Monocyte-expressed urokinase regulates human vascular smooth muscle cell migration in a coculture model

Interactions of vascular smooth muscle cells (VSMC) with monocytes recruited to the arterial wall at a site of injury, with resultant modulation of VSMC growth and migration, are central to the development of vascular intimal thickening. Urokinase-type plasminogen activator (uPA) expressed by monocytes is a potent chemotactic factor for VSMC and might serve for the acceleration of vascular remodeling. In this report, we demonstrate that coculture of human VSMC with freshly isolated peripheral blood-derived human monocytes results in significant VSMC migration that increases during the coculture period. Accordingly, VSMC adhesion was inhibited with similar kinetics. VSMC proliferation, however, was not affected and remained at the same basal level during the whole period of coculture. The increase of VSMC migration in coculture was equivalent to the uPA-induced migration of monocultured VSMC and was blocked by addition into coculture of soluble uPAR (suPAR). Analysis of uPA and uPAR expression in cocultured cells demonstrated that monocytes are a major source of uPA, whose expression increases in coculture five-fold, whereas VSMC display an increased expression of cell surface-associated uPAR. These findings indicate that upregulated uPA production by monocytes following vascular injury acts most likely as an endogenous activator of VSMC migration contributing to the remodeling of vessel walls.     

IFN-gamma amplifies IL-6 and IL-8 responses by airway epithelial-like cells via indoleamine 2,3-dioxygenase

Respiratory viral infections increase inflammatory responses to concurrent or secondary bacterial challenges, thereby worsening disease outcome. This potentiation of inflammation is explained at least in part by IFN-gamma promoting increased sensitivity to TNF-alpha and LPS. We sought to determine whether and, if so, how IFN-gamma can modulate proinflammatory responses to TNF-alpha and LPS by epithelial cells, which are key effector cells in the airways. Preincubation of airway epithelial-like NCI-H292 cells with IFN-gamma resulted in a hyperresponsive IL-6 and IL-8 production to TNF-alpha and LPS. The underlying mechanism involved the induction of indoleamine 2,3-dioxygenase, which catabolized the essential amino acid, tryptophan. Depletion of tryptophan led to stabilization of IL-6 and IL-8 mRNA and increased IL-6 and IL-8 responses, whereas supplementing tryptophan largely restored these changes. This novel mechanism may be implicated in enhanced inflammatory responses to bacterial challenges following viral infection.     

Methodology and Indicators of Economy‐wide Material Flow Accounting

This contribution presents the state of the art of economy‐wide material flow accounting. Starting from a brief recollection of the intellectual and policy history of this approach, we outline system definition, key methodological assumptions, and derived indicators. The next section makes an effort to establish data reliability and uncertainty for a number of existing multinational (European and global) material flow accounting (MFA) data compilations and discusses sources of inconsistencies and variations for some indicators and trends. The results show that the methodology has reached a certain maturity: Coefficients of variation between databases lie in the range of 10% to 20%, and correlations between databases across countries amount to an average R² of 0.95. After discussing some of the research frontiers for further methodological development, we conclude that the material flow accounting framework and the data generated have reached a maturity that warrants material flow indicators to complement traditional economic and demographic information in providing a sound basis for discussing national and international policies for sustainable resource use.     

2-D differential membrane proteome analysis of scarce protein samples

Proteome studies with small sample amounts are difficult to perform, especially when membrane proteins are the focus of interest. In our study a new method for the analysis of scarce membrane protein samples combining large gel 2-D-CTAB/SDS-PAGE with fluorescence dye saturation labelling (satDIGE) was developed, allowing a highly sensitive differential analysis of different cell states. After Triton X-114 phase partitioning, enriched membrane protein samples of T cells were labelled at cysteine residues using fluorescence dyes and separated by large gel 2D-CTAB/SDS-PAGE. For a differential analysis 3 mug protein was found to be sufficient to detect proteins in a widespread well-separated diagonal spot pattern.