Expression levels and network analysis of inflammamiRs in peripheral blood mononuclear cells exposed to DDE "in vitro".

Recent studies have demonstrated that dichlorodiphenyldichloroethylene (DDE) induced a pro-inflammatory condition in peripheral blood mononuclear cells (PBMC). However, the molecular mechanisms implicated in this condition are poorly understood. Therefore, this study aimed to evaluate miR-155, miR-126, and miR-21 expression levels in PBMC exposed "in vitro" to DDE. PBMC were dosed with increasing concentrations of DDE (10-80 µg mL-1) at different treatment times (0-24 h). The results showed an up-regulation in the expression levels of assessed miRNAs (miR-155, miR-146, and miR-21) after PBMCs were exposed to DDE. Besides, bioinformatic analysis was performed to understand the biological roles of assessed miRNAs. The bioinformatic analysis shows that assessed miRNAs are associated with regulating signaling pathways involved in cancer, apoptosis, cell cycle, inflammation, metabolism, etc. These findings offer new insights into the molecular mechanisms related to the inflammatory processes and their regulation induced by DDE in PBMC exposed "in vitro".

Assessment of persistent organic pollutants levels in blood samples from Quintana Roo, Mexico.

The Stockholm Convention on persistent organic pollutants (POPs) sought to determine baseline exposures to POPs in the general population; however, in developing countries, exposure to these chemicals in hot spots may be an issue of public health considering its magnitude. Therefore, the aim of this study was to assess the levels of POPs in the blood of children living in three communities in the Southeastern Region of Mexico. During 2007, we studied a total of 96 healthy children (aged 6-12 years). Quantitative analyses were performed using gas chromatography coupled with mass spectrometry. High levels of p,p'-DDT and its principal metabolite, p,p'-DDE, were found in the blood of children living in the three communities studied, the levels ranged from 463.5 to 9046.3 ng/g lipid and from 490.8 to 57,712.4 ng/g lipid for DDT and DDE, respectively. In addition, high levels of lindane (γ-HCH) were found, with mean levels ranging between 575.4 and 6580.6 ng/g lipid. Moreover, children living in the study region were also exposed to polychlorinated biphenyls (PCBs), and the levels of these compounds in the blood of children were very similar between the communities with mean levels of around 3000 ng/g lipid (total PCBs). In conclusion, we demonstrated that children living in the studied communities were exposed to complex chemical mixtures (DDT, DDE, lindane and PCBs) rather than to individual compounds. Therefore, in future studies it is important to understand the potential interactions between the components of these mixtures.