Intestinal fibrosis is a major complication of inflammatory bowel disease (IBD), leading to a high incidence of surgical interventions and significant disability. Despite its clinical relevance, no targeted pharmacological therapies are currently available. This review aims to explore the underlying mechanisms driving intestinal fibrosis and address unresolved scientific questions, offering insights into potential future therapeutic strategies. We conducted a literature review using data from PubMed up to October 2024, focusing on studies related to IBD and fibrosis. Intestinal fibrosis results from a complex network involving stromal cells, immune cells, epithelial cells, and the gut microbiota. Chronic inflammation, driven by factors such as dysbiosis, epithelial injury, and immune activation, leads to the production of cytokines like interleukin (IL)-1β, IL-17, and transforming growth factor (TGF)-β. These mediators activate various stromal cell populations, including fibroblasts, pericytes, and smooth muscle cells. The activated stromal cells secrete excessive extracellular matrix components, thereby promoting fibrosis. Additionally, stromal cells influence the immune microenvironment through cytokine production. Future research would focus on elucidating the temporal and spatial relationships between immune cell-driven inflammation and stromal cell-mediated fibrosis. Additionally, investigations are needed to clarify the differentiation origins of excessive extracellular matrix-producing cells, particularly fibroblast activation protein (FAP) + fibroblasts, in the context of intestinal fibrosis. In conclusion, aberrant stromal cell activation, triggered by upstream immune signals, is a key mechanism underlying intestinal fibrosis. Further investigations into immune-stromal cell interactions and stromal cell activation are essential for the development of therapeutic strategies to prevent, alleviate, and potentially reverse fibrosis.
Humans ; Fibrosis/metabolism* ; Inflammatory Bowel Diseases/pathology* ; Animals ; Transforming Growth Factor beta/metabolism* ; Intestines/pathology*

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

Child ; Humans ; Malacoplakia/pathology* ; Intestines/pathology*

Objective: To analyze the clinicopathological features and gene mutations of primary gastrointestinal stromal tumors (GISTs) of the stomach and intestine and the prognosis of intermediate- and high-risk GISTs. Methods: This was a retrospective cohort study. Data of patients with GISTs admitted to Tianjin Medical University Cancer Institute and Hospital from January 2011 to December 2019 were collected retrospectively. Patients with primary gastric or intestinal disease who had undergone endoscopic or surgical resection of the primary lesion and were confirmed pathologically as GIST were included. Patients treated with targeted therapy preoperatively were excluded. The above criteria were met by 1061 patients with primary GISTs, 794 of whom had gastric GISTs and 267 intestinal GISTs. Genetic testing had been performed in 360 of these patients since implementation of Sanger sequencing in our hospital in October 2014. Gene mutations in KIT exons 9, 11, 13, and 17 and PDGFRA exons 12 and 18 were detected by Sanger sequencing. The factors investigated in this study included: (1) clinicopathological data, such as sex, age, primary tumor location, maximum tumor diameter, histological type, mitotic index (/5 mm²), and risk classification; (2) gene mutation; (3) follow-up, survival, and postoperative treatment; and (4) prognostic factors of progression-free survival (PFS) and overall survival (OS) for intermediate- and high-risk GIST. Results: (1) Clinicopathological features: The median ages of patients with primary gastric and intestinal GIST were 61 (8-85) years and 60 (26-80) years, respectively; The median maximum tumor diameters were 4.0 (0.3-32.0) cm and 6.0 (0.3-35.0) cm, respectively; The median mitotic indexes were 3 (0-113)/5 mm² and 3 (0-50)/5 mm², respectively; The median Ki-67 proliferation indexes were 5% (1%-80%) and 5% (1%-50%), respectively. The rates of positivity for CD117, DOG-1, and CD34 were 99.7% (792/794), 99.9% (731/732), 95.6% (753/788), and 100.0% (267/267), 100.0% (238/238), 61.5% (163/265), respectively. There were higher proportions of male patients (χ²=6.390, P=0.011), tumors of maximum diameter > 5.0 cm (χ²=33.593, P<0.001), high-risk (χ²=94.957, P<0.001), and CD34-negativity (χ²=203.138, P<0.001) among patients with intestinal GISTs than among those with gastric GISTs. (2) Gene mutations: Gene mutations were investigated in 286/360 patients (79.4%) with primary gastric GISTs and 74/360 (20.6%) with primary intestinal GISTs. Among the 286 patients with gastric primary GISTs, 79.4% (227/286), 8.4% (24/286), and 12.2% (35/286), had KIT mutations, PDGFRA mutations, and wild-type, respectively. Among the 74 patients with primary intestinal GISTs, 85.1% (63/74) had KIT mutations and 14.9% (11/74) were wild-type. The PDGFRA mutation rate was lower in patients with intestinal GISTs than in those with gastric GISTs[ 0% vs. 8.4%(24/286), χ²=6.770, P=0.034], whereas KIT exon 9 mutations occurred more often in those with intestinal GISTs [22.2% (14/63) vs. 1.8% (4/227), P<0.001]. There were no significant differences between gastric and intestinal GISTs in the rates of KIT exon 11 mutation type and KIT exon 11 deletion mutation type (both P>0.05). (3) Follow-up, survival, and postoperative treatment: After excluding 228 patients with synchronous and metachronous other malignant tumors, the remaining 833 patients were followed up for 6-124 (median 53) months with a follow-up rate of 88.6% (738/833). None of the patients with very low or low-risk gastric (n=239) or intestinal GISTs (n=56) had received targeted therapy postoperatively. Among 179 patients with moderate-risk GISTs, postoperative targeted therapy had been administered to 88/155 with gastric and 11/24 with intestinal GISTs. Among 264 patients with high-risk GISTs, postoperative targeted therapy had been administered to 106/153 with gastric and 62/111 with intestinal GISTs. The 3-, 5-, and 10-year PFS of patients with gastric or intestinal GISTs were 96.5%, 93.8%, and 87.6% and 85.7%, 80.1% and 63.3%, respectively (P<0.001). The 3-, 5-, and 10-year OS were 99.2%, 98.8%, 97.5% and 94.8%, 92.1%, 85.0%, respectively (P<0.001). (4) Analysis of predictors of intermediate- and high-risk GISTs: The 5-year PFS of patients with gastric and intestinal GISTs were 89.5% and 73.2%, respectively (P<0.001); The 5-year OS were 97.9% and 89.3%, respectively (P<0.001). Multivariate analysis showed that high risk (HR=2.918, 95%CI: 1.076-7.911, P=0.035) and Ki-67 proliferation index > 5% (HR=2.778, 95%CI: 1.389-5.558, P=0.004) were independent risk factors for PFS in patients with intermediate- and high-risk GISTs (both P<0.05). Intestinal GISTs (HR=3.485, 95%CI: 1.407-8.634, P=0.007) and high risk (HR=3.753,95%CI:1.079-13.056, P=0.038) were independent risk factors for OS in patients with intermediate- and high-risk GISTs (both P<0.05). Postoperative targeted therapy was independent protective factor for PFS and OS (HR=0.103, 95%CI: 0.049-0.213, P<0.001; HR=0.210, 95%CI:0.078-0.564,P=0.002). Conclusions: Primary intestinal GIST behaves more aggressively than gastric GISTs and more frequently progress after surgery. Moreover, CD34 negativity and KIT exon 9 mutations occur more frequently in patients with intestinal GISTs than in those with gastric GISTs.
Male ; Humans ; Gastrointestinal Stromal Tumors/surgery* ; Retrospective Studies ; Ki-67 Antigen ; Stomach Neoplasms/pathology* ; Prognosis ; Mutation ; Intestines/pathology* ; Proto-Oncogene Proteins c-kit/genetics* ; Receptor, Platelet-Derived Growth Factor alpha/genetics*

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

Objective To investigate the relationship between intestinal inflammatory group 2 innate lymphoid cells (iILC2s) and lung ILC2s and its inflammatory response in chronic obstructive pulmonary disease (COPD). Methods Mouse COPD model was established by smoking method. The mice were randomly divided into normal group and COPD group. HE staining was used to detect the pathological changes in lung and intestine tissues of mice in normal group and COPD group, and the contents of natural ILC2s(nILC2s) and iILC2s cells were measured by flow cytometry. Wright-Giemsa staining was used to measure the number of immune cells in the bronchoalveolar lavage fluid (BALF) of mice in normal group and COPD group, and the concentration of IL-13 and IL-4 was detected by ELISA. Results In COPD mice, epithelial cells of the lung and intestinal tissues exhibited pathological hyperplasia, partial atrophy or deletion, inflammatory cell infiltration, increased pathological score and significantly increased neutrophils, monocytes, and lymphocytes in BALF. Lung iILC2s, intestinal nILC2s and iILC2s were increased significantly in the COPD group. The contents of IL-13 and IL-4 in BALF were significantly increased. Conclusion The increase of iILC2s and their related cytokines in COPD lung may be related to intestinal inflammatory ILC2s.
Mice ; Animals ; Cytokines ; Immunity, Innate ; Interleukin-13 ; Interleukin-4 ; Lymphocytes ; Lung/pathology* ; Pulmonary Disease, Chronic Obstructive ; Bronchoalveolar Lavage Fluid ; Disease Models, Animal ; Intestines

The mammalian intestine contains many different cell types but is comprised of 2 main cell types: epithelial cells and smooth muscle cells. Recent in vivo and in vitro evidence has revealed that various alterations to the DNA methylation apparatus within both of these cell types can result in a variety of cellular phenotypes including modified differentiation status, apoptosis, and uncontrolled growth. Methyl groups added to cytosines in regulatory genomic regions typically act to repress associated gene transcription. Aberrant DNA methylation patterns are often found in cells with abnormal growth/differentiation patterns, including those cells involved in burdensome intestinal pathologies including inflammatory bowel diseases and intestinal pseudo-obstructions. The altered methylation patterns being observed in various cell cultures and DNA methyltransferase knockout models indicate an influential connection between DNA methylation and gastrointestinal cells' development and their response to environmental signaling. As these modified DNA methylation levels are found in a number of pathological gastrointestinal conditions, further investigations into uncovering the causative nature, and controlled regulation, of this epigenetic modification is of great interest.
Apoptosis ; Cell Culture Techniques ; Cell Differentiation ; DNA Methylation ; DNA ; Epigenomics ; Epithelial Cells ; In Vitro Techniques ; Inflammatory Bowel Diseases ; Intestinal Mucosa ; Intestinal Pseudo-Obstruction ; Intestines ; Methylation ; Muscle, Smooth ; Myocytes, Smooth Muscle ; Pathology ; Phenotype

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver dysfunction and a significant global health problem with substantial rise in prevalence over the last decades. It is becoming increasingly clear that NALFD is not only predominantly a hepatic manifestation of metabolic syndrome, but also involves extra-hepatic organs and regulatory pathways. Therapeutic options are limited for the treatment of NAFLD. Accordingly, a better understanding of the pathogenesis of NAFLD is critical for gaining new insight into the regulatory network of NAFLD and for identifying new targets for the prevention and treatment of NAFLD. In this review, we emphasize on the current understanding of the inter-organ crosstalk between the liver and peripheral organs that contributing to the pathogenesis of NAFLD.
Adipose Tissue ; pathology ; Animals ; Extracellular Vesicles ; metabolism ; Humans ; Hypothalamus ; metabolism ; Intestines ; microbiology ; pathology ; Non-alcoholic Fatty Liver Disease ; etiology ; metabolism ; microbiology ; pathology

BackgroundIncreasing evidence has supported the link of intestinal Fusobacterium nucleatum infection to colorectal cancer (CRC). However, the value of F. nucleatum as a biomarker in CRC detection has not been fully defined. In order to reduce the random error and bias of individual research, this meta-analysis aimed to evaluate the diagnostic performance of intestinal F. nucleatum in CRC patients and provide evidence-based data to clinical practice.

MethodsAn article search was performed from PubMed, Embase, Cochrane Library, and Web of Science databases up to December 2017, using the following key words: "Fusobacterium nucleatum", "Fusobacterium spp.", "Fn", "colorectal cancer(s)", "colorectal carcinoma(s)", "colorectal neoplasm(s)", and "colorectal tumor(s)". Articles on relationships between F. nucleatum and CRC were selected according to the preestablished inclusion and exclusion criteria. This meta-analysis was performed using STATA 12.0 software, which included mapping of forest plots, heterogeneity tests, meta-regression, subgroup analysis, sensitivity analysis, and publication bias. The sensitivity, specificity, positive likelihood ratio (LR), negative LR, diagnostic odds ratio (DOR), and their corresponding 95% confidence interval (CI) of each eligible study were summarized.

ResultsFinally, data for 1198 participants (629 CRC and 569 healthy controls) in 10 controlled studies from seven articles were included. The summary receiver operator characteristic curve was mapped. The diagnostic performance of intestinal F. nucleatum infection on CRC was as follows: the area under the curve: 0.86 (95% CI: 0.83-0.89), the pooled sensitivity: 0.81 (95% CI: 0.64-0.91), specificity: 0.77 (95% CI: 0.59-0.89), and DOR: 14.00 (95% CI: 9.00-22.00).

ConclusionIntestinal F. nucleatum is a valuable marker for CRC diagnosis.

Colonic Neoplasms ; microbiology ; Colorectal Neoplasms ; microbiology ; Fusobacterium nucleatum ; physiology ; Humans ; Intestines ; microbiology ; pathology

PURPOSE: Early application of protease inhibitors through the intestinal lumen could increase survival following experimental shock by blocking the pancreatic digestive enzymes. Hence, it was hypothesized that two-route injection (intraintestinal + intravenous) of ulinastatin (UTI), a broad-spectrum protease inhibitor, could better alleviate intestinal injury than single-route injection (either intravenous or intraintestinal). METHODS: A sepsis model induced by lipopolysaccharide on rats was established. The rats were randomly divided into five groups: sham, sepsis, UTI intravenous injection (Uiv), UTI intraintestinal injection (Uii), and UTI intraintestinal + intravenous injection (Uii + Uiv) groups. The mucosal barrier function, enzyme-blocking effect, levels of systemic inflammatory cytokines, and 5-day survival rate were compared among groups. The small intestinal villus height (VH), crypt depth (CD), and two components of mucosal barrier (E-cadherin and mucin-2) were measured to evaluate the mucosal barrier function. The levels of trypsin and neutrophil elastase (NE) in the intestine, serum, and vital organs were measured to determine the enzyme-blocking effect. RESULTS: Compared with the single-route injection group (Uiv or Uii), the two-route injection (Uii + Uiv) group displayed: (1) significantly higher levels of VH, VH/CD, E-cadherin, and mucin-2; (2) decreased trypsin and NE levels in intestine, plasma, and vital organs; (3) reduced systemic inflammatory cytokine levels; and (4) improved survival of septic rats. CONCLUSION Two-route UTI injection was superior to single-route injection in terms of alleviating intestinal injury, which might be explained by extensive blockade of proteases through different ways.
Animals ; Cadherins ; metabolism ; Cytokines ; metabolism ; Disease Models, Animal ; Glycoproteins ; administration & dosage ; pharmacology ; Inflammation Mediators ; metabolism ; Injections, Intralesional ; Injections, Intravenous ; Intestinal Diseases ; drug therapy ; etiology ; metabolism ; Intestinal Mucosa ; metabolism ; pathology ; Intestines ; Leukocyte Elastase ; metabolism ; Male ; Mucin-2 ; metabolism ; Rats, Wistar ; Sepsis ; complications ; Trypsin ; metabolism ; Trypsin Inhibitors ; administration & dosage ; pharmacology