Rapid enhancement of beta 2-interferon/B-cell differentiation factor BSF-2 gene expression in human fibroblasts by diacylglycerols and the calcium ionophore A23187.

Abstract

The expression in human fibroblasts of the p2-interferon (IFN-.82) gene, which is now recognized to be identical to the gene encoding B-cell differentiation factor BSF-2, is enhanced by several cytokines that affect cell growth (tumor necrosis factor, interleukin 1, platelet-derived growth factor, and fi1-interferon). We have examined the possibility that IFN-.82 gene expression is regulated through activation, by diacylglycerol, of the protein kinase C pathway. MATERIALS AND METHODSThe human foreskin diploid fibroblast strain FS-4 was obtained from J. Vildek (New York University School of Medicine, New York); procedures for its growth in cell culture and for the IFN-p2 mRNA induction experiments have been described (1,5,12,13). In brief, FS-4 cells were grown to confluence in T-175 Falcon flasks in Eagle's minimal essential medium supplemented with 10% (vol/vol) heat-inactivated fetal bovine serum (GIBCO). The cultures were refed at weekly intervals, and confluent cultures were used for experiments 6-8 days after the last medium change. Concentrated solutions of the experimental reagents were added directly to the spent medium in the cultures. 1,2-Dioctanoylglycerol (diC8) was purchased from Avanti Polar Abbreviations: diC8, 1,2-dioctanoylglycerol; H7, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride; H8, N-[2-(methylamino)ethyl]-5-isoquinolinesulfonamide dihydrochloride; IFN, interferon; IL-1, interleukin 1; OAG, 1-oleoyl-2-acetylglycerol; TNF, tumor necrosis factor; VSV, vesicular stomatitis virus. 3663The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.

Effect of Protein Kinase C Inhibitors on Interferon-beta Production by Viral and Non-viral Inducers

“…The role of PKC in regulation of protein biosynthesis in eukaryotic cells is well documented. From the results of our present study and those of other reports (Sehgal et al, 1987;Gessani et al, 1989), it is likely that PKC activity is involved in the induction of IFN-fl by poly(rI), poly(rC). Furthermore data presented in Table 4 show also that calcium--calmodulin-mediated cellular processes are not involved in IFN-fl production by poly(rI), poly(rC).…”

“…However we measured PKC activity in cytosol and in the membrane fraction of BG-9 and L-929 cells and demonstrated that concentrations of K252a at 0.01 to 0-10 I-tM indeed inhibited PKC activity. Our observations with K252a and H-7, together with results from other laboratories utilizing activators of PKC (Gessani et al, 1989;Sehgal et al, 1987), strongly support a regulatory role for this kinase in the induction by poly(rI), poly(rC) of IFN-fl. The possibility that kinase activity other than that of PKC is involved in IFN-fl induction by poly(rI), poly-(rC) is not excluded in the present studies.…”

“…2). Similar conclusions were also reached by Sehgal et al (1987) using diacylglycerol as an enhancer of IFN-fl2 mRNA synthesis in human cells. However when K252a was added at 4 h after induction, the amount of biologically active IFN produced was significantly reduced in K252a-treated cells ( Fig.…”

Interleukin 1 and tumour necrosis factor increase phosphorylation of fibroblast proteins

“…They activate connective tissue cells directly to increase glycolysis [9] and the synthesis of a variety of products in- cluding prostaglandins, proteinases [1,2] and interleukin 6 [10]. Since protein phosphorylation is the major known mechanism by which extracellular signals regulate intracellular processes, we decided to investigate whether ILl or TNF caused early changes in such phosphorylation in fibroblasts.…”

Amniotic fluid interleukin-6 in preterm labor: Association with infection

“…This cytokine consists of a group of differentially modified phosphoglycoproteins ranging in size from 23 to 30 kD and additional complexes of 43-45 kD (8)(9)(10)(11)(12)(13) derived from a single gene located at 7p2l in the human genome (14)(15)(16). IL-6 gene expression is induced by several inflammation-associated cytokines (including IL-1, TNF, and interferons), bacterial products, RNAand DNA-containing viruses, and second messenger agonists (diacylglycerol, cAMP, and Ca2+) that activate any ofthe three major signal transduction pathways (17)(18)(19)(20)(21)(22)(23)(24)(25)(26). Cell types capable of secreting IL-6 in response to stimulation include fibroblasts, monocytes/macrophages, endothelial cells, keratinocytes, and endometrial stromal cells .…”