Geraniin Alleviates Inflammation in Caco-2 Cells and Dextran Sulfate Sodium-Induced Colitis Mice by Targeting IL-1β

IL-1β is an important cytokine implicated in the progression of inflammatory bowel disease (IBD) and intestinal barrier dysfunction. The polyphenolic compound, geraniin, possesses bioactive properties, such as antitumor, antioxidant, anti-inflammatory, antihypertensive, and antiviral activities; however, its IL-1β-targeted anticolitis activity remains unclear. Here, we evaluated the inhibitory effect of geraniin in IL-1β-stimulated Caco-2 cells and a dextran sulfate sodium (DSS)-induced colitis mouse model. Geraniin blocked the interaction between IL-1β and IL-1R by directly binding to IL-1β and inhibited the IL-1β activity. It suppressed IL-1β-induced intestinal tight junction damage in human Caco-2 cells by inhibiting IL-1β-mediated MAPK, NF-kB, and MLC activation. Moreover, geraniin administration effectively reduced colitis symptoms and attenuated intestinal barrier injury in mice by suppressing elevated intestinal permeability and restoring tight junction protein expression through the inhibition of MAPK, NF-kB, and MLC activation. Thus, geraniin exhibits anti-IL-1β activity and anticolitis effect by hindering the IL-1β and IL-1R interaction and may be a promising therapeutic anti-IL-1β agent for IBD treatment.

Exopolysaccharides Produced by Bifidobacterium longum subsp. longum YS108R Ameliorates DSS-Induced Ulcerative Colitis in Mice by Improving the Gut Barrier and Regulating the Gut Microbiota

Ulcerative colitis (UC) is a major disease that has endangered human health. Our previous study demonstrated that Bifidobacterium longum subsp. longum YS108R, a ropy exopolysaccharide (EPS)-producing bacterium, could alleviate UC in mice, but it is unclear whether EPS is the key substance responsible for its action. In this study, we proposed to investigate the remitting effect of EPS from B. longum subsp. longum YS108R on UC in a DSS-induced UC mouse model. Water extraction and alcohol precipitation were applied to extract EPS from the supernatant of B. longum subsp. longum YS108R culture. Then the animal trial was performed, and the results indicated that YS108R EPS ameliorated colonic pathological damage and the intestinal barrier. YS108R EPS suppressed inflammation via NF-κB signaling pathway inhibition and attenuated oxidative stress via the Nrf2 signaling pathway activation. Remarkably, YS108R EPS regulated gut microbiota, as evidenced by an increase in short-chain fatty acid (SCFA)-producing bacteria and a decline in Gram-negative bacteria, resulting in an increase of propionate and butyrate and a reduction of lipopolysaccharide (LPS). Collectively, YS108R EPS manipulated the intestinal microbiota and its metabolites, which further improved the intestinal barrier and inhibited inflammation and oxidative stress, thereby alleviating UC.

Telmisartan loading thermosensitive hydrogel repairs gut epithelial barrier for alleviating inflammatory bowel disease

Inflammatory bowel disease (IBD) remains a global health concern with a complex and incompletely understood pathogenesis. In the course of IBD development, damage to intestinal epithelial cells and a reduction in the expression of tight junction (TJ) proteins compromise the integrity of the intestinal barrier, exacerbating inflammation. Notably, the renin-angiotensin system and angiotensin II receptor type 1 (AT1R) play a crucial role in regulating the pathological progression including vascular permeability, and immune microenvironment. Thus, Telmisartan (Tel), an AT1R inhibitor, loading thermosensitive hydrogel was constructed to investigate the potential of alleviating inflammatory bowel disease through rectal administration. The constructed hydrogel exhibits an advantageous property of rapid transformation from a solution to a gel state at 37°C, facilitating prolonged drug retention within the gut while mitigating irritation associated with rectal administration. Results indicate that Tel also exhibits a beneficial effect in ameliorating colon shortening, colon wall thickening, cup cell lacking, crypt disappearance, and inflammatory cell infiltration into the mucosa in colitis mice. Moreover, it significantly upregulates the expression of TJ proteins in colonic tissues thereby repairing the intestinal barrier damage and alleviating the ulcerative colitis (UC) disease process. In conclusion, Tel-loaded hydrogel demonstrates substantial promise as a potential treatment modality for IBD.

Indole-3-acetic acid ameliorates dextran sulfate sodium-induced colitis via the ERK signaling pathway

Microbiota-derived catabolism of nutrients is closely related to ulcerative colitis (UC). The level of indole-3-acetic acid (IAA), a microbiota-dependent metabolite of tryptophan, was decreased significantly in the feces of UC patients. Thus supplementation with IAA could be a potential therapeutic method for ameliorating colitis. In this work, the protective effect of supplementation with IAA on dextran sulfate sodium (DSS)-induced colitis was evaluated, and the underlying mechanism was elucidated. The results indicated that the administration of IAA significantly relieved DSS-induced weight loss, reduced the disease activity index (DAI), restored colon length, alleviated intestinal injury, and improved the intestinal tight junction barrier. Furthermore, IAA inhibited intestinal inflammation by reducing the expression of proinflammatory cytokines and promoting the production of IL-10 and TGF-β1. In addition, the ERK signaling pathway is an important mediator of various physiological processes including inflammatory responses and is closely associated with the expression of IL-10. Notably, IAA treatment induced the activation of extracellular signal-regulated kinase (ERK), which is involved in the progression of colitis, while the ERK inhibitor U0126 attenuated the beneficial effects of IAA. In summary, IAA could attenuate the clinical symptoms of colitis, and the ERK signaling pathway was involved in the underlying mechanism. Supplementation with IAA could be a potential option for preventing or ameliorating UC.

Effect of chronic low-dose treatment with chitooligosaccharides on microbial dysbiosis and inflammation associated chronic ulcerative colitis in Balb/c mice

The study aimed to investigate the potential of low dose chitooligosaccharide (COS) in ameliorating dextran sodium sulfate (DSS) induced chronic colitis by regulating microbial dysbiosis and pro-inflammatory responses. Chronic colitis was induced in BALB/c mice by DSS (4% w/v, 3 cycles of 5 days) administration. The mice were divided into four groups: vehicle, DSS, DSS + mesalamine and DSS+COS. COS and mesalamine were administered orally, daily once, from day 1 to day 30 at a dose of 20 mg/kg and 50 mg/kg respectively. The disease activity index (DAI), colon length, histopathological score, microbial composition, and pro-inflammatory cytokine expression were evaluated. COS (20 mg/kg, COSLow) administration reduced the disease activity index, and colon shortening, caused by DSS significantly. Furthermore, COSLow restored the altered microbiome in the gut and inhibited the elevated pro-inflammatory cytokines (IL-1 and IL-6) in the colon against DSS-induced chronic colitis in mice. Moreover, COSLow treatment improved the probiotic microflora thereby restoring the gut homeostasis. In conclusion, this is the first study where microbial dysbiosis and pro-inflammatory responses were modulated by chronic COSLow treatment against DSS-induced chronic colitis in Balb/c mice. Therefore, COS supplementation at a relatively low dose could be efficacious for chronic inflammatory bowel disease.

Anemoside B4, a new pyruvate carboxylase inhibitor, alleviates colitis by reprogramming macrophage function

OBJECTIVES

Colitis is a global disease usually accompanied by intestinal epithelial damage and intestinal inflammation, and an increasing number of studies have found natural products to be highly effective in treating colitis. Anemoside B4 (AB4), an abundant saponin isolated from Pulsatilla chinensis (Bunge), which was found to have strong anti-inflammatory activity. However, the exact molecular mechanisms and direct targets of AB4 in the treatment of colitis remain to be discovered.

METHODS

The anti-inflammatory activities of AB4 were verified in LPS-induced cell models and 2, 4, 6-trinitrobenzene sulfonic (TNBS) or dextran sulfate sodium (DSS)-induced colitis mice and rat models. The molecular target of AB4 was identified by affinity chromatography analysis using chemical probes derived from AB4. Experiments including proteomics, molecular docking, biotin pull-down, surface plasmon resonance (SPR), and cellular thermal shift assay (CETSA) were used to confirm the binding of AB4 to its molecular target. Overexpression of pyruvate carboxylase (PC) and PC agonist were used to study the effects of PC on the anti-inflammatory and metabolic regulation of AB4 in vitro and in vivo.

RESULTS

AB4 not only significantly inhibited LPS-induced NF-κB activation and increased ROS levels in THP-1 cells, but also suppressed TNBS/DSS-induced colonic inflammation in mice and rats. The molecular target of AB4 was identified as PC, a key enzyme related to fatty acid, amino acid and tricarboxylic acid (TCA) cycle. We next demonstrated that AB4 specifically bound to the His879 site of PC and altered the protein's spatial conformation, thereby affecting the enzymatic activity of PC. LPS activated NF-κB pathway and increased PC activity, which caused metabolic reprogramming, while AB4 reversed this phenomenon by inhibiting the PC activity. In vivo studies showed that diisopropylamine dichloroacetate (DADA), a PC agonist, eliminated the therapeutic effects of AB4 by changing the metabolic rearrangement of intestinal tissues in colitis mice.

CONCLUSION

We identified PC as a direct cellular target of AB4 in the modulation of inflammation, especially colitis. Moreover, PC/pyruvate metabolism/NF-κB is crucial for LPS-driven inflammation and oxidative stress. These findings shed more light on the possibilities of PC as a potential new target for treating colitis.

Regulation of Gut Microbiota and Microbial Metabolome of Kefir Supernatant against Fusobacterium nucleatum and DSS-Coinduced Colitis

The aim of this study was to investigate the intervention effect of kefir supernatant (KS) on the initiation and progression of an ulcerative colitis (UC) murine model. We established an UC murine model by orally administrating with 109 CFUs of Fusobacterium nucleatum for 3 weeks and 3% dextran sulfate sodium (DSS) treatment in the third week. KS was used to intervene in this colitis model. Our results showed that KS supplementation ameliorated the symptoms, restrained the secretion of pro-inflammatory cytokines (TNF-α, IL-6, and IL-17F), promoted the release of anti-inflammatory cytokines (IL-4 and IL-10), and ameliorated oxidative stress. Furthermore, the increased number of goblet cells and upregulated expression of MUC2, occludin and claudin-1 indicated that the colon barrier was protected by KS. Additionally, KS supplementation mitigated gut microbiota dysbiosis in the UC murine model, leading to an increase in the abundance of Blautia and Akkermansia and a decrease in the level of Bacteroides. The altered gut microbiota also affected colon metabolism, with differential metabolites mainly associated with the biosynthesis of the l-arginine pathway. This study revealed that KS supplementation restored the community structure of gut microbiota, altered the biosynthesis of l-arginine, and thereby modulated the process of colonic inflammation.

Deficiency of inflammation-sensing protein neuropilin-2 in myeloid-derived macrophages exacerbates colitis via NF-κB activation

Neuropilin-2 (NRP2) is a multifunctional protein engaged in the regulation of angiogenesis, lymphangiogenesis, axon guidance, and tumor metastasis, but its function in colitis remains unclear. Here, we found that NRP2 was an inflammation-sensing protein rapidly and dramatically induced in myeloid cells, especially in macrophages, under inflammatory contexts. NRP2 deficiency in myeloid cells exacerbated dextran sulfate sodium salt-induced experimental colitis by promoting polarization of M1 macrophages and colon injury. Mechanistically, NRP2 could be induced via NF-κB activation by TNF-α in macrophages, but exerted an inhibitory effect on NF-κB signaling, forming a negative feedback loop with NF-κB to sense and alleviate inflammation. Deletion of NRP2 in macrophages broke this negative feedback circuit, leading to NF-κB overactivation, inflammatory exacerbation, and more severe colitis. Collectively, these findings reveal inflammation restriction as a role for NRP2 in macrophages under inflammation contexts and suggest that NRP2 in macrophages may relieve inflammation in inflammatory bowel disease. © 2023 The Pathological Society of Great Britain and Ireland.

Basis with RNA-Seq and WGCNA to explore the effect of Frankincense essential oil on dextran sodium sulfate-induced ulcerative colitis through MAPK/NF-κB signaling

PURPOSE

Frankincense has been shown in studies to have healing benefits for people with ulcerative colitis (UC). However, its underlying mechanisms have not been fully investigated. The objective of this study was to explore the potential molecular mechanisms of Frankincense essential oil (FREO) in improving dextran sodium sulfate (DSS)-induced UC from multiple perspectives.

METHODS

The FREO components were analyzed by GC-MS, and the interactions between the key active components and the mechanism of FREO were determined based on RNA-seq, "quantity-effect" weighting coefficient network pharmacology, WGCNA and pharmacodynamic experiments. The protection of FREO against DSS-induced UC mice was assessed by behavioral and pathological changes through mice. The expression of pro-inflammatory cytokines was measured using enzyme-linked immunosorbent assay. The expression of MAPK and NF-κB-related proteins by the Western Blotting and immunohistochemistry method.

RESULTS

Treatment with FREO significantly improved the symptoms of weight loss, diarrhea, stool blood, and colon shortening in UC mice. Reduced intestinal mucosal damage and the degree of inflammatory cell infiltration in the colon. Decreased TNF-α and IL-6 levels in mice's serum and inhibited phosphorylation of ERK, p65 in MAPK and NF-κB signaling.

CONCLUSION

FREO may decrease the inflammatory response to reduce the symptoms of UC by modulating the MAPK/ NF-κB pathway. This may be due to the synergistic interaction of the effective ingredient Hepten-2-yl tiglate, 6-methyl-5-, Isoneocembrene A and P-Cymene. This study provides a promising drug candidate and a new concept for the treatment of UC.

Protective role of estrogen through G-protein coupled receptor 30 in a colitis mouse model

Estrogen and its receptors are involved in the pathogenesis of gastrointestinal diseases such as colitis. However, the role of the membrane estrogen receptor G-protein-coupled receptor 30 (GPR30) in colitis is poorly understood. We therefore investigated the effect of estrogen in dextran sulfate sodium (DSS)-induced colitis. Male C57BL/6 mice were administered 1.5% DSS for 5 days and treated with 17β-estradiol (E2), GPR30 agonist (G1), or GPR30 antagonist (G15) for 8 days. Inflammation grade was evaluated by disease activity index (DAI) and histomorphological score. Colon tissues were immunohistochemically analyzed and revealed high expression of membrane GPR30, histone 3 lysine 36 dimethylation, and lysine 79 trimethylation in normal mouse colon epithelial cells but significantly decreased expression in DSS-treated mice, whereas the expression was partially preserved after treatment with E2 or G1. Colon shortening and DAI were significantly lower in E2- and G1-treated mice compared to DSS-treated mice. Caudal type homeobox 2 (CDX2) expression and cell proliferation differed in normal colon epithelial cells but overlapped in those of DSS-treated mice. Administration of E2 and G1 reduced CDX2 expression and cell proliferation. Altered expression of claudin-2 and occludin were observed in the colonic epithelium of DSS-treated mice, and these changes were significantly lower in the colon of E2- and G1-treated mice. These results indicate that estrogen regulates histone modification, cell proliferation, and CDX2 expression through GPR30, which affects intestinal epithelial barrier function. We conclude that estrogen protects against intestinal epithelial damage through GPR30 by enhancing intestinal epithelial barrier function in DSS-induced colitis in mice.

Ginsenoside Rg1 attenuates dextran sodium sulfate-induced ulcerative colitis in mice

Ulceration colitis (UC) is a chronic and recurrent inflammatory disorder in the gastro-intestinal tract. The purpose of our study is to explore the potential mechanisms of ginsenoside Rg1 (GS Rg1) on dextran sulfate sodium (DSS)-induced colitis in mice and lipopolysaccharide (LPS)-induced RAW 264.7 cells. Acute colitis was induced in male C57BL/6 mice. In vitro model of LPS-induced RAW 264.7 cells to simulate enteritis model. The disease activity index (DAI), colon length, body weight and histopathological analysis were performed in vivo. Pro-inflammatory cytokines and markers for oxidative and anti-oxidative stress, MPO level were measured in vivo and in vitro. Nuclear erythroid 2-related factor 2 (Nrf2) and NF-?B p65 protein levels were analyzed using western blotting. Our results indicated that the UC models were established successfully by drinking DSS water. GS Rg1 significantly attenuated UC-related symptoms, including preventing weight loss, decreasing DAI scores, and increasing colon length. GS Rg1 ameliorated the DSS-induced oxidative stress. IL-1beta, IL-6, and TNF-alpha levels were significantly increased in serum and cell supernatant effectively, while treatment with the GS Rg1 significantly reduced these factors. GS Rg1 reduced MPO content in the colon. GS Rg1 treatment increased SOD and decreased MDA levels in the serum, colon, and cell supernatant. GS Rg1 restored the Nrf-2/HO-1/NF-?B pathway in RAW 264.7 cells and UC mice, and these changes were blocked by Nrf-2 siRNA. Overall, GS Rg1 ameliorated inflammation and oxidative stress in colitis via Nrf-2/HO-1/NF-kappaB pathway. Thus, GS Rg1 could serve as a potential therapeutic agent for the treatment of UC.

Ginsenoside Rg1 Alleviates Ulcerative Colitis in Obese Mice by Regulating the Gut Microbiota-Lipid Metabolism-Th1/Th2/Th17 Cells Axis

Ginsenoside Rg1 (G-Rg1) has various pharmacological properties including antiobesity, immunomodulatory, and anti-inflammatory effects. This study aimed to explore the therapeutic effects and underlying mechanisms of G-Rg1 on colitis complicated by obesity. The results indicate that G-Rg1 effectively alleviates colitis in obese mice and improves serum lipid levels and liver function. Importantly, G-Rg1 improved the composition of gut microbiota in obese mice with colitis, with increases in alpha diversity indexes Sobs, Ace, and Chao, a significant down-regulation of the relative abundance of Romboutsia, and a significant up-regulation of Rikenellaceae_RC9_gut_group, Lachnospiraceae_NK4A136_group, Enterorhabdus, Desulfovibrio, and Alistipes. Meanwhile, G-Rg1 improved lipid metabolism in the colonic contents of obese mice with colitis. Additionally, G-Rg1 significantly reduced the percentages of helper T (Th)1, Th17, central memory T (TCM), and effector memory T (TEM) cells in obese mice with colitis while significantly increasing Naïve T and Th2 cells. In conclusion, G-Rg1 could be a promising therapeutic option for alleviating obesity complicated by colitis through regulation of the gut microbiota and lipid metabolism as well as Th1/Th2/Th17 cell differentiation.

Walnut-Derived Peptide Improves Cognitive Impairment in Colitis Mice Induced by Dextran Sodium Sulfate via the Microbiota-Gut-Brain Axis (MGBA)

In this study, we investigated the protective mechanism of walnut-derived peptide LPLLR (LP-5) against cognitive impairment induced in a dextran sodium sulfate (DSS)-induced colitis mouse model, with emphasis on the microbiota-gut-brain axis (MGBA). The results revealed that LP-5 could improve the learning ability and memory of mice with cognitive impairment and mitigate colitis symptoms, including weight loss, bloody stools, colon shortening, and histopathological changes. Additionally, LP-5 protected the integrity of the intestinal barrier by promoting the expression of tight junction proteins (TJs) while attenuating colonic inflammation by suppressing proinflammatory cytokine and epithelial cell apoptosis. Western blotting indicated that LP-5 treatment suppressed the inflammatory NF-κB/MLCK/MLC signaling pathway activity. Furthermore, LP-5 ameliorated hippocampal neuron damage and protected blood-brain barrier (BBB) integrity by downregulating microglia marker protein Iba-1, increasing TJ protein expression, and restoring the deterioration of synaptic proteins. Importantly, 16S rRNA sequencing results indicated that LP-5 reshaped the abundance of a wide range of gut microbiota at the phylum and genus levels, with increased Prevotella and Akkermansia associated with tryptophan (TRP), 5-hydroxytryptamine (5-HT), and 5-hydroxyindoleacetic acid (5-HIAA). These findings suggest that LP-5 could maintain intestinal barrier and BBB integrity, reverse gut dysbiosis, and improve learning and memory ability in colitis mice, providing novel insights into alterations of gut microbes in colitis and a potential new mechanism by which it causes cognitive impairment.

Sec1 regulates intestinal mucosal immunity in a mouse model of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a common immune-mediated condition with its molecular pathogenesis remaining to be fully elucidated. This study aimed to deepen our understanding of the role of FUT2 in human IBD, by studying a new surrogate gene Sec1, a neighboring gene of Fut2 and Fut1 that co-encodes the α 1,2 fucosyltransferase in mice. CRISPR/Cas9 was used to prepare Sec1 knockout (Sec1-/-) mice. IBD was induced in mice using 3% w/v dextran sulphate sodium. Small interfering RNA (siRNA) was employed to silence Sec1 in murine colon cancer cell lines CT26.WT and CMT93. IBD-related symptoms, colonic immune responses, proliferation and apoptosis of colon epithelial cells were assessed respectively to determine the role of Sec1 in mouse IBD. Impact of Sec1 on the expression of death receptor 5 (DR5) and other apoptosis-associated proteins were determined. Sec1 knockout was found to be associated with deterioration of IBD in mice and elevated immune responses in the colonic mucosa. Silencing Sec1 in CT26.WT and CMT93 cells led to greater secretion of inflammatory cytokines IL-1β, IL-6 and TNF-α. Cell counting kit 8 (CCK8) assay, flow cytometry and TUNEL detection suggested that Sec1 expression promoted the proliferation of colon epithelial cells, inhibited cell apoptosis, reduced cell arrest in G0/G1 phase and facilitated repair of inflammatory injury. Over-expression of DR5 and several apoptosis-related effector proteins was noticed in Sec1-/- mice and Sec1-silenced CT26.WT and CMT93 cells, supporting a suppressive role of Sec1 in cell apoptosis. Our results depicted important regulatory roles of Sec1 in mouse IBD, further reflecting the importance of FUT2 in the pathogenesis of human IBD.

Dextran sulfate sodium and uracil induce inflammatory effects and disrupt the chitinous peritrophic matrix in the midgut of Tribolium castaneum

Dextran sulfate sodium is used in inflammatory bowel disease (IBD) mice models to trigger chronic intestinal inflammation. In this study, we have analyzed DSS effects in the genetic model and pest beetle, Tribolium castaneum, which can be easily and cost-effectively cultivated and examined in very large quantities compensating for individual variations. We fed the larvae with DSS and uracil, which is known to induce the production of reactive oxygen species by activating DUOX, a member of the NADPH oxidase family. Both chemicals induced IBD-like phenotypes, including impaired growth and development, midgut thickening, epithelial swelling, and a loss of epithelial barrier function. RNAi mediated knockdown of DUOX expression enhanced the effects of DSS and uracil on mortality. Finally, we showed that both treatments result in an altered activity of the intestinal microbiome, similar as observed in IBD patients. Our findings suggest that both chemicals impair the epithelial barrier by increasing the permeability of the peritrophic matrix. The loss of the barrier function may facilitate the entry of midgut bacteria triggering innate immune responses that also affect the intestinal microbiome. As the observed effects resemble those induced by DSS treatment in mice, T. castaneum might be suitable high-throughput invertebrate model for IBD research and preclinical studies.

F. prausnitzii-derived extracellular vesicles attenuate experimental colitis by regulating intestinal homeostasis in mice

BACKGROUND

Emerging evidence has shown that extracellular vesicles (EVs) derived from gut bacteria play a crucial role in microbiota-host interactions. Here, we aimed to evaluate the attenuating effect of EVs derived from a reduced commensal bacterium, F. prausnitzii (Fp-EVs), in inflammatory bowel disease (IBD) on dextran sulfate sodium (DSS)-induced colitis in mice.

RESULTS

Fp-EVs isolated by ultracentrifugation and typically exhibited a double concave disc shape with an average diameter of 172 nm. Fp-EVs treatment reduced DSS-induced weight loss, disease activity index (DAI) score, colon length shortening, histological damage, neutrophil infiltration and increased intestinal epithelial apoptotic cells in DSS-induced colitis mice. Fp-EVs upregulated the protein expression of zona occludens (ZO)-1 and Occludin and increased the ratio of Tregs in the colon tissue of colitis mice. Furthermore, Fp-EVs downregulated the expression of the proinflammatory cytokines interleukin-1β (IL-1β), IL-2, IL-6, IL-12a, IL-17a, Interferon-γ (IFN-γ), tumor necrosis factor - α (TNF-α), granulocyte-macrophage colony stimulating factor (GM-CSF) and upregulated the anti-inflammatory cytokines IL-4, IL-10, and transforming growth factor β (TGF-β) in DSS-treated mice. Moreover, Fp-EV treatment markedly reduced the phosphorylation of these proteins Nuclear factor-κB (NF-κB) and Mitogen activated protein kinase (MAPK), and regulated the expression of nuclear factor erythroid 2-related factor (Nrf2) and heme oxygenase-1 (HO-1).

CONCLUSION

Our findings revealed that Fp-EVs attenuated DSS-induced colitis by modulating the intestinal mucosal barrier function and immunological profile. Our findings reveal that Fp-EVs attenuate DSS-induced colitis by modulating intestinal mucosal barrier function and the immunological profile.

Effect of minocycline, methyl prednisolone, or combination treatment on the colonic bacterial population in a state of colonic inflammation using the murine dextran sulfate sodium model

BACKGROUND

Several reports demonstrated anti-inflammatory properties of minocycline in various inflammatory disorders including colitis. We have experimental evidence suggesting synergistic anti-inflammatory effect of minocycline with methyl prednisolone in reducing colitis severity in mice, but if this effect is in part related to modulating the composition of colonic microbiota is still unknown.

METHODS

the effect of vehicle (V), minocycline (M), methyl prednisolone (MP), or combination (C) regimen on the composition of the microbiota of mice in a state of colon inflammation compared to untreated (UT) healthy mice was determined using 16s metagenomic sequencing, and the taxonomic and functional profiles were summarized.

RESULTS

Overall, the bacterial flora from the phylum Firmicutes followed by Bacteroidota were found to be predominant in all the samples. However, the composition of Firmicutes was decreased relatively in all the treatment groups compared to UT group. A relatively higher percentage of Actinobacteriota was observed in the samples from the C group. At the genus level, Muribaculaceae, Bacteroides, Bifidobacterium, and Lactobacillus were found to be predominant in the samples treated with both drugs (C). Whereas "Lachnospiraceae NK4A136 group" and Helicobacter in the M group, and Helicobacter in the MP group were found to be predominant. But, in the UT group, Weissella and Staphylococcus were found to be predominant. Eubacterium siraeum group, Clostridia vadinBB60 group, Erysipelatoclostridium and Anaeroplasma genera were identified to have a significant (FDR p < 0.05) differential abundance in V compared to C and UT groups. While at the species level, the abundance of Helicobacter mastomyrinus, Massiliomicrobiota timonensis and uncultured Anaeroplasma were identified as significantly low in UT, C, and M compared to V group. Functional categories related to amino acid, carbohydrate, and energy metabolism, cell motility and cell cycle control were dominated overall across all the samples. Methane metabolism was identified as an enriched pathway. For the C group, "Colitis (decrease)" was among the significant (p = 1.81E-6) associations based on the host-intrinsic taxon set.

CONCLUSION

Combination regimen of minocycline plus methyl prednisolone produces a synergistic anti-inflammatory effect which is part related to alternation in the colonic microbiota composition.

Muc2 mucin O-glycosylation interacts with enteropathogenic Escherichia coli to influence the development of ulcerative colitis based on the NF-kB signaling pathway

BACKGROUND

Ulcerative colitis (UC) is a chronic inflammatory disease of the intestine characterized by a compromised intestinal epithelial barrier. Mucin glycans are crucial in preserving barrier function during bacterial infections, although the underlying mechanisms remain largely unexplored.

METHODS

A cohort comprising 15 patients diagnosed with UC and 15 healthy individuals was recruited. Stool samples were collected to perform 16S rRNA gene sequencing, while biopsy samples were subjected to nanocapillary liquid chromatography-tandem mass spectrometry (nanoLC-MS/MS) to assess O-glycosylation. Gene expression was evaluated through qPCR analysis and Western blotting. Furthermore, animal experiments were conducted to investigate the effects of Escherichia coli and/or O-glycan inhibitor benzyl-α-GalNAc on the development of colitis in mice.

RESULTS

Our findings revealed that the mucus barrier was disrupted during the early stages of UC, while the MUC2 protein content remained unaltered. Additionally, a noteworthy reduction in the O-glycosylation of MUC2 was observed, along with significant changes in the intestinal microbiota during the early stages of UC. These changes included a decrease in intestinal species richness and an increase in the abundance of Escherichia coli (E. coli). Moreover, subsequent to the administration of galactose or O-glycan inhibitor to intestinal epithelial cells, it was observed that the cell culture supernatant had the ability to modify the proliferation and adhesive capacity of E. coli. Furthermore, when pathogenic E. coli or commensal E. coli were cocultured with intestinal epithelium, both strains elicited activation of the NF-KB signaling pathway in epithelial cells and facilitated the expression of serine protease in comparison to the untreated control. Consistently, the inhibition of O-glycans has been observed to enhance the pathogenicity of E. coli in vivo. Furthermore, a correlation has been established between the level of O-glycans and the development of ulcerative colitis. Specifically, a reduction in the O-glycan content of MUC2 cells has been found to increase the virulence of E. coli, thereby compromising the integrity of the intestinal epithelial barrier.

CONCLUSIONS

Together, there exist complex interactions between the intestinal epithelium, O-glycans, and the intestinal microbiota, which may inform the development of novel therapeutic strategies for the treatment of ulcerative colitis.

Identification of OLA1 as a Novel Protein Target of Vitexin to Ameliorate Dextran Sulfate Sodium-Induced Colitis with Tissue Thermal Proteome Profiling

Vitexin, which exists in various medicinal plants and food sources, has recently received increasing attention because of its anti-inflammatory properties. This study aims to identify the protein target of vitexin that ameliorates dextran sulfate sodium (DSS)-induced colitis. The results showed that vitexin not only alleviated the clinical symptoms and colonic damage in mice with DSS-induced colitis but also suppressed the colonic production of inflammatory cytokines (IL-1β, IL-6, ICAM, and VCAM) and enhanced the expression of barrier-associated proteins (ZO-1, Occludin, and E-cadherin). Based on tissue thermal proteome profiling (Tissue-TPP) and molecular docking, OLA1 was creatively identified as a potential protein target for vitexin. Further siRNA-mediated knockdown of the OLA1 gene in Caco-2 cells demonstrated the ability of OLA1 to increase Nrf2 protein expression and, thus, mediated the anti-inflammatory effects of vitexin. Interaction of the OLA1-vitexin complex with Keap1 protein to disrupt the Keap1-Nrf2 interaction may be required for activating Nrf2. Our findings revealed a novel role for OLA1 as a protein target of vitexin that contributes to its anti-inflammatory action by activating Nrf2, which may provide a promising molecular mechanism for novel therapeutic strategies to treat colitis and the associated systemic inflammation.

Wheat Germ-Derived Peptide Alleviates Dextran Sulfate Sodium-Induced Colitis in Mice

This study explores the protective properties and potential mechanisms of wheat-germ-derived peptide APEPEPAF (APE) against ulcerative colitis. Colitis mice induced by dextran sulfate sodium (DSS) were used as the animal model. The results showed that the APE peptide could alleviate colitis symptoms including weight loss, colon shortening, and histopathological changes. This peptide attenuated the generation of inflammatory cytokines by inhibiting the phosphorylation of protein kinase PKCζ (Thr410) and NF-κB transcriptional activity in DSS-induced mice, suggesting that APE ameliorates colitis inflammation by regulating the PKCζ/NF-κB signaling pathway. APE also preserved the barrier function of the colon by dose-dependently promoting the expression of tight junction proteins (claudin-1, zonula occluded-1, and occludin). In addition, APE significantly decreased the abundance of Bacteroides and increased the abundance of Dubosiella and Lachnospiraceae_UCG-006 to improve the intestinal flora imbalance in DSS-induced colitis mice. Therefore, wheat germ peptide APE can be used as a novel agent and dietary supplement to treat ulcerative colitis..

Colon-targeted EMSCs conditional medium hydrogel for treatment of ulcerative colitis in mice

Oral ecto-mesenchymal stem cells-conditional medium (EMSCs-CM) is a promising strategy for treating ulcerative colitis (UC). However, this therapy is currently limited by the harsh gastrointestinal environment and poor colonic targeting ability. Herein, a glutamine transaminase 2 (TG2) crosslinked EMSCs-CM hydrogel (EMSCs-CM-Gel) was fabricated by combining EMSCs-CM with negatively chargedγ-polyglutamic acid (γ-PGA) hydrogel. Intestinal epithelial cell 6 (IEC-6) was applied to construct a cell model with lipopolysaccharide to evaluate the anti-inflammatory potential of EMSCs-CMin vitro. The crosslinked gel was orally administered to mice in liquid form to access the effects of EMSCs-CM-Gelin vivo. This study was based on the fact that the hydrogel containing EMSCs-CM has negative charges, which ensure it remains at the positively charged inflamed colon tissue. The EMSCs-CM could continuously be released in the damaged colon mucosa along with the degradation of theγ-PGA hydrogel. Immunofluorescence and western blot were performed to assess the effects of EMSCs-CM-Gel on mice. The resultsin vivoshowed that EMSCs-CM-Gel could significantly suppress the expression of inflammatory cytokines, prevent the shortening of the length of the intestine and repair the intestinal barrier. Collectively, our findings provided a novel colon-targeted strategy, hoping to benefit UC patients a lot.

Zinc-Rutin Particles Ameliorate DSS-Induced Acute and Chronic Colitis via Anti-inflammatory and Antioxidant Protection of the Intestinal Epithelial Barrier

In patients suffering from inflammatory bowel diseases (IBDs), the immune system is disrupted and the intestinal barrier function is compromised. Here, six zinc-flavonoid particles were produced by one-step reaction via changing flavonoids (myricetin, quercetin, and rutin) and solvent (water and ethanol), and then their cytocompatibility and ability to scavenge H2O2, free radicals, and LPS-induced ROS were compared. Zinc-rutin particles (W-ZnRT) composed of rutin (78.92 wt %), Na12[ZnPO4]12·12H2O (6.76 wt %), and crystal water were screened out because W-ZnRT exhibited 80.8 ± 15% cell viability against RAW264.7, could rapidly scavenge 78.1 ± 1% of H2O2 and 71.6 ± 2% of DPPH within 30 min, and reduced LPS-increased intracellular ROS to normal levels. In addition, the therapeutic effects of rutin and W-ZnRT were also compared in dextran sulfate sodium (DSS)-induced acute and chronic colitis in mice. W-ZnRT was superior to rutin alone in chronic colitis (n = 9), although they were equally effective in acute colitis (n = 7). Compared to rutin, 11 oral doses of W-ZnRT (40 mg kg-1) significantly improved intestinal permeability (p = 0.0299) and colon length (p = 0.0025), reduced intestinal proinflammatory factors (IL-6, IL-1β, and TNF-α), and upregulated tight junction proteins to maintain intestinal barrier function. Taken together, these results identified W-ZnRT as an efficient and safe therapeutic strategy for IBD.

Dauricine exhibits anti-inflammatory property against acute ulcerative colitis via the regulation of NF-κB pathway

We aim to investigate the therapeutic effect of dauricine on ulcerative colitis (UC). Our results indicated that dauricine attenuated the reduction of colonic length, weight loss, disease activity index, colonic tissue damage, and inflammatory cytokine levels in dextran sulfate sodium mice. In addition, dauricine reduced lipopolysaccharide-induced inflammation in HT-29 cells. Mechanically, dauricine docked with p65, a member of nuclear transcription factor kappaB (NF-κB) family, through which reduced the inflammatory cytokine release from HT-29 cells. Together, the above results inferred that dauricine had therapeutic effect for UC by suppressing NF-κB pathway, which provided a promising mean for UC treatment.

Transgenic mice overexpressing human ALOX15 under the control of the aP2 promoter are partly protected in the complete Freund's adjuvant-induced paw inflammation model

BACKGROUND, OBJECTIVES AND DESIGN

Arachidonic acid 15-lipoxygenase (ALOX15) has been implicated in the pathogenesis of inflammatory diseases but since pro- and anti-inflammatory roles have been suggested, the precise function of this enzyme is still a matter of discussion. To contribute to this discussion, we created transgenic mice, which express human ALOX15 under the control of the activating protein 2 promoter (aP2-ALOX15 mice) and compared the sensitivity of these gain-of-function animals in two independent mouse inflammation models with Alox15-deficient mice (loss-of-function animals) and wildtype control animals.

MATERIALS AND METHODS

Transgenic aP2-ALOX15 mice were tested in comparison with Alox15 knockout mice (Alox15-/-) and corresponding wildtype control animals (C57BL/6J) in the complete Freund's adjuvant induced hind-paw edema model and in the dextran sulfate sodium induced colitis (DSS-colitis) model. In the paw edema model, the degree of paw swelling and the sensitivity of the inflamed hind-paw for mechanic (von Frey test) and thermal (Hargreaves test) stimulation were quantified as clinical readout parameters. In the dextran sodium sulfate induced colitis model the loss of body weight, the colon lengths and the disease activity index were determined.

RESULTS

In the hind-paw edema model, systemic inactivation of the endogenous Alox15 gene intensified the inflammatory symptoms, whereas overexpression of human ALOX15 reduced the degree of hind-paw inflammation. These data suggest anti-inflammatory roles for endogenous and transgenic ALOX15 in this particular inflammation model. As mechanistic reason for the protective effect downregulation of the pro-inflammatory ALOX5 pathways was suggested. However, in the dextran sodium sulfate colitis model, in which systemic inactivation of the Alox15 gene protected female mice from DSS-induced colitis, transgenic overexpression of human ALOX15 did hardly impact the intensity of the inflammatory symptoms.

CONCLUSION

The biological role of ALOX15 in the pathogenesis of inflammation is variable and depends on the kind of the animal inflammation model.

Rosmarinic Acid Restores Colonic Mucus Secretion in Colitis Mice by Regulating Gut Microbiota-Derived Metabolites and the Activation of Inflammasomes

Maintaining a steady state of mucus barrier is an important potential target for polyphenol to exert its anticolitis activity. This study elucidates the pivotal role of polyphenol rosmaric acid (RA) in regulating the mucus barrier function and alleviating inflammation by identifying its gut microbiota-derived metabolites and evaluating its inhibitory effect on inflammasomes in colitis mice. Results demonstrated that RA treatment promoted the proliferation of goblet cells and restored the level of mucus secretion, especially Muc2. RA reshaped the microbiota of colitis mice, particularly the boost of core probiotics, such as p. Bacteroidaceae, f. Muribaculaceae, g. Muribaculaceae, g. Alistipes, and g. Clostridia_UCG-014. Nontargeted metabonomics and targeted metabonomics confirmed a significant increase in the bile acids and their metabolites (7-sulfocholic acid, stercobilin, chenodeoxycholic acid 3-sulfate, chenodeoxycholic acid sulfate, and ursodeoxycholic acid 3-sulfate), indole metabolites ((R)-2,3-dihydro-3,5-dihydroxy-2-oxo-3-indoleacetic acid, frovatriptan, 3-formyl-6-hydroxyindole, and brassicanal A), and short-chain fatty acids (SCFAs) (acetic acid, butyric acid, isobutyric acid, isovaleric acid, and valeric acid) that contributed to the strengthened mucus barrier function. In addition, being absorbed mainly in the lower digestive tract, RA inhibited the overexpression of inflammasomes (especially NLRP6) that occurred in colitis mice to promote the mucus secretion of goblet cells. These data confirmed that RA, as a promising candidate to enhance gut health, restored colonic mucus secretion in colitis mice by mediating the production of gut microbiota-derived metabolites and the overexpression of inflammasomes. The presented study provides scientific evidence explaining the apparent paradox of low bioavailability and high bioactivity in polyphenols.

Epoxy Triglyceride Enhances Intestinal Permeability via Caspase-1/NLRP3/GSDMD and cGAS-STING Pathways in Dextran Sulfate Sodium-Induced Colitis Mice

Oxidized triglyceride monomers are the main cytotoxic products of deep-frying oil. However, its impact on the intestinal barrier, the first health guardian, remains unknown. In this study, HPLC-MS/MS analysis revealed that the epoxy group is the main oxidation product, indicating that it may be the main cytotoxic factor. Therefore, 1-9,10-epoxystearic ester, 2,3-dioleic acid (EGT) and glycerol trioleate (GT) were used to reveal the effect of the epoxy group on the intestinal barrier of dextran sulfate sodium-induced colitis. Characteristics analysis showed that EGT could aggravate intestinal damage. The relative mRNA expression analysis suggested that EGT could activate Caspase-1/NLRP3/GSDMD, thereby inducing pyroptosis. The proinflammatory cytokines activated by pyroptosis and the cGAS-STING pathway were released through the pores, thus inducing the disintegration of the tight junction between the intestinal epithelial cells and enhancing intestinal permeability. Metabonomics further confirmed that EGT can change the composition and content of phospholipids on the cell membrane, indicating the morphological changes of the intestinal epithelial cell membrane. In conclusion, this study highlights that EGT induced intestinal dysfunction via Caspase-1/NLRP3/GSDMD and cGAS-STING pathways.

Bifidobacterium longum CCFM1206 Promotes the Biotransformation of Glucoraphanin to Sulforaphane That Contributes to Amelioration of Dextran-Sulfate-Sodium-Induced Colitis in Mice

Glucoraphanin, rich in broccoli seed extract (BSE), is generally inert but can be biotransformed into active sulforaphane by gut bacteria. This study aimed to screen probiotics with glucoraphanin-metabolizing ability and explore the effect of a combination of strain and BSE on colitis induced by dextran sulfate sodium (DSS) in mice. Bifidobacterium longum CCFM1206 was isolated from healthy adult feces. Ultra-high-performance liquid chromatography Q Exactive mass spectrometry analysis revealed the presence of sulforaphane, sulforaphane-l-cysteine, and erucin in the BSE supernatant fermented by B. longum CCFM1206 in vitro. Combined and individual interventions of BSE and B. longum CCFM1206 were applied to explore the effects on DSS-induced colitis. The results suggested that the combination of B. longum CCFM1206 and BSE could ameliorate colitis symptoms, relieve colonic inflammatory reactions and oxidative stress, and protect the intestinal barrier in DSS-induced mice. In comparison to the BSE intervention alone, the combined intervention of B. longum CCFM1206 and BSE promoted the generation of sulforaphane and sulforaphane-N-acetylcysteine in mice colon from 220.88 ± 19.81 to 333.99 ± 36.46 nmol/g and from 232.04 ± 26.48 to 297.50 ± 40.08 nmol/g dry weight feces, respectively. According to quantitative reverse transcription polymerase chain reaction and immunohistochemical analysis, B. longum CCFM1206 and BSE effectively activated the transcription and expression of genes related to the Nrf2 signaling pathway. These results were intended to elucidate that probiotics could elevate the bioactivity of dietary phytochemicals in vivo, and the combination had potential for therapeutic treatment of colitis.

Colitis aggravated by Mrgprb2 knockout is associated with altered immune response, intestinal barrier function and gut microbiota

NEW FINDINGS

What is the central question of this study? What is the role of mas-related G protein-coupled receptor X2 (MRGPRX2/Mrgprb2) in ulcerative colitis in relation to the intestinal flora, intestinal barrier and immune response? What is the main finding and its importance? Knockout of mouse Mrgprb2 aggravates dextran sulfate sodium (DSS)-induced colitis, which is associated with altered gut microbiota and immune response and disruption of the intestinal barrier. MRGPRB2 may have a protective effect on DSS-induced colitis.

ABSTRACT

Ulcerative colitis (UC) is a chronic immune-related disease, and changes in the intestinal microbiota and damage to the intestinal barrier contribute to its pathogenesis. Mast cells (MCs) are widely distributed in the gastrointestinal tract and are thought to be related to the pathogenesis of UC. Human mas-related G protein-coupled receptor X2 (MRGPRX2) and its mouse homologue, Mrgprb2, are selectively expressed on MCs to recruit immune cells and modulate host defence against microbial infection. To investigate the role of Mrgprb2 in UC in mice, we compared the differences between Mrgprb2 knockout (b2KO) male mice and wild-type (WT) male mice with dextran sulfate sodium (DSS)-induced colitis in the severity of clinical symptoms, inflammatory cell infiltration, degree of intestinal barrier damage and composition of the intestinal flora. The results showed that weight loss, disease activity index score, colon shortening and colonic pathological damage were significantly increased in b2KO mice while MC activation, cytokine and chemokine secretion, and inflammatory cell infiltration were decreased. In addition, the abundance and diversity of the intestinal microbiota were reduced in b2KO mice. B2KO mice also exhibited a reduction of probiotics such as norank_f_Muribaculaceae and Lactobacillus and increase of harmful bacteria like Escherichia-Shigella. Intestinal mucosal barrier damage of b2KO mice was more severe than that of WT mice due to the attenuated expression of mucin-2 and occludin. These results demonstrated that MRGPRB2 may have a protective effect on DSS-induced colitis by altering the intestinal flora, participating in barrier repair and recruiting inflammatory cells to eliminate pathogens.

Eurotium cristatum Exhibited Anti-Colitis Effects via Modulating Gut Microbiota-Dependent Tryptophan Metabolism

Fu-brick tea (FBT) has attracted the attention of researchers because of its unique nutritional value, but it remains unknown whether Eurotium cristatum, the critical fungus from FBT, is responsible for the observed anti-colitis effects of FBT. Herein, the effects of E. cristatum on dextran sulfate sodium (DSS)-induced ulcerative colitis was first discussed. The results illustrated that the oral administration of E. cristatum inhibited DSS-induced colon damage. Microbiota analysis revealed that E. cristatum improved the intestinal homeostasis of colitis mice, especially increased the proportion of Lactobacillus, followed by an obvious increase in fecal short-chain fatty acids (SCFAs). Besides, E. cristatum markedly promoted tryptophan metabolism and increased the fecal contents of tryptophan metabolites in colitis mice. Furthermore, E. cristatum drastically increased the content of colonic IL-22 and the expression of tight-junction proteins. Conclusively, these results suggest that E. cristatum can resist colon damage and other implications of colitis by regulating the microbiota and enhancing tryptophan metabolism to strengthen intestinal barriers.

Green tea EGCG effectively alleviates experimental colitis in middle-aged male mice by attenuating multiple aspects of oxi-inflammatory stress and cell cycle deregulation

Age-dependent increased risk of inflammatory bowel diseases such as ulcerative colitis is being increasingly realized, and yet therapies targeting this disorder within the purview of aging are limited. The present study attempted to assess the efficacy of green tea epigallocatechin gallate (EGCG) consumption in preventing the severity and progression of dextran sulphate sodium (DSS)-induced ulcerative colitis in 18 months old middle-aged male mice. Acute colitis was induced in animals using DSS and protective effects of EGCG consumption were examined. Different parameters related to disease progression and molecular markers related to oxi-inflammatory stress, localized and systemic cytokine response, epithelial barrier integrity, and cell cycle progression profile were evaluated. DSS treatment induced rapid and severe symptoms of colitis such as consistently increased DAI score, shortened and inflamed colon accompanied by increased levels of inflammatory proteins (TNFα/IL-6/IL-1β) in both the colon tissue and cultured splenocytes indicating exaggerated Th1 immune response. Markers of oxidative stress increased while antioxidant defences and the expression of tight junction genes in the colonic cells were attenuated. Dysregulation in the expression of cell cycle inhibitory genes (p53/p21^WAF1/p16^Ink4a) indicated possible induction of colitis-induced dysplasia. On the other hand, EGCG consumption strongly attenuated all the measured ostensible as well as molecular markers of the disease progression as evidenced by improved DAI score, cellular antioxidant capacity, attenuated Th1 cytokine response both in the colon and cultured splenocytes, enhanced expression of tight junction genes, and cell cycle inhibitors thereby suggesting systemic effects of EGCG. Together, these observations suggest that drinking EGCG-rich green tea can be a significant way of managing the severity of colitis during aging.

Orally Administered Ginkgolide C Attenuates DSS-Induced Colitis by Maintaining Gut Barrier Integrity, Inhibiting Inflammatory Responses, and Regulating Intestinal Flora

Ulcerative colitis (UC), one of the foremost common forms of inflammatory bowel disease, poses a serious threat to human health. Currently, safe and effective treatments are not available. This study investigated the protective effect of ginkgolide C (GC), a terpene lactone extracted from Ginkgo biloba leaves, on UC and its underlying mechanism. The results showed that GC remarkably mitigated the severity of DSS-induced colitis in mice, as demonstrated by decreased body weight loss, reduced disease activity index, mitigated tissue damage, and increased colon length. Furthermore, GC inhibited DSS-induced hyperactivation of inflammation-related signaling pathways (NF-κB and MAPK) to reduce the production of inflammatory mediators, thereby mitigating the inflammatory response in mice. GC administration also restored gut barrier function by elevating the number of goblet cells and boosting the levels of tight junction-related proteins (claudin-3, occludin, and ZO-1). In addition, GC rebalanced the intestinal flora of DSS-treated mice by increasing the diversity of the flora, elevating the abundance of beneficial bacteria, such as Lactobacillus and Allobaculum, and decreasing the abundance of harmful bacteria, such as Bacteroides, Oscillospira, Ruminococcus, and Turicibacter. Taken together, these results suggest that GC administration effectively alleviates DSS-induced colitis by inhibiting the inflammatory response, maintaining mucosal barrier integrity, and regulating intestinal flora. This study may provide a scientific basis for the rational use of GC in preventing colitis and other related diseases.

Ameliorative Effect of Saccharomyces cerevisiae JKSP39 on Fusobacterium nucleatum and Dextran Sulfate Sodium-Induced Colitis Mouse Model

The aim of this study was to evaluate the ability of the Saccharomyces cerevisiae strain with probiotic properties isolated from Tibetan kefir grains to ameliorate Fusobacterium nucleatum (Fn) infection and dextran sulfate sodium (DSS) treatment-induced murine model of colitis. The tolerance to simulated gastrointestinal conditions, hydrophobicity test, autoaggregation assay, and the antioxidant effect of strains was used to screen one strain with colonization and probiotic potential. The murine model of colitis was established by giving 10⁹ cfu Fn 3 weeks by intragastric administration and 3% DSS in water 1 week before sacrifice. The results indicated that S. cerevisiae JKSP39 (SC) possessed optimal probiotic characteristics in vitro. Supplementation with SC increased the body weight and the expression of anti-inflammatory cytokines (IL-4 and IL-10), while decreasing the disease activity index score and expression of proinflammatory cytokines (TNF-α, IL-6, and IL-17F) in mice undergoing experimental colitis as compared with the colitis model group. Additionally, tight junction proteins and the number of goblet cells per crypt were significantly increased in the SC group, which indicated that the gut barrier was well repaired. The mechanism of SC ameliorating Fn-DSS-induced colitis could be related to the decreased levels of reactive oxygen species (myeloperoxidase, total superoxide dismutase, catalase, H₂O₂, and malondialdehyde) in the colon, the inhibition of endoplasmic reticulum stress, and the regulation of gut microbiota.

Ameliorative effect of two structurally divergent hydrazide derivatives against DSS-induced colitis by targeting Nrf2 and NF-κB signaling in mice

The environmental factors and genetic vulnerability trigger the inflammatory bowel diseases (IBDs) such as ulcerative colitis and Crohn's disease. Furthermore, the oxidative stress and inflammatory cytokines have been implicated in the aggravation of the IBDs. The aim of the present study was to investigate the effect of N-(benzylidene)-2-((2-hydroxynaphthalen-1-yl)diazenyl)benzohydrazides (NCHDH and NTHDH) compounds against the DSS-induced colitis in mice. The colitis was induced by 5% dextran sulfate sodium (DSS) dissolved in normal saline for 5 days. The effect of the NCHDH and NTHDH on the behavioral, biochemical, histological, and immunohistological parameters was assessed. The NCHDH and NTHDH treatment improved the behavioral parameters such as food intake, disease activity index, and diarrhea score significantly compared to DSS control. The NCHDH and NTHDH treatments significantly increased the antioxidant enzymes, whereas oxidative stress markers were markedly reduced. Similarly, the NCHDH and NTHDH treatments significantly suppressed the activity of nitric oxide (NO), myeloperoxidase (MPO), and eosinophil peroxidase (EPO). The histological studies showed a significant reduction in inflammation, immune cell infiltration, and fibrosis in the NCHDH- and NTHDH-treated groups. The immunohistochemical results demonstrated that NCHDH and NTHDH treatments markedly increase the expression level of Nrf2, HO-1 (hemeoxygenase-1), TRX (thioredoxin reductase), and IκB compared to the DSS-induced group. In the same way, the NCHDH and NTHDH significantly reduced the NF-κB and COX-2 (cyclooxygenase-2) expression levels. The NCHDH and NTHDH treatment significantly improved the symptoms associated with colitis via inducing antioxidants and attenuating oxidative stress markers.

Bifidobacterium bifidum H3-R2 and Its Molecular Communication within the Context of Ulcerative Colitis

Bifidobacteria are important mediators of immune system development within the gastrointestinal system and immunological homeostasis. The present study explored the anti-colitic activity of Bifidobacterium bifidum H3-R2 in a murine dextran sulfate sodium (DSS)-induced model of ulcerative colitis (UC). Moreover, this study offers novel insight regarding the molecular basis for the probiotic properties of B. bifidum H3-R2 by analyzing the underlying mechanisms whereby B. bifidum H3-R2-derived proteins affect the intestinal barrier. B. bifidum H3-R2 administration was sufficient to alleviate clinical manifestations consistent with DSS-induced colitis, restoring aberrant inflammatory cytokine production, enhancing tight junction protein expression, and positively impacting overall intestinal microecological homeostasis in these animals. Moreover, the bifidobacteria-derived GroEL and transaldolase (TAL) proteins were found to regulate tight junction protein expression via the NF-κB, myosin light chain kinase (MLCK), RhoA/Rho-associated protein kinase (ROCK), and mitogen-activated protein kinase (MAPK) signaling pathways, preventing the lipopolysaccharide (LPS)-mediated disruption of the intestinal epithelial cell barrier.

Cysteine protease of Clonorchis sinensis alleviates DSS-induced colitis in mice

Background

Currently, inflammatory bowel disease (IBD) has become a global chronic idiopathic disease with ever-rising morbidity and prevalence. Accumulating evidence supports the IBD-hygiene hypothesis that helminths and their derivatives have potential therapeutic value for IBD. Clonorchis sinensis (C. sinensis) mainly elicit Th2/Treg-dominated immune responses to maintain long-term parasitism in the host. This study aimed to evaluate the therapeutic effects of cysteine protease (CsCP) and adult crude antigen (CsCA) of C. sinensis, and C. sinensis (Cs) infection on DSS-induced colitis mice.

Methods

BALB/c mice were given 5% DSS daily for 7 days to induce colitis. During this period, mice were treated with rCsCP, CsCA or dexamethasone (DXM) every day, or Cs infection which was established in advance. Changes in body weight, disease activity index (DAI), colon lengths, macroscopic scores, histopathological findings, myeloperoxidase (MPO) activity levels, regulatory T cell (Treg) subset levels, colon gene expression levels, serum cytokine levels, and biochemical indexes were measured.

Results

Compared with Cs infection, rCsCP and CsCA alleviated the disease activity of acute colitis more significant without causing abnormal blood biochemical indexes. In comparison, rCsCP was superior to CsCA in attenuating colonic pathological symptoms, enhancing the proportion of Treg cells in spleens and mesenteric lymph nodes, and improving the secretion of inflammatory-related cytokines (e.g., IL-2, IL-4, IL-10 and IL-13) in serum. Combined with RNA-seq data, it was revealed that CsCA might up-regulate the genes related to C-type lectin receptor and intestinal mucosal repair related signal pathways (e.g., Cd209d, F13a1 and Cckbr) to reduce colon inflammation and benefit intestinal mucosal repair. Dissimilarly, rCsCP ameliorated colitis mainly through stimulating innate immunity, such as Toll like receptor (TLR) signaling pathway, down-regulating the expression of inflammatory cytokines (e.g., IL-12b, IL-23r and IL-7), thereby restraining the differentiation of Th1/Th17 cells.

Conclusions

Both rCsCP and CsCA showed good therapeutic effects on the treatment of acute colitis, but rCsCP is a better choice. rCsCP is a safe, effective, readily available and promising therapeutic agent against IBD mainly by activating innate immunity and regulating the IL-12/IL-23r axis.

Anti-inflammatory effect of Bifidobacterium animalis subsp. lactis A6 on DSS-induced colitis in mice

AIMS

This study aimed to investigate the protective effect of Bifidobacterium animalis subsp. lactis A6 on dextran sodium sulphate (DSS)-induced colitis in C57BL/6J mice.

METHODS AND RESULTS

Mice were randomly divided into three groups (n = 8 per group). Each group was administered with PBS (Control and DSS group) or B. lactis A6 with a dosage of ~4.0 × 109  CFU day-1 (DSS + A6 group) for 21 consecutive days. The DSS and DSS + A6 group mice were ad libitum drinking 2.5% DSS water during day 15-21, while the Control group mice were given normal water. The administration of B. lactis A6 significantly inhibited DSS-induced bodyweight loss and colon shortening (p < 0.001), but showed no significant influence on the spleen enlargement (p > 0.05). The intestinal barrier integrity was improved by reducing colonic damage, recovering mucus layer loss and enhancing tight junction expression including ZO-1, occludin and claudin-1. In addition, B. lactis A6 attenuated the oxidative stress by decreasing MDA and increasing SOD and GSH levels in colon tissues. Moreover, B. lactis A6 suppressed DSS-induced inflammatory responses via downregulating TNF-α, IL-1β and IL-6 levels and upregulating IL-10 level in colon tissues.

CONCLUSION

B. lactis A6 effectively alleviated DSS-induced colitis by maintaining intestinal barrier integrity, reducing oxidative stress and inhibiting inflammatory responses.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study suggests that B. lactis A6 could act as a candidate probiotic for UC treatment.

NF-κB-coupled IL17 mediates inflammatory signaling and intestinal inflammation in Artemia sinica

Nuclear factor-κB (NF-κB) plays a role as a rheostatic transcription factor in regulating intestinal inflammation, and its disruption or constitutive activation leads to inflammation and injury. However, the molecular mechanisms of NF-κB regulation remain largely unknown. In this study, the NF-κB-regulated host defenses against pathogen infections and facilitation of IL17 expression during stimulation with different bacteria were investigated. Intestinal inflammation was induced by dextran sulfate sodium, and NF-κB activity was inhibited in an intestinal injury model. Mannose receptor C type, ABF1/2, serpin B13, lysozyme, and β-arrestin were significantly controlled by NF-κB in the inflamed intestinal tissue. High levels of NF-κB activation resulted in less pervasive intestinal damage and the maintenance of intestinal barrier integrity. Intestinal injury robustly increased the expression of IL17. NF-κB activation was enhanced by IL17 deficiency in the intestinal injury model. IL17 inhibition aggravated intestinal inflammation, leading to loss of epithelial architecture and the infiltration of inflammatory cells. These data suggest that NF-κB and IL17 play key mediator roles in the maintenance of gut epithelial integrity and immune homeostasis.

Bacillus coagulans in Combination with Chitooligosaccharides Regulates Gut Microbiota and Ameliorates the DSS-Induced Colitis in Mice

Ulcerative colitis (UC) are chronic inflammatory disorders, which may be caused by intestinal barrier dysfunction, immune system disorders and intestinal microbiota dysbiosis. Synbiotic, the combination of probiotics and prebiotics, is thought to be a pragmatic approach in mitigating inflammation in UC. Bacillus coagulans has been recognized as a potential probiotic for treating intestinal diseases because of its favorable industrial and probiotic properties, including sporulation and lactic acid production. In this study, we evaluated the treatment effects of the B. coagulans FCYS01 spores with or without the chitooligosaccharides (COSs) on UC generated using dextran sulfate sodium (DSS) in mice. Supplementation of B. coagulans spores, prebiotic COSs or the synbiotic (the spores + COSs) had a significant positive effect on DSS-induced UC. The disease activity index and histological damage score were significantly reduced after these supplementations. Compared to DSS group, these supplementations also significantly modulated the cytokines IL-4, IL-6, IL-8, IL-10, and C-reactive protein (CRP) levels and significantly maintained expressions of tight junction proteins and mucin protein and promotes recovery of the intestinal barrier. In addition, these supplementations regulate the composition of gut microbiota and improve the production of short-chain fatty acids (SCFAs), through enrichment of SCFA-producing bacteria, such as Akkermansia and Ruminococcus species. In summary, the synbiotic ameliorated the overall inflammatory status of the experimental UC model and showed a better treatment effect than B. coagulans or COSs did alone as revealed by the markers such as, colon length, IL-4 and Occludin levels. IMPORTANCE Probiotic and prebiotic are believed to be useful in alleviating the inflammatory, thereby resolving or preventing the severity of UC. Spore-forming bacteria Bacillus coagulans show advantages of stability and probiotic effects, being suggested as the important probiotics for UC treatment. Here, we demonstrate that administration of B. coagulans spores, chitooligosaccharides (COSs), or the synbiotic attenuates DSS-induced colitis and significantly correlates with altered gut immune responses. The treatment effect of the synbiotic is inferred to be relied on the enrichment of probiotic bacteria, such as Akkermansia and Ruminococcaceae species, which are reported to be crucial important for gut health. Our findings facilitate the development of therapeutic and preventive strategies for UC using spore-forming lactic acid bacteria in combination with COSs.

[Experimental study on effects of berberine combined with 6-shogaol on intestinal inflammation and flora in mice with ulcerative colitis]

Cold-heat combination is a common method in the treatment of ulcerative colitis, which is represented by classic drug pair, Coptidis Rhizoma and Zingiberis Rhizoma.The present study explored the synergetic effects of berberine and 6-shogaol, the primary components of Coptidis Rhizoma and Zingiberis Rhizoma, respectively, on intestinal inflammation and intestinal flora in mice with ulcerative colitis to reveal the effect and mechanism of cold-heat combination in the treatment of ulcerative colitis.The ulcerative colitis model was induced by dextran sulfate sodium(DSS) in mice.The model mice were administered with berberine(100 mg·kg~(-1)), 6-shogaol(100 mg·kg~(-1)), and berberine(50 mg·kg~(-1)) combined 6-shogaol(50 mg·kg~(-1)) by gavage, once per day.After 20 days of drug administration, mouse serum, colon tissues, and feces were sampled.Hematoxylin-eosin(HE) staining was used to observe histopathological changes in colon tissues.Alcian blue/periodic acid-Schiff(AB/PAS) staining was used to observe the changes in the mucus layer of colon tissues.Enzyme-linked immunosorbent assay(ELISA) was employed to detect the serum content of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), and interleukin-6(IL-6).Immunohistochemical method was adopted to detect the protein expression of macrophage surface markers F4/80, mucin-2, claudin-1, and zonula occludens-1(ZO-1) in colon tissues.High-throughput Meta-amplicon library sequencing was used to detect changes in the intestinal flora of mice.The results indicated that the 6-shogaol group, the berberine group, and the combination group showed significantly relieved intestinal injury, reduced number of F4/80-labeled positive macrophages in colon tissues, increased protein expression of mucin-2, claudin-1, and ZO-1, and decreased serum le-vels of TNF-α, IL-1β, and IL-6.Shannon, Simpson, Chao, and Ace indexes of the intestinal flora of mice in the 6-shogaol group and the combination group significantly increased, and Chao and Ace indexes in the berberine group significantly increased.As revealed by the bioinformatics analysis of intestinal flora sequencing, the relative abundance of Verrucomicrobia at the phylum, class, and order levels decreased significantly in all treatment groups after drug administration, while that of Bacillibacteria gradually increased.In the 6-shogaol group and the combination group, Akkermansia muciniphila completely disappeared, but acid-producing bacillus still existed in large quantities.As concluded, both 6-shogaol and berberine can inhibit intestinal inflammation, reduce the infiltration and activation of macrophages, relieve intestinal damage, reduce intestinal permeability, improve the structure of flora, and promote intestinal microecological balance.The combined application of berberine and 6-shogaol has a significant synergistic effect.

Inhibition of TLR4 Suppresses the Inflammatory Response in Inflammatory Bowel Disease (IBD) by Modulating the PDK1-Induced Metabolism Reprogramming via a m6A-Denpendent Manner

Objective

To investigate the role of TLR4 and PDK1 genes in IBD.

Methods

The DSS mouse model was established by inducing BALB/C with 5% DSS solution. The behavior of DSS mice was detected, and the m6A modification was detected by m6A methylation chip. At the same time, the expressions of TLR and PDK1 were detected by fluorescence real-time quantitative PCR.

Results

The results showed that the model of dextran sodium sulfate colitis in mice was successful, and the colon membrane of mice had obvious naked eye inflammation. Through comparison, it was found that there were differences in m6A modification between the blank group and the model group, and compared with the blank group, the expression of PKD1 in DSS group was significantly reduced and the expression of TLR4 was significantly increased.

Conclusion

TLR4 inhibition inhibits the inflammatory response in inflammatory bowel disease (IBD) in a m6A-dependent manner by regulating PDK1-induced metabolic reprogramming.

Polyphenolic Extracts of Coffee Cherry Husks Alleviated Colitis-Induced Neural Inflammation via NF-κB Signaling Regulation and Gut Microbiota Modification

Coffee cherry husks, the main byproduct of coffee production, contain an abundance of polyphenols. In this study, dextran sodium sulfate (DSS)-induced colitis mice were used to study the protective effects of polyphenolic extracts of coffee cherry husks (CCHP) on inflammation. The results indicated that CCHP administration alleviated the histological changes of DSS-induced colitis in mice and downregulated the mRNA level of TNF-α, IL-1β, IL-6 and Cox-2. Interestingly, CCHP inhibited the activation of microglia and suppressed neural inflammation in the brain. The TLR4/Myd88/NF-κB signaling pathway was examined and found to be inhibited by CCHP. Furthermore, a determination of the gut microbiota showed that an alteration of microbiota induced by DSS was restored by CCHP, including the decrease of the relative abundance of Proteobacteria and the increase of Bacteroidota. In conclusion, our results revealed the great potential of CCHP to alleviate brain inflammation in colitis mice by inhibiting the NF-κB signaling pathway and regulating gut microbiota.

Industrially Produced Rice Protein Ameliorates Dextran Sulfate Sodium-Induced Colitis via Protecting the Intestinal Barrier, Mitigating Oxidative Stress, and Regulating Gut Microbiota

Inflammatory bowel disease (IBD) poses a threat to health and compromises the immune system and gut microflora. The present study aimed to explore the effects of rice protein (RP) purified from rice dregs (RD) on acute colitis induced by dextran sulfate sodium (DSS) and the underlying mechanisms. Results showed that RP treatment could alleviate the loss of body weight, colon shortening and injury, and the level of disease activity index, repair colonic function (claudin-1, ZO-1 and occludin), regulate inflammatory factors, and restore oxidative balance (malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), and total antioxidant capability (T-AOC)) in mice. Also, RP treatment could activate the Kelch-like ECH-associating protein 1 (Keap1)-nuclear factor E2-related factor 2 (Nrf2) signaling pathway, mediate the expression of downstream antioxidant protease (NQO-1, HO-1, and Gclc), regulate gut microbiota by enhancing the relative abundance of Akkermansia and increasing the value of F/B, and adjust short-chain fatty acid levels to alleviate DSS-induced colitis in mice. Thus, RP may be an effective therapeutic dietary resource for ulcerative colitis.

LENTINULA EDODES POLYSACCHARIDES SUPPRESSED PRO-INFLAMMATORY CYTOKINES EXPRESSION AND COLITIS IN MICE

BACKGROUND

Polysaccharides from edible mushrooms possess immunomodulatory, anti-inflammatory, and anti-tumor activities. Recent studies indicated that necroptosis plays a role in the pathogenesis of inflammatory diseases and mediates increased expression of inflammatory cytokines.

OBJECTIVE

Therefore, it is imperative to determine the impact of polysaccharide extract from Lentinula edodes (L. edodes) on inflammatory cytokines in experimental model of colitis in mice.

METHODS

Female C57BL/6 mice divided into three or four mice per group were used for this study. Polysaccharide sample was orally administered to mice prior to (7 days) and during colitis induction with 2.5% dextran sodium sulfate (7 days), followed by additional 3 days of administration. Changes in body weight and colon length were used as markers for colitis, and pro-inflammatory cytokines and tumor necrosis factor receptor 1 (TNFR1) expressions, as well as necroptosis were analyzed in the colon of colitis mice. Data obtained were analysed by Tukey-Kramer and two-tailed standard t tests.

RESULTS

The results indicated that the polysaccharide sample suppressed colitis in mice using effects on the body weight and colon length as markers. Also, it was demonstrated that necrostatin-1, a specific inhibitor of necroptosis, suppressed the expression of interleukin (IL)-8, a pro-inflammatory chemokine, in Caco-2 cells induced necroptosis induced by zVAD and TNF-α, an indication that necroptosis may be involved in the expression of pro-inflammatory cytokines. Moreover, the polysaccharide sample suppressed the expression of pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α, IL-6, IL-1β, and interferon (IFN)-γ in the colon of mice.

CONCLUSION

These results suggested that the suppressive effects of the polysaccharide sample on inflammatory cytokines expression may contribute to its anti-colitis effect, and so may serve as a potent therapeutic agent against inflammatory bowel disease.

Preventive empagliflozin activity on acute acetic acid-induced ulcerative colitis in rats via modulation of SIRT-1/PI3K/AKT pathway and improving colon barrier

BACKGROUND

Ulcerative colitis (UC) is a chronic colon inflammation that is linked to exposure to environmental factors leading to improper immune responses to enteric microbes in genetically susceptible individuals. This study was designed to explore the possible protective impact of Empagliflozin (EMPA), an anti-diabetic sodium-glucose cotransporter-2 (SGLT2) inhibitor, on acetic acid (AA)-induced UC in rats.

METHOD

Intrarectal instillation of AA (2 ml, 3% v/v) was used to induce UC. EMPA (10 & 30 mg/kg) was administered orally for 11 days.

RESULTS

EMPA successfully counteracted AA-induced UC that was manifested by improving colonic histopathological architecture concomitant with a marked decrease in disease activity index (DAI), colon weight, weight/length ratio, serum lactate dehydrogenase (LDH) activity, and C-reactive protein (CRP) level. Additionally, EMPA successfully restored the disrupted oxidant/antioxidants balance induced by AA. Moreover, EMPA significantly induced silent information regulator-1(SIRT-1) expression along with a significant reduction in phosphatidylinositol-3-Kinase (PI3K), Protein Kinase B (AKT), nuclear factor kappa B (NF-κB), tumor necrosis factor (TNF)-α and interleukins (IL-1β and IL-6) expression in colonic tissues. Furthermore, EMPA successfully improved the colonic barrier that was appeared from the marked induction of tight junction proteins level (occludin and claudin-1).

CONCLUSION

EMPA successfully counteracted AA-induced UC in rats via the modulation of SIRT1/PI3K/AKT/NF-κB inflammatory pathway, normalizing oxidant/antioxidants balance, and improving the integrity of colon barrier.

Genkwanin Alleviates Mitochondrial Dysfunction and Oxidative Stress in a Murine Model of Experimental Colitis: The Participation of Sirt1

OBJECTIVE

Genkwanin is a biologically active O-methylated flavone extracted from Daphne genkwa. An increasing number of studies have described the modulatory effects of genkwanin on human diseases, including antitumor, anti-inflammatory, and antioxidant activities. However, little is known about whether genkwanin might be a therapeutic agent for inflammatory bowel disease or its possible underlying mechanisms.

MATERIALS AND METHODS

Forty C57BL/6 male mice were orally administered dextran sulfate sodium (DSS) to generate the colitis model, and genkwanin was orally administered at the indicated concentrations. Body weight, disease activity index, colon length, and H&E staining were used to evaluate colitis. Oxidative stress and antioxidant levels were measured by detecting ROS generation and malondialdehyde, superoxide dismutase and glutathione levels. The levels of proinflammatory cytokines (TNF-α, IL-1β, IFNγ and IL-6) were measured using ELISAs. Cell viability was determined using the CCK-8 assay. Mitochondrial function was evaluated by measuring the oxygen consumption rate, mtDNA content, and activities of electron transfer chain (ETC) complexes I, II, and IV. The expression of SIRT1, Nrf2 and its target genes was determined using qRT-PCR and western blotting. SIRT1 was depleted by lentivirus-mediated knockdown.

RESULTS

In this study, oral administration of genkwanin alleviated colitis induced by oral administration of DSS in mice, as evidenced by reduced weight loss, colon length shortening and histopathology scores. Furthermore, genkwanin relieved oxidative stress and reduced the production of proinflammatory cytokines. In vitro assays revealed that genkwanin administration inhibited reactive oxygen species (ROS) production and improved mitochondrial function in human intestinal epithelial cells. Genkwanin also upregulated the expression of SIRT1, and lentivirus-mediated SIRT1 knockdown partially abrogated the protective effect of genkwanin on oxidative stress and mitochondrial dysfunction.

CONCLUSIONS

Findings from our murine model and cell culture experiments provide a promising basis for genkwanin to be studied as a treatment for IBD in clinical trials.

The antiinflammatory and antifibrotic effect of olive phenols and Lactiplantibacillus plantarum IMC513 in dextran sodium sulfate-induced chronic colitis

OBJECTIVES

After a chronic intestinal injury, several intestinal cells switch their phenotype to activated myofibroblasts, which in turn release an abnormal amount of extracellular matrix proteins, leading to the onset of the fibrotic process. To date, no resolutive pharmacological treatments are available, and the identification of new therapeutic approaches represents a crucial goal to achieve. The onset, maintenance, and progression of inflammatory bowel disease are related to abnormal intestinal immune responses to environmental factors, including diet and intestinal microflora components. This study aimed to evaluate the potential antiinflammatory and antifibrotic effect of a biologically debittered olive cream and its probiotic oral administration in an experimental model of dextran sodium sulfate (DSS)-induced chronic colitis.

METHODS

Chronic colitis was induced in mice by three cycles of oral administration of 2.5% DSS (5 d of DSS followed by 7 d of tap water). Mice were randomly divided into five groups: 10 control mice fed with standard diet (SD), 20 mice receiving SD and DSS (SD+DSS), 20 mice receiving an enriched diet (ED) with olive cream and DSS (ED+DSS), 20 mice receiving SD plus probiotics (PB; Lactiplantibacillus plantarum IMC513) and DSS (SD+PB+DSS), and 20 mice receiving ED plus PB and DSS (ED+ PB+DSS). Clinical features and large bowel macroscopic, histologic, and immunohistochemical findings were evaluated.

RESULTS

The simultaneous administration of ED and PB induced a significant reduction in macroscopic and microscopic colitis scores compared with the other DSS-treated groups. In addition, ED and PB led to a significant decrease in the expression of inflammatory cytokines and profibrotic molecules.

CONCLUSIONS

The concomitant oral administration of a diet enriched with biologically debittered olive cream and a specific probiotic strain (Lactiplantibacillus plantarum IMC513) can exert synergistic antiinflammatory and antifibrotic action in DSS-induced chronic colitis. Further studies are needed to define the cellular and molecular mechanisms modulated by olive cream compounds and by Lactiplantibacillus plantarum IMC513.

Dietary Ethanolamine Plasmalogen Alleviates DSS-Induced Colitis by Enhancing Colon Mucosa Integrity, Antioxidative Stress, and Anti-inflammatory Responses via Increased Ethanolamine Plasmalogen Molecular Species: Protective Role of Vinyl Ether Linkages

Dietary ethanolamine plasmalogen (PlsEtn) has been reported to have several health benefits; however, its functional role during colon pathophysiology remains elusive. The present study investigated the anticolitis effect of dietary ethanolamine glycerophospholipids (EtnGpls) with high PlsEtn from ascidian muscle (86.2 mol %) and low PlsEtn from porcine liver (7.7 mol %) in dextran sulfate sodium (DSS)-induced colitis in mice. Dietary EtnGpls lowered myeloperoxidase activity, thiobarbituric acid-reactive substances, proinflammatory cytokines and proapoptosis-related protein levels in colon mucosa after 16 days of DSS treatment, with ascidian muscle (0.1% EtnGpl in diet) showing higher suppression than porcine liver (0.1% EtnGpl in diet). Moreover, dietary EtnGpls suppressed DSS symptoms after 38 days of DSS treatment as evidenced by increased body weight, colon length, and ameliorated colon mucosa integrity. Additionally, dietary EtnGpls elevated short-chain fatty acid production in DSS-treated mice. Altogether, these results indicate the potential of utilizing diets with abundant PlsEtn for the prevention of colon inflammation-related disorders.

Enzymatically Inactive Tissue-Type Plasminogen Activator Reverses Disease Progression in the Dextran Sulfate Sodium Mouse Model of Inflammatory Bowel Disease

Enzymatically inactive tissue-type plasminogen activator (EI-tPA) does not activate fibrinolysis, but interacts with the N-methyl-d-aspartate receptor (NMDA-R) and low-density lipoprotein receptor-related protein-1 (LRP1) in macrophages to block innate immune system responses mediated by toll-like receptors. Herein, we examined the ability of EI-tPA to treat colitis in mice, induced by dextran sulfate sodium. In two separate studies, designed to generate colitis of differing severity, a single dose of EI-tPA administered after inflammation established significantly improved disease parameters. EI-tPA-treated mice demonstrated improved weight gain. Stools improved in character and became hemoccult negative. Abdominal tenderness decreased. Colon shortening significantly decreased in EI-tPA-treated mice, suggesting attenuation of irreversible tissue damage and remodeling. Furthermore, histopathologic evidence of disease decreased in the distal 25% of the colon in EI-tPA-treated mice. EI-tPA did not decrease the number of CD45-positive leukocytes or F4/80-positive macrophage-like cells detected in extracts of colons from dextran sulfate sodium-treated mice as assessed by flow cytometry. However, multiple colon cell types expressed the NMDA-R, suggesting the ability of diverse cells, including CD3-positive cells, CD103-positive cells, Ly6G-positive cells, and epithelial cell adhesion molecule-positive epithelial cells to respond to EI-tPA. Mesenchymal cells that line intestinal crypts and provide barrier function expressed LRP1, thereby representing another potential target for EI-tPA. These results demonstrate that the NMDA-R/LRP1 receptor system may be a target for drug development in diseases characterized by tissue damage and chronic inflammation.

Bacteroides ovatus Promotes IL-22 Production and Reduces Trinitrobenzene Sulfonic Acid-Driven Colonic Inflammation

The intestinal microbiota influences the development and function of the mucosal immune system. However, the exact mechanisms by which commensal microbes modulate immunity is not clear. We previously demonstrated that commensal Bacteroides ovatus ATCC 8384 reduces mucosal inflammation. Herein, we aimed to identify immunomodulatory pathways employed by B. ovatus. In germ-free mice, mono-association with B. ovatus shifted the CD11b+/CD11c+ and CD103+/CD11c+ dendritic cell populations. Because indole compounds are known to modulate dendritic cells, B. ovatus cell-free supernatant was screened for tryptophan metabolites by liquid chromatography-tandem mass spectrometry and larger quantities of indole-3-acetic acid were detected. Analysis of cecal and fecal samples from germ-free and B. ovatus mono-associated mice confirmed that B. ovatus could elevate indole-3-acetic acid concentrations in vivo. Indole metabolites have previously been shown to stimulate immune cells to secrete the reparative cytokine IL-22. Addition of B. ovatus cell-free supernatant to immature bone marrow-derived dendritic cells stimulated IL-22 secretion. The ability of IL-22 to drive repair in the intestinal epithelium was confirmed using a physiologically relevant human intestinal enteroid model. Finally, B. ovatus shifted the immune cell populations in trinitrobenzene sulfonic acid-treated mice and up-regulated colonic IL-22 expression, effects that correlated with decreased inflammation. Our data suggest that B. ovatus-produced indole-3-acetic acid promotes IL-22 production by immune cells, yielding beneficial effects on colitis.

Sulfated polysaccharides interact with fibroblast growth factors and protect from denaturation

Fibroblast growth factors (FGFs) regulate embryonic development and homeostasis, including tissue and organ repair and specific aspects of metabolism. The basic FGF and acidic FGF, now known as FGF2 and FGF1, are widely used protein drugs for tissue repair. However, they are susceptible to denaturation at ambient temperatures and during long-time storage, which will reduce their biological activity. The interaction of FGFs with the sulfated domains of heparan sulfate and heparin is essential for their cellular signaling and stability. Therefore, we analyzed the interactions of FGF1 and FGF2 with four sulfated polysaccharides: heparin, dextran sulfate (DXS), λ-carrageenan, and chondroitin sulfate. The results of thermal stability and cell proliferation assays demonstrate that heparin, DXS, and λ-carrageenan bound to both FGFs and protected them from denaturation. Our results suggest heparin, DXS, and λ-carrageenan are potential formulation materials that bind and stabilize FGFs, and which may also potentiate their activity and control their delivery.