Fipronil Triggers Immunotoxicity Through Reactive Oxygen Species-Driven Mitochondrial Apoptosis in Thymocytes

Fipronil (FPN), a widely used pesticide, is associated with significant immunotoxic effects, particularly impacting thymocyte survival and immune homeostasis. This study explores the mechanistic pathways underlying FPN-induced apoptosis and oxidative stress. Short-term FPN exposure (1–10 mg/kg) nota...

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Main Authors: Jui-Fang Kuo, Yai-Ping Hsiao, Yao-De Wang, Hsin-Pei Weng, Chia-Chi Wang
Format: Article
Language:English
Published: MDPI AG 2025-03-01
Series:Toxics
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Online Access:https://www.mdpi.com/2305-6304/13/3/204
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author Jui-Fang Kuo
Yai-Ping Hsiao
Yao-De Wang
Hsin-Pei Weng
Chia-Chi Wang
author_facet Jui-Fang Kuo
Yai-Ping Hsiao
Yao-De Wang
Hsin-Pei Weng
Chia-Chi Wang
author_sort Jui-Fang Kuo
collection DOAJ
description Fipronil (FPN), a widely used pesticide, is associated with significant immunotoxic effects, particularly impacting thymocyte survival and immune homeostasis. This study explores the mechanistic pathways underlying FPN-induced apoptosis and oxidative stress. Short-term FPN exposure (1–10 mg/kg) notably suppressed the expression of both anti-apoptotic (<i>Bcl-2</i>, <i>Bcl-6</i>, <i>Mcl-1</i>) and pro-apoptotic (<i>Bnip3</i>, <i>Bim</i>) genes in thymic tissues in vivo. Additionally, in isolated primary thymocytes, FPN directly decreased the expression of <i>Bcl-2</i>, <i>Bcl-6</i>, <i>Mcl-1</i>, and <i>Bnip3</i> expression, coupled with a significant increase in pro-apoptotic <i>Bim</i> expression in a dose-dependent manner. FPN treatment directly led to elevated reactive oxygen species (ROS), lipid peroxidation, mitochondrial membrane depolarization, reduced cellular metabolic activity, and depleted intracellular calcium and glutathione (GSH) levels, indicating mitochondrial dysfunction and oxidative stress. Annexin V/PI staining confirmed that FPN induced late-stage apoptosis and necrosis in primary thymocytes. These findings elucidate the immunotoxic effects of FPN on thymocytes, highlighting its detrimental impact on immune system integrity, thymic development, and T cell maturation through oxidative damage and mitochondrial-mediated apoptosis.
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spelling doaj-art-8d4dc48f293d415595fa26196ffdd1d92025-08-20T01:49:00ZengMDPI AGToxics2305-63042025-03-0113320410.3390/toxics13030204Fipronil Triggers Immunotoxicity Through Reactive Oxygen Species-Driven Mitochondrial Apoptosis in ThymocytesJui-Fang Kuo0Yai-Ping Hsiao1Yao-De Wang2Hsin-Pei Weng3Chia-Chi Wang4School of Veterinary Medicine, National Taiwan University, Taipei 106, TaiwanDepartment of Biochemistry and Molecular Medicine, UC Davis Comprehensive Cancer Center, University of California Davis, Sacramento, CA 95817, USASchool of Veterinary Medicine, National Taiwan University, Taipei 106, TaiwanSchool of Veterinary Medicine, National Taiwan University, Taipei 106, TaiwanSchool of Veterinary Medicine, National Taiwan University, Taipei 106, TaiwanFipronil (FPN), a widely used pesticide, is associated with significant immunotoxic effects, particularly impacting thymocyte survival and immune homeostasis. This study explores the mechanistic pathways underlying FPN-induced apoptosis and oxidative stress. Short-term FPN exposure (1–10 mg/kg) notably suppressed the expression of both anti-apoptotic (<i>Bcl-2</i>, <i>Bcl-6</i>, <i>Mcl-1</i>) and pro-apoptotic (<i>Bnip3</i>, <i>Bim</i>) genes in thymic tissues in vivo. Additionally, in isolated primary thymocytes, FPN directly decreased the expression of <i>Bcl-2</i>, <i>Bcl-6</i>, <i>Mcl-1</i>, and <i>Bnip3</i> expression, coupled with a significant increase in pro-apoptotic <i>Bim</i> expression in a dose-dependent manner. FPN treatment directly led to elevated reactive oxygen species (ROS), lipid peroxidation, mitochondrial membrane depolarization, reduced cellular metabolic activity, and depleted intracellular calcium and glutathione (GSH) levels, indicating mitochondrial dysfunction and oxidative stress. Annexin V/PI staining confirmed that FPN induced late-stage apoptosis and necrosis in primary thymocytes. These findings elucidate the immunotoxic effects of FPN on thymocytes, highlighting its detrimental impact on immune system integrity, thymic development, and T cell maturation through oxidative damage and mitochondrial-mediated apoptosis.https://www.mdpi.com/2305-6304/13/3/204fipronilimmunotoxicityapoptosisBCL-2 familyreactive oxygen speciesmitochondrial membrane potential
spellingShingle Jui-Fang Kuo
Yai-Ping Hsiao
Yao-De Wang
Hsin-Pei Weng
Chia-Chi Wang
Fipronil Triggers Immunotoxicity Through Reactive Oxygen Species-Driven Mitochondrial Apoptosis in Thymocytes
Toxics
fipronil
immunotoxicity
apoptosis
BCL-2 family
reactive oxygen species
mitochondrial membrane potential
title Fipronil Triggers Immunotoxicity Through Reactive Oxygen Species-Driven Mitochondrial Apoptosis in Thymocytes
title_full Fipronil Triggers Immunotoxicity Through Reactive Oxygen Species-Driven Mitochondrial Apoptosis in Thymocytes
title_fullStr Fipronil Triggers Immunotoxicity Through Reactive Oxygen Species-Driven Mitochondrial Apoptosis in Thymocytes
title_full_unstemmed Fipronil Triggers Immunotoxicity Through Reactive Oxygen Species-Driven Mitochondrial Apoptosis in Thymocytes
title_short Fipronil Triggers Immunotoxicity Through Reactive Oxygen Species-Driven Mitochondrial Apoptosis in Thymocytes
title_sort fipronil triggers immunotoxicity through reactive oxygen species driven mitochondrial apoptosis in thymocytes
topic fipronil
immunotoxicity
apoptosis
BCL-2 family
reactive oxygen species
mitochondrial membrane potential
url https://www.mdpi.com/2305-6304/13/3/204
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AT yaodewang fiproniltriggersimmunotoxicitythroughreactiveoxygenspeciesdrivenmitochondrialapoptosisinthymocytes
AT hsinpeiweng fiproniltriggersimmunotoxicitythroughreactiveoxygenspeciesdrivenmitochondrialapoptosisinthymocytes
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