Mucin Expression Research Articles

Dietary Fermented Blueberry Pomace Supplementation Improves Small Intestinal Barrier Function and Modulates Cecal Microbiota in Aged Laying Hens.

This study aimed to investigate the effects of fermented blueberry pomace (FBP) on the intestinal barrier function and cecal microbiome of aged laying hens. A total of 320 Yukou Jingfen No. 8 laying hens (345-day-old) were randomly divided into a control group, 0.25% FBP group, 0.5% FBP group, or 1.0% FBP group. The results showed that the villus height (VH) in the jejunum of the 0.25-0.5% FBP groups and villus surface area in the jejunum of the 0.25% FBP group were higher (p < 0.05), while 0.25% FBP supplementation displayed a higher (p = 0.070) VH in the ileum compared to the control group. Mucin-2 expression was upregulated (p < 0.05) in the jejunum of the 0.5% FBP group and the ileum of the 0.25-0.5% FBP groups. Compared to the control group, interleukin (IL)-4 and IL-13 expressions were upregulated (p < 0.05) in the 1.0% FBP group. Microbiota analysis revealed that Prevotella abundance in the cecum of the 0.5-1.0% FBP groups was higher (p < 0.05) than in the 0.25% FBP group. In addition, microbial function prediction analysis showed that cecal microbiota in the 0.25% FBP group were mainly enriched by alanine/aspartate/glutamate metabolism and methane metabolism. Moreover, Spearman's correlation analysis revealed the potential correlations between the abundance of the cecal microbiota and intestinal-barrier-function-related gene expressions, as well as the short-chain fatty acid content, of laying hens. In summary, dietary FBP supplementation enhanced intestinal barrier function by improving intestinal morphology, upregulating gene expressions related to barrier function, and altering the cecal microbiota of aged laying hens.

Multi-omics analysis reveals the enhancing effects of Glycyrrhiza polysaccharides on the respiratory health of broilers

This study investigated the impact of Glycyrrhiza polysaccharides (GPS) on the respiratory health of broilers. Specifically, 240 one-day-old male Arbor Acres (AA) broilers were randomly assigned to two groups: basal diet (CON) and GPS (supplemented with 150 mg/kg of Glycyrrhiza polysaccharides). When compared with the CON group, the GPS group significantly increased the broiler average daily gain, serum immunoglobulin A, immunoglobulin M, immunoglobulin G, antioxidant capacity, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and tracheal messenger RNA (mRNA) expression levels of SOD1, SOD2, and GSH-Px. The GPS group also had a reduced feed conversion ratio, reduced lung IL-1β and IL-6 levels, and upregulated tracheal mRNA expression of Occludin, Claudin1, and Mucin-2. Additionally, the GPS group had alterations in lung microbial diversity and composition. Transcriptomic and metabolomic analyses revealed the activation of the T cell receptor (TCR) signaling pathway and linoleic acid metabolic pathway in the GPS group. Correlation analysis demonstrated significant associations between differential bacteria, genes, serum metabolites, and phenotypic indicators. In conclusion, Glycyrrhiza polysaccharide supplementation positively influenced the respiratory health of broilers by modulating the lung microbiota, activating the TCR signaling pathway, and affecting the linoleic acid metabolism pathway.

Porcine ex-vivo intestinal mucus has age-dependent blocking activity against transmissible gastroenteritis virus

Transmissible gastroenteritis virus (TGEV) causes high mortality in young piglets (< 3 days of age). With aging, the susceptibility/morbidity/mortality rates drop. We previously hypothesized that the age-related changes in the intestinal mucus could be responsible for this resistance. Hence, this study investigated the effect of porcine intestinal mucus from 3-day and 3-week-old pigs on the free mobility of the virulent TGEV Miller strain, and on the infection in swine testicle (ST) cells. Single particle tracking (SPT) revealed that TGEV had significantly higher diffusion coefficients in 3-day mucus compared to 3-week mucus. TGEV and charged and uncharged control nanoparticles diffused freely in 3-day mucus but were hindered by 3-week mucus in the diffusion model; TGEV mimicked the diffusion behavior of negatively charged carboxylated particles. Inoculation of ST cells with TGEV in the presence of 3-week mucus resulted in a significantly lower average number of infected cells (30.9 ± 11.9/5 fields) compared with 3-day mucus (84.6 ± 16.4/5 fields). These results show that 3-week mucus has a significant TGEV-blocking activity compared to 3-day mucus in free diffusion and infection of the underlying susceptible cells. Additionally, a label-free proteomics analysis revealed an increased expression of mucin 13, known for negatively regulating the tight junctions in intestinal epithelium, in 3-day-old pigs. In 3-week-old pigs, a higher expression of mucin 2, a type of secreted mucin which is known for inhibiting coronavirus infection, was observed. Concludingly, this study demonstrated a protective effect of 3-week mucus against viral infections.

Arctium lappaL. polysaccharides alleviate oxidative stress and inflammation in the liver and kidney of aging mice by regulating intestinal homeostasis

Arctium lappa L. polysaccharide (ALP) is a prominent bioactive compound renowned for its multifaceted functional properties, including anti-inflammatory, antioxidant, antifibrotic, immunomodulatory, and pro-apoptotic effects. This study evaluated the aging-delaying effect of ALP and its mechanisms using a D-galactose (D-gal)-induced aging model. After an 8-week treatment, ALP significantly ameliorated D-gal-induced inflammation and oxidative stress in the liver, kidneys, and intestines. Notably, ALP administration led to a marked reduction of the pathogenic bacterium Desulfovibrio and a substantial increase in the beneficial bacterium Muribaculum. These microbial shifts were associated with upregulated expression of intestinal tight junction proteins and intestinal mucins, leading to enhanced intestinal barrier integrity. Consequently, the leakage of enterotoxins and inflammatory mediators was effectively reduced. The findings indicate that ALP alleviates tissue inflammation and oxidative stress, while also delaying aging in mice. This effect is achieved through the regulation of intestinal ecological homeostasis and the repair of the intestinal immune barrier.

Proinflammatory Microenvironment in Adenocarcinoma Tissue of Colorectal Carcinoma.

Cancer-promoting proinflammatory microenvironment influences colorectal cancer (CRC) development. We examined the biomarkers of inflammation, intestinal differentiation, and DNA activity correlated with the clinical parameters to observe progression and prognosis in the adenocarcinoma subtype of CRC. Their immunohistology, immunoblotting, and RT-PCR analyses were performed in the adenocarcinoma and neighboring healthy tissues of 64 patients with CRC after routine colorectal surgery. Proinflammatory nuclear factor kappa B (NFκB) signaling as well as interleukin 6 (IL-6) and S100 protein levels were upregulated in adenocarcinoma compared with nearby healthy colon tissue. In contrast to nitrotyrosine expression, the oxidative stress marker 8-Hydroxy-2'-deoxyguanosine (8-OHdG) was increased in adenocarcinoma tissue. Biomarkers of intestinal differentiation β-catenin and mucin 2 (MUC2) were inversely regulated, with the former upregulated in adenocarcinoma tissue and positively correlated with tumor marker CA19-9. Downregulation of MUC2 expression correlated with the increased 2-year survival rate of patients with CRC. Proliferation-related mammalian target of rapamycin (mTOR) signaling was activated, and Ki67 frequency was three-fold augmented in positive correlation with metastasis and cancer stage, respectively. Conclusion: We demonstrated a parallel induction of oxidative stress and inflammation biomarkers in adenocarcinoma tissue that was not reflected in the neighboring healthy colon tissue of CRC. The expansiveness of colorectal adenocarcinoma was confirmed by irregular intestinal differentiation and elevated proliferation biomarkers, predominantly Ki67. The origin of the linked inflammatory factors was in adenocarcinoma tissue, with an accompanying systemic immune response.

Effect of Butyrate on Food-Grade Titanium Dioxide Toxicity in Different Intestinal In Vitro Models.

Short-chain fatty acids (SCFA) are an important energy source for colonocytes and crucial messenger molecules both locally in the intestine and systemically. Butyrate, one of the most prominent and best-studied SCFA, was demonstrated to exert anti-inflammatory effects, improve barrier integrity, enhance mucus synthesis in the intestine, and promote cell differentiation of intestinal epithelial cells in vitro. While the physiological relevance is undisputed, it remains unclear if and to what extent butyrate can influence the effects of xenobiotics, such as food-grade titanium dioxide (E171, fgTiO2), in the intestine. TiO2 has been controversially discussed for its DNA-damaging potential and banned as a food additive within the European Union (EU) since 2022. First, we used enterocyte Caco-2 monocultures to test if butyrate affects the cytotoxicity and inflammatory potential of fgTiO2 in a pristine state or following pretreatment under simulated gastric and intestinal pH conditions. We then investigated pretreated fgTiO2 in intestinal triple cultures of Caco-2, HT29-MTX-E12, and THP-1 cells in homeostatic and inflamed-like state for cytotoxicity, barrier integrity, cytokine release as well as gene expression of mucins, oxidative stress markers, and DNA repair. In Caco-2 monocultures, butyrate had an ambivalent role: pretreated but not pristine fgTiO2 induced cytotoxicity in Caco-2 cells, which was not observed in the presence of butyrate. Conversely, fgTiO2 induced the release of interleukin 8 in the presence but not in the absence of butyrate. In the advanced in vitro models, butyrate did not affect the characteristics of the healthy or inflamed states and caused negligible effects in the investigated end points following fgTiO2 exposure. Taken together, the effects of fgTiO2 strongly depend on the applied testing approach. Our findings underline the importance of the experimental setup, including the choice of in vitro model and the physiological relevance of the exposure scenario, for the hazard testing of food-grade pigments like TiO2.

Itaconic Acid Alleviates Perfluorooctanoic Acid-Induced Oxidative Stress and Intestinal Damage by Regulating the Keap1/Nrf2/Ho-1 Pathway and Reshaping the Gut Microbiota.

Itaconic acid (IA) is recognized for its potential application in treating intestinal diseases owing to the anti-inflammatory and antioxidant properties. Perfluorooctanoic acid (PFOA) can accumulate in animals and result in oxidative and inflammatory damages to multi-tissue and organ, particularly in the intestinal tract. This study aimed to explore whether IA could mitigate intestinal damage induced by PFOA exposure in laying hens and elucidate its potential underlying mechanisms. The results showed that IA improved the antioxidant capacity of laying hens and alleviated the oxidative damage induced by PFOA, as evidenced by the elevated activities of T-SOD, GSH-Px, and CAT, and the decreased MDA content in both the jejunum and serum. Furthermore, IA improved the intestinal morphological and structural integrity, notably attenuating PFOA-induced villus shedding, length reduction, and microvillus thinning. IA also upregulated the mRNA expression of ZO-1, Occludin, Claudin-1, and Mucin-2 in the jejunum, thereby restoring intestinal barrier function. Compared with the PF group, IA supplementation downregulated the gene expression of Keap1 and upregulated the HO-1, NQO1, SOD1, and GPX1 expression in the jejunum. Meanwhile, the PF + IA group exhibited lower expressions of inflammation-related genes (NF-κB, IL-1β, IFN-γ, TNF-α, and IL-6) compared to the PF group. Moreover, IA reversed the PFOA-induced imbalance in gut microbiota by reducing the harmful bacteria such as Escherichia-Shigella, Clostridium innocuum, and Ruminococcus torques, while increasing the abundance of beneficial bacteria like Lactobacillus. Correlation analysis further revealed a significant association between gut microbes, inflammatory factors, and the Keap1/Nrf2/HO-1 pathway expression. In conclusion, dietary IA supplementation could alleviate the oxidative and inflammatory damage caused by PFOA exposure in the intestinal tract by reshaping the intestinal microbiota, modulating the Keap1/Nrf2/HO-1 pathway and reducing oxidative stress and inflammatory response, thereby promoting intestinal homeostasis.

Continuous Oral Administration of the Superantigen Staphylococcal Enterotoxin C2 Activates Intestinal Immunity and Modulates the Gut Microbiota in Mice.

Staphylococcal Enterotoxin C2 (SEC2), a classical superantigen, is an antitumor immunotherapy agent. However, the injectable formulation of SEC2 limits its clinical application. Here, it is reported that oral administration of SEC2 activates the intestinal immune system and benefits intestinal health in a mouse model. Theseresults indicate that intact SEC2 is detected in the stomach, intestine, and serum after oral administration. Continuous oral administration of SEC2 activates immune cells in gut-associated lymphoid tissues, promoting extensive differentiation and proliferation of CD4+ and CD8+ T cells and CD19+ B cells, leading to increased production of cytokines and secretory immunoglobulin A. SEC2 also enhances intestinal barrier function, as demonstrated by an increased villus length/crypt depth ratio and elevated expression of mucins and tight junction proteins. Additionally, SEC2 indirectly influenced gut microbiota, reinforcing potential probiotics and short-chain fatty acid synthesis. Enhanced differentiation of T and B cells in the spleen, coupled with elevated serum interleukin-2 levels, suggests systemic immune enhancement following oral administration of SEC2. Thesefindings provide a scientific basis for the development of SEC2 as an oral immunostimulant for immune enhancement and anti-tumor immunotherapy.

The Expression and Clinicopathological Significance of BRAF V600E and Mucin 6 in Intrahepatic Cholangiocarcinoma: A Retrospective Study.

Aim. The study aims to explore the expression levels and clinicopathological significance of BRAF V600E and mucin 6 in intrahepatic cholangiocarcinoma. Method. Immunohistochemistry for BRAF V600E and mucin 6 was performed in 110 patients with intrahepatic cholangiocarcinoma. Subsequently, a comprehensive review of medical records and clinicopathological analysis was undertaken. Results. BRAF V600E expression was detected in 11 patients (10%); mucin 6 expression was observed in 19 intrahepatic cholangiocarcinoma specimens (17%). Thereafter, Cox regression models indicated that positive expression of either MUC6 positive (hazard ratio = 0.091, 95% confidence interval = 0.034-0.247, P < .001) and BRAF V600E positive (hazard ratio =0.150, 95% confidence interval = 0.058-0.388, P < .001) was significantly linked with longer overall survival for intrahepatic cholangiocarcinoma patients. Conclusion. The study concludes that positive expression of BRAF V600E and mucin 6 could potentially implied significant survival benefits for patients diagnosed with intrahepatic cholangiocarcinoma.

2′-Fucosyllactose alleviate immune checkpoint blockade-associated colitis by reshaping gut microbiota and activating AHR pathway

Immune checkpoint blockade (ICB) therapeutics are highly effective in cancer immunotherapy, but gastrointestinal toxicity limited the application. Intestinal microbiota plays a crucial role in ICB-associated colitis. 2′-Fucosyllactose (2′FL) is most abundance prebiotic in human milk that can reshape gut microbiota and exert immune regulatory effect. The study aimed to determine the effects of 2′FL on ICB-associated colitis and to uncover the mediating mechanism. ICB-associated colitis was induced by the ipilimumab and dextran sulfate sodium. Oral administration of 2′FL (0.6 g/(kg∙day)) ameliorated ICB-induced colitis by enhancing regulatory T cells (Treg) and the M2/M1 ratio of macrophages in colon. 2′FL treatment also increased the expression of tight junction proteins (zonula occludens-1 (ZO-1) and mucin 2 (MUC2)) and antioxidant stress indicators (superoxide dismutase (SOD) and catalase (CAT)). In addition, administration of 2′FL increased the abundance of Bifidobacterium and Lactobacillus, and elevated the levels of microbial metabolites, such as indole-3-lactic acid (ILA), which activated the aryl hydrocarbon receptor ligands (AHR) pathway. The protective effect of 2′FL was abolished upon depletion of gut microbiota, and ILA treatment partially simulated the protective effect of 2′FL. Notably, 2′FL did not exhibit inhibition of antitumor immunity. These findings suggest that 2′FL could serve as a potential protective strategy for ICB-associated colitis by modulating the intestinal microbiota and bacterial metabolites.

Long-Term Exposure to Polystyrene Microspheres and High-Fat Diet-Induced Obesity in Mice: Evaluating a Role for Microbiota Dysbiosis.

Microplastics (MPs) have become a global environmental problem, emerging as contaminants with potentially alarming consequences. However, long-term exposure to polystyrene microspheres (PS-MS) and its effects on diet-induced obesity are not yet fully understood. We aimed to investigate the effect of PS-MS exposure on high-fat diet (HFD)-induced obesity and underlying mechanisms. In the present study, C57BL/6J mice were fed a normal diet (ND) or a HFD in the absence or presence of PS-MS via oral administration for 8 wk. Antibiotic depletion of the microbiota and fecal microbiota transplantation (FMT) were performed to assess the influence of PS-MS on intestinal microbial ecology. We performed 16S rRNA sequencing to dissect microbial discrepancies and investigated the dysbiosis-associated intestinal integrity and inflammation in serum. Compared with HFD mice, mice fed the HFD with PS-MS exhibited higher body weight, liver weight, metabolic dysfunction-associated steatotic liver disease (MASLD) activity scores, and mass of white adipose tissue, as well as higher blood glucose and serum lipid concentrations. Furthermore, 16S rRNA sequencing of the fecal microbiota revealed that mice fed the HFD with PS-MS had greater -diversity and greater relative abundances of Lachnospiraceae, Oscillospiraceae, Bacteroidaceae, Akkermansiaceae, Marinifilaceae, Deferribacteres, and Desulfovibrio, but lower relative abundances of Atopobiaceae, Bifidobacterium, and Parabacteroides. Mice fed the HFD with PS-MS exhibited lower expression of MUC2 mucin and higher levels of lipopolysaccharide and inflammatory cytokines [tumor necrosis factor- (TNF-), interleukin-6 (IL-6), IL-1, and IL-17A] in serum. Correlation analyses revealed that differences in the microbial flora of mice exposed to PS-MS were associated with obesity. Interestingly, microbiota-depleted mice did not show the same PS-MS-associated differences in Muc2 and Tjp1 expression in the distal colon, expression of inflammatory cytokines in serum, or obesity outcomes between HFD and HFD + PS-MS. Importantly, transplantation of feces from HFD + PS-MS mice to microbiota-depleted HFD-fed mice resulted in a lower expression of mucus proteins, higher expression of inflammatory cytokines, and obesity outcomes, similar to the findings in HFD + PS-MS mice. Our findings provide a new gut microbiota-driven mechanism for PS-MS-induced obesity in HFD-fed mice, suggesting the need to reevaluate the adverse health effects of MPs commonly found in daily life, particularly in susceptible populations. https://doi.org/10.1289/EHP13913.

In vitro and in vivo effects of pectin‐type polysaccharides isolated from crabapples (Malus prunifolia) on inflammatory colitis models

SummaryThe aim of this study was to investigate the anti‐inflammatory effects of polysaccharides extracted from crabapples (Malus prunifolia; MP) in vitro and in vivo. Crabapples were subjected to hot water extraction to obtain MP‐HW, which was further separated into low (MP‐L) and high molecular weight (MW) (crude polysaccharide; MP‐CP) fractions by ethanol precipitation. Based on MW distribution, general composition, component sugars, and Fourier transform infrared spectroscopy, MP‐CP was identified as a pectin‐type polysaccharide rich in galacturonic acid with an MW of 106.2 kDa. MP‐CP inhibited the production and mRNA expression of proinflammatory factors in an IL‐1β‐treated intestinal epithelial cell model. In addition, MP‐CP significantly alleviated the body weight, disease activity index score, colon length, and spleen weight in mice with dextran sulfate sodium (DSS)‐induced colitis. The MP‐CP‐treated group showed effective regulation of the expression of pro‐ and anti‐inflammatory factors and immunoglobulin A than the DSS‐treated group. Haematoxylin and eosin and Alcian blue staining revealed that MP‐CP alleviated inflammatory manifestations and mucin expression in the intestinal lumen. Collectively, pectin‐type polysaccharides isolated from crabapples may be used as a new functional food and pharmaceutical agent for the prevention and treatment of inflammatory colitis.

Nippostrongylus brasiliensis alleviates dextran sulfate sodium salt-induced ulcerative colitis in mice: a preliminary study

To investigate the alleviation of Nippostrongylus brasiliensis infection on dextran sulfate sodium salt (DSS)-induced ulcerative colitis in mice, and to explore the underlying mechanism. Thirty male C57BL/6J mice of the SPF grade, each weighing approximately 25 g, were randomly divided into three groups, including the blank control group (NC group), DSS modeling group (DSS group), and N. brasiliensis treatment group (Nb + DSS group), of 10 mice in each group. Mice in the DSS group were orally administered with 3.5% DSS daily since day 1 (D0) for 6 successive days, and given normal drinking water since D6, and animals in the Nb + DSS group were subcutaneously injected with the third-stage larvae of N. brasiliensis at a dose of 500 larvae per mice 5 days prior to D0, followed by oral administration with 3.5% DSS daily since D0 for 6 successive days and normal drinking water since D6, while mice in the NC group were given normal drinking water. Mouse body weight and stool were observed and the disease activity index (DAI) was scored in each group during the study period. All mice were sacrificed on D9. The mouse colon length was measured, and mouse colon specimens were subjected to hematoxylin-eosin (HE) staining and histopathological scoring. In addition, the mRNA and protein expression of interleukin (IL)-1β and IL-10 was quantified in mouse colon specimens using quantitative fluorescent real-time PCR (qPCR) assay and enzyme-linked immunosorbent assay (ELISA), and the mRNA and protein expression of mucosal repair-associated molecules zonula occludens-1 (ZO-1), mucin 2 (MUC2) and claudin-1 was detected in mouse colon specimens using qPCR assay and immunofluorescence assay. The mice body weights, DAI scores and colon lengths were (26.26 ± 1.93), (22.39 ± 1.65), (25.00 ± 1.58) g (F = 8.06, P < 0.01); (1.89 ± 0.34), (0.47 ± 0.39), 0 points (F = 57.61, P < 0.000 1); and (42.50 ± 5.75), (56.20 ± 5.96) mm and (61.17 ± 7.88) mm (F = 13.72, P < 0.001) in the NC, DSS and Nb + DSS groups on D9, respectively, and elevated mouse body weight (P < 0.05), reduced DAI score (P < 0.000 1) and increased colon length (P < 0.01) were observed in the Nb + DSS group relative to the DSS group on D9. Pathological examinations showed that the colonic crypts were relatively intact and the inflammatory cell infiltration was lower in the mouse colon specimens in the Nb + DSS group than in DSS the group. There was a significant difference in the histopathological scores of mouse colon specimens among the NC group (0 point), the DSS group [(2.00 ± 1.22) points] and the Nb + DSS group [(0.20 ± 0.45) points] (F = 10.71, P < 0.01), respectively, and the histopathological score of mouse colon specimens was significantly higher in the DSS group than in the NC and Nb + DSS groups (both P values < 0.01). qPCR assay quantified that the relative IL-10 and IL-1β mRNA expression was 1.25 ± 0.08, 0.44 ± 0.14 and 1.30 ± 0.45 (F = 10.66, P < 0.01), and 0.22 ± 0.13, 1.14 ± 0.31 and 0.41 ± 0.19 (F = 16.89, P < 0.001) in mouse colon specimens in the NC, DSS and Nb + DSS groups, respectively, and higher IL-10 mRNA expression and lower IL-1β mRNA expression were found in mouse colon specimens in the Nb + DSS group than in the DSS group (both P values < 0.01). The relative MUC2, claudin-1 and ZO-1 mRNA expression was 0.87 ± 0.25, 0.34 ± 0.26 and 4.21 ± 0.55 (F = 121.60, P < 0.000 1), 1.05 ± 0.41, 0.16 ± 0.09 and 0.22 ± 0.11 (F = 14.00, P < 0.01), and 1.03 ± 0.10, 0.60 ± 0.11 and 1.64 ± 0.28 (F = 32.16, P < 0.000 1) in mouse colon specimens in the NC, DSS and Nb + DSS groups, respectively, and significantly higher MUC2 and ZO-1 mRNA expression was quantified in mouse colon specimens in the Nb + DSS group than in the DSS group (both P values < 0.05). The mean fluorescence intensities of ZO-1 and claudin-1 were 17.18 ± 2.08, 12.38 ± 1.21 and 18.06 ± 2.59 (F = 8.95, P < 0.01) and 13.50 ± 1.63, 9.66 ± 2.03 and 13.61 ± 0.97 (F = 6.96, P < 0.05) in mouse colon specimens in the NC, DSS and Nb + DSS groups, respectively, and the mean fluorescence intensities of ZO-1 and claudin-1 were significantly greater in mouse colon specimens in the Nb + DSS group than in the DSS group (both P values < 0.05). N. brasiliensis infection may remarkably alleviate DSS-induced ulcerative colitis in mice through promoting expression of anti-inflammatory cytokines, inhibiting expression of pro-inflammatory cytokines and facilitating mucosal repair in colon tissues.

Possible Correlation between Mucin Gene Expression and Symptoms of Dry Eye Syndrome Secondary to Sjogren’s Disease

(1) Background: It is estimated that 10% of dry eye disease (DED) occurs in patients with Sjogren’s syndrome (SS-DED) and represents a challenge when it comes to treatment. Both innate and adaptive immunity participate in the pathogenesis of SS-DED. Previous studies suggest that Th1 and Th17 cell immune responses are the main actors associated with the pathogenesis of this disease. Ocular surface mucins play a fundamental role in ocular surface homeostasis. In particular, the main transmembrane mucins, MUC1, MUC4 and MUC16, are dysregulated in DED and could be involved in the activation of pro-inflammatory cytokines at the ocular interface. Thus, the objective of this work was to analyze mucin and cytokine expression in ocular surface (OS) damage and correlate it with clinical symptoms.; (2) Methods: 18 patients with SS-DED and 15 healthy controls were included in the study. Samples of conjunctival cells were obtained through cytology impression. RNA was extracted from the collected samples and used to determine the expression of MUC1, 4 and 16 by qRT-PCR. Pro-inflammatory cytokines associated with DED pathogenesis (IL17 and IL-22) were also evaluated. The results were contrasted with the clinical findings on examination of the patients. (3) Results: We observed a significant increase in the expression of MUC1 and MUC4 in patients with SS-DED. MUC4 significantly correlated with both lower production and stability of the tear film, as well as greater superficial keratopathy. On the other hand, MUC1 and MUC16 were positively correlated with the presence of more severe DED symptoms. However, we could not reproduce an increase in IL-17 and IL-22 in DED patients as previously reported; (4) Conclusions: This work constitutes an approach to understanding how the gene expression of transmembrane mucins associates with SS-DED symptoms and clinical signs.

Salivary gland organoid transplantation as a therapeutic option for radiation-induced xerostomia

BackgroundXerostomia is a pathological condition characterized by decreased salivation due to salivary gland dysfunction and is frequently attributed to irreversible damage as a side effect of radiation therapy. Stem cell–derived organoid therapy has garnered attention as a promising avenue for resolving this issue. However, Matrigel, a hydrogel commonly used in organoid culture, is considered inappropriate for clinical use due to its undefined composition and immunogenicity. In this study, we aimed to develop a method for culturing collagen-based human salivary gland organoids (hSGOs) suitable for clinical applications and evaluated their therapeutic effectiveness.MethodsHuman salivary gland stem cells were isolated from the salivary gland tissues and cultured in both Matrigel and collagen. We compared the gene and protein expression patterns of salivary gland–specific markers and measured amylase activity in the two types of hSGOs. To evaluate the therapeutic effects, we performed xenogeneic and allogeneic transplantation using human and mouse salivary gland organoids (hSGOs and mSGOs), respectively, in a mouse model of radiation-induced xerostomia.ResultshSGOs cultured in Matrigel exhibited self-renewal capacity and differentiated into acinar and ductal cell lineages. In collagen, they maintained a comparable self-renewal ability and more closely replicated the characteristics of salivary gland tissue following differentiation. Upon xenotransplantation of collagen-based hSGOs, we observed engraftment, which was verified by detecting human-specific nucleoli and E-cadherin expression. The expression of mucins, especially MUC5B, within the transplanted hSGOs suggested a potential improvement in the salivary composition. Moreover, the allograft procedure using mSGOs led to increased salivation, validating the efficacy of our approach.ConclusionsThis study showed that collagen-based hSGOs can be used appropriately in clinical settings and demonstrated the effectiveness of an allograft procedure. Our research has laid the groundwork for the future application of collagen-based hSGOs in allogeneic clinical trials.

Prophylactic supplementation with selenium nanoparticles protects against foodborne toxin zearalenone-induced intestinal barrier dysfunction

Selenium nanoparticles (SeNPs) have been used as a potential alternative to other forms of selenium in nutritional supplements for the treatment and prevention of inflammatory and oxidative stress-related diseases. Zearalenone (ZEA) is a foodborne mycotoxin present in grains that poses a health threat. Here, we investigated the adverse impacts of ZEA on intestinal homeostasis and explored the protective effects of probiotic-synthesized SeNPs against its damage. Results showed that ZEA reduced mucin and tight junction proteins expression in jejunum, induced inflammatory process and oxidative stress which in turn increased intestinal permeability in mice. ZEA-induced intestinal toxicity was further verified in vitro. Intracellular redox imbalance triggered endoplasmic reticulum (ER) stress in intestinal epithelial cells, which caused structural damage to the ER. Remarkably, SeNPs exhibited a counteractive effect by inducing a decrease in intracellular levels of Inositol 1,4,5-trisphosphate (IP3) and Ca2+, along with a reduction in the expression level of IP3 receptor. SeNPs effectively mitigated ZEA-induced ER stress was related to the increased activity of selenium-dependent antioxidant enzymes and the expression of ER-resident selenoproteins. Furthermore, SeNPs significantly inhibited the activation of PERK/eIF2α/ATF4/CHOP pathway in vitro and in vivo. In addition, SeNPs effectively reversed ZEA-induced gut microbiota dysbiosis and increased the abundance of short-chain fatty acid-producing beneficial bacteria (Alloprevotella and Muribaculaceae). The Spearman correlation analysis suggested that the structure of gut microbiota was closely related to the SeNPs attenuation of ZEA-induced intestinal toxicity. This study provides new insights into ZEA-induced intestinal toxicity and identifies a novel potential nutrient SeNPs to overcome adverse effects.

ALKBH5-Mediated m6A Modification Drives Apoptosis in Renal Tubular Epithelial Cells by Negatively Regulating MUC1.

Dysregulation of renal tubular epithelial cell (RTEC) apoptosis is one of the critical steps underlying the occurrence and development of nephrolithiasis. Although N6-methyladenosine (m6A) modification has been extensively studied and associated with various pathologic processes, research onits specific role in RTEC injury and apoptosis remains limited. In this study, we found that overexpression of ALKBH5 reduced the level of m6A modification in RTEC cells and notably promoted RTEC apoptosis. Further mechanism studies revealed that ALKBH5 mainly decreased the m6A level on the mRNA of Mucin 1 (MUC1) gene in RTECs. Moreover, ALKBH5 impaired the stability of MUC1mRNA in RTECs, leading to attenuated expression of MUC1. Finally, we determined that the ALKBH5-MUC1 axis primarily facilitated RTEC apoptosis by regulating the PI3K/Akt signaling pathway. This study revealed the critical role of the ALKBH5-MUC1-PI3K/Akt regulatory system in RTEC apoptosis and provided new therapeutic targets for treating nephrolithiasis.

Variability in morphology and immunohistochemistry of Crohn's disease-associated small bowel neoplasms: implications of Claudin 18 and Cadherin 17 expression for tumor-targeted immunotherapies.

Inflammatory bowel disease-associated colorectal carcinomas are known to have different morphology, immunoprofile, and genetic findings from sporadic colorectal carcinomas; however, little is known for Crohn's disease-associated small bowel neoplasms (CD-SBNs). Cadherin 17 is a useful biomarker of adenocarcinomas with intestinal phenotype and recently reported as an ideal target for chimeric antigen receptor T-cells (CAR-T) therapy for gastrointestinal carcinoma. Claudin 18 is a cell adhesion protein, and Claudin18 isoform 2 (CLDN18.2) is frequently expressed at high levels in gastric-type adenocarcinoma. Zolbetuximab, a targeted monoclonal antibody, has been developed for CLDN18.2-positive gastroesophageal adenocarcinoma. We examined a series of CD-SBNs for both Cadherin 17 and Claudin 18, and also hypothesized that expression of Claudin 18 was associated with gastric phenotype. We performed histological and immunohistochemical examinations on 25 CD-SBNs. Most of adenocarcinomas showed tubular morphology as seen in gastric carcinomas, whereas a subset of dysplasia was morphologically similar to that of the large bowel. Cadherin17 and Claudin 18 expression was identified in 93% and 57% CD-associated adenocarcinomas respectively. In Cadherin 17-positive CD-SBNs, frequent MUC5AC, MUC6, and Claudin18 expression was identified (61%, 57%, and 57%, respectively). Claudin 18-positive CD-SBNs showed significantly more MUC5AC and MUC6 expression than Claudin 18-negative CD-SBNs (P = 0.005, < 0.001 respectively). In CD-associated small bowel adenocarcinomas, Cadherin 17 expression was frequently retained and Claudin 18 was frequently co-expressed. Claudin 18 had a positive correlation with the expression of gastric mucins. These results suggest that CD-associated small bowel adenocarcinomas may be candidates for Cadherin 17- and Claudin 18-targeted immunotherapies.

Polysaccharide from Areca catechu L. inflorescence enhances the intestinal mucosal immunity to maintain immune homeostasis

Being the first line of defense, intestinal mucosal immunity serves as in maintaining immune homeostasis among organisms. This study investigated the impact of the areca inflorescence polysaccharide (AFP) on intestinal mucosal immunity and elucidated the mechanisms responsible for the immunomodulatory effects of AFP. The immunosuppression mouse model was established using the cyclophosphamide. The intestinal mucosal status was evaluated based on the intestinal integrity, chemical and mucosal immune barriers, and intestinal flora. According to the findings, AFP enhances intestinal integrity by up-regulating the expression of tight junction proteins and reinforcing the chemical barrier through increased mucin-2, β-defensins, and SIgA expression and secretion. Furthermore, AFP restores the mucosal immune barrier by regulating immune cells within Peyer's patches and lamina propria. AFP also reverses the intestinal flora balance and regulates its metabolism. Additionally, AFP effectively modulates the immune response in the spleen and peripheral blood. Together, these results indicated that AFP repairs mucosal damage and restores mucosal immunity, thereby preserving the immune homeostasis of organisms.

Dietary vitamin B6 supplementation alleviates heat stress-induced intestinal barrier impairment by regulating the gut microbiota and metabolites in broilers

Heat stress (HS) brings great challenges to the poultry industry. Vitamin B6 (VB6) is an essential micro-nutrient for animals to maintain normal physiological functions and possesses antioxidant and anti-inflammatory properties. This study aimed to explore the effect of VB6 on alleviating HS-induced intestinal barrier impairment in broilers. A total of 250 broilers (609.76 ± 0.34 g) were randomly allocated to 5 groups with 5 replicate cages of 10 birds each. The broilers in thermoneutral (TN) group were raised in thermoneutral conditions (23 ± 1°C) and fed with a basal diet. The birds in other four groups were housed under cycle high temperature (34 ± 1°C for 8 h/d) from d 21 to 35 and fed with the basal diet (HS group) or basal diet supplemented with 6, 12, or 24 mg/kg VB6 (HB-6, HB-12, HB-24 groups). The results showed that HS reduced the growth performance, increased ileum inflammatory cytokines levels, and impaired the gut barrier function (P < 0.05). Compared to the HS group, final body weight, average daily gain, and average daily feed intake, and the feed conversion ratio were improved by VB6 supplementation. The diamine oxidase, interleukin (IL)-1β, tumor necrosis factor-α, IL-18, IL-10, and interferon-γ levels were reduced by VB6 supplementation (P < 0.05). Moreover, VB6 supplementation linearly or quadratically enhanced villus height and villus height-to-crypt depth ratio of duodenum and jejunum, and decreased crypt depth of duodenum and ileum. The mRNA expression of Occlaudin, ZO1, Mucin2, Mucin4, E-cadhein, and β-catenin were increased by VB6 treatment (P < 0.05). Furthermore, dietary VB6 altered the diversity and community of gut microbiota (P < 0.05). A total of 83 differential metabolites associated with the amelioration of VB6 were identified, which were primarily enriched in glycerophospholipid metabolism, caffeine metabolism, and glutathione metabolism pathway. Collectively, VB6 may improve the growth performance and intestinal barrier function of heat-stressed broilers by regulating the ileal microbiota and metabolic homeostasis.