ABSTRACT
PURPOSE: This study aimed to investigate the impact of hepatocyte growth factor (HGF) on colonic morphology and gut microbiota in a rat model of short bowel syndrome (SBS). METHODS: SD rats underwent jugular vein catheterization for total parenteral nutrition (TPN) and 90% small bowel resection [TPN + SBS (control group) or TPN + SBS + intravenous HGF (0.3 mg/kg/day, HGF group)]. Rats were harvested on day 7. Colonic morphology, gut microflora, tight junction, and Toll-like receptor-4 (TLR4) were evaluated. RESULTS: No significant differences were observed in the colonic morphological assessment. No significant differences were observed in the expression of tight junction-related genes in the proximal colon. However, the claudin-1 expression tended to increase and the claudin-3 expression tended to decrease in the distal colon of the HGF group. The Verrucomicrobiota in the gut microflora of the colon tended to increase in the HGF group. The abundance of most LPS-producing microbiota was lower in the HGF group than in the control group. The gene expression of TLR4 was significantly downregulated in the distal colon of the HGF group. CONCLUSION: HGF may enhance the mucus barrier through the tight junctions or gut microbiome in the distal colon.
Subject(s)
Colon , Disease Models, Animal , Gastrointestinal Microbiome , Hepatocyte Growth Factor , Rats, Sprague-Dawley , Short Bowel Syndrome , Animals , Rats , Hepatocyte Growth Factor/metabolism , Hepatocyte Growth Factor/genetics , Gastrointestinal Microbiome/drug effects , Colon/microbiology , Colon/pathology , Short Bowel Syndrome/metabolism , Short Bowel Syndrome/microbiology , Male , Toll-Like Receptor 4/metabolism , Toll-Like Receptor 4/genetics , Tight Junctions/drug effects , Tight Junctions/metabolism , Claudin-1/metabolism , Claudin-1/geneticsABSTRACT
Hypoxia plays an important role in the pathological process of bladder outlet obstruction. Previous research has mostly focused on the dysfunction of bladder smooth muscle cells, which are directly related to bladder contraction. This study delves into the barrier function changes of the urothelial cells under exposure to hypoxia. Results indicated that after a 5-day culture, SV-HUC-1 formed a monolayer and/or bilayer of cell sheets, with tight junction formation, but no asymmetrical unit membrane was observed. qPCR and western blotting revealed the expression of TJ-associated proteins (occludin, claudin1 and ZO-1) was significantly decreased in the hypoxia group in a time-dependent manner. No expression changes were observed in uroplakins. When compared to normoxic groups, immunofluorescent staining revealed a reduction in the expression of TJ-associated proteins in the hypoxia group. Transepithelial electrical resistance (TEER) revealed a statistically significant decrease in resistance in the hypoxia group. Fluorescein isothiocyanate-conjugated dextran assay was inversely proportional to the results of TEER. Taken together, hypoxia down-regulates the expression of TJ-associated proteins and breaks tight junctions, thus impairing the barrier function in human urothelial cells.
Subject(s)
Cell Hypoxia , Tight Junction Proteins , Tight Junctions , Urothelium , Humans , Urothelium/metabolism , Urothelium/pathology , Tight Junctions/metabolism , Tight Junction Proteins/metabolism , Tight Junction Proteins/genetics , Cell Line , Zonula Occludens-1 Protein/metabolism , Zonula Occludens-1 Protein/genetics , Occludin/metabolism , Occludin/genetics , Claudin-1/metabolism , Claudin-1/genetics , Electric Impedance , Gene Expression RegulationABSTRACT
Claudin-1 (CLDN1) is highly expressed in human lung adenocarcinoma-derived A549 cells and is involved in the augmentation of chemoresistance. However, the mechanism of chemoresistance is not fully understood. In the tumor microenvironment, cancer cells are exposed to stress conditions such as hypoxia and malnutrition. Here, we investigated the effect of CLDN1 expression on amino acid (AA) flux and chemoresistance using A549 cells. The expression of L-type AA transporters, LAT1 and LAT3, was decreased by CLDN1 silencing in A549 spheroids. A reduction in extracellular AA concentration increased the expression of these AA transporters in two-dimensional (2D) cultured cells. The paracellular AA flux except for Ser, Thr, Tyr, Ala, and Gly was enhanced by CLDN1 silencing. These results suggest that CLDN1 forms a paracellular barrier to some AAs, leading to the elevation of LAT1/3 expression in spheroids. The production of reactive oxygen species in the mitochondria and cytosol was decreased by CLDN1 silencing in spheroids, resulting in downregulation of the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its target antioxidant genes. CLDN1 silencing enhanced the cytotoxicity of anticancer drugs including doxorubicin and cisplatin, which was blocked by sulforaphane, an inducer of Nrf2 signaling. Similarly, the anticancer-induced toxicity was enhanced by Nrf2 silencing. In 2D cultured cells, the anticancer-induced toxicity was attenuated by AA deficiency and sulforaphane. We suggest that CLDN1 forms an AA barrier in spheroids, leading to the augmentation of Nrf2-dependent chemoresistance in A549 cells.
Subject(s)
Adenocarcinoma of Lung , Claudin-1 , Drug Resistance, Neoplasm , Lung Neoplasms , Humans , A549 Cells , Claudin-1/metabolism , Claudin-1/genetics , Adenocarcinoma of Lung/metabolism , Adenocarcinoma of Lung/genetics , Adenocarcinoma of Lung/pathology , Lung Neoplasms/metabolism , Lung Neoplasms/genetics , Lung Neoplasms/pathology , Lung Neoplasms/drug therapy , Amino Acids/metabolism , Reactive Oxygen Species/metabolism , Large Neutral Amino Acid-Transporter 1/metabolism , Large Neutral Amino Acid-Transporter 1/genetics , NF-E2-Related Factor 2/metabolism , NF-E2-Related Factor 2/genetics , Spheroids, Cellular/metabolism , Spheroids, Cellular/drug effects , Gene SilencingABSTRACT
Growing evidence showed the capacity of (poly)phenols to exert a protective role on intestinal health. Nevertheless, the existing findings are still heterogeneous and the underlying mechanisms remain unclear. This study investigated the potential benefits of a red raspberry (Rubus idaeus) powder on the integrity of the intestinal barrier, focusing on its ability to mitigate the effects of tumor necrosis factor-α (TNF-α)-induced intestinal permeability. Human colorectal adenocarcinoma cells (i.e., Caco-2 cells) were used as a model to assess the impact of red raspberry on intestinal permeability, tight junction expression, and oxidative stress. The Caco-2 cells were differentiated into polarized monolayers and treated with interferon-γ (IFN-γ) (10 ng mL-1) for 24 hours, followed by exposure to TNF-α (10 ng mL-1) in the presence or absence of red raspberry extract (1-5 mg mL-1). The integrity of the intestinal monolayer was evaluated using transepithelial electrical resistance (TEER) and fluorescein isothiocyanate-dextran (FITC-D) efflux assay. Markers of intestinal permeability (claudin-1, occludin, and zonula occludens-1 (ZO-1)) and oxidative stress (8-hydroxy-2-deoxyguanosine (8-OHdG) and protein carbonyl) were assessed using ELISA kits. Treatment with red raspberry resulted in a significant counteraction of TEER value loss (41%; p < 0.01) and a notable reduction in the efflux of FITC-D (-2.5 times; p < 0.01). Additionally, red raspberry attenuated the levels of 8-OHdG (-48.8%; p < 0.01), mitigating the detrimental effects induced by TNF-α. Moreover, red raspberry positively influenced the expression of the integral membrane protein claudin-1 (+18%; p < 0.01), an essential component of tight junctions. These findings contribute to the growing understanding of the beneficial effects of red raspberry in the context of the intestinal barrier. The effect of red raspberry against TNF-α-induced intestinal permeability observed in our in vitro model suggests, for the first time, its potential as a dietary strategy to promote gastrointestinal health.
Subject(s)
Intestinal Mucosa , Oxidative Stress , Permeability , Plant Extracts , Rubus , Tight Junctions , Tumor Necrosis Factor-alpha , Humans , Rubus/chemistry , Caco-2 Cells , Oxidative Stress/drug effects , Tumor Necrosis Factor-alpha/metabolism , Intestinal Mucosa/metabolism , Intestinal Mucosa/drug effects , Plant Extracts/pharmacology , Permeability/drug effects , Tight Junctions/drug effects , Tight Junctions/metabolism , Occludin/metabolism , Occludin/genetics , Claudin-1/metabolism , Claudin-1/genetics , Zonula Occludens-1 Protein/metabolism , Zonula Occludens-1 Protein/genetics , Interferon-gamma/metabolism , Fruit/chemistryABSTRACT
Microplastics, which are tiny plastic particles less than 5 mm in diameter, are widely present in the environment, have become a serious threat to aquatic life and human health, potentially causing ecosystem disorders and health problems. The present study aimed to investigate the effects of microplastics, specifically microplastics-polystyrene (MPs-PS), on the structural integrity, gene expression related to tight junctions, and gut microbiota in mice. A total of 24 Kunming mice aged 30 days were randomly assigned into four groups: control male (CM), control female (CF), PS-exposed male (PSM), and PS-exposed female (PSF)(n = 6). There were significant differences in villus height, width, intestinal surface area, and villus height to crypt depth ratio (V/C) between the PS group and the control group(C) (p <0.05). Gene expression analysis demonstrated the downregulation of Claudin-1, Claudin-2, Claudin-15, and Occludin, in both duodenum and jejunum of the PS group (p < 0.05). Analysis of microbial species using 16S rRNA sequencing indicated decreased diversity in the PSF group, as well as reduced diversity in the PSM group at various taxonomic levels. Beta diversity analysis showed a significant difference in gut microbiota distribution between the PS-exposed and C groups (R2 = 0.113, p<0.01), with this difference being more pronounced among females exposed to MPs-PS. KEGG analysis revealed enrichment of differential microbiota mainly involved in seven signaling pathways, such as nucleotide metabolism(p<0.05). The relative abundance ratio of transcriptional pathways was significantly increased for the PSF group (p<0.01), while excretory system pathways were for PSM group(p<0.05). Overall findings suggest that MPs-PS exhibit a notable sex-dependent impact on mouse gut microbiota, with a stronger effect observed among females; reduced expression of tight junction genes may be associated with dysbiosis, particularly elevated levels of Prevotellaceae.
Subject(s)
Gastrointestinal Microbiome , Microplastics , Polystyrenes , Tight Junctions , Animals , Gastrointestinal Microbiome/drug effects , Microplastics/toxicity , Polystyrenes/toxicity , Mice , Male , Female , Tight Junctions/drug effects , Tight Junctions/metabolism , RNA, Ribosomal, 16S/genetics , Intestinal Mucosa/drug effects , Intestinal Mucosa/metabolism , Intestinal Mucosa/microbiology , Occludin/metabolism , Occludin/genetics , Claudins/genetics , Claudins/metabolism , Claudin-1/genetics , Claudin-1/metabolism , Tight Junction Proteins/metabolism , Tight Junction Proteins/geneticsABSTRACT
Bronchopulmonary dysplasia (BPD) remains a significant challenge in neonatal care, the pathogenesis of which potentially involves altered lipid metabolism. Given the critical role of lipids in lung development and the injury response, we hypothesized that specific lipid species could serve as therapeutic agents in BPD. This study aimed to investigate the role of the lipid Phosphatidylcholine (PC) (16:0/14:0) in modulating BPD pathology and to elucidate its underlying mechanisms of action. Our approach integrated in vitro and in vivo methodologies to assess the effects of PC (16:0/14:0) on the histopathology, cellular proliferation, apoptosis, and molecular markers in lung tissue. In a hyperoxia-induced BPD rat model, we observed a reduction in alveolar number and an enlargement in alveolar size, which were ameliorated by PC (16:0/14:0) treatment. Correspondingly, in BPD cell models, PC (16:0/14:0) intervention led to increased cell viability, enhanced proliferation, reduced apoptosis, and elevated surfactant protein C (SPC) expression. RNA sequencing revealed significant gene expression differences between BPD and PC (16:0/14:0) treated groups, with a particular focus on Cldn1 (encoding claudin 1), which was significantly enriched in our analysis. Our findings suggest that PC (16:0/14:0) might protect against hyperoxia-induced alveolar type II cell damage by upregulating CLDN1 expression, potentially serving as a novel therapeutic target for BPD. This study not only advances our understanding of the role of lipids in BPD pathogenesis, but also highlights the significance of PC (16:0/14:0) in the prevention and treatment of BPD, offering new avenues for future research and therapeutic development.
Subject(s)
Alveolar Epithelial Cells , Bronchopulmonary Dysplasia , Claudin-1 , Hyperoxia , Phosphatidylcholines , Up-Regulation , Animals , Bronchopulmonary Dysplasia/metabolism , Bronchopulmonary Dysplasia/pathology , Bronchopulmonary Dysplasia/etiology , Hyperoxia/metabolism , Hyperoxia/complications , Hyperoxia/pathology , Rats , Claudin-1/metabolism , Claudin-1/genetics , Phosphatidylcholines/metabolism , Alveolar Epithelial Cells/metabolism , Alveolar Epithelial Cells/pathology , Rats, Sprague-Dawley , Apoptosis , Cell Proliferation , Humans , Pulmonary Alveoli/pathology , Pulmonary Alveoli/metabolism , Animals, Newborn , Disease Models, AnimalABSTRACT
OBJECTIVES: To investigate the effect of Peitu Yimu(strengthening spleen and soothing liver) acupuncture on intestinal mucosal barrier function and corticotropin-releasing factor (CRF)/CRF receptor 1 (CRFR1) pathway in rats with diarrhea-predominant irritable bowel syndrome (IBS-D), so as to explore its underlying mechanism in alleviating IBS-D. METHODS: Forty female SD rats were randomly divided into blank, model, electroacupuncture (EA), and agonist groups, with 10 rats in each group. Except for the blank group, rats in the other groups were given folium sennae infusion by gavage combined with chronic unpredictable mild stress to establish IBS-D model. Rats in the EA group received acupuncture at "Tianshu"(ST25) and EA at "Zusanli"(ST36) and "Taichong"(LR3) (2 Hz/15 Hz) on one side for 20 min, with the side chosen alternately every other day, for 14 days after modeling. Rats in the agonist group received acupuncture 30 min after intravenous injection of CRFR1 agonist urocortin, with the same manipulation method and time as the EA group. Before and after intervention, visceral pain threshold and stool Bristol scores were measured. Elevated plus maze test and open field test were used to detect anxiety and depression like behavior of rats. ELISA was used to detect the contents of CRF and CRFR1 in rats serum. Immunohistochemistry was used to detect the positive expressions of CRF, CRFR1, zonula occludens protein 1(ZO-1), occlusal protein(Occludin), and closure protein 1 (Claudin-1) in colon tissue. RESULTS: Compared with the blank group, the visceral pain threshold, open arm time percentage (OT%), total distance of movement in the open field test, and positive expression of ZO-1, Occludin, and Claudin-1 in colon were decreased (P<0.01, P<0.05), while Bristol stool scores, serum CRF and CRFR1 contents, and positive expressions of CRF and CRFR1 in colon were increased (P<0.01) in the model group. After intervention and compared with the model group, the visceral pain threshold, OT%, total distance of movement in the open field test, and positive expressions of ZO-1, Occludin, and Claudin-1 in colon were increased (P<0.05, P<0.01), while Bristol stool scores, serum CRF and CRFR1 contents, and positive expressions of CRF and CRFR1 in colon were decreased (P<0.01) in the EA groupï¼the Bristol stool scores, serum CRF content, and CRF positive expression in colon were significantly decreased in the agonist group (P<0.01). CONCLUSIONS: Peitu Yimu acupuncture can significantly improve visceral hypersensitivity and anxiety-depression state in IBS-D rats. Its mechanism may be related to the inhibition of CRF/CRFR1 pathway and restoration of intestinal tight junction protein expressions.
Subject(s)
Acupuncture Therapy , Diarrhea , Intestinal Mucosa , Irritable Bowel Syndrome , Receptors, Corticotropin-Releasing Hormone , Animals , Female , Humans , Rats , Acupuncture Points , Claudin-1/metabolism , Claudin-1/genetics , Corticotropin-Releasing Hormone/metabolism , Corticotropin-Releasing Hormone/genetics , Diarrhea/therapy , Diarrhea/metabolism , Diarrhea/genetics , Disease Models, Animal , Intestinal Mucosa/metabolism , Irritable Bowel Syndrome/therapy , Irritable Bowel Syndrome/metabolism , Irritable Bowel Syndrome/genetics , Rats, Sprague-Dawley , Receptors, Corticotropin-Releasing Hormone/metabolism , Receptors, Corticotropin-Releasing Hormone/genetics , Zonula Occludens-1 Protein/metabolism , Zonula Occludens-1 Protein/geneticsABSTRACT
The transmembrane protein claudin-1 is critical for formation of the epidermal barrier structure called tight junctions (TJ) and has been shown to be important in multiple disease states. These include neonatal ichthyosis and sclerosing cholangitis syndrome, atopic dermatitis and various viral infections. To develop a model to investigate the role of claudin-1 in different disease settings, we used CRISPR/Cas9 to generate human immortalized keratinocyte (KC) lines lacking claudin-1 (CLDN1 KO). We then determined whether loss of claudin-1 expression affects epidermal barrier formation/function and KC differentiation/stratification. The absence of claudin-1 resulted in significantly reduced barrier function in both monolayer and organotypic cultures. CLDN1 KO cells demonstrated decreases in gene transcripts encoding the barrier protein filaggrin and the differentiation marker cytokeratin-10. Marked morphological differences were also observed in CLDN1 KO organotypic cultures including diminished stratification and reduced formation of the stratum granulosum. We also detected increased proliferative KC in the basale layer of CLDN1 KO organotypic cultures. These results further support the role of claudin-1 in epidermal barrier and suggest an additional role of this protein in appropriate stratification of the epidermis.
Subject(s)
Cell Differentiation , Claudin-1 , Epidermis , Filaggrin Proteins , Keratinocytes , Keratinocytes/metabolism , Claudin-1/metabolism , Claudin-1/genetics , Humans , Filaggrin Proteins/metabolism , Epidermis/metabolism , Epidermis/pathology , Skin Diseases/genetics , Skin Diseases/metabolism , Tight Junctions/metabolism , Keratin-10/metabolism , Keratin-10/genetics , Gene Knockout Techniques , Cell Proliferation , CRISPR-Cas SystemsABSTRACT
Human breast milk promotes maturation of the infant gastrointestinal barrier, including the promotion of mucus production. In the quest to produce next generation infant milk formula (IMF), we have produced IMF by membrane filtration (MEM-IMF). With a higher quantity of native whey protein, MEM-IMF more closely mimics human breast milk than IMF produced using conventional heat treatment (HT-IMF). After a 4-week dietary intervention in young pigs, animals fed a MEM-IMF diet had a higher number of goblet cells, acidic mucus and mucin-2 in the jejunum compared to pigs fed HT-IMF (P < 0.05). In the duodenum, MEM-IMF fed pigs had increased trypsin activity in the gut lumen, increased mRNA transcript levels of claudin 1 in the mucosal scrapings and increased lactase activity in brush border membrane vesicles than those pigs fed HT-IMF (P < 0.05). In conclusion, MEM-IMF is superior to HT-IMF in the promotion of mucus production in the young gut.
Subject(s)
Filtration , Infant Formula , Mucus , Animals , Infant Formula/chemistry , Mucus/metabolism , Swine , Whey Proteins/metabolism , Intestine, Small/metabolism , Trypsin/metabolism , Humans , Goblet Cells/metabolism , Claudin-1/metabolism , Claudin-1/genetics , Lactase/metabolism , Lactase/genetics , Mucin-2/metabolism , Mucin-2/genetics , Intestinal Mucosa/metabolism , Duodenum/metabolism , Jejunum/metabolism , RNA, Messenger/metabolism , RNA, Messenger/genetics , Milk Proteins/metabolism , Milk Proteins/analysisABSTRACT
OBJECTIVE: To investigate the role of the EGFR/MAPK signaling pathway in PM2.5 in promoting the MUC5AC hypersecretion in airway and exacerbating airway inflammation. METHODS: By establishing rat model exposed to PM2.5, overexpressing miR-133b-5p and Claudin1, the content of IL-1 and TNF-α in serum were detected by ELISA, the pathology of lung tissue was observed by HE staining, p-EGFR, Claudin1, MUC5AC, p-ERK1/2, p-JNK, p-p38 in rats lung tissue were detected by immunohistochemical and WB, the expression level of miR-133b-5p in rats lung tissue were detected by qPCR. RESULTS: After the rats were exposed to PM2.5, the content of inflammatory factors in serum increased, the inflammatory damage of lung tissues occurred, the expression of miR-133b-5p was down-regulated, and the expression of MUC5AC protein was increased. The ELISA test results showed that the expression of IL-1 and TNF-α in the model group was significantly higher than that in the control group, and the model +AG1478 treatment group was down-regulated compared with the model group, and the +miR-133b-5p agomir treatment group was significantly lower than that in the control group, the model group and the model +Claudin1 overexpression blank load group, and the model +Claudin1 overexpression group was down-regulated compared with the model group and the model +Claudin1 overexpression blank load group. The protein detection results showed that the expression of p-EGFR, MUC5AC, p-ERK1/2, p-JNK and p-p38 proteins was increased and the expression of Claudin1 protein was decreased in the model group compared with the control group. In the model + AG1478 treatment group, model + miR-133b-5p agomir treatment group and model + Claudin1 overexpression group, compared with the model group, p-EGFR, MUC5AC, p-ERK1/2, p-JNK, p-p38 protein expression was down-regulated, and Claudin1 protein expression was up-regulated. CONCLUSIONS: PM2.5 inhibited the expression of miR-133b-5p to activate the EGFR/MAPK signal pathway, induce the hypersecretion of MUC5AC, thus aggravating PM2.5-related airway inflammation in rats.
Subject(s)
Claudin-1 , ErbB Receptors , MicroRNAs , Mucin 5AC , Particulate Matter , Animals , MicroRNAs/metabolism , MicroRNAs/genetics , Mucin 5AC/metabolism , Mucin 5AC/genetics , Rats , ErbB Receptors/metabolism , ErbB Receptors/genetics , Particulate Matter/toxicity , Claudin-1/metabolism , Claudin-1/genetics , Male , Rats, Sprague-Dawley , Lung/metabolism , Lung/pathology , Mucus/metabolism , Signal Transduction , Tumor Necrosis Factor-alpha/metabolism , MAP Kinase Signaling SystemABSTRACT
The time for diabetic nephropathy (DN) to progress from mild to severe is long. Thus, methods to continuously repress DN are required to exert long-lasting effects mediated through epigenetic regulation. In this study, we demonstrated the ability of nicotinamide adenine dinucleotide (NAD) and its metabolites to reduce albuminuria through Sirt1- or Nampt-dependent epigenetic regulation. We previously reported that proximal tubular Sirt1 was lowered before glomerular Sirt1. Repressed glomerular Sirt1 was found to epigenetically elevate Claudin-1. In addition, we reported that proximal tubular Nampt deficiency epigenetically augmented TIMP-1 levels in Sirt6-mediated pathways, leading to type-IV collagen deposition and diabetic fibrosis. Altogether, we propose that the Sirt1/Claudin-1 axis may be crucial in the onset of albuminuria at the early stages of DN and that the Nampt/Sirt6/TIMP-1 axis promotes diabetic fibrosis in the middle to late stages of DN. Finally, administration of NMN, an NAD precursor, epigenetically potentiates the regression of the onset of DN to maintain Sirt1 and repress Claudin-1 in podocytes, suggesting the potential use of NAD metabolites as epigenetic medications for DN.
Subject(s)
Albuminuria , Claudin-1 , Diabetic Nephropathies , Epigenesis, Genetic , NAD , Sirtuin 1 , Tissue Inhibitor of Metalloproteinase-1 , Animals , Humans , Albuminuria/genetics , Claudin-1/genetics , Claudin-1/metabolism , Cytokines/metabolism , Diabetic Nephropathies/genetics , Diabetic Nephropathies/metabolism , Fibrosis , Kidney Tubules, Proximal/metabolism , Kidney Tubules, Proximal/drug effects , Mice, Inbred C57BL , Mice, Knockout , NAD/metabolism , Nicotinamide Mononucleotide/pharmacology , Nicotinamide Phosphoribosyltransferase/genetics , Nicotinamide Phosphoribosyltransferase/metabolism , Podocytes/metabolism , Sirtuin 1/metabolism , Sirtuin 1/genetics , Sirtuins/genetics , Sirtuins/metabolism , Tissue Inhibitor of Metalloproteinase-1/metabolism , Tissue Inhibitor of Metalloproteinase-1/geneticsABSTRACT
Different levels of EspP2 expression are seen in strains of Glaesserella parasuis with high and low pathogenicity. As a potential virulence factor for G. parasuis, the pathogenic mechanism of EspP2 in infection of host cells is not clear. To begin to elucidate the effect of EspP2 on virulence, we used G. parasuis SC1401 in its wild-type form and SC1401, which was made EspP2-deficient. We demonstrated that EspP2 causes up-regulation of claudin-1 and occludin expression, thereby promoting the adhesion of G. parasuis to host cells; EspP2-deficiency resulted in significantly reduced adhesion of G. parasuis to cells. Transcriptome sequencing analysis of EspP2-treated PK15 cells revealed that the Rap1 signaling pathway is stimulated by EspP2. Blocking this pathway diminished occludin expression and adhesion. These results indicated that EspP2 regulates the adhesion of Glaesserella parasuis via Rap1 signaling pathway.
Subject(s)
Haemophilus parasuis , Signal Transduction , rap1 GTP-Binding Proteins , Animals , Haemophilus parasuis/pathogenicity , Haemophilus parasuis/genetics , rap1 GTP-Binding Proteins/metabolism , rap1 GTP-Binding Proteins/genetics , Bacterial Adhesion , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Occludin/metabolism , Occludin/genetics , Claudin-1/metabolism , Claudin-1/genetics , Cell Line , SwineABSTRACT
BACKGROUND: Early weaning is prone to damage intestinal barrier function, resulting in diarrhea, whereas rutin, as a natural flavonoid with multiple biological functions, shows potential in piglets. Therefore, the effects of dietary rutin on growth, antidiarrheal, barrier function, antioxidant status and cecal microbiota of weaned piglets were investigated with the control group (CON) (basal diet) and Rutin (basal diet+500 mg kg-1 rutin) groups fed for 14 days. RESULTS: The results showed that dietary 500 mg kg-1 rutin significantly decreased diarrhea index, serum diamine oxidase activity and total aerobic bacterial population in mesenteric lymph nodes, whereas it significantly increased the gain-to-feed ratio (G:F) and serum growth hormone content, jejunal villus height and villus height to crypt depth ratio, and also enhanced jejunal claudin-1 and zonula occludens-1 mRNA and protein expression. Meanwhile, dietary rutin significantly decreased inflammation-associated mRNA expression, malondialdehyde (MDA) content, swollen mitochondrial number and mitochondrial area in the jejunum, whereas it increased the total superoxide dismutase (T-SOD) and glutathione peroxidase activities and activated the Nrf2 signaling pathway. Moreover, dietary rutin significantly increased Firmicutes abundance and decreased Campylobacterota abundance, which were closely associated with the decreased diarrhea index and MDA content or increased Claudin-1 expression and T-SOD activity. CONCLUSION: Dietary 500 mg kg-1 rutin increased G:F by improving intestinal morphology, and alleviated diarrhea by enhancing intestinal barrier, which might be associated with the enhanced antioxidant capacity via activating the Nrf2/Keap1 signaling pathway and the improved cecal microbial composition in weaned piglets. © 2024 Society of Chemical Industry.
Subject(s)
Antidiarrheals , Antioxidants , Cecum , Diarrhea , Gastrointestinal Microbiome , Intestinal Mucosa , Rutin , Weaning , Animals , Swine/metabolism , Swine/growth & development , Gastrointestinal Microbiome/drug effects , Antioxidants/metabolism , Cecum/microbiology , Cecum/metabolism , Intestinal Mucosa/metabolism , Diarrhea/microbiology , Diarrhea/diet therapy , Diarrhea/veterinary , Antidiarrheals/administration & dosage , Bacteria/classification , Bacteria/isolation & purification , Bacteria/genetics , Bacteria/metabolism , Swine Diseases/microbiology , Swine Diseases/metabolism , Claudin-1/metabolism , Claudin-1/genetics , Animal Feed/analysis , Jejunum/metabolism , Jejunum/microbiology , Dietary Supplements/analysis , Male , Superoxide Dismutase/metabolism , Malondialdehyde/metabolism , Intestinal Barrier FunctionABSTRACT
Claudins (CLDN1-CLDN24) are a family of tight junction proteins whose dysregulation has been implicated in tumorigeneses of many cancer types. In colorectal cancer (CRC), CLDN1, CLDN2, CLDN4, and CLDN18 have been shown to either be upregulated or aberrantly expressed. In the normal colon, CLDN1 and CLDN3-7 are expressed. Although a few claudins, such as CLDN6 and CLDN7, are expressed in CRC their levels are reduced compared to the normal colon. The present review outlines the expression profiles of claudin proteins in CRC and those that are potential biomarkers for prognostication.
Subject(s)
Claudins , Colorectal Neoplasms , Humans , Claudin-1/genetics , Claudins/genetics , Tight Junction Proteins , Colorectal Neoplasms/geneticsABSTRACT
The global increase in antibiotic consumption is related to increased adverse effects, such as antibiotic-associated diarrhea (AAD). This study investigated the chemical properties of Zingiber officinale Rosc (ZO) extract and its ameliorative effects using a lincomycin-induced AAD mouse model. Intestinal tissues were evaluated for the expression of lysozyme, claudin-1, and α-defensin-1, which are associated with intestinal homeostasis. The cecum was analyzed to assess the concentration of short-chain fatty acids (SCFAs). The chemical properties analysis of ZO extracts revealed the levels of total neutral sugars, acidic sugars, proteins, and polyphenols to be 86.4%, 8.8%, 4.0%, and 0.8%, respectively. Furthermore, the monosaccharide composition of ZO was determined to include glucose (97.3%) and galactose (2.7%). ZO extract administration ameliorated the impact of AAD and associated weight loss, and water intake also returned to normal. Moreover, treatment with ZO extract restored the expression levels of lysozyme, α-defensin-1, and claudin-1 to normal levels. The decreased SCFA levels due to induced AAD showed a return to normal levels. The results indicate that ZO extract improved AAD, strengthened the intestinal barrier, and normalized SCFA levels, showing that ZO extract possesses intestinal-function strengthening effects.
Subject(s)
Zingiber officinale , alpha-Defensins , Mice , Animals , Muramidase , Claudin-1/genetics , Diarrhea/chemically induced , Diarrhea/drug therapy , Anti-Bacterial Agents/adverse effects , SugarsABSTRACT
Pancreatic cancer (PC) is one of the most malignant and deadly tumors of digestive system with complex etiology and pathogenesis. Dysregulations of oncogenes and tumor suppressors due to epigenetic modifications causally affect tumorogenesis; however the key tumor suppressors and their regulations in PC are only partially defined. In this study, we found that Claudin-1 (encoded by CLDN1 gene) was significantly suppressed in PC that correlated with a poor clinical prognosis. Claudin-1 knockdown enhanced PC cell proliferation, migration, and stemness. Pancreatic specific Cldn1 knockout in KPC (LSLKrasG12D/Pdx1-Cre/Trp53R172H+) and KC (LSLKrasG12D/Pdx1-Cre) mice reduced mouse survival, promoted acinar-to-ductal metaplasia (ADM) process, and accelerated the development of pancreatic intraepithelial neoplasia (PanIN) and PC. Further investigation revealed that Claudin-1 suppression was mainly caused by aberrant DNA methylatransferase 1 (DNMT1) and DNMT3A elevations and the resultant CLDN1 promoter hypermethylation, as a DNMT specific inhibitor SGI-1027 effectively reversed the Claudin-1 suppression and inhibited PC progression both in vitro and in vivo in a Claudin-1 preservation-dependent manner. Together, our data suggest that Claudin-1 functions as a tumor suppressor in PC and its epigenetic suppression due to DNMT aberrations is a crucial event that promotes PC development and progression.
Subject(s)
Carcinoma, Pancreatic Ductal , Pancreatic Neoplasms , Animals , Mice , Carcinoma, Pancreatic Ductal/pathology , Claudin-1/genetics , Disease Progression , Pancreas/pathology , Pancreatic Neoplasms/pathologyABSTRACT
The tight junction (TJ) in epithelial cells is formed by integral membrane proteins and cytoplasmic scaffolding proteins. The former contains the claudin family proteins with four transmembrane segments, while the latter includes Par3, a PDZ domain-containing adaptor that organizes TJ formation. Here we show the single membrane-spanning protein TMEM25 localizes to TJs in epithelial cells and binds to Par3 via a PDZ-mediated interaction with its C-terminal cytoplasmic tail. TJ development during epithelial cell polarization is accelerated by depletion of TMEM25, and delayed by overexpression of TMEM25 but not by that of a C-terminally deleted protein, indicating a regulatory role of TMEM25. TMEM25 associates via its N-terminal extracellular domain with claudin-1 and claudin-2 to suppress their cis- and trans-oligomerizations, both of which participate in TJ strand formation. Furthermore, Par3 attenuates TMEM25-claudin association via binding to TMEM25, implying its ability to affect claudin oligomerization. Thus, the TJ protein TMEM25 appears to negatively regulate claudin assembly in TJ formation, which regulation is modulated by its interaction with Par3.
Subject(s)
Claudins , Tight Junctions , Tight Junctions/metabolism , Claudins/genetics , Claudins/metabolism , Carrier Proteins/metabolism , Epithelial Cells , Claudin-1/genetics , Claudin-1/metabolismABSTRACT
Small-cell lung cancer (SCLC), which accounts for about 15 % of all lung cancers, progresses more rapidly than other histologic types and is rarely detected at an operable early stage. Therefore, chemotherapy, radiation therapy, or their combination are the primary treatments for this type of lung cancer. However, the tendency to acquire resistance to anticancer drugs is a severe problem. Recently, we found that an intercellular adhesion molecule, claudin (CLDN) 1, known to be involved in the migration and invasion of lung cancer cells, is involved in the acquisition of anticancer drug resistance. In the present study, we investigated the effect of CLDN1 on the anticancer-drug sensitivity of SCLC SBC-3 cells. Since epithelial-mesenchymal transition (EMT), which is involved in cancer cell migration and invasion, is well known for its involvement in anticancer-drug sensitivity via inhibition of apoptosis, we also examined EMT involvement in decreased anticancer-drug sensitivity by CLDN1. Sensitivity to doxorubicin (DOX) in SBC-3 cells was significantly decreased by CLDN1 overexpression. CLDN1 overexpression resulted in increased TGF-ß1 levels, enhanced EMT induction, and increased migratory potency of SBC-3 cells. The decreased sensitivity of SBC-3 cells to anticancer drugs upon TGF-ß1 treatment suggested that activation of the TGF-ß1/EMT signaling pathway by CLDN1 causes the decreased sensitivity to anticancer drugs and increased migratory potency. Furthermore, treatments with antiallergic agents tranilast and zoledronic acid, known EMT inhibitors, significantly mitigated the decreased sensitivity of CLDN1-overexpressing SBC-3 cells to DOX. These results suggest that EMT inhibitors might effectively overcome reduced sensitivity to anticancer drugs in CLDN1-overexpressing SCLC cells.
Subject(s)
Antineoplastic Agents , Lung Neoplasms , Small Cell Lung Carcinoma , Humans , Lung Neoplasms/pathology , Small Cell Lung Carcinoma/drug therapy , Small Cell Lung Carcinoma/genetics , Claudin-1/genetics , Transforming Growth Factor beta1/metabolism , Cell Line, Tumor , Doxorubicin/pharmacology , Doxorubicin/therapeutic use , Signal Transduction , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Epithelial-Mesenchymal TransitionABSTRACT
Neonatal ichthyosis and sclerosing cholangitis syndrome (NISCH), also known as ichthyosis, leukocyte vacuoles, alopecia, and sclerosing cholangitis (ILVASC), is an extremely rare disease of autosomal recessive inheritance, resulting from loss of function of the tight junction protein claudin-1. Its clinical presentation is highly variable, and is characterized by liver and ectodermal involvement. Although most ILVASC cases described to date were attributed to homozygous truncating variants in CLDN1, a single missense variant CLDN1 p.Arg81His, associated with isolated skin ichthyosis phenotype, has been recently reported in a family of Moroccan Jewish descent. We now describe seven patients with ILVASC, originating from four non consanguineous families of North African Jewish ancestry (including one previously reported family), harboring CLDN1 p.Arg81His variant, and broaden the phenotypic spectrum attributed to this variant to include teeth, hair, and liver/bile duct involvement, characteristic of ILVASC. Furthermore, we provide additional evidence for pathogenicity of the CLDN1 p.Arg81His variant by transmission electron microscopy of the affected skin, revealing distorted tight junction architecture, and show through haplotype analysis in the vicinity of the CLDN1 gene, that this variant represents a founder variant in Jews of Moroccan descent with an estimated carrier frequency of 1:220.
Subject(s)
Cholangitis, Sclerosing , Ichthyosis , Leukocyte Disorders , Humans , Infant, Newborn , Alopecia/genetics , Cholangitis, Sclerosing/genetics , Claudin-1/genetics , Ichthyosis/genetics , Jews/genetics , Leukocyte Disorders/complications , Leukocyte Disorders/genetics , SyndromeABSTRACT
SCOPE: Torreya grandis kernel has traditionally been used to remove intestinal parasites and increases intestinal motility. However, the effect of Torreya grandis kernel oil (TKO) on constipation has not yet been investigated. Therefore, mouse model is used to investigate the effect of TKO on slow transit constipation (STC) and its possible mechanism. METHODS AND RESULTS: The effects of TKO on intestinal motility of STC mice are evaluated by fecal weight, fecal water content, colon length, defecation test, and intestinal propulsion test. The mechanism of TKO alleviating STC is explored by detecting biochemical analysis, histological analysis, western blot, qRT-PCR, immunohistochemistry, and gut microbiota analysis. The results reveal that TKO effectively promotes defecation and intestinal motility, increases the level of endothelin-1, and restores the histopathological morphology of the colon under LOP pretreatment. The expression levels of occludin, claudin-1, and zonula occludens-1 (ZO-1) mRNA and protein are up-regulated in mice receiving TKO treatment. The colonic 5-hydroxytryptamine 3R/4R (5-HT3R/5-HT4R) expressions are also increased by TKO supplementation. Additionally, TKO rescues LOP-caused disorders of the gut microbiota. CONCLUSION: Consumption of TKO is beneficial to STC recovery, and it can alleviate LOP-induced STC by up-regulating the colonic expressions of Occludin/Claudin-1/ZO-1 and 5-HT3R/5-HT4R.