Expression Of Zonula Occludens-1 Research Articles

A probiotic multi-strain mixture combined with hydroxyectoine improves intestinal barrier function by alleviating inflammation in lipopolysaccharide stimulated differentiated Caco-2 cells.

Many studies have highlighted the role of probiotics in re-establishing the gut microbiota balance and preventing intestinal barrier dysfunction. In fact, they can also contribute to the upregulation of anti-inflammatory genes and the downregulation of pro-inflammatory genes, which are known to contribute to the development of the inflammatory bowel disease (IBD) syndrome. The present study aims to investigate the effect of the compatible solute hydroxyectoine (HOE), to be used as a cryopreservant but also for its intrinsic biological properties, to obtain a new formula containing three probiotic strains (Limosilactobacillus fermentum (L. fermentum), Levilactobacillus brevis SP-48 (L. brevis), and Bifidobacterium lactis HN019 (B. lactis)), and evaluate the latter for its ability to prevent lipopolysaccharide (LPS)-induced inflammation in an in vitro bi-dimensional model of the intestinal barrier using a Caco-2 cell monolayer. The mRNA expression levels of the inflammatory cytokines (IL-6, IL-1β, and TNF-α) were analyzed by real-time PCR. Changes in the modulation of (TLR-4 and NF-κB) proteins were assessed by western blotting, and the effect of the HOE/PRO formula on the intestinal epithelial barrier function was also assessed using an immunofluorescence microscope for the tight junction protein zonula occludens-1 (ZO-1). This study found that this novel probiotic formulation containing HOE is capable of decreasing LPS-induced cytokines, as confirmed by the results of RT-PCR and ELISA and preserving the integrity of tight junctions as demonstrated by the relevant expression of ZO-1. HOE/PRO was shown to be effective in reducing the expression of TLR-4 and NF-κB. The latter plays a key role as an inflammation modulator as shown through experiments run with the THP-1/NF-κB reporter gene. Collectively, our data indicate that the HOE/PRO formula is a good candidate for potential preventive and/or therapeutic implementation in IBD.

Exploring the Role of Gut Vascular Barrier Proteins in HIV-Induced Mucosal Damage: A Comparative Study.

This study aims to compare intestinal mucosal damage and the expression levels of occludin, zonula occludens-1 (ZO-1), vascular endothelial (VE)-cadherin, β-catenin, and plasmalemma vesicle-associated protein (PLVAP) in the gut vascular barrier (GVB) among people living with HIV (PLWH), asymptomatic PLWH, and healthy volunteers (non-PLWH). Three groups were selected for the study: PLWH, asymptomatic PLWH, and healthy volunteers. Colonic mucosal tissue samples were collected via colonoscopy from all participants. Histological examination of the colonic mucosa was conducted using hematoxylin and eosin staining. The expression levels of occludin, ZO-1, VE-cadherin, β-catenin, and PLVAP were assessed using RT-qPCR, immunohistochemistry, and western blot analyses. Pathological scores of colonic mucosa in PLWH and asymptomatic PLWH were significantly higher than those in non-PLWH (p < .001 and p = .0056, respectively). CD4+ T cell counts in asymptomatic PLWH and non-PLWH were significantly higher than in PLWH (p < 0.05). The CD4+/CD8+ T cell ratio in non-PLWH significantly exceeded those in PLWH and asymptomatic PLWH (p < .05). Analysis of protein and mRNA expression revealed: (1) no statistically significant differences in PLVAP-mRNA expression across all groups (p > .05); (2) higher PLVAP protein levels in PLWH compared with asymptomatic PLWH and non-PLWH (p < .05), with no significant differences between asymptomatic PLWH and non-PLWH (p = .632); (3) significantly higher PLVAP expression in the colonic mucosa of PLWH and asymptomatic PLWH compared with non-PLWH (p = .034 and p = .011, respectively), with no significant differences between PLWH and asymptomatic PLWH (p > .999). ZO-1 expression was significantly lower in PLWH than in non-PLWH (p = .012), with no notable differences between asymptomatic PLWH and other groups. PLWH, compared with healthy controls, exhibit significant inflammatory changes in the intestinal mucosa. PLVAP expression serves as a potential indicator to assess the extent of GVB damage and disease progression in PLWH.

Study repair function of mucin-2 on the tight junction protein of uterine epithelial cells under bacterial endotoxins

To analysis repair function of mucin-2(MUC2) and glycoprotein particles on the tight junction protein of uterus under bacterial endotoxins. In this experiment, we showed that the thicker mucus layer of the uterus is used to prevent the translocation of endotoxin at 21d postdelivery. When endotoxin acts on the uterus to thin its mucous layer, the cells in the lamina propria of the uterus secrete a large number of glycoprotein particles at 27d postdelivery. Due to a significantly decrease in the expression of glycosyltransferase, the glycoprotein particles are incompletely glycosylation MUC2, which can interact with the cell membrane and are released in large quantities in the form of exocytosis. These glycoprotein particles can significantly repair tight junction proteins in the inter-cellular space and significantly increase the expression of Claudin-1, JAM (Junction adhesion molecule-A), E-cadherin, ZO-1(Zonula occludens-1) and desmosome proteins after endotoxin treatment. The results of the present study show that endotoxins can thin the uterine mucus layer and accelerate the release of incompletely glycosylated MUC2 from lamina propria cells. In inter-cellular spaces, MUC2 can increase its expression levels and distribution area to repair the tight junction structure of cells with larger gaps. Further strengthening of the barrier prevents endotoxin translocation by repairing the tight junction structure of uterine epithelial cells.

The essential oils from Asarum sieboldii Miq. alleviate allergic rhinitis by regulating tight junction and inflammation; Network analysis and preclinical validation

Ethnopharmacological relevanceEssential oils from herbs, including those from Asarum sieboldii Miq., are readily absorbed through mucous membranes, explaining their widespread use in inhalation formulations. Asarum sieboldii Miq. has a long history of traditional use for various medicinal purposes, attributed to its anti-inflammatory, antiallergic, and antioxidant properties. Despite research on Asarum sieboldii Miq. for allergic inflammation in respiratory diseases, detailed mechanistic studies are still lacking. Aim of the studyWe utilized bioinformatics and network pharmacology to identify the effectiveness of Asarum sieboldii Miq. in treating allergic rhinitis (AR). Our aim is to elucidate the potential therapeutic effects of essential oil derived from Asarum sieboldii Miq. (ASO), which is recognized for its diverse pharmacological properties, on AR. Materials and methodsCommon genes associated with the active compounds of ASO and AR were utilized to construct a related network and predict their mode of action. AR was induced in BALB/c mice by exposing them to ovalbumin (OVA) and particulate matter 10 (PM10; airborne particles <10 μm). With induction, aerosolized ASO (0.0002% and 0.02%) were administered via nebulizer for 5 minutes per day, three times a week for 7 weeks. Mice were examined for histopathological changes in the nasal tissue, nasal epithelial inflammation, the production of allergen-specific cytokine response in vitro and in vivo. ResultsThe common genes of ASO and AR were predicted to include 'Tight junction', 'Apoptosis', and 'TGF-beta signaling', which are the main pathways of pathogenesis in AR. Consistent with network prediction, nebulized ASO treatment effectively improved the expression of tight junction-related factors, zonula occludens-1, claudin-1, occludin and junction adhesion molecule A, in OVA+PM10 induced mice. Additionally, it reduced hyperplasia of nasal epithelial thickness, goblet cell counts, and inflammatory cell infiltration (eosinophils, neutrophils, macrophages, and lymphocytes) in nasal lavage fluid, while also alleviating allergic symptoms such as sneezing, rubbing, and serum IgE level when compared to the AR-induced group. The levels of mRNA and protein expression related to tight junctions were restored to normal levels by ASO, as confirmed in immunofluorescence analysis in nasal epithelial cells RPMI2650. Furthermore, treatment of ASO on PM10-treated nasal epithelial cells significantly reduced ROS production, recovered mitochondria membrane potential, and inhibition of the production of proinflammatory cytokines (TNF-α, IL-4, and IL-13) and inflammatory mediators linked to the MAPK/NF-κB signaling pathways. ConclusionIntranasal nebulization of ASO improves TJs and alleviates allergic nasal inflammation in AR. It supports the potential pharmaceutical application of ASO treatment for AR.

Hydroxy-selenomethionine helps cows to overcome heat stress by enhancing antioxidant capacity and alleviating blood-milk barrier damage

Heat stress can lead to decreased feed intake, apoptosis of mammary epithelial cells, and decreased milk yield and quality. Selenium is an important element in the composition of at least 25 selenoproteins. Hydroxy-selenomethionine (HMSeBA; Andy Su Life Science Products Co., Ltd., Shanghai, China) is a novel organic selenium that has been shown to have a better deposition effect. However, whether HMSeBA alleviates damage to the mammary gland blood-milk barrier caused by heat stress and how this affects the performance of dairy cows remain largely unexplored. Therefore, 32 healthy Holstein cows with similar gestation days (150.41 ± 20.07 d), milk yield (36.15 ± 3.02 kg) and parity (3.25 ± 0.51) were selected and randomly divided into two total mixed rations with different selenium (Se) sources: sodium selenite (SSe) and HMSeBA. This study evaluated the outcomes of HMSeBA on antioxidant capacity, immunity, and blood-milk barrier damage in dairy cows during heat stress by collecting the samples of blood, rumen fluid and mammary gland biopsy. The experiment was conducted over 35 d, including a 5-day pre-feeding period and a 30-day experimental period. The temperature and humidity index (THI) were all above 80 throughout the experiment period. The results showed that HMSeBA decreased the respiratory rate (P < 0.001) and the content of inflammatory cytokines in the serum and increased the content of immune factors and antioxidant capacity (P < 0.05). In addition, HMSeBA reduced the expression of inflammatory cytokines and heat shock proteins in mammary gland (P < 0.05). Hematoxylin-eosin-stained pathological sections showed massive thickening of acinar walls and severe destruction of glandular structures in the SSe group, but the structure of the acinar mammary gland in the HMSeBA group was intact. Furthermore, HMSeBA promoted the expression of the phosphatidylinositol 3-kinase (PI3K, P < 0.001)/protein kinase B (AKT, P = 0.011)/mammalian target of rapamycin (mTOR, P = 0.008) pathway and improved the expression of zonula occludens-1 (ZO-1, P = 0.014) and occluding (OCLN, P = 0.012) in the mammary gland, suggesting less damage caused by heat stress to the blood-milk barrier. Our results demonstrated that HMSeBA can improve the antioxidant capacity and immunity of dairy cows and the expression of tight junction proteins in mammary gland to help alleviate the blood-milk barrier damage by heat stress, which could reduce the damage of heat stress on milk yield.

High-concentrate diet supplemented with hydrolysable tannin improves the slaughter performance, intestinal antioxidant ability and barrier function of fattening lambs

The objective of current experiment was to study the potential influence of hydrolysable tannin supplementation on slaughter performance, meat quality, intestinal digestive enzyme activity, antioxidant ability and barrier function in fattening lambs. In total, 36 male Hu sheep lambs with similar body weight (15.83 ± 0.48 kg) and days in age (55 ± 2 d) were randomly assigned to one of three groups of 12 animals each: control without tannin (CON) and tannin supplementation groups (TA1, 3 g/d per lamb; TA2, 6 g/d per lamb). All the lambs were reared in individual hutches, and the experiment lasted for 60 d. On d 61, 8 lambs from each group were randomly selected to slaughter. Results showed that the serum diamine oxidase and lipopolysaccharide contents of TA2 group were higher (p &amp;lt; 0.05) than those of CON group. Compared with CON group, the carcass weight and intramuscular fat content of lambs in TA1 group were increased (p &amp;lt; 0.05) and the meat shear force was decreased (p &amp;lt; 0.05). The trypsin activity in the jejunum and ileum of TA1 group was higher (p &amp;lt; 0.05) than that of CON and TA2 groups. Also, tannin supplementation significantly increased (p &amp;lt; 0.05) the level of jejunal and ileal total antioxidant capacity and reduced (p &amp;lt; 0.05) the jejunal malondialdehyde concentration in lambs. The jejunum and ileum of TA1 lambs showed reduced (p &amp;lt; 0.05) tumor necrosis factor-alpha and increased (p &amp;lt; 0.05) interleukin-10 mRNA levels compared with CON lambs. In the jejunum, the secretory immunoglobulin A content of TA1 group was higher (p &amp;lt; 0.05) than that of CON and TA2 groups. Lambs supplemented with tannin at the level of 3 g/d increased (p &amp;lt; 0.05) the gene expressions of claudin-1, claudin-4 and zonula occludens-1 in the jejunum when compared to those of CON and TA2 groups. In summary, tannin supplementation at the level of 3 g/d per animal can improve the production performance and intestinal function of fattening lambs fed a high-concentrate diet.

Cow Placenta Extract Ameliorates Cyclophosphamide-Induced Intestinal Damage by Enhancing the Intestinal Barrier, Improving Immune Function, and Restoring Intestinal Microbiota

Immunosuppression undermines intestinal barrier integrity. Cow placenta extract (CPE) primarily consists of active peptides with immunomodulatory and antioxidant effects. This study aimed to examine the preventive effect of CPE against intestinal damage induced by cyclophosphamide (Cy) in immunosuppressed mice. Thirty-six mice were randomly allocated into three groups: control group (C), model group (M), and treatment group (CPE). The mice in the CPE group were provided with 1500 mg/kg/day of CPE via gavage. In the last 3 days, mice in the groups M and CPE received intraperitoneal injections of 80 mg/kg/day of Cy. The results showed that CPE improved intestinal barrier function by decreasing serum d-Lactate (D-LA) levels and diamine oxidase (DAO) activity, while elevating the relative expression of Occludin, zonula occludens-1 (ZO-1), and mucin-2 (MUC-2) mRNA. Additionally, CPE improved the immune organ index and elevated the levels of secretory immunoglobulin A (sIgA), superoxide dismutase (SOD), interleukin-1beta (IL-1β), interleukin-4 (IL-4), interleukin-10 (IL-10), and tumor necrosis factor-α (TNF-α) in the intestine, thereby enhancing intestinal mucosal immune function. Furthermore, CPE improved the diversity of intestinal microbiota and increased the abundance of Candidatus_Saccharimonas, Psychrobacter, and Enterorhabdus, which promoted the proper functioning of the intestines. These findings suggest that CPE effectively ameliorates Cy-induced intestinal damage by enhancing the intestinal barrier, improving immune function, and restoring intestinal microbiota.

GZMA suppressed GPX4-mediated ferroptosis to improve intestinal mucosal barrier function in inflammatory bowel disease

BackgroundOur previous study has demonstrated a decreased colonic CD8+CD39+ T cells, enrichment of granzyme A (GZMA), was found in pediatric-onset colitis and inflammatory bowel disease (IBD) characterized by impaired intestinal barrier function. However, the influence of GZMA on intestinal barrier function remains unknown.MethodsWestern blotting(WB), real-time PCR (qPCR), immunofluorescence (IF) and in vitro permeability assay combined with intestinal organoid culture were used to detect the effect of GZMA on intestinal epithelial barrier function in vivo and in vitro. Luciferase, immunoprecipitation (IP) and subcellular fractionation isolation were performed to identify the mechanism through which GZMA modulated intestinal epithelial barrier function.ResultsHerein, we, for the first time, demonstrated that CD8+CD39+ T cells promoted intestinal epithelial barrier function through GZMA, leading to induce Occludin(OCLN) and Zonula Occludens-1(ZO-1) expression, which was attributed to enhanced CDX2-mediated cell differentiation caused by increased glutathione peroxidase 4(GPX4)-induced ferroptosis inhibition in vivo and in vitro. Mechanically, GZMA inhibited intestinal epithelial cellular PDE4B activation to trigger cAMP/PKA/CREB cascade signaling to increase CREB nuclear translocation, initiating GPX4 transactivity. In addition, endogenous PKA interacted with CREB, and this interaction was enhanced in response to GZMA. Most importantly, administration of GZMA could alleviate DSS-induced colitis in vivo.ConclusionThese findings extended the novel insight of GZMA contributed to intestinal epithelial cell differentiation to improve barrier function, and enhacement of GZMA could be a promising strategy to patients with IBD.

Integrated Small Intestine Microbiota and Serum Metabolomics Reveal the Potential Mechanisms of Wine Steaming in Alleviating Rhubarb-Induced Diarrhea.

Long-term use of rhubarb (RH) commonly leads to diarrhea, which can be alleviated by steaming with wine. However, the specific mechanism by which wine steaming alleviates RH-induced diarrhea remains unknown. This study aims to reveal the underlying mechanisms of wine steaming in alleviating RH-induced diarrhea by examining small intestinal flora and serum metabolomics. Major anthraquinone and anthrone components were detected using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). Eighty-four ICR mice were randomly divided into control, RH, and RH steamed with wine (PRH) groups and were administered RH and PRH (1, 4, and 8 g/kg, i.g). for 14 consecutive days. Histopathological analysis was performed using hematoxylin-eosin staining. Levels of inflammatory factors and tight junction proteins, zonula occludens-1 (ZO-1) and occludin, in the small intestine were measured. The small intestine content was analyzed using 16S rRNA sequencing, and UPLC-MS was used to analyze endogenous metabolites. Levels of major anthraquinone and anthrone components decreased in PRH. Both RH and PRH groups showed varying degrees of loose stools and increased fecal water rates; the RH group exhibited more severe effects. Compared with the control group, RH caused small intestine injuries, increased levels of inflammatory cytokines, downregulated the expression of ZO-1 and occludin, and induced gut microbiota (GM) imbalance. The relative abundance of Lactobacillus decreased, while the relative abundance of Shigella and Streptococcus increased. However, PRH had a milder impact than RH. The glycerophospholipid metabolic pathway was involved in this effect. The levels of inflammatory cytokines and potential metabolites (sn-glycero-3-phosphoethanolamine) were positively correlated with Streptococcus infection, while the levels of ZO-1 and occludin were negatively correlated with Streptococcus infection. GM imbalance and abnormal glycerophospholipid metabolism contributed to impaired intestinal barrier function and inflammatory factor release, which may underlie RH-induced diarrhea, though PRH had a weaker effect. PRH alleviated RH-induced diarrhea by recovering GM balance, reducing ZO-1 and occludin expression, and decreasing the release of inflammatory factors. This mechanism may be linked to the reduced anthraquinone content. This study is the first to explore the mechanism of wine steaming in alleviating RH-induced diarrhea through small intestinal flora and serum metabolomics. It provides data to support the broader clinical use of RH and its safer application.

Curcumin-mediated enhancement of lung barrier function in rats with high-altitude-associated acute lung injury via inhibition of inflammatory response

BackgroundExposure to a hypobaric hypoxic environment at high altitudes can lead to lung injury. In this study, we aimed to determine whether curcumin (Cur) could improve lung barrier function and protect against high-altitude-associated acute lung injury.MethodsTwo hundred healthy rats were randomly divided into standard control, high-altitude control (HC), salidroside (40 mg/kg, positive control), and Cur (200 mg/kg) groups. Each group was further divided into five subgroups. Basic vital signs, lung injury histopathology, routine blood parameters, plasma lactate level, and arterial blood gas indicators were evaluated. Protein and inflammatory factor (tumor necrosis factor α (TNF-α), interleukin [IL]-1β, IL-6, and IL-10) concentrations in bronchoalveolar lavage fluid (BALF) were determined using the bicinchoninic acid method and enzyme-linked immunosorbent assay, respectively. Inflammation-related and lung barrier function-related proteins were analyzed using immunoblotting.ResultsCur improved blood routine indicators such as hemoglobin and hematocrit and reduced the BALF protein content and TNF-α, IL-1β, and IL-6 levels compared with those in the HC group. It increased IL-10 levels and reduced pulmonary capillary congestion, alveolar hemorrhage, and the degree of pulmonary interstitial edema. It increased oxygen partial pressure, oxygen saturation, carbonic acid hydrogen radical, and base excess levels, and the expression of zonula occludens 1, occludin, claudin-4, and reduced carbon dioxide partial pressure, plasma lactic acid, and the expression of phospho-nuclear factor kappa.ConclusionsExposure to a high-altitude environment for 48 h resulted in severe lung injury in rats. Cur improved lung barrier function and alleviated acute lung injury in rats at high altitudes.

Effect of Probiotics on Improving Intestinal Mucosal Permeability and Inflammation after Surgery.

We explored the mechanisms underlying the improvement of postoperative ileus (POI) following probiotic pretreatment. We assessed intestinal permeability, inflammation, tight junction (TJ) protein expression in the gut epithelium, and plasma interleukin (IL)-17 levels in a guinea pig model of POI. Guinea pigs were divided into control, POI, and probiotic groups. The POI and probiotic groups underwent surgery, but the probiotic group received probiotics before the procedure. The ileum and proximal colon were harvested. Intestinal permeability was measured via horseradish peroxidase permeability. Inflammation was evaluated via leukocyte count in the intestinal wall muscle layer, and calprotectin expression in each intestinal wall layer was analyzed immunohistochemically. TJ proteins were analyzed using immunohistochemical staining, and plasma IL-17 levels were measured using an enzyme-linked immunosorbent assay. The POI group exhibited increased intestinal permeability and inflammation, whereas probiotic pretreatment reduced the extent of these POI-induced changes. Probiotics restored the expression of TJ proteins occludin and zonula occludens-1 in the proximal colon, which were increased in the POI group. Calprotectin expression significantly increased in the muscle layer of the POI group and was downregulated in the probiotic group; however, no distinct differences were observed between the mucosal and submucosal layers. Plasma IL-17 levels did not significantly differ among the groups. Probiotic pretreatment may relieve POI by reducing intestinal permeability and inflammation and TJ protein expression in the gut epithelium. These findings suggest a potential therapeutic approach for POI management.

Lacticaseibacillus rhamnosus KY16 Improves Depression by Promoting Intestinal Secretion of 5-HTP and Altering the Gut Microbiota.

Increasing research suggests a connection between gut microbiota and depressive disorders. Targeted changes to the intestinal flora may contribute to alleviating anxiety and depression. This study aimed to identify probiotics that could attenuate stress-induced abnormal behavior and explore potential mechanisms. The administration of LR.KY16 significantly reduced stress-induced abnormal behaviors and physiological dysfunction. The mechanism may be via regulating the structure of the intestinal microbiota in mice, increasing the abundance of Akkermansia muciniphila, prompting enterochromaffin cells to secrete 5-HTP in the gut, which enters the brain through the bloodstream and promotes the synthesis of 5-HT in the brain, and then activates brain-derived neurotrophic factor (BDNF)/tyrosine kinase receptor B (TrkB) through the 5-HT1A receptor. In addition, LR.KY16 also increased the expression of claudin-7, occludin, and zonula occludens-1 (ZO-1) in the colon, inhibited microglial M1 polarization, and inhibited systemic inflammation.

Unraveling the role of gut microbiota by fecal microbiota transplantation in rat model of kidney stone disease

Emerging research on the microbiome highlights the significant role of gut health in the development of kidney stones, indicating that an imbalance in gut bacteria or dysbiosis can influence the formation of stones by altering oxalate metabolism and urinary metabolite profiles. In particular, the overabundance of specific bacteria such as Enterococcus and Oxalobacter spp., which are known to affect oxalate absorption, is observed in patients with urolithiasis. This study investigates the effects of gut dysbiosis on urolithiasis through fecal microbiota transplantation (FMT) from patients to rats and its impact on urinary mineral excretion and stone formation. Fecal samples from eight patients with calcium oxalate stones and ten healthy volunteers were collected to assess the gut microbiome. These samples were then transplanted to antibiotic-pretreated Wistar rats for a duration of four weeks. After transplantation, we evaluated changes in the fecal gut microbiome profile, urinary mineral excretion rates, and expression levels of intestinal zonula occluden-1 (ZO-1), SLC26A6 and renal NF-κB. In humans, patients with urolithiasis exhibited increased urinary calcium and oxalate levels, along with decreased citrate excretion and increased urinary supersaturation index. The fecal microbiota showed a notable abundance of Bacteroidota. In rodents, urolithiasis-FMT rats showed urinary disturbances similar to patients, including elevated pH, oxalate level, and supersaturation index, despite negative renal pathology. In addition, a slight elevation in the expression of renal NF-κB, a significant intestinal SLC26A6, and a reduction in ZO-1 expression were observed. The gut microbiome of urolithiasis-FMT rats showed an increased abundance of Bacteroidota, particularly Muribaculaceae, compared to their healthy FMT counterparts. In conclusion, the consistent overabundance of Bacteroidota in both urolithiasis patients and urolithiasis-FMT rats is related to altered intestinal barrier function, hyperoxaluria, and renal inflammation. These findings suggest that gut dysbiosis, characterized by an overgrowth of Bacteroidota, plays a crucial role in the pathogenesis of calcium oxalate urolithiasis, underscoring the potential of targeting the gut microbiota as a therapeutic strategy.

PSVII-16 Recombinant bovine lactoferrin expressed in Schizochytrium sp. alleviates inflammation and oxidative damage in calf intestinal epithelial cells

Abstract This study aims to generate recombinant bovine lactoferrin (rbLF) by expressing it in Schizochytrium sp. (SZ) and evaluate its effects on calf intestinal epithelial cells (CIECs) exposed to lipopolysaccharide (LPS) or hydrogen peroxide-induced damage. The bovine lactoferrin expression cassette was transfected into Schizochytrium sp. via 18s rRNA gene recombination. Primary CIECs were utilized in this investigation, and the optimal dose of rbLF was evaluated by cell counting kit-8 assay after being treated with different concentrations of rbLF for 24 h. The optimal dose of rbLF was then used as a medium supplement before or after 24 h of 80 μg/mL LPS challenge or 4 h of 400 μM of hydrogen peroxide (H2O2) challenge. Cell viability, gene expression of tumor necrosis factor (TNF) -α, toll-like receptor (TLR) -4, interleukin (IL) -17A, zonula occludens-1 (ZO-1), and claudin-1, as well as protein levels of TNF-α, IL-17A, ZO-1, and claudin-1, were assessed to elucidate the preventive and therapeutic effects of rbLF. Data analysis was performed using SAS 9.4 by F-test, The statistical significance was declared at P &amp;lt; 0.05. Results indicate that rbLF demonstrated no cytotoxicity within the 50 to 1,000 μg/mL range on CIECs. Treatment with 175 μg/mL rbLF for 24 h increased cell viability, expression, and protein concentrations of ZO-1 and claudin following hydrogen peroxide challenge (P &amp;lt; 0.05). Moreover, rbLF pretreatment for 24 hours, despite decreasing cell viability after the H2O2 challenge, increased the expression and protein concentrations of ZO-1 and claudin-1 compared with non-rbLF-treated groups (P &amp;lt; 0.05). When used to prevent LPS-induced inflammation, rbLF enhanced the gene expression and protein concentrations of TNF-α, ZO-1, and claudin-1 compared with controls (P &amp;lt; 0.05). As a treatment for LPS-induced inflammation, rbLF decreased TLR4, TNF-α, and IL-17A expression levels (P &amp;lt; 0.05). These findings suggest that SZ-expressed rbLF is safe for calve intestinal cells and 175 μg/mL of rbLF may mitigate inflammation-induced intestinal barrier dysfunction.

The protective effects of apelin-13 in HIV-1 tat- induced macrophage infiltration and BBB impairment

ABSTRACT Impairment of the blood – brain barrier (BBB) and subsequent inflammatory responses contribute to the development of human immunodeficiency virus (HIV)-1-associated neurocognitive disorders (HAND). Apelin-13, the most abundant member of the apelin family, acts as the ligand of the angiotensin receptor-like 1 (APJ). However, its pharmacological function in HAND and its underlying mechanism are unknown. In the current study, we report that the presence of HIV-1 Tat reduced the levels of Apelin-13 and APJ in the cortex tissue of mice. Importantly, Apelin-13 preserved BBB integrity against HIV-1 Tat in mice by increasing the expression of the tight junction protein zonula occludens-1 (ZO-1) and occludin. Interestingly, increased macrophage infiltration, indicated by elevated CD68-positive staining was observed in the cortex after stimulation with HIV-1, which was mitigated by the administration of Apelin-13. Correspondingly, Apelin-13 reduced the expression of monocyte chemoattractant protein-1; (MCP-1). An in vitro two-chamber and two-cell trans-well assay demonstrated that HIV-1 Tat challenge significantly promoted macrophage migration, which was notably attenuated by the introduction of Apelin-13. Accordingly, treatment with Apelin-13 restored the HIV-1 Tat-induced reduction of occludin and ZO-1, while preventing the upregulation of MCP-1 in human brain microvascular endothelial cells (HBMVECs). Our results suggest that Apelin-13 may reduce macrophage infiltration into brain tissues and mitigate BBB dysfunction in patients with HAND.

Treatment with Gac Fruit Extract and Probiotics Reduces Serum Trimethylamine N-Oxide in Chronic Kidney Disease Rats.

Chronic kidney disease (CKD) affects more than 850 million people worldwide, contributing to morbidity and mortality, particularly through cardiovascular disease (CVD). The altered composition in CKD patients leads to increased production and absorption of uremic toxins such as trimethylamine (TMA) and its oxidized form, trimethylamine N-oxide (TMAO), which are associated with cardiovascular risks. This study investigated the potential of supplementary interventions with high-carotenoid-content gac fruit extract and probiotics to mitigate serum TMAO by modulating the gut microbiota. We conducted an animal study involving 48 male Wistar rats, divided into six groups: the control, CKD control, and four treatment groups receiving gac fruit extract, carotenoid extract, or combinations with Ligilactobacillus salivarius and Lactobacillus crispatus and Lactobacillus casei as a standard probiotic. CKD was induced in rats using cisplatin and they were supplemented with choline to enhance TMA production. The measures included serum creatinine, TMAO levels, gut microbiota composition, and the expression of fecal TMA lyase and intestinal zonula occluden-1 (ZO-1). CKD rats showed increased TMA production and elevated serum levels of TMAO. Treatment with gac fruit extract and selective probiotics significantly altered the composition of the gut microbiota by decreasing Actinobacteriota abundance and increasing the abundance of Bacteroides. This combination effectively promoted ZO-1 expression, reduced fecal TMA lyase, and subsequently lowered serum TMAO levels, demonstrating the therapeutic potential of these interventions. Our results highlight the benefits of gac fruit extract combined with probiotics for the effective reduction in serum TMAO levels in rats with CKD, supporting the further exploration of dietary and microbial interventions to improve outcomes in patients with CKD.

Capsaicin Reduces Obesity by Reducing Chronic Low-Grade Inflammation.

Chronic low-grade inflammation (CLGI) is associated with obesity and is one of its pathogenetic mechanisms. Lipopolysaccharide (LPS), a component of Gram-negative bacterial cell walls, is the principal cause of CLGI. Studies have found that capsaicin significantly reduces the relative abundance of LPS-producing bacteria. In the present study, TRPV1-knockout (TRPV1-/-) C57BL/6J mice and the intestinal epithelial cell line Caco-2 (TRPV1-/-) were used as models to determine the effect of capsaicin on CLGI and elucidate the mechanism by which it mediates weight loss in vivo and in vitro. We found that the intragastric administration of capsaicin significantly blunted increases in body weight, food intake, blood lipid, and blood glucose in TRPV1-/- mice fed a high-fat diet, suggesting an anti-obesity effect of capsaicin. Capsaicin reduced LPS levels in the intestine by reducing the relative abundance of Proteobacteria such as Helicobacter, Desulfovibrio, and Sutterella. Toll-like receptor 4 (TLR4) levels decreased following decreases in LPS levels. Then, the local inflammation of the intestine was reduced by reducing the expression of tumor necrosis factor (TNF)-α and interleukin (IL)-6 mediated by TLR4. Attenuating local intestinal inflammation led to the increased expression of tight junction proteins zonula occludens 1 (ZO-1) and occludin and the restoration of the intestinal barrier function. Capsaicin increased the expression of ZO-1 and occludin at the transcriptional and translational levels, thereby increasing trans-endothelial electrical resistance and restoring intestinal barrier function. The restoration of intestinal barrier function decreases intestinal permeability, which reduces the concentration of LPS entering the circulation, and reduced endotoxemia leads to decreased serum concentrations of inflammatory cytokines such as TNF-α and IL-6, thereby attenuating CLGI. This study sheds light on the anti-obesity effect of capsaicin and its mechanism by reducing CLGI, increasing our understanding of the anti-obesity effects of capsaicin. It has been confirmed that capsaicin can stimulate the expression of intestinal transmembrane protein ZO-1 and cytoplasmic protein occludin, increase the trans-epithelial electrical resistance value, and repair intestinal barrier function.

Engineering a 3D Biomimetic Peptides Functionalized-Polyethylene Glycol Hydrogel Model Cocultured with Endothelial Cells and Astrocytes: Enhancing In Vitro Blood-Brain Barrier Biomimicry.

The blood-brain barrier (BBB) poses a significant challenge for drug delivery and is linked to various neurovascular disorders. In vitro BBB models provide a tool to investigate drug permeation across the BBB and the barrier's response to external injury events. Yet, existing models lack fidelity in replicating the BBB's complexity, hindering a comprehensive understanding of its functions. This study introduces a three-dimensional (3D) model using polyethylene glycol (PEG) hydrogels modified with biomimetic peptides that represent recognition sequences of key proteins in the brain. Hydrogels were functionalized with recognition sequences for laminin (IKVAV) and fibronectin peptides (RGD) and chemically cross-linked with matrix metalloprotease-sensitive peptides (MMPs) to mimic the extracellular matrix of the BBB. Astrocytes and endothelial cells were seeded within and on the surface of the hydrogels, respectively. The barrier integrity was assessed through different tests including transendothelial electrical resistance (TEER), the permeability of sodium fluorescence (Na-F), the permeability of Evan's blue bound to albumin (EBA), and the expression of zonula occluden-1 (ZO-1) in seeded endothelial cells. Hydrogels with a combination of RGD and IKVAV peptides displayed superior performance, exhibiting significantly higher TEER values (55.33 ± 1.47 Ω·cm2) at day 5 compared to other 2D controls including HAECs-monoculture and HAECs-cocultured with NHAs seeded on well inserts and 3D controls including RGD hydrogel and RGD-IKVAV monoculture with HAECs and RGD hydrogel cocultured with HAECs and NHAs. The designed 3D system resulted in the lowest Evan's blue permeability at 120 min (0.215 ± 0.055 μg/mL) compared to controls. ZO-1 expression was significantly higher and formed a relatively larger network in the functionalized hydrogel cocultured with astrocytes and endothelial cells compared to the controls. Thus, the designed 3D model effectively recapitulates the main BBB structure and function in vitro and is expected to contribute to a deeper understanding of pathological CNS angiogenesis and the development of effective CNS medications.

Resveratrol attenuates non-steroidal anti-inflammatory drug-induced intestinal injury in rats in a high-altitude hypoxic environment by modulating the TLR4/NFκB/IκB pathway and gut microbiota composition.

Non-steroidal anti-inflammatory drugs (NSAIDs) are currently the most widely used anti-inflammatory medications, but their long-term use can cause damage to the gastrointestinal tract(GIT). One of the risk factors for GIT injury is exposure to a high-altitude hypoxic environment, which can lead to damage to the intestinal mucosal barrier. Taking NSAIDs in a high-altitude hypoxic environment can exacerbate GIT injury and impact gut microbiota. The aim of this study is to investigate the mechanisms by which resveratrol (RSV) intervention alleviates NSAID-induced intestinal injury in a high-altitude hypoxic environment, as well as its role in regulating gut microbiota. Aspirin was administered orally to rats to construct a rat model of intestinal injury induced by NSAIDs. Following the induction of intestinal injury, rats were administered RSV by gavage, and the expression levels of TLR4, NF-κB,IκB as well as Zonula Occludens-1 (ZO-1) and Occludin proteins in the different treatment groups were assessed via Western blot. Furthermore, the expression of the inflammatory factors IL-10, IL-1β, and TNF-α was evaluated using Elisa.16sRNA sequencing was employed to investigate alterations in the gut microbiota. The HCk group showed elevated expression of TLR4/NF-κB/IκB pathway proteins, increased expression of pro-inflammatory factors IL-1β and TNF-α, decreased expression of the anti-inflammatory factor IL-10, and expression of intestinal mucosal barrier proteins ZO-1 and Occludin. The administration of NSAIDs drugs in the plateau hypoxic environment exacerbates intestinal inflammation and damage to the intestinal mucosal barrier. After treatment with RSV intervention, the expression of TLR4/NF-κB/IκB signaling pathway proteins would be reduced, thereby lowering the expression of inflammatory factors in the HAsp group. The results of HE staining directly show the damage to the intestines and the repair of intestinal mucosa after RSV intervention. 16sRNA sequencing results show significant differences (P<0.05) in Ruminococcus, Facklamia, Parasutterella, Jeotgalicoccus, Coprococcus, and Psychrobacter between the HCk group and the Ck group. Compared to the HCk group, the HAsp group shows significant differences (P<0.05) in Facklamia, Jeotgalicoccus, Roseburia, Psychrobacter, and Alloprevotella. After RSV intervention, Clostridium_sensu_stricto bacteria significantly increase compared to the HAsp group. Resveratrol can attenuate intestinal damage caused by the administration of NSAIDs at high altitude in hypoxic environments by modulating the TLR4/NF-κB/IκB signaling pathway and gut microbiota composition.

Red light-induced localized release of carbon monoxide for alleviating postoperative cognitive dysfunction

Inflammation within the central nervous system (CNS), which may be triggered by surgical trauma, has been implicated as a significant factor contributing to postoperative cognitive dysfunction (POCD). The relationship between mitigating inflammation at peripheral surgical sites and its potential to attenuate the CNS inflammatory response, thereby easing POCD symptoms, remains uncertain. Notably, carbon monoxide (CO), a gasotransmitter, exhibits pronounced anti-inflammatory effects. Herein, we have developed carbon monoxide-releasing micelles (CORMs), a nanoparticle that safely and locally liberates CO upon exposure to 650 nm light irradiation. In a POCD mouse model, treatment with CORMs activated by light (CORMs + hv) markedly reduced the concentrations of interleukin (IL)-6, IL-1β, and tumor necrosis factor-alpha (TNF-α) in both the peripheral blood and the hippocampus, alongside a decrease in ionized calcium-binding adapter molecule 1 in the hippocampal CA1 region. Furthermore, CORMs + hv treatment diminished Evans blue extravasation, augmented the expression of tight junction proteins zonula occludens-1 and occludin, enhanced neurocognitive functions, and fostered fracture healing. Bioinformatics analysis and experimental validation has identified Htr1b and Trhr as potential key regulators in the neuroactive ligand-receptor interaction signaling pathway implicated in POCD. This work offers new perspectives on the mechanisms driving POCD and avenues for therapeutic intervention.