidative stress, IL-6 signaling, apoptosis, altered lipoprotein metabolism, fluid shear stress and atherosclerosis, and other mechanisms. In this review, we discuss the known and potential roles of heavy metals in MetS etiology as well as potential targeted pathways that are associated with MetS. Furthermore, we describe how new approaches involving proteomic and transcriptome analysis, as well as bioinformatic tools, may help bring about an understanding of the involvement of heavy metals and metalloids in MetS.

ARSENIC IN DRINKING WATER AND URINE AND ITS RELATIONSHIP WITH MALIGNANT TUMORS OF URINARY TRACT IN OSIJEK-BARANJA COUNTY, CROATIA

Increased values of arsenic in potable water in eastern Croatia has been a matter of scientific interest for the past two decades due to numerous health effects, including carcinogenic ones. This study investigated whether prolonged exposure to increased arsenic from water could be detectable through increased arsenic in urine, and whether it influenced the incidence of kidney and bladder cancer in Osijek-Baranja County. Inductively coupled plasma mass spectrometry (ICP-MS) was used for analysis of water samples from available water sources (wells, aqueducts). In addition, examinees from Osijek, Našice, Vladislavci, Čepin and Dalj gave their urine samples for analysis. Data on cancer incidence were obtained from the Institute for Public Health Registry and cumulative incidence of kidney and bladder cancer was calculated for the period between January 1, 2000 and December 31, 2018. Elevated arsenic concentration in drinking water was recorded in Vladislavci, Čepin and Osijek area with values above the allowed maximum according to the EU standards (10 µg L-1) and as a result, arsenic levels in urine of the inhabitants were also elevated. Cumulative incidence for bladder cancer showed correlation between increased arsenic in water and urine in the areas affected by increased arsenic in water. Epidemiologic data suggest a conclusion that elevated arsenic could be considered at least as a cofounding factor for urinary tract cancer.

Short-term exposure to some heavy metals carried with PM10 and cardiovascular system biomarkers during dust storm

This study aimed to evaluate the effect of short-term exposure to heavy metals (HM) extracted from PM₁₀ on CB in workers' population in an outdoor space located in southern Iran during a dust storm. At first, 44 healthy and non-smoking workers were selected. Then PM₁₀ and Blood samples were collected before and after the dust storm. Finally, HMs associated with PM₁₀ measured by ICP-MS and its effect on the CB, including fibrinogen, CRP, TNF-α, and BP were estimated by ANOVA, Pearson correlation, and Odd Ratio (OR) in SPSS23. Based on the results, the concentration of PM₁₀ and extracted HM such as Cr, As, and Cd was higher than the WHO/EPA standards in dust storms they increased the CB and BP remarkably. Moreover, the level of fibrinogen, blood pressure (BP) and TNF-α in dust storms were higher than in normal conditions (p < 0.05, OR > 3). In addition, As and Cd decreased fibrinogen concentration and systolic BP, respectively. Whereas, TNF-α was associated with concentration of Pb (R = - 0.85) on normal days. Consequently, the HM on PM₁₀ such as As, interferes with the level of investigated CB. These results considered a potential risk for the residents in the southern regions of Iran.

Association of multi-metals with the risk of hypertension and the interaction with obesity: A cross-sectional study in China

Background

Environmental exposure to multiple metals have been inconsistently associated with hypertension. Obesity is an important independent risk factor for hypertension, and few studies have assessed the interaction between obesity and metals in this context. We aimed to clarify their association and interaction.

Methods

This cross-sectional study included 3,063 adults from 11 districts or counties, Guangdong. We measured the whole blood levels of 13 metals and used multipollutant-based statistical methods to analyze the association of metals with hypertension. The interaction between metals and obesity on hypertension was assessed on additive and multiplicative scales.

Results

Four metals (manganese, arsenic, cadmium, and lead) were significantly associated with hypertension risk, five metals (manganese, zinc, arsenic, cadmium, and lead) were related to elevated SBP levels, five metals (manganese, zinc, selenium, cadmium, and lead) were associated with elevated DBP levels in single-metal model. Manganese remained significantly related to hypertension risk [odds ratio, 1.35 (1.02–1.78)] after adjusting for these four metals. Significant positive dose-response relationships between manganese, arsenic, cadmium, lead and hypertension risk were observed (P for overall &lt; 0.001, P for non-linearity &gt; 0.05). Compared with those in the lowest quartile, participants in the highest manganese quartile had a 2.83 mmHg (95% Cl: 0.71–4.96) (PFDR = 0.040) higher level of SBP. Individuals in the highest quartiles of zinc and lead had a 1.45 mmHg (0.10–2.81) (PFDR = 0.033) and 2.06 mmHg (0.59–3.53) (PFDR = 0.020) higher level of DBP, respectively. The negative interactions between cadmium, lead and obesity influences hypertension risk. BKMR analysis showed a significant joint effect of manganese, arsenic, cadmium and lead on hypertension when the concentrations of four metals were at or above their 55th percentile compared to their median values.

Conclusions

The combined effect of four metals (manganese, arsenic, cadmium and lead) were associated with the prevalence of hypertension. Potential interaction effects of cadmium, lead and obesity on hypertension risk may exist. Further cohort studies in larger population are needed to clarify these findings.

The mechanism of low-level arsenic exposure-induced hypertension: Inhibition of the activity of the angiotensin-converting enzyme 2

It is now well-established that arsenic exposure induces hypertension in humans. Although arsenic-induced hypertension is reported in many epidemiological studies, the underlying molecular mechanism of arsenic-induced hypertension is not fully characterized. In the human body, blood pressure is primarily regulated by a well-known physiological system known as the renin-angiotensin system (RAS). Hence, we explored the potential molecular mechanisms of arsenic-induced hypertension by investigating the regulatory roles of the RAS. Adult C57BL/6JJcl male mice were divided into four groups according to the concentration of arsenic in drinking water (0, 8, 80, and 800 ppb) provided for 8 weeks. Arsenic significantly raised blood pressure in arsenic-exposed mice compared to the control group, and significantly raised plasma MDA and Ang II and reduced Ang (1-7) levels. RT-PCR results showed that arsenic significantly downregulated ACE2 and MasR in mice aortas. In vitro studies of endothelial HUVEC cells treated with arsenic showed increased level of MDA and Ang II and lower levels of Ang (1-7), compared with the control. Arsenic significantly downregulated ACE2 and MasR expression, as well as those of Sp1 and SIRT1; transcriptional activators of ACE2, in HUVECs. Arsenic also upregulated markers of endothelial dysfunction (MCP-1, ICAM-1) and inflammatory cytokines (IL-6, TNF-α) in HUVECs. Our findings suggest that arsenic-induced hypertension is mediated, at least in part, by oxidative stress-mediated inhibition of ACE2 as well as by suppressing the vasoprotective axes of RAS, in addition to the activation of the classical axis.

Assessment of Arsenic in Hair of the Inhabitants of East Croatia—Relationship to Arsenic Concentrations in Drinking Water

The problem of elevated arsenic concentrations in water and environment is an increasing public health concern. The aim of the study was to assess the arsenic content in human hair in selected areas of eastern Croatia and to compare them with measured values after installation of a new water supply system. The hair samples were taken in the areas of wider Osijek and Vinkovci area and analyzed using the ICP–MS method. These data were also compared with data for Vinkovci previously published in 2004. Depending on the investigated area, the median concentrations ranged from 0.02 to 0.9 µg g−1, whereby this last value exceeded the upper range of the reference value (0.319 µg g−1). The arsenic concentrations from the Našice, Osijek and Vinkovci areas were within or slightly above the maximum allowed reference range. The highest median values in hair samples were detected in Čepin, with arsenic-contaminated potable water, while in areas where the water source was changed, the values were significantly lower. The results add to the conclusion that there has been significant reduction in hair arsenic concentrations in the population that was given access to clean, uncontaminated water from other regional sources.