SLAMF8 Downregulates Mouse Macrophage Microbicidal Mechanisms via PI3K Pathways.

Signaling lymphocytic activation molecule family 8 (SLAMF8) is involved in the negative modulation of NADPH oxidase activation. However, the impact of SLAMF8 downregulation on macrophage functionality and the microbicide mechanism remains elusive. To study this in depth, we first analyzed NADPH oxidase activation pathways in wild-type and SLAMF8-deficient macrophages upon different stimulus. Herein, we describe increased phosphorylation of the Erk1/2 and p38 MAP kinases, as well as increased phosphorylation of NADPH oxidase subunits in SLAMF8-deficient macrophages. Furthermore, using specific inhibitors, we observed that specific PI3K inhibition decreased the differences observed between wild-type and SLAMF8-deficient macrophages, stimulated with either PMA, LPS, or Salmonella typhimurium infection. Consequently, SLAMF8-deficient macrophages also showed increased recruitment of small GTPases such as Rab5 and Rab7, and the p47phox subunit to cytoplasmic Salmonella, suggesting an impairment of Salmonella-containing vacuole (SCV) progression in SLAMF8-deficient macrophages. Enhanced iNOS activation, NO production, and IL-6 expression were also observed in the absence of SLAMF8 upon Salmonella infection, either in vivo or in vitro, while overexpression of SLAMF8 in RAW264.7 macrophages showed the opposite phenotype. In addition, SLAMF8-deficient macrophages showed increased activation of Src kinases and reduced SHP-1 phosphate levels upon IFNγ and Salmonella stimuli in comparison to wild-type macrophages. In agreement with in vitro results, Salmonella clearance was augmented in SLAMF8-deficient mice compared to that in wild-type mice. Therefore, in conclusion, SLAMF8 intervention upon bacterial infection downregulates mouse macrophage activation, and confirmed that SLAMF8 receptor could be a potential therapeutic target for the treatment of severe or unresolved inflammatory conditions.

High-yield synthesis of CsPbBr3nanoparticles: diphenylphosphine as a reducing agent and its effect in Pb-seeding nucleation and growth.

Based on the reported nucleation mechanisms for CsPbX3and II-VI/IV-VI quantum dots, CsPbBr3nanoparticles with a higher reaction-yield (up to 393% mass-increment) were synthetized by the hot-injection method. The introduction of diphenylphosphine (DPP) as a reducing agent improved nanoparticle nucleation and growth, giving out evidence for Pb-seeding in CsPbBr3nanoparticles formation. Additionally, a clear influence of the DPP in a CsPbBr3-Cs4PbBr6incomplete phase transformation was observed, marked by the appearance of several PbBr2nanoparticles. This indicated the need for an improved ratio between the stabilizing agents and the precursors, due to the increased number of nucleation sites produced by DPP. The resulting CsPbBr3nanoparticles showed high quality, as they displayed 70%-90% photoluminescence quantum yield; narrow size distribution with an average nanoparticle size of∼10 nm; and the characteristic cubic morphology reported in previous works. This increment in CsPbBr3nanoparticles' reaction yield will contribute to making them a more attractive option for different optoelectronic applications.

TCERG1L allelic variation is associated with cisplatin-induced hearing loss in childhood cancer, a PanCareLIFE study.

In children with cancer, the heterogeneity in ototoxicity occurrence after similar treatment suggests a role for genetic susceptibility. Using a genome-wide association study (GWAS) approach, we identified a genetic variant in TCERG1L (rs893507) to be associated with hearing loss in 390 non-cranial irradiated, cisplatin-treated children with cancer. These results were replicated in two independent, similarly treated cohorts (n = 192 and 188, respectively) (combined cohort: P = 5.3 × 10-10, OR 3.11, 95% CI 2.2-4.5). Modulating TCERG1L expression in cultured human cells revealed significantly altered cellular responses to cisplatin-induced cytokine secretion and toxicity. These results contribute to insights into the genetic and pathophysiological basis of cisplatin-induced ototoxicity.

Medicinal Chemistry Optimization of a Diaminopurine Chemotype: Toward a Lead for Trypanosoma brucei Inhibitors.

Human African trypanosomiasis (HAT), or sleeping sickness, is caused by the protozoan parasite Trypanosoma brucei and transmitted through the bite of infected tsetse flies. The disease is considered fatal if left untreated. To identify new chemotypes against Trypanosoma brucei, previously we identified 797 potent kinase-targeting inhibitors grouped into 59 clusters plus 53 singleton compounds with at least 100-fold selectivity over HepG2 cells. From this set of hits, a cluster of diaminopurine-derived compounds was identified. Herein, we report our medicinal chemistry investigation involving the exploration of structure-activity and structure-property relationships around one of the high-throughput screening (HTS) hits, N2-(thiophen-3-yl)-N6-(2,2,2-trifluoroethyl)-9H-purine-2,6-diamine (1, NEU-1106). This work led to the identification of a potent lead compound (4aa, NEU-4854) with improved in vitro absorption, distribution, metabolism, and excretion (ADME) properties, which was progressed into proof-of-concept translation of in vitro antiparasitic activity to in vivo efficacy.

Study on photovoltaic stability and performance by incorporating tetrabutyl phosphonium iodide into the active layer of a perovskite type photovoltaic cell.

A simple synthesis of an ionic liquid is carried out using a trialkylphosphine and an alkyl halide. The results showed that the quality of perovskite crystals is enhanced by the incorporation of B4PI, when the percentage is 1.5% the PCE of champion PSCs MA98.5(B4PI)1.5PbI3 increases significantly from 15.5%, with a V OC of 0.957 mV, J SC of 23.6 mA cm-2, and an FF of 68.4%. Stability tests show that excess B4PI by 20% has a protective effect against humidity, MA80(B4PI)20PbI3 was more stable towards humidity, losing only 20% efficiency for 200 h.

Selectivity and Physicochemical Optimization of Repurposed Pyrazolo[1,5-b]pyridazines for the Treatment of Human African Trypanosomiasis.

From a high-throughput screen of 42 444 known human kinases inhibitors, a pyrazolo[1,5-b]pyridazine scaffold was identified to begin optimization for the treatment of human African trypanosomiasis. Previously reported data for analogous compounds against human kinases GSK-3ß, CDK-2, and CDK-4 were leveraged to try to improve the selectivity of the series, resulting in 23a which showed selectivity for T. b. brucei over these three human enzymes. In parallel, properties known to influence the absorption, distribution, metabolism, and excretion (ADME) profile of the series were optimized resulting in 20g being progressed into an efficacy study in mice. Though 20g showed toxicity in mice, it also demonstrated CNS penetration in a PK study and significant reduction of parasitemia in four out of the six mice.

Evaluation of a class of isatinoids identified from a high-throughput screen of human kinase inhibitors as anti-Sleeping Sickness agents.

New treatments are needed for neglected tropical diseases (NTDs) such as Human African trypanosomiasis (HAT), Chagas disease, and schistosomiasis. Through a whole organism high-throughput screening campaign, we previously identified 797 human kinase inhibitors that grouped into 59 structural clusters and showed activity against T. brucei, the causative agent of HAT. We herein report the results of further investigation of one of these clusters consisting of substituted isatin derivatives, focusing on establishing structure-activity and -property relationship scope. We also describe their in vitro absorption, distribution, metabolism, and excretion (ADME) properties. For one isatin, NEU-4391, which offered the best activity-property profile, pharmacokinetic parameters were measured in mice.

Inhibitor of apoptosis proteins, NAIP, cIAP1 and cIAP2 expression during macrophage differentiation and M1/M2 polarization.

Monocytes and macrophages constitute the first line of defense of the immune system against external pathogens. Macrophages have a highly plastic phenotype depending on environmental conditions; the extremes of this phenotypic spectrum are a pro-inflammatory defensive role (M1 phenotype) and an anti-inflammatory tissue-repair one (M2 phenotype). The Inhibitor of Apoptosis (IAP) proteins have important roles in the regulation of several cellular processes, including innate and adaptive immunity. In this study we have analyzed the differential expression of the IAPs, NAIP, cIAP1 and cIAP2, during macrophage differentiation and polarization into M1 or M2. In polarized THP-1 cells and primary human macrophages, NAIP is abundantly expressed in M2 macrophages, while cIAP1 and cIAP2 show an inverse pattern of expression in polarized macrophages, with elevated expression levels of cIAP1 in M2 and cIAP2 preferentially expressed in M1. Interestingly, treatment with the IAP antagonist SMC-LCL161, induced the upregulation of NAIP in M2, the downregulation of cIAP1 in M1 and M2 and an induction of cIAP2 in M1 macrophages.

Aerobic physical training does not condition against strenuous exercise-induced changes in immune function but modulates T cell proliferative responses.

BACKGROUND: Exercise-induced stress induces considerable changes in the immune system. To better understand the mechanisms related to these immune changes during acute and chronic physical stress, we studied the effects of aerobic physical training (APT) on several parameters of the immune system. METHODS: Previously untrained males (18-25 years of age) were divided into a group that was subjected to 6 months of APT (N.=10) and a sedentary control group (N.=7). The subjects performed a cardiopulmonary exercise test (CET) at 0, 3, and 6 months of the APT program. B cell (CD19+), T cell (CD4+ and CD8+), and natural killer cell (CD56+) levels, and mitogen-induced T cell proliferation and cytokine production (interleukin-1, interleukin-4, interleukin-12, and interferon-γ) were evaluated before and at 30 seconds and 24 hours after the CET. RESULTS: There was a significant increase in CD4+ T cells and natural killer cells and a significant reduction in T cell proliferation in both groups 30 seconds after the CET at 0, 3 and 6 months of the APT program. Of note, the trained group showed significantly lower resting T cell proliferation (before and 24 hour after the CET) than the sedentary control groups at 0, 3 and 6 months of the APT program. There were no significant differences in cytokine production after the CET between both groups at any time point of the APT program. CONCLUSIONS: These data show that APT does not condition against strenuous exercise-induced immune changes but significantly modulates T cell proliferative responses.

Ultrasonic irradiation-assisted synthesis of Bi2S3 nanoparticles in aqueous ionic liquid at ambient condition.

In this work, an easy, fast and environmentally friendly method to obtain Bi2S3 nanostructures with sphere-like morphology is introduced. The promising material was successfully synthesized by a sonochemical route in 20% 1-ethyl-3-methylimidazolium ethyl sulfate [EMIM][EtSO4] ionic liquid solution (IL). Morphological studies by electron microscopy (SEM and TEM) show that the use of IL in the synthesis of Bi2S3 favors the formation of nanocrystals non-agglomerated. Micro Raman and energy dispersive X-ray spectroscopy (EDXS) were used to determine the composition and purity of the synthesized material. X-ray powder diffraction (XRD) and selective area electron diffraction (SAED) revealed that ultrasonic radiation accelerated the crystallization of Bi2S3 into orthorhombic bismuthinite structure. The band gap calculated from the diffuse reflectance spectra (DRS) was found to be 1.5eV.

Infants, famílies i pediatres en un Ponent canviant. Sessió inaugural del curs 2015-2016 de la Societat Catalana de Pediatria / Children, families and pediatricians in a changing ponent

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Incidencia de leptospirosis en España entre 2009-2012 / Incidence of leptospirosis in Spain, 2009-2012

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Encapsulation and immobilization of papain in electrospun nanofibrous membranes of PVA cross-linked with glutaraldehyde vapor.

In this paper, papain enzyme (E.C. 3.4.22.2, 1.6 U/mg) was successfully immobilized in poly(vinyl alcohol) (PVA) nanofibers prepared by electrospinning. The morphology of the electrospun nanofibers was characterized by scanning electron microscopy (SEM) and the diameter distribution was in the range of 80 to 170 nm. The presence of the enzyme within the PVA nanofibers was confirmed by infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDXS) analyses. The maximum catalytic activity was reached when the enzyme loading was 13%. The immobilization of papain in the nanofiber membrane was achieved by chemical crosslinking with a glutaraldehyde vapor treatment (GAvt). The catalytic activity of the immobilized papain was 88% with respect to the free enzyme. The crosslinking time by GAvt to immobilize the enzyme onto the nanofiber mat was 24h, and the enzyme retained its catalytic activity after six cycles. The crosslinked samples maintained 40% of their initial activity after being stored for 14 days. PVA electrospun nanofibers are excellent matrices for the immobilization of enzymes due to their high surface area and their nanoporous structure.

SUMOylation by the E3 ligase TbSIZ1/PIAS1 positively regulates VSG expression in Trypanosoma brucei.

Bloodstream form trypanosomes avoid the host immune response by switching the expression of their surface proteins between Variant Surface Glycoproteins (VSG), only one of which is expressed at any given time. Monoallelic transcription of the telomeric VSG Expression Site (ES) by RNA polymerase I (RNA pol I) localizes to a unique nuclear body named the ESB. Most work has focused on silencing mechanisms of inactive VSG-ESs, but the mechanisms involved in transcriptional activation of a single VSG-ES remain largely unknown. Here, we identify a highly SUMOylated focus (HSF) in the nucleus of the bloodstream form that partially colocalizes with the ESB and the active VSG-ES locus. SUMOylation of chromatin-associated proteins was enriched along the active VSG-ES transcriptional unit, in contrast to silent VSG-ES or rDNA, suggesting that it is a distinct feature of VSG-ES monoallelic expression. In addition, sequences upstream of the active VSG-ES promoter were highly enriched in SUMOylated proteins. We identified TbSIZ1/PIAS1 as the SUMO E3 ligase responsible for SUMOylation in the active VSG-ES chromatin. Reduction of SUMO-conjugated proteins by TbSIZ1 knockdown decreased the recruitment of RNA pol I to the VSG-ES and the VSG-ES-derived transcripts. Furthermore, cells depleted of SUMO conjugated proteins by TbUBC9 and TbSUMO knockdown confirmed the positive function of SUMO for VSG-ES expression. In addition, the largest subunit of RNA pol I TbRPA1 was SUMOylated in a TbSIZ-dependent manner. Our results show a positive mechanism associated with active VSG-ES expression via post-translational modification, and indicate that chromatin SUMOylation plays an important role in the regulation of VSG-ES. Thus, protein SUMOylation is linked to active gene expression in this protozoan parasite that diverged early in evolution.

Identification and characterization of hundreds of potent and selective inhibitors of Trypanosoma brucei growth from a kinase-targeted library screening campaign.

In the interest of identification of new kinase-targeting chemotypes for target and pathway analysis and drug discovery in Trypanosomal brucei, a high-throughput screen of 42,444 focused inhibitors from the GlaxoSmithKline screening collection was performed against parasite cell cultures and counter-screened against human hepatocarcinoma (HepG2) cells. In this way, we have identified 797 sub-micromolar inhibitors of T. brucei growth that are at least 100-fold selective over HepG2 cells. Importantly, 242 of these hit compounds acted rapidly in inhibiting cellular growth, 137 showed rapid cidality. A variety of in silico and in vitro physicochemical and drug metabolism properties were assessed, and human kinase selectivity data were obtained, and, based on these data, we prioritized three compounds for pharmacokinetic assessment and demonstrated parasitological cure of a murine bloodstream infection of T. brucei rhodesiense with one of these compounds (NEU-1053). This work represents a successful implementation of a unique industrial-academic collaboration model aimed at identification of high quality inhibitors that will provide the parasitology community with chemical matter that can be utilized to develop kinase-targeting tool compounds. Furthermore these results are expected to provide rich starting points for discovery of kinase-targeting tool compounds for T. brucei, and new HAT therapeutics discovery programs.

Establishment of a structure-activity relationship of 1H-imidazo[4,5-c]quinoline-based kinase inhibitor NVP-BEZ235 as a lead for African sleeping sickness.

Compound NVP-BEZ235 (1) is a potent inhibitor of human phospoinositide-3-kinases and mammalian target of rapamycin (mTOR) that also showed high inhibitory potency against Trypanosoma brucei cultures. With an eye toward using 1 as a starting point for anti-trypanosomal drug discovery, we report efforts to reduce host cell toxicity, to improve the physicochemical properties, and to improve the selectivity profile over human kinases. In this work, we have developed structure-activity relationships for analogues of 1 and have prepared analogues of 1 with improved solubility properties and good predicted central nervous system exposure. In this way, we have identified 4e, 9, 16e, and 16g as the most promising leads to date. We also report cell phenotype and phospholipidomic studies that suggest that these compounds exert their anti-trypanosomal effects, at least in part, by inhibition of lipid kinases.

Prevalence and characteristics of bone disease in cirrhotic patients under evaluation for liver transplantation.

BACKGROUND: We performed a retrospective study to examine the prevalence of bone disease (BD) among cirrhotic patients being evaluated for liver transplantation (OLT) using bone densitometry dual-energy x-ray absorptiometry in the hip/femoral neck and lumbar spine. The associations of BD with demographic and clinical data, disease etiology and liver function were studied by univariate and multivariate logistic regression analyses. Osteopenia and osteoporosis were defined by World Health Organization criteria. RESULTS: We included 486 patients (79% men of mean age, 53 ± 8.8 years (range, 21-69) who included 62.6% smoker and 23.7% diabetic subjects. Body mass index (BMI) was 28.8 ± 5.7 kg/m(2) (range, 16-43). The liver disease was Child-Pugh class A (22%), B (51%), or C (27%); the Model for End-Stage Liver Disease (MELD) score was 14.6 ± 5.4 (range, 7-33). The disease etiology was alcohol (59%), hepatitis C (32%), hepatitis B (10%), primary biliary cirrhosis (PBC) (2.3%), secondary biliary cirrhosis, (2%) or other causes (10%). In all, 350 patients (72%) had BD in the hip/femoral neck and/or lumbar spine: Global hip, 26% (osteopenia, 22%; osteoporosis, 4%); femoral neck, 48% (osteopenia, 43%; osteoporosis, 5%) and lumbar spine, 63% (osteopenia, 40%; osteoporosis, 23%). Univariate analysis showed the BD risk to increase with the following variables: Female gender (odds ratio [OR], 1.88; P = .023) and lower BMI (OR, 0.95; P = .012). Upon multivariate analysis, female gender (OR, 2.43; P = .004), lower BMI (OR, 0.96; P = .016), and tobacco use (OR, 1.59; P = .043) were significant. PBC showed BD in 100% of cases. By adjusting bone mineral density (BMD) values to age (Z-score) in relation to that defined by T-score, we observed a decrease in BD prevalence in both the femoral neck (20% vs 48%) and the lumbar spine (44% vs 63%). CONCLUSION: BD, especially in the lumbar spine, is common among cirrhotic patients under evaluation for OLT. Cirrhosis is a major BD risk factor that remains even when BMD values are adjusted for age. Female gender, lower BMI, and tobacco consumption are major risk factors for BD in cirrhotic patients. Bone densitometry must be included in the OLT evaluation of all patients.

Response to vaccination against hepatitis B virus with a schedule of four 40-µg doses in cirrhotic patients evaluated for liver transplantation: factors associated with a response.

We performed a retrospective study to evaluate the rate of and factors associated with a response to recombinant hepatitis B virus (HBV) vaccination using 4 intramuscular doses (40 µg) administered at 0, 1, 2, and 6 months among 278 cirrhotic patients being evaluated for orthotopic liver transplantation (OLT). We re-vaccinated 57 non-responders with the same schedule. The 39.2% overall response rate to vaccination included 36% after three and 40.7% after four doses, namely, a median anti-HBs level of 100 IU/mL (range, 10 to 1000 IU/mL). The 51% revaccination response rate achieved a median hepatitis B surface antibody (anti-HBs) level of 99 IU/mL (range, 11 to >1000 IU/mL). Upon univariate analysis, variables associated with a higher response were: better liver function (Child-Pugh class [A, 53.8% B, 33.3%, C, 30.1%; P = .002), Model for End-stage Liver-Disease (MELD) score (11.4 versus 13.6; P = .001]), absence of diabetes (43.6% versus 20.8%; P = .002), presence of isolated hepatitis B core antibody (anti-HBc) positivity (80% versus 37.7%; P = .007), and younger age (< 45 years, 52.2%; range, 45 to 55 years, 40.4%; > 55 years, 34.1%; P = .031). Upon multivariate logistic regression analysis, lower MELD score (odds ratio [OR]: 0.922; P = .046), absence of diabetes (OR:0.359; P = .008) and isolated anti-HBc positivity (OR:5.826; P = .034) were associated with a higher response. No differences were observed to be associated with gender, weight, body mass index, etiology or tobacco consumption. Among the same patient cohort (n = 79), the responses after the third and fourth doses were 36.7% and 51.9% respectively. In conclusion, the response rate to HBV vaccination in cirrhotic patients evaluated for OLT reached more than 35% among those who received at least 3 doses. It was higher among patients who showed isolated anti-HBc positivity, better liver function, younger age, and non-diabetic status. The fourth dose only increased the response rate by 24% over that obtained after the first three doses, whereas a revaccination achieved a 50% response rate, which probably accounts for revaccination after no response to 3 doses. Vaccination should be introduced against HBV in the early stages of the disease.