A Stochastic Petri Net-Based Model of the Involvement of Interleukin 18 in Atherosclerosis

Interleukin 18 (IL-18) is a proinflammatory and proatherogenic cytokine with pleiotropic properties, which is involved in T and NK cell maturation and the synthesis of other inflammatory cytokines and cell adhesion molecules. It plays a significant role in orchestrating the cytokine cascade, accelerates atherosclerosis and influences plaque vulnerability. To investigate the influence of IL-18 cytokine on atherosclerosis development, a stochastic Petri net model was built and then analyzed. First, MCT-sets and t-clusters were generated, then knockout and simulation-based analysis was conducted. The application of systems approach that was used in this research enabled an in-depth analysis of the studied phenomenon. Our results gave us better insight into the studied phenomenon and allow revealing that activation of macrophages by the classical pathway and IL-18-MyD88 signaling axis is crucial for the modeled process.     

Biological Characteristics and Osteogenic Differentiation of Ovine Bone Marrow Derived Mesenchymal Stem Cells Stimulated with FGF-2 and BMP-2

Cell-based therapies using mesenchymal stem cells (MSCs) are a promising tool in bone tissue engineering. Bone regeneration with MSCs involves a series of molecular processes leading to the activation of the osteoinductive cascade supported by bioactive factors, including fibroblast growth factor-2 (FGF-2) and bone morphogenetic protein-2 (BMP-2). In this study, we examined the biological characteristics and osteogenic differentiation potential of sheep bone marrow MSCs (BM-MSCs) treated with 20 ng/mL of FGF-2 and 100 ng/mL BMP-2 in vitro. The biological properties of osteogenic-induced BM-MSCs were investigated by assessing their morphology, proliferation, phenotype, and cytokine secretory profile. The osteogenic differentiation was characterized by Alizarin Red S staining, immunofluorescent staining of osteocalcin and collagen type I, and expression levels of genetic markers of osteogenesis. The results demonstrated that BM-MSCs treated with FGF-2 and BMP-2 maintained their primary MSC properties and improved their osteogenic differentiation capacity, as confirmed by increased expression of osteocalcin and collagen type I and upregulation of osteogenic-related gene markers BMP-2, Runx2, osterix, collagen type I, osteocalcin, and osteopontin. Furthermore, sheep BM-MSCs produced a variety of bioactive factors involved in osteogenesis, and supplementation of the culture medium with FGF-2 and BMP-2 affected the secretome profile of the cells. The results suggest that sheep osteogenic-induced BM-MSCs may be used as a cellular therapy to study bone repair in the preclinical large animal model.     

Characterization of a class of spatially interconnected systems (ladder circuits) using two-dimensional systems theory

Multidimensional Systems and Signal Processing - This paper considers a class of spatially interconnected systems formed by ladder circuits using two-dimensional systems theory. The individual...     

Why Do We Need More Active ATRP Catalysts?

Atom transfer radical polymerization (ATRP) is a staple technique for the preparation of polymers with well-defined architecture. In ATRP, the catalyst governs the equilibrium between propagating radicals and dormant species, thus affecting the polymerization control for a range of monomers and transferable atoms employed in the process. The design and the use of highly active catalysts could diminish the amount of transition metal complexes, extend ATRP to less active monomers and give access to new chain-end functionalities. At the same time, very active catalysts can be involved in formation of organometallic species. Herein, the role of the catalyst on the ATRP equilibrium is carefully elucidated, together with recent observations on the impact of the catalyst nature on formation of organometallic species and relevant side reactions. Based on this knowledge, a perspective on the benefits and challenges that derive from the use of highly active ATRP catalysts is presented.