A novel synthesis of fused isothiazole ring systems

The reaction of aromatic and heteroaromatic aldehydes with bis(trimethylsilyl)sulfide leads to the corresponding thioaldehydes, which, through a fine tuning of the reaction conditions, are trapped both intermolecularly and intramolecularly, thus disclosing a novel methodology for the synthesis of fused isothiazole ring system

Two novel precursors of the hiv-1 protease inhibitor darunavir target the UPR/proteasome system in human hepatocellular carcinoma cell line HepG2

Background: Several pre-clinical and clinical reports suggest that HIV-1 protease inhibitors, in addition to the antiretroviral properties, possess pleiotropic pharmacological effects including anti-cancer action. Therefore, we investigated the pro-apoptotic activity in tumor cells of two molecules, RDD-19 and RDD-142, which are hydroxyethylamine derivatives’ precursors of darunavir and several HIV-1 protease inhibitors. Methods: Three hepatoma cell lines and one non-pathological cell line were treated with RDD-19 and RDD-142, and cell viability was assessed. The expression levels of several markers for ER stress, autophagy, cellular ubiquitination, and Akt activation were quantified in HepG2 cells treated with RDD-19 and RDD-142 to evaluate apoptotic and non-apoptotic cell death. Results: RDD-19 and RDD-142 showed a greater dose-dependent cytotoxicity towards the hepatic tumor cell line HepG2 compared to the non-pathological hepatic cell line IHH. Both molecules caused two types of cell death, a caspase-dependent apoptosis, which was ascertained by a series of biochemical and morphological assays, and a caspase-independent death that was characterized by the induction of ER stress and autophagy. The strong increase of ubiquitinated proteins inside the cells suggested that the target of these molecules could be the proteasome and in silico molecular docking analysis that was used to support the plausibility of this hypothesis. Furthermore, cells treated with the two compounds displayed decreased levels of p-AKT, which interferes with cell survival and proliferation. Conclusions: These findings demonstrate that two compounds, RDD-19 and RDD-142, have pleiotropic effects and that they may represent promising anticancer candidates

Synthesis and biological evaluation of new simple indolic non peptidic HIV Protease inhibitors: The effect of different substitution patterns

New structurally simple indolic non peptidic HIV Protease inhibitors were synthesized from (S)- glycidol by regioselective methods. Following the concept of targeting the protein backbone, different substitution patterns were introduced onto the common stereodefined isopropanolamine core modifying the type of functional group on the indole, the position of the functional group on the indole and the type of the nitrogen containing group (sulfonamides or perhydroisoquinoline), alternatively. The systematic study on in vitro inhibition activity of such compounds confirmed the general beneficial effect of the 5-indolyl substituents in presence of arylsulfonamide moieties, which furnished activities in the micromolar range. Preliminary docking analysis allowed to identify several key features of the binding mode of such compounds to the protease

PEGylated Liposomes Loaded with Carbamate Inhibitor ANP0903 Trigger Apoptosis by Enhancing ER Stress in HepG2 Cancer Cells

Liver cancer is one of the most common causes of cancer death worldwide. In recent years, substantial progress has been made in the development of systemic therapies, but there is still the need for new drugs and technologies that can increase the survival and quality of life of patients. The present investigation reports the development of a liposomal formulation of a carbamate molecule, reported as ANP0903, previously tested as an inhibitor of HIV-1 protease and now evaluated for its ability to induce cytotoxicity in hepatocellular carcinoma cell lines. PEGylated liposomes were prepared and characterized. Small, oligolamellar vesicles were produced, as demonstrated by light scattering results and TEM images. The physical stability of the vesicles in biological fluids was demonstrated in vitro, alongside the stability during storage. An enhanced cellular uptake was verified in HepG2 cells treated with liposomal ANP0903, resulting in a greater cytotoxicity. Several biological assays were performed to elucidate the molecular mechanisms explaining the proapoptotic effect of ANP0903. Our results allow us to hypothesize that the cytotoxic action in tumor cells is probably due to the inhibition of the proteasome, resulting in an increase in the amount of ubiquitinated proteins within the cells, which in turn triggers activation of autophagy and apoptosis processes, resulting in cell death. The proposed liposomal formulation represents a promising approach to deliver a novel antitumor agent to cancer cells and enhance its activity

The obesity and inflammatory marker haptoglobin attracts monocytes via interaction with chemokine (C-C motif) receptor 2 (CCR2)

<p>Abstract</p> <p>Background</p> <p>Obesity is a chronic low inflammatory state. In the obesity condition the white adipose tissue (WAT) is massively infiltrated with monocytes/macrophages, and the nature of the signals recruiting these inflammatory cells has yet to be fully elucidated. Haptoglobin (Hp) is an inflammatory marker and its expression is induced in the WAT of obese subjects. In an effort to elucidate the biological significance of Hp presence in the WAT and of its upregulation in obesity we formulated the hypothesis that Hp may serve as a macrophage chemoattractant.</p> <p>Results</p> <p>We demonstrated by chemotaxis assay that Hp is able to attract chemokine (C-C motif) receptor 2 (CCR2)-transfected pre-B lymphocytes and monocytes in a dose-dependent manner. Moreover, Hp-mediated migration of monocytes is impaired by CCR2-specific inhibition or previous cell exposure to monocyte chemoattractant protein 1 (MCP1) (also known as CCR2 ligand or chemokine (C-C motif) ligand 2 (CCL2)). Downstream effects of Hp/CCR2 interaction were also investigated: flow cytometry proved that monocytes treated with Hp show reduced CCR2 expression on their surface; Hp interaction induces calcium release that is reduced upon pretreatment with CCR2 antagonist; extracellular signal-regulated kinase (ERK)1/2, a signal transducer activated by CCR2, is phosphorylated following Hp treatment and this phosphorylation is reduced when cells are pretreated with a specific CCR2 inhibitor. Consistently, blocking the ERK1/2 pathway with U0126, the selective inhibitor of the ERK upstream mitogen-activated protein (MAP)-ERK kinase (MEK), results in a dramatic reduction (by almost 100%) of the capability of Hp to induce monocyte migration.</p> <p>Conclusions</p> <p>Our data show that Hp is a novel monocyte chemoattractant and that its chemotactic potential is mediated, at least in part. by its interaction with CCR2.</p

Study of cosmogenic activation above ground for the DarkSide-20k experiment

The activation of materials due to exposure to cosmic rays may become an important background source for experiments investigating rare event phenomena. DarkSide-20k, currently under construction at the Laboratori Nazionali del Gran Sasso, is a direct detection experiment for galactic dark matter particles, using a two-phase liquid-argon Time Projection Chamber (TPC) filled with 49.7 tonnes (active mass) of Underground Argon (UAr) depleted in 39Ar. Despite the outstanding capability of discriminating / background in argon TPCs, this background must be considered because of induced dead time or accidental coincidences mimicking dark-matter signals and it is relevant for low-threshold electron-counting measurements. Here, the cosmogenic activity of relevant long-lived radioisotopes induced in the experiment has been estimated to set requirements and procedures during preparation of the experiment and to check that it is not dominant over primordial radioactivity; particular attention has been paid to the activation of the 120 t of UAr used in DarkSide-20k. Expected exposures above ground and production rates, either measured or calculated, have been considered in detail. From the simulated counting rates in the detector due to cosmogenic isotopes, it is concluded that activation in copper and stainless steel is not problematic. The activity of 39Ar induced during extraction, purification and transport on surface is evaluated to be 2.8% of the activity measured in UAr by DarkSide-50 experiment, which used the same underground source, and thus considered acceptable. Other isotopes in the UAr such as 37Ar and 3H are shown not to be relevant due to short half-life and assumed purification methods

Measurement of isotopic separation of argon with the prototype of the cryogenic distillation plant Aria for dark matter searches

The Aria cryogenic distillation plant, located in Sardinia, Italy, is a key component of the DarkSide-20k experimental program for WIMP dark matter searches at the INFN Laboratori Nazionali del Gran Sasso, Italy. Aria is designed to purify the argon, extracted from underground wells in Colorado, USA, and used as the DarkSide-20k target material, to detector-grade quality. In this paper, we report the first measurement of argon isotopic separation by distillation with the 26&nbsp;m tall Aria prototype. We discuss the measurement of the operating parameters of the column and the observation of the simultaneous separation of the three stable argon isotopes: 36Ar , 38Ar , and 40Ar . We also provide a detailed comparison of the experimental results with commercial process simulation software. This measurement of isotopic separation of argon is a significant achievement for the project, building on the success of the initial demonstration of isotopic separation of nitrogen using the same equipment in 2019

Study on cosmogenic activation above ground for the DarkSide-20k project

The activation of materials due to the exposure to cosmic rays may become an important background source for experiments investigating rare event phenomena. DarkSide-20k is a direct detection experiment for galactic dark matter particles, using a two-phase liquid argon time projection chamber filled with 49.7 tonnes (active mass) of Underground Argon (UAr) depleted in 39Ar. Here, the cosmogenic activity of relevant long-lived radioisotopes induced in the argon and other massive components of the set-up has been estimated; production of 120 t of radiopure UAr is foreseen. The expected exposure above ground and production rates, either measured or calculated, have been considered. From the simulated counting rates in the detector due to cosmogenic isotopes, it is concluded that activation in copper and stainless steel is not problematic. Activation of titanium, considered in early designs but not used in the final design, is discussed. The activity of 39Ar induced during extraction, purification and transport on surface, in baseline conditions, is evaluated to be 2.8% of the activity measured in UAr from the same source, and thus considered acceptable. Other products in the UAr such as 37Ar and 3H are shown to not be relevant due to short half-life and assumed purification methods

Directionality of nuclear recoils in a liquid argon time projection chamber

The direct search for dark matter in the form of weakly interacting massive particles (WIMP) is performed by detecting nuclear recoils (NR) produced in a target material from the WIMP elastic scattering. A promising experimental strategy for direct dark matter search employs argon dual-phase time projection chambers (TPC). One of the advantages of the TPC is the capability to detect both the scintillation and charge signals produced by NRs. Furthermore, the existence of a drift electric field in the TPC breaks the rotational symmetry: the angle between the drift field and the momentum of the recoiling nucleus can potentially affect the charge recombination probability in liquid argon and then the relative balance between the two signal channels. This fact could make the detector sensitive to the directionality of the WIMP-induced signal, enabling unmistakable annual and daily modulation signatures for future searches aiming for discovery. The Recoil Directionality (ReD) experiment was designed to probe for such directional sensitivity. The TPC of ReD was irradiated with neutrons at the INFN Laboratori Nazionali del Sud, and data were taken with 72 keV NRs of known recoil directions. The direction-dependent liquid argon charge recombination model by Cataudella et al. was adopted and a likelihood statistical analysis was performed, which gave no indications of significant dependence of the detector response to the recoil direction. The aspect ratio R of the initial ionization cloud is estimated to be 1.037 +/- 0.027 and the upper limit is R < 1.072 with 90% confidence levelComment: 20 pages, 10 figures, submitted to Eur. Phys. J.