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George J, Sadiq E, Moola I, Maharaj S, Mochan A. Informal gold miners with mercury toxicity: Novel asymmetrical neurological presentations. S Afr Med J 2023; 113:20. [PMID: 38525630 DOI: 10.7196/samj.2023.v113i12.1127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Indexed: 03/26/2024] Open
Abstract
Mercury is a highly toxic heavy metal that may cause neurological, respiratory, gastrointestinal and dermatological illnesses. Previously described neurological manifestations of mercury toxicity are symmetrical, and include a pancerebellar syndrome, generalised seizures and encephalopathy. Mercury is used in the gold mining process, and in artisanal or illicit gold mining, often without necessary protection. Here we describe the cases of two artisanal gold miners from western Johannesburg, South Africa, who presented with atypical neurological manifestations of mercury toxicity. Patient 1 presented with focal seizures, an asymmetrical cerebellar syndrome and an acute encephalopathy. Patient 2 had unilateral cerebellar ataxia. Both patients had toxic mercury levels, with no other cause identified for their symptoms. Patient 1 responded well to chelation therapy, but patient 2 refused admission and further medical treatment. The neurological manifestations of mercury toxicity are typically symmetrical, whereas our two patients presented with markedly asymmetrical features. It is important to maintain a high index of suspicion for mercury poisoning, even in patients with atypical and unilateral or asymmetrical presentations. A prompt diagnosis and the commencement of early chelation therapy have the potential to produce good outcomes.
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Affiliation(s)
- J George
- Division of Neurology, Department of Neurosciences, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
| | - E Sadiq
- Division of Neurology, Department of Neurosciences, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
| | - I Moola
- Division of Neurology, Department of Neurosciences, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
| | - S Maharaj
- Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
| | - A Mochan
- Division of Neurology, Department of Neurosciences, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
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Pu ZQ, Liu D, Lobo Mouguegue HPP, Jin CW, Sadiq E, Qin DD, Yu TF, Zong C, Chen JC, Zhao RX, Lin JY, Cheng J, Yu X, Li X, Zhang YC, Liu YT, Guan QB, Wang XD. NR4A1 counteracts JNK activation incurred by ER stress or ROS in pancreatic β-cells for protection. J Cell Mol Med 2020; 24:14171-14183. [PMID: 33124187 PMCID: PMC7754045 DOI: 10.1111/jcmm.16028] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 09/08/2020] [Accepted: 10/05/2020] [Indexed: 12/20/2022] Open
Abstract
Sustained hyperglycaemia and hyperlipidaemia incur endoplasmic reticulum stress (ER stress) and reactive oxygen species (ROS) overproduction in pancreatic β‐cells. ER stress or ROS causes c‐Jun N‐terminal kinase (JNK) activation, and the activated JNK triggers apoptosis in different cells. Nuclear receptor subfamily 4 group A member 1 (NR4A1) is an inducible multi‐stress response factor. The aim of this study was to explore the role of NR4A1 in counteracting JNK activation induced by ER stress or ROS and the related mechanism. qPCR, Western blotting, dual‐luciferase reporter and ChIP assays were applied to detect gene expression or regulation by NR4A1. Immunofluorescence was used to detect a specific protein expression in β‐cells. Our data showed that NR4A1 reduced the phosphorylated JNK (p‐JNK) in MIN6 cells encountering ER stress or ROS and reduced MKK4 protein in a proteasome‐dependent manner. We found that NR4A1 increased the expression of cbl‐b (an E3 ligase); knocking down cbl‐b expression increased MKK4 and p‐JNK levels under ER stress or ROS conditions. We elucidated that NR4A1 enhanced the transactivation of cbl‐b promoter by physical association. We further confirmed that cbl‐b expression in β‐cells was reduced in NR4A1‐knockout mice compared with WT mice. NR4A1 down‐regulates JNK activation by ER stress or ROS in β‐cells via enhancing cbl‐b expression.
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Affiliation(s)
- Ze-Qing Pu
- Department of Cell Biology, Shandong University School of Medicine, Jinan, China
| | - Dong Liu
- Department of Cell Biology, Shandong University School of Medicine, Jinan, China
| | | | - Cheng-Wen Jin
- Department of Cell Biology, Shandong University School of Medicine, Jinan, China
| | - Esha Sadiq
- Department of Cell Biology, Shandong University School of Medicine, Jinan, China
| | - Dan-Dan Qin
- Department of Cell Biology, Shandong University School of Medicine, Jinan, China
| | - Tian-Fu Yu
- Department of Cell Biology, Shandong University School of Medicine, Jinan, China
| | - Chen Zong
- Department of Cell Biology, Shandong University School of Medicine, Jinan, China
| | - Ji-Cui Chen
- Blood Transfusion Department, Qilu Hospital of Shandong University, Jinan, China
| | - Ru-Xing Zhao
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, China
| | - Jing-Yu Lin
- Department of Physiology, Shandong University School of Medicine, Jinan, China
| | - Jie Cheng
- Department of Physiology, Shandong University School of Medicine, Jinan, China
| | - Xiao Yu
- Department of Physiology, Shandong University School of Medicine, Jinan, China.,Key Laboratory of Protein Sciences for Chronic Degenerative Diseases in Universities of Shandong (Shandong University), Jinan, China
| | - Xia Li
- Department of Cell Biology, Shandong University School of Medicine, Jinan, China
| | - Yu-Chao Zhang
- Department of Endocrinology, Qingdao Municipal Hospital, Qingdao, China
| | - Yuan-Tao Liu
- Department of Endocrinology, Qingdao Municipal Hospital, Qingdao, China
| | - Qing-Bo Guan
- Department of Endocrinology, Shandong Provincial Hospital, Affiliated to Shandong University, Jinan, China
| | - Xiang-Dong Wang
- Department of Cell Biology, Shandong University School of Medicine, Jinan, China.,Key Laboratory of Protein Sciences for Chronic Degenerative Diseases in Universities of Shandong (Shandong University), Jinan, China
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