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The Sam (sterile alpha motif) domain from the lipid phosphatase Ship2 binds the Sam domain from the EphA2 receptor to negatively regulate receptor endocytosis and degradation. This interaction is primarily linked to pro-oncogenic effects. We report on the design and evaluation of EphA2-Sam/Ship2-Sam peptide inhibitors provided with positive charges and different aromatic characters. Starting from the sequence of previously identified Ship2-Sam targeting peptides, an in silico approach was set up to predict higher affinity peptide ligands. A few peptides were experimentally tested through an interdisciplinary approach. Interaction studies were performed by nuclear magnetic resonance spectroscopy and biolayer interferometry. 3D models of Ship2-Sam/peptide complexes were predicted by AlphaFold2. Cell-based assays were carried out to investigate whether such peptide sequences might have an influence on EphA2 signaling. The approach led to the identification of novel Ship2-Sam ligands and shed further light on original approaches to design inhibitors of the Ship2-Sam/EphA2-Sam interaction.

Clays are used in various cosmetic formulations, such as sunscreens, toothpastes, deodorants, creams, hair cosmetics, makeups, nail polish, facial masks, and shampoos, among others, to improve the organoleptic and physicochemical characteristics, to increase the stability, or to facilitate elaboration. Together with their technological functionalities, clays are cosmetologically active ingredients with cleaning, anti-aging, anti-wrinkling, and sun-care functionalities. Talc, kaolinite, mica, and some smectites are the clay minerals used most frequently in cosmetic products, but several other phyllosilicates as well as modified and synthetic clays are also used. Sometimes, clays are useful in the design of cosmetics just because they are made of rigid, small, and anisometric particles. Kaolinite and mica are made of hard prismatic particles which are lightly abrasive over the skin, teeth, or hair. Electric charges in smectites result in ion-exchange capacities useful in the loading of active cosmetics but also adsorbing and cleaning waste substances. Intermediate net negative charges of smectites result in layer expansion in polar media and specific rheological properties that are very useful in cosmetic formulations. The absence of charged particles in talc and kaolin make them flow easily resulting in lubricant effects. Protection against radiation from the sun by clay particles and decorative effects complete the possibilities of clays in cosmetics. The nomenclature for clays used as ingredients in cosmetics follows historical use and the names of commercial products, rather than following strict compositional principles. In this sense, an effort was made here to correlate the names of the minerals that make up each of the clay-based cosmetic ingredients.

The first aim of the present study is the development of a new ruthenium(III) complex, belonging to NAMI-A class, with a potentially high cytotoxic ability. The presence of a fully protected sugar moiety as ruthenium ligand should increase the complex ability to cross cellular membranes. Furthermore, it sets this molecule in the area of biocompatible agents as tumor drug. The second, more relevant, purpose is to verify the ruthenium complexes activity after loading into liposomes. We reported the characterization and in vitro biological assays of pyridine derivatives of ruthenium complexes loaded into Egg l-α-phosphatidylcholine cholesterol/DSPE-PEG liposomes. Dynamic light scattering estimates that the sizes of all obtained liposomes are in the 100 nm range. This value is suitable for in vivo use. The loading ability and release kinetic allowed selecting the best ratio between the lipid fraction and metal to be tested in cellular experiments. The growth inhibitory effects of both liposomal and free complex in PC-3 prostate cancer cell lines demonstrate a high cytotoxic ability of the liposome entrapped ruthenium (III) complex suggesting additional role further the antimetastatic function.

New liposomal aggregates, prepared by combining together, in a 90:10 molar ratio, two amphiphilic monomers, one containing two hydrocarbon chains in the hydrophobic region and the anionic DOTA chelating agent as hydrophilic moiety, and the other containing the same hydrophobic moiety and the CCK8 peptide, are described. The liposomal aggregates because of the presence of the specific moiety, constituted by the CCK8 peptide, which selectively recognizes CCK receptors on tumor cells are used as drug carriers with the aim to deliver into tumor cells the appropriate antitumor drug. The drug loading content and the releasing properties of the liposomal aggregates are studied by the use of the cytotoxic doxorubicin as drug model. The doxorubicin loading content determination reveals that above 95% of the total drug was uptaken with a corresponding drug/lipid w/w ratio of 0.134. The cellular uptake of the targeted liposomal doxorubicin with respect to the self-assembled, nonspecific, liposomal doxorubicin is evaluated using flow cytometry assays. The doxorubicin cell content for two types of cell systems, namely, A431 and HuVEC cells, for peptide derivatized liposomes was 70- and 8-fold higher, respectively, than for nontargeted liposomes, indicating that the bioactive CCK8 peptide is able to enhance the doxorubicin uptake into the carcinoma cells in vitro. The cytotoxicity effect of liposomal doxorubicin on A431 cells has been assessed by MTT assays: in presence of drug amounts ranged between 250 and 1000 ng/ml, incubation with peptide derivatized liposomes showed significantly lower cell survival compared with nontargeted liposomes. © 2010 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 96: 88–96, 2011.

Vascular endothelial growth factor (VEGF) is a potent angiogenic factor. Its biological activity is mediated by the binding to the extracellular domain of two tyrosine kinase transmembrane receptors: VEGFR1 and VEGFR2. Deletion studies showed that VEGF binding site resides in the first three domains of VEGFR1 and in domains 2 and 3 of VEGFR2. In particular, the second extracellular domain of VEGFR1 (VEGFR1D2) contains most of the VEGF binding requirements. Here, we report an efficient expression protocol and the molecular characterization by spectroscopic techniques of VEGFR1D2. The protein was expressed in E. coliand refolded from inclusion bodies. The recombinant protein assumes the correct fold as assessed by a combination of biochemical and functional assays as well as by NMR characterization. Furthermore, the recombinant VEGFR1D2was analyzed by circular dichroism and fluorescence spectroscopy. The protein obtained by this procedure is suitable for the structural characterization of the complexes with receptor binders and to be used in interaction/screening studies. © 2010 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 94: 800–809, 2010.

The sea star Oreaster reticulatus contains, along with the known ophidiacerebrosides C–E, nine new glycosphingolipids named oreacerebrosides A–I. Their structures were elucidated by a combination of spectroscopic methods and chemical degradation. All compounds contain a 4,8,10-triunsaturated sphingoid base. Oreacerebrosides A–C have a β-glucopyranoside as the sugar residue, as found in ophidiacerebrosides C–E and in all known compounds of this type; in contrast, oreacerebrosides D–I are the first examples of β-galactosylceramides containing this unusual sphingoid base. Four representative glycosphingolipids were tested for cytotoxic activity on rat glioma C6 cells and were shown to be mildly cytotoxic; the glucosylceramides were more active than the galactosylceramides. In addition, oreacerebroside I, but not ophidiacerebroside E, was shown to exert proangiogenic activity and was able to increase VEGF-induced human endothelial cell proliferation.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Several malignant cell lines are resistant to CD95(Apo1/Fas)‐mediated apoptosis, even when the CD95 receptor is highly expressed. Sensitivity to CD95‐induced apoptosis can be restored using different molecules. In this study, we showed that quercetin, a naturally occurring flavonoid, in association with the agonistic anti‐CD95 monoclonal antibody, increases DNA fragmentation and caspase‐3 activity in HPB‐ALL cells. These cells have been selected for their known resistance to CD95‐induced apoptosis. At molecular level, quercetin lowers the level of intracellular reactive oxygen species, reduces mitochondrial transmembrane potential, thereby leaving the expression of CD95 receptor unchanged.

Several malignant cell lines are resistant to CD95(Apo1/Fas)-mediated apoptosis, even when the CD95 receptor is highly expressed. Sensitivity to CD95-induced apoptosis can be restored using different molecules. In this study, we showed that quercetin, a naturally occurring flavonoid, in association with the agonistic anti-CD95 monoclonal antibody, increases DNA fragmentation and caspase-3 activity in HPB-ALL cells. These cells have been selected for their known resistance to CD95-induced apoptosis. At molecular level, quercetin lowers the level of intracellular reactive oxygen species, reduces mitochondrial transmembrane potential, thereby leaving the expression of CD95 receptor unchanged.

Human osteoblasts were obtained by migration and proliferation of cells from embryonic membranous bone on glass fragments. Light and electron microscopy analyses revealed a typical osteoblast-like appearance with high protein synthesis activity. The cells showed high alkaline phosphatase activity that was associated with plasma membranes and matrix vesicles and was 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] responsive. In contrast to the adult osteoblasts, embryonic cells could not produce detectable levels of osteocalcin, not even in the presence of 1,25(OH)2D3. Osteoblasts grown in multilayers produced a thick extracellular matrix, mainly composed of type I collagen, that mineralized in the presence of 10 mM ß-glycerophosphate. Because of their intrinsic osteogenic capacity, embryonic osteoblasts represent a valuable model for studying the mineralization process in vitro. In addition, the embryonic origin of these cells renders them a precious experimental system for the elucidation of mechanisms at the basis of differentiation of osteoblastic lineage.