Next Article in Journal
Next Article in Special Issue
Previous Article in Journal
Previous Article in Special Issue
Int. J. Mol. Sci. 2012, 13(6), 7710-7738; doi:10.3390/ijms13067710
Article

Effects of Methylmercury Contained in a Diet Mimicking the Wayana Amerindians Contamination through Fish Consumption: Mercury Accumulation, Metallothionein Induction, Gene Expression Variations, and Role of the Chemokine CCL2

1,* , 1
, 1
, 1
, 1
, 1
, 2
, 3
, 4
, 4
 and 5
Received: 1 May 2012; in revised form: 11 June 2012 / Accepted: 14 June 2012 / Published: 21 June 2012
(This article belongs to the Special Issue Molecular Mechanisms of Organ-Specific Toxicity)
View Full-Text   |   Download PDF [1667 KB, uploaded 19 June 2014]   |   Browse Figures
Abstract: Methylmercury (MeHg) is a potent neurotoxin, and human beings are mainly exposed to this pollutant through fish consumption. We addressed the question of whether a diet mimicking the fish consumption of Wayanas Amerindians from French Guiana could result in observable adverse effects in mice. Wayanas adult men are subjected to a mean mercurial dose of 7 g Hg/week/kg of body weight. We decided to supplement a vegetarian-based mice diet with 0.1% of lyophilized Hoplias aimara fish, which Wayanas are fond of and equivalent to the same dose as that afflicting the Wayanas Amerindians. Total mercury contents were 1.4 ± 0.2 and 5.4 ± 0.5 ng Hg/g of food pellets for the control and aimara diets, respectively. After 14 months of exposure, the body parts and tissues displaying the highest mercury concentration on a dry weight (dw) basis were hair (733 ng/g) and kidney (511 ng/g), followed by the liver (77 ng/g). Surprisingly, despite the fact that MeHg is a neurotoxic compound, the brain accumulated low levels of mercury (35 ng/g in the cortex). The metallothionein (MT) protein concentration only increased in those tissues (kidney, muscles) in which MeHg demethylation had occurred. This can be taken as a molecular sign of divalent mercurial contamination since only Hg2+ has been reported yet to induce MT accumulation in contaminated tissues. The suppression of the synthesis of the chemokine CCL2 in the corresponding knockout (KO) mice resulted in important changes in gene expression patterns in the liver and brain. After three months of exposure to an aimara-containing diet, eight of 10 genes selected (Sdhb, Cytb, Cox1, Sod1, Sod2, Mt2, Mdr1a and Bax) were repressed in wild-type mice liver whereas none presented a differential expression in KO Ccl2/ mice. In the wild-type mice brain, six of 12 genes selected (Cytb, Cox1, Sod1, Sod2, Mdr1a and Bax) presented a stimulated expression, whereas all remained at the basal level of expression in KO Ccl2/ mice. In the liver of aimara-fed mice, histological alterations were observed for an accumulated mercury concentration as low as 32 ng/g, dw, and metal deposits were observed within the cytoplasm of hepatic cells.
Keywords: methylmercury; fish consumption; chemokine; mercury accumulation; metallothionein; demethylation methylmercury; fish consumption; chemokine; mercury accumulation; metallothionein; demethylation
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Export to BibTeX |
EndNote


MDPI and ACS Style

Bourdineaud, J.-P.; Laclau, M.; Maury-Brachet, R.; Gonzalez, P.; Baudrimont, M.; Mesmer-Dudons, N.; Fujimura, M.; Marighetto, A.; Godefroy, D.; Rostène, W.; Brèthes, D. Effects of Methylmercury Contained in a Diet Mimicking the Wayana Amerindians Contamination through Fish Consumption: Mercury Accumulation, Metallothionein Induction, Gene Expression Variations, and Role of the Chemokine CCL2. Int. J. Mol. Sci. 2012, 13, 7710-7738.

AMA Style

Bourdineaud J-P, Laclau M, Maury-Brachet R, Gonzalez P, Baudrimont M, Mesmer-Dudons N, Fujimura M, Marighetto A, Godefroy D, Rostène W, Brèthes D. Effects of Methylmercury Contained in a Diet Mimicking the Wayana Amerindians Contamination through Fish Consumption: Mercury Accumulation, Metallothionein Induction, Gene Expression Variations, and Role of the Chemokine CCL2. International Journal of Molecular Sciences. 2012; 13(6):7710-7738.

Chicago/Turabian Style

Bourdineaud, Jean-Paul; Laclau, Muriel; Maury-Brachet, Régine; Gonzalez, Patrice; Baudrimont, Magalie; Mesmer-Dudons, Nathalie; Fujimura, Masatake; Marighetto, Aline; Godefroy, David; Rostène, William; Brèthes, Daniel. 2012. "Effects of Methylmercury Contained in a Diet Mimicking the Wayana Amerindians Contamination through Fish Consumption: Mercury Accumulation, Metallothionein Induction, Gene Expression Variations, and Role of the Chemokine CCL2." Int. J. Mol. Sci. 13, no. 6: 7710-7738.



Int. J. Mol. Sci. EISSN 1422-0067 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert