OBJECTIVE: To investigate the effect of Yinlai Decoction (YD) on the microstructure of colon, and activity of D-lactic acid (DLA) and diamine oxidase (DAO) in serum of pneumonia mice model fed with high-calorie and high-protein diet (HCD). METHODS: Sixty male Kunming mice were randomly divided into 6 groups by the random number table method: normal control, pneumonia, HCD, HCD with pneumonia (HCD-P), YD (229.2 mg/mL), and dexamethasone (15.63 mg/mL) groups, with 10 in each group. HCD mice were fed with 52% milk solution by gavage. Pneumonia mice was modeled with lipopolysaccharide inhalation and was fed by gavage with either the corresponding therapeutic drugs or saline water, twice daily, for 3 days. After hematoxylin-eosin staining, the changes in the colon structure were observed under light microscopy and transmission electron microscope, respectively. Enzyme-linked immunosorbent assay was used to detect the protein levels of DLA and DAO in the serum of mice. RESULTS: The colonic mucosal structure and ultrastructure of mice in the normal control group were clear and intact. The colonic mucosal goblet cells in the pneumonia group tended to increase, and the size of the microvilli varied. In the HCD-P group, the mucosal goblet cells showed a marked increase in size with increased secretory activity. Loose mucosal epithelial connections were also observed, as shown by widened intercellular gaps with short sparse microvilli. These pathological changes of intestinal mucosa were significantly reduced in mouse models with YD treatment, while there was no significant improvement after dexamethasone treatment. The serum DLA level was significantly higher in the pneumonia, HCD, and HCD-P groups as compared with the normal control group (P<0.05). Serum DLA was significantly lower in the YD group than HCD-P group (P<0.05). Moreover, serum DLA level significantly increased in the dexamethasone group as compared with the YD group (P<0.01). There was no statistical significance in the serum level of DAO among groups (P>0.05). CONCLUSIONS YD can protect function of intestinal mucosa by improving the tissue morphology of intestinal mucosa and maintaining integrity of cell connections and microvilli structure, thereby reducing permeability of intestinal mucosa to regulate the serum levels of DLA in mice.
Mice ; Male ; Animals ; Lactic Acid/pharmacology* ; Intestinal Mucosa ; Colon/pathology* ; Dexamethasone/pharmacology* ; Diet, High-Protein ; Pneumonia/pathology*

Objective To investigate the effect of intestinal mucosal Toll-like receptor 4/nuclear factor κB (TLR4/NF-κB) signaling pathway on renal damage in pseudo-sterile IgA nephropathy (IgAN) mice. Methods C57BL/6 mice were randomly divided into experimental group (pseudosterile mouse model group), control group (IgAN mouse model group), pseudosterile mouse blank group, and normal mouse blank group. Pseudosterile mice were established by intragastric administration of quadruple antibiotics once a day for 14 days. The pseudosterile IgAN mouse model was set up by combination of oral bovine serum albumin (BSA) administration and staphylococcal enterotoxin B (SEB) injection. The pathological changes of renal tissue were observed by immunofluorescence staining and PAS staining, and the intestinal mucosa barrier damage indicators lipopolysaccharide(LPS), soluble intercellular adhesion molecule 1(sICAM-1) and D-lactate(D-LAC) were analyzed by ELISA. Biochemical analysis was used to test 24 hour urine protein, serum creatinine and blood urea nitrogen. The mRNA and protein levels of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and nuclear factor κB (NF-κB) were detected by reverse transcription PCR and Western blot analysis. Results The kidney damage of pseudosterile IgAN mice was more severe than that of IgAN mice, and the expressions of intestinal mucosal barrier damage markers (LPS, sICAM-1 and D-LAC) were significantly increased in pseudosterile IgAN mice. In addition, the expressions of TLR4, MyD88, and NF-κB level were all up-regulated in the intestinal tissues of IgAN pseudosterile mice. Conclusion Intestinal flora disturbance leads to intestinal mucosal barrier damage and induces activation of TLR4 signaling pathway to mediate renal injury in IgAN.
Animals ; Mice ; Mice, Inbred C57BL ; Glomerulonephritis, IGA ; NF-kappa B ; Toll-Like Receptor 4/genetics* ; Lipopolysaccharides ; Myeloid Differentiation Factor 88/genetics* ; Kidney ; Intestinal Mucosa ; Infertility ; Disease Models, Animal

The pathogenesis of inflammatory bowel disease (IBD) is not fully elucidated. However, it has been considered that inflammatory macrophages may be involved in the imbalance of the intestinal mucosal immunity to regulate several signaling pathways, leading to IBD progression. The ratio of M1 to M2 subtypes of activated macrophages tends to increase in the inflamed intestinal section. There are challenges in the diagnosis and treatment of IBD, such as unsatisfactory specificity of imaging findings, low drug accumulation in the intestinal lesions, unstable therapeutic efficacy, and drug-related systemic toxicity. Recently developed nanoparticles may provide a new approach for the diagnosis and treatment of IBD. Nanoparticles targeted to macrophages can be used as contrast agents to improve the imaging quality or used as a drug delivery vector to increase the therapeutic efficiency of IBD. This article reviews the research progress on macrophage-targeting nanoparticles for the diagnosis and treatment of IBD to provide a reference for further research and clinical application.
Humans ; Inflammatory Bowel Diseases/therapy* ; Intestines ; Macrophages/metabolism* ; Intestinal Mucosa/pathology* ; Nanoparticles

This study aimed to investigate the recovery effect of Zuogui Jiangtang Qinggan Prescription on intestinal flora homeostasis control and intestinal mucosal barrier in type 2 diabetes mellitus(T2DM) with nonalcoholic fatty liver disease(NAFLD) induced by a high-fat diet. NAFLD was established in MKR transgenic mice(T2DM mice) by a high-fat diet(HFD), and subsequently treated for 8 weeks with Zuogui Jiangtang Qinggan Prescription(7.5, 15 g·kg~(-1)) and metformin(0.067 g·kg~(-1)). Triglyceride and liver function were assessed using serum. The hematoxylin-eosin(HE) staining and Masson staining were used to stain the liver tissue, while HE staining and AB-PAS staining were used to stain the intestine tissue. 16S rRNA sequencing was utilized to track the changes in the intestinal flora of the mice in each group. Polymerase chain reaction(PCR) and immunofluorescence were used to determine the protein and mRNA expression levels of ZO-1, Occludin, and Claudin-1. The results demonstrated that Zuogui Jiangtang Qinggan Prescription increased the body mass of T2DM mice with NAFLD and decreased the hepatic index. It down-regulated the serum biomarkers of liver function and dyslipidemia such as alanine aminotransferase(ALT), aspartate transaminase(AST), and triglycerides(TG), increased insulin sensitivity, and improved glucose tolerance. According to the results of 16S rRNA sequencing, the Zuogui Jiangtang Qinggan Prescription altered the composition and abundance of the intestinal flora, increasing the relative abundances of Muribaculaceae, Lactobacillaceae, Lactobacillus, Akkermansia, and Bacteroidota and decreasing the relative abundances of Lachnospiraceae, Firmicutes, Deslfobacteria, Proteobacteria, and Desulfovibrionaceae. According to the pathological examination of the intestinal mucosa, Zuogui Jiangtang Qinggan Prescritpion increased the expression levels of the tight junction proteins ZO-1, Occludin, and Claudin-1, promoted intestinal mucosa repair, protected intestinal villi, and increased the height of intestinal mucosa villi and the number of goblet cells. By enhancing intestinal mucosal barrier repair and controlling intestinal microbiota homeostasis, Zuogui Jiangtang Qinggan Prescription reduces intestinal mucosal damage induced by T2DM and NAFLD.
Mice ; Animals ; Non-alcoholic Fatty Liver Disease/metabolism* ; Gastrointestinal Microbiome ; RNA, Ribosomal, 16S ; Diabetes Mellitus, Type 2/metabolism* ; Occludin/pharmacology* ; Claudin-1/metabolism* ; Intestinal Mucosa ; Liver ; Triglycerides/metabolism* ; Diet, High-Fat ; Homeostasis ; Mice, Inbred C57BL

Interactions between gut microbiome and host immune system are fundamental to maintaining the intestinal mucosal barrier and homeostasis. At the host-gut microbiome interface, cell wall-derived molecules from gut commensal bacteria have been reported to play a pivotal role in training and remodeling host immune responses. In this article, we review gut bacterial cell wall-derived molecules with characterized chemical structures, including peptidoglycan and lipid-related molecules that impact host health and disease processes via regulating innate and adaptive immunity. Also, we aim to discuss the structures, immune responses, and underlying mechanisms of these immunogenic molecules. Based on current advances, we propose cell wall-derived components as important sources of medicinal agents for the treatment of infection and immune diseases.
Gastrointestinal Microbiome ; Intestinal Mucosa ; Bacteria ; Immune System ; Symbiosis ; Immunity, Mucosal ; Immunity, Innate

Humans ; Goblet Cells ; Stomach Neoplasms ; Carcinoma

OBJECTIVE: To investigate the mechanism by which fibroblasts with high WNT2b expression causes intestinal mucosa barrier disruption and promote the progression of inflammatory bowel disease (IBD). METHODS: Caco-2 cells were treated with 20% fibroblast conditioned medium or co-cultured with fibroblasts highly expressing WNT2b, with the cells without treatment with the conditioned medium and cells co-cultured with wild-type fibroblasts as the control groups. The changes in barrier permeability of Caco-2 cells were assessed by measuring transmembrane resistance and Lucifer Yellow permeability. In Caco-2 cells co-cultured with WNT2b-overexpressing or control intestinal fibroblasts, nuclear entry of β-catenin was detected with immunofluorescence assay, and the expressions of tight junction proteins ZO-1 and E-cadherin were detected with Western blotting. In a C57 mouse model of dextran sulfate sodium (DSS)-induced IBD-like enteritis, the therapeutic effect of intraperitoneal injection of salinomycin (5 mg/kg, an inhibitor of WNT/β-catenin signaling pathway) was evaluated by observing the changes in intestinal inflammation and detecting the expressions of tight junction proteins. RESULTS: In the coculture system, WNT2b overexpression in the fibroblasts significantly promoted nuclear entry of β-catenin (P < 0.01) and decreased the expressions of tight junction proteins in Caco-2 cells; knockdown of FZD4 expression in Caco-2 cells obviously reversed this effect. In DSS-treated mice, salinomycin treatment significantly reduced intestinal inflammation and increased the expressions of tight junction proteins in the intestinal mucosa. CONCLUSION Intestinal fibroblasts overexpressing WNT2b causes impairment of intestinal mucosal barrier function and can be a potential target for treatment of IBD.
Humans ; Mice ; Animals ; Caco-2 Cells ; beta Catenin/metabolism* ; Culture Media, Conditioned/pharmacology* ; Tight Junctions/metabolism* ; Intestinal Mucosa ; Inflammatory Bowel Diseases ; Tight Junction Proteins/metabolism* ; Inflammation/metabolism* ; Fibroblasts/metabolism* ; Mice, Inbred C57BL ; Glycoproteins/metabolism* ; Wnt Proteins/pharmacology* ; Frizzled Receptors/metabolism*

The intestinal mucosal barrier (IMB), which consists of mechanical barrier, chemical barrier, biological barrier and immune barrier, plays an important role in the maintenance of intestinal epithelium integrity and defense against invasion of bacteria, endotoxins and foreign antigens. Impaired IMB, characterized by increased intestinal mucosal permeability (IMP) and decreased transmembrane resistance (TR), has been implicated in the pathogenesis of various digestive, urinary, circulatory, neurological and metabolic dysfunctions. Electrophysiological recording of TR in the ex vivo intestinal tissues or cultured epithelial cell monolayers, or biochemical quantification of transepithelial movement of orally-administered molecular probes or specific endogenous protein molecules has frequently been used in the evaluation of IMB. In this paper, the composition and function of IMB will be summarized, with emphasis on the evaluation methods of IMP.
Cells, Cultured ; Inosine Monophosphate/metabolism* ; Intestinal Mucosa ; Permeability

Objective: To study the mechanisms of cold exposure mediated ileum mechanical barrier injury in mice. Methods: Twenty mice were randomly divided into the control and cold exposure groups. Both the control and cold exposure groups were placed in the climate room with (24±2)℃ and 40% humidity. The mice in the cold exposure group were moved to the climate room at (4±2)℃ every day for 3 hours for three consecutive weeks. Three weeks later, the ileum tissues of mice were collected. Changes in ileum tissue structure were observed by hematoxylin-eosin staining and Masson staining. The related protein expression levels of the tight junction, inflammatory cytokines, and the NF-κB pathway were detected by Western blot. Results: Compared with the control group, the circular muscle layer of the ileum in cold exposed mice became thin, a large number of inflammatory cells infiltrated, the length of villi became short, the depth of recess was increased, and tissue fibrosis appeared. The expression levels of ideal tight junction-associated proteins in cold exposed mice were decreased significantly (P＜0.05), while the protein expression levels of IL-1β, IL-6 and phosphorescent p65 were increased significantly (P＜0.05). Conclusion: Cold exposure can damage the tight junction of the mouse ileum, destroy the integrity of the mechanical barrier and activate the NF-κB signaling pathway to promote the occurrence of the inflammatory response.
Animals ; Cytokines/metabolism* ; Ileum/metabolism* ; Intestinal Mucosa ; Mice ; NF-kappa B/metabolism* ; Tight Junctions/metabolism*

OBJECTIVE: To evaluate the protective function of Babao Dan (BBD) on 5-flurouracil (5-FU)-induced intestinal mucositis (IM) and uncover the underlying mechanism. METHODS: A total of 18 male mice were randomly divided into 3 groups by a random number table, including control, 5-FU and 5-FU combined BBD groups, 6 mice in each group. A single intraperitoneal injection of 5-FU (150 mg/kg) was performed in 5-FU and 5-FU combined BBD groups on day 0. Mice in 5-FU combined BBD group were gavaged with BBD (250 mg/kg) daily from day 1 to 6. Mice in the control group were gavaged with saline solution for 6 days. The body weight and diarrhea index of mice were recorded daily. On the 7th day, the blood from the heart of mice was collected to analyze the proportional changes of immunological cells, and the mice were subsequently euthanized by mild anesthesia with 2% pentobarbital sodium. Colorectal lengths and villus heights were measured. Intestinal-cellular apoptosis and proliferation were evaluated by Tunel assay and immunohistochemical staining of proliferating cell nuclear antigen, respectively. Immunohistochemistry and Western blot were performed to investigate the expressions of components in Wnt/β-catenin pathway (Wnt3, LRP5, β-catenin, c-Myc, LRG5 and CD44). RESULTS: BBD obviously alleviated 5-FU-induced body weight loss and diarrhea, and reversed the decrease in the number of white blood cells, including monocyte, granulocyte and lymphocyte, and platelet (P<0.01). The shortening of colon caused by 5-FU was also reversed by BBD (P<0.01). Moreover, BBD inhibited apoptosis and promoted proliferation in jejunum tissues so as to reduce the intestinal mucosal damage and improve the integrity of villus and crypts. Mechanically, the expression levels of Wnt/β -catenin mediators such as Wnt3, LRP5, β-catenin were upregulated by BBD, activating the transcription of c-Myc, LRG5 and CD44 (P<0.01). CONCLUSIONS BBD attenuates the adverse effects induced by 5-FU via Wnt/β-catenin pathway, suggesting it may act as a potential agent against chemotherapy-induced intestinal mucositis.
Animals ; Male ; Mice ; Antineoplastic Agents/therapeutic use* ; beta Catenin/metabolism* ; Diarrhea/drug therapy* ; Fluorouracil/pharmacology* ; Intestinal Mucosa ; Mucositis/metabolism* ; Pentobarbital/therapeutic use* ; Proliferating Cell Nuclear Antigen/metabolism* ; Saline Solution