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*

Malignant proliferating liver cancer cells possess the ability to detect and respond to various body signals, thereby facilitating tumor growth, invasion, and metastasis. One crucial mechanism through which hepatocellular carcinoma (HCC) cells interpret these signals is crosstalk. Within liver cancer tissues, cancer cells engage in communication with hepatic stellate cells (HSCs), tumor-associated macrophages (TAMs), and immune cells. This interaction plays a pivotal role in regulating the proliferation, invasion, and metastasis of HCC cells. Crosstalk occurs in multiple ways, each characterized by distinct functions. Its molecular mechanisms primarily involve regulating immune cell functions through the expression of specific receptors, such as CD24 and CD47, modulating cell functions by secreting cytokines like transforming growth factor-β (TGF-β) and platelet-derived growth factor (PDGF), and mediating cell growth and proliferation by activating pathways such as Wnt/β-catenin and Hedgehog. A comprehensive understanding of the mechanisms and interactions within crosstalk is essential for unraveling the pathogenesis of HCC. It also opens up new avenues for the development of innovative therapeutic strategies. This article reviews the relationship between crosstalk and the progression of HCC, offering insights and inspiration for future research.
Humans ; Carcinoma, Hepatocellular/metabolism* ; Liver Neoplasms/metabolism* ; Hepatic Stellate Cells/physiology* ; Disease Progression ; Signal Transduction/physiology* ; Transforming Growth Factor beta/metabolism* ; Cell Proliferation ; Hedgehog Proteins/metabolism* ; Tumor-Associated Macrophages ; Platelet-Derived Growth Factor/metabolism* ; Cell Communication/physiology*

Persistent inflammation plays a pivotal role in the initiation and progression of renal fibrosis. Activation of the pattern recognition receptor retinoic acid-inducible gene-I (RIG-I) is implicated in the initiation of inflammation. This study aimed to investigate the upstream mechanisms that regulates the activation of RIG-I and its downstream signaling pathway. Eight-week-old male C57BL/6 mice were used to establish unilateral ureteral obstruction (UUO)-induced renal fibrosis model, and the renal tissue samples were collected 14 days later for analysis. Transforming growth factor-β (TGF-β)-treated mouse renal tubular epithelial cells were used in in vitro studies. The results demonstrated that, compared to the control group, UUO kidney exhibited significant fibrosis, which was accompanied by the increases of RIG-I, p-NF-κB p65 and inflammatory cytokines, such as TNF-α and IL-1β. Additionally, the protein level of the E3 ubiquitin ligase RNF125 was significantly downregulated and predominantly localized in the renal tubular epithelial cells. Similarly, the treatment of tubular cells with TGF-β induced the increases in RIG-I, p-NF-κB p65 and inflammatory cytokines while decreasing RNF125. Co-immunoprecipitation (Co-IP) assays confirmed that RNF125 was able to interact with RIG-I. Overexpression of RNF125 promoted the ubiquitination of RIG-I, and accelerated its degradation via the ubiquitin-proteasome pathway. Overexpression of RNF125 in UUO kidneys and in vitro tubular cells effectively mitigated the inflammatory response and renal fibrosis. In summary, our results demonstrated that the decrease in RNF125 under pathological conditions led to reduction in RIG-I ubiquitination and degradation, activation of the downstream NF-κB signaling pathway and increase in inflammatory cytokine production, which promoted the progression of renal fibrosis.
Animals ; Fibrosis ; Male ; Ubiquitination ; Mice ; Mice, Inbred C57BL ; DEAD Box Protein 58 ; Ubiquitin-Protein Ligases/physiology* ; Inflammation/metabolism* ; Ureteral Obstruction/complications* ; Kidney/pathology* ; Signal Transduction ; Transforming Growth Factor beta/pharmacology*

OBJECTIVES: To evaluate the protective effect of Schistosoma japonicum cystatin (rSj-Cystatin) in a mouse mode of "two-hit" sepsis. METHODS: Sixty male C57BL/6 mice randomized equally into sham-operated group, protein group, "two-hit" modeling group, and protein intervention group. In the former two groups, the mice received an intraperitoneal injection of 100 μL PBS followed by exposure of the cecum and then by intraperitoneal injection of 100 μL PBS or 25 μg rSj-Cystatin 30 min later; In the latter two groups, 100 μL PBS containing LPS (5 mg/kg) was injected intraperitoneally 24 h before cecal ligation and puncture (CLP), and 100 μL PBS or 25 μg rSj-Cystatin were injected 30 min after CLP. At 12 h after rSj-Cystatin treatment, 6 mice from each group were sacrificed for detection of TNF-α, IL-6, IL-10, TGF-β, iNOS and Arg-1 in the serum, spleen, liver, lung and kidney tissues using ELISA, for examinations of liver, lung and kidney pathologies with HE staining, and for analysis of CD3⁺CD4⁺CD25⁺Foxp3⁺ T cell percentage in the spleen using flow cytometry. The remaining mice were observed for general condition and 72-h survival. RESULTS: The 72-h survival rates in the 4 groups were 100%, 100%, 0% and 20%, respectively, showing significant differences between the latter two groups. The mouse models of "two-hit" sepsis exhibited obvious tissue pathologies and significant elevations of TNF-α and IL-6 in both the serum and tissue homogenate, which were significantly ameliorated by rSj-Cystatin treatment. Treatment with rSj-Cystatin also increased IL-10 and TGF-β levels and spleen CD3⁺CD4⁺CD25⁺Foxp3⁺ T cell percentage. The septic mouse models also showed increased iNOS levels in all the detected tissues and a decreased Arg-1 level in the kidney, and these changes were obviously improved by rSj-Cystatin treatment. CONCLUSIONS rSj-Cystatin has a protective effect against "two-hit" sepsis in mice by regulating the inflammatory microenvironment.
Animals ; Mice ; Sepsis/drug therapy* ; Male ; Schistosoma japonicum/chemistry* ; Mice, Inbred C57BL ; Cystatins/therapeutic use* ; Interleukin-10/metabolism* ; Interleukin-6/blood* ; Tumor Necrosis Factor-alpha/blood* ; Disease Models, Animal ; Transforming Growth Factor beta/metabolism*

OBJECTIVES: To investigate the mechanism by which transforming growth factor‑β (TGF‑β) regulates major histocompatibility complex class I (MHC-I) expression in hepatocellular carcinoma (HCC) cells and its role in immune evasion of HCC. METHODS: HCC cells treated with TGF‑β alone or in combination with SB-431542 (a TGF-β type I receptor inhibitor) were examined for changes in MHC-I expression using RT-qPCR and Western blotting. A RNA interference experiment was used to explore the role of miR-23a-3p/IRF1 signaling in TGF‑β‑mediated regulation of MHC-I. HCC cells with different treatments were co-cultured with human peripheral blood mononuclear cells (PBMCs), and the changes in HCC cell proliferation was assessed using CCK-8 and colony formation assays. T-cell cytotoxicity in the co-culture systems was assessed with lactate dehydrogenase (LDH) release and JC-1 mitochondrial membrane potential assays, and T-cell activation was evaluated by flow cytometric analysis of CD69 cells and ELISA for TNF-α secretion. RESULTS: TGF‑β treatment significantly suppressed MHC-I expression in HCC cells and reduced T-cell activation, leading to increased tumor cell proliferation and decreased HCC cell death in the co-culture systems. Mechanistically, TGF-β upregulated miR-23a-3p, which directly targeted IRF1 to inhibit MHC-I transcription. Overexpression of miR-23a-3p phenocopied TGF‑β‑induced suppression of IRF1 and MHC-I. CONCLUSIONS We reveal a novel immune escape mechanism of HCC, in which TGF‑β attenuates T cell-mediated antitumor immunity by suppressing MHC-I expression through the miR-23a-3p/IRF1 signaling axis.
Humans ; MicroRNAs/genetics* ; Carcinoma, Hepatocellular/metabolism* ; Liver Neoplasms/metabolism* ; Interferon Regulatory Factor-1/metabolism* ; Transforming Growth Factor beta/metabolism* ; Signal Transduction ; Histocompatibility Antigens Class I/metabolism* ; Cell Line, Tumor ; Tumor Escape ; Coculture Techniques

OBJECTIVES: To explore the promoting effect of ginsenoside Rb3 (Rb3) on osteogenesis in periodontitis environment, and to explain its mechanism. METHODS: Human periodontal ligament stem cells (hPDLSCs) were cultured by tissue block method and identified by flow cytometry. Cell counting kit-8 (CCK8) method and calcein acetoxymethyl ester/propidium iodide staining were used to detect the effect of Rb3 on the viability of hPDLSCs cells. In vitro cell experiments were divided into control group, 10 μg/mL lipopolysaccharides (LPS) group, 10 μg/mL LPS+100 μmol/L Rb3 group and 10 μg/mL LPS+200 μmol/L Rb3 group. Alkaline phosphatase (ALP) staining was used to detect the ALP activity of hPDLSCs in each group after osteogenesis induction. The expression of hPDLSCs interleukin-6 (IL-6), interleukin-8 (IL-8), runt-related transcription factor 2 (RUNX2) and transforming growth factor-β (TGF-β)genes in each group after osteogenesis was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR) method. Western blot was used to detect the protein expression of hPDLSCs phosphorrylated extracellular signal-regulated kinase (p-ERK) in each group. Sprague-Dawley rats were randomly divided into the control group, ligation group and ligation+Rb3 group. The left molar-maxillary tissue was subjected to micro-computed tomography (micro-CT) scanning. After the scanning, the left molar-maxilla was made into periodontal tissue sections. Hematoxylin-eosin (HE) staining was used to detect the infiltration and loss of adhesion of inflammatory cells. Masson staining was used to detect the destruction of gingival collagen fibers. Immunofluorescence staining was used to detect the protein expression of RUNX2 and p-ERK. The expression of TGF-β in rat gingival tissue was detected by qRT-PCR. The protein expression of IL-6 in peripheral serum of rats was detected by enzyme-linked immunosorbent assay (ELISA). Flow cytometry was used to detect the proportion of Treg cells in rat heart blood. The experimental data were statistically analyzed by Graph Pad Prism10.1.2 software. RESULTS: Rb3 had no effect on the cell activity of hPDLSCs. The results of qRT-PCR and ALP staining showed that Rb3 could inhibit the gene expression of IL-6 and IL-8 in inflammatory hPDLSCs, promote TGF-β gene and promote the osteogenic differentiation of inflammatory hPDLSCs. Western blot showed that Rb3 inhibited the protein expression of inflammatory hPDLSCs p-ERK. The results from micro-CT, Masson staining, and HE staining demonstrated that Rb3 promotes alveolar bone formation in rats with periodontitis, while simultaneously inhibiting the destruction of periodontal fibrous tissue, reducing attachment loss, and suppressing inflammatory cell infiltration. The results of flow cytometry showed that Rb3 could promote the differentiation of Treg cells in peripheral blood of periodontitis rats. The results of ELISA and qRT-PCR showed that Rb3 could inhibit the protein expression of IL-6 and promote the gene expression of TGF-β in periodontitis rats. Immunofluorescence results showed that Rb3 could promote the protein expression of RUNX2 and inhibit the protein expression of p-ERK in periodontitis rats. CONCLUSIONS Rb3 can reduce the inflammatory reaction of periodontal tissues in periodontitis rats, and promote the osteogenic differentiation of hPDLSCs by regulating p-ERK pathways.
Animals ; Ginsenosides/pharmacology* ; Osteogenesis/drug effects* ; Periodontitis/metabolism* ; Rats ; Periodontal Ligament/cytology* ; Humans ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Stem Cells/drug effects* ; Interleukin-6/metabolism* ; Rats, Sprague-Dawley ; Interleukin-8/metabolism* ; Cells, Cultured ; MAP Kinase Signaling System/drug effects* ; Transforming Growth Factor beta/metabolism* ; Signal Transduction ; Male ; Phosphorylation ; Lipopolysaccharides ; Extracellular Signal-Regulated MAP Kinases/metabolism* ; Alkaline Phosphatase/metabolism*

OBJECTIVE: To review the role and research progress of mechanotransduction signaling pathway in distraction osteogenesis, so as to provide theoretical basis and reference for clinical treatment. METHODS: The role and research progress of mechanotransduction signaling pathway in distraction osteogenesis were summarized by extensive review of relevant literature at home and abroad. RESULTS: The mechanotransduction signaling pathway plays a central role of "sensation-transformation-execution" in distraction osteogenesis, and activates a series of molecular mechanisms to promote the regeneration and remodeling of bone tissue by integrating external mechanical signals. Mechanical stimuli are converted into mechanotransduction signals through the perception of integrins, Piezo1 ion channels and bone cell networks. Activate downstream molecules are transduce through signal pathways such as Wnt/β-catenin, transforming growth factor β/bone morphogenetic protein-Smad, mitogen-activated protein kinase, protein kinase Hippo-Yes-associated protein/transcriptional coactivator with PDZ-binding motif, and phosphatidylinositol 3-kinase/ protein kinase B, so as to achieve the effects of promoting osteoblasts proliferation, accelerating endochondral ossification, regulating bone resorption and the like, thereby promoting the regeneration of new bone in the distraction area. The study of mechanotransduction signaling pathways in distraction osteogenesis is expected to optimize the mechanical parameters of distraction osteogenesis and provide targeted intervention strategies for accelerating new bone regeneration and mineralization in the distraction zone. However, the specific mechanism of mechanotransduction signaling pathway in distraction osteogenesis remains to be further elucidated, and artificial intelligence and multi-omics analysis may be the future development direction of mechanotransduction signaling pathway. CONCLUSION In distraction osteogenesis, mechanotransduction signal transduction is the core mechanism of bone regeneration in the distraction zone, which regulates cell behavior and tissue regeneration by converting mechanical stimulation into biochemical signals.
Mechanotransduction, Cellular/physiology* ; Osteogenesis, Distraction/methods* ; Humans ; Signal Transduction ; Bone Regeneration ; Animals ; Osteoblasts/metabolism* ; Osteogenesis ; Transforming Growth Factor beta/metabolism* ; Ion Channels/metabolism* ; Integrins/metabolism* ; beta Catenin/metabolism* ; Bone Morphogenetic Proteins/metabolism* ; Smad Proteins/metabolism*

Objective To investigate the impact of Astragaloside-IV (AS-IV) on the progression of myocardial infarction (MI) through macrophage-dependent mechanisms by regulating Snail1 lactylation and acetylation, as well as the transforming growth factor β (TGF-β) pathway. Methods Oxygen glucose deprivation (OGD) was used to establish an in vitro myocardial ischemia model in rat cardiomyocytes (H9c2), which were then treated with AS-IV. Cell viability was assessed using CCK-8, apoptosis was evaluated by flow cytometry, and LDH levels were measured to assess cellular damage. RAW246.7 cells were treated with LPS, and lactate levels in the supernatant were measured using ELISA, while expression of macrophage phenotype markers was evaluated using Western blot. RAW246.7 cell-conditioned medium (CM) was co-cultured with H9c2 cells to assess the protective effects of AS-IV on macrophage CM-mediated H9c2 damage. RAW246.7 cells were induced to differentiate into M1-like macrophages using LPS (100 ng/mL) + IFN-γ (20 ng/mL), and Snail1 was overexpressed in M1 macrophages. Transfected M1 macrophage CM was co-cultured with H9c2 cells to validate the mechanisms of AS-IV in MI. An MI rat model was established by ligation of the left anterior descending coronary artery (LAD), and was treated with AS-IV. Cardiac function, myocardial cell apoptosis, and cardiac tissue pathology were studied using echocardiography, TUNEL, and HE staining, respectively. Results Compared to the OGD group, AS-IV treatment promoted cell viability, reduced apoptosis and decreased LDH release. LPS upregulated lactate levels in the supernatant of RAW246.7 cell cultures and induced polarization of RAW246.7 cells to the M1 phenotype. AS-IV attenuated the damaging effects of RAW246.7 cell CM on H9c2 cells . Overexpression of Snail1 in M1 macrophages weakened the protective effects of AS-IV on H9c2 cells . In vivo study, results showed that, compared to the MI group, AS-IV treatment reduced lactate levels in the hearts of MI rats, improved cardiac function and myocardial injury and attenuated myocardial cell apoptosis. Conclusion AS-IV inhibits TGF-β pathway activation through the suppression of Snail1 lactylation and acetylation in a macrophage-dependent manner, thereby mitigating myocardial cell damage following MI.
Animals ; Myocardial Infarction/drug therapy* ; Rats ; Snail Family Transcription Factors/metabolism* ; Macrophages/cytology* ; Myocytes, Cardiac/metabolism* ; Triterpenes/pharmacology* ; Saponins/pharmacology* ; Acetylation/drug effects* ; Apoptosis/drug effects* ; Mice ; Cell Line ; RAW 264.7 Cells ; Transforming Growth Factor beta/metabolism*

Objective To explore the mechanism by which gentiopicroside (GPS) prevents macrophage-mediated hepatic fibrosis by regulating the macrophage migration inhibitory factor (MIF)-secreted phosphoprotein 1 (SPP1) signaling pathway in hepatic stellate cells. Methods LX-2 cells were divided into control group, transforming growth factor β(TGF-β) group, and TGF-β combined with GPS (25, 50, 100, 150 μmol/mL) groups. Cell proliferation was detected by EDU assay, cell invasion was assessed by Transwell^TM assay, and the protein expressions of α-smooth muscle actin (α-SMA) and type I collagen (COL1A1) were measured by Western blot. M1-type macrophage-conditioned medium (M1-CM) was used to treat LX-2 cells in the TGF-β group and TGF-β combined with GPS group. The concentrations of inducible nitric oxide synthase (iNOS) and arginase 1 (Arg1) in the cell supernatant, as well as cell proliferation, invasion ability, and the expressions of α-SMA and COL1A1 were detected. Bioinformatics analysis was performed to identify the target intersections of GPS, hepatic fibrosis, and macrophage-related genes. Drug affinity responsive target stability (DARTS) experiments and Western blot were used to verify the regulatory effect of GPS on MIF. Furthermore, LX-2 cells were divided into control group, TGF-β group, TGF-β combined with M2-CM group, TGF-β and oe-NC combined with M2-CM group, and TGF-β and oe-MIF combined with M2-CM group to analyze the concentrations of iNOS and Arg1 in the cell supernatant, as well as changes in cell proliferation, invasion, and the expressions of α-SMA and COL1A1. LX-2 cells were also divided into control group, TGF-β group, TGF-β combined with oe-NC group, TGF-β combined with oe-MIF group, and TGF-β and oe-MIF combined with GPS group to determine the protein expressions of MIF and SPP1 by Western blot. A rat model of hepatic fibrosis was constructed to explore the potential therapeutic effects of GPS on hepatic fibrosis in vivo. Results Compared with the control group, the proliferation and invasion abilities of LX-2 cells in the TGF-β group were increased, and the protein expressions of α-SMA and COL1A1 were enhanced. GPS intervention inhibited the proliferation and invasion of LX-2 cells under TGF-β conditions and reduced the expressions of α-SMA and COL1A1. Compared with the control group, the concentration of iNOS in the cell supernatant of the TGF-β group was upregulated, while the concentration of Arg1 was decreased. M1-CM treatment further increased the concentration of iNOS, decreased the concentration of Arg1, and promoted cell proliferation and invasion, as well as upregulated the expressions of α-SMA and COL1A1 on the basis of TGF-β intervention. However, GPS could reverse the effects of M1-CM intervention. Bioinformatics analysis revealed that MIF was one of the target intersections of GPS, hepatic fibrosis, and macrophage-related genes, and GPS could target and inhibit its expression. Compared with the TGF-β group, after M2-CM intervention, the concentration of iNOS in the cell supernatant decreased, the concentration of Arg1 increased, the proliferation and invasion abilities of LX-2 cells were reduced, and the expressions of α-SMA and COL1A1 were weakened. However, overexpression of MIF reversed the effects of M2-CM intervention. Western blot results showed that compared with the control group, the protein expressions of MIF and SPP1 were enhanced in the TGF-β group. Overexpression of MIF further enhanced the expressions of MIF and SPP1, while GPS intervention inhibited the expressions of MIF and SPP1. In the animal experiment, GPS intervention treatment alleviated liver injury in rats with hepatic fibrosis and inhibited the expressions of MIF and SPP1, as well as α-SMA and COL1A1 in liver tissue. Conclusion GPS may prevent macrophage-mediated hepatic fibrosis by inhibiting the MIF-SPP1 signaling pathway in hepatic stellate cells.
Hepatic Stellate Cells/metabolism* ; Signal Transduction/drug effects* ; Macrophage Migration-Inhibitory Factors/genetics* ; Liver Cirrhosis/prevention & control* ; Macrophages/drug effects* ; Iridoid Glucosides/pharmacology* ; Humans ; Cell Proliferation/drug effects* ; Animals ; Cell Line ; Collagen Type I/metabolism* ; Collagen Type I, alpha 1 Chain ; Intramolecular Oxidoreductases/genetics* ; Rats ; Transforming Growth Factor beta/pharmacology* ; Actins/metabolism*

Tumor progression is closely related to tumor tissue metabolism and reshaping of the microenvironment. Oral squamous cell carcinoma (OSCC), a representative hypoxic tumor, has a heterogeneous internal metabolic environment. To clarify the relationship between different metabolic regions and the tumor immune microenvironment (TME) in OSCC, Single cell (SC) and spatial transcriptomics (ST) sequencing of OSCC tissues were performed. The proportion of TME in the ST data was obtained through SPOTlight deconvolution using SC and GSE103322 data. The metabolic activity of each spot was calculated using scMetabolism, and k-means clustering was used to classify all spots into hyper-, normal-, or hypometabolic regions. CD4T cell infiltration and TGF-β expression is higher in the hypermetabolic regions than in the others. Through CellPhoneDB and NicheNet cell-cell communication analysis, it was found that in the hypermetabolic region, fibroblasts can utilize the lactate produced by glycolysis of epithelial cells to transform into inflammatory cancer-associated fibroblasts (iCAFs), and the increased expression of HIF1A in iCAFs promotes the transcriptional expression of CXCL12. The secretion of CXCL12 recruits regulatory T cells (Tregs), leading to Treg infiltration and increased TGF-β secretion in the microenvironment and promotes the formation of a tumor immunosuppressive microenvironment. This study delineates the coordinate work axis of epithelial cells-iCAFs-Tregs in OSCC using SC, ST and TCGA bulk data, and highlights potential targets for therapy.
Humans ; Carcinoma, Squamous Cell/metabolism* ; Squamous Cell Carcinoma of Head and Neck ; Mouth Neoplasms/metabolism* ; Immunosuppression Therapy ; Transforming Growth Factor beta ; Head and Neck Neoplasms ; Gene Expression Profiling ; Tumor Microenvironment