Arsenite, a well-established human carcinogen and toxic compound, promotes the formation of mitochondrial superoxide (mitoO) via a Ca-dependent mechanism, in which an initial stimulation of the inositol 1, 4, 5-trisphosphate receptor (IPR) is followed by the activation of the ryanodine receptor (RyR), critical for providing Ca to the mitochondria. We now report that, under the same conditions, arsenite triggers endoplasmic reticulum (ER) stress and a threefold increase in ER oxidoreductin 1α (ERO1 α) levels in proliferating U937 cells. EN460, an inhibitor of ERO1 α, recapitulated all the effects associated with RyR inhibition or downregulation, including prevention of RyR-induced Ca accumulation in mitochondria and the resulting O formation.
View Article and Find Full Text PDFArsenite induces many critical effects associated with the formation of reactive oxygen species (ROS) through different mechanisms. We focused on Ca-dependent mitochondrial superoxide (mitoO) formation and addressed questions on the effects of low concentrations of arsenite on the mobilization of the cation from the endoplasmic reticulum and the resulting mitochondrial accumulation. Using various differentiated and undifferentiated cell types uniquely expressing the inositol-1, 4, 5-triphosphate receptor (IPR), or both the IPR and the ryanodine receptor (RyR), we determined that expression of this second Ca channel is an absolute requirement for mitoO formation and for the ensuing mitochondrial dysfunction and downstream apoptosis.
View Article and Find Full Text PDFObjective: Countries have major differences in the acceptance of face mask use for the prevention of COVID-19. This work aims at studying the information online in different countries in terms of information quality and content.
Design: Content analysis.
The fact that Internet companies may record our personal data and track our online behavior for commercial or political purpose has emphasized aspects related to online privacy. This has also led to the development of search engines that promise no tracking and privacy. Search engines also have a major role in spreading low-quality health information such as that of anti-vaccine websites.
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