Membrane fusogenic lysine type lipid assemblies possess enhanced NLRP3 inflammasome activation potency

Lysine (K) type cationic lipid with a propyl spacer and ditetradecyl hydrophobic moieties composing liposomes, K3C14, previously studied for gene delivery, were reported to activate the NLRP3 inflammasomes in human macrophages via the conventional phagolysosomal pathway. In this study, K3C16, a propyl spacer bearing lysine type lipids with dihexadecyl moieties (an extension of two hydrocarbon tail length) were compared with K3C14 as liposomes. Such a small change in tail length did not alter the physical properties such as size distribution, zeta potential and polydispersity index (PDI). The NLRP3 activation potency of K3C16 was shown to be 1.5-fold higher. Yet, the toxicity was minimal, whereas K3C14 has shown to cause significant cell death after 24 h incubation. Even in the presence of endocytosis inhibitors, cytochalasin D or dynasore, K3C16 continued to activate the NLRP3 inflammasomes and to induce IL-1β release. To our surprise, K3C16 liposomes were confirmed to fuse with the plasma membrane of human macrophages and CHO-K1 cells. It is demonstrated that the change in hydrophobic tail length by two hydrocarbons drastically changed a cellular entry route and potency in activating the NLRP3 inflammasomes.     

Regulation of autophagy in bovine mammary epithelial cells

The bovine mammary gland undergoes intensive remodelling during the lactation cycle, and the escalation of this process is observed during dry periods. The main type of cell death responsible for bovine mammary gland involution is apoptosis; however, there are also a lot of cells exhibiting morphological features of autophagy during drying off. Our in vitro and in vivo studies of bovine mammary gland physiology suggest that the enhanced process of autophagy, observed at the end of lactation and during dry periods, is the result of: (1) decreased level of lactogenic hormones (GH, IGF-I), (2) decreased GH-R and IGF-IR alpha expression, (3) increased expression of auto/paracrine apoptogenic peptides (IGFBPs, TGFbeta), (4) increased influence of sex steroids (17beta-estradiol and progesterone) and (5) enhanced competition between the between the intensively developing fetus and the mother organism for nutritional and bioactive compounds. The above conditions may create a state of temporary malnutrition of mammary epithelial cells, which forces the cells to the induction of autophagy, as a mechanism for stabilizing intracellular supplies of energy and amino acids, especially during the enhanced activity of apoptogenic factors.     

Adjoint systems for models of cell signaling pathways and their application to parameter fitting

The paper concerns the problem of fitting mathematical models of cell signaling pathways. Such models frequently take the form of sets of nonlinear ordinary differential equations. While the model is continuous in time, the performance index used in the fitting procedure involves measurements taken at discrete time moments. Adjoint sensitivity analysis is a tool which can be used for finding the gradient of a performance index in the space of parameters of the model. In the paper, a structural formulation of adjoint sensitivity analysis called the generalized backpropagation through time (GBPTT) is used. The method is especially suited for hybrid, continuous-discrete time systems. As an example, we use the mathematical model NF-kappaB of the regulatory module, which plays a major role in the innate immune response in animals.     

Human Sperm Characteristics with Regard to Cobalt,Chromium, and Lead in Semen and Activity of Catalase in Seminal Plasma

Biological Trace Element Research - We analyzed cobalt (Co), chromium (Cr), and lead (Pb) concentrations in human semen and catalase CAT activity in seminal plasma and the effects of their...     

A novel method for cloning of coding sequences of highly toxic proteins

Background

During standard gene cloning, the recombinant protein appearing in bacteria as the result of expression leakage very often inhibits cell proliferation leading to blocking of the cloning procedure. Although different approaches can reduce transgene basal expression, the recombinant proteins, which even in trace amounts inhibit bacterial growth, can completely prevent the cloning process.