Search results for "Signaling"

Bio-inorganic Nanomaterials for Biomedical Applications (Bio-silica and Polyphosphate)

2014

Bio-silica represents the main mineral component of the sponge skeletal elements (siliceous spicules), while bio-polyphosphate (polyP), a multifunctional polymer existing in microorganisms and animals, acts, among others, as reinforcement for pores in cell membranes. These natural inorganic bio-polymers, which can be readily prepared, either by recombinant enzymes (bio-silica and polyP) or chemically (polyP), are promising materials/substances for the amelioration and/or treatment of human bone diseases and dysfunctions. Bone defects in human, caused by fractures/nonunions or trauma, have an increasing impact and have become a medical challenge in the present-day aging population. Frequentl…

The cell signalling disruption theory of ageing: importance in Alzheimer’s disease and sarcopenia

2015

Should Treatment of Sepsis Include Statins?

2005

During the past decade, HMG-CoA reductase inhibitors (statins) have been shown to improve survival in patients with cardiovascular disease. Initially, the beneficial effects of statins were attributed simply to lipid reduction1; however, more recent data suggest that “pleiotropic” properties such as improvement of endothelial dysfunction, increased nitric oxide bioavailability, and antioxidative and antiinflammatory properties may contribute to the improvement of prognosis in patients with coronary artery disease. Many of these pleiotropic effects of statins are mediated by the ability to block the synthesis of important isoprenoid intermediates, which have been shown to serve as lipid atta…

Collective Cell Migration in Tissue Building

2015

Collective cell migration (CCM) is an essential process during tissue building and morphogenesis of animal body plans, but it can also occur in pathogenic situations. A detailed study of this cell behaviour in several model systems has allowed to determine that cells move coordinately but interact differently while migrating together, thus defining several categories of collective cell movements. They are regulated by guidance signals that act as chemoattractants and allow directionality of movement and whose levels, together with the action of repulsive molecular cues, influence this movement. Besides, cells in the moving group affect each other through cell–cell interactions but they also…

Interplay of oxidants and antioxidants during exercise: Implications for muscle health

2010

Muscle contraction results in generation of reactive oxygen and nitrogen species (RONS) at a rate determined by the intensity, frequency, and duration of the exercise protocols. Strenuous exercise causes oxidation of protein, lipid, and DNA, release of cytosolic enzymes, and other signs of cell damage; however, only exhaustive exercise is detrimental. Indeed, the regulation of vascular tone, the excitation-contraction coupling, growth, and differentiation in skeletal muscle, are governed in part by RONS. This is accomplished by RONS interaction with redox-sensitive transcription factors, leading to increased gene expression of antioxidant enzymes, cytoprotective proteins, and other enzymes …

TGF-β superfamily signaling is essential for tooth and hair morphogenesis and differentiation

2007

Members of the transforming growth factor beta (TGF-beta) superfamily of signaling molecules are involved in the regulation of many developmental processes that involve the interaction between mesenchymal and epithelial tissues. Smad7 is a potent inhibitor of many members of the TGF-beta family, notably TGF-beta and activin. In this study, we show that embryonic overexpression of Smad7 in stratified epithelia using a keratin 5 promoter, results in severe morphogenetic defects in skin and teeth and leads to embryonic and perinatal lethality. To further analyze the functions of Smad7 in epithelial tissues of adult mice, we used an expression system that allowed a controlled overexpression of …

Extrinsic and Intrinsic Factors Modulating Proliferation and Self-renewal of Multipotential CNS Progenitors and Adult Neural Stem Cells of the Subven…

2006

Although stem cell therapy has been proposed for therapeutic strategies aimed at repairing functions, it is important to realize that as yet, relatively little is known about the behavior of embryonic and adult stem cells in terms of responsiveness to extracellular cues and intracellular signaling molecules.

Streptomyces coelicolor Vesicles: Many Molecules To Be Delivered

2022

ABSTRACT Streptomyces coelicolor is a model organism for the study of Streptomyces, a genus of Gram-positive bacteria that undergoes a complex life cycle and produces a broad repertoire of bioactive metabolites and extracellular enzymes. This study investigated the production and characterization of membrane vesicles (MVs) in liquid cultures of S. coelicolor M145 from a structural and biochemical point of view; this was achieved by combining microscopic, physical and -omics analyses. Two main populations of MVs, with different sizes and cargos, were isolated and purified. S. coelicolor MV cargo was determined to be complex, containing different kinds of proteins and metabolites. In particul…

Role of lipid rafts in virus infection

2009

Rafts are domains of the plasma membrane, enriched in cholesterol and sphingolipids; they form a platform for signaling proteins and receptors. The lipid rafts are utilized in the replication cycle of numerous viruses. Internalization receptors of many viruses localize to rafts or are recruited there after virus binding. Arrays of signal transduction proteins found in rafts contribute to efficient trafficking and productive infection. Some viruses are dependent on raft domains for the biogenesis of their membranous replication structures. Finally, rafts are often important in virus assembly and budding. Subsequently, raft components in the viral envelope may be vital for the entry to a new…

Fusion of bone-marrow-derived cells with Purkinje neurons, cardiomyocytes and hepatocytes

2003

Recent studies have suggested that bone marrow cells possess a broad differentiation potential, being able to form new liver cells, cardiomyocytes and neurons1,2. Several groups have attributed this apparent plasticity to ‘transdifferentiation’3,4,5. Others, however, have suggested that cell fusion could explain these results6,7,8,9. Using a simple method based on Cre/lox recombination to detect cell fusion events, we demonstrate that bone-marrow-derived cells (BMDCs) fuse spontaneously with neural progenitors in vitro. Furthermore, bone marrow transplantation demonstrates that BMDCs fuse in vivo with hepatocytes in liver, Purkinje neurons in the brain and cardiac muscle in the heart, resul…