Safety, tolerability, and acceptability of Lactobacillus crispatus CTV-05 (LACTIN-V) in pregnant women at high-risk of preterm birth.

The vaginal microbiota is a determinant for the risk of preterm birth (PTB). Dominance of the vaginal niche by Lactobacillus crispatus associates with term delivery. This is the first observational clinical study of live vaginal biotherapeutics (Lactobacillus crispatus CTV-05 (LACTIN-V)) in pregnant women at high-risk of PTB. The primary aim was to explore safety, tolerability and acceptability of LACTIN-V in pregnancy. Women were offered a course of LACTIN-V at 14 weeks gestation for five consecutive days followed by weekly administration for six weeks. Participants were followed up at 15, 18-, 20-, 28- and 36-weeks' gestation and at delivery for assessment of adverse events, compliance and tolerability. Participants completed a questionnaire to gauge experience and acceptability. In total, 73 women were recruited, of whom eight withdrew, leaving a final cohort size of 61. Self-reported compliance to the course was high (56/60, 93%). Solicited adverse events were reported in 13 women (19%) including changes in vaginal discharge, odour, colour or consistency of urine, itching and vaginal bleeding. One unsolicited adverse event was reported as haematuria at 38 weeks gestation, but was judged to be unrelated to LACTIN-V. No serious adverse events occurred. One mild adverse event led to study withdrawal. Thirty-one women completed an experience and acceptability questionnaire. Women found LACTIN-V easy and comfortable to use and the majority (30/31, 97%) would use LACTIN-V in future pregnancies. Eight women (8/31, 26%) found the schedule of use difficult to remember. The rate of PTB <34 weeks in this cohort was 3.3% compared to 7% in a historical cohort of 2,190 women at similar background PTB risk. With satisfactory uptake and good compliance, we demonstrate that LACTIN-V is safe and accepted in pregnancy, with high tolerability. Further studies are needed to assess colonisation of Lactobacillus crispatus CTV-05 and clinical efficacy.

Upregulation of Bcl-x and Bfl-1 as a potential mechanism of chemoresistance, which can be overcome by NF-kappaB inhibition.

In A549 human lung adenocarcinoma cells, we found that TNF-alpha and several commonly used chemotherapeutic agents upregulated the expression of Bcl-x and/or Bfl-1/A1 through an NF-kappaB-dependent pathway. While parental A549 cells were resistant to the cytotoxic effects of both TNF-alpha and chemotherapy agents, NF-kappaB-blocked A549 cells were sensitized to both. Expression of either Bcl-x or Bfl-1/A1 in the NF-kappaB-deficient cells at physiological levels provided differential protection against TNF-alpha and chemotherapeutic treatment. These studies provide a potential mechanism for the phenomenon of chemotherapy-induced chemoresistance, and also reveal a potential strategy by which chemoresistance can be overcome.

Activation of intercellular adhesion molecule 1 expression by Helicobacter pylori is regulated by NF-kappaB in gastric epithelial cancer cells.

Interactions between leukocytes and epithelial cells may play a key role in Helicobacter pylori-associated gastric mucosal inflammation. This process is mediated by various cell adhesion molecules. The present study examined the molecular mechanisms leading to H. pylori-induced epithelial cell intercellular adhesion molecule-1 (ICAM-1; also called CD54) expression. Coculture of epithelial cells with cytotoxin-associated gene pathogenicity island-positive (cag PAI(+)) H. pylori strains, but not with a cag PAI(-) strain or H. pylori culture supernatants, resulted in upregulation of steady-state mRNA levels and cell surface expression of ICAM-1. Coculture with H. pylori induced an increase in luciferase activity in cells which were transfected with a luciferase reporter gene linked to the 5'-flanking region of the ICAM-1 gene. H. pylori activated the ICAM-1 promoter via the NF-kappaB binding site. An inducible nuclear protein complex bound to the ICAM-1 NF-kappaB site and was identified as the NF-kappaB p50-p65 heterodimer. H. pylori induced the degradation of IkappaB-alpha, a major cytoplasmic inhibitor of NF-kappaB, and stimulated the expression of IkappaB-alpha mRNA. Pretreatment of epithelial cells with pyrrolidine dithiocarbamate, which blocks NF-kappaB activation, inhibited H. pylori-induced ICAM-1 expression. THP-1 macrophagic cells, peripheral blood mononuclear cells, and purified neutrophils adhered to H. pylori-infected epithelial cells to a greater extent than to uninfected cells. These results show that H. pylori directly induces expression of ICAM-1 on gastric epithelial cells in an NF-kappaB-dependent manner that may support leukocyte attachment during inflammation.

Specificities of CD40 signaling: involvement of TRAF2 in CD40-induced NF-kappaB activation and intercellular adhesion molecule-1 up-regulation.

Several tumor necrosis factor receptor-associated factor (TRAF) family proteins including TRAF2, TRAF3, TRAF5, and TRAF6, as well as Jak3, have been implicated as potential mediators of CD40 signaling. An extensive in vitro binding study indicated that TRAF2 and TRAF3 bind to the CD40 cytoplasmic tail (CD40ct) with much higher affinity than TRAF5 and TRAF6 and that TRAF2 and TRAF3 bind to different residues of the CD40ct. Using CD40 mutants incapable of binding TRAF2, TRAF3, or Jak3, we found that the TRAF2-binding site of the CD40ct is critical for NF-kappaB and stress-activated protein kinase activation, as well as the up-regulation of the intercellular adhesion molecule-1 (ICAM-1) gene, whereas binding of TRAF3 and Jak3 is dispensable for all of these functions. Overexpression of a dominantly active IkappaBalpha strongly inhibited CD40-induced NF-kappaB activation, ICAM-1 promoter activity, and cell-surface ICAM-1 up-regulation. These studies suggest a potential signal transduction pathway from the CD40 receptor to the transcriptional activation of the ICAM-1 gene.

Cooperative binding and synergistic activation by RelA and C/EBPbeta on the intercellular adhesion molecule-1 promoter.

Intercellular adhesion molecule-1 (ICAM-1) is up-regulated on numerous cell types in response to inflammatory cytokines. Tumor necrosis factor-alpha (TNF-alpha) activates the ICAM-1 promoter through a variant nuclear factor-kappaB (NF-kappaB) site at -187/-178 bp upstream of the transcription start site. In this investigation, we provide biochemical and functional evidence that an adjacent CCAAT/enhancer binding protein (C/EBP) site and this variant NF-kappaB site define a composite element for activation of the ICAM-1 promoter in certain cell lines. We detected an endogenous TNF-alpha-inducible DNA-protein complex in nuclear extracts from A549, HeLa, and EVC304 cells that contained both RelA and C/EBPbeta but not other family members. Complex formation required intact C/EBP and NF-kappaB sites and was absolutely dependent on translocation of RelA into the nucleus. Complex formation and cooperative binding were also demonstrated using recombinant proteins, and as above, both binding sites were necessary. Interestingly, the RelA/C/EBPbeta complex was not detected in either Jurkat or Raji cells, indicating cell type specificity. Functional studies with various reporter gene constructs revealed that both binding sites were required for maximal activation of the ICAM-1 promoter in response to TNF-alpha and for synergistic activation by RelA and C/EBPbeta. This is the first detailed analysis of how RelA and C/EBPbeta function to regulate ICAM-1 expression, and this study has important implications for how this gene is activated in specific cell types.

Transcriptional regulation of the intercellular adhesion molecule-1 gene by inflammatory cytokines in human endothelial cells. Essential roles of a variant NF-kappa B site and p65 homodimers.

Intercellular adhesion molecule-1 (ICAM-1) is greatly up-regulated on endothelial cells at sites of inflammation and is involved in leukocyte attachment and extravasation. Previously, we had shown that the ICAM-1 gene expression in human umbilical vein endothelial cells (HUVECs) was transcriptionally regulated by tumor necrosis factor-alpha (TNF-alpha) (Wertheimer, S. J., Myers, C. L., Wallace, R. W., and Parks, T. P. (1992) J. Biol. Chem. 267, 12030-12035). In the present investigation, TNF-alpha-induced transcription was found to be initiated exclusively at two sites, 40 and 41 base pairs upstream of the translation start site. Deletion analysis of the 5' regulatory region of the ICAM-1 gene revealed a 92-base pair sequence which was both necessary and sufficient to confer TNF-alpha responsiveness to a linked luciferase reporter gene in transient transfection assays. This TNF-alpha-responsive region contained a variant NF-kappa B site at -187 to -178, which when mutated, completely abolished ICAM-1 promoter activation by TNF-alpha, interleukin-1 beta, and lipopolysaccharide. Two inducible nuclear protein complexes bound to the ICAM-1 kappa B and were identified as the NF-kappa B p65 homodimer and p65/p50 heterodimer. Overexpression of p65, but not p50, transactivated the ICAM-1 promoter in a kappa B site-dependent manner in HUVECs. In addition, p65-mediated transactivation was suppressed by co-expression of p50. Our results suggest that cytokine activation of the ICAM-1 promoter in HUVECs may critically depend on p65 homodimers binding to a variant kappa B site.

Inhibition of lipid mediator biosynthesis in human inflammatory cells by BIRM 270.

BIRM 270 was developed as a potent and enantioselective inhibitor of LTB4 biosynthesis by human neutrophils, and was also found to inhibit LTC4 production by human eosinophils and lung mast cells. BIRM 270 inhibited LTB4 synthesis in neutrophils by preventing arachidonate release from membrane phospholipids, and over the same concentration range, inhibited PAF biosynthesis. BIRM 270 did not directly inhibit acylhydrolases which have been implicated in eicosanoid and PAF biosynthesis, suggesting an indirect mode of action.

Intercellular adhesion molecule-1 gene expression in human endothelial cells. Differential regulation by tumor necrosis factor-alpha and phorbol myristate acetate.

Intercellular adhesion molecule-1 (ICAM-1) is an inducible glycoprotein expressed on the surface of inflamed endothelium which mediates in part the extravasation of granulocytes into sites of infection or injury. ICAM-1 mRNA is not detected in unstimulated human umbilical vein endothelial cells (HUVECs), but accumulates transiently following tumor necrosis factor-alpha (TNF-alpha) or phorbol myristate acetate (PMA) treatment with maximal steady state levels occurring at 2 or 4 h, respectively. Pretreating HUVECs with PMA for 72 h down-regulates protein kinase C and inhibits the subsequent induction of ICAM-1 mRNA by PMA, but does not affect TNF-alpha-induced message accumulation. Nuclear run-on assays showed that the ICAM-1 gene is transcribed under basal conditions in HUVECs, and that TNF-alpha stimulates transcriptional activity 3- to 4-fold within 30 min of treatment. In contrast, PMA has little effect on ICAM-1 gene transcription up to 4 h following stimulation. Message stability studies established that ICAM-1 mRNA induced by PMA has a longer half-life than the TNF-alpha-induced message. These results suggest that PMA acts through protein kinase C to up-regulate ICAM-1 expression primarily at a post-transcriptional level by stabilizing ICAM-1 mRNA, whereas TNF-alpha transcriptionally regulates ICAM-1 gene expression through an undefined, protein kinase C-independent pathway.

Purification and characterization of a phospholipase A2 from human osteoarthritic synovial fluid.

Phospholipase A2 (PLA2) from human osteoarthritic synovial fluid was purified to homogeneity in three steps. The NH2-terminal amino acid sequence and biochemical characteristics of the enzyme were identical to the Peak A PLA2 activity of rheumatoid synovial fluid (1). The enzyme exhibited an apparent mass of 14,000, an absolute Ca+(+)-dependence, an alkaline pH optimum, and was inhibited by sodium deoxycholate (DOC), NaCl and 0.5 M Tris-HCl. The enzyme strongly preferred phosphatidylethanolamine (PE) as substrate over phosphatidylcholine (PC) or phosphatidylinositol (PI), and hydrolyzed PE containing arachidonic acid or linoleic acid in the sn-2 position at similar rates. Heparin bound to the enzyme but did not inhibit catalytic activity. In addition, the human enzyme was not inhibited by the acidic 'chaperone' subunit of crotoxin despite considerable sequence similarity with the basic PLA2 subunit of the neurotoxin. The enzyme was capable of hydrolyzing E. coli membrane phospholipids in the presence of the neutrophil bactericidal/permeability increasing protein (BPI). This finding, coupled to the reported pro-inflammatory activity and presence of the enzyme in inflammatory cells, supports the hypothesis that it may be a component of the host defense mechanism which can, under certain conditions, contribute to the pathogenesis of inflammatory disease.

The cyclic nucleotide-dependent phosphorylation of aortic smooth muscle membrane proteins.

Membrane proteins of Mr 240,000, 130,000, and 85,000 (GS-proteins) were rapidly and selectively phosphorylated in particulate fractions of rabbit aortic smooth muscle in the presence of [Mg-32P]ATP and low concentrations of cGMP (Ka = 0.01 microM) or cAMP (Ka = 0.2 microM). The effects of both cyclic nucleotides in this preparation were mediated entirely by an endogenous, membrane-bound form of cGMP-dependent protein kinase (G-kinase). The GS-proteins were also phosphorylated by the soluble form of G-kinase purified from bovine lung; this effect was most evident following removal of endogenous G-kinase from the membranes using Na2CO3 and high salt washes. The membrane-bound and cytosolic forms of G-kinase phosphorylated the Mr 130,000 GS-protein with the same specificity as determined by two-dimensional peptide mapping. Despite this functional homology between the two forms of G-kinase, only the particulate enzyme appears to play a role in phosphorylating the GS-proteins. Although little endogenous cAMP-dependent protein kinase (A-kinase) activity was detected in washed aortic smooth muscle membranes, the GS-proteins could be phosphorylated when purified A-kinase catalytic subunit was added to this preparation. Peptide mapping of the Mr 130,000 GS-protein indicated that A-kinase phosphorylated a subset of the same peptides labeled by the two forms of G-kinase. The endogenous A-kinase of rabbit aortic smooth muscle homogenates was also found to phosphorylate the GS-proteins. Since the intracellular concentrations of cGMP or cAMP can be selectively elevated by different stimuli, these results suggest several possible mechanisms by which the phosphorylation state of the GS-proteins may be regulated by cyclic nucleotides: activation of the membrane-bound G-kinase by cGMP or cAMP; and activation of cytosolic A-kinase by cAMP.

Prostaglandin endoperoxide metabolism by bovine cerebral microvessels.

Isolated bovine cerebral microvessels were found to contain two prostaglandin endoperoxide-metabolizing activities: prostaglandin H2-E2 isomerase and prostacyclin synthetase. At low tissue protein concentrations (i.e., less than 1 mg/ml) and in the presence of reduced glutathione, formation of prostaglandin E2 was favored (about 80% of total prostaglandin products), whereas at higher protein concentrations, in the presence or absence of reduced glutathione, 6-keto-prostaglanding F1 alpha, the stable breakdown product of prostacyclin, was the major product (40-50% of total). Despite an increase in apparent prostacyclin formation, glutathione-enhanced prostaglandin E2 production was still evident at protein concentrations exceeding 1 mg/ml. No apparent enzymatic prostaglandin E2 forming activity was evident in whole cerebral cortex or pial artery homogenates although some GSH-enhanced prostaglandin E2 formation could be demonstrated in microsomes prepared from these tissues. These findings indicate that prostaglandin E2 formation is a dominant enzymatic endoperoxide-metabolizing activity in microvessels, and that this pathway may be primarily localized to the microvasculature. However, they also indicate that enzyme/substrate ratios and endogenous cofactor availability may affect the outcome of endoperoxide metabolism in the bovine cerebral microvasculature, Prostaglandin E2 and prostacyclin generated in the microvasculature could participate in the regulation of various functions, e.g., regional flow and capillary permeability.