These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Di-(2-ethylhexyl) phthalate suppresses IL-12p40 production by GM-CSF-dependent macrophages via the PPARα/TNFAIP3/TRAF6 axis after lipopolysaccharide stimulation.
    Author: Yamaguchi R, Sakamoto A, Yamamoto T, Narahara S, Sugiuchi H, Hisada A, Katoh T, Yamaguchi Y.
    Journal: Hum Exp Toxicol; 2018 Jun; 37(6):596-607. PubMed ID: 28673093.
    Abstract:
    Activation of peroxisome proliferator-activated receptor α (PPARα) by di-(2-ethylhexyl) phthalate (DEHP) has an anti-inflammatory effect. This study investigated the potential combined influence of PPARα, tumor necrosis factor α-induced protein 3 (TNFAIP3/A20), and tumor necrosis factor receptor-associated factor 6 (TRAF6) on interleukin (IL)-12p40 production by macrophages exposed to DEHP and stimulated with lipopolysaccharide (LPS). LPS upregulated IL-12p40 expression by granulocyte-macrophage colony-stimulating factor-dependent macrophages (on day 9 of culture), whereas adding DEHP to cultures significantly attenuated the response of IL-12p40 to LPS stimulation. PPARα protein was also reduced by DEHP. Interestingly, transfection of macrophages with small interfering RNA (siRNA) duplexes for PPARα, TNFAIP3/A20, or dual oxidase 2 restored the response of IL-12p40 protein to LPS stimulation in the presence of DEHP. siRNAs for various protein kinase Cs (PKCs) (α, β, γ, or δ) also restored IL-12p40 production by macrophages exposed to LPS and DEHP. While LPS upregulated both IL-12p40 and TNFAIP3/A20 production, adding DEHP to cultures dramatically reduced IL-12p40 and TNFAIP3/A20 levels. Silencing of PKCα reduced TNFAIP3/A20 production, whereas PKCγ siRNA (but not PKCβ or δ siRNA) significantly increased TNFAIP3/A20. TRAF6 was also attenuated by macrophages with DEHP. The PPARα/TNFAIP3/TRAF6 axis may have an important role in the mechanism through which DEHP reduces IL-12p40 production by LPS-stimulated macrophages.
    [Abstract] [Full Text] [Related] [New Search]