We investigated the mechanisms by which primary human monocyte migration and the production of important cytokines are co-regulated. Motile monocytes underwent cyclic morphologic and adhesive changes that were associated with intracellular free calcium changes; in such cells, cytokine transcripts were unstable and translationally repressed. Agents that activate monocytes, including lipopolysacharrides (LPS), cytomegalovirus (CMV), and tumor necrosis factor (TNFalpha), have been shown to de-repress translation and these agents stabilize adhesion-induced transcripts for IL-lbeta and IL-8 and markedly diminish cell migration in the presence of autologous serum.
View Article and Find Full Text PDFThe nuclear factor kappaB (NF-kappaB) regulates the transcription of genes bearing the kappaB consensus motif. Transmigration of NF-kappaB from the cytoplasm to the nucleus is regulated by the IkappaB family of inhibitory NF-kappaB-binding proteins. Dissociation of the NF-kappaB-IkappaB complex requires both phosphorylation and degradation of IkappaBs.
View Article and Find Full Text PDFAm J Obstet Gynecol
September 1995
Objective: The purpose of this study was to determine and compare the expression of the alpha 2-, alpha 3-, alpha 4- and alpha 5-subunits of the beta 1-family of integrins in both the normal and the carcinomatous cervix.
Study Design: A total of 22 solid tissue specimens (18 cancer and 4 normal) were analyzed immunohistochemically. The double-stain technique used an avidin-biotin complex kit to identify the various integrins and alkaline phosphatase-anti-alkaline phosphatase kit to identify the epithelial cells.
Activation of cytoplasmic tyrosine kinases is an important aspect of signal transduction mediated by integrins. In the human monocytic cell line THP-1, either integrin-dependent cell adhesion to fibronectin or ligation of beta 1 integrins with antibodies causes a rapid and intense tyrosine phosphorylation of two sets of proteins of about 65-75 and 120-125 kDa. In addition, integrin ligation leads to nuclear translocation of the p50 and p65 subunits of the NF-kappa B transcription factor, to activation of a reporter gene driven by a promoter containing NF-kappa B sites, and to increased levels of mRNAs for immediate-early genes, including the cytokine interleukin (IL)-1 beta.
View Article and Find Full Text PDFThe regulation of the inhibitor of nuclear factor kappa B (I kappa B) by interleukin 1 (IL1) was investigated in HeLa cells. Two forms of I kappa B were resolved by ion-exchange chromatography. The major form (75%) was identified as MAD3 by specific antisera.
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