RESUMEN
The aging process in the elderly results in heightened skin fragility associated with various disorders, including pressure ulcers (PUs). Despite the high incidence of PUs in the elderly population, there is a limited body of research specifically examining the impact of aging on the development of pressure ulcers. Therefore, investigating age-related physiological abnormalities is essential to elucidate the pathogenesis of PUs. Ischemia-reperfusion (I/R) injury and the subsequent oxidative stress caused by reactive oxygen species (ROS) play essential roles in the early stage of PUs. In this study, we used a mouse model of proteasomal dysfunction with an age-related phenotype to examine the role of proteasome activity in cutaneous I/R injury in vivo. Decreased proteasome function did not affect the expression of inflammatory cytokines and adhesion molecules in the I/R area in transgenic mice; however, proteasome inhibition increased oxidative stress that was not attenuated by activation of the oxidative stress response mediated by NF-E2-related factor 2 (Nrf2). In dermal fibroblasts (FCs) subjected to hypoxia-reoxygenation (H/R), proteasome inhibition induced oxidative stress and ROS production, and Nrf2 activation did not adequately upregulate antioxidant enzyme expression, possibly leading to antioxidant/oxidant imbalance. The free radical scavenger edaravone had protective effects against I/R injury in vivo and decreased oxidative stress in FCs treated with a proteasome inhibitor and subjected to H/R in vitro. The results suggest that the age-related decline in proteasome activity promotes cutaneous I/R injury-induced oxidative stress, and free radical scavengers may exert protective effects by preventing oxidative stress in the early stage of PUs.
Asunto(s)
Factor 2 Relacionado con NF-E2 , Estrés Oxidativo , Úlcera por Presión , Complejo de la Endopetidasa Proteasomal , Especies Reactivas de Oxígeno , Daño por Reperfusión , Úlcera por Presión/metabolismo , Úlcera por Presión/patología , Animales , Complejo de la Endopetidasa Proteasomal/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Ratones , Daño por Reperfusión/patología , Daño por Reperfusión/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Factor 2 Relacionado con NF-E2/genética , Ratones Transgénicos , Fibroblastos/metabolismo , Fibroblastos/patología , Fibroblastos/efectos de los fármacos , Modelos Animales de Enfermedad , Humanos , Masculino , Piel/patología , Piel/metabolismo , Piel/efectos de los fármacos , Ratones Endogámicos C57BLRESUMEN
Low-grade chronic inflammation contributes to both aging and the pathogenesis of age-related diseases. White adipose tissue (WAT) in obese individuals exhibits chronic inflammation, which is associated with obesity-related disorders. Aging exacerbates obesity-related inflammation in WAT; however, the molecular mechanisms underlying chronic inflammation and its exacerbation by aging remain unclear. Age-related decline in activity of the proteasome, a multisubunit proteolytic complex, has been implicated in age-related diseases. This study employed a mouse model with decreased proteasomal function that exhibits age-related phenotypes to investigate the impact of adipocyte senescence on WAT inflammation. Transgenic mice expressing proteasomal subunit ß5t with weak chymotrypsin-like activity experience reduced lifespan and develop age-related phenotypes. Mice fed with a high-fat diet and experiencing proteasomal dysfunction exhibited increased WAT inflammation, increased infiltration of proinflammatory M1-like macrophages, and increased proinflammatory adipocytokine-like monocyte chemoattractant protein-1, plasminogen activator inhibitor-1, and tumor necrosis factor-α, which are all associated with activation of endoplasmic reticulum (ER) stress-related pathways. Impaired proteasomal activity also activated ER stress-related molecules and induced expression of proinflammatory adipocytokines in adipocyte-like cells differentiated from 3T3-L1 cells. Collectively, the results suggesed that impaired proteasomal activity increases ER stress and that subsequent inflammatory pathways play pivotal roles in WAT inflammation. Because proteasomal function declines with age, age-related proteasome impairment may be involved in obesity-related inflammation among elderly individuals.
Asunto(s)
Estrés del Retículo Endoplásmico , Inflamación , Ratones Transgénicos , Obesidad , Complejo de la Endopetidasa Proteasomal , Animales , Complejo de la Endopetidasa Proteasomal/metabolismo , Estrés del Retículo Endoplásmico/fisiología , Inflamación/patología , Inflamación/metabolismo , Obesidad/metabolismo , Obesidad/patología , Ratones , Tejido Adiposo Blanco/metabolismo , Tejido Adiposo Blanco/patología , Ratones Endogámicos C57BL , Dieta Alta en Grasa/efectos adversos , Adipocitos/metabolismo , Adipocitos/patología , Masculino , Macrófagos/metabolismo , Macrófagos/patología , Envejecimiento/patología , Envejecimiento/metabolismo , Tejido Adiposo/patología , Tejido Adiposo/metabolismo , Células 3T3-L1 , Enfermedad CrónicaRESUMEN
Pressure ulcers represent a crucial clinical problem, especially in hospitalized patients. Ischemia-reperfusion (I-R) is an important cause of these lesions. Natural killer (NK), invariant NK T (iNKT), and dendritic epidermal T-cells, which express the natural killer group 2, member D (NKG2D) receptor, have been reported to have physiological roles in skin tissue repair and wound healing. However, a role for NKG2D-NKG2D ligand interactions in I-R-induced skin injury has not been determined. Using a murine pressure ulcer model, we demonstrated that I-R-induced ulcers in NKG2D-deficient mice were larger than those in wild-type or T-cell receptor δ knockout mice. Histopathological evaluation revealed that accumulation of macrophages and neutrophils at the peripheral deep dermis and subcutaneous tissue of the ulcers was enhanced in NKG2D-deficient mice. Rae-1 mRNA, which encodes an NKG2D ligand, was induced, and RAE-1 protein was detected immunohistochemically in fibroblasts and inflammatory cells in the dermis after reperfusion. RAE-1 expression was also increased in primary mouse fibroblasts treated with sodium arsenite. These results suggested that NKG2D ligand expression was induced by oxidative stress after I-R injury and support a putative role for this ligand in wound repair. Furthermore, the influx of NKG2D-positive cells at I-R sites may mitigate pressure ulcers via NKG2D-NKG2D ligand interactions.
Asunto(s)
Úlcera por Presión , Daño por Reperfusión , Ratones , Animales , Subfamilia K de Receptores Similares a Lectina de Células NK/genética , Subfamilia K de Receptores Similares a Lectina de Células NK/metabolismo , Ligandos , Úlcera , Ratones Noqueados , Estrés Oxidativo , Ratones Endogámicos C57BLRESUMEN
The proteasome is a multisubunit protease that degrades intracellular proteins into small peptides. Besides playing a pivotal role in many cellular processes indispensable for survival, it is involved in the production of peptides presented by major histocompatibility complex class I molecules. In addition to the standard proteasome shared in all eukaryotes, jawed vertebrates have two specialized forms of proteasome known as immunoproteasomes and thymoproteasomes. The immunoproteasome, which contains cytokine-inducible catalytic subunits with distinct cleavage specificities, produces peptides presented by class I molecules more efficiently than the standard proteasome. The thymoproteasome, which contains a unique catalytic subunit ß5t, is a tissue-specific proteasome expressed exclusively in cortical thymic epithelial cells. It plays a critical role in CD8+ cytotoxic T cell development via positive selection. This review provides a brief overview on the structure and function of these specialized forms of proteasome and their involvement in human disease.
Asunto(s)
Complejo de la Endopetidasa Proteasomal , Animales , Presentación de Antígeno , Enfermedades Autoinmunes/inmunología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Antígenos de Histocompatibilidad Clase I/metabolismo , Humanos , Neoplasias/inmunología , Complejo de la Endopetidasa Proteasomal/inmunología , Complejo de la Endopetidasa Proteasomal/metabolismo , Timoma/inmunología , Virosis/inmunologíaRESUMEN
AIM: The immunoproteasome is a specific proteasome isoform whose proteolytic activity enhances the generation of antigenic peptides to be presented by major histocompatibility complex class I molecules to CD8+ T cells. Physiologically, it is expressed abundantly in immune cells and is induced in somatic cells by cytokines, especially interferon-γ. Recently, variable expression of immunoproteasomes has been demonstrated in different types of cancers. However, the clinical significance of immunoproteasome expression in malignant tumours is poorly understood. In this study, we performed clinicopathological evaluation of immunoproteasome subunit ß5i in non-small cell lung carcinomas (NSCLCs). METHODS: Tumour tissues were collected from 155 patients with NSCLCs, and immunohistochemical analysis for ß5i was performed in relation to the prognosis of patients. RESULTS: High expression of ß5i was found in about 20% of all NSCLCs and was found significantly more frequently (40%) in the adenocarcinoma subset. High expression of ß5i was associated with a better 5-year relative survival rate in patients with pStage I to II adenocarcinoma and was also a significant and independent favourable prognostic factor in adenocarcinoma patients. In addition, when we performed in vitro analysis using NSCLC cell lines, combined treatment with the immunoproteasome-specific inhibitor ONX0914 and the proteasome inhibitor MG132 enhanced cell death in ß5i-expressing NSCLC cell lines. CONCLUSION: The expression of immunoproteasome can be explored as both a prognostic factor and a potential therapeutic target in NSCLCs. Since immunoproteasomes have crucial role in the antigen presentation, further studies may help to provide essential knowledge for therapeutic strategies in anticancer immunotherapy.
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Biomarcadores de Tumor/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/enzimología , Neoplasias Pulmonares/enzimología , Complejo de la Endopetidasa Proteasomal/metabolismo , Células A549 , Anciano , Antineoplásicos/farmacología , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/patología , Femenino , Humanos , Inmunohistoquímica , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Pronóstico , Inhibidores de Proteasoma/farmacologíaRESUMEN
AIM: Cathepsins are proteases that regulate a wide range of physiological processes, including protein turnover, cell signalling and antigen presentation. Recent studies have shown that cathepsins are highly upregulated in many types of tumours. Of the 15 cathepsins in humans, cathepsins V and S are abundantly expressed in the thymus, and we previously showed that the immunostaining of these cathepsins could serve as diagnostic markers for thymic epithelial tumours. However, little is known about the expression of other cathepsins in thymic epithelial tumours. To determine the diagnostic implications of cathepsins, we performed immunohistochemical analysis of cathepsin B (CTB), cathepsin D (CTD) and cathepsin K (CTK), all of which have been reported to correlate with the progression of squamous cell carcinoma. METHODS: The association between cathepsin expression and clinicopathological features was evaluated in 122 cases of thymoma and thymic carcinoma. RESULTS: CTB and CTD were frequently expressed in type A and type AB thymomas. In contrast, CTB and CTD were significantly less common in type B thymomas than in type A or AB thymomas. In type AB thymomas, the expression of CTB correlated with histological features, and was found predominantly in the type A component. Notably, CTK was expressed most commonly in thymic carcinomas, and patients who died of the disease showed increased expression of CTK. CONCLUSIONS: The expression of CTB and CTD correlated with the histological subtype of thymoma. In addition, the expression of CTK appears to be useful for the diagnosis of thymic carcinomas and as a prognostic marker.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Catepsina B/biosíntesis , Catepsina D/biosíntesis , Catepsina K/biosíntesis , Neoplasias Glandulares y Epiteliales/patología , Neoplasias del Timo/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/análisis , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Glandulares y Epiteliales/metabolismo , Neoplasias del Timo/metabolismo , Adulto JovenRESUMEN
Alzheimer disease (AD) is a progressive neurodegenerative disorder and the most common type of dementia worldwide. There is considerable evidence of age-related disruption of proteostasis being responsible for the development of AD. The proteasome is a multicatalytic enzyme complex that degrades both normal and damaged proteins, and an age-related decline in its activity has been implicated in age-related pathologies. Although proteasomal dysfunction is assumed to be a key AD hallmark, it remains unclear whether its role in disease onset is causative or secondary. In this study, we demonstrate that mice with proteasomal dysfunction exhibited memory impairment with associated neuronal loss, accumulation of phosphorylated tau, and activation of endoplasmic reticulum (ER) stress-related apoptosis pathways. Impaired proteasomal activity also activated ER stress-related apoptosis pathways in HT-22, a murine hippocampal neuronal cell line. HT-22 cell death, caused by proteasomal inhibition, was prevented by an inhibitor of c-Jun N-terminal kinase, an ER stress-related molecule. Collective evidence suggests that impaired proteasomal activity alters proteostasis, and subsequent ER stress-mediated pathways play pivotal roles in neuronal loss. Because aging decreases proteasomal function, age-related impairment of proteasomes may be involved in the development and progression of AD in elderly patients.
Asunto(s)
Encéfalo/patología , Estrés del Retículo Endoplásmico/fisiología , Trastornos de la Memoria/patología , Neuronas/patología , Complejo de la Endopetidasa Proteasomal/metabolismo , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Animales , Apoptosis/fisiología , Encéfalo/metabolismo , Trastornos de la Memoria/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Neuronas/metabolismo , Proteínas tau/metabolismoRESUMEN
Jawless vertebrates diverged from an ancestor of jawed vertebrates approximately 550 million years ago. They mount adaptive immune responses to repetitive antigenic challenges, despite lacking major histocompatibility complex molecules, immunoglobulins, T cell receptors, and recombination-activating genes. Instead of B cell and T cell receptors, agnathan lymphocytes express unique antigen receptors named variable lymphocyte receptors (VLRs), which generate diversity through a gene conversion-like mechanism. Although gnathostome antigen receptors and VLRs are structurally unrelated, jawed and jawless vertebrates share essential features of lymphocyte-based adaptive immunity, including the expression of a single type of receptor on each lymphocyte, clonal expansion of antigen-stimulated lymphocytes, and the dichotomy of cellular and humoral immunity, indicating that the backbone of the adaptive immune system was established in a common ancestor of all vertebrates. Furthermore, recent evidence indicates that, unlike previously thought, agnathans have a unique classical pathway of complement activation where VLRB molecules act as antibodies instead of immunoglobulins. It seems likely that the last common ancestor of all vertebrates had an adaptive immune system resembling that of jawless vertebrates, suggesting that, as opposed to jawed vertebrates, agnathans have retained the prototype of vertebrate adaptive immunity.
Asunto(s)
Inmunidad Adaptativa/genética , Inmunidad Adaptativa/inmunología , Vertebrados/inmunología , Animales , Anticuerpos/genética , Anticuerpos/inmunología , Evolución Biológica , Vía Clásica del Complemento , Citidina Desaminasa/genética , Citidina Desaminasa/inmunología , Citocinas/genética , Citocinas/inmunología , Inmunidad Innata , Linfocitos/citología , Linfocitos/inmunología , Receptores de Antígenos/genética , Receptores de Antígenos/inmunología , Receptores Toll-Like/genética , Receptores Toll-Like/inmunología , Vertebrados/genéticaRESUMEN
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMEN
Comparative analyses suggest that the MHC was derived from a prevertebrate "primordial immune complex" (PIC). PIC duplicated twice in the well-studied two rounds of genome-wide duplications (2R) early in vertebrate evolution, generating four MHC paralogous regions (predominantly on human chromosomes [chr] 1, 6, 9, 19). Examining chiefly the amphibian Xenopus laevis, but also other vertebrates, we identified their MHC paralogues and mapped MHC class I, AgR, and "framework" genes. Most class I genes mapped to MHC paralogues, but a cluster of Xenopus MHC class Ib genes (xnc), which previously was mapped outside of the MHC paralogues, was surrounded by genes syntenic to mammalian CD1 genes, a region previously proposed as an MHC paralogue on human chr 1. Thus, this gene block is instead the result of a translocation that we call the translocated part of the MHC paralogous region (MHCtrans) Analyses of Xenopus class I genes, as well as MHCtrans, suggest that class I arose at 1R on the chr 6/19 ancestor. Of great interest are nonrearranging AgR-like genes mapping to three MHC paralogues; thus, PIC clearly contained several AgR precursor loci, predating MHC class I/II. However, all rearranging AgR genes were found on paralogues derived from the chr 19 precursor, suggesting that invasion of a variable (V) exon by the RAG transposon occurred after 2R. We propose models for the evolutionary history of MHC/TCR/Ig and speculate on the dichotomy between the jawless (lamprey and hagfish) and jawed vertebrate adaptive immune systems, as we found genes related to variable lymphocyte receptors also map to MHC paralogues.
Asunto(s)
Antígenos CD1/genética , Bases de Datos Genéticas , Antígenos de Histocompatibilidad Clase I/genética , Proteínas de Xenopus/genética , Animales , Antígenos CD1/inmunología , Antígenos de Histocompatibilidad Clase I/inmunología , Proteínas de Xenopus/inmunología , Xenopus laevisRESUMEN
Cancer vaccines consist of a tumor-associated antigen (TAA) and adjuvant. These vaccines induce and activate proliferation of TAA-specific cytotoxic T lymphocytes (CTLs), suppressing tumor growth. The therapeutic efficacy of TAA-specific CTLs depends on the properties of tumor microenvironment. The environments make immunosuppressive by function of regulatory T cells and tumor-associated myeloid cells; thus, regulation of these cells is important for successful cancer immunotherapy. We report here that L-ergothioneine (EGT) with the adjuvant Toll-like receptor 2 (TLR2) ligand modulated suppressive microenvironments to be immune-enhancing. EGT did not augment DC-mediated CTL priming or affect CTL activation in draining lymph node and spleen. However, EGT decreased the immuno-suppressive function of tumor-associated macrophages (TAMs). TLR2 stimulation accompanied with EGT administration downregulated expression of PD-L1, CSF-1R, arginase-1, FAS ligand, and TRAIL in TAMs, reflecting reduction of CTL suppression. An anti-oxidative thiol-thione residue of EGT was essential to dampening CTL suppression. The effect was specific to the thiol-thione residue of EGT because no effect was observed with another anti-oxidant N-acetyl-L-cysteine (NAC). A CTL-suppressive environment made by TLR2 is relieved to be improved by the addition of EGT, which may ameliorate the efficacy of vaccine immunotherapy.
Asunto(s)
Antioxidantes/farmacología , Vacunas contra el Cáncer/inmunología , Ergotioneína/farmacología , Inmunoterapia , Microambiente Tumoral/efectos de los fármacos , Microambiente Tumoral/inmunología , Animales , Antioxidantes/química , Línea Celular Tumoral , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Ergotioneína/química , Femenino , Humanos , Inmunización , Ligandos , Linfocitos Infiltrantes de Tumor , Ratones , Modelos Moleculares , Neoplasias/inmunología , Neoplasias/metabolismo , Neoplasias/patología , Neoplasias/terapia , Linfocitos T Citotóxicos/efectos de los fármacos , Linfocitos T Citotóxicos/inmunología , Linfocitos T Citotóxicos/metabolismo , Receptor Toll-Like 2/metabolismo , Receptor Toll-Like 6/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Proteasomes are a multi-subunit protease complex that produces peptides bound by major histocompatibility complex (MHC) class I molecules. Phylogenetic studies indicate that two specialized forms of proteasomes, immunoproteasomes and thymoproteasomes, and the proteasome activator PA28αß emerged in a common ancestor of jawed vertebrates which acquired adaptive immunity based on the MHC, T cell receptors, and B cell receptors ~ 500 million years ago. Comparative genomics studies now provide strong evidence that the genes coding for the immunoproteasome subunits emerged by genome-wide duplication. On the other hand, the gene encoding the thymoproteasome subunit ß5t emerged by tandem duplication from the gene coding for the ß5 subunit. Strikingly, birds lack immunoproteasomes, thymoproteasomes, and the proteasome activator PA28αß, raising an interesting question of whether they have evolved any compensatory mechanisms.
Asunto(s)
Inmunidad Adaptativa/inmunología , Presentación de Antígeno/inmunología , Evolución Molecular , Antígenos de Histocompatibilidad Clase I/inmunología , Complejo de la Endopetidasa Proteasomal/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Linfocitos T/inmunología , Animales , Antígenos de Histocompatibilidad Clase I/metabolismo , Humanos , Complejo de la Endopetidasa Proteasomal/metabolismo , Receptores de Antígenos de Linfocitos T/metabolismo , Linfocitos T/metabolismoRESUMEN
The thymoproteasome subunit ß5t is specifically expressed in cortical thymic epithelial cells (TECs) and generates unique peptides to support positive selection. In this study, using a mouse model ubiquitously expressing ß5t, we showed that aberrant expression of self-peptides generated by ß5t affects CD8+ T cell homeostasis, including thymic selection and maintenance of the peripheral naive pool of CD8+ T cells. In mice in which ß5t was expressed both in cortical and medullary TECs, the abundance of CD8+ lineage thymocytes was reduced, and extra-thymic expression of ß5t caused accumulation of CD8+ T cells with the memory or exhausted phenotype and induced autoreactive T cell responses. We found that thymoproteasomes are essential for positive selection but that the subsequent change in peptide repertoire in the medulla is also crucial for thymic selection and that ß5t-derived peptide must be confined to the thymus to avoid autoimmunity in peripheral tissues.
Asunto(s)
Linfocitos T CD8-positivos/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Timocitos/metabolismo , Animales , Homeostasis , Humanos , RatonesRESUMEN
The MILL family, composed of MILL1 and MILL2, is a group of nonclassical MHC class I molecules that occur in some orders of mammals. It has been reported that mouse MILL2 is involved in wound healing; however, the molecular mechanisms remain unknown. Here, we determine the crystal structure of MILL2 at 2.15 Å resolution, revealing an organization similar to classical MHC class I. However, the α1-α2 domains are not tightly fixed on the α3-ß2m domains, indicating unusual interdomain flexibility. The groove between the two helices in the α1-α2 domains is too narrow to permit ligand binding. Notably, an unusual basic patch on the α3 domain is involved in the binding to heparan sulfate which is essential for MILL2 interactions with fibroblasts. These findings suggest that MILL2 has a unique structural architecture and physiological role, with binding to heparan sulfate proteoglycans on fibroblasts possibly regulating cellular recruitment in biological events.
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Heparitina Sulfato/metabolismo , Antígenos de Histocompatibilidad Clase I/química , Antígenos de Histocompatibilidad Clase I/metabolismo , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/metabolismo , Animales , Ratones , Modelos Moleculares , Unión Proteica , Dominios Proteicos , Estructura Secundaria de Proteína , Proteínas Recombinantes/metabolismoRESUMEN
Pancreatic ductal adenocarcinoma (PDAC) reportedly progresses very rapidly through the initial carcinogenesis stages including DNA damage and disordered cell death. However, such oncogenic mechanisms are largely studied through observational diagnostic methods, partly because of a lack of live in vitro tumour imaging techniques. Here we demonstrate a simple live-tumour in vitro imaging technique using micro-patterned plates (micro/nanoplates) that allows dynamic visualisation of PDAC microtumours. When PDAC cells were cultured on a micro/nanoplate overnight, the cells self-organised into non-spheroidal microtumours that were anchored to the micro/nanoplate through cell-in-cell invasion. This self-organisation was only efficiently induced in small-diameter rough microislands. Using a time-lapse imaging system, we found that PDAC microtumours actively stretched to catch dead cell debris via filo/lamellipoedia and suction, suggesting that they have a sophisticated survival strategy (analogous to that of starving animals), which implies a context for the development of possible therapies for PDACs. The simple tumour imaging system visualises a potential of PDAC cells, in which the aggressive tumour dynamics reminds us of the need to review traditional PDAC pathogenesis.
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Carcinoma Ductal Pancreático/patología , Técnicas de Cultivo de Célula/instrumentación , Neoplasias Pancreáticas/patología , Imagen de Lapso de Tiempo/métodos , Tubulina (Proteína)/metabolismo , Animales , Carcinoma Ductal Pancreático/metabolismo , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Supervivencia Celular , Humanos , Masculino , Ratones , Microscopía Fluorescente , Nanoestructuras , Invasividad Neoplásica , Trasplante de Neoplasias , Neoplasias Pancreáticas/metabolismo , Fosfatidilserinas/metabolismo , Transducción de Señal , Células Tumorales CultivadasRESUMEN
The basic principle of adaptive immunity is to strictly discriminate between self and non-self, and a central challenge to overcome is the enormous variety of pathogens that might be encountered. In cell-mediated immunity, immunological discernment takes place at a molecular or cellular level. Central to both mechanisms of discernment is the generation of antigenic peptides associated with MHC class I molecules, which is achieved by a proteolytic complex called the proteasome. To adequately accomplish the discrimination between self and non-self that is essential for adaptive immunity and self-tolerance, two proteasome subtypes have evolved via gene duplication: the immunoproteasome and the thymoproteasome. In this Review, we describe various aspects of these immunity-dedicated proteasomes, from their discovery to recent findings.
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Enfermedades Autoinmunes/inmunología , Evolución Molecular , Complejo de la Endopetidasa Proteasomal/inmunología , Timo/inmunología , Inmunidad Adaptativa , Animales , Autoantígenos/inmunología , Duplicación de Gen , Antígenos de Histocompatibilidad Clase I/inmunología , Humanos , Péptidos/inmunología , Complejo de la Endopetidasa Proteasomal/genética , Proteolisis , AutotoleranciaRESUMEN
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal refractory cancers. Aggressive features in PDAC cells have been well studied, but those exhibited by a population of PDAC cells are largely unknown. We show here that coculture with epithelial-like feeder cells confers more malignant phenotypes upon PDAC cells forming anchorage-dependent multicellular aggregates (Ad-MCAs, a behavior of collective cells), in vitro. When CD44v3-10high/CD44slow PDAC cell lines, which exhibited an epithelial phenotype before the onset of epithelial-mesenchymal transition (EMT), were cocultured with a monolayer of HEK293T cells overnight, they formed Ad-MCAs on the feeder layer and acquired gemcitabine resistance. CD44v8-10 expression was dramatically increased and Ki-67 staining decreased, suggesting that PDAC cells forming Ad-MCAs acquired cancer stem cell (CSC)-like intractable properties. We found that highly downregulated genes in PDAC cells cocultured with HEK293T cells were significantly upregulated in malignant lesions from pancreatic cancer patients. Our work implies that PDAC cells forming Ad-MCAs partially return to a normal tissue gene profile before the onset of EMT. The collective cell behavior like Ad-MCA formation by PDAC cells may mimic critical events that occur in cancer cells at the very early phase of metastatic colonization.
RESUMEN
PSF3 (Partner of SLD Five 3) is a member of the heterotetrameric complex termed GINS. Previous studies have shown that PSF3 is up-regulated in several cancers and is associated with tumor malignancy. However, the clinicopathological significance of PSF3 expression in endometrial lesions is still poorly understood. To investigate whether PSF3 could serve as a useful biomarker for endometrial carcinomas, we performed immunohistochemical analysis of PSF3 expression. In 155 cases of endometrial carcinomas (ECs), the mean tumor proportion score of PSF3 expression was 30.7% in G1 endometrioid carcinoma, 55.0% in G2 endometrioid carcinoma, 59.0% in G3 endometrioid carcinoma, and 58.9% in nonendometrioid carcinomas. In 25 cases of atypical hyperplasia, the mean tumor proportion score of PSF3 expression was significantly lower (10.4%). High expression of PSF3 was associated with more advanced pathologic T stage (Pâ¯=â¯.000), lymphatic invasion (Pâ¯=â¯.001), and poor clinical outcomes such as shorter relapse-free survival (Pâ¯=â¯.000) and overall survival (Pâ¯=â¯.001). When we compared the immunostaining of PSF3 and Ki-67, the proportions of PSF3-positive cells in tumor epithelial cells were comparable to those of Ki-67-positive cells. However, PSF3-positive cells were selectively found in tumor cells, whereas Ki-67-positive cells were also found in tumor stromal cells. These results demonstrated that PSF3 immunostaining was valuable as a histopathologic marker for differential diagnosis between atypical hyperplasia and ECs, for tumor histologic grading, and for determining a patient's prognosis. PSF3 may play a crucial role in tumor progression in EC.