Necrotizing enterocolitis (NEC) is an intestinal inflammatory and necrotic disease seen in premature infants, and remains the leading cause of death resulted from gastrointestinal diseases in premature infants. The specific pathogenesis of NEC is still unclear. In recent years, a lot of studies have reported that Toll-like receptor 4 (TLR4) plays a key role in the pathogenesis of NEC. TLR4, which is abundantly expressed in intestinal epithelial cells of premature infants, binds to bacterial lipopolysaccharide (LPS) to activate downstream signaling pathways, leading to disruption of intestinal epithelial integrity and bacterial translocation, resulting in intestinal ischemic necrosis and inflammatory responses, which may rapidly progress to severe sepsis, multiple organ dysfunction, and death. This paper reviews the mechanism of TLR4-related signaling pathways in intestinal epithelial injury and inflammatory responses in newborns with NEC, providing a reference to study new therapeutic targets for NEC.
Enterocolitis, Necrotizing/pathology* ; Toll-Like Receptor 4/metabolism* ; Humans ; Infant, Newborn ; Signal Transduction ; Inflammation/metabolism* ; Animals ; Intestines/immunology* ; Intestinal Mucosa/pathology* ; Infant, Premature

OBJECTIVE: To elucidate the effect of Huanglian-Renshen-Decoction (HRD) on ameliorating type 2 diabetes mellitus by maintaining islet β -cell identity through regulating paracrine and endocrine glucagon-like peptide-1 (GLP-1)/GLP-1 receptor (GLP-1R) in both islet and intestine. METHODS: The db/db mice were divided into the model (distilled water), low-dose HRD (LHRD, 3 g/kg), high-dose HRD (HHRD, 6 g/kg), and liraglutide (400 µ g/kg) groups using a random number table, 8 mice in each group. The db/m mice were used as the control group (n=8, distilled water). The entire treatment of mice lasted for 6 weeks. Blood insulin, glucose, and GLP-1 levels were quantified using enzyme-linked immunosorbent assay kits. The proliferation and apoptosis factors of islet cells were determined by immunohistochemistry (IHC) and immunofluorescence (IF) staining. Then, GLP-1, GLP-1R, prohormone convertase 1/3 (PC1/3), PC2, v-maf musculoaponeurotic fibrosarcoma oncogene homologue A (MafA), and pancreatic and duodenal homeobox 1 (PDX1) were detected by Western blot, IHC, IF, and real-time quantitative polymerase chain reaction, respectively. RESULTS: HRD reduced the weight and blood glucose of the db/db mice, and improved insulin sensitivity at the same time (P<0.05 or P<0.01). HRD also promoted mice to secrete more insulin and less glucagon (P<0.05 or P<0.01). Moreover, it also increased the number of islet β cell and decreased islet α cell mass (P<0.01). After HRD treatment, the levels of GLP-1, GLP-1R, PC1/3, PC2, MafA, and PDX1 in the pancreas and intestine significantly increased (P<0.05 or P<0.01). CONCLUSION HRD can maintain the normal function and identity of islet β cell, and the underlying mechanism is related to promoting the paracrine and endocrine activation of GLP-1 in pancreas and intestine.
Animals ; Glucagon-Like Peptide 1/metabolism* ; Diabetes Mellitus, Type 2/metabolism* ; Glucagon-Like Peptide-1 Receptor/metabolism* ; Insulin-Secreting Cells/pathology* ; Drugs, Chinese Herbal/pharmacology* ; Male ; Blood Glucose/metabolism* ; Insulin/blood* ; Mice ; Intestinal Mucosa/pathology* ; Apoptosis/drug effects* ; Cell Proliferation/drug effects* ; Islets of Langerhans/pathology*

OBJECTIVE: To explore the mechanism of colon dialysis with Yishen Decoction (YS) in improving the autophagy disorder of intestinal epithelial cells in chronic renal failure (CRF) in vivo and in vitro. METHODS: Thirty male SD rats were randomly divided into normal, CRF, and colonic dialysis with YS groups by a random number table method (n=10). The CRF model was established by orally gavage of adenine 200 mg/(kg•d) for 4 weeks. CRF rats in the YS group were treated with colonic dialysis using YS 20 g/(kg•d) for 14 consecutive days. The serum creatinine (SCr) and urea nitrogen (BUN) levels were detected by enzyme-linked immunosorbent assay. Pathological changes of kidney and colon tissues were observed by hematoxylin and eosin staining. Autophagosome changes in colonic epithelial cells was observed with electron microscopy. In vitro experiments, human colon cancer epithelial cells (T84) were cultured and divided into normal, urea model (74U), YS colon dialysis, autophagy activator rapamycin (Ra), autophagy inhibitor 3-methyladenine (3-MA), and SIRT1 activator resveratrol (Re) groups. RT-PCR and Western blot were used to detect the mRNA and protein expressions of zonula occludens-1 (ZO-1), Claudin-1, silent information regulator sirtuin 1 (SIRT1), LC3, and Beclin-1 both in vitro and in vivo. RESULTS: Colonic dialysis with YS decreased SCr and BUN levels in CRF rats (P<0.05), and alleviated the pathological changes of renal and colon tissues. Expressions of SIRT1, ZO-1, Claudin-1, Beclin-1, and LC3II/I were increased in the YS group compared with the CRF group in vivo (P<0.05). In in vitro study, compared with normal group, the expressions of SIRT1, ZO-1, and Claudin-1 were decreased, and expressions of Beclin-1, and LC3II/I were increased in the 74U group (P<0.05). Compared with the 74U group, expressions of SIRT1, ZO-1, and Claudin-1 were increased, whereas Beclin-1, and LC3II/I were decreased in the YS group (P<0.05). The treatment of 3-MA and rapamycin regulated autophagy and the expression of SIRT1. SIRT1 activator intervention up-regulated autophagy as well as the expressions of ZO-1 and Claudin-1 compared with the 74U group (P<0.05). CONCLUSION Colonic dialysis with YS could improve autophagy disorder and repair CRF intestinal mucosal barrier injury by regulating SIRT1 expression in intestinal epithelial cells.
Animals ; Sirtuin 1/metabolism* ; Drugs, Chinese Herbal/therapeutic use* ; Autophagy/drug effects* ; Male ; Intestinal Mucosa/drug effects* ; Rats, Sprague-Dawley ; Epithelial Cells/metabolism* ; Colon/drug effects* ; Humans ; Kidney Failure, Chronic/drug therapy* ; Signal Transduction/drug effects* ; Renal Dialysis ; Rats ; Kidney/drug effects*

The gut microbiota is an indispensable symbiotic entity within the human holobiont, serving as a critical regulator of host lipid metabolism homeostasis. Therefore, it has emerged as a central subject of research in the pathophysiology of metabolic disorders. This microbial consortium orchestrates key aspects of host lipid dynamics-including absorption, metabolism, and storage-through multifaceted mechanisms such as the enzymatic processing of dietary polysaccharides, the facilitation of long-chain fatty acid uptake by intestinal epithelial cells (IECs), and the bidirectional modulation of adipose tissue functionality. Mounting evidence underscores that gut microbiota-derived metabolites not only directly mediate canonical lipid metabolic pathways but also interface with host immune pathways, epigenetic machinery, and circadian regulatory systems, thereby establishing an intricate crosstalk that coordinates systemic metabolic outputs. Perturbations in microbial composition (dysbiosis) drive pathological disruptions to lipid homeostasis, serving as a pathogenic driver for conditions such as obesity, hyperlipidemia, and non-alcoholic fatty liver disease (NAFLD). This review systematically examines the emerging mechanistic insights into the gut microbiota-mediated regulation of intestinal lipid metabolism, while it elucidates its translational implications for understanding metabolic disease pathogenesis and developing targeted therapies.
Humans ; Gastrointestinal Microbiome/physiology* ; Lipid Metabolism ; Animals ; Intestinal Mucosa/metabolism* ; Homeostasis ; Dysbiosis ; Obesity/metabolism* ; Intestines/microbiology* ; Non-alcoholic Fatty Liver Disease/metabolism* ; Metabolic Diseases/metabolism*

OBJECTIVES: To investigate the therapeutic mechanism of nodakenin for Crohn's disease (CD)-like colitis in mice. METHODS: Using a colonic organoid model with lipopolysaccharide (LPS)- and ATP-induced pyroptosis, we investigated the effects of nodakenin on pyroptosis, intestinal barrier function and inflammatory response by detecting key pyroptosis-regulating factors and assessing changes in permeability and pro-inflammatory factors. In a mouse model of 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced CD-like colitis, the therapeutic effect of nodakenin was evaluated by measuring changes in body weight, DAI score, colonic histopathologies, inflammation score, intestinal barrier function and intestinal epithelial cell pyroptosis. The mechanism of nodakenin protection against pyroptosis of intestinal epithelial cells was explored using network pharmacology analysis and in vivo and in vitro experiments. RESULTS: In LPS- and ATP-induced colonic organoids, treatment with nodakenin significantly inhibited the expressions of NLRP3, GSDMD-N, cleaved caspase-1 and caspase-11, improved intestinal FITC-dextran (FD4, 4000) permeability, and decreased the levels of IL-1β and IL-18. In the mouse model of TNBS-induced colitis, nodakenin treatment significantly alleviated weight loss, reduced DAI score, inflammatory cell infiltration and inflammation score, and decreased serum FD4 and I-FABP levels and bacteria translocation to the mesenteric lymph nodes, spleen and liver. The mice with nodakenin treatment had also lowered expressions of NLRP3, GSDMD-N, cleaved caspase-1 and caspase-11 in the intestinal mucosa. Network pharmacology analysis suggested that the inhibitory effect of nodakenin on colitis was associated with the PI3K/Akt pathway. In both the colonic organoid model and mouse models of colitis, nodakenin effectively inhibited the activation of the PI3K/Akt pathway, and the application of IGF-1, a PI3K/Akt pathway activator, strongly attenuated the protective effect of nodakenin against intestinal epithelial cell pyroptosis and intestinal barrier dysfunction. CONCLUSIONS Nodakenin protects intestinal barrier function and alleviates CD-like colitis in mice at least partly by inhibiting PI3K/Akt signaling to reduce intestinal epithelial cell pyroptosis.
Animals ; Pyroptosis/drug effects* ; Mice ; Trinitrobenzenesulfonic Acid ; Colitis/drug therapy* ; Epithelial Cells/drug effects* ; Intestinal Mucosa/cytology* ; Disease Models, Animal ; Coumarins/pharmacology* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Crohn Disease/drug therapy*

OBJECTIVES: To investigate the therapeutic effects of cimifugin on Crohn's disease (CD)-like colitis in mice and its possible mechanism. METHODS: Thirty adult male C57BL/6 mice were randomized equally into control group, 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced CD-like colitis model group, and cimifugin treatment (daily gavage at 12.5 mg/kg) group. The therapeutic effect of cimifugin was evaluated by observing changes in body weight, disease activity index (DAI) scores, colon length, histopathological inflammation scores, and inflammatory cytokine levels in the colonic mucosa. Intestinal barrier integrity in the mice was assessed using immunofluorescence assay and Western blotting for claudin-1 and ZO-1; T-helper (Th) cell subset ratios in the mesenteric lymph nodes were analyzed with flow cytometry. Network pharmacology, KEGG enrichment analysis and molecular docking were used to predict the targets of cimifugin and analyze the key pathways and cimifugin-MAPK protein interactions, which were validated by Western blotting in the mouse models. RESULTS: In mice with TNBS-induced colitis, cimifugin treatment significantly attenuated body weight loss and colon shortening, lowered DAI and histopathological scores, decreased IFN-γ and IL-17 levels, and increased IL-4 and IL-10 levels in the colonic mucosa. Cimifugin treatment also significantly improved TNBS-induced claudin-1 dislocation and reduction of goblet cells, upregulated claudin-1 and ZO-1 expressions, reduced Th1 and Th17 cell percentages, and increased Th2 and Treg cell percentages in the colonic mucosa of the mice. KEGG analysis suggested a possible connection between the effect of cimifugin and MAPK signaling, and molecular docking showed strong binding affinity between cimifugin and MAPK core proteins. Western blotting demonstrated significantly decreased phosphorylation levels of JNK, ERK, and p38 in the colonic mucosa of cimifugin-treated mouse models. CONCLUSIONS Cimifugin alleviates TNBS-induced CD-like colitis by repairing intestinal barrier damage and restoring Th1/Th2 and Th17/Treg balance via suppressing MAPK pathway activation.
Animals ; Mice, Inbred C57BL ; Male ; Mice ; Crohn Disease/immunology* ; Colitis/immunology* ; MAP Kinase Signaling System/drug effects* ; Trinitrobenzenesulfonic Acid ; T-Lymphocytes, Helper-Inducer/drug effects* ; Intestinal Mucosa ; Disease Models, Animal

OBJECTIVES: To investigate the effect of moslosooflavone (MOS) for ameliorating dextran sulfate sodium (DSS)-induced colitis in mice and the underlying molecular mechanism. METHODS: C57BL/6J mice with or without DSS exposure in the drinking water were both randomized into two groups for treatment with intraperitoneal injections with MOS (200 mg/kg) or normal saline for 7 days (n=6). Disease severity of the mice was assessed by observing changes in body weight, colon length, histopathology (HE staining), intestinal barrier function, and TUNEL staining. In the in vitro studies, lipopolysaccharide (LPS)-stimulated mouse colon organoids were treated with MOS (120 μmol/L) for 24 h, and the changes in barrier dysfunction and inflammation were analyzed. Network pharmacology and Western blotting were employed to identify functional pathways and apoptotic protein regulation associated with the therapeutic effect of MOS on colitis. RESULTS: In the mouse models of DSS-indcued colitis, MOS treatment significantly reduced body weight loss, disease activity index (DAI) scores and colon shortening, ameliorated colonic histopathological changes and inflammation, and lowered pro-inflammatory cytokine levels (TNF-α, IL-1β, IL-6, and IFN-γ). MOS effectively restored intestinal barrier integrity in the mice by reducing serum FITC-dextran and I-FABP concentrations while enhancing the tight junction proteins (ZO-1 and claudin-1). In the colon organoids, MOS significantly suppressed LPS-induced inflammatory responses and epithelial barrier disruption. Western blotting revealed that MOS downregulated C-caspase-3 and BAX and upregulated Bcl-2 expressions in both models. Mechanistically, MOS suppressed PI3K and AKT phosphorylation in both DSS-treated mouse colonic tissues and LPS-stimulated organoids. CONCLUSIONS MOS alleviates experimental colitis in mice by inhibiting intestinal epithelial apoptosis via inhibiting the PI3K/AKT pathway, thereby restoring intestinal barrier integrity and reducing inflammation.
Animals ; Dextran Sulfate ; Mice, Inbred C57BL ; Colitis/metabolism* ; Mice ; Signal Transduction/drug effects* ; Intestinal Mucosa/metabolism* ; Apoptosis/drug effects* ; Proto-Oncogene Proteins c-akt/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Flavones/pharmacology* ; Male

OBJECTIVES: To investigate the mechanism through which pinostrobin (PSB) alleviates dextran sulfate sodium (DSS)-induced colitis in mice. METHODS: C57BL/6 mice were randomized into control group, DSS model group, and PSB intervention (30, 60, and 120 mg/kg) groups. Colitis severity of the mice was assessed by examining body weight changes, disease activity index (DAI), colon length, and histopathology. The expressions of tight junction proteins ZO-1 and claudin-1 in the colon tissues were examined using immunofluorescence staining, and macrophage infiltration and polarization were analyzed with flow cytometry. ELISA and RT-qPCR were used for detecting the expressions of inflammatory factors (TNF‑α and IL-6) and chemokines (CCL₂, CXCL₁₀, and CX₃CL₁) in the colon tissues, and PI3K/AKT phosphorylation levels were analyzed with Western blotting. In cultured Caco-2 and RAW264.7 cells, the effect of PSB on CCL₂-mediated macrophage migration was assessed using Transwell assay. Network pharmacology analysis was performed to predict the key pathways that mediate the therapeutic effect of PSB. RESULTS: In DSS-induced mouse models, PSB at 60 mg/kg optimally alleviated colitis, shown by reduced weight loss and DAI scores and increased colon length. PSB treatment significantly upregulated ZO-1 and claudin-1 expressions in the colon tissues, inhibited colonic macrophage infiltration, and promoted the shift of macrophage polarization from M1 to M2 type. In cultured intestinal epithelial cells, PSB significantly inhibited PI3K/AKT phosphorylation and suppressed chemokine CCL₂ expression. PSB treatment obviously blocked CCL₂-mediated macrophage migration of RAW264.7 cells, which could be reversed by exogenous CCL₂. Network pharmacology analysis and rescue experiments confirmed PI3K/AKT and CCL₂ signaling as the core targets of PSB. CONCLUSIONS PSB alleviates DSS-induced colitis in mice by targeting intestinal epithelial PI3K/AKT signaling, reducing CCL₂ secretion, and blocking macrophage chemotaxis and migration, highlighting the potential of PSB as a novel natural compound for treatment of inflammatory bowel disease.
Animals ; Mice ; Mice, Inbred C57BL ; Phosphatidylinositol 3-Kinases/metabolism* ; Colitis/drug therapy* ; Dextran Sulfate ; Proto-Oncogene Proteins c-akt/metabolism* ; Macrophages ; Chemokine CCL2/metabolism* ; Humans ; Signal Transduction/drug effects* ; Caco-2 Cells ; RAW 264.7 Cells ; Epithelial Cells/drug effects* ; Intestinal Mucosa/metabolism*

OBJECTIVE: To observe the effect of moxibustion on small intestinal mucosal immune barrier in rats with diarrhea-predominant irritable bowel syndrome (IBS-D) and explore its underlying mechanisms. METHODS: Of 38 newborn rats from 4 healthy SPF pregnant rats, 12 neonatal rats were randomly selected in a normal group. IBS-D model was prepared by the combined measures for the rest rats, including neonatal maternal separation, acetic acid enema and chronic restraint stress. Twenty-four successfully-modeled rats were randomized into a model group and a moxibustion group, 12 rats in each one. In the moxibustion group, suspending moxibustion was delivered at bilateral "Tianshu" (ST25) and "Shangjuxu" (ST37), 20 min each time, once daily and for 7 consecutive days. Separately, before acetic acid enema (aged 35 days), after modeling (aged 45 days) and after intervention (aged 53 days), the body mass, loose stool rate (LSR) and and the minimum volume threshold when abdominal withdrawal reflex (AWR) scored 3 were observed in the rats of each group. After intervention (aged 53 days), using HE and PAS staining, the morphology of duodenum was observed, the length of villus and the depth of crypt were measured, the ratio of the length of villus to the depth of crypt was calculated; and the numbers of mucosal intraepithelial lymphocytes (IELs) and goblet cells were counted. With ELISA adopted, the contents of γ-interferon (IFN-γ), interleukin-4 (IL-4) and secretory immunoglobulin A (sIgA) in duodenal mucosa of rats were detected. The proportion of T cell subsets in duodenal mucosa was detected using flow cytometry. The microvilli and tight junctions of duodenal mucosal epithelial cells were observed by transmission electron microscopy, and the integrity of duodenal mucosa observed by scanning electron microscopy. RESULTS: Compared with the normal group, for the rats in the model group, the body mass, the minimum volume threshold when AWR scored 3, the length of duodenal villus and the the ratio of the length of villus to the depth of crypt, as well as the proportion of CD₈⁺ T subset were all reduced (P<0.01, P<0.05), the counts of goblet cells in duodenal mucosa decreased (P<0.01); LRS, the proportion of CD₄⁺ T subset and CD₄⁺/CD₈⁺, as well as the contents of IFN-γ, IL-4 and sIgA in duodenal mucosa and IFN-γ/IL-4 were all elevated (P<0.01); and the numbers of IELs rose (P<0.01). The morphology of duodenal mucosa was irregular, the villi got shorter, sparse and scattered, with uneven density. The morphology of epithelial cells was destroyed and the tight junctions damaged, with larger spaces. When compared with the model group, in the moxibustion group, the body mass, the minimum volume threshold when AWR scored 3, the length of duodenal villus and the ratio of the length of villus to the depth of crypt, as well as the counts of goblet cells in duodenal mucosa increased (P<0.01); LRS, the proportion of CD₄⁺ T subset, and CD₄⁺/CD₈⁺, as well as the contents of IFN-γ, IL-4 and sIgA in duodenal mucosa and IFN-γ/IL-4 were reduced (P<0.01); and the numbers of IELs was dropped (P<0.01). The morphology of duodenal mucosa was more regular, the villi were grew, got longer and arranged regularly, with even density. The morphology of epithelial cells was slightly destroyed, and the tight junctions partially damaged. CONCLUSION Moxibustion at "Tianshu" (ST25) and "Shangjuxu" (ST37) can reduce visceral hypersensitivity in IBS-D rats and relieve abdominal pain, diarrhea and other symptoms. Its effect mechanism may be related to the repair of small intestinal mucosal immune barrier and the improvement in the immune function in IBS-D.
Animals ; Irritable Bowel Syndrome/immunology* ; Rats ; Moxibustion ; Intestinal Mucosa/immunology* ; Female ; Diarrhea/therapy* ; Intestine, Small/immunology* ; Male ; Humans ; Rats, Sprague-Dawley ; Disease Models, Animal

The small intestine is essential for digestion, nutrient absorption, immune regulation, and microbial balance. Its epithelial lining, containing specialized cells like Paneth cells and tuft cells, is crucial for maintaining intestinal homeostasis. Paneth cells produce antimicrobial peptides and growth factors that support microbial regulation and intestinal stem cells, while tuft cells act as chemosensors, detecting environmental changes and modulating immune responses. Along with immune cells such as intraepithelial lymphocytes, innate lymphoid cells, T cells, and macrophages, they form a strong defense system that protects the epithelial barrier. Disruptions in this balance contribute to chronic inflammation, microbial dysbiosis, and compromised barrier function-key features of inflammatory bowel disease, celiac disease, and metabolic syndromes. Furthermore, dysfunctions in the small intestine and immune cells are linked to systemic diseases like obesity, diabetes, and autoimmune disorders. Recent research highlights promising therapeutic strategies, including modulation of epithelial and immune cell functions, probiotics, and gene editing to restore gut health and address systemic effects. This review emphasizes the pivotal roles of small intestinal epithelia and immune cells in maintaining intestinal homeostasis, their involvement in disease development, and emerging treatments for intestinal and systemic disorders.
Humans ; Intestinal Mucosa/cytology* ; Intestine, Small/cytology* ; Animals ; Inflammatory Bowel Diseases/immunology* ; Celiac Disease/immunology* ; Paneth Cells/immunology*