Interleukin 3- receptor targeted exosomes inhibit in vitro and in vivo chronic myelogenous Leukemia cell growth

Despite Imatinib (IM), a selective inhibitor of Bcr-Abl, having led to improved prognosis in Chronic Myeloid Leukemia (CML) patients, acquired resistance and long-term adverse effects is still being encountered. There is, therefore, urgent need to develop alternative strategies to overcome drug resistance. According to the molecules expressed on their surface, exosomes can target specific cells. Exosomes can also be loaded with a variety of molecules, thereby acting as a vehicle for the delivery of therapeutic agents. In this study, we engineered HEK293T cells to express the exosomal protein Lamp2b, fused to a fragment of Interleukin 3 (IL3). The IL3 receptor (IL3-R) is overexpressed in CML…

Fibrillogenesis of hen egg-white lysozyme at acidic pH

Thermodynamic versus Conformational Metastability in Fibril-Forming Lysozyme Solutions

The role of intermolecular interaction in fibril-forming protein solutions and its relation with molecular conformation is a crucial aspect for the control and inhibition of amyloid structures. Here, we study the fibril formation and the protein-protein interactions of lysozyme at acidic pH and low ionic strength. The amyloid formation occurs after a long lag time and is preceded by the formation of oligomers, which seems to be off-pathway with respect to fibrillation. By measuring the osmotic isothermal compressibility and the collective diffusion coefficient of lysozyme in solution, we observe that the monomeric solution is kept in a thermodynamically metastable state by strong electrosta…

Additional file 1: of CD90+ liver cancer cells modulate endothelial cell phenotype through the release of exosomes containing H19 lncRNA

(a) Characterization of isolated exosomes. Left panel: DSL for exosomes released by SKHep Middle panel: Western blot forTsg101 and HSC70 in SkHep cells and their relative exosomes. Right panel: Confocal microscopy analysis on HUVECs treated for 1, 3 and 6 hours with 5 mg/ml of SKHep-derived exosomes. HUVECs were stained with phalloidin Alexa Fluor (green), nuclear counterstaining was performed using DAPI (blue), exosomes were labelled with PKH26 (red). (b) Target analysis. Real time-PCR analysis on HUVECs treated for 18 h with 5 mg/ml of SkHep-derived exosomes. Normalized for b-actin the DDct were indicated as fold of induction respect to control (untreated cells). *p<0.05. (c) Tubulogen…

Lysozyme Aggregation Driven by Unfolding: the Role of Metal Ions

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

Abstract 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…

Multiple myeloma-derived exosomes are enriched of amphiregulin (AREG) and activate the epidermal growth factor pathway in the bone microenvironment leading to osteoclastogenesis

Background Multiple myeloma (MM) is a clonal plasma cell malignancy associated with osteolytic bone disease. Recently, the role of MM-derived exosomes in the osteoclastogenesis has been demonstrated although the underlying mechanism is still unknown. Since exosomes-derived epidermal growth factor receptor ligands (EGFR) are involved in tumor-associated osteolysis, we hypothesize that the EGFR ligand amphiregulin (AREG) can be delivered by MM-derived exosomes and participate in MM-induced osteoclastogenesis. Methods Exosomes were isolated from the conditioned medium of MM1.S cell line and from bone marrow (BM) plasma samples of MM patients. The murine cell line RAW264.7 and primary human CD1…

Intermolecular interactions in metastable protein solutions.

Influence of TFE on the proteins interactions of a lysozyme solution: a small angle X-ray scattering study

Role of repulsive interaction on the fibrillogenesis of hen egg-white lysozyme

CD90+ liver cancer cells modulate endothelial cell phenotype through the release of exosomes containing H19 lncRNA

Background CD90+ liver cancer cells have been described as cancer stem-cell-like (CSC), displaying aggressive and metastatic phenotype. Using two different in vitro models, already described as CD90+ liver cancer stem cells, our aim was to study their interaction with endothelial cells mediated by the release of exosomes. Methods Exosomes were isolated and characterized from both liver CD90+ cells and hepatoma cell lines. Endothelial cells were treated with exosomes, as well as transfected with a plasmid containing the full length sequence of the long non-coding RNA (lncRNA) H19. Molecular and functional analyses were done to characterize the endothelial phenotype after treatments. Results …

Osteosarcoma cell-derived exosomes affect tumor microenvironment by specific packaging of microRNAs

Abstract Bone microenvironment provides growth and survival signals essential for osteosarcoma (OS) initiation and progression. OS cells regulate communications inside tumor microenvironment through different ways and, among all, tumor-derived exosomes support cancer progression and metastasis. To define the contribution of OS-derived exosomes inside the microenvironment, we investigated the effects induced in bone remodeling mechanism and tumor angiogenesis. We demonstrated that exosomes promoted osteoclasts differentiation and bone resorption activity. Furthermore, exosomes potentiated tube formation of endothelial cells and increased angiogenic markers expression. We therefore investigat…

Fibrillogenesis of Hen Egg-White Lysozyme at acid pH

Irreversible gelation of thermally unfolded proteins:structural and mechanical properties of lysozyme aggregates

The formation of protein aggregates is important in many fields of life science and technology. The morphological and mechanical properties of protein solutions depend upon the molecular conformation and thermodynamic and environmental conditions. Non-native or unfolded proteins may be kinetically trapped into irreversible aggregates and undergo precipitation or gelation. Here, we study the thermal aggregation of lysozyme in neutral solutions. We characterise the irreversible unfolding of lysozyme by differential scanning calorimetry. The structural properties of aggregates and their mechanisms of formation with the eventual gelation are studied at high temperature by spectroscopic, rheolog…

Existence of metastable intermediate lysozyme conformation highlights the role of alcohols in altering protein stability.

Alcohols have a manifold effect on the conformational and thermodynamic stability of native proteins. Here, we study the effect of moderate concentrations of trifluoroethanol (TFE) on the thermal stability of hen egg-white lysozyme (HEWL), by far-UV circular dichroism and by steady-state and time-resolved photoluminescence of intrinsic tryptophans. Our results highlight that TFE affects lysozyme stability by preferential solvation of the protein molecule. Furthermore, we discovered the existence at 20% TFE of an equilibrium partially folded state of lysozyme, intermediate between the native and the unfolded state. A three-state model is therefore used to interpolate the thermal denaturation…

Curcumin inhibits in vitro and in vivo chronic myelogenous leukemia cells growth : a possible role for exosomal disposal of miR-21

// Simona Taverna 1 , Marco Giallombardo 1 , Marzia Pucci 1 , Anna Flugy 1 , Mauro Manno 2 , Samuele Raccosta 2 , Christian Rolfo 3 , Giacomo De Leo 1 , Riccardo Alessandro 1, 4 1 Dipartimento di Biopatologia e Metodologie Biomediche, Sezione di Biologia e Genetica, Universita di Palermo, Italy 2 Istituto di Biofisica, CNR, Palermo, Italy 3 Phase I - Early Clinical Trials Unit Oncology Department and Center of Oncological Research (CORE), University Hospital Antwerp & Antwerp University, Belgium 4 Istituto di Biomedicina e Immunologia Molecolare (IBIM), Consiglio Nazionale delle Ricerche, Palermo, Italy Correspondence to: Riccardo Alessandro, e-mail: riccardo.alessandro@unipa.it Keywords: e…

Role of electrostatic interactions in the fibrillogenesis of lysozyme

Involvement of multiple myeloma cell-derived exosomes in osteoclast differentiation

Bone disease is the most frequent complication in multiple myeloma (MM) resulting in osteolytic lesions, bone pain, hypercalcemia and renal failure. In MM bone disease the perfect balance between bone-resorbing osteoclasts (OCs) and bone-forming osteoblasts (OBs) activity is lost in favour of OCs, thus resulting in skeletal disorders. Since exosomes have been described for their functional role in cancer progression, we here investigate whether MM cell-derived exosomes may be involved in OCs differentiation. We show that MM cells produce exosomes which are actively internalized by Raw264.7 cell line, a cellular model of osteoclast formation. MM cell-derived exosomes positively modulate pre-…

Preliminary Results of CitraVes™ Effects on Low Density Lipoprotein Cholesterol and Waist Circumference in Healthy Subjects after 12 Weeks: A Pilot Open-Label Study

Appropriate monitoring and control of modifiable risk factors, such as the level of low-density lipoprotein cholesterol (LDL-C) and other types of dyslipidemia, have an important role in the prevention of cardiovascular diseases (CVD). Recently, various nutraceuticals with lipid-lowering effects have gained attention. In addition to the plant-derived bioactive compounds, recent studies suggested that plant cells are able to release small lipoproteic structures named extracellular vesicles (EVs). The interaction between EVs and mammalian cells could lead to beneficial effects through anti-inflammatory and antioxidant activities. The present study aimed to assess the safety of the new patente…

Preferential solvatation of TFE in lysozyme: a luminescence study

Additional file 1: of Multiple myeloma-derived exosomes are enriched of amphiregulin (AREG) and activate the epidermal growth factor pathway in the bone microenvironment leading to osteoclastogenesis

Figure S1. Evaluation by quantitative Real Time PCR of mRNA expression of AREG in HMCLs (A) and in MM1.S cells and exosomes (B). (TIFF 2501 kb)

Additional file 2: of Multiple myeloma-derived exosomes are enriched of amphiregulin (AREG) and activate the epidermal growth factor pathway in the bone microenvironment leading to osteoclastogenesis

Figure S2. Schematic representation of the role of MM-exosomes in bone microenvironment. (TIF 3372 kb)