Predictors of mitochondrial DNA copy number and damage in a mercury‐exposed rural Peruvian population near artisanal and small‐scale gold mining: An exploratory study

Abstract

Mitochondrial DNA (mtDNA) copy number (CN) and damage in circulating white blood cells have been proposed as effect biomarkers for pollutant exposures. Studies have shown that mercury accumulates in mitochondria and affects mitochondrial function and integrity; however, these data are derived largely from experiments in model systems, rather than human population studies that evaluate the potential utility of mitochondrial exposure biomarkers. We measured mtDNA CN and damage in white blood cells (WBCs) from 83 residents of nine communities in the Madre de Dios region of the Peruvian Amazon that vary in proximity to artisanal and small‐scale gold mining. Prior research from this region reported high levels of mercury in fish and a significant association between food consumption and human total hair mercury level of residents. We observed that mtDNA CN and damage were both associated with consumption of fruit and vegetables, higher diversity of fruit consumed, residential location, and health characteristics, suggesting common environmental drivers. Surprisingly, we observed negative associations of mtDNA damage with both obesity and age. We did not observe any association between total hair mercury or, in contrast to previous results, age, with either mtDNA damage or CN. The results of this exploratory study highlight the importance of combining epidemiological and laboratory research in studying the effects of stressors on mitochondria, suggesting that future work should incorporate nutritional and social characteristics, and caution should be taken when applying conclusions from epidemiological studies conducted in the developed world to other regions, as results may not be easily translated. Environ. Mol. Mutagen. 60: 197–210, 2019. © 2018 Wiley Periodicals, Inc.

High exposure variance enables candidate biomarker detection in a small EWAS of methylmercury-exposed Peruvian adults

“…2C-D ), as well as promoter hypermethylation of the RIG-1 signaling pathway ( Supplemental Table S4 ) through which DAMPs trigger innate immune responses 139 . Although prior papers have not reported clear associations between mitochondrial biomarkers and MeHg exposure, it was unclear whether this lack of signal was statistical or biological 140,141 . The clear signal in immune signaling pathways in our data, coupled with the lack of association between mitochondrial biomarkers and MeHg, indicates that the biological role of mitochondria in the response to MeHg is more complex than previously thought.…”

Bioenergetic function is decreased in peripheral blood mononuclear cells of veterans with Gulf War Illness

“…difference in averages between three different communities in Peru, despite high variability within each community [56], indicating that a significant portion of the variability was nonrandom. Second, in the current study, we identified two individuals with a surprisingly low mtDNA CN values.…”

Health Studies in the Context of Artisanal and Small-Scale Mining: A Scoping Review

“…Besides chemical pollutants, blood, and urine samples were also analysed for other physiological parameters, such as blood lactate and cyanide [73,74], haematological parameters, and other blood chemistry [47,75], mitochondrial DNA, and other DNA mutations [48,[76][77][78], immunological response to vaccines, and other immune-related proteins [50,79,80], renal and respiratory parameters [75,81], and infectious diseases, such as malaria [82] and HIV [47,83]. Saliva (cortisol salivary) [84], Buccal cells (DNA damage and mutations) [63,77], and stool samples (soil-transmitted helminths and Vibrio cholerae) [85,86] were also reported.…”