Cadmium toxicity symptoms and uptake mechanism in plants: a review / Sintomas de toxicidade de cádmio e mecanismo de absorção em plantas: uma revisão

Cadmium (Cd) is one of non-essential heavy metals which is released into environment naturally or anthropogenically. It is highly persistent toxic metals that are exceptionally distressing industrial and agriculture activities by contaminating soil, water and food. Its long-duration endurance in soil and water results in accumulation and uptake into plants, leading to the food chain. This becomes a serious global problem threatening humans and animals as food chain components. Living organisms, especially humans, are exposed to Cd through plants as one of the main vegetative food sources. This review paper is concentrated on the symptoms of the plants affected by Cd toxicity. The absorption of Cd triggers several seen and unseen symptoms by polluted plants such as stunted growth, chlorosis, necrosis and wilting. Apart from that, factors that affect the uptake and translocation of Cd in plants are elaborated to understand the mechanism that contributes to its accumulation. By insight of Cd accumulation, this review also discussed the phytoremediation techniques-phytoextraction, phytostimulation, phytostabilization, phytovolatization and rhizofiltration in bioremediating the Cd.

O cádmio (Cd) é um dos metais pesados ​​não essenciais que é liberado no meio ambiente de forma natural ou antropogênica. São metais tóxicos altamente persistentes que prejudicam excepcionalmente as atividades industriais e agrícolas, contaminando o solo, a água e os alimentos. Sua resistência de longa duração no solo e na água resulta em acúmulo e absorção pelas plantas, levando à cadeia alimentar. Isso se torna um sério problema global que ameaça humanos e animais como componentes da cadeia alimentar. Os organismos vivos, principalmente os humanos, são expostos ao Cd através das plantas como uma das principais fontes de alimento vegetativo. Este artigo de revisão concentra-se nos sintomas das plantas afetadas pela toxicidade do Cd. A absorção de Cd desencadeia vários sintomas visíveis e invisíveis por plantas poluídas, como crescimento atrofiado, clorose, necrose e murcha. Além disso, são elaborados fatores que afetam a absorção e translocação de Cd nas plantas para entender o mecanismo que contribui para o seu acúmulo. A partir do conhecimento do acúmulo de Cd, esta revisão também discutiu as técnicas de fitorremediação - fitoextração, fitoestimulação, fitoestabilização, fitovolatização e rizofiltração na biorremediação do Cd.

Cadmium toxicity symptoms and uptake mechanism in plants: a review

Abstract Cadmium (Cd) is one of non-essential heavy metals which is released into environment naturally or anthropogenically. It is highly persistent toxic metals that are exceptionally distressing industrial and agriculture activities by contaminating soil, water and food. Its long-duration endurance in soil and water results in accumulation and uptake into plants, leading to the food chain. This becomes a serious global problem threatening humans and animals as food chain components. Living organisms, especially humans, are exposed to Cd through plants as one of the main vegetative food sources. This review paper is concentrated on the symptoms of the plants affected by Cd toxicity. The absorption of Cd triggers several seen and unseen symptoms by polluted plants such as stunted growth, chlorosis, necrosis and wilting. Apart from that, factors that affect the uptake and translocation of Cd in plants are elaborated to understand the mechanism that contributes to its accumulation. By insight of Cd accumulation, this review also discussed the phytoremediation techniques-phytoextraction, phytostimulation, phytostabilization, phytovolatization and rhizofiltration in bioremediating the Cd.

Resumo O cádmio (Cd) é um dos metais pesados não essenciais que é liberado no meio ambiente de forma natural ou antropogênica. São metais tóxicos altamente persistentes que prejudicam excepcionalmente as atividades industriais e agrícolas, contaminando o solo, a água e os alimentos. Sua resistência de longa duração no solo e na água resulta em acúmulo e absorção pelas plantas, levando à cadeia alimentar. Isso se torna um sério problema global que ameaça humanos e animais como componentes da cadeia alimentar. Os organismos vivos, principalmente os humanos, são expostos ao Cd através das plantas como uma das principais fontes de alimento vegetativo. Este artigo de revisão concentra-se nos sintomas das plantas afetadas pela toxicidade do Cd. A absorção de Cd desencadeia vários sintomas visíveis e invisíveis por plantas poluídas, como crescimento atrofiado, clorose, necrose e murcha. Além disso, são elaborados fatores que afetam a absorção e translocação de Cd nas plantas para entender o mecanismo que contribui para o seu acúmulo. A partir do conhecimento do acúmulo de Cd, esta revisão também discutiu as técnicas de fitorremediação - fitoextração, fitoestimulação, fitoestabilização, fitovolatização e rizofiltração na biorremediação do Cd.

Network-based Toxicogenomics Approach to Unraveling the Influence of Lead and Cadmium Mixture on the Development and Progression of Hypertension

Heavy metals, generally characterized by high densities and atomic weights, are ubiquitous in the environment and are a public health concern due to the several health issues they pose to humans. Of all heavy metals, lead and cadmium among others are known to be capable of inducing multiple health effects even at a low rate of exposure. Hypertension (HYP), a major cause of death and a risk factor for other cardiovascular diseases, is known to be caused by both lead and cadmium. While the mechanism underlying the development of HYP induced by independent exposure to lead and cadmium has been well studied, the mechanism underlying the induction and progression of HYP upon lead and cadmium co-exposure remains mildly explored. Hence, this study aimed to elucidate the mechanism using a toxicogenomic approach. The set of genes affected by both heavy metals was identified using the comparative toxicogenomics database (CTD) while HYP targets were retrieved from the Gene Cards database. The shared genes between the heavy metals and the disease were identified and subjected to further analysis. The results of our analysis revealed the signaling pathways that are dysregulated by lead and cadmium co-exposure while oxidative stress, inflammation, and endothelial dysfunction were revealed as processes pertinent to the induction and progression of HYP by lead and cadmium co-exposure. Biomarkers that could be used for prognosis evaluation were also identified. Ultimately, this study supports and advances the growing body of finding on the roles played by lead and cadmium co-exposure in inducing HYP.

Does L-carnitine prevent cadmium-induced damage in gastrointestinal contractility and histological changes in prepubertal rat / ¿La L-carnitina previene el daño inducido por cadmio en la contractilidad gastrointestinal y los cambios histológicos en ratas prepúberes?

SUMMARY: Cadmium (Cd) is the industrial and environmental toxic heavy metal which is found in air, water and soil. Cd, adversely affects many organs in humans such as kidney, intestine, liver, testis and lungs. L-carnitine (LC) is an important agent that plays essential role in energy metabolism. In our study, we aimed to work out whether LC application has any protective effect on intestinal contractility and morphologic damage of prepubertal rat duodenum on Cd-induced toxicity. Twenty eight prepubertal female Wistar rats were divided into four groups. The first group is control (C), second group; Cd group; Cadmium chloride was given 2 mg/kg 28 days with a one-day break by i.p. The third group; Cd+LC, which cadmium chloride was given 2 mg/kg i.p. and LC was given orally by gastric lavage. The LC dose was given as 75 mg/kg. The fourth group; LC, which only LC was given orally. The intestinal segments were isolated and suspended in tissue bath. Contractile responses were induced by acetylcholine (ACh) and relaxation was achieved with phenylephrine. Also the segments were examined for histological changes by light microscopy. Ach-induced contractions were higher in Cd+LC, LC, and control group compared to the Cd group in duodenal segments. The phenylephrine-induced relaxations were lower in Cd groups as compared with Control, Cd+LC and LC group in duodenal segments. In Cd group intestinal morphology was observed to be severely damaged whereas in Cd+LC group the damage was noticeably lower. Cd administration caused severe cellular damage and decreased gastrointestinal motility. Treatment with the LC has affected the gastrointestinal contractility and reduced the damage in intestinal morphology, which occured after Cd application.

El cadmio (Cd) es el metal pesado tóxico industrial y ambiental que se encuentra en el aire, el agua y el suelo. El Cd afecta negativamente a muchos órganos humanos, como los riñones, los intestinos, el hígado, los testículos y los pulmones. La L-carnitina (LC) es un agente importante que juega un rol esencial en el metabolismo energético. El objetivo de este estudio fue determinar si la aplicación de LC tiene algún efecto protector sobre la contractilidad intestinal y el daño morfológico del duodeno de rata prepuberal sobre la toxicidad inducida por Cd. Veintiocho ratas Wistar hembras prepúberes se dividieron en cuatro grupos. El primer grupo control (C), segundo grupo; grupo cd; Se administró cloruro de cadmio 2 mg/kg durante 28 días con un descanso de un día por vía i.p. El tercer grupo; Cd+LC, al que se administró cloruro de cadmio 2 mg/kg i.p. y LC se administró por vía oral mediante lavado gástrico. La dosis de LC se administró como 75 mg/kg. El cuarto grupo; LC, al cual solo LC se administraba por vía oral. Los segmentos intestinales fueron aislados y suspendieron en baño de tejido. Las respuestas contráctiles fueron inducidas por acetilcolina (ACh) y la relajación se logró con fenilefrina. También se examinaron los segmentos en busca de cambios histológicos mediante microscopía óptica. Las contracciones inducidas por Ach fueron mayores en Cd+LC, LC y el grupo control en comparación con el grupo Cd en los segmentos duodenales. Las relajaciones inducidas por fenilefrina fueron menores en los grupos Cd en comparación con el grupo Control, Cd+LC y LC en los segmentos duodenales. En el grupo Cd se observó que la morfología intestinal estaba severamente dañada mientras que en el grupo Cd+LC el daño fue notablemente menor. La administración de Cd causó daño celular severo y disminución de la motilidad gastrointestinal. El tratamiento con LC afectó la contractilidad gastrointestinal y redujo el daño en la morfología intestinal, que ocurría después de la aplicación de Cd.

Exposição ao cádmio e Síndromes Hipertensivas da Gestação: uma revisão sistemática / Cadmium exposure and Hypertensive Disorders of Pregnancy: a systematic review

RESUMO As Síndromes Hipertensivas da Gestação (SHG) são uma das principais causas de morbimortalidade materna. Evidências crescentes indicam a associação entre a exposição ao cádmio e a hipertensão arterial na população em geral, mas não as SHG. Afim de investigar esse tema, realizou-se uma revisão sistemática seguindo as diretrizes PRISMA, nas bases de dados BVS/Lilacs, PubMed/Medline e SciELO e no repositório da Universidade de São Paulo (USP) até agosto de 2021. A qualidade metodológica foi avaliada pelo checklist Downs and Black. Selecionaram-se dezenove artigos, sendo treze caso-controle, quatro coortes e dois seccionais. No total, 11.451 participantes foram avaliadas, sendo 1.445 (12,6%) com SHG e, destas, 1.071 (74,1%) com pré-eclâmpsia. Observou-se o ajuste inadequado para confundimento em onze estudos. Dos sete estudos considerados de boa qualidade metodológica, quatro relataram associação positiva e três não a observaram, enquanto somente um estudo observou diferença de média, que foi maior nas gestantes com SHG. Atribuiu-se a divergência dos resultados às diferenças metodológicas e ao ajuste inadequado para os fatores de confusão. Como o cádmio é um metal tóxico que pode levar ao aumento do estresse oxidativo, que desempenha papel importante na fisiopatologia das SHG, estudos adicionais são necessários para elucidar esta associação.

ABSTRACT Hypertensive Disorders of Pregnancy (HDP) are one of the main causes of maternal morbimortality. Strong evidence point to an association between cadmium and hypertension in the general population, but not HDP. A systematic review was carried out to investigate this potential relationship, following PRISMA guidelines, in the BVS/LILACS, PubMed/MEDLINE, and SciELO databases and a repository (University of São Paulo - USP) until August 2021. The methodological quality was assessed using the Downs and Black checklist. Nineteen articles were selected, thirteen of which were case-control, four were cohorts, and two were cross-sectional. A total of 11.451 participants were evaluated, 1.445 (12.6%) with HDP, and of these 1.071 (74.1%) with preeclampsia. The inadequate adjustment for confounding was observed in eleven studies. Out of the seven studies considered good methodological quality, four reported a positive association, and three did not observe it. In contrast, only one observed a mean difference, which was higher in HDP. The inconsistency of the results was attributed to the methodological differences and inadequate adjustment for confounding. As cadmium is a toxic metal that can induce an increase in oxidative stress, which plays an essential role in the pathophysiology of HDP, additional studies are needed to elucidate this association.

Association between combined exposure of heavy metals and biomarkers of early renal damage in occupational population / 中国职业医学

Objective: To investigate the effect of combined exposure to four heavy metals (lead, cadmium, arsenic, mercury) on early kidney injury in occupational population. Methods: A total of 384 workers exposed to combined heavy metals in a non-ferrous metal smelting plant in Guangdong Province were selected as the research subjects using judgment sampling method. The levels of blood lead, urinary cadmium and urinary arsenic were detacted by inductively coupled plasma mass spectrometry, while urinary mercury levels were measured using cold atomic absorption spectroscopy (acidic tin chloride reduction method). The levels of biomarkers such as urinary β2-microglobulin (β2-MG), kidney injury molecule-1 (Kim-1) and neutrophil gelatinase-associated lipocalin (NGAL) were detected by enzyme-linked immunosorbent assay. Spearman correlation analysis, linear regression, weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) models were used to analyze the association between the exposure to the four heavy metals and early kidney injury biomarkers. Results: The median of blood lead, urinary cadmium, urinary arsenic and urinary mercury were 0.47 μmol/L and 4.450, 27.790 and 0.520 μg/gCr, respectively. The median of urinary β2-MG, Kim-1 and NGAL were 62.960, 1.130 and 18.150 μg/gCr, respectively. Spearman correlation analysis showed that urinary levels of β2-MG, Kim-1, and NGAL were weakly correlated with blood lead and urinary mercury levels (all P<0.01), but not correlated with urinary cadmium and urinary arsenic (all P>0.05). The results of multiple linear regression analysis showed that urinary mercury was positively correlated with urinary β2-MG, Kim-1 and NGAL (all P<0.01), urinary arsenic was positively correlated with urinary β2-MG level (P<0.01), and blood lead was negatively correlated with urinary β2-MG and Kim-1 (all P<0.05). The WQS regression analysis showed that the combined effect of the four heavy metals was positively correlated with urinary β2-MG, Kim-1 and NGAL (all P<0.01), with mercury having the highest impact and lead the lowest. BKMR model analysis showed the increasing trend in urinary β2-MG, Kim-1 and NGAL with the increasing levels of the combined exposure to the four heavy metals. Urinary β2-MG, Kim-1 and NGAL decreased when urinary mercury level increased from the 25th percentile to the 75th percentile and the other metals were correspondingly fixed at a certain level. When the blood exposure levels of other metals remained at the corresponding median levels, urinary β2-MG, Kim-1 and NGAL levels were positively correlated with urinary arsenic level, but no significant linear dose-response relationship was observed with the other three heavy metals. Conclusion: sLead, arsenic, and mercury are independently associated with early kidney injury biomarkers in occupational population from non-ferrous metal smelting. The four heavy metals had positive combined effects on urinary β2-MG, Kim-1 and NGAL, with mercury having the greatest impact.

Research progress on shortened telomere length in newborns and impaired cardiovascular metabolic health in children caused by exposure to cadmium during pregnancy / 环境与职业医学

Cadmium exposure during pregnancy is a non-negligible public health problem which may increase the risk of shortened telomere length in newborns and cardiovascular metabolic health damage in children, and has attracted attention from many researchers in recent years. This article reviewed recent studies both domestically and internationally on the associations among cadmium exposure during pregnancy, shortened telomere length in newborns, and cardiovascular metabolic abnormalities in children, and briefly outlined possible mechanisms of shortened telomere length in newborns by cadmium exposure during pregnancy. Current research results showed that cadmium exposure during pregnancy is related to shortened telomere length in newborns and cardiovascular metabolic abnormalities in children, and shortened telomere length in newborns is also related to cardiovascular metabolic abnormalities in children. It suggested that telomere length in newborns may be a biomarker reflecting cardiovascular metabolic abnormalities in children caused by cadmium exposure during pregnancy. In addition, the current potential mechanisms of cadmium exposure during pregnancy accelerating neonatal telomere length shortening include inflammatory reaction, mitochondrial dysfunction, antioxidant consumption/antioxidant enzyme inactivation, and DNA methylation, and these biological mechanisms are associated with cardiovascular metabolic abnormalities through certain factors, such as obesity, elevated blood pressure, impaired fasting blood glucose, and dyslipidemia in children, suggesting that cardiovascular metabolic abnormalities in children may be programmed in early life, but there are still few relevant studies. In the future, research should be conducted on the association among cadmium exposure during pregnancy, telomere length, and offspring cardiovascular metabolism, as well as possible mediating efficacy and related biological mechanisms of telomere length, aiming to provide early-life biological information for the prevention of cardiovascular and metabolic diseases.

Association between exposure to lead, cadmium, and arsenic and blood pressure in workers from a smelter / 环境与职业医学

Background Occupational exposure to lead, cadmium, or arsenic is a potential risk factor for blood pressure elevation. Current studies mainly focus on the relationship between a single metal and blood pressure. However, mixed metal exposure often exists in the actual working environment, and the interactive effects of polymetallic interactions on blood pressure and the dose-effect relationship remain unclear yet. Objective To explore the influence proportion of occupational exposure to lead, cadmium, or arsenic on blood pressure and their interactive effects. Methods From January to December 2021, workers from a smelter in southern China were selected. Demographic characteristics, height, weight, and blood pressure of workers were collected through questionnaire and physical examination. At the same time, their urine samples were collected and the levels of urinary lead, urinary cadmium, and urinary arsenic were detected by inductively coupled plasma mass spectrometry, and corrected by urinary creatinine (Cr). Linear regression and logistic regression were used to analyze the relationship between urinary lead, cadmium, and arsenic and blood pressure. Weighted quantile sum (WQS) regression was applied to evaluate the dose-effect relationship between urinary lead, cadmium, and arsenic exposures and blood pressure and the effect weight of each metal on blood pressure. Generalized linear regression and additive/multiplicative scaling were used to identify interactive effects of the three metals on blood pressure. Results A total of 1075 workers were included in this study, with a mean age of (44.68±5.11) years and mean working seniority of (24.66±5.23) years. There were 891 males (88.9%) and 184 were females (17.1%); 24.7% workers were drinkers and 45.7% workers were smokers; 302 workers (28.1%) reported hypertension and 37 of them were taking antihypertensive drugs. The P50 (P25, P75) levels of urinary lead, urinary cadmium, and urinary arsenic were 6.11 (3.71, 11.08), 3.88 (2.68, 5.44), and 26.04 (19.99, 35.11) μg·g−1, respectively. After adjusting for gender, age, working seniority, body mass index, smoking, drinking, and the usage of antihypertensive drugs, systolic and diastolic blood pressure increased by 0.772 and 0.418 mmHg respectively for 10% increase in lead, cadmium, and arsenic mixed exposure. Urinary cadmium, among the three single exposures, had the greatest effect on systolic and diastolic blood pressure, weight (w)=0.523 and 0.551 respectively. The interaction of urinary lead and urinary cadmium was positively correlated with the occurrence of hypertension, multiplicative interaction OR (ORint)=1.88 (95%CI: 1.09, 3.63), attributable proportion due to interaction (AP)=1.19 (95%CI: 0.40, 8.18). Conclusion This study shows that mixed exposure to lead, cadmium, and arsenic has a positive relationship with blood pressure, in which cadmium plays a major role. Co-exposure to lead and cadmium has a positive interactive effect on hypertension development and systolic blood pressure elevation.

Effects of cadmium chloride on testicular autophagy and blood-testis barrier integrity in prepubertal male rats / 中华劳动卫生职业病杂志

Objective: To study the effects of cadmium chloride (CdCl(2)) exposure on testicular autophagy levels and blood-testis barrier integrity in prepubertal male SD rats and testicular sertoli (TM4) cells. Methods: In July 2021, 9 4-week-old male SD rats were randomly divided into 3 groups: control group (normal saline), low dose group (1 mg/kg·bw CdCl(2)) and high dose group (2 mg/kg·bw CdCl(2)), and were exposed with CdCl(2) by intrabitoneal injection. 24 h later, HE staining was used to observe the morphological changes of testis of rats, biological tracer was used to observe the integrity of blood-testis barrier, and the expression levels of microtubule-associated protein light chain 3 (LC3) -Ⅰ and LC3-Ⅱ in testicular tissue were detected. TM4 cells were treated with 0, 2.5, 5.0 and 10.0 μmol/L CdCl(2) for 24 h to detect the toxic effect of cadmium. The cells were divided into blank group (no exposure), exposure group (10.0 μmol/L CdCl(2)), experimental group[10.0 μmol/L CdCl(2)+60.0 μmol/L 3-methyladenine (3-MA) ] and inhibitor group (60.0 μmol/L 3-MA). After 24 h of treatment, Western blot analysis was used to detect the expression levels of LC3-Ⅱ, ubiquitin binding protein p62, tight junction protein ZO-1 and adhesion junction protein N-cadherin. Results: The morphology and structure of testicular tissue in the high dose group were obvious changed, including uneven distribution of seminiferous tubules, irregular shape, thinning of seminiferous epithelium, loose structure, disordered arrangement of cells, abnormal deep staining of nuclei and vacuoles of Sertoli cells. The results of biological tracer method showed that the integrity of blood-testis barrier was damaged in the low and high dose group. Western blot results showed that compared with control group, the expression levels of LC3-Ⅱ in testicular tissue of rats in low and high dose groups were increased, the differences were statistically significant (P<0.05). Compared with the 0 μmol/L, after exposure to 5.0, 10.0 μmol/L CdCl(2), the expression levels of ZO-1 and N-cadherin in TM4 cells were significantly decreased, and the expression level of p62 and LC3-Ⅱ/LC3-Ⅰ were significantly increased, the differences were statistically significant (P<0.05). Compared with the exposure group, the relative expression level of p62 and LC3-Ⅱ/LC3-Ⅰ in TM4 cells of the experimental group were significantly decreased, while the relative expression levels of ZO-1 and N-cadherin were significantly increased, the differences were statistically significant (P<0.05) . Conclusion: The mechanism of the toxic effect of cadmium on the reproductive system of male SD rats may be related to the effect of the autophagy level of testicular tissue and the destruction of the blood-testis barrier integrity.

Relationship between cadmium exposure and pulmonary function level and chronic obstructive pulmonary disease / 中华劳动卫生职业病杂志

Objective: To analyze the levels and distribution characteristics of blood cadmium and urinary cadmium in American adults, to analyze the relationship between blood cadmium and urinary cadmium and pulmonary function dose response, and to explore the effect of this index on the risk of chronic obstructive pulmonary disease. Methods: In March 2022, 3785 patients from 2007 to 2012 in NHANES database were selected as the subjects. Collect demography data such as gender and age, and test data such as lung function, blood cadmium concentration and Urine cadimium concentration. The relationship between blood and urine cadmium levels and lung function and pulmonary function and chronic obstructive pulmonary diease (COPD) was analyzed by Mann-Whitney U test or Kruskal-Wallis H test, multivariate linear regression and restricted cubic spline method. Results: The geometric mean of blood cadmium and urine cadmium in American adults was 0.37 g/L and 0.28 g/L, FEV(1) and FEV(1)/FVC among different cadmium exposure groups was statistically significant, and there was a negative linear dose-response relationship between serum Cd and urine Cd concentrations and FEV(1)/FVC levels (P(overall)<0.001, P(non-linear)=0.152; P(overall)<0.001, P(non-linear)=0.926). Compared with the lowest quartile concentration (Q1), the highest quartile blood cadmium concentration (Q4) (OR=1.934, P(trend)=0.000) and urinary cadmium concentration (OR=1.683, P(trend)=0.000) may increased the risk of chronic obstructive pulmonary disease. Conclusion: There is a negative correlation between blood cadmium, urinary cadmium levels and lung function in American adults, and cadmium may increase the risk of chronic obstructive pulmonary disease.

Maternal liver damage induced by cadmium exposure in pregnant mice through hypoxia inducible factor-1α-mediated upregulation in DRP1 / 环境与职业医学

Background Mitochondrial dynamin-related protein 1 (DRP1) regulates mitochondrial division and plays an important role in maintaining hepatocyte function. However, the role of DRP1 in cadmium exposure-induced maternal liver damage in pregnant mice remains unclear. Objective To investigate the role and mechanism of DRP1 in maternal liver damage induced by cadmium exposure during pregnancy. Methods This study consisted of animal experiments and cell experiments. (1) Animal experiments. Mice at 14 days of gestation were randomly divided into three groups: a control group, a low-dose cadmium group (LCd group: 2.5 mg·kg−1), and a high-dose cadmium group (HCd group: 5 mg·kg−1). The pregnant mice were intraperitoneally injected with cadmium chloride (CdCl2) for 6 and 24 h in the next morning. The weights of pregnant mice, uterus, maternal liver, and fetal mice were recorded after sacrifice. Serum and liver of pregnant mice were collected, the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum were detected, and liver tissues were stained with HE to observe changes in liver function and liver tissue structure. The expressions of oxidative phosphorylation-related proteins, hypoxia inducible factor-1α (HIF-1α) and DRP1 proteins in liver of pregnant mice were detected by Western blotting. (2) Cell experiments. AML12 cells were treated with CdCl2 (10 μmol·L−1) for 0, 2, 6, 12, and 24 h. The expressions of oxidative phosphorylation-related proteins, DRP1, and hypoxia inducible factor-1α (HIF-1α) proteins were detected. AML12 cells were pretreated with DRP1 inhibitor Mdivi-1 for 1 h and then CdCl2 (10 μmol·L−1) for 12 h to detect the expression of oxidative phosphorylation-related proteins and DRP1 protein. AML12 cells were treated with Hif-1α siRNA for 48 h and CdCl2 (10 μmol·L−1) for 6 h to detect the expression of HIF-1α and DRP1 proteins. Results The results of animal experiments showed that cadmium exposure in pregnant mice had no effects on maternal liver weight and liver coefficient. However, the histomorphological changes and necrosis in hepatocytes were observed. Compared with the control group, the serum ALT and AST levels of pregnant mice in the LCd group were significantly increased after 6 h (P＜0.05), and the levels in the HCd group were significantly increased after 6 and 24 h (P＜0.05). Cadmium exposure during pregnancy significantly up-regulated HIF-1α and DRP1 expressions and down-regulated the expressions of oxidative phosphorylation-related proteins in maternal livers. In vitro cell experiments showed that the expressions of oxidative phosphorylation-related proteins was significantly decreased and HIF-1α and DRP1 protein expressions were significantly increased in the AML12 cells treated with CdCl2 for 6 h. Mdivi-1 pretreatment significantly antagonized the inhibitory effect of cadmium on the expressions of oxidative phosphorylation-related proteins in AML12 cells, while Hif-1α siRNA pretreatment significantly antagonized the up-regulative effect of cadmium on DRP1 expression in AML12 cells. Conclusion Cadmium exposure in pregnant mice may up-regulate DRP1 expression by activating HIF-1α signaling, then inhibit oxidative phosphorylation level of hepatic cells, and ultimately lead to maternal liver damage.

Microbial remediation of cadmium-contaminated soils and its mechanisms: a review / 生物工程学报

Excessive levels of cadmium (Cd) in soil exert serious negative impacts on soil ecosystems. Microorganisms are a common component of soil and show great potential for mitigating soil Cd. This review summarizes the application and remediation mechanisms of microorganisms, microbial-plants, and microbial-biochar in Cd-contaminated soil. Microorganisms such as Bacillus, Acinetobacter, Pseudomonas, and arbuscular mycorrhizal fungi (AMF) can change the biological validity of Cd through adsorption, mineralization, precipitation and dissolution. Different factors such as pH, temperature, biomass, concentration, and duration have significant effects on Cd bioavailability by microorganisms. Pseudomonas, Burkholderia, and Flavobacterium can promote the uptake of Cd2+ by hyperaccumulator through promotion and activation. Biochar, a soil amendment, possesses unique physicochemical properties and could act as a shelter for microorganisms in agriculture. The use of combined microbial-biochar can further stabilize Cd compared to using biochar alone.

Potentilla anserina polysaccharide alleviates cadmium-induced oxidative stress and apoptosis of H9c2 cells by regulating the MG53-mediated RISK pathway / 中国天然药物

Oxidative stress plays a crucial role in cadmium (Cd)-induced myocardial injury. Mitsugumin 53 (MG53) and its mediated reperfusion injury salvage kinase (RISK) pathway have been demonstrated to be closely related to myocardial oxidative damage. Potentilla anserina L. polysaccharide (PAP) is a polysaccharide with antioxidant capacity, which exerts protective effect on Cd-induced damage. However, it remains unknown whether PAP can prevent and treat Cd-induced cardiomyocyte damages. The present study was desgined to explore the effect of PAP on Cd-induced damage in H9c2 cells based on MG53 and the mediated RISK pathway. For in vitro evaluation, cell viability and apoptosis rate were analyzed by CCK-8 assay and flow cytometry, respectively. Furthermore, oxidative stress was assessed by 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) staining and using superoxide dismutase (SOD), catalase (CAT), and glutathione/oxidized glutathione (GSH/GSSG) kits. The mitochondrial function was measured by JC-10 staining and ATP detection assay. Western blot was performed to detect the expression of proteins related to MG53, the RISK pathway, and apoptosis. The results indicated that Cd increased the levels of reactive oxygen species (ROS) in H9c2 cells. Cd decreased the activities of SOD and CAT and the ratio of GSH/GSSG, resulting in decreases in cell viability and increases in apoptosis. Interestingly, PAP reversed Cd-induced oxidative stress and cell apoptosis. Meanwhile, Cd reduced the expression of MG53 in H9c2 cells and inhibited the RISK pathway, which was mediated by decreasing the ratio of p-AktSer473/Akt, p-GSK3βSer9/GSK3β and p-ERK1/2/ERK1/2. In addition, Cd impaired mitochondrial function, which involved a reduction in ATP content and mitochondrial membrane potential (MMP), and an increase in the ratio of Bax/Bcl-2, cytoplasmic cytochrome c/mitochondrial cytochrome c, and Cleaved-Caspase 3/Pro-Caspase 3. Importantly, PAP alleviated Cd-induced MG53 reduction, activated the RISK pathway, and reduced mitochondrial damage. Interestingly, knockdown of MG53 or inhibition of the RISK pathway attenuated the protective effect of PAP in Cd-induced H9c2 cells. In sum, PAP reduces Cd-induced damage in H9c2 cells, which is mediated by increasing MG53 expression and activating the RISK pathway.

Epidemiological research progress in the effects of metal exposure on kidney / 中南大学学报(医学版)

Chronic kidney disease (CKD) is suffered progressive loss of kidney function lasting more than 3 months and is classified according to the degree of kidney damage (level of proteinuria) and the decreased glomerular filtration rate (GFR). The most severe form of CKD is end-stage renal disease. The prevalence of CKD is high with fast growth rate and the disease burden has become increasingly serious. CKD has become an important public health problem threatening human health. The etiology of CKD is complex. In addition to genetic factors, environmental factors are an important cause of CKD. With the development of industrialization, environmental metal pollution has become increasingly severe, and its impact on human health has received widespread attention. A large number of studies have shown that metals such as lead, cadmium, and arsenic can accumulate in the kidney, which can cause damage to the structure and function of the kidney, and play an important role in the development of CKD. Therefore, summarizing the epidemiological research progress in the relationship between arsenic, cadmium, lead, and other metal exposures and kidney diseases can provide new ideas for the prevention and control of kidney diseases caused by metal exposure.

Physiological and biochemical mechanisms of brassinosteroid in improving anti-cadmium stress ability of Panax notoginseng / 中国中药杂志

In this study, the effect of brassinosteroid(BR) on the physiological and biochemical conditions of 2-year-old Panax notoginseng under the cadmium stress was investigated by the pot experiments. The results showed that cadmium treatment at 10 mg·kg~(-1) inhibited the root viability of P. notoginseng, significantly increased the content of H_2O_2 and MDA in the leaves and roots of P. noto-ginseng, caused oxidative damage of P. notoginseng, and reduced the activities of SOD and CAT. Cadmium stress reduced the chlorophyll content of P. notoginseng, increased leaf F_o, reduced F_m, F_v/F_m, and PIABS, and damaged the photosynthesis system of P. notoginseng. Cadmium treatment increased the soluble sugar content of P. notoginseng leaves and roots, inhibited the synthesis of soluble proteins, reduced the fresh weight and dry weight, and inhibited the growth of P. notoginseng. External spray application of 0.1 mg·L~(-1) BR reduced the H_2O_2 and MDA content in P. notoginseng leaves and roots under the cadmium stress, alleviated cadmium-induced oxidative damage to P. notoginseng, improved the antioxidant enzyme activity and root activity of P. notoginseng, increased the content of chlorophyll, reduced the F_o of P. notoginseng leaves, increased F_m, F_v/F_m, and PIABS, alleviated the cadmium-induced damage to the photosynthesis system, and improved the synthesis ability of soluble proteins. In summary, BR can enhance the anti-cadmium stress ability of P. notoginseng by regulating the antioxidant enzyme system and photosynthesis system of P. notoginseng under the cadmium stress. In the context of 0.1 mg·L~(-1) BR, P. notoginseng can better absorb and utilize light energy and synthesize more nutrients, which is more suitable for the growth and development of P. notoginseng.

Effect of VIT1/VIT2 overexpression on Fe and Cd accumulation in rice endosperm / 生物工程学报

Iron (Fe) deficiency and excess cadmium (Cd) in rice grain are important problems to be solved in agricultural production. Previous studies have shown that OsVIT1 and OsVIT2 are vacuolar iron transporters. In this study, wild-type ZH11 was selected as the background material and OsVIT1 and OsVIT2 were overexpressed in endosperm by using endosperm specific promoter Glb-1. Field experiments were conducted to study the effect of OsVIT1 and OsVIT2 overexpression on Fe and Cd accumulation in different parts of rice. The results showed that OsVIT1 overexpression in endosperm significantly reduced Fe content in grain by about 50%, while significantly increased zinc (Zn) and copper (Cu) contents in straw and Cu content in grain. OsVIT2 overexpression in endosperm significantly decreased Fe and Cd contents in grain by about 50%, and significantly increased Fe content in straw by 45%-120%. Overexpression of OsVIT1 and OsVIT2 in endosperm did not affect the agronomic traits of rice. In conclusion, OsVIT1 and OsVIT2 overexpression in endosperm reduced Fe accumulation in rice grain, which did not achieve the expected effect. OsVIT2 overexpression in endosperm also decreased Cd accumulation in grain and increased Fe accumulation in straw, which provided reference for iron biofortification and cadmium reduction in rice.

Impacts of cadmium on mouse neural stem cells based on dose-response metabomics / 环境与职业医学

Background Cadmium (Cd) is a ubiquitous and toxic heavy metal that can accumulate in human body. Previous studies have shown that Cd exposure can induce neurotoxicity, but the underlying mechanism remains unclear. Objective To investigate the metabolic impacts of multiple doses of Cd on mouse neural stem cells (NSCs), and to explore the potential mechanism and biomarkers of its neurotoxicity. Methods The NSCs were obtained from the subventricular zone (SVZ) of 1-day-old neonatal C57BL/6 mice. The passage 3 (P3) NSCs were exposed to CdCl2 at designed doses (0, 0.5, 1.0, and 1.5 μmol·L−1). The cells were treated with seven replicates, of which one plate was for cell counting. After 24 h of exposure, the intracellular and extracellular metabolites were extracted respectively and then detected by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS). The orthogonal partial least-squares discriminant analysis (OPLS-DA) was applied to visualize the alterations of metabolomic profiles and to identify the differential metabolites (DMs) based on their variable importance for the projection (VIP) value >1 and P<0.05. The metabolite set enrichment analysis (MSEA) and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis were performed to recognize the significantly altered metabolite sets and pathways. The dose-response relationships were established and the potential biomarkers of Cd exposure were identified by 10% up-regulated or 10% down-regulated effective concentration (EC) of target metabolites. Results A total of 1201 metabolites were identified in the intracellular metabolomic samples and 1207 for the extracellular metabolomic samples. The intracellular and extracellular metabolome of Cd-treated NSCs were distinct from that of the control group, and the difference grew more distant as the Cd dosage increased. At 0.5, 1.0, and 1.5 μmol·L−1 dosage of Cd, 87, 83, and 185 intracellular DMs and 161, 176, and 166 extracellular DMs were identified, respectively. Within the significantly changed metabolites among the four groups, 176 intracellular DMs and 167 extracellular DMs were identified. Both intracellular and extracellular DMs were enriched in multiple lipid metabolite sets. Intracellular DMs were mainly enriched in taurine and hypotaurine metabolism, glycerophospholipid metabolism, and glycerolipid metabolism pathways. Extracellular DMs changed by Cd were mainly enriched in glycerophospholipid metabolism, steroid hormone biosynthesis, and cysteine and methionine metabolism pathways. Among intracellular DMs, 125 metabolites were fitted with dose-response relationships, of which 108 metabolites showed linear changes with the increase of Cd dosage. And 134 metabolites were fitted with dose-response relationships among extracellular DMs, of which 86 metabolites showed linear changes. The intracellular DMs with low EC values were hypotaurine, ethanolamine, phosphatidylethanolamine, and galactose, while the extracellular DMs with low EC values were acetylcholine and 1,5-anhydrosorbitol. Conclusion Cd treatment can significantly alter the intracellular and extracellular metabolome of mouse NSCs in a dose-dependent manner. The neurotoxicity of Cd may be related to glycerophospholipid metabolism. Acetylcholine, ethanolamine, and phosphatidylethanolamine involved in glycerophospholipid metabolism pathway might be potential biomarkers of Cd-induced neurotoxicity.

Characteristics and source analysis of heavy metal pollution in environment in Guizhou Province / 环境与职业医学

Heavy metal pollution poses a serious threat to the environment and human health. Guizhou is a province with apparent regional features of heavy metal pollution such as lead, zinc, mercury, and arsenic in agriculture and mining soils. The coefficient of variation results showed that heavy metal pollution in the soils of agricultural planting areas and mine caves was closely related to human activities, and arsenic and zinc were greatly affected by human activities. In the water environment, mercury pollution presents in mine cave water samples, and cadmium, mercury, and lead pollution present in scenic park water samples. The results of single-factor pollution index showed that mercury in mine cave water samples and cadmium, mercury, and lead in scenic park water samples were graded as severe pollution. The results of Nemero pollution index showed the highest comprehensive pollution level of heavy metals was in scenic park water samples. In atmospheric dust fall, cadmium, mercury, lead are the most prominent pollution. Potential risks to ecological environment were identified for cadmium and mercury in all study areas and lead in other areas outside Wanshan. The results of integrated potential ecological risk index indicated a high-risk level of heavy metal pollution in atmospheric dust fall in the current study area. At present, the heavy metal pollutants in the environment of Guizhou are mainly originated from natural factors such as geological background content and soil-forming parent material, and human activities such as mining, metal smelting, agricultural activities, and sewage irrigation. The analysis showed serious heavy metal pollution in the environment of Guizhou, which caused harm to the local environment. It is crucial that environmental protection measures be taken during human activities.

Analysis and exposure evaluation of cadmium residues in different tissues of portunus and mantis shrimp / 上海预防医学

ObjectiveTo understand the concentration of heavy metal cadmium and cadmium in portunus and mantis shrimp， and to timely identify food safety problems and potential hazards. MethodsPortunus and mantis shrimp samples from different provinces were collected and categorized based on different regions and locations， and some samples were made from tissue parts. Graphite furnace atomic absorption spectrometry was used to detect cadmium items， the cadmium exposure of portunus and mantis shrimp was evaluated simultaneously ResultsThe detection rate of cadmium in 124 batches of portunus sold in Shanghai was 100% （124/124）， the detection rate of cadmium in 63 batches of mantis shrimp sold in the market was also 100% （63/63）. The cadmium content varied in different tissue parts， and the cadmium enrichment in hepatopancreas was the highest in the edible parts of portunus and mantis shrimp. The average detection value， 50th percentile value， 95th percentile value of cadmium in the hepatopancreas of portunus accounted for 52.64%， 49.28% and 98.65% of the PTMI， respectively. The average detection value， 50th percentile value and 95th percentile value of cadmium in the hepatopancreas of mantis shrimp accounted for 30.76%， 32.04% and 46.16% of the PTMI， respectively. ConclusionThe average residual levels of heavy metal cadmium in portunus and mantis shrimp are within the safe range.

Effect of cadmium chloride toxicity on olfactory mucosa / Efecto de la toxicidad del cloruro de cadmio en la mucosa olfativa

SUMMARY: Cadmium is a highly toxic metal and affects the respiratory mucosa. The aim of the study is to show the inflammation and degenerative effect of cadmium on the olfactory mucosa. In this study, eight-week-old Wistar rats with an average weight of 170-190 g were divided into two groups (control and experiment) with 20 animals in each group and used in the experiments. The rats in the experimental group were given 2 mg/kg/day powdered cadmium chloride dissolved in water intraperitoneally every day for two weeks. At the end of the experiment, the nasal cavity was completely removed with anesthesia. Concha nasalis superior was separated, fixed with zinc-Formalin solution and decalcified with 5 % EDTA (Ethylene-diaminetetraacetic acid). After routine histopathological procedure, APAF-1 antibody was used for expression of Hematoxylin-Eosin (HE) and immunohistochemistry. Histopathological examination revealed interruptions in the basement membrane structure due to cadmium and degenerative changes in stem cells, degeneration in sensory cells and pycnosis in nuclei, dilatation in blood vessels and increased inflammation in connective tissue. APAF-1 expression was found to increase in epithelial cells and olfactory glands (Bowman gland) cells. It has been thought that cadmium toxicity increases cell degeneration and inflammation in the olfactory mucosa and may significantly affect cell death and olfactory metabolism by inducing the pro-apoptotic process.

El cadmio es un metal altamente tóxico que afecta la mucosa respiratoria. El objetivo fue mostrar el efecto inflamatorio y degenerativo del cadmio sobre la mucosa olfativa. En este estudio, ratas Wistar de ocho semanas de edad con un peso promedio de 170-190 g se dividieron en dos grupos (control y experimental) con 20 animales en cada grupo. Las ratas del grupo experimental recibieron 2 mg/kg/día de cloruro de cadmio en polvo disuelto en agua por vía intraperitoneal todos los días durante dos semanas. En los animales se exirpó la cavidad nasal bajo anestesia. Se separó la concha nasal superior, se fijó con solución de zinc-Formalina y se descalcificó con EDTA (ácido etilendiaminotetraacético) al 5 %. Después del procedimiento histopatológico de rutina, Hematoxilina- Eosina (HE) e inmunohistoquímica, se utilizó el anticuerpo APAF-1. El examen histopatológico reveló interrupciones en la estructura de la membrana basal debido al cadmio y cambios degenerativos en las células madre, degeneración en las células sensoriales y picnosis en los núcleos, dilatación de los vasos sanguíneos y aumento de la inflamación en el tejido conjuntivo. Se encontró que la expresión de APAF-1 aumenta en las células epiteliales y en las células de las glándulas olfatorias (glándulas de Bowman). Se ha pensado que la toxicidad del cadmio aumenta la degeneración celular y la inflamación en la mucosa olfativa y puede afectar significativamente la muerte celular y el metabolismo olfativo al inducir el proceso proapoptótico.