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OBJECTIVE AND DESIGN: The aim of this study was to investigate the effects of ethanol exposure on epigenetic markers in bone marrow (BM) and their impact on inflammatory response during Aspergillus fumigatus infection. RESULTS: Chronic ethanol exposure decreased H3K27me3 enrichment in the Il6 promoter region while increased H3K4me3 enrichment in Tnf. Chimeric mice were generated by transplanting BM from mice exposed to ethanol or water. Infection of ethanol-chimeric mice culminated in higher clinical scores, although there was no effect on mortality. However, previous chronic exposure to ethanol affects persistently the inflammatory response in lung tissue, demonstrated by increased lung damage, neutrophil accumulation and IL-6, TNF and CXCL2 production in ethanol-chimeric mice, resulting in a decreased neutrophil infiltration into the alveolar space. Neutrophil killing and phagocytosis were also significantly lower. Moreover, BM derived macrophages (BMDM) from ethanol-chimeric mice stimulated with A. fumigatus conidia exhibited higher levels of TNF, CXCL2 and IL-6 release and a higher killing activity. The Il6 promoter of BMDM from ethanol-chimeric mice exhibited a reduction in H3K27me3 enrichment, a finding also observed in BM donors exposed to ethanol. CONCLUSIONS: These evidences demonstrate that prior chronic alcohol exposure of bone-marrow modify immune effector cells functions impairing the inflammatory response during A. fumigatus infection. These findings highlight the persistent impact of chronic ethanol exposure on infectious disease outcomes.
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INTRODUCTION: Probiotics provide therapeutic benefits not only in the gut but also other mucosal organs, including the lungs. OBJECTIVE AND DESIGN: To evaluate the effects of the probiotic strain L. delbrueckii UFV-H2b20 oral administration in an experimental murine model of A. fumigatus pulmonary infection. BALB/c mice were associated with L. delbrueckii and infected with Aspergillus fumigatus and compared with non-associated group. METHODS: We investigated survival, respiratory mechanics, histopathology, colony forming units, cytokines in bronchoalveolar lavage, IgA in feces, efferocytosis, production of reactive oxygen species and the cell population in the mesenteric lymph nodes. RESULTS: L. delbrueckii induces tolerogenic dendritic cells, IL-10+macrophages and FoxP3+regulatory T cells in mesenteric lymph nodes and increased IgA levels in feces; after infection with A. fumigatus, increased survival and decreased fungal burden. There was decreased lung vascular permeability without changes in the leukocyte profile. There was enhanced neutrophilic response and increased macrophage efferocytosis. L. delbrueckii-treated mice displayed more of FoxP3+Treg cells, TGF-ß and IL-10 levels in lungs, and concomitant decreased IL-1ß, IL-17 A, and CXCL1 production. CONCLUSION: Uur results indicate that L. delbrueckii UFV H2b20 ingestion improves immune responses, controlling pulmonary A. fumigatus infection. L. delbrueckii seems to play a role in pathogenesis control by promoting immune regulation.
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Colorectal cancer (CRC) responses to KRAS-targeted inhibition have been limited due to low response rates, the mechanisms of which remain unknown. Herein, we explored the cancer-associated fibroblasts (CAFs) secretome as a mediator of resistance to KRAS silencing. CRC cell lines HCT15, HCT116, and SW480 were cultured either in recommended media or in conditioned media from a normal colon fibroblast cell line (CCD-18Co) activated with rhTGF-ß1 to induce a CAF-like phenotype. The expression of membrane stem cell markers was analyzed by flow cytometry. Stem cell potential was evaluated by a sphere formation assay. RNAseq was performed in KRAS-silenced HCT116 colonospheres treated with either control media or conditioned media from CAFs. Our results demonstrated that KRAS-silencing up-regulated CD24 and down-regulated CD49f and CD104 in the three cell lines, leading to a reduction in sphere-forming efficiency. However, CAF-secreted factors restored stem cell marker expression and increased stemness. RNA sequencing showed that CAF-secreted factors up-regulated genes associated with pro-tumorigenic pathways in KRAS-silenced cells, including KRAS, TGFß, NOTCH, WNT, MYC, cell cycle progression and exit from quiescence, epithelial-mesenchymal transition, and immune regulation. Overall, our results suggest that resistance to KRAS-targeted inhibition might derive not only from cell-intrinsic causes but also from external elements, such as fibroblast-secreted factors.
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BACKGROUND: Latin America (LATAM) encompasses a vast region with diverse populations. Despite publicly funded health care systems providing universal coverage, significant socioeconomic and ethno-racial disparities persist in health care access across the region. Breast cancer (BC) incidence and mortality rates in Brazil are comparable to those in other LATAM countries, supporting the relevance of Brazilian data, with Brazil's health care policies and expenditures often serving as models for neighboring countries. We evaluated the impact of mobility on oncological outcomes in LATAM by analyzing studies of patients with BC reporting commuting routes or travel distances to receive treatment or diagnosis. METHODS: We searched MEDLINE (PubMed), Embase, Cochrane CENTRAL, LILACS, and Google Scholar databases. Studies eligible for inclusion were randomized controlled trials and observational studies of patients with BC published in English, Portuguese, or Spanish and conducted in LATAM. The primary outcome was the impact of mobility or travel distance on oncological outcomes. Secondary outcomes included factors related to mobility barriers and access to health services. For studies meeting eligibility, relevant data were extracted using standardized forms. Risk of bias was assessed using the Newcastle-Ottawa Scale. Quantitative and qualitative evidence synthesis focused on estimating travel distances based on available data. Heterogeneity across distance traveled or travel time was addressed by converting reported travel time to kilometers traveled and estimating distances for unspecified locations. RESULTS: Of 1142 records identified, 14 were included (12 from Brazil, 1 from Mexico, and 1 from Argentina). Meta-analysis revealed an average travel distance of 77.8 km (95% CI, 49.1-106.48) to access BC-related diagnostic or therapeutic resources. Nonetheless, this average fails to precisely encapsulate the distinct characteristics of each region, where notable variations persist in travel distance, ranging from 88 km in the South to 448 km in the North. CONCLUSION: The influence of mobility and travel distance on access to BC care is multifaceted and should consider the complex interplay of geographic barriers, sociodemographic factors, health system issues, and policy-related challenges. Further research is needed to comprehensively understand the variables impacting access to health services, particularly in LATAM countries, where the challenges women face during treatment remain understudied. TRIAL REGISTRATION: CRD42023446936.
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Neoplasias de la Mama , Accesibilidad a los Servicios de Salud , Viaje , Humanos , Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Femenino , Neoplasias de la Mama/terapia , Neoplasias de la Mama/etnología , América Latina , Viaje/estadística & datos numéricos , Disparidades en Atención de Salud/etnología , Disparidades en Atención de Salud/estadística & datos numéricosRESUMEN
PURPOSE: Our study aimed to explore real-world treatment scenarios for children and adolescents with neurotrophic tropomyosin receptor kinase (NTRK)-fused tumors, emphasizing access, responses, side effects, and outcomes. PATIENTS AND METHODS: Pooled clinical data from 17 pediatric cases (11 soft-tissue sarcomas, five brain tumors, and one neuroblastoma) treated with larotrectinib and radiologic images for 14 patients were centrally reviewed. Testing for gene fusions was prompted by poor response to treatment, tumor progression, or aggressiveness. RESULTS: Six different NTRK fusion subtypes were detected, and various payment sources for testing and medication were reported. Radiologic review revealed objective tumor responses (OR) in 11 of 14 patients: Complete responses: two; partial responses: nine; and stable disease: three cases. Grades 1 or 2 Common Terminology Criteria for Adverse Events adverse effects were reported in five patients. Regarding the entire cohort's clinical information, 15 of 17 patients remain alive (median observation time: 25 months): four with no evidence of disease and 11 alive with disease (10 without progression). One patient developed resistance to the NTRK inhibitor and died from disease progression while another patient died due to an unrelated cause. CONCLUSION: This real-world study confirms favorable agnostic tumor OR rates to larotrectinib in children with NTRK-fused tumors. Better coordination to facilitate access to medication remains a challenge, particularly in middle-income countries like Brazil.
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Inhibidores de Proteínas Quinasas , Pirazoles , Humanos , Niño , Masculino , Femenino , Adolescente , Pirazoles/uso terapéutico , Preescolar , Inhibidores de Proteínas Quinasas/uso terapéutico , Pirimidinas/uso terapéutico , Receptor trkA/genética , Receptor trkA/antagonistas & inhibidores , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/genética , Sarcoma/tratamiento farmacológico , Sarcoma/genética , Neuroblastoma/tratamiento farmacológico , Neuroblastoma/genética , Lactante , Receptor trkB/genética , Receptor trkC/genética , Ensayos Clínicos como AsuntoRESUMEN
Sodium-glucose cotransporter-2 inhibitors (SGLT2i) reduce blood pressure (BP) in patients with hypertension, yet the precise molecular mechanisms remain elusive. SGLT2i inhibits proximal tubule (PT) NHE3-mediated sodium reabsorption in normotensive rodents, yet no hypotensive effect is observed under this scenario. This study examined the effect of empagliflozin (EMPA) on renal tubular sodium transport in normotensive and spontaneously hypertensive rats (SHRs). It also tested the hypothesis that EMPA-mediated PT NHE3 inhibition in normotensive rats is associated with upregulation of distal nephron apical sodium transporters. EMPA administration for 14 days reduced BP in 12-wk-old SHRs but not in age-matched Wistar rats. PT NHE3 activity was inhibited by EMPA treatment in both Wistar and SHRs. In Wistar rats, EMPA increased NCC activity, mRNA expression, protein abundance, and phosphorylation levels, but not in SHRs. SHRs showed higher NKCC2 activity and an abundance of cleaved ENaC α and γ subunits compared with Wistar rats, none of which were affected by EMPA. Another set of male Wistar rats was treated with EMPA, the NCC inhibitor hydrochlorothiazide (HCTZ), and EMPA combined with HCTZ or vehicle for 14 days. In these rats, BP reduction was observed only with combined EMPA and HCTZ treatment, not with either drug alone. These findings suggest that NCC upregulation counteracts EMPA-mediated inhibition of PT NHE3 in male normotensive rats, maintaining their baseline BP. Moreover, the reduction of NHE3 activity without further upregulation of major apical sodium transporters beyond the PT may contribute to the BP-lowering effect of SGLT2i in experimental models and patients with hypertension.NEW & NOTEWORTHY This study suggests that reduced NHE3-mediated sodium reabsorption in the renal proximal tubule may account, at least in part, for the BP-lowering effect of SGLT2 inhibitors in the setting of hypertension. It also demonstrates that chronic treatment with SGLT2 inhibitors upregulates NCC activity, phosphorylation, and expression in the distal tubule of normotensive but not hypertensive rats. SGLT2 inhibitor-mediated upregulation of NCC seems crucial to counteract proximal tubule natriuresis in subjects with normal BP.
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Compuestos de Bencidrilo , Glucósidos , Hipertensión , Ratas Endogámicas SHR , Ratas Wistar , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Intercambiador 3 de Sodio-Hidrógeno , Regulación hacia Arriba , Animales , Masculino , Intercambiador 3 de Sodio-Hidrógeno/metabolismo , Intercambiador 3 de Sodio-Hidrógeno/genética , Intercambiador 3 de Sodio-Hidrógeno/antagonistas & inhibidores , Hipertensión/tratamiento farmacológico , Hipertensión/metabolismo , Hipertensión/fisiopatología , Glucósidos/farmacología , Compuestos de Bencidrilo/farmacología , Regulación hacia Arriba/efectos de los fármacos , Ratas , Inhibidores del Cotransportador de Sodio-Glucosa 2/farmacología , Presión Sanguínea/efectos de los fármacos , Miembro 3 de la Familia de Transportadores de Soluto 12/metabolismo , Miembro 3 de la Familia de Transportadores de Soluto 12/genética , Túbulos Renales Proximales/efectos de los fármacos , Túbulos Renales Proximales/metabolismo , Riñón/metabolismo , Riñón/efectos de los fármacosRESUMEN
Cardiometabolic diseases are often associated with heightened levels of angiotensin II (Ang II), which accounts for the observed oxidative stress, inflammation, and fibrosis. Accumulating evidence indicates a parallel upregulation of dipeptidyl dipeptidase 4 (DPP4) activity in cardiometabolic diseases, with its inhibition shown to mitigate oxidative stress, inflammation, and fibrosis. These findings highlight an overlap between the pathophysiological mechanisms used by Ang II and DPP4. Recent evidence demonstrates that targeted inhibition of DPP4 prevents the rise in Ang II and its associated molecules in experimental models of cardiometabolic diseases. Similarly, inhibitors of the angiotensin I-converting enzyme (ACE) or Ang II type 1 receptor (AT1R) blockers downregulate DPP4 activity, establishing a bidirectional relationship between DPP4 and Ang II. Here, we discuss the current evidence supporting the cross talk between Ang II and DPP4, along with the potential mechanisms promoting this cross regulation. A comprehensive analysis of this bidirectional relationship across tissues will advance our understanding of how DPP4 and Ang II collectively promote the development and progression of cardiometabolic diseases.
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Angiotensina II , Enfermedades Cardiovasculares , Humanos , Dipeptidil Peptidasa 4 , Peptidil-Dipeptidasa A , Receptor de Angiotensina Tipo 1 , Inflamación , Fibrosis , Angiotensina IRESUMEN
Given the changes in the digestive tract post-bariatric surgery, adapting to a new pattern of eating behavior becomes crucial, with special attention to the specifics of chewing mechanics. This study aimed to investigate the association between self-perception of chewing, chewing behavior, and the presence of gastrointestinal symptoms in preoperative patients undergoing bariatric surgery. Sixty adult candidates for bariatric surgery at a public hospital in Belém (Brazil) were analyzed. Participants predominantly exhibited unilateral chewing patterns (91.6%), a fast chewing rhythm (73.3%), a large food bolus (80%), liquid intake during meals (36.7%), and 41.7% reported that chewing could cause some issue. Significant associations were found between the perception of causing problems and chewing scarcity (p = 0.006), diarrhea (p = 0.004), absence of slow chewing (p = 0.048), and frequent cutting of food with front teeth (p = 0.034). These findings reveal a relationship between the perception of chewing problems and chewing scarcity, presence of diarrhea, and fast chewing.
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Cirugía Bariátrica , Masticación , Autoimagen , Humanos , Femenino , Masculino , Adulto , Persona de Mediana Edad , Conducta Alimentaria/psicología , Enfermedades Gastrointestinales/psicología , Enfermedades Gastrointestinales/etiología , Diarrea/etiología , Brasil , Estudios Transversales , Obesidad Mórbida/cirugía , Obesidad Mórbida/psicologíaRESUMEN
Clinical data revealed that KRAS mutant tumors, while initially sensitive to treatment, rapidly bypass KRAS dependence to acquire a drug-tolerant phenotype. However, the mechanisms underlying the transition from a drug-sensitive to a drug-tolerant state still elude us. Here, we show that global chromatin reorganization is a recurrent and specific feature of KRAS-dependent cells that tolerated KRAS silencing. We show that KRAS-dependent cells undergo G0/G1 cell cycle arrest after KRAS silencing, presenting a transcriptomic signature of quiescence. Proteomic analysis showed upregulated chromatin-associated proteins and transcription-associated biological processes. Accordingly, these cells shifted euchromatin/heterochromatin states, gained topologically associating domains, and altered the nanoscale physical organization of chromatin, more precisely by downregulating chromatin packing domains, a feature associated with the induction of quiescence. In addition, they also accumulated transcriptional alterations over time leading to a diversification of biological processes, linking chromatin alterations to transcriptional performance. Overall, our observations pinpoint a novel molecular mechanism of tolerance to KRAS oncogenic loss driven not by specific gene alterations but by global reorganization of genomic information, in which cells transition chromatin domain structure towards a more quiescent state and gain transcriptional reprogramming capacity.
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Objetivo: Analisar as estratégias de treinamento em segurança do paciente para profissionais de saúde no contexto da atenção primária. Métodos: Trata-se de uma revisão integrativa conduzida nas bases de dados Medical Literature Analysis and Retrieval System Online, Literatura Latino-Americana e do Caribe em Ciências da Saúde, Base de Dados de Enfermagem, Web of Sciencee Scopus, com os descritores "Capacitação Profissional", "Segurança do Paciente" e "Atenção Primária à Saúde". Resultados: Foram identificados 390 estudos nas bases de dados, os quais resultaram em uma amostra final de seis artigos para a composição da revisão. Estes foram publicados entre os anos de 2017 e 2019, desenvolvidos em países da Europa, da América do Norte e Oceania. Conclusão: Descaram-se como estratégias de treinamento os seguintes itens: workshop, implementação de programa de segurança medicamentosa, identificação de fatores-chave para elevação da qualidade, feedback e aprendizagem através de erros. Descritores: Capacitação Profissional; Atenção Primária à Saúde; Segurança do Paciente; Pessoal de Saúde
Objective: To analyze patient safety training strategies for health professionals in the context of primary care.Methods: This is an integrative review conducted in the Medical Literature Analysis and Retrieval System Online, Latin American and Caribbean Center on Health Sciences Information, Base de Dados de Enfermagem, Web of Science and Scopus databases, with the descriptors "Professional Training", "Patient Safety" and "Primary Health Care". Results: A total of 390 studies were identified in the databases, which resulted in a final sample of six articles for the composition of the review. These were published between the years 2017 and 2019, developed in countries in Europe, North America and Oceania. Conclusion: The following items were described as training strategies: workshop, implementation of a medication safety program, identification of key factors for quality improvement, feedback and learning through errors.Descriptors:Professional Training; Primary Health Care; Patient Safety; Health Personnel
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Atención Primaria de Salud , Personal de Salud , Capacitación Profesional , Seguridad del PacienteRESUMEN
Purpose: Medulloblastomas are the most common primary malignant brain tumors in children. They are divided into molecular subgroups: WNT-activated, SHH-Activated, TP53 mutant or wild type, and non-WNT/non-SHH (Groups 3 and 4). WNT-activated medulloblastomas are usually caused by mutations in the CTNNB1 gene (85%-90%), and most remaining cases of CTNNB1 wild type are thought to be caused by germline mutations in APC. So far, the frequencies of CTNNB1 have been reported mainly in North American and European populations. The aim of this study was to report the frequency of CTNNB1 mutations in WNT-activated medulloblastomas in a Latin-Iberian population and correlate with their clinicopathological characteristics. Methods: A total of 266 medulloblastomas from seven different institutions from Brazil (n=211), Portugal (n=38), and Argentina (n=17) were evaluated. Following RNA and DNA isolation from formalin-fixed, paraffin-embedded (FFPE) tumor tissues, the molecular classification and CTNNB1 mutation analysis were performed by nCounter and Sanger sequencing, respectively. Results: WNT-activated medulloblastomas accounted for 15% (40/266) of the series. We observed that 73% of WNT-activated medulloblastomas harbored CTNNB1 mutations. CTNNB1 wild-type cases (27%) were more prevalent in female individuals and suggested to be associated with a worse outcome. Among the CTNNB1 wild-type cases, the available analysis of family history revealed two cases with familiar adenomatous polyposis, harboring APC germline variants. Conclusion: We observed a lower incidence of CTNNB1 mutations in WNT-activated medulloblastomas in our Latin-Iberian cohort compared to frequencies previously described in other populations. Considering that CTNNB1 wild-type cases may exhibit APC germline mutations, our study suggests a higher incidence (~30%) of hereditary WNT-activated medulloblastomas in the Latin-Iberian population.
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Many pathogenic organisms need to reach either an intracellular compartment or the cytoplasm of a target cell for their survival, replication or immune system evasion. Intracellular pathogens frequently penetrate into the cell through the endocytic and phagocytic pathways (clathrin-mediated endocytosis, phagocytosis and macropinocytosis) that culminates in fusion with lysosomes. However, several mechanisms are triggered by pathogenic microorganisms - protozoan, bacteria, virus and fungus - to avoid destruction by lysosome fusion, such as rupture of the phagosome and thereby release into the cytoplasm, avoidance of autophagy, delaying in both phagolysosome biogenesis and phagosomal maturation and survival/replication inside the phagolysosome. Here we reviewed the main data dealing with phagosome maturation and evasion from lysosomal killing by different bacteria, protozoa, fungi and virus.
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Lisosomas , Fagocitosis , Lisosomas/microbiología , Fagosomas/metabolismo , Fagosomas/microbiología , Endocitosis , Evasión InmuneRESUMEN
Ethanol abuse is a risk factor for the development of pneumonia caused by Streptococcus pneumoniae, a critical pathogen for public health. The aim of this article was to investigate the inflammatory mechanisms involved in pneumococcal pneumonia that may be associated with chronic ethanol exposure. Male C57BL6/J-Unib mice were exposed to 20% (v/v) ethanol for twelve weeks and intranasally infected with 5x104 CFU of S. pneumoniae. Twenty-four hours after infection, lungs, bronchoalveolar lavage and blood samples were obtained to assess the consequences of chronic ethanol exposure during infection. Alcohol-fed mice showed increased production of nitric oxide and CXCL1 in alveoli and plasma during pneumococcal pneumonia. Beside this, ethanol-treated mice exhibited a decrease in leukocyte infiltration into the alveoli and reduced frequency of severe lung inflammation, which was associated with an increase in bacterial load. Curiously, no changes were observed in survival after infection. Taken together, these results demonstrate that chronic ethanol exposure alters the inflammatory response during S. pneumoniae lung infection in mice with a reduction in the inflammatory infiltrate even in the presence of higher levels of the chemoattractant CXCL1.
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Neumonía Neumocócica , Masculino , Ratones , Animales , Neumonía Neumocócica/microbiología , Etanol/efectos adversos , Óxido Nítrico , Líquido del Lavado Bronquioalveolar , Streptococcus pneumoniae , LeucocitosRESUMEN
Introduction: People with hazardous alcohol use are more susceptible to viral, bacterial, and fungal infections due to the effect of alcohol on immune system cell function. Metabolized ethanol reduces NAD+ to NADH, affecting critical metabolic pathways. Here, our aim was to investigate whether alcohol is metabolized by bone marrow cells and if it impacts the metabolic pathways of leukocyte progenitor cells. This is said to lead to a qualitative and quantitative alteration of key metabolites which may be related to the immune response. Methods: We addressed this aim by using C57BL/6 mice under chronic ethanol administration and evaluating the metabolomic profile of bone marrow total cells by gas chromatography-coupled mass spectrometry (GC-MS). Results: We identified 19 metabolites. Our data demonstrated that chronic ethanol administration alters the metabolomic profile in the bone marrow, resulting in a statistically diminished abundance of five metabolites in ethanol-treated animals: uracil, succinate, proline, nicotinamide, and tyrosine. Discussion: Our results demonstrate for the first time in the literature the effects of alcohol consumption on the metabolome content of hematopoietic tissue and open a wide range of further studies to investigate mechanisms by which alcohol compromises the cellular function of the immune system.
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Médula Ósea , Etanol , Ratones , Animales , Ratones Endogámicos C57BL , Etanol/farmacología , Metabolómica/métodos , MetabolomaRESUMEN
KRAS mutations have been shown to extend their oncogenic effects beyond the cancer cell, influencing the tumor microenvironment. Herein, we studied the impact of mutant KRAS on the modulation of the pro-tumorigenic properties of cancer-associated fibroblasts (CAFs), including α-SMA expression, TGFß1 and HGF production, extracellular matrix components and metalloproteinases expression as well as collagen contraction and migration capacities. To do so, CCD-18Co normal-like colon fibroblasts were challenged with conditioned media from control and KRAS silenced colorectal cancer (CRC) cells. Our results showed that the mutant KRAS CRC cell-secreted factors were capable of turning normal-like fibroblasts into CAF-like by modulating the α-SMA expression, TGFß1 and HGF production and migration capacity. Oncogenic KRAS played a secondary role as its silencing did not completely impair the capacity of CRC cells to modulate most of the fibroblast properties analyzed. In summary, our work suggests that mutant KRAS does not play a major role in controlling the CRC cell-secreted factors that modulate the behavior of fibroblasts. The fact that CRC cells retain the capacity to modulate the pro-tumorigenic features of fibroblasts independently of KRAS silencing is likely to negatively impact their response to KRAS inhibitors, thus standing as a putative mechanism of resistance to KRAS inhibition with potential therapeutical relevance.
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Fibroblastos Asociados al Cáncer , Neoplasias Colorrectales , Fibroblastos Asociados al Cáncer/metabolismo , Carcinogénesis/patología , Neoplasias Colorrectales/patología , Fibroblastos/metabolismo , Humanos , Fenotipo , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Microambiente TumoralRESUMEN
AIMS: Emerging evidence suggests the existence of a crosstalk between dipeptidyl peptidase 4 (DPP4) and the renin-angiotensin system (RAS). Therefore, combined inhibition of DPP4 and RAS may produce similar pharmacological effects rather than being additive. This study tested the hypothesis that combining an inhibitor of DPP4 with an angiotensin II (Ang II) receptor blocker does not provide additional cardioprotection compared to monotherapy in heart failure (HF) rats. MAIN METHODS: Male Wistar rats were subjected to left ventricle (LV) radiofrequency ablation or sham operation. Six weeks after surgery, radiofrequency-ablated rats who developed HF were assigned into four groups and received vehicle (water), vildagliptin, valsartan, or both drugs, for four weeks by oral gavage. KEY FINDINGS: Vildagliptin and valsartan in monotherapy reduced LV hypertrophy, alleviated cardiac interstitial fibrosis, and improved systolic and diastolic function in HF rats, with no additional effect of combination treatment. HF rats displayed higher cardiac and serum DPP4 activity and abundance than sham. Surprisingly, not only vildagliptin but also valsartan in monotherapy downregulated the catalytic function and expression levels of systemic and cardiac DPP4. Moreover, vildagliptin and valsartan alone or in combination comparably upregulate the components of the cardiac ACE2/Ang-(1-7)/MasR while downregulating the ACE/Ang II/AT1R axis. SIGNIFICANCE: Vildagliptin or valsartan alone is as effective as combined to treat cardiac dysfunction and remodeling in experimental HF. DPP4 inhibition downregulates classic RAS components, and pharmacological RAS blockade downregulates DPP4 in the heart and serum of HF rats. This interplay between DPP4 and RAS may affect HF progression and pharmacotherapy.
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Dipeptidil Peptidasa 4 , Insuficiencia Cardíaca , Animales , Dipeptidil Peptidasa 4/metabolismo , Insuficiencia Cardíaca/tratamiento farmacológico , Masculino , Ratas , Ratas Wistar , Sistema Renina-Angiotensina , Valsartán/farmacología , Valsartán/uso terapéutico , Vildagliptina/farmacología , Vildagliptina/uso terapéuticoRESUMEN
Understanding how mutant KRAS signaling is modulated by exogenous stimuli is of utmost importance to elucidate resistance mechanisms underlying pathway inhibition failure, and to uncover novel therapeutic targets for mutant KRAS patients. Hence, aiming at perceiving KRAS-autonomous versus -non autonomous mechanisms, we studied the response of two mutant KRAS colorectal cancer cell lines (HCT116 and LS174T) upon KRAS silencing and treatment with rhTGFß1-activated fibroblasts secretome. A proteomic analysis revealed that rhTGFß1-activated fibroblast-secreted factors triggered cell line-specific proteome alterations and that mutant KRAS governs 43% and 38% of these alterations in HCT116 and LS174T cells, respectively. These KRAS-dependent proteins were localized and displayed molecular functions that were common to both cell lines (e.g., extracellular exosome, RNA binding functions). Moreover, 67% and 78% of the KRAS-associated proteome of HCT116 and LS174T cells, respectively, was controlled in a KRAS-non-autonomous manner, being dependent on fibroblast-secreted factors. In HCT116 cells, KRAS-non-autonomously controlled proteins were mainly involved in proteoglycans in cancer, p53, and Rap1 signaling pathways; whereas in LS174T cells, they were associated with substrate adhesion-dependent cell-spreading and involved in metabolic processes. This work highlights the context-dependency of KRAS-associated signaling and reinforces the importance of integrating the tumor microenvironment in the study of KRAS-associated effects.
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Neoplasias Colorrectales , Proteoma , Línea Celular Tumoral , Neoplasias Colorrectales/patología , Humanos , Mutación/genética , Proteoma/metabolismo , Proteómica , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Microambiente TumoralRESUMEN
Genetic alterations influence the malignant potential of cancer cells, and so does the tumor microenvironment. Herein, we combined the study of KRAS oncogenic effects in colorectal cancer cells with the influence of fibroblast-derived factors. Results revealed that mutant KRAS regulates cell fate through both autonomous and nonautonomous signaling mechanisms. Specifically, processes such as proliferation and cell-cell aggregation were autonomously controlled by mutant KRAS independently of the stimulation with fibroblasts conditioned media. However, cancer cell invasion revealed to be a KRAS-dependent nonautonomous effect, resulting from the cooperation between fibroblast-derived HGF and mutant KRAS regulation of C-MET expression. C-MET downregulation upon KRAS silencing rendered cells less responsive to HGF and thus less invasive. Yet, in one cell line, KRAS inhibition triggered invasion upon stimulation with fibroblasts conditioned media. Inhibition of PIK3CA oncogene did not promote invasion, thus showing a KRAS-specific effect. Moreover, the invasive capacity also depended on the HGF-C-MET axis. Overall, our study awards oncogenic KRAS an important role in modulating the response to fibroblast-secreted factors either by promoting or impairing invasion, and depicts the HGF-C-MET axis as a putative therapeutic target to impair the invasive properties of mutant KRAS cancer cells.
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Neoplasias Colorrectales , Factor de Crecimiento de Hepatocito , Línea Celular Tumoral , Fosfatidilinositol 3-Quinasa Clase I/genética , Fosfatidilinositol 3-Quinasa Clase I/metabolismo , Neoplasias Colorrectales/patología , Medios de Cultivo Condicionados/metabolismo , Medios de Cultivo Condicionados/farmacología , Fibroblastos/patología , Factor de Crecimiento de Hepatocito/genética , Factor de Crecimiento de Hepatocito/metabolismo , Humanos , Proteínas Proto-Oncogénicas c-met/genética , Proteínas Proto-Oncogénicas c-met/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Microambiente TumoralRESUMEN
Aspergillus fumigatus is a ubiquitous and saprophytic filamentous fungus and the main etiologic agent of aspergillosis. Infections caused by A. fumigatus culminate in a strong inflammatory response that can evolve into respiratory failure and may be lethal in immunocompromised individuals. In the last decades, it has been demonstrated that extracellular vesicles (EVs) elicit a notable biological response in immune cells. EVs carry a variety of biomolecules, therefore are considered potential antigen delivery vehicles. The role of EVs as a strategy for modulating an effective response against infections caused by A. fumigatus remains unexplored. Here we investigate the use of EVs derived from A. fumigatus as an immunization tool to induce a more robust immune response to A. fumigatus pulmonary infection. In order to investigate that, male C57BL/6 mice were immunized with two doses of EVs and infected with A. fumigatus. Pre-exposure of mice to EVs was able to induce the production of specific IgG serum for fungal antigens. Besides that, the immunization with EVs reduced the neutrophilic infiltrate into the alveoli, as well as the extravasation of total proteins and the production of proinflammatory mediators IL-1ß, IL-6, and CXCL-1. In addition, immunization prevented extensive lung tissue damage and also improved phagocytosis and fungus clearance. Noteworthy, immunization with EVs, associated with subclinical doses of Amphotericin B (AmB) treatment, rescued 50% of mice infected with A. fumigatus from lethal fungal pneumonia. Therefore, the present study shows a new role for A. fumigatus EVs as host inflammatory response modulators, suggesting their use as immunizing agents.