Chlorella alleviates the intestinal damage of tilapia caused by microplastics

Polyethylene microplastics (MPs) of the different sizes may result in different response in fish. Studies showed microorganisms adhered to the surface of MPs have toxicological effect. Juveniles tilapia (Oreochromis niloticus, n = 600, 26.5 ± 0.6 g) were dispersed into six groups: the control group (A), 75 nm MP exposed group (B), 7.5 μm group (C) and 750 (D) μm group, 75 nm + 7.5 μm+750 μm group (E) and 75 nm + Chlorella vulgaris group (F), and exposed for 10 and 14 days. The intestinal histopathological change, enzymic activities, and the integrated "omics" workflows containing transcriptomics, proteomics, microbiota and metabolomes, have been performed in tilapia. Results showed that MPs were distributed on the surface of goblet cells, Chlorella group had severe villi fusion without something like intestinal damage, as in other MPs groups. The intestinal Total Cholesterol (TC, together with group E) and Tumor Necrosis Factor α (TNFα, except for group B) contents in group F were significantly increased, cytochrome p450 1a1 (EROD, group B and E) significantly increased, adenosine triphosphate (ATP), lipoprotein lipase (LPL) and caspase 3 (except group B) also significantly increased at 14 d. At 14 days, group E saw considerably higher regulation of the actin cytoskeleton, focal adhesion, insulin signaling pathway, and AGE-RAGE signaling pathway in diabetes complications. Whereas, chlorella enhanced the focal adhesion, cytokine-cytokine receptor interaction, and MAPK signaling pathways. PPAR signaling pathway has been extremely significantly enriched via the proteomics method. Candidatus latescibacteria, C. uhrbacteria, C. abyssubacteria, C. cryosericota significantly decreased caused by MPs of different particle sizes. Carboxylic acids and derivatives, indoles and derivatives, organooxygen compounds, fatty acyls and organooxygen compounds significantly increased with long-term duration, especially PPAR signaling pathway. MPs had a size-dependent long-term effect on histopathological change, gene and protein expression, and gut microbial metabolites, while chlorella alleviates the intestinal histopathological damage via the integrated "omics" workflows.

Macauba (Acrocomia aculeata) pulp oil has the potential to enhance the intestinal barrier morphology, goblet cell proliferation and gut microbiota composition in mice fed a high-fat diet

Macauba (Acrocomia aculeata) is a palm tree native from Brazil, whose pulp is rich in oil that has a high content of oleic acid and carotenoids. Macauba pulp oil can bring health benefits due to its bioactive compounds; however, its effects on gut health are unknown. Thus, the objective of this study was to evaluate the effect of macauba pulp oil on the intestinal health in mice fed a high-fat (HF) diet. Male C57BL1/6 mice were randomly divided into three groups (10 animals/group): control diet, HF diet and HF diet with 4 % of macauba pulp oil (HFM). Concentration of short-chain fatty acids (SCFA), faecal pH and histomorphometric analysis of the colon were performed. Content of colon samples was used on microbiome analysis using 16S rRNA amplicon sequencing. Animals from the HFM group had higher butyric acid content and goblet cells number, greater circular and longitudinal muscle layer and higher α-diversity compared with the HF group. Moreover, consumption of MPO reduced Desulfobacterota phylum, Ruminococcaceae, Oscillospiraceae, Prevotellaceae, Bifidobacteriaceae family, Faecalibacterium, Prevotella, Ruminococcus and Enterorhabdus genus. Therefore, macauba pulp oil was able to modulate the gut microbiota and enhance intestinal barrier morphology, showing preventive effects on gut dysbiosis in mice fed a HF diet.

GLP-1R signaling modulates colonic energy metabolism, goblet cell number and survival in the absence of gut microbiota

OBJECTIVES

Gut microbiota increases energy availability through fermentation of dietary fibers to short-chain fatty acids in conventionally raised mice. Energy deficiency in germ-free (GF) mice increases glucagon-like peptide-1 (GLP-1) levels, which slows intestinal transit. To further analyze the role of GLP-1-mediated signaling in this model of energy deficiency, we re-derived mice lacking GLP-1 receptor (GLP-1R KO) as GF.

METHODS

GLP-1R KO mice were rederived as GF through hysterectomy and monitored for 30 weeks. Mice were subjected to rescue experiments either through feeding an energy-rich diet or colonization with a normal cecal microbiota. Histology and intestinal function were assessed at different ages. Intestinal organoids were assessed to investigate stemness.

RESULTS

Unexpectedly, 25% of GF GLP-1R KO mice died before 20 weeks of age, associated with enlarged ceca, increased cecal water content, increased colonic expression of apical ion transporters, reduced number of goblet cells and loss of colonic epithelial integrity. Colonocytes from GLP-1R KO mice were energy-deprived and exhibited increased ER-stress; mitochondrial fragmentation, increased oxygen levels and loss of stemness. Restoring colonic energy levels either by feeding a Western-style diet or colonization with a normal gut microbiota normalized gut phenotypes and prevented lethality.

CONCLUSIONS

Our findings reveal a heretofore unrecognized role for GLP-1R signaling in the maintenance of colonic physiology and survival during energy deprivation.

Impact of feed additives and host-related factors on bacterial metabolites, mucosal integrity and immune response in the ileum of broilers

The present study aimed to investigate the effect of age, breed, and sex of broilers, as well as a probiotic or phytobiotic product on mucosal morphology, bacterial metabolites, and immune traits in the ileum of broilers. A total of 2,880 one-day-old male and female broiler chicks from two breeds (Ross308® and Cobb500®) were randomly assigned to 72 pens. Broilers were offered a wheat-soybean diet without (CO), or with either a probiotic (PO; 2.4 × 109 CFU/kg of Bacillus subtilis DSM32324 and DSM32325 and B. amyloliquefaciens DSM25840) or a phytobiotic (PY; grape extract, 165 ppm procyanidin and 585 ppm polyphenols of the diet) product. The trial was conducted with a 3 × 2 × 2 factorial arrangement of diet, breed, and sex in a completely randomized design (6 replicate-pens per treatment). At day 7, 21, and 35, one chicken per pen was slaughtered for collecting ileal tissue to evaluate of histomorphology and mRNA expression, as well as ileal digesta to measure bacterial metabolites. Data were subjected to ANOVA (the main factors; age, diet, breed, and sex) and Four-Way ANOVA (interactions) using GLM procedure. Overall, the concentration of acetate and total short chain fatty acids reached the peak and lactate decreased to its lowest on day 21, but their concentrations at day 7 and 35 were similar (p > 0.05). Spermine, spermidine, and ammonia decreased after day 7, while putrescine and cadaverine increased after day 21 (p < 0.05). mRNA expression of cytokines, mucin 2 (MUC2) and claudin 5 (CLDN5) was similar; increased from day 7 to 21 and decreased afterward (p < 0.05). Villus height, crypt depth and villus surface area increased with age (p < 0.05). Acidic goblet cells (GC) number and density increased after day 21 (p < 0.05). Ross broilers showed higher D-lactate concentration and IFN-γ expression, while Cobb broilers had greater IL-4, IL-6 and TNF-α expression and higher total GC number (p < 0.05). Female displayed higher villus height and GC number and density (mixed and total GC) than male (p < 0.05). The effect of dietary treatment was not found on any investigated variables (p > 0.05). In conclusion, aging of broilers affected ileal histomorphology, cytokine expression, and barrier integrity, as well as bacterial activity. These observed impacts could be attributed to host-microbiota interaction and the direct effects of bacterial metabolites on intestinal cells and immune system.

Endogenous mucin conveyed to the mucosa with microbes can assure lumen fermentation and large intestinal security-swine versus fowl

Endogenous protein leaving the ileum largely consists of accrued mucins from the upper gastrointestinal tract (GIT) that had resisted digestion. The amounts released rely on their mucosal generation during enteral feeding which vary with age as well as diet. These digestion resistant proteins of endogenous origin continue to be unavailable in the large intestine, whereas those of dietary origin provide amino acids that largely support the existing microbial population while denying limited amounts for absorption. Other mucins pre-exist within the large intestine as two layers at the lumen surface. A loose layer harboring a diverse microbial population is superimposed on the unstirred water layer (USWL) which simultaneously acts as an obstacle to microbes at the loose layer while performing as a molecular sieve for nutrients. The USWL is formed through interplay between enterocyte and goblet cells; however, the basis for presence of the loose layer is elusive. Large intestinal fermentation predominates within the colon of swine, whereas fowl employ their ceca. Motility within the colon of swine segregates fine materials into haustrae out-pocketings that parallel their placement within the ceca of fowl. Viscous mucins from small intestinal endogenous losses may envelop microbes within the large intestinal lumen to present successive adherents on the USWL that assemble its loose layer. The loose layer continually functions as a microbial reservoir in support of lumen fermentation. Microbial catabolism of mucin within the loose layer is known to be slow, but its proximity to the enterocyte is of advantage to enterocyte absorption with by-product amino acids fostering the USWL.

Primary intestinal-type adenocarcinoma of the vulva. A case report and review of the literature

Background

Primary non-squamous cell carcinomas of the vulva are rare entities including various tumor types. Among these, primary vulvar intestinal-type adenocarcinoma (vPITA) is extremely rare. Until 2021, less than twenty-five cases have been reported in the literature.

Case presentation

We report a case of vPITA in a 63 years old woman with a histopathological diagnosis of signet-ring cell intestinal type adenocarcinoma at vulvar biopsy. Accurate clinical and pathological work-up excluded secondary metastatic localization, and vPITA was diagnosed. The patient was treated with radical vulvectomy and bilateral inguinofemoral dissection. Adjuvant chemo-radiotherapy was performed because of a positive lymph node. At 20 months follow-up the patient was alive and free of disease.

Conclusion

 The prognosis of this very rare disease is unclear and optimal treatment is not well established. About 40% of clinical early-stage diseases reported in literature had positive inguinal nodes, more than in vulvar squamous cell carcinomas. A proper histopathologic and clinical diagnosis is mandatory to exclude secondary disease and to recommend an adequate treatment.

Orchestration of MUC2 - The key regulatory target of gut barrier and homeostasis: A review

The gut mucosa of human is covered by mucus, functioning as a crucial defense line for the intestine against external stimuli and pathogens. Mucin2 (MUC2) is a subtype of secretory mucins generated by goblet cells and is the major macromolecular component of mucus. Currently, there is an increasing interest on the investigations of MUC2, noting that its function is far beyond a maintainer of the mucus barrier. Moreover, numerous gut diseases are associated with dysregulated MUC2 production. Appropriate production level of MUC2 and mucus contributes to gut barrier function and homeostasis. The production of MUC2 is regulated by a series of physiological processes, which are orchestrated by various bioactive molecules, signaling pathways and gut microbiota, etc., forming a complex regulatory network. Incorporating the latest findings, this review provided a comprehensive summary of MUC2, including its structure, significance and secretory process. Furthermore, we also summarized the molecular mechanisms of the regulation of MUC2 production aiming to provide developmental directions for future researches on MUC2, which can act as a potential prognostic indicator and targeted therapeutic manipulation for diseases. Collectively, we elucidated the micro-level mechanisms underlying MUC2-related phenotypes, hoping to offer some constructive guidance for intestinal and overall health of mankind.

Solithromycin inhibits IL-13-induced goblet cell hyperplasia and MUC5AC, CLCA1, and ANO1 in human bronchial epithelial cells

Solithromycin is a novel fluoroketolide antibiotic belonging to the class of macrolide antibiotics. Activation of the interleukin (IL)-13 receptor leads to STAT6 activation and subsequent induction of SAM pointed domain containing ETS transcription factor (SPDEF), chloride channel accessory 1 (CLCA1), and anoctamin-1 (ANO1), all of which are associated with the induction of MUC5AC. We examined the effects of solithromycin on mucin production led by IL-13 signaling. Normal human bronchial epithelial cells were grown at the air-liquid interface with IL-13 with/without solithromycin for 14 days. Histochemical analysis was performed using hematoxylin and eosin staining and MUC5AC immunostaining. MUC5AC, SPDEF, CLCA1, and ANO1 mRNA expressions were examined using real-time polymerase chain reaction. Western blot analysis was performed to assess CLCA1 and ANO1 proteins, and phosphorylation of STAT6 and ERK. Solithromycin attenuated IL-13 induction of goblet cell hyperplasia and MUC5AC, CLCA1 and ANO1 mRNA and protein expression induced by IL-13, but had no effect on the phosphorylation of STAT6 and ERK. Our results indicate that solithromycin could attenuate goblet cell hyperplasia and MUC5AC induced by IL-13 through inhibition of CLCA1 and ANO1 mRNA and protein expression. However, much more information is required to clarify the molecular mechanisms underlying the inhibition of CLCA1 and ANO1 by solithromycin.

Extraction and Verification of Mouse and Human Mucins from Tissue and Fecal Material

Gel-forming mucins are highly O-glycosylated polymeric glycoproteins which have critical roles in tissue protection from environmental insult. To understand their biochemical properties, these samples must be extracted and enriched from biological samples. Here we describe how to extract and semi-purify human and murine mucins from intestinal scrapings or fecal material. As mucins have high molecular weights, traditional gel electrophoresis methods are unable to effectively separate these glycoproteins for analysis. We describe the procedure for making composite sodium dodecyl sulfate urea agarose-polyacrylamide (SDS-UAgPAGE) gels, which allows for accurate verification and band separation of extracted mucins.

Specific activation of hypoxia-inducible factor-2α by propionate metabolism via a β-oxidation-like pathway stimulates MUC2 production in intestinal goblet cells

Microbiota-derived short-chain fatty acids (SCFAs) are known to stimulate mucin expression in the intestine, which contributes to the gut mucosal immune responses, and the gut mucosal immune system extends to the brain and other organs through several axes. Hypoxia-inducible factors (HIFs), especially HIF-1α, are known to act as the master regulator of mucin expression, however, underlying mechanism of mucin expression during hypoxia by SCFAs remains unclear. In this study, we investigated the mechanism of MUC2 expression by propionate, an SCFA, in intestinal goblet cells. The real time oxygen consumption rate (OCR) and ATPase activity were measured to investigate the induction of hypoxia by propionate. Using 2-dimensional electrophoresis (2-DE), microarray analysis, and siRNA-induced gene silencing, we found that propionate is metabolized via a β-oxidation-like pathway instead of the vitamin B₁₂-dependent carboxylation pathway (also known as the methylmalonyl pathway). We verified the results by analyzing several intermediates in the pathway using LC-MS and GC-MS. Propionate metabolism via the β-oxidation-like pathway leads to the depletion of oxygen and thereby induces hypoxia. Analysis of HIFs revealed that HIF-2α is the primary HIF whose activation is induced by propionate metabolism in a hypoxic environment and that HIF-2α regulates the expression of MUC2. Thus, hypoxia induced during propionate metabolism via a β-oxidation-like pathway specifically activates HIF-2α, stimulating MUC2 production in LS 174 T goblet cells. Our findings show that propionate-induced selective HIF-2α stimulation contributes to intestinal mucosal defense.

Significant impairment of intestinal health in zebrafish after subchronic exposure to methylparaben

Methylparaben (MeP) is a ubiquitous pollutant in aquatic environment, which has caused severe pollution worldwide. However, aquatic toxicology of MeP is still largely unknown. In the present study, adult zebrafish were exposed to environmentally realistic concentrations of MeP (0, 1, 3, and 10 μg/L) for 28 days. In terms of the antimicrobial nature, dysregulation of gut microbiota and zebrafish health by MeP were elucidated after exposure. High-throughput amplicon sequencing showed that MeP subchronic exposure was able to disrupt the composition and diversity of gut microbial community, which was characterized by the alterations in alpha diversity and divergent distribution by principal component analysis. In addition, MeP exposure increased the body length and body weight of female fish, implying stimulated growth at low doses. In male intestine, consistent increases were notable in goblet cell density, tight junction protein (TJP) 2 expression, and serotonin neurotransmitter concentration after MeP exposure. In contrast, female intestine exposed to MeP had lower density of goblet cells, inhibited expression of TJP2, reduced concentration of serotonin, but up-regulated transcription of pro-inflammatory cytokine. Under the stress of MeP pollutant, intestinal catalase antioxidant enzyme was activated, thus contributing to the removal of oxidative free radicals. Correlation analysis verified the modulation of TJP2 expression by Lactobacillus probiotic bacteria. Disturbances in goblet cell, tight junctions, and serotonin by MeP may be combined to interfere with gut barrier function. Overall, the present study highlights the impairment of intestinal health by environmentally realistic concentrations of MeP, which necessitates an urgent risk assessment.

Seasonal variations in the skin epidermal structure and mucosal immune parameters of rainbow trout skin (Oncorhynchus mykiss) at different stages of farming

The aim of this study was to investigate the seasonal changes in the epidermal structure and the innate immunity parameters of skin mucus in rainbow trout. The skin epidermis and mucus samples were collected over three consecutive seasons including winter, spring and late summer from three different weight groups i.e., 2-20 g (W1), 100-200 g (W2) and 400-600 g (W3) fish. The skin mucosal immunity analysis of rainbow trout showed that the haemagglutination activity increased significantly with increasing fish size from W1 to W3 in all three seasons, while no significant seasonal changes occurred in haemagglutination activity. Moreover, the bactericidal activity against fish pathogens increased significantly with increasing water bacterial load in late summer. The SDS-PAGE analysis of mucus showed a high amount of low molecular weight proteins (<35 kDa) in the late summer that was correlated with the increase in bactericidal activity. Histological analysis of the epidermis structure of rainbow trout skin showed that the density and size of goblet cells and consequently the mucus secretion significantly increased in W3 group in all seasons. In all three weight groups of fish, the density of goblet cells significantly increased from winter to spring and late summer along with increasing water temperature. Moreover, the goblet cell density showed a significant positive relationship with the soluble protein concentration and haemagglutination activity (p < 0.01). The results of this study demonstrated the more active immune role of the skin epidermal cells and mucus in rainbow trout during summer to protect fish against the pathogenic microorganisms. Given its potent bactericidal properties and the lack of haemolytic activity, the rainbow trout mucus might be used as a safe and inexpensive source for developing antimicrobial agents to prevent and treat some bacterial diseases in human and fish.

Regenerative capacity of bone marrow stem cells on aged albino rat's parotid excretory duct

OBJECTIVE

To appraise structural features of parotid excretory duct during senility and probable effect of bone marrow-mesenchymal stem cells (BM-MSCs).

DESIGN

A total of 14 healthy male albino rats were used. Seven adult rats (24-34-week-old) represented the control group (Group I). Seven senile rats (72-80-week-old) were utilized in which the left parotid gland served as "Old" (Group II) and were injected by 0.2 ml phosphate buffered saline; the right side represented "Old treated" (Group III) and got local injection of 1-1.5 million allogeneic BM-MSCs. One month later, glands were dissected and assessed structurally, ultra-structurally and statistically.

RESULT

Histologically, Group I showed normal duct histology. In Group II duct lining lost its pseudostratification which was recovered in Group III. PCNA immunolocalization showed moderate reactivity in Group I, negative to mild reaction in Group II, and strong reaction in some of Group III cells. Ultra-structural features of Group I were ordinary in which basal cell had a large flat nucleus, and dark and light cells showed electron-dense cytoplasm and electron-lucent cytoplasm respectively. Tuft cell displayed long microvilli. Mucous droplets filled goblet cell. Group II revealed an apparent reduction in cells size, organelles and absence of tuft cell. In Group III all cell types were detected and they recovered their organelles, cell and nucleus shape. The highest mean area% of PCNA immunoreactivity was in Group I followed by Group III then Group II.

CONCLUSIONS

Aging has a deteriorating effect on structure and ultra-structure of parotid gland excretory duct that could be amended by BM-MSCs.

Characterization of human nasal organoids from chronic rhinosinusitis patients

Patient-derived organoids grown in three-dimensional cultures provide an excellent platform for phenotypic high-throughput screening and drug-response research. Organoid technology has been applied to study stem cell biology and various human pathologies. This study investigates the characteristics and cellular morphology of organoids derived from primary human nasal epithelial cells (HNECs) of chronic rhinosinusitis (CRS) patients. Nasal organoids were cultured up to 20 days and morphological, cell composition and functional parameters were measured by immunofluorescence, RT-qPCR, western blot and FACS analysis. The results showed that nasal organoids expressed the stem cell marker leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5), and markers for apical junction genes, goblet cells and ciliated cells. Moreover, we were able to regrow and expand the nasal organoids well after freezing and thawing. This study provides an effective and feasible method for development of human nasal organoids, suitable for the phenotypic high-throughput screening and drug response research.

Summary: This study provides an effective and feasible method for development of human nasal organoids from chronic rhinosinusitis patients, suitable for phenotypic high-throughput screening and drug-response research.

Defects in NLRP6, autophagy and goblet cell homeostasis are associated with reduced duodenal CRH receptor 2 expression in patients with functional dyspepsia

Functional dyspepsia (FD) affects up to 15% of the population and is characterised by recurring upper gastrointestinal (GI) symptoms occurring in the absence of clinically identifiable pathology. Psychological stress is a key factor associated with the onset of FD and locally acting hypothalamic-pituitary-adrenal (HPA) axis hormones have been implicated in GI motility and barrier dysfunction. Recent pre-clinical work has identified mechanistic pathways linking corticotropin-releasing hormone (CRH) with the innate epithelial immune protein NLRP6, an inflammasome that has been shown to regulate GI mucus secretion. We recruited twelve FD patients and twelve healthy individuals to examine whether dysregulation of hypothalamic-pituitary adrenal (HPA) axis hormones and altered NLRP6 pathways were evident in the duodenal mucosa. Protein expression was assessed by immunoblot and immunohistochemistry in D2 duodenal biopsies. Plasma HPA axis hormones were assayed by ELISA and enteroid and colorectal cancer cell line cultures were used to verify function. FD patients exhibited reduced duodenal CRH-receptor 2, compared to non-GI disease controls, indicating a dysregulation of duodenal HPA signalling. The loss of CRH-receptor 2 correlated with reduced NLRP6 expression and autophagy function, processes critical for maintaining goblet cell homeostasis. In accordance, duodenal goblet cell numbers and mucin exocytosis was reduced in FD patients compared to controls. In vitro studies demonstrated that CRH could reduce NLRP6 in duodenal spheroids and promote mucus secretion in the HT29-MTX-E12 cell line. In conclusion, FD patients exhibit defects in the NLRP6-autophagy axis with decreased goblet cell function that may drive symptoms of disease. These features correlated with loss of CRH receptor 2 and may be driven by dysregulation of HPA signalling in the duodenum of FD patients.

Human ocular mucins: The endowed guardians of sight

Mucins are an ancient group of glycoproteins that provide viscoelastic, lubricating and hydration properties to fluids bathing wet surfaced epithelia. They are involved in the protection of underlying tissues by forming a barrier with selective permeability properties. The expression, processing and spatial distribution of mucins are often determined by organ-specific requirements that in the eye involve protecting against environmental insult while allowing the passage of light. The human ocular surface epithelia have evolved to produce an extremely thin and watery tear film containing a distinct soluble mucin product secreted by goblet cells outside the visual axis. The adaptation to the ocular environment is notably evidenced by the significant contribution of transmembrane mucins to the tear film, where they can occupy up to one-quarter of its total thickness. This article reviews the tissue-specific properties of human ocular mucins, methods of isolation and detection, and current approaches to model mucin systems recapitulating the human ocular surface mucosa. This knowledge forms the fundamental basis to develop applications with a promising biological and clinical impact.

Targeted deletion of keratin 8 in intestinal epithelial cells disrupts tissue integrity and predisposes to tumorigenesis in the colon

Keratin 8 (K8) is the main intestinal epithelial intermediate filament protein with proposed roles for colonic epithelial cell integrity. Here, we used mice lacking K8 in intestinal epithelial cells (floxed K8 and Villin-Cre1000 and Villin-CreERt2) to investigate the cell-specific roles of intestinal epithelial K8 for colonocyte function and pathologies. Intestinal epithelial K8 deletion decreased K8 partner proteins, K18-K20, 75-95%, and the remaining keratin filaments were located at the colonocyte apical regions with type II K7, which decreased 30%. 2-Deoxy-2-[18F]-fluoroglucose positron emission tomography in vivo imaging identified a metabolic phenotype in the lower gut of the conditional K8 knockouts. These mice developed intestinal barrier leakiness, mild diarrhea, and epithelial damage, especially in the proximal colon. Mice exhibited shifted differentiation from enterocytes to goblet cells, displayed longer crypts and an increased number of Ki67 + transit-amplifying cells in the colon. Significant proproliferative and regenerative signaling occurred in the IL-22, STAT3, and pRb pathways, with minor effects on inflammatory parameters, which, however, increased in aging mice. Importantly, colonocyte K8 deletion induced a dramatically increased sensitivity to azoxymethane-induced tumorigenesis. In conclusion, intestinal epithelial K8 plays a significant role in colonocyte epithelial integrity maintenance, proliferation regulation and tumor suppression.

Single or Combined Applications of Zinc and Multi-strain Probiotic on Intestinal Histomorphology of Broilers Under Cyclic Heat Stress

Two-hundred-eighty-day-old broiler chicks were divided into seven groups. The groups were designated as T1, thermoneutral zone; T2, heat stressed (HS); T3, HS + zinc (Zn) supplementation (30 mg/kg); T4, HS + Zn (60 mg/kg); T5, HS + probiotic (0.1 g/kg); T6, HS + probiotic (0.1 g/kg) + Zn (30 mg/kg); and T7, HS + Zn (60 mg/kg) + probiotic (0.1 g/kg). Significant decrease (p < 0.05) was observed in villus height (VH), VH to crypt depth ratio, and villus surface area of all intestinal segments in the T2 group when compared with the T1 group. The same parameters had significantly higher (p < 0.05) values in the jejunum and ileum of the Zn- and probiotic-supplemented groups (alone + combination) when compared with the T2 group. The birds exposed to HS showed fewer (p < 0.05) intraepithelial lymphocytes (IELs) in the jejunum and ileum than the T1 group, while their count increased in the jejunum and ileum with dietary treatments. In conclusion, Zn and probiotic positively modulated the intestinal microstructures of broilers kept under high environmental temperature.

Anticoccidial effect of toltrazuril and Radix Sophorae Flavescentis combination: Reduced inflammation and promoted mucosal immunity

An anticoccidial model of chicken infected with Eimeria tenella was established to investigate the effect of toltrazuril (Tol) combined with the Radix Sophorae Flavescentis (RSF) on coccidiosis. The anticoccidial index (ACI) was evaluated, and the cecal developmental parameters (i.e., villus height, [VH], crypt depth, [CD], and VH/CD) were determined. The distributions of glycoproteins and goblet cells in the cecal tissue were determined through the Periodic Acid-Schiff (PAS) and Alcian blue PAS staining methods, respectively. The mRNA expression levels of interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-10, and IL-17 of the cecal tissue were determined through quantitative real-time PCR. The moderate ACI was obtained using the combination of Tol and RSF. Compared with the normal control (NC) group, the infected control (IC) group showed remarkably lower VH and VH/CD at five and seven days postinfection. Compared with the IC group, the IC + RSF and IC + TolRSF groups showed remarkably higher VH and VH/CD at five and seven days postinfection. Compared with the NC group, the IC group contained fewer glycoproteins and goblet cells, but the Tol and RSF treatment promoted more glycoproteins and goblet cells at five and seven days postinfection. The mRNA expression levels of IL-1β, IL-2, IL-4, IL-6, IL-10, and IL-17 in the IC group were upregulated (P < 0.01) compared with those in the NC group. The IC + RSF and IC + TolRSF groups had downregulated mRNA expression levels of IL-1β, IL-6, and IL-17 cytokines (P < 0.01), and upregulated mRNA expression levels of IL-2 and IL-4 cytokines (P < 0.01) compared with the IC group. Results showed that the combination of Tol and RSF exerts anticoccidial effect by reducing inflammation and promoting intestinal mucosal immunity.

Anti-inflammatory effects of Radix Aucklandiae herbal preparation ameliorate intestinal mucositis induced by 5-fluorouracil in mice

ETHNOPHARMACOLOGICAL RELEVANCE

5-Fluorouracil (5-FU) is a chemotherapy agent that is widely used in clinical oncologic practice. However, intestinal mucositis is the most frequently occurring side effect of cancer therapy with 5-FU. Based on a literature survey, Radix Aucklandiae herbal preparation potentially ameliorates intestinal mucositis in 5-FU-treated mice.

AIM OF THE STUDY

The aim of this study was to investigate the inflammation and gastrointestinal regulation of intestinal mucositis induced by 5-FU, including the intestinal morphology, as well as the reduction in food intake, body weight loss, and diarrhea.

MATERIALS AND METHODS

Intestinal mucositis was induced in mice by 5-FU (30 mg/kg, i.p., for 5 consecutive days). The dose-dependent Radix Aucklandiae herbal preparation (0.3, 1, and 3 g/kg/day, p.o.), loperamide (3 mg/kg/day, p.o.) or celecoxib (40 mg/kg/day, p.o.) was concurrently administered until the 7th day. Physical status observation, diarrhea assessment, serum proinflammatory cytokine levels, intestinal villus height and crypt depth, and total goblet cells from tissues were assessed.

RESULTS

The dosage regimen of 5-FU administration caused severe intestinal mucositis in mice, including damage to the intestinal morphology, accompanied by a reduction in food intake, body weight loss, and diarrhea. The high-dose Radix Aucklandiae herbal preparation significantly relieves 5-FU-induced intestinal mucositis by enhancing proliferative activity in epithelial crypts; improving anepithymia, body weight loss, and diarrhea; and displaying protective effects on goblet cells in intestinal mucosal epithelia. Activation of NF-κB in the intestinal mucositis model was also suppressed by the Radix Aucklandiae herbal preparation, suggesting that it is a potent inhibitor of NF-κB and proinflammatory cytokines, such as IL-1β, IL-6, TNF-α, and COX-2.

CONCLUSIONS

Our data support the conclusion that the Radix Aucklandiae herbal preparation could effectively ameliorate 5-FU-induced gastrointestinal toxicity and be applied clinically for the prevention of intestinal mucositis during chemotherapy.

Qingchang Huashi Formula attenuates DSS-induced colitis in mice by restoring gut microbiota-metabolism homeostasis and goblet cell function

ETHNOPHARMACOLOGICAL RELEVANCE

Inflammatory bowel disease (IBD) is a chronic and relapsing inflammatory disease of the gastrointestinal tract, consisting of ulcerative colitis (UC) and Crohn's disease (CD). Gut microbiota and their metabolites may play a role in the pathogen of IBD, especially of the UC. Qingchang Huashi Formula (QHF), a traditional Chinese medicine formula, has shown therapeutic effect on treating UC based on the clinical practice without clear pharmacological mechanism.

AIM OF THE STUDY

The aim of this study was to clearly define the effect of QHF and its components, Baitouweng (PBR) and Baizhi (ADR) on treating UC.

MATERIALS AND METHODS

Pharmacodynamic effects of QHF and single herb were evaluated in dextran sulfate sodium (DSS) induced acute or chronic colitis mice. Body weight loss, disease activity index (DAI) and colon length were estimated. Histological changes were observed by H&E staining. The number and abundance of gut microbiota were measured with 16S rRNA sequencing. LC-MS and GC-MS were used to detect the concentration of metabolites (e.g., bile acids (BAs) and short chain fatty acids (SCFAs)). The goblet cell was observed by Alcian blue/periodic acid-Schiff (AB/PAS) straining and the crypt stem cell was estimated by immunohistochemical analyses. The colorectal tissues were used to detect levels of IL-1β, IL-6 and TNF-α by ELISA or qRT-PCR. The expression of NLRP3, Caspase 1 and IL-1β were examined by western blotting.

RESULTS

QHF significantly inhibited colitis, protected mice from the loss of body weight and colon shorten. Comparatively, ADR and PBR showed strong efficacy in inhibiting DSS-induced colitis. We verified that while ADR was responsible for QHF's effect on maintaining gut microbiota homeostasis and metabolism, PBR was more prominent in keeping crypt stem cells proliferation and colonic goblet cells function. Moreover, we demonstrated that the alleviation of colitis by QHF was associated with the restoration of gut microbiota-metabolism homeostasis, protection of intestinal epithelial barrier and regulation of NLRP3/IL-1β pathway.

CONCLUSIONS

The finding of the present study suggested that QHF is curative in DSS-induced colitis by restoring gut microbiota-metabolism homeostasis and goblet cells function. An optimized QHF was constituted by ADR and PBR, which showed comparable efficacy on colitis to that of QHF. Our work probed out the active constitutes as well as the relevant pharmacological mechanisms of QHF, shedding light on potential new drug combination for the treatment of IBD.

The distribution of conjunctival goblet cells in mice

PURPOSE

To evaluate the density and distribution of conjunctival goblet cells in mice without clinical evidence of ocular surface diseases.

METHODS

Immediately after euthanasia of C57BL/6 wild-type mice, the eyes including eyelids were removed and fixed in paraformaldehyde. Entire eyeballs and eyelids were cut in series along the sagittal axis from nasal to temporal on a microtome and then stained with Periodic Acid-Schiff acid to visualize the goblet cells. At each section stained in this way, the conjunctival goblet cells of the entire upper and lower lid conjunctiva were counted by light microscopy. Additional (transmission electron microscopy) (TEM)-Analysis on ultrathin sections was performed to evaluate morphological differences.

RESULTS

The total number of conjunctival goblet cells differs markedly between individual animals. Categorisation into upper eyelid (UL) and lower eyelid (LL) and into regions (nasal, middle, temporal) revealed a significant increase of goblet cells from nasal to temporal in the UL and a significant decrease in the LL.

CONCLUSION

The distribution of conjunctival goblet cells in mice differs considerably from humans and between individual animals. Therefore, precise selection of sampling and methods are needed to obtain comparable data. We recommend to use the middle region of the conjunctiva of UL/LL for goblet cell studies in mice. These findings are of particular interest for dry eye mouse models as well as pharmacological studies on mice with influence on their goblet cells.

Compromised Ileal Mucus Barrier Due to Impaired Epithelial Homeostasis Caused by Notch1 Signaling in Cirrhotic Rats

BACKGROUND

In liver cirrhosis, intestinal mucus barrier is rarely studied.

AIMS

This study aimed to investigate whether mucus barrier in ileum is altered in cirrhotic rats and its underlying mechanisms.

METHODS

Thioacetamide was injected to induce liver cirrhosis in rats. Serum from portal vein blood, and ileum and liver tissues were obtained for further analysis. Goblet cell-like Ls174T cells were cultured for in vitro experiments.

RESULTS

The ileal mucus was thin, loose, and porous with small bubbles in cirrhotic rats. mRNA expressions of Muc2 and TFF3 were also down-regulated in cirrhotic rats. Bacteria located near to crypts and LPS were increased in the serum from portal vein in cirrhotic rats. Smaller theca area and few goblet cells were found in cirrhotic rats compared with control. Increased proliferation of ileal epithelia was observed in cirrhotic rats. Notch1, Dll1, and Hes1 expressions were enhanced, and KLF4 expression was suppressed in ileum of cirrhotic rats. In Ls174T cells, EDTA and NICD plasmid induced NICD and Hes1 expression and suppressed KLF4 concomitantly, and mucus expression almost vanished in these cells. NICD plasmid induced more proliferation in Ls174T cells. Oppositely, after DBZ treatment, NICD and Hes1 were inhibited along with augmentation of KLF4 and increased mucous expression in Ls174T cells, while proliferation of the cells was suppressed.

CONCLUSIONS

In cirrhotic rats, mucus barrier was impaired. This might be attributed to increased proliferation and decreased differentiation of epithelia, which might be mediated by Notch1-Hes1-KLF4 signaling.

Glucocorticoid receptors involved in melatonin inhibiting cell apoptosis and NLRP3 inflammasome activation caused by bacterial toxin pyocyanin in colon

The immunoinhibitory effect of glucocorticoid and immunoenhancing attributes of melatonin (MEL) are well known, however, the involvement of glucocorticoid receptor (GR) in melatonin modulation of bacterial toxins caused-inflammation has not been studied in colon. Pyocyanin (PCN), a toxin released by Pseudomonas aeruginosa, can destroy cells through generating superoxide products and inflammatory response. Here we report that PCN treatment elevated the generation of reactive oxygen species (ROS), which further lead to mitochondrial swelling and caspase cascades activation both in vivo and in vitro. However, MEL treatment alleviated the oxidative stress caused by PCN on cells through scavenging ROS and restoring the expression of antioxidant enzyme so that to effectively alleviate the apoptosis. Large amounts of ROS can activate the NLRP3 signaling pathway, so MEL inhibited PCN induced NLRP3 inflammasome activation and inflammatory cytokines (IL-1β, IL-8, and TNF-α) secretion. In order to further investigate the molecular mechanism, goblet cells were exposed to MEL and PCN in the presence of luzindole and RU486, inhibitors of MEL receptors and GR respectively. It was found that PCN significantly inhibited the expression level of GR, and MEL effectively alleviated the inhibition phenomenon. Moreover, we found that MEL mainly upregulated the expression of GR to achieve its anti-inflammatory and anti-apoptotic functions rather than through its own receptor (MT2) in colon goblet cells. Therefore, MEL can reverse the inhibitory effects of PCN on GR/p-GR expression to present its anti-oxidative and anti-apoptotic function.

KLF4 Regulates Goblet Cell Differentiation in BMI1＋ Reserve Intestinal Stem Cell Lineage during Homeostasis

Krüppel-like factor 4 (KLF4) is a zinc-finger transcription factor, expressed in villus cells of the intestinal epithelium, that promotes cellular differentiation and tissue homeostasis. Previous studies suggest that BMI1⁺ cells represent secretory progenitors with reserve intestinal stem cell (rISC) activity. However, it has not been elucidated how KLF4 contributes to crypt regeneration originated from BMI1⁺ rISC lineage during homeostasis. In this study, Bmi1-Cre^ER;Rosa26^eYFP (Bmi1^Ctrl) and Bmi1-Cre^ER;Rosa26^eYFP;Klf4^fl/fl (Bmi1^ΔKlf4) mice were injected with tamoxifen to label BMI1⁺ cells and their lineage and to delete Klf4. During homeostasis, MUC2⁺ goblet cells appeared in the BMI1⁺ cell lineage 2, 3 and 7 days after tamoxifen administration. After Klf4 deletion in BMI1⁺ cells, the number of KLF4⁺ and MUC2⁺ cells in eYFP⁺ cells decreased in Bmi1^ΔKlf4 mice compared with Bmi1^Ctrl mice. Thus, KLF4 was positively correlated with goblet cell differentiation in BMI1⁺ cell derived lineage. In ex-vivo analysis, organoids derived from single eYFP⁺ cells of Bmi1^Ctrl mice contained MUC2-expressing cells that co-expressed KLF4. On the other hand, organoids derived from Klf4-deleted eYFP⁺ cells from Bmi1^ΔKlf4 mice showed reduced number of MUC2-expressing cells. In conclusion, these results suggest that KLF4 regulates goblet cell differentiation in BMI1⁺ ISC-derived lineage during homeostasis.

Eriobotrya japonica leaf extract attenuates airway inflammation in ovalbumin-induced mice model of asthma

ETHNOPHARMACOLOGICAL RELEVANCE

Eriobotrya japonica leaves has a very long history of medicinal use as an anti-inflammatory and antitussive agent for bronchial inflammation.

AIM OF THE STUDY

The aim of this study was to evaluate the anti-inflammatory activities of Eriobotrya japonica (EJ) leaf water extract in an ovalbumin (OVA)-induced murine asthma model and human tracheal smooth muscle cell (HTSMC).

MATERIALS AND METHODS

Mice were sensitized by intra peritoneal OVA and challenged with nebulized OVA. EJ extract was administered orally at various dose. Bronchoalveolar lavage fluid (BALF) was quantified for nitric oxide (NO), eosinophil peroxidase (EPO), interleukin (IL)-4, IL-13 level and immunoglobulin (Ig) E was quantified in serum. Lung tissue sections were stained with hematoxylin and eosin for assessment of inflammatory cell infiltration whereas mucus production and goblet cell hyperplasia were studied by periodic acid schiff staining. Western blot was done for analysis of pERK1/2 expression and NFκB translocation in HTSMC whereas iNOS and COX-2 expression in RAW264.7 cell.

RESULTS

EJ significantly reduced the levels of BALF's NO, EPO, MMPs, IL-4, IL-13, and serum IgE. It also decreases inflammatory cell infiltration and mucus production. EJ also attenuated the proliferation of HTSMC, inhibits overexpression of ERK 1/2 and translocation of NFκB in HTSMC as well as iNOS and COX-2 expression in RAW 264.7 cell.

CONCLUSION

Present study suggest that, EJ effectively protects against allergic airway inflammation thus possessing potential therapeutic option for allergic asthma management.

NLRP6 inflammasome

NOD-like receptor family pyrin domain containing 6 (NLRP6) is a novel NLR family member, that shows high expression in the intestine and liver (in contrast to NLRP3 in myeloid cells), to regulate inflammation and host defense against microbes. NLRP6 is reported to involved in inflammasome activation, regulation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling, antiviral interferon (IFN) signaling, mucus secretion, and antimicrobial peptide (AMP) production. Here, we discuss the recent findings as well as debates regarding: how NLRP6 is induced ("signal I″) and activated ("signal II"); its roles in intestinal cells and immune cells; how NLRP6 and NLRP9 coordinate to regulate the anti-viral immune response in the intestine; potential targeting of NLRP6 in human diseases.

TRIM34 attenuates colon inflammation and tumorigenesis by sustaining barrier integrity

Loss of the colonic inner mucus layer leads to spontaneously severe colitis and colorectal cancer. However, key host factors that may control the generation of the inner mucus layer are rarely reported. Here, we identify a novel function of TRIM34 in goblet cells (GCs) in controlling inner mucus layer generation. Upon DSS treatment, TRIM34 deficiency led to a reduction in Muc2 secretion by GCs and subsequent defects in the inner mucus layer. This outcome rendered TRIM34-deficient mice more susceptible to DSS-induced colitis and colitis-associated colorectal cancer. Mechanistic experiments demonstrated that TRIM34 controlled TLR signaling-induced Nox/Duox-dependent ROS synthesis, thereby promoting the compound exocytosis of Muc2 by colonic GCs that were exposed to bacterial TLR ligands. Clinical analysis revealed that TRIM34 levels in patient samples were correlated with the outcome of ulcerative colitis (UC) and the prognosis of rectal adenocarcinoma. This study indicates that TRIM34 expression in GCs plays an essential role in generating the inner mucus layer and preventing excessive colon inflammation and tumorigenesis.

Lipoteichoic acid from the cell wall of a heat killed Lactobacillus paracasei D3-5 ameliorates aging-related leaky gut, inflammation and improves physical and cognitive functions: from C. elegans to mice

Increased inflammation associated with leaky gut is a major risk factor for morbidity and mortality in older adults; however, successful preventive and therapeutic strategies against these conditions are not available. In this study, we demonstrate that a human-origin Lactobacillus paracasei D3-5 strain (D3-5), even in the non-viable form, extends life span of Caenorhabditis elegans. In addition, feeding of heat-killed D3-5 to old mice (> 79 weeks) prevents high- fat diet-induced metabolic dysfunctions, decreases leaky gut and inflammation, and improves physical and cognitive functions. D3-5 feeding significantly increases mucin production, and proportionately, the abundance of mucin-degrading bacteria Akkermansia muciniphila also increases. Mechanistically, we show that the lipoteichoic acid (LTA), a cell wall component of D3-5, enhances mucin (Muc2) expression by modulating TLR-2/p38-MAPK/NF-kB pathway, which in turn reduces age-related leaky gut and inflammation. The findings indicate that the D3-5 and its LTA can prevent/treat age-related leaky gut and inflammation.

Immune - Goblet cell interaction in the conjunctiva

The conjunctiva is a goblet cell rich mucosal tissue. Goblet cells are supported by tear growth factors and IL-13 produced by resident immune cells. Goblet cell secretions are essential for maintaining tear stability and ocular surface homeostasis. In addition to producing tear stabilizing mucins, they also produce cytokines and retinoic acid that condition monocyte-derived phagocytic cells in the conjunctiva. Aqueous tear deficiency from lacrimal gland disease and systemic inflammatory conditions results in goblet cell loss that amplifies dry eye severity. Reduced goblet cell density is correlated with more severe conjunctival disease, increased IFN-γ expression and antigen presenting cell maturation. Sterile Alpha Motif (SAM) pointed domain epithelial specific transcription factor (Spdef) gene deficient mice that lack goblet cells have increased infiltration of monocytes and dendritic cells with greater IL-12 expression in the conjunctiva. Similar findings were observed in the conjunctiva of aged mice. Reduced retinoic acid receptor (RXRα) signaling also increases conjunctival monocyte infiltration, IFN-γ expression and goblet cell loss. Evidence suggests that dry eye therapies that suppress IFN-γ expression preserve conjunctival goblet cell number and function and should be considered in aqueous deficiency.

Lactobacillus plantarum CBT LP3 ameliorates colitis via modulating T cells in mice. Int J Med Microbiol. 2020;310:151391. [PMID: 32007342 DOI: 10.1016/j.ijmm.2020.151391]

Lactobacillus plantarum has been identified as a probiotic bacterium owing to its role in immune regulation and maintenance of intestinal permeability. Here, we investigated the anti-colitic effects and mechanism of L. plantarum CBT LP3 (LP3). This in vivo study was performed using dextran sodium sulfate (DSS) to induce colitis in mice. Mice were randomly divided into three groups: a control supplied with normal drinking water, a DSS-treated group followed by oral administration of vehicle, and a DSS-treated group gavaged with LP3 daily for 7 days following DSS administration. An analysis of macrophages and T cell subsets harvesting from peritonium cavity cells and splenocytes was performed using a flow cytometric assay. Gene expression and cytokine profiles were measured using quantitative reverse transcriptase polymerase chain reaction. The administration of LP3 significantly attenuated disease activity and histolopathology compared to control. LP3 had anti-inflammatory effects, with increased induction of regulatory T cells and type 2 helper T cells in splenocytes and restoration of goblet cells accompanied by suppression of proinflammatory cytokine expressions. These findings suggest that L. plantarum CBT LP3 can be used as a potent immunomodulator, which has significant implications for IBD treatment.

Occupational effect of sugarcane biomass burning on the conjunctival mucin profile of harvest workers and residents of an adjacent town - A Brazilian panel study

Pre-harvest burning of sugarcane fields produces large amounts of air pollutants which are known to cause health problems, including ocular surface abnormalities. In this study, we evaluated the effect of biomass burning on mucus quality and mucin gene expression (MUC1, MUC5AC, MUC16) in the conjunctiva of sugarcane workers (SWs) and residents of an adjacent town (RTs). Impression cytology samples of the inferior tarsal and bulbar conjunctiva of 78 SWs and 32 RTs were collected before (T1) and immediately after (T2) a 6-month harvest period. The neutral, acid and total mucus content of goblet cells was determined by PAS and AB staining. The levels of MUC5AC, MUC1 and MUC16 mRNA in the conjunctiva were measured by real-time PCR. Compared to RTs, SWs had higher levels of bulbar acid mucus and MUC16 mRNA and tarsal MUC5AC mRNA at T2 and lower levels of neutral mucus at T1 and T2. In the SW group, MUC1 mRNA levels were higher at T2 than at T1, but the levels of neutral and acid mucus were similar. In the RT group, acid mucus decreased and neutral mucus increased in the bulbar and tarsal conjunctiva at T2. In conclusion, our findings show that sugarcane harvesting is associated with abnormalities in mucus quality and content and changes in mucin mRNA levels on the ocular surface. This may help explain the ocular inflammatory signs and symptoms observed in subjects exposed to air pollutants and high temperatures from sugarcane biomass burning.

Differentiation of Gastrointestinal Cell Lines by Culture in Semi-wet Interface

Epithelial cells grown in vitro provide opportunities to elucidate cellular mechanisms in response to chemical, viral, or bacterial agents in isolation from the effects of other bodily functions, such as hormonal and immune responses. However, cells that do not form a tight epithelium, polarize or secrete mucins lack some of the important protection mechanisms intrinsic to epithelial cells in vivo, increasing their susceptibility to external agents, and exposing basolateral targets for interactions that may not occur in vivo. Here, we present a method that transforms some epithelial cell lines into mucin secreting polarized epithelial surfaces with high transepithelial resistance: the cells are cultured on semi-permeable membranes in differentiation medium for the first 6 days, followed by culture under semi-wet interface with mechanical stimulation for 22 days. The procedure can be performed using standard laboratory reagents and equipment. A description on how to fix and paraffin embed these in vitro mucosal membranes for histology purposes is also included.

Upper gastrointestinal pathophysiology due to mouse malaria Plasmodium berghei ANKA infection

Background

Epigastric pain, vomiting, and other gastrointestinal problems are among the most important symptoms of malaria infection as they suggest the possibility that the condition is serious. Pathophysiologies such as gastric mucosal changes and delayed gastric emptying have been reported in serious cases of malaria infection. However, it is unclear whether or not pathophysiological involvement of the upper gastrointestinal tract occurs in Plasmodium berghei ANKA (PbA)-infected mice.

Methods

PbA-infective Anopheles mosquitoes were used to infect mice via the natural route of infection. Fifteen PbA-C57BL/6 mice were used as a cerebral malaria model and the same numbers of PbA-BALB/c mice were used as a cerebral malaria-resistant model, and then we investigated the pathophysiological involvement of the stomach and small intestine.

Results

On day 8 post infection, six PbA-C57BL/6 mice showed cerebral malaria and nine others had uncomplicated infection. All the PbA-C57BL/6 mice on that same day showed severe weight loss with multiple, red gastric patches and changes to the course of the small intestine with villus goblet cell enlargement. In addition, cerebral malaria cases showed gastric gas retention with submucosal edema and small intestinal shortening. In PbA-BALB/c mice, overextension of the stomach and gas retention were evident from week 2 after PbA infection, as well as changes to the course of the small intestine and mesenteric thinning with fragility.

Conclusions

We described the upper gastrointestinal pathophysiology representing new findings directly linked to malarial severity and subsequent death in PbA-infected mice as a mouse model of malaria infection.

Short-term consumption of a high-fat diet increases host susceptibility to Listeria monocytogenes infection

BACKGROUND

A westernized diet comprising a high caloric intake from animal fats is known to influence the development of pathological inflammatory conditions. However, there has been relatively little focus upon the implications of such diets for the progression of infectious disease. Here, we investigated the influence of a high-fat (HF) diet upon parameters that influence Listeria monocytogenes infection in mice.

RESULTS

We determined that short-term administration of a HF diet increases the number of goblet cells, a known binding site for the pathogen, in the gut and also induces profound changes to the microbiota and promotes a pro-inflammatory gene expression profile in the host. Host physiological changes were concordant with significantly increased susceptibility to oral L. monocytogenes infection in mice fed a HF diet relative to low fat (LF)- or chow-fed animals. Prior to Listeria infection, short-term consumption of HF diet elevated levels of Firmicutes including Coprococcus, Butyricicoccus, Turicibacter and Clostridium XIVa species. During active infection with L. monocytogenes, microbiota changes were further exaggerated but host inflammatory responses were significantly downregulated relative to Listeria-infected LF- or chow-fed groups, suggestive of a profound tempering of the host response influenced by infection in the context of a HF diet. The effects of diet were seen beyond the gut, as a HF diet also increased the sensitivity of mice to systemic infection and altered gene expression profiles in the liver.

CONCLUSIONS

We adopted a systems approach to identify the effects of HF diet upon L. monocytogenes infection through analysis of host responses and microbiota changes (both pre- and post-infection). Overall, the results indicate that short-term consumption of a westernized diet has the capacity to significantly alter host susceptibility to L. monocytogenes infection concomitant with changes to the host physiological landscape. The findings suggest that diet should be a consideration when developing models that reflect human infectious disease.

Heterogeneity of Pulmonary Stem Cells

Epithelial stem cells reside within multiple regions of the lung where they renew various region-specific cells. In addition, there are multiple routes of regeneration after injury through built-in heterogeneity within stem cell populations and through a capacity for cellular plasticity among differentiated cells. These processes are important facets of respiratory tissue resiliency and organism survival. However, this regenerative capacity is not limitless, and repetitive or chronic injuries, environmental stresses, or underlying factors of disease may ultimately lead to or contribute to tissue remodeling and end-stage lung disease. This chapter will review stem cell heterogeneity among pulmonary epithelia in the lower respiratory system, discuss recent findings that may challenge long-held scientific paradigms, and identify several clinically relevant research opportunities for regenerative medicine.

Peroxisome proliferator-activated receptor gamma activation promotes intestinal barrier function by improving mucus and tight junctions in a mouse colitis model

BACKGROUND AND AIMS

Defects in mucus and intestinal epithelia can lead to intestinal inflammation in colitis. Reduced peroxisome proliferator-activated receptor gamma (PPAR_γ) in the mucosa may contribute to inflammation. However, the roles of PPAR_γ in the intestinal barrier remain poorly understood.

METHODS

Chronic colitis was induced in C57BL/6 mice by administration of dextran sulfate sodium (DSS) for 27 days. Three days before DSS treatment, mice were treated with the PPAR_γ agonist rosiglitazone (Ro) orally at 20 mg kg^-1 day^-1.

RESULTS

The colitis based on disease activity index and colonic histopathology was significantly ameliorated in the DSS + Ro group. Additionally, mice in the DSS + Ro group had a thicker mucous layer than those in DSS + NS group, and muc2 mRNA expression was elevated significantly along with the mouse atonal homolog, SAM-pointed domain-containing Ets-like factor, and anterior gradient 2 genes. Moreover, tight junctions were up-regulated, whereas long myosin light chain kinase and phosphorylation of the myosin II light chain were lower in DSS + Ro mice. Similarly, after HT-29 and Caco-2 cells were treated by LPS or LPS + Ro, PPAR_γ activation by Ro could effectively improve the intestinal barrier, including intestinal mucus and tight junctions.

CONCLUSIONS

Our results demonstrate that activated PPAR_γ could effectively promote intestinal mucus integrity by increasing the number of goblet cells, the glycosylation of mucins, and tight junctions via an MLCK-dependent mechanism.

SCF/c-KIT signaling promotes mucus secretion of colonic goblet cells and development of mucinous colorectal adenocarcinoma

Mucinous colorectal adenocarcinoma (MCA) is characterized by a great mount of extracellular mucus fundamentally composed of Mucin2 (MUC2) which is significantly correlated with the high malignancy and strong invasive ability of MCA. However, rare is known about the underlying mechanism of the mucus accumulation in MCA. Our latest study demonstrated that SCF/c-KIT signaling was highly activated in MCA patients and mouse model, which up-regulated MUC2 transcription. In the present study, we paid a special interest in whether and how SCF/c-KIT signaling promoted mucus secretion by using wild-type (WT) C57BL mice and their littermates who harbor mutational c-kit gene (Wads^m/m), clinical colorectal cancer (CRC) samples, as well as human CRC cell lines. Our results clearly showed that the inner mucus layer of colon was thinner and the intracellular mucin residual was more in Wads^m/m mice than those in WT mice by Alcian blue and PAS staining, suggesting that the mucus secretion process was crippled when SCF/c-KIT signaling was hypo-activated. Inhibiting SCF/c-KIT signaling by Imatinib also resulted in weakened mucus secretion in WT mice. Intraperitoneal administration of MANS which competitively inhibits the activity of the vesicular transport protein MARCKS efficiently reduced mucus secretion in colonic goblet cells of WT mice. Significantly, phosphorylated MARCKS (p-MARCKS) was overtly decreased in colonic mucosa of Wads^m/m mice compared with WT mice, indicating that SCF/c-KIT signaling-regulated mucus secretion was probably mediated by MARCKS activation. Similar results were obtained in MCA patients and mouse model. Moreover, SCF/c-KIT signaling was activated or inhibited in HT-29 and LS174T CRC cells, which potently increased or decreased MARCKS activity, respectively. Finally, we found that PKCδ, a known kinase for MARCKS, was activated in WT and MCA mice along with MARCKS. Inhibition or activation of SCF/c-KIT signaling resulted in decreased or increased PKCδ activity respectively in vitro. In conclusion, we demonstrated that SCF/c-KIT signaling can promote the mucus secretion by activating PKCδ-MARCKS, which provided a new insight into understanding the mechanism of mucus secretion of goblet cells and MCA development.

Internal biliary drainage superior to external biliary drainage in improving gut mucosa barrier because of goblet cells and mucin-2 up-regulation

Backgroud: Obstructive jaundice increases intestinal permeability, but the pathological mechanisms remain obscure, which results in debates about the necessity of performing preoperative biliary drainage in patients with obstructive jaundice. Mucin-2 (MUC2) and goblet cells regulated by bile acids play an important role in maintaining the function of intestinal mucosal barrier. The present study was to investigate the role of goblet cells and MUC2 in obstructive jaundice and evaluate the effect of biliary drainage on intestinal permeability.

STUDY DESIGN

We enrolled patients with malignant biliary obstruction and controls. We also did animal studies with four groups of rats: sham operation, obstructive jaundice, internal biliary drainage, and external biliary drainage. Histopathological analysis, biochemical measurement, and electron microscopy examination were done on pertinent samples.

RESULTS

Compared with the control group, the small intestinal mucosa was significantly damaged; goblet cells and MUC2 were significantly decreased and serum endotoxin level was significantly increased in patients and rats with obstructive jaundice. Biliary drainage, especially internal biliary drainage, significantly increased goblet cells and MUC2 and attenuated the damage of small intestinal mucosa.

CONCLUSIONS

In obstructive jaundice condition, goblet cells and MUC2 were reduced which were involved in the damage of intestinal mucosa barrier; biliary drainage increased goblet cells and MUC2, repaired mucosa layer and restored the intestinal mucosa barrier function.

Altered goblet cell function in Hirschsprung's disease

AIMS AND OBJECTIVES

Hirschsprung's disease-associated enterocolitis (HAEC) is the most serious complication of Hirschsprung's disease (HSCR). HAEC occurs in 17-50% of patients with HSCR and may occur before or after a properly performed pull-through operation. The pathogenesis of HAEC is poorly understood. It is well recognized that a complex mucosal barrier protects, as the first line of defense, the surface of healthy intestinal tract from adhesion and invasion by luminal micro-organisms. Within the intestinal epithelium, goblet cells secrete gel-forming mucins, the major component of mucus, which block the direct attachment of commensal bacteria to the epithelial layer. Mucin 2 (MUC2) is the predominant mucin expressed in humans. Trefoil factor 3 (TFF3) synergizes with mucin and enhances the protective barrier properties of the mucus layer. SAM pointed domain-containing ETS transcription factor (SPDEF) drives terminal differentiation and maturation of secretory progenitors into goblet cells. Krueppel-like factor 4 (KLF4) is a goblet cell-specific differentiation factor in the colon and controls goblet cell differentiation and activates mucin synthesis. We hypothesized that the goblet cell function in the ganglionic pulled-through bowel in HSCR is abnormal and, therefore, we investigated the changes in goblet cell differentiation and functional expression of mucin in the bowel specimens from patients with HSCR.

MATERIAL AND METHODS

We investigated MUC2, TFF3, SPDEF and KLF4 expression, and the goblet cell population in the ganglionic and aganglionic bowel of HSCR patients (n = 10) and controls (n = 10) by qPCR, Western blotting, confocal immunofluorescence, and alcian blue staining.

RESULTS

The qPCR and Western blotting analysis revealed that TFF3, SPDEF and KLF4 expressions were significantly downregulated in the aganglionic and ganglionic colon of patients with HSCR as compared to controls (p < 0.05). Alcian blue staining revealed that the goblet cell population was significantly decreased in aganglionic and ganglionic colon as compared to controls (p < 0.05). Confocal microscopy revealed a markedly decreased expression of TFF3, SPDEF and KLF4 in colonic epithelium of patients with HSCR as compared to controls.

CONCLUSION

This is, to our knowledge, the first report of decreased expression of TFF3, SPDEF, KLF4, and goblet cell population in the colon of patients with HSCR. Altered goblet cell function may result in intestinal barrier dysfunction contributing to the development of HAEC.

Manipulating and Analyzing Cell Type Composition of the Xenopus Mucociliary Epidermis

The Xenopus embryonic epidermis serves as a model to investigate the development, cell biology, and regeneration of vertebrate mucociliary epithelia. Its fast development as well as the ease of manipulation and analysis in this system facilitate novel approaches and sophisticated experiments addressing the principle mechanisms of mucociliary signaling, transcriptional regulation, and morphogenesis. This protocol describes how cell type composition can be manipulated and analyzed, and how mucociliary organoids can be generated and used for "omics"-type of experiments.

Persistent induction of goblet cell differentiation in the airways: Therapeutic approaches

Dysregulated induction of goblet cell differentiation results in excessive production and retention of mucus and is a common feature of several chronic airways diseases. To date, therapeutic strategies to reduce mucus accumulation have focused primarily on altering the properties of the mucus itself, or have aimed to limit the production of mucus-stimulating cytokines. Here we review the current knowledge of key molecular pathways that are dysregulated during persistent goblet cell differentiation and highlights both pre-existing and novel therapeutic strategies to combat this pathology.

Dose dependent treatment with isotretinoin induces more changes in the ileum than in the duodenum and jejunum in Wistar rats

Acne is the most common skin disorder and can directly affect the patients' self-esteem. Systemic treatment has been indicated for nodular, cystic or persistent acne rather than another type of treatment, such as a topic one. Isotretinoin is an analogue of vitamin A and by suppressing the sebaceous glands the disease can be controlled. This study was designed to mimic the treatment performed in young patients using the dosage of 1mg/kg, and a higher one of 10mg/kg, for 60days in young male Wistar rats. 24 Wistar rats were divided into four groups: control(water), D0(soybean oil, control group), D1(1mg/kg of Isotretinoin solution), D10(10mg/kg of Isotretinoin solution). Using the morphometry tool and histochemical techniques we evaluated the villus, intestinal crypts, and goblet cells to find signs of possible alterations of the duodenum, jejunum and ileum segments of the small intestine. We found no signs of changes in the jejunum mucosa after 60 days of treatment with 1mg/kg and 10mg/kg. The duodenum is also less affected, whereas significant modifications were found in the ileum. The goblet cell frequency was altered, indicating a proliferative potential for the substance. Although some patients have described intestinal symptoms, no important alterations were found with this protocol, reaffirming the security involved in the treatment with this substance.

A disturbance of intestinal epithelial cell population and kinetics in APC1638T mice

The adenomatous polyposis coli (APC) is a multifunctional protein as well as a tumor suppressor. To determine the functions of the C-terminal domain of APC, we explored APC ^1638T/1638T (APC1638T) mice that express a truncated APC lacking the C-terminal domain. The APC1638T mice were tumor free and exhibited growth retardation. In the present study, we compared small intestinal crypt-villus cells homeostasis in APC ^+/+ (WT) mice and APC1638T mice. The body weight of APC1638T mice was significantly smaller than that of WT mice at all ages. The length of small intestine of APC1638T mice was significantly shorter than that of WT mice. The crypt-villus axis was significantly elongated, and the number of intestinal epithelial cells also increased in APC1638T mice compared with those in WT mice. However, the number of intestinal epithelial cells per 100 µm of villi was not different between WT and APC1638T mice. Migration and proliferation of intestinal epithelial cells in APC1638T mice were faster than that in WT mice. The population of Goblet cells, Paneth cells, and enteroendocrine cells was significantly altered in APC1638T mice. These results indicate that C-terminal domain of APC has a role in the regulation of intestinal epithelium homeostasis.

Conditioned medium from LS 174T goblet cells treated with oxyresveratrol strengthens tight junctions in Caco-2 cells

BACKGROUND

Strengthening of intestinal tight junctions provides an effective barrier from the external environment. Goblet cell-derived trefoil factor 3 (TFF3) increases transepithelial resistance by upregulating the expression of tight junction proteins. Oxyresveratrol (OXY) is a hydroxyl-substituted stilbene found in the roots, leaves, stems, and fruit of many plants and known to have various biological activities. In this study, we investigated the strengthening effect of OXY on intestinal tight junctions through stimulation of TFF production in goblet cells.

METHODS

We prepared conditioned medium from LS 174T goblet cells treated with OXY (GCO-CM) and investigated the effect of GCO-CM on strengthening tight junctions of Caco-2 cells. The mRNA and protein expression levels of major tight junction components (claudin-1, occludin, and ZO-1) were measured by quantitative real-time PCR and western blotting, respectively. Transepithelial electric resistance (TEER) was measured using an ohm/V meter. Monolayer permeability was evaluated by paracellular transport of fluorescein isothiocyanate-dextran.

RESULTS

OXY showed a strong antioxidant activity. It significantly increased the expression level of TFF3 in LS 174T goblet cells. GCO-CM prepared by treatment with 2.5, 5, and 10μg/ml OXY did not show cytotoxicity in Caco-2 cells. GCO-CM increased the mRNA and protein expression levels of claudin-1, occludin, and ZO-1. It also significantly increased tight junction integrity and reduced permeability in a dose-dependent manner.

CONCLUSION

OXY stimulates the expression of TFF3 in goblet cells, which might increase the integrity of the intestinal tight junction barrier.

Goblet cell depletion in small intestinal villous and crypt epithelium of conventional nursing and weaned pigs infected with porcine epidemic diarrhea virus

Intestinal goblet cells secret mucins to form mucus layers critical for maintaining the integrity of the intestinal epithelium. Porcine epidemic diarrhea virus (PEDV) causes watery diarrhea and high mortality of suckling pigs. PEDV mainly infects villous epithelial cells of the small intestine, and infected cells undergo acute, massive necrosis, followed by severe villous atrophy. Conventional 9-day-old nursing pigs [PEDV-inoculated (n=9); Mock (n=11)] and 26-day-old weaned [PEDV-inoculated (n=11); Mock (n=9)] were inoculated orally [8.9 log₁₀ genomic equivalents/pig] with PEDV strain PC21A or mock. We used alcian blue or Periodic-Acid-Schiff staining for the detection of acidic or neutral mucin-secreting goblet cells in the small intestine. We demonstrated that PEDV infection of the nursing pigs at post-inoculation days (PIDs) 1-5 and weaned pigs at PIDs 3-5 led to depletion or significant reduction in the number of goblet cells (and also the number of villous goblet cells normalized by jejunal villous crypt height to crypt depth ratios) in the villi or crypts. These findings coincided with the development of intestinal villous atrophy. By immunohistochemistry, a few PEDV antigen-positive goblet cells were identified in the jejunal or ileal villous epithelium of the infected nursing or weaned pigs. During the early stages of PEDV infection, goblet cell mucins in the small intestine may be decreased, possibly leading to an impaired mucus layer and increased susceptibility to secondary enteric bacterial infection.

Goblet cells of the conjunctiva: A review of recent findings

Goblet cells within the conjunctival epithelium are specialized cells that secrete mucins onto the surface of the eye. Recent research has demonstrated new characteristics of the cells, including factors influencing their differentiation, their gene products and their functions at the ocular surface. The following review summarizes the newly discovered aspects of the role of Spdef, a member of the Ets transcription factor family in conjunctival goblet cell differentiation, the newly discovered goblet cell products including claudin2, the Wnt inhibitor Frzb, and the transmembrane mucin Muc16. The current concepts of conjunctival goblet cell function, including debris removal and immune surveillance are reviewed, as are changes in the goblet cell population in ocular surface diseases. Major remaining questions regarding conjunctival cell biology are discussed.

Epithelial Cell-Derived a Disintegrin and Metalloproteinase-17 Confers Resistance to Colonic Inflammation Through EGFR Activation

Epithelial regeneration is a key process for the recovery from ulcerative colitis (UC). Here we demonstrate that a disintegrin and metalloproteinase-17 (ADAM17), a main sheddase for tumor necrosis factor (TNF)-α, is essential for defensive epithelial properties against UC by promoting epithelial cell growth and goblet cell differentiation in mouse and human. Mice with systemic deletion of Adam17 developed severe dextran sulfate sodium-induced colitis when compared to mice with myeloid cell Adam17 deletion or control littermates. ADAM17 was predominantly expressed by regenerating epithelia in control mice, and its loss or inhibition attenuated epidermal growth factor receptor (EGFR) activation, epithelial proliferation, mucus production and barrier functions. Conversely, ectopic EGFR stimulation promoted epithelial regeneration thereby partially rescuing the severe colitis caused by ADAM17 deficiency. In UC patients, epithelial ADAM17 expression positively correlated with both cell proliferation and goblet cell number. These findings suggest that maintaining ADAM17–EGFR epithelial signaling is necessary for the recovery from UC and would be beneficial to therapeutic strategies targeting ADAM17-mediated TNF-α shedding.

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Mice with systemic deletion of ADAM17, but not with its myeloid cell-specific deficiency, are more sensitive to colitis.

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ADAM17-EGFR axis promotes repair processes through epithelial cell proliferation and goblet cell differentiation.

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Epithelial ADAM17 expression correlates with cell growth and mucus production in ulcerative colitis patients.

Epithelial regeneration is a key process for the recovery from ulcerative colitis (UC). We now demonstrate that a disintegrin and metalloproteinase-17 (ADAM17) is essential for defensive epithelial properties against UC by driving repair processes in mouse and human. During colonic inflammation, ADAM17 is up-regulated in regenerating epithelia, and its loss or inhibition attenuated epidermal growth factor receptor (EGFR) activation, epithelial proliferation, mucus production and barrier functions. These findings suggest that maintaining ADAM17–EGFR epithelial signaling is necessary for the recovery from UC and would be beneficial to therapeutic strategies targeting ADAM17-mediated tumor necrosis factor-α shedding.

Alterations in juvenile flatfish gill epithelia induced by sediment-bound toxicants: A comparative in situ and ex situ study

Juvenile Solea senegalensis were exposed in the laboratory (ex situ) and field (in situ) to different sediments of a moderately impacted estuary (the Sado, Portugal) for 28 days. A qualitative histopathological screening yielded scant lesions to gills, albeit alterations such as epithelial hyperplasia being evident and more frequent in fish exposed ex situ. Fully quantitative traits, namely chloride and goblet cell count and size revealed differences between the two bioassay approaches, with ex situ experiments likely enhancing bioavailability of toxicants. Chloride cells endured autolytic processes that could, at least in part, relate to contamination by mixed metals and polycyclic aromatic hydrocarbons (PAHs). Goblet cells did not reveal changes in the chemistry of mucous. Still, their number and size was reduced in fish exposed ex situ to the sediments most contaminated by PAHs, with evidence for adaptation. Also, copper histochemistry revealed the potential role of mucocytes in the regulation of metals.

FTY720 ameliorates Dry Eye Disease in NOD mice: Involvement of leukocytes inhibition and goblet cells regeneration in ocular surface tissue

FTY720 is a promising drug in attenuating multiple sclerosis, prolonging survival of organ allograft, and many other protective effects. Its mechanism of action is considered to be mediated by the internalization of sphingosine 1-phosphate receptors (S1PRs). In the current study, we investigated the efficacy of FTY720 in Non-Obese Diabetic (NOD) mice, serving as a model of Dry Eye Disease (DED). NOD mice were divided into six study groups, i.e., FTY720-treated groups with 3 concentrations of FTY720 (0.05%, 0.005%, and 0.001%), 0.05% Cyclosporin A (CsA) treated group, normal saline treated group, and no treatment control group. FTY720 was reconstituted with normal saline and prepared as eye drop. The stability and production of tear film was measured by Tear Break up Time test (TBUT) and phenol red cotton thread test (PRCTT), respectively. Tear fluid washings were collected and assessed by ELISA. Cytokines were detected in lacrimal glands by RT-PCR. Inflammation in conjunctiva was assessed by immunohistochemistry, goblet cells and conjunctival epithelia were examined and evaluated by impression cytology. Our results indicated that FTY720 had a significantly therapeutic effect in NOD mice. After FTY720 intervention, TBUT and PRCTT data were greatly improved (p < 0.01), the interleukin 1β (IL-1β) level was markedly decreased in tear fluid washings compared to control and normal saline groups after 2 weeks (

CONTROL

1.06 ± 0.12, Normal saline:0.97 ± 0.09 pg/ml, CsA:0.22 ± 0.02 pg/ml, 0.001% FTY720:0.23 ± 0.02 pg/ml, 0.005% FTY720:0.14 ± 0.03 pg/ml, 0.05% FTY720: 0.18 ± 0.03 pg/ml. CsA group and 3 FTY720 groups VS. control group and normal saline groups: p < 0.01). Proinflammatory factors were greatly decreased in lacrimal glands (p < 0.01). Leukocytes were identified and markedly decreased in conujnctiva (p < 0.01), inflammatory reaction of DED was greatly relieved. More importantly, the goblet cells were largely restored and ocular surface lesions were significantly ameliorated (p < 0.01). Thus, we observed FTY720 alleviated DED in NOD mice by inhibiting leukocytes, the function of ocular surface tissue in NOD mice was partially restored via inhibiting ocular surface inflammation and increasing the density of goblet cells and conjunctival epithelia. FTY720 may offer a novel strategy for the treatment of inflammatory disorders in the ocular surface.