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Inappropriate CD4 + T helper (T H ) cell differentiation leads to progression of inflammatory and autoimmune diseases, yet the regulatory mechanisms governing stability and activity of transcription factors controlling T H cell differentiation remain elusive. Here, we describe how pseudokinase serine threonine kinase 40 (STK40) facilitates T H 1/T H 17 differentiation under pathological conditions. STK40 in T cells is dispensable for immune homeostasis in resting mice. However, mice with T cell-specific deletion of STK40 exhibit attenuated symptoms of experimental autoimmune encephalomyelitis and colitis, accompanied by diminished T H 1 and T H 17 cell differentiation. Mechanistically, STK40 facilitates K48-linked polyubiquitination and proteasomal degradation of FOXO1/4 through promoting their interaction with E3 ligase COP1. Inhibition of FOXO4 or FOXO1, respectively, restores differentiation potential of STK40-deficient T H 1/T H 17 cells. Together, our data suggest a crucial role of STK40 in T H 1 and T H 17 cell differentiation, thereby enabling better understanding of the molecular regulatory network of CD4 + T cell differentiation and providing effective targets for the treatment of autoimmune diseases.

Inflammatory bowel diseases (IBDs) are chronic debilitating conditions without cure, the etiologies of which are unknown, that shorten the lifespans of 7 million patients worldwide by nearly 10%. Here, we found that decreased autonomic parasympathetic tone resulted in increased IBD susceptibility and mortality in mouse models of disease. Conversely, vagal stimulation restored neuromodulation and ameliorated colitis by inhibiting the posttranslational modification SUMOylation through a mechanism independent of the canonical interleukin-10/α7 nicotinic cholinergic vagal pathway. Colonic biopsies from patients with IBDs and mouse models showed an increase in small ubiquitin-like modifier (SUMO)2 and SUMO3 during active disease. In global genetic knockout mouse models, the deletion of Sumo3 protected against development of colitis and delayed onset of disease, whereas deletion of Sumo1 halted the progression of colitis. Bone marrow transplants from Sumo1 -knockout (KO) but not Sumo3 -KO mice into wild-type mice conferred protection against development of colitis. Electric stimulation of the cervical vagus nerve before the induction of colitis inhibited SUMOylation and delayed the onset of colitis in Sumo1 -KO mice and resulted in milder symptoms in Sumo3 -KO mice. Treatment with TAK-981, a first-in-class inhibitor of the SUMO-activating enzyme, ameliorated disease in three murine models of IBD and reduced intestinal permeability and bacterial translocation in a severe model of the disease, suggesting the potential to reduce progression to sepsis. These results reveal a pathway of vagal neuromodulation that reprograms endogenous stress-adaptive responses through inhibition of SUMOylation and suggest SUMOylation as a therapeutic target for IBD.

Peroxisome dynamics are crucial for intestinal stem cell (ISC) differentiation and gut regeneration. However, the precise mechanisms that govern peroxisome dynamics within ISCs during gut regeneration remain unknown. Using mouse colitis and Drosophila intestine models, we have identified a negative-feedback control mechanism involving the transcription factors peroxisome proliferator-activated receptors (PPARs) and SOX21. This feedback mechanism effectively regulates peroxisome abundance during gut regeneration. Following gut injury, the released free very long-chain fatty acids (VLCFAs) increase peroxisome abundance by stimulating PPARs-PEX11s signaling. PPARs act to stimulate peroxisome fission and inhibit pexophagy. SOX21, which acts downstream of peroxisomes during ISC differentiation, induces peroxisome elimination through pexophagy while repressing PPAR expression. Hence, PPARs and SOX21 constitute a finely tuned negative-feedback loop that regulates peroxisome dynamics. These findings shed light on the complex molecular mechanisms underlying peroxisome regulation in ISCs, contributing to our understanding of gut renewal and repair., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Various signaling pathways are essential for both the innate immune response and the maintenance of cell homeostasis, requiring coordinated interactions among them. In this study, a mutation in the caspase-1 recognition site within MyD88 abolished inflammasome-dependent negative regulation, causing phenotypic changes in mice with some similarities to human NEMO-deficiencies. The MyD88 D162E mutation reduced MyD88 protein levels and colon inflammation in DSS-induced colitis mice but did not affect cytokine expression in bone marrow-derived macrophages (BMDMs). However, compared to MyD88 wt counterparts, MyD88 D162E BMDMs had increased oxidative stress and dysfunctional mitochondria, along with reduced prosurvival Bcl-xL and BTK expression, rendering cells more prone to apoptosis, exacerbated by ibrutinib treatment. NF-κB activation by lipopolysaccharide mitigated this sensitive phenotype. These findings underscore the importance of MyD88 wt signaling for NF-κB activation, protecting against macrophage premature apoptosis at resting state. Targeting MyD88 quantity rather than just its signaling could be a promising strategy for MyD88-driven lymphoma treatment., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Eosinophils were previously reported to play a role in intestinal inflammation and fibrosis. Whether this is as a bystander or as an active participant is still up for debate. Moreover, data describing a causal relationship between eosinophils and intestinal fibrosis are scarce. We here aimed to elucidate the role of eosinophils in the pathogenesis of intestinal inflammation and fibrosis. Therefore, we stimulated fibroblasts with (active) eosinophils or with Eosinophil Cationic Protein (ECP), and assessed fibroblast activation via flow cytometry and immunocytochemistry. We observed decreased fibroblast activation when fibroblasts were co-cultured with active eosinophils or after stimulation with ECP in comparison to monoculture conditions, but not in case of co-culturing with inactivated eosinophils. Furthermore, eosinophil depletion in a RAG -/- chronic DSS colitis model resulted in decreased inflammation, but increased development of fibrosis. In this model, we could show increased expression of the anti-inflammatory protein IL-10 and the pro-fibrotic factors IL-1β, FGF-21 and TGF-β3 in the eosinophil-depleted mice compared to the control mice. In conclusion, our in vitro data revealed an anti-fibrotic role for eosinophils. In line, in a chronic murine colitis model, we observed a pro-inflammatory, but an anti-fibrotic, role for eosinophils. Furthermore, we identified an increased presence of anti-inflammatory and pro-fibrotic cytokines in the eosinophil depleted group., (© 2024. The Author(s).)

Resistant starch (RS) is present in various natural and processed foods as well as medications. It has garnered significant attention from both scientists and consumers due to its notable health benefits. However, there is a limited understanding of how RS particles are absorbed at the cellular level and their metabolic behavior, resulting in a lack of clarity regarding the intestinal safety implications of prolonged RS exposure. Here, we demonstrate that rice-derived RS nanoparticles (RSNs) can lead to colitis in mice by triggering lysosomal exocytosis. The research shows that RSNs enter the cells through macropinocytosis and clathrin- and caveolin-mediated endocytosis and activate TRPML1 thereafter, causing the release of lysosomal calcium ions. This, in turn, triggered the TFEB signaling pathway and thus upregulated the lysosomal exocytosis level, leading to lysosomal enzymes to be released to the intestinal lumen. As a result, a decreased number of intestinal goblet cells, diminished tight junction protein expression, and imbalanced intestinal flora in mice were observed. These damages to the intestinal barrier ultimately led to the occurrence of colitis. Our study offers important insights into the cellular bioeffects and detrimental effects on intestinal health caused by RS particles and emphasizes the need to re-evaluate the safety of long-term RS consumption.

Gasdermin C is one of the least studied members of the gasdermin family of proteins, known for their critical involvement in pyroptosis and host defense. Furthermore, evidence for the role of Gasdermin C in the intestine is scarce and partly controversial. Here, we tested the functional role of Gasdermin C in intestinal homeostasis, inflammation and tumorigenesis. : We studied Gasdermin C in response to cytokines in intestinal organoids. We evaluated epithelial differentiation, cell death and immune infiltration under steady state conditions in a new mouse line deficient in Gasdermin C. The role of Gasdermin C was analyzed in acute colitis, infection and colitis-associated cancer. Gasdemin C is highly expressed in the intestinal epithelium and strongly induced by the type 2 cytokines IL-4 and IL-13 in a STAT6-dependent manner. Gasdermin C-deficient mice show no changes in tissue architecture and epithelial homeostasis. Epithelial organoids deficient in Gasdermin C develop normally and show no alterations in proliferation or cell death. No changes were found in models of acute colitis, type 2 intestinal infection and colitis-associated cancer. Gasdermin C genes are upregulated by type 2 immunity, yet appear dispensable for the development of intestinal inflammation, infection and colitis-associated cancer., (© 2024. The Author(s).)

Understanding the complex link between inflammation, gut health, and dietary amino acids is becoming increasingly important in the pathophysiology of inflammatory bowel disease (IBD). This study tested the hypothesis that a leucine-rich diet could attenuate inflammation and improve gut health in a mouse model of IBD. Specifically, we investigated the effects of a leucine-rich diet on dextran sulfate sodium (DSS)-induced colitis in germ-free (GF) SAMP1/YitFC (SAMP) mice colonized with human gut microbiota (hGF-SAMP). hGF-SAMP mice were fed one of four different diets: standard mouse diet (CHOW), American diet (AD), leucine-rich AD (AD + AA), or leucine-rich CHOW diet (CH + AA). Body weight, myeloperoxidase (MPO) activity, gut permeability, colonoscopy scores, and histological analysis were measured. Mice on a leucine-rich CHOW diet showed a decrease in fecal MPO prior to DSS treatment as compared to those on a regular diet ( p > 0.05); however, after week five, prior to DSS, this effect had diminished. Following DSS treatment, there was no significant difference in gut permeability, fecal MPO activity, or body weight changes between the leucine-supplemented and control groups. These findings suggest that while a leucine-rich diet may transiently affect fecal MPO levels in hGF-SAMP mice, it does not confer protection against DSS-induced colitis symptoms or mitigate inflammation in the long term.

Background: Imbalances in Th1/Th2 and Th17/Treg immune axes, coupled with disruptions in the gut microbiota (GM), play a pivotal role in the pathogenesis of inflammatory bowel disease (IBD). Cordycepin, a natural anti-inflammatory compound, holds promise in mitigating IBD by rebalancing these immune axes in conjunction with modulating the GM. The aim of this experiment is to investigate the potential of cordycepin in mitigating enteritis and elucidate the underlying mechanisms associated with its ameliorative effects on enteritis., Methods: On the day of inducing experimental colitis with Dextran Sulfate Sodium (DSS), mice in the DSS + Cordycepin and Cordycepin groups received 50 mg/kg/day Cordycepin via intra-gastric administration (i.g.) for seven consecutive days, respectively. Mice in the DSS and control groups were treated with equal volumes of saline. On day 8, all mice were euthanized under pentobarbital sodium anesthesia., Results: In a DSS-induced colitis mouse model, Cordycepin treatment led to a significant reduction in the disease activity index (DAI), splenic weight, and colonic pathological injury while simultaneously improving body weight and colonic length. Furthermore, it positively impacted GM composition, resulting in decreased Th1 and Th17 cells, alongside an increase in Th2 and Treg cells. The contents of the mouse colon were extracted for microbial community analysis. Mouse blood was prepared into a single-cell suspension, and flow cytometry was used to assess the expressio of Treg, Th17, Th1, and Th2 immune cells., Conclusions: These results underscored the effective intervention of cordycepin in ameliorating DSS-induced colitis by harmonizing the interplay between GM and immune homeostasis., Competing Interests: Declaration of Competing Interest I, Jingting Jiang, declare that there are no conflicts of interest in relation to the manuscript titled "Cordycepin Mitigates Dextran Sulfate Sodium-Induced Colitis through Improving Gut Microbiota Composition and Modulating Th1/Th2 and Th17/Treg Balance" submitted to Biomedicine Pharmacotherapy. I confirm that the results and interpretations reported in the manuscript are original and have not been plagiarized. I certify that I have read and understand the Biomedicine Pharmacotherapy conflict of interest policy, and I understand that failure to disclose a conflict of interest may result in the manuscript being rejected or retracted. I also certify that I have disclosed any financial or non-financial relationships that may be interpreted as constituting a conflict of interest in relation to this manuscript. I understand that this information will be subject to peer review, and I am willing to provide further information or clarification if required. I confirm that I have no known conflicts of interest that would influence the results or interpretation of the data presented in this manuscript, and I understand that failure to disclose a conflict of interest is unethical and may result in sanctions being imposed on me., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Inflammatory bowel disease (IBD) is a disorder causing chronic inflammation in the gastrointestinal tract, and its pathophysiological mechanisms are still under investigation. Here, we find that mice deficient of YOD1, a deubiquitinating enzyme, are highly susceptible to dextran sulfate sodium (DSS)-induced colitis. The bone marrow transplantation experiment reveals that YOD1 derived from hematopoietic cells inhibits DSS colitis. Moreover, YOD1 exerts its protective role by promoting nucleotide-binding oligomerization domain 2 (NOD2)-mediated physiological inflammation in macrophages. Mechanistically, YOD1 inhibits the proteasomal degradation of receptor-interacting serine/threonine kinase 2 (RIPK2) by reducing its K48 polyubiquitination, thereby increasing RIPK2 abundance to enhance NOD2 signaling. Consistently, the protective function of muramyldipeptide, a NOD2 ligand, in experimental colitis is abolished in mice deficient of YOD1. Importantly, YOD1 is upregulated in colon-infiltrating macrophages in patients with colitis. Collectively, this study identifies YOD1 as a novel regulator of colitis., (© 2024. The Author(s).)

This study aimed to validate the DFS (direct fast scarlet) staining in the diagnosis of EC (eosinophilic colitis). The study included 50 patients with EC and 60 with control colons. Among the 60 control samples, 39 and 21 were collected from the ascending and descending colons, respectively. We compared the median number of eosinophils and frequency of eosinophil degranulation by HE (hematoxylin and eosin) and DFS staining between the EC and control groups. In the right hemi-colon, eosinophil count by HE was useful in distinguishing between EC and control (41.5 vs. 26.0 cells/HPF, p < 0.001), but the ideal cutoff value is 27.5 cells/HPF (high-power field). However, this method is not useful in the left hemi-colon (12.5 vs. 13.0 cells/HPF, p = 0.990). The presence of degranulation by DFS allows us to distinguish between the groups even in the left hemi-colon (58% vs. 5%, p < 0.001). DFS staining also enabled a more accurate determination of degranulation than HE. According to the current standard to diagnose EC (count by HE staining ≥20 cells/HPF), mucosal sampling from left hemi-colon is problematic since the number of eosinophils could not be increased even in EC. Determination of degranulated eosinophils by DFS may potentiate the diagnostic performance even in such conditions., (© 2024 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.)

Colon cancer is on the rise in younger adults. Despite multimodal treatment strategies, clinical outcomes in advanced stage colon cancer patients remain poor. Neoadjuvant/adjuvant chemotherapy efficacy is limited due to chemoresistance, toxicity, and negative side effects. Overwhelming evidence supporting the small-molecule metabolites derived from breakdown of food or microbial sources confer an extensive array of host benefits, including chemo-preventive role in colon cancer. Our previous study indicated that the introduction of glyoxylate (Glx), an intermediate product of microbial or plant metabolism, exerts a cytotoxic effect in colon cancer cells. This study was designed to evaluate the effects of Glx on colon cancer with molecular insights. For this, we established an AOM/DSS-induced colitis associated colon cancer model in mice. Supplementation of Glx in vivo reduced colitis associated tumor growth and altered the metabolic characteristics of tumor tissue in mice without initiating any severe liver or renal toxicity. More specifically, intake of glyoxylate accumulated glycine in the colon tissue by elevation of alanine-glyoxylate transferase (AGXT) activity. Glycine accumulation increased intracellular Ca 2+ concentration via glycine receptor activation and dysregulation of Ca 2+ homeostasis lead to induction of apoptosis that resulted in arresting tumor growth. Interestingly, elevation of AGXT activity or Glx related specific metabolic pathway provides better survival in colon cancer patients. Collectively, our exclusive findings support the exploration of Glx either as a preventive molecule or its inclusion in the treatment regimens for colon cancer., (© 2024 Wiley Periodicals LLC.)

The unknown mechanism that controls intestinal barrier dysfunction in individuals with Crohn's disease (CD) plays a crucial role in the onset of intestinal inflammation. Testin, an intercellular linker protein, has the potential to protect epithelial barrier function. This study aimed to analyse the effects of Testin on CD-like colitis and explore the possible underlying mechanism. Colon samples from CD patients and trinitrobenzene-sulfonic acid (TNBS)-treated mice were collected to examine changes in Testin expression. To assess the therapeutic effects of Testin on CD-like colitis in mice, we examined the symptoms of enteritis, performed histological analysis, and evaluated intestinal barrier permeability. The ability of Testin to stabilize tight junction (TJ) proteins was investigated via immunofluorescence and western blotting. We conducted in vivo and in vitro experiments using colonic organoids and blocking techniques to explore how Testin safeguards the integrity of the intestinal barrier. Testin expression was downregulated in the colons of CD patients and TNBS-treated mice. Increasing Testin expression led to amelioration of colitis symptoms and reduced the production of inflammatory cytokines in the colons of TNBS-induced colitis model mice. Furthermore, increased Testin expression resulted in decreased depletion of TJ proteins (ZO-1 and Claudin-1) and promoted the effectiveness of the intestinal barrier in mice with TNBS-induced colon damage and in lipopolysaccharide (LPS)-stimulated colonic organoids. Elevated Testin levels inactivated the JNK/P38 signalling pathway, potentially contributing to the beneficial impact of Testin on the intestinal barrier. Testin can inhibit the loss of TJ proteins in CD mice by inactivating the JNK/P38 pathway. These findings help to clarify how Testin alleviates CD-like colitis in mice by protecting intestinal barrier function. These findings could lead to the use of a new treatment approach for CD in clinical practice., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Acute gastrointestinal (GI) inflammation induces neuroplasticity that produces long-lasting changes in gut motor function and pain. The endocannabinoid system is an attractive target to correct pain and dysmotility, but how inflammation changes endocannabinoid control over cellular communication in enteric neurocircuits is not understood. Enteric glia modulate gut neurons that control motility and pain and express monoacylglycerol lipase (MAGL) which controls endocannabinoid availability. We used a combination of in situ calcium imaging, chemogenetics, and selective drugs to study how endocannabinoid mechanisms affect glial responses and subsequent enteric neuron activity in health and following colitis in Wnt1 Cre;GCaMP5g-tdT ;GFAP::hM3Dq mice. Trpv1 Cre;GCaMP5gtdT mice were used to study nociceptor sensitivity and Sox10 CreERT2 ;Mgll f/f mice were used to test the role of glial MAGL in visceral pain. The data show that endocannabinoid signaling regulates neuro-glial signaling in gut neurocircuits in a sexually dimorphic manner. Inhibiting MAGL in healthy samples decreased glial responsiveness but this effect was lost in females following colitis and converted to an excitatory effect in males. Manipulating CB1 and CB2 receptors revealed further sex differences amongst neuro-glia signaling that were impacted following inflammation. Inflammation increased gut nociceptor sensitivity in both sexes but only females exhibited visceral hypersensitivity in vivo. Blocking MAGL normalized nociceptor responses in vitro and deleting glial Mgll in vivo rescued visceral hypersensitivity in females. These results show that sex and inflammation impact endocannabinoid mechanisms that regulate intercellular enteric glia-neuron communication. Further, targeting glial MAGL could provide therapeutic benefits for visceral nociception in a sex-dependent manner., (© 2024 The Author(s). GLIA published by Wiley Periodicals LLC.)

Oxidative stress has long been known as a pathogenic factor of ulcerative colitis. Superoxide dismutase (SOD) has been demonstrated to mitigate gut mucosal injury via combating oxidative stress. Herein, we developed SOD-loaded multivesicular liposomes (S-MVLs) as sustained-release depot for ulcerative colitis treatment. S-MVLs were spherical honeycomb-like particles with average particle size of 27.3 ± 5.4 μm and encapsulating efficiency of 78.7 ± 2.6 %. Moreover, the two-phase release profiles of SOD from S-MVLs were exhibited, that was, the burst release phase within 4 h and the sustained-release phase within 96 h. After intraperitoneally injecting S-MVLs, in situ retention time of SOD at bowel cavity extended by 4-fold in comparison with SOD solution. In vitro cells experiment showed that S-MVLs had the protective effect on LPS-treated RAW 264.7 cells via scavenging ROS and inhibiting pro-inflammatory cytokines production. S-MVLs ameliorated the body weight loss, DAI score and the colon shortening of colitis mice. Meanwhile, the colonic morphology and the epithelial barrier of colitis mice were effectively recovered after S-MVLs treatment. The therapeutic mechanism might be associated with polymerizing M1 macrophages to M2 phenotypes and alleviating oxidative stress. Collectively, multivesicular liposomes might be a promising sustained-release depot of SOD for ulcerative colitis treatments., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests. Helin Xu reports financial support was provided by Wenzhou Medical University. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (Copyright © 2024 Elsevier B.V. All rights reserved.)

Ulcerative colitis is a chronic pathology characterized by relapsing-remitting phases of intestinal inflammation. Additionally, some patients develop neuropsychiatric disorders, such as depression and anxiety, or cognitive deficits. We aimed to investigate whether the development of chronic colitis elicits memory, locomotion, and mood impairments. It further examined whether these impairments are influenced by the relapsing-remitting phases of the colitis or by sex. Here, we used a chronic colitis model in male and female rats, induced with sodium dextran sulfate, mirroring the phases of human ulcerative colitis. Our results revealed that the severity of colitis was slightly higher in males than females. Chronic colitis triggered motor and short-term memory deficits and induced anxiety- and depression-like behaviors that remained throughout the development of the disease. There are also sex differences under control or inflammatory conditions. Therefore, in both situations, females compared to males displayed: (i) slightly lower locomotion, (ii) increased anxiety-like behaviors, (iii) similar depression-like behaviors, and (iv) similar short-term memory deficit. Additionally, under control conditions, the mRNA levels of IL-1β, IL-6, and TNF-α were higher in the female hippocampus. In both sexes, when chronic colitis was established, the neuroinflammation was evidenced by increased mRNA levels of these three cytokines in the hippocampus and in the motor and prefrontal cortices. Interestingly, this neuroinflammation was slightly greater in males. In summary, we show that the development of chronic colitis caused persistent behavioral abnormalities, highlighting sex differences, and that could be a consequence, at least in part, of the increase in IL-1β, IL-6, and TNF-α in the brain., (© 2024 The Author(s). The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.)

Colorectal cancer represents one of the most serious complications of inflammatory bowel disease. The NLRP3 inflammasome plays a pivotal role in the onset and progression of inflammatory bowel disease and is also implicated in colorectal cancer. This study aimed to investigate whether NLRP3 deficiency or glyburide, a sulfonylurea used for diabetes management and known as an NLRP3 inhibitor, could suppress colitis and its related colorectal tumorigenesis. Mice were divided into three groups: a control group, a glyburide group, and an NLRP3-deficient group. We investigated acute colitis and inflammation-related tumor models using azoxymethane and dextran sodium sulfate. In the colitis model, the colonic inflammation grade was significantly increased in NLRP3-deficient mice but not in mice administered glyburide. In the colorectal carcinogenesis model, fewer colorectal tumors were observed in both NLRP3-deficient and glyburide-treated groups. Additionally, a reduction in the expression levels of inflammatory cytokine genes was detected in the colonic mucosa of the mice of these groups. These findings suggest that NLRP3 deficiency may exacerbate acute colitis, while pharmacological inhibition, as well as deficiency of NLRP3, suppresses colitis-related tumorigenesis, presumably due to the attenuation of chronic inflammation in the colorectum. Glyburide holds promise as a potential chemopreventive agent for colitis-related colorectal cancer.

Probiotics therapy has garnered significant attention in the treatment of inflammatory bowel disease (IBD). However, a large number of oral administrated probiotics are inactivated after passing through the gastric acid environment, and their ability to colonize in the intestine is also weak. Herein, this study develops a novel probiotics formulation (GM-EcN) by incorporating Escherichia coli Nissle 1917 (EcN) into intracellularly gelated macrophages (GM). Intracellular hydrogel is designed to load and prevent EcN from digestion in gastric juice, and GM acts as a macrophage-like carrier to carry the attached probiotics to colonize in the inflammatory intestine. In addition, hydrogel serves as an ideal cytoskeletal structure to maintain the intact cell morphology and membrane structure of GM, comparable to source macrophages. Due to the receptor-ligand interaction, inflammation-related membrane proteins enable GM as a cell sponge to sequestrate and neutralize multiple inflammatory cytokines. In vivo treatment demonstrates that GM-EcN efficiently alleviates IBD symptoms and enhances gut microbiota recovery.

Ulcerative colitis (UC) is an inflammatory bowel disease that predominantly impacts the colon, typically starting in the rectum. A significant characteristic of UC is its propensity to affect the distal colon, which is particularly beneficial for targeted treatments such as enemas. This localized approach ensures that the medication is delivered directly to the affected areas, resulting in minimal systemic absorption. In this research, we have formulated a novel stimuli-responsive quercetin-loaded guanosine borate supramolecular hydrogel (named GBQ hydrogel), designed to prolong the residence time of the drug and protect the ulcerated intestinal tissues. The GBQ hydrogel has exhibited excellent injectability, self-healing capabilities, and biocompatibility, rendering it an ideal candidate for enema administration. In vitro studies have highlighted its ROS/pH dual-responsive release profile, which mimics the microenvironment of intestinal inflammation. Furthermore, we assessed the efficacy of the GBQ hydrogel on dextran sulfate sodium (DSS)-induced colitis, a common animal model for UC. Our findings indicate that the GBQ hydrogel significantly reduces disease activity, mitigates oxidative stress, restores the intestinal mucosal barrier, and prevents colonic cell apoptosis. Collectively, this study underscores the therapeutic potential of the GBQ hydrogel in managing inflammatory bowel conditions and paves the way for a novel hydrogel enema-based treatment strategy for UC.

Intestinal stem cells (ISCs) are responsible for intestinal homeostasis and are important for the regeneration of damaged intestine. We established an ionizing radiation (IR)-induced intestinal injury model and observed that Gelsolin KO mice had increased radiosensitivity. The deletion of Gelsolin aggravated intestinal damage and reduced the number of ISCs after lethal IR. The intestinal organoid experiments showed that Gelsolin deletion inhibited ISCs function after IR. Notably, RNA sequencing and RT-PCR results showed IL-17 signaling pathway was down-regulated and Th17 cells differentiation was inhibited in Gelsolin KO mice. Moreover, recombinant IL-17 A ameliorated IR-induced intestinal injury and promoted ISCs regeneration. To figure out the role of Gelsolin in Th17 cells differentiation, flow cytometry was used and we found that Gelsolin targets Th17 cells functionality via the p-STAT3/RORγt axis. By establishing the co-culture system, we proved that Th17 cells promoted self-renewal and budding abilities in Gelsolin-deficient organoids. Finally, we found that Gelsolin was protective against DSS-induced colitis and that this protective effect was not specific or limited to the IR induced intestinal injury model. Based on these results, we proved Gelsolin maintained the regeneration of ISCs by sustaining Th17 cells functions via the p-STAT3/RORγt axis., (© 2024. The Author(s).)

The intestines are in a constant state of motion and self-renewal. The mechanical breakdown of food facilitates intestinal movement and aids digestion. It is believed that mechanical stimulation, triggered by changes in osmotic pressure within the intestines, plays a crucial role in regulating gastrointestinal motility. While TRPs and PIEZO1/2 have been identified as mechanosensitive ion channels involved in this process, there still exist numerous unidentified channels with similar properties. In this study, we demonstrate that the TMEM63B expressed in intestinal stem cells contributes to the regulation of intestinal motility and digestion. The deletion of TMEM63B in intestinal stem cells not only decelerates intestinal motility and impairs digestion but also attenuates the proliferation of intestinal stem cells and exacerbates DSS-induced colitis in mice. Collectively, our findings unveil the pivotal role of TMEM63B in governing optimal digestive function and modulating intestinal motility.

Cells that lack p53 signaling frequently occur in ulcerative colitis (UC) and are considered early drivers in UC-associated colorectal cancer (CRC). Epithelial injury during colitis is associated with transient stem cell reprogramming from the adult, homeostatic to a "fetal-like" regenerative state. Here, we use murine and organoid-based models to study the role of Trp53 during epithelial reprogramming. We find that p53 signaling is silent and dispensable during homeostasis but strongly up-regulated in the epithelium upon DSS-induced colitis. While in WT cells this causes termination of the regenerative state, crypts that lack Trp53 remain locked in the highly proliferative, regenerative state long-term. The regenerative state in WT cells requires high Wnt signaling to maintain elevated levels of glycolysis. Instead, Trp53 deficiency enables Wnt-independent glycolysis due to overexpression of rate-limiting enzyme PKM2. Our study reveals the context-dependent relevance of p53 signaling specifically in the injury-induced regenerative state, explaining the high abundance of clones lacking p53 signaling in UC and UC-associated CRC.

Cystathionine γ-lyase (CTH) is a critical enzyme in the reverse transsulfuration pathway, the major route for the metabolism of sulfur-containing amino acids, notably converting cystathionine to cysteine. We reported that CTH supports gastritis induced by the pathogen Helicobacter pylori. Herein our aim was to investigate the role of CTH in colonic inflammation. First, we found that CTH is induced in the colon mucosa in mice with dextran sulfate sodium-induced colitis. Expression of CTH was completely absent in the colon of Cth -/- mice. We observed that clinical and histological parameters are ameliorated in Cth-deficient mice compared to wild-type animals. However, Cth deletion had no effect on tumorigenesis and the level of dysplasia in mice treated with azoxymethane-DSS, as a reliable model of colitis-associated carcinogenesis. Mechanistically, we determined that the deletion of the gene Slc7a11 encoding for solute carrier family 7 member 11, the transporter of the anionic form of cysteine, does not affect DSS colitis. Lastly, we found that the richness and diversity of the fecal microbiota were significantly increased in Cth -/- mice compared to both WT and Slc7a11 -/- mice. In conclusion, our data suggest that the enzyme CTH represents a target for clinical intervention in patients with inflammatory bowel disease, potentially by beneficially reshaping the composition of the gut microbiota., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

MicroRNAs, including the tumor-suppressor miR-126 and the oncogene miR-221, regulate tumor formation and growth in colitis-associated cancer (CAC) and colorectal cancer (CRC). This study explores the impact of the epithelial cytokine heparin-binding epidermal growth factor (HB-EGF) and its receptor epidermal growth factor receptor (EGFR) on the pathogenesis of CAC and CRC, particularly in the regulation of microRNA-driven tumor growth and protease expression. In murine models of CRC and CAC, lack of miR-126 and elevated miR-221 expression in colonic tissues enhanced tumor formation and growth. MiR-126 downregulation in colon cells established a pro-tumorigenic proteolytic niche by targeting HB-EGF-active metalloproteinase-7, -9 (MMP7/MMP9), disintegrin, and metalloproteinase domain-containing protein 9, and modulating chemokine-mediated recruitment of HB-EGF-loaded inflammatory cells. Mechanistically, downregulation of HB-EGF and EGFR in the colon suppressed miR-221 and enhanced miR-126 expression via activating enhancer-binding protein 2 alpha. Reintroducing miR-126 reduced tumor development and HB-EGF expression. Combining miR-126 reintroduction, which targets specific HB-EGF-active proteases but not ADAM17, with MMP inhibitors like Batimastat or Marimastat effectively suppressed tumor growth. This combination normalized protease expression and balanced miR-126 and miR-221 levels in developing and growing tumors. These findings demonstrate that suppressing HB-EGF and EGFR1 shifts the balance from oncogenic miR-221 to tumor-suppressive miR-126 action. Consequently, normalizing miR-126 expression could open new avenues for treating patients with CAC and CRC, and this normalization is intertwined with the anticancer efficacy of MMP inhibitors., (© 2024. The Author(s).)

Inflammatory bowel disease (IBD) significantly diminishes an individual's quality of life and increases the risk of colorectal cancer. Recent clinical and experimental findings suggest that infection with parasitic helminths may suppress the development of certain inflammatory conditions. The objective of this study was to evaluate the immunoregulatory effects of Dicrocoelium eggs on experimentally induced colitis in C57BL/6 mice using dextran sulfate sodium (DSS). C57BL/6 mice received 3.5% DSS orally for 7 days to induce colitis, during which they were treated intraperitoneally with Dicrocoelium eggs. The severity of colitis was assessed through parameters such as body weight, stool consistency or bleeding, disease activity index (DAI), colon lengths, macroscopic scores, histopathological findings, colon gene expression levels, and serum cytokine levels. Our results indicated that Dicrocoelium eggs administration significantly reduced the severity of colitis and disease activity. Histopathological scores improved, correlating with downregulation of IFN-γ and upregulation of IL-4 expression. This findings suggest the therapeutic potential of Dicrocoelium eggs in treating colitis. Immunotherapy involving Dicrocoelium eggs primarily induces a Th2 response and modulates IFN-γ, contributing to reduced inflammation in colitis. Thus, this approach could be a promising therapeutic strategy for alleviating inflammation in IBD., (© 2024. The Author(s).)

Experimental evidence suggests that, in the inflamed gut of inflammatory bowel disease (IBD) patients, interleukin-34 (IL-34) triggers detrimental signaling pathways. Factors/mechanisms regulating IL-34 production in IBD remain poorly characterized. Bromodomain-containing 4 (BRD4), a transcriptional and epigenetic regulator, is over-expressed in IBD, and studies in cancer cells suggest that BRD4 might positively control IL-34 expression. This study aimed to assess whether, in IBD, BRD4 regulates IL-34 expression. In IBD, there was an up-regulation of both IL-34 and BRD4 compared to the controls, and the two proteins co-localized in both lamina propria mononuclear cells (LPMCs) and epithelial cells. Flow cytometry analysis of CD45+ LPMCs confirmed that the percentages of IL-34- and BRD4-co-expressing cells were significantly higher in IBD than in the controls and showed that more than 80% of the IL-34-positive CD45-LPMCs expressed BRD4. IL-34 and BRD4 were mainly expressed by T cells and macrophages. IL-34 expression was reduced in IBD LPMCs transfected with BRD4 antisense oligonucleotide and in the colons of mice with dextran sulfate sodium-induced colitis treated with JQ1, a pharmacological inhibitor of BRD4. These data indicate that BRD4 is a positive regulator of IL-34 in IBD, further supporting the pathogenic role of BRD4 in IBD-associated mucosal inflammation.

Extracellular vesicles (EVs) are physiological vectors for the intercellular transport of a variety of molecules. Among these, small RNAs, and especially microRNAs (miRNAs), have been identified as prevalent components, and there has thus been a robust investigation of EVs for therapeutic miRNAs delivery. However, intrinsic levels of EV-associated miRNAs are generally too low to enable efficient and effective therapeutic outcomes. We hypothesized that miRNA localization to EVs could be improved by limiting competing interactions that occur throughout the miRNA biogenesis process. Using miR-146a-5p as a model, modulation of transcription, nuclear export, and enzymatic cleavage steps of miRNA biogenesis were tested for impact on EV miRNA loading. Working in HEK293T cells, various alterations in the EV biogenesis pathway were shown to impact miRNA localization to EVs. The system was then applied in induced pluripotent stem cells (iPSCs), a more promising substrate for therapeutic EV production, and EVs were separated and assessed for anti-inflammatory efficacy in vitro and in a murine colitis model, where the preservation of function was validated. Overall, the results highlight necessary considerations when designing a cell culture system for the devoted production of miRNA-loaded EVs.

Colorectal cancer CRC remains one of the leading causes of cancer-related deaths worldwide, with chronic intestinal inflammation identified as a major risk factor. Notably, the tumor suppressor TP53 undergoes mutation at higher rates and earlier stages during human inflammation-driven colon tumorigenesis than in sporadic cases. We investigated whether deleting Trp53 affects inflammation-induced tumor growth and the expression of Lgr5+ cancer stem cells in mice. We examined azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colon tumorigenesis in wild-type Trp53 (+/+) , heterozygous (+/-) , and knockout (-/-) mice. Trp53-/- mice showed increased sensitivity to DSS colitis and earlier accelerated tumorigenesis with 100% incidence. All groups could develop invasive tumors, but knockouts displayed the most aggressive features. Unlike wild-type CRC, knockouts selectively showed increased populations of Lgr5+ colon cancer stem-like cells. Trp53 loss also boosted laminin, possibly facilitating the disruption of the tumor border. This study highlights how Trp53 deletion promotes the perfect storm of inflammation and stemness, driving colon cancer progression. Trp53 deletion dramatically shortened AOM/DSS latency and improved tumor induction efficiency, offering an excellent inflammation-driven CRC model.

Each life is challenged to adapt to an ever-changing environment with integrity-simply put, to maintain identity. We hypothesize that this mission statement of adaptive homeostasis is particularly poignant in an adaptive response, like inflammation. A maladaptive response of unresolved inflammation can seed chronic disease over a lifetime. We propose the concept of a molecular thumbprint: a biological signature of loss of identity as a measure of incomplete return to homeostasis after an inflammatory response. Over time, personal molecular thumbprints can measure dynamic and precise trajectories to chronic inflammatory diseases and further loss of self to cancer. Why is this important? Because the phenotypes and molecular signatures of established complex inflammatory diseases are a far cry from the root of the complex problem, let alone the initial seed. Understanding the science behind key germinating seeds of disease helps to identify molecular factors of susceptibility, resilience, and early dietary or drug intervention. We pilot this hypothesis in a rat colitis model that is well-established for understanding molecular mechanisms of colonic health, disease, and transition of colitis to cancer.

Chemokines are integral components of the immune system and deeply involved in the pathogenesis and progression of inflammatory bowel disease (IBD) and colorectal cancer (CRC). Although a considerable amount of transcriptome data has been accumulated on these diseases, most of them are limited to a specific stage of the disease. The purpose of this study is to visually demonstrate the dynamic changes in chemokines across various stages of bowel diseases by integrating relevant datasets. Integrating the existing datasets for IBD and CRC, we compare the expression changes of chemokines across different pathological stages. This study collected 11 clinical databases from various medical centers around the world. Patients: Data of patient tissue types were classified into IBD, colorectal adenoma, primary carcinoma, metastasis, and healthy control according to the publisher's annotation. The expression changes in chemokines in various pathological stages are statistically analyzed. The chemokines were clustered by different expression patterns. The chemokine family was clustered into four distinct expression patterns, which correspond to varying expression changes in different stages of colitis and tumor development. Certain chemokines and receptors associated with inflammation and tumorigenesis have been identified. Furthermore, it was confirmed that the 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis model and the azoxymethane (AOM)/ dextran sulfate sodium (DSS)-induced colon cancer model shows stronger correlations with the clinical data in terms of chemokine expression levels. This study paints a panoramic picture of the expression profiles of chemokine families at multiple stages from IBD to advanced colon cancer, facilitating a comprehensive understanding of the regulation patterns of chemokines and guiding the direction of drug development. This study provides researchers with a clear atlas of chemokine expression in the pathological processes of inflammatory bowel disease and colon cancer.

Background: The incidence of inflammatory bowel disease (IBD) is on the rise in developing countries, and investigating the underlying mechanisms of IBD is essential for the development of targeted therapeutic interventions. Interferon regulatory factor 7 (IRF7) is known to exert pro-inflammatory effects in various autoimmune diseases, yet its precise role in the development of colitis remains unclear., Methods: We analyzed the clinical significance of IRF7 in ulcerative colitis (UC) by searching RNA-Seq databases and collecting tissue samples from clinical UC patients. And, we performed dextran sodium sulfate (DSS)-induced colitis modeling using WT and Irf7 -/- mice to explore the mechanism of IRF7 action on colitis., Results: In this study, we found that IRF7 expression is significantly reduced in patients with UC, and also demonstrated that Irf7 -/- mice display heightened susceptibility to DSS-induced colitis, accompanied by elevated levels of colonic and serum pro-inflammatory cytokines, suggesting that IRF7 is able to inhibit colitis. This increased susceptibility is linked to compromised intestinal barrier integrity and impaired expression of key molecules, including Muc2, E-cadherin, β-catenin, Occludin, and Interleukin-28A (IL-28A), a member of type III interferon (IFN-III), but independent of the deficiency of classic type I interferon (IFN-I) and type II interferon (IFN-II). The stimulation of intestinal epithelial cells by recombinant IL-28A augments the expression of Muc2, E-cadherin, β-catenin, and Occludin. The recombinant IL-28A protein in mice counteracts the heightened susceptibility of Irf7 -/- mice to colitis induced by DSS, while also elevating the expression of Muc2, E-cadherin, β-catenin, and Occludin, thereby promoting the integrity of the intestinal barrier., Conclusion: These findings underscore the pivotal role of IRF7 in preserving intestinal homeostasis and forestalling the onset of colitis., (© 2024. The Author(s).)

Inflammatory Bowel Diseases (IBDs) are associated with aberrant immune function, widespread inflammation, and altered intestinal blood flow. Perivascular adipose tissue (PVAT) surrounding the mesenteric vasculature can modulate vascular function and control the local immune cell population, but its structure and function have never been investigated in IBD. We used an IL10 -/- mouse model of colitis that shares features with human IBD to test the hypothesis that IBD is associated with (1) impaired ability of PVAT to dilate mesenteric arteries and (2) changes in PVAT resident adipocyte and immune cell populations. Pressure myography and electrical field stimulation of isolated mesenteric arteries show that PVAT not only loses its anti-contractile effect but becomes pro-contractile in IBD. Quantitative immunohistochemistry and confocal imaging studies found significant adipocyte hyperplasia and increased PVAT leukocytes, particularly macrophages, in IBD. PCR arrays suggest that these changes occur alongside the altered cytokine and chemokine gene expression associated with altered NF-κB signaling. Collectively, these results show that the accumulation of macrophages in PVAT during IBD pathogenesis may lead to local inflammation, which ultimately contributes to increased arterial constriction and decreased intestinal blood flow with IBD.

Mucosal healing is associated with better clinical outcomes in patients with inflammatory bowel disease. But the epithelial-specific contribution to mucosal healing in vivo is poorly understood. We evaluated mucosal healing in an acute dextran sulfate sodium mouse model that shows an alleviated colitis response after epithelial-specific loss of Smad4. We find that enhanced epithelial wound healing alleviates the fibrotic response. Dextran sulfate sodium caused increased mesenchymal collagen deposition-indicative of fibrosis-within a week in the WT but not in the Smad4 KO colon. The fibrotic response correlated with decreased epithelial proliferation in the WT, whereas uninterrupted proliferation and an expanded zone of proliferation were observed in the Smad4 KO colon epithelium. Furthermore, the Smad4 KO colon showed epithelial extracellular matrix alterations that promote epithelial regeneration. Our data suggest that epithelium is a key determinant of the mucosal healing response in vivo, implicating mucosal healing as a strategy against fibrosis in inflammatory bowel disease patients., (© 2024 Hashemi et al.)

Colorectal cancer (CRC) resulting from chronic inflammation is a crucial issue in patients with inflammatory bowel disease (IBD). Although many reports established that intestinal resident CX3CR1 high macrophages play an essential role in suppressing intestinal inflammation, their function in colitis-related CRC remains unclear. In this study, we found that colonic CX3CR1 high macrophages, which were positive for MHC-II, F4/80 and CD319, promoted colitis-associated CRC. They highly expressed Col1a1, Tgfb, II10, and II4, and were considered to be fibrocytes with an immunosuppressive M2-like phenotype. CX3CR1 deficiency led to reductions in the absolute numbers of CX3CR1 high fibrocytes through increased apoptosis, thereby preventing the development of colitis-associated CRC. We next focused statins as drugs targeting CX3CR1 high fibrocytes. Statins have been actively discussed for patients with IBD and reported to suppress the CX3CL1/CX3CR1 axis. Statin treatment after azoxymethane/dextran sulfate sodium-induced inflammation reduced CX3CR1 high fibrocyte counts and suppressed colitis-associated CRC. Therefore, CX3CR1 high fibrocytes represent a potential target for carcinogenesis-preventing therapy, and statins could be safe therapeutic candidates for IBD., (© 2024. The Author(s).)

Background: The ATP2B1 gene encodes for a calcium pump, which plays a role in removing Ca2+ from cells and maintaining intracellular Ca2+ homeostasis. Reduction of the intracellular Ca2+ concentration in CD4+ T cells is thought to reduce the severity of colitis, while elevation of Ca2+ in CD4+ T cells induces T cell hyperactivity. Our aim was to clarify the role of ATP2B1 in CD4+ T cells and in inflammatory bowel disease development., Methods: A murine CD4+ T cell-specific knockout (KO) of ATP2B1 was created using a Cre-loxP system. CD4+ T cells were isolated from thymus, spleen, and blood using fluorescence-activated cell sorting. To quantify messenger RNA levels, quantitative real-time polymerase chain reaction was performed., Results: Although the percentages of CD4+ T cells in both KO mouse spleen and blood decreased compared with those of the control samples, both T-bet (a T helper 1 [Th1] activity marker) and GATA3 (a Th2 activity marker) expression levels were further increased in KO mouse blood CD4+ T cells (vs control blood). Diarrhea and colonic wall thickening (with mucosal changes, including crypt distortion) were seen in KO mice but not in control mice. Prior to diarrhea onset, the KO mouse colon length was already noted to be shorter, and the KO mouse stool water and lipid content were higher than that of the control mice. Tumor necrosis factor α and gp91 expressions were increased in KO mouse colon., Conclusions: Lack of ATP2B1 in CD4+ T cells leads to Th1 and Th2 activation, which contributes to colitis via elevation of tumor necrosis factor α and oxidative stress., (© The Author(s) 2024. Published by Oxford University Press on behalf of Crohn’s & Colitis Foundation. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Human interleukin-22 (IL-22) is known as a "dual function" cytokine that acts as a master regulator to maintain homeostasis, structural integrity of the intestinal epithelial barrier, and shielding against bacterial pathogens. On the other hand, the overexpression of IL-22 is associated with hyper-proliferation and recruitment of pathologic effector cells, leading to tissue damage and chronic inflammation in specific diseases including inflammatory bowel disease (IBD). To study a role of IL-22-mediated signaling axis during intestinal inflammation, we generated a set of small protein blockers of IL-22R1 and verified their inhibitory potential on murine model of colitis., Methods: We used directed evolution of proteins to identify binders of human IL-22 receptor alpha (IL-22R1), designated as ABR ligands. This approach combines the assembly of a highly complex combinatorial protein library derived from small albumin-binding domain scaffold and selection of promising protein variants using ribosome display followed by large-scale ELISA screening. The binding affinity and specificity of ABR variants were analyzed on transfected HEK293T cells by flow cytometry and LigandTracer. Inhibitory function was further verified by competition ELISA, HEK-Blue IL-22 reporter cells, and murine dextran sulfate sodium (DSS)-induced colitis., Results: We demonstrate that ABR specifically recognizes transgenic IL-22R1 expressed on HEK293T cells and IL-22R1 on TNFα/IFNγ-activated HaCaT cells. Moreover, some ABR binders compete with the IL-22 cytokine and function as IL-22R1 antagonists in HEK-Blue IL22 reporter cells. In a murine model of DSS-induced acute intestinal inflammation, daily intraperitoneal administration of the best IL-22R1 antagonist, ABR167, suppressed the development of clinical and histological markers of colitis including prevention of mucosal inflammation and architecture deterioration. In addition, ABR167 reduces the DSS-induced increase in mRNA transcript levels of inflammatory cytokines such as IL-1β, IL-6, IL-10, and IL-17A., Conclusions: We developed small anti-human IL-22R1 blockers with antagonistic properties that ascertain a substantial role of IL-22-mediated signaling in the development of intestinal inflammation. The developed ABR blockers can be useful as a molecular clue for further IBD drug development., (© 2024. The Author(s).)

Background: Ulcerative colitis (UC) is a chronic inflammatory condition affecting the colon, with a global incidence that is rising. Despite the increasing prevalence, effective treatment options for UC remain limited., Methods: We utilized an NF-κB promoter dual fluorescence reporter system to screen for compounds that could inhibit p65 and IκBα phosphorylation. The anti-hypertension drug lacidipine was identified as a candidate. Its efficacy was further evaluated in a murine model of dextran sulfate sodium (DSS)-induced colitis. The analysis included the assessment of colon lesions, inflammation markers, and signal pathway activation, with a focus on NF-κB and Notch signaling., Results: Lacidipine effectively inhibited p65 and IκBα phosphorylation in the reporter system. In the DSS-induced colitis murine model, lacidipine treatment led to a reduction in colon lesions and inflammatory markers. Target analysis showed significant enrichment of the Notch signaling pathway. Additionally, lacidipine inhibited both NF-κB and Notch activation in DSS-stimulated colons., Conclusion: Lacidipine demonstrated a protective effect in UC, reducing inflammation and modulating key signaling pathways. These findings suggest that lacidipine could be a promising candidate for the treatment of UC., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Scope: Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory condition of unknown etiology, although recent evidence suggests that it is caused by an excessive immune response to mucosal antigens. We determined the anti-inflammatory properties of novel compound DJ-X-013 in vitro in lipopolysaccharide (LPS)-induced macrophages and in an in vivo dextran sodium sulfate (DSS)-induced model of colitis., Methods and Results: To evaluate the anti-inflammatory properties of DJ-X-013, we used LPS-activated RAW 264.7 macrophages in vitro and a DSS-induced experimental model of colitis in vivo. We examine cellular morphology, and tissue architecture by histology, flow cytometry, RT-qPCR, multiplex, and immunoblot analysis to perform cellular and molecular studies. DJ-X-013 treatment altered cell morphology and expression of inflammatory cytokines in LPS-activated macrophages as compared to cells treated with LPS alone. DJ-X-013 also impeded the migration of RAW 264.7 macrophages by modulating cytoskeletal organization and suppressed the expression of NF-κB and inflammatory markers as compared to LPS alone. DJ-X-013 treatment improved body weight, and colon length and attenuated inflammation in the colon of DSS-induced colitis. Intriguingly, DSS-challenged mice treated with DJ-X-013 induced the numbers of myeloid-derived suppressor cells (MDSCs), dendritic cells (DCs), and natural killer T cells (NKT) in the colon lamina propria (LP) relative to DSS. DJ-X-013 also reduced the influx of neutrophils, TNF-α producing macrophages, restricted the number of Th17 cells, and suppressed inflammatory cytokines and NF-κB in the LP relative to DSS., Conclusion: DJ-X-013 is proposed to be a therapeutic strategy for ameliorating inflammation and experimental colitis., Competing Interests: Declaration of Competing Interest The authors declare that they do not have any competing interests that might influence this study and have had no involvement with study sponsors., (Published by Elsevier Masson SAS.)

Saccharomyces boulardii (Sb) is a probiotic yeast for the treatment of gastrointestinal disorders, including inflammatory bowel disease (IBD). Little is known about the modulatory capacity of the Sb in IBD. Here, we found that oral gavage of Sb supernatant (SbS) alleviated gut inflammation, protected the intestinal barrier, and reversed DSS-induced down-regulated activation of epidermal growth factor receptor (EGFR) in colitis. Mass spectrum analysis showed that thioredoxin (Trx) is one of the critical secreted soluble proteins participating in EGFR activation detected in SbS. Trx exerted an array of significant effects on anti-inflammatory activity, including alleviating inflammation, protecting gut barrier, suppressing apoptosis, as well as reducing oxidative stress. Mechanistically, Trx promoted EGFR ligand gene expression and transactivated EGFR in a concentration-dependent manner. EGFR kinase inhibitor could block Trx-mediated preventive effects of intestinal epithelial injury. Our data suggested that Sb-derived soluble protein Trx could serve as a potential prophylactic, as a novel postbiotic against colitis, which provides a new strategy for the precision prevention and treatment of IBD., Competing Interests: Declaration of Competing Interest The authors declare that the research was conducted in the absence of any commercial or financial relationship that could be construed as a potential conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Inflammatory bowel disease (IBD) and food allergy (FA) increase in tandem, but the potential impact of IBD on FA remains unclear. We sought to determine the role of IBD on FA. We first assessed the changes of FA-related risk factors in dextran sulphate sodium salt (DSS) induced colitis mice model. Then, we evaluated the role of IBD on FA in mice. FA responses were determined using a clinical allergy score, body temperature change, serum antibody levels, cytokines level and mouse mast cell protease 1 (MMCP-1) concentration. Accumulation of regulatory T cells was tested using flow cytometry. Intestinal changes were identified by histology, immunohistochemistry, gene expression and gut microbial community structure. In DSS-induced colitis mice model, we found the intestinal damage, colonic neutrophil infiltration, and downregulation of splenic Th2 cytokines and Tregs in mesenteric lymph nodes (MLN). Moreover, we also found that IBD can alleviate the FA symptoms and lead to the significant downregulation of Th2 cytokines, serum IgE and MMCP-1. However, IBD exacerbates intestinal injury and promotes the gene expression levels of IL-33 and IL-5 in the small intestine, damages the intestinal tissue structure and aggravates intestinal dysbiosis in FA. IBD functions as a double-edged sword in FA. From the perspective of clinical symptoms and humoral immune responses, IBD can reduce FA response by downregulating Th2 cytokines. But from the perspective of the intestinal immune system, IBD potentially disrupts intestinal tolerance to food antigens by damaging intestinal tissue structure and causing intestinal dysbiosis., (© 2024 John Wiley & Sons Ltd.)

Background: The Bacillus-derived cyclic lipopeptides (surfactin, iturin, and fengycin) form potent Heterogeneous Lipopeptide Micelle (HeLM) complexes. HeLM is a small molecule that has been shown to have immunomodulatory effects. However, how HeLM regulates inflammation is not clear, moreover its application to Inflammatory Bowel Disease (IBD), specifically Ulcerative Colitis (UC), has not been tested before., Aims: To use a murine model of IBD and determine the effects of HeLM and related molecular mechanisms of action., Methods: Colitis was induced in mice by administration of 4% Dextran Sodium Sulfate. Three preparations were tested against negative and positive controls: Purified HeLM, the wild-type strain that produces it, and an isogenic mutant that does not produce HeLM. Clinical, biochemical, and histological scoring systems were used to assess the severity of colitis. RT-qPCR and cell cultures were used to determine the levels of molecular signaling. Fecal samples were processed for metagenomic analysis., Results: Purified HeLM, and the wild-type strain, significantly decreased the severity of colitis as determined by the disease activity index (DAI), mouse colitis histology index (MCHI), fecal calprotectin, and colonic length. This effect was not seen in the mutant. HeLM was found to be an agonist to TLR-2, seemingly activating the Toll-Like Receptor 2/IL-10 pathway, with subsequent downregulation of inflammatory cytokines (TNF-α, IL-1β, and IL-6). At higher concentrations HeLM inhibited lipopolysaccharide ligands from activating TLR-4. The reduction in colitis was not due to microbiome modulation, as had previously been hypothesized., Conclusion: Our results indicate that HeLM ameliorates colitis by TLR-2-induced IL-10 production and possibly via the inhibition of lipopolysaccharide., (© 2024. The Author(s).)

This study aimed to investigate whether bergapten (BG), a furanocoumarin phytohormone, holds promise for Crohn's disease (CD)-like colitis treatment and to preliminarily explore its potential mechanisms. 2,4,6-Trinitrobenzenesufonic acid (TNBS)-treated mice were applied to establish an in vivo research model, and BG was administered with different concentrations. The status of mice in each group was evaluated by disease activity index (DAI), and the severity was evaluated by pathological sections. The intestinal barrier was assessed by measuring in vivo intestinal permeability, peripheral blood intestinal fatty acid-binding protein (I-FABP) levels, epithelial resistance values, and tight junction protein levels. Markers were then used to assess Th17/Treg levels, mitophagy, and the peroxisome proliferator-activated receptor (PPAR)γ/ nuclear factor kappa B (NF-κB) signaling pathway. BG significantly reduced colon tissue damage in a concentration-dependent manner. DAI scores showed that the loose feces, occult blood, and weight loss of mice in the BG treatment were significantly reduced, and pathological section results revealed reduced inflammatory infiltration and fibrosis. Reduced serum FITC-dextran and I-FABP and increased levels of epithelial resistance and tight junction proteins support that the intestinal barrier was protected upon BG. The proportion of Th17 in mesenteric lymph nodes increased while Treg decreased in the model group. BG treatment effectively reduced the conversion of Treg to Th17. Additionally, BG was found to enhance mitophagy and activate the PPARγ/NF-κB signaling. BG demonstrates promising effects in ameliorating intestinal barrier damage and Th17/Treg imbalance in a murine model of CD-like colitis, while also promoting intracellular mitophagy. The PPARγ/NF-κB signaling pathway may serve as a key mediator of BG's regulatory mechanisms., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The mammalian target of rapamycin (mTOR) pathway plays a key role in determining immune cells function through modulation of their metabolic status. By specific deletion of Rictor in CD11c+ myeloid cells (referred to here as CD11cRicΔ/Δ), we investigated the role of mTOR complex 2 (mTORC2) signaling in dendritic cells (DCs) function in mice. We showed that upon dextran sulfate sodium-induced colitis, the lack of mTORC2 signaling CD11c+ cells diminishes the colitis score and abrogates DC migration to the mesenteric lymph nodes, thereby diminishing the infiltration of T helper 17 cells in the lamina propria and subsequent inflammation. These findings corroborate with the abrogation of cytoskeleton organization and the decreased activation of Rac1 and Cdc42 GTPases observed in CD11c+-mTORC2-deficient cells. Meta-analysis on colonic samples from ulcerative colitis patients revealed increased gene expression of proinflammatory cytokines, which coincided with augmented expression of the mTOR pathway, a positive correlation between the DC marker ITGAX and interleukin-6, the expression of RICTOR, and CDC42. Together, this work proposes that targeting mTORC2 on DCs offers a key to hamper inflammatory responses, and this way, ameliorates the progression and severity of intestinal inflammatory diseases., Competing Interests: Conflict of interest statement. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© The Author(s) 2024. Published by Oxford University Press on behalf of Society for Leukocyte Biology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Our previous study indicated that Hcy exacerbated DSS-induced colitis by facilitating the differentiation of intestinal T helper cell 17 (Th17), but the precise mechanism remains unidentified. Therefore, our current research aims to elucidate the signaling pathway through which Hcy promotes the differentiation of Th17 cells., Methods: BALb/c mice were randomly assigned into six groups. The model of mice colitis was induced using 3% DSS, while the model of Hyperhomocysteinemia was induced using 1.7% methionine. The concentrations of Hcy and prostaglandin E2 (PGE2) were measured using enzyme-linked immunosorbent assay (ELISA). The protein expressions of cytosolic phospholipase A2 (cPLA2), phosphorylated-cPLA2 (p-cPLA2), cyclooxygenase 2 (COX2), cyclic adenosine monophosphate (cAMP), signal transducer and activator of transcription 3 (STAT3), phosphorylated-STAT3 (p-STAT3), interleukin-17A (IL-17A), and retinoid-related orphan nuclear receptor-γt (RORγt) were assessed using western blot analysis., Results: Compared to the DSS + HHcy group, the addition of the COX inhibitor did not significantly alter the protein expression of p-PLA2/PLA2, but led to significant decreases in serum PGE2 concentration, cAMP, and p-STAT3/STAT3 protein expression. The protein expressions of p-PLA2/PLA2, COX2, and cAMP upstream of STAT3 inhibitor addition did not exhibit significant changes. However, PGE2 concentration and p-STAT3/STAT3 protein expression were notably reduced. After the COX inhibitor and STAT3 inhibitor added, the protein expression of IL-17A and RORγt and the levels of IL-17A and IL-23R in CD4 + T cells were significantly reduced., Conclusion: HHcy aggravated DSS-induced colitis by promoting the differentiation and proliferation of Th17 cells through the PGE2 / STAT3 signaling pathway., (© 2024. The Author(s).)

IL-21/IL-21R signaling dysregulation is linked to multiple chronic intestinal inflammatory disorders in humans and animal models of human diseases. In addition to its critical requirement for the generation and development of germinal center B cells, IL-21/IL-21R signaling can also regulate the effector functions of a variety of T-cell subsets. The antibody-mediated abrogation of IL-21/IL-21R signaling led to the impaired expression of IFN-γ by mucosal CD4+ T cells from human subjects with colitis, suggesting an IL-21/IL-21R-triggered positive feedback loop of the TH1 immune response in the colon. Despite recent advances in our understanding of the mechanisms underpinning the regulation of proinflammatory immune responses by the IL-21/IL-21R signaling axis, it remains unclear how this pathway or its downstream molecules contribute to inflammation during bacterial-induced colitis. This study found that IL-21 enhances the surface expression of IL-12Rβ2, but not IL-12Rβ1, in CD4+ T cells, leading to TH1 differentiation and stability. Consistently, these findings also point to an indispensable role of the IL-12Rβ2 signaling axis in promoting proinflammatory immune responses during Citrobacter rodentium-induced colitis. Genetic deletion of the IL-12Rβ2 signaling pathway led to the attenuation of C. rodentium-induced colitis in vivo. The genetic deletion of the IL-12Rβ2 signaling pathway did not alter the host's ability to respond adequately to C. rodentium infection or the ability of Il12rb2-/- mice to express antigen-specific cytokines (IFN-γ, IL-17A). IL-21 is a pleiotropic cytokine exerting a wide range of immunomodulatory functions in multiple tissues, and its direct targeting may result in undesirable off-target consequences. These findings highlight the possibility for targeted manipulations of signaling cascades downstream of main regulators of proinflammatory responses to control invading pathogens while preserving the integrity of host immune responses. A better understanding of the novel mechanisms by which IL-21/IL-21R signaling regulates bacterial-induced colitis will provide insights into the development of new therapeutic and preventive strategies to harness IL-21/IL-21R signaling or its downstream molecules to treat infectious colitis., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of Society for Leukocyte Biology.)

Isoorientin (ISO) is a naturally occurring flavonoid with diverse functional properties that mitigate the risk of diseases stemming from oxidation, inflammation, and cancer cell proliferation. P-glycoprotein (P-gp) is a vital component of the intestinal epithelium and may play a role in the onset of intestinal inflammatory conditions, such as inflammatory bowel disease (IBD). Recent studies have suggested that short-chain fatty acids (SCFAs) and secondary bile acids (SBAs) produced by the gut microbiota stimulate the increase of P-gp expression, alleviating excessive inflammation and thereby preservation of intestinal homeostasis. ISO has been shown to improve colon health and modulate the gut microbiota. In this study, we aimed to explore whether ISO can modulate the microbes and their metabolites to influence P-gp expression to alleviate IBD. First, the impact of ISO on dextran sulfate sodium (DSS)-treated colitis in mice was investigated. Second, 16S rRNA gene sequencing was conducted. The present study indicated that ISO mitigated the symptoms and pathological damage associated with DSS-treated colitis in mice. Western blot analysis revealed ISO upregulated P-gp in colon tissues, suggesting the critical role of P-gp protein in intestinal epithelial cells. 16S microbial diversity sequencing revealed ISO restored the richness and variety of intestinal microorganisms in colitis-bearing mice and enriched SCFA-producing bacteria, such as Lachnospiraceae&#95;NK4A136&#95;group . The experiments also revealed that the ISO fecal microbiota transplantation (FMT) inoculation of DSS-treated mice had similarly beneficial results. FMT mice showed a reduction in colitis symptoms, which was more pronounced in ISO-FMT than in CON-FMT mice. Meanwhile, ISO-FMT expanded the abundance of beneficial microorganisms, increased the expression of metabolites, such as SCFAs and total SBAs, and significantly upregulated the expression of P-gp protein. In addition, Spearman's correlation analysis demonstrated a positive correlation between the production of SCFAs and SBAs and the expression of P-gp. The present study identified that ISO increases the expression of P-gp in the intestinal epithelium by regulating intestinal microorganisms and their metabolites, which maintains colonic homeostasis, improves the integrity of the colonic epithelium, and alleviates colitis.

Akkermansia muciniphila (A. muciniphila), a probiotic, has been linked to macrophage phenotypic polarization in different diseases. However, the role and mechanisms of A. muciniphila in regulating macrophage during ulcerative colitis (UC) are not clear. This research aimed to examine the impact of A. muciniphila on dextran sulfate sodium (DSS)-induced acute colitis and elucidate the underlying mechanism related to macrophage phenotypic polarization. A. muciniphila inhibited weight loss, increased disease activity index, and ameliorated inflammatory injury in colonic tissues in mice induced with DSS. Furthermore, A. muciniphila reduced macrophage M1 polarization and ameliorated epithelial barrier damage in colonic tissues of DSS-induced mice through inhibition of histone deacetylase 5 (HDAC5). In contrast, the effect of A. muciniphila was compromised by HDAC5 overexpression. HDAC5 deacetylated H3K9ac modification of the disabled homolog 2 (DAB2) promoter, which led to repressed DAB2 expression. DAB2 overexpression blocked HDAC5-induced pro-inflammatory polarization of macrophages, whereas knockdown of DAB2 resulted in the loss of effects of A. muciniphila against colonic injury in DSS-induced mice. Taken together, A. muciniphila-induced loss of HDAC5 hampered the deacetylation of DAB2 and enhanced the expression of DAB2. Our findings propose that A. muciniphila may be a possible probiotic agent for alleviating DSS-induced acute colitis., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Environmental stress is a significant contributor to the development of inflammatory bowel disease (IBD). The involvement of temperature stimulation in the development of IBD remains uncertain. Our preliminary statistical data suggest that the prevalence of IBD is slightly lower in colder regions compared to non-cold regions. The observation indicates that temperature changes may play a key role in the occurrence and progression of IBD. Here, we hypothesized that cold stress has a protective effect on IBD., Methods: The cold exposure model for mice was placed in a constant temperature and humidity chamber, maintained at a temperature of 4 °C. Colitis models were induced in the mice using TNBS or DSS. To promote the detection methods more clinically, fluorescence confocal endoscopy was used to observe the mucosal microcirculation status of the colon in the live model. Changes in the colonic wall of the mice were detected using 9.4 T Magnetic Resonance Imaging (MRI) imaging and in vivo fluorescence imaging. Hematoxylin and eosin (H&E) and Immunofluorescence (IF) staining confirmed the pathological alterations in the colons of sacrificed mice. Molecular changes at the protein level were assessed through Western blotting and Enzyme-Linked Immunosorbent Assay (ELISA) assays. RNA sequencing (RNA-seq) and metabolomics (n = 18) were jointly analyzed to investigate the biological changes in the colon of mice treated by cold exposure., Results: Cold exposure decreased the pathologic and disease activity index scores in a mouse model. Endomicroscopy revealed that cold exposure preserved colonic mucosal microcirculation, and 9.4 T MRI imaging revealed alleviation of intestinal wall thickness. In addition, the expression of the TLR4 and PP65 proteins was downregulated and epithelial cell junctions were strengthened after cold exposure. Intriguingly, we found that cold exposure reversed the decrease in ZO-1 and occludin protein levels in dextran sulfate sodium (DSS)- and trinitrobenzenesulfonic acid-induced colitis mouse models. Multi-omics analysis revealed the biological landscape of DSS-induced colitis under cold exposure and identified that the peroxisome proliferator-activated receptor (PPAR) signaling pathway mediates the effects of cold on colitis. Subsequent administration of rosiglitazone (PPAR agonist) enhanced the protective effect of cold exposure on colitis, whereas GW9662 (PPAR antagonist) administration mitigated these protective effects. Overall, cold exposure ameliorated the progression of mouse colitis through the PPARγ/NF-κB signaling axis and preserved the intestinal mucosal barrier., Conclusion: Our study provides a mechanistic link between intestinal inflammation and cold exposure, providing a theoretical framework for understanding the differences in the prevalence of IBD between the colder regions and non-cold regions, and offering new insights into IBD therapy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Ulcerative colitis (UC) is a major inflammatory bowel disease (IBD) characterized by intestinal epithelium damage. Recently, Lipocalin-2 (LCN2) has been identified as a potential fecal biomarker for patients with UC. However, further investigation is required to explore its pro-inflammatory role in UC and the underlying mechanism. The biological analysis revealed that Lcn2 serves as a putative signature gene in the colon mucosa of patients with UC and its association with the capsase/pyroptosis signaling pathway in UC. In wild-type mice with DSS-induced colitis, LCN2 overexpression in colon mucosa via in vivo administration of Lcn2 overexpression plasmid resulted in exacerbation of colitis symptoms and epithelium damage, as well as increased expression levels of pyroptosis markers (cleaved caspase1, GSDMD, IL-1β, HMGB1 and IL-18). Additionally, we observed downregulation in the expression levels of pyroptosis markers following in vivo silencing of LCN2. However, the pro-inflammatory effect of LCN2 overexpression was effectively restrained in GSDMD-KO mice. Moreover, single-cell RNA-sequencing analysis revealed that Lcn2 was predominantly expressed in the intestinal epithelial cells (IECs) within the colon mucosa of patients with UC. We found that LCN2 effectively regulated pyroptosis events by modulating the NF-κB/NLRP3/GSDMD signaling axis in NCM460 cells stimulated by LPS and ATP. These findings demonstrate the pro-inflammatory role of LCN2 in colon epithelium and provide a potential target for inhibiting pyroptosis in UC., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: The therapeutic potential of adipose-derived mesenchymal stromal cells (AMSCs) in the treatment of intestinal fibrosis occured in patients with Crohn's disease (CD) remains unclear. Tumor necrosis factor-stimulated gene 6 (TSG6) protein plays a critical role in inflammation regulation and tissue repair. This study aimed to determine if AMSCs attenuate intestinal fibrosis by secreting paracrine TSG6 protein and explore the underlying mechanisms., Methods: Two murine models for intestinal fibrosis were established using 2,4,6-trinitrobenzene sulfonic acid in BALB/c mice and dextran sulfate sodium in C57BL/6 mice. Primary human fibroblasts and CCD-18co cells were incubated with transforming growth factor (TGF)-β1 to build two fibrosis cell models in vitro., Results: Intraperitoneally administered AMSCs attenuated intestinal fibrosis in the two murine models, as evidenced by significant alleviation of colon shortening, collagen protein deposits, and submucosal thickening, and also decrease in the endoscopic and fibrosis scores (P < 0.001). Although intraperitoneally injected AMSCs did not migrate to the colon lesions, high levels of TSG6 expression and secretion were noticed both in vivo and in vitro. Similar to the role of AMSCs, injection of recombinant human TSG6 attenuated intestinal fibrosis in the mouse models, which was not observed with the administration of AMSCs with TSG6 knockdown or TSG6 neutralizing antibody. Mechanistically, TSG6 alleviates TGF-β1-stimulated upregulation of α-smooth muscle actin (αSMA) and collagen I by inhibiting Smad2 phosphorylation. Furthermore, the expression of TSG6 is lower in intestinal fibrosis tissue of patients with Crohn's disease and can reduce pro-fibrotic protein (αSMA) secretion from primary ileal fibrotic tissue., Conclusions: AMSCs attenuate intestinal fibrosis by secreting paracrine TSG6 protein, which inhibits Smad2 phosphorylation. TSG6, a novel anti-fibrotic factor, could potentially improve intestinal fibrosis treatments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)