Renin activity and angiotensin I concentration in genetically selective inbred line of hypertensive mice

Blood pressure lowering kallikrein-kinin and blood pressure raising renin-angiotensin systems play a major role in the maintenance of normal blood pressure. In a previous study, we have shown that a kallikrein-like prorenin converting enzyme (PRCE C) is elevated in the submandibular gland tissue of a mouse line (BPH) that was genetically selected and inbred for high blood pressure in comparison to normotensive line (BPN) that was derived from the ancestors of BPH line. In the present investigation we wanted to find out if elevated levels of PRCE C were involved in the modulation of tissue (local) renin-angiotensin system in the submandibular gland tissue. Results indicate significantly high renin activity but low angiotensin I level in the tissue of BPH mouse model. These results tend to suggest PRCE C's involvement in tissue (local) renin-angiotensin system.     

Suppression of somatostatin levels in the hepatic portal and systemic plasma of the rat by synthetic human pancreatic polypeptide.

The 1:1 Cu(II), Co(II), Co(II)-O₂, Fe(II)-NO, and Fe(III) complexes of depBLM have been investigated by ESR spectroscopy and compared with the corresponding metal complexes of BLM. DepBLM which lacks the α-amino group of β-aminoalanine portion in BLM molecule, forms the metal complexes different from BLM with regard to the fifth axial donor. In addition, the formation of hydroxyl radical by the depBLM-Fe(II) complex is remarkably lower than that by the BLM-Fe(II) complex. This study indicates an important effect of fifth axial nitrogen on metal coordination and oxygen activation of BLM.     

Urine as a source for clinical proteome analysis: From discovery to clinical application

The success of clinical proteome analysis should be assessed based on the clinical impact following implementation of findings. Although there have been several technological advancements in mass spectrometry in the last years, these have not resulted in similar advancements in clinical proteomics. In addition, application of proteomic biomarkers in clinical diagnostics and practical improvement in the disease management is extremely rare. In this review, we discuss the relevant issues associated with identification of robust biomarkers of clinical value. Urine appears to be an ideal source of biomarkers, for theoretical, methodological, and practical reasons. Therefore, this review is focused on the search for biomarkers in urine within the last decade. Urine can be used for non-invasive assessment of a variety of diseases including those affecting the urogenital tract and also other pathologies such as cardiovascular disease or appendicitis. We also discuss the importance of data validation, an essential step in translating biomarkers into the clinical practice. Furthermore, we examine several examples of apparently successful proteomic biomarker discovery studies and their implications for disease diagnosis, prognosis, and therapy evaluation. We also discuss some current challenges in this field and reflect on future research prospects. This article is part of a Special Issue entitled: Biomarkers: A Proteomic Challenge.     

The production of hydroxyl radical from copper(I) complex systems of bleomycin and tallysomycin: comparison with copper(II) and iron(II) systems.

In contrast with BLM(or TALM)-Cu(II) complex system, Cu(I)-O₂ system of BLM(or TALM) as well as the corresponding Fe(II) system evidently produces reactive oxygen radicals as detected by ESR spin trapping. The sulfhydryl compound strongly prevented the generation of hydroxyl radical in BLM(or TALM)-Cu(I)-O₂ system. TALM forms metal complexes similar to BLM. The action mechanism of BLM and TALM has been proposed to be substantially same.     

Kallikrein-like prorenin-converting enzymes in inbred hypertensive mice

Kallikreins are a group of serine proteases and are distinguished by having serine residue at their active site. Their general function is to convert inactive pro-peptide into its biologically active form. In recent years, emerging evidence indicates that some kallikrein-kinin enzymes also play a role in the modulation of renin-angiotensin system. These kallikrein-like prorenin converting enzymes act on renin-angiotensin by converting prorenin into biologically active renin. In this investigation, kallikrein-like prorenin converting enzyme (PRCE C) (mK9) is isolated from genetically inbred high blood pressure (BPH) and their normal counterparts (BPN) mice, and its protein levels are quantitated. Levels of mRNA expression are also compared. Additionally, localization of the enzyme is visualized by in situ hybridization histochemistry. Results indicated higher levels of PRCE C (mK9) enzyme in BPH mice in comparison to their normal counterparts. mRNA expression was also higher in BPH mice. In situ hybridization histochemistry results localized PRCE C (mK9) in the striated duct cells of submandibular gland.     

The interaction of pentosan polysulphate (SP54) with human neutrophil elastase and connective tissue matrix components

The binding of pentosan polysulphate (SP54) to human polymorphonuclear leucocyte elastase (PMNE) and some of its natural and synthetic substrates has been investigated. Using an ion exchange (DE52) assay system the binding of SP54 to PMNE was found to be 100 times stronger than to collagen or proteoglycan (PG). While the order for in vitro binding of the drug to purified substrates was found to be PG greater than gelatin greater than type I collagen, in vivo experiments indicated that SP54 was localized in tissues rich in collagen. Using gel-exclusion chromatography it was shown that these tissues also contained proteinaceous components other than PG and collagen which interacted with SP54. These results indicate that the potent inhibitor activity of SP54 against PMNE (50% inhibition at 1.7 X 10(-7)M) probably occurs by a specific interaction with the enzyme rather than by substrate binding inhibition, although the latter interaction may be important for localising the drug in these tissues.     

The nucleoporin Nup358 associates with and regulates interphase microtubules

The nucleoporin Nup358 resides on the cytoplasmic face of the interphase nuclear pore complex (NPC). During metaphase, its recruitment to kinetochores is important for correct microtubule-kinetochore attachment. Here, we report that a fraction of endogenous Nup358 interacts with interphase microtubules through its N-terminal region (BPN). Cells overexpressing the microtubule targeting domain of Nup358 displayed dramatic alteration in the microtubule organization including increased microtubule bundling and stability. Ectopic expression of BPN and full-length Nup358 exhibited significantly higher levels of acetylated microtubules that were resistant to nocodazole, a microtubule depolymerizing agent. Furthermore, RNAi mediated depletion of Nup358 affected polarized stabilization of microtubules during directed cell migration, confirming the in vivo role of Nup358 in regulating interphase microtubules.     

Purification and characterization of an acidic trypsin/subtilisin inhibitor from tortoise egg white

Egg whites of three species of tortoise and turtle have been compared by gel chromatography for inhibitory activity against proteases. The egg white of Geomda trijuga trijuga Schariggar contains trypsin/subtilisin inhibitor while the egg white of Caretta caretta Linn. contains both trypsin and chymotrypsin inhibitors. No protease inhibitory activity has been detected in the egg white of Trionyx gangeticus Cuvier. An acidic trypsin/subtilisin inhibitor has been purified to homogeneity from the egg white of tortoise (G. trijuga trijuga). It is a single polypeptide chain of 100 amino acid residues, having a molecular weight of 11 700. It contains six disulphide bonds and is devoid of methionine and carbohydrate moiety. Its isoelectric point is at pH 5.95 and is stable at 100°C for 4 h at neutral pH. The inhibitor inhibits both trypsin and subtilisin by forming enzyme-inhibitor complexes at a molar ratio close to unity. Their dissociation contants are 7.2·10^?9 M for bovine trypsin adn 5.5·10^?7 M for subtilisin. Chemical modification of amino groups with trinitrobenzene sulfonate has reduced its inhibitory activities against both trypsin and subtilisin, but the loss of its trypsin inhibitory activity is faster than of its subtilisin inhibitory activity. It has independent binding sites for inhibition of trypsin and subtilisin.