RESUMO
Autophagy supports both cellular and organismal homeostasis. However, whether autophagy should be inhibited or activated for cancer therapy remains unclear. Deletion of essential autophagy genes increased the sensitivity of mouse mammary carcinoma cells to radiation therapy in vitro and in vivo (in immunocompetent syngeneic hosts). Autophagy-deficient cells secreted increased amounts of type I interferon (IFN), which could be limited by CGAS or STING knockdown, mitochondrial DNA depletion or mitochondrial outer membrane permeabilization blockage via BCL2 overexpression or BAX deletion. In vivo, irradiated autophagy-incompetent mammary tumors elicited robust immunity, leading to improved control of distant nonirradiated lesions via systemic type I IFN signaling. Finally, a genetic signature of autophagy had negative prognostic value in patients with breast cancer, inversely correlating with mitochondrial abundance, type I IFN signaling and effector immunity. As clinically useful autophagy inhibitors are elusive, our findings suggest that mitochondrial outer membrane permeabilization may represent a valid target for boosting radiation therapy immunogenicity in patients with breast cancer.
Assuntos
Proteína 5 Relacionada à Autofagia/genética , Proteína 7 Relacionada à Autofagia/genética , Autofagia/genética , Neoplasias da Mama/radioterapia , DNA Mitocondrial/genética , Neoplasias Mamárias Animais/radioterapia , Mitocôndrias/metabolismo , Adulto , Idoso , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/mortalidade , Linhagem Celular Tumoral , Citotoxicidade Imunológica , Feminino , Humanos , Interferon Tipo I/metabolismo , Neoplasias Mamárias Animais/genética , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Prognóstico , Tolerância a Radiação , Transdução de Sinais , Análise de SobrevidaRESUMO
Hyperglycemia and hyperlipidemia are often observed in individuals with type II diabetes (T2D) and related mouse models. One dysmetabolic biochemical consequence is the non-enzymatic reaction between sugars, lipids, and proteins, favoring protein glycation, glycoxidation, and lipoxidation. Here, we identified oxidative alterations in key components of the major histocompatibility complex (MHC) class II molecule antigen processing and presentation machinery in vivo under conditions of hyperglycemia-induced metabolic stress. These modifications were linked to epitope-specific changes in endosomal processing efficiency, MHC class II-peptide binding, and DM editing activity. Moreover, we observed some quantitative and qualitative changes in the MHC class II immunopeptidome of Ob/Ob mice on a high-fat diet compared with controls, including changes in the presentation of an apolipoprotein B100 peptide associated previously with T2D and metabolic syndrome-related clinical complications. These findings highlight a link between glycation reactions and altered MHC class II antigen presentation that may contribute to T2D complications.
Assuntos
Apresentação de Antígeno/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Estresse Fisiológico/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Diabetes Mellitus Experimental/imunologia , Diabetes Mellitus Tipo 2/imunologia , Modelos Animais de Doenças , Epitopos/imunologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Peptídeos/imunologia , Ligação Proteica/imunologiaRESUMO
Mammalian cells respond to stress by activating mechanisms that support cellular functions and hence maintain microenvironmental and organismal homeostasis. Intracellular responses to stress, their regulation and their pathophysiological implications have been extensively studied. However, little is known about the signals that emanate from stressed cells to enable a coordinated adaptive response across tissues, organs and the whole organism. Considerable evidence has now accumulated indicating that the intracellular mechanisms that are activated in response to different stresses - which include the DNA damage response, the unfolded protein response, mitochondrial stress signalling and autophagy - as well as the mechanisms ensuring the proliferative inactivation or elimination of terminally damaged cells - such as cell senescence and regulated cell death - are all coupled with the generation of signals that elicit microenvironmental and/or systemic responses. These signals, which involve changes in the surface of stressed cells and/or the secretion of soluble factors or microvesicles, generally support systemic homeostasis but can also contribute to maladaptation and disease.
Assuntos
Homeostase/fisiologia , Estresse Fisiológico/fisiologia , Animais , Microambiente Celular/fisiologia , Senescência Celular/fisiologia , Humanos , Transdução de Sinais/fisiologiaRESUMO
Cancer cells undergoing immunogenic cell death (ICD) can initiate adaptive immune responses against dead cell-associated antigens, provided that (1) said antigens are not perfectly covered by central tolerance (antigenicity), (2) cell death occurs along with the emission of immunostimulatory cytokines and damage-associated molecular patterns (DAMPs) that actively engage immune effector mechanisms (adjuvanticity), and (3) the microenvironment of dying cells is permissive for the initiation of adaptive immunity. Finally, ICD-driven immune responses can only operate and exert cytotoxic effector functions if the microenvironment of target cancer cells enables immune cell infiltration and activity. Multiple forms of radiation, including non-ionizing (ultraviolet) and ionizing radiation, elicit bona fide ICD as they increase both the antigenicity and adjuvanticity of dying cancer cells. Here, we review the molecular determinants of ICD as elicited by radiation as we critically discuss strategies to reinforce the immunogenicity of cancer cells succumbing to clinically available radiation strategies.
Assuntos
Antineoplásicos , Neoplasias , Humanos , Morte Celular Imunogênica , Morte Celular , Imunidade Adaptativa , Microambiente TumoralRESUMO
While intracellular adenosine triphosphate (ATP) occupies a key position in the bioenergetic metabolism of all the cellular compartments that form the tumor microenvironment (TME), extracellular ATP operates as a potent signal transducer. The net effects of purinergic signaling on the biology of the TME depend not only on the specific receptors and cell types involved, but also on the activation status of cis- and trans-regulatory circuitries. As an additional layer of complexity, extracellular ATP is rapidly catabolized by ectonucleotidases, culminating in the accumulation of metabolites that mediate distinct biological effects. Here, we discuss the molecular and cellular mechanisms through which ATP and its degradation products influence cancer immunosurveillance, with a focus on therapeutically targetable circuitries.
Assuntos
Trifosfato de Adenosina/imunologia , Trifosfato de Adenosina/metabolismo , Neoplasias/imunologia , Neoplasias/metabolismo , Animais , Humanos , Transdução de Sinais/imunologia , Microambiente Tumoral/imunologia , Microambiente Tumoral/fisiologiaRESUMO
Inhibition of immune regulatory checkpoints, such as CTLA-4 and the PD-1-PD-L1 axis, is at the forefront of immunotherapy for cancers of various histological types. However, such immunotherapies fail to control neoplasia in a significant proportion of patients. Here, we review how a range of cancer-cell-autonomous cues, tumor-microenvironmental factors, and host-related influences might account for the heterogeneous responses and failures often encountered during therapies using immune-checkpoint blockade. Furthermore, we describe the emerging evidence of how the strong interrelationship between the immune system and the host microbiota can determine responses to cancer therapies, and we introduce a concept by which prior or concomitant modulation of the gut microbiome could optimize therapeutic outcomes upon immune-checkpoint blockade.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Receptores Coestimuladores e Inibidores de Linfócitos T/imunologia , Resistencia a Medicamentos Antineoplásicos , Imunoterapia/métodos , Neoplasias/terapia , Animais , Receptores Coestimuladores e Inibidores de Linfócitos T/antagonistas & inibidores , Humanos , Terapia de Alvo Molecular , Neoplasias/imunologia , Evasão Tumoral , Microambiente TumoralRESUMO
Checkpoint blockade immunotherapies can be extraordinarily effective, but might benefit only the minority of patients whose tumors are pre-infiltrated by T cells. Here, using lung adenocarcinoma mouse models, including genetic models, we show that autochthonous tumors that lacked T cell infiltration and resisted current treatment options could be successfully sensitized to host antitumor T cell immunity when appropriately selected immunogenic drugs (e.g., oxaliplatin combined with cyclophosphamide for treatment against tumors expressing oncogenic Kras and lacking Trp53) were used. The antitumor response was triggered by direct drug actions on tumor cells, relied on innate immune sensing through toll-like receptor 4 signaling, and ultimately depended on CD8(+) T cell antitumor immunity. Furthermore, instigating tumor infiltration by T cells sensitized tumors to checkpoint inhibition and controlled cancer durably. These findings indicate that the proportion of cancers responding to checkpoint therapy can be feasibly and substantially expanded by combining checkpoint blockade with immunogenic drugs.
Assuntos
Adenocarcinoma/terapia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Imunoterapia/métodos , Neoplasias Pulmonares/terapia , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Adenocarcinoma/imunologia , Animais , Linhagem Celular Tumoral , Sensibilização do Sistema Nervoso Central/efeitos dos fármacos , Ciclofosfamida/administração & dosagem , Modelos Animais de Doenças , Tratamento Farmacológico/métodos , Genes cdc/efeitos dos fármacos , Humanos , Imunidade Inata , Neoplasias Pulmonares/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Compostos Organoplatínicos/administração & dosagem , Oxaliplatina , Receptor 4 Toll-Like/metabolismoRESUMO
The efficacy of the anti-cancer immunomodulatory agent cyclophosphamide (CTX) relies on intestinal bacteria. How and which relevant bacterial species are involved in tumor immunosurveillance, and their mechanism of action are unclear. Here, we identified two bacterial species, Enterococcus hirae and Barnesiella intestinihominis that are involved during CTX therapy. Whereas E. hirae translocated from the small intestine to secondary lymphoid organs and increased the intratumoral CD8/Treg ratio, B. intestinihominis accumulated in the colon and promoted the infiltration of IFN-γ-producing γδT cells in cancer lesions. The immune sensor, NOD2, limited CTX-induced cancer immunosurveillance and the bioactivity of these microbes. Finally, E. hirae and B. intestinihominis specific-memory Th1 cell immune responses selectively predicted longer progression-free survival in advanced lung and ovarian cancer patients treated with chemo-immunotherapy. Altogether, E. hirae and B. intestinihominis represent valuable "oncomicrobiotics" ameliorating the efficacy of the most common alkylating immunomodulatory compound.
Assuntos
Ciclofosfamida/farmacologia , Streptococcus faecium ATCC 9790/imunologia , Fatores Imunológicos/imunologia , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Animais , Colo/imunologia , Colo/microbiologia , Memória Imunológica/imunologia , Imunoterapia/métodos , Interferon gama/imunologia , Intestino Delgado/imunologia , Intestino Delgado/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Monitorização Imunológica , Proteína Adaptadora de Sinalização NOD2/imunologia , Células Th1/imunologiaRESUMO
BACKGROUND: Preclinical evidence from us and others demonstrates that the anticancer effects of cyclin-dependent kinase 4/6 (CDK4/6) inhibitors can be enhanced with focal radiation therapy (RT), but only when RT is delivered prior to (rather than after) CDK4/6 inhibition. Depending on tumor model, cellular senescence (an irreversible proliferative arrest that is associated with the secretion of numerous bioactive factors) has been attributed beneficial or detrimental effects on response to treatment. As both RT and CDK4/6 inhibitors elicit cellular senescence, we hypothesized that a differential accumulation of senescent cells in the tumor microenvironment could explain such an observation, i.e., the inferiority of CDK4/6 inhibition with palbociclib (P) followed by RT (PâRT) as compared to RT followed by palbociclib (RTâP). METHODS: The impact of cellular senescence on the interaction between RT and P was assessed by harnessing female INK-ATTAC mice, which express a dimerizable form of caspase 8 (CASP8) under the promoter of cyclin dependent kinase inhibitor 2A (Cdkn2a, coding for p16Ink4), as host for endogenous mammary tumors induced by the subcutaneous implantation of medroxyprogesterone acetate (MPA, M) pellets combined with the subsequent oral administration of 7,12-dimethylbenz[a]anthracene (DMBA, D). This endogenous mouse model of HR+ mammary carcinogenesis recapitulates key immunobiological aspects of human HR+ breast cancer. Mice bearing M/D-driven tumors were allocated to RT, P or their combination in the optional presence of the CASP8 dimerizer AP20187, and monitored for tumor growth, progression-free survival and overall survival. In parallel, induction of senescence in vitro, in cultured human mammary hormone receptor (HR)+ adenocarcinoma MCF7 cells, triple negative breast carcinoma MDA-MB-231 cells and mouse HR+ mammary carcinoma TS/A cells treated with RT, P or their combination, was determined by colorimetric assessment of senescence-associated ß-galactosidase activity after 3 or 7 days of treatment. RESULTS: In vivo depletion of p16Ink4-expressing (senescent) cells ameliorated the efficacy of PâRT (but not that of RTâP) in the M/D-driven model of HR+ mammary carcinogenesis. Accordingly, PâRT induced higher levels of cellular senescence than RâTP in cultured human and mouse breast cancer cell lines. CONCLUSIONS: Pending validation in other experimental systems, these findings suggest that a program of cellular senescence in malignant cells may explain (at least partially) the inferiority of PâRT versus RTâP in preclinical models of HR+ breast cancer.
Assuntos
Neoplasias da Mama , Feminino , Humanos , Camundongos , Animais , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/radioterapia , Neoplasias da Mama/patologia , Quinase 6 Dependente de Ciclina , Senescência Celular/fisiologia , Proteínas de Transporte/metabolismo , Carcinogênese , Microambiente Tumoral , Quinase 4 Dependente de Ciclina/metabolismoRESUMO
The therapeutic efficacy of anthracyclines relies on antitumor immune responses elicited by dying cancer cells. How chemotherapy-induced cell death leads to efficient antigen presentation to T cells, however, remains a conundrum. We found that intratumoral CD11c(+)CD11b(+)Ly6C(hi) cells, which displayed some characteristics of inflammatory dendritic cells and included granulomonocytic precursors, were crucial for anthracycline-induced anticancer immune responses. ATP released by dying cancer cells recruited myeloid cells into tumors and stimulated the local differentiation of CD11c(+)CD11b(+)Ly6C(hi) cells. Such cells efficiently engulfed tumor antigens in situ and presented them to T lymphocytes, thus vaccinating mice, upon adoptive transfer, against a challenge with cancer cells. Manipulations preventing tumor infiltration by CD11c(+)CD11b(+)Ly6C(hi) cells, such as the local overexpression of ectonucleotidases, the blockade of purinergic receptors, or the neutralization of CD11b, abolished the immune system-dependent antitumor activity of anthracyclines. Our results identify a subset of tumor-infiltrating leukocytes as therapy-relevant antigen-presenting cells.
Assuntos
Antraciclinas/administração & dosagem , Células Apresentadoras de Antígenos/imunologia , Antineoplásicos/administração & dosagem , Células Dendríticas/imunologia , Neoplasias Experimentais/imunologia , Transferência Adotiva , Animais , Antraciclinas/efeitos adversos , Antígenos Ly/metabolismo , Antígenos de Neoplasias/imunologia , Antineoplásicos/efeitos adversos , Apoptose , Antígeno CD11b/metabolismo , Antígeno CD11c/metabolismo , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Células Precursoras de Granulócitos/imunologia , Imunidade Celular , Camundongos , Camundongos Endogâmicos C57BL , Células Precursoras de Monócitos e Macrófagos/imunologia , Neoplasias Experimentais/tratamento farmacológico , Nucleotidases/metabolismo , Receptores Purinérgicos/metabolismoRESUMO
Some strains of lactic acid bacteria (LAB) have anti-inflammatory effects, but the mechanism underlying the alleviation of inflammation by LAB is not fully understood. In this study, we examined the inhibitory effect of a certain strain of LAB, Lactobacillus paracasei, on inflammasome activation, which is associated with various inflammatory disorders. Using bone marrow-derived macrophages from BALB/c mice, we found that L. paracasei, but not L. rhamnosus, suppressed NLRP3 inflammasome activation and inhibited subsequent caspase-1 activation and IL-1ß secretion. L. paracasei also had inhibitory effects on AIM2 and NLRC4 inflammasome activation as well as the NLRP3 inflammasome. These inhibitory effects of L. paracasei on inflammasome activation were dependent on autocrine IL-10 induced by L. paracasei-stimulated macrophages. Furthermore, IL-10 production by L. paracasei-stimulated macrophages was involved with phagocytosis and the NOD2 signaling pathway in macrophages. In addition to in vitro studies, oral administration of L. paracasei in C57BL/6 mice reduced monosodium urate crystal-induced peritoneal inflammation in vivo. Moreover, continuous intake of L. paracasei in C57BL/6 mice alleviated high fat diet-induced insulin resistance and aging-induced expression of biomarkers for T cell senescence. Taken together, we demonstrated that L. paracasei inhibits inflammasome activation in vitro and exhibits an anti-inflammatory function in vivo. These results indicate that LAB that have inhibitory effects on inflammasome activation might contribute to the alleviation of inflammation-related disorders.
Assuntos
Inflamassomos/imunologia , Lacticaseibacillus paracasei/imunologia , Macrófagos/imunologia , Transdução de Sinais/imunologia , Animais , Proteínas Reguladoras de Apoptose/imunologia , Proteínas de Ligação ao Cálcio/imunologia , Caspase 1/imunologia , Proteínas de Ligação a DNA/imunologia , Inflamação/induzido quimicamente , Inflamação/imunologia , Inflamação/prevenção & controle , Interleucina-10/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Proteína Adaptadora de Sinalização NOD2/imunologiaRESUMO
In recent years, fracture image diagnosis using a convolutional neural network (CNN) has been reported. The purpose of the present study was to evaluate the ability of CNN to diagnose distal radius fractures (DRFs) using frontal and lateral wrist radiographs. We included 503 cases of DRF diagnosed by plain radiographs and 289 cases without fracture. We implemented the CNN model using Keras and Tensorflow. Frontal and lateral views of wrist radiographs were manually cropped and trained separately. Fine-tuning was performed using EfficientNets. The diagnostic ability of CNN was evaluated using 150 images with and without fractures from anteroposterior and lateral radiographs. The CNN model diagnosed DRF based on three views: frontal view, lateral view, and both frontal and lateral view. We determined the sensitivity, specificity, and accuracy of the CNN model, plotted a receiver operating characteristic (ROC) curve, and calculated the area under the ROC curve (AUC). We further compared performances between the CNN and three hand orthopedic surgeons. EfficientNet-B2 in the frontal view and EfficientNet-B4 in the lateral view showed highest accuracy on the validation dataset, and these models were used for combined views. The accuracy, sensitivity, and specificity of the CNN based on both anteroposterior and lateral radiographs were 99.3, 98.7, and 100, respectively. The accuracy of the CNN was equal to or better than that of three orthopedic surgeons. The AUC of the CNN on the combined views was 0.993. The CNN model exhibited high accuracy in the diagnosis of distal radius fracture with a plain radiograph.
Assuntos
Aprendizado Profundo , Cirurgiões Ortopédicos , Humanos , Redes Neurais de Computação , Radiografia , Punho/diagnóstico por imagemRESUMO
Lactobacillus paracasei KW3110 (KW3110) has anti-inflammatory effects, including the prevention of blue light exposure induced retinal inflammation and ageing-related chronic inflammation in mice. The mechanism involves the promotion of anti-inflammatory cytokine interleukin (IL)-10 production by KW3110, leading to reduced pro-inflammatory cytokine IL-1ß production. Although various stress-induced mitochondrial damages are associated with excessive inflammatory responses, the effect of KW3110 on inflammatory-stress-induced mitochondrial damage remains unknown. In this study, we investigated the effect of KW3110 on inflammatory stress-induced mitochondrial damage using the murine macrophage-like cell line J774A.1. KW3110 treatment suppressed lipopolysaccharide (LPS)-induced mitochondrial dysfunction, including downregulation of membrane potential, induction of reactive oxygen species, and respiratory dysfunction. In addition, KW3110 prevented LPS-induced disruption of mitochondrial morphology including cristae structures. IL-10 treatment also ameliorated LPS-induced mitochondrial dysfunction and morphology disruption. These results suggest that KW3110 prevents LPS-induced mitochondrial dysfunction, potentially via promoting IL-10 production in mouse macrophages. We are the first to reveal a suppressive effect of lactic acid bacteria on mitochondrial morphology disruption in inflammatory-stressed macrophages. Our findings contribute to understanding inflammatory-stress-induced mitochondrial damage and developing food ingredients with preventive effects on mitochondrial-damage-derived inflammatory conditions.
Assuntos
Interleucina-10/metabolismo , Lacticaseibacillus paracasei/fisiologia , Lipopolissacarídeos/efeitos adversos , Macrófagos/citologia , Mitocôndrias/metabolismo , Animais , Anti-Inflamatórios/metabolismo , Linhagem Celular , Regulação da Expressão Gênica/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Mitocôndrias/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Probióticos , Piroptose/efeitos dos fármacosRESUMO
Ionizing irradiation has been extensively employed for the clinical management of solid tumors, with therapeutic or palliative intents, for decades. Until recently, radiation therapy (RT) was believed to mediate antineoplastic activity mostly (if not only) as a consequence of cancer cell-intrinsic effects. Indeed, the macromolecular damage imposed to malignant cells by RT initiates one or multiple signal transduction cascades that drive a permanent proliferative arrest (cellular senescence) or regulated cell death. Both these phenomena show a rather linear dose-response correlation. However, RT also mediates consistent immunological activity, not only as an "on-target effect" originating within irradiated cancer cells, but also as an "off-target effect" depending on the interaction between RT and stromal, endothelial, and immune components of the tumor microenvironment. Interestingly, the immunological activity of RT does not exhibit linear dose-response correlation. Here, we discuss the mechanisms whereby RT alters the capacity of the immune system to recognize and eliminate irradiated cancer cells, either as an "on-target" or as on "off-target" effect. In particular, we discuss the antagonism between the immunostimulatory and immunosuppressive effects of RT as we delineate combinatorial strategies to boost the former at the expenses of the latter.
Assuntos
Morte Celular , Citotoxicidade Imunológica , Imunidade , Neoplasias/radioterapia , Animais , Antígenos de Neoplasias/imunologia , Autofagia , Terapia Combinada , Humanos , Neoplasias/imunologia , Radiação Ionizante , Transdução de Sinais , Microambiente TumoralRESUMO
Cancer cells are subjected to constant selection by the immune system, meaning that tumors that become clinically manifest have managed to subvert or hide from immunosurveillance. Immune control can be facilitated by induction of autophagy, as well as by polyploidization of cancer cells. While autophagy causes the release of ATP, a chemotactic signal for myeloid cells, polyploidization can trigger endoplasmic reticulum stress with consequent exposure of the "eat-me" signal calreticulin on the cell surface, thereby facilitating the transfer of tumor antigens into dendritic cells. Hence, both autophagy and polyploidization cause the emission of adjuvant signals that ultimately elicit immune control by CD8+ T lymphocytes. We investigated the possibility that autophagy and polyploidization might also affect the antigenicity of cancer cells by altering the immunopeptidome. Mass spectrometry led to the identification of peptides that were presented on major histocompatibility complex (MHC) class I molecules in an autophagy-dependent fashion or that were specifically exposed on the surface of polyploid cells, yet lost upon passage of such cells through immunocompetent (but not immunodeficient) mice. However, the preferential recognition of autophagy-competent and polyploid cells by the innate and cellular immune systems did not correlate with the preferential recognition of such peptides in vivo. Moreover, vaccination with such peptides was unable to elicit tumor growth-inhibitory responses in vivo. We conclude that autophagy and polyploidy increase the immunogenicity of cancer cells mostly by affecting their adjuvanticity rather than their antigenicity.
Assuntos
Adjuvantes Imunológicos , Antígenos de Neoplasias/imunologia , Morte Celular , Vigilância Imunológica , Neoplasias/imunologia , Trifosfato de Adenosina/metabolismo , Animais , Estresse do Retículo Endoplasmático , Humanos , Camundongos , Monitorização Imunológica , Transdução de SinaisRESUMO
Matured hop bitter acids (MHBA) are bitter acid oxides derived from hops, widely consumed as food ingredients to add bitterness and flavor in beers. Previous studies have suggested a potential gut-brain mechanism in which MHBA simulates enteroendocrine cells to produce cholecystokinin (CCK), a gastrointestinal hormone which activates autonomic nerves, resulting in body fat reduction and cognitive improvement; however, the MHBA recognition site on enteroendocrine cells has not been fully elucidated. In this study, we report that MHBA is recognized by specific human and mouse bitter taste receptors (human TAS2R1, 8, 10 and mouse Tas2r119, 130, 105) using a heterologous receptor expression system in human embryonic kidney 293T cells. In addition, knockdown of each of these receptors using siRNA transfection partially but significantly suppressed an MHBA-induced calcium response and CCK production in enteroendocrine cells. Furthermore, blocking one of the essential taste signaling components, transient receptor potential cation channel subfamily M member 5, remarkably inhibited the MHBA-induced calcium response and CCK production in enteroendocrine cells. Our results demonstrate that specific bitter taste receptor activation by MHBA drives downstream calcium response and CCK production in enteroendocrine cells. These findings reveal a mechanism by which food ingredients derived from hops in beer activate the gut-brain axis for the first time.
Assuntos
Cerveja/análise , Colecistocinina/metabolismo , Células Enteroendócrinas/metabolismo , Hormônios Gastrointestinais/metabolismo , Humulus/química , Receptores Acoplados a Proteínas G/metabolismo , Animais , Cálcio/metabolismo , Linhagem Celular , Técnicas de Silenciamento de Genes , Humanos , Camundongos , RNA Interferente Pequeno , Receptores Acoplados a Proteínas G/genética , Transdução de Sinais/fisiologia , PaladarRESUMO
Two resource articles recently published in Cell demonstrate that the elevated phenotypic complexity of the immune infiltrate in human lung adenocarcinomas and renal cell carcinomas can be reliably dissected with mass cytometry. These findings may pave the way to a new era of precision cancer immunotherapy.
Assuntos
Citometria de Fluxo , Espectrometria de Massas , Metais Pesados , Análise de Célula Única/instrumentação , Análise de Célula Única/métodos , Microambiente Tumoral/imunologia , Humanos , Imunoterapia , Medicina de PrecisãoRESUMO
Immunogenic cell death (ICD) is a particular form of cell death that can initiate adaptive immunity against antigens expressed by dying cells in the absence of exogenous adjuvants. This implies that cells undergoing ICD not only express antigens that are not covered by thymic tolerance, but also deliver adjuvant-like signals that enable the recruitment and maturation of antigen-presenting cells toward an immunostimulatory phenotype, culminating with robust cross-priming of antigen-specific CD8+ T cells. Such damage-associated molecular patterns (DAMPs), which encompass cellular proteins, small metabolites and cytokines, are emitted in a spatiotemporally defined manner in the context of failing adaptation to stress. Radiation therapy (RT) is a bona fide inducer of ICD, at least when employed according to specific doses and fractionation schedules. Here, we discuss the mechanisms whereby DAMPs emitted by cancer cells undergoing RT-driven ICD alter the functional configuration of the tumor microenvironment.
Assuntos
Alarminas , Morte Celular Imunogênica , Neoplasias/imunologia , Microambiente Tumoral/imunologia , Linfócitos T CD8-Positivos , Citocinas , HumanosRESUMO
RATIONALE: Hepatocellular carcinoma (HCC) is a highly malignant disease for which the development of prospective or prognostic biomarkers is urgently required. Although metabolomics is widely used for biomarker discovery, there are some bottlenecks regarding the comprehensiveness of detected features, reproducibility of methods, and identification of metabolites. In addition, information on localization of metabolites in tumor tissue is needed for functional analysis. Here, we developed a wide-polarity global metabolomics (G-Met) method, identified HCC biomarkers in human liver samples by high-definition mass spectrometry (HDMS), and demonstrated localization in cryosections using desorption electrospray ionization MS imaging (DESI-MSI) analysis. METHODS: Metabolic profiling of tumor (n = 38) and nontumor (n = 72) regions in human livers of HCC was performed by an ultrahigh-performance liquid chromatography quadrupole time-of-flight MS (UHPLC/QTOFMS) instrument equipped with a mixed-mode column. The HCC biomarker candidates were extracted by multivariate analyses and identified by matching values of the collision cross section and their fragment ions on the mass spectra obtained by HDMS. Cryosections of HCC livers, which included both tumor and nontumor regions, were analyzed by DESI-MSI. RESULTS: From the multivariate analysis, m/z 904.83 and m/z 874.79 were significantly high and low, respectively, in tumor samples and were identified as triglyceride (TG) 16:0/18:1(9Z)/20:1(11Z) and TG 16:0/18:1(9Z)/18:2(9Z,12Z) using the synthetic compounds. The TGs were clearly localized in the tumor or nontumor areas of the cryosection. CONCLUSIONS: Novel biomarkers for HCC were identified by a comprehensive and reproducible G-Met method with HDMS using a mixed-mode column. The combination analysis of UHPLC/QTOFMS and DESI-MSI revealed that the different molecular species of TGs were associated with tumor distribution and were useful for characterizing the progression of tumor cells and discovering prospective biomarkers.
Assuntos
Carcinoma Hepatocelular/diagnóstico , Neoplasias Hepáticas/diagnóstico , Fígado/patologia , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/metabolismo , Carcinoma Hepatocelular/metabolismo , Cromatografia Líquida de Alta Pressão , Humanos , Fígado/metabolismo , Neoplasias Hepáticas/metabolismo , Metaboloma , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
Lactobacillus paracasei KW3110 (KW3110) has anti-inflammatory effects and mitigates retinal pigment epithelium (RPE) cell damage caused by blue-light exposure. We investigated whether KW3110 suppresses chronic inflammatory stress-induced RPE cell damage by modulating immune cell activity and whether it improves ocular disorders in healthy humans. First, we showed that KW3110 treatment of mouse macrophages (J774A.1) produced significantly higher levels of interleukin-10 as compared with other lactic acid bacterium strains (all p < 0.01). Transferring supernatant from KW3110- and E. coli 0111:B4 strain and adenosine 5'-triphosphate (LPS/ATP)-stimulated J774A.1 cells to human retinal pigment epithelium (ARPE-19) cells suppressed senescence-associated phenotypes, including proliferation arrest, abnormal appearance, cell cycle arrest, and upregulation of cytokines, and also suppressed expression of tight junction molecule claudin-1. A randomized, double-blind, placebo-controlled parallel-group study of healthy subjects (n = 88; 35 to below 50 years) ingesting placebo or KW3110-containing supplements for 8 weeks showed that changes in critical flicker frequency, an indicator of eye fatigue, from the week-0 value were significantly larger in the KW3110 group at weeks 4 (p = 0.040) and 8 (p = 0.036). These results suggest that KW3110 protects ARPE-19 cells against premature senescence and aberrant expression of tight junction molecules caused by chronic inflammatory stress, and may improve chronic eye disorders including eye fatigue.