Intestinal Inflammatory Injury Research Articles

Cynaroside ameliorates methotrexate-induced enteritis in rats through inhibiting NLRP3 inflammasome activation

IntroductionCynaroside exhibits various biological properties, including anti-inflammatory, antiviral, antitumor, and cardioprotective effects. However, its involvement in methotrexate (MTX)-induced intestinal inflammation remains inadequately understood. Thus, we investigated the impact of cynaroside on MTX-induced intestinal inflammation and its potential mechanisms.MethodsTo assess the protective potential of cynaroside against intestinal inflammation, Sprague-Dawley rats were subjected to a regimen of 7 mg/kg MTX for 3 days, followed by treatment with cynaroside at varying doses (10, 20, or 40 mg/kg). Histopathological evaluations were conducted alongside measurements of inflammatory mediators to elucidate the involvement of the NLRP3 inflammasome in alleviating intestinal inflammation.ResultsAdministration of 7 mg/kg MTX resulted in decreased daily food intake, increased weight loss, and elevated disease activity index in rats. Conversely, treatment with cynaroside at 20 or 40 mg/kg ameliorated the reductions in body weight and daily food intake and suppressed the MTX-induced elevation in the disease activity index. Notably, cynaroside administration at 20 or 40 mg/kg attenuated inflammatory cell infiltration, augmented goblet cell numbers and lowered serum levels of tumor necrosis factor-α, interleukin (IL)-1β, and IL-18, as well as the CD68-positive cell rate in the intestines of MTX-induced rats. Furthermore, cynaroside downregulated the expression levels of NLRP3, cleaved caspase 1, and cleaved IL-1β in MTX-induced rats.DiscussionCollectively, our findings indicated that cymaroside alleviates intestinal inflammatory injury by inhibiting the activation of NLRP3 inflammasome in MTX-induced rats.

Xylitol attenuates diabetes induced intestinal permeability changes and inflammatory injury by improving intestinal tight junction protein expression and mucus secretion in rats

ABSTRACT The purpose of this study was to investigate the protective effect of xylitol on gut mucosal barrier injury in a type 2 diabetes rat model. Treatment with xylitol not only ameliorated diabetic-induced changes to small intestinal mucosa morphology and decreased diamine oxidase concentration in the serum of diabetic rats, but also modified the inflammatory infiltrates and improved the secretory IgA levels of the small intestinal epithelium. Increased expression of zo-1, occludin, mucin-2 and intestinal trefoil factor also was detected in small intestinal tissue. Intragastric administration of xylitol suppressed diabetes-induced increases of myeloperoxidase, eosinophil peroxidase, IL-6 and TNF-α. These results suggest that xylitol reduces mucosal inflammatory lesions and improves the intestinal barrier in diabetic rats by maintaining the structural integrity of the mucous layer, inhibiting the expression of inflammatory mediators and enhancing the expression of tight junction proteins associated with intestinal permeability.

Baicalin attenuates lipopolysaccharide-induced intestinal inflammatory injury via suppressing PARP1-mediated NF-κB and NLRP3 signalling pathway

Bacterial lipopolysaccharide (LPS) exposure is a key inducer of intestinal inflammatory injury in weaned piglets, resulting in decreased growth performance of pigs and causing severe economic losses to the swine industry; however, the mechanism of intestinal inflammatory injury is still unclear. Baicalin is one of the main active ingredients extracted from the natural plant Scutellaria baicalensis that has biological functions, including anti-inflammatory activity. The aim of this study is to investigate the effect and mechanism of baicalin intervention on intestinal inflammatory injury caused by bacterial LPS exposure. In the present study, network pharmacology, molecular docking and DARTS results identified that baicalin has the potential to target PARP1, thereby potentially regulating a series of inflammation-related pathways, including the MAPK, NF-κB and Toll-like receptor signalling pathways, which play the role of antagonizing LPS-induced intestinal inflammatory injury. Further application of the LPS-induced IPEC-J2 cell model validated the finding that baicalin could alleviate LPS-induced intestinal inflammatory injury by inhibiting the PARP1-mediated NF-κB and NLRP3 signalling pathway. These findings demonstrate that baicalin can regulate the expression of PARP1 and that PARP1 has the potential to serve as an effective therapeutic target in the LPS-induced intestinal inflammatory injury.

Bound polyphenols in insoluble dietary fiber of navel orange peel modulate LPS-induced intestinal-like co-culture inflammation through CSF2-mediated NF-κB/JAK-STAT pathway.

Our laboratory previously extracted bound polyphenols (BPP) in insoluble dietary fiber from navel orange peel (NOP-IDF), and the aim of this study was to investigate the anti-inflammatory activity and potential molecular mechanisms of BPP by establishing an LPS-induced intestinal-like Caco-2/RAW264.7 co-culture inflammation model. The results demonstrated that BPP reduced the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), as well as the production of pro-inflammatory cytokines, nitric oxide (NO), and reactive oxidative species (ROS) during the inflammatory damage process. Furthermore, BPP alleviated the lipopolysaccharides (LPS)-induced intestinal barrier damage by attenuating the decrease in trans-epithelial electrical resistance (TEER), diamine oxidase (DAO) activity, and intestinal alkaline phosphatase (IAP) activity, as well as the downregulation of ZO-1, Occludin, and Claudin-1 protein expression levels. RNA-seq results on RAW264.7 cells in the co-culture model showed that the NF-κB and JAK-STAT pathways belonged to the most significantly affected signaling pathways in the KEGG analysis, and western blot confirmed that they are essential for the role of BPP in intestinal inflammation. Additionally, overexpression of the granulocyte-macrophage colony-stimulating factor (CSF2) gene triggered abnormal activation of the NF-κB and JAK-STAT pathways and high-level expression of inflammatory factors, while BPP effectively improved this phenomenon. The above results suggested that BPP could inhibit intestinal inflammatory injury and protect intestinal barrier integrity through CSF2-mediated NF-κB and JAK-STAT pathways.

Generation of Porcine Angiogenin 4-Expressing Pichia pastoris and Its Protection against Intestinal Inflammatory Injury.

Antimicrobial peptides have been extensively studied as potential alternatives to antibiotics. Porcine angiogenin 4 (pANG4) is a novel antimicrobial peptide in the angiogenin (ANG) family, which may have a regulatory effect on intestinal microflora. The object of present study is obtained pANG4 protein by heterologous expression, so as to explore the biological function of recombinant pANG4 (rpANG4). The pANG4 was expressed in Pichia pastoris (P. pastoris) and anti-inflammatory effects were investigated in intestinal porcine epithelial cell line-J2 (IPEC-J2) and mice. Purified rpANG4 had bacteriostatic activity and did not cause hemolysis or cytotoxicity at concentrations below 128 μg/mL. Purified rpANG4 increased the activity of IPEC-J2 and reduced apoptosis in vitro. rpANG4 reduced the pro-inflammatory gene expression and upregulated tight junction protein gene expression during inflammation. rpANG4 alleviated lipopolysaccharide (LPS)-induced liver and spleen damage, intestinal inflammation, jejunal apoptosis genes' expression, and improved immune function in an in vivo mice model. rpANG4 increased tight junction protein gene expression in jejunum, thereby improving the jejunum intestinal barrier function. In conclusion, rpANG4 had antibacterial activity, inhibited intestinal inflammation, improved intestinal barrier function, and alleviated liver and spleen damage. The current study contributes to the development of antibiotic substitutes and the improvement of animal health.

Reparative effect of different dietary additives on soybean meal-induced intestinal injury in yellow drum (Nibea albiflora).

Soybean meal (SBM) is an acceptable replacement for unsustainable marine fish meal (FM) in aquaculture. However, we previously reported that high dietary SBM supplementation causes intestinal inflammatory injury in yellow drum (Nibea albiflora). Accordingly, a 4-week SBM-induced enteritis (SBMIE) in yellow drum trial was conducted first, followed by a 4-week additive-supplemented reparative experiment to evaluate the reparative effect of five additives on SBMIE in yellow drum. The control diet comprised 50% FM protein substituted with SBM. The additive-supplemented diet was added with 0.02% curcumin (SBMC), 0.05% berberine (SBM-BBR), 0.5% tea polyphenols (SBM-TPS), 1% taurine (SBM-TAU), or 0.8% glutamine (SBM-GLU) based on the control diet, respectively. The weight gain (WG), specific growth rate (SGR), feed efficiency ratio (FER), and survival rate (SR) of fish fed the additive-supplemented diets were significantly higher than those of fish fed the SBM diet. The WG, SGR, and FER of fish fed the SBMC, SBM-GLU and SBM-TAU diets were significantly higher than those of fish fed other diets. Moreover, fish fed the additive-supplemented diets SBMC and SBM-GLU, exhibited significantly increased intestinal villus height (IVH), intestinal muscular thickness (IMRT), and intestinal mucosal thickness (IMLT) and significantly decreased crypt depth (CD) in comparison with those fed the SBM diets. The relative expression of intestinal tight junction factors (ocln, zo1), cytoskeletal factors (f-actin, arp2/3), and anti-inflammatory cytokines (il10, tgfb) mRNA was remarkably elevated in fish fed additive-supplemented diets than those of fish fed the SBM diet. Whereas, the relative expression of intestinal myosin light chain kinase (mlck) and pro-inflammatory cytokines (il1, il6, tnfa) mRNA was markedly lower in fish fed the additive-supplemented diets. The highest relative expression of intestinal ocln, f-actin, and arp2/3 and the lowest relative expression of intestinal mlck were found in fish fed the SBMC diet. Hence, all five dietary additives effectively repaired the intestinal injury induced by SBM, with curcumin exhibiting the strongest repair effect for SBMIE in yellow drum.

Tanshinone IIA protects intestinal epithelial cells from deoxynivalenol-induced pyroptosis

Deoxynivalenol (DON) is the most common mycotoxin in food and feed, which can cause undesirable effects, including diarrhea, emesis, weight loss, and growth delay in livestock. Intestinal epithelial cells were the main target of DON, which can cause oxidative stress and inflammatory injury. Tanshinone IIA (Tan IIA) is fat-soluble diterpene quinone, which is the most abundant active ingredient in salvia miltiorrhiza plant with antioxidant and anti-inflammatory characteristics. However, it is not clear whether Tan IIA can protect against or inhibit intestinal oxidative stress and inflammatory injury under DON exposure. This study aimed to explore the protective effect of Tan IIA on DON-induced toxicity in porcine jejunum epithelial cells (IPEC-J2). Cells were exposed to 0, 0.5, 1.0, 2.0 µM DON and/or 45 µg/mL TAN ⅡA to detect oxidative stress indicators. inflammatory cytokines, NF-κB expression, NLRP3 inflammasome and pyroptosis-related factors. In this study, DON exposure caused IPEC-J2 cells oxidative stress by elevating ROS and 8-OHdG content, inhibited GSH-Px activity. Furthermore, DON increased pro-inflammatory factor (TNF-α, IL-1β, IL-18 and IL-6) expression and decreased the anti-inflammatory factor (IL-10) expression, causing inflammatory response via triggering NF-κB pathway. Interestingly, above changes were alleviated after Tan IIA treatment. In addition, Tan IIA relieved DON-induced pyroptosis by suppressing the expression of pyroptosis-related factors (NLRP3, Caspase-1, GSDMD, IL-1β, and IL-18). In general, our data suggested that Tan IIA can ameliorate DON-induced intestinal epithelial cells injury associated with suppressing the pyroptosis signaling pathway. Our findings pointed that Tan IIA could be used as the potential therapeutic drugs on DON-induced enterotoxicity.

Integrating network pharmacology and experimental validation to explore the mechanisms of luteolin in alleviating fumonisin B1–induced intestinal inflammatory injury

Contamination with fumonisin B1 (FB1) represents a global health problem. FB1 exposure may also trigger intestinal injury by activating inflammatory responses, leading to a reduction in production performance and economic benefits. However, the mechanism of FB1-induced intestinal inflammatory injury is still unclear. At the same time, it is urgent to develop antibiotic alternatives and therapeutic targets to alleviate antibiotic resistance and to ensure effective treatment of intestinal inflammatory injury. We combined network pharmacology and in vitro experiments to explore the core therapeutic targets and potential mechanism of luteolin in FB1-induced intestinal inflammatory injury. Network pharmacology and molecular docking revealed that nuclear factor kappa B (NF-κB) p65, extracellular signal-regulated kinase (ERK), interleukin 6 (IL-6) and IL-1β are the important targets, and the NF-κB and ERK signalling pathways are critical in FB1-induced intestinal inflammatory injury. Besides, in vitro experiments further demonstrated that luteolin can inhibit FB1-induced intestinal inflammatory injury by inhibiting activation of the NF-κB and ERK signalling pathways and reducing the expression of IL-6 and IL-1β in IPEC-J2 cells. We have comprehensively illustrated the potential targets and molecular mechanism by which luteolin can alleviate FB1-induced intestinal inflammatory injury. Luteolin may be an effective antibiotic alternative to prevent intestinal inflammatory injury.

Role of microencapsulated Lactobacillus plantarum in alleviating intestinal inflammatory damage through promoting epithelial proliferation and differentiation in layer chicks.

The alleviating effects of Lactobacillus plantarum in microencapsulation (LPM) on lipopolysaccharide (LPS)-induced intestinal inflammatory injury were investigated in layer chicks. A total of 252 healthy Hy-Line Brown layer chicks were randomly divided into six groups. Birds were injected with saline or LPS except for the control, and the diets of birds subjected to LPS were supplemented with nothing, L. plantarum, LPM, and wall material of LPM, respectively. The viable counts of LPM reached 109 CFU/g, and the supplemental levels of L. plantarum, LPM, and WM were 0.02 g (109 CFU), 1.0 g, and 0.98 g, per kilogram feed, respectively. LPS administration caused intestinal damage in layer chicks, evidenced by increased proinflammatory factors accompanied by poor intestinal development and morphology (p < 0.05). LPM/LPS significantly increased body weight, small intestine weight and length, villus height, villus height/crypt depth, and mRNA relative expression of tight junction protein genes (p < 0.05) and performed better than free L. plantarum. These findings could be attributed to the significant increase in viable counts of L. plantarum in the small intestine (p < 0.05), as well as the enhanced levels of Actinobacteriota, Lactobacillaceae, and Lactobacillus in intestinal microbiota (p < 0.05). Such results could further significantly increase goblet and PCNA+ cell percentage (p < 0.05); the mRNA relative expressions of epithelial cell, fast-cycling stem cell, quiescent stem cell, endocrine cell, and Paneth cell; and goblet and proliferative cell marker genes, including E-cadherin, Lgr-5, Bmi-1, ChA, Lysozome, Mucin-2, and PCNA (p < 0.05). Furthermore, the mRNA relative expressions of key genes involved in epithelial cell proliferation, namely, c-Myc, Cyclin-1, Wnt-3, Lrp-5, and Olfm-4, exhibited significant upregulation compared with the LPS treatment, as well as the differentiating genes Notch-1 and Hes-1 (p < 0.05). To sum up, microencapsulated L. plantarum supplementation could alleviate intestinal injury in layer chicks induced by LPS by promoting the proliferation and differentiation of intestinal epithelial cells, which could be attributed to the increase in viable count of L. plantarum in the gut and optimization in intestinal microbial flora.

Arsenic induced neurotoxicity in the brain of ducks: The potential involvement of the gut-brain axis

BackgroundArsenic is a widely distributed ecotoxic pollutant that has been found to cause neurotoxicity in a variety of species. Gut-brain axis is a two-way information network between the gut microbiome and the brain, which is closely related to organismal health. However, the role of the gut-brain axis in arsenic-induced neurotoxicity remains largely unknown. MethodsIn order to explore whether there is a relationship between brain and gut microbiota of meat ducks, we performed molecular biological detection including RT-qPCR and Western blot, as well as morphological detection including, HE staining and immunohistochemistry. Meanwhile, intestinal contents were analyzed using 16 S ribosomal RNA gene sequencing and analysis ResultsIn this study, we investigated whether arsenic trioxide (ATO) can activate the gut microbiome-brain axis to induce intestinal and brain injury. The results showed that ATO-exposure disrupted the diversity balance of intestinal microbiota and integrity and injured the intestinal structure. ATO-exposure also reduced the number of glycogen and goblet cells in the duodenum. In addition, exposure to ATO caused intestinal inflammatory injury by activating NF-κB signaling pathway and promoting the expression of its target genes. Meanwhile, the tight junction-related proteins (ZO-1, occludin) of gut and brain were reduced by ATO exposure. Furthermore, results also revealed that ATO-exposure induced brain injury, including neuronal cell vacuolization and reduced numbers of neuronal cells in the cortex and hippocampus. Remarkably, ATO-exposure also disrupted neurotransmitter levels. Additionally, our further molecular mechanism study revealed that ATO-exposure increased the expression of autophagy and apoptosis related mRNA and proteins levels in the brain tissues. ConclusionAltogether, these findings provide a new insight into that ATO-exposure induced intestinal injury and aggravated neurotoxicity via the gut-brain axis.

Protective effects of maternal administration of total saponins of Codonopsis pilosula in the mice offspring following diarrhea: role of immune function, antioxidant function, and intestinal inflammatory injury.

Total saponins of Codonopsis (TSC) are a kind of critical bioactive substances in Codonopsis, which have anti-inflammatory, antioxidant, anti-ulcer, immunomodulatory effects, and protective effects on ulcerative enteritis. In this study, TSC (3.75 mL/kg, gavage) was administered once a day to 13-day gestation Kunming mice for 5 days. On day 13 of birth, the offspring were given Escherichia coli solution (0.15 mL/mouse, intraperitoneal injection) and senna leaf decoction (0.15 mL/mouse, gavage) once a day for 6 days. The results showed that gestation maternal administration of TSC effectively reduced the diarrhea index, increased the content of sIgA, IgG, SOD, and GSH, inhibited the TLR4/MyD88/NF-κB pathway in the intestine, reduced the expression of inflammatory factors, and alleviated intestinal injury in the littermates. The results provided a critical reference for the clinical application of TSC to control diarrhea in animal offspring.

Astragalus polysaccharide protects experimental colitis through an aryl hydrocarbon receptor-dependent autophagy mechanism.

Disruption of intestinal barriers plays a vital role in the pathogenesis of colitis. The aryl hydrocarbon receptor (AhR) is a recognition sensor that mediates intestinal immune homeostasis and minimizes intestinal inflammation. Astragalus polysaccharide (APS) exerts pharmacological actions in colitis; however, the mechanism has not been elucidated. We investigated whether APS protects through AhR-dependent autophagy. The symptoms of dextran sulfate sodium (DSS)-induced colitis in mice involving intestinal barrier function and inflammatory injury were evaluated after APS administration. Intestinal-specific Becn1 conditional knockout (Becn1 cKO) mice were constructed and compared with wild-type mice. Autophagy and the effects of APS were investigated after the deactivation of AhRs. The relationship between APS-induced AhRs and autophagic Becn1 was investigated using a dual-luciferase reporter system and chromatin immunoprecipitation (ChIP)-quantitative polymerase chain reaction assay. Caco-2 cells were used to investigate inflammatory responses and AhR-dependent autophagy. APS improved intestinal barrier function in inflammatory injury in colitis mice. APS triggered autophagic flow; however, knockout of Becn1 in the gut increased susceptibility to colitis, leading to diminished epithelial barrier function and severe intestinal inflammation, impairing the protective effects of APS. Mechanistically, APS-triggered autophagy depends on AhR expression. Activated AhR binds to the promoter Becn1 to operate transcription of genes involved in anti-inflammation and intestinal barrier repair, while deactivation of AhR correlated with intestinal inflammation and the therapeutic function of APS. APS protects colitis mice by targeting autophagy, especially as the AhR stimulates the repair of damaged intestinal barrier functions.

Research progress in effects of pyroptosis on intestinal inflammatory injury.

Inflammatory injury of the intestine is often accompanied by symptoms such as damage to intestinal mucosa, increased intestinal permeability, and intestinal motility dysfunction. Inflammatory factors spread throughout the body via blood circulation, and can cause multi-organ failure. Pyroptosis is a newly discovered way of programmed cell death, which is mainly characterized by the formation of plasma membrane vesicles, cell swelling until the rupture of the cell membrane, and the release of cell contents, thereby activating a drastic inflammatory response and expanding the inflammatory response cascade. Pyroptosis is widely involved in the occurrence of diseases, and the underlying mechanisms for inflammation are still a hot spot of current research. The caspase-1 mediated canonical inflammasome pathway of pyroptosis and caspase-4/5/8/11-mediated non-canonical inflammasome pathway are closely related to the occurrence and development of intestinal inflammation. Therefore, investigation of the signaling pathways and molecular mechanisms of pyroptosis in intestinal injury in sepsis, inflammatory bowel diseases, infectious enteristic, and intestinal tumor is of great significance for the prevention and treatment of intestinal inflammatory injury.

Protective effects of activated vitamin D receptor on radiation‐induced intestinal injury

Radiation-induced intestinal injury (RIII) is a common complication after radiation therapy in patients with pelvic, abdominal, or retroperitoneal tumours. Recently, in the model of DSS (Dextran Sulfate Sodium Salt) -induced intestinal inflammatory injury, it has been found in the study that transgenic mice expressing hVDR in IEC (Intestinal Epithelial Cell) manifest highly anti-injury properties in colitis, suggesting that activated VDR in the epithelial cells of intestine may inhibit colitis by protecting the mucosal epithelial barrier. In this study, we investigated the effect of the expression and regulation of VDR on the protection of RIII, and the radiosensitivity in vitro experiments, and explored the initial mechanism of VDR in regulating radiosensitivity of IEC. As a result, we found that the expression of VDR in intestinal tissues and cells in mice can be induced by ionizing radiation. VDR agonists are able to prolong the average survival time of mice after radiation and reduce the radiation-induced intestinal injury. For lack of vitamin D, the radiosensitivity of intestinal epithelial cells in mice increased, which can be reduced by VDR activation. Ensuing VDR activation, the radiation-induced intestinal stem cells damage is decreased, and the regeneration and differentiation of intestinal stem cells is promoted as well. Finally, on the basis of sequencing analysis, we validated and found that VDR may target the HIF/PDK1 pathway to mitigate RIII. We concluded that agonism or upregulation of VDR expression attenuates radiation-induced intestinal damage in mice and promotes the repair of epithelial damage in intestinal stem cells.

The Protective Effects of Iron Free Lactoferrin on Lipopolysaccharide-Induced Intestinal Inflammatory Injury via Modulating the NF-κB/PPAR Signaling Pathway.

Research evidence shows that effective nutritional intervention could prevent or reduce intestinal inflammatory injury in newborn infants. Iron free lactoferrin (apo-LF), one of the main types of lactoferrin (LF), is a bioactive protein in milk that plays a vital role in maintaining intestinal health. The potential mechanism by which apo-LF modulates intestinal inflammation is, however, still unclear. In the study we first explored key genes and pathways in vitro by transcriptome date analysis and then validated them in vivo to reveal the underlying molecular mechanism. The results showed that apo-LF pretreatment effectively inhibited lipopolysaccharide (LPS)-induced primary intestinal epithelial cells (IECs) inflammation in the co-culture system (primary IECs and immune cells), which was specifically manifested as the reduction of the concentration of TNF-α, IL-6 and IL-1β and increased the concentration of IFN-γ. In addition, transcriptome data analysis revealed that the key pathway for apo-LF to exert anti-inflammatory effects was the NF-κB/PPAR signaling pathway. Further validation was performed using western blotting in colonic tissues of young mice and it was found that the major proteins of NF-κB signaling pathway (NF-κB, TNF-α and IL-1β) were inhibited by apo-LF and the target proteins of PPAR signaling pathway (PPAR-γ and PFKFB3) were activated by apo-LF. Taken together, this suggests that apo-LF has a protective effect against LPS-induced intestinal inflammatory injury via modulating the NF-κB/PPAR signaling pathway, which provides new insights for further anti-inflammatory study of apo-LF.

MicroRNA-9a-5p-NOX4 inhibits intestinal inflammatory injury by regulating the M1 polarization of intestinal macrophages.

We found that the expression of microRNA (miRNA)-9a-5p decreased in inflammatory bowel diseases (IBD; ulcerative colitis and Crohn's disease). Further, we revealed the effects and mechanisms of miRNA-9a-5p for regulatingIBD progression. In C57BL/6N mice, IBD was induced with dextran sodium sulfate (DSS), and the effects of endogenous miRNA-9a-5p were mimicked/antagonized through intraperitoneal injection of miRNA-9a-5p agomir and antagomir. In animal experimentation, agomir could inhibit intestinal inflammation and tissue damage, and reduce the mucosal barrier permeability. Antagomir, on the other hand, could promote barrier damage, whose effect was associated with the M1 macrophage polarization.This study finds that miRNA-9a-5p targets NOX4 to suppressROS production, which plays an important role in mucosal barrier damage in IBD.

Activation of pyroptosis and ferroptosis is involved in radiation-induced intestinal injury in mice

Radiation-induced intestinal injury (RIII) is one of the most common abdominal and pelvic radiation therapy complications. RIII seriously affects the treatment and prognosis of cancer patients, and there are no effective interventions. Radiation can cause intestinal tissue damage, inflammatory cell infiltration, and pro-inflammatory cytokine release. We established an RIII mouse model by subjecting C57BL/6 mice to abdominal irradiation. Our results show that both pyroptosis and ferroptosis play a key role in RIII. VX-765 and Ferrostatin-1 (Fer-1) can inhibit these two types of programmed cell death and ameliorate RIII, respectively. Activation of the nuclear factor-κB (NF-κB) signaling pathway exacerbates the chemotaxis of inflammatory cells. In the present study, we hypothesized that the activation of NF-κB signaling pathway plays an important role in intestinal inflammatory injury. We demonstrated that the nuclear expression levels of the NF-κB subunit p65 increased after irradiation treatment. Reduced release of inflammatory factors and intestinal tissue damage was observed after pretreatment with pyrrolidinedithiocarbamate ammonium (PDTC). Moreover, after PDTC treatment, the indicators related to pyroptosis and ferroptosis were reversed. Collectively, these results suggest that the activation of the intestinal NF-κB signaling pathway may be associated with pyroptosis, ferroptosis, and subsequent intestinal injury after irradiation.

Protective Effect of Bilberry Anthocyanin Extracts on Dextran Sulfate Sodium-Induced Intestinal Damage in Drosophila melanogaster.

Inflammatory bowel disease (IBD) is a chronic recurrent disease that can be controlled by various natural extracts. Anthocyanins (ANCs) from bilberry have significant antioxidant capacity and are widely used as food colors and antioxidants. In this study, we investigated the protective effects of bilberry anthocyanin extracts (BANCs) against dextran sulphate sodium (DSS)-induced intestinal inflammation in a Drosophila melanogaster (D. melanogaster) model, and the effects on the lifespan, antioxidant capacity, intestinal characteristics, and microbiome and gene expression profiles were analyzed to elucidate the underlying biological mechanisms. In DSS-induced normal and axenic D. melanogaster, BANCs significantly increased the survival rate, maintained the intestinal morphology and integrity, and reduced the number of dead intestinal epithelial cells and the ROS level of these cells. BANC supplementation had no significant effect on the intestinal microflora of DSS-induced D. melanogaster, as demonstrated by a 16S rDNA analysis, but improved the antioxidant capacity by activating the relative gene expression of NRF2 signaling pathways in the intestine of D. melanogaster with DSS-induced inflammation. Therefore, the results demonstrate that BANCs effectively alleviate intestinal inflammatory injury induced by DSS and improve the antioxidant capacity of D. melanogaster by modulating NRF2 signaling pathways, and could thus promote the application of BANCs as functional foods.

MTOR-Mediated Autophagy Regulates Fumonisin B1-Induced Intestinal Inflammation via Pyroptosis In Vivo and In Vitro.

Fumonisin B1 (FB1) is a fungal metabolite, which has an incremental detection rate in grains and feed worldwide. The nucleotide-binding oligomerization domain-like pyrin domain containing protein 3 (NLRP3) inflammasome is a critical element in pyroptosis activation, which participates in regulating enteritis. Meanwhile, autophagy is also engaged in intestinal inflammation. However, the function of pyroptosis and autophagy in FB1-mediated enterotoxicity remains unclear. In this study, we explored the effects of FB1 on enteritis and the underlying mechanism in vivo and in vitro. Our data showed that FB1 exposure damaged the intestinal epithelium and promoted the secretion of inflammatory cytokines. Meanwhile, FB1 exposure significantly upregulated the expression of pyroptosis-related genes. Then, MCC950, an inhibitor of NLRP3, significantly blocked FB1-induced pyroptosis in IPEC-J2 cells. In addition, FB1 treatment elevated the levels of autophagy. Moreover, the phosphorylation of the mammalian target of rapamycin (mTOR), an upstream protein of the autophagy pathway, was inhibited by FB1 exposure. Notably, rapamycin, an inhibitor of mTOR, instead of MHY1485, an agonist of mTOR, could ameliorate FB1-induced intestinal inflammatory injury and inhibit the upregulation of pyroptosis-related genes. In summary, we demonstrated that autophagy exhibited a protective effect against NLRP3 inflammasome-dependent pyroptosis on FB1-induced enteritis. Our data clarify a favorable protective role for the activation of autophagy in FB1 poisoning.

Protective effects of recombinant lactoferrin with different iron saturations on enteritis injury in young mice

Infant intestinal development is immature and, thus, is vulnerable to bacterial and viral infections, which damage intestinal development and even induce acute enteritis. Numerous studies have investigated that lactoferrin (LF) has protective effects on the intestine and may play a role in preventing intestinal inflammation in infants. Lactoferrin is divided into 2 types, namely apo-LF and holo-LF, depending on the degree of iron saturation, which may affect its bioactivities. However, the role of LF iron saturation in protecting infant intestinal inflammation has not been clearly clarified. Therefore, in this study, young mice models with intestinal damage induced by lipopolysaccharides (LPS) in vivo and primary intestinal epithelial cells in vitro were constructed to enteritis injury in infants for investigation. The apo-LF and holo-LF were subsequently applied to the mouse models to investigate and compare their levels of protection in the intestinal inflammatory injury, as well as to identify which LF was most active. Moreover, the specific mechanism of the LF with optimal iron saturation was further investigated through Western blot assay. Results demonstrated that disease activity index, shortened length of colon tissue, and histopathological score were significantly decreased in the apo-LF group compared with those of the LPS group and the holo-LF group. In the apo-LF group, the concentration of LPS in the intestinal tract and the number of gram-negative bacteria colonies decreased significantly and the expression levels of proinflammatory factors in the colon tissue were downregulated, in comparison with those in the LPS group. The findings of this study thus verify that apo-LF can significantly alleviate enteritis injury caused by LPS, through regulating the PPAR-γ/PFKFB3/NF-κB inflammatory pathway.