Recognition mechanism of p63 by the E3 ligase Itch Novel strategy in the study and inhibition of this interaction.

The HECT-containing E3 ubiquitin ligase Itch mediates the degradation of several proteins, including p63 and p73, involved in cell specification and fate. Itch contains four WW domains, which are essential for recognition on the target substrate, which contains a short proline-rich sequence. Several signaling complexes containing these domains have been associated with human diseases such as muscular dystrophy, Alzheimer’s or Huntington’s diseases. To gain further insight into the structural determinants of the Itch-WW2 domain, we investigated its interaction with p63. We assigned, by 3D heteronuclear NMR experiments, the backbone and side chains of the uniformly 13C-15N-labeled Itch-WW2. In vitro interaction of Itch-WW2 domain with p63 was studied using its interactive p63 peptide, pep63. Pep63 is an 18-mer peptide corresponding to the region from 534–551 residue of p63, encompassing the PP xY motif that interacts with the Itch-WW domains, and we identified the residues involved in this molecular recognition. Moreover, here, a strategy of stabilization of the conformation of the PP xY peptide has been adopted, increasing the WW-ligand binding. We demonstrated that cyclization of pep63 leads to an increase of both the biological stability of the peptide and of the WW-ligand complex. Stable metal-binding complexes of the pep63 have been also obtained, and localized oxidative damage on Itch-WW2 domain has been induced, demonstrating the possibility of use of metal-pep63 complexes as models for the design of metal drugs to inhibit the Itch-WW-p63 recognition in vivo. Thus, our data suggest a novel strategy to study and inhibit the recognition mechanism of Itch E3-ligase

Can COVID-19 pandemic boost the epidemic of neurodegenerative diseases?

The pandemic of Coronavirus Disease 2019 (COVID-19) presents the world with the medical challenge associated with multifactorial nature of this pathology. Indeed COVID-19 affects several organs and systems and presents diversified clinical picture. COVID-19 affects the brain in many ways including direct infection of neural cells with SARS-CoV-2, severe systemic inflammation which floods the brain with pro-inflammatory agents thus damaging nervous cells, global brain ischaemia linked to a respiratory failure, thromboembolic strokes related to increased intravascular clotting and severe psychological stress. Often the COVID-19 is manifested by neurological and neuropsychiatric symptoms that include dizziness, disturbed sleep, cognitive deficits, delirium, hallucinations and depression. All these indicate the damage to the nervous tissue which may substantially increase the incidence of neurodegenerative diseases and promote dementia

Thiosulfate-cyanide sulfurtransferase a mitochondrial essential enzyme: from cell metabolism to the biotechnological applications

Thiosulfate: cyanide sulfurtransferase (TST), also named rhodanese, is an enzyme widely distributed in both prokaryotes and eukaryotes, where it plays a relevant role in mitochondrial function. TST enzyme is involved in several biochemical processes such as: cyanide detoxification, the transport of sulfur and selenium in biologically available forms, the restoration of iron-sulfur clusters, redox system maintenance and the mitochondrial import of 5S rRNA. Recently, the relevance of TST in metabolic diseases, such as diabetes, has been highlighted, opening the way for research on important aspects of sulfur metabolism in diabetes. This review underlines the structural and functional characteristics of TST, describing the physiological role and biomedical and biotechnological applications of this essential enzyme

Allyl sulfur compounds and cellular detoxification system: effects and perspectives in cancer therapy

Natural organosulfur compounds (OSCs) have been shown to have chemopreventive effects and to suppress the proliferation of tumor cells in vitro through the induction of apoptosis. The biochemical mechanisms underlying the antitumorigenic and anti-proliferative effects of garlic-derived OSCs are not fully understood. Several modes of action of these compounds have been proposed, and it seems likely that the rate of clearance of allyl sulfur groups from cells is a determinant of the overall response. The aim of this review is to focus attention on the effects of natural allyl sulfur compounds on the cell detoxification system in normal and tumor cells. It has been already reported that several natural allyl sulfur compounds induce chemopreventive effects by affecting xenobiotic metabolizing enzymes and inducing their down-activation. Moreover, different effects of water- and oil-soluble allyl sulfur compounds on enzymes involved in the detoxification system of rat tissues have been observed. A direct interaction of the garlic allyl sulfur compounds with proteins involved in the detoxification system was studied in order to support the hypothesis that proteins possessing reactive thiol groups and that are involved in the detoxification system and in the cellular redox homeostasis, are likely the preferential targets of these compounds. The biochemical transformation of the OSCs in the cell and their adducts with thiol functional groups of these proteins, could be considered relevant events to uncover the anticancer properties of the allyl sulfur compounds. Although additional studies, using proteomic approaches and transgenic models, are needed to identify the molecular targets and modes of action of these natural compounds, the allyl sulfur compounds can represent potential ideal agents in anticancer therapy, either alone or in association with other antitumor drugs

Photo-polymerization damage protection by hydrogen sulfide donors for 3d-cell culture systems optimization

Photo-polymerized hydrogels are ideally suited for stem-cell based tissue regeneration and three dimensional (3D) bioprinting because they can be highly biocompatible, injectable, easy to use, and their mechanical and physical properties can be controlled. However, photo-polymerization involves the use of potentially toxic photo-initiators, exposure to ultraviolet light radiation, formation of free radicals that trigger the cross-linking reaction, and other events whose effects on cells are not yet fully understood. The purpose of this study was to examine the effects of hydrogen sulfide (H2S) in mitigating cellular toxicity of photo-polymerization caused to resident cells during the process of hydrogel formation. H2S, which is the latest discovered member of the gasotransmitter family of gaseous signalling molecules, has a number of established beneficial properties, including cell protection from oxidative damage both directly (by acting as a scavenger molecule) and indirectly (by inducing the expression of anti-oxidant proteins in the cell). Cells were exposed to slow release H2S treatment using pre-conditioning with glutathione-conjugated-garlic extract in order to mitigate toxicity during the photo-polymerization process of hydrogel formation. The protective effects of the H2S treatment were evaluated in both an enzymatic model and a 3D cell culture system using cell viability as a quantitative indicator. The protective effect of H2S treatment of cells is a promising approach to enhance cell survival in tissue engineering applications requiring photo-polymerized hydrogel scaffolds

Hydrogen sulfide as potential regulatory gasotransmitter in arthritic diseases

The social and economic impact of chronic inflammatory diseases, such as arthritis, explains the growing interest of the research in this field. The antioxidant and anti-inflammatory properties of the endogenous gasotransmitter hydrogen sulfide (H2S) were recently demonstrated in the context of different inflammatory diseases. In particular, H2S is able to suppress the production of pro-inflammatory mediations by lymphocytes and innate immunity cells. Considering these biological effects of H2S, a potential role in the treatment of inflammatory arthritis, such as rheumatoid arthritis (RA), can be postulated. However, despite the growing interest in H2S, more evidence is needed to understand the pathophysiology and the potential of H2S as a therapeutic agent. Within this review, we provide an overview on H2S biological effects, on its role in immune-mediated inflammatory diseases, on H2S releasing drugs, and on systems of tissue repair and regeneration that are currently under investigation for potential therapeutic applications in arthritic diseases

Differences in the vascular and metabolic profiles between metabolically healthy and unhealthy obesity

Abstract Individuals suffering from severe obesity but not presenting the typical metabolic alterations, are included in a subclass of obesity defined Metabolically Healthy Obesity (MHO). The physiological factors underlying what seems a protective and favourable metabolic profile remain unclear. MHO individuals are more insulin-sensitive, have relatively lower visceral/ectopic fat accumulation and reduced levels of chronic low-grade inflammation, compared to obese subjects with co-morbidities. The study of MHO subjects represents a great opportunity for the recognition of the mechanisms that lead to the vascular and metabolic complications in obesity. Finding the differences among the metabolic profile of visceral adipose tissue between metabolically healthy and unhealthy obesity may lead to future personalized and stratified therapies.This review article summarizes the pathomechanisms and metabolic changes in MHO and metabolically unhealthy obesity (MUO), reviews clinical studies on the subject, and discusses preventive and therapeutic options

Specificity of ε and non-ε isoforms of Arabidopsis 14-3-3 proteins towards the H+-ATPase and other targets

14-3-3 proteins are a family of ubiquitous dimeric proteins that modulate many cellular functions in all eukaryotes by interacting with target proteins. 14-3-3s exist as a number of isoforms that in Arabidopsis identifies two major groups named ε and non-ε. Although isoform specificity has been demonstrated in many systems, the molecular basis for the selection of specific sequence contexts has not been fully clarified. In this study we have investigated isoform specificity by measuring the ability of different Arabidopsis 14-3-3 isoforms to activate the H+-ATPase. We observed that GF14 isoforms of the non-εgroup were more effective than ε group isoforms in the interaction with the H+-ATPase and in the stimulation of its activity. Kinetic and thermodynamic parameters of the binding of GF14ε and GF14ω isoforms, representative of ε and non-ε groups respectively, with the H+-ATPase, have been determined by Surface Plasmon Resonance analysis demonstrating that the higher affinity of GF14ω is mainly due to slower dissociation. The role of the C-terminal region and of a Gly residue located in the loop 8 and conserved in all non-ε isoforms has also been studied by deletion and site-specific mutagenesis. The C-erminal domains, despite their high divergence, play an auto-inhibitory role in both isoforms and they, in addition to a specific residue located in the loop 8, contribute to isoform specificity. To investigate the generality of these findings, we have used the SPOT-synthesis technology to array a number of phosphopeptides matching known or predicted 14-3-3 binding sites present in a number of clients. The results of this approach confirmed isoform specificity in the recognition of several target peptides, suggesting that the isoform specificity may have an impact on the modulation of a variety of additional protein activities, as suggested by probing of a phosphopeptide array with members of the two 14-3-3 groups. © 2014 Pallucca et al

Optimum sizing of cogeneration plants by means of a genetic algorithm optimization: A case study

In the context of increasing energy consumption, multi-generation systems such as combined heat and power generation (CHP) are attractive to meet the increasingly stringent requirements regarding energy saving in buildings. Hospitals are great consumers of energy, both electrical and thermal: the use of heating and cooling equipment for maintaining satisfactory comfort and indoor air quality for the patients as well as the adoption of several electrical health equipment result in the highest energy consumption per unit floor area of the entire building sector. In the present study, co/tri-generation systems\u2019 optimal set-up, size and operation are investigated for small/medium size hospital facilities. More specifically, after the presentation of the energy consumption profiles for a medium size hospital with 600 beds, set as reference case for this study, a parametric analysis has been carried out varying the peak loads of the user. For each of the proposed scenarios, the optimal plant configuration (sizing of all the energy production systems) has been outlined by means of a numerical code (Trigen 3.0) in-house developed. Afterwards, in order to optimize the load distribution in a smart grid characterized by electrical, thermal, cooling and fuel energy fluxes, an ulterior numerical investigation has been performed. The software, named EGO (Energy Grids Optimizer) consists of a genetic algorithm procedure: it defines the optimal load distribution of a number of energy systems operating into a smart grid based on the minimization of an objective function which expresses the total cost of energy production. Finally, an economic analysis has been carried out in order to evaluate the profitability of the proposed CHP-heat pump scenario