TY - JOUR
T1 - Iκb-ζ plays an important role in the ERK-dependent dysregulation of malaria parasite GPI-induced IL-12 expression
AU - Zhu, Jianzhong
AU - Weinberg, Rebecca
AU - Wu, Xianzhu
AU - Gowda, Nagaraj M.
AU - Muta, Tatsushi
AU - Gowda, D. Channe
PY - 2012/2
Y1 - 2012/2
N2 - Plasmodium falciparum glycosylphosphatidylinositols (GPIs) have been proposed as malaria pathogenic factors based on their ability to induce proinflammatory responses in macrophages and malaria-like symptoms in mice. Parasite GPIs induce the production of inflammatory cytokines by activating the mitogen-activated protein kinase (MAPK) and NF-κB signaling pathways. Importantly, inhibition of the extracellular-signal-regulated kinase (ERK) pathway upregulates a subset of cytokines, including IL-12. We investigated the role of nuclear transcription factor, IκB-ζ, in the GPI-induced dysregulated expression of IL-12 on inhibition of the ERK pathway. GPIs efficiently induced the expression of IκB-ζ in macrophages regardless of whether cells were pretreated or untreated with ERK inhibitors, indicating that ERK has no role in IκB-ζ expression. However, on ERK inhibition followed by stimulation with GPIs, NF-κB binding to Il12b promoter κB site was markedly increased, suggesting that the ERK pathway regulates Il12b transcription. Knockdown of IκB-ζ using siRNA markedly reduced the GPI-induced IL-12 production and abrogated the dysregulated IL-12 production in ERK inhibited cells. Together these results demonstrate that ERK modulates IL-12 expression by regulating IκB-ζ-dependent binding of NF-κB transcription factors to Il12b gene promoter. Additionally, our finding that IκB-ζ can be knocked down efficiently in primary macrophages is valuable for studies aimed at gaining further insights into IκB-ζ function.
AB - Plasmodium falciparum glycosylphosphatidylinositols (GPIs) have been proposed as malaria pathogenic factors based on their ability to induce proinflammatory responses in macrophages and malaria-like symptoms in mice. Parasite GPIs induce the production of inflammatory cytokines by activating the mitogen-activated protein kinase (MAPK) and NF-κB signaling pathways. Importantly, inhibition of the extracellular-signal-regulated kinase (ERK) pathway upregulates a subset of cytokines, including IL-12. We investigated the role of nuclear transcription factor, IκB-ζ, in the GPI-induced dysregulated expression of IL-12 on inhibition of the ERK pathway. GPIs efficiently induced the expression of IκB-ζ in macrophages regardless of whether cells were pretreated or untreated with ERK inhibitors, indicating that ERK has no role in IκB-ζ expression. However, on ERK inhibition followed by stimulation with GPIs, NF-κB binding to Il12b promoter κB site was markedly increased, suggesting that the ERK pathway regulates Il12b transcription. Knockdown of IκB-ζ using siRNA markedly reduced the GPI-induced IL-12 production and abrogated the dysregulated IL-12 production in ERK inhibited cells. Together these results demonstrate that ERK modulates IL-12 expression by regulating IκB-ζ-dependent binding of NF-κB transcription factors to Il12b gene promoter. Additionally, our finding that IκB-ζ can be knocked down efficiently in primary macrophages is valuable for studies aimed at gaining further insights into IκB-ζ function.
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U2 - 10.1002/iub.592
DO - 10.1002/iub.592
M3 - Article
C2 - 22131231
AN - SCOPUS:84862919818
VL - 64
SP - 187
EP - 193
JO - Biochemistry and Molecular Biology International
JF - Biochemistry and Molecular Biology International
SN - 1521-6543
IS - 2
ER -