Astrovirus infects actively secreting goblet cells and alters the gut mucus barrier

Abstract Goblet cells, specialized epithelial cells that produce mucus, are essential for gut health. Dysfunctional goblet cell secretion can weaken the mucus barrier, bringing commensal microbes and other lumenal contents in contact with the epithelial barrier, triggering inflammation. We recently discovered that murine astroviruses infect goblet cells in the small intestine, making it the first enteric virus in which this tropism has been recognized in vivo. To first determine whether astrovirus infection alters mucus production in goblet cells, we used periodic acid-Schiff staining of small intestinal tissues and found a thicker mucus layer in infected compared to mock-infected animals (1.85 to 2.51-fold, p<0.001). Because changes to the mucus barrier can alter the microbial environment in the gut, we used 16S metagenomic to characterize the microbiome after infection. We found that the relative frequency of well-characterized mucus-degrading bacteria significantly increased after infection (p<0.001). Using phylogenetic edge principal components analysis, we also identified distinct microbiome shifts between 0 and 14 days post-infection, corresponding to peak infection. Finally, to determine the extent to which these changes in the mucus barrier could have a functional consequence to host disease susceptibility, we developed a neonatal model for astrovirus and tested whether animals inoculated with enteropathogenic E. coli (EPEC), an adherent bacterial pathogen, would be protected from colonization. In comparison to animals inoculated with EPEC alone, co-infected animals had significantly reduced EPEC colonization (p<0.01). Together, these studies reveal a new avenue of enteric virus regulation of gut homeostasis and immunity via goblet cells and highlight astroviruses as a novel model to study the mucus barrier. Future studies are needed to determine whether astrovirus-induced increases in the mucus barrier protect from other gastrointestinal diseases and how these data translate to human astroviruses, which predominately infect children <1-year-old and coincides with the development of gut immunity.

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The Difference in the Mucus Organization Between the Small and Large Intestine and Its Protection of Selected Natural Substances. A Review

Folia Veterinaria ◽

10.2478/fv-2018-0037 ◽

2018 ◽

Vol 62 (4) ◽

pp. 48-55

Author(s):

R. Szabóová ◽

Z. Faixová ◽

Z. Maková ◽

E. Piešová

Keyword(s):

Goblet Cells ◽

Mucus Layer ◽

Mucus Production ◽

Natural Substances ◽

Intestinal Mucus ◽

The Difference ◽

Mucus Barrier ◽

Microbial Toxins ◽

Natural Additives

Abstract The mucus layer of the intestinal tract plays an important role of forming the front line of innate host defense. Recent studies have suggested that the involvement of feeding natural additives on protection/prevention/promotion of mucus production in the intestinal environment is beneficial. The goblet cells continually produce mucins for the retention of the mucus barrier under physiological conditions, but different factors (e. g. microorganisms, microbial toxins, viruses, cytokines, and enzymes) can have profound effects on the integrity of the intestinal epithelium covered by a protective mucus. The intestinal mucus forms enterocytes covered by transmembrane mucins and goblet cells produce by the secreted gel-forming mucins (MUC2). The mucus is organized in a single unattached mucus layer in the small intestine and in two mucus layers (inner, outer) in the colon. The main part of the review evaluates the effects of natural additives/substances supplementation to stimulate increased expression of MUC2 mucin in the intestine of animals.

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Mucins Dynamics in Physiological and Pathological Conditions

International Journal of Molecular Sciences ◽

10.3390/ijms222413642 ◽

2021 ◽

Vol 22 (24) ◽

pp. 13642

Author(s):

Hassan Melhem ◽

Daniel Regan-Komito ◽

Jan Hendrik Niess

Keyword(s):

Inflammatory Bowel Disease ◽

Epithelial Cells ◽

Molecular Mechanisms ◽

Expression Profiles ◽

Goblet Cells ◽

Mucus Layer ◽

Intestinal Mucus ◽

Pathological Conditions ◽

Inflammatory Bowel ◽

Mucus Barrier

Maintaining intestinal health requires clear segregation between epithelial cells and luminal microbes. The intestinal mucus layer, produced by goblet cells (GCs), is a key element in maintaining the functional protection of the epithelium. The importance of the gut mucus barrier is highlighted in mice lacking Muc2, the major form of secreted mucins. These mice show closer bacterial residence to epithelial cells, develop spontaneous colitis and became moribund when infected with the attaching and effacing pathogen, Citrobacter rodentium. Furthermore, numerous observations have associated GCs and mucus layer dysfunction to the pathogenesis of inflammatory bowel disease (IBD). However, the molecular mechanisms that regulate the physiology of GCs and the mucus layer remain obscured. In this review, we consider novel findings describing divergent functionality and expression profiles of GCs subtypes within intestinal crypts. We also discuss internal (host) and external (diets and bacteria) factors that modulate different aspects of the mucus layer as well as the contribution of an altered mucus barrier to the onset of IBD.

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Faculty Opinions recommendation of Astrovirus infects actively secreting goblet cells and alters the gut mucus barrier.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.737853502.793574660 ◽

2020 ◽

Author(s):

Terence Dermody ◽

Alexa Roth

Keyword(s):

Goblet Cells ◽

Mucus Barrier

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Intestinal Goblet Cell Loss during Chorioamnionitis in Fetal Lambs: Mechanistic Insights and Postnatal Implications

International Journal of Molecular Sciences ◽

10.3390/ijms22041946 ◽

2021 ◽

Vol 22 (4) ◽

pp. 1946

Author(s):

Charlotte van Gorp ◽

Ilse H. de Lange ◽

Kimberly R. I. Massy ◽

Lilian Kessels ◽

Alan H. Jobe ◽

...

Keyword(s):

Er Stress ◽

Goblet Cell ◽

Intestinal Inflammation ◽

Cell Loss ◽

Goblet Cells ◽

Premature Delivery ◽

Cell Numbers ◽

Cell Counts ◽

Cell Alterations ◽

Mucus Barrier

Chorioamnionitis, an important cause of preterm birth, is linked to necrotizing enterocolitis (NEC). NEC is characterized by a disrupted mucus barrier, goblet cell loss, and endoplasmic reticulum (ER) stress of the intestinal epithelium. These findings prompted us to investigate the mechanisms underlying goblet cell alterations over time in an ovine chorioamnionitis model. Fetal lambs were intra-amniotically (IA) exposed to lipopolysaccharides (LPS) for 5, 12, or 24 h, or 2, 4, 8, or 15 d before premature delivery at 125 d gestational age (GA). Gut inflammation, the number, distribution, and differentiation of goblet cells, ER stress, and apoptosis were measured. We found a biphasic reduction in goblet cell numbers 24 h–2 d after, and 15 d after IA LPS exposure. The second decrease of goblet cell numbers was preceded by intestinal inflammation, apoptosis, and crypt ER stress, and increased SAM-pointed domain-containing ETS transcription factor (SPDEF)-positive cell counts. Our combined findings indicated that ER stress drives apoptosis of maturating goblet cells during chorioamnionitis, ultimately reducing goblet cell numbers. As similar changes have been described in patients suffering from NEC, these findings are considered to be clinically important for understanding the predecessors of NEC, and targeting ER stress in this context is interesting for future therapeutics.

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Stress disrupts intestinal mucus barrier in rats via mucin O-glycosylation shift: prevention by a probiotic treatment

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00290.2013 ◽

2014 ◽

Vol 307 (4) ◽

pp. G420-G429 ◽

Cited By ~ 56

Author(s):

Stéphanie Da Silva ◽

Catherine Robbe-Masselot ◽

Afifa Ait-Belgnaoui ◽

Alessandro Mancuso ◽

Myriam Mercade-Loubière ◽

...

Keyword(s):

Physical Properties ◽

Goblet Cells ◽

Visceral Hypersensitivity ◽

Ex Situ ◽

Mucus Layer ◽

Visceral Sensitivity ◽

Intestinal Mucus ◽

Mucin Expression ◽

Muc2 Expression ◽

Mucus Barrier

Despite well-known intestinal epithelial barrier impairment and visceral hypersensitivity in irritable bowel syndrome (IBS) patients and IBS-like models, structural and physical changes in the mucus layer remain poorly understood. Using a water avoidance stress (WAS) model, we aimed at evaluating whether 1) WAS modified gut permeability, visceral sensitivity, mucin expression, biochemical structure of O-glycans, and related mucus physical properties, and 2) whether Lactobacillus farciminis treatment prevented these alterations. Wistar rats received orally L. farciminis or vehicle for 14 days; at day 10, they were submitted to either sham or 4-day WAS. Intestinal paracellular permeability and visceral sensitivity were measured in vivo. The number of goblet cells and Muc2 expression were evaluated by histology and immunohistochemistry, respectively. Mucosal adhesion of L. farciminis was determined ex situ. The mucin O-glycosylation profile was obtained by mass spectrometry. Surface imaging of intestinal mucus was performed at nanoscale by atomic force microscopy. WAS induced gut hyperpermeability and visceral hypersensitivity but did not modify either the number of intestinal goblet cells or Muc2 expression. In contrast, O-glycosylation of mucins was strongly affected, with the appearance of elongated polylactosaminic chain containing O-glycan structures, associated with flattening and loss of the mucus layer cohesive properties. L. farciminis bound to intestinal Muc2 and prevented WAS-induced functional alterations and changes in mucin O-glycosylation and mucus physical properties. WAS-induced functional changes were associated with mucus alterations resulting from a shift in O-glycosylation rather than from changes in mucin expression. L. farciminis treatment prevented these alterations, conferring epithelial and mucus barrier strengthening.

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Intercrypt goblet cells — the key to colonic mucus barrier function

Nature Reviews Gastroenterology & Hepatology ◽

10.1038/s41575-021-00460-2 ◽

2021 ◽

Author(s):

Katrina Ray

Keyword(s):

Barrier Function ◽

Goblet Cells ◽

Mucus Barrier

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An intercrypt subpopulation of goblet cells is essential for colonic mucus barrier function

Science ◽

10.1126/science.abb1590 ◽

2021 ◽

Vol 372 (6539) ◽

pp. eabb1590

Author(s):

Elisabeth E. L. Nyström ◽

Beatriz Martinez-Abad ◽

Liisa Arike ◽

George M. H. Birchenough ◽

Eric B. Nonnecke ◽

...

Keyword(s):

Expression Profiles ◽

Goblet Cells ◽

Specific Gene ◽

Intestinal Mucus ◽

Chemically Induced ◽

Gene And Protein Expression ◽

Homogeneous Cell ◽

Increased Sensitivity ◽

Mucus Barrier ◽

Protein Expression Profiles

The intestinal mucus layer, an important element of epithelial protection, is produced by goblet cells. Intestinal goblet cells are assumed to be a homogeneous cell type. In this study, however, we delineated their specific gene and protein expression profiles and identified several distinct goblet cell populations that form two differentiation trajectories. One distinct subtype, the intercrypt goblet cells (icGCs), located at the colonic luminal surface, produced mucus with properties that differed from the mucus secreted by crypt-residing goblet cells. Mice with defective icGCs had increased sensitivity to chemically induced colitis and manifested spontaneous colitis with age. Furthermore, alterations in mucus and reduced numbers of icGCs were observed in patients with both active and remissive ulcerative colitis, which highlights the importance of icGCs in maintaining functional protection of the epithelium.

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Histological examination of rat small intestine after surgical removal of obturation small bowel obstruction and peptide stimulation of lymph flow

ZHurnal «Patologicheskaia fiziologiia i eksperimental`naia terapiia» ◽

10.25557/0031-2991.2018.04.157-162 ◽

2018 ◽

pp. 157-162

Author(s):

А.А. Коваленко ◽

Г.П. Титова ◽

В.К. Хугаева

Keyword(s):

Small Intestine ◽

Surgical Treatment ◽

Survival Rate ◽

Small Bowel ◽

Goblet Cells ◽

Intestinal Wall ◽

Structure And Function ◽

Lymph Flow ◽

Intestinal Lumen ◽

And Function

Оперативное лечение различных заболеваний кишечника сопровождается осложнениями в виде нарушений микроциркуляции в области анастомоза кишки. Ранее нами показана способность лимфостимуляторов пептидной природы восстанавливать нарушенную микроциркуляцию, что послужило основой для настоящего исследования. Цель работы - оценка влияния стимуляции лимфотока в стенке кишки на процессы восстановления микроциркуляции, структуры и функции тонкой кишки в области оперативного вмешательства. Методика. В экспериментах на наркотизированных крысах (хлоралгидрат в дозе 0,6 г/кг в 0,9% растворе NaCl) моделировали различные поражения тонкой кишки (наложение лигатуры, перевязка 1-3 брыжеечных артерий, перекрут петли кишки вокруг оси брыжейки, сочетание нескольких видов повреждений). Резекция поврежденного участка через 1 сут. с последующим созданием тонкокишечного анастомоза завершалась орошением операционного поля раствором пептида-стимулятора лимфотока (40 мкг/кг массы животного в 1 мл 0,9% раствора NaCl). На 7-е сут. после операции проводили гистологическое исследование фрагмента кишки в области анастомоза. Результаты. На 7-е сут. после резекции у выживших животных (летальность вследствие кишечной непроходимости составляла 30%) имеют место морфологические признаки острых сосудистых нарушений стенки кишки, изменений кровеносных и лимфатических микрососудов, интерстициальный отек всех слоев стенки кишки, дилатация просвета кишки, повреждение всасывающего эпителия ворсин с истончением щеточной каемки клеток, морфологические признаки гиперфункции бокаловидных клеток. Использование лимфостимулятора пептидной природы после операции увеличивало выживаемость животных на 24%. У части животных отмечалось уменьшение расширения просвета кишки, у других практически полная его нормализация. Восстанавливалась форма кишечных ворсин и распределение бокаловидных клеток. Отсутствовали признаки внутриклеточного и межмышечного отека. Отмечено умеренное полнокровие венул. Заключение. Использование лимфостимулятора при хирургическом лечении кишечной непроходимости увеличивает выживаемость животных на 24% по сравнению с контролем, способствует более раннему восстановлению структуры и функции тонкой кишки. Полученные результаты свидетельствуют о перспективности использования стимуляции лимфотока при операциях на кишечнике. Surgical treatment of bowel diseases is associated with complications that cause microcirculatory disturbances in the anastomosis area and may lead to a fatal outcome. This study was based on our previous finding that peptide-type lymphatic stimulators are able to restore impaired microcirculation. The aim of this work was stimulating the lymph flow in the intestinal wall to facilitate recovery of microcirculation, structure and function of the small intestine in the area of surgical intervention. Methods. In experiments on anesthetized rats (0.6 g/kg chloral hydrate in 0.9% NaCl), various small bowel lesions were modeled (bowel ligation, ligation of 1-3 mesenteric arteries, gut torsion, combination of several lesion types). In 24 h, the damaged area was resected, and a small intestine anastomosis was creased. The surgery was completed with irrigation of the operative field with a solution of lymph flow stimulating peptide (40 мg/kg body weight in 1 ml of 0.9% NaCl). A gut fragment from the anastomosis area was examined histologically on day 7 after the surgery. Results. On the 7th day after removing the intestinal obstruction, the surviving animals (lethality 30%) had morphological signs of acute vascular disorders in the intestinal wall; changes in blood and lymphatic microvessels; interstitial edema of all intestinal wall layers; dilatation of the intestinal lumen; damage to the absorptive epithelium of villi with thinning of the brush border, and hyperfunction of mucous (goblet) cells. The use of the peptide after surgery increased the survival rate of animals by 24% and provided a smaller dilatation of the intestinal lumen in some animals. In other animals, the lumen recovered. The shape of intestinal villi and distribution of goblet cells were restored. Signs of intracellular and intermuscular edema were absent. Moderate venular congestion was noticed. Conclusion. Using the lymphatic stimulator in surgical treatment of intestinal obstruction increases the survival rate of animals by 24% compared to the control, facilitates earlier restoration of the small intestine structure and function. The obtained results indicated the effectiveness of lymphatic stimulation in intestinal surgery.

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