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Ruiz D, Regnier SM, Kirkley AG, Hara M, Haro F, Aldirawi H, Dybala MP, Sargis RM. Developmental exposure to the endocrine disruptor tolylfluanid induces sex-specific later-life metabolic dysfunction. Reprod Toxicol 2019; 89:74-82. [PMID: 31260803 DOI: 10.1016/j.reprotox.2019.06.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 06/16/2019] [Accepted: 06/26/2019] [Indexed: 02/06/2023]
Abstract
Endocrine-disrupting chemicals (EDCs) are implicated in the developmental mis-programming of energy metabolism. This study examined the impact of combined gestational and lactational exposure to the fungicide tolylfluanid (TF) on metabolic physiology in adult offspring. C57BL/6 J dams received standard rodent chow or the same diet containing 67 mg/kg TF. Offspring growth and metabolism were assessed up to 22 weeks of age. TF-exposed offspring exhibited reduced weaning weight. Body weight among female offspring remained low throughout the study, while male offspring matched controls by 17 weeks of age. Female offspring exhibited reduced glucose tolerance, markedly enhanced systemic insulin sensitivity, reduced adiposity, and normal gluconeogenic capacity during adulthood. In contrast, male offspring exhibited impaired glucose tolerance with unchanged insulin sensitivity, no differences in adiposity, and increased gluconeogenic capacity. These data indicate that developmental exposure to TF induces sex-specific metabolic disruptions that recapitulate key aspects of other in utero growth restriction models.
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Affiliation(s)
- Daniel Ruiz
- Committee on Molecular Metabolism and Nutrition, Chicago, IL, United States; University of Chicago, Chicago, IL, United States
| | - Shane M Regnier
- Committee on Molecular Metabolism and Nutrition, Chicago, IL, United States; Pritzker School of Medicine, Chicago, IL, United States; University of Chicago, Chicago, IL, United States
| | - Andrew G Kirkley
- Committee on Molecular Pathogenesis and Molecular Medicine, Chicago, IL, United States; University of Chicago, Chicago, IL, United States
| | - Manami Hara
- Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Chicago, IL, United States; University of Chicago, Chicago, IL, United States
| | - Fidel Haro
- University of Chicago, Chicago, IL, United States
| | - Hani Aldirawi
- Department of Mathematics, Statistics, and Computer Science, University of Illinois at Chicago, Chicago, IL, United States
| | - Michael P Dybala
- Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Chicago, IL, United States
| | - Robert M Sargis
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, IL, United States.
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Davis AF, Thomas AA, Shorter KS, Brown SL, Baumgarner BL. Cellular fatty acid level regulates the effect of tolylfluanid on mitochondrial dysfunction and insulin sensitivity in C2C12 skeletal myotubes. Biochem Biophys Res Commun 2018; 505:392-8. [PMID: 30262144 DOI: 10.1016/j.bbrc.2018.09.131] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 09/20/2018] [Indexed: 01/08/2023]
Abstract
Previous research suggests that the endocrine disrupting chemical tolylfluanid (TF) may promote metabolic dysfunction and insulin resistance in humans. The potential impact of TF on skeletal muscle metabolism has yet to be fully investigated. The purpose of this study was to determine whether TF can promote insulin resistance and metabolic dysfunction in mammalian skeletal muscle cells. C2C12 murine skeletal myotubes were exposed to 1 ppm TF for 24 h. To examine the potential effect of cellular fatty acid levels on TF-dependent regulation of mitochondrial metabolism and insulin signaling, we treated skeletal myotubes with 0.25 mM or 1.0 mM oleic acid (OA) during TF exposure trials. Tolylfluanid (1-10 ppm) reduced lipid accumulation by approximately 20% in 0.25 and 1.0 mM OA treated cells. The addition of 0.25 mM OA completely inhibited the TF-dependent reduction in maximal mitochondrial oxygen consumption rate (OCR) while 1.0 mM OA exacerbated the TF-dependent reduction in mitochondrial OCR. Exposing skeletal myotubes to 1 ppm TF promoted an 80% reduction in mitochondrial membrane potential, which was completely inhibited by 0.25 mM OA and partially inhibited by1.0 mM OA. The addition of 0.25 mM OA promoted a TF-dependent increase in insulin-dependent P-Akt (Ser473). In contrast, the addition of 1.0 mM OA promoted a significant reduction in insulin-dependent P-Akt (Ser473). Further, the addition of 1 ppm TF significantly reduced insulin-dependent mTORC1 activity regardless of OA concentration. Finally, TF significantly reduced insulin-dependent protein synthesis in the 1 mM OA treated cells only. Our results demonstrate that the effect of 1 ppm TF on mitochondrial function and insulin-dependent protein synthesis in skeletal myotubes was largely dependent upon cellular fatty acid levels.
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Fukunaga E, Enma K, Saitoh S, Nishimura-Danjyobara Y, Oyama Y, Akaike N. Increase in intracellular Ca(2+) level by phenylsulfamide fungicides, tolylfluanid and dichlofluanid, in rat thymic lymphocytes. Environ Toxicol Pharmacol 2015; 40:149-155. [PMID: 26119233 DOI: 10.1016/j.etap.2015.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 05/28/2015] [Accepted: 06/02/2015] [Indexed: 06/04/2023]
Abstract
Tolylfluanid, a phenylsulfamide fungicide, is one of the many pesticides that are frequently detected in crops. Therefore, its health risk is a concern. Micromolar concentrations of tolylfluanid induce chromosomal aberrations and micronuclei in mammalian lymphocytes. The findings prompted us to study the cellular actions of tolylfluanid and another frequently detected pesticide, dichlofluanid, at submicromolar and micromolar concentrations. Of the cellular actions of chemicals, the action on cellular Ca(2+) homeostasis is important since Ca(2+) is involved in cell signaling and death. Consequently, in this study, the effects of phenylsulfamide fungicides were examined on rat thymocytes by using fluorescent probes in order to further characterize the cellular actions of phenylsulfamide fungicides. Both phenylsulfamide fungicides exhibited biphasic, early and late, increase in intracellular Ca(2+) levels. The early phase was dependent on intracellular Ca(2+) release and increased membrane Ca(2+) permeability. The late phase was owing to Ca(2+) influx via activation of store-operated Ca(2+) channels and the further increase of membrane ionic permeability. Voltage-dependent Ca(2+) channels were not involved. The increases in intracellular Ca(2+) levels by phenylsulfamide fungicides were observed at drug concentrations of 0.1 μM or more (up to 10 μM). Thus, it is plausible that micromolar concentrations of phenylsulfamide fungicides deregulate intracellular Ca(2+) homeostasis in rat thymocytes. Both phenylsulfamide fungicides at 10 μM promoted the transition from intact living cells to living cells with phosphatidylserine-exposed membranes. This was not the case for phenylsulfamide fungicides at 3 μM. The potency of tolylfluanid was similar to that of dichlofluanid. Although the information on residual concentrations of tolylfluanid and dichlofluanid is very limited, their residual concentrations do not reach micromolar levels. It is unlikely that humans will develop adverse effects on exposure to phenylsulfamide fungicides under present environmental conditions.
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Affiliation(s)
- Eri Fukunaga
- Graduate School of Integrated Arts and Sciences, The University of Tokushima, Tokushima 770-8502, Japan
| | - Kana Enma
- Graduate School of Integrated Arts and Sciences, The University of Tokushima, Tokushima 770-8502, Japan
| | - Shohei Saitoh
- Graduate School of Integrated Arts and Sciences, The University of Tokushima, Tokushima 770-8502, Japan
| | | | - Yasuo Oyama
- Graduate School of Integrated Arts and Sciences, The University of Tokushima, Tokushima 770-8502, Japan.
| | - Norio Akaike
- Kumamoto Health Science University, Kumamoto 861-5598, Japan
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