Showing papers on "Protoporphyrins published in 2008"

Inhibition of plasminogen activator inhibitor-1 expression in vascular smooth muscle cells by protoporphyrins through a heme oxygenase-independent mechanism

Abstract: Heme oxygenase-1 (HO-1), a rate-limiting enzyme in heme catabolism, has been shown to play a regulatory role in the expression of plasminogen activator inhibitor-1 (PAI-1), a risk factor for vascular disease. Accordingly, we examined the effect of protoporphyrins, both HO inhibitors and activators, on PAI-1 expression in human vascular smooth muscle cells (VSMCs). Tin-protoporphyrin (SnPP) markedly inhibited the transforming growth factor beta1 (TGFbeta1)-induced expression of PAI-1 protein. Protoporphyrins, whether they are inhibitors or activators of HO, produced a similar inhibitory effect. However, SnPP had no effect on the level of PAI-1 mRNA transcripts. Knockdown of human HO-1 with a specific siRNA did not reduce the PAI-1 protein level in TGFbeta1-treated cells. In addition, the proteasome inhibitor lactacystin reversed the inhibitory effect of SnPP on PAI-1 protein expression. Both cobalt-protoporphyrin (CoPP) and CoCl2 markedly induced HO-1 expression. However, CoPP did not affect PAI-1 gene expression, whereas CoCl2 upregulated PAI-1 mRNA in a dose-dependent manner. Our results demonstrate that protoporphyrins can block the TGFbeta1-mediated induction of PAI-1 protein in VSMCs and that this inhibitory effect is independent of HO activity.

Effects of metal protoporphyrins on burn wound conversion

Abstract: EFFECTS OF METAL PROTOPORPHYRINS ON BURN WOUND CONVERSION By Katie Lynne Braun, M.S. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at Virginia Commonwealth University. Virginia Commonwealth University, 2008 Major Director: Dorne R. Yager, Ph. D. Associate Professor & Director of Research, Department of Surgery A murine model was utilized to test the influence of heavy metal protoporphyrins on burn conversion, heme oxygenase – 1 (HO-1) expression, and inflammation. Heavy metal protoporphyrins, such as cobalt protoporphyrin (Co PP) and tin protoporphyrin (Sn PP), were used to influence the heme oxygenase activity. The effects of these heavy metal protoporphyrins on burn wound conversion were examined using a burn comb model in rats. In addition to assessing the extent of conversion, HO-1 expression and parameters of inflammation were also examined in the area of injury (interspace region) subject to conversion. These studies demonstrate proof in principal that pharmacologic

Immunological detection method and device of protoporphyrins in biological sample

Abstract: PROBLEM TO BE SOLVED: To provide a method and device capable of noninvasively diagnosing a tumor of the digestive system. SOLUTION: The detection method and device of protoporphyrins in a biological sample comprise an immunoassay for detecting protoporphyrins in a biological sample using an antibody to one compound selected from the group consisting of protoporphyrins. The antibody is fixed at a prescribed position of a membrane carrier to form an uptake site, and protoporphyrins in the biological sample can be detected by an immunochromatography for competitively binding them and labeled protoporphyrins to the uptake site. COPYRIGHT: (C)2008,JPO&INPIT

Metallation of protoporphyrins used as fluorescent chemosensor for imidazole recognition

Abstract: Metalloporphyrin Complexes play significant roles in many biological and catalytic systems. The diversity of their functions is due in part to the variety of metals that bind in the “pocket” of the porphyrin ring system. Two kinds of metalloporphyrin derivatives, Cu (II) and Zn (II) protoporphyrins (PP), were microscale synthesized ((1) and (2)) and characterized by spectroscopic methods and magnetic measurements. A PP ligand bound to each metal center in a tetradentate fashion including four amine nitrogen atoms in the equatorial planes. These complexes were found to recognize imidazolyl groups of histidine and histamine derivatives as guest molecules by coordination and additional non-covalent interactions. These added analytes displace the selective fluorescent indicator, which when released to the solution displays its full fluorescence. Thus, analyte recognition is signaled by the sharp appearance of the fluorescence of the indicators. The binding affinities of (1) and (2) to histidine and histamine were investigated and accounted for different complexation properties. Moreover, we demonstrated that careful choice of a fluorescent indicator with tuned affinity toward the receptor can provide discrimination in sensing of a desired substrate and the role that the metal coordination plays on the hypsochromic shift and loss of fluorescence distincted characteristics of hypsoporphyrins were also discussed.