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Satarug S, Vesey DA, Gobe GC, Phelps KR. The pathogenesis of albuminuria in cadmium nephropathy. Curr Res Toxicol 2023; 6:100140. [PMID: 38116328 PMCID: PMC10726218 DOI: 10.1016/j.crtox.2023.100140] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 11/16/2023] [Accepted: 11/30/2023] [Indexed: 12/21/2023] Open
Abstract
Background Urinary cadmium excretion (ECd) rises with renal tissue content of the metal. Whereas glomerulopathies are sometimes associated with massive albuminuria, tubular accumulation of Cd typically causes modest albuminuria. Since β2-microglobulinuria (Eβ2M) is an established marker of proximal tubular dysfunction, we hypothesized that a comparison of albuminuria (Ealb) to Eβ2M in Cd-exposed subjects would provide evidence of similar mishandling of both proteins. Methods To depict excretion rates per functional nephron, ECd, Ealb, and Eβ2M were normalized to creatinine clearance (Ccr), a surrogate for the glomerular filtration rate (GFR). Estimation of GFR itself (eGFR) was accomplished with CKD-EPI formulas (2009). Linear and logistic regression analyses were performed to relate Ealb/Ccr, Eβ2M/Ccr, and eGFR to several independent variables. Simple linear regressions of eGFR, Ealb/Ccr, and Eβ2M/Ccr on ECd/Ccr were examined before and after adjustment of dependent variables for age. All regressions were performed after log-transformation of ratios and standardization of all variables. Increments in Ealb/Ccr and Eβ2M/Ccr and decrements in eGFR were quantified through four quartiles of ECd/Ccr. Results As age or ECd/Ccr rose, Ealb/Ccr and Eβ2M/Ccr also rose, and eGFR fell. In linear regressions, slopes relating Ealb/Ccr and Eβ2M/Ccr to ECd/Ccr were similar. After adjustment of dependent variables for age, coefficients of determination (R2) for all regressions rose by a multiple, and slopes approached unity. Ealb/Ccr and Eβ2M/Ccr were similarly associated with each other. Mean Ealb/Ccr and Eβ2M/Ccr rose and mean eGFR fell in stepwise fashion through quartiles of ECd/Ccr. Whereas Eβ2M/Ccr did not vary with blood pressure, Ealb/Ccr rose in association with hypertension in two of the four quartiles. Conclusions Our data indicate that Cd in renal tissue affected tubular reabsorption of albumin and β2M similarly in a large cohort of exposed subjects. The results suggest that Cd reduced receptor-mediated endocytosis and subsequent lysosomal degradation of each protein by a shared mechanism.
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Affiliation(s)
- Soisungwan Satarug
- Centre for Kidney Disease Research, Translational Research Institute, Brisbane, Australia
| | - David A. Vesey
- Centre for Kidney Disease Research, Translational Research Institute, Brisbane, Australia
- Department of Kidney and Transplant Services, Princess Alexandra Hospital, Brisbane, Australia
| | - Glenda C. Gobe
- Centre for Kidney Disease Research, Translational Research Institute, Brisbane, Australia
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
- NHMRC Centre of Research Excellence for CKD QLD, UQ Health Sciences, Royal Brisbane and Women’s Hospital, Brisbane, Australia
| | - Kenneth R. Phelps
- Stratton Veterans Affairs Medical Center and Albany Medical College, Albany, NY, USA
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Satarug S, Vesey DA, Khamphaya T, Pouyfung P, Gobe GC, Yimthiang S. Estimation of the Cadmium Nephrotoxicity Threshold from Loss of Glomerular Filtration Rate and Albuminuria. TOXICS 2023; 11:755. [PMID: 37755765 PMCID: PMC10534899 DOI: 10.3390/toxics11090755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 09/28/2023]
Abstract
Cadmium (Cd) is a pervasive, toxic environmental pollutant that preferentially accumulates in the tubular epithelium of the kidney. Current evidence suggests that the cumulative burden of Cd here leads to the progressive loss of the glomerular filtration rate (GFR). In this study, we have quantified changes in estimated GFR (eGFR) and albumin excretion (Ealb) according to the levels of blood Cd ([Cd]b) and excretion of Cd (ECd) after adjustment for confounders. ECd and Ealb were normalized to creatinine clearance (Ccr) as ECd/Ccr and Ealb/Ccr. Among 482 residents of Cd-polluted and non-polluted regions of Thailand, 8.1% had low eGFR and 16.9% had albuminuria (Ealb/Ccr) × 100 ≥ 20 mg/L filtrate. In the low Cd burden group, (ECd/Ccr) × 100 < 1.44 µg/L filtrate, eGFR did not correlate with ECd/Ccr (β = 0.007) while an inverse association with ECd/Ccr was found in the medium (β = -0.230) and high burden groups (β = -0.349). Prevalence odds ratios (POR) for low eGFR were increased in the medium (POR 8.26) and high Cd burden groups (POR 3.64). Also, eGFR explained a significant proportion of Ealb/Ccr variation among those with middle (η2 0.093) and high [Cd]b tertiles (η2 0.132) but did not with low tertiles (η2 0.001). With an adjustment of eGFR, age and BMI, the POR values for albuminuria were increased in the middle (POR 2.36) and high [Cd]b tertiles (POR 2.74) and those with diabetes (POR 6.02) and hypertension (2.05). These data indicate that (ECd/Ccr) × 100 of 1.44 µg/L filtrate (0.01-0.02 µg/g creatinine) may serve as a Cd threshold level based on which protective exposure guidelines should be formulated.
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Affiliation(s)
- Soisungwan Satarug
- The Centre for Kidney Disease Research, Translational Research Institute, Brisbane 4102, Australia; (D.A.V.); (G.C.G.)
| | - David A. Vesey
- The Centre for Kidney Disease Research, Translational Research Institute, Brisbane 4102, Australia; (D.A.V.); (G.C.G.)
- Department of Kidney and Transplant Services, Princess Alexandra Hospital, Brisbane 4102, Australia
| | - Tanaporn Khamphaya
- Occupational Health and Safety, School of Public Health, Walailak University, Nakhon Si Thammarat 80160, Thailand; (T.K.); (P.P.); (S.Y.)
| | - Phisit Pouyfung
- Occupational Health and Safety, School of Public Health, Walailak University, Nakhon Si Thammarat 80160, Thailand; (T.K.); (P.P.); (S.Y.)
| | - Glenda C. Gobe
- The Centre for Kidney Disease Research, Translational Research Institute, Brisbane 4102, Australia; (D.A.V.); (G.C.G.)
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia
- NHMRC Centre of Research Excellence for CKD QLD, UQ Health Sciences, Royal Brisbane and Women’s Hospital, Brisbane 4029, Australia
| | - Supabhorn Yimthiang
- Occupational Health and Safety, School of Public Health, Walailak University, Nakhon Si Thammarat 80160, Thailand; (T.K.); (P.P.); (S.Y.)
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Yimthiang S, Pouyfung P, Khamphaya T, Vesey DA, Gobe GC, Satarug S. Evidence Linking Cadmium Exposure and β 2-Microglobulin to Increased Risk of Hypertension in Diabetes Type 2. TOXICS 2023; 11:516. [PMID: 37368616 DOI: 10.3390/toxics11060516] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 05/31/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023]
Abstract
The most common causes of chronic kidney disease, diabetes, and hypertension are significant public health issues worldwide. Exposure to the heavy metal pollutant, cadmium (Cd), which is particularly damaging to the kidney, has been associated with both risk factors. Increased levels of urinary β2-microglobulin (β2M) have been used to signify Cd-induced kidney damage and circulating levels have been linked to blood pressure control. In this study we investigated the pressor effects of Cd and β2M in 88 diabetics and 88 non-diabetic controls, matched by age, gender and locality. The overall mean serum β2M was 5.98 mg/L, while mean blood Cd and Cd excretion normalized to creatinine clearance (Ccr) as ECd/Ccr were 0.59 µg/L and 0.0084 µg/L of filtrate (0.95 µg/g creatinine), respectively. The prevalence odds ratio for hypertension rose by 79% per every ten-fold increase in blood Cd concentration. In all subjects, systolic blood pressure (SBP) showed positive associations with age (β = 0.247), serum β2M (β = 0.230), and ECd/Ccr (β = 0.167). In subgroup analysis, SBP showed a strong positive association with ECd/Ccr (β = 0.303) only in the diabetic group. The covariate-adjusted mean SBP in the diabetics of the highest ECd/Ccr tertile was 13.8 mmHg higher, compared to the lowest tertile (p = 0.027). An increase in SBP associated with Cd exposure was insignificant in non-diabetics. Thus, for the first time, we have demonstrated an independent effect of Cd and β2M on blood pressure, thereby implicating both Cd exposure and β2M in the development of hypertension, especially in diabetics.
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Affiliation(s)
- Supabhorn Yimthiang
- Occupational Health and Safety, School of Public Health, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - Phisit Pouyfung
- Occupational Health and Safety, School of Public Health, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - Tanaporn Khamphaya
- Occupational Health and Safety, School of Public Health, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - David A Vesey
- The Centre for Kidney Disease Research, Translational Research Institute, Brisbane 4102, Australia
- Department of Kidney and Transplant Services, Princess Alexandra Hospital, Brisbane 4102, Australia
| | - Glenda C Gobe
- The Centre for Kidney Disease Research, Translational Research Institute, Brisbane 4102, Australia
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia
- NHMRC Centre of Research Excellence for CKD QLD, UQ Health Sciences, Royal Brisbane and Women's Hospital, Brisbane 4029, Australia
| | - Soisungwan Satarug
- The Centre for Kidney Disease Research, Translational Research Institute, Brisbane 4102, Australia
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Liu J, Ning K, Fu Y, Sun Y, Liang J. Sulfur quantum dots as a fluorescent sensor for N-acetyl-beta-D-glucosaminidase detection. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 294:122553. [PMID: 36893676 DOI: 10.1016/j.saa.2023.122553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 02/21/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
N-acetyl-beta-D-glucosaminidase (NAG) is an important biomarker for early clinical diagnosis of renal disease, suggesting the necessity to develop a fast and sensitive method for its detection. In this paper, we developed a fluorescent sensor based on polyethylene glycol (400) (PEG-400)-modified and H2O2-assisted etched sulfur quantum dots (SQDs). According to the fluorescence inner filter effect (IFE), the fluorescence of SQDs can be quenched by the p-nitrophenol (PNP) generated by NAG-catalyzed hydrolysis of p-Nitrophenyl-N-acetyl-β-D-glucosaminide (PNP-NAG). We successfully used the SQDs as a nano-fluorescent probe to detect the NAG activity from 0.4 to 7.5 U·L-1, with a detection limit of 0.1 U·L-1. Furthermore, the method is highly selective and was successfully used in the detection of NAG activity in bovine serum samples, suggesting its great application prospect in clinical detection.
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Affiliation(s)
- Jiaxin Liu
- College of Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Keke Ning
- College of Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Yao Fu
- College of Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Yujie Sun
- College of Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Jiangong Liang
- College of Science, Huazhong Agricultural University, Wuhan 430070, China.
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Satarug S, Vesey DA, Gobe GC, Phelps KR. Estimation of health risks associated with dietary cadmium exposure. Arch Toxicol 2023; 97:329-358. [PMID: 36592197 DOI: 10.1007/s00204-022-03432-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 12/13/2022] [Indexed: 01/03/2023]
Abstract
In much of the world, currently employed upper limits of tolerable intake and acceptable excretion of cadmium (Cd) (ECd/Ecr) are 0.83 µg/kg body weight/day and 5.24 µg/g creatinine, respectively. These figures were derived from a risk assessment model that interpreted β2-microglobulin (β2MG) excretion > 300 μg/g creatinine as a "critical" endpoint. However, current evidence suggests that Cd accumulation reduces glomerular filtration rate at values of ECd/Ecr much lower than 5.24 µg/g creatinine. Low ECd/Ecr has also been associated with increased risks of kidney disease, type 2 diabetes, osteoporosis, cancer, and other disorders. These associations have cast considerable doubt on conventional guidelines. The goals of this paper are to evaluate whether these guidelines are low enough to minimize associated health risks reliably, and indeed whether permissible intake of a cumulative toxin like Cd is a valid concept. We highlight sources and levels of Cd in the human diet and review absorption, distribution, kidney accumulation, and excretion of the metal. We present evidence for the following propositions: excreted Cd emanates from injured tubular epithelial cells of the kidney; Cd excretion is a manifestation of current tissue injury; reduction of present and future exposure to environmental Cd cannot mitigate injury in progress; and Cd excretion is optimally expressed as a function of creatinine clearance rather than creatinine excretion. We comprehensively review the adverse health effects of Cd and urine and blood Cd levels at which adverse effects have been observed. The cumulative nature of Cd toxicity and the susceptibility of multiple organs to toxicity at low body burdens raise serious doubt that guidelines concerning permissible intake of Cd can be meaningful.
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Affiliation(s)
- Soisungwan Satarug
- Kidney Disease Research Collaborative, Level 5, Translational Research Institute, Brisbane, QLD, Australia.
| | - David A Vesey
- Kidney Disease Research Collaborative, Level 5, Translational Research Institute, Brisbane, QLD, Australia
- Department of Nephrology, Princess Alexandra Hospital, Brisbane, QLD, Australia
| | - Glenda C Gobe
- Kidney Disease Research Collaborative, Level 5, Translational Research Institute, Brisbane, QLD, Australia
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
- NHMRC Centre of Research Excellence for CKD QLD, UQ Health Sciences, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - Kenneth R Phelps
- Stratton Veterans Affairs Medical Center and Albany Medical College, Albany, NY, USA
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Satarug S, Đorđević AB, Yimthiang S, Vesey DA, Gobe GC. The NOAEL Equivalent of Environmental Cadmium Exposure Associated with GFR Reduction and Chronic Kidney Disease. TOXICS 2022; 10:614. [PMID: 36287894 PMCID: PMC9607051 DOI: 10.3390/toxics10100614] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/12/2022] [Accepted: 10/14/2022] [Indexed: 06/16/2023]
Abstract
Cadmium (Cd) is a highly toxic metal pollutant present in virtually all food types. Health guidance values were established to safeguard against excessive dietary Cd exposure. The derivation of such health guidance figures has been shifted from the no-observed-adverse-effect level (NOAEL) to the lower 95% confidence bound of the benchmark dose (BMD), termed BMDL. Here, we used the PROAST software to calculate the BMDL figures for Cd excretion (ECd) associated with a reduction in the estimated glomerular filtration rate (eGFR), and an increased prevalence of chronic kidney disease (CKD), defined as eGFR ≤ 60 mL/min/1.73 m2. Data were from 1189 Thai subjects (493 males and 696 females) mean age of 43.2 years. The overall percentages of smokers, hypertension and CKD were 33.6%, 29.4% and 6.2%, respectively. The overall mean ECd normalized to the excretion of creatinine (Ecr) as ECd/Ecr was 0.64 µg/g creatinine. ECd/Ecr, age and body mass index (BMI) were independently associated with increased prevalence odds ratios (POR) for CKD. BMI figures ≥24 kg/m2 were associated with an increase in POR for CKD by 2.81-fold (p = 0.028). ECd/Ecr values of 0.38-2.49 µg/g creatinine were associated with an increase in POR for CKD risk by 6.2-fold (p = 0.001). The NOAEL equivalent figures of ECd/Ecr based on eGFR reduction in males, females and all subjects were 0.839, 0.849 and 0.828 µg/g creatinine, respectively. The BMDL/BMDU values of ECd/Ecr associated with a 10% increase in CKD prevalence were 2.77/5.06 µg/g creatinine. These data indicate that Cd-induced eGFR reduction occurs at relatively low body burdens and that the population health risk associated with ECd/Ecr of 2.77-5.06 µg/g creatinine was not negligible.
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Affiliation(s)
- Soisungwan Satarug
- Kidney Disease Research Collaborative, Translational Research Institute, Brisbane 4102, Australia
| | - Aleksandra Buha Đorđević
- Department of Toxicology “Akademik Danilo Soldatović”, University of Belgrade-Faculty of Pharmacy, 11000 Belgrade, Serbia
| | - Supabhorn Yimthiang
- Occupational Health and Safety, School of Public Health, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - David A. Vesey
- Kidney Disease Research Collaborative, Translational Research Institute, Brisbane 4102, Australia
- Department of Nephrology, Princess Alexandra Hospital, Brisbane 4102, Australia
| | - Glenda C. Gobe
- Kidney Disease Research Collaborative, Translational Research Institute, Brisbane 4102, Australia
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia
- NHMRC Centre of Research Excellence for CKD QLD, UQ Health Sciences, Royal Brisbane and Women’s Hospital, Brisbane 4029, Australia
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Satarug S, Vesey DA, Gobe GC. Dose-Response Analysis of the Tubular and Glomerular Effects of Chronic Exposure to Environmental Cadmium. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph191710572. [PMID: 36078287 PMCID: PMC9517930 DOI: 10.3390/ijerph191710572] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 08/21/2022] [Accepted: 08/22/2022] [Indexed: 06/01/2023]
Abstract
We retrospectively analyzed data on the excretion of cadmium (ECd), β2-microglobulin (Eβ2M) and N-acetyl-β-D-glucosaminidase (ENAG), which were recorded for 734 participants in a study conducted in low- and high-exposure areas of Thailand. Increased Eβ2M and ENAG were used to assess tubular integrity, while a reduction in the estimated glomerular filtration rate (eGFR) was a criterion for glomerular dysfunction. ECd, Eβ2M and ENAG were normalized to creatinine clearance (Ccr) as ECd/Ccr, Eβ2M/Ccr and ENAG/Ccr to correct for interindividual variation in the number of surviving nephrons and to eliminate the variation in the excretion of creatinine (Ecr). For a comparison, these parameters were also normalized to Ecr as ECd/Ecr, Eβ2M/Ecr and ENAG/Ecr. According to the covariance analysis, a Cd-dose-dependent reduction in eGFR was statistically significant only when Ecd was normalized to Ccr as ECd/Ccr (F = 11.2, p < 0.001). There was a 23-fold increase in the risk of eGFR ≤ 60 mL/min/1.73 m2 in those with the highest ECd/Ccr range (p = 0.002). In addition, doubling of ECd/Ccr was associated with lower eGFR (β = -0.300, p < 0.001), and higher ENAG/Ccr (β = 0.455, p < 0.001) and Eβ2M/Ccr (β = 0.540, p < 0.001). In contrast, a covariance analysis showed a non-statistically significant relationship between ECd/Ecr and eGFR (F = 1.08, p = 0.165), while the risk of low eGFR was increased by 6.9-fold only among those with the highest ECd/Ecr range. Doubling of ECd/Ecr was associated with lower eGFR and higher ENAG/Ecr and Eβ2M/Ecr, with the β coefficients being smaller than in the Ccr-normalized dataset. Thus, normalization of Cd excretion to Ccr unravels the adverse effect of Cd on GFR and provides a more accurate evaluation of the severity of the tubulo-glomerular effect of Cd.
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Affiliation(s)
- Soisungwan Satarug
- Kidney Disease Research Collaborative, Translational Research Institute, Brisbane 4102, Australia
| | - David A. Vesey
- Department of Nephrology, Princess Alexandra Hospital, Brisbane 4075, Australia
| | - Glenda C. Gobe
- Kidney Disease Research Collaborative, Translational Research Institute, Brisbane 4102, Australia
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia
- NHMRC Centre of Research Excellence for CKD QLD, UQ Health Sciences, Royal Brisbane and Women’s Hospital, Brisbane 4029, Australia
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Effects of Environmental Exposure to Cadmium and Lead on the Risks of Diabetes and Kidney Dysfunction. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19042259. [PMID: 35206446 PMCID: PMC8871722 DOI: 10.3390/ijerph19042259] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/14/2022] [Accepted: 02/15/2022] [Indexed: 02/01/2023]
Abstract
Environmental exposure to cadmium (Cd) or lead (Pb) is independently associated with increased risks of type 2 diabetes, and chronic kidney disease. The aim of this study was to examine the effects of concurrent exposure to these toxic metals on the risks of diabetes and kidney functional impairment. The Cd and Pb exposure levels among study subjects were low to moderate, evident from the means for blood concentrations of Cd and Pb ([Cd]b and [Pb]b) of 0.59 µg/L and 4.67 µg/dL, respectively. Of 176 study subjects (mean age 60), 71 (40.3%) had abnormally high fasting plasma glucose levels. Based on their [Cd]b and [Pb]b, 53, 71, and 52 subjects were assigned to Cd and Pb exposure profiles 1, 2, and 3, respectively. The diagnosis of diabetes was increased by 4.2-fold in those with an exposure profile 3 (p = 0.002), and by 2.9-fold in those with the estimated glomerular filtration (eGFR) ≤ 60 mL/min/1.73 m2 (p = 0.029). The prevalence odds ratio (POR) for albuminuria was increased by 5-fold in those with plasma glucose levels above kidney threshold of 180 mg/dL (p = 0.014), and by 3.1-fold in those with low eGFR) (p = 0.050). Collectively, these findings suggest that the Cd and Pb exposure profiles equally impact kidney function and diabetes risk.
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Lin CT, Chen TH, Yang CC, Luo KH, Chen TH, Chuang HY. Epidermal Growth Factor Receptor (EGFR) Gene Polymorphism May be a Modifier for Cadmium Kidney Toxicity. Genes (Basel) 2021; 12:genes12101573. [PMID: 34680968 PMCID: PMC8535213 DOI: 10.3390/genes12101573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 09/25/2021] [Accepted: 10/01/2021] [Indexed: 11/16/2022] Open
Abstract
The results of many studies indicate that cadmium (Cd) exposure is harmful to humans, with the proximal tubule of the kidney being the main target of Cd accumulation and toxicity. Studies have also shown that Cd has the effect of activating the pathway of epidermal growth factor receptor (EGFR) signaling and cell growth. The EGFR is a family of transmembrane receptors, which are widely expressed in the human kidney. The aim of this study was to investigate the kidney function estimated glomerular filtration rate (eGFR), and its relationship with plasma Cd level and EGFR gene polymorphism. Using data from Academia Sinica Taiwan biobank, 489 subjects aged 30-70 years were analyzed. The demographic characteristics was determined from questionnaires, and biological sampling of urine and blood was determined from physical examination. Kidney function was assessed by the eGFR with CKD-EPI formula. Plasma Cd (ug/L) was measured by inductively coupled plasma mass spectrometry. A total of 97 single-nucleotide polymorphisms (SNPs) were identified in the EGFR on the Taiwan biobank chip, however 4 SNPs did not pass the quality control. Multiple regression analyses were performed to achieve the study aim. The mean (±SD) plasma Cd level of the study subjects was 0.02 (±0.008) ug/L. After adjusting for confounding variables, rs13244925 AA, rs6948867 AA, rs35891645 TT and rs6593214 AA types had higher eGFR (4.89 mL/min/1.73 m2 (p = 0.035), 5.54 mL/min/1.73 m2 (p = 0.03), 4.96 mL/min/1.73 m2 (p = 0.048) and 5.16 mL/min/1.73 m2 (p = 0.048), respectively). Plasma cadmium and rs845555 had an interactive effect on eGFR. In conclusion, EGFR polymorphisms could be modifiers of Cd kidney toxicity, in which rs13244925 AA, rs6948867 AA, rs35891645 TT and rs6593214 AA may be protective, and Cd interacting with rs845555 may affect kidney function.
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Affiliation(s)
- Chun-Ting Lin
- Department of Public, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (C.-T.L.); (T.-H.C.)
| | - Ting-Hao Chen
- Department of Public, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (C.-T.L.); (T.-H.C.)
| | - Chen-Cheng Yang
- Departments of Occupational Medicine and Family Medicine, Kaohsiung Municipal Siaogang Hospital, and Kaohsiung Medical University, Kaohsiung 807, Taiwan;
| | - Kuei-Hau Luo
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan;
| | - Tzu-Hua Chen
- Department of Family Medicine, Kaohsiung Municipal Ta-Tung Hospital, and Kaohsiung Medical University, Kaohsiung 807, Taiwan;
| | - Hung-Yi Chuang
- Department of Occupational and Environmental Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan
- Department of Public Health and Environmental Medicine, College of Medicine, and Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Correspondence: ; Tel.: +886-7312-1101 (ext. 6849)
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Abstract
Cadmium (Cd) is an environmental toxicant with serious public health consequences due to its persistence within arable soils, and the ease with which it enters food chains and then, accumulates in human tissues to induce a broad range of adverse health effects. The present review focuses on the role of zinc (Zn), a nutritionally essential metal, to protect against the cytotoxicity and carcinogenicity of Cd in urinary bladder epithelial cells. The stress responses and defense mechanisms involving the low-molecular-weight metal binding protein, metallothionein (MT), are highlighted. The efflux and influx transporters of the ZnT and Zrt-/Irt-like protein (ZIP) gene families are discussed with respect to their putative role in retaining cellular Zn homeostasis. Among fourteen ZIP family members, ZIP8 and ZIP14 mediate Cd uptake by cells, while ZnT1 is among ten ZnT family members solely responsible for efflux of Zn (Cd), representing cellular defense against toxicity from excessively high Zn (Cd) intake. In theory, upregulation of the efflux transporter ZnT1 concomitant with the downregulation of influx transporters such as ZIP8 and ZIP14 can prevent Cd accumulation by cells, thereby increasing tolerance to Cd toxicity. To link the perturbation of Zn homeostasis, reflected by the aberrant expression of ZnT1, ZIP1, ZIP6, and ZIP10, with malignancy, tolerance to Cd toxicity acquired during Cd-induced transformation of a cell model of human urothelium, UROtsa, is discussed as a particular example.
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