L-Fucose ameliorates DSS-induced acute colitis via inhibiting macrophage M1 polarization and inhibiting NLRP3 inflammasome and NF-kB activation

DIAMMONIUM GLYCYRRHIZINATE INHIBITED INFLAMMATORY RESPONSE AND MODULATED SERUM METABOLISM IN POLY(I:C)-INDUCED PNEUMONIA MODEL MICE

ABSTRACT

Currently, the coronavirus disease 2019 (COVID-19) is becoming a serious threat to human health worldwide. Therefore, there is a great need to develop effective drugs against viral pneumonia. Diammonium glycyrrhizinate (DG), derived from Glycyrrhiza glabra L., has been demonstrated with significant anti-inflammatory properties. However, the therapeutic effects and mechanisms of DG on pneumonia require further clarification. In this study, mice received intratracheal injection of polyinosinic-polycytidylic acid (poly(I:C)) to induce pneumonia and were treated with DG. First, we evaluated the therapeutic potential of DG on poly(I:C)-induced pneumonia. Second, the anti-inflammatory and antioxidative activities and the impact of DG on the toll-like receptor 3 (TLR3) pathway were investigated. Third, the mechanism of DG was analyzed through untargeted metabolomics techniques. Our results revealed that DG intervention decreased permeability and reduced abnormal lung alterations in poly(I:C)-induced pneumonia model mice. DG intervention also downregulated cytokine levels in bronchoalveolar lavage fluid. Moreover, DG treatment inhibited the activation of TLR3 pathway. Furthermore, untargeted metabolomics analysis revealed that DG intervention could modulate serum metabolites involved in amino and nucleotide sugar metabolism, fructose and mannose metabolism, tyrosine metabolism, and phenylalanine, tyrosine, and tryptophan biosynthesis pathways. In conclusion, our study showed that DG could ameliorate poly(I:C)-induced pneumonia by inactivating the TLR3 pathway and affecting amino and nucleotide sugar, fructose and mannose metabolism, as well as tryptophan, phenylalanine, and tyrosine biosynthesis.

Polysaccharides extracted from larvae of Lucilia sericata ameliorated ulcerative colitis by regulating the intestinal barrier and gut microbiota

Pest management technology has been a promising bioconversion method for waste resource utilization. Unlike many pests that consume waste, the larvae of Lucilia sericata, also known as maggots, have many outstanding advantages as following: with their strong adaption to environment and not easily infected and exhibiting a medicinal nutritional value. Herein, the potential efficacies of maggot polysaccharides (MP), as well as their underlying mechanisms, were explored in Dextran sulfate sodium (DSS)-induced colitis mice and TNF-α-elicited Caco-2 cells. We extracted two bioactive polysaccharides from maggots, MP-80 and MP-L, whose molecular weights were 4.25 × 103 and 2.28 × 103 g/mol, respectively. MP-80 and MP-L contained nine sugar residues: 1,4-α-Arap, 1,3-β-Galp, 1,4,6-β-Galp, 1,6-α-Glcp, 1-α-Glcp, 1,4-β-Glcp, 1-β-Xylp, 1,2-α-Manp, and 1-β-Manp. We demonstrated that MP-80 and MP-L significantly ameliorated DSS-induced symptoms and histopathological damage. Immuno-analysis revealed that compared with MP-L, MP-80 could better restore intestinal barrier and reduced inflammation by suppressing NLRP3/NF-κB pathways, which might be attributed to its enriched galactose fraction. Moreover, 16S rRNA sequencing revealed that MP-80 and MP-L both improved the dysbiosis and diversity of gut microbiota and acted on multiple microbial functions. Our study sheds new light on the possibility of using maggot polysaccharides as an alternative therapy for colitis.

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

Introduction

Cynaroside exhibits various biological properties, including anti-inflammatory, antiviral, antitumor, and cardioprotective effects. However, its involvement in methotrexate (MTX)-induced intestinal inflammation remains inadequately understood. Thus, we investigated the impact of cynaroside on MTX-induced intestinal inflammation and its potential mechanisms.

Methods

To assess the protective potential of cynaroside against intestinal inflammation, Sprague-Dawley rats were subjected to a regimen of 7 mg/kg MTX for 3 days, followed by treatment with cynaroside at varying doses (10, 20, or 40 mg/kg). Histopathological evaluations were conducted alongside measurements of inflammatory mediators to elucidate the involvement of the NLRP3 inflammasome in alleviating intestinal inflammation.

Results

Administration of 7 mg/kg MTX resulted in decreased daily food intake, increased weight loss, and elevated disease activity index in rats. Conversely, treatment with cynaroside at 20 or 40 mg/kg ameliorated the reductions in body weight and daily food intake and suppressed the MTX-induced elevation in the disease activity index. Notably, cynaroside administration at 20 or 40 mg/kg attenuated inflammatory cell infiltration, augmented goblet cell numbers and lowered serum levels of tumor necrosis factor-α, interleukin (IL)-1β, and IL-18, as well as the CD68-positive cell rate in the intestines of MTX-induced rats. Furthermore, cynaroside downregulated the expression levels of NLRP3, cleaved caspase 1, and cleaved IL-1β in MTX-induced rats.

Discussion

Collectively, our findings indicated that cymaroside alleviates intestinal inflammatory injury by inhibiting the activation of NLRP3 inflammasome in MTX-induced rats.

Resatorvid (TAK-242) Ameliorates Ulcerative Colitis by Modulating Macrophage Polarization and T Helper Cell Balance via TLR4/JAK2/STAT3 Signaling Pathway

Resatorvid (TAK-242), a specific inhibitor of Toll-like receptor-4 (TLR4), has attracted attention for its anti-inflammatory properties. Despite this, few studies have evaluated its effects on ulcerative colitis (UC). This study aimed to investigate the effects of TAK-242 on macrophage polarization and T helper cell balance and the mechanism by which it alleviates UC. Our findings indicated that TLR4 expression was elevated in patients with UC, a mouse model of UC, and HT29 cells undergoing an inflammatory response. TAK‑242 treatment reduced apoptosis in TNF-α and LPS-stimulated HT29 cells and alleviated symptoms of dextran sulfate sodium (DSS)‑induced colitis in vivo. TAK‑242 downregulated TLR4 expression and decreased the secretion of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β while enhancing IL-10 production. TAK-242 also reduced M1 macrophage polarization and diminished Th1 and Th17 cell infiltration while increasing Th2 cell infiltration and M2 macrophage polarization both in vitro and in vivo. Mechanistically, TAK-242 inhibited the JAK2/STAT3 signaling pathway, an important regulator of macrophage polarization and T helper cell balance. Furthermore, the in vivo and in vitro effects of TAK-242 were partially negated by the administration of the JAK2/STAT3 antagonist AG490, suggesting that TAK-242 inhibits the JAK2/STAT3 pathway to exert its biological activities. Taken together, this study underscores TAK-242 as a promising anti-UC agent, functioning by modulating macrophage polarization and T helper cell balance via the TLR4/JAK2/STAT3 signaling pathway.

Fucoidan MF4 from Fucus vesiculosus inhibits Lewis lung cancer via STING-TBK1-IRF3 pathway

Fucoidan, a sulfated polysaccharide of marine origin found in brown algae and sea cucumbers, has been identified as a neuroprotective compound. In this study, a novel fucoidan MF4 was extracted from Fucus vesiculosus and isolated using Q-Sepharose fast-flow ion-exchange chromatography. The physicochemical properties of MF4 were characterized. MF4 is primarily composed of fucose, xylose, galactose, glucose, and mannose in a molar ratio of 12.3: 4.9: 1.1: 1.0: 1.1, with an average molecular weight of 67.7 kDa. Notably, MF4 demonstrated suppression of LLC tumor growth in vivo. RNA-sequencing analysis revealed that MF4 enhanced the expression of type I interferon-associated downstream genes in macrophages. Furthermore, MF4 increased the levels of phosphorylated TBK1 and IRF3 proteins in vitro. By activating the STING-TBK1-IRF3 signaling pathway, MF4 may enhance the antitumor activity of macrophages. Taken together, MF4 has promising potential as an antitumor and immunomodulatory agent.

Mogroside Ⅴ Inhibits M1 Polarization and Inflammation of Diabetic Mouse Macrophages via p38 MAPK/NF-Κb Signaling Pathway

BACKGROUND

Mogroside V (MV) has anti-inflammatory properties. However, its impact on macrophage polarization under diabetic condition is yet unclear. This study aimed to investigate effects and underlying mechanisms of MV on inflammatory response and M1 polarization of bone marrow-derived macrophages (BMDMs) from diabetic mice.

METHODS

BMDMs were isolated from normal and diabetic C57BL/6 mice. LPS and IFN-γwere used to produce M1-polarized BMDMs. MV treatment was administered throughout the M1 polarization process with or without SB203580 or PDTC. Surface markers CD11b, F4/80 and CD86 of macrophages were identified using flow cytometry or immunofluorescence staining. Inflammatory cytokines IL-1β and IL-6 and phosphorylation levels of p65 and p38 were examined by western blot.

RESULTS

High glucose increased proportion of CD11b+F4/80+CD86+ cells, protein levels of inflammatory cytokines IL-1β and IL-6 and phosphorylation levels of p65 and p38 in LPS+IFN-γ-induced BMDMs, while they were decreased upon MV treatment. Additionally, these effects were further downregulated when MV was co-added with SB203580 or PDTC.

CONCLUSIONS

MV suppressed M1 macrophage polarization and inflammatory response, which was partially through NF-κB and p38 MAPK in LPS+IFN-γ induced BMDMs under high glucose condition, implying the potential of MV in treatment for inflammatory complications of diabetes.

Polyphenol Extracts from Ziziphus jujuba Mill. "Junzao" Attenuates Ulcerative Colitis by Inhibiting the NLRP3 and MAPKs Signaling Pathways and Regulating Gut Microbiota Homeostasis in Mice

SCOPE

Polyphenols are the major active substances in red jujube fruit, and their anti-inflammatory and antioxidant activities suggest their potential utility in the prevention of ulcerative colitis (UC).

METHODS AND RESULTS

In this study, the effect of polyphenol extracts from red jujube (Ziziphus jujuba Mill. "Junzao") (PERJ) on the dextron sulfate sodium (DSS)-induced UC mice is investigated. The result shows that PERJ effectively improves clinical symptoms, including food and water intake, the disease activity insex (DAI) and spleen index, and routine blood levels, and alleviates the shortening of the colon, in mice with DSS-induced UC. Meanwhile, PERJ remarkably decreases the expression of proinflammatory factors. Moreover, PERJ repairs intestinal barrier damage by increasing the expression level of mucin 2 and mucin 3, and the result is also confirmed in the histological assessment. Besides, the expression levels of Nod-like receptor family pyrin domain-containing 3 (NLRP3) and mitogen-activated protein kinase cascade (MAPKs) signaling pathway-related proteins are inhibited by the PERJ administration. Finally, 16S rRNA sequencing analyses reveal that PERJ reverses intestinal microbiota dysbiosis by enhancing the abundance of Firmicutes and decreasing that of Proteobacteria and Bacteroidetes.

CONCLUSION

PERJ probably inhibits the development of UC by suppressing the NLRP3 and MAPKs signaling pathways and regulating gut microbiota homeostasis, and can be considered as a potential resource for preventing UC.

L-fucose and fucoidan alleviate high-salt diet-promoted acute inflammation

Excessive salt intake is a widespread health issue observed in almost every country around the world. A high salt diet (HSD) has a strong correlation with numerous diseases, including hypertension, chronic kidney disease, and autoimmune disorders. However, the mechanisms underlying HSD-promotion of inflammation and exacerbation of these diseases are not fully understood. In this study, we observed that HSD consumption reduced the abundance of the gut microbial metabolite L-fucose, leading to a more substantial inflammatory response in mice. A HSD led to increased peritonitis incidence in mice, as evidenced by the increased accumulation of inflammatory cells and elevated levels of inflammatory cytokines, such as tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and monocyte chemotactic protein-1 (MCP-1, also known as C-C motif chemokine ligand 2 or CCL2), in peritoneal lavage fluid. Following the administration of broad-spectrum antibiotics, HSD-induced inflammation was abolished, indicating that the proinflammatory effects of HSD were not due to the direct effect of sodium, but rather to HSD-induced alterations in the composition of the gut microbiota. By using untargeted metabolomics techniques, we determined that the levels of the gut microbial metabolite L-fucose were reduced by a HSD. Moreover, the administration of L-fucose or fucoidan, a compound derived from brown that is rich in L-fucose, normalized the level of inflammation in mice following HSD induction. In addition, both L-fucose and fucoidan inhibited LPS-induced macrophage activation in vitro. In summary, our research showed that reduced L-fucose levels in the gut contributed to HSD-exacerbated acute inflammation in mice; these results indicate that L-fucose and fucoidan could interfere with HSD-promotion of the inflammatory response.

Triclosan induces liver injury in long-life exposed mice via activation of TLR4/NF-κB/NLRP3 pathway

Triclosan (TCS) is a widely used synthetic, with broad-spectrum antibacterial properties found in both pharmaceuticals and personal care products. More specifically, it is hepatotoxic in rodents and exhibits differential effects in mice and humans. However, the mechanisms underlying TCS-induced liver toxicity have not been elucidated. This study examined the role of the toll-like receptor 4 (TLR4)/ nuclear factor kappa B (NF-κB)/ nod-like receptor protein 3 (NLRP3) pathway in TCS-exposed liver toxicity by established a long-life TCS-exposed mice liver injury model. The 24 C57BL/6 pregnant mice exposed to TCS (0, 50 and 100 mg/kg) every day during the gestation and nursing period. After weaning, the male mice were left to continue administrate with TCS until 8 weeks of age. Then, mice in each group were sacrificed for investigation. Long-life exposure to TCS resulted in a reduction of body weight in growth mice. TCS exposure caused the increase of serum ALT, AST and ALP. The situation of inflammatory cell infiltration, macrophage recruitment and collagen fiber deposition in TCS-exposed mice liver tissues were performed by histological analysis including hematoxylin-eosin, Masson, Sirius red, and immunohistochemistry staining. Protein expression levels in TLR4/NF-κB/NLRP3 pathway was measured through Western blot, and the NLRP3 inflammasome activation was measured using real-time quantitative PCR (RT-qPCR). The results showed that exposure to TCS elevated TLR4, myeloid differentiation factor 88 (Myd88), TNF receptor associated factor 6 (TRAF6), enhanced NF-κB activation, and affected NLRP3 inflammasome activation in mice liver. Collectively, these findings indicate that long-life exposure to TCS-induced mice by upregulating the TLR4-Myd88-TRAF6 pathway, activating the NF-κB signaling cascade, initiating the NLRP3 inflammasome pathway, and ultimately leading to liver injury, including inflammation, hepatocyte pyroptosis and hepatofibrosis. Henceforth, the TLR4/NF-κB/NLRP3 pathway may now provide a theoretical basis and valuable therapeutic targets for overcoming TCS-induced liver toxicity.

Fucoxanthin Alleviates Dextran Sulfate Sodium-Induced Colitis and Gut Microbiota Dysbiosis in Mice

The purpose of this study was to evaluate the preventive role and underlying mechanisms of fucoxanthin (Fx) on dextran sulfate sodium (DSS)-induced colitis in mice. The present data demonstrated that oral administration of Fx (50 and 200 mg/kg body weight/day) for 36 days significantly alleviated the severity of colitis in DSS-treated mice, as evidenced by attenuating body weight loss, bloody stool, diarrhea, shortened colon length, colonic epithelium distortion, a thin mucus layer, goblet cell depletion, damaged crypts, and extensive infiltration of inflammatory cells in the colonic mucosa. Additionally, Fx notably relieved DSS-induced intestinal epithelial barrier dysfunction via maintaining the tight junction function and preventing excessive apoptosis of colonic epithelial cells. Moreover, Fx effectively diminished colonic inflammation and oxidative stress in DSS-treated mice, and its mechanisms might be due to blunting the activation of NF-κB and NLRP3 inflammasome signaling pathways. Furthermore, Fx also modulates DSS-induced gut microbiota dysbiosis via recovering the richness and diversity of gut microbiota and reshaping the structure of gut microbiota, such as increasing the Firmicutes and Bacteroidota (F/B) ratio and elevating the relative abundance of some potential beneficial bacteria, including Lactobacillaceae and Lachnospiraceae. Overall, Fx might be developed as a promising functional ingredient to prevent colitis and maintain intestinal homeostasis.

Potential Role of Bmal1 in Lipopolysaccharide-Induced Depression-Like Behavior and its Associated "Inflammatory Storm"

Inflammation plays an important role in the pathogenesis of depression; however, the underlying mechanisms remain unclear. Apart from the disordered circadian rhythm in animal models and patients with depression, dysfunction of clock genes has been reported to be involved with the progress of inflammation. This study aimed to investigate the role of circadian clock genes, especially brain and muscle ARNT-like 1 (Bmal1), in the linkage between inflammation and depression. Lipopolysaccharide (LPS)-challenged rats and BV2 cells were used in the present study. Four intraperitoneal LPS injections of 0.5 mg/kg were administered once every other day to the rats, and BV2 cells were challenged with LPS for 24 h at the working concentration of 1 mg/L, with or without the suppression of Bmal1 via small interfering RNA. The results showed that LPS could successfully induce depression-like behaviors and an "inflammatory storm" in rats, as indicated by the increased immobility time in the forced swimming test and the decreased saccharin preference index in the saccharin preference test, together with hyperactivity of the hypothalamic-pituitary-adrenal axis, hyperactivation of astrocyte and microglia, and increased peripheral and central abundance of tumor necrosis factor-α, interleukin 6, and C-reactive protein. Moreover, the protein expression levels of brain-derived neurotrophic factor, triggering receptor expressed on myeloid cells 1, Copine6, and Synaptotagmin1 (Syt-1) decreased in the hippocampus and hypothalamus, whereas the expression of triggering receptor expressed on myeloid cells 2 increased. Interestingly, the fluctuation of temperature and serum concentration of melatonin and corticosterone was significantly different between the groups. Furthermore, protein expression levels of the circadian locomotor output cycles kaput, cryptochrome 2, and period 2 was significantly reduced in the hippocampus of LPS-challenged rats, whereas Bmal1 expression was significantly increased in the hippocampus but decreased in the hypothalamus, where it was co-located with neurons, microglia, and astrocytes. Consistently, apart from the reduced cell viability and increased phagocytic ability, LPS-challenged BV2 cells presented a similar trend with the changed protein expression in the hippocampus of the LPS model rats. However, the pathological changes in BV2 cells induced by LPS were reversed after the suppression of Bmal1. These results indicated that LPS could induce depression-like pathological changes, and the underlying mechanism might be partly associated with the imbalanced expression of Bmal1 and its regulated dysfunction of the circadian rhythm.

Research progress on the functions, preparation and detection methods of l-fucose

l-fucose is a six-carbon sugar that has potential applications in many fields. It exerts antitumor effects and could relieve intestinal disease. It exhibits potential as an emulsifier in the food industry. It is also used as a functional food and in anti-aging skincare products. However, at present, it is not possible to prepare high-purity l-fucose on a large scale, and its preparation needs further development. This review summarizes the preparation methods of l-fucose including chemical synthesis, enzymatic synthesis, microbial fermentation, and separation and purification from algae. The detection methods of l-fucose are also introduced in detail, such as l-fucose-specific lectin, detection l-fucose dehydrogenase, cysteine-sulfuric acid method, high-performance liquid chromatography, gas chromatography, and biosensors. In this review, the properties and pharmacological effects of l-fucose; preparation methods, and the commonly used detection methods of l-fucose are reviewed to serve as a reference material.

Anemoside B4 ameliorates dextran sulfate sodium (DSS)-induced colitis through inhibiting NLRP3 inflammasome and modulating gut microbiota

Ulcerative colitis (UC) has been recognized as a chronic and relapsing inflammatory disease of the gastrointestinal tract. Clinically, aminosalicylates, immunosuppressants and biological agents are commonly used to treat UC at different stages of the disease. However, these drugs often have side effects. Here, we investigated the anti-UC activity of Anemoside B4 (AB4) in mice with dextran sulfate sodium (DSS) induced colitis. Colon tissues, serum, and colonic contents were collected for assessment of intestinal barrier function, inflammatory cytokines production and microenvironment of intestinal microbiota. Results showed that AB4 alleviated colon shortening, weight lossing and histopathological damage in DSS-induced mice. In addition, we demonstrated both in vivo and in vitro that AB4 remarkably ameliorated colonic inflammation through suppressing NLRP3 pathway. Moreover, AB4 strengthened the intestinal epithelial barrier by regulating myosin light chain kinase (MLCK)-phosphorylated myosin light chain 2 (pMLC2) signaling pathway. Furthermore, we performed 16 S rRNA gene sequencing and fecal microbiome transplantation (FMT) experiments to demonstrate that AB4 alleviated colitis through regulating dysbiosis of intestinal microbiota. These results revealed that AB4 effectively ameliorate experimental UC mainly through regulating MLCK/pMLC2 pathway, NLRP3 pathway and dysbiosis of microbiota, provided new insights into the development of novel anti-UC drugs.

Effects of polyphenolic maqui (Aristotelia chilensis) extract on the inhibition of NLRP3 inflammasome and activation of mast cells in a mouse model of Crohn's disease-like colitis

Introduction

Crohn's disease (CD) involves activation of mast cells (MC) and NF-кB in parallel with the PPAR-α/NLRP3 inflammasome/IL-1β pathway in the inflamed colon. Whether polyphenols from maqui (Aristotelia chilensis) represent a natural alternative treatment for CD is unclear. Therefore, we used an animal model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced CD-like colitis to investigate protective effects of maqui extract through monitoring NLRP3 inflammasome and MC activation in colon tissue.

Methods

Maqui extract was administered via orogastric route to mice after (post-Treatment group) or prior (pre-Treatment group) to TNBS-induction. Colon pathology was characterized by histoarchitectural imaging, disease activity index (DAI), and assessing NF-кB, p-NF-кB, PPAR-α/NLRP3 expression and IL-1β levels.

Results

Compared to mice treated with TNBS alone administration of anthocyanin-rich maqui extract improved the DAI, colon histoarchitecture and reduced both colon wet-weight and transmural inflammation. Induction with TNBS significantly increased colonic NLPR3 inflammasome activation, while co-treatment with maqui extract (either post- or pre-Treatment) significantly downregulated NLRP3, ASC and caspase-1 levels, which manifested as reduced colonic IL-1β levels. Supplemented maqui extract marginally diminished NF-кB activity in epithelial cells but reached statistical significance in immune cells (as judged by decreased NF-кB phosphorylation). PPAR-α signaling was largely unaffected by Maqui whereas MC infiltration into the colon mucosa and submucosa decreased and their level of degranulation was suppressed.

Conclusion

These outcomes show the post- and pre- Treatment effect of a polyphenolic extract rich in anthocyanins from maqui the acute phase of TNBS- induced CD-like colitis is linked to suppression of the NLRP3 inflammasome and reduced MC responses. These data indicate that maqui extract represents a potential nutraceutical for the treatment of inflammatory bowel disease (IBD).

The role of inflammasomes in human diseases and their potential as therapeutic targets

Inflammasomes are large protein complexes that play a major role in sensing inflammatory signals and triggering the innate immune response. Each inflammasome complex has three major components: an upstream sensor molecule that is connected to a downstream effector protein such as caspase-1 through the adapter protein ASC. Inflammasome formation typically occurs in response to infectious agents or cellular damage. The active inflammasome then triggers caspase-1 activation, followed by the secretion of pro-inflammatory cytokines and pyroptotic cell death. Aberrant inflammasome activation and activity contribute to the development of diabetes, cancer, and several cardiovascular and neurodegenerative disorders. As a result, recent research has increasingly focused on investigating the mechanisms that regulate inflammasome assembly and activation, as well as the potential of targeting inflammasomes to treat various diseases. Multiple clinical trials are currently underway to evaluate the therapeutic potential of several distinct inflammasome-targeting therapies. Therefore, understanding how different inflammasomes contribute to disease pathology may have significant implications for developing novel therapeutic strategies. In this article, we provide a summary of the biological and pathological roles of inflammasomes in health and disease. We also highlight key evidence that suggests targeting inflammasomes could be a novel strategy for developing new disease-modifying therapies that may be effective in several conditions.

Macrophage polarization in inflammatory bowel disease

The growing prevalence of inflammatory bowel disease (IBD) has encouraged research efforts, which have contributed to gradual improvements in our understanding of IBD diagnosis and therapeutic approaches. The pathogenesis of IBD has not been fully elucidated; however, the combined actions of environmental, genetic, immune factors, and microbial organisms are believed to cause IBD. In the innate immune system, macrophages play important roles in maintaining intestinal health and in the development of IBD. Macrophages can be polarized from M0 into several phenotypes, among which M1 and M2 play critical roles in IBD development and the repair of intestinal homeostasis and damage. Certain macrophage-related IBD studies already exist; however, the functions of each phenotype have not been fully elucidated. As technology develops, understanding the link between macrophages and IBD has increased, including the growing knowledge of the developmental origins of intestinal macrophages and their performance of comprehensive functions. This review describes macrophage polarization in IBD from the perspectives of macrophage development and polarization, macrophage changes in homeostasis and IBD, metabolic changes, and the mechanisms of macrophage polarization in IBD. The discussion of these topics provides new insights into immunotherapy strategies for IBD. Video Abstract.

MiR-146b-5p enriched bioinspired exosomes derived from fucoidan-directed induction mesenchymal stem cells protect chondrocytes in osteoarthritis by targeting TRAF6

Osteoarthritis (OA) is a common degenerative joint disease characterized by progressive cartilage degradation and inflammation. In recent years, mesenchymal stem cells (MSCs) derived exosomes (MSCs-Exo) have attracted widespread attention for their potential role in modulating OA pathology. However, the unpredictable therapeutic effects of exosomes have been a significant barrier to their extensive clinical application. In this study, we investigated whether fucoidan-pretreated MSC-derived exosomes (F-MSCs-Exo) could better protect chondrocytes in osteoarthritic joints and elucidate its underlying mechanisms. In order to evaluate the role of F-MSCs-Exo in osteoarthritis, both in vitro and in vivo studies were conducted. MiRNA sequencing was employed to analyze MSCs-Exo and F-MSCs-Exo, enabling the identification of differentially expressed genes and the exploration of the underlying mechanisms behind the protective effects of F-MSCs-Exo in osteoarthritis. Compared to MSCs-Exo, F-MSCs-Exo demonstrated superior effectiveness in inhibiting inflammatory responses and extracellular matrix degradation in rat chondrocytes. Moreover, F-MSCs-Exo exhibited enhanced activation of autophagy in chondrocytes. MiRNA sequencing of both MSCs-Exo and F-MSCs-Exo revealed that miR-146b-5p emerged as a promising candidate mediator for the chondroprotective function of F-MSCs-Exo, with TRAF6 identified as its downstream target. In conclusion, our research results demonstrate that miR-146b-5p encapsulated in F-MSCs-Exo effectively inhibits TRAF6 activation, thereby suppressing inflammatory responses and extracellular matrix degradation, while promoting chondrocyte autophagy for the protection of osteoarthritic cartilage cells. Consequently, the development of a therapeutic approach combining fucoidan with MSC-derived exosomes provides a promising strategy for the clinical treatment of osteoarthritis.

Metabolomics of cerebrospinal fluid reveals prognostic biomarkers in pediatric status epilepticus

AIMS

Status epilepticus (SE) is the most common neurological emergency in pediatric patients. This study aimed to screen for prognostic biomarkers of SE in the cerebrospinal fluid (CSF) using metabolomics.

METHODS

Ultra-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF-MS) was conducted to identify prognostic biomarkers in CSF metabolomics by comparing the poor outcome group (N = 13) with the good outcome group (N = 15) of children with SE. Differentially expressed metabolites were identified using Mann-Whitney U test corrected by Benjamini-Hochberg and partial least squares discriminant analysis (PLS-DA).

RESULTS

The PLS-DA model identified and validated significant metabolic differences between the poor and good outcome groups of children with SE (PLS-DA with R2 Y = 0.992 and Q2  = 0.798). A total of 49 prognosis-related metabolites were identified. Of these metabolites, 20 including glutamyl-glutamine, 3-iodothyronamine, and L-fucose had an area under the curve (AUC) ≥ 80% in prognostic prediction of SE. The logistic regression model combining glutamyl-glutamine and 3-iodothyronamine produced an AUC value of 0.976, with a sensitivity of 0.863 and specificity of 0.956. Pathway analysis revealed that dysregulation of the citrate cycle (TCA) and arginine biosynthesis may contribute to poor SE prognosis.

CONCLUSIONS

This study highlighted the prognosis-related metabolomic disturbances in the CSF of children with SE and identified potential prognostic biomarkers. A prognostic prediction model combining glutamyl-glutamine and 3-iodothyronamine with high predictive value was established.

Luteolin ameliorates DSS-induced colitis in mice via suppressing macrophage activation and chemotaxis

OBJECTIVES

Luteolin, known for its multifaceted therapeutic properties against inflammatory diseases, holds potential for addressing the unmet need for effective treatments in ulcerative colitis (UC), a prevalent subtype of inflammatory bowel disease (IBD). This study aimed to comprehensively assess luteolin's therapeutic efficacy in a dextran sulfate sodium (DSS)-induced colitis mouse model, shedding light on its anti-UC mechanisms.

METHODS

Our investigation encompassed in vivo assessments of luteolin's therapeutic potential against DSS-induced colitis through rigorous histopathological examination and biochemical analyses. Furthermore, we scrutinized luteolin's anti-inflammatory prowess in vitro using lipopolysaccharide (LPS)-stimulated RAW264.7 cells and primary peritoneal macrophages. Additionally, we quantitatively evaluated the impact of luteolin on C-C motif chemokine ligand 2 (CCL2)-induced macrophage migration employing Transwell and Zigmond chambers. Furthermore, cellular thermal shift assay (CETSA), drug affinity responsive target stability (DARTS) assay, and molecular docking were employed to identify potential therapeutic targets of luteolin and investigate their binding sites and interaction patterns.

RESULTS

Luteolin demonstrated therapeutic potential against DSS-induced colitis by ameliorating colitis symptoms, restoring intestinal barrier integrity, and inhibiting proinflammatory cytokine production in the colonic tissues. Moreover, luteolin demonstrated robust anti-inflammatory activity in vitro, in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and primary peritoneal macrophages. Notably, luteolin suppressed the phosphorylation of IKKα/β, IκBα, and p65, along with preventing IκBα degradation in LPS-treated RAW264.7 cells and peritoneal macrophages. Furthermore, luteolin impaired the migratory behavior of RAW264.7 cells and peritoneal macrophages, as evidenced by reduced migration distance and velocity of luteolin-treated macrophages. Mechanistically, luteolin was found to antagonize IKKα/β, subsequently inhibiting IKKα/β phosphorylation and the activation of NF-κB signaling.

CONCLUSION

Luteolin emerges as a promising lead compound for the clinical therapy of colitis by virtue of its ability to ameliorate DSS-induced colitis, antagonize IKKα/β, suppress NF-κB signaling, and impede macrophage activation and migration.

Pulsatillae radix extract alleviates DSS-induced colitis via modulating gut microbiota and inflammatory signaling pathway in mice

Ethnopharmacological relevance

Ulcerative colitis (UC) is a chronic relapsing intestinal disease with complex pathogenesis. The increasing morbidity and mortality of UC become a global public health threat. Baitouweng decoction (BD), a formulated prescription of Traditional Chinese Medicine, has been applied to cure UC for many centuries. However, the therapeutic efficacy and working mechanisms of this medicine are not well studied.

Aim of study

In this study we determined whether Pulsatillae radix, one of four ingredients in BD, had a therapeutic effect on colitis. And explore the underlying mechanism of Pulsatilla chinensis (Bunge) Regel radix in the improvement of DSS-induced colitis in mice model.

Methods

The active compounds of Pulsatilla chinensis was identified by UPLC. The composition of the mice's cecum microbiota was determined by 16S rRNA sequencing. And gene expression profile of colon was detected by transcriptome.

Results

The results showed that Pulsatillae radix significantly improved the clinical symptom, prevented the shorten of colon length, and decreased the diseased activity index (DAI) in an 3 % DSS-induced ulcerative colitis mouse model. We found that Pulsatillae radix reversed the dysbiosis of gut microbiota as evidenced by increase in the relative abundance of Bacteroidetes, Deferribacteres, and Proteobacteria phyla and decrease in Firmicutes, as well as by decrease in the genera levels of Bacteroides, Parabacteroides, Prevotella, Mucispirillum, Coprococcus, Oscillospira, and Escherichia. The results of transcriptome showed Pulsatillae radix administration led to 128 genes up-regulation, and 122 genes down-regulation, up-regulate NOD-like receptor signaling pathway, down-regulate Cytokine-cytokine receptor interaction, and TNF and IL-17 signaling pathways.

Conclusion

in this study, we demonstrate Pulsatillae radix alleviates DSS-induced colitis probably via modulating gut microbiota and inflammatory signaling pathway in DSS-induced colitis mouse model.

Combined Lycium barbarum Polysaccharides with Plasmon-Activated Water Affect IFN-γ/TNF-α Induced Inflammation in Caco-2 Cells

The effects of Lycium barbarum polysaccharides (LBP) and plasmon-activated water (PAW) against IFN-γ/TNF-α induced inflammation in human colon Caco-2 cells were investigated. Cells were divided into the control, induction, LBP treatment (100-500 μg/mL), and combination groups with PAW. Inflammation was induced 24 h with 10 ng/mL IFN-γ when cell confluency reached >90%, and various doses of LBP with or without PAW were treated for 3 h, and subsequently 50 ng/mL TNF-α was added for another 24 h to provoke inflammation. Combination of LBP with PAW significantly decreased the secretion of IL-6 and IL-8. Cyclooxygenase-2 and inducible NO synthase expression was attenuated in all LBP-treated groups with or without PAW. NLRP3 inflammasome and related protein PYCARD expression were inhibited by LBP at the highest dose (500 μg/mL). All doses of LBP alone significantly decreased p-ERK expression, but combination with PAW increased p-ERK expression compared to those without PAW. Additionally, 250 and 500 μg/mL of LBP with or without PAW inhibited procaspase-3/caspase-3 expression. Therefore, LBP possesses anti-inflammation and anti-apoptosis by inhibiting the secretion of inflammatory cytokines and the expression of NLRP3 inflammasome-related protein. The combination with PAW exerts additive or synergistic effect on anti-inflammation.

Degradation of NLRP3 by p62-dependent-autophagy improves cognitive function in Alzheimer's disease by maintaining the phagocytic function of microglia

BACKGROUND

Activation of the NLRP3 inflammasome promotes microglia to secrete inflammatory cytokines and induce pyroptosis, leading to impaired phagocytic and clearance functions of microglia in Alzheimer's disease (AD). This study found that the autophagy-associated protein p62 interacts with NLRP3, which is the rate-limiting protein of the NLRP3 inflammasome. Thus, we aimed to prove that the degradation of NLRP3 occurs through the autophagy-lysosome pathway (ALP) and also demonstrate its effects on the function of microglia and pathological changes in AD.

METHODS

The 5XFAD/NLRP3-KO mouse model was established to study the effect of NLRP3 reduction on AD. Behavioral experiments were conducted to assess the cognitive function of the mice. In addition, immunohistochemistry was used to evaluate the deposition of Aβ plaques and morphological changes in microglia. BV2 cells treated with lipopolysaccharide (LPS) followed by Aβ1-42 oligomers were used as in vitro AD inflammation models and transfected with lentivirus to regulate the expression of the target protein. The pro-inflammatory status and function of BV2 cells were detected by flow cytometry and immunofluorescence (IF). Co-immunoprecipitation, mass spectrometry, IF, Western blot (WB), quantitative real-time PCR, and RNA-seq analysis were used to elucidate the mechanisms of molecular regulation.

RESULTS

Cognitive function was improved in the 5XFAD/NLRP3-KO mouse model by reducing the pro-inflammatory response of microglia and maintaining the phagocytic and clearance function of microglia to the deposited Aβ plaque. The pro-inflammatory function and pyroptosis of microglia were regulated by NLRP3 expression. Ubiquitinated NLRP3 can be recognized by p62 and degraded by ALP, slowing down the proinflammatory function and pyroptosis of microglia. The expression of autophagy pathway-related proteins such as LC3B/A, p62 was increased in the AD model in vitro.

CONCLUSIONS

P62 recognizes and binds to ubiquitin-modified NLRP3. It plays a vital role in regulating the inflammatory response by participating in ALP-associated NLRP3 protein degradation, which improves cognitive function in AD by reducing the pro-inflammatory status and pyroptosis of microglia, thus maintaining its phagocytic function.

Limosilactobacillus mucosae and Lactobacillus amylovorus Protect Against Experimental Colitis via Upregulation of Colonic 5-Hydroxytryptamine Receptor 4 and Transforming Growth Factor-β2

BACKGROUND

Limosilactobacillusmucosae (LM) exerts anti-inflammatory and health-promoting effects. However, its role in the modulation of gut serotonin or 5-hydroxytryptamine (5-HT) metabolism and 5-HT receptors (HTRs) in inflammation requires further investigation.

OBJECTIVES

We compared LM with Lactobacillus amylovorus (LA) for the regulation of 5-HT, HTRs, inflammatory mediators, and their correlations in the colon of mice with experimental colitis.

METHODS

Male C57BL/6 mice were randomly assigned to 6 groups: control (Con), LM, LA, dextran sodium sulfate (DSS), and DSS with pre-administration of LM (+LM) or LA (+LA). After 7 d of DSS treatment, mice were killed to analyze the expression of inflammatory mediators, HTRs, and concentrations of 5-HT and microbial metabolites in the colon.

RESULTS

LM was more effective than LA in alleviating DSS-induced colonic inflammation. Compared with mice in the DSS group, mice receiving DSS + LM or DSS + LA treatment had lower (P < 0.05) colonic mRNA expression of proinflammatory cytokines. DSS + LM treatment had lower mRNA expression of Il1b, Tnfa, and Ccl3, an abundance of p-STAT3, and greater expression of Tgfb2 and Htr4 in the colon (P < 0.05). The expression of inflammatory mediators (including Tgfb-1) was positively correlated (P < 0.05) with 5-HT and Htr2a and negatively correlated (P < 0.05) with Htr4. However, the expression of Tgfb-2 showed reversed correlations with the 5-HT and HTRs described above. Patterns for these correlations were different for LM and LA. Mice receiving the DSS + LM treatment had greater (P < 0.05) concentrations of acetate and valerate and lower (P < 0.05) concentrations of indole-3-acetic acid in the cecal and colonic contents.

CONCLUSIONS

LM showed greater efficacy than LA in alleviating DSS-induced colonic inflammation. The coordinated regulation of transforming growth factor-β subtypes and serotonin receptors in the colon may be one of the most important mechanisms underlying the probiotic effects of lactobacilli in gut inflammation.

Macrophage polarization in bone implant repair: A review

Macrophages (MΦ) are highly adaptable and functionally polarized cells that play a crucial role in various physiological and pathological processes. Typically, MΦ differentiate into two distinct subsets: the proinflammatory (M1) and anti-inflammatory (M2) phenotypes. Due to their potent immunomodulatory and anti-inflammatory properties, MΦ have garnered significant attention in recent decades. In the context of bone implant repair, the immunomodulatory function of MΦ is of paramount importance. Depending on their polarization phenotype, MΦ can exert varying effects on osteogenesis, angiogenesis, and the inflammatory response around the implant. This paper provides an overview of the immunomodulatory and inflammatory effects of MΦ polarization in the repair of bone implants.

Ginsenosides from Panax ginseng as Key Modulators of NF-κB Signaling Are Powerful Anti-Inflammatory and Anticancer Agents

Nuclear factor kappa B (NF-κB) signaling pathways progress inflammation and immune cell differentiation in the host immune response; however, the uncontrollable stimulation of NF-κB signaling is responsible for several inflammatory illnesses regardless of whether the conditions are acute or chronic. Innate immune cells, such as macrophages, microglia, and Kupffer cells, secrete pro-inflammatory cytokines, such as TNF-α, IL-6, and IL-1β, via the activation of NF-κB subunits, which may lead to the damage of normal cells, including neurons, cardiomyocytes, hepatocytes, and alveolar cells. This results in the occurrence of neurodegenerative disorders, cardiac infarction, or liver injury, which may eventually lead to systemic inflammation or cancer. Recently, ginsenosides from Panax ginseng, a historical herbal plant used in East Asia, have been used as possible options for curing inflammatory diseases. All of the ginsenosides tested target different steps of the NF-κB signaling pathway, ameliorating the symptoms of severe illnesses. Moreover, ginsenosides inhibit the NF-κB-mediated activation of cancer metastasis and immune resistance, significantly attenuating the expression of MMPs, Snail, Slug, TWIST1, and PD-L1. This review introduces current studies on the therapeutic efficacy of ginsenosides in alleviating NF-κB responses and emphasizes the critical role of ginsenosides in severe inflammatory diseases as well as cancers.

Beneficial Effects of Hordenine on a Model of Ulcerative Colitis

Hordenine, a phenethylamine alkaloid, is found in a variety of plants and exhibits a broad array of biological activities and pharmacological properties, including anti-inflammatory and anti-fibrotic effects. However, the efficacy and underlying mechanisms of hordenine in treating ulcerative colitis (UC) remain unclear. To address this, we examined the therapeutic effects of hordenine on dextran sodium sulphate (DSS)-induced UC by comparing disease activity index (DAI), colon length, secretion of inflammatory factors, and degree of colonic histological lesions across diseased mice that were and were not treated with hordenine. We found that hordenine significantly reduced DAI and levels of pro-inflammatory factors, including interleukin (IL)-6, IL-1β, and tumor necrosis factor alpha (TNF-α), and also alleviated colon tissue oedema, colonic lesions, inflammatory cells infiltration and decreased the number of goblet cells. Moreover, in vitro experiments showed that hordenine protected intestinal epithelial barrier function by increasing the expression of tight junction proteins including ZO-1 and occludin, while also promoting the healing of intestinal mucosa. Using immunohistochemistry and western blotting, we demonstrated that hordenine reduced the expression of sphingosine kinase 1 (SPHK1), sphingosine-1-phosphate receptor 1 (S1PR1), and ras-related C3 botulinum toxin substrate 1 (Rac1), and it inhibited the expression of phosphorylated signal transducer and activator of transcription 3 (p-STAT3) in colon tissues. Thus, hordenine appears to be effective in UC treatment owing to pharmacological mechanisms that favor mucosal healing and the inhibition of SPHK-1/S1PR1/STAT3 signaling.

Hydroxysafflor yellow A protects against colitis in mice by suppressing pyroptosis via inhibiting HK1/NLRP3/GSDMD and modulating gut microbiota

Hydroxysafflor yellow A (HSYA), a chalcone glycoside, is a component of Carthamus tinctorius L. and exerts anti-inflammatory and antioxidative effects. However, the therapeutic effect and the underlying mechanism of HSYA on ulcerative colitis is unclear. This study aimed to investigate the unexplored protective effects and underlying mechanisms of HSYA on UC. In vitro analyses showed that HSYA reduced the secretion of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and IL-6 and inhibited nucleotide-binding and oligomerization domain-like receptor protein 3 (NLRP3)/gasdermin D (GSDMD)-mediated pyroptosis in lipopolysaccharide/ adenosine-5'-triphosphate (LPS/ATP)-stimulated macrophages. Gas chromatography-mass spectrometry (GC-MS) profiling of intracellular metabolites showed that HSYA reduced the increased levels of glucose, glucose 6-phosphate, and lactic acid, and inhibited the increased hexokinase 1 (HK1) expression caused by LPS/ATP stimulation. HK1 shRNA transfection further confirmed that HSYA inhibited the NLRP3/GSDMD-mediated pyroptosis via HK1 downregulation. In vivo analyses showed that HSYA drastically attenuated UC symptoms by relieving body weight loss, a decline in colon length, and inflammatory infiltration in colonic tissues induced by dextran sulfate sodium (DSS). HSYA also reduced the secretion of pro-inflammatory cytokines including IL-1β, IL-6, TNF-α, and IL-18. Moreover, HSYA inhibited HK1/NLRP3/GSDMD-mediated pyroptosis in DSS-induced colitis mice. Finally, 16S rRNA sequencing analyses of gut microbiota revealed that HSYA reversed gut microbiota dysbiosis by reducing the abundance of Proteobacteria and increasing that of Bacteroidetes. This study demonstrated that HSYA not only exerted anti-inflammatory effects by inhibiting HK1/NLRP3/GSDMD and suppressing pyroptosis but also regulated gut microbiota in mice with DSS-induced colitis. Our findings provide new experimental evidence that HSYA might be a potential candidate for treating inflammatory bowel diseases.

Therapeutic interventions target the NLRP3 inflammasome in ulcerative colitis: Comprehensive study

One of the significant health issues in the world is the prevalence of ulcerative colitis (UC). UC is a chronic disorder that mainly affects the colon, beginning with the rectum, and can progress from asymptomatic mild inflammation to extensive inflammation of the entire colon. Understanding the underlying molecular mechanisms of UC pathogenesis emphasizes the need for innovative therapeutic approaches based on identifying molecular targets. Interestingly, in response to cellular injury, the NLR family pyrin domain containing 3 (NLRP3) inflammasome is a crucial part of the inflammation and immunological reaction by promoting caspase-1 activation and the release of interleukin-1β. This review discusses the mechanisms of NLRP3 inflammasome activation by various signals and its regulation and impact on UC.

Ginsenoside Rg3 Ameliorates DSS-Induced Colitis by Inhibiting NLRP3 Inflammasome Activation and Regulating Microbial Homeostasis

Ulcerative colitis (UC) is a recurrent inflammatory disease without a specific cure or treatment for improvement. Here, we investigated the potential therapeutic effect and mechanism of ginsenoside Rg3 (Gin Rg3) on UC. We constructed an in vitro cellular inflammatory model and a dextran sulfate sodium (DSS)-induced UC mouse model. We also used Gin Rg3, MCC950 (NLRP3 inhibitor), MSU (NLRP3 activator), and fecal transplantation (FMT) to intervene the model. The results showed that Gin Rg3 inhibited NLRP3 inflammasome activation, pyroptosis, and apoptosis in vitro and in vivo. DSS-induced changes in the abundance of gut microbiota at the phylum or genus level were partially restored by Gin Rg3. Furthermore, gin Rg3 affected intestinal metabolism in mice by inhibiting the activation of NLRP3 inflammasome. The gut microbiota treated with Gin Rg3 was sufficient to alleviate DSS-induced UC. In summary, Gin Rg3 alleviated DSS-induced UC by inhibiting NLRP3 inflammasome activation and regulating gut microbiota homeostasis.

Cinnamaldehyde Ameliorates Dextran Sulfate Sodium-Induced Colitis in Mice by Modulating TLR4/NF-κB Signaling Pathway and NLRP3 Inflammasome Activation

Ulcerative colitis (UC) is a chronic inflammatory gastrointestinal disease mainly associated with immune dysfunction and microbiota disturbance. Cinnamaldehyde (CIN) is an active ingredient of Cinnamomum cassia with immunomodulatory and anti-inflammatory properties. However, the therapeutic effect and detailed mechanism of CIN on UC remains unclear, and warrant further dissection. In this study, network pharmacology and molecular docking analyses were introduced to predict the potential targets and mechanism of CIN against UC. The therapeutic effect and the predicted targets of CIN on UC were further validated by in vivo and in vitro experiments. Seven intersection targets shared by CIN and UC were obtained, and four hub targets, i. e., toll-like receptor 4 (TLR4), transcription factor p65 (NF-κB), NF-kappa-B inhibitor alpha (IκBα), prostaglandin G/H synthase 2 (COX2) were acquired, which were mainly involved in NF-κB, tumor necrosis factor (TNF), Toll-like receptor and NOD-like receptor signaling pathways. CIN alleviated the symptoms of dextran sulfate sodium (DSS)-induced colitis by decreasing the disease active index (DAI), restoring colon length, and relieving colonic pathology. CIN attenuated systemic inflammation by reducing serum myeloperoxidase (MPO), TNF-α, interleukin-6 (IL-6), and interleukin-1β (IL-1β), down-regulating TLR4, phosphorylated-NF-κB (p-NF-κB), phosphorylated-IκBα (p-IκBα), and COX2 expression in colonic tissues, and decreasing NOD-like receptor protein 3 (NLRP3), Caspase-1, and IL-1β protein expression in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. These results indicate that CIN alleviates DSS-induced colitis inflammation by modulating TLR4/NF-κB signaling pathway and NLRP3 inflammasome activation.

FUT2-dependent fucosylation of HYOU1 protects intestinal stem cells against inflammatory injury by regulating unfolded protein response

The intestinal epithelial repair after injury is coordinated by intestinal stem cells (ISCs). Fucosylation catalyzed by fucosyltransferase 2 (FUT2) of the intestinal epithelium is beneficial to mucosal healing but poorly defined is the influence on ISCs. The dextran sulfate sodium (DSS) and lipopolysaccharide (LPS) model were used to assess the role of FUT2 on ISCs after injury. The apoptosis, function, and stemness of ISCs were analyzed using intestinal organoids from WT and Fut2^ΔISC (ISC-specific Fut2 knockout) mice incubated with LPS and fucose. N-glycoproteomics, UEA-1 chromatography, and site-directed mutagenesis were monitored to dissect the regulatory mechanism, identify the target fucosylated protein and the corresponding modification site. Fucose could alleviate intestinal epithelial damage via upregulating FUT2 and α-1,2-fucosylation of ISCs. Oxidative stress, mitochondrial dysfunction, and cell apoptosis were impeded by fucose. Meanwhile, fucose sustained the growth and proliferation capacity of intestinal organoids treated with LPS. Contrarily, FUT2 depletion in ISCs aggravated the epithelial damage and disrupted the growth and proliferation capacity of ISCs via escalating LPS-induced endoplasmic reticulum (ER) stress and initiating the IRE1/TRAF2/ASK1/JNK branch of unfolded protein response (UPR). Fucosylation of the chaperone protein HYOU1 at the N-glycosylation site of asparagine (Asn) 862 mediated by FUT2 was identified to facilitate ISCs survival and self-renewal, and improve ISCs resistance to ER stress and inflammatory injury. Our study highlights a fucosylation-dependent protective mechanism of ISCs against inflammation, which may provide a fascinating strategy for treating intestinal injury disorders.

Surfactin Mitigates Dextran Sodium Sulfate-Induced Colitis and Behavioral Disorders in Mice by Mediating Gut-Brain-Axis Balance

Ulcerative colitis (UC) is associated with brain neurotransmitter disorders and intestinal dysbiosis. Bacillus amyloliquefaciens fmb50 produces the lipopeptide surfactin, which has a wide range of biological activities. However, the effects of surfactin on DSS-induced colitis have not been reported. In the present study, oral surfactin significantly ameliorated colitis in a mouse model and reduced depression-like behavior, such as slowed walking speed, shortened movement distance in the open field test, and weakened exploration ability in the light-dark shuttle test. Surfactin noticeably improved gut microbial dysbiosis, intestinal barrier dysfunction in the colon, and blood-brain barrier dysfunction in the brain. Furthermore, the colon levels of occludin were upregulated by 68.51%, and the brain levels of occludin and ZO-1 were upregulated by 77.81% and 36.42%, respectively. Surfactin supplementation also inhibited inflammatory responses by inactivating the tumor necrosis factor-α (TNF-α), nuclear factor kappa-B (NF-κB), and NLRP3 signaling pathways in the colon and brain. Thus, we believe that surfactin improved the behavioral disorders by upregulating the levels of 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), norepinephrine (NE), and brain-derived neurotrophic factor (BDNF), suppressing the inflammatory responses, and improving the blood-brain barrier dysfunction. Surfactin also reduced the abundances of gut microbes that are related to colitis, especially targeting facultative anaerobes of the phylum Proteobacteria, and it increased the abundance of beneficial bacteria such as Lactobacillus and unidentified Prevotella. Combined with its nontoxic nature observed in this long-term study in mice, oral surfactin might be a promising intervention strategy for preventing colitis by acting on the microbiota-gut-brain axis.

Brucea javanica oil alleviates intestinal mucosal injury induced by chemotherapeutic agent 5-fluorouracil in mice

Background: Brucea javanica (L.) Merr, has a long history to be an anti-dysentery medicine for thousand of years, which is commonly called "Ya-Dan-Zi" in Chinese. The common liquid preparation of its seed, B. javanica oil (BJO) exerts anti-inflammatory action in gastrointestinal diseases and is popularly used as an antitumor adjuvant in Asia. However, there is no report that BJO has the potential to treat 5-Fluorouracil (5-FU)-induced chemotherapeutic intestinal mucosal injury (CIM). Aim of the study: To test the hypothesis that BJO has potential intestinal protection on intestinal mucosal injury caused by 5-FU in mice and to explore the mechanisms. Materials and methods: Kunming mice (half male and female), were randomly divided into six groups: normal group, 5-FU group (5-FU, 60 mg/kg), LO group (loperamide, 4.0 mg/kg), BJO group (0.125, 0.25, 0.50 g/kg). CIM was induced by intraperitoneal injection of 5-FU at a dose of 60 mg/kg/day for 5 days (from day 1 to day 5). BJO and LO were given orally 30 min prior to 5-FU administration for 7 days (from day 1 to day 7). The ameliorative effects of BJO were assessed by body weight, diarrhea assessment, and H&E staining of the intestine. Furthermore, the changes in oxidative stress level, inflammatory level, intestinal epithelial cell apoptosis, and proliferation, as well as the amount of intestinal tight junction proteins were evaluated. Finally, the involvements of the Nrf2/HO-1 pathway were tested by western blot. Results: BJO effectively alleviated 5-FU-induced CIM, as represented by the improvement of body weight, diarrhea syndrome, and histopathological changes in the ileum. BJO not only attenuated oxidative stress by upregulating SOD and downregulating MDA in the serum, but also reduced the intestinal level of COX-2 and inflammatory cytokines, and repressed CXCL1/2 and NLRP3 inflammasome activation. Moreover, BJO ameliorated 5-FU-induced epithelial apoptosis as evidenced by the downregulation of Bax and caspase-3 and the upregulation of Bcl-2, but enhanced mucosal epithelial cell proliferation as implied by the increase of crypt-localized proliferating cell nuclear antigen (PCNA) level. Furthermore, BJO contributed to the mucosal barrier by raising the level of tight junction proteins (ZO-1, occludin, and claudin-1). Mechanistically, these anti-intestinal mucositis pharmacological effects of BJO were relevant for the activation of Nrf2/HO-1 in the intestinal tissues. Conclusion: The present study provides new insights into the protective effects of BJO against CIM and suggests that BJO deserves to be applied as a potential therapeutic agent for the prevention of CIM.

Cayratia japonica Prevents Ulcerative Colitis by Promoting M2 Macrophage Polarization through Blocking the TLR4/MAPK/NF-κB Pathway

Background and Aims

Several components of Cayratia japonica (CJ) such as rutin and quercetin have shown anti-inflammatory effect, yet its function in ulcerative colitis (UC) remains to be clarified. This study focuses on the modulatory effect of CJ on UC as well as molecular mechanism by which CJ regulates macrophage polarization in UC.

Methods

The targets related to CJ components and UC were, respectively, obtained through in silico analysis, and their intersection targets were selected for pathway enrichment analysis. RAW264.7 cells were stimulated with lipopolysaccharide (LPS) to induce M1 macrophages. Expression of the macrophage polarization M1 marker CD11b and M2 marker CD206 was measured to determine the phenotype of macrophages. The mouse model was treated with dextran sodium sulfate (DSS) to induce UC to observe the effects of CJ on UC in vivo.

Results

The in silico analysis suggested the crucial significance of TLR4 and its downstream MAPK/NF-κB pathways in the modulatory effect of CJ on UC. Furthermore, experimental data revealed that CJ could promote M2 macrophage polarization but alleviate immune inflammation and reduce colon damage in DSS-evoked UC model. Additionally, CJ can inhibit the expression of TLR4/MAPK/NF-κB signaling pathway to enhance the M2-like polarization.

Conclusion

Hence, CJ may exert anti-inflammatory effects and an inhibitory role in UC by inhibiting the TLR4/MAPK/NF-κB pathway and subsequent M1-like macrophage polarization.

L-fucose reduces gut inflammation due to T-regulatory response in Muc2 null mice

Fucose, the terminal glycan of the intestinal glycoprotein Mucin2, was shown to have an anti-inflammatory effect in mouse colitis models and modulate immune response due to macrophage polarization changes. In this study we evaluated the effect of 0.05% L-fucose supplementation of drinking water on immune parameters in the intestine of homozygous mutant Muc2-/-, compared to Muc2+/+ mice. To get into innate and adaptive immunity mechanisms of gut inflammation, we tested PrkdcSCIDMuc2-/- strain, Muc2 knockout on SCID background, that is characterized by lack of lymphocytes, in comparison with PrkdcSCID mice. We evaluated intestinal cytokine profiling, macrophage and eosinophil infiltration, and expression of Nos2 and Arg1 markers of macrophage activation in all strains. Markers of Th1, Treg and Th17 cells (Tbx21, Foxp3, and Rorc expression) were evaluated in Muc2-/- and Muc2+/+ mice. Both Muc2-/- and PrkdcSCIDMuc2-/- mice demonstrated increased numbers of macrophages, eosinophils, elevated levels of TNFa, GM-CSF, and IL-10 cytokines. In Muc2-/- mice we observed a wide range of pro-inflammatory cytokines elevated, such as IFN-gamma, IL-1b, IL-12p70, IL-6, M-CSF, G-CSF, IL-17, MCP-1, RANTES, MIP1b, MIP2. Muc2-/- mice demonstrated increase of Nos2, Tbx21 and Foxp3 genes mRNA, while in PrkdcSCIDMuc2-/- mice Arg1 expression was increased. We found that in Muc2-/- mice L-fucose reduced macrophage infiltration and IL-1a, TNFa, IFNgamma, IL-6, MCP-1, RANTES, MIP1b levels, decreased Nos2 expression, and induced the expression of Treg marker Foxp3 gene. On the contrary, in PrkdcSCIDMuc2-/- mice L-fucose had no effect on macrophage and eosinophil numbers, but increased TNFa, GM-CSF, IL-12p70, IL-6, IL-15, IL-10, MCP1, G-CSF, IL-3 levels and Nos2 gene expression, and decreased Arg1 gene expression. We demonstrated that anti-inflammatory effect of L-fucose observed in Muc2-/- mice is not reproduced in PrkdcSCIDMuc2-/-, which lack lymphocytes. We conclude that activation of Treg cells is a key event that leads to resolution of inflammation upon L-fucose supplementation in Muc2-/- mice.

The prognostic value of NLRP1/NLRP3 and its relationship with immune infiltration in human gastric cancer

BACKGROUND

Inflammasomes are related to tumorigenesis and immune-regulation. Here, we investigated the prognostic value of the NLR family pyrin domain containing (NLRP) 1/NLRP3 inflammasome and its potential mechanisms in immune-regulation in gastric cancer (GC).

METHODS

We analyzed the differential expression of NLRP1/NLRP3 between tumor and normal tissues using the Oncomine and Tumor Immune Estimate Resource (TIMER) databases. Immunohistochemistry and western blotting were used to detect NLRP1/NLRP3 protein expression in GC tissues. Correlations between NLRP1/NLRP3 expression levels and patient survival were analyzed using Kaplan-Meier survival curves. The relationships of NLRP1/NLRP3 expression and tumor-infiltrating immune cells/marker genes were assessed using the TIMER database. NLRP1/NLRP3 and immune checkpoint gene correlations were verified by single-gene co-expression analyses, and tumor immune-related pathways involving NLRP1/NLRP3 were analyzed using gene set enrichment analysis (GSEA).

RESULTS

Elevated NLRP1/NLRP3 expression was significantly correlated with lymph node metastasis, poor survival, immune-infiltrating cell abundances, and immune cell markers. NLRP3 showed stronger correlations with immune infiltration and the prognosis of gastric cancer. NLRP1 and NLRP3 might be involved in the same tumor immune-related pathways. Thus, high NLRP1/NLRP3 expression promotes immune cell infiltration and poor prognosis in GC. NLRP1/NLRP3, particularly NLRP3, may have important roles in immune infiltration and may serve as a prognostic biomarker for GC.

CONCLUSIONS

NLRP1/NLRP3, particularly NLRP3, may have important roles in immune infiltration and may serve as a prognostic biomarker for GC.

Sulforaphane alleviates LPS-induced inflammatory injury in ARPE-19 cells by repressing the PWRN2/NF-kB pathway

BACKGROUND

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly population and its pathogenesis has been associated with inflammatory damage to retinal pigment epithelial (RPE) cells. Here, we explored the ability of sulforaphane to protect ARPE-19 cells from lipopolysaccharide (LPS)-induced inflammatory injury and elucidated the underlying molecular mechanism.

METHODS

Cell viability, apoptosis, inflammation, PWRN2 expression, nuclear transcription factor-kappa B (NF-kB) activity, and the interaction between PWRN2 and the IkBa protein were assessed in RPE cells under- or over-expressing PWRN2 that had been treated with LPS and sulforaphane.

RESULTS

Overexpression of PWRN2 in LPS-treated cells promoted NF-kB activation by interacting with IkBa, thus reducing cell viability. In contrast, PWRN2 downregulation repressed LPS-induced NF-kB activation and apoptosis in RPE cells. Similarly, sulforaphane downregulated PWRN2 and inhibited NF-kB activation in a concentration-dependent manner. Conversely, PWRN2 overexpression or NF-kB upregulation weakened the anti-inflammatory effects of sulforaphane.

CONCLUSION

Our results suggest that sulforaphane protects RPE cells from LPS-induced inflammatory injury by suppressing the PWRN2/NF-kB pathway.

Structural Characterization and In Vivo Anti-Inflammatory Activity of Fucoidan from Cystoseira crinita (Desf.) Borry

The aim of this study was to evaluate the effects of fucoidan isolated from C. crinita on histamine-induced paw inflammation in rats, and on the serum levels of TNF-α, IL-1β, IL-6, and IL-10 in rats during systemic inflammation response. The levels of TNF-α in a model of acute peritonitis in rats were also investigated. The isolated crude fucoidan was identified as a sulfated xylogalactofucan with high, medium, and low molecular weight fractions and a content of fucose of 39.74%, xylose of 20.75%, and galactose of 15.51%. Fucoidan from C. crinita showed better anti-inflammatory effects in the rat paw edema model, and this effect was present during all stages of the experiment. When compared to controls, a commercial fucoidan from F. vesiculosus, the results also displayed anti-inflammatory activity on the 60th, 90th, and 120th minute of the experiment. A significant decrease in serum levels of IL-1β in rats treated with both doses of C. crinita fucoidan was observed in comparison to controls, whereas TNF-α concentrations were reduced only in the group treated with fucoidan from C. crinita at the dose of 25 mg/kg bw. In the model of carrageenan-induced peritonitis, we observed a tendency of decrease in the levels of the pro-inflammatory cytokine TNF-α in peritoneal fluid after a single dose of C. crinita fucoidan, but this did not reach the statistical significance margin. Single doses of C. crinita fucoidan did not alter serum levels of the anti-inflammatory cytokine IL-10 in animals with lipopolysaccharide-induced systemic inflammation.

Promoting Effect of L-Fucose on the Regeneration of Intestinal Stem Cells through AHR/IL-22 Pathway of Intestinal Lamina Propria Monocytes

The recovery of the intestinal epithelial barrier is the goal for curing various intestinal injurious diseases, especially IBD. However, there are limited therapeutics for restoring intestinal epithelial barrier function in IBD. The stemness of intestinal stem cells (ISCs) can differentiate into various mature intestinal epithelial cells, thus playing a key role in the rapid regeneration of the intestinal epithelium. IL-22 secreted by CD4⁺ T cells and ILC3 cells was reported to maintain the stemness of ISCs. Our previous study found that L-fucose significantly ameliorated DSS-induced colonic inflammation and intestinal epithelial injury. In this study, we discovered enhanced ISC regeneration and increased intestinal IL-22 secretion and its related transcription factor AHR in colitis mice after L-fucose treatment. Further studies showed that L-fucose promoted IL-22 release from CD4⁺ T cells and intestinal lamina propria monocytes (LPMCs) via activation of nuclear AHR. The coculture system of LPMCs and intestinal organoids demonstrated that L-fucose stimulated the proliferation of ISCs through an indirect manner of IL-22 from LPMCs via the IL-22R-p-STAT3 pathway, and restored TNF-α-induced organoid damage via IL-22-IL-22R signaling. These results revealed that L-fucose helped to heal the epithelial barrier by accelerating ISC proliferation, probably through the AHR/IL-22 pathway of LPMCs, which provides a novel therapy for IBD in the clinic.

NLRP3 inflammasome in digestive diseases: From mechanism to therapy

Digestive system diseases remain a formidable challenge to human health. NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is the most characteristic multimeric protein complex and is involved in a wide range of digestive diseases as intracellular innate immune sensors. It has emerged as a research hotspot in recent years. In this context, we provide a comprehensive review of NLRP3 inflammasome priming and activation in the pathogenesis of digestive diseases, including clinical and preclinical studies. Moreover, the scientific evidence of small-molecule chemical drugs, biologics, and phytochemicals, which acts on different steps of the NLRP3 inflammasome, is reviewed. Above all, deep interrogation of the NLRP3 inflammasome is a better insight of the pathomechanism of digestive diseases. We believe that the NLRP3 inflammasome will hold promise as a novel valuable target and research direction for treating digestive disorders.

Evolving Experimental Platforms to Evaluate Ulcerative Colitis

Ulcerative colitis (UC) is a multifactorial disease defined by chronic intestinal inflammation with idiopathic origins. It has a predilection to affect the mucosal lining of the large intestines and rectum. Management of UC depends upon numerous factors that include disease pathogenesis and severity that are maintained via medical or surgical means. Chronic inflammation that is left untreated or managed poorly from a clinical stance can result in intestinal ulceration accompanied by resulting physiological dysfunction. End-stage UC is mediated by surgical intervention with the resection of diseased tissue. This can lead to numerous health-related quality of life issues but is considered a curative approach. Regimens to treat UC are ever evolving and find their basis within various platforms to evaluate and treat UC. Numerous modeling systems have been examined to delineate potential mechanisms of action. However, UC is a heterogenous disease spanning unknown genetic origins coupled with environmental factors that can influence disease outcomes and related treatment procedures. Unfortunately, there is no one-size-fits-all model to fully assess all facets of UC. Within the context of this review article, the utility of various approaches that have been employed to gain insight into different aspects of UC will be investigated.

Homoharringtonine Attenuates Dextran Sulfate Sodium-Induced Colitis by Inhibiting NF-κB Signaling

Homoharringtonine (HHT) exhibits an anti-inflammatory activity. The potential protective effects and mechanisms of HHT on dextran sulfate sodium- (DSS-) induced colitis were investigated. DSS-induced colitis mice were intraperitoneally injected with HHT. Body weight, colon length, disease activity index (DAI), and histopathological change were examined. The relative contents of interleukin- (IL-) 1β, tumor necrosis factor- (TNF-) α, IL-6, and the chemokine (C-C motif) ligand 2 (CCL2) in the colon tissues and HHT-treated RAW264.7 cells were detected with the enzyme-linked immunosorbent assay. In the meantime, the levels of p-p65 and p-IκBα were detected by Western blot. The proportion of macrophages (CD11b+F4/80+) in the colon tissues was detected by flow cytometry. HHT alleviated DSS-induced colitis with downregulated TNF-α, IL-1β, IL-6, and CCL2 expression; reduced activation of nuclear factor-kappa B (NF-κB) signaling; and diminished proportion of recruited macrophages in colon tissues. It was further testified that HHT inhibited lipopolysaccharide-induced macrophage activation with reduced activation of NF-κB signaling. In addition, HHT inhibited the M1 polarization of both human and mouse macrophages, while HHT did not affect the differentiation of human CD4 T cells into Th17, Th1, or Treg cells and did not affect the proliferation and migration of human colon epithelial cells. In summary, HHT attenuates DSS-induced colitis by inhibiting macrophage-associated NF-κB activation and M1 polarization, which could be an option for the treatment of ulcerative colitis.

5-Aminosalicylic acid ameliorates dextran sulfate sodium-induced colitis in mice by modulating gut microbiota and bile acid metabolism

Colitis develops via the convergence of environmental, microbial, immunological, and genetic factors. The medicine 5-aminosalicylic acid (5-ASA) is widely used in clinical practice for colitis (especially ulcerative colitis) treatment. However, the significance of gut microbiota in the protective effect of 5-ASA on colitis has not been explored. Using a dextran sulfate sodium (DSS)-induced colitis mouse model, we found that 5-ASA ameliorated colitis symptoms in DSS-treated mice, accompanied by increased body weight gain and colon length, and a decrease in disease activity index (DAI) score and spleen index. Also, 5-ASA alleviated DSS-induced damage to colonic tissues, as indicated by suppressed inflammation and decreased tight junction, mucin, and water-sodium transport protein levels. Moreover, the 16S rDNA gene sequencing results illustrated that 5-ASA reshaped the disordered gut microbiota community structure in DSS-treated mice by promoting the abundance of Bifidobacterium, Lachnoclostridium, and Anaerotruncus, and reducing the content of Alloprevotella and Desulfovibrio. Furthermore, 5-ASA improved the abnormal metabolism of bile acids (BAs) by regulating the Farnesoid X receptor (FXR) and Takeda G-protein-coupled receptor 5 (TGR5) signaling pathways in DSS-treated mice. In contrast, 5-ASA did not prevent the occurrence of colitis in mice with gut microbiota depletion, confirming the essential role of gut microbiota in colitis treatment by 5-ASA. In conclusion, 5-ASA can ameliorate DSS-induced colitis in mice by modulating gut microbiota and bile acid metabolism. These findings documented the new therapeutic mechanisms of 5-ASA in clinical colitis treatment.

Andrographolide sodium bisulfite ameliorates dextran sulfate sodium-induced colitis and liver injury in mice via inhibiting macrophage proinflammatory polarization from the gut-liver axis

Ulcerative colitis (UC), an inflammatory disease, is widely thought to be associated with colonic barrier damage and inflammatory response. With the destruction of the colonic barrier, lipopolysaccharide (LPS) enters the liver through the portal vein and causes liver injury. Liver injury in turn exacerbates UC to form a vicious cycle, so the treatment of liver injury cannot be ignored. Andrographolide (Andro) has a protective effect against colitis and liver injury, but with low bioavailability. Andrographolide sodium bisulfite (ASB), a water-soluble sulfonate of Andro, has better bioavailability, whether it has a better curative effect against UC and liver injury is rarely reported. Hence, we investigated the protective effect and potential mechanism of ASB against dextran sulfate sodium (DSS)-induced UC and liver injury in mice. The results showed that treatment with ASB significantly relieved the clinical symptoms of UC and liver injury by reducing disease activity index, inhibiting gut-derived LPS leakage, and improving colonic and hepatic injury, and its curative effect was better than Andro. Moreover, ASB effectively decreased the YAP-mediated colonic inflammation and TLR4/MyD88/NF-κB-mediated pro-inflammatory factor release in the liver. Both colonic and hepatic inflammation were associated with macrophage proinflammatory polarization, but they were significantly inhibited by ASB. ASB showed good safety in the treatment of UC and liver injury and has no nephrotoxicity as previously described. In conclusion, ASB has an effective protective effect on DSS-induced UC and liver injury, mainly by suppressing macrophage proinflammatory polarization from the gut-liver axis.

Protective effects of (R)-enantiomers but not (S)-enantiomers of β2-adrenergic receptor agonists against acute colitis: The role of β2AR

The outcomes of ulcerative colitis (UC) treatment remain unsatisfactory. Salbutamol is a β2-adrenergic receptor (β2AR) agonist that is frequently used to treat human airway diseases, and it is a chiral drug with (RS)-isomers. However, the effects of (RS)-enantiomers of this drug on acute ulcerative colitis remain unknown. The present work determined and compared the effects of different chiral β2AR agonists in acute colitis. Acute colitis was established in mice with 3% dextran sulfate sodium and the mice were orally administered different salbutamol isomers. Body weight loss, colon length, disease activity index (DAI), and colon histopathology were assessed. Inflammatory cytokine levels were detected by ELISA. Colonic biopsies were collected from colitis patients. 16S rDNA amplicon sequencing was carried out to assess the composition and relative abundance of the gut microbiome. The expression of M1 and M2 macrophage markers in the colon were assessed by immunofluorescence staining and Western blotting. The results revealed that (R)-salbutamol prevented body weight loss and colonic shortening, decreased the DAI and histopathological scores, and reduced splenomegaly and inflammatory cytokine levels significantly better than (RS)-salbutamol and (S)-salbutamol. (R)-salbutamol downregulated levels of inflammatory protein in LPS-induced human colon tissue specimens. Furthermore, (R)-salbutamol ameliorated gut dysbiosis and macrophage polarization in mice with colitis. The β2AR antagonist ICI-118551 reversed the effect of (R)-salbutamol in ameliorating acute colitis. Taken together, (R)-salbutamol ameliorated the mice with acute colitis, which can serve as a new candidate or lead compound for UC treatment.

Serum untargeted metabolomics analysis of the mechanisms of evodiamine on type 2 diabetes mellitus model rats

Evodiamine (EVO) is an alkaloid extracted from Evodia rutaecarpa and has various pharmacological activities, including hypolipidemic, anti-inflammatory, anti-infective, and antitumor effects. However, the therapeutic effects of EVO on type 2 diabetes mellitus (T2DM) and the possible mechanisms remain unknown. In this study, we used a T2DM rat model using a high-fat diet (HFD) combined with streptozotocin (STZ) injections followed by treatment with EVO. First, we evaluated the therapeutic effects of EVO on T2DM rats, following which we evaluated the anti-inflammatory and anti-oxidative effects of EVO on T2DM rats. Finally, we analyzed the metabolic regulatory mechanism of EVO in T2DM rats using an untargeted metabolomics approach. The results showed that EVO treatment alleviated the hyperglycemia, hyperlipidemia, insulin resistance (IR), and pathological changes of the liver, pancreas and kidneys in T2DM rats. Moreover, EVO treatment ameliorated the oxidative stress and decreased the serum levels of pro-inflammatory cytokines in T2DM model rats. Serum untargeted metabolomics analysis indicated that the EVO treatment affected the levels of 26 metabolites, such as methionine, citric acid, cholesterol, taurocholic acid, pilocarpine, adrenic acid, and other metabolites. These metabolites were mainly related to the amino sugar and nucleotide sugar metabolism, arginine biosynthesis, arginine and proline metabolism, glutathione metabolism, and tryptophan metabolism pathways. In conclusion, EVO can reduce blood glucose and improve oxidative stress and inflammatory response in T2DM rats. These functions are related to the regulation of amino sugar and nucleotide sugar metabolism, arginine biosynthesis, arginine and proline metabolism, glutathione metabolism, and tryptophan metabolism pathways.

HucMSC-Ex carrying miR-203a-3p.2 ameliorates colitis through the suppression of caspase11/4-induced macrophage pyroptosis

BACKGROUND

Inflammatory bowel disease (IBD) is a kind of chronic, idiopathic, and recurrent inflammation, associated with dysregulated intestinal mucosal immunity. Caspase (casp) 11/4-induced macrophage pyroptosis contributes to the development of inflammation, while human umbilical cord mesenchymal stem cell-secreted exosomes (hucMSC-Ex) play a reparative role in IBD.

OBJECTIVE

The present study focused on the treatment of IBD with hucMSC-Ex and its regulatory mechanism via the casp11/4 pathway.

METHODS

BALB/c mice were used to establish a dextran sulfate sodium (DSS)-induced colitis model, and hucMSC-Ex was administered intravenously to estimate its therapeutic effect. In vitro, RAW264.7 cells line, THP-1 cells line, and mouse peritoneal macrophages (MPMs) were stimulated with lipopolysaccharides (LPS) to activate an inflammatory environment of pyroptosis, followed by repairing with hucMSC-Ex. MicroRNA mimics and inhibitors were provided to verify the role of miR-203a-3p.2 from hucMSC-Ex in inflammation. The results were analyzed by Western blot, RT-qPCR、ELISA, and LDH secretion.

RESULTS

HucMSC-Ex inhibited the activation of casp11 and reduced the secretion of interleukin (IL)-1β, IL-6, and casp11, which relieved macrophage pyroptosis to alleviate murine colitis. A consistent outcome was revealed in the cell experiments, where hucMSC-Ex contributed to a decreased casp11/4 expression, and lactate dehydrogenase (LDH) release, as a marker of cell damage. Moreover, miR-203a-3p.2 from hucMSC-Ex functioned as an effective mediator in the interaction with casp4 in THP-1 macrophage pyroptosis.

CONCLUSION

HucMSC-Ex ameliorates colitis through the suppression of casp11/4-induced macrophage pyroptosis, and hucMSC-Ex carrying miR-203a-3p.2 inhibits casp4-induced macrophage pyroptosis in an inflammatory environment.

Trans-10-Hydroxy-2-Decenoic Acid Alleviates Dextran Sulfate Sodium-Induced Colitis in Mice via Regulating the Inflammasome-Mediated Pyroptotic Pathway and Enhancing Colonic Barrier Function

SCOPE

The objective of this study is to explore the effects of 10-hydroxy-2-decenoic acid (10-HDA), the major fatty acid in royal jelly, on dextran sodium sulfate (DSS)-induced mice ulcerative colitis (UC) and its potential mechanism of action.

METHODS AND RESULTS

Forty male C57BL/6 mice are randomly divided into five experimental groups: control, DSS, DSS + 25 (or 100)mg kg^-1  d^-1 10-HDA, and DSS + 200 mg kg^-1  d^-1 mesalazine (ME). UC is induced in mice using 2.5% DSS in drinking water for 7 days. During the induction, these UC mice are orally administrated 10-HDA or ME per day. Meanwhile, lipopolysaccharide (LPS)/adenosine-triphosphate (ATP)-stimulated THP1 cells are used as a model to test the effects of 10-HDA. 10-HDA reduces DSS-induced pathological damage, reactive oxygen species (ROS) accumulation, neutrophil infiltration, and cytokine production in colonic tissue. Compared with the DSS group, the expressions of thioredoxin interacting protein (TXNIP), NOD-like receptor family pyrin domain containing 3 (NLRP3), apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC), cysteinyl aspartate specific proteinase-1 (Caspase-1), gasdermin-D (GSDMD), N-terminal domain of gasdermin-D (N-GSDMD), interleukin-1β (IL-1β), and interleukin-18 (IL-18) in the colon are decreased after administration of 10-HDA. 10-HDA also elevates the barrier integrity and the expressions of zonula occludens-1 (ZO-1) and Occludin in colonic epithelium exposed to DSS. In THP1 cells, the inflammasome-mediated pyroptosis induced by LPS/ATP is inhibited by 10-HDA pretreatment.

CONCLUSION

10-HDA alleviates DSS-induced colitis by regulating the NLRP3 inflammasome-mediated pyroptotic pathway and enhancing colonic barrier function.

Dioscin ameliorates inflammatory bowel disease by up-regulating miR-125a-5p to regulate macrophage polarization

PURPOSE

Dioscin has been proven to have anti-cancer, anti-inflammatory, and anti-infection roles. However, the role of Dioscin in inflammatory bowel disease (IBD) and its related mechanisms is unclear and needs further study.

METHODS

The colitis model in mice was established. After Dioscin (20, 40, or 80 mg/kg) treatment, the colon length was measured by a ruler. Histopathology, inflammatory cytokines, gut permeability, tight junction proteins, macrophage infiltration, macrophage polarization, and miR-125a-5p level were detected by hematoxylin-eosin staining, enzyme-linked immunosorbent assay, quantitative real-time polymerase chain reaction (qRT-PCR), FITC-dextran, Western blot, and flow cytometry. In vitro experiments, after RAW264.7 cells induced by lipopolysaccharide (LPS)/interleukin-4 (IL-4), were treated with Dioscin and miR-125a-5p inhibitor, miR-125a-5p level, cell vitality, inflammatory cytokines, and M1/M2 marker genes were measured by qRT-PCR and MTT assay.

RESULTS

Dioscin (20, 40, or 80 mg/kg) relieved DSS-triggered colitis and restrained the serum and colon of pro-inflammatory cytokines expression. Meanwhile, different concentrations' Dioscin weakened M1 macrophage polarization but facilitated tight junction protein expressions, M2 macrophage polarization, and miR-125a-5p level in colitic mice. Moreover, miR-125a-5p inhibitor reversed the modulation of Dioscin on miR-125a-5p expression, cell vitality, and inflammatory cytokines in lipopolysaccharide (LPS)-induced RAW264.7 cells. We further discovered that Dioscin restrained M1 marker gene (CD16) expression while intensifying M2 marker genes (CD206 and Arginase-1) expressions in vitro, which was reversed by miR-125a-5p inhibitor.

CONCLUSION

Dioscin modulated macrophage polarization by increasing miR-125a-5p, thereby improving the intestinal epithelial barrier function and reducing IBD.