BACKGROUND: Lead is a persistent inorganic environmental pollutant with global implication for human health. Among the diseases associated with lead exposure, the damage to the central nervous system has received considerable attention. It has been reported that long-term lead exposure increases the risk of meningioma; however, the underlying mechanism remains poorly understood. Clinical studies have indicated that loss-of-function and mutations in the neurofibromin-2 (NF2) gene play a crucial role in promoting meningioma formation. METHODS: The effect of Pb on meningioma were tested in-vitro and in-vivo. Two human meningioma cell lines were used in this study, including NF2-wildtype IOMM-Lee cell and NF2-null CH157-MN cell. Cell viability, cell cycle and cell size were examined after Pb exposure. The expression of Merlin, mammalian sterile 20-like kinases 1 and 2 (MST1/2) and Yes-associated protein (YAP) from these two meningioma cells were analyzed by Western blot. A xenograft mouse model was constructed by subcutaneous injection of IOMM-Lee meningioma cells. RESULTS: This study demonstrated that treatment with lead induce dose-dependent proliferation in IOMM-Lee cell (with an EC₅₀ value of 19.6 µM). Moreover, IOMM-Lee cell exhibited augmented cell size in conjunction with elevated levels of phosphorylated histone H3, indicative of altered cell cycle progression resulting from lead exposure. However, no significant change was observed in the CH157-MN cell. Additionally, the Merlin-Hippo signaling pathway was inactivated with decreased Merlin and phosphorylation levels of MST1/2 and YAP, leading to increased YAP nuclear translocation in IOMM-Lee cells. However, there was no change in the Merlin-Hippo signaling pathway in CH157-MN cells after lead treatment. The administration of Pb resulted in an acceleration of the subcutaneous IOMM-Lee meningioma xenograft growth in mice. CONCLUSIONS Overall, the current study elucidates the potential mechanism by which lead exposure promotes the proliferation of meningioma with NF2 expression for the first time.
Meningioma/genetics* ; Neurofibromin 2/genetics* ; Humans ; Cell Proliferation/drug effects* ; Animals ; Signal Transduction/drug effects* ; Mice ; Hippo Signaling Pathway ; Lead/adverse effects* ; Cell Line, Tumor ; Protein Serine-Threonine Kinases/genetics* ; Meningeal Neoplasms ; Environmental Pollutants/adverse effects* ; Female

BACKGROUND: Heavy metals are significant risk factors for kidney function. Numerous studies have shown that exposure to heavy metals negatively correlates with kidney function through oxidative stress pathways, and serum α-klotho is linked to oxidative stress. However, the role of α-klotho in the relationship between blood lead, mercury, and kidney function remains unclear. METHOD: This study evaluated the mediating role of alpha-klotho in the relationship between lead, mercury and renal function, using data from the 2007-2016 National Health and Nutrition Examination Survey (NHANES) in U.S. adults aged 40-79. The sample included 11,032 participants, with blood lead, mercury, α-klotho, and other relevant covariates measured. Inductively coupled plasma mass spectrometry was used to assess blood lead and mercury levels, and enzyme-linked immunosorbent assay (ELISA) was employed to measure serum α-klotho. Kidney function was evaluated using estimated glomerular filtration rate (eGFR) based on creatinine levels. Multivariable linear regression was conducted to analyze the relationships between blood lead, mercury, α-klotho, and eGFR. A mediation analysis model was used to assess whether α-klotho influenced these associations. RESULTS: We observed a significant association between blood lead and eGFR. Mediation analysis revealed that α-klotho accounted for 12.76% of the relationship between serum lead and eGFR in the NHANES population. Subgroup analysis showed that α-klotho mediated 12.43%, 6.87%, 21.50% and 5.44% of the relationship between blood lead and eGFR in women, middle-aged adults (40-59 years old), without cardiovascular disease and hypertension, respectively. However, α-klotho did not mediate the relationship between blood mercury and eGFR in terms of gender or age. This newly identified pathway may provide valuable insights for the prevention and treatment mechanisms related to kidney function impairment. CONCLUSION We found that blood lead was associated with renal function. According to the results of subgroup analysis, for blood lead, serum α-klotho mediated the association in females, middle aged 60-79 years. The relationship between blood mercury and renal function was not clinically significant, and serum α-Klotho mediated the relationship between blood mercury and renal function without significant clinical significance.
Humans ; Middle Aged ; Lead/blood* ; Female ; Klotho Proteins ; Male ; Aged ; Adult ; Mercury/blood* ; Glomerular Filtration Rate ; Nutrition Surveys ; United States ; Kidney/physiology* ; Glucuronidase/blood* ; Environmental Pollutants/blood*

BACKGROUND: Dental caries is a chronic childhood disease and one of the most prevalent public health problems worldwide. Lead is a heavy metal that is taken up by the teeth and bones. However, the association between lead exposure during pregnancy, when the tooth germs are formed, and the prevalence of dental caries in the primary dentition remains unclear. This study aimed to examine the association between maternal blood lead levels and the prevalence of dental caries in the primary dentition of children. METHODS: This cross-sectional study was conducted as an Adjunct Study to the Japan Environment and Children's Study (JECS), which is an ongoing nationwide birth-cohort study. Among children participating in the JECS at the University of Occupational and Environmental Health Sub-Regional Center, those aged 7-8 years underwent oral examination and questionnaire administration. The dft (i.e., sum of the number of decayed and filled primary teeth) was then determined. The dft numerically expresses the dental caries prevalence in the primary dentition (larger value indicates more prevalent dental caries). Poisson regression analyses with robust standard errors were performed to evaluate the association between maternal blood lead levels during pregnancy, measured using frozen samples, and the dft. RESULTS: The study included 139 children, of whom 54.7% were girls, and 89.2% were 7 years old. The median maternal blood lead level was 6.1 ng/g (25-75 percentile, 5.0-7.3). The median dft was 0 (25-75 percentile, 0-4). After adjusting for covariates including age, sex, and oral health status and behavior, maternal blood lead levels were significantly associated with increased dft (prevalence ratio, 1.6; 95% confidence interval, 1.3-1.8; per one standard deviation increase in natural log-transformed maternal blood lead levels). CONCLUSIONS This study found an association between maternal blood lead levels and the prevalence of dental caries in the primary dentition of children aged 7-8 years. Maternal exposure to lead during mid- to late-term pregnancy may affect the caries susceptibility of children after birth.
Humans ; Lead/blood* ; Female ; Dental Caries/epidemiology* ; Prevalence ; Tooth, Deciduous ; Male ; Japan/epidemiology* ; Child ; Cross-Sectional Studies ; Pregnancy ; Adult ; Maternal Exposure/adverse effects* ; Environmental Pollutants/blood* ; Prenatal Exposure Delayed Effects/epidemiology*

OBJECTIVES: To determine the neuroprotective effects of berberine hydrochloride (BBR) against lead-induced injuries on the hippocampus of rats. METHODS: Wistar rats were exposed orally to doses of 100 and 500 ppm lead acetate for 1 and 2 months to develop subchronic and chronic lead poisening models, respectively. For treatment, BBR (50 mg/kg daily) was injected intraperitoneally to rats poisoned with lead. At the end of the experiment, the spatial learning and memory of rats were assessed using the Morris water maze test. Hippocampal tissue changes were examined by hematoxylin and eosin staining. The activity of antioxidant enzymes catalase, superoxide dismutase, glutathione peroxidase, and malondialdehyde levels as parameters of oxidative stress and antioxidant status of the hippocampus were evaluated. RESULTS: BBR reduced cognitive impairment in rats exposed to lead (P<0.05 or P<0.01). The resulting biochemical changes included a decrease in the activity of antioxidants and an increase in lipid peroxidation of the hippocampus of lead-exposed rats (P<0.05 or P<0.01), which were significantly modified by BBR (P<0.05). BBR also increased the density of healthy cells in the hippocampus of leadexposed rats (P<0.05). Significant changes in tissue morphology and biochemical factors of the hippocampus were observed in rats that received lead for 2 months (P<0.05). Most of these changes were insignificant in rats that received lead for 1 month. CONCLUSION BBR can improve oxidative tissue changes and hippocampal dysfunction in lead-exposed rats, which may be due to the strong antioxidant potential of BBR.
Animals ; Hippocampus/pathology* ; Rats, Wistar ; Antioxidants/pharmacology* ; Berberine/therapeutic use* ; Cognition/drug effects* ; Male ; Lead Poisoning/metabolism* ; Chronic Disease ; Oxidative Stress/drug effects* ; Maze Learning/drug effects* ; Rats ; Lipid Peroxidation/drug effects* ; Malondialdehyde/metabolism*

It has been confirmed that exposure to various metal pollutants can induce neurotoxicity, which is closely associated with the occurrence and development of neurological disorders. Ferroptosis is a form of cell death in response to metal pollutant exposure and it is closely related to oxidative stress, iron metabolism and lipid peroxidation. Recent studies have revealed that ferroptosis plays a significant role in the neurotoxicity induced by metals such as lead, cadmium, manganese, nickel, and antimony. Lead exposure triggers ferroptosis through oxidative stress, iron metabolism disorder and inflammation. Cadmium can induce ferroptosis through iron metabolism, oxidative stress and ferroptosis related signaling pathways. Manganese can promote ferroptosis through mitochondrial dysfunction, iron metabolism disorder and oxidative stress. Nickel can promote ferroptosis by influencing mitochondrial function, disrupting iron homeostasis and facilitating lipid peroxidation in the central nervous system. Antimony exposure can induce glutathione depletion by activating iron autophagy, resulting in excessive intracellular iron deposition and ultimately causing ferroptosis. This article reviews the effects of metal pollutants on ferroptosis-related indicators and discusses the specific mechanisms by which each metal triggers ferroptosis. It provides a reference for identifying targets for preventing neurotoxicity and for developing treatment strategies for neurological disorders.
Ferroptosis/drug effects* ; Humans ; Iron/metabolism* ; Oxidative Stress/drug effects* ; Neurotoxicity Syndromes/metabolism* ; Cadmium/adverse effects* ; Animals ; Lipid Peroxidation/drug effects* ; Metals/metabolism* ; Lead/adverse effects* ; Environmental Pollutants/toxicity* ; Manganese/adverse effects* ; Nickel/adverse effects* ; Mitochondria/drug effects* ; Signal Transduction/drug effects*

Child ; Humans ; Lead ; Urban Population ; Nutritional Status ; Health Surveys ; China/epidemiology* ; Rural Population

Objective: To investigate the spatial distribution characteristics and correlation between the prevalence of dental fluorosis and the chemical elemental composition of drinking water sources in coal-fired fluorosis areas. Methods: Based on the survey data on the prevalence of dental fluorosis at CDC in Guizhou Province in 2022, 274 original surface drinking water sources were collected in typical coal-fired fluorosis areas, and fluoride (F), calcium (Ca), magnesium (Mg), aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), molybdenum (Mo), cadmium (Cd), barium (Ba), lead (Pb) 17 elements; apply Moran's I index, Getis-Ord Gi* hotspot analysis of the global spatial autocorrelation of chemical elements in drinking water and the degree of aggregation of each element on the local area, and correlation analysis with the prevalence of dental fluorosis in the region. Results: Except for Cu, Zn, and Cd, global spatial autocorrelation Moran's I was negative, and all other elements were positive. F, Ca, Al, Ti, As, Mo, Cd, and Cu elements showed high values of aggregation in the southeastern low-altitude area; Mg, Ba, Pb, Cr, Mn, and Fe elements were mainly aggregated in the central altitude terrain transition area, Zn and Se elements in water sources are significantly positively correlated with the prevalence of dental fluorosis (P<0.05). In contrast, F, Mg, Al, Ti, As, Mo, Cd, Ba, and Pb elements negatively correlate (P<0.05). Elements in the central region were high-high aggregation, as a hot spot aggregation area with high disease incidence, while F, Al, Mn, Mo, Cd, and Ba elements in the western region were low-low aggregation, as a cold spot aggregation area with a low incidence of fluorosis. Conclusions: The risk of population fluoride exposure in surface drinking water sources is shallow. However, the chemical element content of drinking water sources in coal-fired polluted endemic fluorosis areas has prominent spatial geographical distribution characteristics. There is a significant spatial aggregation effect with the prevalence of dental fluorosis, which may play a synergistic or antagonistic effect on the occurrence and prevalence of dental fluorosis.
Humans ; Drinking Water ; Prevalence ; Coal ; Fluorides/adverse effects* ; Cadmium ; Fluorosis, Dental/epidemiology* ; Lead ; Selenium ; Arsenic

In 2020, the mass concentration of PM_2.5 in Shijiazhuang urban area was(80.30±71.43)μg/m³. The Spearman correlation analysis between metals and metalloids showed that Sb with Cd, Pb, Ni, Se, Cd with Pb, Ni, Se, Pb with Ni, Se, Ni with Se, and Se with Tl were positively correlated, with a coefficient greater than 0.5. The main sources of metals and metalloids of PM_2.5 were traffic emissions, fuel combustion, metal smelting and dust. The HQ values of Pb, Hg and Mn for each population were less than 1, with lower non-carcinogenic risk. The R values of carcinogenic risk of Ni and Cd in each population were less than 1×10^-6, which could be acceptable risk level for the population. The R values of carcinogenic risk of As and Cr in different populations were between 1×10^-6 and 1×10^-4, with potential carcinogenic risk, particularly higher in adult males.
Adult ; Cadmium ; Carcinogens/analysis* ; Dust/analysis* ; Environmental Monitoring ; Humans ; Lead ; Male ; Metalloids/analysis* ; Risk Assessment

Objective: To understand the distribution and characteristics of suspected occupational chronic lead poisoning reported online by Jiangsu Province, and to track the final diagnosis of suspected cases. Methods: The suspected occupational chronic lead poisoning cases in Jiangsu Province reported online from 2014 to 2018 were collected as the survey objects. Based on the reporting of the Occupational Disease Report Card from January 1, 2014 to November 5, 2019, the distribution characteristics and reporting institutions of suspected cases and final confirmed cases were analyzed. Results: From 2014 to 2018, 312 cases of suspected occupational chronic lead poisoning were reported online in Jiangsu Province. There were significant differences in the number of online reported cases of occupational chronic lead poisoning, online reported cases of suspected occupational chronic lead poisoning and confirmed cases of suspected occupational chronic lead poisoning in different years (P<0.05) , especially in 2015. Among the suspected occupational lead poisoning cases reported online, 236 cases (75.6%) were male, mainly distributed in the manufacturing industry, and 246 cases (79.1%) were operators. All the suspected occupational chronic lead poisoning cases reported online were concentrated in private enterprises, 229 cases (73.4%) in small and medium-sized enterprises. The top three cities were Suqian with 111 cases (35.6%) , Yangzhou with 79 cases (25.3%) and Huai'an with 50 cases (16.0%) . From 2014 to 2018, 19 suspected cases of occupational chronic lead poisoning were finally confirmed in Jiangsu Province, with a diagnosis rate of 6.1%. Conclusion: The majority of suspected occupational chronic lead poisoning cases reported online in Jiangsu Province are men, manufacturing and small and medium-sized enterprises, and the final diagnosis rate of suspected occupational chronic lead poisoning cases reported online is low.
China/epidemiology* ; Cities ; Female ; Humans ; Lead ; Lead Poisoning/epidemiology* ; Male ; Manufacturing Industry ; Occupational Diseases/epidemiology*

Objective: To explore the effect of lead exposure on the neurobehavior and gut microbiota community structure in mice. Methods: In August 2019, 64 C57BL/6 mice were randomly divided into 4 groups: control group (0 ppm) , low lead exposure group (20 mg/l) , medium lead exposure group (100 mg/l) and high lead exposure group (500 mg/l) . During the experiment, they were free to eat and drink. The drinking water of the lead exposure group was mixed with lead acetate, and sodium acetate was added in the control group. After 10 weeks of exposure, the Morris water maze was used to test the learning and memory ability of each group of mice, and then they were sacrificed for sampling. ICP-MS was used to detect lead content in whole blood and brain tissue. ELISA was used to determine the level of IL-1β in mouse serum. 16S rRNA sequencing was used to detect the structural diversity of the intestinal flora in feces, and then the correlation between the flora and behavior indicators was analyzed. Results: In the Morris water maze experiment, compared with the control group, there was no significant difference in the body weight and swimming speed of the mice in the lead exposure groups. The escape latency of the mice in the 100 mg/l and 500 mg/l dose groups was prolonged, and the number of platform crossings decreased (P<0.05) ; meanwhile, the staying time of the mice in the 500 mg/l Pb-treated group in the target quadrant was lower than that of the control group, and the difference was statistically significant (P<0.05) . Compared with the control group, the blood lead content of the mice in each lead exposure group was significantly increased, and the brain lead content of mice in the 500 mg/l dose group was significantly elevated (P<0.05) . The serum IL-1β levels of mice in each lead exposure group were higher than those of the control group (P<0.05) . At the phylum level, the relative abundance of the Proteobacteria phylum in all of Pb-treated groups was significantly increased (P<0.05) ; at the genus level, Allobaculum, Desulfovibrio, Lachnospiraceae_NK4A136_group, Turicibacter and Ureaplasma were significantly increased (P<0.05) . Among them. The relative abundance of Desuffaoibrio, Turici bacter, and Ureaplasma was negatively correlated with the residence time of mice in the quadrant of the platform (r=-0.32, -0.29, -0.44, P<0.05) . Conclusion: Lead exposure induced learning and memory impairments in mice, which may be related to the disturbance of the gut microbiota.
Animals ; Gastrointestinal Microbiome ; Lead/toxicity* ; Maze Learning ; Memory Disorders ; Mice ; Mice, Inbred C57BL ; RNA, Ribosomal, 16S/genetics*