Response Of Intestinal Cells Research Articles

Analysis of twelve human milk oligosaccharides over fifteen months post-partum in human milk from Chinese mothers

Human milk Oligosaccharides (HMOs) are a major component in human milk and recognized to play an important role in modulating gut microbiota, intestinal cell response, and the development of the brain and immune system. While HMOs levels from Chinese mothers across different regions of China have been reported, data from Hebei are lacking. Twelve HMOs were measured from a cross-section of Hebei Han mothers over a 15-month lactation period. The average total of the 12 measured HMOs was 4872 ± 1902 mg/L, similar to that reported for Han mothers from other Chinese regions. Hebei Han mothers had much lower LNnT (59.0 ± 53.1 mg/L), LNFP II (257.5 ± 211.0 mg/L) and LNFP III (149.9 ± 121.7 mg/L) levels and higher 3FL levels (1875.2 ± 1065.3 mg/L) compared to other regional Chinese mother cohorts. The distribution of secretor and Lewis status for this Hebei mother cohort was measured at 68.5 %, 21.9 %, 8.2 % and 1.4 % respectively for Se+Le+, Se-Le+, Se+Le- and Se-Le- respectively. The results from this study suggest that location has influence over the HMOs concentration.

Two major bovine milk whey proteins induce distinct responses in IEC-6 intestinal cells

Abstract α-Lactalbumin (α-LA) and β-lactoglobulin (β-LG) are major whey proteins in bovine milk. We studied the effects of these molecules on the intestinal cell response by comparing the native form with the denatured form containing oligomers obtained by treatment with 2,2,2-trifluoroethanol (TFE). We previously reported that proteins in native and TFE-treated forms exhibited cell growth stimulation and cytotoxicity, respectively, in undifferentiated rat crypt IEC-6 and human colon Caco-2 cells. However, neither whey protein showed cytotoxicity even in the TFE-treated form in differentiated Caco-2 cells. Only undifferentiated immature intestinal cells can distinguish between these native and denatured proteins. Moreover, α-LA and β-LG exhibited different oligomer formation characteristics during the TFE treatment. In the present study, we compared the effects of native and TFE-treated whey proteins on IEC-6 cells in more detail. The native forms of both whey proteins exhibited cell proliferative effects in a concentration-dependent manner. For the TFE-treated forms, α-LA showed rapid and potent cytotoxicity, whereas β-LG altered cell responses depending on its concentration and exposure time; lower concentration/shorter exposure and higher concentration/longer exposure induced cell growth stimulation and cytotoxicity, respectively. Pre-treatment of the cell membrane with cholesterol suppressed the effects on the cell response only in TFE-treated β-LG (TFE-β-LG). In a preliminary examination using inhibitors of signal transduction, TFE-treated α-LA acted on the intrinsic apoptosis pathway via Bcl-2-associated X and p53, whereas the action of TFE-LG did not require this pathway. Tyrosine phosphorylation is necessary for the cell proliferation effect of both native whey proteins; however, native α-LA, but not native β-LG, also required activation of the pathway with selective epidermal growth factor receptor tyrosine kinase and Janus kinase 2/3. In summary, the two major bovine milk whey proteins induced similar yet discrete responses in undifferentiated intestinal cells. Even when oligomers are formed, β-LG may be much less hazardous to immature intestinal cells than α-LA.

Inhibition of a cyclic nucleotide-gated channel on neuronal cilia activates unfolded protein response in intestinal cells to promote longevity

Ciliary defects are linked to ciliopathies, but impairments in the sensory cilia of Caenorhabditis elegans neurons extend lifespan, a phenomenon with previously unclear mechanisms. Our study reveals that neuronal cilia defects trigger the unfolded protein response of the endoplasmic reticulum (UPR ER ) within intestinal cells, a process dependent on the insulin/insulin-like growth factor 1 (IGF-1) signaling transcription factor and the release of neuronal signaling molecules. While inhibiting UPR ER doesn’t alter the lifespan of wild-type worms, it normalizes the extended lifespan of ciliary mutants. Notably, deactivating the cyclic nucleotide-gated (CNG) channel TAX-4 on the ciliary membrane promotes lifespan extension through a UPR ER -dependent mechanism. Conversely, constitutive activation of TAX-4 attenuates intestinal UPR ER in ciliary mutants. Administering a CNG channel blocker to worm larvae activates intestinal UPR ER and increases adult longevity. These findings suggest that ciliary dysfunction in sensory neurons triggers intestinal UPR ER , contributing to lifespan extension and implying that transiently inhibiting ciliary channel activity may effectively prolong lifespan.

Exposure to benzo(a)pyrene interfered with cell composition and immune ability of common carp (Cyprinus carpio) intestine through inducing cell heterogeneous responses

The intricate heterogeneity of fish intestinal cell types response to environmental stressors has remained largely unaddressed due to previous technological limitations. Emerging single-cell sequencing technology (scRNA-seq), derived from the 2010s, may be a key breakthrough in this area, which could accurately obtain the transcriptome of each cell. In this context, common carp (Cyprinus carpio), which takes the intestine as the main immune organ, was selected as the test subject in this study. The study, mainly based on single-cell sequencing technology and supplemented by gas chromatography mass spectrometry (GC/MS), histological sectioning techniques and transcriptome analysis, revealed the detailed heterogeneity responses of intestinal cells in common carp after benzo(a)pyrene (B[a]P) exposure. Our findings showed a dose-dependent effect on B[a]P accumulation within the common carp intestine as the B[a]P concentration increased. B[a]P exposure led to mucous lamina propria edema and confluent intestinal villi. The high concentration group exhibited uneven and adherent intestinal villi, an abnormal decrease in mucosal epithelial cells, vacuolation, and an anomalously widened base thickness.In the intestinal atlas, an increased proportion of T_cells and a decreased proportion of ECs were identified as the most significant features. These changes primarily affected the intestine by impairing development processes and boosting immunocompetence. A comprehensive analysis of the heterogeneous responses of ECs and T_cells to B[a]P exposure revealed that the lysosome-phagosome pathway, strengthened by the “Lysosome” pathway in the EC1 subset and the “Phagosome” pathway in T_cell 2 subset, might be one of the most critical defense mechanisms within the common carp's intestine. In conclusion, our research presents the first description of the intestinal atlas and the heterogeneous responses in common carp following B[a]P exposure. Our findings enrich the understanding of the impact of polyaromatic hydrocarbons, exemplified by B[a]P, on cyprinidae fish.

Prooxidant capacity of phenolic acids defines antioxidant potential

Phenolic acids derived from vegetables, fruits and beverages are considered abundant sources of natural antioxidants consumed in the human diet. In addition to having well-known antioxidant activity, phenolic acids also exhibit pro-oxidant activity under selected conditions. We hypothesized that the availability of extracellular H2O2 derived from phenolic acid autoxidation will diffuse across cell membranes to participate as a messenger molecule to activate intracellular redox signaling in response to oxidative stress. We report on the relative activity of structurally different phenolic acids to generate specific changes in the extracellular - intracellular H2O2 flux that induces intracellular redox signaling corresponding to a function to reduce intracellular oxidative stress. HyPer-3 methodology was used to measure increases in intracellular H2O2 in differentiated Caco-2 intestinal cells in response to phenolic acid autoxidation and changes in extracellular H2O2 production. The potential for different phenolic acids to autoxidize and generate H2O2 was dependent on the structure and concentration of phenolic acid. Activation of nuclear factor erythroid 2-related factor (Nrf2) cell signaling was enhanced (p < 0.05) by phenolic acid induced H2O2 production, and mitigated when present along with catalase (p < 0.05), or, alternatively by blocking aquaporin 3 (AQP3) function (p < 0.05) using DFP00173 as the AQP3 inhibitor. The relative capacity of phenolic acids to generate H2O2 via autoxidation was structure specific and corresponded to the level of Nrf2 cell signaling in differentiated Caco-2 epithelial cells. The Nrf2-Keap1 response paralleled the extent of reduced oxidative stress observed in differentiated Caco-2 cells determined by dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay.

From worms to humans: Understanding intestinal lipid metabolism via model organisms

The intestine is responsible for efficient absorption and packaging of dietary lipids before they enter the circulatory system. This review provides a comprehensive overview of how intestinal enterocytes from diverse model organisms absorb dietary lipid and subsequently secrete the largest class of lipoproteins (chylomicrons) to meet the unique needs of each animal. We discuss the putative relationship between diet and metabolic disease progression, specifically Type 2 Diabetes Mellitus. Understanding the molecular response of intestinal cells to dietary lipid has the potential to undercover novel therapies to combat metabolic syndrome.

P914 An adult zebrafish model for adherent-invasive Escherichia coli indicates protection from infection by treatment with probiotic E. coli Nissle

Abstract Background Adherent-invasive Escherichia coli (AIEC) is an opportunistic pathogen associated with major inflammatory bowel disease (IBD), Crohn’s disease (CD) and ulcerative colitis (UC). AIEC is a human commensal but during unfavorable gastric conditions it exhibits pathogenic properties and induces inflammation in the gut, sometimes progressing to inflammation-induced colon cancer. The exact mechanisms for AIEC pathogenesis are still being discovered. As a human opportunistic pathogen, AIEC has few animal models. In recent years, zebrafish have emerged as a useful model for studies of various human pathogens. Here, a zebrafish model to study AIEC infection was developed. Methods Colonization of AIEC from overnight culture was determined with different infectious doses (103, 104, 105 and 106 CFU/ml of infection water) in zebrafish, incubating fish with AIEC in water for 6 h and then in fresh water for 18 h at 28o C. The invasive property of AIEC in zebrafish gut was determine by gentamycin protection assay. Persistent colonization of AIEC in zebrafish gut was also assessed for 10 days. Induction of pro-inflammatory markers such as IL-1β, TNFα, IFNγ and S100A-10b (akin to human calprotectin) in zebrafish intestinal cells in response to AIEC infection was determined by qRT PCR and ELISA. A probiotic strain, E. coli Nissle 1917 (EcN) was used as a therapeutic and prophylactic against AIEC infection. Propionic acid was used to augment the AIEC infection and the efficacy of ECN was tested against the hyper-infectious condition of AIEC in zebrafish. Results Bath inoculation with AIEC resulted in colonization, invasion and tissue disruption in the zebrafish intestine. The AIEC infection induced neutrophil recruitment and showed significant pro-inflammatory responses in zebrafish gut. S100A-10b protein of zebrafish, equivalent of a human IBD marker, calprotectin, was significantly increased in the zebrafish gut during AIEC infection. The probiotic E. coli Nissle 1917 (EcN) reduced AIEC colonization, tissue damage and pro-inflammatory responses in zebrafish in both prophylactic and therapeutic ways. Furthermore, EcN diminished the propionic acid-augmented hyper infection of AIEC in the zebrafish model. Conclusion In this study a new zebrafish model was developed to study the infection and inflammation induced by AIEC. Probiotic strain, EcN was used successfully against AIEC to reduce the inflammation in AIEC-zebrafish model.

Micro-sized polyethylene particles affect cell viability and oxidative stress responses in human colorectal adenocarcinoma Caco-2 and HT-29 cells

Plastic is a widely utilized material and polyethylene is one of the most used plastic types. Microplastics are plastic particles (size <5 mm) which are primarily a micro-size range or results from degeneration of larger plastic pieces in the environment. Drinking water and food are two main human exposure sources for microplastics and consequently effects of microplastics in gastrointestinal tract are considered important. Still, only little is known how microplastics and plastic associated chemicals affect the human health. The aim of our study was to evaluate the ability of micro-sized polyethylene to cause harmful effects in human intestinal cells. Raw ultra-high molecular-weight polyethylene (size 5–60 μm) was used. In addition, polyethylene particles were extracted with ethanol to determine the effect of extraction process on toxicity of the particles. In the experiments, human colorectal adenocarcinoma Caco-2 and HT-29 cells were exposed to polyethylene (0.25–1.0 mg/ml) or extracts for 48 h. After exposure, cell viability and cytotoxicity were assessed with MTT and lactate dehydrogenase assay. Reactive oxygen species (ROS) production was measured with dichlorofluorescin diacetate and cytoplasmic production of superoxide with dihydroethidium and mitochondrial superoxide production with MitoSOX. The 48-h exposure to polyethylene decreased dose-dependently cell viability and increased oxidative stress, especially mitochondrial superoxide production, in both cell lines. Effects on ROS or cytosolic superoxide production were not observed. Also, exposure to extracts decreased cell viability and increased oxidative stress in cell cultures, but there were differences between cell lines. These effects were most probably caused by the remaining particles rather than the compounds released from the plastic during the extraction. In conclusion, our study shows that micro-sized polyethylene and ethanol-extracted polyethylene in high concentrations decreased cell viability and increased oxidative stress responses in intestinal cells. These results contribute to the existing evidence on potential adverse human health effects of microplastics.

Peptide release, radical scavenging capacity, and antioxidant responses in intestinal cells are determined by soybean variety and gastrointestinal digestion under simulated conditions

This research evaluated the association between the different protein and peptide composition of seven soybean varieties and their radical scavenging and antioxidant properties throughout simulated gastrointestinal digestion. Glycinin and β-conglycinin were the primary and more varying proteins among soybean varieties. Protein composition determined the degree of hydrolysis, which negatively correlated with glycinin concentration (r = −0.911). Peptide sequencing evidenced the diversity of released peptides among soybean varieties. Although potentially less absorbable in intestinal cells, bigger peptides exhibited a stronger in silico binding affinity with Keap1 (r = 0.806). Digested soybean radical scavenging and antioxidant properties were positively associated with protein (r = 0.900) and glycinin (r = 0.824) concentration. Soybean digested fractions reduced oxidative stress (21–118%) and cell death in intestinal epithelial cells by activating (1.2–3.6-fold) Nrf2-dependent antioxidant responses. Differences in the protein and peptide composition influence soybean health-promoting properties and will guide the production of healthier soybean-based products.

Immune responses to prebiotics in farmed salmonid fish: How transcriptomic approaches help interpret responses

Within aquaculture, prebiotics are composed of complex carbohydrate molecules that cannot be digested by the fish directly but are metabolised by the microbial communities within the host gut, with the desire that “healthy” bacterial species are promoted with subsequently improved performance of the fish, there are likely some direct responses of intestinal cells to these dietary components. The sources and processing of prebiotics, which fall under the overarching theme of “functional feeds” are highly varied between species and types of prebiotics administered. How these feeds exert their effect, and the host responses are hard to determine, but new technologies and the development of high-throughput technologies (omics) are enabling the mechanisms and methods of action to be further understood. The recent advances in the availability of ‘omics’ technologies with the transition from single gene assays to microarray and RNA-seq in fish health have enabled novel functional ingredients to be analysed. This review will focus on recent studies on targeted gene expression and ‘omics’ technologies to characterize immune responses. Comparisons between the immunomodulatory effect of different prebiotics have been made and specific examples of how transcriptomics techniques have been used to identify immune responses to prebiotics are given.

TANNylation of mesoporous silica nanoparticles and bioactivity profiling in intestinal cells

Tannic acid (TA) is a hydrophilic polyphenol belonging to the family of tannins. Due to the presence of several functional hydroxyl groups, tannic acid is prone to interactions with cell structures, especially surface enzymes or receptor proteins. Here, different TANNylation methods were developed for the modification of mesoporous silica nanoparticles (MSNs) in order to investigate the impact of this surface functionality on the performance/biocompatibility of these nanocarriers. For the particle modification, a tannic acid silane linking-ligand was designed and subsequently installed on the MSN surface using post-grafting procedures. Grafting efficacy as well as the structural and physicochemical characteristics of the resulting particles were assessed. Then, two intestinal cell lines, HT29 and HCEC-1CT, were used for activity profiling, benchmarking the effect on the cytotoxic potential and endoplasmic reticulum (ER) stress response. The structure-activity relationships demonstrated that, in addition to the tannic acid itself, the different chemical linkers used for the binding of the polyphenol play an essential role in driving the biological response of intestinal cells. For equivalent TA concentrations, the type of coupling method not only strongly influences the grafting efficiency, but significantly alters the resulting ER response as well. The results underline that TANNylation is a promising method for enhancing cellular interactions with MSNs, although an adequate linking chemistry has to be implemented.

Foodborne compounds that alter plasma membrane architecture can modify the response of intestinal cells to shear stress in vitro

In order to ensure barrier function, intestinal cells need to respond promptly to biomechanical stimulation and to adapt constantly to physical cues. To this aim, cell membranes are essential and rely extensively on lipid metabolism and turnover. These can be tuned via nutrition, pharmacological treatment, or exposure to xenobiotics, however, knowledge on the impact of lifestyle and diet on intestinal cells' biomechanical compliance is relatively limited. Building on this, two intestinal cell models (non-transformed human colon epithelial cells HCEC-1CT and the colon adenocarcinoma cell line HT-29) were systematically compared in terms of cholesterol content, membrane fluidity, actin cytoskeletal organization, expression of mechano-gated PIEZO1 channels and caveolin-1. Biomechanical compliance was evaluated with the application of fluid shear stress (force response 0.75–1.5 dyn/cm2). As model substances the food contaminant mycotoxin alternariol (AOH, 0.01–10 μM) was chosen in virtue of its putative structural analogy with cholesterol. AOH was compared to the cholesterol lowering agent lovastatin (LOVA, 0.01–10 μM) and to water-soluble cholesterol (MβCD-CHOL, 0.01–10 μg/ml). Exposure to AOH, LOVA and MβCD-CHOL coherently modulated membrane cholesterol, expression of PIEZO1 and caveolin-1 as well as the formation of actin stress fibers. These effects were functionally relevant since they modified the force response profile to fluid shear stress (morphological adaption and [Ca2+]i). In sum, we could demonstrate a novel role for exogenous or endogenous molecules in shaping intestinal mechanotransduction via regulation of cholesterol homeostasis and plasma membrane architecture.

Berberine Attenuates Neonatal Sepsis in Mice By Inhibiting FOXA1 and NF-κB Signal Transduction Via the Induction of MiR-132-3p.

Neonatal sepsis (NS) is a severe syndrome in newborns that is induced by infections, and the initiation and development of NS are closely associated with the function of miRs. In the current study, the effects of berberine, which is a functional component in traditional Chinese medicine (TCM), against NS were assessed by focusing on the interaction of berberine with miR-132-3p-mediated signaling. An NS model was induced using cecal slurry (CS) in vivo and LPS in vitro, and berberine treatment was applies. The changes in survival rate, intestinal structure, and systemic inflammation in mice and the viability, apoptosis, and inflammatory response in intestinal cells were measured. At the molecular level, miR-132-3p levels and the activities of the FOXA1 and NF-κB pathways were analyzed. The data showed that berberine increased the survival rates of CS-induced mice. The intestinal injuries induced by CS were also attenuated by berberine, which was associated with inhibition of the production of systemic IL-6, IL-1β, and TNF-α. At the molecular level, the expression of miR-132-3p was upregulated, suppressing the expression of FOXA1, p-IκBα, and p65 while inducing the expression of IκBα. The effects of berberine on NS-induced impairments were blocked by the injection of the miR-132-3p antagomir, which exacerbated intestinal injuries, induced systemic inflammation, and reactivated the FOXA1 and NF-κB pathways. The findings in the in vivo model were validated with in vitro assays. Collectively, the findings outlined in the current study indicated that berberine had solid protective effects against NS-induced symptoms in newborn mice, and the effects depended on the upregulation of miR-132-3p.

Lactobacillus fermentum (MTCC-5898) alleviates Escherichia coli-induced inflammatory responses in intestinal epithelial cells by modulating immune genes and NF-κB signalling.

Dietary intervention using probiotic bacteria has emerged as a promising preventive strategy in addressing foodborne infections or gastrointestinal disorders. This study investigated the immunomodulatory effects of Lactobacillus fermentum (MTCC-5898) on Escherichia coli-induced inflammatory responses in intestinal epithelial cells. The immune response of intestinal cells (Caco-2) in the presence of probiotic Lact. fermentum was determined during exclusion, competition and displacement of E.coli as the inflammatory agent. To achieve this objective, transcriptional modulation of key immune-related genes (cytokines, pattern recognition receptors and NF-κB), release of cytokines and nuclear translocation of the NF-κB subunit p-65 were studied. Expression of pro-inflammatory cytokines IL-8, TNF-α, IFN-ϒ and IL-23 was high in E.coli-exposed intestinal cells. However, overexpression of these E.coli-induced pro-inflammatory cytokines was prevented by Lact. fermentum during exclusion and competition assays. It also modulated the transcriptional expression of regulatory cytokines (IL-10 and TGF-β), pattern recognition receptors (TLR-2 and TLR-4) and genes associated with master inflammatory regulators (NF-κB and SIGIRR) to reduce E.coli-induced inflammation. The protective effect of Lact. fermentum was further confirmed by suppression of nuclear translocation of cytoplasmic NF-κB subunit (p-65). Lactobacillus fermentum alleviated E.coli-induced inflammatory responses by modulating the NF-κB signalling besides pro-inflammatory and regulatory cytokines expression. Lactobacillus fermentum holds significant promise as a potent nutraceutical that prevents and manages inflammatory gut-associated dysfunctions.

Ketogenesis alleviates TNFα-induced apoptosis and inflammatory responses in intestinal cells

The disturbance of strictly regulated self-regeneration in mammalian intestinal epithelium is associated with various intestinal disorders, particularly inflammatory bowel diseases (IBDs). TNFα, which plays a critical role in the pathogenesis of IBDs, has been reported to inhibit production of ketone bodies such as β-hydroxybutyrate (βHB). However, the role of ketogenesis in the TNFα-mediated pathological process is not entirely known. Here, we showed the regulation and role of HMGCS2, the rate-limiting enzyme of ketogenesis, in TNFα-induced apoptotic and inflammatory responses in intestinal epithelial cells. Treatment with TNFα dose-dependently decreased protein and mRNA expression of HMGCS2 and its product, βHB production in human colon cancer cell lines HT29 and Caco2 cells and mouse small intestinal organoids. Moreover, the repressed level of HMGCS2 protein was found in intestinal epithelium of IBD patients with Crohn's disease and ulcerative colitis as compared with normal tissues. Furthermore, knockdown of HMGCS2 enhanced and in contrast, HMGCS2 overexpression attenuated, the TNFα-induced apoptosis and expression of pro-inflammatory chemokines (CXCL1-3) in HT29, Caco2 cells and DLD1 cells, respectively. Treatment with βHB or rosiglitazone, an agonist of PPARγ, which increases ketogenesis, attenuated TNFα-induced apoptosis in the intestinal epithelial cells. Finally, HMGCS2 knockdown enhanced TNFα-induced reactive oxygen species (ROS) generation. In addition, hydrogen peroxide, the major ROS contributing to intestine injury, decreased HMGCS2 expression and βHB production in the intestinal cells and mouse organoids. Our findings demonstrate that increased ketogenesis attenuates TNFα-induced apoptosis and inflammation in intestinal cells, suggesting a protective role for ketogenesis in TNFα-induced intestinal pathologies.

Glucagon-like peptide-1 regulation by food proteins and protein hydrolysates.

Glucagon-like peptide-1 (GLP-1) is an enterohormone with a key role in several processes controlling body homeostasis, including glucose homeostasis and food intake regulation. It is secreted by the intestinal cells in response to nutrients, such as glucose, fat and amino acids. In the present review, we analyse the effect of protein on GLP-1 secretion and clearance. We review the literature on the GLP-1 secretory effects of protein and protein hydrolysates, and the mechanisms through which they exert these effects. We also review the studies on protein from different sources that has inhibitory effects on dipeptidyl peptidase-4 (DPP4), the enzyme responsible for GLP-1 inactivation, with particular emphasis on specific sources and treatments, and the gaps there still are in knowledge. There is evidence that the protein source and the hydrolytic processing applied to them can influence the effects on GLP-1 signalling. The gastrointestinal digestion of proteins, for example, significantly changes their effectiveness at modulating this enterohormone secretion in both in vivo and in vitro studies. Nevertheless, little information is available regarding human studies and more research is required to understand their potential as regulators of glucose homeostasis.

Differences in Toxic Response Induced by Three Variants of the Diarrheic Shellfish Poisoning Phycotoxins in Human Intestinal Epithelial Caco-2 Cells.

Diarrheic shellfish poisoning (DSP) is caused by the consumption of shellfish contaminated with a group of phycotoxins that includes okadaic acid (OA), dinophysistoxin-1 (DTX-1), and dinophysistoxin-2 (DTX-2). These toxins are inhibitors of serine/threonine protein phosphatases 1 (PP1) and 2A (PP2A), but show distinct levels of toxicity. Aside from a difference in protein phosphatases (PP) inhibition potency that would explain these differences in toxicity, others mechanisms of action are thought to be involved. Therefore, we investigated and compared which mechanisms are involved in the toxicity of these three analogues. As the intestine is one of the target organs, we studied the transcriptomic profiles of human intestinal epithelial Caco-2 cells exposed to OA, DTX-1, and DTX-2. The pathways specifically affected by each toxin treatment were further confirmed through the expression of key genes and markers of toxicity. Our results did not identify any distinct biological mechanism for OA and DTX-2. However, only DTX-1 induced up-regulation of the MAPK transduction signalling pathway, and down-regulation of gene products involved in the regulation of DNA repair. As a consequence, based on transcriptomic results, we demonstrated that the higher toxicity of DTX-1 compared to OA and DTX-2 was consistent with certain specific pathways involved in intestinal cell response.

Food-borne Lactiplantibacillus plantarum protect normal intestinal cells against inflammation by modulating reactive oxygen species and IL-23/IL-17 axis

Food-associated Lactiplantibacillus plantarum (Lpb. plantarum) strains, previously classified as Lactobacillus plantarum, are a promising strategy to face intestinal inflammatory diseases. Our study was aimed at clarifying the protective role of food-borne Lpb. plantarum against inflammatory damage by testing the scavenging microbial ability both in selected strains and in co-incubation with normal mucosa intestinal cells (NCM460). Here, we show that Lpb. plantarum endure high levels of induced oxidative stress through partially neutralizing reactive oxygen species (ROS), whereas they elicit their production when co-cultured with NCM460. Moreover, pre-treatment with food-borne Lpb. plantarum significantly reduce pro-inflammatory cytokines IL-17F and IL-23 levels in inflamed NCM460 cells. Our results suggest that food-vehicled Lpb. plantarum strains might reduce inflammatory response in intestinal cells by directly modulating local ROS production and by triggering the IL-23/IL-17 axis with future perspectives on health benefits in the gut derived by the consumption of functional foods enriched with selected strains.

Heavy ion space radiation triggers ongoing DNA base damage by downregulating DNA repair pathways

Long-duration space missions outside low earth orbit will expose astronauts to a cumulative dose of high-energy particle radiation especially to highly damaging heavy ion radiation, which poses considerable risk to astronauts’ health. The purpose of the current study was to quantitatively identify oxidatively induced DNA base modifications and assess status of the repair pathways involved in removing the modified bases in mouse intestinal cells after exposure to γ-rays and iron radiation. Mice (C57BL/6J; 6 to 8 weeks; female) were exposed to 0.5 Gy of either γ-rays or iron radiation and control mice were sham-irradiated. Intestinal tissues were collected 2 months after radiation. DNA base lesions were measured using gas chromatography-tandem mass spectrometry with isotope‑dilution. Base excision repair (BER) and nucleotide excision repair (NER) pathways were assessed using PCR and immunoblotting. Effects of iron radiation were compared to γ-rays and sham-irradiated controls. Exposure to iron radiation resulted in significantly higher levels of several DNA base lesions relative to control animals and those exposed to γ radiation. Assessment of BER and NER showed downregulation of pathway factors both at the RNA as well as at the protein levels. Our results not only provide important insight into DNA damage pattern in intestinal cells in response to iron radiation, but they also confirm our previous immunohistochemistry data on oxidatively induced DNA damage. We suggest that downregulation of the BER and NER pathways is contributing to ongoing DNA base damages long time after radiation exposure and has implications for chronic diseases including gastrointestinal diseases after heavy ion radiation exposure during space travel.

Activation of epithelial cells by the major kiwifruit allergen Act d 1 in human and mouse-derived intestinal model

• Act d 1 up-regulates tight junction proteins in Caco-2 monolayers. • Act d 1 up-regulates tight junction proteins in 2-Dimensional intestinal organoids. • Act d 1 induces release of proinflamatory cytokines in 2D organoids and Caco-2 cells. • Act d 1 impaired TJs network of E-cadherin, claudin-3 and ZO-1 in 2D-organoids. • 2D mouse organoids are a promising model for assessment of intestinal cell response. In this study, two intestinal models were employed to assess the modulatory potential of a major kiwifruit allergen on the innate immunity of epithelial cells. Effects of Act d 1 were analyzed in terms of gene expression and structural changes of tight junction (TJ) proteins, as well as up-regulation of pro-inflammatory cytokines in Caco-2 cells and, for the first time, in mouse-derived intestinal 2-dimensional (2D) organoids. Biologically active Act d 1 induced up-regulation of TJ genes for CLDN-2, CLDN-3, CLDN-4, ZO-1, and on the protein level induced release of pro-inflammatory cytokines IL-1β, TNFα and IL-33 in both employed model systems. In 2D-organoids, active Act d 1 impaired the TJ protein networks of E-cadherin, claudin-3, and ZO-1. 2D-organoids generated from mouse intestine are a promising new model system for the assessment of allergen-induced intestinal cell responses and a useful tool for mitigation of risks associated with novel food proteins.