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

IL-1ß 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-1ß-targeted anticolitis activity remains unclear. Here, we evaluated the inhibitory effect of geraniin in IL-1ß-stimulated Caco-2 cells and a dextran sulfate sodium (DSS)-induced colitis mouse model. Geraniin blocked the interaction between IL-1ß and IL-1R by directly binding to IL-1ß and inhibited the IL-1ß activity. It suppressed IL-1ß-induced intestinal tight junction damage in human Caco-2 cells by inhibiting IL-1ß-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-1ß activity and anticolitis effect by hindering the IL-1ß and IL-1R interaction and may be a promising therapeutic anti-IL-1ß agent for IBD treatment.

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.

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.

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 17ß-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.

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.

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-1ß, 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.

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.

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-1ß (IL-1ß), 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 ß (TGF-ß) 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.

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-1ß, 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.

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-1ß, 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.

Saffron Petal, an Edible Byproduct of Saffron, Alleviates Dextran Sulfate Sodium-Induced Colitis by Inhibiting Macrophage Activation and Regulating Gut Microbiota.

Saffron petal (SP) is an agricultural byproduct in the process of the crude drug saffron, accounting for 90% of the dry weight of saffron flowers. To promote the utilization of SP in the food and pharmaceutical industries, its anti-inflammatory activities were evaluated on LPS-activated RAW 264.7 cells and DSS-challenged colitic mice. The results indicated that the SP extract had a notable effect in alleviating the clinical manifestations of colitis, such as reduction in body weight, improvement in disease activity index, mitigation of colon shortening, and alleviation of colon tissue damage. Moreover, SP extract significantly suppressed macrophage infiltration and activation, evidenced by a decrease in colonic F4/80 macrophages and suppression of the transcription and secretion of colonic tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) in DSS-challenged colitic mice. In vitro, SP extract also significantly suppressed nitric oxide production, COX-2 and iNOS expressions, and TNF-α and IL-1ß transcription of activated RAW 264.7 cells. Network pharmacology-guided research identified that SP extract significantly downregulated Akt, p38, ERK, and JNK phosphorylation in vivo and in vitro. In parallel, SP extract also effectively corrected microbial dysbiosis by increasing the abundance of Bacteroides acidifaciens, Bacteroides vulgatus, Lactobacillus murinus, and Lactobacillus gasseri. These findings indicate that the effectiveness of SP extract in treating colitis is demonstrated by its ability to reduce macrophage activation, inhibit the PI3K/Akt and MAPK pathways, and regulate gut microbiota, suggesting that SP extract holds great potential as a therapeutic option for colitis.

[Effect and mechanism of Bovis Calculus on ulcerative colitis by inhibiting IL-17/IL-17RA/Act1 signaling pathway].

This study aimed to elucidate the effect and underlying mechanism of Bovis Calculus in the treatment of ulcerative colitis(UC) through network pharmacological prediction and animal experimental verification. Databases such as BATMAN-TCM were used to mine the potential targets of Bovis Calculus against UC, and the pathway enrichment analysis was conducted. Seventy healthy C57BL/6J mice were randomly divided into a blank group, a model group, a solvent model(2% polysorbate 80) group, a salazosulfapyridine(SASP, 0.40 g·kg~(-1)) group, and high-, medium-, and low-dose Bovis Calculus Sativus(BCS, 0.20, 0.10, and 0.05 g·kg~(-1)) groups according to the body weight. The UC model was established in mice by drinking 3% dextran sulfate sodium(DSS) solution for 7 days. The mice in the groups with drug intervention received corresponding drugs for 3 days before modeling by gavage, and continued to take drugs for 7 days while modeling(continuous administration for 10 days). During the experiment, the body weight of mice was observed, and the disease activity index(DAI) score was recorded. After 7 days of modeling, the colon length was mea-sured, and the pathological changes in colon tissues were observed by hematoxylin-eosin(HE) staining. The levels of tumor necrosis factor-α(TNF-α), interleukin-1ß(IL-1ß), interleukin-6(IL-6), and interleukin-17(IL-17) in colon tissues of mice were detected by enzyme-linked immunosorbent assay(ELISA). The mRNA expression of IL-17, IL-17RA, Act1, TRAF2, TRAF5, TNF-α, IL-6, IL-1ß, CXCL1, CXCL2, and CXCL10 was evaluated by real-time polymerase chain reaction(RT-PCR). The protein expression of IL-17, IL-17RA, Act1, p-p38 MAPK, and p-ERK1/2 was investigated by Western blot. The results of network pharmacological prediction showed that Bovis Calculus might play a therapeutic role through the IL-17 signaling pathway and the TNF signaling pathway. As revealed by the results of animal experiments, on the 10th day of drug administration, compared with the solvent model group, all the BCS groups showed significantly increased body weight, decreased DAI score, increased colon length, improved pathological damage of colon mucosa, and significantly inhibited expression of TNF-α,IL-6,IL-1ß, and IL-17 in colon tissues. The high-dose BCS(0.20 g·kg~(-1)) could significantly reduce the mRNA expression levels of IL-17, Act1, TRAF2, TRAF5, TNF-α, IL-6, IL-1ß, CXCL1, and CXCL2 in colon tissues of UC model mice, tend to down-regulate mRNA expression levels of IL-17RA and CXCL10, significantly inhibit the protein expression of IL-17RA,Act1,and p-ERK1/2, and tend to decrease the protein expression of IL-17 and p-p38 MAPK. This study, for the first time from the whole-organ-tissue-molecular level, reveals that BCS may reduce the expression of pro-inflammatory cytokines and chemokines by inhibiting the IL-17/IL-17RA/Act1 signaling pathway, thereby improving the inflammatory injury of colon tissues in DSS-induced UC mice and exerting the effect of clearing heat and removing toxins.

[Mechanism of tryptanthrin in treatment of ulcerative colitis in mice based on serum metabolomics].

This study aims to explore the effect of tryptanthrin on potential metabolic biomarkers in the serum of mice with ulcerative colitis(UC) induced by dextran sulfate sodium(DSS) based on liquid chromatography-mass spectrometry(LC-MS) and predict the related metabolic pathways. C57BL/6 mice were randomly assigned into a tryptanthrin group, a sulfasalazine group, a control group, and a model group. The mouse model of UC was established by free drinking of 3% DSS solution for 11 days, and corresponding drugs were adminsitrated at the same time. The signs of mice were observed and the disease activity index(DAI) score was recorded from the first day. Colon tissue samples were collected after the experiment and observed by hematoxylin-eosin(HE) staining. The levels of interleukin-4(IL-4), interleukin-10(IL-10), tumor necrosis factor-α(TNF-α), interleukin-6(IL-6), and interleukin-8(IL-8) in the serum were measured by enzyme linked immunosorbent assay(ELISA). The serum samples were collected from 6 mice in each group for widely targeted metabolomics. The metabolic pathways were enriched by MetaboAnalyst 5.0. The results showed that compared with the model group, tryptanthrin treatment decreased the DAI score(P<0.05), alleviated the injury of the colon tissue and the infiltration of inflammatory cells, lowered the levels of proinflammatory cytokines, and elevated the levels of anti-inflammatory cytokines in the serum. The metabolomic analysis revealed 28 differential metabolites which were involved in 3 metabolic pathways including purine metabolism, arachidonic acid metabolism, and tryptophan metabolism. Tryptanthrin may restore the metabolism of the mice with UC induced by DSS to the normal level by regulating the purine metabolism, arachidonic acid metabolism, and tryptophan metabolism. This study employed metabolomics to analyze the mechanism of tryptanthrin in the treatment of UC, providing an experimental basis for the utilization and development of tryptanthrin.

AMPK activation alleviated dextran sulfate sodium-induced colitis by inhibiting ferroptosis.

OBJECTIVES: Ferroptosis is a newly discovered cell death mode that has been confirmed to occur in the intestinal epithelial cells in ulcerative colitis (UC). In this study we aimed to elucidate the mechanism of ferroptosis and its association with adenosine monophosphate-activated protein kinase (AMPK) in UC. METHODS: Gene expression profiles of colonic mucosa (GSE87473) were downloaded. Both human colonic samples and dextran sodium sulfate (DSS)-induced colitis murine model were used. The molecular markers of ferroptosis were detected using western blot and immunohistochemistry. Symptoms, iron abundance, and lipid peroxidation level of the mouse model were measured to evaluate the role of AMPK activation in ferroptosis. RESULTS: Both gene and protein expressions of GPX4 and FTH1 were decreased in UC patients compared with the healthy controls. An increased iron abundance and lipid peroxidation level in colon tissues and damaged mitochondria were found in DSS-induced colitis. AMPK expression was decreased in UC patients and correlated with FTH1 and GPX4. Activation of AMPK with metformin inhibited ferroptosis in the colon, improved symptoms, and prolonged the lifespan in DSS-induced colitis mice. CONCLUSIONS: Ferroptosis can be observed in colonic tissues in UC. AMPK activation inhibits ferroptosis in murine colitis model, which may act as a potential target for the treatment of colitis.

[Mechanism of famous classical formula Huaihua Powder in treatment of ulcerative colitis based on metabonomics].

Ultra-high performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry(UHPLC-Q-TOF-MS) was employed in this study to observe the effect of Huaihua Powder on the serum metabolites of mice with ulcerative colitis and reveal the mechanism of Huaihua Powder in the treatment of ulcerative colitis. The mouse model of ulcerative colitis was established by dextran sodium sulfate salt(DSS). The therapeutic effect of Huaihua Powder on ulcerative colitis was preliminarily evaluated based on the disease activity index(DAI), colon appearance, colon tissue morphology, and the content of inflammatory cytokines such as tumor necrosis factor-α(TNF-α), interleukin-6(IL-6), and interleukin-1ß(IL-1ß). UHPLC-Q-TOF-MS was employed to profile the endogenous metabolites of serum samples in blank control group, model group, and low-, medium-, and high-dose Huaihua Powder groups. Multivariate analyses such as principal component analysis(PCA), partial least squares discriminant analysis(PLS-DA), and orthogonal partial least squares discriminant analysis(OPLS-DA) were performed for pattern recognition. Potential biomarkers were screened by Mass Profiler Professional(MPP) B.14.00 with the thresholds of fold change≥2 and P<0.05. The metabolic pathways were enriched by MetaboAnalyst 5.0. The results showed that Huaihua Powder significantly improved the general state and colon tissue morphology of mice with ulcerative colitis, reduced DAI, and lowered the levels of TNF-α, IL-6, and IL-1ß in serum. A total of 38 potential biomarkers were predicted to be related to the regulatory effect of Huaihua Powder, which were mainly involved in glycerophospholipid metabolism, glycine, serine, and threonine metabolism, mutual transformation of glucuronic acid, and glutathione metabolism. This study employed metabolomics to analyze the mechanism of Huaihua Powder in the treatment of ulcerative colitis, laying a foundation for the further research.

Exosomes derived from EphB2-overexpressing bone marrow mesenchymal stem cells regulate immune balance and repair barrier function.

BACKGROUND: Disruption of intestinal barrier function and an imbalance in intestinal immunity are crucial for the occurrence and development of ulcerative colitis. Because of their important roles in regulating inflammation and immunity, exosomes (Exos) released from bone marrow mesenchymal stem cells (BMSCs) may be useful for treating ulcerative colitis. The EphB/EphrinB signaling pathway plays a crucial role in the inflammatory process and the development and function of immune cells, and can mediate long-distance intercellular communication through extracellular vesicles. This study was conducted to explore the effects of pre-modified BMSC-Exos expressing EphB2 (EphB2-Exos) on immunoregulation in vitro. METHODS: We transfected a lentivirus vector encoding EphB2 into BMSCs and isolated EphB2-Exos from the culture supernatant. Inflammation and oxidative damage in the human colon adenocarcinoma cell line (Caco-2) were induced by dextran sulfate sodium/hydrogen peroxide. In addition, spleen CD4+ T lymphocytes of rats were sorted in vitro. We conducted a series of experiments to explore the biological functions of EphB2-Exos. RESULTS: EphB2-Exos were successfully isolated and were found to significantly protect the activity, proliferation, and migration of Caco-2 cells that were inhibited by dextran sulfate sodium. EphB2-Exos alleviated inflammation and apoptosis and increased the activity of antioxidant enzymes while inhibiting oxidative stress in Caco-2 cells. EphB2-Exos restored intestinal barrier function by inhibiting the RhoA/ROCK pathway and regulated the polarization of CD4+T cells. CONCLUSION: EphB2-Exos enhanced intestinal barrier function and regulated the immune balance by inhibiting the RhoA/ROCK pathway in vitro. These findings suggest that EphB2-Exos can be applied as a cell-free therapy for ulcerative colitis.

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.

Zinc finger protein 189 promotes the differentiation of lamina propria T helper 17.1 cells in dextran sulfate sodium-induced colitis.

The factors regulating the heterogeneity of interleukin-17A (IL-17A)-expressing CD4+ T cells in inflammatory bowel diseases remain unclear. In the current study, we characterised the expression and function of zinc finger protein 189 (ZFP189) in a murine colitis model. Mice were given dextran sulphate sodium to induce acute colitis. Flow cytometry was applied to recognise and enrich Th17 and Th17.1 cells based on the expression of IL-17A, interferon-γ (IFN-γ), C-X-C motif chemokine receptor 3 (CXCR3), and C-C motif chemokine receptor 4 (CCR4). The expression of ZFP189 in Th17 and Th17.1 cells was determined by Immunoblotting. Lentivirus-mediated ZFP189 knockdown was conducted to evaluate the effect of ZFP189 on the differentiation of Th17 and Th17.1 cells. The adoptive transfer was performed to analyse the pathogenicity of Th17.1 cells in vivo. We found that ZFP189 was mildly up-regulated in IL-17A-expressing CD4+ T cells in colonic lamina propria. Lamina propria Th17.1 cells expressed higher ZFP189 than Th17 cells. In vitro ZFP189 knockdown in CD4+ T cells did not impact Th17 cell differentiation but suppressed Th17.1 cell differentiation, as evidenced by lower T-box expressed in T cells (T-bet) and IFN-γ. When adoptively transferred into mice, ZFP189-deficient Th17.1 cells produced fewer IFN-γ, tumour necrosis factor-alpha (TNF-α), and granulocyte-macrophage colony-stimulating factor (GM-CSF) than ZFP189-expressing Th17.1 cells. Moreover, ZFP189-deficient Th17.1 cells induced less severe colitis than ZFP189-expressing Th17.1 cells, as evidenced by less body weight loss, a lower disease activity index, and a lower colon histological score. In summary, ZFP189 acts as a positive regulator of the differentiation and pathogenicity of lamina propria Th17.1 cells in colitis.

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.