Structural characterization and differentiation of modified isomeric tryptophans

AbstractDifferent mass spectrometry (MS) techniques have been applied to the study of modified tryptophan isomers obtained by photochemical reactions. The gas phase behavior of the molecular ions and the most abundant fragment ions produced under electron ionization has been selectively studied by MS/MS experiments. Both the fragmentation reactions occurring in the ion source, as well as those produced under collision-induced dissociation conditions have allowed to characterize and differentiate each isomer from the others. Investigation of a bisubstituted derivative has been useful in the rationalization of the gas phase behavior of this series of modified tryptophans. This study has allowed the evaluation of the role played by the substituents and their positions at the indolic ring on the gas phase decompositions that are distinctive and selective for each isomer. The occurrence of regiospecific reactions suggests that isomerization phenomena do not occur either in the molecular ions or in the main fragment ions in the gas phase

Pragmatics, Theory of Mind and executive functions in schizophrenia: Disentangling the puzzle using machine learning

OBJECTIVE:Schizophrenia is associated with a severe impairment in the communicative-pragmatic domain. Recent research has tried to disentangle the relationship between communicative impairment and other domains usually impaired in schizophrenia, i.e. Theory of Mind (ToM) and cognitive functions. However, the results are inconclusive and this relationship is still unclear. Machine learning (ML) provides novel opportunities for studying complex relationships among phenomena and representing causality among multiple variables. The present research explored the potential of applying ML, specifically Bayesian network (BNs) analysis, to characterize the relationship between cognitive, ToM and pragmatic abilities in individuals with schizophrenia and healthy controls, and to identify the cognitive and pragmatic abilities that are most informative in discriminating between schizophrenia and controls. METHODS:We provided a comprehensive assessment of different aspects of pragmatic performance, i.e. linguistic, extralinguistic, paralinguistic, contextual and conversational, ToM and cognitive functions, i.e. Executive Functions (EF)-selective attention, planning, inhibition, cognitive flexibility, working memory and speed processing-and general intelligence, in a sample of 32 individuals with schizophrenia and 35 controls. RESULTS:The results showed that the BNs classifier discriminated well between patients with schizophrenia and healthy controls. The network structure revealed that only pragmatic Linguistic ability directly influenced the classification of patients and controls, while diagnosis determined performance on ToM, Extralinguistic, Paralinguistic, Selective Attention, Planning, Inhibition and Cognitive Flexibility tasks. The model identified pragmatic, ToM and cognitive abilities as three distinct domains independent of one another. CONCLUSION:Taken together, our results confirmed the importance of considering pragmatic linguistic impairment as a core dysfunction in schizophrenia, and demonstrated the potential of applying BNs in investigating the relationship between pragmatic ability and cognition

MAPK15 controls cellular responses to oxidative stress by regulating NRF2 activity and expression of its downstream target genes

Oxidation processes in mitochondria and different environmental insults contribute to unwarranted accumulation of reactive oxygen species (ROS). These, in turn, rapidly damage intracellular lipids, proteins, and DNA, ultimately causing aging and several human diseases. Cells have developed different and very effective systems to control ROS levels. Among these, removal of excessive amounts is guaranteed by upregulated expression of various antioxidant enzymes, through activation of the NF-E2-Related Factor 2 (NRF2) protein. Here, we show that Mitogen Activated Protein Kinase 15 (MAPK15) controls the transactivating potential of NRF2 and, in turn, the expression of its downstream target genes. Specifically, upon oxidative stress, MAPK15 is necessary to increase NRF2 expression and nuclear translocation, by inducing its activating phosphorylation, ultimately supporting transactivation of cytoprotective antioxidant genes. Lungs are continuously exposed to oxidative damages induced by environmental insults such as air pollutants and cigarette smoke. Interestingly, we demonstrate that MAPK15 is very effective in supporting NRF2-dependent antioxidant transcriptional response to cigarette smoke of epithelial lung cells. Oxidative damage induced by cigarette smoke indeed represents a leading cause of disability and death worldwide by contributing to the pathogenesis of different chronic respiratory diseases and lung cancer. Therefore, the development of novel therapeutic strategies able to modulate cellular responses to oxidative stress would be highly beneficial. Our data contribute to the necessary understanding of the molecular mechanisms behind such responses and identify new potentially actionable targets

Conservation of Paleontological Finds: the Restoration Materials of the “Problematica Verrucana”

The materials used in the historical restoration of a fossil collection named “Problematica Verrucana”, have been studied in order to contribute to the creation of a catalogue of restoration materials used in the past. Due to the complexity of the mixtures used with different purposes to restore fossil finds, an extractive technique has been employed in order to separate the compounds soluble in solvents with different polarities. Using this procedure several components, even when found in small amounts, have been identified. The chemical composition of the organic and inorganic compounds used in the restoration material has been determined using extractive procedure, FT-IR and 1H-NMR spectroscopies. A preliminary macroscopic characterisation and mineralogical and petrographical analyses have also been performed on the inorganic filling materials found in several samples. The different compositions of various materials used in the restoration of this fossil collection might be related to the particular conservative and esthetic functions of the product applied on the find

Reduced miR-184-3p expression protects pancreatic β-cells from lipotoxic and proinflammatory apoptosis in type 2 diabetes via CRTC1 upregulation

The loss of functional beta-cell mass in type 2 diabetes (T2D) is associated with molecular events that include beta-cell apoptosis, dysfunction and/or dedifferentiation. MicroRNA miR-184-3p has been shown to be involved in several beta-cell functions, including insulin secretion, proliferation and survival. However, the downstream targets and upstream regulators of miR-184-3p have not been fully elucidated. Here, we show reduced miR-184-3p levels in human T2D pancreatic islets, whereas its direct target CREB regulated transcription coactivator 1 (CRTC1) was increased and protects beta-cells from lipotoxicity- and inflammation-induced apoptosis. Downregulation of miR-184-3p in beta-cells leads to upregulation of CRTC1 at both the mRNA and protein levels. Remarkably, the protective effect of miR-184-3p is dependent on CRTC1, as its silencing in human beta-cells abrogates the protective mechanism mediated by inhibition of miR-184-3p. Furthermore, in accordance with miR-184-3p downregulation, we also found that the beta-cell-specific transcription factor NKX6.1, DNA-binding sites of which are predicted in the promoter sequence of human and mouse MIR184 gene, is reduced in human pancreatic T2D islets. Using chromatin immunoprecipitation analysis and mRNA silencing experiments, we demonstrated that NKX6.1 directly controls both human and murine miR-184 expression. In summary, we provide evidence that the decrease in NKX6.1 expression is accompanied by a significant reduction in miR-184-3p expression and that reduction of miR-184-3p protects beta-cells from apoptosis through a CRTC1-dependent mechanism

Magnetically Driven Bioreactors as new Tools in Drug Delivery

The pharmacological properties of many drugs can be improved by drug delivery systems able to drive therapeutic agents to target regions. The use of carriers, in fact, may reduce possible cytotoxic effects of drugs and increase their bioavailability at the site of action, thus improving the efficacy and the safety of treatments. Therefore, we have developed an erythrocyte-based drug delivery system (erythro-magneto-HA virosome), which has the potential to be magnetically guided to specific sites and to fuse with target cells. These engineered erythrocytes have demonstrated in previous work a very high in vitro capability to release anticancer drugs directly inside target cells. Because the erythro-magneto-HA virosomes (EMHVs) proved to be promising carriers, we decided to investigate in more details the effectiveness and safety of this erythrocyte-based drug delivery system. We evaluated the ability of the EMHVs to be specifically localized in vivo to desired sites by means of an external magnetic field and to protect an anticancer drug such as 5-Aza-2\u27-deoxycytidine from degradation. Additionally we have assessed the ability of the EMHVs to act as bioreactors and to convert the pro-drug 5-Aza-2\u27-deoxycytidine into an active drug. Finally, we have studied the interaction of the EMHVs with the host immune system. The pro-drug 5-Aza-2\u27-deoxycytidine has short half-life when systemically injected and needs to be phosphorylated to become an active drug. We found that when inside the engineered erythrocytes it is protected by degradation and is transformed in its active form thus becoming readily available for uptake by the targeted cells. Moreover, we have observed that the EMHVs used didn\u27t cause either a cell-mediated or a humoral immune response in host mice having the same haplotype of the donors. These findings suggest that erythro-magneto-HA virosomes are a safe and useful drug delivery system that may offer numerous advantages for several clinical application

Level of HER2/neu amplification in primary tumours and metastases in HER2-positive breast cancer and survival after trastuzumab therapy

Abstract Background The level of HER2/neu amplification may vary widely in breast cancers with HER2/neu alteration. The clinical significance of this phenomenon is still unclear. This study was aimed to explore the level of HER2/neu amplification in primary tumours and metastases in HER2-positive metastatic breast cancer (MBC) and its potential impact on survival after a trastuzumab-containing therapy. Methods We retrospectively identified MBC patients treated with a trastuzumab-containing therapy and performed dual-colour FISH on tumour samples from either primary tumour and/or metastasis in a central laboratory. Results We retrieved 110 tumour samples from 91 patients and included 79 tumour samples (primary = 56; metastasis = 23) from 63 patients in the final analysis. We found higher level of HER2/neu amplification in the metastases than in the primary tumours (median HER2/CEP17 ratio: 10.5 vs 7.0, respectively). In 69% of patients ( n = 16) with two tumour samples, the level of HER2/neu amplification was higher in the metastasis than in the paired primary tumour (median HER2/CEP17 ratio: 10.9 vs 8.3, respectively, p = 0.004). The incremental gain in level of HER2/neu amplification was associated with significantly shorter OS after trastuzumab-containing therapy ( p = 0.023, HR 1.014, CI95%: 1.002–1.025). Conclusions The level of HER2/neu amplification tends to increase from the primary tumour to the paired metastases in a significant proportion of patients with HER2-positive MBC. This phenomenon, although still not completely understood, could lead to a shorter OS after trastuzumab therapy

Synthesis and preliminary in vitro evaluation of DOTA-Tenatumomab conjugates for theranostic applications in tenascin expressing tumors

Tenatumomab is an anti-tenascin murine monoclonal antibody previously used in clinical trials for delivering radionuclides to tumors by both pre-targeting (biotinylated Tenatumomab within PAGRIT) and direct 131Iodine labeling approaches. Here we present the synthesis and in vitro characterization of three Tenatumomab conjugates to bifunctional chelating agents (NHS-DOTA, NCS-DOTA and NCS-DTPA). Results indicate ST8198AA1 (Tenatumomab-DOTAMA, derived by conjugation of NHS-DOTA), as the most promising candidate in terms of conjugation rate and yield, stability, antigen immunoreactivity and affinity. Labeling efficiency of the different chelators was investigated with a panel of cold metals indicating DOTAMA as the best chelator. Labeling of Tenatumomab-DOTAMA was then optimized with several metals and stability performed confirms suitability of this conjugate for further development. ST8198AA1 represents an improvement of the previous antibody forms because the labeling with radionuclides like 177Lu or 64Cu would allow theranostic applications in patients bearing tenascin expressing tumors

Antibody drug conjugates (ADCs) charged with HDAC inhibitor for targeted epigenetic modulation

We describe here two novel antibody-drug conjugates loaded with the HDAC inhibitor ST7612AA1 (IC50equal to 0.07 μM on NCI-H460 cells), a thiol-based molecule with a moderate toxicity in vivo. Two payloads were prepared using cleavable and non-cleavable linkers. After anchoring to cetuximab through amide bond with lysines, the resulting HDAC inhibitor-antibody conjugates showed ability to recognize EGFR and efficient internalization in tumor cells. Both ADCs induced sensible increment of histones 3 and 4 and alpha-tubulin acetylation. Animal models of human solid tumors showed high anti-tumor efficacy of the conjugates without the toxicity generally observed with traditional ADCs delivering highly potent cytotoxic drugs. These compounds, the first ADCs charged with not highly cytotoxic warheads, are potentially suitable for epigenetic modulation, extending the ADC strategy to the targeted delivery of HDAC inhibitors with many possible therapeutic applications beyond cancer