Characterization of C2C12 cells in simulated microgravity: Possible use for myoblast regeneration

Muscle loss is a major problem for many in lifetime. Muscle and bone degeneration has also been observed in individuals exposed to microgravity and in unloading conditions. C2C12 myoblst cells are able to form myotubes, and myofibers and these cells have been employed for muscle regeneration purposes and in myogenic regeneration and transplantation studies. We exposed C2C12 cells in an random position machine to simulate microgravity and study the energy and the biochemical challenges associated with this treatment. Simulated microgravity exposed C2C12 cells maintain positive proliferation indices and delay the differentiation process for several days. On the other hand this treatment significantly alters many of the biochemical and the metabolic characteristics of the cell cultures including calcium homeostasis. Recent data have shown that these perturbations are due to the inhibition of the ryanodine receptors on the membranes of intracellular calcium stores. We were able to reverse this perturbations treating cells with thapsigargin which prevents the segregation of intracellular calcium ions in the mitochondria and in the sarco/endoplasmic reticula. Calcium homeostasis appear a key target of microgravity exposure. In conclusion, in this study we reported some of the effects induced by the exposure of C2C12 cell cultures to simulated microgravity. The promising information obtained is of fundamental importance in the hope to employ this protocol in the field of regenerative medicine     

Janus kinase inhibitors role in bone remodeling

Janus kinases (JAKs) play a pleiotropic role in several important physiological processes, such as cell maturation, cell proliferation, and cell death, via providing transmission signals from several molecules, such as cytokines, interferons, hormones, and growth factors, to the nucleus. Bone physiology and remodeling are markedly influenced by proinflammatory cytokines. Among them, interleukin-1 (IL-1) and IL-6 are considered potent stimulator of bone resorption. Several cytokine receptors, such as IL-6 receptors, are characterized by tyrosine kinases of the JAK family associated with their intracellular domains. There is an emerging interest in the effects of JAKs inhibition on the cells involved in bone remodeling. JAK inhibitors represent a new class of molecules involved in the therapy of numerous immune-mediated inflammatory diseases. In this review, we want to focus on the role of JAKs inhibitors on bone remodeling and on RANKL-RANK-OPG signal and inflammatory cytokines which are involved in the regulation of bone cells, such as osteoblasts and osteoclasts.     

Exploring the concept of interaction computing through the discrete algebraic analysis of the Belousov–Zhabotinsky reaction

Interaction computing (IC) aims to map the properties of integrable low-dimensional non-linear dynamical systems to the discrete domain of finite-state automata in an attempt to reproduce in software the self-organizing and dynamically stable properties of sub-cellular biochemical systems. As the work reported in this paper is still at the early stages of theory development it focuses on the analysis of a particularly simple chemical oscillator, the Belousov–Zhabotinsky (BZ) reaction. After retracing the rationale for IC developed over the past several years from the physical, biological, mathematical, and computer science points of view, the paper presents an elementary discussion of the Krohn–Rhodes decomposition of finite-state automata, including the holonomy decomposition of a simple automaton, and of its interpretation as an abstract positional number system. The method is then applied to the analysis of the algebraic properties of discrete finite-state automata derived from a simplified Petri net model of the BZ reaction. In the simplest possible and symmetrical case the corresponding automaton is, not surprisingly, found to contain exclusively cyclic groups. In a second, asymmetrical case, the decomposition is much more complex and includes five different simple non-abelian groups whose potential relevance arises from their ability to encode functionally complete algebras. The possible computational relevance of these findings is discussed and possible conclusions are drawn.     

Biochemical modifications of gliadins induced by microbial transglutaminase on wheat flour

Background

Celiac disease (CD) is an immune-mediated disorder caused by the ingestion of wheat gluten. A lifelong, gluten-free diet is required to normalize the intestinal mucosa. We previously found that transamidation by microbial transglutaminase (mTGase) suppressed the gliadin-specific immune response in intestinal T-cell lines from CD patients and in models of gluten sensitivity.

Methods

SDS-PAGE, Western blot, ELISA, tissue transglutaminase (tTGase) assay and nano-HPLC–ESI-MS/MS experiments were used to analyze prolamins isolated from treated wheat flour.

Results

Gliadin and glutenin yields decreased to 7.6 ± 0.5% and 7.5 ± 0.3%, respectively, after a two-step transamidation reaction that produced a water-soluble protein fraction (spf). SDS-PAGE, Western blot and ELISA analyses confirmed the loss of immune cross-reactivity with anti-native gliadin antibodies in residual transamidated gliadins (K-gliadins) and spf as well as the occurrence of neo-epitopes. Nano-HPLC–ESI-MS/MS experiments identified some native and transamidated forms of celiacogenic peptides including p31–49 and confirmed that mTGase had similar stereo-specificity of tTGase. Those peptides resulted to be 100% and 57% modified in spf and K-gliadins, respectively. In particular, following transamidation p31–49 lost its ability to increase tTGase activity in Caco-2 cells. Finally, bread manufactured with transamidated flour had only minor changes in baking characteristics.

Conclusions

The two-step transamidation reaction modified the analyzed gliadin peptides, which are known to trigger CD, without influencing main technological properties.

General significance

Our data shed further light on a detoxification strategy alternative to the gluten free diet and may have important implications for the management of CD patients.     

The impact of high hydrostatic pressure on structure and dynamics of β-lactoglobulin

Methods

Combining small-angle X-ray and neutron scattering measurements with inelastic neutron scattering experiments, we investigated the impact of high hydrostatic pressure on the structure and dynamics of β-lactoglobulin (βLG) in aqueous solution.

Background

βLG is a relatively small protein, which is predominantly dimeric in physiological conditions, but dissociates to monomer below about pH 3.

Results

High-pressure structural results show that the dimer–monomer equilibrium, as well as the protein–protein interactions, are only slightly perturbed by pressure, and βLG unfolding is observed above a threshold value of 3000 bar. In the same range of pressure, dynamical results put in evidence a slowing down of the protein dynamics in the picosecond timescale and a loss of rigidity of the βLG structure. This dynamical behavior can be related to the onset of unfolding processes, probably promoted from water penetration in the hydrophobic cavity.

General significance

Results suggest that density and compressibility of water molecules in contact with the protein are key parameters to regulate the protein flexibility.