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Suresh S, Vellapandian C. Restoring Impaired Neurogenesis and Alleviating Oxidative Stress by Cyanidin against Bisphenol A-induced Neurotoxicity: In Vivo and In Vitro Evidence. Curr Drug Discov Technol 2024; 21:e250124226256. [PMID: 38279724 DOI: 10.2174/0115701638280481231228064532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 11/20/2023] [Accepted: 11/29/2023] [Indexed: 01/28/2024]
Abstract
BACKGROUND Bisphenol A (BPA) is a known neurotoxic compound with potentially harmful effects on the nervous system. Cyanidin (CYN) has shown promise as a neuroprotective agent. OBJECTIVE The current study aims to determine the efficacy of CYN against BPA-induced neuropathology. METHODS In vitro experiments utilized PC12 cells were pre-treated with gradient doses of CYN and further stimulated with 10ng/ml of BPA. DPPH radical scavenging activity, catalase activity, total ROS activity, and nitric oxide radical scavenging activity were done. In vivo assessments employed doublecortin immunohistochemistry of the brain in BPA-exposed Sprague-Dawley rats. Further, In silico molecular docking of CYN with all proteins involved in canonical Wnt signaling was performed using the Autodock v4.2 tool and BIOVIA Discovery Studio Visualizer. RESULTS IC50 values of CYN and ascorbic acid were determined using dose-response curves, and it was found to be 24.68 ± 0.563 μg/ml and 20.69 ± 1.591μg/ml, respectively. BPA-stimulated cells pre-treated with CYN showed comparable catalase activity with cells pre-treated with ascorbic acid (p = 0.0287). The reactive species production by CYN-treated cells was significantly decreased compared to BPA-stimulated cells (p <0.0001). Moreover, CYN significantly inhibited nitric oxide production compared to BPA stimulated and the control cells (p < 0.0001). In vivo CYN positively affected immature neuron quantity, correlating with dosage. During molecular docking analysis, CYN exhibited a binding affinity > -7 Kcal/mol with all the key proteins associated with the Wnt/β- catenin signaling cascade. CONCLUSION Conclusively, our finding suggests that CYN exhibited promise in counteracting BPAinduced oxidative stress, improving compromised neurogenesis in hippocampal and cortical regions, and displaying notable interactions with Wnt signaling proteins. Thereby, CYN could render its neuroprotective potential against BPA-induced neuropathology.
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Affiliation(s)
- Swathi Suresh
- Department of Pharmacology, SRM College of Pharmacy, SRM Institute of Science and Technology, Kattankulathur, Chengalpattu, 603 203, Tamil Nadu, India
| | - Chitra Vellapandian
- Department of Pharmacology, SRM College of Pharmacy, SRM Institute of Science and Technology, Kattankulathur, Chengalpattu, 603 203, Tamil Nadu, India
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Kim J, Kim NH, Youn I, Seo EK, Kim CY. Effects of Allium macrostemon Bunge Extract on Adipose Tissue Inflammation and Hepatic Endoplasmic Reticulum Stress in High-Fat Diet-Fed and Bisphenol A-Treated C57BL/6N Mice. Foods 2023; 12:3777. [PMID: 37893670 PMCID: PMC10606828 DOI: 10.3390/foods12203777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 10/10/2023] [Accepted: 10/12/2023] [Indexed: 10/29/2023] Open
Abstract
The simultaneous exposure to a high-fat (HF) diet and to bisphenol A (BPA) from delivered foods and food-delivery containers is on the rise in humans, according to the increased frequency of food delivery during the COVID-19 pandemic. This co-exposure could cause harmful tissue toxicity in the human body. Here, the preventive effect of Allium macrostemon Bunge (AM) extract against dysfunction in adipose tissue and the liver under co-exposure to BPA and an HF diet was examined using mice. C57BL/6N mice were divided into four groups (n = 6 or 7/group) according to diet and treatment: control diet with vehicle (CON), HF diet with vehicle (HF), HF diet with an oral injection of BPA (HF + BP), and HF diet with an oral injection of BPA and AM extract (HF + BP + AM). HF feeding increased body weight gain compared to CON feeding, while BP + HF and BP + HF + AM feeding suppressed body weight gain compared with HF feeding. The BP + HF group had lower body weight than the HF group, but the two groups had similar epididymal fat mass. The HF + BP + AM group showed lower pro-inflammatory gene expression levels in adipose tissue and epididymal fat mass compared to the HF + BP group. Altered endoplasmic reticulum (ER) stress response in the liver was partly observed in the HF + BP group, as shown by increased total phosphorylated Jun N-terminal kinase protein levels compared to those in the HF group. In addition, ecdysterone 25-O-β-D-glucopyranoside and 6-gingerol were identified in AM extract by mass spectrometry and molecular networking analysis. In summary, the AM extract diminished adipose tissue inflammation and hepatic ER stress in an HF diet and BPA co-exposure condition. To utilize AM as a potential food component to alleviate the harmful effect of an HF diet and BPA exposure, further research investigating the specific impact of AM extract supplementation using additional experimental groups or various treatment doses is warranted.
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Affiliation(s)
- Juhae Kim
- Research Institute of Human Ecology, Yeungnam University, Gyeongsan 38541, Republic of Korea; (J.K.); (N.-H.K.)
| | - Na-Hyung Kim
- Research Institute of Human Ecology, Yeungnam University, Gyeongsan 38541, Republic of Korea; (J.K.); (N.-H.K.)
| | - Isoo Youn
- Graduate School of Pharmaceutical Sciences, College of Pharmacy, Ewha Womans University, Seoul 03760, Republic of Korea; (I.Y.); (E.K.S.)
| | - Eun Kyoung Seo
- Graduate School of Pharmaceutical Sciences, College of Pharmacy, Ewha Womans University, Seoul 03760, Republic of Korea; (I.Y.); (E.K.S.)
| | - Choon Young Kim
- Research Institute of Human Ecology, Yeungnam University, Gyeongsan 38541, Republic of Korea; (J.K.); (N.-H.K.)
- Department of Food and Nutrition, Yeungnam University, Gyeongsan 38541, Republic of Korea
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Martínez-Pinna J, Sempere-Navarro R, Medina-Gali RM, Fuentes E, Quesada I, Sargis RM, Trasande L, Nadal A. Endocrine disruptors in plastics alter β-cell physiology and increase the risk of diabetes mellitus. Am J Physiol Endocrinol Metab 2023; 324:E488-E505. [PMID: 37134142 PMCID: PMC10228669 DOI: 10.1152/ajpendo.00068.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/27/2023] [Accepted: 04/28/2023] [Indexed: 05/05/2023]
Abstract
Plastic pollution breaks a planetary boundary threatening wildlife and humans through its physical and chemical effects. Of the latter, the release of endocrine disrupting chemicals (EDCs) has consequences on the prevalence of human diseases related to the endocrine system. Bisphenols (BPs) and phthalates are two groups of EDCs commonly found in plastics that migrate into the environment and make low-dose human exposure ubiquitous. Here we review epidemiological, animal, and cellular studies linking exposure to BPs and phthalates to altered glucose regulation, with emphasis on the role of pancreatic β-cells. Epidemiological studies indicate that exposure to BPs and phthalates is associated with diabetes mellitus. Studies in animal models indicate that treatment with doses within the range of human exposure decreases insulin sensitivity and glucose tolerance, induces dyslipidemia, and modifies functional β-cell mass and serum levels of insulin, leptin, and adiponectin. These studies reveal that disruption of β-cell physiology by EDCs plays a key role in impairing glucose homeostasis by altering the mechanisms used by β-cells to adapt to metabolic stress such as chronic nutrient excess. Studies at the cellular level demonstrate that BPs and phthalates modify the same biochemical pathways involved in adaptation to chronic excess fuel. These include changes in insulin biosynthesis and secretion, electrical activity, expression of key genes, and mitochondrial function. The data summarized here indicate that BPs and phthalates are important risk factors for diabetes mellitus and support a global effort to decrease plastic pollution and human exposure to EDCs.
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Affiliation(s)
- Juan Martínez-Pinna
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández de Elche, Elche, Spain
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Roberto Sempere-Navarro
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández de Elche, Elche, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Regla M Medina-Gali
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández de Elche, Elche, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Esther Fuentes
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández de Elche, Elche, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Ivan Quesada
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández de Elche, Elche, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Robert M Sargis
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Leonardo Trasande
- Department of Pediatrics, New York University Grossman School of Medicine, New York, New York, United States
- Department of Population Health, New York University Grossman School of Medicine, New York, New York, United States
- Wagner School of Public Service, New York University, New York, New York, United States
| | - Angel Nadal
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández de Elche, Elche, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
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Breynia cernua: Chemical Profiling of Volatile Compounds in the Stem Extract and Its Antioxidant, Antibacterial, Antiplasmodial and Anticancer Activity In Vitro and In Silico. Metabolites 2023; 13:metabo13020281. [PMID: 36837900 PMCID: PMC9966293 DOI: 10.3390/metabo13020281] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 02/11/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023] Open
Abstract
Breynia cernua has been used as an alternative medicine for wounds, smallpox, cervical cancer, and breast cancer. This plant is a potential source of new plant-derived drugs to cure numerous diseases for its multiple therapeutic functions. An in vitro study revealed that the methanol extract of B. cernua (stem) exhibits antioxidant activity according to DPPH and SOD methods, with IC50 values of 33 and 8.13 ppm, respectively. The extract also exerts antibacterial activity against Staphylococcus aureus with minimum bactericidal concentration of 1875 ppm. Further analysis revealed that the extract with a concentration of 1-2 ppm protects erythrocytes from the ring formation stage of Plasmodium falciparum, while the extract with a concentration of 1600 ppm induced apoptosis in the MCF-7 breast cancer cell line. GC-MS analysis showed 45 bioactive compounds consisting of cyclic, alkyl halide, organosulfur, and organoarsenic compounds. Virtual screening via a blind docking approach was conducted to analyze the binding affinity of each metabolite against various target proteins. The results unveiled that two compounds, namely, N-[β-hydroxy-β-[4-[1-adamantyl-6,8-dichloro]quinolyl]ethyl]piperidine and 1,3-phenylene, bis(3-phenylpropenoate), demonstrated the best binding score toward four tested proteins with a binding affinity varying from -8.3 to -10.8 kcal/mol. Site-specific docking analysis showed that the two compounds showed similar binding energy with native ligands. This finding indicated that the two phenolic compounds could be novel antioxidant, antibacterial, antiplasmodial, and anticancer drugs. A thorough analysis by monitoring drug likeness and pharmacokinetics revealed that almost all the identified compounds can be considered as drugs, and they have good solubility, oral bioavailability, and synthetic accessibility. Altogether, the in vitro and in silico analysis suggested that the extract of B. cernua (stem) contains various compounds that might be correlated with its bioactivities.
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Maadurshni GB, Nagarajan M, Priyadharshini S, Singaravelu U, Manivannan J. System-wide health risk prediction for 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene(MBP), a major active metabolite of environmental pollutant and food contaminant - Bisphenol A. Toxicology 2023; 485:153414. [PMID: 36587891 DOI: 10.1016/j.tox.2022.153414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 12/19/2022] [Accepted: 12/28/2022] [Indexed: 12/30/2022]
Abstract
Human exposure to plastic contaminated foods and environmental micro/nano plastic derived chemicals necessitates system-wide health risk assessment. Hence, current study intend to explore the mode of action (MoA) based adverse outcome pathways of 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP), the major active metabolite of bisphenol A (BPA). The computational study employed broad range of target prediction, systems biology tools and molecular docking protocols. Further, validation of MBP targets was done using protein-ligand fluorescence quenching assay, endothelial cell culture and chicken embryo vascular angiogenesis models. Interestingly, the current results illustrate that various physiological signaling pathways (MAPK and VEGF related angiogenesis signaling) and disease progression pathways (hypertension, cancer and endocrine disorders) were enriched as potential targets of MBP. Further, docking studies highlights the possible binding mechanism of MBP with important targets including endothelial nitric oxide synthase (eNOS) and serum albumin (BSA). In addition, the validation studies on MBP-BSA interaction (fluorescence quenching), eNOS derived nitric oxide (NOx) generation in endothelial cells and chicken embryo angiogenesis support the system-wide impacts of MBP with highlights on cardiovascular pathogenesis. Thus, the current observation provides novel insights into the system wide impacts of MBP for the futuristic health risk assessment of plastic derived chemicals.
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Affiliation(s)
| | - Manigandan Nagarajan
- Environmental Health and Toxicology Laboratory, Department of Environmental Sciences, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, India
| | - Saravanan Priyadharshini
- Integrated Biocomputing Lab, Department of Bioinformatics, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, India
| | - Usha Singaravelu
- Integrated Biocomputing Lab, Department of Bioinformatics, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, India
| | - Jeganathan Manivannan
- Environmental Health and Toxicology Laboratory, Department of Environmental Sciences, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, India.
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Exposure to Endocrine Disruptors (Di(2-Ethylhexyl)phthalate (DEHP) and Bisphenol A (BPA)) in Women from Different Residing Areas in Italy: Data from the LIFE PERSUADED Project. Int J Mol Sci 2022; 23:ijms232416012. [PMID: 36555656 PMCID: PMC9783390 DOI: 10.3390/ijms232416012] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/30/2022] [Accepted: 12/10/2022] [Indexed: 12/23/2022] Open
Abstract
Phthalates and bisphenol A (BPA) are plasticizers used in many industrial products that can act as endocrine disruptors and lead to metabolic diseases. During the LIFE PERSUADED project, we measured the urinary concentrations of BPA and Di(2-ethylhexyl)phthalate (DEHP) metabolites in 900 Italian women representative of the Italian female adult population (living in the north, centre, and south of Italy in both rural and urban areas). The whole cohort was exposed to DEHP and BPA with measurable levels above limit of detection in more than 99% and 95% of the samples, respectively. The exposure patterns differed for the two chemicals in the three macro-areas with the highest urinary levels for DEHP in south compared to central and northern Italy and for BPA in northern compared to central and southern Italy. BPA levels were higher in women living in urban areas, whereas no difference between areas was observed for DEHP. The estimated daily intake of BPA was 0.11 μg/kg per day, about 36-fold below the current temporary tolerable daily intake of 4 μg/kg per day established by the EFSA in 2015. The analysis of cumulative exposure showed a positive correlation between DEHP and BPA. Further, the reduction of exposure to DEHP and BPA, through specific legislative measures, is necessary to limit the harmfulness of these substances.
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Volatilomics as an Emerging Strategy to Determine Potential Biomarkers of Female Infertility: A Pilot Study. Biomedicines 2022; 10:biomedicines10112852. [DOI: 10.3390/biomedicines10112852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/02/2022] [Accepted: 11/04/2022] [Indexed: 11/09/2022] Open
Abstract
Due to its high prevalence, infertility has become a prominent public health issue, posing a significant challenge to modern reproductive medicine. Some clinical conditions that lead to female infertility include polycystic ovary syndrome (PCOS), endometriosis, and premature ovarian failure (POF). Follicular fluid (FF) is the biological matrix that has the most contact with the oocyte and can, therefore, be used as a predictor of its quality. Volatilomics has emerged as a non-invasive, straightforward, affordable, and simple method for characterizing various diseases and determining the effectiveness of their current therapies. In order to find potential biomarkers of infertility, this study set out to determine the volatomic pattern of the follicular fluid from patients with PCOS, endometriosis, and POF. The chromatographic data integration was performed through solid-phase microextraction (SPME), followed by gas chromatography–mass spectrometry (GC-MS). The findings pointed to specific metabolite patterns as potential biomarkers for the studied diseases. These open the door for further research into the relevant metabolomic pathways to enhance infertility knowledge and diagnostic tools. An extended investigation may, however, produce a new mechanistic understanding of the pathophysiology of the diseases.
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Norketamine, the Main Metabolite of Ketamine, Induces Mitochondria-Dependent and ER Stress-Triggered Apoptotic Death in Urothelial Cells via a Ca2+-Regulated ERK1/2-Activating Pathway. Int J Mol Sci 2022; 23:ijms23094666. [PMID: 35563057 PMCID: PMC9102902 DOI: 10.3390/ijms23094666] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 04/17/2022] [Accepted: 04/20/2022] [Indexed: 02/01/2023] Open
Abstract
Ketamine-associated cystitis is characterized by suburothelial inflammation and urothelial cell death. Norketamine (NK), the main metabolite of ketamine, is abundant in urine following ketamine exposure. NK has been speculated to exert toxic effects in urothelial cells, similarly to ketamine. However, the molecular mechanisms contributing to NK-induced urothelial cytotoxicity are almost unclear. Here, we aimed to investigate the toxic effects of NK and the potential mechanisms underlying NK-induced urothelial cell injury. In this study, NK exposure significantly reduced cell viability and induced apoptosis in human urinary bladder epithelial-derived RT4 cells that NK (0.01–0.5 mM) exhibited greater cytotoxicity than ketamine (0.1–3 mM). Signals of mitochondrial dysfunction, including mitochondrial membrane potential (MMP) loss and cytosolic cytochrome c release, were found to be involved in NK-induced cell apoptosis and death. NK exposure of cells also triggered the expression of endoplasmic reticulum (ER) stress-related proteins including GRP78, CHOP, XBP-1, ATF-4 and -6, caspase-12, PERK, eIF-2α, and IRE-1. Pretreatment with 4-phenylbutyric acid (an ER stress inhibitor) markedly prevented the expression of ER stress-related proteins and apoptotic events in NK-exposed cells. Additionally, NK exposure significantly activated JNK, ERK1/2, and p38 signaling and increased intracellular calcium concentrations ([Ca2+]i). Pretreatment of cells with both PD98059 (an ERK1/2 inhibitor) and BAPTA/AM (a cell-permeable Ca2+ chelator), but not SP600125 (a JNK inhibitor) and SB203580 (a p38 inhibitor), effectively suppressed NK-induced mitochondrial dysfunction, ER stress-related signals, and apoptotic events. The elevation of [Ca2+]i in NK-exposed cells could be obviously inhibited by BAPTA/AM, but not PD98059. Taken together, these findings suggest that NK exposure exerts urothelial cytotoxicity via a [Ca2+]i-regulated ERK1/2 activation, which is involved in downstream mediation of the mitochondria-dependent and ER stress-triggered apoptotic pathway, consequently resulting in urothelial cell death. Our findings suggest that regulating [Ca2+]i/ERK signaling pathways may be a promising strategy for treatment of NK-induced urothelial cystitis.
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Yang CY, Liu SH, Su CC, Fang KM, Yang TY, Liu JM, Chen YW, Chang KC, Chuang HL, Wu CT, Lee KI, Huang CF. Methylmercury Induces Mitochondria- and Endoplasmic Reticulum Stress-Dependent Pancreatic β-Cell Apoptosis via an Oxidative Stress-Mediated JNK Signaling Pathway. Int J Mol Sci 2022; 23:ijms23052858. [PMID: 35270009 PMCID: PMC8910963 DOI: 10.3390/ijms23052858] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/21/2022] [Accepted: 03/01/2022] [Indexed: 12/21/2022] Open
Abstract
Methylmercury (MeHg), a long-lasting organic pollutant, is known to induce cytotoxic effects in mammalian cells. Epidemiological studies have suggested that environmental exposure to MeHg is linked to the development of diabetes mellitus (DM). The exact molecular mechanism of MeHg-induced pancreatic β-cell cytotoxicity is still unclear. Here, we found that MeHg (1-4 μM) significantly decreased insulin secretion and cell viability in pancreatic β-cell-derived RIN-m5F cells. A concomitant elevation of mitochondrial-dependent apoptotic events was observed, including decreased mitochondrial membrane potential and increased proapoptotic (Bax, Bak, p53)/antiapoptotic (Bcl-2) mRNA ratio, cytochrome c release, annexin V-Cy3 binding, caspase-3 activity, and caspase-3/-7/-9 activation. Exposure of RIN-m5F cells to MeHg (2 μM) also induced protein expression of endoplasmic reticulum (ER) stress-related signaling molecules, including C/EBP homologous protein (CHOP), X-box binding protein (XBP-1), and caspase-12. Pretreatment with 4-phenylbutyric acid (4-PBA; an ER stress inhibitor) and specific siRNAs for CHOP and XBP-1 significantly inhibited their expression and caspase-3/-12 activation in MeHg-exposed RIN-mF cells. MeHg could also evoke c-Jun N-terminal kinase (JNK) activation and reactive oxygen species (ROS) generation. Antioxidant N-acetylcysteine (NAC; 1mM) or 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (trolox; 100 μM) markedly prevented MeH-induced ROS generation and decreased cell viability in RIN-m5F cells. Furthermore, pretreatment of cells with SP600125 (JNK inhibitor; 10 μM) or NAC (1 mM) or transfection with JNK-specific siRNA obviously attenuated the MeHg-induced JNK phosphorylation, CHOP and XBP-1 protein expression, apoptotic events, and insulin secretion dysfunction. NAC significantly inhibited MeHg-activated JNK signaling, but SP600125 could not effectively reduce MeHg-induced ROS generation. Collectively, these findings demonstrate that the induction of ROS-activated JNK signaling is a crucial mechanism underlying MeHg-induced mitochondria- and ER stress-dependent apoptosis, ultimately leading to β-cell death.
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Affiliation(s)
- Ching-Yao Yang
- Department of Surgery, National Taiwan University Hospital, Taipei 100, Taiwan;
- Department of Surgery, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Shing-Hwa Liu
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei 100, Taiwan;
| | - Chin-Chuan Su
- Department of Otorhinolaryngology, Head and Neck Surgery, Changhua Christian Hospital, Changhua County 500, Taiwan;
| | - Kai-Min Fang
- Department of Otolaryngology, Far Eastern Memorial Hospital, New Taipei City 220, Taiwan;
| | - Tsung-Yuan Yang
- Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan;
- School of Medicine, Institute of Medicine, Chung-Shan Medical University, Taichung 402, Taiwan
| | - Jui-Ming Liu
- Department of Urology, Taoyuan General Hospital, Ministry of Health and Welfare, Taoyuan 330, Taiwan;
- Department of Obstetrics and Gynecology, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan
| | - Ya-Wen Chen
- Department of Physiology, School of Medicine, College of Medicine, China Medical University, Taichung 404, Taiwan;
| | - Kai-Chih Chang
- Center for Digestive Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung 404, Taiwan;
| | - Haw-Ling Chuang
- Department of Emergency, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung 427, Taiwan;
| | - Cheng-Tien Wu
- Department of Nutrition and Master Program of Food and Drug Safety, China Medical University, Taichung 40402, Taiwan;
| | - Kuan-I Lee
- Department of Emergency, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung 427, Taiwan;
- Correspondence: (K.-I.L.); (C.-F.H.)
| | - Chun-Fa Huang
- School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung 404, Taiwan
- Department of Nursing, College of Medical and Health Science, Asia University, Taichung 413, Taiwan
- Correspondence: (K.-I.L.); (C.-F.H.)
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