Metabolome and Its Mechanism Profiling in the Synergistic Toxic Effects Induced by Co-Exposure of Tenuazonic Acid and Patulin in Caco-2 Cells.

Tenuazonic acid (TeA), usually found in cereals, fruits, vegetables, oil crops, and their products, was classified as one of the highest public health problems by EFSA as early as 2011, but it has still not been regulated by legislation due to the limited toxicological profile. Moreover, it has been reported that the coexistence of TeA and patulin (PAT) has been found in certain agricultural products; however, there are no available data about the combined toxicity. Considering that the gastrointestinal tract is the physiological barrier of the body, it would be the first target site at which exogenous substances interact with the body. Thus, we assessed the combined toxicity (cell viability, ROS, CAT, and ATP) in Caco-2 cells using mathematical modeling (Chou-Talalay) and explored mechanisms using non-targeted metabolomics and molecular biology methods. It revealed that the co-exposure of TeA + PAT (12.5 µg/mL + 0.5 µg/mL) can induce enhanced toxic effects and more severe oxidative stress. Mechanistically, the lipid and amino acid metabolisms and PI3K/AKT/FOXO signaling pathways were mainly involved in the TeA + PAT-induced synergistic toxic effects. Our study not only enriches the scientific basis for the development of regulatory policies but also provides potential targets and treatment options for alleviating toxicities.

Intestinal epithelial differentiation and barrier function is promoted in vitro by a Cynara cardunculus L. leaf extract through AMPK pathway activation.

Gut epithelial barrier perturbation leads to leaky gut syndrome and permeation of substances activating immune response. Polyphenols can improve intestinal barrier function and represent candidates for preventing development of leaky gut. Herein, we evaluated in vitro the molecular mechanisms involved in the protective effects of a polyphenol-rich extract from leaves of Cynara cardunculus L. (CCLE) on intestinal barrier function and integrity on Caco-2 human epithelial cells. Treatment with CCLE from seeding until complete differentiation improved intestinal function by increasing trans-epithelial electrical resistance (TEER), reducing paracellular permeability to fluorescein, and promoting faster recovery of tight junctions (TJ) assembly in the Ca2+ switch assay. CCLE stimulated epithelial cell differentiation inducing alkaline phosphatase activity and TJ proteins. These CCLE-induced effects were attributed to activation of AMP-activated protein kinase (AMPK) pathway. Our data support the use of Cynara cardunculus L. leaves, an agricultural co-product rich in bioactive polyphenols, for the health of intestinal epithelium.

Advancements in Nano-Mandoor Bhasma: Unravelling the Particle Size-Ascorbic Acid Synergy for Enhanced Iron Bioavailability for Anemia Treatment.

Mandoor Bhasma (MB) medicine, based on classical Indian Ayurveda, was size- and surface-modified to improve its therapeutic efficiency for treating iron-deficient anemia. Physical grinding reduced the size of MB to the nanoparticle (nano-MB) range without changing its chemical composition, as measured by particle size distribution. The surface of nano-MB was modified with ascorbic acid (nano-AA-MB) and confirmed using scanning electron microscopy and Fourier transformed infrared spectroscopy. Enhanced iron dissolution from the surface-modified nano-AA-MB under neutral-to-alkaline pH conditions, and in the intestinal region of the simulated gastrointestinal tract (GIT) digestion model was determined using inductively coupled plasma mass spectroscopy. GIT digestae of MB microparticles and nano-AA-MB were found to be biocompatible in human colon epithelial (Caco-2) cells, with the latter showing threefold higher iron uptake. Subsequently, a dose-dependent increase in cellular ferritin protein was observed in the nano-AA-MB digestae-treated Caco-2 cells, indicating the enhanced bioavailability and storage of dissolved iron. Overall, the study showed that reducing the size of centuries-old traditional Mandoor Bhasma medicine to nanoscale, and its surface-modification with ascorbic acid would help in enhancing its therapeutic abilities for treating iron-deficient anemia.

The zinc absorption of the novel peptide-Zn complex in Caco-2 cells: effects of soybean peptides charge and hydrophobicity.

BACKGROUND: The supplemental effect of zinc depends not only on adequate intake, but also on how efficiently it is absorbed in the small intestine. In the present study, weak hydrophobic peptides (WHP), strong hydrophobic peptides (SHP), positively charged peptides (PCP) and negatively charged peptides (NCP) were isolated from soybean peptides (SP). The peptide-Zn complexes (PCP-Zn, NCP-Zn, WHP-Zn, SHP-Zn and SP-Zn) were prepared to compare their promotion zinc absorption capacity in the Caco-2 cells monolayers model. RESULTS: We found that the carboxyl, carbonyl and amino groups in peptide were the primary binding sites of Zn. Compared with zinc sulfate, the peptide-Zn complexes with different charge and hydrophobic peptides could improve zinc solubility at different pH. NCP-Zn had a lower Zn-binding capacity but a higher zinc absorption capacity compared to that of PCP-Zn in Caco-2 cells. In addition, the capacity of PCP-Zn to promote zinc absorption was lower than the control group (SP-Zn). There were no significant differences in transport rates, retention rates and uptake rates of WHP-Zn, SHP-Zn and SP-Zn. NCP-Zn could improve the activity of Zn-related enzymes, and the expression levels of PepT1 and ZnT1 were higher than other peptide-Zn complexes. CONCLUSION: The promotion zinc absorption capacity of peptide-Zn complexes was not completely dependent on the Zn-binding capacity, but also depended on the charge and hydrophobicity of peptides. © 2024 Society of Chemical Industry.

Perfluoropolyether-Based Gut-Liver-on-a-Chip for the Evaluation of First-Pass Metabolism and Oral Bioavailability of Drugs.

In the evolving field of drug discovery and development, multiorgans-on-a-chip and microphysiological systems are gaining popularity owing to their ability to emulate in vivo biological environments. Among the various gut-liver-on-a-chip systems for studying oral drug absorption, the chip developed in this study stands out with two distinct features: incorporation of perfluoropolyether (PFPE) to effectively mitigate drug sorption and a unique enterohepatic single-passage system, which simplifies the analysis of first-pass metabolism and oral bioavailability. By introducing a bolus drug injection into the liver compartment, hepatic extraction alone could be evaluated, further enhancing our estimation of intestinal availability. In a study on midazolam (MDZ), PFPE-based chips showed more than 20-times the appearance of intact MDZ in the liver compartment effluent compared to PDMS-based counterparts. Notably, saturation of hepatic metabolism at higher concentrations was confirmed by observations when the dose was reduced from 200 µM to 10 µM. This result was further emphasized when the metabolism was significantly inhibited by the coadministration of ketoconazole. Our chip, which is designed to minimize the dead volume between the gut and liver compartments, is adept at sensitively observing the saturation of metabolism and the effect of inhibitors. Using genome-edited CYP3A4/UGT1A1-expressing Caco-2 cells, the estimates for intestinal and hepatic availabilities were 0.96 and 0.82, respectively; these values are higher than the known human in vivo values. Although the metabolic activity in each compartment can be further improved, this gut-liver-on-a-chip can not only be used to evaluate oral bioavailability but also to carry out individual assessment of both intestinal and hepatic availability.

The Effect of Caco-2 Cells on Sporulation and Enterotoxin Expression by Foodborne Clostridium perfringens.

Clostridium perfringens enterotoxin (Cpe)-producing strains cause gastrointestinal infections in humans and account for the second-largest number of all foodborne outbreaks caused by bacterial toxins. The Cpe toxin is only produced during sporulation; this process might be affected when C. perfringens comes into contact with host cells. The current study determined how the cpe expression levels and spore formation changed over time during co-culture with Caco-2 cells (as a model of intestinal epithelial cells). In co-culture with Caco-2 cells, total C. perfringens cell counts first decreased and then remained more or less stable, whereas spore counts were stable over the whole incubation period. The cpe mRNA level in the co-culture with Caco-2 cells increased more rapidly than in the absence of Caco-2 cells (3.9-fold higher levels in coculture than in the absence of Caco-2 cells after 8 h of incubation). Finally, we found that cpe expression is inhibited by a cue released by Caco-2 cells (8.3-fold lower levels in the presence of supernatants of Caco-2 cells than in the absence of the supernatants after 10 h of incubation); as a consequence, the increased expression in co-culture with Caco-2 cells must be caused by a factor associated with the Caco-2 cells.

Combination of Hydrolysable Tannins and Zinc Oxide on Enterocyte Functionality: In Vitro Insights.

The management of gastrointestinal disease in animals represents a significant challenge in veterinary and zootechnic practice. Traditionally, acute symptoms have been treated with antibiotics and high doses of zinc oxide (ZnO). However, concerns have been raised regarding the potential for microbial resistance and ecological detriment due to the excessive application of this compound. These concerns highlight the urgency of minimizing the use of ZnO and exploring sustainable nutritional solutions. Hydrolysable tannins (HTs), which are known for their role in traditional medicine for acute gastrointestinal issues, have emerged as a promising alternative. This study examined the combined effect of food-grade HTs and subtherapeutic ZnO concentration on relevant biological functions of Caco-2 cells, a widely used model of the intestinal epithelial barrier. We found that, when used together, ZnO and HTs (ZnO/HTs) enhanced tissue repair and improved epithelial barrier function, normalizing the expression and functional organization of tight junction proteins. Finally, the ZnO/HTs combination strengthened enterocytes' defense against oxidative stress induced by inflammation stimuli. In conclusion, combining ZnO and HTs may offer a suitable and practical approach for decreasing ZnO levels in veterinary nutritional applications.

Anti-Inflammatory Effects of Barley Sprout Fermented by Lactic Acid Bacteria in RAW264.7 Macrophages and Caco-2 Cells.

The anti-inflammatory effects of supernatants produced from sprouted barley inoculated with Lactiplantibacillus plantarum KCTC3104 (Lp), Leuconostoc mesenteroides KCTC3530 (Lm), Latilactobacillus curvatus KCTC3767 (Lc), or a mixture of these lactic acid bacteria were investigated using RAW264.7 macrophages. BLp and BLc, the lyophilized supernatants of fermented sprouted barley inoculated with Lp and Lc, respectively, effectively reduced the nitric oxide (NO) levels hypersecreted by lipopolysaccharide (LPS)-stimulated RAW264.7 and LPS-stimulated Caco-2 cells. BLp and BLc effectively reduced the NO levels in LPS-stimulated RAW264.7 macrophages, and these effects tended to be concentration-dependent. BLc and BLp also exhibited strong DPPH radical scavenging activity and immunostimulatory effects. BLp and BLc significantly suppressed the levels of NO and pro-inflammatory cytokines such as TNF-α, IL-1ß, and IL-6 in LPS-stimulated RAW264.7 macrophages and LPS-stimulated Caco-2 cells, indicating their anti-inflammatory effects. These effects were greater than those of unfermented barley sprout (Bs). The functional components of Bs, BLp, and BLc were analyzed by HPLC, and it was found that lutonarin and saponarin were significantly increased in the fermented sprouted barley sample inoculated with Lp and Lc (BLp and BLc).

Differences in Metabolite Profiles of Dihydroberberine and Micellar Berberine in Caco-2 Cells and Humans-A Pilot Study.

We investigated the pharmacokinetic pathway of berberine and its metabolites in vitro, in Caco-2 cells, and in human participants following the administration of dihydroberberine (DHB) and micellar berberine (LipoMicel®, LMB) formulations. A pilot trial involving nine healthy volunteers was conducted over a 24 h period; blood samples were collected and subjected to Ultra High-Performance Liquid Chromatography-High Resolution Mass Spectrometry (UHPLC-HRMS) analyses to quantify the concentrations of berberine and its metabolites. Pharmacokinetic correlations indicated that berberrubine and thalifendine follow distinct metabolic pathways. Additionally, jatrorrhizine sulfate appeared to undergo metabolism differently compared to the other sulfated metabolites. Moreover, berberrubine glucuronide likely has a unique metabolic pathway distinct from other glucuronides. The human trial revealed significantly higher blood concentrations of berberine metabolites in participants of the DHB treatment group compared to the LMB treatment group-except for berberrubine glucuronide, which was only detected in the LMB treatment group. Similarly, results from in vitro investigations showed significant differences in berberine metabolite profiles between DHB and LMB. Dihydroberberine, dihydroxy-berberrubine/thalifendine and jatrorrhizine sulfate were detected in LMB-treated cells, but not in DHB-treated cells; thalifendine and jatrorrhizine-glucuronide were detected in DHB-treated cells only. While DHB treatment provided higher blood concentrations of berberine and most berberine metabolites, both in vitro (Caco-2 cells) and in vivo human studies showed that treatment with LMB resulted in a higher proportion of unmetabolized berberine compared to DHB. These findings suggest potential clinical implications that merit further investigation in future large-scale trials.

The Influence of Mesotrione on Human Colorectal Adenocarcinoma Cells and Possibility of Its Toxicity Mitigation by Cichoric Acid.

Mesotrione, as a widely used herbicide, is present in the environment in detectable amounts, causing serious damage. Here, we aimed to investigate the effect of mesotrione on Caco-2 cells and the possibility of its toxicity mitigation by cichoric acid. Therefore, we analyzed the cytotoxicity of both these compounds and the selected oxidative stress parameters, apoptosis and interaction of both the tested compounds with the cell membrane and their accumulation within the cells. In cytotoxicity studies, the stimulating activity of mesotrione was observed, and simultaneously, the inhibitory effect of cichoric acid was noticed. This effect was related to the results of oxidative stress analysis and apoptosis measurements. The activity level of key enzymes (glutathione peroxidase, catalase and superoxide dismutase) in Caco-2 cells exposed to cichoric acid was higher as compared to that of the control. The treatment with mesotrione did not induce apoptosis in the Caco-2 cells. The penetration of the studied compounds into the Caco-2 cells was measured by using an HPLC methodology, and the results indicate mesotrione's high penetration capacity. The distribution of charge on the surface of the cell membranes changed under the influence of both compounds. Considering the mutual interactions of beneficial and potentially toxic food ingredients, it should be noted that, despite the observed favorable trend, cichoric acid is not able to overcome the toxic and cancer-stimulating effects of this pesticide.

Effect of soybean proteins and peptides on the growth and adhesive ability of Limosilactobacillus Reuteri DSM17938.

Limosilactobacillus reuteri DSM17938 is one of the most pivotal probiotics, whose general beneficial effects on the intestinal microbiota are well recognized. Enhancing their growth and metabolic activity can effectively regulate the equilibrium of intestinal microbiota, leading to improved physical health. A common method to promote the growth of Lactobacillus is the addition of prebiotics. Current research suggests that proteins and their hydrolysates from different sources with potential prebiotic activity can also promote the growth of probiotics. In this study, soybean proteins and peptides were effective in promoting the growth, organic acid secretion, and adhesive properties of Limosilactobacillus reuteri DSM17938 to Caco-2 cells. These results illustrate the feasibility of soybean proteins and peptides as prebiotics, providing theoretical and practical advantages for their application.

Bioaccessibility and bioavailability of essential and potentially toxic trace elements in potato cultivars: A comprehensive nutritional evaluation.

Among the most consumed foods in the world is potato, which occupies the first place as a non-grain commodity, demonstrating the importance of its assessment concerning the population's food safety. In this study, the nutrients Ca, Mg, K, P, Cu, Mn, Fe, and Zn and the potentially toxic trace elements Cd, Cr, and Pb were evaluated considering their total contents, bioaccessible and bioavailable fractions in different potato cultivars, in an unpublished approach in the literature. The in vitro standard gastrointestinal digestion method (INFOGEST) and a model of the intestinal epithelial barrier using the Caco-2 cell line were applied for investigate the presence of metals in potato. For the macroelements, the bioaccessibility (% w/w) varied in the ranges: K (57-72 %), P (59-76 %), Mg (83-103 %), and Ca (30-123 %), whereas for the microelements were: Cu (27-74 %) and Mn (4.22-12.02, 60-119 %). The potentially of trace toxic elements, Cd and Pb, were found in 75 % of the samples, however, all the concentration values were below the maximum levels allowed of 0.10 µg/g. Chromium was determined only in potato peels and has no maximum established level. The bioaccessible and bioavailable fractions of Cd, Cr, and Pb were below the limits of quantification of the spectrometric methods (LOQ - µg/L: 0.063 Cd, 0.65 Cr, and 0.44 Pb). The potato samples were considered safe for consumption regarding the presence of potentially toxic trace elements, with a remarkable nutritional contribution.

Lactiplantibacillus plantarum ST-III and Lacticaseibacillus rhamnosus KF7 Enhance the Intestinal Epithelial Barrier in a Dual-Environment In Vitro Co-Culture Model.

Intestinal barrier hyperpermeability, which is characterised by impaired tight junction proteins, is associated with a variety of gastrointestinal and systemic diseases. Therefore, maintaining intestinal barrier integrity is considered one of the effective strategies to reduce the risk of such disorders. This study aims to investigate the potential benefits of two probiotic strains (Lactiplantibacillus plantarum ST-III and Lacticaseibacillus rhamnosus KF7) on intestinal barrier function by using a physiologically relevant in vitro model of the intestinal epithelium. Our results demonstrate that both strains increased transepithelial electrical resistance, a measure of intestinal barrier integrity. Immunolocalisation studies indicated that this improvement in barrier function was not due to changes in the co-localisation of the tight junction (TJ) proteins ZO-1 and occludin. However, we observed several modifications in TJ-related genes in response to the probiotics, including the upregulation of transmembrane and cytosolic TJ proteins, as well as TJ signalling proteins. Gene expression modulation was strain- and time-dependent, with a greater number of differentially expressed genes and higher fold-change being observed in the L. plantarum ST-III group and at the latter timepoint. Further studies to investigate how the observed gene expression changes can lead to enhanced barrier function will aid in the development of probiotic foods to help improve intestinal barrier function.

Molecular mechanisms of extracellular-ATP-mediated colorectal cancer progression: Implication of purinergic receptors-mediated nucleocytoplasmic shuttling of HuR.

One of the leading causes of cancer-related deaths worldwide is colorectal cancer (CRC). Extracellular ATP (e-ATP) and purinergic receptors (P2R) play a central role in CRC proliferation and progression. Human antigen R (HuR) is becoming more and more understood to be essential for the expression of genes linked to cancer. The current study demonstrates that ATP can mediate CRC (Caco-2 cells) progression via induction of HuR nucleocytoplasmic shuttling and subsequent expression of cancer-related genes, a consequence mostly mediated via the P2R receptor. It was also noted that suppression of HuR activity by using dihydrotanshinone I (DHTS) prevents cancer-related gene expression and subsequent CRC (Caco-2 cells) progression induced by ATP. The expression of cyclin A2/cyclin-dependent kinase 2 (CDK2), Bcl-2, ProT-α, hypoxia-inducible factor1-α (HIF1-α), vascular endothelial growth factor A (VEGF-A), transforming growth factor-ß (TGF-ß) and matrix metallopeptidase 9 (MMP-9) induced by ATP were highly reduced in the presence of either PPADS (non-selective P2R antagonist) or DHTS. In addition, e-ATP-induced Caco-2 cell proliferation as well as cell survival were highly reduced in the presence of either PPADS or DHTS or selective CDK-2 inhibitor (Roscovitine) or selective Bcl-2 inhibitor (ABT-263). Furthermore, it was found that MMP-9 is critical for Caco-2 cells migration induced by e-ATP as demonstrated by a clear reduction in cells migration in the presence of a selective MMP-9 inhibitor (Marimastat). Collectively, these data demonstrate that ATP through P2R activation can induce HuR nucleocytoplasmic shuttling that could be translated into an increase in cancer-related genes expression and subsequent, cell proliferation and progression.

Effects of okadaic acid, azaspiracid-1, yessotoxin and their binary mixtures on human intestinal Caco-2 cells.

Phycotoxins are responsible for foodborne intoxications. Symptoms depend on the ingested toxins but mostly imply gastro-intestinal and neurological disorders. Importantly, humans are exposed to combinations of several phycotoxins, resulting in possible mixture effects. Most previous studies, however, have been focused on single toxin effects. Thus, the aim of this study was to examine the effects of binary mixtures of three main phycotoxins, okadaic acid (OA), azaspiracid-1 (AZA1) and yessotoxin (YTX), on human intestinal Caco-2 cells. The focus was placed on cell viability studies and inflammation responses using a multi-parametric approach to assess cell population (nuclei staining), cell metabolism/viability (reductase activity and lysosomal integrity), and release of inflammation markers (e.g., interleukins). Mixture effects were evaluated using the concentration addition (CA) and independent action (IA) models. Our assays show that none of the toxins had an impact on the cell population in the tested concentration range. Only OA modulated reductase activity, while all three toxins had strong effects on lysosomal integrity. Furthermore, all toxins triggered the release of interleukin 8 (IL-8), with OA being most potent. Mixture effect analysis showed additivity in most cases. However, supra-additivity was observed in regards to IL-6 and IL-8 release for combinations implying high concentrations of OA. This study extends the knowledge on mixture effects of phycotoxins in human cells.

Investigating the Transepithelial Transport and Enzymatic Stability of Lactononadecapeptide (NIPPLTQTPVVVPPFLQPE), a 19-Amino Acid Casein-Derived Peptide in Caco-2 Cells.

Lactononadecapeptide (LNDP; NIPPLTQTPVVVPPFLQPE), a casein-derived peptide comprising 19 residues, is known for its capacity to enhance cognitive function. This study aimed to explore the transepithelial transport and stability of LNDP. Results showed that LNDP retained over 90% stability after 2 h of treatment with gastrointestinal enzymes. The stability of LNDP on Caco-2 cell monolayers ranged from 93.4% ± 0.9% to 101.1% ± 1.2% over a period of 15-60 min, with no significant differences at each time point. The permeability of LNDP across an artificial lipid membrane was very low with the effective permeability of 3.6 × 10-11 cm/s. The Caco-2 assay demonstrated that LNDP could traverse the intestinal epithelium, with an apparent permeability of 1.22 × 10-6 cm/s. Its transport was significantly inhibited to 67.9% ± 5.0% of the control by Gly-Pro, a competitor of peptide transporter 1 (PEPT1). Furthermore, PEPT1 knockdown using siRNA significantly inhibited LNDP transport by 77.6% ± 1.9% in Caco-2 cell monolayers. The LNDP uptake in PEPT1-expressing HEK293 cells was significantly higher (54.5% ± 14.6%) than that in mock cells. These findings suggest that PEPT1 plays a crucial role in LNDP transport, and LNDP exhibits good resistance to gastrointestinal enzymes.

Fabrication of phenolic loaded spray-dried nanoliposomes stabilized by chitosan and whey protein: Digestive stability, transepithelial transport and bioactivity retention of phenolics.

Low bioavailability of phenolic compounds (phenolics) results in low in vivo bioactivity, thus their co-encapsulation could enhance potential health benefits. In this study, reconstitutable nanoliposomes loaded with phenolics varying in solubility were fabricated using spray drying after stabilized by chitosan (CH) or whey protein (WP). The physicochemical properties, biocompatibility, digestive fate, and bioactivity retention of phenolics in different forms were investigated. The surface charge of nanoliposomes (NL) shifted from -18.7 mV to positive due to conjugation with cationic CH (53.1 mV) and WP (14 mV) after spray drying while it was -26.6 mV for only spray-dried phenolics (SDP). Encapsulation efficiency of the tested phenolics ranged between 64.7 % and 95.1 %. Simulated gastrointestinal digestion/Caco-2 cell model was used to estimate the digestive fate of the phenolics yielding up to 3-fold higher bioaccessibility for encapsulated phenolics compared to their native form, combined or individually. However, the cellular uptake or transepithelial transport of phenolics did not differ significantly among formulations, except trans-resveratrol in WP-NL. On the contrary, the suppressive effect of phenolics on fatty acid induced hepatocellular lipid accumulation was strongly dependent on the encapsulation method, no activity was retained by SDP. These findings suggested that reconstitutable nanoliposomes can improve the absorption of phenolics by facilitating their bioaccessibility and thermal and/or processing stability during spray drying.

Stability, Digestion, and Cellular Transport of Soy Isoflavones Nanoparticles Stabilized by Polymerized Goat Milk Whey Protein.

Soy isoflavones (SIF) are bioactive compounds with low bioavailability due to their poor water solubility. In this study, we utilized polymerized goat milk whey protein (PGWP) as a carrier to encapsulate SIF with encapsulation efficiency of 89%, particle size of 135.53 nm, and zeta potential of -35.16 mV. The PGWP-SIF nanoparticles were evaluated for their stability and in vitro digestion properties, and their ability to transport SIF was assessed using a Caco-2 cell monolayer model. The nanoparticles were resistant to aggregation when subjected to pH changes (pH 2.0 to 8.0), sodium chloride addition (0-200 mM), temperature fluctuations (4 °C, 25 °C, and 37 °C), and long-term storage (4 °C, 25 °C, and 37 °C for 30 days), which was mainly attributed to the repulsion generated by steric hindrance effects. During gastric digestion, only 5.93% of encapsulated SIF was released, highlighting the nanoparticles' resistance to enzymatic digestion in the stomach. However, a significant increase in SIF release to 56.61% was observed during intestinal digestion, indicating the efficient transport of SIF into the small intestine for absorption. Cytotoxicity assessments via the MTT assay showed no adverse effects on Caco-2 cell lines after encapsulation. The PGWP-stabilized SIF nanoparticles improved the apparent permeability coefficient (Papp) of Caco-2 cells for SIF by 11.8-fold. The results indicated that using PGWP to encapsulate SIF was an effective approach for delivering SIF, while enhancing its bioavailability and transcellular transport.

mTOR signaling pathway regulation HIF-1 α effects on LPS induced intestinal mucosal epithelial model damage.

BACKGROUND: Sepsis-induced small-intestinal injury is associated with increased morbidity and mortality. Our previous study and other papers have shown that HIF-1α has a protective effect on intestinal mucosal injury in septic rats. The purpose of this study is to further verify the protective effect of HIF-1α on intestinal mucosa and its molecular mechanism in vitro experiments. METHODS: Caco-2 cells were selected and experiment was divided into 2 parts. Part I: HIF-1α activator and inhibitor were used to treat lipopolysacchrides (LPS)-stimulated Caco-2 cells respectively, to explore the effect of HIF-1α on LPS induced Caco-2 cell epithelial model; Part II: mTOR activator or inhibitor combined with or without HIF-1α activator, inhibitor to treat LPS-stimulated Caco-2 cells respectively, and then the molecular mechanism of HIF-1α reducing LPS induced Caco-2 cell epithelial model damage was detected. RESULTS: The results showed that HIF-1α activator decreased the permeability and up regulated tight junction (TJ) expression, while HIF-1α inhibitor had the opposite effect with the HIF-1α activator. mTOR activation increased, while mTOR inhibition decreased HIF-1α protein and expression of its downstream target molecules, which can be attenuated by HIF-1α activator or inhibitor. CONCLUSION: This study once again confirmed that HIF-1α alleviates LPS-induced mucosal epithelial model damage through P70S6K signalling pathway. It is of great value to explore whether HIF-2α plays crucial roles in the regulation of mucosal epithelial model functions in the future.

Cryopreservation and Rapid Recovery of Differentiated Intestinal Epithelial Barrier Cells at Complex Transwell Interfaces Is Enabled by Chemically Induced Ice Nucleation.

Cell-based models, such as organ-on-chips, can replace and inform in vivo (animal) studies for drug discovery, toxicology, and biomedical science, but most cannot be banked "ready to use" as they do not survive conventional cryopreservation with DMSO alone. Here, we demonstrate how macromolecular ice nucleators enable the successful cryopreservation of epithelial intestinal models supported upon the interface of transwells, allowing recovery of function in just 7 days post-thaw directly from the freezer, compared to 21 days from conventional suspension cryopreservation. Caco-2 cells and Caco-2/HT29-MTX cocultures are cryopreserved on transwell inserts, with chemically induced ice nucleation at warmer temperatures resulting in increased cell viability but crucially retaining the complex cellular adhesion on the transwell insert interfaces, which other cryoprotectants do not. Trans-epithelial electrical resistance measurements, confocal microscopy, histology, and whole-cell proteomics demonstrated the rapid recovery of differentiated cell function, including the formation of tight junctions. Lucifer yellow permeability assays confirmed that the barrier functions of the cells were intact. This work will help solve the long-standing problem of transwell tissue barrier model storage, facilitating access to advanced predictive cellular models. This is underpinned by precise control of the nucleation temperature, addressing a crucial biophysical mode of damage.