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Leukotriene (LT) [B.sub.4] is a powerful chemotactic and immune modulating agent that signals via two receptors denoted [BLT.sub.1] and [BLT.sub.2]. Here we report that [BLT.sub.1] and [BLT.sub.2] are expressed at low levels in an apparently silent state in human umbilical vein endothelial cells (HUVEC). However, treatment with LPS leads to a > 10 fold increase in the levels of [BLT.sub.1] mRNA without any significant effects on [BLT.sub.2] mRNA. In parallel, LPS also increases the amounts of [BLT.sub.1] protein. Tumor necrosis factor-[alpha] (TNF-[alpha]) increases the expression of [BLT.sub.2] mRNA [approximately equal to] 6 times above basal levels with only a modest increase in [BLT.sub.1] mRNA. Interleukin-1 [beta] causes variable and parallel increases of both [BLT.sub.1] and [BLT.sub.2] mRNA. The natural ligand [LTB.sub.4] also increases [BLT.sub.1], but not [BLT.sub.2], mRNA and protein expression. Along with the induction of [BLT.sub.1] and/or [BLT.sub.2], HUVEC acquire the capacity to respond to [LTB.sub.4] with increased levels of intracellular calcium and these signals can be blocked by isotype selective BLT antagonists, CP-105696 and LY-255283. In addition, treatment of HUVEC with [LTB.sub.4] causes increased release of both nitrite, presumably reflecting nitric oxide (NO), and monocyte chemoattractant protein-1. Our data indicate that expression of functional BLT receptors may occur at the surface of endothelial cells in response to LPS, cytokines, and ligand, which in turn may have functional consequences during the early vascular responses to inflammation. Moreover, the results point to BLT receptors as potential targets for pharmacological intervention in LT-dependent inflammatory diseases such as asthma, rheumatoid arthritis, and arteriosclerosis. inflammation | arteriosclerosis | rheumatoid arthritis | asthma | nitric oxide

We describe a facile method to activate or repress transcription of endogenous genes in a quantitative and specific manner by treatment with designed regulatory proteins (DRPs), in which artificial transcription factors (ATFs) are fused to cell-penetrating peptides (CPPs). Penetration of DRPs into cells is mediated by an N-terminal CPP fused to a nuclear localization signal; a DNA-binding domain and a transactivation domain follow. The DNA-binding domain was targeted to the vascular endothelial growth factor (VEGF)-A gene. An agonist DRP was rapidly taken up by cells and transported to the nucleus; soon after, the cells began transcribing the gene and secreting VEGF-A protein in a dose-dependent manner. Multiple copies of a short oligopeptide derived from a minimal transactivation domain of human [beta]-catenin was stronger than VP-16. The SRDX domain from the plant transcription factor, SUPERMAN, changed the DRP to a hypoxia-induced antagonist of VEGF-A. DRPs combine many of the potential benefits of transgenes with those of recombinant proteins.

Single strands of DNA serve, in rare instances, as promoters for transcription; duplex DNA promoters with individual strands that also have a promoter capacity/function have not been described. We show that the nontranscribed strand of the Saccharomyces cerevisiae U6 snRNA gene directs transcription initiation factor IIIB-requiring and accurately initiating transcription by RNA polymerase III. The nontranscribed strand promoter is much more extended than its duplex DNA counterpart, comprising the U6 gene TATA box, a downstream [T.sub.7] tract, and an upstream-lying segment. A requirement for placement of the 3' end of the transcribed (template) strand within the confines of the transcription bubble is seen as indicating that the nontranscribed strand provides a scaffold for RNA polymerase recruitment but is deficient at a subsequent step of transcription initiation factor IIIB's direct involvement in promoter opening.

Studies the effects of the Escherichia coli DNA-binding protein H-NS on rRNA transcription in vivo. Comparison of rRNA synthesis rates in cells that differ in expression of functional H-NS molecules; Role of H-NS in the shut-off of rRNA synthesis during the cell cycle; Effect of H-NS on rRNA synthesis under stress conditions.