1
|
Gong Y, Liu J, Xue Y, Zhuang Z, Qian S, Zhou W, Li X, Qian J, Ding G, Sun Z. Non-monotonic dose-response effects of arsenic on glucose metabolism. Toxicol Appl Pharmacol 2019; 377:114605. [PMID: 31170414 DOI: 10.1016/j.taap.2019.114605] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 05/29/2019] [Accepted: 05/31/2019] [Indexed: 01/08/2023]
Abstract
BACKGROUND Inorganic arsenic (iAs) is a widespread environmental toxin. In addition to being a human carcinogen, its effect on diabetes has started to gain recognition recently. Insulin is the key hormone regulating systemic glucose metabolism. The in vivo effect of iAs on insulin sensitivity has not been directly addressed. OBJECTIVES Here we use mouse models to dissect the dose-dependent effects of iAs on glucose metabolism in vivo. METHODS We performed hyperinsulinemic-euglycemic clamp, the gold standard analysis of systemic insulin sensitivity. We also performed dynamic metabolic testings and RNA-seq analysis. RESULTS We found that a low-dose exposure (0.25 ppm iAs in drinking water) caused glucose intolerance in adult male C57BL/6 mice, likely by disrupting glucose-induced insulin secretion without affecting peripheral insulin sensitivity. However, a higher-dose exposure (2.5 ppm iAs) had diminished effects on glucose tolerance despite disrupted pancreatic insulin secretion. Insulin Clamp analysis showed that 2.5 ppm iAs actually enhanced systemic insulin sensitivity by simultaneously enhancing insulin-stimulated glucose uptake in skeletal muscles and improved insulin-mediated suppression of endogenous glucose production. RNA-seq analysis of skeletal muscles revealed that 2.5 ppm iAs regulated expression of many genes involved in the metabolism of fatty acids, pyruvate, and amino acids. CONCLUSION These findings suggest that iAs has opposite glycemic effects on distinct metabolic tissues at different dose thresholds. Such non-monotonic dose-response effects of iAs on glucose tolerance shed light on the complex interactions between iAs and the systemic glucose metabolism, which could potentially help reconcile some of the conflicting results in human epidemiological studies.
Collapse
Affiliation(s)
- Yingyun Gong
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China; Department of Medicine-Endocrinology, Baylor College of Medicine, Houston, TX, United States of America
| | - Jidong Liu
- Department of Medicine-Endocrinology, Baylor College of Medicine, Houston, TX, United States of America
| | - Yanfeng Xue
- Department of Medicine-Endocrinology, Baylor College of Medicine, Houston, TX, United States of America
| | - Zhong Zhuang
- Department of Medicine-Endocrinology, Baylor College of Medicine, Houston, TX, United States of America
| | - Sichong Qian
- Department of Medicine-Endocrinology, Baylor College of Medicine, Houston, TX, United States of America
| | - Wenjun Zhou
- Department of Medicine-Endocrinology, Baylor College of Medicine, Houston, TX, United States of America
| | - Xin Li
- Department of Medicine-Endocrinology, Baylor College of Medicine, Houston, TX, United States of America
| | - Justin Qian
- Department of Medicine-Endocrinology, Baylor College of Medicine, Houston, TX, United States of America
| | - Guolian Ding
- Department of Medicine-Endocrinology, Baylor College of Medicine, Houston, TX, United States of America; The International Peace Maternity and Child Health Hospital, Institute of Embryo-Fetal Original Adult Disease, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Zheng Sun
- Department of Medicine-Endocrinology, Baylor College of Medicine, Houston, TX, United States of America; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, United States of America.
| |
Collapse
|
2
|
Bizoń A, Antonowicz-Juchniewicz J, Milnerowicz M, Śliwińska-Mossoń M, Milnerowicz H. The effect of occupational exposure on pro/antioxidant balance in the blood of non-smoking and smoking smelters with diabetes. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2016; 44:99-106. [PMID: 27137107 DOI: 10.1016/j.etap.2016.04.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 04/21/2016] [Accepted: 04/26/2016] [Indexed: 06/05/2023]
Abstract
Arsenic, lead and cadmium, potent environmental toxicants have been reported to induce diabetes mellitus, but their potential biological mechanism(s) have not been much investigated. The present study was designed to correlate parameters of pro/antioxidant balance with occupational exposure on heavy metals and smoking in smelters with diabetes compared on control group. The results showed a significant increase in the concentration of arsenic, cadmium and lead in the blood and urine of smelters, while smoking caused a further increase in the concentration of these metals. Increasing γ-glutamyltransferase activity and lead concentration due to occupational exposure in copper foundry, tobacco smoke and co-existing diabetes were observed. Also these factors have synergistic effects on metallothionein and glutathione concentrations as well as glutathione dependent enzymes activities. Our data suggests that sub-chronic arsenic, lead and cadmium exposure induces diabetic condition which may be mediated due to increased oxidative stress in blood.
Collapse
Affiliation(s)
- A Bizoń
- Department of Biomedical and Environmental Analysis, Wroclaw Medical University, Borowska 211, 50-556 Wrocław, Poland.
| | - J Antonowicz-Juchniewicz
- Professor Emeritus from Department and Clinic of Internal and Occupational Diseases and Hypertension, Wroclaw Medical Uniwersity, Borowska 213, 50-556 Wrocław, Poland
| | - M Milnerowicz
- Faculty of Medicine, Wroclaw Medical University, Wrocław, Poland
| | - M Śliwińska-Mossoń
- Department of Biomedical and Environmental Analysis, Wroclaw Medical University, Borowska 211, 50-556 Wrocław, Poland
| | - H Milnerowicz
- Department of Biomedical and Environmental Analysis, Wroclaw Medical University, Borowska 211, 50-556 Wrocław, Poland.
| |
Collapse
|
3
|
Tsuji JS, Perez V, Garry MR, Alexander DD. Association of low-level arsenic exposure in drinking water with cardiovascular disease: a systematic review and risk assessment. Toxicology 2014; 323:78-94. [PMID: 24953689 DOI: 10.1016/j.tox.2014.06.008] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 06/04/2014] [Accepted: 06/18/2014] [Indexed: 02/02/2023]
Abstract
The U.S. Environmental Protection Agency (EPA) is developing an integrated assessment of non-cancer and cancer risk assessment of inorganic arsenic (iAs). Cardiovascular disease (CVD) in association with iAs exposure has been examined in a number of studies and provides a basis for evaluating a reference dose (RfD) for assessing potential non-cancer health risks of arsenic exposure. In this systematic review of low-level iAs exposure (i.e., <100-150μg/L arsenic water concentration) and CVD in human populations, 13 cohort and case-control studies from the United States, Taiwan, Bangladesh, and China were identified and critically examined for evidence for derivation of a RfD. Eight cross-sectional and ecological studies from the United States were also examined for additional information. Prospective cohort data from Bangladesh provided the strongest evidence for determining the point of departure in establishing a candidate RfD based on a combined endpoint of mortality from "ischemic heart disease and other heart diseases." This study as well as the overall literature supported a no-observed-adverse-effect level of 100μg/L for arsenic in water, which was equivalent to an iAs dose of 0.009mg/kg-day (based on population-specific water consumption rates and dietary iAs intake). The study population was likely sensitive to arsenic toxicity because of nutritional deficiencies affecting arsenic methylation and one-carbon metabolism, as well as increasing CVD risk. Evidence is less clear on the interaction of CVD risk factors in the United States (e.g., diabetes, obesity, and hypertension) with arsenic at low doses. Potential uncertainty factors up to 3 resulted in a RfD for CVD in the range of 0.003-0.009mg/kg-day. Although caution should be exercised in extrapolating these results to the U.S. general population, these doses allow a margin of exposure that is 10-30 times the current RfD derived by EPA (based on skin lesions in Southwest Taiwan). These findings suggest that the current EPA RfD is protective of CVD.
Collapse
|
4
|
Becker A, Axelrad D. Arsenic and type 2 diabetes: commentary on association of inorganic arsenic exposure with type 2 diabetes mellitus: a meta-analysis by Wanget al. J Epidemiol Community Health 2014; 68:393-5. [DOI: 10.1136/jech-2013-203463] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|