Antonella Bongiovanni

Identification and characterization of the nano‐sized vesicles released by muscle cells

Several cell types secrete small membranous vesicles that contain cell‐specific collections of proteins, lipids, and genetic material. The function of these vesicles is to allow cell‐to‐cell signaling and the horizontal transfer of their cargo molecules. Here, we demonstrate that muscle cells secrete nano‐sized vesicles and that their release increases during muscle differentiation. Analysis of these nanovesicles allowed us to characterize them as exosome‐like particles and to define the potential role of the multifunctional protein Alix in their biogenesis.

Applying Quality and Project Management methodologies in biomedical research laboratories: a public research network’s case study

Quality principles and Project Management (PM) methodologies have long been ignored in non-regulated scientific research, even though they have been widely used in industrial and business applications, improving management and results and reducing costs. A groundbreaking project named Quality and Project Management OpenLab was implemented by a network of Italian National Research Council institutes, with the aim to realize and disseminate within the scientific community an innovative way to plan and organize research activity, inspired by Quality and PM principles and customized for needs and requisites of biomedical research laboratories. The results show better use of time and project consistency. Our experience of working side by side with Quality consultants clearly shows that the proper and accurate application of Quality and PM methodologies to intellectual and scientific production can facilitate and strengthen research, providing tools to make it faster and more efficient without imposing any undue constraints.

Identification and characterization of PlAlix, the Alix homologue from the Mediterranean sea urchin Paracentrotus lividus.

The sea urchin provides a relatively simple and tractable system for analyzing the early stages of embryo development. Here, we use the sea urchin species, Paracentrotus lividus, to investigate the role of Alix in key stages of embryogenesis, namely the egg fertilization and the first cleavage division. Alix is a multifunctional protein involved in different cellular processes including endocytic membrane trafficking, filamentous (F)‐actin remodeling, and cytokinesis. Alix homologues have been identified in different metazoans; in these organisms, Alix is involved in oogenesis and in determination/differentiation events during embryo development. Herein, we describe the identification of the sea urchin homologue of Alix, PlAlix. The deduced amino acid sequence shows that Alix is highly conserved in sea urchins. Accordingly, we detect the PlAlix protein cross‐reacting with monoclonal Alix antibodies in extracts from P. lividus, at different developmental stages. Focusing on the role of PlAlix during early embryogenesis we found that PlAlix is a maternal protein that is expressed at increasingly higher levels from fertilization to the 2‐cell stage embryo. In sea urchin eggs, PlAlix localizes throughout the cytoplasm with a punctuated pattern and, soon after fertilization, accumulates in larger puncta in the cytosol, and in microvilli‐like protrusions. Together our data show that PlAlix is structurally conserved from sea urchin to mammals and may open new lines of inquiry into the role of Alix during the early stages of embryo development.

A sea urchin in vivo model to evaluate Epithelial-Mesenchymal Transition

Epithelial‐mesenchymal transition (EMT) is an evolutionarily conserved cellular program, which is a prerequisite for the metastatic cascade in carcinoma progression. Here, we evaluate the EMT process using the sea urchin Paracentrotus lividus embryo. In sea urchin embryos, the earliest EMT event is related to the acquisition of a mesenchymal phenotype by the spiculogenetic primary mesenchyme cells (PMCs) and their migration into the blastocoel. We investigated the effect of inhibiting the epidermal growth factor (EGF) signaling pathway on this process, and we observed that mesenchyme cell differentiation was blocked. In order to extend and validate our studies, we investigated the migratory capability and the level of potential epidermal growth factor receptor (EGFr) targets in a breast cancer cell line after EGF modulation. Altogether, our data highlight the sensitivity of the sea urchin embryo to anti‐EMT drugs and pinpoint the sea urchin embryo as a valuable in vivo model system for studying EMT and the screening of anti‐EMT candidates.

Quality-based model for Life Sciences research guidelines

Nowadays, the requirement to define adequate standards and to identify and validate general guidelines for scientific activity is becoming increasingly apparent also in non-regulated scientific research. Guidelines are fundamental tools to provide valid indications for proper conduct in a research laboratory, the correct use of equipment and procedures, as well as for aligning and standardizing the procedures used in different scientific contexts. The identification, dissemination and application of common guidelines can improve significantly the reproducibility of the scientific results and the exchange of materials and data in the context of scientific consortia, comprising also industrial partners and meta-analysis projects. A Quality and Project Management OpenLab research network was formed in 2012 to develop and apply Total Quality Management models to Life Sciences research laboratories. One of the main tasks of the network has been the definition of a model for the drafting of guidelines, firmly based on quality principles and documentation management. The outcome is an operational flow describing all the phases of the process, which has been validated by four different drafting groups through the production of 13 guidelines ranging from research activity to equipment and facility management. Different institutes of the National Research Council are currently following these guidelines; some of them have also been used to define the procedures included in a certified Quality Management System for a research laboratory. Our experience shows that the model for guidelines we have developed makes drafting guidelines easier and more immediate, and significantly, it is applicable to different scientific contexts and disciplines, including both non-regulated research and technology transfer-oriented research, and also the Quality Management System of a scientific laboratory.

Pro-invasive stimuli and the interacting protein Hsp70 favour the route of alpha-enolase to the cell surface

Cell surface expression of alpha-enolase, a glycolytic enzyme displaying moonlighting activities, has been shown to contribute to the motility and invasiveness of cancer cells through the protein non-enzymatic function of binding plasminogen and enhancing plasmin formation. Although a few recent records indicate the involvement of protein partners in the localization of alpha-enolase to the plasma membrane, the cellular mechanisms underlying surface exposure remain largely elusive. Searching for novel interactors and signalling pathways, we used low-metastatic breast cancer cells, a doxorubicin-resistant counterpart and a non-tumourigenic mammary epithelial cell line. Here, we demonstrate by a combination of experimental approaches that epidermal growth factor (EGF) exposure, like lipopolysaccharide (LPS) exposure, promotes the surface expression of alpha-enolase. We also establish Heat shock protein 70 (Hsp70), a multifunctional chaperone distributed in intracellular, plasma membrane and extracellular compartments, as a novel alpha-enolase interactor and demonstrate a functional involvement of Hsp70 in the surface localization of alpha-enolase. Our results contribute to shedding light on the control of surface expression of alpha-enolase in non-tumourigenic and cancer cells and suggest novel targets to counteract the metastatic potential of tumours.

Applying Design of Experiments Methodology to PEI Toxicity Assay on Neural Progenitor Cells

Design of Experiments (DoE) statistical methodology permits the simultaneous evaluation of the effects of different factors on experimental performance and the analysis of their interactions in order to identify their optimal combinations. Compared to classical approaches based on changing only one factor at a time (OFAT), DoE facilitates the exploration of a broader range of parameters combinations, as well as providing the possibility to select a limited number of combinations covering the whole frame. The advantage of DoE is to maximise the amount of information provided and to save both time and money. DoE has been primarily used in industry to maximise process robustness, but recently it has also been applied in biomedical research to different types of multivariable analyses, from determination of the best cell media composition to the optimisation of entire multi-step laboratory protocols such as cell transfection.

Palmitoylation is a post-translational modification of Alix regulating the membrane organization of exosome-like small extracellular vesicles

BACKGROUND Virtually all cell types have the capacity to secrete nanometer-sized extracellular vesicles, which have emerged in recent years as potent signal transducers and cell-cell communicators. The multifunctional protein Alix is a bona fide exosomal regulator and skeletal muscle cells can release Alix-positive nano-sized extracellular vesicles, offering a new paradigm for understanding how myofibers communicate within skeletal muscle and with other organs. S-palmitoylation is a reversible lipid post-translational modification, involved in different biological processes, such as the trafficking of membrane proteins, achievement of stable protein conformations, and stabilization of protein interactions. METHODS Here, we have used an integrated biochemical-biophysical approach to determine whether S-palmitoylation contributes to the regulation of extracellular vesicle production in skeletal muscle cells. RESULTS We ascertained that Alix is S-palmitoylated and that this post-translational modification influences its protein-protein interaction with CD9, a member of the tetraspanin protein family. Furthermore, we showed that the structural organization of the lipid bilayer of the small (nano-sized) extracellular vesicle membrane with altered palmitoylation is qualitatively different compared to mock control vesicles. CONCLUSIONS We propose that S-palmitoylation regulates the function of Alix in facilitating the interactions among extracellular vesicle-specific regulators and maintains the proper structural organization of exosome-like extracellular vesicle membranes. GENERAL SIGNIFICANCE Beyond its biological relevance, our study also provides the means for a comprehensive structural characterization of EVs.