Unconventional p65/p52 NF-κB module regulates key tumor microenvironment-related genes in breast tumor-associated macrophages (TAMs).

The complex heterogeneity of tumor microenvironment (TME) of triple-negative breast cancer (TNBC) presents a significant obstacle to cytotoxic immune response and successful treatment, building up one of the most hostile oncological phenotypes. Among the most abundant TME components, tumor-associated macrophages (TAMs) have pivotal pro-tumoral functions, involving discordant roles for the nuclear factor kappa-B (NF-κB) transcription factors and directing to higher levels of pathway complexity. In both resting macrophages and TAMs, we recently revealed the existence of the uncharacterized NF-κB p65/p52 dimer. In the present study, we demonstrated its enhanced active nuclear localization in TAMs and validated selected immune target genes as directly regulated by dimer binding on DNA sequences. We demonstrated by ChIP-qPCR that p65/p52 enrichment on HSPG2 and CSF-1 regulatory regions is strictly dependent on macrophage polarization and tumor environment. Our data provide novel mechanisms of transcriptional regulation in TAMs, orchestrated by the varied and dynamic nature of NF-κB combinations, which needs to be considered when targeting this pathway in cancer therapies. Our results offer p65/p52, together with identified regulatory regions on genes impacting macrophage behavior and tumor biology, as novel molecular targets for TNBC, aimed at modulating TAMs functions towards anti-tumoral phenotypes and thus improving cancer treatment outcomes.

Exposure to serum from exclusive heated tobacco product smokers induces mTOR activation and fibrotic features in human cardiac stromal cells.

Chronic smokers have increased risk of fibrosis-related atrial fibrillation. The use of heated-tobacco products (HTPs) is increasing exponentially, and their health impact is still uncertain. We aim to investigate the effects of circulating molecules in exclusive HTP chronic smokers on the fibrotic behavior of human atrial cardiac stromal cells (CSCs). CSCs were isolated from atrial tissue of elective cardiac surgery patients, and exposed to serum lots from young healthy subjects, stratified in exclusive HTP smokers, tobacco combustion cigarette (TCC) smokers, or nonsmokers (NS). CSCs treated with TCC serum displayed impaired migration and increased expression of pro-inflammatory cytokines. Cells cultured with HTP serum showed increased levels of pro-fibrotic markers, and reduced expression of connexin-43. Both TCC and HTP sera increased collagen release and reduced secretion of angiogenic protective factors from CSCs, compared to NS serum. Paracrine support to tube-formation by endothelial cells and to viability of cardiomyocytes was significantly impaired. Treatment with sera of both smokers groups impaired H2O2/NO release balance by CSCs and reduced early phosphorylation of several pathways compared to NS serum, leading to mTOR activation. Cotreatment with rapamycin was able to reduce mTOR phosphorylation and differentiation into aSMA-positive myofibroblasts in CSCs exposed to TCC and HTP sera. In conclusion, the circulating molecules in the serum of chronic exclusive HTP smokers induce fibrotic behavior in CSCs through activation of the mTOR pathway, and reduce their beneficial paracrine effects on endothelial cells and cardiomyocytes. These results point to a potential risk for cardiac fibrosis in chronic HTP users.

Early Impairment of Paracrine and Phenotypic Features in Resident Cardiac Mesenchymal Stromal Cells after Thoracic Radiotherapy.

Radiotherapy-induced cardiac toxicity and consequent diseases still represent potential severe late complications for many cancer survivors who undergo therapeutic thoracic irradiation. We aimed to assess the phenotypic and paracrine features of resident cardiac mesenchymal stromal cells (CMSCs) at early follow-up after the end of thoracic irradiation of the heart as an early sign and/or mechanism of cardiac toxicity anticipating late organ dysfunction. Resident CMSCs were isolated from a rat model of fractionated thoracic irradiation with accurate and clinically relevant heart dosimetry that developed delayed dose-dependent cardiac dysfunction after 1 year. Cells were isolated 6 and 12 weeks after the end of radiotherapy and fully characterized at the transcriptional, paracrine, and functional levels. CMSCs displayed several altered features in a dose- and time-dependent trend, with the most impaired characteristics observed in those exposed in situ to the highest radiation dose with time. In particular, altered features included impaired cell migration and 3D growth and a and significant association of transcriptomic data with GO terms related to altered cytokine and growth factor signaling. Indeed, the altered paracrine profile of CMSCs derived from the group at the highest dose at the 12-week follow-up gave significantly reduced angiogenic support to endothelial cells and polarized macrophages toward a pro-inflammatory profile. Data collected in a clinically relevant rat model of heart irradiation simulating thoracic radiotherapy suggest that early paracrine and transcriptional alterations of the cardiac stroma may represent a dose- and time-dependent biological substrate for the delayed cardiac dysfunction phenotype observed in vivo.

Effect of traditional or heat-not-burn cigarette smoking on circulating miRNAs in healthy subjects.

BACKGROUND: Traditional combustion cigarette (TCC) smoking is an established risk factor for several types of cancer and cardiovascular diseases. Circulating microRNAs (miRNAs) represent key molecules mediating pathogenetic mechanisms, and potential biomarkers for personalized risk assessment. TCC smoking globally changes the profile of circulating miRNAs. The use of heat-not-burn cigarettes (HNBCs) as alternative smoking devices is rising exponentially worldwide, and the circulating miRNA profile of chronic HNBC smokers is unknown. We aimed at defining the circulating miRNA profile of chronic exclusive HNBC smokers, and identifying potentially pathogenetic signatures. METHODS: Serum samples were obtained from 60 healthy young subjects, stratified in chronic HNBC smokers, TCC smokers and nonsmokers (20 subjects each). Three pooled samples per group were used for small RNA sequencing, and the fourth subgroup constituted the validation set. RESULTS: Differential expression analysis revealed 108 differentially expressed miRNAs; 72 exclusively in TCC, 10 exclusively in HNBC and 26 in both smoker groups. KEGG pathway analysis on target genes of the commonly modulated miRNAs returned cancer and cardiovascular disease associated pathways. Stringent abundance and fold-change criteria nailed down our functional bioinformatic analyses to a network where miR-25-3p and miR-221-3p are main hubs. CONCLUSION: Our results define for the first time the miRNA profile in the serum of exclusive chronic HNBC smokers and suggest a significant impact of HNBCs on circulating miRNAs.

Metabolomic NMR analysis and organoleptic perceptions of pomegranate wines: Influence of cultivar and yeast on the product characteristics.

Pomegranate (Punica granatum L.) fruits are a historical agricultural product of the Mediterranean basin that became increasingly popular in the latest years for being rich in antioxidants and other micronutrients, and are extensively commercialized as fruits, juice, jams and, in some Eastern countries, as a fermented alcoholic beverage. In this work, four different pomegranate wines specifically designed using combinations of two cultivars (Jolly Red and Smith) and two yeast starters with markedly different characteristics (Saccharomyces cerevisiae Clos and Saccharomyces cerevisiae ex-bayanus EC1118) were analyzed. The chemical characterization of the wines together with the originating unfermented juices was performed by 1H NMR spectroscopy metabolomic analysis. The full spectra were used for unsupervised and supervised statistical multivariate analysis (MVA), namely Principal Component Analysis (PCA), Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA), and sparse PCA (SPCA). The MVA of the wines showed a clear discrimination between the cultivars, and a smaller, yet significant, discrimination between the yeasts used. In particular, a higher content of citrate and gallate was observed for the Smith cv. and, on the contrary, a statistically significant higher content of fructose, malate, glycerol, 2,3 butanediol, trigonelline, aromatic amino acids and 4-hydrophenylacetate was observed in Jolly Red pomegranate wines samples. Significant interaction among the pomegranate cultivar and the fermenting yeast was also observed. Sensorial analysis was performed by a panel of testing experts. MVA of tasting data showed that the cultivar significantly affected the organoleptic parameters considered, while the yeast had a minor impact. Correlation analysis between NMR-detected metabolites and organoleptic descriptors identified several potential sensorially-active molecules as those significantly impacting the characteristics of the pomegranate wines.

Modified Risk Tobacco Products and Cardiovascular Repair: Still Very "Smoky".

Smoking habits represent a cardiovascular risk factor with a tremendous impact on health. Other than damaging differentiated and functional cells of the cardiovascular system, they also negatively affect reparative mechanisms, such as those involved in cardiac fibrosis and in endothelial progenitor cell (EPC) activation. In recent years, alternative smoking devices, dubbed modified tobacco risk products (MRPs), have been introduced, but their precise impact on human health is still under evaluation. Also, they have not been characterized yet about the possible negative effects on cardiovascular reparative and regenerative cells, such as EPCs or pluripotent stem cells. In this perspective, we critically review the still scarce available data on the effects of MRPs on molecular and cellular mechanisms of cardiovascular repair and regeneration.

A Review of Therapeutic Strategies against Cardiac Fibrosis: From Classical Pharmacology to Novel Molecular, Epigenetic, and Biotechnological Approaches.

Cardiovascular diseases are the first cause of death worldwide, with a heavy social and economic impact. They include a wide range of pathological conditions, among which cardiac fibrosis represents a common pathogenetic hallmark. The fibrotic process is driven by cardiac mesenchymal stromal cells, namely fibroblasts, which become activated, proliferate, and differentiate into myofibroblasts in response to several stimuli, in the end secreting extracellular matrix proteins, and mediating cardiac tissue remodelling and stiffening. A specific therapy for the exclusive treatment of cardiac fibrosis is still lacking. Given the growing quest for reducing the burden of cardiovascular diseases, there is increasing interest in the search for new effective anti-fibrotic therapies. In this review, we will briefly summarize the limited pharmacological therapies known to act, at least in part, against cardiac fibrosis. Then we will present novel potential active molecules, molecular targets, and biotechnological approaches emerged in the last decade, as possible future therapeutic strategies for cardiac fibrosis, with a specific focus on targeting fibroblast activation and function.

Multicellular 3D Models for the Study of Cardiac Fibrosis.

Ex vivo modelling systems for cardiovascular research are becoming increasingly important in reducing lab animal use and boosting personalized medicine approaches. Integrating multiple cell types in complex setups adds a higher level of significance to the models, simulating the intricate intercellular communication of the microenvironment in vivo. Cardiac fibrosis represents a key pathogenetic step in multiple cardiovascular diseases, such as ischemic and diabetic cardiomyopathies. Indeed, allowing inter-cellular interactions between cardiac stromal cells, endothelial cells, cardiomyocytes, and/or immune cells in dedicated systems could make ex vivo models of cardiac fibrosis even more relevant. Moreover, culture systems with 3D architectures further enrich the physiological significance of such in vitro models. In this review, we provide a summary of the multicellular 3D models for the study of cardiac fibrosis described in the literature, such as spontaneous microtissues, bioprinted constructs, engineered tissues, and organs-on-chip, discussing their advantages and limitations. Important discoveries on the physiopathology of cardiac fibrosis, as well as the screening of novel potential therapeutic molecules, have been reported thanks to these systems. Future developments will certainly increase their translational impact for understanding and modulating mechanisms of cardiac fibrosis even further.

Human platelet lysate-derived extracellular vesicles enhance angiogenesis through miR-126.

OBJECTIVES: Extracellular vesicles (EVs) are key biological mediators of several physiological functions within the cell microenvironment. Platelets are the most abundant source of EVs in the blood. Similarly, platelet lysate (PL), the best platelet derivative and angiogenic performer for regenerative purposes, is enriched of EVs, but their role is still too poorly discovered to be suitably exploited. Here, we explored the contribution of the EVs in PL, by investigating the angiogenic features extrapolated from that possessed by PL. METHODS: We tested angiogenic ability and molecular cargo in 3D bioprinted models and by RNA sequencing analysis of PL-derived EVs. RESULTS: A subset of small vesicles is highly represented in PL. The EVs do not retain aggregation ability, preserving a low redox state in human umbilical vein endothelial cells (HUVECs) and increasing the angiogenic tubularly-like structures in 3D endothelial bioprinted constructs. EVs resembled the miRNome profile of PL, mainly enriched with small RNAs and a high amount of miR-126, the most abundant angiogenic miRNA in platelets. The transfer of miR-126 by EVs in HUVEC after the in vitro inhibition of the endogenous form, restored angiogenesis, without involving VEGF as a downstream target in this system. CONCLUSION: PL is a biological source of available EVs with angiogenic effects involving a miRNAs-based cargo. These properties can be exploited for targeted molecular/biological manipulation of PL, by potentially developing a product exclusively manufactured of EVs.

Unusual Association of NF-κB Components in Tumor-Associated Macrophages (TAMs) Promotes HSPG2-Mediated Immune-Escaping Mechanism in Breast Cancer.

The cellular heterogeneity of the tumor environment of breast cancer (BC) is extremely complex and includes different actors such as neoplastic, stromal, and immunosuppressive cells, which contribute to the chemical and mechanical modification of the environment surrounding the tumor-exasperating immune-escaping mechanisms. In addition to molecular signals that make the tumor microenvironment (TME) unacceptable for the penetrance of the immune system, the physical properties of tumoral extracellular matrix (tECM) also have carved out a fundamental role in the processes of the protection of the tumor niche. Tumor-associated macrophages (TAMs), with an M2 immunosuppressive phenotype, are important determinants for the establishment of a tumor phenotype excluded from T cells. NF-κB transcription factors orchestrate innate immunity and represent the common thread between inflammation and cancer. Many studies have focused on canonical activation of NF-κB; however, activation of non-canonical signaling predicts poor survival and resistance to therapy. In this scenario, we demonstrated the existence of an unusual association of NF-κB components in TAMs that determines the deposition of HSPG2 that affects the stiffness of tECM. These results highlight a new mechanism counterbalanced between physical factors and a new perspective of mechano-pathology to be targeted to counteract immune evasion in BC.

Reduction of Cardiac Fibrosis by Interference With YAP-Dependent Transactivation.

BACKGROUND: Conversion of cardiac stromal cells into myofibroblasts is typically associated with hypoxia conditions, metabolic insults, and/or inflammation, all of which are predisposing factors to cardiac fibrosis and heart failure. We hypothesized that this conversion could be also mediated by response of these cells to mechanical cues through activation of the Hippo transcriptional pathway. The objective of the present study was to assess the role of cellular/nuclear straining forces acting in myofibroblast differentiation of cardiac stromal cells under the control of YAP (yes-associated protein) transcription factor and to validate this finding using a pharmacological agent that interferes with the interactions of the YAP/TAZ (transcriptional coactivator with PDZ-binding motif) complex with their cognate transcription factors TEADs (TEA domain transcription factors), under high-strain and profibrotic stimulation. METHODS: We employed high content imaging, 2-dimensional/3-dimensional culture, atomic force microscopy mapping, and molecular methods to prove the role of cell/nuclear straining in YAP-dependent fibrotic programming in a mouse model of ischemia-dependent cardiac fibrosis and in human-derived primitive cardiac stromal cells. We also tested treatment of cells with Verteporfin, a drug known to prevent the association of the YAP/TAZ complex with their cognate transcription factors TEADs. RESULTS: Our experiments suggested that pharmacologically targeting the YAP-dependent pathway overrides the profibrotic activation of cardiac stromal cells by mechanical cues in vitro, and that this occurs even in the presence of profibrotic signaling mediated by TGF-ß1 (transforming growth factor beta-1). In vivo administration of Verteporfin in mice with permanent cardiac ischemia reduced significantly fibrosis and morphometric remodeling but did not improve cardiac performance. CONCLUSIONS: Our study indicates that preventing molecular translation of mechanical cues in cardiac stromal cells reduces the impact of cardiac maladaptive remodeling with a positive effect on fibrosis.

Progressive stages of dysmetabolism are associated with impaired biological features of human cardiac stromal cells mediated by the oxidative state and autophagy.

Cardiac stromal cells (CSCs) are the main players in fibrosis. Dysmetabolic conditions (metabolic syndrome-MetS, and type 2 diabetes mellitus-DM2) are strong pathogenetic contributors to cardiac fibrosis. Moreover, modulation of the oxidative state (OxSt) and autophagy is a fundamental function affecting the fibrotic commitment of CSCs, that are adversely modulated in MetS/DM2. We aimed to characterize CSCs from dysmetabolic patients, and to obtain a beneficial phenotypic setback from such fibrotic commitment by modulation of OxSt and autophagy. CSCs were isolated from 38 patients, stratified as MetS, DM2, or controls. Pharmacological modulation of OxSt and autophagy was obtained by treatment with trehalose and NOX4/NOX5 inhibitors (TREiNOX). Flow-cytometry and real-time quantitative polymerase chain reaction (RT-qPCR) analyses showed significantly increased expression of myofibroblasts markers in MetS-CSCs at baseline (GATA4, ACTA2, THY1/CD90) and after starvation (COL1A1, COL3A1). MetS- and DM2-CSCs displayed a paracrine profile distinct from control cells, as evidenced by screening of 30 secreted cytokines, with a significant reduction in vascular endothelial growth factor (VEGF) and endoglin confirmed by enzyme-linked immunoassay (ELISA). DM2-CSCs showed significantly reduced support for endothelial cells in angiogenic assays, and significantly increased H2 O2 release and NOX4/5 expression levels. Autophagy impairment after starvation (reduced ATG7 and LC3-II proteins) was also detectable in DM2-CSCs. TREiNOX treatment significantly reduced ACTA2, COL1A1, COL3A1, and NOX4 expression in both DM2- and MetS-CSCs, as well as GATA4 and THY1/CD90 in DM2, all versus control cells. Moreover, TREiNOX significantly increased VEGF release by DM2-CSCs, and VEGF and endoglin release by both MetS- and DM2-CSCs, also recovering the angiogenic support to endothelial cells by DM2-CSCs. In conclusion, DM2 and MetS worsen microenvironmental conditioning by CSCs. Appropriate modulation of autophagy and OxSt in human CSCs appears to restore these features, mostly in DM2-CSCs, suggesting a novel strategy against cardiac fibrosis in dysmetabolic patients. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

The impact of autophagy modulation on phenotype and survival of cardiac stromal cells under metabolic stress.

Cardiac stromal cells (CSCs) embrace multiple phenotypes and are a contributory factor in tissue homeostasis and repair. They can be exploited as therapeutic mediators against cardiac fibrosis and remodeling, but their survival and cardioprotective properties can be decreased by microenvironmental cues. We evaluated the impact of autophagy modulation by different pharmacological/genetic approaches on the viability and phenotype of murine CSCs, which had been subjected to nutrient deprivation or hyperglycemia, in order to mimic relevant stress conditions and risk factors of cardiovascular diseases. Our results show that autophagy is activated in CSCs by nutrient deprivation, and that autophagy induction by trehalose or autophagy-related protein 7 (ATG7)-overexpression can significantly preserve CSC viability. Furthermore, autophagy induction is associated with a higher proportion of primitive, non-activated stem cell antigen 1 (Sca1)-positive cells, and with a reduced fibrotic fraction (positive for the discoidin domain-containing receptor 2, DDR2) in the CSC pool after nutrient deprivation. Hyperglycemia, on the other hand, is associated with reduced autophagic flux in CSCs, and with a significant reduction in primitive Sca1+ cells. Autophagy induction by adenoviral-mediated ATG7-overexpression maintains a cardioprotective, anti-inflammatory and pro-angiogenic paracrine profile of CSCs exposed to hyperglycemia for 1 week. Finally, autophagy induction by ATG7-overexpression during hyperglycemia can significantly preserve cell viability in CSCs, which were subsequently exposed to nutrient deprivation, reducing hyperglycemia-induced impairment of cell resistance to stress. In conclusion, our results show that autophagy stimulation preserves CSC viability and function in response to metabolic stressors, suggesting that it may boost the beneficial functions of CSCs in cardiac repair mechanisms.

The dynamic facets of the cardiac stroma: from classical markers to omics and translational perspectives.

Cardiac stromal cells have been long underestimated in their functions in homeostasis and repair. Recent evidence has changed this perspective in that many more players and facets than just "cardiac fibroblasts" have entered the field. Single cell transcriptomic studies on cardiac interstitial cells have shed light on the phenotypic plasticity of the stroma, whose transcriptional profile is dynamically regulated in homeostatic conditions and in response to external stimuli. Different populations and/or functional states that appear in homeostasis and pathology have been described, particularly increasing the complexity of studying the cardiac response to injury. In this review, we outline current phenotypical and molecular markers, and the approaches developed for identifying and classifying cardiac stromal cells. Significant advances in our understanding of cardiac stromal populations will provide a deeper knowledge on myocardial functional cellular components, as well as a platform for future developments of novel therapeutic strategies to counteract cardiac fibrosis and adverse cardiac remodeling.

Corrigendum: Very Early Involvement of Innate Immunity in Peripheral Nerve Degeneration in SOD1-G93A Mice.

[This corrects the article DOI: 10.3389/fimmu.2020.575792.].

Inhibition of miR-155 Attenuates Detrimental Vascular Effects of Tobacco Cigarette Smoking.

Background The role of microRNAs dysregulation in tobacco cigarette smoking-induced vascular damage still needs to be clarified. We assessed the acute effects of tobacco cigarette smoking on endothelial cell-related circulating microRNAs in healthy subjects. In addition, we investigated the potential role of microRNAs in smoking-dependent endothelial cell damage. Methods and Results A panel of endothelial-related microRNAs was quantified in healthy subjects before and after smoking 1 tobacco cigarette. Serum levels of miR-155 were found to be significantly increased shortly after smoking. We also observed a progressive and significant miR-155 accumulation in culture media of human endothelial cells after 30 minutes and up to 4 hours of cigarette smoke condensate treatment in vitro without evidence of cell death, indicating that miR-155 can be released by endothelial cells in response to smoking stress. Cigarette smoke condensate appeared to enhance oxidative stress and impair cell survival, angiogenesis, and NO metabolism in human endothelial cells. Notably, these effects were abrogated by miR-155 inhibition. We also observed that miR-155 inhibition rescued the deleterious effects of cigarette smoke condensate on endothelial-mediated vascular relaxation and oxidative stress in isolated mouse mesenteric arteries. Finally, we found that exogenous miR-155 overexpression mimics the effects of smoking stress by inducing the upregulation of inflammatory markers, impairing angiogenesis and reducing cell survival. These deleterious effects were associated with downregulation of vascular endothelial growth factor and endothelial NO synthetase. Conclusions Our results suggest that miR-155 dysregulation may contribute to the deleterious vascular effects of tobacco smoking.

Very Early Involvement of Innate Immunity in Peripheral Nerve Degeneration in SOD1-G93A Mice.

Recent preclinical and clinical evidence suggest that immune system has a role in the progression and prognosis of Amyotrophic Lateral Sclerosis (ALS), but the identification of a clear mechanism and immune players remains to be elucidated. Here, we have investigated, in 30 and 60 days (presymptomatic) and 120 days (symptomatic) old SOD1-G93A mice, systemic, peripheral, and central innate and adaptive immune and inflammatory response, correlating it with the progression of the neurodegeneration in neuromuscular junction, sciatic nerves, and spinal cord. Surprisingly, we found a very initial (45-60 days) presence of IgG in sciatic nerves together with a gradual enhancement of A20/TNFAIP3 (protein controlling NF-κB signalling) and a concomitantly significant increase and activation of circulating mast cells (MCs) as well as MCs and macrophages in sciatic nerve and an enhancement of IL-6 and IL-10. This immunological frame coincided with a myelin aggregation. The 30-60 days old SOD1-G93A mice didn't show real elements of neuroinflammation and neurodegeneration in spinal cord. In 120 days old mice macrophages and monocytes are widely diffused in sciatic nerves, peripheral neurodegeneration reaches the tip, high circulating levels of TNFα and IL-2 were found and spinal cord exhibits clear signs of neural damage and infiltrating immune cells. Our results underpin a clear immunological disorder at the origin of ALS axonopathy, in which MCs are involved in the initiation and sustaining of inflammatory events. These data cannot be considered a mere epiphenomenon of motor neuron degeneration and reveal new potential selective immune targets in ALS therapy.