Ulcerative Colitis

The mechanism of traditional medicine in alleviating ulcerative colitis: regulating intestinal barrier function

Ulcerative colitis (UC) is an idiopathic inflammatory disease mainly affects the large bowel and the rectum. The pathogenesis of this disease has not been fully elucidated, while the disruption of the intestinal barrier function triggered by various stimulating factors related to the host genetics, immunity, gut microbiota, and environment has been considered to be major mechanisms that affect the development of UC. Given the limited effective therapies, the treatment of this disease is not ideal and its incidence and prevalence are increasing. Therefore, developing new therapies with high efficiency and efficacy is important for treating UC. Many recent studies disclosed that numerous herbal decoctions and natural compounds derived from traditional herbal medicine showed promising therapeutic activities in animal models of colitis and have gained increasing attention from scientists in the study of UC. Some of these decoctions and compounds can effectively alleviate colonic inflammation and relieve clinical symptoms in animal models of colitis via regulating intestinal barrier function. While no study is available to review the underlying mechanisms of these potential therapies in regulating the integrity and function of the intestinal barrier. This review aims to summarize the effects of various herbal decoctions or bioactive compounds on the severity of colonic inflammation via various mechanisms, mainly including regulating the production of tight junction proteins, mucins, the composition of gut microbiota and microbial-associated metabolites, the infiltration of inflammatory cells and mediators, and the oxidative stress in the gut. On this basis, we discussed the related regulators and the affected signaling pathways of the mentioned traditional medicine in modulating the disruption or restoration of the intestinal barrier, such as NF-κB/MAPK, PI3K, and HIF-1α signaling pathways. In addition, the possible limitations of current studies and a prospect for future investigation and development of new UC therapies are provided based on our knowledge and current understanding. This review may improve our understanding of the current progression in studies of traditional medicine-derived therapies in protecting the intestinal barrier function and their roles in alleviating animal models of UC. It may be beneficial to the work of researchers in both basic and translational studies of UC.

Fluoxetine Ameliorates the Aggravation of UC Symptoms in C57BL/6 Mice Induced by CUMS

OBJECTIVE

Patients with chronic ulcerative colitis (UC) often have mental symptoms such as depression and anxiety, and stress can lead to gastrointestinal diseases. However, the correlation between mental stress and UC is unclear. In this paper, chronic unpredictable mild stress (CUMS) was utilized to evaluate the involvement of mental factors in the pathogenesis of UC.

METHODS

The CUMS model was used to evaluate the direct/indirect involvement of mental factors in the pathogenesis of UC. The behavior was evaluated by the open field, forced swimming, and tail suspension tests. Body weight, the disease activity index (DAI) score, colon length, and HE staining of colon tissue were used to evaluate the action of CUMS and fluoxetine.

RESULTS

The results showed that weight loss and the DAI score increased in CUMS mice, but they had no meaningful effect on colon length and morphological structure of colon tissue. However, CUMS aggravated dextran sulfate sodium (DSS)-induced colon length shortening and colon morphological structure damage. Fluoxetine significantly improved the DAI score, shortened colon length, and damaged morphology and structure of the colons induced by CUMS combined with DSS in mice. Fluoxetine also decreased the level of IL-6 in the serum and the TNF-α and IFN-γ levels of colon tissue. Fluoxetine simultaneously improved behavioral abnormalities induced by CUMS combined with DSS in mice.

CONCLUSION

CUMS aggravated the UC symptoms induced by DSS, and fluoxetine could improve the UC symptoms due to its improvement in the inflammatory level and behavioral abnormalities.

Oxysophocarpine suppresses TRAF6 level to ameliorate oxidative stress and inflammatory factors secretion in mice with dextran sulphate sodium (DSS) induced-ulcerative colitis

PURPOSE

Ulcerative colitis is an inflammation-related disease with a high recurrence risk. Oxysophocarpine (OSC) is a traditional Chinese medicine isolated from legumes and exerts vital functions on many human diseases. However, the OSC's role in ulcerative colitis has not been fully elucidated. This research aimed to investigate the OSC's impact on ulcerative colitis and its mechanisms.

METHODS

A mouse model of ulcerative colitis was induced by dextran sulphate sodium (DSS). The effect of OSC on ulcerative colitis was examined using Disease Activity Index detection, hematoxylin-eosin (HE) staining, and enzyme-linked immunosorbent assay (ELISA). Meanwhile, the mechanism of OSC in ulcerative colitis was assessed by immunohistochemistry assay, Western blot, HE staining, and ELISA.

RESULTS

For the OSC's function in ulcerative colitis, OSC increased the mice weight, decreased Disease Activity Index scores, and alleviated colitis cell infiltration and epithelial cell destruction in DSS-induced ulcerative colitis. Also, OSC mitigated oxidative stress (decreased PGE2, MPO levels, and increased SOD levels) and inflammation (decreased IL-6, TNF-α and IL-1β levels) in DSS-induced ulcerative colitis. For the OSC's mechanism in ulcerative colitis, OSC inhibited the level of tumor necrosis factor receptor-associated Factor 6 (TRAF6) and the phosphorylation of nuclear factor-κB (NF-κB). TRAF6 overexpression abolished the effect of OSC on DSS-induced colon injury and its associated oxidative stress and inflammatory properties in ulcerative colitis.

CONCLUSION

OSC decreased the TRAF6 level to reduce oxidative stress and inflammatory factors secretion in mice with DSS induced-ulcerative colitis.

1,8-cineole ameliorates colon injury by downregulating macrophage M1 polarization via inhibiting the HSP90-NLRP3-SGT1 complex

Ulcerative colitis (UC) is characterized by chronic relapsing intestinal inflammation. Currently, there is no effective treatment for the disease. According to our preliminary data, 1,8-cineole, which is the main active compound of Amomum compactum Sol. ex Maton volatile oil and an effective drug for the treatment of pneumonia, showed remarkable anti-inflammatory effects on colitis pathogenesis. However, its mechanism of action and direct targets remain unclear. This study investigated the direct targets and mechanism through which 1,8-cineole exerts its anti-inflammatory effects using a dextran sulfate sodium salt-induced colitis mouse model. The effects of 1,8-cineole on macrophage polarization were investigated using activated bone marrow-derived macrophages and RAW264.7 cells. In addition, 1,8-cineole targets were revealed by drug affinity responsive target stability, thermal shift assay, cellular thermal shift assay, and heat shock protein 90 (HSP90) adenosine triphosphatases (ATPase) activity assays. The results showed that 1,8-cineole exhibited powerful anti-inflammatory properties in vitro and in vivo by inhibiting the macrophage M1 polarization and protecting intestinal barrier function. Mechanistically, 1,8-cineole directly interacted with HSP90 and decreased its ATPase activity, also inhibited nucleotide-binding and oligomerization domain-, leucine rich repeat-, and pyrin domain-containing 3 (NLRP3) binding to HSP90 and suppressor of G-two allele of SKP1 (SGT1) and suppressed NLRP3 inflammasome activation in macrophages. These results demonstrated that 1,8-cineole is a potential drug candidate for UC treatment.

Identification of Lipocalin 2 as a Potential Ferroptosis-related Gene in Ulcerative Colitis

BACKGROUND

Ulcerative colitis (UC) is a chronic nonspecific inflammatory disease generally limited to the mucosa and submucosa of the colon. Recent studies suggest that ferroptosis is a novel programmed cell death that may be involved in the process of UC. However, the mechanism of ferroptosis in UC remains to be further investigated.

METHODS

The genes associated with UC and ferroptosis were screened by bioinformatics methods, and a random forest model was constructed to identify the core genes of UC and validated with external data sets. Establishment of dextran sodium sulfate (DSS) induced UC in an animal model in vivo. Interferon (IFN)-γ primed immortalized bone marrow-derived macrophages cells stimulated with Lipopolysaccharides (LPS) inflammation model and LPS-stimulated Caco-2 cells colitis model in vitro were constructed. The potential link between Lipocalin-2 (LCN2) and UC ferroptosis was explored by flow cytometry, Fe2+ assay, Western Blot, gene knockdown, hematoxylin and eosin staining, and immunohistochemistry staining.

RESULTS

Analysis of differentially expressed genes (DEGs) showed that LCN2 was highly expressed in UC. The protein-protein interaction (PPI) networks showed that ferroptosis-associated DEGs were highly correlated with the immune gene LCN2. The most important gene in the random forest model, LCN2, was identified as a core gene in UC. In the LPS/IFN-γ-induced inflammation model, LCN2 expression was elevated, lipid peroxidation, Fe2+, ACSL4 and COX-2 levels increased, whereas GPX4 and FTH1 expression decreased. Similarly, in the DSS-induced UC mouse model, Occludin, ZO-1, Claudin-1, and GPX4 expression were significantly decreased, but ACSL4 and LCN2 expression were elevated. In addition, the use of Ferrostatin-1 (Fer-1) can significantly reverse its trend. More importantly, silencing of LCN2 suppressed ferroptosis events in both the LPS/IFN-γ-induced inflammation model and the LPS-stimulated colitis model.

CONCLUSION

In conclusion, our study demonstrates that LCN2 is a key factor in the regulation of ferroptosis in UC and provides additional evidence for the important role of ferroptosis in UC.

The alleviating effect and mechanism of GLP-1 on ulcerative colitis

Ulcerative Colitis (UC) is a major type of chronic inflammatory bowel disease of the colonic mucosa and exhibits progressive morbidity. The incidence and prevalence of UC is increasing worldwide. The global burden of UC, which can substantially reduce quality of life, is clearly increasing. These data highlight the need for research into prevention of UC and innovations in health-care systems to manage this complex and costly disease. Glucagon-like peptide-1 (GLP-1), a new antidiabetic drug, is used to treat Type 2 Diabetes Mellitus (T2DM). Accumulating evidence suggests that GLP-1 has additional roles other than glucose-lowering effects. Despite the abundance of GLP-1 research, studies in UC have been less consistent, especially body weight; for example, body weight, colon length, colon injury score, intestinal microbiota, remain to be studied further. To date, the molecular mechanism of the protective effect of GLP-1 on UC remains obscure. The effect of GLP-1 was studied by using a dextran sulfate sodium (DSS)-induced colitic mice and lipopolysaccharide (LPS) treated RAW264.7 cells (macrophage cell line) under in vivo and in vitro conditions, respectively. Our results indicate that GLP-1 significantly relieves ulcerative colitis as it represses the production of proinflammatory mediators. In addition, GLP-1 blocks the activation of the protein kinase B (AKT)/nuclear factor-κB (NF-κB), and mitogen-activated protein kinase (MAPK) signaling pathways. GLP-1 also alleviates DSS-induced injury to the intestinal mucosa and dysbiosis of gut microbiota. Altogether, GLP-1 has protection effect on ulcerative colitis. Thus, GLP-1 can be considered as a potential therapeutic candidate for the treatment of UC.

Injectable Bioadhesive Hydrogels Scavenging ROS and Restoring Mucosal Barrier for Enhanced Ulcerative Colitis Therapy

Despite the progress in the therapy of ulcerative colitis (UC), long-lasting UC remission can hardly be achieved in the majority of UC patients. The key pathological characteristics of UC include an impaired mucosal barrier and local inflammatory infiltration. Thus, a two-pronged approach aiming at repairing damaged mucosal barrier and scavenging inflammatory mediators simultaneously might hold great potential for long-term remission of UC. A rectal formulation can directly offer preferential and effective drug delivery to inflamed colon. However, regular intestinal peristalsis and frequent diarrhea in UC might cause transient drug retention. Therefore, a bioadhesive hydrogel with strong interaction with intestinal mucosa might be preferable for rectal administration to prolong drug retention. Here, we designed a bioadhesive hydrogel formed by the cross-linking of sulfhydryl chondroitin sulfate and polydopamine (CS-PDA). The presence of PDA would ensure the mucosa-adhesive behavior, and the addition of CS in the hydrogel network was expected to achieve the restoration of the intestinal epithelial barrier. To scavenge the key player (excessive reactive oxygen species, ROS) in inflamed colon, sodium ferulic (SF), a potent ROS inhibitor, was incorporated into the CS-PDA hydrogel. After rectal administration, the SF-loaded CS-PDA hydrogel could adhere to the colonic mucosa to allow prolonged drug retention. Subsequently, sustained SF release could be achieved to persistently scavenge ROS in inflammatory areas. Meanwhile, the presence of CS would promote the restoration of the mucosal barrier. Ultimately, scavenging ROS and restoring the mucosal barrier could be simultaneously achieved via this SF-loaded bioadhesive hydrogel scaffold. Our two-pronged approach might provide new insight for effective UC treatment.

Evaluation of appendectomy as a potential risk factor for immune checkpoint inhibitor-associated enterocolitis

Aims: The relationship between appendectomy and immune checkpoint inhibitor (ICI) enterocolitis was explored. Methods: Patients who began ICIs between July 2010 and September 2020 (n = 10,907) were included. The exposure group included patients with evidence of appendectomy prior to ICIs in operative notes (n = 380). The control group included patients with evidence of normal appendix in radiologic reports (n = 3602). ICI enterocolitis was defined as histopathologic evidence of colitis or enteritis attributed to ICIs. The association between appendectomy and ICI enterocolitis was characterized by multivariate logistic regression. Results: 248 patients (6.2%) developed ICI enterocolitis. The odds of ICI enterocolitis were similar among those with prior appendectomy and those without appendectomy (adjusted odds ratio: 0.82; 95% CI: 0.49-1.36; p = 0.449). Conclusion: No association was found between prior appendectomy and ICI enterocolitis.

Updated immunomodulatory roles of gut flora and microRNAs in inflammatory bowel diseases

Inflammatory bowel disease is a heterogeneous intestinal inflammatory disorder, including ulcerative colitis (UC) and Crohn's disease (CD). Existing studies have shown that the pathogenesis of IBD is closely related to the host's genetic susceptibility, intestinal flora disturbance and mucosal immune abnormalities, etc. It is generally believed that there are complicated interactions between host immunity and intestinal microflora/microRNAs during the occurrence and progression of IBD. Intestinal flora is mainly composed of bacteria, fungi, viruses and helminths. These commensals are highly implicated in the maintenance of intestinal microenvironment homeostasis alone or in combination. MiRNA is an endogenous non-coding small RNA with a length of 20 to 22 nucleotides, which can perform a variety of biological functions by silencing or activating target genes through complementary pairing bonds. A large quantity of miRNAs are involved in intestinal inflammation, mucosal barrier integrity, autophagy, vesicle transportation and other small RNA alterations in IBD circumstance. In this review, the immunomodulatory roles of gut flora and microRNAs are updated in the occurrence and progression of IBD. Meanwhile, the gut flora and microRNA targeted therapeutic strategies as well as other immunomodulatory approaches including TNF-α monoclonal antibodies are also emphasized in the treatment of IBD.

Terminalia bellirica Fruit Extract Alleviates DSS-Induced Ulcerative Colitis by Regulating Gut Microbiota, Inflammatory Mediators, and Cytokines

Ulcerative colitis (UC) is a chronic inflammatory disease significantly impacting patients' lives. This study aimed to elucidate the alleviating effect of ethyl acetate extract (TBEA) from Terminalia bellirica fruit on UC and to explore its mechanism. TBEA was the fraction with the best anti-inflammatory activity screened using in vitro anti-inflammatory assays, and HPLC initially characterized its composition. The mice model of ulcerative colitis was established after free drinking of 2.5% dextran sulfate sodium for six days, and the experimental group was treated with 50 mg/kg and 100 mg/kg TBEA for seven days. We found that TBEA significantly alleviated symptoms in UC mice, including a physiologically significant reduction in disease activity index and pathological damage to colonic tissue. TBEA dramatically slowed down oxidative stress and inflammatory process in UC mice, as evidenced by decreasing myeloperoxidase and malondialdehyde activities and increasing glutathione and catalase levels by reducing the concentrations of IL-6, IL-1β, TNF-α, and NO in UC mice, as well as by regulating key proteins in the IL-6/JAK2/STAT3 pathway. Meanwhile, TBEA maintained intestinal homeostasis by regulating intestinal flora structure. Our study provides new ideas for developing TBEA into a new drug to treat UC.

Qing Hua Chang Yin alleviates chronic colitis of mice by protecting intestinal barrier function and improving colonic microflora

Background: Qing Hua Chang Yin (QHCY) is a famous formula of traditional Chinese medicine (TCM) and has been proven to have protective effect on ulcerative colitis. However, its protective effect and potential therapeutic mechanisms in chronic colitis remain unclear. The purpose of this study is to explore the effects and underlying mechanisms of QHCY on dextran sulfate sodium (DSS)-induced chronic colitis mice model. Methods: The chronic colitis model was established by administration of 2% DSS for three consecutive cycles of 7 days with two intervals of 14 days for recovery by drinking water. The experiment lasted 49 days. The DSS + QHCY group received QHCY administration by oral gavage at doses of 1.6 g/kg/d, DSS + Mesalazine group was administrated Mesalazine by oral gavage at doses of 0.2 g/kg/d. The control and DSS group were given equal volume of distilled water. The body weight, stool consistency and blood in stool were monitored every 2 days. The disease activity index (DAI) was calculated. The colon length was measured after the mice were sacrificed. The histomorphology of colonic tissues was checked by the HE and PAS staining. Immunohistochemistry was performed to detect the expressions of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6), tight junction proteins (ZO-1, occludin) and Mucin2 (MUC2). 16S rRNA sequencing analysis was conducted to study the diversity and abundance of gut microbiota changes. Results: QHCY treatment not only significantly attenuated DSS-induced the weight loss, DAI score increase, colon shortening and histological damage in mice, but also decreased the expression of pro-inflammatory cytokines in colonic tissues and increased the expression of ZO-1, occludin, and MUC2. Furthermore, QHCY enhanced the diversity of gut microbes and regulated the structure and composition of intestinal microflora in mice with chronic colitis. Conclusion: QHCY has a therapeutic effect on a murine model of chronic colitis. It can effectively reduce the clinical and pathological manifestations of colitis and prevent alterations in the gut microbiota.

Analysis of cuproptosis-related genes in Ulcerative colitis and immunological characterization based on machine learning

Cuproptosis is a novel form of cell death, mediated by protein lipid acylation and highly associated with mitochondrial metabolism, which is regulated in the cell. Ulcerative colitis (UC) is a chronic inflammatory bowel disease that recurs frequently, and its incidence is increasing worldwide every year. Currently, a growing number of studies have shown that cuproptosis-related genes (CRGs) play a crucial role in the development and progression of a variety of tumors. However, the regulatory role of CRGs in UC has not been fully elucidated. Firstly, we identified differentially expressed genes in UC, Likewise, CRGs expression profiles and immunological profiles were evaluated. Using 75 UC samples, we typed UC based on the expression profiles of CRGs, followed by correlative immune cell infiltration analysis. Using the weighted gene co-expression network analysis (WGCNA) methodology, the cluster's differentially expressed genes (DEGs) were produced. Then, the performances of extreme gradient boosting models (XGB), support vector machine models (SVM), random forest models (RF), and generalized linear models (GLM) were constructed and predicted. Finally, the effectiveness of the best machine learning model was evaluated using five external datasets, receiver operating characteristic curve (ROC), the area under the curve of ROC (AUC), a calibration curve, a nomogram, and a decision curve analysis (DCA). A total of 13 CRGs were identified as significantly different in UC and control samples. Two subtypes were identified in UC based on CRGs expression profiles. Immune cell infiltration analysis of subtypes showed significant differences between immune cells of different subtypes. WGCNA results showed a total of 8 modules with significant differences between subtypes, with the turquoise module being the most specific. The machine learning results showed satisfactory performance of the XGB model (AUC = 0.981). Finally, the construction of the final 5-gene-based XGB model, validated by the calibration curve, nomogram, decision curve analysis, and five external datasets (GSE11223: AUC = 0.987; GSE38713: AUC = 0.815; GSE53306: AUC = 0.946; GSE94648: AUC = 0.809; GSE87466: AUC = 0.981), also proved to predict subtypes of UC with accuracy. Our research presents a trustworthy model that can predict the likelihood of developing UC and methodically outlines the complex relationship between CRGs and UC.

A precise molecular subtyping of ulcerative colitis reveals the immune heterogeneity and predicts clinical drug responses

BACKGROUND AND AIMS

We sought to identify novel molecular subtypes of ulcerative colitis (UC) based on large-scale cohorts and establish a clinically applicable subtyping system for the precision treatment of the disease.

METHODS

Eight microarray profiles containing colon samples from 357 patients were utilized. Expression heterogeneity was screened out and stable subtypes were identified among UC patients. Immune infiltration pattern and biological agent response were compared among subtypes to assess the value in guiding treatment. The relationship between PRLR and TNFSF13B genes with the highest predictive value was further validated by functional experiments.

RESULTS

Three stable molecular subtypes were successfully identified. Immune cell infiltration analysis defined three subtypes as innate immune activated UC (IIA), whole immune activated UC (WIA), and immune homeostasis like UC (IHL). Notably, the response rate towards biological agents (infliximab/vedolizumab) in WIA patients was the lowest (less than 10%), while the response rate in IHL patients was the highest, ranging from 42 to 60%. Among the featured genes of subtypes, the ratio of PRLR to TNFSF13B could effectively screen for IHL UC subtype suitable for biological agent therapies (Area under curve: 0.961-0.986). Furthermore, we demonstrated that PRLR expressed in epithelial cells could inhibit the expression of TNFSF13B in monocyte-derived macrophages through the CXCL1-NF-κB pathway.

CONCLUSIONS

We identified three stable UC subtypes with a heterogeneous immune pattern and different response rates towards biological agents for the first time. We also established a precise molecular subtyping system and classifier to predict clinical drug response and provide individualized treatment strategies for UC patients.

Protective Effects of Different Molecular Weights of Purslane (Portulaca oleracea L.) Aqueous Extract on DSS-Induced Ulcerative Colitis in Mice

Purslane, a common wild vegetable, contains active substances with various biological functions. However, its effects have been under-investigated in ulcerative colitis (UC). Therefore, this study investigated the therapeutic effects of purslane macromolecular (POEM) and small molecular extracts (POES) on dextran sulfate sodium (DSS)-induced UC in mice. Membrane separation was used to obtain extracts of different molecular weights, and their compositional differences were compared using liquid chromatography-mass spectrometry (LC/MS). POEM contained more proteins and polysaccharides, whereas POES contained more organic acids and alkaloids. These differences in composition were directly responsible for the different degrees of remission of the alleviated UC in model mice. POEM may alleviate UC by regulating the antioxidant capacity and the gut microbiota, whereas the major alleviatory effect of POES was primarily related to the regulation of antioxidant capacity. The POEM and POES effects identified in this study provide a theoretical basis for the development of purslane as a functional food.

pH-sensitive HPMCP-chitosan nanoparticles containing 5-aminosalicylic acid and berberine for oral colon delivery in a rat model of ulcerative colitis

Ulcerative colitis (UC) with continuous and extensive inflammation is limited to the colon mucosa and can lead to abdominal pain, diarrhea, and rectal bleeding. Conventional therapies are associated with several limitations, such as systemic side effects, drug degradation, inactivation, and limited drug uptake, leading to poor bioavailability. These restrictions necessitate drug delivery to the colon so that the drug passes through the stomach unchanged and has selective access to the colon. The present study aimed to formulate 5-aminosalicylic acid (5-ASA) and berberine (BBR) in chitosan nanoparticles cross-linked by HPMCP (hydroxypropyl methylcellulose phthalate) as a colon drug delivery system for UC. Spherical nanoparticles were prepared. They showed appropriate drug release in the simulated intestinal fluid (SIF), while the release did not occur in the simulated gastric fluid (SGF). They improved disease activity parameters (DAI) and ulcer index, increased the length of the colon, and decreased the wet weight of the colon. Furthermore, histopathological colon studies showed an improved therapeutic effect of 5-ASA/HPMCP/CSNPs and BBR/HPMCP/CSNPs. In conclusion, although 5-ASA/HPMCP/CSNPs showed the best effect in the treatment of UC, BBR/HPMCP/CSNPs, and 5-ASA/BBR/HPMCP/CSNPs were also effective in vivo study, and this study anticipated they could be helpful in future clinical applications for the management of UC.

The role of Nrf2 in the pathogenesis and treatment of ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease involving mainly the colorectal mucosa and submucosa, the incidence of which has been on the rise in recent years. Nuclear factor erythroid 2-related factor 2 (Nrf2), known for its key function as a transcription factor, is pivotal in inducing antioxidant stress and regulating inflammatory responses. Numerous investigations have demonstrated the involvement of the Nrf2 pathway in maintaining the development and normal function of the intestine, the development of UC, and UC-related intestinal fibrosis and carcinogenesis; meanwhile, therapeutic agents targeting the Nrf2 pathway have been widely investigated. This paper reviews the research progress of the Nrf2 signaling pathway in UC.

Prediction and Verification of Potential Therapeutic Targets for Non-Responders to Infliximab in Ulcerative Colitis

Background

Infliximab (IFX) has been widely used in ulcerative colitis (UC) patients. However, the subsequent effective treatment of IFX non-response in UC patients remains a challenge. This study aims to predict potential therapeutic targets for non-responders by performing a bioinformatic analysis of the data in the Gene Expression Omnibus (GEO) database and validation by biopsies.

Methods

Colonic mucosal biopsies expression profiles of IFX-treated UC patients (GSE73661, GSE16879) were utilized to predict potential therapeutic targets. Bioinformatics analyses were used to explore potential biological mechanisms. CytoHubba was performed to screen hub genes. We used a validation dataset and colonic mucosal biopsies of UC patients to validate hub genes.

Results

A total of 147 DEGs were identified (119 upregulated genes and 28 downregulated genes). GSEA showed that DEGs in GSE73661 were enriched in the pathways of the cytokine-cytokine receptor, the chemokine, and the adhesion molecules system. Based on the PPI network analysis, we identified four hub genes (and the transcription factor NF-κB). Then, we validate the expression of hub genes by reverse transcription-polymerase chain reaction (RT-PCR). We found higher expression of IL-6, IL1B, CXCL8, and CCL2 in non-responders compared to responders.

Conclusion

In summary, four potential targets (IL-6, IL1B, CXCL8, and CCL2) were finally identified by performing a bioinformatics analysis of the datasets in the GEO database. Their expression was confirmed in colonic mucosal biopsies of patients with UC. These results can help to further explore the mechanism of non-responders to IFX in UC and to provide potential targets for their subsequent treatment.

Pharmacological updates of nifuroxazide: Promising preclinical effects and the underlying molecular mechanisms

Nifuroxazide (NFX) is a safe nitrofuran antibacterial drug used clinically to treat acute diarrhea and infectious traveler diarrhea or colitis. Recent studies revealed that NFX displays multiple pharmacological effects, including anticancer, antioxidant, and anti-inflammatory effects. NFX has potential roles in inhibiting thyroid, breast, lung, bladder, liver, and colon cancers and osteosarcoma, melanoma, and others mediated by suppressing STAT3 as well as ALDH1, MMP2, MMP9, Bcl2 and upregulating Bax. Moreover, it has promising effects against sepsis-induced organ injury, hepatic disorders, diabetic nephropathy, ulcerative colitis, and immune disorders. These promising effects appear to be mediated by suppressing STAT3 as well as NF-κB, TLR4, and β-catenin expressions and effectively decreasing downstream cytokines TNF-α, IL-1β, and IL-6. Our review summarizes the available studies on the molecular biological mechanisms of NFX in cancer and other diseases and it is recommended to translate the studies in experimental animals and cultured cells and repurpose NFX in various diseases for scientific evidence based on human studies.

Human TFF2-Fc fusion protein alleviates DSS-induced ulcerative colitis in C57BL/6 mice by promoting intestinal epithelial cells repair and inhibiting macrophage inflammation

The clinical drugs for ulcerative colitis mainly affect the inflammatory symposiums with limited outcomes and various side effects. Repairing the damaged intestinal mucosa is a promising and alternative strategy to treat ulcerative colitis. Trefoil factor family 2 (TFF2) could repair the intestinal mucosa, however, it has a short half-life in vivo. To improve the stability of TFF2, we have prepared a new fusion protein TFF2-Fc with much stability, investigated the therapeutic effect of TFF2-Fc on ulcerative colitis, and further illustrated the related mechanisms. We found that intrarectally administered TFF2-Fc alleviated the weight loss, the colon shortening, the disease activity index, the intestinal tissue injury, and the lymphocyte infiltration in dextran sulfate sodium (DSS)-induced colitis mice. In vitro, TFF2-Fc inhibited Caco2 cells injury and apoptosis, promoted cellular migration, and increased the expression of Occludin and ZO-1 by activating P-ERK in the presence of H₂O₂ or inflammatory conditioned medium (LPS-RAW264.7/CM). Moreover, TFF2-Fc could reduce lipopolysaccharide (LPS)-induced production of inflammation cytokines and reactive oxygen species in RAW264.7 cells, and also inhibits the polarization of RAW264.7 cells to M1 phenotype by reducing glucose consumption and lactate production. Taken together, in this work, we have prepared a novel fusion protein TFF2-Fc, which could alleviate ulcerative colitis in vivo via promoting intestinal epithelial cells repair and inhibiting macrophage inflammation, and TFF2-Fc might serve as a promising ulcerative colitis therapeutic agent.

Atractylodes macrocephala Koidz. volatile oil relieves acute ulcerative colitis via regulating gut microbiota and gut microbiota metabolism

Background

Atractylodes macrocephala Koidz. (AM) is a functional food with strong ant-colitis activity. AM volatile oil (AVO) is the main active ingredient of AM. However, no study has investigated the improvement effect of AVO on ulcerative colitis (UC) and the bioactivity mechanism also remains unknown. Here, we investigated whether AVO has ameliorative activity on acute colitis mice and its mechanism from the perspective of gut microbiota.

Methods

Acute UC was induced in C57BL/6 mice by dextran sulfate sodium and treated with the AVO. Body weight, colon length, colon tissue pathology, and so on were assessed. The gut microbiota composition was profiled using 16s rRNA sequencing and global metabolomic profiling of the feces was performed. The results showed that AVO can alleviate bloody diarrhea, colon damage, and colon inflammation in colitis mice. In addition, AVO decreased potentially harmful bacteria (Turicibacter, Parasutterella, and Erysipelatoclostridium) and enriched potentially beneficial bacteria (Enterorhabdus, Parvibacter, and Akkermansia). Metabolomics disclosed that AVO altered gut microbiota metabolism by regulating 56 gut microbiota metabolites involved in 102 KEGG pathways. Among these KEGG pathways, many metabolism pathways play an important role in maintaining intestine homeostasis, such as amino acid metabolism (especially tryptophan metabolism), bile acids metabolism, and retinol metabolism.

Conclusion

In conclusion, our study indicated that AVO can be expected as novel prebiotics to treat ulcerative colitis, and modulating the composition and metabolism of gut microbiota may be its pharmacological mechanism.

Preventive effect of tilapia skin collagen hydrolysates on ulcerative colitis mice based on metabonomic and 16 S rRNA gene sequencing

BACKGROUND

Tilapia skin collagen hydrolysates (TSCHs) are the product of enzymatic hydrolysis of collagen, which is mainly extracted from tilapia skin. The components of TSCHs have recently been reported to play a preventive role in dextran sulfate sodium (DSS)-induced ulcerative colitis (UC). However, it has not been illustrated whether TSCHs can prevent against DSS-induced UC via the gut microbiota and its derived metabolites.

RESULTS

TSCHs are mainly composed of amino acids, which have similar characteristics to collagen, with most having a molecular weight below 5 kDa. In a mouse model of UC, TSCHs had no toxic effect at a dose of 60 g kg^-1 and could reduce body weight changes, colon length, histopathological changes and score, and the level of the serum inflammatory cytokine interleukin (IL)-6. Concurrently, 16 S rRNA sequencing showed that TSCHs significantly reduced the abundance of Bacteroidetes and Proteobacteria at the phylum level and norank_f__Muribaculaceae and Escherichia-Shigella at the genus level, while they increased the abundance of Firmicutes at the phylum level and Lachnoclostridium, Allobaculum, Enterorhabdus, and unclassified__f__Ruminococcaceae at the genus level. Target metabolomic analysis showed that TSCHs elevated the concentration of total acid, acetic acid, propanoic acid, and butanoic acid, but reduced isovaleric acid concentrations. Moreover, Pearson correlation analysis revealed that Allobaculum, unclassified_Ruminococcaceae, and Enterorhabdus were positively correlated with acetic acid and butyric acid, but not Escherichia-Shigella.

CONCLUSION

These findings suggest that TSCHs can prevent UC by modulating gut microbial and microbiota-derived metabolites. © 2023 Society of Chemical Industry.

Protocatechuic Acid Alleviates Dextran-Sulfate-Sodium-Induced Ulcerative Colitis in Mice via the Regulation of Intestinal Flora and Ferroptosis

Protocatechuic acid (PCA) is a natural component with multiple biological activities. However, the underlying mechanisms of the effects of PCA on anti-ulcerative colitis (UC) are unclear. A UC mouse model was established by allowing the mice to freely drink a dextran sulfate sodium solution. The mice were administered PCA intragastrically for 7 days. Histological pathology, intestinal flora, and ferroptosis regulators were determined in vivo. Additionally, ferroptotic Caco-2 cells were modeled to investigate the role of PCA in ferroptosis. Our results showed that PCA reduced the levels of the disease activity index, inflammatory factors, and histological damage in UC mice. We also found that the regulation of intestinal flora, especially Bacteroidetes, was one of the potential mechanisms underlying the protective effects of PCA anti-UC. Moreover, PCA downregulated the level of ferroptosis in the colon tissue, as evidenced by a reduced iron overload, decreased glutathione depletion, and a lower level of malondialdehyde production compared with the model group. Similar effects of PCA on ferroptosis were observed in Erastin-treated Caco-2 cells. The results obtained using reactive oxygen species assays and the changes in mitochondrial structure observed via scanning electron microscopy also support these results. Our findings suggested that PCA protected against UC by regulating intestinal flora and ferroptosis.

Behavioral abnormalities in C57BL/6 mice with chronic ulcerative colitis induced by DSS

BACKGROUND

Clinical epidemiological studies have found that some patients with ulcerative colitis (UC) are prone to mental disorders. DSS-induced acute and chronic UC models are often used to evaluate the efficacy of anti-UC drugs. However, whether DSS has an effect on mouse behavior has not been reported.

METHODS

Acute and chronic UC models were induced by 3% DSS and 1.5% DSS, respectively. The bloody stool, the changes in the colon length, and histopathological changes in the colon were used to evaluate the success of the animal model. The behavior of mice was evaluated by open field experiment, tail suspension experiment and Sucrose preference test.

RESULTS

The weight of mice in 3% DSS group decreased significantly, the DAI score increased significantly, the colon length of mice was significantly shortened, and the structure of colonic crypts was abnormal, which showed inflammatory cell infiltration and shrinkage of crypts. Compared with the control group, the immobility time of 3%DSS group mice in the tail suspension test and forced swimming test had no effect, the number of running and grooming times was significantly reduced, and there was no significant difference in the number of standing times. No abnormality was observed in HE staining of the hippocampus. However, in 1.5% DSS-induced chronic UC model, behavioral and hippocampal abnormalities were observed not only UC symptoms.

CONCLUSIONS

The acute UC model induced by 3% DSS has certain influence on the behavior of mice, but the mental state of mice is normal, which may be the abnormal behavior caused by UC symptoms; However, the chronic UC model induced by 1.5% DSS has a significant effect on the behavior of mice, and the mice have mental disorders, which are caused by mental disorders.

Atherosclerotic Cardiovascular Disease in Inflammatory Bowel Disease: The Role of Chronic Inflammation and Platelet Aggregation

Background and Objectives: Atherosclerosis is one of inflammatory bowel disease’s most significant cardiovascular manifestations. This research aimed to examine the relationship between biochemical, haemostatic, and immune parameters of atherosclerosis and ulcerative colitis patients and its relationship to platelet aggregation. Materials and Methods: A clinical, observational cross-sectional study was performed, during which the tested parameters were compared in the experimental and control groups. The patients were divided into four groups. The first group had 25 patients who had ulcerative colitis and atherosclerosis. The second group included 39 patients with ulcerative colitis without atherosclerosis. The third group comprised 31 patients suffering from atherosclerosis without ulcerative colitis, and the fourth group comprised 25 healthy subjects. Results: In our study, we registered statistically higher levels of inflammatory markers like SE, CRP, Le, fecal calprotectin, TNF-α, and IL-6, as well as the higher value of thrombocytes and thrombocyte aggregation in the group of patients with ulcerative colitis compared to the control group. Lower levels of total cholesterol and LDL were also recorded in patients with ulcerative colitis and atherosclerosis and ulcerative colitis without atherosclerosis compared to healthy control. Triglyceride and remnant cholesterol were higher in patients with ulcerative colitis and atherosclerosis when compared to patients with ulcerative colitis and healthy control but lower than in patients with atherosclerosis only. Conclusions: Several inflammatory markers and platelet aggregation could be good discrimination markers for subjects with ulcerative colitis with the highest risk of atherosclerosis.

Discovery, Preliminary Structure-Activity Relationship, and Evaluation of Oleanane-Type Saponins from Pulsatilla chinensis for the Treatment of Ulcerative Colitis

To discover ulcerative colitis (UC) treatment agents, 28 oleanane-type triterpenoid saponins (1-28) including three new saponins, pulsatillosides P-R (1-3), were isolated from Pulsatilla chinensis. The isolated saponins could observably ameliorate UC by improving the intestinal epithelial cell barrier and intestinal flora in vivo. The structure-activity relationship indicated that the oligosaccharide chain at C-28 was essential for their anti-UC activities; the methyl group at the C-23 site of triterpene saponins showed important effects on anti-UC efficacy; the chain length of oligosaccharides at position C-28 had little effect on their anti-UC activities. In vivo investigation of representative saponins 1 and 13 further confirmed that 23-methyl-3,28-bisdesmosidic oleanane-type saponins inhibited the TNFα-NFκB-MLCK axis to improve the intestinal epithelial cell barrier of the colon in UC mice. These findings revealed the potential of 23-methyl-3,28-bisdesmosidic oleanane-type saponins from P. chinensis as promising candidates for the treatment of UC.

Sodium Butyrate Inhibits Oxidative Stress and NF-κB/NLRP3 Activation in Dextran Sulfate Sodium Salt-Induced Colitis in Mice with Involvement of the Nrf2 Signaling Pathway and Mitophagy

BACKGROUND

Sodium butyrate (NaB) is a short-chain fatty acid produced by intestinal microbial fermentation of dietary fiber, and has been shown to be effective in inhibiting ulcerative colitis (UC). However, how NaB regulates inflammation and oxidative stress in the pathogenesis of UC is not clear.

AIMS

The purpose of this study was to use a dextran sulfate sodium salt (DSS)-induced murine colitis model, and determine the effects of NaB and the related molecular mechanisms.

METHODS

Colitis model was induced in mice by administration of 2.5%(wt/vol) DSS. 0.1 M NaB in drinking water, or intraperitoneal injection of NaB (1 g/kg body weight) was given during the study period. In vivo imaging was performed to detect abdominal reactive oxygen species (ROS). Western blotting and RT-PCR were used to determine the levels of target signals.

RESULTS

The results showed that NaB decreases the severity of colitis as determined by an improved survival rate, colon length, spleen weight, disease activity index (DAI), and histopathological changes. NaB reduced oxidative stress as determined by a reduction in abdominal ROS chemiluminescence signaling, inhibition of the accumulation of myeloperoxidase and malondialdehyde, and restoration of glutathione activity. NaB activated the COX-2/Nrf2/HO-1 pathway by increasing the expressions of COX-2, Nrf2, and HO-1 proteins. NaB inhibited the phosphorylation of NF-κB and activation of NLRP3 inflammasomes, and reduced the secretion of corresponding inflammatory factors. Furthermore, NaB promoted the occurrence of mitophagy via activating the expression of Pink1/Parkin.

CONCLUSIONS

In conclusion, our results indicate that NaB improves colitis by inhibiting oxidative stress and NF-κB/NLRP3 activation, which may be via COX-2/Nrf2/HO-1 activation and mitophagy.

Role of Interleukin-22 in ulcerative colitis

Ulcerative Colitis (UC) is a chronic disease, in the progression of which an immune overreaction may play an important role. IL-22 is a member of the IL-10 superfamily of cytokines and is pleiotropic in immune regulation and inflammatory responses. IL-22 can produce protective effects, promote wound healing and tissue regeneration, while it can also induce inflammatory reactions when it is chronically overexpressed. Extensive literatures reported that IL-22 played an essential role in the pathogenic development of UC. IL-22 participates in the whole disease process of UC involving signaling pathways, gene expression regulation, and intestinal flora imbalance, making IL-22 a possible candidate for the treatment of UC. In this paper, the latest knowledge to further elucidate the role of IL-22 in UC was summarized and analyzed.

IBD disease-modifying therapies: insights from emerging therapeutics

Inflammatory bowel disease (IBD) pathogenesis is associated with gut mucosal inflammation, epithelial damage, and dysbiosis leading to a dysregulated gut mucosal barrier. However, the extent and underlying mechanisms remain largely unknown. Current treatment regimens have focused mainly on treating IBD symptoms; however, such treatment strategies do not address mucosal epithelial repair, barrier homeostasis, or intestinal dysbiosis. Although attempts have been made to identify new therapeutic modalities to enhance gut barrier functions, these are at an early developmental stage and have not been wholly successful. We review conventional therapies, the possible relevant role of gut barrier-protecting agents, and biomaterial strategies relating to combination therapies that may pave the way towards developing new therapeutic approaches for IBD.

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.

Hericium erinaceus mycelium-Derived Polysaccharide Alleviates Ulcerative Colitis and Modulates Gut Microbiota in Cynomolgus Monkeys

SCOPE

Ulcerative colitis (UC) is rapidly increasing worldwide but prolong use of available corticosteroids treatment is associated with numerous adverse effects. There is the urgent need to develop novel therapeutic options. However, this requires the use of suitable disease models, but current models are generated with chemical agents mainly in rodents, which are unable to recapitulate the human occurrence. The aim of this study is to validate the occurrence of spontaneous UC in cynomolgus monkeys and explore the potential of Hericium erinaceus mycelium-derived polysaccharide in reversing UC pathologies.

METHODS AND RESULTS

Postmortem bowel evaluation and biochemical analysis including inflammatory markers and fecal occult blood testing (FOBT) as well as nutrition status parameters, confirm the non-artificial induced spontaneous occurrence of UC in cynomolgus monkeys. Subsequently, H. erinaceus mycelium-derived polysaccharide supplementation significantly attenuates UC pathologies, improves nutritional status, reduces the incidence of diarrhea, and reduces inflammation in UC monkeys. Importantly, the polysaccharides administration enhances intestinal function and reshapes the gut microbiota.

CONCLUSION

The study confirms the spontaneous UC monkeys can closely mimic the occurrence of UC in humans. Moreover, H. erinaceus mycelium-derived polysaccharide can effectively restore UC in monkeys, which show the prospects as precision nutritional supplement for the management of UC.

An oral ratiometric NIR-II fluorescent probe for reliable monitoring of gastrointestinal diseases in vivo

Early monitoring of gastrointestinal diseases via orally delivered NIR-II ratiometric fluorescent probes represents a promising noninvasive diagnostic modality, but is challenging due to the limitation of harsh digestive environment. Here, we report a single-component NIR-II ratiometric molecular nanoprobe (LC-1250 NP) to monitor gastrointestinal disease with high specificity to its biomarker H₂O₂ via oral administration. LC-1250 NP displays stable fluorescence in the channel of 1250 long-pass (F_1250LP) before and after the gastrointestinal disease detection as the reference, while it presents significantly enhanced fluorescence signal in the response channel of 1150 nm short-pass (F_1150SP) in diseased gastrointestinal environment due to the intramolecular cyclization of LC-1250 molecules activated by H₂O₂. The fluorescence ratio (F_1150SP/F_1250LP) increases linearly with the concentration of H₂O₂ with a low detection limit of 20 nM. Therefore, when delivered orally, LC-1250 NP can accurately map the diseased areas and surmount the false-positive interference from biological heterogeneity by NIR-II ratiometric fluorescence imaging, providing sensitive and reliable evaluation for the progress of gastroenteritis.

Safety and tolerability of spesolimab in patients with ulcerative colitis

BACKGROUND

Interleukin (IL)-36 signaling has been shown to be increased in ulcerative colitis (UC). Spesolimab, a novel humanized monoclonal antibody, targets the IL-36 pathway.

RESEARCH DESIGN AND METHODS

We report safety, immunogenicity, and efficacy data of intravenous (IV) spesolimab in UC. Study 1: phase II, randomized, placebo-controlled trial (300 mg single dose; 450 mg every 4 weeks [q4w]; or 1,200 mg q4w, three doses). Study 2: phase IIa, randomized, placebo-controlled trial (1,200 mg q4w). Study 3: phase IIa, open-label, single-arm trial (1,200 mg q4w). Studies lasted 12 weeks, with a 12-, 24-, and 16-week safety follow-up, respectively.

RESULTS

Adver+se event (AE) rates were similar for spesolimab and placebo in Studies 1 (N = 98; 64.9%; 65.2%) and 2 (N = 22; 86.7%; 71.4%); all patients in Study 3 (N = 8) experienced AEs. The most frequent investigator-assessed drug-related (spesolimab; placebo) AEs were skin rash (5.4%; 0%) and nasopharyngitis (4.1%; 0%) in Study 1; acne (13.3%; 0%) in Study 2; one patient reported skin rash, nasopharyngitis, headache, and acne in Study 3. Efficacy endpoints were not met.

CONCLUSIONS

Spesolimab was generally well tolerated, with no unexpected safety concerns. The safety data are consistent with studies in other inflammatory diseases.

Deferasirox alleviates DSS-induced ulcerative colitis in mice by inhibiting ferroptosis and improving intestinal microbiota

AIMS

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) caused by multiple factors. Studies have shown that epithelial cell damage was associated with ferroptosis in UC. Therefore, our research focused on the effects and mechanism of iron chelator deferasirox in UC.

MAIN METHODS

The UC model was induced by 2.5 % dextran sulfate sodium salt (DSS) and administered with deferasirox (10 mg/kg) for 7 days. Histological pathologies, inflammatory response, ferrous iron contents, oxidative stress and ferroptosis regulators were determined. Intestinal microbiota alteration and short-chain fatty acids (SCFAs) production were analyzed through 16S rRNA gene sequencing and targeted metabolomics.

KEY FINDINGS

Deferasirox significantly relieved the DSS-induced UC in mice, as evidenced by weight loss, survival rate, colon length shortening disease activity index (DAI) score and histology score. Deferasirox treatment reduced the level of pro inflammatory cytokines (IL-1β, IL-6, TNF-α and INF-γ). Ferroptosis was induced in mice with UC, as evidenced by ferrous iron accumulation, increased ROS production, SOD and GSH depletion, decreased the expression of GPX-4 and FTH, accompanied by increased expression of TF. Deferasirox treatment strongly reversed the alterations caused by ferroptotic characteristics in DSS-induced mice. Moreover, deferasirox treatment reshaped the composition of intestinal microbiota. The results revealed the genera of norank_f__Muribaculaceae, Lachnospiraceae_NK4A136_group, Prevotellaceae_UCG-001, Odoribacter and Blautia were increased distinctly, while Escherichia-Shigella and Streptococcus were significantly decreased by deferasirox treatment. Targeted metabolomics analysis indicated the SCFAs production enhanced in deferasirox-treated mice.

SIGNIFICANCE

Our results suggested that deferasirox could treat DSS-induced UC in mice by inhibiting ferroptosis and improving intestinal microbiota.

Sodium houttuyfonate derived from Houttuynia cordata Thunb improves intestinal malfunction via maintaining gut microflora stability in Candida albicans overgrowth aggravated ulcerative colitis

Candida albicans is a common opportunistic pathogen and normally resides in the human gut. Increasing number of reports link the overgrowth of C. albicans to the severity of ulcerative colitis (UC). Sodium houttuyfonate (SH), a derivative of the medicinal herb Houttuynia cordata Thunb, has been demonstrated to exhibit decent antifungal and anti-inflammatory activities. We showed previously that SH could ameliorate colitis mice infected with C. albicans. However, it is unclear whether the therapeutic effect of SH is connected to its modulation of intestinal microflora in UC. In this study, the impact of SH on the gut microbiota was explored in both cohabitation and non-cohabitation patterns. The results showed that in UC mice inflicted by C. albicans, the administration of SH could greatly improve the pathological signs, weaken the oxidative stress and inflammatory response, and enhance the intestinal mucosal integrity. By 16S rRNA gene sequencing, we found that C. albicans interference caused intestinal microbiota dysbiosis accompanied by an increase of some harmful pathogens including Klebsiella and Bacteroides. In contrast, SH could modulate the abundance and diversity of microbiota with an increase of several beneficial bacteria comprising short-chain fatty acid-producing bacteria (Lachnospiraceae_NK4A136_group, Intestinimonas) and probiotics (Lactobacillus and Alloprevotella). Furthermore, the cohabitation strategy could also prove the efficacy of SH, indicating a role of transmissible gut flora in the colitis model. These findings suggest that SH might be an effective compound for the treatment of UC complicated by C. albicans overgrowth through maintaining gut microbiota homeostasis, thereby improving intestinal function.

Pulsatilla decoction improves DSS-induced colitis via modulation of fecal-bacteria-related short-chain fatty acids and intestinal barrier integrity

ETHNOPHARMACOLOGICAL RELEVANCE

Pulsatilla decoction (PD), is an herbal formula commonly used for the treatment of ulcerative colitis (UC) in clinical practice, but the mechanism of PD alters the colitis remains elusive.

AIM OF THE STUDY

To evaluate the intervention effect of PD on Dextran Sodium Sulfate (DSS)-induced UC based on gut microbiota and intestinal short-chain fatty acid (SCFAs) metabolism, and to investigate the mechanism of action of PD in treating UC.

MATERIALS AND METHODS

A 3% (wt/vol) DSS-induced ulcerative colitis model in C57BL/6 male mice was used to evaluate the effect of oral PD in treating UC. The changes in gut microbiota in mice were analyzed by 16SrDNA gene sequencing, and the content of SCFAs in the intestinal contents of mice was determined by gas chromatography-mass spectrometry (GC-MS). Enzyme-linked immunosorbent assay (ELISA) was applied to analyze the expression of inflammatory cytokines in serum and colonic tissues, and western blotting (WB) was applied to analyze the expression of tight junction proteins in colonic tissues.

RESULTS

PD can alleviate the symptoms of UC mice, Pulsatilla Decoction high dose treatment group (PDHT) shows the best effect. Compared with the DSS group, the PDHT had significantly lower body mass, disease activity index (DAI) score, colonic macroscopic damage index (CMDI) score, and pathological damage score, at the phylum level, the relative abundance of Bacteroidetes increased while that of Firmicutes and Proteobacteria decreased, at the Genus level, the abundance of Bacteroides and Lachnospiraceae.NK4A136.group increased while that of Clostridium. sensu.stricto。, Escherichia. shigella and Turicibacter decreased. Compared with the DSS group, acetate, propionate, and total SCFAs in the PDHT with significantly higher levels. The concentrations of interleukin-1β (L-1β), tumor necrosis factor-alpha (TNF-α), and interleukin-17 (IL-17) decreased whereby the concentration of interleukin-10 (IL-10) increased in the PDHT group. The expression levels of Occludin, zonula occludens-1 (ZO-1), Claudin1, Claudin5, G protein-coupled receptor43 (GPR43) protein, and the relative expression of ZO-1 and Occludin mRNA were significantly increased PDHT group.

CONCLUSIONS

PD has a good therapeutic effect on UC mice. The pharmacological mechanism is probably maintaining the homeostasis and diversity of gut microbiota, increasing the content of SCFAs, and repairing the colonic mucosal barrier.

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

NEW FINDINGS

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

ABSTRACT

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

Efficacy of Bifidobacterium longum alone or in multi-strain probiotic formulations during early life and beyond

The significance of Bifidobacterium to human health can be appreciated from its early colonization of the neonatal gut, where Bifidobacterium longum represents the most abundant species. While its relative abundance declines with age, it is further reduced in several diseases. Research into the beneficial properties of B. longum has unveiled a range of mechanisms, including the production of bioactive molecules, such as short-chain fatty acids, polysaccharides, and serine protease inhibitors. From its intestinal niche, B. longum can have far-reaching effects in the body influencing immune responses in the lungs and even skin, as well as influencing brain activity. In this review, we present the biological and clinical impacts of this species on a range of human conditions beginning in neonatal life and beyond. The available scientific evidence reveals a strong rationale for continued research and further clinical trials that investigate the ability of B. longum to treat or prevent a range of diseases across the human lifespan.

Pectic polysaccharides derived from Hainan Rauwolfia ameliorate NLR family pyrin domain-containing 3-mediated colonic epithelial cell pyroptosis in ulcerative colitis

Pectic polysaccharides (PPs) could exert functions on ulcerative colitis (UC), which is classified as a nonspecific inflammatory disorder. This study investigated the molecular mechanism of PPs derived from Rauwolfia in UC. First, the dextran sodium sulfate (DSS)-induced mouse colitis models and lipopolysaccharide (LPS)-treated colonic epithelial cell (YAMC) models were established and treated with PP. Subsequently, the effects of PPs on mucosal damages in DSS mice were detected, and the levels of inflammatory cytokines, pyroptosis-related factors, oxidative stress-related markers, and the tight junction-related proteins in the tissues or cells were examined, and the results suggested that PPs ameliorated colonic mucosal damages and cell pyroptosis in DSS mice, and limited colonic epithelial cell pyroptosis in in vitro UC models. Subsequently, the binding relations of retinol-binding protein 4 (RBP4) to miR-124-3p and NLR pyrin domain-containing 3 (NLRP3) were analyzed. miR-124-3p targeted RBP4 and reduced the binding of RBP4 to NLRP3, thus inhibiting NLRP3-mediated pyroptosis. Finally, functional rescue experiments revealed that miR-124-3p suppression or RBP4 overexpression promoted colonic epithelial cell pyroptosis. Collectively, Rauwolfia-derived PPs limited miR-124-3p and targeted RBP4 and reduced the binding potency of RBP4 to NLRP3 to inhibit NLRP3-mediated pyroptosis, resulting in the alleviation of colonic epithelial cell pyroptosis and mucosal damages in UC.

Exploration of the shared pathways and common biomarker PAN3 in ankylosing spondylitis and ulcerative colitis using integrated bioinformatics analysis

Background

Ulcerative colitis (UC) is a chronic autoimmune-related disease that causes inflammation of the intestine. Ankylosing spondylitis (AS) is a common extraintestinal complication of UC involving the sacroiliac joint. However, the pathogenesis of AS secondary to UC has not been studied. This study aimed to investigate the shared pathways and potential common biomarkers of UC and AS.

Methods

Microarray data downloaded from the Gene Expression Omnibus (GEO) database were used to screen differentially expressed genes (DEGs) in the UC and AS datasets. Weighted gene co-expression network analysis (WGCNA) was performed to identify co-expression modules related to UC and AS. Shared genes were then further analyzed for functional pathway enrichment. Next, the optimal common biomarker was selected using SVM-RFF and further validated using two independent GEO datasets. Finally, immune infiltration analysis was used to investigate the correlation of immune cell infiltration with common biomarkers in UC and AS.

Results

A total of 4428 and 2438 DEGs in UC and AS, respectively, were screened. Four modules were identified as significant for UC and AS using WGCNA. A total of 25 genes overlapped with the strongest positive and negative modules of UC and AS. KEGG analysis showed these genes may be involved in the mitogen-activated protein kinase (MAPK) signaling pathway. GO analysis indicated that these genes were significantly enriched for RNA localization. PAN3 was selected as the optimal common biomarker for UC and AS. Immune infiltration analysis showed that the expression of PAN3 was correlated with changes in immune cells.

Conclusion

This study first explored the common pathways and genetic diagnostic markers involved in UC and AS using bioinformatic analysis. Results suggest that the MAPK signaling pathway may be associated with both pathogeneses and that PAN3 may be a potential diagnostic marker for patients with UC complicated by AS.

Angelica oil restores the intestinal barrier function by suppressing S100A8/A9 signalling in mice with ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) progression is driven by the activation of immune cells that release pro-inflammatory mediators to disrupt intestinal epithelial barrier integrity. This study aimed to investigate the potential protective effects of Angelica oil (AO) on the intestinal epithelial barrier in mice with UC and the underlying mechanisms.

METHODS

Improvement of the disease state and protective effect of AO on the intestinal epithelial barrier were observed in mice with dextran sulphate sodium salt (DSS)-induced UC. Protein microarrays were used to screen AO-affected cytokine pools and their recruited immune cells for accumulation in the tissues. Furthermore, quantitative proteomics was applied to search for AO-acting molecules and to verify in vitro the functions of key molecules between inflammation and the intestinal mucosal barrier.

RESULTS

AO significantly alleviated intestinal inflammation, reduced intestinal permeability, and retained barrier function in mice with UC. Furthermore, cytokines inhibited by AO mainly promoted monocyte and neutrophil activation or chemotaxis. Moreover, proteomic screening revealed that S100A8/A9 was a key molecule significantly regulated by AO, and its mediated TLR4/NF-κB pathway was also inhibited. Finally, we verified that AO inhibited the activation of the S100A8/A9/TLR4 signalling pathway and enhanced the expression of tight junctions (TJs) proteins using a cellular model of intestinal barrier damage induced by S100A8/A9 or macrophage-derived medium. And the enhancement of TJs in intestinal epithelial cells and the inhibition of inflammatory signalling by AO were significantly attenuated due to the application of S100A8/A9 monoclonal antibody.

CONCLUSION

These results demonstrated that AO improves intestinal mucosal barrier damage in the inflammatory environment of mice with UC by inhibiting the expression of S100A8/A9 and the activation of its downstream TLR4/NF-κB signalling pathway.

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.

Sishen Wan Treats Ulcerative Colitis in Rats by Regulating Gut Microbiota and Restoring the Treg/Th17 Balance

Objective

This study was aimed to explore the mechanism of Sishen Wan (SSW) in treating ulcerative colitis (UC) in a rat model of spleen-kidney yang deficiency pattern by regulating gut microbiota and the content of butyric acid in short-chain fatty acid (SCFAs) and restoring regulatory T (Treg)/T helper type 17 (Th17) balance from the perspective of the correlation between gut microbiota and immune function.

Methods

The UC rat model of spleen-kidney yang deficiency pattern was established by the method of combining disease and syndrome (intragastric administration of senna leaf, subcutaneous injection of hydrocortisone, and enema with 2,4-dinitrobenzenesulfonic acid (DNBS)/ethanol solution). After successful modeling, rats were randomly divided into six groups: the blank group, model group, low-, middle-, and high-dose Sishen Wan groups, and mesalazine group. Samples were taken after continuous administration for 3 weeks. The general conditions and body weight of the rats were observed and recorded, and the disease activity index (DAI) score was calculated. Colonic mucosal injury was observed, and a colonic mucosal damage index (CMDI) score was calculated. Histopathological changes in colon tissues were determined by hematoxylin and eosin (H&E) staining, and the histopathological score (HS) was calculated. The serum levels of transforming growth factor-β1 (TGF-β1), interleukin (IL)-6, IL-10, and IL-17 were determined by enzyme-linked immunosorbent assay (ELISA) assays. The expression of TGF-β1, signal transducer and activator of transcription 3 (STAT3), and peroxisome proliferator-activated receptor γ (PPARγ) was determined by Western blot analysis. The proportion of Th17 and Treg cells in colon tissue was determined by flow cytometry. The relative abundance of gut microbiota was determined by 16S rDNA sequencing, and the concentration of butyric acid of SCFAs was determined by gas chromatography-mass spectrometry (GC-MS).

Results

Administration of SSW significantly improved the pathological changes of colon tissue in UC rats and could attenuate the DAI and CMDI scores, and the HS. SSW significantly decreased the serum levels of IL-6 and IL-17 and increased the serum levels of TGF-β1 and IL-10. In addition, SSW increased the expression of TGF-β1 and PPARγ and decreased the expression of STAT3 in colon tissue in a dose-dependent manner. Furthermore, SSW significantly decreased the proportion of Th17 cells and increased the proportion of Treg cells in colon tissue. Additionally, SSW altered the gut microbiota, including an increase in the relative abundance of Firmicutes and a decrease in Bacteroidota at the phylum level and an increase in the relative abundance of Lactobacillus at the genus level. Moreover, SSW significantly increased the concentration of butyric acid.

Conclusions

Combined, these data suggested that SSW increased the relative abundance of firmicutes and the level of butyric acid and restored the balance of Treg/Th17 immune axis and gut homeostasis, thus delaying the progress of UC.

A variant rs6214 within IGF-1 confers risk for ulcerative colitis in Chinese Han populations

Insulin growth factor-1 (IGF-1) has been found to correlate with various diseases such as cancer and cardiovascular diseases including ulcerative colitis (UC). The present study aimed to investigate the plausible association of rs6214 (C > T) within IGF-1 and UC susceptibility in Chinese Han populations. A total of 977 UC patients and 1029 healthy controls were enrolled, and rs6214 was genotyped with PCR and direct sequencing on the ABI 3730XL DNA analyzer platform. Logistic regression analysis was applied for the correlation of rs6214 and UC susceptibility via calculation of odds ratio (OR) with a 95% confidence interval (95% CI) adjusted for age and sex under different genetic models. The difference of clinical parameters between genotypes was measured by one-way analysis of variance (ANOVA). Additional functional assays were conducted to establish the probable relationship. The results indicated that the T allele of rs6214 showed roughly 37% greater risk for UC risk in the additive model (OR = 1.37, 95% CI = 1.21-1.55, P < 0.000001) when compared with C allele carriers, and the pattern was similar in other three genetic models. Further stratified analysis suggested that the association was particularly noteworthy in UC patients with extensive colitis and severe condition. Moreover, the blood level of IGF-1 was downregulated in UC patients, and the mRNA level was lower in T allele carriers in rectal tissues of UC cases. Additional luciferase assay demonstrated that rs6214 regulates IGF-1 expression via promoting miR-2053. Collectively, rs6214 increased UC susceptibility and suppresses IGF-1 expression by enhancing miR-2053 binding. The current findings provided evidence that rs6214 is a promising biomarker for UC prediction and prognosis.

3,6-dichlorobenzo[b]thiophene-2-carboxylic acid alleviates ulcerative colitis by suppressing mammalian target of rapamycin complex 1 activation and regulating intestinal microbiota

BACKGROUND

3,6-dichlorobenzo[b]thiophene-2-carboxylic acid (BT2) is a benzothiophene carboxylate derivative that can suppress the catabolism of branched-chain amino acid (BCAA)-associated mammalian target of rapamycin complex 1 (mTORC1) activation. Previous studies have demonstrated the therapeutic effects of BT2 on arthritis, liver cancer, and kidney injury. However, the effects of BT2 on ulcerative colitis (UC) are unknown.

AIM

To investigate the anti-UC effects of BT2 and the underlying mechanism.

METHODS

Mouse UC models were created through the administration of 3.5% dextran sodium sulfate (DSS) for 7 d. The mice in the treated groups were administered salazosulfapyridine (300 mg/kg) or BT2 (20 mg/kg) orally from day 1 to day 7. At the end of the study, all of the mice were sacrificed, and colon tissues were removed for hematoxylin and eosin staining, immunoblot analyses, and immunohistochemical assays. Cytokine levels were measured by flow cytometry. The contents of BCAAs including valine, leucine, and isoleucine, in mouse serum were detected by liquid chromatography-tandem mass spectrometry, and the abundance of intestinal flora was analyzed by 16S ribosomal DNA sequencing.

RESULTS

Our results revealed that BT2 significantly ameliorated the inflammatory symptoms and pathological damage induced by DSS in mice. BT2 also reduced the production of the proinflammatory cytokines interleukin 6 (IL-6), IL-9, and IL-2 and increased the anti-inflammatory cytokine IL-10 level. In addition, BT2 notably improved BCAA catabolism and suppressed mTORC1 activation and cyclooxygenase-2 expression in the colon tissues of UC mice. Furthermore, high-throughput sequencing revealed that BT2 restored the gut microbial abundance and diversity in mice with colitis. Compared with the DSS group, BT2 treatment increased the ratio of Firmicutes to Bacteroidetes and decreased the abundance of Enterobacteriaceae and Escherichia-Shigella.

CONCLUSION

Our results indicated that BT2 significantly ameliorated DSS-induced UC and that the latent mechanism involved the suppression of BCAA-associated mTORC1 activation and modulation of the intestinal flora.

Long-term outcomes of sporadic rectal cancer versus ulcerative colitis-associated rectal cancer: a matched case-control study

BACKGROUND

Although patients with ulcerative colitis (UC) are at increased risk of rectal cancer compared to the general population, it remains unclear whether their oncologic outcomes are different than sporadic rectal cancer (S-RC).We aimed to compare survival and oncologic outcomes in S-RC versus UC-associated rectal cancer (UC-RC).

METHODS

We performed a retrospective case-control study of patients who underwent surgical resection for rectal cancer between 2005 and 2015. Data collected included patient demographics, intraoperative variables, postoperative outcomes, and oncological outcomes.

RESULTS

A total of 138 patients were included; 92 patients with S-RC and 46 with UC-RC. Both groups were comparable in terms of demographics, oncologic characteristics, oncologic treatment strategies, perioperative complications and operative factors except for preoperative radiotherapy. At a median follow-up time of 3.7 years the 3-and 5-year OS rates; the 1-and 3-year DFS rates were comparable between the groups.

CONCLUSION

Ulcerative colitis-associated rectal cancer patients have similar survival and oncologic outcomes as sporadic rectal cancer patients.

Methanogens and Hydrogen Sulfide Producing Bacteria Guide Distinct Gut Microbe Profiles and Irritable Bowel Syndrome Subtypes

INTRODUCTION

Irritable bowel syndrome (IBS) includes diarrhea-predominant (IBS-D) and constipation-predominant (IBS-C) subtypes. We combined breath testing and stool microbiome sequencing to identify potential microbial drivers of IBS subtypes.

METHODS

IBS-C and IBS-D subjects from 2 randomized controlled trials (NCT03763175 and NCT04557215) were included. Baseline breath carbon dioxide, hydrogen (H 2 ), methane (CH 4 ), and hydrogen sulfide (H 2 S) levels were measured by gas chromatography, and baseline stool microbiome composition was analyzed by 16S rRNA sequencing. Microbial metabolic pathways were analyzed using Kyoto Encyclopedia of Genes and Genomes collection databases.

RESULTS

IBS-C subjects had higher breath CH 4 that correlated with higher gut microbial diversity and higher relative abundance (RA) of stool methanogens, predominantly Methanobrevibacter , as well as higher absolute abundance of Methanobrevibacter smithii in stool. IBS-D subjects had higher breath H 2 that correlated with lower microbial diversity and higher breath H 2 S that correlated with higher RA of H 2 S-producing bacteria, including Fusobacterium and Desulfovibrio spp. The predominant H 2 producers were different in these distinct microtypes, with higher RA of Ruminococcaceae and Christensenellaceae in IBS-C/CH 4 + (which correlated with Methanobacteriaceae RA) and higher Enterobacteriaceae RA in IBS-D. Finally, microbial metabolic pathway analysis revealed enrichment of Kyoto Encyclopedia of Genes and Genomes modules associated with methanogenesis and biosynthesis of methanogenesis cofactor F420 in IBS-C/CH 4 + subjects, whereas modules associated with H 2 S production, including sulfate reduction pathways, were enriched in IBS-D.

DISCUSSION

Our findings identify distinct gut microtypes linked to breath gas patterns in IBS-C and IBS-D subjects, driven by methanogens such as M. smithii and H 2 S producers such as Fusobacterium and Desulfovibrio spp, respectively.

Extracellular vesicles produced by bone marrow mesenchymal stem cells overexpressing programmed death-ligand 1 ameliorate dextran sodium sulfate-induced ulcerative colitis in rats by regulating Th17/Treg cell balance through PTEN/PI3K/AKT/mTOR axis

BACKGROUND AND AIM

Programmed death-ligand 1 (PD-L1) was involved in regulating Th17/Treg cell balance in ulcerative colitis (UC). Extracellular vesicles (EVs) from genetically modified bone marrow mesenchymal stem cells (BMSCs) can serve as a stable delivery system to overexpress PD-L1. The study was designed to evaluate the therapeutic mechanism of BMSC-EVs overexpressing PD-L1 (PD-L1-EVs) on ulcerative colitis.

METHODS

Experimental model of UC was established in rats by drinking 5% dextran sulfate sodium (DSS). Apoptosis-related proteins, inflammatory response-related factors and oxidative stress related mediators were detected. Westernblot was used to detecte key proteins in the PI3K/AKT signaling pathway and its downstream effectors. The CD4⁺ Foxp3⁺ Treg cells and CD4⁺ IL-17A⁺ Th17 cells in spleen and mesenteric lymph nodes (MLNs) was detected by flow cytometry.

RESULTS

PD-L1-EVs significantly alleviated the manifestations and pathological damage of UC rats by inhibiting the expression of IFN-γ, IL-1β, IL-8, IL-6, IL-2, BAX, NF-κB, TNF-α, MPO, and MDA, and up-regulating the expression of IL-4, BCL-2, SOD, and GSH. Furthermore, the proportions of Th17 cells were decreased and that of Treg cells were upregulated by PD-L1-EVs treatment. PTEN inhibitors (bpv) partially abolished the inhibitory effect of PD-L1-EVs on PI3K-AKT signaling and impaired the therapeutic efficacy of PD-L1-EVs.

CONCLUSIONS

PD-L1-EVs mitigated colonal inflammation, apoptosis and oxidative stress through blocking the activation of PI3K/Akt/mTOR pathway and regulating the balance of Th17/Treg cells.

Qing-Chang-Hua-Shi granule ameliorates DSS-induced colitis by activating NLRP6 signaling and regulating Th17/Treg balance

BACKGROUND

Chinese herbal medicine Qing-Chang-Hua-Shi granule (QCHS) is widely used to treat ulcerative colitis in China. However, the molecular mechanisms of QCHS remains largely unknown.

PURPOSE

To assess the therapeutic effects of QCHS on colitis and to reveal its mechanisms of action.

METHODS

The main components of QCHS were identified using a UHPLC-QTOF-MS method and the efficacy of QCHS was evaluated using an DSS-induced mice model. The inflammatory responses and mucosal integrity in colon were comprehensively assessed. Flow cytometry was used to analysis the proportion of Th17 and Treg cells. Detect the signal transduction of the NOD-like receptor family pyrin domain containing 6 (NLRP6) both in vitro and in vivo. Furthermore, siNLRP6 transfection was used to validate the functional targets of QCHS.

RESULTS

QCHS treatment significantly alleviated colitis in mice by improving symptoms and pathological damage. Moreover, QCHS treatment suppressed the inflammatory response and preserved the integrity of colon tissue. Most importantly, QCHS balanced the Th17/Treg response of UC mice. Mechanistically, by activating NLRP6 inflammasome pathway, QCHS regulated the maturation of interleukin (IL)-1β and IL-18 to affect inflammation and drive Th17 cell differentiation.

CONCLUSIONS

The effect of QCHS on UC mice is dose-dependent, with high-dose QCHS being superior to 5-Aminosalicylic acid (200 mg/kg/day). QCHS acts through the NLRP6 signaling pathway to modulate Th17/Treg balance, resulting in the protective effects against colitis. This study investigated the relevant pharmacological mechanisms of QCHS, providing further evidence for the application of QCHS in UC treatment.

New Baitouweng decoction combined with fecal microbiota transplantation alleviates DSS-induced colitis in rats by regulating gut microbiota metabolic homeostasis and the STAT3/NF-κB signaling pathway

AIM OF THE STUDY

We aimed to elucidate the synergistic effect and potential mechanism of New Baitouweng Decoction (NBD) combined with fecal microbiota transplantation (FMT) in rats with DSS-induced ulcerative colitis (UC).

MATERIALS AND METHODS

Colitis was induced by 5% (w/v) dextran sulfate sodium (DSS) in drinking water for 7 days. NBD or NBD combined with FMT were administered to the colitis rats. Body weight and disease activity index were measured, and the colon histological change was imaged to further examine the efficacy of NBD and FMT. The specific effects of NBD on STAT3/NF-κB signaling pathway and gut microbiota in rats with UC were also investigated.

RESULTS

The efficacy of NBD in combination with FMT was demonstrated by the lower disease activity index scores; increased tight junction proteins expression; and a lower expression of macrophage marker (F4/80) in colon tissues. NBD combined with FMT elevated the concentrations of short-chain fatty acids and inhibited activation of the JAK2/STAT3/NF-κB related proteins. Furthermore, 16SrDNA sequencing indicated that the gut microbiota in rats with UC was perturbed, in contrast to that in healthy rats. After treatment with NBD and FMT, the diversity and abundance of intestinal flora showed clear improvements. Spearman correlation analysis indicated a strong correlation between specific microbiota and fecal concentrations of acetate, propionate and butyrate.

CONCLUSIONS

The protective mechanism of NBD combined with FMT may be linked to regulation NF-κB/STAT3 and restoration of the intestinal flora.