curcumin and herbimycin

Prostacyclin (PGI(2)), a potent smooth muscle relaxant, is a major prostaglandin secreted from human myometrium. The concentrations of PGI(2) metabolites in the maternal plasma were reported to be elevated during pregnancy, especially in labor. To clarify the mechanism in PGI(2) secretion from the myometrium, we first investigated the protein expression of cytosolic phospholipase A(2), cyclooxygenase (COX)-1, COX-2, and prostacyclin synthase (PGIS) in the human uterine myometrium at various gestational ages before labor. To elucidate the involvement of labor in the increase in PGI(2) production during labor, we next examined the effect of labor-like cyclic mechanical stretch on PGI(2) production by cultured human myometrial cells. Pregnancy specifically increased COX-1 and PGIS protein expression in the myometrial tissues before labor (P < 0.01 for both). Cyclic mechanical stretch augmented PGIS promoter activity, via activation of activator protein-1 site, and PGIS mRNA and protein expression in cultured human myometrial cells and resulted in a 3.5-fold increase in the concentration of 6-keto-prostaglandin F(1alpha), the stable metabolite of PGI(2), in the culture medium (P < 0.05). However, stretch did not affect the levels of prostaglandin E(2), prostaglandin F(2alpha), or thromboxane A(2) secreted into the same culture media. These results suggest that cyclic mechanical stretch during labor may contribute to the increase in the PGI(2) concentration in the maternal plasma during parturition.

Topics: Benzoquinones; Biomechanical Phenomena; Blotting, Western; Cells, Cultured; Culture Media, Conditioned; Curcumin; Cyclooxygenase 1; Cyclooxygenase 2; Cytochrome P-450 Enzyme System; Dinoprost; Dinoprostone; Epoprostenol; Female; Gene Expression; Genistein; Gestational Age; Humans; Intramolecular Oxidoreductases; Isoenzymes; Labor, Obstetric; Lactams, Macrocyclic; Membrane Proteins; Muscle Spindles; Myometrium; Phospholipases A; Pregnancy; Promoter Regions, Genetic; Prostaglandin-Endoperoxide Synthases; Quinones; Reverse Transcriptase Polymerase Chain Reaction; Rifabutin; RNA, Messenger; Thromboxane A2

Extracellular matrix facilitates anchorage-dependent cell survival via interaction of its arginine-glycine-aspartate (RGD) motif with integrins. In this report, we describe an unexpected, apoptosis-promoting the effect of immobilized RGD (iRGD) on tumor necrosis factor-alpha (TNF-alpha)-induced apoptosis. Mesangial cells cultured on RGD-coated plates showed enhanced susceptibility to TNF-alpha-induced apoptosis. iRGD alone did not affect cell survival. In contrast, iRGD did not facilitate but inhibited apoptosis induced by H(2)O(2). Mitogen-activated protein (MAP) kinases and tyrosine kinases are important mediators for the RGD-integrin signaling. Pretreatment with MAP kinase kinase inhibitor PD098059, c-Jun N-terminal kinase (JNK)-c-Jun/AP-1 inhibitor curcumin or p38 MAP kinase inhibitor SB203580 did not attenuate the apoptosis-promoting effect of iRGD. Consistently, transfection with dominant-negative mutants of extracellular signal-regulated kinases, JNK or p38 MAP kinase did not inhibit the effect of iRGD. In contrast, protein tyrosine kinase inhibitors, genistein, and herbimycin A, abrogated the apoptosis-promoting effect of iRGD. Of note, TNF-alpha-induced apoptosis on uncoated plates was not attenuated by tyrosine kinase inhibitors. These data provide the first evidence that iRGD accelerates certain apoptosis. We identified that the effect was mediated by the tyrosine kinase-dependent, MAP kinase-independent mechanism.

Topics: Animals; Apoptosis; Benzoquinones; Cells, Cultured; Curcumin; Enzyme Inhibitors; Flavonoids; Genes, Dominant; Genistein; Glomerular Mesangium; Hydrogen Peroxide; Imidazoles; JNK Mitogen-Activated Protein Kinases; Lactams, Macrocyclic; MAP Kinase Signaling System; Microscopy, Phase-Contrast; Mitogen-Activated Protein Kinases; Mutation; Oligopeptides; p38 Mitogen-Activated Protein Kinases; Protein-Tyrosine Kinases; Pyridines; Quinones; Rats; Rifabutin; Time Factors; Transcription Factor AP-1; Transfection; Tumor Necrosis Factor-alpha

The replication of human immunodeficiency virus type 1 (HIV-1) requires cellular components to interact with regulatory elements located in the long terminal repeat (LTR) as well as viral proteins Tat and Rev. Several well known signaling transduction inhibitors were tested to determine their effects on the Tat-mediated transactivation using a transfection assay with the bacterial chloramphenicol acetyltransferase gene under the control of the HIV-1 LTR. The protein kinase C inhibitors curcumin and staurosporine, but not a tyrosine kinase inhibitor herbimycine A, inhibited Tat-mediated LTR-driven transactivation. Two antimalarial drugs quinacrine and chloroquine, that are also arachidonic acid metabolism inhibitors, were found to inhibit the Tat-mediated LTR-driven gene expression. Another inhibitor of arachidonic acid metabolism 4-bromophenacyl bromide was also found to inhibit Tat-mediated gene expression driven by HIV-1 LTR. However, the antimalarial drug quinine elicited no effects on Tat-mediated transactivation. These results suggest that the anti-arachidonic acid metabolism properties of quinacrine and chloroquine may be responsible for their ability to inhibit Tat-mediated LTR-regulated gene expression.

Topics: Acetophenones; Alkaloids; Antimalarials; Benzoquinones; Cell Line; Cell Survival; Chloroquine; Curcumin; Gene Expression Regulation, Viral; Gene Products, tat; HIV Long Terminal Repeat; HIV-1; Humans; Lactams, Macrocyclic; Quinacrine; Quinones; Rifabutin; Staurosporine; tat Gene Products, Human Immunodeficiency Virus; Transcriptional Activation; Tumor Cells, Cultured; Virus Replication

Lipopolysaccharide (LPS) induces expression of inflammatory cytokines in monocytes/macrophages via CD14, one of the LPS receptors, which is expressed predominantly in these cells. It has been demonstrated that Porphyromonas gingivalis LPS (P-LPS) also is able to induce inflammatory cytokines in human gingival fibroblasts. Therefore, it is important to determine whether CD14 is expressed in gingival fibroblasts and to define the P-LPS-mediated signal-transducing mechanism in the cells. In this study, we observed unexpectedly by immunohistochemical, Western blotting (immunoblotting), and Northern (RNA) blotting assays that CD14 is expressed at high density in human gingival fibroblasts. P-LPS-induced expression of the monocyte chemoattractant protein 1 (MCP-1) gene in the cells was inhibited markedly by treatment with anti-human CD14 antibody and was completely inhibited by herbimycin A, a potent inhibitor of tyrosine kinase. The inhibitor also dramatically inhibited monocyte chemotactic activity of and MCP-1 production by the cells. Furthermore, P-LPS-induced expression of the MCP-1 gene in the cells also was blocked by inhibitors of two transcription factors, i.e., curcumin, an inhibitor of AP-1, and pyrolidine dithiocarbamate, an inhibitor of NF-kappaB. Both inhibitors inhibited monocyte chemotactic activity in the culture supernatant of P-LPS-treated cells. Gel shift mobility assay showed stimulation of the AP-1 and NF-kappaB contents in P-LPS-treated cells. This study is the first to demonstrate the expression of CD14 in human gingival fibroblasts and to show that the signal-transducing pathway of P-LPS in the cells is mediated by CD14.

Topics: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; Benzoquinones; Cells, Cultured; Chemokine CCL2; Chemotaxis, Leukocyte; Curcumin; Enzyme Inhibitors; Fibroblasts; Gene Expression; Gingiva; Humans; Lactams, Macrocyclic; Lipopolysaccharide Receptors; Lipopolysaccharides; Monocytes; NF-kappa B; Porphyromonas gingivalis; Proline; Protein Kinase C; Protein-Tyrosine Kinases; Quinones; Rifabutin; Signal Transduction; Staurosporine; Thiocarbamates; Transcription Factor AP-1