Search Results (382)

Cystic fibrosis (CF), the most common hereditary lung disease in Caucasians, is caused by dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR). We evaluated CFTR function using a newly developed Ussing chamber system, the Multi Trans Epithelial Current Clamp (MTECC), in an in vitro model of human airway epithelia. Air–liquid interface (ALI) cultures were established from nasal brushings of healthy controls (HC) and CF patients with biallelic CFTR variants. ALI layer thickness was similar between groups (HC: 62 ± 13 µm; CF: 55 ± 9 µm). Immunofluorescence showed apical CFTR expression in HC, but reduced or absent signal in CF cultures. MTECC enabled continuous measurement of transepithelial resistance (Rt), potential difference (PD), and conductance (G_t). G_t was significantly reduced in CF cultures compared to HC (0.825 ± 0.024 vs. −0.054 ± 0.016 mS/cm²), indicating impaired cAMP-inducible ion transport by CFTR. Treatment of CF cultures with elexacaftor, tezacaftor, and ivacaftor (Trikafta^®) increased G_t, reflecting partial restoration of CFTR function. These findings demonstrate the utility of MTECC in detecting functional differences in CFTR activity and support its use as a platform for evaluating CFTR-modulating therapies. Our model may contribute to the development of personalized treatment strategies for CF patients. Full article

Disruption of the intestinal epithelial barrier is a key driver of gut-derived inflammation in various disorders, yet strategies to preserve or restore barrier integrity remain limited. To address this, we evaluated a four-strain Bifidobacterium mixture—selected for complementary anti-inflammatory potency and industrial scalability—in lipopolysaccharide (LPS)-challenged RAW 264.7 macrophages and a Caco-2/THP-1 transwell co-culture model. Pretreatment with the probiotic blend reduced nitric oxide (NO) release in a dose-dependent manner by 25.9–48.3% and significantly down-regulated the pro-inflammatory markers in macrophages. In the co-culture system, the formulation decreased these markers, increased transepithelial electrical resistance (TEER) by up to 31% at 10⁵ colony-forming unit (CFU)/mL after 48 h, and preserved the membrane localization of tight junction (TJ) proteins. Adhesion to Caco-2 cells (≈ 6%) matched that of the benchmark probiotic Lacticaseibacillus rhamnosus GG, suggesting direct epithelial engagement. These in vitro findings demonstrate that this probiotic mixture can attenuate LPS-driven inflammation and reinforce epithelial architecture, providing a mechanistic basis for its further evaluation in animal models and clinical studies of intestinal inflammatory disorders. Full article

Oxidative stress, driven by impaired antioxidant defence systems, is a major contributor to cognitive decline and neurodegenerative processes in brain ageing. This study investigates the neuroprotective effects of a natural compound mixture—composed of Hericium erinaceus, Palmitoylethanolamide, Bilberry extract, and Centella asiatica—using a multi-step in vitro strategy. An initial evaluation in a 3D intestinal epithelial model demonstrated that the formulation preserves barrier integrity and may be bioaccessible, as evidenced by transepithelial electrical resistance (TEER) and the expression of tight junctions. Subsequent analysis in an integrated gut–brain axis model under oxidative stress conditions revealed that the formulation significantly reduces inflammatory markers (NF-κB, TNF-α, IL-1β, and IL-6; about 1.5-fold vs. H₂O₂), reactive oxygen species (about 2-fold vs. H₂O₂), and nitric oxide levels (about 1.2-fold vs. H₂O₂). Additionally, it enhances mitochondrial activity while also improving antioxidant responses. In a co-culture of neuronal and astrocytic cells, the combination upregulates neurotrophic factors such as BDNF and NGF (about 2.3-fold and 1.9-fold vs. H₂O₂). Crucially, the formulation also modulates key biomarkers associated with cognitive decline, reducing APP and phosphorylated tau levels (about 98% and 1.6-fold vs. H₂O₂) while increasing Sirtuin 1 and Nrf2 expression (about 3.6-fold and 3-fold vs. H₂O₂). These findings suggest that this nutraceutical combination may support the cellular pathways involved in neuronal resilience and healthy brain ageing, offering potential as a functional food ingredient or dietary supplement. Full article

Background/Objectives: Selective serotonin reuptake inhibitors (SSRIs), widely prescribed for anxiety disorders, may negatively impact the gut microbiota, contributing to dysbiosis. Considering the gut–brain axis’s importance in mental health, probiotics could represent an effective adjunctive strategy. This study evaluated the effects of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 on microbiota composition, metabolic activity, and immune markers in fecal samples from patients with anxiety on SSRIs, using the SHIME^® (Simulator of the Human Intestinal Microbial Ecosystem) model. Methods: The fecal microbiotas of four patients using sertraline or escitalopram were inoculated in SHIME^® reactors simulating the ascending colon. After stabilization, a 14-day probiotic intervention was performed. Microbial composition was assessed by 16S rRNA sequencing. Short-chain fatty acids (SCFAs), ammonia, and GABA were measured, along with the prebiotic index (PI). Intestinal barrier integrity was evaluated via transepithelial electrical resistance (TEER), and cytokine levels (IL-6, IL-8, IL-10, TNF-α) were analyzed using a Caco-2/THP-1 co-culture system. The statistical design employed in this study for the analysis of prebiotic index, metabolites, intestinal barrier integrity and cytokines levels was a repeated measures ANOVA, complemented by post hoc Tukey’s tests to assess differences across treatment groups. For the 16S rRNA sequencing data, alpha diversity was assessed using multiple metrics, including the Shannon, Simpson, and Fisher indices to evaluate species diversity, and the Chao1 and ACE indices to estimate species richness. Beta diversity, which measures microbiota similarity across groups, was analyzed using weighted and unweighted UniFrac distances. To assess significant differences in beta diversity between groups, a permutational multivariate analysis of variance (PERMANOVA) was performed using the Adonis test. Results: Probiotic supplementation increased Bifidobacterium and Lactobacillus, and decreased Klebsiella and Bacteroides. Beta diversity was significantly altered, while alpha diversity remained unchanged. SCFA levels increased after 7 days. Ammonia levels dropped, and PI values rose. TEER values indicated enhanced barrier integrity. IL-8 and TNF-α decreased, while IL-6 increased. GABA levels remained unchanged. Conclusions: The probiotic combination of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 modulated gut microbiota composition, metabolic activity, and inflammatory responses in samples from individuals with anxiety on SSRIs, supporting its potential as an adjunctive strategy to mitigate antidepressant-associated dysbiosis. However, limitations—including the small pooled-donor sample, the absence of a healthy control group, and a lack of significant GABA modulation—should be considered when interpreting the findings. Although the SHIME^® model is considered a gold standard for microbiota studies, further clinical trials are necessary to confirm these promising results. Full article

Impedance-based cellular assays allow determination of biological functions of cell populations in real-time by measuring electrical impedance. As compared to end-point assays, such as trans-epithelial electrical resistance assays, for example, they enable fast, non-invasive, and easy detection of cell kinetics—their growth, attachment, and interaction can be monitored over time. In our experiment, Caco-2 cells were cultured on E-plates 16. Next, fully differentiated cells were treated with either TNF-α or 3,4-dihydroxy-L-phenylalanine (L-DOPA). We aimed to verify the possibility of real-time testing of the viability, monolayer formation, and integrity (i.e., the presence of a functional and polarized monolayer) of Caco-2 cells by the xCELLigence real-time cell analyzer (RTCA) S16 system (Agilent Technologies). Full article

Chickpeas are used as alternative protein sources in healthy snacks due to their bioactive compounds beneficial for gut health. Combining chickpeas with dark chocolate improves palatability and may enhance biological functionality, although mechanistic evidence is still limited. In this explorative research, we evaluate the nutrigenomic, antioxidant and anti-inflammatory properties of a chickpea and chocolate snack using in vitro Caco-2 (colon adenocarcinoma cells) and THP-1 (monocyte-derived macrophages) models. The total polyphenol content and antioxidant activity were measured after in vitro digestion (30.30 mg/mL to 1.9 mg/mL). Caco-2 epithelia and THP-1 were pre-treated for 4 days (2 h/day) with high (15.1 mg/mL) or low (3.8 mg/mL) concentrations of digests. Inflammation was induced for 3 h by LPS (Lipopolysaccharides) and IL-1β (Interleukin-1β). Transepithelial electrical resistance (TEER) was measured to assess barrier integrity. Gene expression related to tight junctions and inflammation was analysed using qPCR (quantitative polymerase chain reaction). Chocolate and snack digests showed the highest total polyphenol content and 2,2-diphenyl-1-picrylhydrazyl activity. Barrier integrity improved with all treatments. Chickpea upregulated tight junction gene expression. Chickpea and chocolate reduced IL-1β expression in both cell types. In THP-1, the chocolate and the snack upregulated CD206 (mannose receptor C-type 1) expression. IL-10 increased with all treatments. These results pave the way for future research that may support the potential use of this snack as a functional food with antioxidant, gut-protective and anti-inflammatory effects. Full article

Age-related macular degeneration (AMD) is the main cause of blindness in Western nations. AMD models addressing specific pathological pathways are desired. Through this study, a best-practice protocol for polarized porcine single-eye retinal pigment epithelium (RPE) preparation for AMD-relevant models of RPE barrier and polarity is established. Single-eye porcine primary RPE cells (from one eye for one well) were prepared in 12-well plates including Transwell inserts. Different coatings (laminin (Lam), Poly-ᴅ-Lysine (PDL), fibronectin (Fn) and collagens) and varying serum contents (1%, 5% and 10%) were investigated to determine optimal culture parameters for this model. Success rates of cultures, cell number (trypan-blue exclusion assay), morphology/morphometry (light and fluorescence microscopy), protein secretion/expression (ELISA, Western blot), gene expression (qPCR), transepithelial electric resistance (TEER) and polar location of bestrophin 1 (BEST1) by cryosectioning (IHC-Fr) were assessed. Cells seeded on Lam exhibited the highest level of epithelial cells and confluence properties. Fn resulted in the highest cell number growth. Lam and Fn exhibited the highest culture success rates. TEER values and vascular endothelial growth factor secretion were highest when Lam was used. For the first time, polar (Transwell) porcine single-eye RPE morphometry parameters were determined. RPE on Lam showed bigger cells with a higher variety of cell shapes. CIV displayed the lowest claudin 19 expression. The highest basolateral expression of BEST1 was achieved with Lam coating. The higher the serum, the better the cell number increase and confluence success. A reduction in serum on Lam showed positive results for RPE morphology, while morphometry remained stable. A five percent serum on Lam showed the highest culture success rate and best barrier properties. RPE65 expression was reduced by using 10% serum. Altogether, the most suitable coating of Transwell inserts was Lam, and a reduction in serum to 5% is recommended, as well as a cultivation time of 28 days. A protocol for the use of polar porcine single-eye cultures with validated parameters was established and is provided herein. Full article

Previously, we developed a porcine bronchial epithelial cell line designated as PBE cells and demonstrated that this cell line possesses functional Toll-like receptor 3 (TLR3), triggering the expressions of interferons (IFNs), antiviral factors, and inflammatory cytokines after its stimulation with the synthetic double-stranded ARN poly(I:C). In this work, we aimed to further characterize the PBE cell line as a reliable in vitro model for investigating swine influenza virus (SIV) infection and immunity. We evaluated the capacity of two SIV subtypes, H1N1 and H3N2, to replicate and induce cytopathic effects in PBE cells and to modulate the expressions of IFNs, antiviral factors, inflammatory cytokines, and negative regulators of the TLR signaling. We demonstrated that PBE cells are susceptible to both H1N1 and H3N2. SIV infected PBE cells inducing notable cytopathic effects as shown by the alteration of transepithelial electrical resistance (TEER) and cilia. Both SIV subtypes replicated in PBE cells in similar proportion and altered TEER values in comparable magnitudes. However, SIV H3N2 induced higher alterations of cilia than H1N1. SIV infection induced changes in all the immune factors evaluated in PBE cells. We detected quantitative differences when the subtypes H1N1 and H3N2 were compared. The fold expression changes of IFN-β, Mx1, Mx2, IFITM1, OAS1, OAS2, and OASL were higher in PBE cells infected with H3N2 than in cells challenged with H1N1. In addition, although both subtypes stimulated IL-8 expression, only the H3N2 induced IL-6 in infected PBE cells. SIV H1N1 and H3N2 also upregulated the expressions of the negative regulators A20, BCL-3, and MKP-1, while only H1N1 increased SIGIRR and Tollip. Immortalized respiratory cell lines from pigs can be useful in vitro systems for the study of viral infections and immune responses. These studies are of importance in the context of influenza infections not only for the agricultural field because pigs are natural hosts of these viruses but also because these animals serve as intermediate reservoirs of viruses that can threaten humans’ health. We demonstrated here that the PBE cell line can be a useful in vitro model to study SIV infection and immunity. 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

Esophageal barrier dysfunction is a crucial pathophysiological mechanism of gastroesophageal reflux disease (GERD). However, treatments mainly aim to reduce gastric acidity rather than improve tissue integrity. This study evaluated the protective and mucoadhesive properties of a formulation containing xyloglucan, pea proteins, and polyacrylic acid (XPPA) in gastric and esophageal cells. Cells were exposed to hydrochloric acid (HCl) and subsequently treated with the test compound. Trans-epithelial electrical resistance (TEER), tight junction (TJ) expression, and mucoadhesion of XPPA on gastric and esophageal cells were evaluated. To further confirm the protective ability of XPPA, a Lucifer Yellow assay was performed on a human reconstructed esophageal epithelium to assess the ability of XPPA to prevent HCl-induced hyperpermeability. XPPA possesses noteworthy mucoadhesive properties, ensuring an extended contact time between the product and the damaged mucosa to allow sustained mucosal protection. Furthermore, XPPA effectively restored gastroesophageal barrier integrity after HCl-induced damage, as assessed with TEER, after 1 h (p < 0.05). Finally, XPPA helped to restore TJ expression (p < 0.05) and protected the tissues from hyperpermeability for at least 2 h (p < 0.05). These results pave the way for using XPPA as a promising treatment to ameliorate gastroesophageal barrier properties in GERD patients. Full article

Butyrate and its derivatives may influence inflammatory status and physiology in a variety of organisms and organ systems. Inflammatory conditions of the gastrointestinal tract, such as post-weaning diarrhea, negatively impact swine. Dietary intervention with butyrate-based compounds should be considered a strategy to improve disease resistance in pigs. We aimed to assess the properties of different forms of butyrate treatments using porcine cell culture experiments. This assessment may inform future in vivo feed experiments designed to determine its potential application of the dietary supplements for pigs. An intestinal porcine enterocyte cell line, IPEC-J2, was seeded at 5 × 10³ cells/mL in 96-well plates to confirm cell viability by MTT assay for each dose range used in the current experiments (0, 0.5, 1, 2, 4 mM butyric acid or tributyrin; 0, 1, 2, 4, 8 mM sodium butyrate or monobutyrin). For transepithelial electrical resistance (TEER) analysis, IPEC-J2 was seeded at 5 × 10⁵ cells/mL in 12-well transwell inserts and treated with 5 levels of each butyrate derivative after adherence (n = 5). TEER was measured at 24, 48, and 72 h post-treatment to quantify intestinal barrier integrity of IPEC-J2 monolayers. Butyric acid, sodium butyrate, and monobutyrin significantly increased (p < 0.05) TEER in IPEC-J2 at different time points compared with control. Further, porcine alveolar macrophages (PAMs) were harvested from donor weaned piglets (n = 6) via bronchoalveolar lavage and isolated for primary culture (6 × 10⁵ cells/well, 6-well plates). PAMs were treated with five levels of each butyrate derivative with or without lipopolysaccharide (LPS, 1 μg/mL) challenge. The concentrations of TNF-α and IL-1β in cell culture supernatants were measured by enzyme-linked immunosorbent assay (ELISA). Butyric acid and sodium butyrate treatments reduced the production of TNF-α in LPS-challenged PAMs (linear; p < 0.05). Different butyrate derivatives exerted anti-inflammatory properties and improved intestinal barrier integrity. Full article

Acrylamide, a harmful substance generated during the normal thermal treatment of foods, has been shown to adversely affect human health, particularly the vital intestinal barrier function. Meanwhile, natural polysaccharides are recognized to exert an important biofunction in the intestine by protecting barrier integrity. In this study, the non-starch, water-soluble, and nondigestive yam polysaccharide (YP) was extracted from fresh Chinese yam, while two selenylated derivatives with different extents of selenylation were prepared via the HNO₃-Na₂SeO₃ reaction system, and designated as YPSe-I and YPSe-II, respectively. Their protective activities and the associated molecular mechanisms of these substances against acrylamide-induced damage in rat intestinal epithelial (IEC-6) cells were thereby investigated. The experimental results demonstrated that the selenium contents of YPSe-I and YPSe-II were 0.80 and 1.48 g/kg, respectively, whereas that of the original YP was merely 0.04 g/kg. In IEC-6 cells, in comparison with YP, both YPSe-I and YPSe-II showed higher efficacy than YP in alleviating acrylamide-induced cell toxicity through promoting cell viability, suppressing the release of lactate dehydrogenase, and decreasing the generation of intracellular reactive oxygen species. Both YPSe-I and YPSe-II could also manifest higher effectiveness than YP in maintaining cell barrier integrity against the acrylamide-induced barrier disruption. The mentioned barrier protection was achieved by increasing transepithelial electrical resistance, reducing paracellular permeability, facilitating the distribution and expression of F-actin between the cells, and up-regulating the production of three tight junctions, namely ZO-1, occludin, and claudin-1. Additionally, acrylamide was observed to trigger the activation of the MAPK signaling pathway, thereby leading to cell barrier dysfunction. In contrast, YPSe-I and particularly YPSe-II were capable of down-regulating two MAPK-related proteins, namely p-p38 and p-JNK, and thereby inhibiting the acrylamide-induced activation of the MAPK signaling pathway. Moreover, YPSe-II in the cells was consistently shown to provide greater barrier protection than YPSe-I. In conclusion, chemical selenylation of YP could cause higher activity in mitigating acrylamide-induced cytotoxicity and intestinal barrier dysfunction, while the efficacy of activity enhancement was positively affected by the selenylation extent. Full article

(1) Background: Respiratory allergens, particularly ragweed (RW) pollen and house dust mites (HDMs), are major triggers of respiratory inflammation and allergic diseases. This study investigated the impact of single- versus combined-allergen exposure on the barrier function of normal human bronchial epithelial (NHBE) cells cultured at the air–liquid interface (ALI). (2) Methods: NHBE cells were exposed to RW pollen extract (200 µg/mL), HDM extract (200 µg/mL) and their combination at varying concentrations (200 µg/mL, 100 µg/mL, 50 µg/mL, 25 µg/mL). Additional groups included a mixture of Amb a 1, Amb a 11 and Amb a 12 (100 mg/mL) and combinations of Der p 1 with the ragweed allergens (50 mg/mL, 100 µg/mL). Transepithelial electrical resistance (TEER) was recorded over 72 hours to assess barrier integrity, and immunofluorescence (IF) staining for zonula occludens-1 (ZO-1) was performed to evaluate tight junction alterations. (3) Results: TEER measurements showed a significant reduction in epithelial barrier integrity following allergen exposure, with the most pronounced disruption observed with the combined exposure to RW and HDM groups. IF staining confirmed extensive tight junction damage, highlighting their synergistic impact. (4) Conclusions: These findings emphasize the importance of assessing cumulative allergen effects, as combined exposure may exacerbate epithelial dysfunction and represent a key aspect in the management of allergic rhinitis and asthma. Full article

Airway basal cells from chronic obstructive pulmonary disease patients show a reduction in HOXA1 expression and generate an abnormal airway epithelium. Because the specific role of HOXA1 in airway basal cells is not known, we investigated the contribution of HOXA1 in the generation of the airway epithelium, which depends on basal cell proliferation, polarization, and differentiation. Airway stem cells were transduced with an inducible HOXA1 shRNA lentivector to knock down HOXA1 in either proliferating cells or100% confluent cells. The bronchial epithelium expresses HOXA1 near the basement membrane, likely representing basal cells. HOXA1 knockdown in proliferating basal cells attenuated cell proliferation. HOXA1 knockdown in confluent monolayers of basal cells generated an abnormal airway epithelium characterized by goblet cell hyperplasia and an inflammatory phenotype. Compared to the control, HOXA1 knockdown cells showed a decrease in transepithelial resistance, localization of occludin and E-cadherin to the intercellular junctions, reduced expression of occludin but not E-cadherin, and increased expression of TNF-α. Blocking TNF-α increased the expression of occludin in HOXA1 K/D cells. Based on these results, we conclude that HOXA1 plays an important role in cell proliferation, polarization, and differentiation, which are essential steps in airway epithelial generation. Additionally, HOXA1 may regulate occludin expression by inhibiting TNF-α expression. Full article

The kidneys are integral to homeostasis but are susceptible to nephrotoxic compounds. Proximal tubular epithelial cells (PTECs) mediate drug metabolism and transport and are widely used in preclinical studies. However, commercial PTECs are limited in availability and physiological relevance. This study aimed to develop a novel, reliable protocol for isolating and culturing PTECs from human kidney biopsies. Primary PTECs were isolated from kidney biopsies of two patients (MFUM-RPTEC-1 and MFUM-RPTEC-2). Their morphology, population doubling time, transepithelial electrical resistance (TEER), and phenotypic markers were evaluated. Polarization and transporter expression were analyzed using cells cultured on Transwell inserts. Colonies formed within 24–48 h, with confluence reached by 8–10 days and dome (hemicyst) formation by day 13. TEER values peaked at 190 Ω/cm² after 7–14 days, confirming tight junction formation. Immunostaining identified characteristic markers (e.g., SGLT2, OAT1/3, OCT2, P-gp, MRP4, MATE1, N-cadherin, ZO-1, CK-18). Cells cultured on Transwell plates exhibited native polarization, expressing transporters crucial for drug excretion on apical and basolateral surfaces. We present two robust protocols for isolating and characterizing PTECs, offering a scalable method to obtain functional, polarized cells from scarce biopsy material. The isolated PTECs, therefore, present a valuable platform for preclinical studies, especially for drug excretion testing through the expressed transporters. Drug competition for these transporters during tubular secretion is also a common cause of nephrotoxicity. Full article