Oxidative stress and repetitive element methylation changes in artisanal gold miners occupationally exposed to mercury

Narváez, Diana; Groot, Helena; Díaz, Sonia M.; Palma, Ruth Marién; Muñoz, Nathalia; Cros, Marie-Pierre; Hernández-Vargas, Héctor

doi:10.1016/j.heliyon.2017.e00400

Cited by 17 publications

(7 citation statements)

References 41 publications

(51 reference statements)

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“…fact that "GSH replacing" antioxidants, such as of alpha-tocopherol acetate, N-acetyl cysteine, methionine, SAM, and folic acid methyl group donors also reversed the phenomenon of LINE-1 hypomethylation [49]. Since oxidative stress induces hypermethylation of the repetitive LINE-1 elements of SOD enzyme family and GSTM5 promoters [50,51] as well, and these positive feedback mechanisms have been disrupted by the substances studied in our model. DNA methylation and histone methylation are epigenetic factors that play a central role in tumor biology and are involved in the antitumor effects of polyphenols (e.g.…”

Section: Plos Onementioning

confidence: 65%

The effects of flavonoids, green tea polyphenols and coffee on DMBA induced LINE-1 DNA hypomethylation

et al. 2021

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The intake of carcinogenic and chemopreventive compounds are important nutritional factors related to the development of malignant tumorous diseases. Repetitive long interspersed element-1 (LINE-1) DNA methylation pattern plays a key role in both carcinogenesis and chemoprevention. In our present in vivo animal model, we examined LINE-1 DNA methylation pattern as potential biomarker in the liver, spleen and kidney of mice consuming green tea (Camellia sinensis) extract (catechins 80%), a chinese bayberry (Morella rubra) extract (myricetin 80%), a flavonoid extract (with added resveratrol) and coffee (Coffee arabica) extract. In the organs examined, carcinogen 7,12-dimethylbenz(a)anthracene (DMBA)-induced hypomethylation was prevented by all test materials except chinese bayberry extract in the kidneys. Moreover, the flavonoid extract caused significant hypermethylation in the liver compared to untreated controls and to other test materials. The tested chemopreventive substances have antioxidant, anti-inflammatory properties and regulate molecular biological signaling pathways. They increase glutathione levels, induce antioxidant enzymes, which decrease free radical damage caused by DMBA, and ultimately, they are able to increase the activity of DNA methyltransferase enzymes. Furthermore, flavonoids in the liver may inhibit the procarcinogen to carcinogen activation of DMBA through the inhibition of CYP1A1 enzyme. At the same time, paradoxically, myricetin can act as a prooxidant as a result of free radical damage, which can explain that it did not prevent hypomethylation in the kidneys. Our results demonstrated that LINE-1 DNA methylation pattern is a useful potential biomarker for detecting and monitoring carcinogenic and chemopreventive effects of dietary compounds.

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Section: Plos Onementioning

confidence: 65%

The effects of flavonoids, green tea polyphenols and coffee on DMBA induced LINE-1 DNA hypomethylation

et al. 2021

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“…Additionally, LINE1 methylation was positively correlated with 8-hydroxy-2-deoxyguanosine(8-OHdG) and Hg levels. (24) These findings emphasize the negative effect of Hg on oxidative stress and DNA methylation in gold miners. Various studies (25, 87, 88) have reported alterations in membrane permeability as well as changes in macromolecular structure due to the high affinity of cellular mercury for sulfhydryl and thiol groups leading to DNA damage.…”

Section: Health Implications Of Mercury Exposure To Asgmsmentioning

confidence: 78%

The Clinical Importance of the Mercury Problem in Artisanal Small-Scale Gold Mining

Afrifa

Opoku

Ofori

et al. 2019

Front. Public Health

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Artisanal small-scale mining is widely operated in various countries serving as a livelihood to many rural communities. However, it is a significant source of environmental mercury contamination which affects human health. Amalgamation and amalgam smelting, two significant steps in the artisanal small-scale mining operations generate lots of mercury vapors, leading to chronic exposure among miners. Thus, this article seeks to provide a topical review of recent findings on organ damage and metabolic disorders among mercury-exposed artisanal small-scale miners with emphasis on the contributing factors such as personal protective equipment usage and artisanal small-scale gold mining-specific occupational activities. Also, insights into the effect of mercury intoxication and mechanisms of action on organ and metabolic systems among exposed individuals are provided.

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“…There is now some evidence that reactive oxygen species may induce changes in LINE-1 methylation. For example, in gold miners, oxidative stress associated with increased mercury levels, is associated with increased LINE-1 methylation (Narvaez et al, 2017). LINE-1 methylation is reduced in cells treated with peroxides (Kloypan, Srisa-art, Mutirangura, & Boonla, 2015), while antioxidants, including alpha-tocopherol, N-acetyl cysteine and NAC, Sadenosylmethionine and folic acid, may restore LINE-1 hypomethylation.…”

Section: Discussionmentioning

confidence: 99%

Paranoid schizophrenia and methamphetamine-induced paranoia are both characterized by a similar LINE-1 partial methylation profile, which is more pronounced in paranoid schizophrenia

Kalayasiri

Kraijak

Mutirangura

et al. 2019

Schizophrenia Research

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Background: There is evidence that schizophrenia is a neuro-immune disorder. Genes linked to intragenic LINE-1 methylation show a strong association with immune-associated disorders including psychosis. The aim of this study was to examine LINE-1 methylation patterns in paranoid schizophrenia and methamphetamine-induced paranoia, a model for schizophrenia.Methods: This study recruited 31 patients with paranoid schizophrenia, 94 with methamphetamine-induced paranoia (MIP) and 163 normal controls. LINE-1 methylation patterns were assayed in peripheral blood mononuclear cells and a combined bisulphite restriction analysis and COBRA were used to estimate global methylation (mC) and LINE-1 CpG dinucleotide methylation patterns, namely 2 methylated (mCmC) and 2 unmethylated (uCuC) CpGs and the partially methylated loci mCuC (5'm with 3'u) and uCmC (5'u with 3'm).Results: Patients with paranoid schizophrenia show highly significant changes in LINE-1 partial methylation patterns, namely a higher % mCuC and lower % uCmC as compared with controls and MIP patients, while the latter show higher % mCuC but lower % uCmC as compared with controls. Higher % mCuC significantly predicts paranoid schizophrenia with a sensitivity of 51.6%, specificity of 97.5% and an area under the ROC curve of 0.895. Conclusions:The results indicate that a common dysfunction in LINE-1 partial methylation may underpin both paranoid schizophrenia and MIP and that this methylation pattern is significantly more expressed in paranoid schizophrenia than MIP. Reciprocal links between impairments in LINE-1 methylation and neuro-immune and neuro-oxidative pathways may underpin the pathophysiology of both MIP and paranoid schizophrenia..

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Oxidative stress and repetitive element methylation changes in artisanal gold miners occupationally exposed to mercury

Cited by 17 publications

References 41 publications

The effects of flavonoids, green tea polyphenols and coffee on DMBA induced LINE-1 DNA hypomethylation

The effects of flavonoids, green tea polyphenols and coffee on DMBA induced LINE-1 DNA hypomethylation

The Clinical Importance of the Mercury Problem in Artisanal Small-Scale Gold Mining

Paranoid schizophrenia and methamphetamine-induced paranoia are both characterized by a similar LINE-1 partial methylation profile, which is more pronounced in paranoid schizophrenia

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