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

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 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

OBJECTIVES: Ulcerative colitis (UC) is a chronic, relapsing inflammation of the colon. Impaired epithelial repair is an important biological features of UC. Accelerating intestinal epithelial repair to achieve endoscopic mucosal healing has become a key goal in UC. Yes-associated protein (YAP) is a key transcriptional coactivator that regulates organ size, tissue growth and tumorigenesis. Growing studies have focused on the role of YAP in intestinal epithelial regeneration. This study explore the molecular mechanism for the role YAP in modulating colonic epithelial proliferation, repair, and the development of colitis associated cancer. METHODS: We constructed the acute colitis mouse model through successive 5 days of 3% dextran sulfate sodium salt (DSS) induction. Then YAP-overexpressed mouse model was constructed by intraperitoneal injection the YAP overexpressed and negative control lentivirus into DSS mice. On the 5th day of DSS induction and the 5th day of normal drinking water after removing DSS (5+5 d), the mice were killed by spinal dislocation. The colon was taken to measure the length, and the bowel 1-2 cm near the anal canal was selected for immunohistochemical and Western blotting. We used YAP over-expressed colonic epithelial cells and small interfering signal transducer and activator of transcription 3 (STAT3) RNA to probe the regulation of YAP on STAT3, using cell counting kit-8 and scratch assays to explore the role of YAP on colonic epithelial cell proliferation. Finally, we conducted co-immunoprecipitation to test the relationship between YAP and STAT3. RESULTS: After DSS treatment, the expression of YAP was dramatically diminished in crypts. Compared with the empty control mice, overexpression of YAP drastically accelerated epithelial regeneration after DSS induced colitis, presenting with more intact of structural integrity in intestinal epithelium and a reduction in the number of inflammatory cells in the mucosa. Further Western blotting, functional experiment and co-immunoprecipitation analyses showed that the expression of YAP in nucleus was significantly increased by 2 h post DSS cessation, accompanied with up-regulated total protein levels of STAT3 and phosphorylated-STAT3 (p-STAT3). Overexpression of YAP enhanced the expression of STAT3, p-STAT3, and their transcriptional targets including c-Myc and Cyclin D1. In addition, it promoted the proliferation and the "wound healing" of colonic cells. However, these effects were reversed when silencing STAT3 on YAP-overexpressed FHC cells. Moreover, protein immunoprecipitation indicated that YAP could directly interact with STAT3 in the nucleus, up-regulatvng the expressvon of STAT3. Finally, during the process of CAC, overexpression of YAP mutant caused the down-regulated expression of STAT3 and inhibited the development and progress of CAC. CONCLUSIONS YAP activates STAT3 signaling in regulation of epithelial cell proliferation and promotes mucosal regeneration after DSS induced colitis, which may serve as a potential therapeutic target in UC. However, persistent and excessive YAP activation may promote CAC development.
Animals ; Mice ; Cell Proliferation ; Colitis/drug therapy* ; Colon/metabolism* ; Dextran Sulfate/adverse effects* ; Disease Models, Animal ; Intestinal Mucosa ; Mice, Inbred C57BL ; Neoplasm Recurrence, Local/metabolism* ; STAT3 Transcription Factor/metabolism* ; YAP-Signaling Proteins/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

This study aims to investigate the potential mechanism of curcumin in mediating interleukin-6(IL-6)/signal transducer and activator of transcription 3(STAT3) signaling pathway to repair intestinal mucosal injury induced by 5-fluorouracil(5-FU) chemotherapy for colon cancer. SD rats were intraperitoneally injected with 60 mg·kg~(-1)·d~(-1) 5-FU for 4 days to establish a model of intestinal mucosal injury. Then the rats were randomly divided into model group(equal volume of normal saline), curcumin low, medium and high dose groups(50, 100, 200 mg·kg~(-1)), and normal SD rats were used as control group(equal volume of normal saline). Each group received gavage administration for 4 consecutive days, and the changes of body weight and feces were recorded every day. After administration, blood was collected from the heart, and jejunum tissues were collected. The levels of serum interleukin-1β(IL-1β) and tumor necrosis factor-α(TNF-α) were detected by ELISA, and at the same time, the concentration of Evans blue(EB) in jejunum was measured. Hematoxylin-eosin(HE) staining was used to observe the pathological state of jejunum, and the length of jejunum villi and the depth of crypt were measured. The positive expression levels of claudin, occludin and ZO-1 were detected by immunohistochemistry. Western blot was used to detect the protein expression of IL-6, p-STAT3, E-cadherin, vimentin and N-cadherin in jejunum tissues. The results showed that, curcumin significantly increased body weight and fecal weight(P<0.05 or P<0.01), decreased fecal score, EB concentration, IL-1β and TNF-α levels(P<0.05 or P<0.01) in rats. In addition, curcumin maintained the integrity of mucosal surface and villi structure of jejunum to a large extent, and reduced pathological changes in a dose-dependent manner. Meanwhile, curcumin could increase the positive expression of occludin, claudin and ZO-1(P<0.05 or P<0.01), repair intestinal barrier function, downregulate the protein expression of IL-6, p-STAT3, vimentin and N-cadherin in jejunum tissues(P<0.05 or P<0.01), and upregulate the protein expression of E-cadherin(P<0.05). Therefore, curcumin could repair the intestinal mucosal injury induced by 5-FU chemotherapy for colon cancer, and the mechanism may be related to the inhibition of IL-6/STAT3 signal and the inhibition of epithelial-mesenchymal transition(EMT) process.
Animals ; Colonic Neoplasms/drug therapy* ; Curcumin ; Fluorouracil/toxicity* ; Interleukin-6/genetics* ; Intestinal Mucosa/metabolism* ; Rats ; Rats, Sprague-Dawley ; STAT3 Transcription Factor/metabolism* ; Signal Transduction

OBJECTIVE: To study the biodegradation properties of multi-laminated small intestinal submucosa (mSIS) through in vitro and in vivo experiments, comparing with Bio-Gide, the most widely used collagen membrane in guided bone regeneration (GBR) technique, for the purpose of providing basis to investigate whether mSIS meets the requirements of GBR in dental clinics. METHODS: The degradation properties were evaluated in vitro and in vivo. In vitro degradation was performed using prepared collagenase solution. Morphology of mSIS and Bio-Gide in degradation solution were observed and the degradation rate was calculated at different time points. In in vivo experiments, nine New Zealand rabbits were used for subcutaneous implantation and were divided into three groups according to observation intervals. Six unconnected subcutaneous pouches were made on the back of each animal and were embedded with mSIS and Bio-Gide respectively. At the end of weeks 4, 8, and 12 after operation, gross observation and HE staining were used to evaluate the degree of degradation and histocompatibility. RESULTS: In vitro degradation experiments showed that mSIS membrane was completely degraded at the end of 12 days, while Bio-Gide was degraded at the end of 7 days. Besides, mSIS maintained its shape for longer time in the degradation solution than Bio-Gide, indicating that mSIS possessed longer degradation time, and had better ability to maintain space than Bio-Gide. In vivo biodegradation indicated that after 4 weeks of implantation, mSIS remained intact. Microscopic observation showed that collagen fibers were continuous with a few inflammatory cells that infiltrated around the membrane. Bio-Gide was basically intact and partially adhered with the surrounding tissues. HE staining showed that collagen fibers were partly fused with surrounding tissues with a small amount of inflammatory cells that infiltrated as well. Eight weeks after operation, mSIS was still intact, and was partly integrated with connective tissues, whereas Bio-Gide membrane was mostly broken and only a few residual fibers could be found under microscope. Only a small amount of mSIS debris could be observed 12 weeks after surgery, and Bio-Gide could hardly be found by naked eye and microscopic observation at the same time. CONCLUSION In vitro degradation time of mSIS is longer than that of Bio-Gide, and the space-maintenance ability of mSIS is better. The in vivo biodegradation time of subcutaneous implantation of mSIS is about 12 weeks and Bio-Gide is about 8 weeks, both of which possess good biocompatibility.
Animals ; Biocompatible Materials/metabolism* ; Bone Regeneration ; Connective Tissue ; Intestinal Mucosa ; Intestine, Small ; Membranes, Artificial ; Rabbits

OBJECTIVE: To establish a congenital chloride diarrhea (CCD)-associated SLC26A3 c.392C>G (p.P131R) polymorphism-expressing cell model, and to investigate its biological function. METHODS: The sequence of the SLC26A3 gene in GenBank was used to design the upstream and downstream single-guide RNA (sgRNA) that could specifically recognize the 392 locus of the SLC26A3 gene, and the sgRNA was mixed with the pSpCas9-puro vector after enzyme digestion to construct an eukaryotic recombinant expression plasmid (pSpCas9-SLC26A3). Caco-2 cells were transfected with the recombinant plasmid and synthesized single-stranded DNA oligonucleotides (ssODNs), and Taqman genotyping assay and Sanger sequencing were used to identify the expression of SLC26A3 c.392C>G (p.P131R) in Caco-2 cells. Wild-type Caco-2 cells were selected as normal control group and the Caco-2 cells with successful expression of SLC26A3 c.392C>G (p.P131R) was selected as P131R group. Both groups were treated with 100 ng/mL tumor necrosis factor-α (TNF-α), and then the normal control group was named as TNF-α group, and the P131R group was named as TNF-α+P131R group. Electric cell-substrate impedance sensing (ECIS) assay was used to evaluate the change in the monolayer barrier function of intestinal epithelial cells in the above four groups, and Western blot was used to measure the change in the expression of SLC26A3 protein in the normal control group and the P131R group. RESULTS: The eukaryotic recombinant expression plasmid (pSpCas9-SLC26A3) was successfully constructed. Both Taqman genotyping assay and Sanger sequencing confirmed the successful establishment of the Caco-2 cell model of SLC26A3 c.392C>G (p.P131R) expression. ECIS assay showed that compared with the normal control group, the P131R group had a significant increase in the monolayer permeability of intestinal epithelial cells (P<0.05), and at the same time, the P131R group had a significantly greater increase in cell membrane permeability after the induction with 100 ng/mL TNF-α (P<0.05). Western blot showed that compared with the normal control group, the P131R group had a significant reduction in the expression of SLC26A3 protein (P=0.001). CONCLUSIONS SLC26A3 c.392C>G (p.P131R) can reduce the expression of SLC26A3 protein, increase the monolayer permeability of intestinal epithelial cells, and thus lead to diarrhea.
Caco-2 Cells ; Chloride-Bicarbonate Antiporters ; genetics ; Diarrhea ; congenital ; genetics ; Humans ; Intestinal Mucosa ; Metabolism, Inborn Errors ; genetics ; Polymorphism, Single Nucleotide ; Sulfate Transporters ; genetics ; Tight Junctions ; Tumor Necrosis Factor-alpha