An NMR Toolkit to Probe Amyloid Oligomer Inhibition in Neurodegenerative Diseases: From Ligand Screening to Dissecting Binding Topology and Mechanisms of Action

The aggregation of amyloid peptides and proteins into toxic oligomers is a hallmark of neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease. Inhibition of amyloid oligomers formation and interactions with biological counterparts, as well as the triggering of non-toxic amorphous aggregates, are strategies towards preventive interventions against these pathologies. NMR spectroscopy addresses the need for structural characterization of amyloid proteins and their aggregates, their binding to inhibitors, and rapid screening of compound libraries for ligand identification. Here we briefly discuss the solution experiments constituting the NMR spectroscopist's toolkit and provide examples of their application.

Cell-Free and In Vivo Characterization of the Inhibitory Activity of Lavado Cocoa Flavanols on the Amyloid Protein Ataxin-3: Toward New Approaches against Spinocerebellar Ataxia Type 3

Spinocerebellar ataxia type 3 (SCA3) is a neurodegenerative disorder characterized by ataxia and other neurological manifestations, with a poor prognosis and a lack of effective therapies. The amyloid aggregation of the ataxin-3 protein is a hallmark of SCA3 and one of the main biochemical events prompting its onset, making it a prominent target for the development of preventive and therapeutic interventions. Here, we tested the efficacy of an aqueous Lavado cocoa extract and its polyphenolic components against ataxin-3 aggregation and neurotoxicity. The combination of biochemical assays and atomic force microscopy morphological analysis provided clear evidence of cocoa flavanols' ability to hinder ATX3 amyloid aggregation through direct physical interaction, as assessed by NMR spectroscopy. The chemical identity of the flavanols was investigated by ultraperformance liquid chromatography-high-resolution mass spectrometry. The use of the preclinical model Caenorhabditis elegans allowed us to demonstrate cocoa flavanols' ability to ameliorate ataxic phenotypes in vivo. To the best of our knowledge, Lavado cocoa is the first natural source whose extract is able to directly interfere with ATX3 aggregation, leading to the formation of off-pathway species.

Adjuvant Effect of Cinnamon Polyphenolic Components in Colorectal Cancer Cell Lines

Colorectal cancer (CRC) is the second-leading cause of cancer death, with a worldwide incidence rate constantly increasing; thus, new strategies for its prevention or treatment are needed. Here, we describe the adjuvant effect of the polyphenol-enriched fractions of cinnamon, from cinnamon bark and buds, when co-administered with a potent anticancer drug, cetuximab, used for CRC therapy. The co-administration significantly reduces the cetuximab dose required for the antiproliferative activity against colorectal cancer cell line E705, which is sensitive to EGFR-targeted therapy. The anticancer activity of these cinnamon-derived fractions, whose major components (as assessed by UPLC-HRMS analysis) are procyanidins and other flavonoids, strictly correlates with their ability to induce apoptosis in cancer cell lines through ERK activation and the mitochondrial membrane potential impairment. Due to the severe side effects of cetuximab administration, our results suggest the use of nutraceuticals based on the polyphenolic fractions of cinnamon extracts as adjuvants in the therapy of CRC.

Multivalent calix[4]arene-based mannosylated dendrons as new FimH ligands and inhibitors

We report the synthesis and biological characterization of a novel class of multivalent glycoconjugates as hit compounds for the design of new antiadhesive therapies against urogenital tract infections (UTIs) caused by uropathogenic E. coli strains (UPEC). The first step of UTIs is the molecular recognition of high mannose N-glycan expressed on the surface of urothelial cells by the bacterial lectin FimH, allowing the pathogen adhesion required for mammalian cell invasion. The inhibition of FimH-mediated interactions is thus a validated strategy for the treatment of UTIs. To this purpose, we designed and synthesized d-mannose multivalent dendrons supported on a calixarene core introducing a significant structural change from a previously described family of dendrimers bearing the same dendrons units on a flexible pentaerythritol scaffold core. The new molecular architecture increased the inhibitory potency against FimH-mediated adhesion processes by about 16 times, as assessed by yeast agglutination assay. Moreover, the direct molecular interaction of the new compounds with FimH protein was assessed by on-cell NMR experiments acquired in the presence of UPEC cells.

Antarctic Soil Metabolomics: A Pilot Study

In Antarctica, ice-free areas can be found along the coast, on mountain peaks, and in the McMurdo Dry Valleys, where microorganisms well-adapted to harsh conditions can survive and reproduce. Metabolic analyses can shed light on the survival mechanisms of Antarctic soil communities from both coastal sites, under different plant coverage stages, and inner sites where slow-growing or dormant microorganisms, low water availability, salt accumulation, and a limited number of primary producers make metabolomic profiling difficult. Here, we report, for the first time, an efficient protocol for the extraction and the metabolic profiling of Antarctic soils based on the combination of NMR spectroscopy and mass spectrometry (MS). This approach was set up on samples harvested along different localities of Victoria Land, in continental Antarctica, devoid of or covered by differently developed biological crusts. NMR allowed for the identification of thirty metabolites (mainly sugars, amino acids, and organic acids) and the quantification of just over twenty of them. UPLC-MS analysis identified more than twenty other metabolites, in particular flavonoids, medium- and long-chain fatty acids, benzoic acid derivatives, anthracenes, and quinones. Our results highlighted the complementarity of the two analytical techniques. Moreover, we demonstrated that their combined use represents the "gold standard" for the qualitative and quantitative analysis of little-explored samples, such as those collected from Antarctic soils.

Cheese-whey permeate improves the fitness of Escherichia coli cells during recombinant protein production

BACKGROUND

Escherichia coli cells are the most frequently used hosts in recombinant protein production processes and mainly require molecules such as IPTG or pure lactose as inducers of heterologous expression. A possible way to reduce the production costs is to replace traditional inducers with waste materials such as cheese whey permeate (CWP). CWP is a secondary by-product generated from the production of the valuable whey proteins, which are obtained from ultrafiltration of cheese whey, a main by-product of the dairy industry, which is rich in lactose.

RESULTS

The effects of CWP collected from an Italian plant were compared with those of traditional inducers on the production of two model proteins (i.e., green fluorescent protein and the toxic Q55 variant of ataxin-3), in E. coli BL21 (DE3) cells. It was found that the high lactose content of CWP (165 g/L) and the antioxidant properties of its micronutrients (vitamins, cofactors and osmolytes) sustain production yields similar to those obtained with traditional inducers, accompanied by the improvement of cell fitness.

CONCLUSIONS

CWP has proven to be an effective and low-cost alternative inducer to produce recombinant proteins. Its use thus combines the advantage of exploiting a waste product with that of reducing the production costs of recombinant proteins.

Alzheimer's Disease Prevention through Natural Compounds: Cell-Free, In Vitro, and In Vivo Dissection of Hop (Humulus lupulus L.) Multitarget Activity

The relevant social and economic costs associated with aging and neurodegenerative diseases, particularly Alzheimer's disease (AD), entail considerable efforts to develop effective preventive and therapeutic strategies. The search for natural compounds, whose intake through diet can help prevent the main biochemical mechanisms responsible for AD onset, led us to screen hops, one of the main ingredients of beer. To explore the chemical variability of hops, we characterized four hop varieties, i.e., Cascade, Saaz, Tettnang, and Summit. We investigated the potential multitarget hop activity, in particular its ability to hinder Aβ1-42 peptide aggregation and cytotoxicity, its antioxidant properties, and its ability to enhance autophagy, promoting the clearance of misfolded and aggregated proteins in a human neuroblastoma SH-SY5Y cell line. Moreover, we provided evidence of in vivo hop efficacy using the transgenic CL2006Caenorhabditis elegans strain expressing the Aβ3-42 peptide. By combining cell-free and in vitro assays with nuclear magnetic resonance (NMR) and MS-based metabolomics, NMR molecular recognition studies, and atomic force microscopy, we identified feruloyl and p-coumaroylquinic acids flavan-3-ol glycosides and procyanidins as the main anti-Aβ components of hop.

NMR-Driven Identification of Cinnamon Bud and Bark Components With Anti-Aβ Activity

The anti-Alzheimer disease (AD) activity reported for an aqueous cinnamon bark extract prompted us to investigate and compare the anti-amyloidogenic properties of cinnamon extracts obtained from both bark and bud, the latter being a very little explored matrix. We prepared the extracts with different procedures (alcoholic, hydroalcoholic, or aqueous extractions). An efficient protocol for the rapid analysis of NMR spectra of cinnamon bud and bark extracts was set up, enabling the automatic identification and quantification of metabolites. Moreover, we exploited preparative reverse-phase (RP) chromatography to prepare fractions enriched in polyphenols, further characterized by UPLC-HR-MS. Then, we combined NMR-based molecular recognition studies, atomic force microscopy, and in vitro biochemical and cellular assays to investigate the anti-amyloidogenic activity of our extracts. Both bud and bark extracts showed a potent anti-amyloidogenic activity. Flavanols, particularly procyanidins, and cinnamaldehydes, are the chemical components of cinnamon hindering Aβ peptide on-pathway aggregation and toxicity in a human neuroblastoma SH-SY5Y cell line. Together with the previously reported ability to hinder tau aggregation and filament formation, these data indicate cinnamon polyphenols as natural products possessing multitarget anti-AD activity. Since cinnamon is a spice increasingly present in the human diet, our results support its use to prepare nutraceuticals useful in preventing AD through an active contrast to the biochemical processes that underlie the onset of this disease. Moreover, the structures of cinnamon components responsible for cinnamon anti-AD activities represent molecular templates for designing and synthesizing new anti-amyloidogenic drugs.

Green and Roasted Coffee Extracts Inhibit Interferon-β Release in LPS-Stimulated Human Macrophages

The anti-inflammatory activity of coffee extracts is widely recognized and supported by experimental evidence, in both in vitro and in vivo settings, mainly murine models. Here, we investigated the immunomodulatory properties of coffee extracts from green (GCE) and medium-roasted (RCE) Coffea canephora beans in human macrophages. The biological effect of GCE and RCE was characterized in LPS-stimulated THP-1-derived human macrophages (TDM) as a model of inflammation. Results showed decreased amounts of TNF-α, IL-6 and IL-1β and a strong dose-dependent inhibition of interferon-β (IFN-β) release. Molecular mechanism of IFN-β inhibition was further investigated by immunofluorescence confocal microscopy analysis that showed a diminished nuclear translocation of p-IRF-3, the main transcription factor responsible for IFN-β synthesis. The inhibition of IFN-β release by RCE and GCE was also confirmed in human primary CD14⁺ monocytes-derived macrophages (MDM). The main component of coffee extracts, 5-O-caffeoylquinic acid (5-CQA) also inhibited IFN-β production, through a mechanism occurring downstream to TLR4. Inhibition of IFN-β release by coffee extracts parallels with the activity of their main phytochemical component, 5-CQA, thus suggesting that this compound is the main responsible for the immunomodulatory effect observed. The application of 5-CQA and coffee derived-phytoextracts to target interferonopathies and inflammation-related diseases could open new pharmacological and nutritional perspectives.

Tubulin binding potentially clears up Bortezomib and Carfilzomib differential neurotoxic effect

Proteasome inhibitors (PIs) represent the gold standard in the treatment of multiple myeloma. Among PIs, Bortezomib (BTZ) is frequently used as first line therapy, but peripheral neuropathy (PN), occurring approximately in 50% of patients, impairs their life, representing a dose-limiting toxicity. Carfilzomib (CFZ), a second-generation PI, induces a significantly less severe PN. We investigated possible BTZ and CFZ off-targets able to explain their different neurotoxicity profiles. In order to identify the possible PIs off-targets we used the SPILLO-PBSS software that performs a structure-based in silico screening on a proteome-wide scale. Among the top-ranked off-targets of BTZ identified by SPILLO-PBSS we focused on tubulin which, by contrast, did not turn out to be an off-target of CFZ. We tested the hypothesis that the direct interaction between BTZ and microtubules would inhibit the tubulin alfa GTPase activity, thus reducing the microtubule catastrophe and consequently furthering the microtubules polymerization. This hypothesis was validated in a cell-free model, since BTZ (but not CFZ) reduces the concentration of the free phosphate released during GTP hydrolysis. Moreover, NMR binding studies clearly demonstrated that BTZ, unlike CFZ, is able to interact with both tubulin dimers and polymerized form. Our data suggest that different BTZ and CFZ neurotoxicity profiles are independent from their proteasome inhibition, as demonstrated in adult mice dorsal root ganglia primary sensory neurons, and, first, we demonstrate, in a cell free model, that BTZ is able to directly bind and perturb microtubules.

On-cell saturation transfer difference NMR for the identification of FimH ligands and inhibitors

We describe the development of an on-cell NMR method for the rapid screening of FimH ligands and the structural identification of ligand binding epitopes. FimH is a mannose-binding bacterial adhesin expressed at the apical end of type 1 pili of uropathogenic bacterial strains and responsible for their d-mannose sensitive adhesion to host mammalian epithelial cells. Because of these properties, FimH is a key virulence factor and an attractive therapeutic target for urinary tract infection. We prepared synthetic d-mannose decorated dendrimers, we tested their ability to prevent the FimH-mediated yeast agglutination, and thus we used the compounds showing the best inhibitory activity as models of FimH multivalent ligands to set up our NMR methodology. Our experimental protocol, based on on-cell STD NMR techniques, is a suitable tool for the screening and the epitope mapping of FimH ligands aimed at the development of new antiadhesive and diagnostic tools against urinary tract infection pathogens. Notably, the study is carried out in a physiological environment, i.e. at the surface of living pathogen cells expressing FimH.

The Multi-Level Mechanism of Action of a Pan-Ras Inhibitor Explains its Antiproliferative Activity on Cetuximab-Resistant Cancer Cells

Ras oncoproteins play a crucial role in the onset, maintenance, and progression of the most common and deadly human cancers. Despite extensive research efforts, only a few mutant-specific Ras inhibitors have been reported. We show that cmp4–previously identified as a water-soluble Ras inhibitor– targets multiple steps in the activation and downstream signaling of different Ras mutants and isoforms. Binding of this pan-Ras inhibitor to an extended Switch II pocket on HRas and KRas proteins induces a conformational change that down-regulates intrinsic and GEF-mediated nucleotide dissociation and exchange and effector binding. A mathematical model of the Ras activation cycle predicts that the inhibitor severely reduces the proliferation of different Ras-driven cancer cells, effectively cooperating with Cetuximab to reduce proliferation even of Cetuximab-resistant cancer cell lines. Experimental data confirm the model prediction, indicating that the pan-Ras inhibitor is an appropriate candidate for medicinal chemistry efforts tailored at improving its currently unsatisfactory affinity.

Targeting GRP receptor: Design, synthesis and preliminary biological characterization of new non-peptide antagonists of bombesin

We report the rational design, synthesis, and in vitro preliminary evaluation of a new small library of non-peptide ligands of Gastrin Releasing Peptide Receptor (GRP-R), able to antagonize its natural ligand bombesin (BN) in the nanomolar range of concentration. GRP-R is a transmembrane G-protein coupled receptor promoting the stimulation of cancer cell proliferation. Being overexpressed on the surface of different human cancer cell lines, GRP-R is ideal for the selective delivery to tumor cells of both anticancer drug and diagnostic devices. What makes very challenging the design of non-peptide BN analogues is that the 3D structure of the GRP-R is not available, which is the case for many membrane-bound receptors. Thus, the design of GRP-R ligands has to be based on the structure of its natural ligands, BN and GRP. We recently mapped the BN binding epitope by NMR and here we exploited the same spectroscopy, combined with MD, to define BN conformation in proximity of biological membranes, where the interaction with GRP-R takes place. The gained structural information was used to identify a rigid C-galactosidic scaffold able to support pharmacophore groups mimicking the BN key residues' side chains in a suitable manner for binding to GRP-R. Our BN antagonists represent hit compounds for the rational design and synthesis of new ligands and modulators of GRP-R. The further optimization of the pharmacophore groups will allow to increase the biological activity. Due to their favorable chemical properties and stability, they could be employed for the active receptor-mediated targeting of GRP-R positive tumors.

NMR-based Lavado cocoa chemical characterization and comparison with fermented cocoa varieties: Insights on cocoa's anti-amyloidogenic activity

The metabolic profile of Lavado cocoa was characterized for the first time by NMR spectroscopy, then compared with the profiles of fermented and processed varieties, Natural and commercial cocoa. The significant difference in the contents of theobromine and flavanols prompted us to examine the cocoa varieties to seek correlations between these metabolite concentrations and the anti-amyloidogenic activity reported for cocoa in the literature. We combined NMR spectroscopy, preparative reversed-phase (RP) chromatography, atomic force microscopy, in vitro biochemical and cell assays, to investigate and compare the anti-amyloidogenic properties of extracts and fractions enriched in different metabolite classes. Lavado variety was the most active and the catechins and theobromine were the chemical components of cocoa hindering Aβ peptide on-pathway aggregation and toxicity in a human neuroblastoma SH-SY5Y cell line.

Correction to: Different phytotoxic effect of Lolium multiflorum Lam. leaves against Echinochloa oryzoides (Ard.) Fritsch and Oryza sativa L

In the title, it should be Oryza instead of Oriza.

Different phytotoxic effect of Lolium multiflorum Lam. leaves against Echinochloa oryzoides (Ard.) Fritsch and Oryza sativa L

Rice cultivation, particularly prone to weed issues, requires practices able to effectively control them, however reducing the use of herbicides, responsible for damage to human health and ecosystem sustainability. Alternative strategies for weed management can be based on plant-plant interaction phenomena. In this context, a group of organic farmers has developed a pragmatic approach for weed containment using Lolium multiflorum Lam. as a cover crop before rice. The present study aimed to confirm the farmer field observations reporting a preferential inhibitory effect of L. multiflorum on Echinochloa oryzoides (Ard.) Fritsch, one of the most yield-damaging rice weed, compared with Oryza sativa L. The study showed that L. multiflorum was able to significantly reduce the seed germination of E. oryzoides. It was found to be more susceptible than O. sativa both to the effect of the aqueous extract and powder of L. multiflorum leaves (23-79% vs. 3-57% and 26-100% vs. 23-31%, respectively). In addition, the leaf extract was able to affect E. oryzoides growth starting from 20% concentration both in relation to the root and shoot length while O. sativa exhibited differences compared with the control only under the influence of extract 50%. The L. multiflorum leaf characterization by NMR and UPLC-HR-MS analyses led to the identification of 35 compounds including several polyphenols, glycosyl flavonoids and glycosyl terpenoids, as well as different amino acids and organic acids. Some of them (e.g. protocatechuic and gallic acids) are already known as allelochemicals confirming that L. multiflorum is a source of plant growth inhibitors.

Metabolomic profiling of beers: Combining 1H NMR spectroscopy and chemometric approaches to discriminate craft and industrial products

The authentication and traceability of craft beers is an important issue for both beer consumers and producers. Reliable analytical methods able to identify and discriminate products are needed to protect the craft brew market against fraud and counterfeit. Here, ¹H NMR analysis of 31 beer samples, differing for beer style and brewing method (craft or industrial) was combined with multivariate statistical analysis, following both an untargeted and a targeted approach. NMR-based analysis of beer samples was sped developing a specific protocol enabling the automatic identification and quantification of metabolites in approximately thirty seconds per spectrum. A clear discrimination was achieved by exploiting ¹H NMR analysis and multivariate chemometric methods and the targeted approach identified the metabolites responsible for the segregation. Overall, this study reports an analytical approach addressing beer traceability and is the starting point for the development of a standardized protocol for the discrimination of industrial and craft beers.

PLGA Based Nanoparticles for the Monocyte-Mediated Anti-Tumor Drug Delivery System

Together with the development of new therapeutic agents, innovation in the delivery system of anti-tumor drugs is required to increase tumor-specificity and avoid unexpected toxicity. To achieve higher efficiency, we combined a live cell-mediated drug delivery system with nanotechnology, with the aim to prove that blood monocytes can be a cargo to deliver antitumor drugs encapsulated in Polymeric poly(D, L-lactide-co-glycolide) acid based nanoparticles (PLGA NPs). In this study, we have characterized how isolated purified monocytes efficiently internalize PLGA-NPs and have imaged in vivo their trafficking upon intravenous injection in tumor-bearing mice. Monocytes carrying PLGA-Cy7 NPs were able to reach the tumor site, with superior efficiency than free PLGA-Cy7 NPs, and the bio-distribution analysis confirmed that tumors were the most reached among peripheral tissues. We further demonstrate that monocytes carrying Doxorubicin encapsulated PLGA NPs (PLGA-Doxo) induced strong killing of co-cultured tumor cells. Our studies provide proof-of-concept evidence that monocytes can be exploited in approaches of live cell-mediated drug delivery systems for tumor therapy.

Anticancer Effects of Wild Mountain Mentha longifolia Extract in Adrenocortical Tumor Cell Models

Mint [Mentha longifolia (L.) Hudson] is an aromatic plant that belongs to Lamiaceae family. It is traditionally used as herbal tea in Europe, Australia and North Africa and shows numerous pharmacological effects, such as spasmolytic, antioxidant, antimicrobial and anti-hemolytic. Recently, its antiproliferative role has been suggested in a small number of tumor cell models, but no data are available on adrenocortical carcinoma, a malignancy with a survival rate at 5 years of 20%-30% which frequently metastasize. This work aimed to study the effects of Mentha longifolia L. crude extract (ME) on two adrenocortical tumor cell models (H295R and SW13 cells). Chemical composition of ME was assessed by gas-chromatography/mass spectrometry and NMR spectroscopy analysis. Brine shrimp lethality assay showed ME effects at >0.5 µg/µl (p < 0.05). Cell viability and vitality were determined by MTT, SRB, and trypan blue assays in H295R and SW13 cells. The anti-proliferative effects of ME were more evident in SW13 cells at 72 h (ME > 0.5 µg/µl, p < 0.05). Combination of ME with mitotane (approved drug for adrenocortical carcinoma) seemed not to reinforce the efficacy of the herb. As control, human fibroblasts were treated with ME with no effect on cell viability. Clonogenic assay was concordant with previous cell viability tests (ME > 0.5 µg/µl, p < 0.05), while Wright staining demonstrated the presence of both necrotic and apoptotic cells. Cell cycle analysis showed a strong increase in subG0/G1 phase, related to cell death. Furthermore, MAPK and PI3k/Akt pathways were modulated by Western blot analysis when treating cells with ME alone or combined with mitotane. The crude methanolic extract of wild mountain mint can decrease cell viability, vitality and survival of adrenocortical tumor cell models, in particular of SW13 cells. These data show the potential anticancer effects of ME, still more work is needed to corroborate these findings.

Glycodendron–rhenium complexes as luminescent probes for lectin sensing

Enhanced emission intensity of novel Re(i)-glycoprobes resulting from the specific recognition of carbohydrate-binding proteins as a potential tool in bioimaging applications.

Natural Compounds in Cancer Prevention: Effects of Coffee Extracts and Their Main Polyphenolic Component, 5-O-Caffeoylquinic Acid, on Oncogenic Ras Proteins

Recent epidemiological studies have demonstrated that the consumption of healthy foods that are particularly rich in polyphenols might reduce the incidence of cancer and neurodegenerative diseases. In particular, chlorogenic acids (CGAs) occur ubiquitously in food and represent the most abundant polyphenols in the human diet. A number of beneficial biological effects of CGAs, such as anti-inflammatory activity, anti-carcinogenic activity, and protection against neurodegenerative diseases, have been reported. However, the molecular mechanisms at the base of these biological activities have not yet been investigated in depth. By combining NMR spectroscopy, molecular docking, surface plasmon resonance and ex vivo assays of the Ras-dependent breast cancer cell line MDA-MB-231, we contribute to the elucidation of the molecular basis of the activity of CGAs and natural extracts from green and roasted coffee beans as chemoprotective dietary supplements.

Pharmacological inhibition of mannose-binding lectin ameliorates neurobehavioral dysfunction following experimental traumatic brain injury

Mannose-binding lectin is present in the contusion area of traumatic brain-injured patients and in that of traumatic brain-injured mice, where mannose-binding lectin-C exceeds mannose-binding lectin-A. The reduced susceptibility to traumatic brain injury of mannose-binding lectin double knock-out mice (mannose-binding lectin^-/-) when compared to wild type mice suggests that mannose-binding lectin may be a therapeutic target following traumatic brain injury. Here, we evaluated the effects of a multivalent glycomimetic mannose-binding lectin ligand, Polyman9, following traumatic brain injury in mice. In vitro surface plasmon resonance assay indicated that Polyman9 dose-dependently inhibits the binding to immobilized mannose residues of plasma mannose-binding lectin-C selectively over that of mannose-binding lectin-A. Male C57Bl/6 mice underwent sham/controlled cortical impact traumatic brain injury and intravenous treatment with Polyman9/saline. Ex-vivo surface plasmon resonance studies confirmed that Polyman9 effectively reduces the binding of plasma mannose-binding lectin-C to immobilized mannose residues. In vivo studies up to four weeks post injury, showed that Polyman9 induces significant improvement in sensorimotor deficits (by neuroscore and beam walk), promotes neurogenesis (73% increase in doublecortin immunoreactivity), and astrogliosis (28% increase in glial fibrillary acid protein). Polyman9 administration in brain-injured mannose-binding lectin^-/- mice had no effect on post-traumatic brain-injured functional deficits, suggestive of the specificity of its neuroprotective effects. The neurobehavioral efficacy of Polyman9 implicates mannose-binding lectin-C as a novel therapeutic target for traumatic brain injury.

Glyco-functionalized dinuclear rhenium(i) complexes for cell imaging

New luminescent glycosilated rhenium complexes were synthesized and evaluated as dyes for optical imaging.

A New Surface Plasmon Resonance Assay for In Vitro Screening of Mannose-Binding Lectin Inhibitors

Mannose-binding lectin (MBL) is a circulating protein that acts as a soluble pattern recognition molecule of the innate immunity. It binds to carbohydrate patterns on the surface of pathogens or of altered self-cells, with activation of the lectin pathway of the complement system. Recent evidence indicates that MBL contributes to the pathophysiology of ischemia-reperfusion injury and other conditions. Thus, MBL inhibitors offer promising therapeutic strategies, since they prevent the interaction of MBL with its target sugar arrays. We developed and characterized a novel assay based on surface plasmon resonance for in vitro screening of these compounds, which may be useful before the more expensive and time-consuming in vivo studies. The assay measures the inhibitor's ability to interfere with the binding of murine MBL-A or MBL-C, or of human recombinant MBL, to mannose residues immobilized on the sensor chip surface. We have applied the assay to measure the IC50 of synthetic glycodendrimers, two of them with neuroprotective properties in animal models of MBL-mediated injuries.

Solution Behavior of Amphiphilic Glycodendrimers with a Rod-Like Core

Glycodendrimers based on aromatic cores have an amphiphilic character and have been reported to generate supramolecuar assemblies in water. A new group of glycodendrimers with an aromatic rod-like core were recently described as potent antagonists of DC-SIGN-mediated viral infections. A full characterization of the aggregation properties of these materials is presented here. The results show that these compounds exist mostly as monomers in water solution, in dynamic equilibrium with small aggregates (dimers or trimers). Larger aggregates observed by dynamic light scattering and transmission Electron Microscopy for some of the dendrimers are found to be portions of materials not fully solubilized and can be removed either by optimizing the dissolution protocol or by centrifugation of the samples.

Towards a Universal Approach Based on Omics Technologies for the Quality Control of Food

In the last decades, food science has greatly developed, turning from the consideration of food as mere source of energy to a growing awareness on its importance for health and particularly in reducing the risk of diseases. Such vision led to an increasing attention towards the origin and quality of raw materials as well as their derived food products. The continuous advance in molecular biology allowed setting up efficient and universal omics tools to unequivocally identify the origin of food items and their traceability. In this review, we considered the application of a genomics approach known as DNA barcoding in characterizing the composition of foodstuffs and its traceability along the food supply chain. Moreover, metabolomics analytical strategies based on Nuclear Magnetic Resonance (NMR) and Mass Spectroscopy (MS) were discussed as they also work well in evaluating food quality. The combination of both approaches allows us to define a sort of molecular labelling of food that is easily understandable by the operators involved in the food sector: producers, distributors, and consumers. Current technologies based on digital information systems such as web platforms and smartphone apps can facilitate the adoption of such molecular labelling.

Designing nanomolar antagonists of DC-SIGN-mediated HIV infection: ligand presentation using molecular rods

DC-SIGN antagonists were designed combining one selective monovalent glycomimetic ligand with trivalent dendrons separated by a rigid core of controlled length. The design combines multiple multivalency effects to achieve inhibitors of HIV infection, which are active in nanomolar concentration.

Structure-activity studies on arylamides and arysulfonamides Ras inhibitors

This paper reports the synthesis of a panel of small molecules with arylamides and arylsulfonamides groups and their biological activity in inhibiting nucleotide exchange on human Ras. The design of these molecules was guided by experimental and molecular modelling data previously collected on similar compounds. Aim of this work is the validation of the hypothesis that a phenyl hydroxylamine group linked to a second aromatic moiety generates a pharmacophore capable to interact with Ras and to inhibit its activation. In vitro experiments on purified human Ras clearly show that the presence of an aromatic hydroxylamine and a sulfonamide group in the same molecule is a necessary condition for Ras binding and nucleotide exchange inhibition. The inhibitor potency is lower in molecules in which either the hydroxylamine has been replaced by other functional groups or the sulfonamide has been replaced by an amide. In the case both these moieties, the hydroxylamine and sulfonamide are absent, inactive compounds are obtained.

First experimental identification of Ras-inhibitor binding interface using a water-soluble Ras ligand

By combining in the same molecule Ras-interacting aromatic moieties and a sugar, we prepared a water-soluble Ras ligand that binds Ras and inhibits guanine nucleotide exchange. With this compound it was possible to determine experimentally by a (15)N-edited HSQC NMR experiment the ligand-Ras binding interface.