RESUMO
Colorectal cancer (CRC) is a major life-threatening disease, being the third most common cancer and a leading cause of death worldwide. Enhanced adiposity, particularly visceral fat, is a major risk factor for CRC, and obesity-associated alterations in metabolic, inflammatory and immune profiles in visceral adipose tissue (VAT) strongly contribute to promoting or sustaining intestinal carcinogenesis. The role of diet and nutrition in obesity and CRC has been extensively demonstrated, and AT represents the main place where diet-induced signals are integrated. Among the factors introduced with diet and processed or enriched in AT, ω3/ω6 polyunsaturated fatty acids (PUFAs) are endowed with pro- or anti-inflammatory properties and have been shown to exert either promoting or protective roles in CRC. In this study, we investigated the impact of ex vivo exposure to the ω3 and ω6 PUFAs docosahexaenoic and arachidonic acids on VAT adipocyte whole transcription in healthy lean, obese and CRC-affected individuals. High-throughput sequencing of protein-coding and long non-coding RNAs allowed us to identify specific pathways and regulatory circuits controlled by PUFAs and highlighted an impaired responsiveness of obese and CRC-affected individuals as compared to the strong response observed in healthy lean subjects. This further supports the role of healthy diets and balanced ω3/ω6 PUFA intake in the primary prevention of obesity and cancer.
Assuntos
Neoplasias Colorretais , Ácidos Graxos Ômega-3 , RNA Longo não Codificante , Humanos , Ácidos Graxos Ômega-3/farmacologia , Ácidos Graxos Ômega-3/metabolismo , Ácidos Graxos Insaturados , Adipócitos/metabolismo , Obesidade/genética , Obesidade/metabolismo , Neoplasias Colorretais/genéticaRESUMO
UNLABELLED: The interplay between dendritic cells (DC) and γδ T lymphocytes represents a network of paracrine and cell contact interactions important for an integrated immune response to pathogens. HIV-1 infection dramatically affects the number and functions of both cell populations, and DC/γδ T cell cross talk may represent a target of virus-induced immune escape. We investigated whether HIV-exposed DC could deliver aberrant signals to interacting γδ T cells. Here we report that the interaction of human γδ T lymphocytes with HIV-1-exposed autologous monocyte-derived DC, but not direct exposure to the virus, impairs lymphocyte expansion and gamma interferon (IFN-γ) production in response to phosphoantigens. This effect is independent of virus strain and occurred in 55% of the donors analyzed. The donor-dependent variation observed relies on the responsiveness of DC to HIV-1 and is strictly related to the capacity of the virus to suppress the maturation-induced expression of interleukin 12 (IL-12). In fact, γδ T cell response to phosphoantigens is almost completely recovered when this cytokine is exogenously added to the DC/lymphocyte cocultures. Interestingly, we show that γδ T lymphocytes are recruited by HIV-1-exposed DC through a CCR5-mediated mechanism and exert a CCL4-mediated control on virus dissemination within DC and susceptible CD4(+) T lymphocytes. These results demonstrate an association between HIV-induced DC dysfunction and alterations of γδ T cell responses. The aberrant cross talk between these two cell populations may contribute to the pathogenesis of HIV infection by further reducing the strength of antiviral immune response. IMPORTANCE: This study provides new evidence on the mechanisms exploited by HIV-1 to evade the host immune response. We report that HIV-1 impairs the cross talk between DC and γδ T lymphocytes, by reducing the capacity of DC to promote functional γδ T cell activation. Interestingly, the virus does not per se interfere with γδ T cell activation, thus highlighting the key role of early DC-HIV-1 interaction in this phenomenon. Furthermore, the results obtained unravel the novel role of γδ T cells in controlling HIV-1 dissemination within the DC population as well as virus transfer to susceptible CD4(+) T lymphocytes. The interactions of DC with innate lymphocytes represent a major control mechanism for an integrated immune response to infection. Understanding how HIV-1 harnesses these pathways may provide important insights on the pathogenesis of disease and offer new opportunities for therapeutic interventions.
Assuntos
Células Dendríticas/imunologia , HIV-1/imunologia , HIV-1/fisiologia , Evasão da Resposta Imune , Linfócitos T/imunologia , Proliferação de Células , Humanos , Interferon gama/metabolismo , Interleucina-12/antagonistas & inibidoresRESUMO
Marked changes in socioeconomic status, cultural traditions, population growth, and agriculture have been affecting diets worldwide. Nutrition is known to play a pivotal role in the pathogenesis of several chronic diseases, and the use of bioactive food compounds at pharmacologic doses is emerging as a preventive and/or therapeutic approach to target metabolic dysregulations occurring in aging, obesity-related chronic diseases, and cancer. Only recently have data on the effects of specific nutrients or food on the immune system become available, and studies regarding the human immune system are still in their infancy. Beyond providing essential nutrients, diet can actively influence the immune system. Understanding how diet and nutritional status influence the innate and adaptive arms of our immune system represents an area of scientific need, opportunity, and challenge. The insights gleaned should help to address several pressing global health problems. Recently, biologically active polyphenols, which are widespread constituents of fruit and vegetables, have gained importance as complex regulators of various cellular processes, critically involved in the maintenance of body homeostasis. This review outlines the potential effects of polyphenols on the function of dendritic cells (DCs), key players in the orchestration of the immune response. Their effects on different aspects of DC biology including differentiation, maturation, and DC capacity to shift immune response toward tolerance or immune activation will be outlined.
Assuntos
Células Dendríticas/citologia , Dieta , Polifenóis/química , Animais , Disponibilidade Biológica , Diferenciação Celular/efeitos dos fármacos , Modelos Animais de Doenças , Frutas/química , Marcadores Genéticos , Humanos , Verduras/químicaRESUMO
BACKGROUND: MicroRNAs (miRs) are an abundant class of small non-coding RNAs (~22 nt) that reprogram gene expression by targeting mRNA degradation and translational disruption. An emerging concept implicates miR coupling with transcription factors in myeloid cell development and function, thus contributing to host defense and inflammation. The important role that these molecules play in the pathogenesis of HIV-1 is only now emerging. RESULTS: We provide evidence that exposure of monocyte-derived dendritic cells (MDDCs) to recombinant HIV-1 R5 gp120, but not to CCR5 natural ligand CCL4, influences the expression of a panel of miRs (i.e., miR-21, miR-155 and miR-181b) regulated by STAT3 and potentially targeting genes belonging to the STAT3 signaling pathway. The blockage of gp120-induced STAT3 activation impairs gp120 capacity to modulate the expression level of above mentioned miRs. Predictive analysis of miR putative targets emphasizes that these miRs share common target genes. Furthermore, gene ontology and pathway enrichment analysis outline that these genes mainly belong to biological processes related to regulation of transcription, in a complex network of interactions involving pathways relevant to HIV-DC interaction. CONCLUSIONS: Overall, these results point to gp120-triggered modulation of miR expression via STAT3 activation as a novel molecular mechanism exploited by HIV-1 to affect DC biology and thus modulate the immune response through complex regulatory loops involving, at the same time, miRs and transcription factors.
Assuntos
Células Dendríticas/metabolismo , Expressão Gênica/genética , Proteína gp120 do Envelope de HIV/genética , HIV-1/genética , MicroRNAs/genética , Monócitos/metabolismo , Fator de Transcrição STAT3/genética , Células Dendríticas/virologia , Humanos , Monócitos/virologia , Transdução de Sinais/genéticaRESUMO
BACKGROUND: Macrophages are key targets of HIV-1 infection. We have previously described that the expression of CC chemokine ligand 2 (CCL2) increases during monocyte differentiation to macrophages and it is further up-modulated by HIV-1 exposure. Moreover, CCL2 acts as an autocrine factor that promotes viral replication in infected macrophages. In this study, we dissected the molecular mechanisms by which CCL2 neutralization inhibits HIV-1 replication in monocyte-derived macrophages (MDM), and the potential involvement of the innate restriction factors protein sterile alpha motif (SAM) histidine/aspartic acid (HD) domain containing 1 (SAMHD1) and apolipoprotein B mRNA-editing, enzyme-catalytic, polypeptide-like 3 (APOBEC3) family members. RESULTS: CCL2 neutralization potently reduced the number of p24 Gag+ cells during the course of either productive or single cycle infection with HIV-1. In contrast, CCL2 blocking did not modify entry of HIV-1 based Virus Like Particles, thus demonstrating that the restriction involves post-entry steps of the viral life cycle. Notably, the accumulation of viral DNA, both total, integrated and 2-LTR circles, was strongly impaired by neutralization of CCL2. Looking for correlates of HIV-1 DNA accumulation inhibition, we found that the antiviral effect of CCL2 neutralization was independent of the modulation of SAMHD1 expression or function. Conversely, a strong and selective induction of APOBEC3A expression, to levels comparable to those of freshly isolated monocytes, was associated with the inhibition of HIV-1 replication mediated by CCL2 blocking. Interestingly, the CCL2 neutralization mediated increase of APOBEC3A expression was type I IFN independent. Moreover, the transcriptome analysis of the effect of CCL2 blocking on global gene expression revealed that the neutralization of this chemokine resulted in the upmodulation of additional genes involved in the defence response to viruses. CONCLUSIONS: Neutralization of endogenous CCL2 determines a profound restriction of HIV-1 replication in primary MDM affecting post-entry steps of the viral life cycle with a mechanism independent of SAMHD1. In addition, CCL2 blocking is associated with induction of APOBEC3A expression, thus unravelling a novel mechanism which might contribute to regulate the expression of innate intracellular viral antagonists in vivo. Thus, our study may potentially lead to the development of new therapeutic strategies for enhancing innate cellular defences against HIV-1 and protecting macrophages from infection.
Assuntos
Quimiocina CCL2/antagonistas & inibidores , DNA Viral/metabolismo , HIV-1/fisiologia , Macrófagos/virologia , Replicação Viral , Células Cultivadas , Quimiocina CCL2/imunologia , Citidina Desaminase/antagonistas & inibidores , Citidina Desaminase/genética , Expressão Gênica , Perfilação da Expressão Gênica , Humanos , Proteínas Monoméricas de Ligação ao GTP/genética , Proteínas/antagonistas & inibidores , Proteínas/genética , Proteína 1 com Domínio SAM e Domínio HD , Internalização do VírusRESUMO
MicroRNAs (miRNAs) are a class of small noncoding RNAs acting as post-transcriptional gene expression regulators in many physiological and pathological conditions. During the last few years, many novel mammalian miRNAs have been predicted experimentally with bioinformatics approaches and validated by next-generation sequencing. Although these strategies have prompted the discovery of several miRNAs, the total number of these genes still seems larger. Here, by exploiting the species conservation of human, mouse, and rat hairpin miRNAs, we discovered a novel rat microRNA, mir-155. We found that mature miR-155 is overexpressed in rat spleen myeloid cells treated with LPS, similarly to humans and mice. Rat mir-155 is annotated only on the alternate genome, suggesting the presence of other "hidden" miRNAs on this assembly. Therefore, we comprehensively extended the homology search also to mice and humans, finally validating 34 novel mammalian miRNAs (two in humans, five in mice, and up to 27 in rats). Surprisingly, 15 of these novel miRNAs (one for mice and 14 for rats) were found only on the alternate and not on the reference genomic assembly. To date, our findings indicate that the choice of genomic assembly, when mapping small RNA reads, is an important option that should be carefully considered, at least for these animal models. Finally, the discovery of these novel mammalian miRNA genes may contribute to a better understanding of already acquired experimental data, thereby paving the way to still unexplored investigations and to unraveling the function of miRNAs in disease models.
Assuntos
Genoma , MicroRNAs/genética , Animais , Sequência de Bases , Biologia Computacional , Genômica , Humanos , Camundongos , MicroRNAs/metabolismo , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Ratos , Análise de Sequência de RNARESUMO
UNLABELLED: Dendritic cells (DCs) are fundamental for the initiation of immune responses and are important players in AIDS immunopathogenesis. The modulation of DC functional activities represents a strategic mechanism for HIV-1 to evade immune surveillance. Impairment of DC function may result from bystander effects of HIV-1 envelope proteins independently of direct HIV-1 infection. In this study, we report that exposure of immature monocyte-derived DCs (MDDCs) to HIV-1 R5 gp120 resulted in the CCR5-dependent production of interleukin-6 (IL-6) via mitogen-activated protein kinase (MAPK)/NF-κB pathways. IL-6 in turn activated STAT3 by an autocrine loop. Concomitantly, gp120 promoted an early activation of STAT3 that further contributed to IL-6 induction. This activation paralleled a concomitant upregulation of the STAT3 inhibitor PIAS3. Notably, STAT3/IL-6 pathway activation was not affected by the CCR5-specific ligand CCL4. These results identify STAT3 as a key signaling intermediate activated by gp120 in MDDCs and highlight the existence of a virus-induced dysregulation of the IL-6/STAT3 axis. HIV-1 gp120 signaling through STAT3 may provide an explanation for the impairment of DC function observed upon HIV exposure. IMPORTANCE: This study provides new evidence for the molecular mechanisms and signaling pathways triggered by HIV-1 gp120 in human DCs in the absence of productive infection, emphasizing a role of aberrant signaling in early virus-host interaction, contributing to viral pathogenesis. We identified STAT3 as a key component in the gp120-mediated signaling cascade involving MAPK and NF-κB components and ultimately leading to IL-6 secretion. STAT3 now is recognized as a key regulator of DC functions. Thus, the identification of this transcription factor as a signaling molecule mediating some of gp120's biological effects unveils a new mechanism by which HIV-1 may deregulate DC functions and contribute to AIDS pathogenesis.
Assuntos
Células Dendríticas/imunologia , Proteína gp120 do Envelope de HIV/imunologia , HIV-1/imunologia , Interleucina-6/imunologia , Fator de Transcrição STAT3/imunologia , Transdução de Sinais/imunologia , Comunicação Autócrina , Diferenciação Celular , Células Cultivadas , Quimiocina CCL4/genética , Quimiocina CCL4/imunologia , Células Dendríticas/virologia , Regulação da Expressão Gênica , Proteína gp120 do Envelope de HIV/genética , HIV-1/genética , Interações Hospedeiro-Patógeno , Humanos , Evasão da Resposta Imune , Interleucina-6/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/imunologia , Chaperonas Moleculares/genética , Chaperonas Moleculares/imunologia , Monócitos/imunologia , Monócitos/virologia , NF-kappa B/genética , NF-kappa B/imunologia , Proteínas Inibidoras de STAT Ativados/genética , Proteínas Inibidoras de STAT Ativados/imunologia , Receptores CCR5/genética , Receptores CCR5/imunologia , Fator de Transcrição STAT3/genéticaRESUMO
Lactoferrin (LF), an iron-binding glycoprotein expressed in most biological fluids, represents a major component of mammalian innate immune system. The multiple activities of LF rely not only on its capacity to bind iron but also to interact with molecular and cellular components of both the host and pathogens. LF can bind and sequester lipopolysaccharide thus preventing proinflammatory pathway activation, sepsis, and tissue damage. However, the interplay between LF and lipopolysaccharide is complex and may lead to different outcomes including both the suppression of inflammatory response and immune activation. Understanding the molecular basis and the functional consequences of this complex interaction is critically relevant in the development of LF-based therapeutic interventions in humans.
Assuntos
Fatores Imunológicos/fisiologia , Lactoferrina/fisiologia , Lipopolissacarídeos/metabolismo , Animais , Interações Hospedeiro-Patógeno , Humanos , Imunidade Inata , Fatores Imunológicos/metabolismo , Lactoferrina/metabolismo , Lipopolissacarídeos/antagonistas & inibidores , Ligação Proteica , Receptor 4 Toll-Like/metabolismoRESUMO
Colorectal cancer (CRC) is a leading cause of death worldwide. Despite advances in surgical and therapeutic management, tumor metastases and resistance to therapy still represent major hurdles. CRC risk is highly modifiable by lifestyle factors, including diet, which strongly influences both cancer incidence and related mortality. Galectin-3 (Gal-3) is a multifaceted protein involved in multiple pathophysiological pathways underlying chronic inflammation and cancer. Its versatility is given by the ability to participate in a wide range of tumor-promoting processes, including cell-cell/cell-matrix interactions, cell growth regulation and apoptosis, and the immunosuppressive tumor microenvironment. This review provides an updated summary of preclinical and observational human studies investigating the pathogenetic role of Gal-3 in intestinal inflammation and CRC, as well as the potential of Gal-3 activity inhibition by plant-source food-derived bioactive compounds to control CRC onset/growth. These studies highlight both direct and immuno-mediated effects of Gal-3 on tumor growth and invasiveness and its potential role as a CRC prognostic biomarker. Substantial evidence indicates natural food-derived Gal-3 inhibitors as promising candidates for CRC prevention and therapy. However, critical issues, such as their bioavailability and efficacy, in controlled human studies need to be addressed to translate research progress into clinical applications.
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Toll-like receptor (TLR) signaling activation by pathogens is critical to the induction of immune responses, and demands tight regulation. We describe in this study that CC chemokine ligand 2 (CCL2) secretion triggered by TLR4 or TLR8 engagement is strongly inhibited upon simultaneous activation of both TLRs in human monocyte-derived dendritic cells (DCs). Impaired CCL2 secretion occurs concomitantly to interleukin-12 up-regulation, being part of a complex regulatory circuit ensuring optimal T helper type 1 polarization. Interestingly, triggering selected TLRs or their combinations differently affects nuclear factor-kappaB p65 activation and microRNA expression. Overall, these results indicate that CCL2 supplies an important immunomodulatory role to DCs, and may contribute to dictate the cytokine profile in T helper type 1 responses induced by DCs.
Assuntos
Polaridade Celular/efeitos dos fármacos , Quimiocina CCL2/metabolismo , Células Dendríticas/efeitos dos fármacos , Células Th1/efeitos dos fármacos , Receptores Toll-Like/agonistas , Células Cultivadas , Quimiocina CCL2/genética , Células Dendríticas/metabolismo , Regulação para Baixo/efeitos dos fármacos , Combinação de Medicamentos , Humanos , Imidazóis/administração & dosagem , Imidazóis/farmacologia , Interferon beta/metabolismo , Interleucina-10/metabolismo , Lipopolissacarídeos/administração & dosagem , Lipopolissacarídeos/farmacologia , Poli I-C/administração & dosagem , Poli I-C/farmacologia , RNA Mensageiro/metabolismo , Células Th1/imunologia , Células Th1/metabolismo , Células Th1/fisiologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
OBJECTIVE: In patients with hepatitis C virus (HCV)/HIV co-infection, a faster progression of liver fibrosis to cirrhosis has been reported. In this study, an investigation was carried out to determine whether gp120, an HIV envelope protein, modulates the biology of human hepatic stellate cells (HSCs), key cell types in the pathogenesis of fibrosis. METHODS: Myofibroblastic HSCs were isolated from normal human liver tissue. Gene expression was measured by real-time PCR. Cell migration was assessed in Boyden chambers. Intracellular signalling pathways were evaluated using phosphorylation-specific antibodies or by transfection of a reporter plasmid. RESULTS: Transcripts for the chemokine receptors CCR5 and CXCR4, which bind gp120, were detectable in human HSCs. Upon exposure to M-tropic recombinant gp120, which binds CCR5, a significant increase in HSC chemotaxis was observed (1.6+/-0.3-fold, p=0.03). The effects of gp120 were prevented by protein inactivation. gp120 also resulted in a significant increase in secretion (1.5+/-0.3-fold, p=0.03) and gene expression (1.47+/-0.13-fold, p=0.02) of the proinflammatory chemokine monocyte chemoattractant protein-1, and in increased gene expression of tissue inhibitor of metalloprotease-1 and interleukin-6 (2.03+/-0.57-fold, p=0.02). gp120-induced migration required Akt activation. gp120 also induced activation of nuclear factor-kappaB (NF-kappaB) and p38(MAPK). Preincubation of HSCs with TAK779, a CCR5 receptor antagonist, prevented gp120-mediated chemotaxis and monocyte chemoattractant protein-1 secretion. Expression of CCR5 was detectable in areas of inflammation and fibrogenesis in liver biopsies of patients with HCV/HIV co-infection. CONCLUSIONS: This study shows that HIV gp120 modulates different aspects of HSC biology, including directional cell movement and expression of proinflammatory cytokines. These results identify a direct pathway possibly linking HIV infection with liver fibrogenesis via envelope proteins.
Assuntos
Proteína gp120 do Envelope de HIV/farmacologia , Infecções por HIV/complicações , Células Estreladas do Fígado/efeitos dos fármacos , Cirrose Hepática/virologia , Células Cultivadas , Quimiocina CCL2/biossíntese , Quimiotaxia/efeitos dos fármacos , Relação Dose-Resposta a Droga , Infecções por HIV/metabolismo , Células Estreladas do Fígado/metabolismo , Humanos , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Reação em Cadeia da Polimerase/métodos , RNA Mensageiro/genética , Receptores CCR5/biossíntese , Receptores CCR5/genética , Receptores CXCR4/biossíntese , Receptores CXCR4/genética , Proteínas Recombinantes/farmacologia , Regulação para Cima/efeitos dos fármacosRESUMO
Type I interferons (IFN-I) are antiviral cytokines endowed with multiple biological actions, including antitumor activity. Studies in mouse models and cancer patients support the concept that endogenous IFN-I play important roles in the control of tumor development and growth as well as in response to several chemotherapy/radiotherapy treatments. While IFN-I signatures in the tumor microenvironment are often considered as biomarkers for a good prognostic response to antitumor therapies, prolonged IFN-I signaling can lead to immune dysfunction, thereby promoting pathogen or tumor persistence, thus revealing the "Janus face" of these cytokines in cancer control, likely depending on timing, tissue microenvironment and cumulative levels of IFN-I signals. Likewise, IFN-I exhibit different and even opposite effects on obesity, a pathologic condition linked to cancer development and growth. As an example, evidence obtained in mouse models shows that localized expression of IFN-I in the adipose tissue results in inhibition of diet-induced obesity, while hyper-production of these cytokines by specialized cells such as plasmacytoid dendritic cells in the same tissue, can induce systemic inflammatory responses leading to obesity. Further studies in mouse models and humans should reveal the mechanisms by which IFN-I can regulate both tumor growth and obesity and to understand the role of factors such as genetic background, diet and microbioma in shaping the production and action of these cytokines under physiological and pathological conditions.
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Lactoferrin (Lf) is a mammalian exclusive protein widely distributed in milk and exocrine secretions exhibiting multifunctional properties. Many of the proven or proposed functions of Lf, apart from its iron binding activity, depend on its capacity to bind to other macromolecules. Lf can bind and sequester lipopolysaccharide (LPS), thus preventing pro-inflammatory pathway activation, sepsis and tissue damage. However, the interplay between Lf and LPS is complex, and may result in different outcomes, including both suppression of the inflammatory response and immune activation. These findings are critically relevant in the development of Lf-based therapeutic interventions in humans. Understanding the molecular basis and functional consequences of Lf-LPS interaction will provide insights for determining its role in health and disease.
Assuntos
Lactoferrina/imunologia , Lactoferrina/metabolismo , Lipopolissacarídeos/imunologia , Lipopolissacarídeos/metabolismo , Animais , HumanosRESUMO
Colorectal cancer (CRC) is a leading cause of cancer-related mortality in the world. Patterns and trends in CRC incidence and mortality correlate with increasing adoption of Western lifestyles and with the overweight/obesity epidemic. Both genetic background and a range of modifiable environmental/lifestyle factors play a role in CRC etiology. Among these the links of body weight, dietary patterns and physical activity (PA) behavior with CRC risk are some of the strongest for any type of cancer, with a different impact in women and men. Nonetheless, gender disparities still represent a neglected aspect of CRC management. This review sheds light on gender-related association of obesity and different dietary/PA habits with CRC risk, highlighting the importance of lifestyle modifications in the prevention of this neoplastic disease. In this scenario, intervention studies are strongly recommended to define the most effective dietary/PA regimens for primary prevention of cancer in women and men.
Assuntos
Neoplasias Colorretais , Estilo de Vida , Obesidade , Neoplasias Colorretais/epidemiologia , Dieta , Comportamento Alimentar , Feminino , Humanos , Masculino , Fatores de Risco , Fatores SexuaisRESUMO
ß-glucans represent a heterogeneous group of naturally occurring and biologically active polysaccharides found in many kinds of edible mushrooms, baker's yeast, cereals and seaweeds, whose health-promoting effects have been known since ancient times. These compounds can be taken orally as food supplements or as part of daily diets, and are safe to use, nonimmunogenic and well tolerated. A main feature of ß-glucans is their capacity to function as biological response modifiers, exerting regulatory effects on inflammation and shaping the effector functions of different innate and adaptive immunity cell populations. The potential to interfere with processes involved in the development or control of cancer makes ß-glucans interesting candidates as adjuvants in antitumor therapies as well as in cancer prevention strategies. Here, the regulatory effects of dietary ß-glucans on human innate immunity cells are reviewed and their potential role in cancer control is discussed.
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Coronavirus disease 2019 (COVID-19) first emerged in late 2019 in China. At the time of writing, its causative agent SARS-CoV-2 has spread worldwide infecting over 9 million individuals and causing more than 460,000 deaths. In the absence of vaccines, we are facing the dramatic challenge of controlling COVID-19 pandemic. Among currently available drugs, type I Interferons (IFN-I) - mainly IFN-α and ß -represent ideal candidates given their direct and immune-mediated antiviral effects and the long record of clinical use. However, the best modalities of using these cytokines in SARS-CoV-2 infected patients is a matter of debate. Here, we discuss how we can exploit the current knowledge on IFN-I system to tailor the most promising dosing, timing and route of administration of IFN-I to the disease stage, with the final aim of making these cytokines a valuable therapeutic strategy in today's fight against COVID-19 pandemic.
Assuntos
Antivirais/uso terapêutico , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/prevenção & controle , Interferon-alfa/uso terapêutico , Interferon beta/uso terapêutico , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , COVID-19 , Humanos , Imunoterapia/métodos , SARS-CoV-2 , Prevenção Secundária/métodosRESUMO
Obesity, and the obesity-associated inflammation, represents a major risk factor for the development of chronic diseases, including colorectal cancer (CRC). Dysfunctional visceral adipose tissue (AT) is now recognized as key player in obesity-associated morbidities, although the biological processes underpinning the increased CRC risk in obese subjects are still a matter of debate. Recent findings have pointed to specific alterations in the expression pattern of non-coding RNAs (ncRNAs), such as microRNAs (miRNAs), and long non-coding RNAs (lncRNAs), as mechanisms underlying dysfunctional adipocyte phenotype in obesity. Nevertheless, the regulatory networks and interrelated processes relevant for adipocyte functions, that may contribute to a tumor-promoting microenvironment, are poorly known yet. To this end, based on RNA sequencing data, we identified lncRNAs and miRNAs, which are aberrantly expressed in visceral adipocytes from obese and CRC subjects, as compared to healthy lean control, and validated a panel of modulated ncRNAs by real-time qPCR. Furthermore, by combining the differentially expressed lncRNA and miRNA profiles with the transcriptome analysis dataset of adipocytes from lean and obese subjects affected or not by CRC, lncRNA-miRNA-mRNA adipocyte networks were defined for obese and CRC subjects. This analysis highlighted several ncRNAs modulation that are common to both obesity and CRC or unique of each disorder. Functional enrichment analysis of network-related mRNA targets, revealed dysregulated pathways associated with metabolic processes, lipid and energy metabolism, inflammation, and cancer. Moreover, adipocytes from obese subjects affected by CRC exhibited a higher complexity, in terms of number of genes, lncRNAs, miRNAs, and biological processes found to be dysregulated, providing evidence that the transcriptional and post-transcriptional program of adipocytes from CRC patients is deeply affected by obesity. Overall, this study adds further evidence for a central role of visceral adipocyte dysfunctions in the obesity-cancer relationship.
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Colorectal cancer (CRC), a multi-step malignancy showing increasing incidence in today's societies, represents an important worldwide health issue. Exogenous factors, such as lifestyle, diet, nutrition, environment and microbiota, contribute to CRC pathogenesis, also influencing non neoplastic cells, including immune cells. Several immune dysfunctions were described in CRC patients at different disease stages. Many studies underline the role of microbiota, obesity-related inflammation, diet and host reactive cells, including dendritic cells (DC), in CRC pathogenesis. Here, we focused on DC, the main cells linking innate and adaptive anti-cancer immunity. Variations in the number and phenotype of circulating and tumor-infiltrating DC have been found in CRC patients and correlated with disease stages and progression. A critical review of DC-based clinical studies and of recent advances in cancer immunotherapy leads to consider new strategies for combining DC vaccination strategies with check-point inhibitors, thus opening perspectives for a more effective management of this neoplastic disease.
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Metabolic chronic diseases, also named noncommunicable diseases (NCDs), are considered multifactorial pathologies, which are dramatically increased during the last decades. Noncommunicable diseases such as cardiovascular diseases, obesity, diabetes mellitus, cancers, and chronic respiratory diseases markedly increase morbidity, mortality, and socioeconomic costs. Moreover, NCDs induce several and complex clinical manifestations that lead to a gradual deterioration of health status and quality of life of affected individuals. Multiple factors are involved in the development and progression of these diseases such as sedentary behavior, smoking, pollution, and unhealthy diet. Indeed, nutrition has a pivotal role in maintaining health, and dietary imbalances represent major determinants favoring chronic diseases through metabolic homeostasis alterations. In particular, it appears that specific nutrients and adequate nutrition are important in all periods of life, but they are essential during specific times in early life such as prenatal and postnatal phases. Indeed, epidemiologic and experimental studies report the deleterious effects of an incorrect nutrition on health status several decades later in life. During the last decade, a growing interest on the possible role of epigenetic mechanisms as link between nutritional imbalances and NCDs development has been observed. Finally, because of the pivotal role of the hormones in fat, carbohydrate, and protein metabolism regulation throughout life, it is expected that any hormonal modification of these processes can imbalance metabolism and fat storage. Therefore, a particular interest to several chemicals able to act as endocrine disruptors has been recently developed. In this review, we will provide an overview and discuss the epigenetic role of some specific nutrients and chemicals in the modulation of physiological and pathological mechanisms.