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Background: Atopic dermatitis (AD) is a chronic inflammatory skin condition that has a significant impact on quality of life. The immune response and allergy symptoms in AD are triggered by the recognition of specific allergens by IgE antibodies. Cross-reactivity can lead to auto-IgE responses, potentially worsening AD symptoms. Our research aimed to enhance our understanding of allergenic sources, including A. fumigatus, and their role in AD. We focused on molecular mimicry between human AQP3 and A. fumigatus aquaporin. Methods: In our in-silico analysis, we compared the amino acid sequences of human aquaporin 3 (AQP3) and A. fumigatus aquaporin with 25 aquaporins from various allergenic sources, sourced from the UniProt and NCBI databases. Phylogenetic relationship analysis and homology-based modeling were conducted. We identified conserved antigenic regions located within the 3D structures. Results: The global identity levels among the studied aquaporins averaged 32.6%. One antigenic site exhibited a remarkable local region, with a conserved identity of 71.4%. We categorized the aquaporins into five monophyletic clades (A-E), with group B showing the highest identity (95%), including six mammalian aquaporins, including AQP3. When comparing A. fumigatus aquaporins, the highest identity was observed with Malassezia sympodialis at 35%. Both human and A. fumigatus aquaporins have three linear and three discontinuous epitopes. Conclusions: We identified potential linear and conformational epitopes of AQP3, indicating a possible molecular mimicry between humans and A. fumigatus aquaporins. This suggests autoreactivity and potential cross-reactivity, although further validation using in vitro and in vivo experiments is required.
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Aquaporina 3 , Aquaporinas , Aspergillus fumigatus , Simulação por Computador , Mimetismo Molecular , Filogenia , Humanos , Aspergillus fumigatus/imunologia , Aspergillus fumigatus/metabolismo , Aquaporina 3/metabolismo , Aquaporinas/metabolismo , Aquaporinas/química , Aquaporinas/genética , Sequência de Aminoácidos , Alérgenos/imunologia , Alérgenos/metabolismo , Hipersensibilidade/imunologia , Hipersensibilidade/microbiologia , Modelos Moleculares , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/imunologiaRESUMO
Epidemiological studies and meta-analyses have shown a strong association between high seroprevalence of Toxoplasma gondii (T. gondii) and schizophrenia. Schizophrenic patients showed higher levels of anti-Toxoplasma immunoglobulins M and G (IgM and IgG) when compared to healthy controls. Previously, in a rat model, we demonstrated that the progeny of mothers immunized with T. gondii lysates before gestation had behavioral and social impairments during adulthood. Therefore, we suggested that T. gondii infection can trigger autoreactivity by molecularly mimicking host brain proteins. Here, we aimed to identify the occurrence of antigenic mimicry between T. gondii epitopes and host brain proteins. Using a bioinformatic approach, we predicted T. gondii RH-88 B cell epitopes and compared them to human cell-surface proteins involved in brain development and differentiation (BrainS). Five different algorithms for B-cell-epitope prediction were used and compared, resulting in 8584 T. gondii epitopes. We then compared T. gondii predicted epitopes to BrainS proteins by local sequence alignments using BLASTP. T. gondii immunogenic epitopes significantly overlapped with 42 BrainS proteins. Among these overlapping proteins essential for brain development and differentiation, we identified HSP90 and NOTCH receptors as the proteins most likely to be targeted by the maternally generated pathogenic antibodies due to their topological overlap at the extracellular region of their sequence. This analysis highlights the relevance of pregestational clinical surveillance and screening for potential pathogenic anti-T. gondii antibodies. It also identifies potential targets for the design of vaccines that could prevent behavioral and cognitive impairments associated with pre-gestational T. gondii exposure.
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Encéfalo , Epitopos de Linfócito B , Mimetismo Molecular , Toxoplasma , Toxoplasma/imunologia , Mimetismo Molecular/imunologia , Humanos , Epitopos de Linfócito B/imunologia , Encéfalo/parasitologia , Encéfalo/imunologia , Encéfalo/metabolismo , Biologia Computacional/métodos , Toxoplasmose/imunologia , Animais , Anticorpos Antiprotozoários/imunologia , RatosRESUMO
PURPOSE: To present an atypical case of severe bilateral ocular toxoplasmosis with systemic involvement that initially mimicked an autoimmune etiology, posing challenges to its diagnosis and treatment. CASE REPORT: A 39-year-old immunocompetent male was admitted to the hospital due to a presumed pulmonary thromboembolism concomitant with an abrupt onset of vision loss. Initial differential diagnoses included antiphospholipid syndrome and systemic lupus erythematosus, prompting the administration of corticosteroid pulses and rituximab. Despite observing a partial systemic response, there was no improvement in visual acuity. Subsequent aqueous humor polymerase chain reaction confirmed Toxoplasma gondii infection, leading to the introduction of oral antibiotic therapy. The patient's condition showed a partially favorable response; however, the treatment could not reverse the permanent retinal damage. CONCLUSION AND IMPORTANCE: This case underscores the importance of ruling out an infectious etiology in all cases of uveitis. Additionally, it alerts clinicians to the possibility that elevated positive autoantibodies may result from a severe inflammatory reaction caused by pathogens rather than an autoimmune or autoinflammatory disease, particularly in instances of poor treatment response or atypical clinical presentation.
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Doenças Autoimunes , Toxoplasma , Toxoplasmose Ocular , Humanos , Masculino , Adulto , Toxoplasmose Ocular/diagnóstico , Toxoplasmose Ocular/tratamento farmacológico , Diagnóstico Diferencial , Toxoplasma/imunologia , Toxoplasma/isolamento & purificação , Doenças Autoimunes/diagnóstico , Doenças Autoimunes/tratamento farmacológico , Doenças Autoimunes/imunologia , Humor Aquoso/parasitologia , Acuidade Visual/fisiologia , DNA de Protozoário/análise , Glucocorticoides/uso terapêutico , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Infecções Oculares Parasitárias/diagnóstico , Infecções Oculares Parasitárias/tratamento farmacológico , Infecções Oculares Parasitárias/parasitologia , Síndrome Antifosfolipídica/diagnóstico , Síndrome Antifosfolipídica/tratamento farmacológico , Síndrome Antifosfolipídica/complicações , Reação em Cadeia da PolimeraseRESUMO
OBJECTIVE: To identify through In Silico analysis the possible molecular mimicry between Der p 23 and antigens from allergenic sources. METHODS: Identity was sought between Der p 23 and proteins from the mite families Pyroglyphidae, Acaridae, Chortoglyphidae and Echimyopodidae, through PSI-BLAST and They used PRALINE and EMBOSS for the alignments. Antigens with resolved experimental structure were obtained from Protein Data Bank and those not reported were generated using Swiss Model server and ALPHAFOLD 2. Epitope prediction was carried out with the Ellipro server and Pymol 2.3 was used to visualize the 3D models. RESULTS: The analysis between Pyroglyphidae allergens and Der p 23 showed identity with the endochitinase-like protein of D. pteronyssinus, and the type 2 chitin binding domain of D. farinae, with identities between 85 and 100%, with coverage of 100%, and 75% respectively. The allergens Der f 23 and Der p 23 of D. farinae and D. pteronyssinus had 100% coverage with identities of 85.42% and 79.59%, respectively. Among the allergens of Tyrophagus putrescentiae, binding to chitin, oviduct-specific glycoprotein and Cda4p were included, which had identity values corresponding to 40%, 42.22% and 34.78%, with coverage values that did not exceed the 55%. No results were found for Chortoglyphidae and Echimyopodidae. CONCLUSION: There is molecular mimicry and structural homology between Der P 23 and allergens from allergic sources of the Pyroglyphidae and Acaridae families. Potential epitopes were identified in Der p 23, which could present cross-reactivity with the proteins of the allergenic sources studied, which must be demonstrated in In vitro and In vivo studies. In vitro and in vivo work is needed to demonstrate the results obtained in the In Silico analysis.
OBJETIVO: Identificar, a través de análisis In Silico, el posible mimetismo molecular entre Der p 23 y antígenos de fuentes alergénicas. MÉTODOS: Se buscó identidad entre Der p 23 y proteínas de las familias de ácaros Pyroglyphidae, Acaridae, Chortoglyphidae y Echimyopodidae, a través de PSI-BLAST, y se utilizaron PRALINE y EMBOSS para los alineamientos. Los antígenos con estructura experimental resuelta se obtuvieron de Protein Data Bank, y aquellos no informados, se generaron mediante Swiss Model Server y ALPHAFOLD 2. La predicción de epítopes se realizó con el servidor Ellipro y para la visualización de los modelos en 3D, se utilizó Pymol 2.3. RESULTADOS: El análisis entre alérgenos de Pyroglyphidae y Der p 23, mostró identidad con la proteína parecida a endoquitinasa de D. pteronyssinus, y el dominio de unión a quitina tipo 2 de D. farinae, con identidades entre 85 y 100%, con coberturas de 100% y 75%, respectivamente. Los alérgenos Der f 23 y Der p 23 de D. farinae y D. pteronyssinu,s tuvieron una cobertura del 100% con identidades del 85,42% y 79,59%, respectivamente. Entre los alérgenos de Tyrophagus putrescentiae, se incluyeron la unión a quitina, glicoproteína específica del oviducto y Cda4p, las cuales tuvieron valores de identidad correspondientes al 40%, 42,22% y 34,78%, con valores de cobertura que no superan el 55%. No se encontraron resultados para Chortoglyphidae y Echimyopodidae. CONCLUSIÓN: Existe mimetismo molecular y homología estructural entre Der P 23 y alérgenos de fuentes alérgicas de las familias Pyroglyphidae y Acaridae. Se identificaron potenciales epítopes en Der p 23, los cuales podrían presentar reactividad cruzada con las proteínas de las fuentes alergénicas estudiadas, lo cual debe ser demostrado en estudios In Vitro e In Vivo. Se necesitan trabajos In Vitro e In Vivo que demuestren los resultados obtenidos en el análisis In Silico.
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Alérgenos , Antígenos de Dermatophagoides , Mimetismo Molecular , Animais , Alérgenos/imunologia , Antígenos de Dermatophagoides/imunologia , Proteínas de Artrópodes/imunologia , Simulação por Computador , Mimetismo Molecular/imunologiaRESUMO
OBJECTIVE: Conduct an in-silico assessment of potential molecular mimicry between human aquaporins, A. fumigatus, and diverse allergenic sources. METHODS: Amino acid sequences of human AQP3 and A. fumigatus aquaporin were compared through multiple alignments with 25 aquaporins from diverse allergenic sources. Phylogenetic analysis and homology-based modeling were executed, and the ElliPro server predicted conserved antigenic regions on 3D structures. RESULTS: Global identity among studied aquaporins was 32.6%, with a specific conserved local region at 71.4%. Five monophyletic clades (A-E) were formed, and Group B displayed the highest identity (95%), including 6 mammalian aquaporins, notably AQP3. A. fumigatus aquaporin exhibited the highest identity with Malassezia sympodialis (35%). Three linear and three discontinuous epitopes were identified in both human and A. fumigatus aquaporins. The Root Mean Square Deviation (RMSD) from overlapping aquaporin structures was 1.006. CONCLUSION: Identification of potential linear and conformational epitopes on human AQP3 suggests likely molecular mimicry with A. fumigatus aquaporins. High identity in a specific antigenic region indicates potential autoreactivity and a probable antigenic site involved in cross-reactivity. Validation through in vitro and in vivo studies is essential for further understanding and confirmation.
OBJETIVO: Realizar una evaluación in silico del posible mimetismo molecular entre las acuaporinas humanas, A. fumigatus y diversas fuentes alergénicas. MÉTODOS: Se compararon secuencias de aminoácidos de AQP3 humana y acuaporina de A. fumigatus mediante alineamientos múltiples con 25 acuaporinas de diversas fuentes alergénicas. Se ejecutaron análisis filogenéticos y modelos basados en homología, y el servidor ElliPro predijo regiones antigénicas preservadas en estructuras 3D. RESULTADOS: La identidad global entre las acuaporinas estudiadas fue del 32.6%, con una región local específica preservada en el 71.4%. Se formaron cinco clados monofiléticos (A-E), y el grupo B mostró la identidad más alta (95%), incluidas 6 acuaporinas de mamíferos, en particular AQP3. A. fumigatus aquaporin exhibió la mayor identidad con Malassezia sympodialis (35%). Se identificaron tres epítopos lineales y tres discontinuos en acuaporinas tanto humanas como de A. fumigatus. La desviación cuadrática media (RMSD) de las estructuras de acuaporinas superpuestas fue de 1,006. CONCLUSIÓN: La identificación de posibles epítopos lineales y conformacionales en AQP3 humano sugiere un probable mimetismo molecular con acuaporinas de A. fumigatus. La identidad alta en una región antigénica específica indica autorreactividad potencial y un sitio antigénico probable implicado en la reactividad cruzada. La validación mediante estudios in vitro e in vivo es desicivo para una mayor comprensión y confirmación.
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Alérgenos , Aquaporina 3 , Aquaporinas , Aspergillus fumigatus , Simulação por Computador , Mimetismo Molecular , Aspergillus fumigatus/imunologia , Humanos , Aquaporinas/química , Aquaporinas/genética , Aquaporinas/metabolismo , Aquaporinas/imunologia , Aquaporina 3/metabolismo , Aquaporina 3/genética , Alérgenos/imunologia , Hipersensibilidade/imunologia , Proteínas Fúngicas/química , Proteínas Fúngicas/imunologia , Proteínas Fúngicas/genética , Sequência de Aminoácidos , Filogenia , Epitopos/imunologiaRESUMO
OBJECTIVE: Analyze the molecular mimicry between Plasmodium spp. and autoantigens associated with GBS, identifying possible antigenic epitopes. METHODS: PSI-Blast, Praline, Emboss, Protein Data Bank, Swiss Model Server, AlphaFold 2, Ellipro and PyMol 2.3 were used to search for homologies, perform alignments, obtain protein structures, and predict epitopes. RESULTS: 17 autoantigens and seven immunological targets of the peripheral nervous system were included, identifying 72 possible epitopes associated with GBS. From the proteome of Plasmodium spp. (298 proteins), only two showed similarities close to 30% with TRIM21 and BACE1, generating seven possible epitopes. CONCLUSION: No significant homologies were observed between the proteome of GBS and Plasmodium spp. The exploration of other mechanisms such as immune-mediated capillary damage, Epitope Spreading or Bystander Activation is suggested to explain the mentioned association. These findings underscore the need to clarify the etiology of autoimmune diseases and the role of pathogens. The need for experimental studies to validate these results is emphasized.
OBJETIVO: Analizar el mimetismo molecular entre Plasmodium spp. y autoantígenos asociados al SGB, identificando posibles epítopos antigénicos. MÉTODOS: Se emplearon PSI-Blast, Praline, Emboss, Protein Data Bank, Swiss Model Server, AlphaFold 2, Ellipro y PyMol 2.3 para buscar homologías, realizar alineamientos, obtener estructuras proteicas y predecir epítopos. RESULTADOS: Se incluyeron 17 autoantígenos y siete objetivos inmunológicos del sistema nervioso periférico, identificándose 72 posibles epítopos asociados al SGB. Del proteoma de Plasmodium spp. (298 proteínas), solo dos mostraron similitud cercana al 30% con TRIM21 y BACE1, generando siete posibles epítopos. CONCLUSIÓN: No se observaron homologías significativas entre el proteoma de SGB y Plasmodium spp. Se sugiere la exploración de otros mecanismos como el daño capilar inmunomediado, Epitope Spreading o Bystander Activation para explicar la asociación mencionada. Estos hallazgos subrayan la necesidad de aclarar la etiología de las enfermedades autoinmunes y el papel de los patógenos. Se enfatiza la necesidad de estudios experimentales para validar estos resultados.
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Síndrome de Guillain-Barré , Mimetismo Molecular , Mimetismo Molecular/imunologia , Síndrome de Guillain-Barré/imunologia , Humanos , Plasmodium/imunologia , Autoantígenos/imunologia , Epitopos/imunologiaRESUMO
Most Aristolochiaceae species studied so far are from temperate regions, bearing self-compatible protogynous trap flowers. Although self-incompatibility has been suggested for tropical species, the causes of self-sterility in this family remain unknown. To fill this gap, we studied the pollination of the tropical Aristolochia esperanzae, including the physical and physiological anti-selfing mechanisms. Floral visitors trapped inside flowers were collected to determine the pollinators. Protogyny was characterized by observing the temporal expression of sexual phases and stigmatic receptivity tests. The breeding system was investigated using hand-pollination treatments. Pollen tube growth was observed using epifluorescence to identify the self-incompatibility mechanism. Flies were the most frequent visitors found inside A. esperanzae trap flowers, with individuals from the family Ulidiidae being potential pollinators since they carried pollen. The characteristic flower odour and presence of larvae indicate that A. esperanzae deceives flies through oviposition-site mimicry. Although this species showed incomplete protogyny, stigmatic receptivity decreased during the male phase, avoiding self-pollination. Fruits developed only after cross- and open pollination, indicating that the population is non-autonomous, non-apomictic, and self-sterile. This occurred through a delay in the growth of geitonogamous pollen tubes to the ovary and lower ovule penetration, indicating a late-acting self-incompatibility mechanism. Our findings expand the number of families in which late-acting self-incompatibility has been reported, demonstrating that it is more widespread than previously thought, especially when considering less-studied tropical species among the basal angiosperms.
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Aristolochia , Flores , Polinização , Polinização/fisiologia , Flores/fisiologia , Aristolochia/fisiologia , Animais , Autoincompatibilidade em Angiospermas/fisiologia , Tubo Polínico/fisiologia , Tubo Polínico/crescimento & desenvolvimento , Frutas/fisiologia , Frutas/crescimento & desenvolvimento , Pólen/fisiologia , Dípteros/fisiologiaRESUMO
OBJECTIVE: Identify molecular mimicry between TPO, eosinophil peroxidase (EPX), thyroglobulin and IL24 and microorganism antigens. METHODS: Through in silico analysis, we performed local alignments between human and microorganism antigens with PSI-BLAST. Proteins that did not present a 3D structure were modeled by homology through the Swiss Modeller server and epitope prediction was performed through Ellipro. Epitopes were located in the 3D models using PYMOL software. RESULTS: A total of 38 microorganism antigens (parasites, bacteria) had identities between 30% and 45%, being the highest with Anisakis simplex. The alignment between 2 candidate proteins from A. simplex and EPX presented significant values, with identities of 43 and 44%. In bacteria, Campylobacter jejuni presented the highest identity with thyroglobulin (35%). 220 linear and conformational epitopes of microorganism antigens were predicted. Peroxidasin-like proteins from Toxocara canis and Trichinella pseudospiralis presented 10 epitopes similar to TPO and EPX, as possible molecules triggering cross-reactivity. No virus presented identity with the human proteins studied. CONCLUSION: TPO and EPX antigens shared potential cross-reactive epitopes with bacterial and nematode proteins, suggesting that molecular mimicry could be a mechanism that explains the relationship between infections and urticaria/hypothyroidism. In vitro work is needed to demonstrate the results obtained in the in silico analysis.
OBJETIVO: Identificar mimetismo molecular entre TPO, eosinofil peroxidasa (EPX), tiroglobulina e IL24 y antígenos de microorganismos. MÉTODOS: A través de análisis in silico, realizamos los alineamientos locales entre los antígenos humanos y de microorganismos con PSI-BLAST. Las proteínas que no presentaban estructura 3D, fueron modeladas por homología a través del servidor Swiss Modeller y se realizó una predicción de epítopes a través de Ellipro. Los epítopes se localizaron en los modelos 3D utilizando el software PYMOL. RESULTADOS: Un total de 38 antígenos de microorganismos (parásitos y bacterias), tuvieron identidades entre 30 y 45%, siendo los más altos con Anisakis simplex. El alineamiento entre dos proteínas candidatas de A. simplex y EPX presentaron valores importantes, con identidades de 43 y 44%. En las bacterias, Campylobacter jejuni presentó la mayor identidad con tiroglobulina (35%). Se predijeron 220 epítopes lineales y conformacionales de antígenos de microorganismos. Las proteínas similares a la peroxidasina de Toxocara canis y Trichinella pseudospiralis presentaron diez epítopes similares a TPO y EPX, como posibles moléculas desencadenantes de una reactividad cruzada. Ningún virus presentó identidad con las proteínas humanas estudiadas. CONCLUSIÓN: Los antígenos TPO y EPX compartieron potenciales epítopes de reacción cruzada con proteínas bacterianas y nematodos, lo que sugiere que el mimetismo molecular podría ser un mecanismo que explique la relación entre infecciones y la urticaria/hipotiroidismo. Se necesitan trabajos in vitro que demuestren los resultados obtenidos en el análisis in silico.
Assuntos
Autoantígenos , Iodeto Peroxidase , Mimetismo Molecular , Tireoglobulina , Mimetismo Molecular/imunologia , Humanos , Tireoglobulina/imunologia , Iodeto Peroxidase/imunologia , Peroxidase de Eosinófilo/imunologia , Animais , Antígenos de Bactérias/imunologia , Reações Cruzadas , Proteínas de Ligação ao Ferro/imunologia , Epitopos/imunologiaRESUMO
Tumors have high requirements in terms of nutrients and oxygen. Angiogenesis is the classical mechanism for vessel formation. Tumoral vascularization has the function of nourishing the cancer cells to support tumor growth. Vasculogenic mimicry, a novel intratumoral microcirculation system, alludes to the ability of cancer cells to organize in three-dimensional (3D) channel-like architectures. It also supplies the tumors with nutrients and oxygen. Both mechanisms operate in a coordinated way; however, their functions in breast cancer stem-like cells and their regulation by microRNAs remain elusive. In the present study, we investigated the functional role of microRNA-204 (miR-204) on angiogenesis and vasculogenic mimicry in breast cancer stem-like cells. Using flow cytometry assays, we found that 86.1% of MDA-MB-231 and 92% of Hs-578t breast cancer cells showed the CD44+/CD24- immunophenotype representative of cancer stem-like cells (CSCs). The MDA-MB-231 subpopulation of CSCs exhibited the ability to form mammospheres, as expected. Interestingly, we found that the restoration of miR-204 expression in CSCs significantly inhibited the number and size of the mammospheres. Moreover, we found that MDA-MB-231 and Hs-578t CSCs efficiently undergo angiogenesis and hypoxia-induced vasculogenic mimicry in vitro. The transfection of precursor miR-204 in both CSCs was able to impair the angiogenesis in the HUVEC cell model, which was observed as a diminution in the number of polygons and sprouting cells. Remarkably, miR-204 mimics also resulted in the inhibition of vasculogenic mimicry formation in MDA-MB-231 and Hs-578t CSCs, with a significant reduction in the number of channel-like structures and branch points. Mechanistically, the effects of miR-204 were associated with a diminution of pro-angiogenic VEGFA and ß-catenin protein levels. In conclusion, our findings indicated that miR-204 abrogates the angiogenesis and vasculogenic mimicry development in breast cancer stem-like cells, suggesting that it could be a potential tool for breast cancer intervention based on microRNA replacement therapies.
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Photuris female fireflies attract males of different firefly species by responding to their flashing signals; then, they try to capture and feed on them. This aggressive mimicry is considered a major selective pressure on the communication systems of the fireflies of the American continent. The intensity of this selective pressure is a function of its efficiency in prey capture. In this study, the rates of attraction and capture of males of the synchronous firefly Photinus palaciosi by the predatory females of Photuris lugubris are reported. Although the females attract numerous males, their hunting success is low. This result is consistent with the few previous measurements published. In agreement with the predicted coevolutionary race between predator and prey, behaviors consistent with predation avoidance in P. palaciosi and increasing prey encounters and prey deception by P. lugubris were observed.
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In snakes that are known to be ambush predators, tail luring, in which the movement of a snake’s tail resembles that of a worm or insect larva and is used to attract prey, has emerged as a complementary hunting strategy. In certain species, some individuals may present a conspicuously bright colour at the tail tip, which eventually disappears with age. Some authors argue that the bright colour enhances the resemblance of the snake’s tail with a potential food item, increasing the success of capture. Here, we tested the influence of geographic variation, sex, and environmental factors on the probability that Common Lanceheads Bothrops jararaca (Wied-Neuwied, 1824) from southeastern Brazil were born with this contrasting tail tip and whether snakes retain this trait throughout adulthood. None of the predictors affected the probability of births with a contrasting tail tip. However, a higher proportion of individuals from the coastal populations retained this trait into adulthood. The absence of difference in the probability of being born with this trait indicates that there are other factors influencing tail tip colour, such as phylogenetic correlates, rather than intrinsic or environmental factors. A higher proportion of ectothermic prey in the diet of coastal populations may explain why this population retains tail luring throughout adulthood.
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SARS-CoV-2 can trigger autoimmune central nervous system (CNS) diseases in genetically susceptible individuals, a mechanism poorly understood. Molecular mimicry (MM) has been identified in other viral diseases as potential triggers of autoimmune CNS events. This study investigated if MM is the process through which SARS-CoV-2 induces the breakdown of immune tolerance. The frequency of autoimmune CNS disorders was evaluated in a prospective cohort with patients admitted to the COVID-19 Intense Care Unity (ICU) in Rio de Janeiro. Then, an in silico analysis was performed to identify the conserved regions that share a high identity between SARS-CoV-2 antigens and human proteins. The sequences with significant identity and antigenic properties were then assessed for their binding capacity to HLA subtypes. Of the 112 patients included, 3 were classified as having an autoimmune disorder. A total of eleven combinations had significant linear and three-dimensional overlap. NMDAR1, MOG, and MPO were the self-antigens with more significant combinations, followed by GAD65. All sequences presented at least one epitope with strong or intermediate binding capacity to the HLA subtypes selected. This study underscores the possibility that CNS autoimmune attacks observed in COVID-19 patients, including those in our population, could be driven by MM in genetically predisposed individuals.
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Vasculogenic mimicry (VM), a process in which aggressive cancer cells form tube-like structures, plays a crucial role in providing nutrients and escape routes. Highly plastic tumor cells, such as those with the triple-negative breast cancer (TNBC) phenotype, can develop VM. However, little is known about the interplay between the cellular components of the tumor microenvironment and TNBC cells' VM capacity. In this study, we analyzed the ability of endothelial and stromal cells to induce VM when interacting with TNBC cells and analyzed the involvement of the FGFR/PI3K/Akt pathway in this process. VM was corroborated using fluorescently labeled TNBC cells. Only endothelial cells triggered VM formation, suggesting a predominant role of paracrine/juxtacrine factors from an endothelial origin in VM development. Via immunocytochemistry, qPCR, and secretome analyses, we determined an increased expression of proangiogenic factors as well as stemness markers in VM-forming cancer cells. Similarly, endothelial cells primed by TNBC cells showed an upregulation of proangiogenic molecules, including FGF, VEGFA, and several inflammatory cytokines. Endothelium-dependent TNBC-VM formation was prevented by AZD4547 or LY294002, strongly suggesting the involvement of the FGFR/PI3K/Akt axis in this process. Given that VM is associated with poor clinical prognosis, targeting FGFR/PI3K/Akt pharmacologically may hold promise for treating and preventing VM in TNBC tumors.
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An increase in the incidence of inflammatory arthritis after COVID-19 has been reported. Since many diseases exhibit population-specific causal effect sizes, we aimed to evaluate the incidence trends of inflammatory arthritis, including rheumatoid arthritis (RA), after COVID-19 in a large admixed Colombian population. Data analysis for this retrospective, population-based cohort study was carried out using the COOSALUD EPS registry. The following codes were selected for analyses: M059, seropositive RA, M069, unspecified RA, M060 seronegative RA, and other RA-related diagnoses: M064, M139, M068, M058, M130 and M053. The study period was limited to January 01, 2018, through December 31, 2022. Incidence rates (IRs) and incidence rate ratios (IRRs) were assessed. A Cox survival model was built to evaluate the influence of age, gender, and COVID-19 vaccination status on the development of inflammatory arthritis. A bioinformatic analysis was performed to evaluate the homology between SARS-CoV-2 and autoantigen peptides related to RA. The entire population study comprised 3,335,084 individuals. During the pandemic period (2020-2022) the total IIR for seropositive and unspecified RA were 1.60 (95% CI, 1.16-2.22) and 2.93 (95% CI, 2.04-4.19), respectively, and the IIR for overall RA-related diagnosis was 2.01 (95% CI 1.59-2.53). The age groups hazard ratios (HRs) were increased until the age group of 51-60 years (HR: 9.16; 95% CI, 7.24-11.59) and then decreased slightly in the age group 61 years or older (HR: 5.364; 95% CI, 4.24-6.78) compared to those within 18-30 years. Men were less at risk than women to develop inflammatory arthritis (HR: 0.21; 95% CI, 0.18-0.24). The greater time since COVID-19 diagnosis was associated with a lower likelihood of developing inflammatory arthritis (HR: 0.99; 95% CI:0.998-0.999). Vaccination (all types of COVID-19 vaccines included) did not prevent the development of inflammatory arthritis after COVID-19. Low identity was found between the SARS-CoV-2 ORF1ab antigen and the human antigens Poly ADP-ribose polymerase 14 and Protein mono-ADP-ribosyltransferase PARP9 isoform D (39% and 29%, respectively). In conclusion, our study confirms increased incidence of inflammatory arthritis, including RA, after COVID-19, with the greatest increase occurring before the first year post-covid. Women in their fifties were more susceptible. Further research is required to examine the effectiveness of vaccination in preventing post-COVID inflammatory arthritis and the mechanisms implicated in the development of RA after COVID-19.
Assuntos
Artrite Reumatoide , COVID-19 , Masculino , Feminino , Humanos , Pessoa de Meia-Idade , Fatores de Risco , Vacinas contra COVID-19 , Estudos de Coortes , Incidência , Estudos Retrospectivos , Teste para COVID-19 , Estudos Prospectivos , COVID-19/complicações , COVID-19/epidemiologia , SARS-CoV-2 , Artrite Reumatoide/complicações , Artrite Reumatoide/epidemiologia , Artrite Reumatoide/diagnósticoRESUMO
BACKGROUND: Osteosarcoma (OS) is a form of primary bone malignancy associated with poor prognostic outcomes. Recent work has highlighted vasculogenic mimicry (VM) as a key mechanism that supports aggressive tumor growth. The patterns of VM-associated gene expression in OS and the relationship between these genes and patient outcomes, however, have yet to be defined. METHODS: Here, 48 VM-related genes were systematically assessed to examine correlations between the expression of these genes and OS patient prognosis in the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) cohort. Patients were classified into three OS subtypes. Differentially expressed genes for these three OS subtypes were then compared with hub genes detected in a weighted gene co-expression network analysis, leading to the identification of 163 overlapping genes that were subject to further biological activity analyses. A three-gene signature (CGREF1, CORT, and GALNT14) was ultimately constructed through a least absolute shrinkage and selection operator Cox regression analysis, and this signature was used to separate patients into low- and high-risk groups. The K-M survival analysis, receiver operating characteristic analysis, and decision curve analysis were adopted to evaluate the prognostic prediction performance of the signature. Furthermore, the expression patterns of three genes derived from the prognostic model were validated by quantitative real-time polymerase chain reaction (RT-qPCR). RESULTS: VM-associated gene expression patterns were successfully established, and three VM subtypes of OS that were associated with patient prognosis and copy number variants were defined. The developed three-gene signature was constructed, which served as independent prognostic markers and prediction factors for the clinicopathological features of OS. Finally, lastly, the signature may also have a guiding effect on the sensitivity of different chemotherapeutic drugs. CONCLUSION: Overall, these analyses facilitated the development of a prognostic VM-associated gene signature capable of predicting OS patient outcomes. This signature may be of value for both studies of the mechanistic basis for VM and clinical decision-making in the context of OS patient management.
Assuntos
Neoplasias Ósseas , Osteossarcoma , Humanos , Prognóstico , Osteossarcoma/genética , Tomada de Decisão Clínica , Perfilação da Expressão Gênica , Neoplasias Ósseas/genéticaRESUMO
Abstract Background Evidence indicates a strong link between Zika virus (ZikV) and neurological complications. Acute myelitis, optic neuritis, polyneuropathy, and encephalomyelitis that mimic inflammatory idiopathic demyelination disorders (HDD) after ZikV infection have been reported in Brazil. Objective The present study aims to investigate the possible occurrence of molecular mimicry between ZikV antigens and Multiple Sclerosis (MS) autoantigens, the most frequent HDD of the central nervous system (CNS). Methods A retrospective cohort study with 305 patients admitted due to suspected arbovirus infection in Rio de Janeiro was performed, all subjects were submitted to neurological examination, and a biological sample was collected for serologic and molecular diagnostic. Bioinformatics tools were used to analyze the peptides shared between ZikV antigens and MS autoantigens. Results Of 305 patients, twenty-six were positive for ZikV and 4 presented IDD patterns found in MS cases. Sequence homology comparisons by bioinformatics approach between NS5 ZikV and PLP MS protein revealed a homology of 5/6 consecutive amino acids (CSSVPV/CSAVPV) with 83% identity, deducing a molecular mimicry. Analysis of the 3D structures revealed a similar conformation with alpha helix presentation. Conclusions Molecular mimicry between NS5 Zika virus antigen and PLP MS autoantigens emerge as a possible mechanism for IDD spectrum in genetically susceptible individuals.
Resumo Antecedentes Evidências indicam uma forte ligação entre o vírus Zika (ZikV) e complicações neurológicas. Mielite aguda, neurite óptica, polineuropatia e encefalomielite que mimetizam distúrbios inflamatórios de desmielinização idiopáticos (DDII) após infecção por ZikV têm sido relatadas no Brasil. Obejtivo O presente estudo tem como objetivo investigar a possível ocorrência de mimetismo molecular entre antígenos do ZikV e autoantígenos da Esclerose Múltipla (EM), a DDII mais frequente do sistema nervoso central (SNC). Métodos Foi realizado um estudo de coorte retrospectivo com 305 pacientes internados por suspeita de infecção por arbovirus no Rio de Janeiro, todos os indivíduos foram submetidos a exame neurológico e coleta de amostra biológica para diagnóstico sorológico e molecular. Ferramentas de bioinformática foram usadas para analisar os peptídeos compartilhados entre antígenos do ZikV e autoantígenos da EM. Resultados Dos 305 pacientes, vinte e seis foram positivos para ZikV e 4 apresentaram padrão IDD encontrado em casos de EM. As comparações de homologia de sequência por abordagem de bioinformática entre a proteína NS5 ZikV e PLP EM revelaram uma homologia de 5/6 aminoácidos consecutivos (CSSVPV/CSAVPV) com 83% de identidade, deduzindo um mimetismo molecular. A análise das estruturas 3D revelou uma conformação semelhante com apresentação em alfa-hélice. Conclusões O mimetismo molecular entre o antígeno NS5 do vírus Zika e o autoantígeno PLP da EM surge como um possível mecanismo para o espectro IDD em indivíduos geneticamente suscetíveis.
RESUMO
SARS-CoV-2, a virus belonging to the large family of coronavirus, aroused great interest following the outbreak of this new strain reported in 2019, in Wuhan China. Its clinical spectrum is highly variable, ranging from a self-limited disease to an acute respiratory distress syndrome with systemic clinical manifestations (COVID-19), in which the immune system plays a key role in the pathophysiology of this disease and in its severity; several studies show the prevalence of some autoimmune markers suggesting that they may lead to autoimmune states. The most important strategy worldwide to protect the population was the development of vaccines to induce immunity to severe COVID-19; however, vaccines have also been shown to have the ability to produce autoimmune states in a small percentage of the world's population; nevertheless, the best strategy remains vaccination. The aim of this review is to show the current overview of the mechanisms of SARS-CoV-2-induced autoimmunity and post-vaccination for a better understanding and identification of these in the population. Publications from 2019 to 2022 were reviewed in PubMed as the primary search source.
El SARS-CoV-2, un virus perteneciente a la gran familia de los coronavirus despertó gran interés después del brote de la nueva cepa reportada en 2019, en Wuhan, China. Las manifestaciones clínicas son variables: desde enfermedad con curación espontánea hasta síndrome de dificultad respiratoria aguda, con alteraciones clínicas sistémicas (COVID-19), donde el sistema inmunitario tiene participación importante en la fi-siopatología de la enfermedad y su gravedad. Diversos estudios demuestran la prevalencia de algunos marcadores autoinmunes, lo que sugiere que pueden conducir a estados de autoinmunidad. La estrategia más importante a nivel mundial para proteger a la población fue el desarrollo de vacunas para inducir inmunidad frente al COVID-19 grave; sin embargo, se ha demostrado que tienen la capacidad de producir estados autoinmunitarios en un pequeño porcentaje de la población; no obstante, siguen siendo la mejor estrategia de tratamiento. El objetivo de esta revisión es mostrar el panorama actual de los mecanismos de autoinmunidad inducidos por SARS-CoV-2 y la post-vacunación, para una mejor comprensión e identificación en la población. Se revisaron las publicaciones de 2019 a 2022 en PubMed como fuente principal de búsqueda.
Assuntos
Doenças Autoimunes , COVID-19 , Humanos , SARS-CoV-2 , COVID-19/prevenção & controle , Autoimunidade , Doenças Autoimunes/etiologia , VacinaçãoRESUMO
BACKGROUND AND AIMS: Trap flowers are fascinating cases of adaptation, often linked to oviposition-site mimicry systems. Some trap flowers do not imprison pollinators for a pre-determined period, but rather force them to move through a specific path, manipulating their movements in a way that culminates in pollen transfer, often as they leave through a secondary opening. METHODS: We investigated the previously unknown pollination system of the lady's slipper orchid Phragmipedium vittatum and assessed the function of micro-morphological traits of its trap flowers. KEY RESULTS: Our observations revealed that P. vittatum is pollinated by females of two hoverfly species (Syrphidae). Eggs laid by flies on or near raised black spots on the flowers indicate that the orchid mimics aphids which serve as food for their aphidophagous larvae. Dark, elevated aphid-like spots appear to attract the attention of hoverflies to a slipping zone. This region has downward projecting papillate cells and mucilage secretion that promote slipperiness, causing potential pollinators to fall into the labellum. They then follow a specific upward route towards inner aphid-like spots by holding onto upward oriented hairs that aid their grip. As hoverflies are funnelled by the lateral constriction of the labellum, they pass the stigma, depositing pollen they may be carrying. Later, they squeeze under one of the articulated anthers which places pollen smears onto their upper thorax. Then, they depart through one of the narrow lateral holes by holding onto hairs projecting from the petals. CONCLUSIONS: This study confirms the system of aphid mimicry in Phragmipedium and highlights the sophisticated micro-morphological traits used by trap flowers in pollinator attraction, trapping, guidance and release, thus promoting precise pollen transfer.
Assuntos
Afídeos , Animais , Feminino , Aclimatação , Brasil , Flores , Pólen , PolinizaçãoRESUMO
Mimicry is a topic widely studied since the last century, firstly mentioned by the naturalists Henry Walter Bates and Alfred Russel Wallace, the studies were mainly about insects. Currently, mimicry research comprises both vertebrate and invertebrate. But there are few that mention a possible mimicry complex between snakes and invertebrates. This work aims to realize a bibliography review about possible mimicry complexes that comprises both snakes and invertebrates, comment about these researches and correlate with distribution data. The surveys were made using digital magazines and libraries, as well as databases for geographic distribution references. Nine publications were found that suggest possible evidence for a mimicry complex between species of invertebrates with snakes. However, there are not, at the present moment, works that indicate datation or origin of the groups here presented so that we can infer who is the mimic and who is the model. Therefore, the conclusions were that more research is necessary, mainly focused to datation analysis.
O Mimetismo é um tema amplamente estudado desde o século passado, iniciado pelos pesquisadores naturalistas Henry Walter Bates e Alfred Russel Wallace, onde os estudos foram principalmente sobre insetos. Atualmente os estudos de mimetismo englobam tanto vertebrados quanto invertebrados, mas são poucos trabalhos que mencionam um possível complexo mimético entre serpentes e invertebrados. Este trabalho objetiva realizar um levantamento bibliográfico acerca de possíveis complexos miméticos que englobam serpentes e invertebrados, discorrer sobre essas pesquisas e relacioná-los com dados de distribuição geográfica. O levantamento foi feito através de pesquisas em bibliotecas e revistas digitais, bem como bancos de dados de espécies para referências de distribuição geográfica. Foram achados no total nove publicações que apontam possíveis evidências para um possível complexo mimético entre espécies de invertebrados com serpentes. No entanto, não existem, até o momento, trabalhos que indiquem a datação ou origem dos grupos aqui apresentados para que possamos inferir quem seria o mímico e quem seria o modelo. Sendo assim, as conclusões do trabalho foram de que são necessárias mais pesquisas, sobretudo voltadas para as análises de datação.
RESUMO
A imitação facial é um comportamento involuntário capaz de facilitar a transmissão de informações não verbais relevantes em diferentes contextos sociais. Este estudo teve por objetivo analisar a capacidade de reconhecimento de expressões emocionais enquanto o observador tensiona a própria face ou imita a face-alvo. A hipótese utilizada foi a de que indivíduos que tensionam a própria face terão menor probabilidade de acertos na execução das tarefas de reconhecimento de expressões emocionais e aqueles que imitam a expressão terão uma maior probabilidade de acertos na execução das mesmas tarefas. A amostra foi composta por 30 participantes, divididos em dois grupos experimentais: o Grupo Imitação (GI) e o Grupo Ruído (GR), ambos com 18 participantes do sexo feminino e 12 do sexo masculino. O experimento consistiu em apresentar fotos de atores expressando facialmente uma emoção básica por 10 segundos. Neste período, os participantes deveriam, então, observar ou intervir facialmente, imitando ou tensionando a própria face (de acordo com o grupo alocado, Imitação ou Ruído). Após os 10 segundos executando a instrução (observar, imitar ou interferir), o participante deveria responder - entre as opções alegria, tristeza, nojo, raiva, surpresa e medo - a emoção correspondente à imagem. Os resultados apresentaram diferenças significativas quando comparadas as tarefas de tensionar ou imitar a face-alvo, sugerindo que a alteração da própria face do observador pode influenciar durante o desempenho de uma tarefa de reconhecimento de emoções em faces.(AU)
Facial mimicry is an involuntary behavior capable of facilitating the transmission of relevant non-verbal information in different social contexts. The present study aimed to analyze the ability to recognize emotional expressions while the observer tenses their own face or imitates the target face. The hypothesis used was that individuals who tension their own face or imitate the expression of facial emotion have less or greater probability of success in performing tasks to recognize emotional expressions on faces, respectively. The sample consisted of 30 participants, divided into two experimental groups: the Imitation Group - GI (18 female participants and 12 male participants) and the Noise Group - GR (18 female participants and 12 male participants). The experiment consisted of presenting pictures of actors facially expressing a basic emotion for 10 seconds; the participants should then observe or intervene facially, imitating or tensing their own face (according to the allocated group, Imitation or Noise). After 10 seconds of executing the instruction (observing, imitating or interfering), the participant should respond - among the options joy, sadness, disgust, anger, surprise and fear - the emotion corresponding to the image. The results showed significant differences when comparing the tasks of tensioning or imitating the target face, suggesting that the alteration of the observer's own face may influence during the performance of a facial emotion recognition task.(AU)
La imitación facial es un comportamiento involuntario capaz de facilitar la transmisión de información no verbal relevante en diferentes contextos sociales. Esto estudio tuvo como objetivo analizar la capacidad de reconocer expresiones emocionales mientras el observador tensa su propio rostro o imita el rostro objetivo. Se utilizó la hipótesis de que los individuos que tensan su propio rostro tendrán menor probabilidad de éxito en la realización de tareas de reconocimiento de expresiones emocionales y los individuos que imitan la expresión tendrán una mayor probabilidad de éxito en la realización de las mismas tareas. La muestra estuvo formada por 30 participantes divididos en dos grupos experimentales: el Grupo de Imitación - GI (18 mujeres y 12 hombres) y el Grupo de Ruido - GR (18 mujeres y 12 hombres). El experimento consistió en presentar imágenes de actores expresando facialmente una emoción básica durante 10 segundos; los participantes deberían entonces observar o intervenir facialmente, imitando o tensando su propio rostro (según el grupo asignado, Imitación o Ruido). Después de 10 segundos de ejecutar la instrucción (observar, imitar o interferir), el participante debería responder - entre las opciones de alegría, tristeza, asco, ira, sorpresa y miedo - la emoción correspondiente a la imagen. Los resultados mostraron diferencias significativas al comparar las tareas de tensar o imitar el rostro objetivo, sugiriendo que la alteración del propio rostro del observador puede influir durante la realización de una tarea de reconocimiento de emociones en rostros.(AU)