Kang HB, Kim YE, Kwon HJ, Sok DE, Lee Y.. Enhancement of NF-kappaB expression and activity upon differentiation of human embryonic stem cell line SNUhES3. Stem Cells Dev 16: 615-623

Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk, 361-763, Korea.
Stem Cells and Development (Impact Factor: 4.2). 09/2007; 16(4):615-23. DOI: 10.1089/scd.2007.0014
Source: PubMed

ABSTRACT NF-kappaB is involved in many biological processes including proliferation, survival, and differentiation. Because human embryonic stem (ES) cells have the potential to differentiate to various lineages, understanding mechanisms involved in stemness and lineage differentiation is an important issue. We investigated expression of NF-kappaB in the human ES cell lines SNUhES3 and MizhES4 and found that expression of NF-kappaB mRNA and protein in these two cell lines was significantly lower compared to those of other adult cell lines. However, when SNUhES3 cells were induced to differentiate by retinoic acid, expression levels of NF-kappaB significantly increased compared to undifferentiated SNUhES3 cells. As the components of tumor necrosis factor-alpha (TNF-alpha) signaling are expressed comparably in undifferentiated and differentiated SNUhES3 cells, we examined the responsiveness of SNUhES3 cells to treatment with TNF-alpha, an agonist of NF-kappaB signaling. Nuclear localization of NF-kappaB in response to TNF-alpha was evident in differentiated, but not undifferentiated, SNUhES3 cells. In agreement with this observation, induction of interleukin-8 (IL-8) in response to TNF-alpha was seen only in differentiated SNUhES3 cells. On the basis of an IkappaB kinase (IKK) inhibitor study, expression of IL-8 induced by TNF-alpha was dependent on NF-kappaB activity. Taken together, our results suggest that expression and activity of NF-kappaB is comparatively low in undifferentiated human ES cells, but increases during differentiation of the ES cells.

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    • "Results are of three experiments, each conducted in duplicate. determine the relative amount of immunoprecipitated DNA from the PAD4 promoter region, the IL8 promoter region with which p50 and p65 are known to interact with as a positive control, and the negative control C4ORF11 (Fig. 5; Kang et al., 2007). ChIP analysis confirmed that p65 was highly enriched at the IL8 promoter but not significantly enriched at the PAD4 promoter upon TNF-α stimulation (Fig. 5A, B). "
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    ABSTRACT: High titers of anti-citrullinated protein/peptide antibodies (ACPAs) have been detected in sera of rheumatoid arthritis (RA) patients, implicating citrullinating enzymes in the pathogenesis of RA. Peptidylarginine deiminase type IV (PAD4) is a member of the PAD family of citrullinating enzymes and has been linked to RA. Therefore, our aim was to determine how transcription of PAD4 is regulated in the human myeloid lineage. We located the PAD4 transcription start site and promoter and phylogenetic comparisons of the area identified a 200bp conserved region. Bioinformatics analysis predicted the presence of a NF-κB binding site and we tested this via luciferase assays. Intriguingly, mutation of the predicted NF-κB site significantly increased biological activity. We used RT-qPCR to quantify PAD4 expression in HL-60 cells treated with TNF-α to activate the canonical NF-κB pathway and found that PAD4 mRNA was reduced in response to TNF-α treatment. Finally, we used chromatin immunoprecipitation (ChIP) to determine NF-κB enrichment at the PAD4 promoter and the p50 subunit of NF-κB was more highly enriched than p65 at the PAD4 promoter. These results suggest that the p50 subunit of NF-κB may play a role in the repression of PAD4 transcription during inflammation.
    Gene 10/2013; DOI:10.1016/j.gene.2013.09.108 · 2.08 Impact Factor
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    • "IL-6 and IL-8 are cytokines involved in infection and immunity, inflammation, autoimmune diseases and cancer [14] [15]. Both cytokines are transcribed by the nuclear factor k B (NFkB) complex in response to bacterial lipopolysaccharides (LPS) and tumor necrosis factor-alpha (TNF-alpha) [16] [17]. In a recent report IL-6 and IL-8 over expression in the epithelial lung cancer cell line H460a was identified as driver of an in vivo resistance "
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    Cytokine 03/2013; 62(1). DOI:10.1016/j.cyto.2013.01.021 · 2.87 Impact Factor
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    • "We have shown that activation of NFkB is upregulated during differentiation of GICs. In agreement with this, it has been described that expression and activity of NFkB is comparatively low in undifferentiated embryonic-initiating cells, but increases following induction of differentiation (Kang et al., 2007; Torres and Watt, 2008). The low activation of NFkB detected in GICs suggests that NFkB may be dispensable for survival and proliferation of these tumor Figure 3 Blockade of NFkB signaling in differentiating GICs accelerates differentiation. "
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