Enhancement of NF-kappaB expression and activity upon differentiation of human embryonic stem cell line SNUhES3.
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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ABSTRACT: Deficiency of the nuclear factor-kappa-B essential modulator (NEMO) is a rare X-linked disorder that presents in boys as hypohydrotic ectodermal dysplasia with immunodeficiency due to defective nuclear factor-κB activation. Here we report on the generation of 2 human embryonic stem cell lines from discarded in vitro fertilization (IVF) embryos ascertained via preimplantation genetic diagnosis. We have derived two human embryonic stem cell lines that carry a T458G hypomorphic mutation in exon 4 of the NEMO (or IKBKG) gene. One of the lines is diploid male; the other is diploid female but has clonally inactivated the X-chromosome that harbors the wild-type IKBKG gene. We show that both lines are pluripotent, have the capacity to differentiate into hematopoietic progenitors, and have defective inhibitor of nuclear factor kappa-B kinase activity. These NEMO deficiency hES cell lines provide an unlimited source for differentiated cell types and may serve as a unique tool to study NEMO deficiency and potentially lead to the development of new therapies for this disease.Stem Cell Research 01/2012; 8(3):410-5. DOI:10.1016/j.scr.2011.12.007 · 3.91 Impact Factor
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ABSTRACT: Bicuspid aortic valves calcify at a significantly higher rate than normal aortic valves, a process that involves increased inflammation. Because we have previously found that bicuspid aortic valve experience greater stretch, we investigated the potential connection between stretch and inflammation in human aortic valve interstitial cells (AVICs). Microarray, quantitative PCR (qPCR), and protein assays performed on AVICs exposed to cyclic stretch showed that stretch was sufficient to increase expression of interleukin and metalloproteinase family members by more than 1.5-fold. Conditioned media from stretched AVICs was sufficient to activate leukocytes. microRNA sequencing and qPCR experiments demonstrated that miR-148a-3p was repressed in both stretched AVICs (43% repression) and, as a clinical correlate, human bicuspid aortic valves (63% reduction). miR-148a-3p was found to be a novel repressor of IKBKB based on data from qPCR, luciferase, and Western blot experiments. Furthermore, increasing miR-148a-3p levels in AVICs was sufficient to decrease NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) signaling and NF-κB target gene expression. Our data demonstrate that stretch-mediated activation of inflammatory pathways is at least partly the result of stretch-repression of miR-148a-3p and a consequent failure to repress IKBKB. To our knowledge, we are the first to report that cyclic stretch of human AVICs activates inflammatory genes in a tissue-autonomous manner via a microRNA that regulates a central inflammatory pathway.-Patel, V., Carrion, K., Hollands, A., Hinton, A., Gallegos, T., Dyo, J., Sasik, R., Leire, E., Hardiman, G., Mohamed, S. A., Nigam, S., King, C. C., Nizet, V., Nigam V. The stretch responsive microRNA miR-148a-3p is a novel repressor of IKBKB, NF-κB signaling, and inflammatory gene expression in human aortic valve cells. © FASEB.The FASEB Journal 01/2015; 29(5). DOI:10.1096/fj.14-257808 · 5.48 Impact Factor
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ABSTRACT: The canonical and noncanonical NFκB signaling pathways regulate a variety of cellular activities; however, their functions in human embryonic stem cells (hESCs) have not been fully investigated. Expression studies during hESC differentiation indicated a significant increase in the expression of two key components of the canonical NFκB pathway (p50 and Ser529 phosphorylated form of p65) as well as a significant reduction in expression of key components of the noncanonical NFκB pathway [v-rel reticuloendotheliosis viral oncogene homolog B (RELB), p52, NIK]. Inhibition of canonical NFκB resulted in hESC apoptosis, changes in cell cycle distribution, and reduced hESC proliferation. In addition, inhibition of canonical NFκB was associated with significant changes in NANOG and OCT4 expression, suppression of differentiation toward all primitive extraembryonic and embryonic lineages with the exception of primitive ectoderm and ectodermal lineages. Inhibition of noncanonical NFκB via small interfering RNA-mediated downregulation of RELB resulted in reduced hESC proliferation and opposite changes to expression of key differentiation lineage markers genes when compared with downregulation of canonical NF-κB. Chromatin immunoprecipitation assays indicated binding of p65 and RELB to regulatory regions of key differentiation marker genes suggesting a direct transcriptional role for both branches of this pathway in hESC. These findings coupled with opposing trends in expression of key components during hESC differentiation, suggests a fine and opposing balance between the two branches of NFκB signaling pathways and their involvement in two distinct processes: the canonical pathway regulating hESC differentiation and the noncanonical pathway maintaining hESC pluripotency.Stem Cells 11/2010; 28(11):1970-80. DOI:10.1002/stem.528 · 7.70 Impact Factor