ZEB1 shapes AML immunological niches, suppressing CD8 T cell activity while fostering Th17 cell expansion

Acute myeloid leukemia (AML) progression is influenced by immune suppression induced by leukemia cells. ZEB1, a critical transcription factor in epithelial-to-mesenchymal transition, demonstrates immune regulatory functions in AML. Silencing ZEB1 in leukemic cells reduces engraftment and extramedullary disease in immune-competent mice, activating CD8 T lymphocytes and limiting Th17 cell expansion. ZEB1 in AML cells directly promotes Th17 cell development that, in turn, creates a self-sustaining loop and a pro-invasive phenotype, favoring transforming growth factor β (TGF-β), interleukin-23 (IL-23), and SOCS2 gene transcription. In bone marrow biopsies from AML patients, immunohistochemistry shows a direct correlation between ZEB1 and Th17. Also, the analysis of ZEB1 expression in larger datasets identifies two distinct AML groups, ZEB1high and ZEB1low, each with specific immunological and molecular traits. ZEB1high patients exhibit increased IL-17, SOCS2, and TGF-β pathways and a negative association with overall survival. This unveils ZEB1's dual role in AML, entwining pro-tumoral and immune regulatory capacities in AML blasts.

Getting everyone to agree on gene signatures for murine macrophage polarization in vitro

Macrophages, key players in the innate immune system, showcase remarkable adaptability. Derived from monocytes, these phagocytic cells excel in engulfing and digesting pathogens and foreign substances as well as contributing to antigen presentation, initiating and regulating adaptive immunity. Macrophages are highly plastic, and the microenvironment can shaper their phenotype leading to numerous distinct polarized subsets, exemplified by the two ends of the spectrum: M1 (classical activation, inflammatory) and M2 (alternative activation, anti-inflammatory). RNA sequencing (RNA-Seq) has revolutionized molecular biology, offering a comprehensive view of transcriptomes. Unlike microarrays, RNA-Seq detects known and novel transcripts, alternative splicing, and rare transcripts, providing a deeper understanding of genome complexity. Despite the decreasing costs of RNA-Seq, data consolidation remains limited, hindering noise reduction and the identification of authentic signatures. Macrophages polarization is routinely ascertained by qPCR to evaluate those genes known to be characteristic of M1 or M2 skewing. Yet, the choice of these genes is literature- and experience-based, lacking therefore a systematic approach. This manuscript builds on the significant increase in deposited RNA-Seq datasets to determine an unbiased and robust murine M1 and M2 polarization profile. We now provide a consolidated list of global M1 differentially expressed genes (i.e. robustly modulated by IFN-γ, LPS, and LPS+ IFN-γ) as well as consolidated lists of genes modulated by each stimulus (IFN-γ, LPS, LPS+ IFN-γ, and IL-4).

Correction to "An Unexpected Deuterium-Induced Metabolic Switch in Doxophylline"

[This corrects the article DOI: 10.1021/acsmedchemlett.2c00166.].

Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) neutralization counteracts T cell immune evasion in breast cancer

BACKGROUND

Nicotinamide phosphoribosyltransferase (NAMPT) is a key intracellular enzyme that participates in nicotinamide adenine dinucleotide (NAD) homeostasis as well as a released cytokine (eNAMPT) that is elevated in inflammatory conditions and in cancer. In patients with breast cancer, circulating eNAMPT is elevated and its plasma levels correlate with prognosis and staging. In light of this, we investigated the contribution of eNAMPT in triple negative mammary carcinoma progression by investigating the effect of its neutralization via a specific neutralizing monoclonal antibody (C269).

METHODS

We used female BALB/c mice injected with 4T1 clone 5 cells and female C57BL6 injected with EO771 cells, evaluating tumoral size, spleen weight and number of metastases. We injected two times a week the anti-eNAMPT neutralizing antibody and we sacrificed the mice after 28 days. Harvested tumors were analyzed by histopathology, flow cytometry, western blot, immunohistochemistry, immunofluorescence and RNA sequencing to define tumor characteristics (isolating tumor infiltrating lymphocytes and tumoral cells) and to investigate the molecular mechanisms behind the observed phenotype. Moreover, we dissected the functional relationship between T cells and tumoral cells using three-dimensional (3D) co-cultures.

RESULTS

The neutralization of eNAMPT with C269 led to decreased tumor size and reduced number of lung metastases. RNA sequencing and functional assays showed that eNAMPT controlled T-cell response via the programmed death-ligand 1/programmed cell death protein 1 (PD-L1/PD-1) axis and its neutralization led to a restoration of antitumoral immune responses. In particular, eNAMPT neutralization was able to activate CD8+IFNγ+GrzB+ T cells, reducing the immunosuppressive phenotype of T regulatory cells.

CONCLUSIONS

These studies indicate for the first time eNAMPT as a novel immunotherapeutic target for triple negative breast cancer.

NAMPT and NAPRT serum levels predict response to anti-TNF therapy in inflammatory bowel disease

Background

Nicotinamide phosphoribosyltransferase (NAMPT) and nicotinic acid phosphoribosyl transferase (NAPRT) are key intracellular enzymes that participate in the biosynthesis on NAD but have also been shown to be released as proinflammatory cytokines. A number of reports have shown that circulating NAMPT is increased in serum of patients with inflammatory disorders, including inflammatory bowel diseases (IBD), while nothing is known regarding circulating NAPRT and the presence of both cytokines in IBD patient stools. In the present study, we evaluated eNAMPT and eNAPRT levels in a large cohort of IBD patients not on biological therapy and in a subset that then was prescribed biologics.

Methods

We conducted a retro-perspective study on 180 patients, of which 111 underwent subsequent biological treatment (adalimumab, vedolizumab, and ustekinumab). We analyzed eNAMPT and eNAPRT concentrations in serum and faces of IBD patients, correlating them with response to biologics.

Results

We now report that eNAMPT and eNAPRT are significantly increased in both serum and stools of IBD patients. NAMPT and NAPRT levels correlate with disease severity, with C reactive protein and with serum IL-6 levels. Importantly, levels of NAMPT in patients starting treatment with adalimumab correlate with response failure at three months: patients with levels above 4 ng/ml were significantly less likely to obtain benefit. Serum NAMPT as a biomarker of response yields a sensitivity of 91% and a specificity of 100%.

Conclusion

The present work strongly suggests that a prospective trial evaluating eNAMPT and eNAPRT levels in relation to response to biologicals in IBD should be initiated.

Reinterpretation of variant of unknown significance in the clinical setting of inherited cardiac conditions

Introduction

In the last years, genetic testing for inherited cardiac conditions (ICCs) is expanded and evolved at an incredible rate. This tool may inform treatment options and lifestyle choices to avoid arrhythmia triggers. Furthermore, identifying the genetic underpinning of the disorder improves risk assessment for asymptomatic or pre-symptomatic family members.

However, despite the large numbers of disease-causative genes identified in the last years, only 60% of the patients with a clinical diagnosis of ICCs carry a pathogenic or likely pathogenic variant. The remaining 40% of the cases have an inconclusive or ambiguous test caused by negative results or mainly by the identification of one or more variants of unknown significance (VUS). In this case, the test results are uninformative and clinically irrelevant, increasing uncertainty about medical management.

Purpose

We investigated whether a periodic re-evaluation of the detected VUS, using the American College of Medical Genetics and Genomics (ACMG) criteria, may impact the clinical setting of patients with suspected ICC and their family members.

Methods

We reevaluated 306 consecutive probands with suspected ICC undergoing genetic testing by next-generation sequencing using the Illumina TruSight Cardio Sequencing panel, from 2017 to 2021.

Results

Thirty-five percent of patients carried at least one variant in a gene associated with the phenotype. Of these, 94 had been previously classified as VUS and were not considered clinically actionable. After an average time of 36 months, they were reevaluated and 26.6% of the VUS were reclassified. In particular, 1 was downgraded to Benign and 24 were upgraded to Likely Pathogenic (16) or Pathogenic (8). According to the different phenotypes, the reclassification rate was 45.8% in Hypertrophic cardiomyopathy, 33.3% in Dilated cardiomyopathy, 27.3% in Arrhythmogenic cardiomyopathy, 12.5% in Brugada syndrome, and 50% in Long QT syndrome patients. This reclassification process allowed to recategorize 24 probands as clinically and molecularly diagnosed and to extend the genetic screening to their at-risk family members.

Conclusions

Given the extent of the clinical impact that genetic testing can have, these findings suggest that a periodic reevaluation of genetic test results, particularly VUS, should be a mandatory step in the ICC diagnostic workflow.

Funding Acknowledgement

Type of funding sources: None.

Deep learning applied to facial features for prediction of high risk coronary atherosclerosis at cardiac CT: preliminary data from LOMBROSO Trial

Background

Cardiac computed tomography (CT) emerged as an accurate tool for non-invasive evaluation of coronary artery disease (CAD), being able to identify high risk non-calcified atherosclerosis. Identification of high risk CAD in its asymptomatic stage could be an interest target for medical therapy. Nowadays no validated tools are available to predict the presence of high risk atherosclerosis, probably due to the multifactorial pathogenesis of atherosclerosis. Facial features may express both genetic and environmental factors that could be associated to high risk atherosclerosis. Aim of the present study was to verify whether deep learning models applied to facial features may accurately predict the presence of high risk coronary atherosclerosis evaluated at cardiac CT

Methods

We enrolled a consecutive cohort of patients who underwent clinical indicated cardiac CT for suspected, CAD. Before CT, 10 facial photos were taken from every patients from random fronts views.

All cardiac CT were analysed for the presence of non-calcified plaque volume (defined as <150 HU at CT); the non-calcified plaque volume was quantified on a per-patient basis in mm3 and a cut off of >23 mm3 was used to define a patients with an elevated volume non-calcified plaque

We built a deep learning model, exploiting the transfer learning technique; briefly, we implemented an “xception” architecture, joining a pre-trained convolutional part with a specific combination of dense layers, in which an output layer follows a hidden layer with 512 neurons and a dropout layer with a dropout rate=0.2. The batch size, the number of epochs and the learning rate were 16, 20, and 0.0001, respectively. A training set composed of 198 face images was fed into the model, while 20 face images served as test set for the prediction of the presence of elevated volume of non-calcified plaque from patients facial features.

Results

We present early results from the first 20 patients enrolled (12 male and 8 female, with mean age of 73±13 years old). In 9 patients cardiac CT resulted completely normal, while in 11 subjects the presence of coronary atherosclerosis was demonstrated. Among them, 9 patients presented non-calcified coronary atherosclerosis, while 6 had an elevated volume of non-calcified plaque.

On the test set, we obtained an accuracy, sensitivity, specificity, positive predictive value, negative predictive values and and AUC equal to 0.90, 1, 0.8, 0.83, 1, and 0.99, respectively for the prediction of the presence of an elevated volume of non-calcified plaque from facial features among all 20 patients enrolled.

Conclusions

Prediction of the presence of high risk atherosclerosis from deep learning models applied to facial features appeared to be feasible and promising. Our results may provide a useful tool for appropriate identification of patients that may merit to underwent cardiac CT, even if asymptomatic, for early identification of high risk atherosclerosis

Funding Acknowledgement

Type of funding sources: None.

An Unexpected Deuterium-Induced Metabolic Switch in Doxophylline

Precision deuteration has become part of the medicinal chemist's toolbox, but its usefulness can be undermined by unpredictable metabolic switch effects. Herein we report the deuteration of doxophylline, a drug used in the treatment of asthma and COPD that undergoes extensive oxidative metabolism. Labeling of the main metabolic soft spots triggered an unexpected multidirectional metabolic switch that, while not improving the pharmacokinetic parameters, changed the metabolic scenario and, in turn, the pharmacodynamic features in two murine models of lung injury.

Extracellular nicotinamide phosphoribosyltransferase boosts IFNγ-induced macrophage polarization independently of TLR4

Nicotinamide phosphoribosyltransferase (NAMPT), alongside being a crucial enzyme in NAD synthesis, has been shown to be a secreted protein (eNAMPT), whose levels are increased in patients affected by immune-mediated disorders. Accordingly, preclinical studies have highlighted that eNAMPT participates in the pathogenesis of several inflammatory diseases. Herein, we analyzed the effects of eNAMPT on macrophage-driven inflammation. RNAseq analysis of peritoneal macrophages (PECs) demonstrates that eNAMPT triggers an M1-skewed transcriptional program, and this effect is not dependent on the enzymatic activity. Noteworthy, both in PECs and in human monocyte-derived macrophages, eNAMPT selectively boosts IFNγ-driven transcriptional activation via STAT1/3 phosphorylation. Importantly, the secretion of eNAMPT promotes the chemotactic recruitment of myeloid cells, therefore providing a potential positive feedback loop to foster inflammation. Last, we report that these events are independent of the activation of TLR4, the only eNAMPT receptor that has hitherto been recognized, prompting the knowledge that other receptors are involved.

Insight Into Nicotinamide Adenine Dinucleotide Homeostasis as a Targetable Metabolic Pathway in Colorectal Cancer

Tumour cells modify their cellular metabolism with the aim to sustain uncontrolled proliferation. Cancer cells necessitate adequate amounts of NAD and NADPH to support several enzymes that are usually overexpressed and/or overactivated. Nicotinamide adenine dinucleotide (NAD) is an essential cofactor and substrate of several NAD-consuming enzymes, such as PARPs and sirtuins, while NADPH is important in the regulation of the redox status in cells. The present review explores the rationale for targeting the key enzymes that maintain the cellular NAD/NADPH pool in colorectal cancer and the enzymes that consume or use NADP(H).

Emergency department reorganisation to cope with COVID-19 outbreak in Milan university hospital: a time-sensitive challenge

BACKGROUND

In March 2020 we faced a huge spread of the epidemic of SARS-CoV2 in northern Italy; the Emergency Departments (ED) and the Emergency Medical Services (EMS) were overwhelmed by patients requiring care. The hospitals were forced to reorganize their services, and the ED was the focal point of this challenge. As Emergency Department in a metropolitan area of the region most affected, we saw an increasing number of patients with COVID-19, and we made some structural and staff implementations according to the evolution of the epidemic.

METHODS

We analysed in a narrative way the weaknesses and the point of strength of our response to COVID-19 first outbreak, focusing point by point on main challenges and minor details involved in our ED response to the pandemics.

RESULTS

The main stems for our response to the pandemic were: use of clear and shared contingency plans, as long as preparedness to implement them; stockage of as much as useful material can be stocked; training of the personnel to be prepared for a fast response, trying to maintain divided pathway for COVID-19 and non-COVID-19 patients, well-done isolation is a key factor; preparedness to de-escalate as soon as needed.

CONCLUSIONS

We evaluated our experience and analysed the weakness and strength of our first response to share it with the rest of the scientific community and colleagues worldwide, hoping to facilitate others who will face the same challenge or similar challenges in the future. Shared experience is the best way to learn and to avoid making the same mistakes.

A Selective Competitive Inhibitor of Aldehyde Dehydrogenase 1A3 Hinders Cancer Cell Growth, Invasiveness and Stemness In Vitro

Simple Summary

The aldehyde dehydrogenases enzymes (ALDHs) are promising drug targets in cancer therapy. ALDHs are members of an enzymatic superfamily composed by 19 isoforms involved in the oxidation of aldehydes, with a scavenger role. Among them, the isoform ALDH1A3 is a cancer biomarker since it is highly expressed in cancer stem cells characterized by a marked drug resistance and the capacity to promote self-renewal, clonogenic growth and tumour-initiating capacity. In this paper, we present the first highly potent and selective ALDH1A3 inhibitor able to induce cytotoxic effects and to reduce cell migration and stemness of ALDH1A3-positive cancer cells. We propose the targeting of the ALDH1A3 enzyme as a promising approach for improving the treatments outcomes of patients affected by ALDH1A3-positive cancers.

Abstract

Aldehyde dehydrogenase 1A3 (ALDH1A3) belongs to an enzymatic superfamily composed by 19 different isoforms, with a scavenger role, involved in the oxidation of a plethora of aldehydes to the respective carboxylic acids, through a NAD+-dependent reaction. Previous clinical studies highlighted the high expression of ALDH1A3 in cancer stem cells (CSCs) correlated to a higher risk of cancer relapses, chemoresistance and a poor clinical outcome. We report on the structural, biochemical, and cellular characterization of NR6, a new selective ALDH1A3 inhibitor derived from an already published ALDH non-selective inhibitor with cytotoxic activity on glioblastoma and colorectal cancer cells. Crystal structure, through X-Ray analysis, showed that NR6 binds a non-conserved tyrosine residue of ALDH1A3 which drives the selectivity towards this isoform, as supported by computational binding simulations. Moreover, NR6 shows anti-metastatic activity in wound healing and invasion assays and induces the downregulation of cancer stem cell markers. Overall, our work confirms the role of ALDH1A3 as an important target in glioblastoma and colorectal cells and propose NR6 as a promising molecule for future preclinical studies.

Prostaglandin E2 and Cancer: Insight into Tumor Progression and Immunity

The involvement of inflammation in cancer progression has been the subject of research for many years. Inflammatory milieu and immune response are associated with cancer progression and recurrence. In different types of tumors, growth and metastatic phenotype characterized by the epithelial mesenchymal transition (EMT) process, stemness, and angiogenesis, are increasingly associated with intrinsic or extrinsic inflammation. Among the inflammatory mediators, prostaglandin E2 (PGE2) supports epithelial tumor aggressiveness by several mechanisms, including growth promotion, escape from apoptosis, transactivation of tyrosine kinase growth factor receptors, and induction of angiogenesis. Moreover, PGE2 is an important player in the tumor microenvironment, where it suppresses antitumor immunity and regulates tumor immune evasion, leading to increased tumoral progression. In this review, we describe the current knowledge on the pro-tumoral activity of PGE2 focusing on its role in cancer progression and in the regulation of the tumor microenvironment.

Estimation of the right atrial pressure by ultrasound-assessed internal jugular vein in patients with advanced chronic heart failure

Background

In patients with systolic chronic heart failure (CHF) clinical signs of congestion cannot always be evident at clinical examination. Right atrial pressure (RAP) measured by right heart catheterization (RHC) is an accurate and reproducible marker of blood volume. A non-invasive accurate tool to identify CHF patients with normal RAP would be desirable to tailor therapy.

Purpose

To validate an ultrasound (US)-assessed internal jugular vein distensibility (JVD) ratio to identify patients with normal mean RAP (defined as 7 mmHg or less) measured by RHC.

Methods

We first identify the JVD ratio that allows the most accurate identification of patients with normal RAP in a prospective calibration cohort of 100 patients with systolic CHF. Then, we tested the JVD ratio threshold to identify patients with normal RAP in a validation cohort of 101 consecutive patients with systolic CHF. All patients had a left ventricular ejection fraction (LVEF)<50% and underwent RHC in the setting of heart transplant work-up. At the time of jugular vein puncture, we recorded the internal jugular vein diameter by conventional linear probes. JVD ratio was calculated as the ratio between maximum diameter (during Valsalva maneuver) and rest diameter of the vein (FIGURE). Finally, we assessed the prognostic value of the JVD ratio in the follow up of the first 100 patients.

Results

In the calibration cohort (mean age 53 years, 13% female; median LVEF 25%, 81% in NYHA class III/IV) we define the best threshold of the JVD ratio to identify patients with normal RAP that has 1.6 with an area under the curve (AUC of 0.74; p<0.0001). Based on this JVD ratio threshold we defined patients with low JVD ratio (≤1.6; n=58; median RAP 8 mmHg) and patients with high JVD ratio (>1.6, n=42; median RAP 4 mmHg). High JVD ratio and low JVD ratio groups had similar clinical and laboratory characteristics. In the validation cohort (mean age 55 years, 13% female; median LVEF 25%; 56% in NYHA class III/IV) using the previously defined 1.6 JVD ratio threshold, we identified 51 patients with low JVD ratio (median RAP 8 mmHg) and 50 patients with high JVD ratio (median RAP 3 mmHg; p<0.0001) The JVD ratio threshold has an accuracy to identify patients with a normal RAP with an AUC of 0.82 (p<0.0001); a predictive positive value of 0.94, negative predictive value of 0.51, specificity of 0.90, and sensitivity of 0.65. Finally, in the calibration cohort, the CHF patients with low JVD ratio (≤1.6) had a higher cumulative incidence of overall death, heart transplant, or left ventricular assist device (42.7% vs. 16.1% in the high JVD ratio group, p log-rank 0.006) at a median of 13-month follow-up.

Conclusions

We found that US-assessed JVD ratio is a convenient and accurate diagnostic tool to identify patients with advanced systolic CHF with normal vs. increased RAP. This tool could be tested in the ambulatory setting to modulate therapies, particularly diuretics and vasodilators.

Figure 1

Funding Acknowledgement

Type of funding source: None

SAT0231 MULTIDIRECTIONAL DYSFUNCTION OF THE IMMUNE RESPONSE IN SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

Systemic lupus erythematosus (SLE) is a multi-organ immune-mediated disease characterised by autoimmunity. Dysfunction in immune tolerance towards allergens and protection from infections has less been studied. Human leukocyte antigen (HLA) genotype affects the risk of developing SLE. Little is known on the role of HLA in shaping SLE phenotype.

Objectives:

To test for potential associations among active SLE, occurrence of infections and hypersensitivity reactions (HyR) at a clinical level and assess whether these events segregate with patients’ HLA-DRB1 typing.

Methods:

224 patients with SLE were prospectively followed up over the course of 1267 consecutive visits with a median interval of five months between each visit. HyR occurring within one month before or after each visit and occurrence of at least one infection leading to antimicrobial treatment and/or absence from work in the interval between each visit were recorded. Disease activity was estimated through the systemic lupus erythematosus disease activity index 2000 (SLEDAI-2K). Remission was surrogated by the Lupus Low Disease Activity State (LLDAS). Demographics and general disease features including a previous history of allergy were retrospectively assessed. HLA-DRB1 genotype was obtained from 188 patients. Data are expressed as median [interquartile range], unless otherwise specified.

Results:

Incidence rates for HyR and infections were 80/1000 person-years and 45/100 person-years. Culprit agents for HyR were drugs in 61% of cases, inhalants, food or other allergens in the remainder 42%. Most frequent sites for infections were the airways (55%), skin and mucosae (16%), the genital and/or urinary tracts (14%) and the gastrointestinal tract (7%). LLDAS was inversely associated with HyR (χ2=20.912; p<0.0001) or infections (χ2=8.234; p=0.005). patients with a recent HyR had a shorter disease duration (9 [2-15] vs 13 [8-22] years; p=0.006) and higher SLEDAI-2K scores (4 [3.5-11] vs 3 [2-4]; p<0.001) compared to patients without recent HyR. HyR were more frequently observed close to recent infections (χ2=15.509; p<0.0001). Patients with HLA-DRB1*11:01 (n=28/188) had more frequently a history of allergy than patients with other HLA-DRB1 genotypes (χ2=4.944; p=0.035). Among patients with at least four prospective visits, HLA-DRB1*11:01 carriers reported a recent infection more frequently (25% [13-40%] vs 14% [0-29%]; p=0.044) and HLA-DRB1*07:01 carriers less frequently (0% [0-17%] vs 18% [11-33%]; p=0.026) compared to patients with other HLA-DRB1 genotypes.

Conclusion:

These data suggest that immune dysfunction in SLE not only affects tolerance to self antigens but also antimicrobial and allergic responses and that genetically determined HLA-restricted mechanisms of antigen presentation might influence the shape of this dysfunctional immune response in patients with SLE.

References:

[1]Teruel M et al. Curr Opin Rheumatol, 2016

[2]Sequeira JF et al., Lupus, 1993

[3]Danza A et al, Lupus, 2013

[4]Park H et al., Allergy Asthma Immunol Res, 2012

[5]Quiralte J et al., J Allergy Clin Immunol, 1999

Disclosure of Interests:

Giuseppe Alvise Ramirez: None declared, Andrea Sorce: None declared, Benedetta Allegra Mazzi: None declared, Luca Moroni: None declared, Emanuel Della Torre: None declared, Giselda Colombo: None declared, Mona-Rita Yacoub: None declared, Enrica Bozzolo: None declared, Lorenzo Dagna Grant/research support from: The Unit of Immunology, Rheumatology, Allergy and Rare Diseases (UnIRAR) received unresctricted research/educational grants from Abbvie, Bristol-Myers Squibb, Celgene, Janssen, Merk Sharp & Dohme, Mundipharma Pharmaceuticals, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI., Consultant of: Prof Lorenzo Dagna received consultation honoraria from Abbvie, Amgen, Biogen, Bristol-Myers Squibb, Celltrion, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI., Angelo Manfredi: None declared

Progress in the Field of Aldehyde Dehydrogenase Inhibitors: Novel Imidazo[1,2-a]pyridines against the 1A Family

Members of the aldehyde dehydrogenase 1A family are commonly acknowledged as hallmarks of cancer stem cells, and their overexpression is significantly associated with poor prognosis in different types of malignancies. Accordingly, treatments targeting these enzymes may represent a successful strategy to fight cancer. In this work we describe a novel series of imidazo[1,2-a]pyridines, designed as aldehyde dehydrogenase inhibitors by means of a structure-based optimization of a previously developed lead. The novel compounds were evaluated in vitro for their activity and selectivity against the three isoforms of the ALDH1A family and investigated through crystallization and modeling studies for their ability to interact with the catalytic site of the 1A3 isoform. Compound 3f emerged as the first in class submicromolar competitive inhibitor of the target enzyme.

Recent Advances in NAMPT Inhibitors: A Novel Immunotherapic Strategy

Nicotinamide adenine dinucleotide (NAD) is a cofactor of many enzymatic reactions as well as being a substrate for a number of NAD-consuming enzymes (e.g., PARPS, sirtuins, etc). NAD can be synthesized de novo starting from tryptophan, nicotinamide, nicotinic acid, or nicotinamide riboside from the diet. On the other hand, the nicotinamide that is liberated by NAD-consuming enzymes can be salvaged to re-form NAD. In this former instance, nicotinamide phosphoribosyltransferase (NAMPT) is the bottleneck enzyme. In the many cells in which the salvage pathway is predominant, NAMPT, therefore, represents an important controller of intracellular NAD concentrations, and as a consequence of energy metabolism. It is, therefore, not surprising that NAMPT is over expressed by tumoral cells, which take advantage from this to sustain growth rate and tumor progression. This has led to the initiation of numerous medicinal chemistry programs to develop NAMPT inhibitors in the context of oncology. More recently, however, it has been shown that NAMPT inhibitors do not solely target the tumor but also have an effect on the immune system. To add complexity, this enzyme can also be secreted by cells, and in the extracellular space it acts as a cytokine mainly through the activation of Toll like Receptor 4 (TLR4), although it has not been clarified yet if this is the only receptor responsible for its actions. While specific small molecules have been developed only against the intracellular form of NAMPT, growing evidences sustain the possibility to target the extracellular form. In this contribution, the most recent evidences on the medicinal chemistry of NAMPT will be reviewed, together with the key elements that sustain the hypothesis of NAMPT targeting and the drawbacks so far encountered.

Neutralization of extracellular NAMPT (nicotinamide phosphoribosyltransferase) ameliorates experimental murine colitis

Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) is increased in inflammatory bowel disease (IBD) patients, and its serum levels correlate with a worse prognosis. In the present manuscript, we show that eNAMPT serum levels are increased in IBD patients that fail to respond to anti-TNFα therapy (infliximab or adalimumab) and that its levels drop in patients that are responsive to these therapies, with values comparable with healthy subjects. Furthermore, eNAMPT administration in dinitrobenzene sulfonic acid (DNBS)-treated mice exacerbates the symptoms of colitis, suggesting a causative role of this protein in IBD. To determine the druggability of this cytokine, we developed a novel monoclonal antibody (C269) that neutralizes in vitro the cytokine-like action of eNAMPT and that reduces its serum levels in rodents. Of note, this newly generated antibody is able to significantly reduce acute and chronic colitis in both DNBS- and dextran sulfate sodium (DSS)-induced colitis. Importantly, C269 ameliorates the symptoms by reducing pro-inflammatory cytokines. Specifically, in the lamina propria, a reduced number of inflammatory monocytes, neutrophils, Th1, and cytotoxic T lymphocytes are found upon C269 treatment. Our data demonstrate that eNAMPT participates in IBD and, more importantly, that eNAMPT-neutralizing antibodies are endowed with a therapeutic potential in IBD. KEY MESSAGES: What are the new findings? Higher serum eNAMPT levels in IBD patients might decrease response to anti-TNF therapy. The cytokine-like activity of eNAMPT may be neutralized with a monoclonal antibody. Neutralization of eNAMPT ameliorates acute and chronic experimental colitis. Neutralization of eNAMPT limits the expression of IBD inflammatory signature. Neutralization of eNAMPT impairs immune cell infiltration in lamina propria.

Discovery of Highly Potent Benzimidazole Derivatives as Indoleamine 2,3-Dioxygenase-1 (IDO1) Inhibitors: From Structure-Based Virtual Screening to in Vivo Pharmacodynamic Activity

In this study, a successful medicinal chemistry campaign that exploited virtual, biophysical, and biological investigations led to the identification of a novel class of IDO1 inhibitors based on a benzimidazole substructure. This family of compounds is endowed with an extensive bonding network in the protein active site, including the interaction with pocket C, a region not commonly exploited by previously reported IDO1 inhibitors. The tight packing of selected compounds within the enzyme contributes to the strong binding interaction with IDO1, to the inhibitory potency at the low nanomolar level in several tumoral settings, and to the selectivity toward IDO1 over TDO and CYPs. Notably, a significant reduction of L-Kyn levels in plasma, together with a potent effect on abrogating immunosuppressive properties of MDSC-like cells isolated from patients affected by pancreatic ductal adenocarcinoma, was observed, pointing to this class of molecules as a valuable template for boosting the antitumor immune system.

The Cytokine Nicotinamide Phosphoribosyltransferase (eNAMPT; PBEF; Visfatin) Acts as a Natural Antagonist of C-C Chemokine Receptor Type 5 (CCR5)

(1) Background: Extracellular nicotinamide phosphoribosyltrasferase (eNAMPT) is released by various cell types with pro-tumoral and pro-inflammatory properties. In cancer, eNAMPT regulates tumor growth through the activation of intracellular pathways, suggesting that it acts through a putative receptor, although its nature is still elusive. It has been shown, using surface plasma resonance, that eNAMPT binds to the C-C chemokine receptor type 5 (CCR5), although the physiological meaning of this finding is unknown. The aim of the present work was to characterize the pharmacodynamics of eNAMPT on CCR5. (2) Methods: HeLa CCR5-overexpressing stable cell line and B16 melanoma cells were used. We focused on some phenotypic effects of CCR5 activation, such as calcium release and migration, to evaluate eNAMPT actions on this receptor. (3) Results: eNAMPT did not induce ERK activation or cytosolic Ca²⁺-rises alone. Furthermore, eNAMPT prevents CCR5 internalization mediated by Rantes. eNAMPT pretreatment inhibits CCR5-mediated PKC activation and Rantes-dependent calcium signaling. The effect of eNAMPT on CCR5 was specific, as the responses to ATP and carbachol were unaffected. This was strengthened by the observation that eNAMPT inhibited Rantes-induced Ca²⁺-rises and Rantes-induced migration in a melanoma cell line. (4) Conclusions: Our work shows that eNAMPT binds to CCR5 and acts as a natural antagonist of this receptor.

A nicotinamide phosphoribosyltransferase-GAPDH interaction sustains the stress-induced NMN/NAD+ salvage pathway in the nucleus

All cells require sustained intracellular energy flux, which is driven by redox chemistry at the subcellular level. NAD⁺, its phosphorylated variant NAD(P)⁺, and its reduced forms NAD(P)/NAD(P)H are all redox cofactors with key roles in energy metabolism and are substrates for several NAD-consuming enzymes (e.g. poly(ADP-ribose) polymerases, sirtuins, and others). The nicotinamide salvage pathway, constituted by nicotinamide mononucleotide adenylyltransferase (NMNAT) and nicotinamide phosphoribosyltransferase (NAMPT), mainly replenishes NAD⁺ in eukaryotes. However, unlike NMNAT1, NAMPT is not known to be a nuclear protein, prompting the question of how the nuclear NAD⁺ pool is maintained and how it is replenished upon NAD⁺ consumption. In the present work, using human and murine cells; immunoprecipitation, pulldown, and surface plasmon resonance assays; and immunofluorescence, small-angle X-ray scattering, and MS-based analyses, we report that GAPDH and NAMPT form a stable complex that is essential for nuclear translocation of NAMPT. This translocation furnishes NMN to replenish NAD⁺ to compensate for the activation of NAD-consuming enzymes by stressful stimuli induced by exposure to H₂O₂ or S-nitrosoglutathione and DNA damage inducers. These results indicate that by forming a complex with GAPDH, NAMPT can translocate to the nucleus and thereby sustain the stress-induced NMN/NAD⁺ salvage pathway.

Identification of potent triazolylpyridine nicotinamide phosphoribosyltransferase (NAMPT) inhibitors bearing a 1,2,3-triazole tail group

The enzyme nicotinamide phosphoribosyltransferase is both a key intracellular enzyme for NAD biosynthesis (iNAMPT) and an extracellular cytokine (eNAMPT). The relationship between this latter role and the catalytic activity of the enzyme is at present unknown. With the intent of discovering inhibitors specifically able to target eNAMPT, we increased the polarity of MV78 (EC₅₀ = 5.8 nM; IC₅₀ = 3.1 nM), a NAMPT inhibitor previously discovered by us. The replacement of a phenyl ring with a 1,2,3-triazole bearing a protonable N,N-dialkyl methanamine group gave a series of molecules which maintained the inhibition of the enzymatic activity but were unable to cross the plasma membrane and affect cell viability in vitro. Compounds 30b and 30f can therefore be considered as the first experimental/pharmacological tools for scientists that wish to understand the role of the catalytic activity of eNAMPT. Serendipitously, we also discovered a compound (25) which, notwithstanding its high polarity, was able to cross the plasma membrane being cytotoxic, a potent NAMPT inhibitor and effective in reducing growth of triple negative mammary carcinoma in mice. In our hands, 25 lacked retinal and cardiac toxicity, although we observed a lesser toxicity of NAMPT inhibitors in general compared to other reports.

MicroRNAs in Female Malignancies

MicroRNAs (miRNAs) are endogenous 22-nucleotide RNAs that can play a fundamental regulatory role in the gene expression of various organisms. Current research suggests that miRNAs can assume pivotal roles in carcinogenesis. In this article, through bioinformatics mining and computational analysis, we determine a single miRNA commonly involved in the development of breast, cervical, endometrial, ovarian, and vulvar cancer, whereas we underline the existence of 7 more miRNAs common in all examined malignancies with the exception of vulvar cancer. Furthermore, we identify their target genes and encoded biological functions. We also analyze common biological processes on which all of the identified miRNAs act and we suggest a potential mechanism of action. In addition, we analyze exclusive miRNAs among the examined malignancies and bioinformatically explore their functionality. Collectively, our data can be employed in in vitro assays as a stepping stone in the identification of a universal machinery that is derailed in female malignancies, whereas exclusive miRNAs may be employed as putative targets for future chemotherapeutic agents or cancer-specific biomarkers.

NAMPT: A pleiotropic modulator of monocytes and macrophages

Nicotinamide phosphoribosyltransferase (NAMPT) is the bottleneck enzyme of the NAD salvage pathway and thereby is a controller of intracellular NAD concentrations. It has been long known that the same enzyme can be secreted by a number of cell types and acts as a cytokine, although its receptor is at present unknown. Investigational compounds have been developed that target the enzymatic activity as well as the extracellular action (i.e. neutralizing antibodies). The present contribution reviews the evidence that links intracellular and extracellular NAMPT to myeloid biology, for example governing monocyte/macrophage differentiation, polarization and migration. Furthermore, it reviews the evidence that links this protein to some disorders in which myeloid cells have a prominent role (acute infarct, inflammatory bowel disease, acute lung injury and rheumatoid arthritis) and the data showing that inhibition of the enzymatic activity or the neutralization of the cytokine is beneficial in preclinical animal models.

MOv18 Monoclonal Antibody in Diagnostic Applications: Capability to Recognize the Histotype of the Original Tumor

Cells from 52 ascitic fluids and 28 abdominopelvic cavity washings, obtained from 46 ovarian cancer patients, 17 patients bearing malignancies of non ovarian sites and 17 patients with non-malignant ovarian diseases, were tested using 2 methods: traditional cytology and monoclonal antibody immunofluorescence. The immunologic test using the MOv18 MAb, raised against ovarian carcinoma, revealed immunoreactive cells in 83 % of the 36 cytologically positive fluids and in one of the 8 negative fluids from ovarian carcinoma patients and in 18% of the 17 fluids from patients with non-malignant ovarian disease. Forty six cytologically positive ascitic fluids from malignant patients were analyzed in order to evaluate the ability of this MAb to identify the histotype of metastatic cells. Ninety-three percent (26/28) of the effusions from non-mucinous ovarian carcinomas contained MOv18-positive cells, whereas no reactive cells were found in cytologically malignant fluids from patients with ovarian tumors of other oncotypes or with carcinomas of non-ovarian origin. The MOv18 reagent, used as an adjuvant in cytological analysis, can help in the identification of the histotype of metastatic cells of unknown origin.

A Case of Carcinoid of Meckel's Diverticulum Associated with Gastric Adenocarcinoma

Meckel's diverticulum is an uncommon gastrointestinal congenital anomaly that occurs in 1-3% of the population. It is sometimes associated with complications related to the presence of ectopic tissue (obstruction, ulceration, hemmorhage, inflammation, perforation, fistula and tumors). Neoplastic degeneration of Meckel's diverticulum mucosa is rare, developing in only 1-5% of all diverticula, usually asymptomatic and occasionally discovered. Disease is metastatic, usually to the liver, in 25% of cases. We report a case of asymptomatic unsuspected carcinoid of Meckel's diverticulum with ileal, hepatic and mesenteric metastasis discovered during a gastrectomy performed for gastric adenocarcinoma. The patient underwent ileal and Meckel diverticulum resection, excision of mesenterial metastasis and liver bisegmentectomy. Furthermore, total gastrectomy with esophago-jejunal anastomosis was performed. After an 18-month follow-up period, the patient is alive and disease free. Owing to possible neoplastic degeneration, Meckel's diverticulum should be resected when occasionally discovered. In the presence of a carcinoid tumor, even if associated with metastatic disease, extended resection is recommended.

Postoperative complications in cirrhotic pediatric deceased donor liver transplantation: Focus on transfusion therapy

Intraoperative transfusions seem associated with patient death and graft failure after PLTx. A retrospective analysis of recipients' and donors' characteristics and transplantation data in a cohort of patients undergoing PLTx from 2002 to 2009 at the Bergamo General Hospital was performed. A two-stage hierarchical Cox proportional hazard regression with forward stepwise selection was used to identify the main risk factors for major complications. In addition, propensity score analysis was used to adjust risk estimates for possible selection biases in the use of blood products. Over the 12-year period, 232 pediatric cirrhotic patients underwent PLTx. One-year patient and graft survival rates were 92.3% and 83.7%, respectively. The Kaplan-Meier shows that the main decrease in both graft and patient survival occurs during the first months post-transplantation. At the same time, it appears that most of the complications occur during the first month post-transplantation. One-month and 1-year patient complication-free survival rates were 24.8% and 12.1%, respectively. Our study shows that intraoperative red blood cells and platelet transfusions are independent risk factors for developing one or more major complications in the first year after PLTx. Decreasing major complications will improve the health status and overall long-term patient survival after pediatric PLTx.

Illness perception, mood and coping strategies in allergic rhinitis: are there differences among ARIA classes of severity?

BACKGROUND

This study was designed to assess if illness perception, mood state and coping strategies differ according to allergic rhinitis (AR) persistence and severity.

METHODS

Illness perception, mood profiles, coping behaviors and rhinitis symptoms were assessed by means of validated tools inpatients classified according to the Allergic Rhinitis and Its Impact on Asthma (ARIA) guidelines.

RESULTS

Two hundred and thirty-one patients underwent data analysis. No difference in age, sex, socio-economic status, smoking habits was detected comparing patients according to AR severity, duration or 4 ARIA classes. Patients with intermittent AR reported higher scores than those with persistent AR in confusion-bewilderment of Profile of Mood States (POMS); patients with moderate/severe rhinitis had significantly higher scores than those with mild rhinitis in TSSS, Identity and Consequences. No differences were detected in all assessed outcomes in the 4 ARIA classes.

CONCLUSIONS

The patient's perspective about AR is independent of persistence and severity of symptoms. This may explain why AR remains under-diagnosed and under-treated, even in its most severe forms. Self-management plans should consider the patient's perspective.

Shrimp Allergy: Analysis of Commercially Available Extracts for In Vivo Diagnosis

BACKGROUND AND OBJECTIVE

Skin prick testing (SPT) with commercial extracts is the first step in the diagnosis of shrimp allergy, although its clinical efficiency is unknown. Objective: To analyze the clinical usefulness of all commercial crustacean extracts available for SPT in Italy.

METHODS

We performed a multicenter study of 157 shrimp-allergic patients who underwent SPT with 5 commercial crustacean extracts and with house dust mite (HDM) extract. Commercial extracts were analyzed using SDS-PAGE and compared with a freshly prepared in-house shrimp extract. IgE to Pen a 1/Pen m 1, Pen m 2, and Pen m 4 was determined, and immunoblot analysis was performed on a large number of sera.

RESULTS

The skin reactions caused by commercial crustacean extracts were extremely heterogeneous, resulting in 32 clinical profiles, with marked differences in protein content and missing proteins at molecular weights corresponding to those of major shrimp allergens. Only strong Pen a 1/Pen m 1 reactors reacted to both HDM and all 5 commercial extracts in SPT. Most patients, including those who were tropomyosin-negative, reacted to HDM. Patients reacted to a large and variable array of proteins, and IgE reactivity was common at high molecular weights (>50 kDa).

CONCLUSIONS

The in vivo diagnosis of shrimp allergy must continue to be based on SPT with fresh material. Shrimp-allergic patients frequently react to a number of ill-defined high-molecular-weight allergens, thus leaving currently available materials for component-resolved diagnosis largely insufficient. Mites and crustaceans probably share several allergens other than tropomyosin.

Patients with breakthrough reactions to iodinated contrast media have low incidence of positive skin tests

BACKGROUND

The term "breakthrough reactions" designates repeated hypersensitivity reactions to iodinated contrast media (ICM) despite premedication with glucocorticoids and antihistamines. We aimed to retrospectively evaluate the rate of positive skin test (STs) in our cohort of patients with previous breakthrough reactions to different ICMs.

METHODS

A series of 35 patients, who experienced at least one breakthrough reaction to ICM and who underwent STs within 6 months from the reaction were studied, and results were compared to a control group of patients with a first hypersensitivity reaction occurred without premedication. Skin prick tests (SPT), intradermal tests (IDT) and patch tests (PT) at different dilutions, with a set of three to four ICM were performed.

RESULTS

Of the 35 patients with prior breakthrough reactions, 57% had an immediate reaction (IR) and 43% had a non-immediate reaction (NIR). Patients who experienced the first hypersensitivity IR or NIR, later had one or more breakthrough IR or NIR, respectively. Overall, 29% (10/35) of patients with prior breakthrough reactions resulted positive to STs compared to 57% (16/28) of the control group (p < 0.05). No significant difference in allergy history, age, sex, other clinical / demographic features nor chronic use of ACE-inhibitor, beta-blockers or NSAIDs was observed.

CONCLUSION

This preliminary finding suggests that patients with prior breakthrough reactions have significantly lower immunologically proven ICM reactions (positive STs) if compared to non-breakthrough patients. According to that, a considerable number of breakthrough reactions seems to be non-allergic hypersensitivity reactions or reactions which could be mostly prevented by a proper, well-timed skin testing. Larger prospective studies are needed to confirm these results, with a more careful analysis of patients' risk factors, a laboratory assessment that includes an in vitro allergy diagnostics, and hopefully a drug provocation test for selected cases.

Caracterização bioquímica e molecular de Cryptococcus spp. isolados de excretas ambientais de pombos (Columba livia domestica)

Os pombos possuem uma rica diversidade de microrganismo, entre eles fungos sapróbios, como do gênero Cryptococcus, que podem atuar como agentes patogênicos para o homem e animais. Objetivou-se o isolamento, a caracterização bioquímica e a molecular de amostras de Cryptococcus spp. de excretas ambientas de pombos. Foram colhidas 100 amostras ambientais de pontos equidistantes e representativos da área da cidade de Araçatuba, São Paulo. As amostras foram rasteladas do solo de vias públicas, armazenadas em frasco coletor e encaminhadas para o Laboratório de Bacteriologia e Micologia da FMVA, onde foram processadas e cultivadas em duplicata, em placas de Petri contendo ágar Sabouraud dextrose a 4% e Niger. Em seguida, foram incubadas à temperatura ambiente e a 30ºC, respectivamente, por um período não inferior a 15 dias. Após a observação diária, as colônias sugestivas para levedura foram reisoladas em ágar Niger e submetidas a testes bioquímicos para posterior caracterização molecular pela técnica da PCR. Como resultado, a caracterização bioquímica e a molecular isolaram 32 colônias leveduriformes, sendo 8% dos cultivos positivos para Cryptococcus neoformans var. neoformans, 17% para Rhodotorula rubidae e 7% Candida albicans. Pelo exposto, concluiu-se que excretas ambientais de pombos constituem um microfoco para Cryptococcus neoformans var. neoformans e outras leveduras com potencial patogênico, representando um risco à saúde pública, sendo necessárias medidas preventivas, como a higienização com a correta remoção das excretas, a fim de minimizar os riscos de exposição ambiental.