DeLong, Lauren Nicole;
Barbosa, Jeremie Rose;
Nyland, Jennifer
Assessing the Effects of Inorganic Arsenic on IL‐1β and TNFɑ Secretion, Gene Expression, and DNA Methylation in Murine Macrophages to Gauge Immunotoxic Effects of Heavy Metals
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Media type:
E-Article
Title:
Assessing the Effects of Inorganic Arsenic on IL‐1β and TNFɑ Secretion, Gene Expression, and DNA Methylation in Murine Macrophages to Gauge Immunotoxic Effects of Heavy Metals
Contributor:
DeLong, Lauren Nicole;
Barbosa, Jeremie Rose;
Nyland, Jennifer
Description:
<jats:p>Trivalent inorganic arsenic, arsenite, is a natural component of the earth and is often found in drinking water in areas where the composition is high. Some studies have suggested that, especially at moderate to high exposure levels, arsenite is toxic to individuals who are chronically exposed through drinking water, characterized by an increase in inflammatory cytokine release, specifically interleukin‐1β (IL‐1β) and tumor necrosis factor‐ɑ (TNFɑ). Other epidemiological studies at low to moderate exposures did not find the same correlation with inflammation. We aim to characterize and quantify the effects of arsenite exposure to macrophages to gauge any potential inflammatory response.</jats:p><jats:p>M1 macrophages are key players in inflammatory response and secrete IL‐1β and TNFɑ in response to Danger Associated Molecular Patterns (DAMPs) released by neighboring cells undergoing necrosis, in coordination with Pathogen Associated Molecular Patterns (PAMPs), molecules associated with pathogens, such as lipopolysaccharide, or LPS. We obtained a murine macrophage cell line to study the effects of arsenic on inflammatory cytokine secretion <jats:italic>in vitro</jats:italic>. A dose response curve was developed including varying concentrations of arsenite with and without 50 ng/mL LPS, using the same treatments without arsenite as controls. Cytolethality was determined by differential staining and counting. Secretion of cytokines after 24 hours of exposure was quantified using ELISA. Results were statistically analyzed using Student's t‐test and One‐Way ANOVA. IL‐1β was not differentially secreted for any concentration of arsenite, but cytolethality and TNFɑ secretion were significantly increased for 200 nM arsenite with LPS as opposed to 200 nM arsenite without LPS, possibly indicating that some inflammatory augmentation occurs in the presence of both arsenite exposure and a PAMP.</jats:p><jats:p>Future steps include analyzing alterations in expression of genes responsible for proteins involved in the secretory pathways of these cytokines. For example, the genes involved in manufacturing the pieces of the NLRP3 inflammasome, key in production of IL‐1β, or TNFɑ Converting Enzyme, involved in cleavage of the TNFɑ precursor, may be potential targets. Additionally, we will explore differential DNA methylation using methylation sensitive and insensitive restriction enzyme digestion to examine epigenetic control of cytokine secretion in response to arsenite. These results will be reported to appraise the immunotoxic effects of arsenic exposure.</jats:p><jats:p><jats:bold>Support or Funding Information</jats:bold></jats:p><jats:p>This research is supported by the Salisbury University Department of Biological Sciences and the Salisbury University Honors College.</jats:p><jats:p>This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in <jats:italic>The FASEB Journal</jats:italic>.</jats:p>