RESUMO
Although SARS-CoV-2 induces mucin hypersecretion in the respiratory tract, hyposalivation/xerostomia has been reported by COVID-19 patients. We evaluate the submandibular gland (SMGs) pathogenesis in SARS-CoV-2-infected K18-hACE2 mice, focusing on the impact of infection on the mucin production and structural integrity of acini, ductal system, myoepithelial cells (MECs) and telocytes. The spike protein, the nucleocapsid protein, hACE2, actin, EGF, TNF-α and IL-1ß were detected by immunofluorescence, and the Egfr and Muc5b expression was evaluated. In the infected animals, significant acinar hypertrophy was observed in contrast to ductal atrophy. Nucleocapsid proteins and/or viral particles were detected in the SMG cells, mainly in the nuclear membrane-derived vesicles, confirming the nuclear role in the viral formation. The acinar cells showed intense TNF-α and IL-1ß immunoexpression, and the EGF-EGFR signaling increased, together with Muc5b upregulation. This finding explains mucin hypersecretion and acinar hypertrophy, which compress the ducts. Dying MECs and actin reduction were also observed, indicating failure of contraction and acinar support, favoring acinar hypertrophy. Viral assembly was found in the dying telocytes, pointing to these intercommunicating cells as viral transmitters in SMGs. Therefore, EGF-EGFR-induced mucin hypersecretion was triggered by SARS-CoV-2 in acinar cells, likely mediated by cytokines. The damage to telocytes and MECs may have favored the acinar hypertrophy, leading to ductal obstruction, explaining xerostomia in COVID-19 patients. Thus, acinar cells, telocytes and MECs may be viral targets, which favor replication and cell-to-cell viral transmission in the SMG, corroborating the high viral load in saliva of infected individuals.
Assuntos
COVID-19 , Receptores ErbB , SARS-CoV-2 , Glândula Submandibular , Xerostomia , COVID-19/patologia , COVID-19/virologia , COVID-19/metabolismo , Animais , Glândula Submandibular/virologia , Glândula Submandibular/patologia , Glândula Submandibular/metabolismo , SARS-CoV-2/fisiologia , Camundongos , Xerostomia/etiologia , Xerostomia/patologia , Xerostomia/virologia , Xerostomia/metabolismo , Receptores ErbB/metabolismo , Humanos , Enzima de Conversão de Angiotensina 2/metabolismo , Mucina-5B/metabolismo , Células Acinares/patologia , Células Acinares/metabolismo , Células Acinares/virologia , Interleucina-1beta/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Modelos Animais de DoençasRESUMO
Akkermansia, a relevant mucin degrader from the vertebrate gut microbiota, is a member of the deeply branched Verrucomicrobiota, as well as the only known member of this phylum to be described as inhabitants of the gut. Only a few Akkermansia species have been officially described so far, although there is genomic evidence addressing the existence of more species-level variants for this genus. This niche specialization makes Akkermansia an interesting model for studying the evolution of microorganisms to their adaptation to the gastrointestinal tract environment, including which kind of functions were gained when the Akkermansia genus originated or how the evolutionary pressure functions over those genes. In order to gain more insight into Akkermansia adaptations to the gastrointestinal tract niche, we performed a phylogenomic analysis of 367 high-quality Akkermansia isolates and metagenome-assembled genomes, in addition to other members of Verrucomicrobiota. This work was focused on three aspects: the definition of Akkermansia genomic species clusters and the calculation and functional characterization of the pangenome for the most represented species; the evolutionary relationship between Akkermansia and their closest relatives from Verrucomicrobiota, defining the gene families which were gained or lost during the emergence of the last Akkermansia common ancestor (LAkkCA) and; the evaluation of the evolutionary pressure metrics for each relevant gene family of main Akkermansia species. This analysis found 25 Akkermansia genomic species clusters distributed in two main clades, divergent from their non-Akkermansia relatives. Pangenome analyses suggest that Akkermansia species have open pangenomes, and the gene gain/loss model indicates that genes associated with mucin degradation (both glycoside hydrolases and peptidases), (micro)aerobic metabolism, surface interaction, and adhesion were part of LAkkCA. Specifically, mucin degradation is a very ancestral innovation involved in the origin of Akkermansia. Horizontal gene transfer detection suggests that Akkermansia could receive genes mostly from unknown sources or from other Gram-negative gut bacteria. Evolutionary metrics suggest that Akkemansia species evolved differently, and even some conserved genes suffered different evolutionary pressures among clades. These results suggest a complex evolutionary landscape of the genus and indicate that mucin degradation could be an essential feature in Akkermansia evolution as a symbiotic species.
RESUMO
BACKGROUND: To elucidate the role of Mucin1 (MUC1) in the trophoblast function (glucose uptake and apoptosis) of gestational diabetes mellitus (GDM) women through the Wnt/ß-catenin pathway. METHODS: Glucose uptake was analyzed by plasma GLUT1 and GLUT4 levels with ELISA and measured by the expression of GLUT4 and INSR with immunofluorescence and Western blotting. Apoptosis was measured by the expression of Bcl-2 and Caspase3 by Western blotting and flow cytometry. Wnt/ß-catenin signaling measured by Western blotting. In vitro studies were performed using HTR-8/SVneo cells that were cultured and treated with high glucose (HG), sh-MUC1 and FH535 (inhibitor of Wnt/ß-catenin signaling). RESULTS: MUC1 was highly expressed in the placental trophoblasts of GDM, and the Wnt/ß-catenin pathway was activated, along with dysfunction of glucose uptake and apoptosis. MUC1 knockdown resulted in increased invasiveness and decreased apoptosis in trophoblast cells. The initial linkage between MUC1, the Wnt/ß-catenin pathway, and glucose uptake was confirmed by using an HG-exposed HTR-8/SVneo cell model with MUC1 knockdown. MUC1 knockdown inhibited the Wnt/ß-catenin signaling pathway and reversed glucose uptake dysfunction and apoptosis in HG-induced HTR-8/SVneo cells. Meanwhile, inhibition of Wnt/ß-catenin signaling could also reverse the dysfunction of glucose uptake and apoptosis. CONCLUSIONS: In summary, the increased level of MUC1 in GDM could abnormally activate the Wnt/ß-catenin signaling pathway, leading to trophoblast dysfunction, which may impair glucose uptake and induce apoptosis in placental tissues of GDM women.
Assuntos
Diabetes Gestacional , Trofoblastos , Gravidez , Humanos , Feminino , Via de Sinalização Wnt , beta Catenina , Placenta , GlucoseRESUMO
Association between ovine ß-globin polymorphisms and resistance against haemonchosis was described and related to the mechanism of high oxygen affinity ßA â ßC switch during anaemia, but there are no studies regarding the involved local host responses. Phenotypic parameters and local responses were evaluated in sheep from two ß-globin haplotypes naturally infected with Haemonchus contortus. Morada Nova lambs were monitored at 63, 84 and 105 days of age for faecal egg counts and packed cell volume (PCV) under natural infection with H. contortus. At 210 days of age, lambs of Hb-AA and Hb-BB ß-globin haplotypes were euthanised, and the fundic region of abomasum was sampled for evaluation of microscopic lesions and relative expression of genes related to immune, mucin and lectin activities. Lambs harbouring the ßA allele presented an improved resistance/resilience against clinical haemonchosis, showing higher PCV during infection. Hb-AA animals presented increased eosinophilia in the abomasum compared to Hb-BB animals, accompanied by higher Th2 profile, mucin and lectin activity transcripts, while the inflammatory response was increased in Hb-BB animals. This is the first report to demonstrate an enhanced local response in the primary site of H. contortus infection related to ßA allele of ß-globin haplotype.
Assuntos
Hemoncose , Haemonchus , Doenças dos Ovinos , Animais , Ovinos , Haemonchus/genética , Hematócrito/veterinária , Mucinas/genética , Lectinas , Fezes , Contagem de Ovos de Parasitas/veterináriaRESUMO
OBJECTIVES: The objective of this study was to assess the effects of in situ saliva compared to in vitro human saliva, with or without mucin, on inhibiting erosion and promoting enamel rehardening. DESIGN: Bovine enamel blocks were randomly distributed into groups (n = 23): Gsitu (human saliva in situ), Gvitro (collected human saliva) and GvitroM (collected human saliva with mucin). The enamel blocks underwent a 2-hour period for the formation of salivary pellicle, based on the assigned groups. Subsequently, they were subjected to three erosive cycles, each of them consisting of an erosive challenge (immersion in 0.65 % citric acid, pH 3.5, 1 min) and saliva exposure (immersion in situ or in vitro saliva for 2 h). Microhardness measurements were performed at each cycle, after each experimental step (erosive challenge and exposure to saliva). RESULTS: After the first demineralization, in vitro saliva groups presented greater hardness loss, with no statistical difference between GVitroM and GVitro. After the third erosive demineralization the in situ saliva resulted in less hardness loss compared to the first demineralization. In relation to surface hardness recovery, there was no difference among types of saliva but there was a decrease in hardness as the cycles progressed. CONCLUSION: Saliva groups had different behaviors between the first and third demineralization, being similar after the third cycle in terms of hardness loss. Regarding hardness recovery, all saliva promoted enamel gain, but there was a gradual decrease with the progression of the cycles.
Assuntos
Saliva , Erosão Dentária , Animais , Bovinos , Humanos , Erosão Dentária/prevenção & controle , Esmalte Dentário , Película Dentária , Dureza , MucinasRESUMO
Cystic echinococcosis is caused by the larval stages (hydatids) of cestode parasites belonging to the species cluster Echinococcus granulosus sensu lato, with E. granulosus sensu stricto being the main infecting species. Hydatids are bladderlike structures that attain large sizes within various internal organs of livestock ungulates and humans. Hydatids are protected by the massive acellular laminated layer (LL), composed mainly of mucins. Parasite growth requires LL turnover, and abundant LL-derived particles are found at infection sites in infected humans, raising the question of how LL materials are dealt with by the hosts. In this article, we show that E. granulosus sensu stricto LL mucins injected into mice are taken up by Kupffer cells, the liver macrophages exposed to the vascular space. This uptake is largely dependent on the intact mucin glycans and on Clec4F, a C-type lectin receptor which, in rodents, is selectively expressed in Kupffer cells. This uptake mechanism operates on mucins injected both in soluble form intravenously (i.v.) and in particulate form intraperitoneally (i.p.). In mice harboring intraperitoneal infections by the same species, LL mucins were found essentially only at the infection site and in the liver, where they were taken up by Kupffer cells via Clec4F. Therefore, shed LL materials circulate in the host, and Kupffer cells can act as a sink for these materials, even when the parasite grows in sites other than the liver.
Assuntos
Equinococose , Echinococcus granulosus , Animais , Humanos , Camundongos , Equinococose/parasitologia , Echinococcus granulosus/química , Genótipo , Células de Kupffer , Lectinas , MucinasRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Wormwood (Artemisia absinthium L.) is traditionally used for stomach pain and gastric relief. However, its possible gastroprotective effect has not yet been experimentally evaluated. AIM OF THE STUDY: This study evaluated the gastroprotective effect of aqueous extracts obtained through hot and room temperature maceration of A. absinthium aerial parts in rats. MATERIALS AND METHODS: The gastroprotective effect of hot aqueous extract (HAE) and room temperature aqueous extract (RTAE) from A. absinthium aerial parts were evaluated in rats using a model of acute gastric ulcer induced by ethanol p.a. The stomachs were collected to measure the gastric lesion area and histological and biochemical analysis. UHPLC-HRMS/MS analysis was used to determine the chemical profile of the extracts. RESULTS: Eight main peaks in the UHPLC chromatogram were identified in both HAE and RTAE extracts: tuberonic acid glycoside (1), rupicolin (2), 2-hydroxyeupatolide (3), yangabin (4), sesartemin (5), artemetin (6), isoalantodiene (7), and dehydroartemorin (8). For RTAE, a higher diversity of sesquiterpene lactones was observed. The groups treated with RTAE at 3%, 10%, and 30% presented a gastroprotective effect, reducing the lesion area by 64.68%, 53.71%, and 90.04%, respectively, when compared with the vehicle (VEH)-treated group. On the other hand, the groups treated with HAE at 3%, 10%, and 30% presented values of lesion areas higher than those of the VEH group. Changes in the submucosa layer, inflammatory process with edema, cellular infiltration, and mucin depletion were detected in the gastric mucosa exposed to ethanol, which was fully prevented by RTAE treatment. Neither HAE nor RTAE could increase the reduced glutathione levels in the injured gastric tissue, but RTAE (30%) reduced the formation of lipid hydroperoxides. When the rats were pre-treated with NEM (a chelator of non-protein thiols) or L-NAME (non-selective nitric oxide synthase inhibitor), the RTAE lost the ability to protect the gastric mucosa. CONCLUSIONS: This study corroborates the ethnopharmacological use of this specie to treat gastric disorders revealing the gastroprotective effect of the room-temperature aqueous extract of A. absinthium aerial parts. Its mode of action may involve the ability of the infusion to maintain the gastric mucosal barrier integrity.
Assuntos
Antiulcerosos , Artemisia absinthium , Plantas Medicinais , Úlcera Gástrica , Ratos , Animais , Extratos Vegetais/efeitos adversos , Ratos Wistar , Antiulcerosos/farmacologia , Antiulcerosos/uso terapêutico , Mucosa Gástrica , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/tratamento farmacológico , Úlcera Gástrica/prevenção & controle , Etanol/farmacologia , FitoterapiaRESUMO
The larval stages of the cestode parasites belonging to the genus Echinococcus grow within internal organs of humans and a range of animal species. The resulting diseases, collectively termed echinococcoses, include major neglected tropical diseases of humans and livestock. Echinococcus larvae are outwardly protected by the laminated layer (LL), an acellular structure that is unique to this genus. The LL is based on a fibrillar meshwork made up of mucins, which are decorated by galactose-rich O-glycans. In addition, in the species cluster termed E. granulosus sensu lato, the LL features nano-deposits of the calcium salt of myo-inositol hexakisphosphate (Insp6). The main purpose of our article is to update the immunobiology of the LL. Major recent advances in this area are (i) the demonstration of LL "debris" at the infection site and draining lymph nodes, (ii) the characterization of the decoy activity of calcium Insp6 with respect to complement, (iii) the evidence that the LL mucin carbohydrates interact specifically with a lectin receptor expressed in Kupffer cells (Clec4F), and (iv) the characterization of what appear to be receptor-independent effects of LL particles on dendritic cells and macrophages. Much information is missing on the immunology of this intriguing structure: we discuss gaps in knowledge and propose possible avenues for research.
Assuntos
Equinococose , Echinococcus granulosus , Echinococcus , Animais , Cálcio , Equinococose/parasitologia , Echinococcus/imunologia , Echinococcus granulosus/química , Echinococcus granulosus/imunologia , MucinasRESUMO
Resumen ANTECEDENTES: Los tumores del apéndice son bastante excepcionales y el adenocarcinoma mucinoso es el más frecuente de estos tumores. Esta patología es aún más infrecuente en pacientes embarazadas. CASO CLÍNICO: Paciente de 43 años, en curso de las 38.1 semanas del primer embarazo. Antecedentes: diabetes gestacional y obesidad mórbida. Se hospitalizó para practicarle la cesárea de urgencia, indicada por restricción del crecimiento intrauterino, sin posibilidad de una conducta expectante. En la ecografía de control prenatal del primer trimestre se describió la existencia de una masa quística, tabicada, de aproximadamente 12 x 12 cm. En la resonancia magnética nuclear de abdomen se encontró una lesión quística en el flanco derecho, de probable origen de masa anexial derecha de 12 x 9 cm. El estudio histopatológico reportó el hallazgo de una neoplasia mucinosa de bajo grado, asociada con extravasación extramural de mucina del apéndice cecal y un pseudomixoma peritoneal. CONCLUSIÓN: El hallazgo de una neoplasia mucinosa del apéndice en una paciente embarazada es sumamente raro. Su diagnóstico supone un reto, sobre todo en quienes no tienen síntomas. Aunque hay padecimientos más frecuentes en las mujeres, como los tumores de ovario o la apendicitis, vale la pena tener en cuenta este cuadro clínico en futuras pacientes. Se requiere mayor investigación de esta neoplasia en embarazadas para optimizar los métodos diagnósticos y poder tratarla de manera oportuna y evitar dañar al feto o la madre.
Abstract BACKGROUND: Tumours of the appendix are quite rare, with mucinous adenocarcinoma being the most frequent of these tumours. This pathology is even rarer in pregnant patients. CLINICAL CASE: 43-year-old patient, in the course of 38.1 weeks of her first pregnancy. History: gestational diabetes and morbid obesity. She was hospitalised for emergency caesarean section, indicated for intrauterine growth restriction, with no possibility of expectant management. The first trimester prenatal ultrasound scan showed a cystic mass, septate, measuring approximately 12 x 12 cm. Magnetic resonance imaging of the abdomen revealed a cystic lesion in the right flank, probably caused by a right adnexal mass measuring 12 x 9 cm. Histopathological study reported the finding of a low-grade mucinous neoplasm associated with extramural extravasation of mucin from the cecal appendix and a peritoneal pseudomyxoma. CONCLUSION: The finding of a mucinous neoplasm of the appendix in a pregnant patient is extremely rare. It is challenging to diagnose, especially in those without symptoms. Although there are more common conditions in women, such as ovarian tumours or appendicitis, this condition is worth considering in future patients. Further investigation of this neoplasm in pregnant women is needed to optimise diagnostic methods to treat it in a timely manner and to avoid harm to the foetus or the mother.
RESUMO
BACKGROUND: Genetic susceptibility to infectious diseases is partly due to the variation in the human genome, and COVID-19 is not the exception. This study aimed to identify whether risk alleles of known genes linked with emphysema (SERPINA1) and pulmonary fibrosis (MUC5B) are associated with severe COVID-19, and whether plasma mucin 5B differs according to patients' outcomes. MATERIALS AND METHODS: We included 1258 Mexican subjects diagnosed with COVID-19. We genotyped rs2892474 and rs17580 of the SERPINA1 gene and rs35705950 of MUC5B. Based on the rs35705950 genotypes, mucin 5B plasma protein levels were quantified. RESULTS: Homozygous for the risk alleles of the three polymorphisms were found in less than 5% of the study population, but no statistically significant difference in the genotype or allele association analysis. At the protein level, non-survivors carrying one or two copies of the risk allele rs35705950 in MUC5B (GT + TT) had lower levels of mucin 5B compared to the survivors (0.0 vs. 0.17 ng/mL, p = 0.0013). CONCLUSION: The polymorphisms rs28929474 and rs17580 of SERPINA1 and rs35705950 of MUC5B are not associated with the risk of severe COVID-19 in the Mexican population. COVID-19 survivor patients bearing one or two copies of the rs35705950 risk allele have higher plasma levels of mucin 5B.