Rate of transport of L-arginine is independent of the expression of inducible nitric oxide synthase in HEK 293 cells

Peer reviewe

Transmembrane signalling mechanisms regulating expression of cationic amino acid transporters and inducible nitric oxide synthase in rat vascular smooth muscle cells

'The final version of record is available at: http://www.biochemj.org/bj/tocprev/toc1999.htm ' --Copyright Biochemical SocietyThe signalling mechanisms involved in the induction of nitric oxide synthase (iNOS) and Larginine transport were investigated in bacterial lypopolysaccharide (LPS) and interferon-γ (IFN-γ)- stimulated rat cultured aortic smooth muscle cells (RASMC). The expression profile of transcripts for cationic amino acid transporters (CATs) and their regulation by LPS and IFN-γ were also examined. Control RASMC expressed mRNA for CAT-1, CAT-2A and CAT-2B. Levels of all three transcripts were significantly elevated in activated cells. Stimulated CAT mRNA expression and L-arginine transport occurred independently of protein kinase C (PKC), protein tyrosine kinase (PTK) and p44/42 mitogen activated kinases (MAPK), but were inhibited by the p38 MAPK inhibitor SB203580, which at 3 μM caused maximum inhibition of both responses. Induction of NO synthesis was independent of p44/42 MAPK activation and only marginally dependent on PKC, but was attenuated markedly by the PTK inhibitors, genistein and herbimycin A. SB203580 differentially regulated iNOS expression and NO production, potentiating both processes at low μM concentrations and inhibiting at concentrations of ≥ 1μM. In conclusion, our data suggest that RASMC constitutively express transcripts for CAT-1, CAT-2A and CAT-2B, and that expression of these transcripts is significantly enhanced by LPS and IFN-γ. Moreover, stimulation of Larginine transport and induction of NO synthesis by LPS and IFN-γ appears to be under critical regulation by the p38 MAPK, since both processes were significantly modified by SB203580 at concentrations so far shown to have no effect on other signalling pathways. Thus, in RASMCs, the p38 MAPK cascade represents an important signalling mechanism, regulating both enhanced L-arginine transport and induced NO synthesis.Peer reviewe

The use of proteomics to identify novel therapeutic targets for the treatment of disease

The completion of the Human Genome Project has revealed a multitude of potential avenues for the identification of therapeutic targets. Extensive sequence information enables the identification of novel genes but does not facilitate a thorough understanding of how changes in gene expression control the molecular mechanisms underlying the development and regulation of a cell or the progression of disease. Proteomics encompasses the study of proteins expressed by a population of cells, and evaluates changes in protein expression, post-translational modifications, protein interactions, protein structure and splice variants, all of which are imperative for a complete understanding of protein function within the cell. From the outset, proteomics has been used to compare the protein profiles of cells in healthy and diseased states and as such can be used to identify proteins associated with disease development and progression. These candidate proteins might provide novel targets for new therapeutic agents or aid the development of assays for disease biomarkers. This review provides an overview of the current proteomic techniques available and focuses on their application in the search for novel therapeutic targets for the treatment of disease

Future treatment strategies in ST-segment elevation myocardial infarction

Cardiolog

Nitric oxide-induced cardioprotection in cultured rat ventricular myocytes

Original article can be found at: http://ajpheart.physiology.org/ Copyright American Physiological Society [Full text of this article is not available in the UHRA]Peer reviewe

Differential regulation of L-arginine transport and nitric oxide synthase induction in cultured smooth muscle cells

"The Version of Record (VoR) is available at www.biochemj.org" [Full text of this article is not available in the UHRA]Peer reviewe

Biological variation of cardiac myosin-binding protein C in healthy individuals

Objectives Cardiac myosin-binding protein C (cMyC) is a novel biomarker of myocardial injury, with a promising role in the triage and risk stratification of patients presenting with acute cardiac disease. In this study, we assess the weekly biological variation of cMyC, to examine its potential in monitoring chronic myocardial injury, and to suggest analytical quality specification for routine use of the test in clinical practice. Methods Thirty healthy volunteers were included. Non-fasting samples were obtained once a week for ten consecutive weeks. Samples were tested in duplicate on the Erenna(R) platform by EMD Millipore Corporation. Outlying measurements and subjects were identified and excluded systematically, and homogeneity of analytical and within-subject variances was achieved before calculating the biological variability (CVI and CVG), reference change values (RCV) and index of individuality (II). Results Mean age was 38 (range, 21-64) years, and 16 participants were women (53%). The biological variation, RCV and II with 95% confidence interval (CI) were: CVA (%) 19.5 (17.8-21.6), CVI (%) 17.8 (14.8-21.0), CVG (%) 66.9 (50.4-109.9), RCV (%) 106.7 (96.6-120.1)/-51.6 (-54.6 to -49.1) and II 0.42 (0.29-0.56). There was a trend for women to have lower CVG. The calculated RCVs were comparable between genders. Conclusions cMyC exhibits acceptable RCV and low II suggesting that it could be suitable for disease monitoring, risk stratification and prognostication if measured serially. Analytical quality specifications based on biological variation are similar to those for cardiac troponin and should be achievable at clinically relevant concentrations