1
|
Yuan J, Huang X, Zhao Y, Gu J, Yuan Y, Liu Z, Zou H, Bian J. Rat Hepatocytes Mitigate Cadmium Toxicity by Forming Annular Gap Junctions and Degrading Them via Endosome-Lysosome Pathway. Int J Mol Sci 2022; 23:ijms232415607. [PMID: 36555247 PMCID: PMC9778680 DOI: 10.3390/ijms232415607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 12/01/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
Gap junction protein connexin 43 (Cx43) plays a critical role in gap junction communication in rat hepatocytes. However, those located between hepatocytes are easily internalized following exposure to poisons. Herein, we investigated the potential of buffalo rat liver 3A (BRL 3A) cells to generate annular gap junctions (AGJs) proficient at alleviating cadmium (Cd) cytotoxic injury through degradation via an endosome-lysosome pathway. Our results showed that Cd-induced damage of liver microtubules promoted Cx43 internalization and increased Cx43 phosphorylation at Ser373 site. Furthermore, we established that Cd induced AGJs generation in BRL 3A cells, and AGJs were subsequently degraded through the endosome-lysosome pathway. Overall, our results suggested that Cx43 internalization and the generation of AGJs were cellular protective mechanisms to alleviate Cd toxicity in rat hepatocytes.
Collapse
Affiliation(s)
- Junzhao Yuan
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Xiaoqian Huang
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Yumeng Zhao
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Jianhong Gu
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Yan Yuan
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Zongping Liu
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Hui Zou
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
- Correspondence: (H.Z.); (J.B.)
| | - Jianchun Bian
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
- Correspondence: (H.Z.); (J.B.)
| |
Collapse
|
2
|
Liu Y, Chen Q, Li Y, Bi L, Jin L, Peng R. Toxic Effects of Cadmium on Fish. TOXICS 2022; 10:622. [PMID: 36287901 PMCID: PMC9608472 DOI: 10.3390/toxics10100622] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/06/2022] [Accepted: 10/17/2022] [Indexed: 06/16/2023]
Abstract
Large amounts of enriched cadmium (Cd) in the environment seriously threatens the healthy and sustainable development of the aquaculture industry and greatly restricts the development of the food processing industry. Studying the distribution and toxic effects of Cd in fish, as well as the possible toxic effects of Cd on the human body, is very significant. A large number of studies have shown that the accumulation and distribution of Cd in fish are biologically specific, cause tissue differences, and seriously damage the integrity of tissue structure and function, the antioxidant defense system, the reproductive regulation system, and the immune system. The physiological, biochemical, enzyme, molecular, and gene expression levels change with different concentrations and times of Cd exposure, and these changes are closely related to the target sites of Cd action and tissues in fish. Therefore, the toxic effects of Cd on fish occur with multiple tissues, systems, and levels.
Collapse
|
3
|
Cell organelles as targets of mammalian cadmium toxicity. Arch Toxicol 2020; 94:1017-1049. [PMID: 32206829 DOI: 10.1007/s00204-020-02692-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 02/25/2020] [Indexed: 02/07/2023]
Abstract
Ever increasing environmental presence of cadmium as a consequence of industrial activities is considered a health hazard and is closely linked to deteriorating global health status. General animal and human cadmium exposure ranges from ingestion of foodstuffs sourced from heavily polluted hotspots and cigarette smoke to widespread contamination of air and water, including cadmium-containing microplastics found in household water. Cadmium is promiscuous in its effects and exerts numerous cellular perturbations based on direct interactions with macromolecules and its capacity to mimic or displace essential physiological ions, such as iron and zinc. Cell organelles use lipid membranes to form complex tightly-regulated, compartmentalized networks with specialized functions, which are fundamental to life. Interorganellar communication is crucial for orchestrating correct cell behavior, such as adaptive stress responses, and can be mediated by the release of signaling molecules, exchange of organelle contents, mechanical force generated through organelle shape changes or direct membrane contact sites. In this review, cadmium effects on organellar structure and function will be critically discussed with particular consideration to disruption of organelle physiology in vertebrates.
Collapse
|
4
|
Morphological evidence of neurotoxic effects in chicken embryos after exposure to perfluorooctanoic acid (PFOA) and inorganic cadmium. Toxicology 2019; 427:152286. [DOI: 10.1016/j.tox.2019.152286] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 08/01/2019] [Accepted: 09/02/2019] [Indexed: 01/09/2023]
|
5
|
Luo S, Terciolo C, Bracarense APFL, Payros D, Pinton P, Oswald IP. In vitro and in vivo effects of a mycotoxin, deoxynivalenol, and a trace metal, cadmium, alone or in a mixture on the intestinal barrier. ENVIRONMENT INTERNATIONAL 2019; 132:105082. [PMID: 31400600 DOI: 10.1016/j.envint.2019.105082] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 05/11/2023]
Abstract
Deoxynivalenol (DON), one of the most widespread mycotoxins in Europe, and cadmium (Cd), a widespread environmental pollutant, are common food contaminants. They exert adverse effects on different organs including kidney, liver, and intestine. The intestine is a common target of DON and Cd when they are ingested. Most studies have focused on their individual effects whereas their combined toxicity has rarely been studied. The aim of this study was thus to evaluate their individual and combined effects on the intestinal barrier function in vitro and in vivo. In vitro, Caco-2 cells were treated with increasing concentrations of DON and Cd (1-30 μM). In vivo, Wistar rats were used as controls or exposed to DON contaminated feed (8.2 mg/kg feed), Cd-contaminated water (5 mg/l) or both for four weeks. In Caco-2 cells, DON, Cd and the DON+Cd mixture reduced transepithelial electrical resistance (TEER) and increased paracellular permeability in a dose-dependent manner. Impairment of the barrier function was associated with a decrease in the amount of E-cadherin and occludin after exposure to the two contaminants alone or combined. A decrease in E-cadherin expression was observed in rats exposed to the two contaminants alone or combined, whereas occludin expression only decreased in animals exposed to DON and DON+Cd. Jejunal crypt depth was reduced in rats exposed to DON or Cd, whereas villi height was not affected. In vitro and in vivo results showed that the effects of exposure to combined DON and Cd on the intestinal barrier function in the jejunum of Wistar rats and in the colorectal cancer cell line (Caco-2) was similar to the effects of each individual contaminant. This suggests that regulations for each individual contaminant are sufficiently protective for consumers.
Collapse
Affiliation(s)
- Su Luo
- Toxalim (Research Center in Food Toxicology), Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse, France
| | - Chloe Terciolo
- Toxalim (Research Center in Food Toxicology), Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse, France
| | | | - Delphine Payros
- Toxalim (Research Center in Food Toxicology), Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse, France
| | - Philippe Pinton
- Toxalim (Research Center in Food Toxicology), Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse, France.
| | - Isabelle P Oswald
- Toxalim (Research Center in Food Toxicology), Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse, France
| |
Collapse
|
6
|
Fujishiro H, Liu Y, Ahmadi B, Templeton DM. Protective effect of cadmium-induced autophagy in rat renal mesangial cells. Arch Toxicol 2017; 92:619-631. [PMID: 29218509 DOI: 10.1007/s00204-017-2103-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 10/24/2017] [Indexed: 12/19/2022]
Abstract
Cadmium damages renal cells, and in particular may cause mesangial cell death by necrosis or apoptosis, depending on exposure conditions in cultured cells. However, there is an uncertainty as to whether Cd2+-induced autophagy can protect mesangial cells against these other mechanisms of cell death. We have used autophagy-incompetent mouse embryonic fibroblast (MEF) cells lacking the Atg16 gene, as well as cultured rat mesangial cells (RMC) in which Atg16 has been silenced, to examine this issue. Measuring the processing of LC3-I to LC3-II and expression of sequestosome-1 (p62), we define conditions under which RMC can be induced to undergo autophagy in response to 0-20 µM CdCl2. Similarly, Cd2+ can initiate autophagy in MEF cells. However, when autophagy is compromised, either by gene knockout in MEF cells or by RNA silencing in RMC, cell viability is decreased, and concomitantly a Cd2+ dose-dependent increase in pro-caspase-3 cleavage indicates the initiation of apoptotic cell death. In contrast to some previous reports, Cd2+-induced autophagy is not correlated with increased levels of cellular reactive oxygen species but, among a panel of kinases investigated, is suppressed by inhibition of the Jun kinase. We conclude that concentrations of Cd2+ that initiate autophagy may afford renal mesangial cells some degree of protection against other modes (apoptosis, necrosis) of cell death.
Collapse
Affiliation(s)
- Hitomi Fujishiro
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, M5S 1A8, Canada
- Laboratory of Molecular Nutrition and Toxicology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima, 770-8514, Japan
| | - Ying Liu
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, M5S 1A8, Canada
| | - Bilal Ahmadi
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, M5S 1A8, Canada
| | - Douglas M Templeton
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, M5S 1A8, Canada.
| |
Collapse
|
7
|
Chen X, Li J, Cheng Z, Xu Y, Wang X, Li X, Xu D, Kapron CM, Liu J. Low Dose Cadmium Inhibits Proliferation of Human Renal Mesangial Cells via Activation of the JNK Pathway. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2016; 13:ijerph13100990. [PMID: 27739415 PMCID: PMC5086729 DOI: 10.3390/ijerph13100990] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 09/29/2016] [Indexed: 12/15/2022]
Abstract
Cadmium (Cd) is a heavy metal and environmental pollutant. The kidney is the principal target organ of Cd exposure. Previously, we found that low concentration of Cd damages the integrity of the glomerular filtration barrier. However, little is known about the effects of Cd on renal mesangial cells, which provide structural support for the glomerular capillary loops and regulate intraglomerular blood flow. In this study, human renal mesangial cells (HRMCs) were cultured in the presence of serum and treated with 4 μM Cd. We found that Cd activates the c-Jun N-terminal kinase (JNK) pathway, and increases the protein levels of c-Jun and c-Fos. Cd treatment also induces a decrease in proliferation and an increase in apoptosis of HRMCs, but only the decrease in HRMC proliferation was reversed by pretreatment with SP600125, an inhibitor of the JNK pathway. In addition, Cd does not change the expression of α-smooth muscle actin and platelet-derived growth factor receptor-β, the markers of mesangial cells, or the alignment of the filamentous actin (F-actin) cytoskeleton of HRMCs. Our data indicate that the JNK pathway mediates the inhibitory effects of Cd on HRMC proliferation.
Collapse
Affiliation(s)
- Xiaocui Chen
- Medical Research Center, Shandong Provincial Qianfoshan Hospital, Shandong University, 16766 Jingshi Road, Jinan 250014, China.
| | - Jing Li
- Key Laboratory of Molecular and Nano Probes, Ministry of Education, College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, China.
| | | | - Yinghua Xu
- Taishan Medical College, Taian 271000, China.
| | - Xia Wang
- Medical Research Center, Shandong Provincial Qianfoshan Hospital, Shandong University, 16766 Jingshi Road, Jinan 250014, China.
| | - Xiaorui Li
- Taishan Medical College, Taian 271000, China.
| | - Dongmei Xu
- Department of Nephrology, Shandong Provincial Qianfoshan Hospital, Shandong University, 16766 Jingshi Road, Jinan 250014, China.
| | - Carolyn M Kapron
- Department of Biology, Trent University, Peterborough, ON K9L0G2, Canada.
| | - Ju Liu
- Medical Research Center, Shandong Provincial Qianfoshan Hospital, Shandong University, 16766 Jingshi Road, Jinan 250014, China.
| |
Collapse
|
8
|
Sandbichler AM, Höckner M. Cadmium Protection Strategies--A Hidden Trade-Off? Int J Mol Sci 2016; 17:ijms17010139. [PMID: 26805823 PMCID: PMC4730378 DOI: 10.3390/ijms17010139] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Revised: 01/15/2016] [Accepted: 01/18/2016] [Indexed: 12/12/2022] Open
Abstract
Cadmium (Cd) is a non-essential transition metal which is introduced into the biosphere by various anthropogenic activities. Environmental pollution with Cd poses a major health risk and Cd toxicity has been extensively researched over the past decades. This review aims at changing the perspective by discussing protection mechanisms available to counteract a Cd insult. Antioxidants, induction of antioxidant enzymes, and complexation of Cd to glutathione (GSH) and metallothionein (MT) are the most potent protective measures to cope with Cd-induced oxidative stress. Furthermore, protection mechanisms include prevention of endoplasmic reticulum (ER) stress, mitophagy and metabolic stress, as well as expression of chaperones. Pre-exposure to Cd itself, or co-exposure to other metals or trace elements can improve viability under Cd exposure and cells have means to reduce Cd uptake and improve Cd removal. Finally, environmental factors have negative or positive effects on Cd toxicity. Most protection mechanisms aim at preventing cellular damage. However, this might not be possible without trade-offs like an increased risk of carcinogenesis.
Collapse
Affiliation(s)
| | - Martina Höckner
- University of Innsbruck, Institute of Zoology, Technikerstraße 25, 6020 Innsbruck, Austria.
| |
Collapse
|
9
|
Papa V, Bimonte VM, Wannenes F, D'Abusco AS, Fittipaldi S, Scandurra R, Politi L, Crescioli C, Lenzi A, Di Luigi L, Migliaccio S. The endocrine disruptor cadmium alters human osteoblast-like Saos-2 cells homeostasis in vitro by alteration of Wnt/β-catenin pathway and activation of caspases. J Endocrinol Invest 2015; 38:1345-56. [PMID: 26335301 DOI: 10.1007/s40618-015-0380-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 08/08/2015] [Indexed: 11/25/2022]
Abstract
PURPOSE The pollutant Cadmium (Cd) is widespread in the environment and causes alterations of human health by acting as an endocrine disruptor. Bone tissue seems to be a crucial target of Cd contamination. Indeed, we have previously demonstrated that this endocrine disruptor induces osteoblast apoptosis and necrosis. Thus, aim of this study was to further evaluate the effect of Cd on osteoblasts homeostasis, investigating potential modification of the Wnt/β-catenin intracellular pathway, the intracellular process involved in programmed cellular death and the cytoskeletal alterations. MATERIAL AND METHODS To this purpose, human osteoblastic Saos-2 cells, a human osteosarcoma osteoblast-like cell line, were cultured and treated with Cd. RESULTS Osteoblastic cells were treated for 6 h with 10μM Cd, which induced nuclear translocation of β-catenin and increased expression of Wnt/β-catenin target genes. Longer exposure to the same Cd concentration induced osteoblastic cell apoptosis. To better characterize the intracellular events involved in these Cd-induced alterations, we evaluated the effect of Cd exposure on actin filaments and proteins associated to cytoskeletal actin, characterized by the presence of LIM domains. Long (15, 24 h) exposure of osteoblasts to Cd reduced LIM proteins expression and induced actin filaments destruction and a significant caspase-3 activation after 24 h. In addition, to prove that Cd induces osteoblastic cells apoptosis after long exposure, we performed TUNEL assay which demonstrated increase of cell apoptosis after 24 h. CONCLUSION In conclusion, our study shows that osteoblasts exposed to Cd for short intervals of time demonstrated an increase in cell proliferation through a Wnt/β-catenin dependent mechanism, likely as a compensatory mechanism in response to cell injury. Longer exposure to the same Cd concentration induced cells apoptosis through cytoskeleton disruption-mediated mechanisms and caspase activation.
Collapse
Affiliation(s)
- V Papa
- Department of Movement, Human and Health Sciences, Section of Health Sciences, "Foro Italico" University of Rome, Largo Lauro De Bosis 15, 00195, Rome, Italy
- LiSa Laboratory, Policlinico di Catania, University of Catania, Catania, Italy
| | - V M Bimonte
- Department of Movement, Human and Health Sciences, Section of Health Sciences, "Foro Italico" University of Rome, Largo Lauro De Bosis 15, 00195, Rome, Italy
- LiSa Laboratory, Policlinico di Catania, University of Catania, Catania, Italy
| | - F Wannenes
- Department of Movement, Human and Health Sciences, Section of Health Sciences, "Foro Italico" University of Rome, Largo Lauro De Bosis 15, 00195, Rome, Italy
- LiSa Laboratory, Policlinico di Catania, University of Catania, Catania, Italy
| | - A S D'Abusco
- Department of Biochemistry, Section of Medical Pathophysiology, Endocrinology and Nutrition, "Sapienza" University of Rome, Rome, Italy
| | - S Fittipaldi
- Department of Movement, Human and Health Sciences, Section of Health Sciences, "Foro Italico" University of Rome, Largo Lauro De Bosis 15, 00195, Rome, Italy
- LiSa Laboratory, Policlinico di Catania, University of Catania, Catania, Italy
| | - R Scandurra
- Department of Biochemistry, Section of Medical Pathophysiology, Endocrinology and Nutrition, "Sapienza" University of Rome, Rome, Italy
| | - L Politi
- Department of Biochemistry, Section of Medical Pathophysiology, Endocrinology and Nutrition, "Sapienza" University of Rome, Rome, Italy
| | - C Crescioli
- Department of Movement, Human and Health Sciences, Section of Health Sciences, "Foro Italico" University of Rome, Largo Lauro De Bosis 15, 00195, Rome, Italy
| | - A Lenzi
- Department of Experimental Medicine, Section of Medical Pathophysiology, Endocrinology and Nutrition, "Sapienza" University of Rome, Rome, Italy
| | - L Di Luigi
- Department of Movement, Human and Health Sciences, Section of Health Sciences, "Foro Italico" University of Rome, Largo Lauro De Bosis 15, 00195, Rome, Italy
| | - S Migliaccio
- Department of Movement, Human and Health Sciences, Section of Health Sciences, "Foro Italico" University of Rome, Largo Lauro De Bosis 15, 00195, Rome, Italy.
| |
Collapse
|
10
|
Cadmium-induced aggregation of iron regulatory protein-1. Toxicology 2014; 324:108-15. [DOI: 10.1016/j.tox.2014.08.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 06/10/2014] [Accepted: 08/03/2014] [Indexed: 11/18/2022]
|
11
|
Choong G, Liu Y, Templeton DM. Interplay of calcium and cadmium in mediating cadmium toxicity. Chem Biol Interact 2014; 211:54-65. [PMID: 24463198 DOI: 10.1016/j.cbi.2014.01.007] [Citation(s) in RCA: 161] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 12/31/2013] [Accepted: 01/13/2014] [Indexed: 01/30/2023]
Abstract
The environmentally important toxic metal, cadmium, exists as the Cd(2+) ion in biological systems, and in this state structurally resembles Ca(2+). Thus, although cadmium exerts a broad range of adverse actions on cells by virtue of its propensity to bind to protein thiol groups, it is now well appreciated that Cd(2+) participates in a number of Ca(2+)-dependent pathways, attributable to its actions as a Ca(2+) mimetic, with a central role for calmodulin, and the Ca(2+)/calmodlin-dependent protein kinase II (CaMK-II) that mediates effects on cytoskeletal dynamics and apoptotic cell death. Cadmium interacts with receptors and ion channels on the cell surface, and with the intracellular estrogen receptor where it binds competitively to residues shared by Ca(2+). It increases cytosolic [Ca(2+)] through several mechanisms, but also decreases transcript levels of some Ca(2+)-transporter genes. It initiates mitochondrial apoptotic pathways, and activates calpains, contributing to mitochondria-independent apoptosis. However, the recent discovery of the role CaMK-II plays in Cd(2+)-induced cell death, and subsequent implication of CaMK-II in Cd(2+)-dependent alterations of cytoskeletal dynamics, has opened a new area of mechanistic cadmium toxicology that is a focus of this review. Calmodulin is necessary for induction of apoptosis by several agents, yet induction of apoptosis by Cd(2+) is prevented by CaMK-II block, and Ca(2+)-dependent phosphorylation of CaMK-II has been linked to increased Cd(2+)-dependent apoptosis. Calmodulin antagonism suppresses Cd(2+)-induced phosphorylation of Erk1/2 and the Akt survival pathway. The involvement of CaMK-II in the effects of Cd(2+) on cell morphology, and particularly the actin cytoskeleton, is profound, favouring actin depolymerization, disrupting focal adhesions, and directing phosphorylated FAK into a cellular membrane. CaMK-II is also implicated in effects of Cd(2+) on microtubules and cadherin junctions. A key question for future cadmium research is whether cytoskeletal disruption leads to apoptosis, or rather if apoptosis initiates cytoskeletal disruption in the context of Cd(2+).
Collapse
Affiliation(s)
- Grace Choong
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto M5S 1A8, Canada
| | - Ying Liu
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto M5S 1A8, Canada
| | - Douglas M Templeton
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto M5S 1A8, Canada.
| |
Collapse
|
12
|
Khamis I, Heikkila JJ. Enhanced HSP30 and HSP70 accumulation in Xenopus cells subjected to concurrent sodium arsenite and cadmium chloride stress. Comp Biochem Physiol C Toxicol Pharmacol 2013; 158:165-72. [PMID: 23919948 DOI: 10.1016/j.cbpc.2013.07.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 07/26/2013] [Accepted: 07/26/2013] [Indexed: 01/31/2023]
Abstract
Heat shock proteins (HSPs) are molecular chaperones that aid in protein folding, translocation and in preventing stress-induced protein aggregation. The present study examined the effect of simultaneous sodium arsenite and cadmium chloride treatment on the pattern of HSP30 and HSP70 accumulation in A6 kidney epithelial cells of the frog, Xenopus laevis. Immunoblot analysis revealed that HSP30 and HSP70 accumulation in concurrent stressor treatments were significantly higher than the sum of HSP30 or HSP70 accumulation in individual treatments. This finding suggested a synergistic action between sodium arsenite and cadmium chloride. KNK437 inhibitor studies indicated that the combined stressor-induced accumulation of HSPs may be regulated, at least in part, at the level of transcription. Immunocytochemistry revealed that simultaneous treatment of cells with the two stressors induced HSP30 accumulation primarily in the cytoplasm in a punctate pattern with some dysregulation of F-actin structure. Increased ubiquitinated protein accumulation was observed with combined sodium arsenite and cadmium chloride treatment compared to individual stressors suggesting an impairment of the ubiquitin proteasome degradation system. The addition of a mild heat shock further enhanced the accumulation of HSP30 and HSP70 in response to relatively low concentrations of sodium arsenite plus cadmium chloride.
Collapse
Affiliation(s)
- Imran Khamis
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | | |
Collapse
|
13
|
Choong G, Liu Y, Templeton DM. Cadmium affects focal adhesion kinase (FAK) in mesangial cells: Involvement of CaMK-II and the actin cytoskeleton. J Cell Biochem 2013; 114:1832-42. [DOI: 10.1002/jcb.24529] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2013] [Accepted: 02/20/2013] [Indexed: 11/06/2022]
|