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1.
Sci Transl Med ; 14(671): eabo3445, 2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36383683

RESUMO

Not all patients with cancer and severe neutropenia develop fever, and the fecal microbiome may play a role. In a single-center study of patients undergoing hematopoietic cell transplant (n = 119), the fecal microbiome was characterized at onset of severe neutropenia. A total of 63 patients (53%) developed a subsequent fever, and their fecal microbiome displayed increased relative abundances of Akkermansia muciniphila, a species of mucin-degrading bacteria (P = 0.006, corrected for multiple comparisons). Two therapies that induce neutropenia, irradiation and melphalan, similarly expanded A. muciniphila and additionally thinned the colonic mucus layer in mice. Caloric restriction of unirradiated mice also expanded A. muciniphila and thinned the colonic mucus layer. Antibiotic treatment to eradicate A. muciniphila before caloric restriction preserved colonic mucus, whereas A. muciniphila reintroduction restored mucus thinning. Caloric restriction of unirradiated mice raised colonic luminal pH and reduced acetate, propionate, and butyrate. Culturing A. muciniphila in vitro with propionate reduced utilization of mucin as well as of fucose. Treating irradiated mice with an antibiotic targeting A. muciniphila or propionate preserved the mucus layer, suppressed translocation of flagellin, reduced inflammatory cytokines in the colon, and improved thermoregulation. These results suggest that diet, metabolites, and colonic mucus link the microbiome to neutropenic fever and may guide future microbiome-based preventive strategies.


Assuntos
Microbioma Gastrointestinal , Transplante de Células-Tronco Hematopoéticas , Neoplasias , Neutropenia , Camundongos , Animais , Propionatos , Verrucomicrobia , Muco/metabolismo , Mucinas/metabolismo , Dieta , Neutropenia/metabolismo , Neoplasias/metabolismo
2.
Gut Microbes ; 14(1): 2143221, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36394293

RESUMO

ß-N-acetylhexosaminidases (EC3.2.1.52), which belong to the glycosyl hydrolase family GH20, are important enzymes for oligosaccharides modification. Numerous microbial ß-N-acetylhexosaminidases have been investigated for applications in biology, biomedicine and biotechnology. Akkermansia muciniphila is an anaerobic intestinal commensal bacterium which possesses specific ß-N-acetylhexosaminidases for gut mucosal layer colonization and mucin degradation. In this study, we assessed the in vitro mucin glycan cleavage activity of the A. muciniphila ß-N-acetylhexosaminidase Am2136 and demonstrated its ability that hydrolyzing the ß-linkages joining N-acetylglucosamine to a wide variety of aglycone residues, which indicated that Am2136 may be a generalist ß-N-acetylhexosaminidase. Structural and enzyme activity assay experiments allowed us to probe the essential function of the inter-domain interactions in ß23-ß33. Importantly, we revealed that the hydrolysis activity of Am2136 was enhanced by nucleotides. We further speculated that this activation mechanism might be associated with the conformational motions between domain III and IV. To our knowledge, this is the first report of nucleotide effector regulated ß-N-acetylhexosaminidase, to reveal its novel biological functions. These findings contribute to understanding the distinct properties within the GH20 family and lay a certain foundation to develop controllable glycan hydrolyzing catalysts.Abbreviations: OD600 - optical cell densities at 600 nm; LB - Luria-Bertani; IPTG - isopropyl ß-D-1-thiogalactopyranoside; PMSF - phenylmethanesulfonyl fluoride; rmsd - root mean square deviation; GlcNAc - N-acetyl-ß-D-glucosamine; GalNAc - N-acetyl-ß-D-galactosamine; Gal - galactose.


Assuntos
Microbioma Gastrointestinal , beta-N-Acetil-Hexosaminidases , beta-N-Acetil-Hexosaminidases/química , beta-N-Acetil-Hexosaminidases/metabolismo , Especificidade por Substrato , Verrucomicrobia/metabolismo , Mucinas/metabolismo , Nucleotídeos/metabolismo
3.
Iran J Immunol ; 19(3): 255-262, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36190380

RESUMO

BACKGROUND: Natural killer (NK) cells are dichotomously involved in chronic hepatitis B (CHB) infection as principal members of innate immunity. An effective treatment should enhance the antiviral potentials of NK cells and not their immunomodulatory roles. TIM-3 (T-cell immunoglobulin and mucin-containing domain) is a molecule with an essential role in controlling immune tolerance. TIM-3 demonstrated the highest expression among NK cells of patients with chronic liver disorders. Statins have been reported to attenuate the levels of TIM-3 on NK cells. OBJECTIVES: To investigate the frequencies of NK cells, NKT cells, and TIM-3+ population in patients with CHB upon rosuvastatin (RSV) intervention. METHODS: Thirty confirmed patients with CHB were randomly assigned into two groups of 15 (receiving 20 mg of RSV or placebo per day) for 12 weeks. We evaluated the percentages of TIM-3+ cells by staining the peripheral blood mononuclear cells (PBMCs) with CD3, CD16, and CD56 markers using flow cytometry. RESULTS: Our findings indicated that RSV administration could increase CD3- CD56+ NK cells (P>0.05) and CD3+ CD16+ CD56+ NKT cells (P<0.05). RSV intervention could reduce the percentages of TIM-3+ cells among NK cells (P<0.01) and NKT cells (P> 0.05) of patients with CHB compared with the placebo group. CONCLUSIONS: The increased population of NK and NKT cells and the effective reduction of TIM-3+ cells among patients with CHB delineated that rosuvastatin could be proposed as an appropriate modulator of innate immune response (regarding NK and NKT cells) in favor of enhancing their antiviral activities.


Assuntos
Hepatite B Crônica , Inibidores de Hidroximetilglutaril-CoA Redutases , Células T Matadoras Naturais , Antivirais/uso terapêutico , Receptor Celular 2 do Vírus da Hepatite A/metabolismo , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/metabolismo , Imunoglobulinas , Células Matadoras Naturais , Mucinas/metabolismo , Rosuvastatina Cálcica/metabolismo , Rosuvastatina Cálcica/uso terapêutico
4.
Microb Cell Fact ; 21(1): 204, 2022 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-36207743

RESUMO

BACKGROUND: Saccharomyces boulardii is a probiotic yeast that exhibits antimicrobial and anti-toxin activities. Although S. boulardii has been clinically used for decades to treat gastrointestinal disorders, several studies have reported weak or no beneficial effects of S. boulardii administration in some cases. These conflicting results of S. boulardii efficacity may be due to nutrient deficiencies in the intestine that make it difficult for S. boulardii to maintain its metabolic activity. RESULTS: To enable S. boulardii to overcome any nutritional deficiencies in the intestine, we constructed a S. boulardii strain that could metabolize L-fucose, a major component of mucin in the gut epithelium. The fucU, fucI, fucK, and fucA from Escherichia coli and HXT4 from S. cerevisiae were overexpressed in S. boulardii. The engineered S. boulardii metabolized L-fucose and produced 1,2-propanediol under aerobic and anaerobic conditions. It also produced large amounts of 1,2-propanediol under strict anaerobic conditions. An in silico genome-scale metabolic model analysis was performed to simulate the growth of S. boulardii on L-fucose, and elementary flux modes were calculated to identify critical metabolic reactions for assimilating L-fucose. As a result, we found that the engineered S. boulardii consumes L-fucose via (S)-lactaldehyde-(S)-lactate-pyruvate pathway, which is highly oxygen dependent. CONCLUSION: To the best of our knowledge, this is the first study in which S. cerevisiae and S. boulardii strains capable of metabolizing L-fucose have been constructed. This strategy could be used to enhance the metabolic activity of S. boulardii and other probiotic microorganisms in the gut.


Assuntos
Probióticos , Saccharomyces boulardii , Animais , Escherichia coli , Fucose/metabolismo , Lactatos/metabolismo , Mamíferos , Análise do Fluxo Metabólico , Mucinas/metabolismo , Oxigênio/metabolismo , Probióticos/metabolismo , Propilenoglicol/metabolismo , Piruvatos/metabolismo , Saccharomyces boulardii/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
5.
Arch Microbiol ; 204(11): 673, 2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36255493

RESUMO

A lectin PCL, from Purpureocillium lilacinum a saprophytic, filamentous fungus was purified from the crude extract of the mycelia using 70% ammonium sulphate precipitation followed by affinity chromatography on mucin-Sepharose 4 B column. PCL is a monomer with an apparent molecular mass of 18.5 kDa as revealed by SDS-PAGE under both reducing and non-reducing conditions. PCL is a blood group non-specific lectin and has highest affinity towards chitin, mucin, asialomucin, fetuin with a MIC of 0.15 µg/mL and also recognizes L-fucose, galactose, lactose, N-acetyl galactosamine, hyaluronic acid. PCL is stable up to 60 °C and within the pH range 4-8. To understand its role in pathogenesis, effect of PCL was evaluated on human corneal epithelial cells (HCECs). PCL showed strong glycan mediated binding to HCECs and PCL showed proinflammatory response at lower concentrations by stimulating secretion of IL-6, 8. In contrast PCL at higher concentrations revealed opposite effect of HCECs growth inhibition. All these results collectively support the involvement of PCL in mediating host pathogen interactions possibly leading to pathogenesis. In addition, considering the entomopathogenic effect of Purpureocillium lilacinum, PCL may be attributed for this beneficiary effect, which needs to be explored.


Assuntos
Antígenos de Grupos Sanguíneos , Ceratite , Humanos , Lectinas , Fucose , Galactose , Lactose , Sulfato de Amônio/metabolismo , Sefarose , Ácido Hialurônico , Interleucina-6 , Ceratite/microbiologia , Quitina/metabolismo , Fetuínas , Mucinas/metabolismo , Misturas Complexas , Galactosamina
6.
Nat Commun ; 13(1): 6257, 2022 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-36270990

RESUMO

Mucin-type-O-glycosylation on proteins is integrally involved in human health and disease and is coordinated by an enzyme family of 20 N-acetylgalactosaminyltransferases (GalNAc-Ts). Detailed knowledge on the biological effects of site-specific O-glycosylation is limited due to lack of information on specific glycosylation enzyme activities and O-glycosylation site-occupancies. Here we present a systematic analysis of the isoform-specific targets of all GalNAc-Ts expressed within a tissue-forming human skin cell line, and demonstrate biologically significant effects of O-glycan initiation on epithelial formation. We find over 300 unique glycosylation sites across a diverse set of proteins specifically regulated by one of the GalNAc-T isoforms, consistent with their impact on the tissue phenotypes. Notably, we discover a high variability in the O-glycosylation site-occupancy of 70 glycosylated regions of secreted proteins. These findings revisit the relevance of individual O-glycosylation sites in the proteome, and provide an approach to establish which sites drive biological functions.


Assuntos
N-Acetilgalactosaminiltransferases , Proteoma , Humanos , Glicosilação , Proteoma/metabolismo , N-Acetilgalactosaminiltransferases/genética , N-Acetilgalactosaminiltransferases/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Linhagem Celular , Mucinas/metabolismo , Polissacarídeos
7.
Int J Mol Sci ; 23(19)2022 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-36232498

RESUMO

Dry eye is one of the most common ocular surface diseases caused by tear film instability and ocular surface damage due to an abnormal quality or quantity of tears. Inflammatory factors can initiate relevant transduction signalling pathways and trigger the inflammatory cascade response, resulting in ocular surface inflammation. It has been shown that the active ingredients in Dendrobium, such as polysaccharides, alkaloids and phenols, have anti-inflammatory, anti-tumour and immunity-boosting effects, and Dendrobium officinale extract can improve glandular secretion function, increase salivary secretion and increase the expression level of water channel protein in salivary glands in patients with dry eye syndromes. We investigated the in vitro cytoprotective effect of Dendrobium extracts in sodium chloride induced hyperosmotic conditions in human cornea keratocytes (HKs). Results showed that Dendrobium officinale Kimura et Migo water extract (DOW) and Dendrobium loddigesii Rolfe water extract (DLW) could upregulate the expression of aquaporins (AQP)5 protein, thus exerting a repairing effect by promoting cell migration. Furthermore, oral administration of DOW and DLW enhanced tear production in rats and exerted a protective effect on ocular surface damage. DOW and DLW could upregulate the expression of AQP5 and mucin (muc)5ac proteins in the lacrimal gland and reduce the inflammatory response. DOW and DLW inhibited the activation of the corresponding mitogen-activated protein kinases (MAPK) and NF-KB pathway, thereby playing a role in improving dry eye symptoms. This study provides a new perspective on dry eye treatment, and DOW and DLW may be potential therapeutic agents for dry eye.


Assuntos
Dendrobium , Síndromes do Olho Seco , Animais , Anti-Inflamatórios/uso terapêutico , Aquaporina 5/metabolismo , Dendrobium/metabolismo , Síndromes do Olho Seco/metabolismo , Humanos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Mucinas/metabolismo , NF-kappa B/metabolismo , Fenóis/metabolismo , Polissacarídeos/metabolismo , Ratos , Cloreto de Sódio/metabolismo , Lágrimas/metabolismo , Água/metabolismo
8.
Discov Med ; 33(168): 27-40, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36274211

RESUMO

Prostate androgen-regulated mucin-like protein (PARM1) is known to promote cell survival via protecting the cell surface, thus being involved in cancer development. The Gene Expression Profiling Interactive Analysis (GEPIA), MEXPRESS database, LinkedOmics database, GeneMANIA database, and the Tumor Immune Estimation Resource (TIMER) database were accessed to explore the epigenetic regulation, prognostic value, biological functions and mechanisms of PARM1 in diffuse large B-cell lymphoma (DLBCL). Hypomethylation and resultant overexpression of PARM1 was found in DLBCL. The high-level expression of PARM1 was related to the poor outcome of DLBCL patients. PARM1 participated in DNA repair, cell cycle, and cellular response to stress. PARM1 was also associated with autophagy, apoptosis, Ras pathway, and MAPK cascade. Significant kinase targets of PARM1 included ATM, CDK1, and CDK2. Significant transcription factor targets of PARM1 involved ELK1, MYC and so on. Significant miRNA targets of PARM1 included miR21, miR202, miR323, and miR345. Further analysis suggested that the PARM1 regulated autophagy through the PI3K-Akt signaling. PARM1 was found to be correlated with immune cell infiltration, which indicated the important roles of PARM1 in microenvironment of DLBCL. Our study lays a foundation for further research on the impact of PARM1 in DLBCL tumorigenesis and precision therapy.


Assuntos
Linfoma Difuso de Grandes Células B , MicroRNAs , Masculino , Humanos , Prognóstico , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Androgênios , Epigênese Genética , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/patologia , MicroRNAs/genética , Fatores de Transcrição/genética , Biomarcadores , Mucinas/genética , Mucinas/metabolismo , Microambiente Tumoral
9.
Virulence ; 13(1): 1741-1751, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36205522

RESUMO

Carbohydrates can both protect against infection and act as targets promoting infection. Mucins are major components of the slimy mucus layer covering the fish epithelia. Mucins can act as decoys for intimate pathogen interaction with the host afforded by binding to glycosphingolipids in the host cell membrane. We isolated and characterized glycosphingolipids from Atlantic salmon skin, gill, stomach, pyloric caeca, and intestine. We characterized the glycosphingolipids using liquid chromatography - mass spectrometry and tandem mass spectrometry and the glycan repertoire was compared with the glycan repertoire of mucins from the same epithelia. We also investigated Aeromonas salmonicida binding using chromatogram and microtiter well based binding assays. We identified 29 glycosphingolipids. All detected acid glycans were of the ganglio-series (unless shorter) and showed a high degree of polysialylation. The non-acid glycans were mostly composed of the neolacto, globo, and ganglio core structures. The glycosphingolipid repertoire differed between epithelia and the proportion of the terminal moieties of the glycosphingolipids did not reflect the terminal moieties on the mucins from the same epithelia. A. salmonicida did not bind the Atlantic salmon glycosphingolipids. Instead, we identified that A. salmonicida binding to sialic acid occurred to α2-6 Neu5Ac but not to α2-3 Neu5Ac. α2-6 Neu5Ac was present on mucins whereas mainly α2-3 Neu5Ac was found on the glycosphingolipids, explaining the difference in A. salmonicida binding ability between these host glycoconjugates. A. salmonicida´s ability to bind to Atlantic salmon mucins, but not the glycosphingolipids, is likely part of the host defence against this pathogen.


Assuntos
Aeromonas salmonicida , Aeromonas salmonicida/metabolismo , Animais , Ceco , Brânquias/metabolismo , Glicoesfingolipídeos , Intestinos , Mucinas/metabolismo , Ácido N-Acetilneuramínico/análise , Polissacarídeos/metabolismo , Estômago , Espectrometria de Massas em Tandem
10.
Front Immunol ; 13: 1021094, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36311778

RESUMO

The intestinal epithelium surface is covered by a layer of mucus that harbors a complex and dynamic population of bacteria termed gut microbiota. In particular, some gut bacteria have the ability to degrade the mucin glycan for nutritional sources. However, the bacterial diversity of mucin-degrading bacteria in human gut microbiota and their role in the gut remains unclear. In this study, we characterized the diversity of mucin-degrading bacteria in the human gut microbiota by an established cultivation-based molecular profiling method. The results showed the gut commensals having the mucin degrading ability were widely distributed in the gut microbiota and were more abundant than previously thought. In addition, many previously uncharacterized mucin degraders were isolated from faecals samples, suggesting the mucin-degrading gut commensals were underappreciated. To gain a better understanding of the interaction between these mucin-degrading gut commensals and the host, the effect of the commensals on intestinal epithelial cells were examined, and the results revealed that the commensals (8 Bacteroides spp., 2 Parabacteroides spp, Akkermanisa muciniphila and Bifidobacterial dentium) incited low level of inflammatory response (IL-8 and TNF-α) but suppressed the inflammatory response induced by E. coli through downregulating the NF-κB pathway. The presence of gut commensals also showed potential in enhancing the epithelial tight junction (TJ) barrier function through regulating the mRNA expression of TJ protein genes such as Zo-1, Occludin, Claudin-1 and E-cadherin. Furthermore, the presence of commensal bacteria P. distasonis, B. thetaiotaomicron and A. muciniphila completely or partly restored the pro-inflammatory cytokine IL-1ß induced TJ barrier disruption. In conclusion, these findings indicate that mucin-degrading gut commensals were widely distributed in the gut microbiota and showed anti-inflammatory effect against pathogen infection and potential in modulating the epithelial barrier function.


Assuntos
Mucinas , Junções Íntimas , Humanos , Junções Íntimas/metabolismo , Mucinas/metabolismo , Escherichia coli/metabolismo , Mucosa Intestinal/metabolismo , Inflamação/metabolismo
11.
Biosci Rep ; 42(10)2022 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-36214107

RESUMO

Protein glycosylation is ubiquitous throughout biology. From bacteria to humans, this post translational modification with sophisticated carbohydrate structures plays a profound role in the interaction of proteins with cells and changes the physiochemical properties of the proteins that carry them. When the glycans are linked to Ser or Thr residues, they are known as O-linked glycans, as the glycosidic linkage is through oxygen. O-glycans are perhaps best known as part of the mucin proteins, however many soluble proteins carry these types of glycans, and that their roles in biology are still being discovered. Many of the soluble proteins that carry O-glycans have a role as therapeutic proteins, and in the 21st century, the application of synthetic biology is starting to be applied to improving these proteins through manipulation of the glycans. This review will explore the role of these O-linked glycans in proteins with pharmaceutical significance, as well as recent advancements in recombinant glycoprotein therapeutics.


Assuntos
Mucinas , Polissacarídeos , Humanos , Glicosilação , Polissacarídeos/química , Mucinas/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas Recombinantes/uso terapêutico , Proteínas Recombinantes/metabolismo
12.
Proc Natl Acad Sci U S A ; 119(43): e2209750119, 2022 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-36252017

RESUMO

Mucins are large, highly glycosylated transmembrane and secreted proteins that line and protect epithelial surfaces. However, the details of mucin biosynthesis and packaging in vivo are largely unknown. Here, we demonstrate that multiple distinct mucins undergo intragranular restructuring during secretory granule maturation in vivo, forming unique structures that are spatially segregated within the same granule. We further identify temporally-regulated genes that influence mucin restructuring, including those controlling pH (Vha16-1), Ca2+ ions (fwe) and Cl- ions (Clic and ClC-c). Finally, we show that altered mucin glycosylation influences the dimensions of these structures, thereby affecting secretory granule morphology. This study elucidates key steps and factors involved in intragranular, rather than intergranular segregation of mucins through regulated restructuring events during secretory granule maturation. Understanding how multiple distinct mucins are efficiently packaged into and secreted from secretory granules may provide insight into diseases resulting from defects in mucin secretion.


Assuntos
Mucinas , Vesículas Secretórias , Grânulos Citoplasmáticos/metabolismo , Glicosilação , Mucinas/metabolismo , Vesículas Secretórias/metabolismo
13.
NPJ Biofilms Microbiomes ; 8(1): 81, 2022 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-36253412

RESUMO

As one of the promising next-generation probiotics (NGPs), Akkermansia muciniphila, a well-known mucin-degrading bacterium, has been proven to be closely related to the metabolic diseases of its human host. However, the role of A. muciniphila in the host's intestinal health remains ambiguous. Here, we comprehensively summarize and discuss the characteristics, the distribution, and the colonization of A. muciniphila in the human gastrointestinal tract (GIT). We propose that the application of A. muciniphila as a biomarker for longevity, for diagnostics and prognostics of intestinal diseases, or for intestinal health should be cautiously considered. Precise dietary regulation can mediate the treatment of intestinal diseases by altering the abundance of A. muciniphila. Although the beneficial role of A. muciniphila and its component in intestinal inflammation has been discovered, in gnotobiotic mice with specific gut microbiota, certain genotype, and colorectal cancer, or in animal models infected with a specific pathogen, A. muciniphila may be related to the occurrence and development of intestinal diseases. Genomic analysis, emphasizing the strain-level phylogenetic differences of A. muciniphila, indicates that a clear description and discussion of each strain is critical before its practical application. Our review provides much needed insight for the precise application of A. muciniphila.


Assuntos
Mucinas , Verrucomicrobia , Akkermansia , Animais , Biomarcadores/metabolismo , Humanos , Camundongos , Mucinas/metabolismo , Filogenia , Verrucomicrobia/metabolismo
14.
Sci Rep ; 12(1): 17407, 2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36258027

RESUMO

Improving maternal nutrition during pregnancy/lactation is a promising strategy to maximise the intestinal health of piglets undergoing abrupt weaning under commercial production conditions. This experiment investigated the effects of maternal supplementation of a casein hydrolysate and yeast ß-glucan (CH-YBG) from day 83 of gestation until weaning (day 28) on sow faecal microbial populations and measures of piglet gastrointestinal health parameters at weaning. Sows (n = 10 sows/group) were assigned to: (1) control diet, and (2) control diet + CH-YBG. Maternal supplementation increased the abundance of the phylum Firmicutes, including members Lactobacillus in the sows faeces, with a concomitant increase in the caecal abundance of Lactobacillus in the weaned piglets compared to the controls. Piglets weaned from the supplemented sows had increased villus height in the duodenum (P < 0.05) and increased villus height to crypt depth ratio in the jejunum, as well as a decreased expression of the proinflammatory cytokine genes (IL6/TNF/TGFB), the tight junction gene CLDN3 and the mucin gene MUC2 in the duodenum/jejunum compared to the controls (P < 0.05). In conclusion, maternal CH-YBG supplementation during pregnancy/lactation improved microbial, structural, and inflammatory measures of gastrointestinal health of piglets at weaning. This is a promising strategy to alleviate the challenges that occur with early abrupt weaning in commercial pig production.


Assuntos
Saccharomyces cerevisiae , beta-Glucanas , Animais , Suínos , Feminino , Gravidez , Desmame , Colostro/química , Ração Animal/análise , Leite/química , beta-Glucanas/metabolismo , Interleucina-6/metabolismo , Lactação , Suplementos Nutricionais , Dieta/veterinária , Mucinas/metabolismo
15.
PLoS Negl Trop Dis ; 16(10): e0010788, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36190932

RESUMO

Host cell invasion is a critical step for infection by Trypanosoma cruzi, the agent of Chagas disease. In natural infection, T. cruzi metacyclic trypomastigote (MT) forms establish the first interaction with host cells. The gp35/50 mucin molecules expressed in MT have been implicated in cell invasion process, but the mechanisms involved are not well understood. We performed a series of experiments to elucidate the mode of gp35/50-mediated MT internalization. Comparing two parasite strains from genetically divergent groups, G strain (TcI) and CL strain (TcVI), expressing variant forms of mucins, we demonstrated that G strain mucins participate in MT invasion. Only G strain-derived mucins bound to HeLa cells in a receptor-dependent manner and significantly inhibited G strain MT invasion. CL strain MT internalization was not affected by mucins from either strain. HeLa cell invasion by G strain MT was associated with actin recruitment and did not rely on lysosome mobilization. To examine the involvement of annexin A2, which plays a role in actin dynamic, annexin A2-depleted HeLa cells were generated. Annexin A2-deficient cell lines were significantly more resistant than wild type controls to G strain MT invasion. In a co-immunoprecipitation assay, to check whether annexin A2 might be the receptor for mucins, protein A/G magnetic beads crosslinked with monoclonal antibody to G strain mucins were incubated with detergent extracts of MT and HeLa cells. Binding of gp35/50 mucins to annexin A2 was detected. Both G strain MT and purified mucins induced focal adhesion kinase activation in HeLa cells. By confocal immunofluorescence microscopy, colocalization of invading G strain MT with clathrin was visualized. Inhibition of clathrin-coated vesicle formation reduced parasite internalization. Taken together, our data indicate that gp35/50-mediated MT invasion is accomplished through interaction with host cell annexin A2 and clathrin-dependent endocytosis.


Assuntos
Anexina A2 , Doença de Chagas , Trypanosoma cruzi , Actinas/metabolismo , Anexina A2/metabolismo , Anticorpos Monoclonais , Doença de Chagas/parasitologia , Clatrina , Detergentes/metabolismo , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Células HeLa , Humanos , Mucinas/metabolismo , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Trypanosoma cruzi/fisiologia
16.
PLoS One ; 17(10): e0275671, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36256656

RESUMO

Human tissue surfaces are coated with mucins, a family of macromolecular sugar-laden proteins serving diverse functions from lubrication to the formation of selective biochemical barriers against harmful microorganisms and molecules. Membrane mucins are a distinct group of mucins that are attached to epithelial cell surfaces where they create a dense glycocalyx facing the extracellular environment. All mucin proteins carry long stretches of tandemly repeated sequences that undergo extensive O-linked glycosylation to form linear mucin domains. However, the repetitive nature of mucin domains makes them prone to recombination and renders their genetic sequences particularly difficult to read with standard sequencing technologies. As a result, human mucin genes suffer from significant sequence gaps that have hampered the investigation of gene function in health and disease. Here we leveraged a recent human genome assembly to characterize a previously unmapped MUC3B gene located at the q22 locus on chromosome 7, within a cluster of four structurally related membrane mucin genes that we name the MUC3 cluster. We found that MUC3B shares high sequence identity with the known MUC3A gene and that the two genes are governed by evolutionarily conserved regulatory elements. Furthermore, we show that MUC3A, MUC3B, MUC12, and MUC17 in the human MUC3 cluster are expressed in intestinal epithelial cells (IECs). Our results complete existing genetic gaps in the MUC3 cluster which is a conserved genetic unit in vertebrates. We anticipate our results to be the starting point for the detection of disease-associated polymorphisms in the human MUC3 cluster. Moreover, our study provides the basis for the exploration of intestinal mucin gene function in widely used experimental models such as human intestinal organoids and genetic mouse models.


Assuntos
Cromossomos Humanos Par 7 , Mucinas , Animais , Humanos , Camundongos , Sequência de Aminoácidos , Cromossomos Humanos Par 7/metabolismo , Mucosa Intestinal/metabolismo , Mucina-2/genética , Mucinas/metabolismo , Família Multigênica , Açúcares/metabolismo
17.
PLoS One ; 17(10): e0266310, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36223404

RESUMO

Airway epithelial damage is a common feature in respiratory diseases such as COPD and has been suggested to drive inflammation and progression of disease. These features manifest as remodeling and destruction of lung epithelial characteristics including loss of small airways which contributes to chronic airway inflammation. Histone deacetylase 6 (HDAC6) has been shown to play a role in epithelial function and dysregulation, such as in cilia disassembly, epithelial to mesenchymal transition (EMT) and oxidative stress responses, and has been implicated in several diseases. We thus used ACY-1083, an inhibitor with high selectivity for HDAC6, and characterized its effects on epithelial function including epithelial disruption, cytokine production, remodeling, mucociliary clearance and cell characteristics. Primary lung epithelial air-liquid interface cultures from COPD patients were used and the impacts of TNF, TGF-ß, cigarette smoke and bacterial challenges on epithelial function in the presence and absence of ACY-1083 were tested. Each challenge increased the permeability of the epithelial barrier whilst ACY-1083 blocked this effect and even decreased permeability in the absence of challenge. TNF was also shown to increase production of cytokines and mucins, with ACY-1083 reducing the effect. We observed that COPD-relevant stimulations created damage to the epithelium as seen on immunohistochemistry sections and that treatment with ACY-1083 maintained an intact cell layer and preserved mucociliary function. Interestingly, there was no direct effect on ciliary beat frequency or tight junction proteins indicating other mechanisms for the protected epithelium. In summary, ACY-1083 shows protection of the respiratory epithelium during COPD-relevant challenges which indicates a future potential to restore epithelial structure and function to halt disease progression in clinical practice.


Assuntos
Inibidores de Histona Desacetilases , Doença Pulmonar Obstrutiva Crônica , Citocinas/metabolismo , Células Epiteliais/metabolismo , Transição Epitelial-Mesenquimal , Desacetilase 6 de Histona/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Humanos , Inflamação/metabolismo , Pulmão/metabolismo , Mucinas/metabolismo , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Doença Pulmonar Obstrutiva Crônica/metabolismo , Mucosa Respiratória/metabolismo , Proteínas de Junções Íntimas/metabolismo , Fator de Crescimento Transformador beta/metabolismo
18.
Cell ; 185(22): 4206-4215.e11, 2022 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-36206754

RESUMO

Mucus protects the epithelial cells of the digestive and respiratory tracts from pathogens and other hazards. Progress in determining the molecular mechanisms of mucus barrier function has been limited by the lack of high-resolution structural information on mucins, the giant, secreted, gel-forming glycoproteins that are the major constituents of mucus. Here, we report how mucin structures we determined enabled the discovery of an unanticipated protective role of mucus: managing the toxic transition metal copper. Using two juxtaposed copper binding sites, one for Cu2+ and the other for Cu1+, the intestinal mucin, MUC2, prevents copper toxicity by blocking futile redox cycling and the squandering of dietary antioxidants, while nevertheless permitting uptake of this important trace metal into cells. These findings emphasize the value of molecular structure in advancing mucosal biology, while introducing mucins, produced in massive quantities to guard extensive mucosal surfaces, as extracellular copper chaperones.


Assuntos
Cobre , Mucinas , Mucinas/metabolismo , Mucina-2 , Cobre/análise , Cobre/metabolismo , Intestinos , Muco/metabolismo , Mucosa Intestinal/metabolismo
19.
Cell ; 185(20): 3705-3719.e14, 2022 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-36179667

RESUMO

The intestinal microbiota is an important modulator of graft-versus-host disease (GVHD), which often complicates allogeneic hematopoietic stem cell transplantation (allo-HSCT). Broad-spectrum antibiotics such as carbapenems increase the risk for intestinal GVHD, but mechanisms are not well understood. In this study, we found that treatment with meropenem, a commonly used carbapenem, aggravates colonic GVHD in mice via the expansion of Bacteroides thetaiotaomicron (BT). BT has a broad ability to degrade dietary polysaccharides and host mucin glycans. BT in meropenem-treated allogeneic mice demonstrated upregulated expression of enzymes involved in the degradation of mucin glycans. These mice also had thinning of the colonic mucus layer and decreased levels of xylose in colonic luminal contents. Interestingly, oral xylose supplementation significantly prevented thinning of the colonic mucus layer in meropenem-treated mice. Specific nutritional supplementation strategies, including xylose supplementation, may combat antibiotic-mediated microbiome injury to reduce the risk for intestinal GVHD in allo-HSCT patients.


Assuntos
Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bacteroides , Carbapenêmicos/farmacologia , Carbapenêmicos/uso terapêutico , Doença Enxerto-Hospedeiro/tratamento farmacológico , Doença Enxerto-Hospedeiro/etiologia , Meropeném , Camundongos , Mucinas/metabolismo , Muco/metabolismo , Polissacarídeos/metabolismo , Xilose
20.
J Clin Invest ; 132(17)2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-36047499

RESUMO

The intestinal tract is protected by epithelium-covering mucus, which is constantly renewed by goblet cells, a specialized type of epithelial cell. Mucus is largely composed of MUC2 mucin, an enormous molecule that poses a high demand on the endoplasmic reticulum (ER) for proper folding and protein assembly, creating a challenge for the secretory machinery in goblet cells. In this issue of the JCI, Grey et al. reveal that the ER resident protein and folding sensor ERN2 (also known as IRE1ß) was instrumental for goblet cells to produce sufficient amounts of mucus to form a protective mucus layer. In the absence of ERN2, mucus production was reduced, impairing the mucus barrier, which allowed bacteria to penetrate and cause an epithelial cell stress response. This study emphasizes the importance of a controlled unfolded protein response (UPR) for goblet cell secretion.


Assuntos
Células Caliciformes , Mucinas , Células Epiteliais/metabolismo , Células Caliciformes/metabolismo , Mucosa Intestinal/metabolismo , Mucina-2/metabolismo , Mucinas/metabolismo , Muco/metabolismo
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