Cadmium-induced immune abnormality is a key pathogenic event in human and rat models of preeclampsia

Adverse effects of cadmium on lymphoid organs, immune cells, and immunological responses

Humans and animals possess robust immune systems to safeguard against foreign pathogens. However, recent reports suggest a greater incidence of immunity breakdown due to exposure to environmental pollutants, with heavy metals emerging as potential candidates in such immuno-toxicological studies. While we have extensive data on the general toxicity resulting from exposure to heavy metals, comprehensive documentation of their role as immune disruptors remains scarce. Cd (Cadmium) exerts immunomodulation by interfering with immune organs and cells, leading to altered structure, physiology, and function, thereby inducing symptoms of immune deregulation, inflammation and/or autoimmunity. This review aims to summarize the link between Cd exposure and immune dysfunction, drawing from case studies on exposed human subjects, as well as research conducted on various model organisms and in-vitro culture systems.

Placenta-specific CYP11A1 overexpression lead to autism-like symptom in offspring with altered steroid hormone biosynthesis in the placenta-brain axis and rescued by vitamin D intervention

Alterations in steroid hormone regulation have been implicated in the etiology and progression of autism spectrum disorders (ASD), with the enzyme cytochrome P450 family 11 subfamily A member 1 (CYP11A1)-a key catalyst in cholesterol side-chain cleavage, prominently expressed in the adrenal glands, ovaries, testes, and placenta-standing at the forefront of these investigations. The potential link between aberrations in placental Cyp11a1 expression and the resultant neurodevelopmental disorders, along with the mechanisms underpinning such associations, remains inadequately delineated. In this study, we employed a placental trophoblast-specific Cyp11a1 Hipp11 (H11) knock-in murine model to dissect the phenotypic manifestations within the placenta and progeny, thereby elucidating the underlying mechanistic pathways. Behavioral analyses revealed a diminution in social interaction capabilities alongside an augmented anxiety phenotype, as evidenced by open field and elevated plus maze assessments; both phenotypes were ameliorated after vitamin D3 supplementation. Electrophysiological assays underscored the augmented inhibition of paired-pulse facilitation, indicating impaired neuroplasticity in Cyp11a1 H11-modified mice. An elevation in progesterone concentrations was noted, alongside a significant upregulation of Th1-related cytokines (IL-6 and TNFα) across the plasma, placental, and frontal cortex-a pathological state mitigable through vitamin D3 intervention. Western blotting revealed a vitamin D-mediated rectification of vitamin D receptor and PGC-1α expression dysregulations. Immunofluorescence assays revealed microglial activation in the knock-in model, which was reversible upon vitamin D3 treatment. In conclusion, Cyp11a1 overexpression in the placenta recapitulated an autism-like phenotype in murine models, and vitamin D3 administration effectively ameliorated the resultant neurobehavioral and neuroinflammatory derangements. This study substantiates the application of Cyp11a1 as a biomarker in prenatal diagnostics and posits that prenatal vitamin D3 supplementation is a viable prophylactic measure against perturbations in steroid hormone metabolism associated with ASD pathogenesis.

Cadmium exposure activates mitophagy through downregulating thyroid hormone receptor/PGC1α signal in preeclampsia

Gestational cadmium exposure increases the risk of preeclampsia. Placenta mitophagy was activated in preeclampsia. The aim of present study was to explore the mechanism of cadmium-induced mitophagy activation and its association with preeclampsia. Mitophagy markers expression levels were detected by quantitative real-time PCR, Western blot, immunofluorescence and immunochemistry in preeclampsia placenta. JEG3 cells were treated with CdCl2, iopanoic acid (IOP), 3-methyladenine and PGC1α SiRNA to verify mechanism of cadmium-induced mitophagy. Mitophagy marker LC3BII/I and P62 expression were increased and mitochondrial membrane receptor protein TOM20 and FUNDC1 expression were decreased in preeclampsia placenta as compared with that in normotension control. Mitophagy marker LC3BII/I and P62 expression were increased and TOM20 and FUNDC1 expression was decreased in CdCl2-treated JEG3 cells. Meanwhile, mitochondrial biogenesis regulator, PGC1α expression was decreased in preeclampsia and CdCl2-treated JEG3 cells. The expressions of LC3B and P62 were increased and the expressions of TOM20, FUNDC1 and PGC1α were decreased in IOP-treated cell. PGC1α SiRNA transfection led to increased expression of LC3BII/I and P62 and decreased expression of TOM20 and FUNDC1. The expression of sFlt1 was increased in preeclampsia placenta, CdCl2-treated cells, in IOP-treated cells and in PGC1α SiRNA transfected cells. 3-methyladenine treatment protected the increased expression of sFlt1 in CdCl2-treated cells, in IOP-treated cells and in PGC1α SiRNA transfected cells. Meanwhile, co-treatment of cadmium and IOP or PGC1αSiRNA led to a reduce expressions of OPA1, MFN1, MFN2 and FUNDC1 as compared to cadmium-treated, IOP-treated and PGC1α SiRNA-treated cells. These results elucidated that maternal cadmium exposure activated placenta mitophagy through downregulation of thyroid hormone receptor signal mediated decreased expression of PGC1α and was associated with the occurrence of preeclampsia.

An integrative data-centric approach to derivation and characterization of an adverse outcome pathway network for cadmium-induced toxicity

Cadmium is a prominent toxic heavy metal that contaminates both terrestrial and aquatic environments. Owing to its high biological half-life and low excretion rates, cadmium causes a variety of adverse biological outcomes. Adverse outcome pathway (AOP) networks were envisioned to systematically capture toxicological information to enable risk assessment and chemical regulation. Here, we leveraged AOP-Wiki and integrated heterogeneous data from four other exposome-relevant resources to build the first AOP network relevant for inorganic cadmium-induced toxicity. From AOP-Wiki, we filtered 309 high confidence AOPs, identified 312 key events (KEs) associated with inorganic cadmium from five exposome-relevant databases using a data-centric approach, and thereafter, curated 30 cadmium relevant AOPs (cadmium-AOPs). By constructing the undirected AOP network, we identified a large connected component of 18 cadmium-AOPs. Further, we analyzed the directed network of 59 KEs and 82 key event relationships (KERs) in the largest component using graph-theoretic approaches. Subsequently, we mined published literature using artificial intelligence-based tools to provide auxiliary evidence of cadmium association for all KEs in the largest component. Finally, we performed case studies to verify the rationality of cadmium-induced toxicity in humans and aquatic species. Overall, cadmium-AOP network constructed in this study will aid ongoing research in systems toxicology and chemical exposome.

An exploratory study on the association of multiple metals in serum with preeclampsia

Background

Individual metal levels are potential risk factors for the development of preeclampsia (PE). However, understanding of relationship between multiple metals and PE remains elusive.

Purpose

The purpose of this study was to explore whether eight metals [zinc (Zn), manganese (Mn), copper (Cu), nickel (Ni), lead (Pb), arsenic (As), cadmium (Cd), and mercury (Hg)] in serum had a certain relationship with PE.

Methods

A study was conducted in Dongguan, China. The concentrations of metals in maternal serum were assessed using inductively coupled plasma mass spectrometry (ICP-MS). Data on various factors were collected through a face-to-face interview and hospital electronic medical records. The unconditional logistic regression model, principal component analysis (PCA) and Bayesian Kernel Machine Regression (BKMR) were applied in our study.

Results

The logistic regression model revealed that the elevated levels of Cu, Pb, and Hg were associated with an increased risk of PE. According to PCA, principal component 1 (PC1) was predominated by Hg, Pb, Mn, Ni, Cu, and As, and PC1 was associated with an increased risk of PE, while PC2 was predominated by Cd and Zn. The results of BKMR indicated a significant positive cumulative effect of serum metals on PE risk, with Ni and Cu exhibiting a significant positive effect. Moreover, BKMR results also revealed the nonlinear effects of Ni and Cd.

Conclusion

The investigation suggests a potential positive cumulative impact of serum metals on the occurrence of PE, with a particular emphasis on Cu as a potential risk factor for the onset and exacerbation of PE. These findings offer valuable insights for guiding future studies on this concern.

The relationship between cadmium exposure and preeclampsia: a systematic review and meta-analysis

Background

Cadmium (Cd) is a heavy metal associated with several human disorders. Preeclampsia is a major cause of maternal mortality worldwide. The association between maternal Cd exposure and preeclampsia remains elusive.

Methods

To better understand this relationship, we conducted a systematic review and meta-analysis of eligible studies from five databases (PubMed, Embase, Web of Science, Scopus, and CNKI) from their inception to September 10, 2022. The quality of these studies was evaluated using the Newcastle-Ottawa quality assessment scale (NOS). We use random-effects models to calculate overall standardized mean differences (SMDs) and 95% confidence intervals (CIs). Sensitivity analyses were performed to assess the robustness of our results. We also evaluated publication bias using Egger's and Begg's tests. Additionally, we conducted meta-regression and sub-group analyses to identify potential sources of heterogeneity between studies.

Results

Our analysis included a total of 17 studies with 10,373 participants. We found a significant association between maternal cadmium exposure and the risk of preeclampsia (SMD 0.27, 95% CI 0.09-0.44, p < 0.01). No significant publication bias was detected in Begg's or Egger's tests. Meta-regression suggested that geographical location, year of publication, cadmium samples, sample size, and measurement methods did not contribute to heterogeneity between studies.

Conclusion

Our findings suggest that maternal blood cadmium levels are associated with an increased risk of preeclampsia. In contrast, the pregnant women's urine or placental levels of cadmium may not suggest preeclamptic risk during pregnancy. Further high-quality clinical studies and animal experiments are needed to understand this association better.

Systematic review registration

PROSPERO, https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=361291, identifier: CRD42022361291.

Mercury and cadmium-induced inflammatory cytokines activation and its effect on the risk of preeclampsia: a review

During the last decade, there has been an increase in exposure to heavy metals that can affect human health and the environment, especially mercury (Hg) and cadmium (Cd). These exposures can pollute the rivers or oceans, then contaminating marine organisms. Humans as the last consumer of this food chain cycle can be a place for the bioaccumulation of Hg and Cd, especially for people living in coastal areas, including pregnant women. Exposure to heavy metals Hg and Cd can have a high risk of triggering blood vessel disorders, penetrating the blood-brain barrier (BBB) and the placental barrier, one of which can increase the risk of preeclampsia. Several immunological biomarkers such as some cytokines associated with Hg and Cd exposure are also involved in the pathophysiology of preeclampsia, which are the placental implantation process and endothelial dysfunction in pregnant women. Therefore, countries that have a high incidence of preeclampsia should be aware of the environmental factors, especially heavy metal pollution such as Hg and Cd.

Single-Cell RNA Sequencing and Microarray Analysis Reveal the Role of Lipid-Metabolism-Related Genes and Cellular Immune Infiltration in Pre-Eclampsia and Identify Novel Biomarkers for Pre-Eclampsia

Pre-eclampsia (PE) is a gestational hypertensive disorder that is characterized by hypertension and proteinuria, typically occurring after 20 weeks of gestation. Despite its global impact on pregnant women, the precise pathogenic mechanisms of PE remain unclear. Dysregulated lipid metabolism and immune cell infiltration contribute to PE development. Our study aimed to identify lipid-metabolism-related genes (LMRG-PEs) and investigate their association with immune infiltration. We utilized the "Seurat" R package for data quality control, cell clustering, and marker gene identification. The "SingleR" package enabled the matching of marker genes to specific cell types. Pseudotemporal ordering analysis was conducted using the "Monocle" package. Weighted correlation network analysis (WGCNA), gene set variation analysis (GSVA), and gene set enrichment analysis (GSEA) approaches were employed to explore lipid-metabolism-related genes, while potential targeted drugs were predicted using the drug-gene interaction database (DGIdb). Hub gene expression was validated through RT-qPCR. By analyzing single-cell RNA sequencing data, we identified and classified 20 cell clusters into 5 distinct types. Differential gene expression analysis revealed 186 DEGs. WGCNA identified 9 critical modules and 265 genes significantly associated with PE diagnosis, emphasizing the importance of the core genes PLA2G7 and PTGS2. RT-qPCR confirmed the significantly decreased expression of PLA2G7 and PTGS2 in PE patient tissues. These findings offer valuable insights into the molecular mechanisms of PE, particularly those involving lipid metabolism and immune infiltration. The identified hub genes have potential as therapeutic targets and biomarkers for future research and clinical applications.

Effects of Xenobiotic Compounds on Preeclampsia and Potential Mechanisms

Preeclampsia (PE) refers to a disease with new hypertension and albuminuria or other end-organ damage after 20 weeks of pregnancy. As a major complication of pregnancy, PE can increase the morbidity and mortality of pregnant women and fetuses and cause serious social burden. Recently, it has been found that exposure to xenobiotic compounds, especially endocrine disruptors in the environment, may contribute to the development of PE. However, the underlying mechanism is still unclear. It is generally believed that PE is related to placental dysplasia, spiral artery remodelling failure, oxidative stress, etc. Therefore, in order to better prevent the occurrence of PE and reduce the damage and impact on mother and fetus, this paper reviews the role and potential mechanism of PE induced by exogenous chemicals and provides an outlook on the environmental etiology of PE.

Cadmium induced immunosuppression through TLR-IκBα-NFκB signaling by promoting autophagic degradation

Environmental and occupational exposure to cadmium (Cd) poses a serious threat to human health. Recent studies indicate that Cd perturbs the immune system and increases the risk of pathogenicity and mortality of bacterial or virus infection. However, the underlying mechanism of Cd-modulated immune responses remains unclear. In this study, we aim to investigate the role of Cd in the immune function of mouse spleen tissues and its primary T cells with Concanavalin A (ConA, a well-known T cell mitogen) activation condition, and elucidate the molecular mechanism. The results showed that Cd exposure inhibited ConA-induced the expressions of tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ) in mouse spleen tissues. Furthermore, the transcriptomic profile by RNA-sequence reveals that: (1) Cd exposure can alter immune system process; (2) Cd may affect the NFκB signaling pathway. Both in vitro and in vivo results showed that Cd exposure reduced ConA-activated toll-like receptor 9 (TLR9)-IκBα-NFκB signaling, and the expressions of TLR9, TNF-α and IFN-γ, which were effectively reversed by autophagy-lysosomal inhibitors. All these results confirmedly demonstrated that, by promoting the autophagy-lysosomal degradation of TLR9, Cd suppressed immune response under ConA activation condition. This study provides insight on the mechanism of Cd immunnotoxicity, which might contribute to the prevention of Cd toxicity in the future.

Cadmium inhibits differentiation of human trophoblast stem cells into extravillous trophoblasts and disrupts epigenetic changes within the promoter region of the HLA-G gene

Cadmium (Cd) is a toxic heavy metal widely distributed in the environment. Maternal whole-blood Cd levels during pregnancy are positively associated with the risk of early preterm birth. We hypothesized that Cd inhibits trophoblast differentiation, resulting in the development of hypertensive disorders of pregnancy and a high risk of early preterm birth. Using the CT27 human trophoblast stem cell line, we found that exposing these cells to 0.1-0.4 µM Cd inhibited their differentiation into extravillous cytotrophoblasts (EVTs). Supporting this finding, we found that expression of the metal-binding protein metallothionein, which suppresses the toxicity of Cd, is low in EVTs. We also found that Cd exposure changes the methylation status of the promoter region of the HLA-G gene, which is specifically expressed in EVTs. Together, these results suggest that Cd inhibits placental formation by suppressing trophoblast differentiation into EVTs. This suppression may underlie the increased risk of gestational hypertension in women with high whole-blood Cd levels.

Increased incidence of spontaneous abortions on exposure to cadmium and lead: a systematic review and meta-analysis

BACKGROUND

Spontaneous abortions are the most severe complication of early pregnancy and are a major reproductive health problem. Although this could be caused due to various cytogenetic, immunological, or endocrinological reasons, role of environmental toxicants cannot be ruled out. In order to explore the role of cadmium and lead in causing spontaneous abortions, current systematic review and meta-analysis had been carried out.

METHODOLOGY

Literature search was performed using appropriate keywords in PubMed, Science Direct, Cochrane Library, and Google Scholar databases up to December 25 2020 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA). Metananalysis was carried out with the help of RevMan software (version 5.3).

RESULTS

Meta-analysis of nine studies on cadmium concentrations in blood of women with at least one spontaneous abortions and controls revealed standardized mean difference (SMD)=3.39, 95% CI (2.17, 4.61), with p < .05. Similarly, meta-analysis of eight studies on lead concentrations revealed standardized mean difference (SMD)=6.24, 95% CI (4.34, 8.14), with p < .05.

CONCLUSION

Populations exposed to heavy metals such as cadmium and lead are at higher risk of pregnancy loss. Therefore, couples experiencing repeated pregnancy losses may be screened for heavy metal load.

Cellular immune responses in the pathophysiology of preeclampsia

Preeclampsia, defined as new-onset hypertension accompanied by proteinuria occurring at 20 weeks of gestation or later, is a leading cause of perinatal morbidity and mortality worldwide. The pathophysiology of this major multi-systemic syndrome includes defective deep placentation, oxidative stress, endothelial dysfunction, the presence of an anti-angiogenic state, and intravascular inflammation, among others. In this review, we provide a comprehensive overview of the cellular immune responses involved in the pathogenesis of preeclampsia. Specifically, we summarize the role of innate and adaptive immune cells in the maternal circulation, reproductive tissues, and at the maternal-fetal interface of women affected by this pregnancy complication. The major cellular subsets involved in the pathogenesis of preeclampsia are regulatory T cells, effector T cells, NK cells, monocytes, macrophages, and neutrophils. We also summarize the literature on those immune cells that have been less characterized in this clinical condition, such as γδ T cells, invariant natural killer T cells, dendritic cells, mast cells, and B cells. Moreover, we discuss in vivo studies utilizing a variety of animal models of preeclampsia to further support the role of immune cells in this disease. Finally, we highlight the existing gaps in knowledge of the immunobiology of preeclampsia that require further investigation. The goal of this review is to promote translational research leading to clinically relevant strategies that can improve adverse perinatal outcomes resulting from the obstetrical syndrome of preeclampsia.

Astragalus Polysaccharide Protects Against Cadmium-Induced Autophagy Injury Through Reactive Oxygen Species (ROS) Pathway in Chicken Embryo Fibroblast

Cadmium (Cd) is a harmful heavy metal pollutant, which can cause oxidative stress in the body and induce cell damage. Reactive oxygen species (ROS) is a general term for substances that contain oxygen and are active in the body. However, excessive ROS can damage the body. Cadmium poisoning can cause a large amount of ROS in cells and autophagy. Astragalus polysaccharide (APS) is a plant polysaccharide with biological functions, such as antioxidant and anti-stress activities. In this study, chicken embryo fibroblasts (CEF) were used to determine the relationship between ROS and autophagy damage of Cd-infected cells and the mechanism of APS on cadmium-induced autophagy damage. The results showed that a 10-μL dose of 10 μmol/L cadmium chloride (CdCl₂) can induce CEF autophagy and damage when CEF was added for 36 h. Cadmium induced CEF autophagy damage by increasing ROS production. APS could significantly reduce ROS production and LC3-II and Beclin-1 protein expression, increase the expression of mTOR and the level of antioxidation, and restore the viability and morphological damage of CEF exposed to Cd. Our study suggests that APS can alleviate Cd-induced CEF autophagy damage by reducing the production of ROS.

Immunomodulation by heavy metals as a contributing factor to inflammatory diseases and autoimmune reactions: Cadmium as an example

Cadmium (Cd) represents a unique hazard because of the long biological half-life in humans (20-30 years). This metal accumulates in organs causing a continuum of responses, with organ disease/failure as extreme outcome. Some of the cellular and molecular alterations in target tissues can be related to immune-modulating potential of Cd. This metal may cause adverse responses in which components of the immune system function as both mediators and effectors of Cd tissue toxicity, which, in combination with Cd-induced alterations in homeostatic reparative activities may contribute to tissue dysfunction. In this work, current knowledge concerning inflammatory/autoimmune disease manifestations found to be related with cadmium exposure are summarized. Along with epidemiological evidence, animal and in vitro data are presented, with focus on cellular and molecular immune mechanisms potentially relevant for the disease susceptibility, disease promotion, or facilitating development of pre-existing pathologies.

Bio-indicators in cadmium toxicity: Role of HSP27 and HSP70

Heat shock proteins (HSPs) are a family of proteins that are expressed by cells in reply to stressors. The changes in concentration of HSPs could be utilized as a bio-indicator of oxidative stress caused by heavy metal. Exposure to the different heavy metals may induce or reduce the expression of different HSPs. The exposure to cadmium ion (Cd²⁺) could increase HSP70 and HSP27 over 2- to 10-fold or even more. The in vitro and in vivo models indicate that the HSP70 family is more sensitive to Cd intoxication than other HSPs. The analyses of other HSPs along with HSP70, especially HSP27, could also be useful to obtain more accurate results. In this regard, this review focuses on examining the literature to bold the futuristic uses of HSPs as bio-indicators in the initial assessment of Cd exposure risks in defined environments.

The association between dietary fatty acid intake and the risk of developing preeclampsia: a matched case-control study

The association between dietary fat intake during pregnancy and the risk of developing preeclampsia has been examined in many epidemiological studies, but the results remain inconsistent. The aim of this study was to clarify this association in pregnant Chinese women. After conducting 1:1 matching, 440 pairs consisting of pregnant women with preeclampsia and hospital-based, healthy pregnant women matched by gestational week (± 1 week) and age (± 3 years) were recruited. A 79-item semi-quantitative food frequency questionnaire administered during face-to-face interviews was used to estimate the participants’ dietary intake of fatty acids. We found that the intakes of arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) were inversely associated with the risk of developing preeclampsia. Compared with the lowest quartile intake, the multivariate-adjusted odds ratios (95% confidence interval) of the highest quartile intake were 0.42 (0.26–0.68, p-trend < 0.001) for EPA, 0.52 (0.3–0.83, p-trend = 0.005) for DHA, and 0.41 (0.19–0.88, p-trend = 0.007) for AA. However, we did not observe any significant associations between the intake of total fatty acids, saturated fatty acids, and mono-unsaturated fatty acids and the risk of developing preeclampsia. Our results showed that the dietary intake of long-chain polyunsaturated fatty acids (i.e., EPA, DHA, and AA) may protect pregnant Chinese women against the development of preeclampsia.

CYP11A1 Upregulation Leads to Trophoblast Oxidative Stress and Fetal Neurodevelopmental Toxicity That can be Rescued by Vitamin D

During normal pregnancy, the placental trophoblast secretes a variety of steroid hormones and participates in the regulation of maternal physiological functions and fetal development. The CYP11A1 gene encodes the cholesterol side-chain cleavage enzyme P450scc, which catalyzes the production of pregnenolone from cholesterol, which is the first step in the synthesis of all steroid hormones. Under the influence of genetic susceptibility and certain environmental factors, such as drugs and toxins, the expression of CYP11A1 can be upregulated, thereby affecting steroid metabolism and physiological functions in trophoblast cells, as well as fetal development. Here, we demonstrate that upregulation of CYP11A1 in the BeWo cell line triggers excessive mitochondrial oxidative stress, leads to mitochondrial damage and interleukin-6 release, and contributes to the inhibition of proliferation and DNA damage in neuronal stem cells (NSCs). Furthermore, oxidative stress and inflammation can be ameliorated by vitamin D₃ in a dose-dependent manner, thereby facilitating the rescue of NSC impairment. Our findings reveal the underlying mechanism in which upregulation of CYP11A1 is detrimental to the physiological function of trophoblasts and demonstrate the beneficial effects of vitamin D supplementation in preventing placental and neurodevelopmental damage associated with CYP11A1 upregulation during pregnancy.

Cadmium exposure reduces invasion of the human trophoblast-derived HTR-8/SVneo cells by inhibiting cell adhesion and matrix metalloproteinase-9 secretion

Preeclampsia and intrauterine growth restriction, multisystemic disorders characterized by a shallow trophoblast invasion, have been associated with maternal cadmium (Cd) exposure. The molecular mechanisms of this association remain unknown. Cell adhesion and matrix metalloproteinase production are essential for an adequate trophoblast invasion. Thus, the aim of this study was to determine the effect of Cd exposure on invasion, adhesion, and matrix metalloproteinase-9 (MMP-9) production in the trophoblast-derived HTR-8/SVneo cell line. Cultured HTR-8/SVneo trophoblast cells were incubated with different concentrations of CdCl₂ for 6 h. Cell invasion was determined by the transwell assay, while cell adhesion was examined on collagen type I. MMP-9 release and activity were measured by ELISA and zymography, respectively. MMP-9 mRNA expression was detected by reverse-transcription polymerase chain reaction, while intracellular MMP-9 protein was assessed by Western blotting. Cd exposure significantly decreased the invasion and adhesion of HTR-8/SVneo cells. Also, MMP-9 levels and activity in the culture medium were significantly reduced after Cd incubation. In contrast, MMP-9 mRNA expression and intracellular protein levels were significantly increased. These data indicate that Cd reduces trophoblast cells invasiveness by inhibiting cell adhesion and MMP-9 secretion.

Chemical elements and preeclampsia - An overview of current problems, challenges and significance of recent research

OBJECTIVES

Data on the elemental status, redistribution of the elements, role of occupational exposure and dietary assessment in preeclampsia (PE) are scarce. There are many disparities in the findings of essential and non-essential elements' role in PE. In this article we overview the changes in the content of selected elements in pregnancy complicated with the disorder of complex and not fully understood etiology. We have focused on important limitations and highlighted shortcomings in research from the last ten years period.

METHODS

The Scopus and PubMed electronic databases have been searched for English-language articles published within the time interval 2008-2018, with full text available and with the key words "preeclampsia" and "chemical element" (i.e. separately: Cd, Pb, As, Ni, Mo, Co, Cr, Mn, Se, I, Fe, Sr, Cu, Zn, Mg, K and Na) appearing in the title, abstract or keywords.

RESULTS

A total of 48 publications were eligible for this overview. Surprisingly only 4% of papers considered environmental exposure, 8%- diet and 2 %- comorbid diseases. In most published papers, occupational exposure was neglected. Meta-analysis was possible for seven elements in serum (Ca, Cu, Fe, Mg, Mn, Se, Zn), and two elements (Se, Zn) in plasma. It showed negative shift for most elements, however only several were statistically significant.

CONLUSIONS

The overview of the published data on PE and chemical elements yields varied results. Some of the reasons may be the difference in not duly validated method of determination, and huge discrepancies in study designs. The lack of detailed description of studied and control population and small number of samples constitute the most common limitations of such studies. Many of them describe the use of a single analytical procedure, therefore the quality of research may be insufficient to obtain reliable results. A history of elements' status and intake before and during pregnancy is usually not examined. Dietary assessment should be done at different stages of pregnancy, and whenever possible in the periconceptional period as well. It still needs to be established whether the deficiency of certain elements or their excess may be an etiopathogenic factor and a developmental cause of PE, and if it may serve as a target of actions in the causal treatment or even prevention of the occurrence of this disease.

Identification of environmental chemicals targeting miscarriage genes and pathways using the comparative toxicogenomics database

BACKGROUND

Miscarriage is a prevalent public health issue and many events occur before women are aware of their pregnancy, complicating research design. Thus, risk factors for miscarriage are critically understudied. Our goal was to identify environmental chemicals with a high number of interactions with miscarriage genes, based on known toxicogenomic responses.

METHODS

We used miscarriage (MeSH: D000022) and chemical gene lists from the Comparative Toxicogenomics Database in human, mouse, and rat. We assessed enrichment for gene ontology biological processes among the miscarriage genes. We prioritized chemicals (n = 25) found at Superfund sites or in the blood or urine pregnant women. For chemical-disease gene sets of sufficient size (n = 13 chemicals, n = 20 comparisons), chi-squared enrichment tests and proportional reporting ratios (PRR) were calculated. We cross-validated enrichment results.

RESULTS

Miscarriage was annotated with 121 genes and overrepresented in inflammatory response (q = 0.001), collagen metabolic process (q = 1 × 10-13), cell death (q = 0.02), and vasculature development (q = 0.005) pathways. The number of unique genes annotated to a chemical ranged from 2 (bromacil) to 5607 (atrazine). In humans, all chemicals tested were highly enriched for miscarriage gene overlap (all p < 0.001; parathion PRR = 7, cadmium PRR = 6.5, lead PRR = 3.9, arsenic PRR = 3.5, atrazine PRR = 2.8). In mice, highest enrichment (p < 0.001) was observed for naphthalene (PRR = 16.1), cadmium (PRR = 12.8), arsenic (PRR = 11.6), and carbon tetrachloride (PRR = 7.7). In rats, we observed highest enrichment (p < 0.001) for cadmium (PRR = 8.7), carbon tetrachloride (PRR = 8.3), and dieldrin (PRR = 5.3). Our findings were robust to 1000 permutations each of variable gene set sizes.

CONCLUSION

We observed chemical gene sets (parathion, cadmium, naphthalene, carbon tetrachloride, arsenic, lead, dieldrin, and atrazine) were highly enriched for miscarriage genes. Exposures to chemicals linked to miscarriage, and thus linked to decreased probability of live birth, may limit the inclusion of fetuses susceptible to adverse birth outcomes in epidemiology studies. Our findings have critical public health implications for successful pregnancies and the interpretation of adverse impacts of environmental chemical exposures on pregnancy.

Cadmium exposure induces apoptosis, inflammation and immunosuppression through CYPs activation and antioxidant dysfunction in common carp neutrophils

Cadmium (Cd) is a bioaccumulative toxic heavy metal element that has been shown to cause irreversible damage to the immune system once contaminated with water, thereby jeopardizing the health of fish and other aquatic organisms. Neutrophils react against multiple invading pathogens through different mechanisms. The effect of Cd immunotoxicity in carp neutrophils has not been thoroughly studied. Here, common carp peripheral blood neutrophils were exposed to 10 μmol/L Cd for 2 h or then stimulated with 20 nmol/L PMA under laboratory conditions to study the effect and potential mechanism of Cd on neutrophils. The results showed that Cd induced mRNA expression of Cytochrome P450s (CYPs) enzymes including CYP1A1, CYP1B1, CYP1C and CYP3A138, increased reactive oxygen species (ROS) levels, and enhanced the expression of antioxidant genes. In addition, Cd activated cysteinyl aspartate specific proteinases (caspase-3) and induced apoptosis by altering the expression of major genes including mitochondrial pathway factors such as B-cell lymphoma-2 (Bcl-2), pro-apoptosis factors Bcl-2-Associated X (BAX), and caspase-9 and death receptor pathways such as Fas/Fas ligand (Fas/FasL), tumour necrosis factor alpha/tumor necrosis factor receptor 1 (TNF-α/TNFR1) and caspase-8. Meanwhile, we found that the accumulation of ROS caused not only oxidative stress but also high expression levels of related inflammatory factors to mediate the immune response including interleukin (IL-6, IL-10, IL-11b, IL-1β) and interferon (IFNg1, IFNph1). Furthermore, Cd also inhibited phorbol myristate acetate (PMA)-induced release of neutrophil extracellular traps (NETs) and respiratory burst. This information will be helpful for the elucidation of how Cd impacts the neutrophils of carp. The associated risk assessment is valuable for effective aquatic environmental management.

Lipoxin A4 suppresses angiotensin II type 1 receptor autoantibody in preeclampsia via modulating caspase-1

Preeclampsia (PE) remains a leading cause of maternal and neonatal morbidity and mortality. Numerous studies have shown that women with PE develop autoantibody, termed angiotensin II type 1 receptor autoantibody (AT1-AA), and key features of the disease result from it. Emerging evidence has indicated that inflammatory cell necrosis, such as pyroptosis, could lead to autoantigen exposure and stimulate autoantibody production. Caspase-1, the central enzyme of inflammasome and key target of pyroptosis, may play roles in AT1R exposure and AT1-AA production. Exploring endogenous regulator that could inhibit AT1-AA production by targeting pyroptosis will be essential for treating PE. Lipoxin A₄ (LXA₄), endogenous dual anti-inflammatory and proresolving lipid mediator, may inhibit AT1-AA production via modulating caspase-1. Thus, we explore whether caspase-1 is essential for AT1-AA production and LXA₄ inhibits AT1-AA via modulating caspase-1. PE patients and mice developed AT1-AA associated with caspase-1 activation. Caspase-1 deletion leaded to AT1-AA decrease in PE mice. Consistent with these findings, we confirmed caspase-1 activation, trophoblast pyroptosis and AT1R exposure in PE mice and trophoblast model, while caspase-1 deficiency showed decreased trophoblast pyroptosis and AT1R exposure in vitro and in vivo. Interestingly, LXA₄ could suppress AT1-AA production via regulating caspase-1 as well as enhancing phagocytosis of dead trophoblasts by macrophages. These results suggest that caspase-1 promotes AT1-AA production via inducing trophoblast pyroptosis and AT1R exposure, while LXA₄ suppresses AT1-AA production via modulating caspase-1, supporting caspase-1 serving as a therapeutic target for attenuating AT1-AA and LXA₄ protecting patients from AT1-AA and PE.

Evaluation of the uterine hormonal control of the bat Artibeus lituratus during the different phases of its reproductive cycle

Artibeus lituratus is a frugivorous bat that directly assists in the restoration of degraded habitats through the effective dispersion of seeds and fruits. Given its great importance, this work aimed to evaluate the uterine hormonal control of A. lituratus during its different reproductive phases. The uteri of 30 sexually mature adult females, five specimens for each of the six sample groups (NON, nonreproductive; P1, initial pregnancy; P2, intermediate pregnancy; P3, advanced pregnancy; LAC, lactating; P + LAC, pregnant-lactating), were submitted to analyses of serum estradiol and progesterone concentrations, in addition to immunohistochemical analyses. Both estradiol and progesterone, gradually increased during pregnancy, with a marked significant increase in P3 females. Both returned to low levels in LAC-females; however, estradiol levels decreased further in P + LAC-females, while progesterone increased in the same group. In general, signs indicative of aromatase expression were observed in the endometrium of all analyzed groups and in the placenta of bats in the gestation groups. Similarly, ERα and PR were expressed in the myometrium, endometrium and placenta at varying levels of intensity. The results indicate that the uterine microenvironment of A. lituratus is directly regulated by serum concentrations of estradiol and progesterone, and fluctuations in these concentrations control morphological and physiological changes of this organ during different phases of the reproductive cycle. RESEARCH HIGHLIGHTS: Increases in serum concentrations of estradiol and progesterone coordinate the gestational period of A. lituratus. Estradiol activates ERα, stimulating cell proliferation in the uterus, in addition to activating the expression of PR, which trigger the quiescence of the myometrium and stimulation of the secretion and differentiation of the endometrium. Results showed several similarities to humans, indicating the use of A. lituratus as an animal model in reproductive studies.

Trace Minerals, Heavy Metals, and Preeclampsia: Findings from the Boston Birth Cohort

Background Preeclampsia is a leading contributor to maternal and perinatal morbidity and mortality. In mice experiments, manganese (Mn) and selenium (Se) are protective whereas cadmium (Cd) is promotive for preeclampsia. Epidemiologic findings on these chemical elements have been inconsistent. To confirm experimental findings in mice, we examined associations of trace minerals (Mn and Se) and heavy metals (Cd, lead [Pb], and mercury [Hg]) with preeclampsia in a birth cohort. Methods and Results A total of 1274 women from the Boston Birth Cohort (enrolled since 1998) had complete data on the exposures and outcome. We measured Mn, Se, Cd, Pb, and Hg from red blood cells collected within 24 to 72 hours after delivery. We ascertained preeclampsia diagnosis from medical records. We used Poisson regression with robust variance models to estimate prevalence ratios (PRs) and 95% CIs. A total of 115 (9.0%) women developed preeclampsia. We observed evidence of a dose-response trend for Mn (P for trend<0.001) and to some extent for Cd (P for trend=0.009) quintiles. After multivariable adjustment, a 1 SD increment in Mn was associated with 32% lower risk of developing preeclampsia (PR=0.68; 95% CI, 0.54-0.86), whereas a 1 SD increment in Cd was associated with 15% higher risk of preeclampsia (PR=1.15; 95% CI, 0.98-1.36). Null associations were observed for Se, Pb, and Hg. Conclusions Findings from our cohort, consistent with evidence from mice experiments and human studies, indicate that women with lower blood concentration of Mn or higher Cd are more likely to develop preeclampsia.

Urinary trace metals, maternal circulating angiogenic biomarkers, and preeclampsia: a single-contaminant and mixture-based approach

BACKGROUND

Exposures to toxic metals and deficiencies in essential metals disrupt placentation and may contribute to preeclampsia. However, effects of exposure to combinations of metals remain unknown.

OBJECTIVE

We investigated the relationship between urinary trace metals, circulating angiogenic biomarkers, and preeclampsia using the LIFECODES birth cohort.

METHODS

Urine samples collected during pregnancy were analyzed for 17 trace metals and plasma samples were analyzed for soluble fms-like tyrosine-1 (sFlt-1) and placental growth factor (PlGF). Cox proportional hazard models were used to estimate the hazard ratios (HR) of preeclampsia associated with urinary trace metals. Linear regression models were used to estimate the relationship between urinary trace metals and angiogenic biomarkers. Principal components analysis (PCA) was used to identify groups of metals and interactions between principal components (PCs) loaded by toxic and essential metals were examined.

RESULTS

In single-contaminant models, several toxic and essential metals were associated with lower PlGF and higher sFlt-1/PlGF ratio. Detection of urinary chromium was associated with preeclampsia: HR (95% Confidence Interval [CI]) = 3.48 (1.02, 11.8) and an IQR-increase in urinary selenium was associated with reduced risk of preeclampsia (HR: 0.28, 95% CI: 0.08, 0.94). Using PCA, 3 PCs were identified, characterized by essential metals (PC1), toxic metals (PC2), and seafood-associated metals (PC3). PC1 and PC2 were associated with lower PlGF levels, but not preeclampsia risk in the overall cohort.

CONCLUSIONS

Trace urinary metals may be associated with adverse profiles of angiogenic biomarkers and preeclampsia.

The Effect of BML-111 in Preeclampsia Rat Model Induced by the Low Dose of Cadmium Chloride

Aim  This article determines the optimal time and dose of cadmium chloride (CdCl ₂ ) injected to pregnant rat to establish experimental preeclampsia (PE) model. In addition, the therapeutic potential of BML-111, a lipoxin A4 analogue, in the CdCl ₂ -induced PE model was also evaluated. Methods  Peritoneal injection of two dose of CdCl ₂ for successive 6 days was tested in the pregnant rats starting from various gestational days (GDs). During this process, the systolic blood pressure and the body weight of pregnant rats and neonatal rats were monitored. The pathological changes of the placenta and kidney were evaluated by hematoxylin and eosin staining. The phosphorylation of extracellular signal-regulated kinase 1/2 and signal transducer and activator of transcription 3 in the placentas was detected by Western blot, and the messenger ribonucleic acid expression of interleukin (IL)-6, tumor necrosis factor-α, and IL-10 in the placentas were detected by real-time polymerase chain reaction. BML-111 at the dose of 1 mg/kg/day was peritoneally injected into the rat after establishing the PE model to test its therapeutic potential. Results  In the present study, we successfully established the PE model in pregnant rats by intraperitoneally injection of CdCl ₂ at the dose of 0.125 mg/kg/day from GD 9 to 14. We recapitulated multiple features of clinical PE in CdCl ₂ -induced rat, including high blood pressure, renal dysfunction, and inflammatory response in placenta. Furthermore, treatment with BML-111 significantly relieved multiple features in our PE rat model. Conclusions  BML-111 has a potential therapeutic effect in pregnant rats with CdCl ₂ -induced PE, which appears to be mediated through inhibition of inflammatory processes in the placenta.

Cadmium exposure induces interleukin-6 production via ROS-dependent activation of the ERK1/2 but independent of JNK signaling pathway in human placental JEG-3 trophoblast cells

Maternal exposure to cadmium (Cd) has been associated with preeclampsia (PE), which is a multisystemic disorder characterized by endothelial dysfunction. Elevated interleukin (IL)-6 expression is linked to PE and has been suggested to contribute to maternal endothelial dysfunction. Cd induces IL-6 production in various cell types through different signaling pathways. Thus, this study was designed to investigate the effect of Cd on IL-6 production and the underlying mechanisms in a trophoblast-derived cell line. Cultured JEG-3 trophoblast cells were exposed to non-toxic concentrations of CdCl₂ in the presence or absence of various MAPK inhibitors or N-Acetyl-L-cysteine (NAC). IL-6 was measured by ELISA. Phosphorylation of ERK1/2, JNK, and c-Jun was assessed by Western blotting. Cd exposure induced IL-6 production and increased ERK1/2, JNK, and c-Jun phosphorylation. NAC and the inhibition of ERK1/2 significantly reduced Cd-induced IL-6 production. These data indicate that Cd induces IL-6 production in trophoblast cells through a ROS-dependent activation of ERK1/2.

Maternal Cadmium Levels During Pregnancy and the Relationship with Preeclampsia and Fetal Biometric Parameters

Preeclampsia, which is caused by multiple factors, still remains one of the most serious complications of pregnancy. This study was designed to determine cadmium levels in women with preeclampsia compared to those of normotensive women. In this case-control study, maternal blood, umbilical cord blood, and placental cadmium levels were measured by an inductively coupled plasma mass spectrometry system in 51 women presenting consecutively with preeclampsia and 51 normotensive pregnant women. Groups were matched for maternal age, parity, and gestational age. Birth outcomes were recorded, such as gestational age at delivery, birth weight, and Apgar score. Median (interquartile range [IQR]) blood cadmium concentration was 1.21 μg/L (0.76-1.84 μg/L) and 1.09 μg/L (0.72-1.31 μg/L) in women with preeclampsia and normotensive, respectively; values for placental cadmium levels of women with preeclampsia and normotensive were 3.61 μg/kg (2.19-4.37 μg/kg) and 4.28 μg/kg (3.06-5.71 μg/kg), respectively. We observed a statistically significant increase in blood and placental cadmium levels in women with preeclampsia compared to healthy pregnant women. After adjusting for pre-pregnancy body mass index, maternal age, parity, gestational age at sample collection, and maternal calcium and magnesium levels, the odds ratio of having preeclampsia in the high tertile was markedly increased (odds ratio, 7.83 [95% CI, 1.64-37.26]) compared with the low tertile. Interestingly, there was no difference in the cadmium level in umbilical cord blood between the groups. Within the preeclamptic group, higher cadmium status was significantly associated with decreased birth weight. Our study suggested that elevated cadmium level in the maternal circulation could potentially increase the risk of preeclampsia. The results also demonstrate that higher cadmium status may contribute to fetal growth restriction in preeclamptic patients.

Environmental Toxicant Exposure and Hypertensive Disorders of Pregnancy: Recent Findings

PURPOSE OF REVIEW

To assess the strength of evidence for associations between environmental toxicants and hypertensive disorders of pregnancy, suggest potential biological mechanisms based on animal and in vitro studies, and highlight avenues for future research.

RECENT FINDINGS

Evidence is strongest for links between persistent chemicals, including lead, cadmium, organochlorine pesticides, and polycyclic biphenyls, and preeclampsia, although associations are sometimes not detectable at low-exposure levels. Results have been inconclusive for bisphenols, phthalates, and organophosphates. Biological pathways may include oxidative stress, epigenetic changes, endocrine disruption, and abnormal placental vascularization. Additional prospective epidemiologic studies beginning in the preconception period and extending postpartum are needed to assess the life course trajectory of environmental exposures and women's reproductive and cardiovascular health. Future studies should also consider interactions between chemicals and consider nonlinear associations. These results confirm recommendations by the International Federation of Gynecology and Obstetrics, the American Society for Reproductive Medicine, the American Academy of Pediatrics, and the Endocrine Society that providers counsel their pregnant patients to limit exposure to environmental toxicants.

Overview of Cadmium Thyroid Disrupting Effects and Mechanisms

Humans are exposed to a significant number of chemicals that are suspected to produce disturbances in hormone homeostasis. Hence, in recent decades, there has been a growing interest in endocrine disruptive chemicals. One of the alleged thyroid disrupting substances is cadmium (Cd), a ubiquitous toxic metal shown to act as a thyroid disruptor and carcinogen in both animals and humans. Multiple PubMed searches with core keywords were performed to identify and evaluate appropriate studies which revealed literature suggesting evidence for the link between exposure to Cd and histological and metabolic changes in the thyroid gland. Furthermore, Cd influence on thyroid homeostasis at the peripheral level has also been hypothesized. Both in vivo and in vitro studies revealed that a Cd exposure at environmentally relevant concentrations results in biphasic Cd dose-thyroid response relationships. Development of thyroid tumors following exposure to Cd has been studied mainly using in vitro methodologies. In the thyroid, Cd has been shown to activate or stimulate the activity of various factors, leading to increased cell proliferation and a reduction in normal apoptotic activity. Evidence establishing the association between Cd and thyroid disruption remains ambiguous, with further studies needed to elucidate the issue and improve our understanding of Cd-mediated effects on the thyroid gland.

Current model systems for the study of preeclampsia

Preeclampsia (PE) is a pregnancy complex disease, distinguished by high blood pressure and proteinuria, diagnosed after the 20th gestation week. Depending on the values of blood pressure, urine protein concentrations, symptomatology, and onset of disease there is a wide range of phenotypes, from mild forms developing predominantly at the end of pregnancy to severe forms developing in the early stage of pregnancy. In the worst cases severe forms of PE could lead to systemic endothelial dysfunction, eclampsia, and maternal and/or fetal death. Worldwide the fetal morbidity and mortality related to PE is calculated to be around 8% of the total pregnancies. PE still being an enigma regarding its etiology and pathophysiology, in general a deficient trophoblast invasion during placentation at first stage of pregnancy, in combination with maternal conditions are accepted as a cause of endothelial dysfunction, inflammatory alterations and appearance of symptoms. Depending on the PE multifactorial origin, several in vitro, in vivo, and in silico models have been used to evaluate the PE pathophysiology as well as to identify or test biomarkers predicting, diagnosing or prognosing the syndrome. This review focuses on the most common models used for the study of PE, including those related to placental development, abnormal trophoblast invasion, uteroplacental ischemia, angiogenesis, oxygen deregulation, and immune response to maternal-fetal interactions. The advances in mathematical and computational modeling of metabolic network behavior, gene prioritization, the protein-protein interaction network, the genetics of PE, and the PE prediction/classification are discussed. Finally, the potential of these models to enable understanding of PE pathogenesis and to evaluate new preventative and therapeutic approaches in the management of PE are also highlighted. Impact statement This review is important to the field of preeclampsia (PE), because it provides a description of the principal in vitro, in vivo, and in silico models developed for the study of its principal aspects, and to test emerging therapies or biomarkers predicting the syndrome before their evaluation in clinical trials. Despite the current advance, the field still lacking of new methods and original modeling approaches that leads to new knowledge about pathophysiology. The part of in silico models described in this review has not been considered in the previous reports.

Progesterone attenuates hypertension and autoantibody levels to the angiotensin II type 1 receptor in response to elevated cadmium during pregnancy

INTRODUCTION

Preeclampsia is associated with the presence of pathogenic angiotensin-receptor-activating autoantibodies. Cadmium is an increasingly prevalent environmental pollutant that can mimic oestrogens, which may enhance immunoglobulin production. Progesterone exerts opposite effects to oestrogen.

METHODS

We measured the levels of cadmium and progesterone in preeclamptic patients and controls. Pregnant rats exposed to cadmium (0.125 mg/kg body weight) from gestational day 9-12 were treated with/without progesterone (3 mg/kg) beginning from gestational day 9 to delivery. We analysed the main features of preeclampsia and circulating level of the angiotensin II type 1 receptor agonistic autoantibody. We also measured the expression of activation-induced cytosine deaminase in B cells.

RESULTS

There were higher cadmium levels and lower progesterone levels in the blood of preeclamptic women than in the blood of those with a healthy pregnancy. Based on this finding, a rat model of preeclampsia was established by intraperitoneally administrating low-dose cadmium on gestational days 9-12. Rats were then treated with/without progesterone. Key features of preeclampsia, including hypertension, proteinuria and placental abnormalities, appeared in pregnant rats after cadmium injection and improved after treatment with progesterone. Cadmium increased immunoglobulin production, mainly angiotensin II type 1-receptor-agonistic autoantibodies, by increasing the expression of activation-induced cytosine deaminase in B cells; progesterone exerted an opposite effect.

CONCLUSION

Cadmium induced immune abnormalities that may be a key pathogenic contributor to preeclampsia. Progesterone supplementation to correct hormonal imbalance may be a viable strategy for preeclampsia management.

Lead and cadmium exposure, higher thyroid antibodies and thyroid dysfunction in Chinese women

BACKGROUND

Exposure to lead(Pb) or cadmium(Cd) has been related to decreasing thyroxine in many previous studies. The underlying mechanisms have not been clarified. Heavy metal-induced thyroid autoimmunity in pregnant women has been found, despite having been rarely explored in the general population.

OBJECTIVES

We aimed to determine whether the blood levels of lead(BPb) or cadmium(BCd) related to the levels of sera antibodies to thyroid proteins and thyroid dysfunction in the general population.

METHODS

Our study included 5628 Chinese adults and was based on the 2014 SPECT-China study. Thyroid dysfunction and subclinical thyroid dysfunction were defined by total triiodothyronine (TT3), total thyroxine(TT4) and thyroid stimulating hormone (TSH).Thyroid peroxidase antibody (TPOAb), thyroglobulin antibodies (TGAb), TT3, TT4, and TSH were measured by immunochemiluminometric assays. BPb and BCd levels were tested by atomic absorption spectrometry. Linear and logistic regression models were used to analyze the associations.

RESULTS

After adjustment for age, body mass index, smoking status (men only) and drinking status, the natural log(ln) BPb was positively related to the lnTPOAb (B = 0.062, P < 0.05) and to the lnTSH (B = 0.047, P < 0.01) in women. The lnBCd in women was positively related to the lnTGAb (B = 0.046, P < 0.05). In the adjusted logistic regression models, the BCd of women was positively related to their hypothyroid status and TGAb tertiles. The ORs of women in the middle and higher TPOAb tertiles were 1.38 (P < 0.001) and 1.35 (P < 0.001) times greater for every ln-unit increase in BPb, respectively. In men, no continuous correlation was found among variables.

CONCLUSIONS

In women, BPb and BCd levels were related to higher TSH and hypothyroid status, respectively, suggesting a Pb and Cd induction of sex-biased thyroid autoimmunity.

Astragalus Polysaccharide Protect against Cadmium-Induced Cytotoxicity through the MDA5/NF-κB Pathway in Chicken Peripheral Blood Lymphocytes

Cadmium (Cd) is a known environmental pollutant that is associated with inflammation, oxidative stress, and cell apoptosis. Astragalus polysaccharide (APS) is a major component of Astragalus membranaceus, a vital qi-reinforcing herb medicine with favorable immuneregulation properties. To study the effect of APS on the inhibition of the cadmium-induced injury of peripheral blood lymphocytes (PBLs) in chickens through the MDA5/NF-κB signaling pathway, PLBs acquired from 15-day-old chickens were divided into control group, Cd group, APS + Cd group, anti-MDA5 mAb + Cd group, BAY 11-7082 (a nuclear factor kappa-light chain-enhancer of activated B cells [NF-κB] inhibitor) +Cd group, APS group, anti-MDA5 mAb group, and BAY 11-7082 group. The transcription levels of melanoma differentiation-associated gene 5 (MDA5), interferon promoter-stimulating factor 1 (IPS-1), NF-κB, and inflammatory factors tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 were measured by quantitative real-time PCR. MDA5 protein expression was measured by western blotting. Levels of malondialdehyde (MDA), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) were measured by corresponding antioxidant kit. The morphological change of PBLs was measured by transmission electron microscopy. The results showed that Cd significantly increased the expression of MDA5, IPS-1, NF-κB, and their downstream cytokines, IL-1β and TNF-α, IL-6 in PLBs. In addition, a high level of MDA was observed in the Cd treatment group; the activities of GSH-Px and SOD were significantly lower in the Cd treatment group than those in controls (p < 0.05). Ultrastructural changes of PBLs showed that Cd promoted autophagy, apoptosis, and necrosis in PBLs. However, APS can efficiently improve Cd-induced cell damage by decreasing the activation of the MDA5 signaling pathway. The effect is consistent with that of anti-MDA5 mAb or/and BAY. The results indicated that APS inhibited Cd-induced cytotoxicity through the regulation of MDA5/NF-κB signaling.

Cadmium Handling, Toxicity and Molecular Targets Involved during Pregnancy: Lessons from Experimental Models

Even decades after the discovery of Cadmium (Cd) toxicity, research on this heavy metal is still a hot topic in scientific literature: as we wrote this review, more than 1440 scientific articles had been published and listed by the PubMed.gov website during 2017. Cadmium is one of the most common and harmful heavy metals present in our environment. Since pregnancy is a very particular physiological condition that could impact and modify essential pathways involved in the handling of Cd, the prenatal life is a critical stage for exposure to this non-essential element. To give the reader an overview of the possible mechanisms involved in the multiple organ toxic effects in fetuses after the exposure to Cd during pregnancy, we decided to compile some of the most relevant experimental studies performed in experimental models and to summarize the advances in this field such as the Cd distribution and the factors that could alter it (diet, binding-proteins and membrane transporters), the Cd-induced toxicity in dams (preeclampsia, fertility, kidney injury, alteration in essential element homeostasis and bone mineralization), in placenta and in fetus (teratogenicity, central nervous system, liver and kidney).