Search Results (350)

Background: Ulcerative colitis (UC), characterized by chronic intestinal inflammation, epithelial barrier dysfunction, and immune imbalance demands novel ameliorative strategies beyond conventional approaches. Methods: In this study, the probiotic properties of Lactobacillus paracasei L21 (L. paracasei L21) and its ability to ameliorate colitis were evaluated using an in vitro lipopolysaccharide (LPS)-induced intestinal crypt epithelial cell (IEC-6) model and an in vivo dextran sulfate sodium (DSS)-induced UC mouse model. Results: In vitro, L. paracasei L21 decreased levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-8) while increasing anti-inflammatory IL-10 levels (p < 0.05) in LPS-induced IEC-6 cells, significantly enhancing the expression of tight junction proteins (ZO-1, occludin, claudin-1), thereby restoring the intestinal barrier. In vivo, both viable L. paracasei L21 and its heat-inactivated postbiotic (H-L21) mitigated weight loss, colon shortening, and disease activity indices, concurrently reducing serum LPS and proinflammatory mediators. Interventions inhibited NF-κB signaling while activating HIF1α/AhR pathways, increasing IL-22 and mucin MUC2 to restore goblet cell populations. Gut microbiota analysis showed that both interventions increased the abundance of beneficial gut bacteria (Lactobacillus, Dubococcus, and Akkermansia) and improved faecal propanoic acid and butyric acid levels. H-L21 uniquely exerted an anti-inflammatory effect, marked by the regulation of Dubosiella, while L. paracasei L21 marked by the Akkermansia. Conclusions: These results highlight the potential of L. paracasei L21 as a candidate for the development of both probiotic and postbiotic formulations. It is expected to provide a theoretical basis for the management of UC and to drive the development of the next generation of UC therapies. Full article

Although Hylocereus polyrhizus pulp residues polysaccharides (HPPP) have shown potential in improving metabolic disorders and intestinal barrier function, the mechanism by which they exert their effects through regulating O-glycosylation modifications in the mucus layer remains unclear. Therefore, this study established a HFD-induced obese colitis mouse model (n = 5 per group) and combined nano-capillary liquid chromatography-tandem mass spectrometry (nanoLC-MS/MS) technology to quantitatively analyze the dynamic changes in O-glycosylation. Additionally, through quantitative O-glycosylation proteomics and whole-proteome analysis, we identified 155 specifically altered O-glycosylation sites in colon tissue, with the glycosylation modification level of the MUC2 core protein increased by approximately 2.1-fold. The results indicate that HPPP alleviates colonic mucosal damage by regulating interactions between mucus O-glycosylation. Overall, we demonstrated that HPPP increases HFD-induced O-glycosylation sites, improves intestinal mucosal structure in obese mice, and provides protective effects against obesity-induced intestinal mucosal damage. Full article

In this study, we established a mouse colitis model using DSS to investigate the impact of curcumin on gut injury, the intestinal microbiota, and fecal metabolites. The findings indicated that curcumin effectively mitigated weight loss and colon shortening caused by colitis, enhanced the expression of anti-inflammatory factor IL-10 mRNA (p < 0.05), and suppressed the expression of pro-inflammatory factors (IL-1β, IL-6, and TNF-α mRNA; p < 0.05). 16S rDNA sequencing analysis showed that in the CUR group, compared to the NC and DSS groups, the abundances of Bacteroides, Lachnospiraceae NK4A136, and Ruminococcaceae UGC 014 significantly increased, while that of Lactobacillus markedly decreased. Additionally, compared with the DSS group, the CUR group demonstrated a significant decrease in levels of metabolites associated with nucleic acid and fat metabolism, including xanthosine, isocitric acid, and D-xylose. Conversely, levels of metabolites of curcumin, such as demethoxycurcumin and tetrahydrocurcumin, were significantly elevated in the CUR group. Curcumin appears to offer protection against mouse colitis by potentially enhancing the composition of the gut microbiota and regulating metabolic and inflammatory processes through its metabolites. Full article

Ulcerative colitis (UC) is a subtype of inflammatory bowel disease (IBD) that has been associated with overconsumption of calories and lipids, compared to the healthy population, and summer temperatures have been reported to be closely related to the prevalence of UC. To evaluate the effects of dietary and lifestyle factors on UC, a combination of 2.0% dextran sulfate sodium (DSS), a high-fat/high-sugar diet, and exposure to high temperature and humidity was used to construct mouse models of UC. Changes in body weight, disease activity index (DAI) scores, histopathological analysis, serum lipid levels, serum diamine oxidase (DAO), and D-Lactate (D-LA) levels, as well as the expression of inflammatory cytokines and tight junction proteins in colonic tissue, were all assessed to study the impacts of the high-fat/high-sugar diet and high-temperature/high-humidity exposure on the progression of UC. The symptoms observed in the UC mouse model induced by 2.0% DSS alone were similar to those seen in patients with UC, while the high-fat and high-sugar diet, along with humid and hot exposure, exacerbated DSS-induced UC in the mice. This included more severe histopathological damage to the colon tissue, increased expression of pro-inflammatory cytokines (IL-6, IL-17A, and IL-1β), and a more significantly compromised intestinal barrier, characterized by the destruction of ZO-1 and elevated levels of DAO and D-LA. Additionally, the high-fat/high-sugar diet and high-temperature/high-humidity exposure led to further disturbances in glucose and lipid metabolism in the mice, which were not observed in those treated with DSS alone. This study is the first to investigate the effects of a high-fat/high-sugar diet and high-temperature/high-humidity exposure on the progression of UC. Full article

Background: PTEN is a tumor suppressor that controls many pathophysiological pathways, including cell proliferation, differentiation, apoptosis and invasiveness. Although PTEN down-modulation is a critical event in neoplastic progression, it becomes apparent that transient and local inhibition of PTEN activity might be beneficial for the healing process. Methods: In the present study, we investigated the impact of PTEN invalidation in mouse intestinal epithelium under a physiological condition and after dextran sulfate sodium (DSS) treatment to induce experimental colitis. PTEN conditional knockout was induced in intestinal epithelial cells after crossing villin-Cre and PTEN^flox/flox mice. Results: PTEN invalidation alleviates experimental colitis induced by DSS, as evidenced by decreased weight loss during the acute phase, the lower expression of inflammation markers, including the proinflammatory cytokines IFN-γ, CXCL1 and CXCL2, reduced mucosal lesions, and faster recovery after resolution of inflammation. This protective effect might result in part from the sustained proliferation of colonic epithelium, leading to hyperplasia and increased colonic crypt depth under physiological conditions, which was further exacerbated in the vicinity of mucosal injury induced by DSS treatment. Furthermore, PTEN knockout decreased paracellular permeability, thereby enhancing the intestinal barrier function. This process was associated with the reinforcement of claudin-3 immunostaining, especially on the surface epithelium of villin-Cre PTEN^flox/flox mice. Conclusions: PTEN inactivation exerts a protective effect on the onset of colitis, and the transient and local down-modulation of PTEN might constitute an approach to drive recovery following acute intestinal inflammation. Full article

Patients with ulcerative colitis exhibit an increased risk for supraventricular arrhythmia during the active disease phase of the disease and show signs of atrial electrophysiological remodeling in remission. The goal of this study was to determine the basis for colitis-induced changes in atrial excitability. In a mouse model (C57BL/6; 3 months) of dextran sulfate sodium (DSS)-induced active colitis (3.5% weight/volume, 7 days), electrocardiograms (ECG) revealed altered atrial electrophysiological properties with a prolonged P-wave duration and PR interval. ECG changes coincided with a decreased atrial conduction velocity in Langendorff perfused hearts. Action potentials (AP) recorded from isolated atrial myocytes displayed an attenuated maximal upstroke velocity and amplitude during active colitis, as well as a prolonged AP duration (APD). Voltage clamp analysis revealed a colitis-induced shift in the voltage-dependent activation of the Na-current (I_Na) to more depolarizing voltages. In addition, protein levels of Na_v1.5 protein and connexin isoform Cx43 were reduced. APD prolongation depended on a reduction in the transient outward K-current (I_to) mostly generated by K_v4.2 channels. The changes in ECG, atrial conductance, and APD were reversible upon remission. The change in conduction velocity predominantly depended on the reversibility of the reduced Cx43 and Na_v1.5 expression. Treatment of mice with inhibitors of Angiotensin-converting enzyme (ACE) or Angiotensin II (AngII) receptor type 1 (AT1R) prevented the colitis-induced atrial electrophysiological remodeling. Our data support a colitis-induced increase in AngII signaling that promotes atrial electrophysiological remodeling and puts colitis patients at an increased risk for atrial arrhythmia. Full article

Background/Objectives: Keratins form a crucial component of the epithelial cytoskeleton, playing an essential role in maintaining tissue architecture and coordinating key cellular functions. KRT80 is a type II keratin that has emerged as an oncogenic driver in several malignancies, yet its involvement in colorectal cancer (CRC) remains unclear. Here, we investigated the molecular interaction between miR-195-5p, KRT80 expression, and CRC growth. Methods: Potential miR-195-5p binding sites in the KRT80 3′-UTR were identified through the use of integrated bioinformatic analyses, while publicly available datasets confirmed a significant overexpression of KRT80 in CRC tissues compared to normal mucosa. This finding was further validated through the use of mRNA and protein analysis in paired tumor and adjacent normal samples from CRC patients. Results: Functional assays involving CRC cell lines showed that transfection with miR-195-5p mimics led to a significant downregulation of KRT80 expression, reflecting the effects of direct KRT80 silencing by siRNA. Both molecular approaches induced G₁-phase cell cycle arrest, concomitantly with reductions in G₂/M populations. Furthermore, the in vivo delivery of miR-195-5p mimics in a mouse model of colitis-associated CRC resulted in a significant reduction in Krt80 expression in the colon. Conclusions: Collectively, our results reveal that miR-195-5p negatively regulates KRT80 expression, contributing to its tumor-suppressive activity in colorectal cancer and highlighting a molecular mechanism with potential therapeutic relevance. Full article

Background/Objectives: Inflammatory bowel disease (IBD) is a chronic inflammatory condition encompassing ulcerative colitis (UC) and Crohn’s disease (CD). The role of environmental factors in the pathogenesis of IBD remains elusive. Nevertheless, evidence suggests a pivotal role of viruses, specifically Epstein–Barr virus (EBV), in the progression of IBD through mechanisms such as molecular mimicry and bystander activation. Our previous findings demonstrate EBV DNA’s significant role in exacerbating colitis symptoms and elevating the levels of the pro-autoimmune cytokine interleukin-17A (IL-17A) in an IBD mouse model via toll-like receptor 9 (TLR9). Therefore, we aimed to examine the role of EBV particles in the pathogenesis of IBD, and the potential role of TLR9 inhibition in ameliorating disease outcomes. Methods: Three days post colitis induction, EBV particles were intra-rectally injected into female C57BL/6J mice, followed by the intra-peritoneal administration of TLR9 inhibitor. Thereupon, mice were monitored daily and the disease activity index (DAI), colon lengths, and damage scores, as well as the number of cells, double-positive for IL-17A+ and IFN-γ+, and triple-positive for IL-17A+, IFN-γ+, and FOXP3+, were evaluated. Results: Our findings revealed a significant role of TLR9 inhibition in mitigating colitis features in an EBV-injected IBD mouse model compared to the control group. Conclusions: These results indicate an essential role of TLR9 in initiating immune responses against recurrent EBV reactivation events, which ultimately contributes to inflammation aggravation in IBD patients. Consequently, TLR9 could serve as a potential therapeutic target to alleviate the severe symptoms of IBD in EBV-infected individuals. Full article

The linear polymer polyphosphate (polyP) is found across all three domains of life and fulfills diverse physiological functions, including phosphorus storage, chaperone activity, and stress tolerance. In bacteria, polyP synthesis is catalyzed by polyphosphate kinase (Ppk), whereas its degradation is carried out by exopolyphosphatases (Ppx). Intracellular polyP levels are determined by the balance between these opposing enzymatic activities, although the regulatory mechanisms governing this balance remain incompletely understood. In higher eukaryotes, polyP participates in diverse physiological processes from cell signaling to blood clotting. In relation to this, polyP from Levilactobacillus brevis has been identified as a protective factor against intestinal damage in a mouse model of acute colitis. Subsequent evidence has confirmed that polyP can confer beneficial effects on human intestinal health, prompting an increased interest in the production of polyP by probiotic lactic acid bacteria. Furthermore, polyP is extensively used in the food industry to enhance food quality, preservation, and nutritional value. This review summarizes the current knowledge on polyP metabolism in these bacteria and explores its functional properties and potential applications. Full article

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) associated with recurrent inflammation and ulceration of the colonic mucosa. Conventional treatments, including corticosteroids, have significant side effects, driving the need for safer, effective alternatives. The present study aimed to investigate the mitigating effects of Epilobium angustifolium extract (EAE) in a Dextran sulfate sodium (DSS)-induced colitis mouse model, in a comparative manner to the reference drug dexamethasone (DXM). The severity and progression of colitis were evaluated through disease activity indices and a range of inflammatory and oxidative stress markers, assessed using multiple analytical methods. EAE treatment significantly reduced colonic inflammation, as indicated by decreased myeloperoxidase (MPO) activity, lower levels of malondialdehyde (MDA), and reduced white blood cell counts. EAE also enhanced antioxidant defenses, increasing glutathione (GSH) levels by 64%, and boosting catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities by 36%, 53%, and 70%, respectively. Histopathological analysis confirmed EAE’s efficacy in attenuating colonic injury and inflammation. The blood parameters hemoglobin, erythrocytes, and hematocrit were also improved. Our study shows that EAE has potential as a natural therapeutic candidate for the treatment of UC, demonstrating efficacy comparable to that of conventional pharmacological treatments. Full article

Ulcerative colitis (UC) is the most prevalent inflammatory bowel disease (IBD) in the USA. Current treatments present clinical limitations, underscoring the need for innovative therapeutics that promote an anti-inflammatory immune response. This study evaluates the anti-inflammatory potential of Fh15, a recombinant Fasciola hepatica fatty acid binding protein, in a DSS-induced UC mouse model. Our results demonstrated that Fh15 treatment significantly ameliorated the severity of colitis by reducing the disease activity index (DAI) and histopathological scores. Moreover, Fh15 also decreased the serum levels of myeloperoxidase (MPO) and chitinase-3-like protein 1 (CHI3L1), and the expression of S100A9, a calcium and zinc binding protein, which is an important marker for the pathogenesis of UC. Furthermore, Fh15 downregulated pro-inflammatory cytokines TNFα and IL-1β in the distal colon, suggesting modulation of macrophage activity. Immunohistochemistry analysis revealed significantly reduced neutrophil and macrophage infiltration in UC Fh15-treated mice. These findings highlight the therapeutic potential of Fh15 for UC, as it modulates inflammatory responses, reduces leukocyte infiltration, and preserves colon integrity. Full article

In this study, large yellow croaker (Pseudosciaena crocea) protein isolates/gellan gum (PG) binary hydrogels with dense microstructure were used for embedding and delivery curcumin (Cur). The colitis-relieving effects of PG-Cur were further investigated using the dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mouse model. Following PG-Cur treatment, weight loss, diarrhea, and shortening of the colon were significantly alleviated. Compared with the free Cur group, weight loss and colon length in the PG-Cur group increased about 1.05- and 1.12-fold. IL-1β, IL-6, TNF-α, and IL-10 levels in PG-Cur group were not significantly different from those of the normal mice, and the MPO and iNOS activities of the PG-Cur group were 29% and 20% lower than those in the Cur group, respectively. Moreover, fecal microbiota analysis of mice revealed that PG-Cur effectively restored gut dysbiosis in DSS-induced colitis, enriching beneficial bacteria while reducing harmful ones. Overall, the PG hydrogels have the potential to serve as carriers for oral curcumin formulations aimed at alleviating UC. Full article

The pathogenesis of inflammatory bowel diseases (IBD), such as ulcerative colitis and Crohn’s disease, remains incompletely understood. Amomum villosum Lour. (Zingiberaceae) is a traditional herbal medicine used across Asia to treat digestive and inflammatory disorders. This study investigated the therapeutic effects of a water extract derived from the fruits of AV (referred to as AVE) in a mouse model of colitis induced by dextran sulfate sodium (DSS). The protective effects of AVE were evaluated by monitoring changes in body weight and colon length, as well as histological and molecular markers of inflammation. Neutrophil infiltration and levels of inflammatory cytokines in colon tissue and serum were assessed, and the integrity of the intestinal epithelial barrier was examined via Western blot analysis. Treatment with AVE significantly alleviated DSS-induced colitis, as evidenced by improved body weight, longer colon length, and reduced inflammatory responses. AVE administration restored tight junction protein expression (zonula occludens-1 [ZO-1] and occludin), suppressed phosphorylation of mitogen-activated protein kinases—specifically, extracellular signal-regulated kinase (ERK) and p38—and inhibited the expression of inflammatory mediators including tumor necrosis factor-alpha (TNF-α), cyclooxygenase-2 (COX-2), interleukin (IL)-6, IL-1β, and myeloperoxidase (MPO) activity. These findings suggest that oral AVE treatment effectively protects against experimental colitis by modulating inflammatory signaling and preserving epithelial barrier integrity. Further studies are warranted to explore the clinical potential and safety of AVE in the management of IBD. Full article

Autoimmune and inflammatory diseases are characterized by aberrant immune responses. The immunoproteasome was proposed as a target for such Th cell-mediated diseases due to its role in the activation, differentiation and function of T cells. Even though many studies demonstrated reductions in Th17 cells upon immunoproteasome inhibition, it is still unclear if the differentiation or survival of these cells is affected. Therefore, this study used DSS-induced colitis and house dust mite airway inflammation mouse models to investigate the effect of immunoproteasome inhibition on Th17 cells and Tregs at different time points. Th17 cells were almost abolished when immunoproteasome inhibition was applied continuously in DSS-induced colitis. In contrast, immunoproteasome inhibition did not decrease levels of already differentiated Th17 cells and did not enhance Treg induction. Dendritic cells were barely affected by immunoproteasome inhibition. Moreover, immunoproteasome inhibition reduced T cell activation in vitro and in vivo, suggesting impaired activation as the underlying mechanism for reduced Th17 differentiation. In conclusion, immunoproteasome inhibition reduces Th17 differentiation by impairing the activation of naïve T cells, but it does not affect the survival of already-differentiated Th17 cells and Tregs. Full article

Ulcerative colitis (UC) is characterized clinically by intestinal inflammation and gut microbiota dysbiosis. The consumption of biologics, although effective in inflammation control, may lead to adverse effects and is inconvenient for at-home administration. Goat milk-derived extracellular vesicles (GMEVs) have been proposed as a supplement to prevent intestinal inflammation. However, their therapeutic potential for colitis remains elusive. This study aimed to explore the preventive effect of GMEVs on colitis and its underlying mechanisms through the microbiota-immune axis using a dextran sodium sulfate (DSS)-induced colitis mouse model. We found that a pre-treatment of 20 mg/kg/d GMEVs effectively prevented body weight loss, colon shortening, the depletion of colonic goblet cells, and the disappearance of crypts, while enhancing the intestinal mucosal barrier. Consistent with these phenotypes, GMEV pre-treatment increased levels of IL-22 and IL-10 and decreased levels of IL-1β, TNF-α, IL-6, and iNOS. However, GMEVs themselves had no effect on normal mice. Paralleling the alleviation of intestinal inflammation, GMEV pre-treatment also restored the reduction in unclassified Muribaculaceae, Dubosiella, and Lactobacillus and suppressed the expansion of Alistipes and Proteobacteria following DSS treatment. Additionally, GMEV intake significantly downregulated the expression of proteins in the NF-κB signaling pathway induced by DSS. In summary, GMEVs could prevent colitis by regulating intestinal inflammation, the intestinal mucosal barrier, gut microbiota, organ damage, and the immune microenvironment. This study demonstrated that GMEVs have potential application prospects for UC prevention. Full article