DSS-induced Colitis Research Articles

Formononetin alleviates ulcerative colitis via reshaping the balance of M1/M2 macrophage polarization in a gut microbiota-dependent manner

BackgroundUlcerative colitis (UC), a type of inflammatory bowel disease, presents substantial challenges in clinical treatment due to the limitations of current medications. Formononetin (FN), a naturally compound with widespread availability, exhibits anti-inflammatory, antioxidant, and immunomodulatory properties. PurposeThis study aimed to investigate the efficacy of FN against UC and its potential regulatory mechanism. MethodsHere, dextran sulfate sodium (DSS) was employed to replicate experimental colitis in mice with concomitant FN treatment. The distribution and localisation of CD68 and F4/80 macrophages in colonic tissues were visualized by immunofluorescence, their chemokine and inflammatory cytokine concentrations were determined by ELISA, and macrophages and M1/M2 subpopulations were determined by flow cytometry. Additionally, 16 s rRNA and LC-MS techniques were used to detect the colonic intestinal microbiota and metabolite profiles, respectively. Correlation analyses was performed to clarify the interactions between differential bacteria, metabolites and M1/M2 macrophages, and pseudo sterile mice were constructed by depletion of gut flora with quadruple antibiotics, followed by faecal microbial transplantation to evaluate its effects on colitis and M1/M2 macrophage polarisation. ResultsFN dose-dependently alleviated clinical symptoms and inflammatory injury in colonic tissues of colitis mice, with its high-dose efficacy comparable to that of 5-ASA. Concurrently, FN not only inhibited inflammatory infiltration of macrophages and their M1/M2 polarisation balance in colitis mice, but also improved the composition of colonic microbiota and metabolite profiles. However, FN lost its protective effects against DSS-induced colitis and failed to restore the equilibrium of M1/M2 macrophage differentiation following intestinal flora depletion through quadruple antibiotic treatment. Importantly, fecal microbiota transplantation from FN-treated mice restored FN's protective effects against DSS-induced colitis and reestablished its regulatory role in M1/M2 macrophage polarization. ConclusionCollectively, FN ameliorated UC through modulating the balance of M1/M2 macrophage polarization in a gut microbiota-dependent manner.

Butyrolactone-I from marine fungi alleviates intestinal barrier damage caused by DSS through regulating Lactobacillus johnsonii and its metabolites in the intestine of mice

Butyrolactone-I (BTL-1), a secondary metabolite from the marine fungus Aspergillus terreus, exhibits numerous biological activities. Previous research has indicated that Butyrolactone-I alleviates intestinal epithelial inflammation via the TLR4/NF-κB and MAPK pathways. However, the mechanisms underlying its protection against intestinal barrier damage remain unclear. This study aims to further elucidate these mechanisms. We observed that BTL-1 administration increased the abundance of Lactobacillus johnsonii (LJ) in both in vivo and in vitro experiments, prompting an investigation into the effects of LJ and its metabolites on DSS-induced inflammatory bowel disease (IBD). The results demonstrated that BTL-1 significantly upregulated tight junction (TJ) and adherens junction (AJ) proteins, maintained intestinal barrier integrity, and alleviated DSS-induced IBD in mice. These effects were associated with the proliferation of LJ and its metabolites, such as butyric and propionic acids, and the inhibition of the MAPK signaling pathway in the colon. Interestingly, administering LJ alone produced a protective effect against DSS-induced IBD similar to that observed with BTL-1. Furthermore, butyric acid, a metabolite of LJ, also upregulated TJ/AJ proteins in intestinal epithelial cells through the MAPK signaling pathway. Our findings suggest that BTL-1 regulates intestinal flora, promotes LJ proliferation, protects intestinal barrier integrity, increases the concentrations of butyric and propionic acids, and ultimately inhibits the activation of the MAPK signaling pathway in mice to alleviate IBD. Therefore, BTL-1 could potentially be used as a natural drug to prevent IBD and maintain intestinal flora balance. ImportanceWe explored how butyrolactone-I exerts a preventive effect on IBD through intestinal bacteria (Lactobacillus johnsonii).

Lipopolysaccharide-regulated RNF31/NRF2 axis in colonic epithelial cells mediates homeostasis of the intestinal barrier in ulcerative colitis

BackgroundAlthough previous studies have shown that the Ring Finger Protein 31 (RNF31) gene confers susceptibility to inflammatory disease and colorectal cancer, the exact function of this protein in ulcerative colitis (UC) has not been determined. MethodsA mouse dextran sulfate sodium (DSS)-induced experimental colitis model was used to study RNF31 and NRF2 in colitis. RNF31 silencing or overexpression in vitro was applied to address the role of RNF31 in colonic mucosal barrier damage. Immunohistochemistry and silico analysis was performed to investigate the expression of RNF31 via taking advantage of UC tissue samples and Gene Expression Omnibus (GEO) data, respectively. The cycloheximide (CHX)-chase experiment and Co-Immunoprecipitation (Co-IP) assays were conducted to explore the association of RNF31 protein with NRF2 and P62. ResultsRNF31 is highly expressed in UC patients, in inflamed murine colon induced DSS and Lipopolysaccharide (LPS)-treated epithelial cells, while the express of NRF2 was Tabdecreased. RNF31-knockdown mice in the DSS-induced colitis model had a less severe phenotype, which was associated with a more integrated barrier of colon epithelial cells. While depletion of NRF2 in colitis model exacerbated intestinal inflammation. Mechanistically, RNF31 promoted the degradation of NRF2 by regulating its ubiquitination. Upon stimulation by RNF31, NRF2 is K63 ubiquitinated, which is associated with the C871 residue of RNF31. Moreover, downregulated NRF2 mediates inflammation by promoting the secretion of IL1β and IL18, leading to damage of the intestinal barrier. Upon LPS stimulation, the interaction of the PUB domain of RNF31 with the UBA domain of P62 increased, resulting in decreased degradation of the RNF31 protein via autophagy. ConclusionOverall, depletion of RNF31 effectively relieves DSS-induced colitis in mice by inhibiting NRF2 degradation, suggesting that RNF31 may be a potential therapy for human ulcerative colitis.

Neuroprotective effects of whey and buttermilk-based formulas on a DSS-induced colitis murine model.

Inflammatory bowel disease is a gut-brain axis disorder that comprises chronic inflammatory conditions affecting the gastrointestinal tract, where alterations in the mood of patients are common. Gut-brain axis is a bidirectional communication that link gut and brain. The close association between inflammatory bowel disease and neuroinflammation has far-reaching implications, as is increasingly recognized as a contributing factor to neuropsychiatric and neurodegenerative diseases. The increasing prevalence and high economic cost, together with the loss of life quality of people suffering from these diseases, point to the need to find alternatives to alleviate them. Exploring new therapeutic avenues prompts us to consider the potential benefits of milk fractions, taking advantage of the use of dairy by-products, such as whey and buttermilk. This study examines the impact of cow's whey- and buttermilk-based formulas supplemented with bovine lactoferrin and milk fat globule membrane on the expression of cytokines, as well as on the components of immune and serotonergic system of the brain in a murine model of DSS-induced colitis. Our results show the potential of these dairy by-products, especially whey, as functional foods in ameliorating neuroinflammation and safeguarding the central nervous system function amid the neurological complications induced or concomitant with intestinal inflammatory processes.

Discovery of a novel AhR–CYP1A1 axis activator for mitigating inflammatory diseases using an in situ functional imaging assay

The aryl hydrocarbon receptor (AhR) plays a crucial role in regulating many physiological processes. Activating the AhR–CYP1A1 axis has emerged as a novel therapeutic strategy against various inflammatory diseases. Here, a practical in situ cell-based fluorometric assay was constructed to screen AhR-CYP1A1 axis modulators, via functional sensing of CYP1A1 activities in live cells. Firstly, a cell-permeable, isoform-specific enzyme-activable fluorogenic substrate for CYP1A1 was rationally constructed for in-situ visualizing the dynamic changes of CYP1A1 function in living systems, which was subsequently used for discovering the efficacious modulators of the AhR–CYP1A1 axis. Following screening of a compound library, LAC-7 was identified as an efficacious activator of the AhR–CYP1A1 axis, which dose-dependently up-regulated the expression levels of both CYP1A1 and AhR in multiple cell lines. LAC-7 also suppressed macrophage M1 polarization and reduced the levels of inflammatory factors in LPS-induced bone marrow-derived macrophages. Animal tests showed that LAC-7 could significantly mitigate DSS-induced ulcerative colitis and LPS-induced acute lung injury in mice, and markedly reduced the levels of multiple inflammatory factors. Collectively, an optimized fluorometric cell-based assay was devised for in situ functional imaging of CYP1A1 activities in living systems, which strongly facilitated the discovery of efficacious modulators of the AhR–CYP1A1 axis as novel anti-inflammatory agents.

Curcumin-loaded polysaccharide microparticles alleviated DSS-induced ulcerative colitis by improving intestinal microecology and regulating MAPK/NF-κB/Nrf2/NLRP3 pathways

Curcumin (Cur) exerts many benefits on the host, but its application is limited by its poor bioavailability. In this study, composite polysaccharide microparticles loading Cur (Cur-CPM) was prepared by food-grade materials and gel technology. Its properties were analyzed via the in vitro and in vivo models, and then its benefit on gut health was assessed in DSS-treated mice. Compared to free Cur, CPM extended the residence time and absorption efficiency of Cur in the intestine, effectively ameliorating the symptoms of colitis. Cur-CPM alleviated colonic inflammation by inhibiting the activation of the MAPK and NF-κB pathways and suppressing NLRP3 inflammasome activity, affecting the expression of inflammation-related cytokines and mediators. In addition, Cur-CPM regulated the levels of antioxidants and oxidants in the colon tissues via Nrf2 activation, alleviating oxidative stress. Cur-CPM protected gut barrier function by maintaining the integrity of colonic mucosal layer and tight junction. The underlying mechanism can be attributed not only to the anti-inflammatory and antioxidant activities of Cur but also to modulation of Cur and CPM on the gut microbiota and metabolites. It suggests that Cur-CPM holds the potential to be developed as a functional component to enhance gut health.

Ginsenoside Rb1 Alleviates DSS-Induced Ulcerative Colitis by Protecting the Intestinal Barrier Through the Signal Network of VDR, PPARγ and NF-κB

Ginsenoside Rb1 Alleviates DSS-Induced Ulcerative Colitis by Protecting the Intestinal Barrier Through the Signal Network of VDR, PPARγ and NF-κB

Identification of SUMOylation-related signature genes associated with immune infiltration in ulcerative colitis through bioinformatics analysis and experimental validation

ObjectiveUlcerative colitis (UC) is a chronic inflammatory disorder challenging to diagnose clinically. We focused on identifying and validating SUMOylation-related signature genes in UC and their association with immune infiltration. MethodsFive eligible gene expression profiles were selected from the Gene Expression Omnibus (GEO) database and merged into a single dataset comprising 260 UC patients and 76 healthy controls (HC). Differentially expressed genes (DEGs) were identified, and these were intersected with SUMOylation-related genes to obtain differentially expressed SUMOylation-related genes (DESRGs). Next, we identify the signature genes and validate them through comprehensive analyses employing GO, KEGG, GSVA, Lasso-cox regression, ROC curves, and clustering analysis. The infiltrating immune cells were analyzed using the CIBERSORT algorithm and Pearson correlation analysis. Finally, in vitro and in vivo experiments validated the identified signature genes. ResultsPALMD, THRB, MAGED1, PARP1, and SLC16A1 were identified. Next, an excellent predictive model for UC was established and distinct subgroups of patients associated with SUMOylation were identified. Moreover, the NF-κB signaling pathway likely plays a pivotal role in the regulation of SUMOylation in UC. Additionally, we validated that the alterations in PALMD, THRB, and MAGED1 expression in LPSinduced Caco-2 cells concurred with our bioinformatics findings, particularly demonstrating statistically significant differences in PALMD and THRB expression. Finally, in a DSS-induced mouse colitis model, we observed a significant upregulation of PALMD expression. Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation. ConclusionThis study comprehensively elucidates the biological roles of SUMOylation-related genes in UC, identifying PALMD, MAGED1, THRB, PARP1, and SLC16A1 as signature genes that represent promising biomarkers for UC diagnosis and prognosis.

Weizmannia coagulans spores alleviates DSS-induced ulcerative colitis model by modulation of gut flora, metabolites and suppressing TLR4/MyD88/NF-κB pathway

<em>Weizmannia coagulans</em> spores alleviates DSS-induced ulcerative colitis model by modulation of gut flora, metabolites and suppressing TLR4/MyD88/NF-κB pathway

Lactobacillus paracasei JY062 and its exopolysaccharide enhance the intestinal barrier through macrophage polarization and Th17/Treg cell balance

Ulcerative colitis (UC) is an immune-mediated intestinal disease without a comprehensive cure, and the alleviation of UC has become an urgent problem. The results showed that JY062 with its EPS group (JEC) alleviated the intestinal barrier damage caused by LPS. After JEC intervention on Caco-2 cells, resulted in upregulation of ZO-1, Claudin-1, Occludin and MUC2 transcript levels and decreased mRNA expression of Claudin-2 (p < 0.05). JEC effectively attenuated the inflammatory response in UC mice and restoration of immunoglobulin levels (IgG, IgM and IgA), which resulted in shortening and swelling of the colon, disappearance of goblet cells, infiltration of inflammatory cells and mucosal damage were alleviated in mice. Similarly, changes in the expression of MUC2 and tight junction proteins after JEC intervention also occurred in UC mice. Administration of JEC significantly inhibited the differentiation of pro-inflammatory Th17 cells in the thymus and peripheral blood, promoted the differentiation of CD4+ T cells to Treg cells, and effectively regulated DSS-induced macrophage imbalance, which was manifested by the polarization of pro-inflammatory M1 macrophages to anti-inflammatory M2 macrophages. This study clearly demonstrates that JEC could significantly prevent intestinal barrier on DSS-induced experimental colitis and could be applied as a potential symbiotic strategy to assist in the alleviation of UC.

Drug screening identifies pyrrolidinedithiocarbamate ammonium ameliorating DSS-induced mouse ulcerative colitis via suppressing Th17 differentiation

T helper 17 (Th17) cells play crucial roles in various autoimmune diseases, including ulcerative colitis (UC), which is characterized by widespread inflammation in the mucosa of the colon and rectum. To identify small-molecule compounds capable of inhibiting CD4+T-cell differentiation into Th17 cells, we established a screening system. Through drug screening, we found that pyrrolidinedithiocarbamate ammonium (PDTC) effectively inhibits Th17 differentiation. In a dextran sulfate sodium (DSS)-induced UC mouse model, administration of PDTC significantly ameliorated colitis. PDTC treatment decreased the production of proinflammatory mediators and inhibited the proportion of Th17 cells in colitis-afflicted mice by suppressing NF-κB activation. These findings showed that PDTC can alleviate colitis by inhibiting NF-κB activation. The therapeutic effects of PDTC observed in a mouse model of UC provided a rationale for its application in clinical settings.

Deubiquitination of RIPK2 by OTUB2 augments NOD2 signalling and protective effects in intestinal inflammation.

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract, but the molecular mechanisms underlying IBD are incompletely understood. In this study, we explored the role and regulating mechanism of otubain 2 (OTUB2), a deubiquitinating enzyme, in IBD. To study the function of OTUB2 in IBD, we generated Otub2-/- mice and treated them with dextran sulfate sodium (DSS) to induce experimental colitis. Bone marrow transplantation was performed to identify the cell populations that were affected by OTUB2 in colitis. The molecular mechanism of OTUB2 in signal transduction was studied by various biochemical methods. OTUB2 was highly expressed in colon-infiltrating macrophages in both humans with IBD and mice with DSS-induced experimental colitis. Colitis was significantly aggravated in Otub2-/- mice and bone marrow chimeric mice receiving Otub2-/- bone marrow. OTUB2-deficiency impaired the production of cytokines and chemokines in macrophages in response to the NOD2 agonist muramyl dipeptide (MDP). Upon MDP stimulation, OTUB2 promoted NOD2 signaling by stabilizing RIPK2. Mechanistically, OTUB2 inhibited the proteasomal degradation of RIPK2 by removing K48-linked polyubiquitination on RIPK2, which was mediated by the active C51 residue in OTUB2. In mice, OTUB2 ablation abolished the protective effects of MDP administration in colitis. This study identified OTUB2 as a novel regulator of intestinal inflammation.

Laoxianghuang polysaccharide promotes the anti-inflammatory cytokine interleukin-10 in colitis via gut microbial linoleic acid

BackgroundOur previous study found that the polysaccharide from Laoxianghuang (LP), fermented fruit of bergamot (traditional Chinese medicine and food), can alter gut microbiota and regulate short-chain fatty acids (SCFAs) in vitro. Nevertheless, there is a paucity of reports on the impact of LP on gut microbiota in vivo. PurposeTo analyze the structures of LP, investigate the influence of LP on the damaged intestinal barrier in DSS-induced colitis mice, and further explore its potential mechanisms. MethodsWe analyzed the physicochemical properties of purified LP by HPLC, SEM, and FT-IR spectrum. Then, to assess the effect of LP in DSS-induced colitis mice, we observed the damage to the colon tissue, measured inflammatory cytokines and tight junction protein expression through RT-qPCR as well as immunofluorescent staining, and investigated the influence of LP on altering gut microbiota and metabolites using 16 s rRNA sequencing and HPLC-MS/MS. Ultimately, the impact of linoleic acid on inflammatory cytokines was confirmed by the LPS-induced RAW264.7 cells. ResultsLP, mainly galactoglucan, could inhibit weight loss and colon shortening, decrease levels of tumor necrosis factor-α (TNF-α), increase levels of interleukin-10 (IL-10) and the intestinal acetic acid and butyric acid, and promote the expression of tight junction proteins ZO-1 and Claudin-1. Meanwhile, LP enhanced the abundance of beneficial bacteria including Romboutsia, Eubacterium_coprostanoligenes_group, and Akkermansia, and regulated linoleic acid metabolism to increase the linoleic acid level. In vitro cell experiment proved that linoleic acid could elevate the level of IL-10 and inhibit inflammatory responses. ConclusionsOur results suggested that LP effectively alleviated colitis by promoting the anti-inflammatory cytokine interleukin-10 via gut microbiota-mediated linoleic acid metabolism.

Human IL-22 receptor-targeted small protein antagonist suppress murine DSS-induced colitis

BackgroundHuman interleukin-22 (IL-22) is known as a “dual function” cytokine that acts as a master regulator to maintain homeostasis, structural integrity of the intestinal epithelial barrier, and shielding against bacterial pathogens. On the other hand, the overexpression of IL-22 is associated with hyper-proliferation and recruitment of pathologic effector cells, leading to tissue damage and chronic inflammation in specific diseases including inflammatory bowel disease (IBD). To study a role of IL-22-mediated signaling axis during intestinal inflammation, we generated a set of small protein blockers of IL-22R1 and verified their inhibitory potential on murine model of colitis.MethodsWe used directed evolution of proteins to identify binders of human IL-22 receptor alpha (IL-22R1), designated as ABR ligands. This approach combines the assembly of a highly complex combinatorial protein library derived from small albumin-binding domain scaffold and selection of promising protein variants using ribosome display followed by large-scale ELISA screening. The binding affinity and specificity of ABR variants were analyzed on transfected HEK293T cells by flow cytometry and LigandTracer. Inhibitory function was further verified by competition ELISA, HEK-Blue IL-22 reporter cells, and murine dextran sulfate sodium (DSS)-induced colitis.ResultsWe demonstrate that ABR specifically recognizes transgenic IL-22R1 expressed on HEK293T cells and IL-22R1 on TNFα/IFNγ-activated HaCaT cells. Moreover, some ABR binders compete with the IL-22 cytokine and function as IL-22R1 antagonists in HEK-Blue IL22 reporter cells. In a murine model of DSS-induced acute intestinal inflammation, daily intraperitoneal administration of the best IL-22R1 antagonist, ABR167, suppressed the development of clinical and histological markers of colitis including prevention of mucosal inflammation and architecture deterioration. In addition, ABR167 reduces the DSS-induced increase in mRNA transcript levels of inflammatory cytokines such as IL-1β, IL-6, IL-10, and IL-17A.ConclusionsWe developed small anti-human IL-22R1 blockers with antagonistic properties that ascertain a substantial role of IL-22-mediated signaling in the development of intestinal inflammation. The developed ABR blockers can be useful as a molecular clue for further IBD drug development.

Effects of Green Tea and Java Pepper Mixture on Gut Microbiome and Colonic MicroRNA-221/222 in Mice with Dextran Sulfate Sodium-Induced Colitis.

In this study, we aimed to investigate the regulatory effects of a green tea and java pepper mixture (GTP) on the gut microbiome and microRNA (miR)-221/222 expression in mice with dextran sulfate sodium (DSS)-induced colitis. Male C57BL/6J mice were divided into four groups: DSS-, DSS+, GTP50, and GTP100. In the GTP50 and GTP100 groups, GTP was orally administered to mice at doses of 50 and 100 mg/kg body weight, respectively, every day for 2 weeks, and colitis was induced in the DSS+, GTP50, and GTP100 groups by adding 3% DSS to their drinking water for 1 week. GTP was found to mitigate the severity of inflammation and the damage to goblet cells caused by DSS-induced colitis. The results showed that compared with the DSS- group, the relative abundance of Bacteroidetes was increased and that of Proteobacteria and Candidatus Melainabacteria was decreased in the GTP100 group. The ratio of Firmicutes to Bacteroidetes was also reduced in the GTP100 group. However, GTP administration did not modulate the microbial diversity. GTP administration upregulated the mRNA and protein levels of occludin and zonula occludens 1. In addition, GTP effectively downregulated the expression of miR-221 and miR-222. Overall, GTP altered the gut microbiota composition and downregulated colonic miR-221/222 expression in mice with DSS-induced colitis.

Network Analysis of Gut Microbial Communities Reveals Key Reason for Quercetin Protects against Colitis

As one of the most representative natural products among flavonoids, quercetin (QUE) has been reported to exhibit beneficial effects on gut health in recent years. In this study, we utilized a dextran sulfate sodium (DSS)-induced colitis mice model to explore the protective effects and underlying mechanisms of QUE on colitis. Our data demonstrated that QUE oral gavage administration significantly ameliorates the symptoms and histopathological changes associated with colitis. Additionally, the concentration of mucin-2, the number of goblet cells, and the expression of tight junction proteins (such as ZO-1, Occludin, and Claudin-1) were all found to be increased. Furthermore, QUE treatment regulated the levels of inflammatory cytokines and macrophage polarization, as well as the oxidative stress-related pathway (Nrf2/HO-1) and associated enzymes. Additionally, 16S rDNA sequencing revealed that QUE treatment rebalances the alterations in colon microbiota composition (inlcuding Bacteroidaceae, Bacteroides, and Odoribacter) in DSS-induced colitis mice. The analysis of network dynamics reveals a significant correlation between gut microbial communities and microenvironmental factors associated with inflammation and oxidative stress, in conjunction with the previously mentioned findings. Collectively, our results suggest that QUE has the potential to treat colitis by maintaining the mucosal barrier, modulating inflammation, and reducing oxidation stress, which may depend on the reversal of gut microbiota dysbiosis.

Demethylzeylasteral alleviates inflammation and colitis via dual suppression of NF-κB and STAT3/5 by targeting IKKα/β and JAK2

BackgroundUlcerative colitis (UC) is a common inflammatory bowel disease and a risk factor of colorectal cancer. Demethylzeylasteral (DZT), a bioactive component mainly isolated from Tripterygium wilfordii, has been shown to inhibit inflammation and cancer. However, its anti-UC function and molecular mechanisms have not been well characterized. This study aims to explore the therapeutic effect and functional targets of demethylzeylasteral against UC. MethodsRT-qPCR, Western blot and ELISA were used to detect the generation of pro-inflammatory cytokines and chemokines in murine macrophage cells. Luciferase reporter gene, Western blot, pull-down, CETSA, DARTS, and virtual docking were employed to detect the anti-inflammatory targets and molecular mechanisms of demethylzeylasteral. The anti-inflammatory and anti-colitis effects of demethylzeylasteral were further determined in DSS-challenged mice. ResultsIn vitro, demethylzeylasteral inhibited NO and PGE2 production by suppressing the mRNA and protein expression of iNOS and COX-2, and suppressed the mRNA expression of TNF-α, IL-1β, IL-6, MCP-1, CXCL9, and CXCL10 in RAW264.7 macrophages stimulated by LPS/IFNγ. Furthermore, demethylzeylasteral was not only capable of inhibiting IKKα/β-NF-κB activation, but also able to block JAKs-STAT3/5 activation in LPS/INFγ-incubated RAW264.7 cells or DSS-exposed colon tissues of mice. Mechanistically, demethylzeylasteral was found to directly bind to IKKα/β and JAK2 kinases, leading to inactivation of pro-inflammatory signaling cascades and reduced generation of cytokines and chemokines. In vivo, oral administration of demethylzeylasteral significantly attenuated DSS-induced colitis, which was mainly manifested as mitigated symptoms of colitis, colonic mucosal barrier damage, and colonic inflammation. ConclusionWe demonstrated that demethylzeylasteral alleviated UC pathology by blocking NF-κB and STAT3/5 pathways via targeting IKKα/β and JAK2 kinases, raising the possibility that demethylzeylasteral could act as a candidate for the treatment of UC.

Qin-Yu-Qing-Chang decoction reshapes colonic metabolism by activating PPAR-γ signaling to inhibit facultative anaerobes against DSS-induced colitis

BackgroundQin-Yu-Qing-Chang decoction (QYQC), an herbal formula from China, is extensively employed to manage ulcerative colitis (UC) and exhibits potential benefits for colonic function. Nevertheless, the fundamental molecular mechanisms of QYQC remain largely uncharted.MethodsThe primary constituents of QYQC were determined utilizing UHPLC-MS/MS analysis and the effectiveness of QYQC was assessed in a mouse model of colitis induced by dextran sulfate sodium. Evaluations of colon inflammatory responses and mucosal barrier function were thoroughly assessed. RNA sequencing, molecular docking, colonic energy metabolism, and 16S rRNA sequencing analysis were applied to uncover the complex mechanisms of QYQC in treating UC. Detect the signal transduction of the peroxisome proliferator-activated receptor-γ (PPAR-γ) both in the nucleus and cytoplasm. Furthermore, a PPAR-γ antagonist was strategically utilized to confirm the functional targets that QYQC exerts.ResultsUtilizing UHPLC-MS/MS, the principal constituents of the nine traditional Chinese medicinal herbs comprising QYQC were systematically identified. QYQC treatment substantially ameliorated colitis in mice, as evidenced by the improvement in symptoms and the reduction in colonic pathological injuries. Besides, QYQC treatment mitigated the inflammatory response and improved mucosal barrier function. Furthermore, QYQC enhanced the mitochondria citrate cycle (TCA cycle) by triggering PPAR-γ signaling and increasing the proportion of PPAR-γ entering the nucleus. This prevented the unconstrained expansion of facultative anaerobes, particularly pathogenic Escherichia coli (E. coli, family Enterobacteriaceae) and thus improved colitis. Results of molecular docking indicated that the representative chemical components of QYQC including Baicalin, Paeoniflorin, Mollugin, and Imperatorin bound well with PPAR-γ. The impact of QYQC on colitis was diminished in the presence of a PPAR-γ antagonist.ConclusionsIn summary, QYQC ameliorates UC by activating PPAR-γ signaling and increasing the proportion of PPAR-γ entering the nucleus, which enhances the energy metabolism of intestinal epithelial cells and thereby preventing the uncontrolled proliferation of facultative anaerobes.

Design, Synthesis, and Bioevaluation of Novel NLRP3 Inhibitor with IBD Immunotherapy from the Virtual Screen.

NLRP3, a crucial member of the NLRP family, plays a pivotal role in immune regulation and inflammatory modulation. Here, we report a potent and specific NLRP3 inhibitor Z48 obtained though docking-based virtual screening and structure-activity relationship studies with an IC50 of 0.26 μM in THP-1 cells and 0.21 μM in mouse bone marrow-derived macrophages. Mechanistic studies indicated that Z48 could bind directly to the NLRP3 protein (KD = 1.05 μM), effectively blocking the assembly and activation of the NLRP3 inflammasome, consequently manifesting anti-inflammatory properties. Crucially, with acceptable mouse pharmacokinetic profiles, Z48 demonstrated notable therapeutic efficacy in a mouse model of DSS-induced ulcerative colitis, while displaying no significant therapeutic impact on NLRP3KO mice. In conclusion, this study provided a promising NLRP3 inflammasome inhibitor with novel molecular scaffold, poised for further development as a therapeutic candidate in the treatment of inflammatory bowel disease.

NPSR1 promotes chronic colitis through regulating CD4+ T cell effector function in inflammatory bowel disease

BackgroundNeuropeptide S receptor 1 (NPSR1) has been implicated in the the onset of inflammatory bowel disease (IBD), though its exact mechanism remains unclear. This study investigates the role of NPSR1 in regulating CD4+ T cell effector function in IBD. MethodsPeripheral blood and colonic mucosal biopsies from IBD patients, as well as dextran sodium sulfate (DSS)-induced mouse colitis models, were analyzed to assess the effects of NPSR1 on colitis and CD4+ T cell-mediated immune responses. NPSR1 knockdown was conducted both in vitro and in vivo to elucidate underlying mechanisms. Expression of NPSR1 and CD4+ T cell-related factors was measured using quantitative real-time PCR, immunoblotting, cytometric bead array, immunofluorescence, and immunohistochemistry. CD4 + T cell effector functions were evaluated through flow cytometry, EdU incorporation assay, Annexin V-FITC/PI staining, and transwell assay. ResultsNPSR1 expression was elevated in the intestinal tissues from IBD patients. Its downregulation provided protection in DSS-induced mouse colitis models. NPSR1 correlated positively with CD4 + T cell-mediated inflammation, and its knockdown reduced CD4+ T cell-mediated immune responses and inhibited CD4+ T cell differentiation. Additionally, NPSR1 knockdown decreased CD4+ T cell proliferation, increased apoptosis, and enhanced CCL2-induced migration in vitro, while significantly reducing Th1 cell chemotaxis in vivo. ConclusionsThis study demonstrates that NPSR1 promotes chronic colitis by regulating CD4 + T cell effector functions in IBD, offering potential new therapeutic strategies for IBD treatment.