Abstract
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.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 187-193 |
| Number of pages | 7 |
| Journal | IUBMB Life |
| Volume | 64 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 2012 |
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All Science Journal Classification (ASJC) codes
- Biochemistry
- Molecular Biology
- Genetics
- Clinical Biochemistry
- Cell Biology
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Iκb-ζ plays an important role in the ERK-dependent dysregulation of malaria parasite GPI-induced IL-12 expression. / Zhu, Jianzhong; Weinberg, Rebecca; Wu, Xianzhu; Gowda, Nagaraj M.; Muta, Tatsushi; Gowda, D. Channe.
In: IUBMB Life, Vol. 64, No. 2, 02.2012, p. 187-193.Research output: Contribution to journal › Article
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.
UR - http://www.scopus.com/inward/record.url?scp=84862919818&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84862919818&partnerID=8YFLogxK
U2 - 10.1002/iub.592
DO - 10.1002/iub.592
M3 - Article
C2 - 22131231
AN - SCOPUS:84862919818
VL - 64
SP - 187
EP - 193
JO - IUBMB Life
JF - IUBMB Life
SN - 1521-6543
IS - 2
ER -