Search Results (578)

In epithelial cells, nonmuscle myosin-2B (NM2B) shows a cortical localization and is tethered to tight junctions (TJs) and adherens junctions (AJs) by the junctional adaptor proteins cingulin and paracingulin. MDCK cells knock-out (KO) for cingulin show decreased apical membrane cortex stiffness and decreased TJ membrane tortuosity, and the rescue of these phenotypes requires the myosin-binding region of cingulin. Here, we investigated whether NM2B contributes to these phenotypes independently of cingulin by generating and characterizing clonal lines of MDCK cells KO for NM2B. The loss of NM2B resulted in decreased stiffness and increased fluidity of the apical cortex and reduced accumulation of E-cadherin and phalloidin-labeled actin filaments at junctions but had no significant effect on TJ membrane tortuosity. Fluorescence recovery after photobleaching (FRAP) showed that the KO of NM2B increased the dynamics of the TJ scaffold protein ZO-1, correlating with decreased ZO-1 accumulation at TJs. Finally, the KO of NM2B increased cell size in cells grown both in 2D and 3D but did not alter lumen morphogenesis of cysts. These results extend our understanding of the functions of NM2B by describing its role in the regulation of the mechanical properties of the apical membrane cortex and cell size and validate our model about the role of cingulin–NM2B interaction in the regulation of ZO-1 dynamics. Full article

Proanthocyanidins (PACs), also called condensed tannins, are oligomers or polymers composed of flavan-3-ols. This review aimed to explore the potential role of PACs in ameliorating oral health problems, with a particular focus on their effects within the intestine—especially the colon, where most orally ingested PACs are believed to accumulate. Previous studies suggest that PACs can be beneficial in periodontal disease as well as in the osseointegration of dental implants in patients with osteoporosis. Periodontal disease is worsened by lipopolysaccharides (LPS) that enter the bloodstream due to disrupted tight junctions of intestinal epithelial cells, along with inflammatory cytokines released by activated macrophages. A similar mechanism is thought to affect osseointegration: LPS-induced inflammatory cytokines originating in the intestine can enter the bloodstream, contributing to bone loss and impaired integration of dental implants. PACs absorbed by intestinal epithelial cells can function as prooxidants, triggering the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, which strengthens the gut barrier. This enhanced barrier reduces the levels of LPS and inflammatory cytokines in the blood, leading to the alleviation of periodontal inflammation and increased alveolar bone density, thereby promoting better osseointegration of dental implants. Full article

Patulin (PAT) is a mycotoxin commonly found in fruits and contaminated feedstuffs, known for its gastrointestinal and systemic toxicity. However, the mechanisms underlying PAT-induced damage to intestinal epithelial cells remain poorly understood. In this study, we demonstrated that 6.5 µM PAT exposure for 24 h reduced glutamine (GLN) uptake and altered the expression of GLN transporters and related metabolic enzymes in IPEC-J2 cells. This concentration was selected based on previous in vitro studies that reported PAT-induced cytotoxicity in porcine intestinal epithelial cells. Moreover, PAT also upregulated ER stress markers (DDIT3, EIF2AK3, ERN1, and HSPA5) and inflammatory cytokines (IL-8, IL-1β, and TNF-α), while decreasing ZO-1 localization, indicating disrupted epithelial barrier integrity. Although 6 mM GLN supplementation only partially mediated ER stress and inflammatory responses, it more effectively restored ZO-1 localization. A high-throughput screening of 324 natural products was conducted to identify potential protective agents, identifying Nymphoides peltata extract as a promising candidate. Co-treatment with 80 ng/μL N. peltata extract improved GLN uptake, partially alleviated ER stress and inflammation, and significantly restored tight junction structure in PAT-exposed cells. Collectively, these findings suggest that N. peltata could serve as a novel natural therapeutic for enhancing intestinal resilience against PAT-induced toxicity. Specifically, this study highlights the potential use of N. peltata extract as a natural feed additive to protect intestinal health in livestock under mycotoxin stress. Full article

Background: The gut–brain axis (GBA) has been demonstrated to be involved in normal neurodevelopment, with its dysfunction potentially contributing to the onset of mental disorders. In this systematic review and meta-analysis, we aimed to examine the relationship between levels of specific biomarkers of intestinal permeability or inflammation and scores of depressive symptoms or suicidality. Methods: All studies investigating the link between depressive symptoms and/or suicidality and biomarkers associated with intestinal permeability or inflammation were included. Studies providing data for comparisons between two groups—depressive or suicidal patients vs. healthy controls, or suicidal vs. non-suicidal patients—were included in the meta-analysis. Studies examining the correlation between depressive symptoms and biomarker levels were also included into the review. Data were independently extracted and reviewed by multiple observers. A random-effects model was employed for the analysis, and Hedge’s g was pooled for the effect size. Heterogeneity was assessed using the I² index. Results: Twenty-two studies provided data for inclusion in the meta-analysis, while nineteen studies investigated the correlation between depressive symptoms and biomarker levels. For depressive symptoms, when compared to the controls, patients showed significantly increased levels of intestinal fatty acid-binding protein (I-FABP) (ES = 0.36; 95% CI = 0.11 to 0.61; p = 0.004; I² = 71.61%), zonulin (ES = 0.69; 95% CI = 0.02 to 1.36; p = 0.044; I² = 92.12%), antibodies against bacterial endotoxins (ES = 0.75; 95% CI = 0.54 to 0.98; p < 0.001; I² = 0.00%), and sCD14 (ES = 0.11; 95% CI = 0.01 to 0.21; p = 0.038; I² = 10.28%). No significant differences were found between the patients and controls in levels of LPS-binding protein (LBP) and alpha-1 antitrypsin (A-1-AT). For suicidality, four studies were identified for quantitative analysis, three of which focused on I-FABP. No significant differences in I-FABP levels were observed between suicidal patients and the controls (ES = 0.24; 95% CI = −0.30 to 0.79; p = 0.378; I² = 86.44%). Studies investigating the correlation between depressive symptoms and levels of intestinal permeability and inflammation biomarkers did not provide conclusive results. Conclusions: A significant difference was observed between patients with depressive symptoms and controls for biomarkers of intestinal permeability (zonulin, which regulates tight junctions), inflammatory response to bacterial endotoxins (antibodies to endotoxins and sCD14—a soluble form of the CD14 protein that modulates inflammation triggered by lipopolysaccharides), and acute intestinal epithelial damage (I-FABP, released upon enterocyte injury). Studies investigating suicidality and related biomarkers were limited in number and scope, preventing definitive conclusions. Overall, these findings suggest that biomarkers of gut permeability represent a promising area for further investigation in both psychiatric and forensic pathology. They may have practical applications, such as supporting diagnostic and therapeutic decision-making in clinical settings and providing pathologists with additional information to help determine the manner of death in forensic investigations. Full article

Background: The escalating prevalence of food allergies, alongside the global call for environmentally sustainable dietary transitions, has drawn attention to plant-based dietary models—particularly those inspired by the EAT-Lancet Commission. These frameworks not only reduce reliance on animal-sourced foods, benefiting planetary health, but may also play a role in modulating immune tolerance and allergic responses. Methods: This scoping review followed PRISMA guidelines and included 53 peer-reviewed studies published between 2000 and 2024, retrieved from PubMed, Scopus, and Google Scholar. Eligible articles were classified into two thematic domains: prevention of food allergy onset (n = 31) and modulation of allergic symptoms in sensitized individuals (n = 22). Included studies comprised randomized controlled trials (n = 6), observational studies (n = 17), systematic reviews and meta-analyses (n = 11), and narrative/scoping reviews (n = 19). Results: Sustainable plant-based diets were consistently associated with a lower incidence of allergic sensitization and reduced symptom severity. These effects were partly due to the exclusion of common allergens (e.g., dairy, eggs, and shellfish) but more importantly due to immunomodulatory mechanisms. Fermentable fibers can enhance short-chain fatty acid (SCFA)-producing bacteria (e.g., Faecalibacterium prausnitzii), elevating butyrate and acetate levels, which interact with G-protein-coupled receptors 43 and 109A (GPR43 and GPR109A) to induce regulatory T cells (Tregs) and reinforce epithelial integrity via tight junction proteins such as occludin and claudin-1. Polyphenols (e.g., quercetin and luteolin) can inhibit Th2-driven inflammation by stabilizing mast cells and downregulating IL-4 and IL-1. Conclusions: Following sustainable dietary guidelines such as those proposed by the EAT-Lancet Commission may confer dual benefits: promoting environmental health and reducing the burden of allergic diseases. By emphasizing plant-based patterns rich in fiber and polyphenols, these diets support microbiota-mediated immune education, mucosal barrier function, and immunological tolerance. When properly supervised, they represent a promising tool for allergy prevention and symptom management. Larger randomized trials and long-term population studies are needed to confirm and operationalize these findings in clinical and public health contexts. Full article

The spore-forming probiotic Bacillus coagulans JBI-YZ6.3 interacts with the gut epithelium via its secreted metabolites as well as its cell walls, engaging pattern-recognition receptors on the epithelium. We evaluated its effects on human T84 gut epithelial cells using in vitro co-cultures, comparing metabolically active germinated spores to the isolated metabolite fraction and cell wall fraction under unstressed versus inflamed conditions. Germinated spores affected epithelial communication via chemokines interleukin-8, interferon gamma-induced protein-10, and macrophage inflammatory protein-1 alpha and beta after 2 and 24 h of co-culture. Non-linear dose responses confirmed that bacterial density affected the epigenetic state of the epithelial cells. In contrast, the cell wall fraction increased cytokine and chemokine levels under both normal and inflamed conditions, demonstrating that the intact bacterium had anti-inflammatory properties, regulating pro-inflammatory signals from its cell walls. During recovery from mechanical wounding, germinated spores accelerated healing, both in the absence and presence of LPS-induced inflammation; both the metabolite and cell wall fractions contributed to this effect. The release of zonulin, a regulator of tight junction integrity, was reduced by germinated spores after 2 h. These findings suggest that B. coagulans JBI-YZ6.3 modulates epithelial chemokine signaling, supports barrier integrity, and enhances epithelial resilience, highlighting its potential as an efficacious multi-faceted probiotic for gut health. Full article

Objectives: This study was designed to investigate the gastroprotective effects of Citrus reticulata ‘Chachi’ polysaccharide (CRP) against alcohol-induced gastric ulcers (GUs) and to elucidate its underlying mechanisms. Methods: CRP was extracted, purified, and structurally characterized. BALB/c mice (50/250 mg/kg CRP) and GES-1 cells (1 mg/mL CRP) were subjected to alcohol-induced injury. Oxidative stress (SOD, MDA, ROS), inflammation (TNF-α, IL-1β, NLRP3 inflammasome), mucosal barrier proteins (ZO-1, occludin, Claudin-5), and Nrf2/HO-1 signaling were analyzed via histopathology, Western blot, flow cytometry, and immunohistochemistry. Results: CRP pretreatment significantly alleviated gastric lesions, decreased oxidative stress, and suppressed inflammatory responses in alcohol-induced mice. Mechanistically, CRP induced the Nrf2/HO-1 antioxidant pathway while inhibiting the activation of the NLRP3 inflammasome. CRP also restored tight junction protein expression, enhanced mucosal repair, and reduced epithelial apoptosis. In vitro, CRP promoted cell proliferation, migration, and survival of GES-1 cells under alcohol stress. Conclusions: CRP mitigated alcohol-induced GU via dual antioxidant, anti-inflammatory, and barrier-protective mechanisms, positioning it as a considerable agent for GU. Full article

Background: Intestinal epithelial barrier (IEB) dysfunction is related to multiple gastrointestinal disorders, notably inflammatory bowel disease (IBD). Betulinic acid (BA), a compound derived from birch bark, has demonstrated potential therapeutic benefits in IBD. Nevertheless, the impact of BA on IEB function has not been fully elucidated. Methods: The current study aimed to explore the potential underlying mechanisms of BA in dextran sodium sulfate (DSS)-induced IBD in mice and co-culture models involving Caco-2/HT29-MTX-E12 cell monolayers or mouse intestinal organoids (IOs) in conjunction with macrophages stimulated by lipopolysaccharide (LPS). Results: In vivo, BA treatment significantly improved body weight and colon length, alleviated disease activity index (DAI) scores, and reduced colonic histopathological injury in IBD mice. In vitro, BA reduced the flux of FITC-dextran; increased the TEER; and decreased the production of IL-6, IL-1β, and TNF-α while increasing IL-10 mRNA levels. Additionally, BA enhanced IEB formation by upregulating ZO-1, occludin (OCLN), and claudin-1 (CLDN1). Molecular docking studies revealed significant docking scores and interactions between BA and PPAR-γ. Moreover, BA significantly upregulated PPAR-γ protein expression, decreased NF-κB and MLC2 phosphorylation, and reduced MLCK protein expression. However, this effect was reversed by GW9662, an effective PPAR-γ antagonist. Conclusions: The findings reveal that BA mitigates IBD by safeguarding the intestinal barrier against dysfunction. This effect may be attributed to its ability to suppress inflammation and enhance the expression of tight junction proteins by modulating the PPAR-γ/NF-κB signaling pathway. Full article

Saccharomyces boulardii (S. boulardii) has attracted widespread attention due to its antimicrobial and anti-inflammatory properties. In this study, we prepared postbiotics from the heat-inactivated cells (HIC) and cell-free supernatant (CFS) of S. boulardii, with the important component L-arginine (Arg) from the metabolic products included as one of the experimental groups. The results showed that in LPS-stimulated Caco-2 cells, HIC, CFS, and Arg protect intestinal epithelial barrier integrity by inhibiting the expression of TNF-α, IL-1β, and IL-6 while enhancing the expression of occludin and ZO-1 proteins. In dextran sulfate sodium (DSS)-induced colitis mice, HIC, CFS, and Arg alleviate symptoms such as weight loss and colonic damage while suppressing the upregulation of pro-inflammatory factors and the downregulation of tight junction proteins. Moreover, these postbiotics help restore the gut microbiota composition and functionality in colitis mice, with potentially superior regulatory effects compared to sulfasalazine (SASP). Overall, HIC and CFS protect the intestinal barrier function and improve DSS-induced colitis, supporting the development of functional food supplements. Full article

Background/Objectives: Oats and oat bran are rich in dietary fiber, polyphenols and other phytochemicals. Methods: In this study, we evaluated the phytochemical content and established LPS-induced RAW 264.7 macrophage inflammation and DSS-induced Caco-2 cell inflammation models to investigate the anti-inflammatory activities of oat and oat bran polyphenols and their molecular mechanisms. Results: The results showed that oat and oat bran polyphenols (free and bound polyphenols) enhanced phagocytosis, decreased the expression of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), reduced the production of NO and ROS, increased the mitochondrial membrane potential, and reduced the inflammatory cytokines (TNF-α, IL-1β, and IL-6) at the gene level in the RAW 264.7 macrophage inflammation model induced by LPS expression, thus demonstrating strong anti-inflammatory activity. In Caco-2 cells, oat and oat bran polyphenols pretreatment attenuated the DSS-induced decrease in trans-epithelial electron resistance value, increased tight junction protein expression, and reduced cell permeability in Caco-2 cell monolayers, which in turn reduced inflammatory damage in the organism. Conclusions: In summary, the present study not only reveals the mechanism by which oat and oat bran polyphenols inhibit macrophage inflammation and impairment of intestinal barrier function at defined concentration in vitro, but also highlights potential for oat bran as a functional food. Full article

Multiple Sclerosis (MS) is a chronic disease with autoimmune and neurodegenerative features that affect the nervous system. Genetic predisposition and environmental factors, such as vitamin D deficiency and dysbiosis activating a pro-inflammatory response, have a role in the etiology of the disease. In this context, the interactions of vitamin D with the gut microbiota and immune system have attracted attention in recent years. Vitamin D (1,25-dihydroxycholecalciferol) modulates the immune response by binding to the Vitamin D receptor (VDR). This pathway supports the functions of regulatory T cells by suppressing the activity of T helper cells 1 and 17 (Th1 and Th17). In MS patients, dysbiosis is characterized by a decrease in microbial diversity, and an increase in pro-inflammatory species is observed when compared to healthy individuals. Vitamin D has protective effects on eubiosis via VDR in intestinal epithelial cells, also reducing intestinal permeability by regulating tight junction proteins. In this way, vitamin D may contribute to the prevention of systemic inflammation. Although the relationship between vitamin D and the immune system is well documented, studies that address the triad of vitamin D level, gut microbiota, and immune response in MS are still limited. Full article

Biological, physiological, and psychological stressors cause a “stress response” in our bodies. Stressors that are sensorily perceived (either acute or chronic) trigger hormonal responses from the sympathetic nervous system—the SAM and HPA axis—that effect intended organs to alert the individual. Other stressors have a direct effect on the target organ(s) of the body—e.g., physical injury and wounds, toxins, ionizing, and UV radiation. Both kinds of stressors change cell equilibrium, often leading to reactive oxygen species (ROS) accumulation and cellular damage. Among the signaling pathways involved in fighting these stressors, the c-Jun-N-terminal kinases (JNK) respond to diverse kinds of stressors. This review focuses on JNK1 and JNK2, both of which are ubiquitously present in all cell types, and attention is paid to gastrointestinal tract epithelial cells and their response—including tight junction disruption and cytoskeletal changes. We discuss the seemingly opposite roles of JNK1 and JNK2 in helping cells choose pro-survival and pro-apoptotic pathways. We examine the common features of the JNK protein structure and the possibilities of discovering JNK-isoform-specific inhibitors since, although JNK1 and JNK2 are involved in multiple diseases, including cancer, obesity, diabetes, musculoskeletal and liver disease, no cell-specific or isoform-specific inhibitors are available. Full article

Dairy products—encompassing yogurt, kefir, cheese, and cultured milk beverages—are emerging as versatile, food-based modulators of gut microbiota and host physiology. This review synthesizes mechanistic insights demonstrating how live starter cultures and their fermentation-derived metabolites (short-chain fatty acids, bioactive peptides, and exopolysaccharides) act synergistically to enhance microbial diversity, reinforce epithelial barrier integrity via upregulation of tight-junction proteins, and modulate immune signaling. Clinical evidence supports significant improvements in metabolic parameters (fasting glucose, lipid profiles, blood pressure) and reductions in systemic inflammation across metabolic syndrome, hypertension, and IBS cohorts. We highlight critical modulatory factors—including strain specificity, host enterotypes and FUT2 genotype, fermentation parameters, and matrix composition—that govern probiotic engraftment, postbiotic yield, and therapeutic efficacy. Despite promising short-term outcomes, current studies are limited by heterogeneous designs and brief intervention periods, underscoring the need for long-term, adaptive trials and integrative multi-omics to establish durability and causality. Looking forward, precision nutrition frameworks that harness baseline microbiota profiling, host genetics, and data-driven fermentation design will enable bespoke fermented dairy formulations, transforming these traditional foods into next-generation functional matrices for targeted prevention and management of metabolic, inflammatory, and neuroimmune disorders. Full article

Hypoxia is a critical factor affecting tissue homeostasis that dramatically alters the tumor microenvironment (TME) through genetic, metabolic, and structural changes, promoting tumor survival and proliferation. Hypoxia-inducible factor-1α (HIF-1α) plays a central role in this process by regulating hundreds of genes involved in the processes of tumorigenesis, angiogenesis, metabolic reprogramming, and immune evasion. This review provides a comprehensive examination of the role of HIF-1α in hypoxia and how hypoxia weakens intercellular junctions—including gap junctions, adherens junctions, tight junctions, and desmosomes. The disruption of gap junctions decreases intercellular communication, which alters signal transduction cascades and tumor suppressive properties. Adherens junctions are comprised of proteins that characterize the tissues and link cells to the actin cytoskeleton, whereby their disruption promotes the epithelial-to-mesenchymal transition (EMT). Under hypoxic conditions, the tight junction proteins are dysregulated, altering paracellular transport and cell polarity. In addition, desmosomes provide linkage to intermediate filaments, and hypoxia compromises tissue integrity. Collectively, the influence of hypoxia on cellular junctions promotes tumorigenesis through reducing cell communication, cytoskeletal interactions, and altering signaling pathways. Activation of matrix metalloproteinases (MMPs) further degrades the extracellular matrix and enhances tumor invasion and metastasis. This process also involves hypoxia-induced angiogenesis, regulated by HIF-1α. A comprehensive understanding of the mechanisms of hypoxia-driven tumor adaptation is essential for developing effective therapeutic strategies. Furthermore, this review examines current treatments aimed at targeting HIF-1α and explores future directions to enhance treatment efficacy and improve patient outcomes. 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