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RESUMEN Desde 1996 esta enfermedad figura en la clasificación de las miocardiopatías de la OMS con el nombre de "miocardiopatía arritmogénica". A fines de la década del 70 se estableció que el ventrículo derecho (VD) puede ser el sustrato para el desarrollo de arritmias. En la década del 80 se describió el reemplazo del miocardio por tejido fibroadiposo y su naturaleza hereditaria. Posteriores descubrimientos permitieron la identificación de varios genes implicados en la producción de proteínas desmosómicas que participan en el acoplamiento intercelular lo cual llevó a definir a la miocardiopatía arritmogénica como una enfermedad desmosómica. El electrocardiograma y el ecocardiograma resultaron fundamentales y la angiocardiografía invasiva se utilizó para detectar disquinesia-aquinesia y aneurismas del VD. La biopsia endomiocárdica se perfiló como el gold standard para el diagnóstico, debido a su capacidad para detectar el reemplazo transmural por tejido fibroadiposo. El advenimiento de la resonancia magnética cardíaca (RMC) con realce tardío de gadolinio ha permitido revelar no solamente anomalías morfológico-funcionales sino también daño tisular. El conocimiento de la estructura del disco intercalar, involucrado en el acoplamiento intercelular ha permitido determinar que no solamente los desmosomas estarían comprometidos, sino que habría varias proteínas constituyentes tanto de los desmosomas, como de las uniones adherentes, las uniones gap, y los canales iónicos, integradas en una unidad conocida como "área composita". Ésta constituye una amalgama entre elementos de sostén y canales iónicos que participan en la propagación del potencial de acción, lo que ha permitido desarrollar el concepto de disco intercalar compuesto por los llamados "nodos excitoadhesivos". Las implicancias clínicas en el desarrollo de arritmias malignas son obvias.
ABSTRACT In 1996 this disease was introduced into the WHO classification of cardiomyopathies with the term "arrhythmogenic cardiomyopathy". By the end of the 70s the right ventricle (RV) was identified as a substrate for the development of arrhythmias. The replacement of the myocardium by fibrofatty tissue and the hereditary nature of this condition were described in the 1980s. Later findings led to the identification of several genes involved in the production of desmosomal proteins participating in intercellular coupling, which led to defining arrhythmogenic cardiomyopathy as a desmosomal disease. Electrocardiography and echocardiography are fundamental tools, and invasive angiocardiography was used to detect dyskinesia-akinesia and right ventricular aneurysms. Endomyocardial biopsy was established as the gold standard for the diagnosis due to its ability to detect transmural replacement by fibrofatty tissue. The advent of cardiac magnetic resonance imaging (CMRI) with late gadolinium enhancement reveals morphological and functional abnormalities and tissue damage. The understanding of intercalated disc structure involved in intercellular coupling has made it possible to determine that, apart from desmosomes, several desmosomal proteins, as adherens junctions, gap junctions and ion channels are integrated into a unit known as the " area composita". The area composita constitutes an amalgam between supporting elements and ion channels that participate in action potential propagation, which has led to develop the concept that intercalated discs are constituted by "adhesion/ excitability nodes". The clinical implications in the development of malignant arrhythmias are obvious.
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Typical carcinoids (TC), atypical carcinoids (AC), large cell neuroendocrine carcinomas (LCNEC), and small cell lung carcinomas (SCLC) encompass a bimodal spectrum of metastatic tumors with morphological, histological and histogenesis differences, The hierarchical structure reveals high cohesiveness between neoplastic cells by mechanical desmosomes barrier assembly in carcinoid tumors and LCNEC, while SCLC does not present an organoid arrangement in morphology, the neoplastic cells are less cohesive. However, the molecular mechanisms that lead to PNENs metastasis remain largely unknown and require further study. In this work, epithelial to mesenchymal transition (EMT) transcription factors were evaluated using a set of twenty-four patients with surgically resected PNENs, including carcinomas. Twelve EMT transcription factors (BMP1, BMP7, CALD1, CDH1, COL3A1, COL5A2, EGFR, ERBB3, PLEK2, SNAI2, STEAP1, and TCF4) proved to be highly expressed among carcinomas and downregulated in carcinoid tumors, whereas upregulation of BMP1, CDH2, KRT14 and downregulation of CAV2, DSC2, IL1RN occurred in both histological subtypes. These EMT transcription factors identified were involved in proliferative signals, epithelium desmosomes assembly, and cell motility sequential steps that support PNENs invasion and metastasis in localized surgically resected primary tumor. We used a two-stage design where we first examined the candidate EMT transcription factors using a whole-genome screen, and subsequently, confirmed EMT-like changes by transmission electron microscopy and then, the EMT-related genes that were differentially expressed among PNENs subtypes were predicted through a Metascape analysis by in silico approach. A high expression of these EMT transcription factors was significantly associated with lymph node and distant metastasis. The sequential steps for invasion and metastasis were completed by an inverse association between functional barrier created by PD-L1 immunosuppressive molecule and EMT transcriptional factors. Our study implicates upregulation of EMT transcription factors to high proliferation rates, mechanical molecular barriers disassembly and increased cancer cell motility, as a critical molecular event leading to metastasis risk in PNENs thus emerging as a promising tool to select and customize therapy.
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OBJECTIVE: Odontogenic keratocyst (OKC) is a benign lesion that tends to recur after surgical treatment. In an attempt to clarify the molecular basis underlining the OKC pathobiology, we aimed to analyze its proteomic profile. MATERIALS AND METHODS: We compared the proteomic profiles of five OKC and matched normal oral mucosa by using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Then, we performed enrichment analysis and a literature search for the immunoexpression of the proteomics targets. RESULTS: We identified 1,150 proteins and 72 differently expressed proteins (log2 fold change ≥ 1.5; p < .05). Twenty-seven peptides were exclusively detected in the OKC samples. We found 35 enriched pathways related to cell differentiation and tissue architecture, including keratinocyte differentiation, keratinization, desmosome, and extracellular matrix (ECM) organization and degradation. The immunoexpression information of 11 out of 50 proteins identified in the enriched pathways was obtained. We found the downregulation of four desmosomal proteins (JUP, PKP1, PKP3, and PPL) and upregulation of ECM proteases (MMP-2, MMP-9, and cathepsins). CONCLUSIONS: Proteomic analysis strengthened the notion that OKC cells have a similar proteomic profile to oral keratinocytes. Contextual investigation of the differentially expressed proteins revealed the deregulation of desmosome proteins and ECM degradation as important alterations in OKC pathobiology.
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Quistes Odontogénicos , Péptido Hidrolasas , Cromatografía Liquida , Matriz Extracelular , Humanos , Recurrencia Local de Neoplasia , Proteómica , Espectrometría de Masas en TándemRESUMEN
BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is associated with variants in desmosome genes. Secondary findings of pathogenic/likely pathogenic variants, primarily loss-of-function (LOF) variants, are recommended for clinical reporting; however, their prevalence and associated phenotype in a general clinical population are not fully characterized. METHODS: From whole-exome sequencing of 61 019 individuals in the DiscovEHR cohort, we screened for putative loss-of-function variants in PKP2, DSC2, DSG2, and DSP. We evaluated measures from prior clinical ECG and echocardiograms, manually over-read to evaluate ARVC diagnostic criteria, and performed a PheWAS (phenome-wide association study). Finally, we estimated expected penetrance using Bayesian inference. RESULTS: One hundred forty individuals (0.23%; 59±18 years old at last encounter; 33% male) had an ARVC variant (G+). None had an existing diagnosis of ARVC in the electronic health record, nor significant differences in prior ECG or echocardiogram findings compared with matched controls without variants. Several G+ individuals satisfied major repolarization (n=4) and ventricular function (n=5) criteria, but this prevalence matched controls. PheWAS showed no significant associations of other heart disease diagnoses. Combining our best genetic and disease prevalence estimates yields an estimated penetrance of 6.0%. CONCLUSIONS: The prevalence of ARVC loss-of-function variants is ≈1:435 in a general clinical population of predominantly European descent, but with limited electronic health record-based evidence of phenotypic association in our population, consistent with a low penetrance estimate. Prospective deep phenotyping and longitudinal follow-up of a large sequenced cohort is needed to determine the true clinical relevance of an incidentally identified ARVC loss-of-function variant.
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Displasia Ventricular Derecha Arritmogénica/genética , Registros Electrónicos de Salud/estadística & datos numéricos , Adulto , Anciano , Desmocolinas/genética , Desmogleína 2/genética , Predisposición Genética a la Enfermedad , Humanos , Persona de Mediana Edad , Fenotipo , Placofilinas/genética , Estudios ProspectivosRESUMEN
The epithelium represents the first and most extensive line of defence against pathogens, toxins and pollutant agents in humans. In general, pathogens have developed strategies to overcome this barrier and use it as an entrance to the organism. Entamoeba histolytica, Naegleriafowleri and Acanthamoeba spp. are amoebae mainly responsible for intestinal dysentery, meningoencephalitis and keratitis, respectively. These amoebae cause significant morbidity and mortality rates. Thus, the identification, characterization and validation of molecules participating in host-parasite interactions can provide attractive targets to timely intervene disease progress. In this work, we present a compendium of the parasite adhesins, lectins, proteases, hydrolases, kinases, and others, that participate in key pathogenic events. Special focus is made for the analysis of assorted molecules and mechanisms involved in the interaction of the parasites with epithelial surface receptors, changes in epithelial junctional markers, implications on the barrier function, among others. This review allows the assessment of initial host-pathogen interaction, to correlate it to the potential of parasite invasion.
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Acanthamoeba/patogenicidad , Entamoeba histolytica/patogenicidad , Células Epiteliales/parasitología , Interacciones Huésped-Parásitos , Naegleria fowleri/patogenicidad , Infecciones por Protozoos/parasitología , Acanthamoeba/metabolismo , Animales , Entamoeba histolytica/metabolismo , Células Epiteliales/metabolismo , Humanos , Naegleria fowleri/metabolismo , Infecciones por Protozoos/metabolismoRESUMEN
Resumen: La miocardiopatía arritmogénica del ventrículo derecho es una patología de origen genético cuya base molecular se encuentra a nivel de los desmosomas, caracterizada por una sustitución progresiva de los miocitos del ventrículo derecho por tejido graso, que conduce a arritmias potencialmente graves y disfunción miocárdica. Es causa de muerte súbita asociada al ejercicio. Es rara la aparición de síntomas antes de los 10 años de edad, lo que obliga a un alto grado de sospecha clínica. Existe afectación familiar hasta en el 50% de los casos, por lo que el estudio en cascada está recomendado y constituye un criterio mayor de enfermedad. Se cree que esta investigación es la forma más frecuente de pesquisa en pediatría, junto con la realización de un electrocardiograma como parte del screening preparticipativo en competencia deportiva. Se debe sospechar ante la objetivación de taquicardia ventricular con imagen de bloqueo de rama izquierda. Las alteraciones clásicas descritas en el ecocardiograma o la resonancia magnética son raras en niños, y deben considerarse las anomalías segmentarias en estas técnicas. La estratificación de riesgo ha debido ser extrapolada de los estudios realizados en adultos, y de acuerdo a esto se debe decidir la pertinencia de la instalación de un desfibrilador automático implantable, sobre todo en caso de muerte súbita cardíaca recuperada o taquicardia ventricular sostenida. La pertinencia del uso de fármacos debe analizarse individualmente. En los casos de diagnóstico definitivo, se debe abolir el ejercicio intensivo, recomendándose solo la actividad física de baja intensidad.
Summary: Arrhythmogenic right ventricle cardiomyopathy is a disease of genetic origin, whose molecular basis is at the level of desmosomes, characterized by a progressive replacement of right ventricle myocytes by fatty tissue, which leads to potentially serious arrhythmias and myocardial dysfunction. It is a cause of sudden death associated with exercise. The appearance of symptoms before 10 years old is rare, which compels a high degree of clinical suspicion. In more than 50% of cases there is a family history of those affected, so the cascade study of the probands is recommended (major criterion of disease). In pediatrics, it is believed that most often is that patients are investigated by this ground, as well among asymptomatic children in whom an electrocardiogram is performed as part of the screening of sports competition. One should suspect arrhythmogenic right ventricle cardiomyopathy with ventricular tachycardia with appearance of left bundle branch block. Classical alterations described in echocardiography or magnetic resonance imaging are rare in children, and segmental abnormalities in these techniques should be considered. The stratification of risk has been extrapolated from the studies of elderly patients, and according to this, the indication of an implantable cardioverter defibrillator must be decided, especially in case of sudden cardiac death recovered or sustained ventricular tachycardia. The relevance of the use of drugs must be individually analyzed. In definite cases, intensive exercises should be abolished, recommending only those of low intensity.
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Entamoeba histolytica trophozoites adhere to epithelium at the cell-cell contact and perturb tight junctions disturbing the transepithelial electrical resistance. Behind tight junctions are the adherens junctions (AJs) that reinforce them and the desmosomes (DSMs) that maintain the epithelium integrity. The damage produced to AJs and DMSs by this parasite is unknown. Here, we studied the effect of the trophozoites, the EhCPADH complex, and the EhCP112 recombinant enzyme (rEhCP112) on AJ and DSM proteins. We found that trophozoites degraded ß-cat, E-cad, Dsp l/ll, and Dsg-2 with the participation of EhCPADH and EhCP112. After contact of epithelial cells with trophozoites, immunofluorescence and transmission electron microscopy assays revealed EhCPADH and rEhCP112 at the intercellular space where they colocalised with ß-cat, E-cad, Dsp l/ll, and Dsg-2. Moreover, our results suggested that rEhCP112 could be internalised by caveolae and clathrin-coated vesicles. Immunoprecipitation assays showed the interaction of EhCPADH with ß-cat and Dsp l/ll. Besides, in vivo assays demonstrated that rEhCP112 concentrates at the cellular borders of the mouse intestine degrading E-cad and Dsp I/II. Our research gives the first clues on the trophozoite attack to AJs and DSMs and point out the role of the EhCPADH and EhCP112 in the multifactorial event of trophozoites virulence.
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Uniones Adherentes/metabolismo , Cisteína Endopeptidasas/metabolismo , Entamoeba histolytica/enzimología , Entamoeba histolytica/metabolismo , Entamebiasis/patología , Uniones Estrechas/metabolismo , Animales , Anticuerpos Monoclonales/inmunología , Anticuerpos Antiprotozoarios/inmunología , Células CACO-2 , Cadherinas/metabolismo , Línea Celular , Desmosomas/metabolismo , Perros , Entamoeba histolytica/inmunología , Entamebiasis/parasitología , Células Epiteliales/metabolismo , Humanos , Mucosa Intestinal/parasitología , Células de Riñón Canino Madin Darby , Masculino , Ratones , Ratones Endogámicos C57BL , beta Catenina/metabolismoRESUMEN
We performed scanning electron microscopy of an inverted blister roof in a case of pemphigus foliaceus. The loss of intercellular adherence could be easily seen with low magnification. The acantholytic keratinocytes displayed an irregular and sometimes polygonal contour. Round cells, typically seen in light microscopy, were also observed. The examination of a blister roof allows ultrastructural documentation of the acantholytic changes.
Realizamos microscopia eletrônica de varredura do teto invertido de uma bolha de um caso de pênfigo foliáceo. Com pequeno aumento, a perda da adesão intercelular pôde ser vista claramente. Os queratinócitos acantolíticos demostraram um contorno irregular, algumas vezes poligonal. Células arredondadas, como vistas tipicamente na microscopia óptica, também foram observadas. O exame de um teto de bolha permite uma documentação ultraestrutural das alterações acantolíticas.
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Acantólisis/patología , Pénfigo/patología , Queratinocitos/ultraestructura , Microscopía Electrónica de RastreoRESUMEN
OBJECTIVE: To examine the epidermis in induced phytophotodermatitis using transmission electron microscopy in order to detect histologic changes even before lesions are visible by light microscopy. INTRODUCTION: In the first six hours after the experimental induction of phytophotodermatitis, no changes are detectable by light microscopy. Only after 24 hours can keratinocyte necrosis and epidermal vacuolization be detected histologically, and blisters form by 48 hours. METHODS: The dorsum of four adult rats (Rattus norvegicus) was manually epilated. After painting the right half of the rat with the peel juice of Tahiti lemon, they were exposed to sunlight for eight minutes under general anesthesia. The left side was used as the control and exposed to sunlight only. Biopsies were performed immediately after photoinduction and one and two hours later, and the tissue was analyzed by transmission electron microscopy. RESULTS: No histological changes were seen on the control side. Immediately after induction, vacuolization in keratinocytes was observed. After one hour, desmosomal changes were also observed in addition to vacuolization. Keratin filaments were not attached to the desmosomal plaque. Free desmosomes and membrane ruptures were also seen. At two hours after induction, similar changes were found, and granular degeneration of keratin was also observed. DISCUSSION: The interaction of sunlight and psoralens generates a photoproduct that damages keratinocyte proteins, leading to keratinocyte necrosis and blister formation. CONCLUSIONS: Transmission electron microscopy can detect vacuolization, lesions of the membrane, and desmosomes in the first two hours after experimental induction of phytophotodermatitis.