Progression Of Colitis Research Articles

Identification of master regulator genes controlling pathogenic CD4+ T cell fate in inflammatory bowel disease through transcriptional network analysis

Inflammatory bowel diseases (IBD) are a group of chronic inflammatory conditions of the gastrointestinal tract associated with multiple pathogenic factors, including dysregulation of the immune response. Effector CD4+ T cells and regulatory CD4+ T cells (Treg) are central players in maintaining the balance between tolerance and inflammation. Interestingly, genetic modifications in these cells have been implicated in regulating the commitment of specific phenotypes and immune functions. However, the transcriptional program controlling the pathogenic behavior of T helper cells in IBD progression is still unknown. In this study, we aimed to find master transcription regulators controlling the pathogenic behavior of effector CD4+ T cells upon gut inflammation. To achieve this goal, we used an animal model of IBD induced by the transfer of naïve CD4+ T cells into recombination-activating gene 1 (Rag1) deficient mice, which are devoid of lymphocytes. As a control, a group of Rag1−/− mice received the transfer of the whole CD4+ T cells population, which includes both effector T cells and Treg. When gut inflammation progressed, we isolated CD4+ T cells from the colonic lamina propria and spleen tissue, and performed bulk RNA-seq. We identified differentially up- and down-regulated genes by comparing samples from both experimental groups. We found 532 differentially expressed genes (DEGs) in the colon and 30 DEGs in the spleen, mostly related to Th1 response, leukocyte migration, and response to cytokines in lamina propria T-cells. We integrated these data into Gene Regulatory Networks to identify Master Regulators, identifying four up-regulated master gene regulators (Lef1, Dnmt1, Mybl2, and Jup) and only one down-regulated master regulator (Foxo3). The altered expression of master regulators observed in the transcriptomic analysis was confirmed by qRT-PCR analysis and found an up-regulation of Lef1 and Mybl2, but without differences on Dnmt1, Jup, and Foxo3. These two master regulators have been involved in T cells function and cell cycle progression, respectively. We identified two master regulator genes associated with the pathogenic behavior of effector CD4+ T cells in an animal model of IBD. These findings provide two new potential molecular targets for treating IBD.

MiRNA-192-5p-targeted activated leukocyte cell adhesion molecule improved inflammatory injury of neonatal necrotizing enterocolitis.

Neonatal necrotizing enterocolitis (NEC) is a common gastrointestinal emergency in neonates. MiRNA-192-5p was found associated with ulcerative colitis (UC) progression, also with aberrant expression in intestinal cancer tissue. However, the effects of miRNA-192-5p on NEC have not been reported. Based on the bioinformatics analysis of the GEO dataset, miR-192-5p was identified as the differentially expressed miRNA in NEC, and activated leukocyte cell adhesion molecule (ALCAM) was predicted as its target. After that, in vitro, rat intestinal epithelial cell-6 (IEC-6) were stimulated with LPS to construct a cell model of NEC. IEC-6 cells were transfected with miRNA-192-5p mimics, miRNA-192-5p inhibitors, or miRNA-192-5p inhibitors + sh-ALCAM, and relevant negative control. In vivo, SD rats were treated with artificial feeding, hypoxic reoxygenation, cold stimulation, and LPS gavage to induce NEC, followed by injection of agomiR-NC or agomiRNA-192-5p. Then effects of miRNA-192-5p on NEC model IEC-6 cell viability, apoptosis, ALCAM expression, Interleukin (IL)-1β and IL-6 levels, intestinal injury, intestinal permeability were detected. MiRNA-192-5p expression was downregulated in NEC IEC-6 cells, whose overexpression increased IEC-6 cell viability. MiRNA-192-5p inhibitors increased IL-1β, IL-6 levels and promoted IEC-6 cell apoptosis. MiRNA-192-5p targeting of ALCAM decreased ALCAM expression, IL-1β, and IL-6 levels. AgomiRNA-192-5p decreased ALCAM, IL-1β, and IL-6 levels in intestinal tissue and pathological damage and increased miRNA-192-5p levels. MiR-192-5p protects against intestinal injury by inhibiting ALCAM-mediated inflammation and intestinal epithelial cells, which would provide a new idea for NEC treatment.

17β-estradiol promotes myeloid-derived suppressor cells functions and alleviates inflammatory bowel disease by activation of Stat3 and NF-κB signalings

Inflammatory bowel disease (IBD) describes a group of clinically common autoimmune diseases characterized by chronic intestinal inflammation, with gender differences in prevalence. Estrogen has been previously shown to exert anti-inflammatory action in IBD development, however, the mechanisms remain obscure. Recent research has revealed that myeloid-derived suppressor cells (MDSCs) play a protective role in IBD pathogenesis. To investigate the molecular mechanisms of estrogen steroid 17β-estradiol (E2) in IBD progression, we established IBD mouse models (DNB-induced) with or without prior ovariectomy (OVX) and E2 implantation. We found that OVX led to worse IBD symptoms and reduced MDSCs frequency, whereas E2 significantly alleviated these effects in vivo. Moreover, in vitro experiments showed that E2 promoted the proliferation and immunosuppressive function of MDSCs through phosphorylation of Stat3 and p65. Mechanistically, E2-mediated Stat3/p65 phosphorylation depends on the interaction between HOTAIR, a long non-coding RNA that are well-known in MDSCs proliferation, and Stat3/p65 respectively. In conclusion, our study revealed that E2 promotes the expansion and immunosuppressive function of MDSCs, and thus diminished the occurrence and development of IBD.

Sex-Related Differences in the Phenotype and Course of Inflammatory Bowel Disease: SEXEII Study of ENEIDA

The impact of patient sex on the presentation of inflammatory bowel disease (IBD) has been poorly evaluated. Our aims were to assess potential disparities in IBD phenotype and progression between sexes. We performed an observational multicenter study that included patients with Crohn's disease (CD) or ulcerative colitis from the Spanish Estudio Nacional en Enfermedad Inflamatoria intestinal sobre Determinantes genéticos y Ambientales registry. Data extraction was conducted in July2021. A total of 51,595 patients with IBD were included, 52% were males and 25,947 had CD. The median follow-up period after diagnosis was 9 years in males and 10 years in females. In CD, female sex was an independent risk factor for medium disease onset (age, 17-40 y) (relative risk ratio, 1.45; 95% CI, 1.31-1.62), later disease onset (age, >40 y) (relative risk ratio, 1.55; 95% CI, 1.38-1.73), exclusive colonic involvement (odds ratio, 1.24; 95% CI, 1.14-1.34), inflammatory behavior (odds ratio, 1.14; 95% CI, 1.07-1.21), and extraintestinal manifestations (odds ratio, 1.48; 95% CI, 1.38-1.59). However, female sex was a protective factor for upper gastrointestinal involvement (odds ratio, 0.84; 95% CI, 0.79-0.90), penetrating behavior (odds ratio, 0.76; 95% CI, 0.70-0.82), perianal disease (odds ratio, 0.77; 95% CI, 0.71-0.82), and complications (odds ratio, 0.73; 95% CI, 0.66-0.80). In ulcerative colitis, female sex was an independent risk factor for extraintestinal manifestations (odds ratio, 1.48; 95% CI, 1.26-1.61). However, female sex was an independent protective factor for disease onset from age 40 onward (relative risk ratio, 0.76; 95% CI, 0.66-0.87), left-sided colonic involvement (relative risk ratio, 0.72; 95% CI, 0.67-0.78), extensive colonic involvement (relative risk ratio, 0.59; 95% CI, 0.55-0.64), and abdominal surgery (odds ratio, 0.78; 95% CI, 0.69-0.88). There is sexual dimorphism in IBD. The patient's sex should be taken into account in the clinical management of the disease.

Investigating the interplay between LIGHT and HIF in inflammatory fibroblast responses

Introduction: Intestinal fibroblast differentiation into an inflammatory phenotype likely plays a key role in Inflammatory Bowel Disease (IBD). However, the mechanisms that control this process are poorly understood. The cytokine TNFSF14 (LIGHT) drives inflammatory fibroblast responses in other diseases such as Eosinophilic esophagitis. Additionally, hypoxia, defined as low cellular or tissue levels of oxygen, is a feature of IBD progression. The use of hydroxylase inhibiting drugs which exhibit hypoxia mimetic conditions have been shown in murine models to have protective effects in IBD. Here we hypothesize the role of LIGHT to be of central importance in intestinal fibroblast differentiation and test how this inflammatory phenotype may be affected by hypoxia mimetic drugs and conversely what effect LIGHT may have on the hypoxic condition. Methods: Primary human colonic fibroblasts (18CO), the hepatic stellate cell line (LX2) and the epithelial cell line (T84) were treated with LIGHT in time course studies. 18COs were also treated with hydroxylase inhibitors Dimethyloxalylglycine (DMOG), JNJ42041935 and Roxadustat. Responses were analysed using qPCR, flowcytometry and Immunoblot-analysis. Results: LIGHT-treated 18COs upregulated CCL2 (7-fold ± increase, p=<0.001, n=5), CXCL10 (14-fold ± increase, p=<0.0001, n=3) and IL34 (30-fold ± increase, p=<0.05 n=5) at transcript level, and surface protein expression of ICAM1 (15% ± increase at 24 hours compared to vehicle, n=4) and VCAM1 (18% ± increase at 24 hours compared to vehicle, n=4) displaying distinct kinetics. This response was absent or to a much less significant degree in LX2s and T84s. DMOG decreased CCL2 (4-fold ± decrease compared to LIGHT treated samples, p=<0.001, n=5) and CXCL10 (11-fold ± decrease compared to LIGHT treated samples, p=<0.0001, n=3) gene expression in 18COs when subsequently treated with LIGHT for 8 hours but did not affect other targets tested such as CSF1, CXCL5, VCAM1 and ICAM1. Immunoblot analysis of 18COs showed a decreased HIF-1α stabilization when treated with hydroxylase inhibitors in the presence of LIGHT compared to hydroxylase inhibitors alone (3 different hydroxylase inhibiting drugs n=3-4, n=11 total). Preliminary data of HIF downstream activated genes VEGFA (14-fold ± increase, p=<0.05 n=3) and GLUT1 (6-fold ± increase, p=<0.05 n=3) show increased gene expression in 18COs when treated with DMOG with noticeable decreases when treated with a LIGHT DMOG combination. Conclusions: Our current studies show that LIGHT is a potential mediator of colonic inflammatory fibroblast differentiation and a possible inhibitor of HIF-1α stabilization. The effects of LIGHT are either significantly weaker or not displayed in colonic epithelial cells or hepatic stellate cells, indicating LIGHT-specific effects on intestinal stroma. Hydroxylase inhibitors show selective effects on the LIGHT driven response. Collectively our data reveals a potential LIGHT-hypoxia network that may be amenable for therapeutic interventions. SFI/IRC Pathway Fellows Award to Dr. Manresa, 21/PATH-S/9621. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The Role of Gut Microbiota in Inflammatory Bowel Disease: Mechanisms and Therapeutic Opportunities

Inflammatory bowel disease (IBD), encompassing Crohn's disease and ulcerative colitis, is characterized by chronic inflammation within the gastrointestinal tract. Emerging research underscores the pivotal role of alterations in gut microbiota composition and function in driving IBD pathogenesis. This paper offers a comprehensive overview of the intricate mechanisms governing the interplay between the gut microbiota and the host immune system, elucidating their contribution to IBD development and progression. Furthermore, we provide in-depth analysis and synthesis of the therapeutic opportunities presented by targeting the gut microbiota for IBD management. Specifically, we explore the application of probiotics, prebiotics, antibiotics, fecal microbiota transplantation, and microbial-based therapies in the field of IBD studies. Each therapeutic modality is examined for its potential in modulating the gut microbiota and restoring microbial balance, thereby alleviating inflammation and ameliorating IBD symptoms. By elucidating these therapeutic opportunities and their applications in IBD research, this review not only enhances our understanding of IBD pathophysiology but also informs the development of innovative treatment strategies aimed at improving patient outcomes and enhancing quality of life.

Inhibition of METTL3 in macrophages provides protection against intestinal inflammation.

Inflammatory bowel disease (IBD) is prevalent, and no satisfactory therapeutic options are available because the mechanisms underlying its development are poorly understood. In this study, we discovered that increased expression of methyltransferase-like 3 (METTL3) in macrophages was correlated with the development of colitis and that depletion of METTL3 in macrophages protected mice against dextran sodium sulfate (DSS)-induced colitis. Mechanistic characterization indicated that METTL3 depletion increased the YTHDF3-mediated expression of phosphoglycolate phosphatase (PGP), which resulted in glucose metabolism reprogramming and the suppression of CD4+ T helper 1 (Th1) cell differentiation. Further analysis revealed that glucose metabolism contributed to the ability of METTL3 depletion to ameliorate colitis symptoms. In addition, we developed two potent small molecule METTL3 inhibitors, namely, F039-0002 and 7460-0250, that strongly ameliorated DSS-induced colitis. Overall, our study suggests that METTL3 plays crucial roles in the progression of colitis and highlights the potential of targeting METTL3 to attenuate intestinal inflammation for the treatment of colitis.

CircSOD2: Disruption of intestinal mucosal barrier function in ulcerative colitis by regulating the miR-378g/Snail1 axis.

Circular RNA (circRNA) has been found to mediate ulcerative colitis (UC) progression by regulating intestinal mucosal barrier function. However, the role of circSOD2 in UC process and its underlying molecular mechanism still need to be further elucidated. Lipopolysaccharide (LPS)-induced Caco2 cells were used to mimic UC cell models. CircSOD2, miR-378g, and Snail1 levels were determined by quantitative real-time PCR. Cell viability was detected using MTT assay, and inflammatory cytokine levels were measured using ELISA. The intestinal mucosal barrier function was evaluated by testing transepithelial electrical resistance and fluorescein isothiocyanate (FITC)-dextran permeability. Snail1 and tight junction-related markers (Zo-1 and Claudin2) protein levels were examined using western blot. The interaction between miR-378g and circSOD2 or Snail1 was confirmed by dual-luciferase reporter assay. Dextran sulfate sodium (DSS) was used to induce UC rat models in vivo. CircSOD2 was overexpressed in UC patients, and its knockdown significantly increased cell viability, transepithelial electrical resistance, and tight junction-related protein expression, while reduced inflammation cytokine levels and the permeability of FITC-dextran in LPS-induced Caco2 cells. In terms of mechanism, circSOD2 sponged miR-378g to positively regulate Snail1 expression. MiR-378g inhibitor reversed the effect of circSOD2 knockdown on intestinal mucosal barrier injury and Snail1 expression in LPS-induced Caco2 cells. In DSS-induced UC rat models, circSOD2 knockdown also could repair the intestinal mucosal barrier injury through regulating miR-378g/Snail1 axis. CircSOD2 could destroy intestinal mucosal barrier function in LPS-induced Caco2 cells and DSS-induced UC rats by miR-378g/Snail1 axis.

Biochanin a ameliorates DSS-induced ulcerative colitis by improving colonic barrier function and protects against the development of spontaneous colitis in the Muc2 deficient mice

There is an increasing appreciation that colonic barrier function is closely related to the development and progression of colitis. The mucus layer is a crucial component of the colonic barrier, responsible for preventing harmful bacteria from invading the intestinal epithelium and causing inflammation. Furthermore, a defective mucus barrier is also a significant characteristic of ulcerative colitis (UC). Biochanin A (BCA), an isoflavonoid, has garnered increasing interest due to its significant biological activities. However, the impact of BCA on UC has not been reported yet. In this study, we used a dextran sodium sulfate (DSS)-induced ulcerative colitis model and the Muc2 deficient (Muc2−/−) mice spontaneous colitis model to explore the mechanisms of BCA in the treatment of UC. Here, we verified that DSS-induced UC was observably attenuated and spontaneous colitis in Muc2−/− mice was relieved by BCA. Treatment with BCA improved colitis-related symptoms and reduced intestinal permeability by upregulating the levels of goblet cells and tight junction (TJ) proteins. In addition, we confirmed that BCA promotes autophagy through the AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)/Unc-51-like kinase 1 (ULK1) pathway, thereby alleviating DSS-induced UC. In addition, the administration of BCA was able to reduce apoptosis and promote proliferation by suppressing Cleaved Caspase-3 (Cleaved Cas-3) expression, and increasing PCNA and Ki67 levels. Further research revealed that BCA treatment ameliorated spontaneous colitis and alleviated epithelial damage in Muc2−/− mice by restoring the intestinal barrier and promoting autophagy. Our results demonstrated that BCA alleviated UC by enhancing intestinal barrier function and promoting autophagy. These findings indicate that BCA may be a novel treatment alternative for UC.

Microbial metabolite deoxycholic acid-mediated ferroptosis exacerbates high-fat diet-induced colonic inflammation

High-fat diet (HFD) has long been recognized as risk factors for the development and progression of ulcerative colitis (UC), but the exact mechanism remained elusive. Here, HFD increased intestinal deoxycholic acid (DCA) levels, and DCA further exacerbated colonic inflammation. Transcriptome analysis revealed that DCA triggered ferroptosis pathway in colitis mice. Mechanistically, DCA upregulated hypoxia-inducible factor-2α (HIF-2α) and divalent metal transporter-1 (DMT1) expression, causing the ferrous ions accumulation and ferroptosis in intestinal epithelial cells, which was reversed by ferroptosis inhibitor ferrostatin-1. DCA failed to promote colitis and ferroptosis in intestine-specific HIF-2α-null mice. Notably, byak-angelicin inhibited DCA-induced pro-inflammatory and pro-ferroptotic effects through blocking the up-regulation of HIF-2α by DCA. Moreover, fat intake was positively correlated with disease activity in UC patients consuming HFD, with ferroptosis being more pronounced. Collectively, our findings demonstrated that HFD exacerbated colonic inflammation by promoting DCA-mediated ferroptosis, providing new insights into diet-related bile acid dysregulation in UC.

Rauwolfia polysaccharide can inhibit the progress of ulcerative colitis through NOS2-mediated JAK2/STAT3 pathway.

Ulcerative colitis (UC) is an inflammatory disease of the digestive tract. Rauwolfia polysaccharide (Rau) has therapeutic effects on colitis in mice, but its mechanism of action needs to be further clarified. In the study, we explored the effect of Rau on the UC cell model induced by Lipopolysaccharide (LPS). We constructed a UC cell model by stimulating HT-29 cells with LPS. Dextran sodium sulfate (DSS) was used to induce mice to construct an animal model of UC. Subsequently, we performed Rau administration on the UC cell model. Then, the therapeutic effect of Rau on UC cell model and was validated through methods such as Cell Counting Kit-8 (CCK8), Muse, Quantitative real‑time polymerase chain reaction (RT-qPCR), Western blotting, and Enzyme-linked immunosorbent assay (ELISA). The results showed that Rau can promote the proliferation and inhibit the apoptosis of the HT-29 cells-induced by LPS. Moreover, we observed that Rau can inhibit the expression of NOS2/JAK2/STAT3 in LPS-induced HT-29 cells. To further explore the role of NOS2 in UC progression, we used siRNA technology to knock down NOS2 and search for its mechanism in UC. The results illustrated that NOS2 knockdown can promote proliferation and inhibit the apoptosis of LPS-induced HT-29 cells by JAK2/STAT3 pathway. In addition, in vitro and in vivo experiments, we observed that the activation of the JAK2/STAT3 pathway can inhibit the effect of Rau on DSS-induced UC model. In short, Rauwolfia polysaccharide can inhibit the progress of ulcerative colitis through NOS2-mediated JAK2/STAT3 pathway. This study provides a theoretical clue for the treatment of UC by Rau.

Alterations in Gut Microbiota as Early Biomarkers for Predicting Inflammatory Bowel Disease Onset and Progression: A Systematic Review.

Inflammatory bowel disease (IBD) is a chronic ailment impacting the digestive system, triggered by an unusual reaction of the immune system. It includes two types of diseases: ulcerative colitis and Crohn's disease. Nonetheless, the diagnosis and evaluation of disease progression in IBDare difficult due to the absence of distinct indicators. While conventional biomarkers from blood plasma and feces, such as C-reactive protein, fecal calprotectin, and S100A12, can be employed to gauge inflammation, they are not exclusive to IBD. There is a broad consensus that intestinal microorganisms significantly contribute to the onset of intestinal imbalance, a condition intimately linked with the cause and development of IBD. Numerous studies have indicated that the makeup of intestinal microorganisms varies between individuals with IBD and those who are healthy, particularly concerning the diversity of microbes and the proportional prevalence of certain bacteria.A total of1475 recordsunderwent examination. Following the eligibility assessment,17 reportswere considered. The final review encompassed12 studies, asfive articles were excluded due to insufficient details regarding cases, controls, and comparability. This article suggests that gut microbiota has potential biomarkers for the noninvasive evaluation of IBD activity. Recognizing the microbiome linked with disease activity paves the way for the development of a group of microbiota-derived indicators to evaluate the initiation and advancement of IBD. This article discusses whether changes in gut microbial compositioncan serve as early indicators of IBD onset and progression.

Flavokawain B inhibits NF-κB inflammatory signaling pathway activation in inflammatory bowel disease by targeting TLR2

Inflammatory bowel disease (IBD) is characterized by recurrent inflammatory reactions in the intestinal mucosa, including ulcerative colitis (UC) and Crohn's disease (CD). The expression of Toll-like receptor 2 (TLR2) has been observed to increase during the progression of IBD. Flavokawain B (FKB), a natural chalcone with potent anti-inflammatory activity, exerts its effects through inhibition of the NF-κB pathway. In this study, we aimed to investigate the effects and mechanisms of FKB targeting TLR2 in IBD. C57BL/6 J mice were treated with 2.5% dextran sulfate sodium (DSS) for 7 days, with administration of FKB or TLR2 inhibitor C29 starting on day 2 to establish the model of IBD. In vitro, bone marrow-derived macrophages (BMDMs) were stimulated with the TLR2 agonist Pam3CSK4 to explore the therapeutic effect of FKB and its pharmacological mechanism. Compared with the model group, the FKB-treated group showed significant reductions in colitis-related injuries in the IBD mouse model, including weight gain, increased colon length and reduced inflammation. FKB decreased the formation of TLR2-MyD88 complex by targeting TLR2, leading to suppression of downstream NF-κB signaling pathway. Similar therapeutic effects were observed in the C29-treated group. Additionally, in vitro data suggested that FKB exerted its anti-inflammatory effect by targeting TLR2 and inhibiting Pam3CSK4-induced activation of the NF-κB pathway. The anti-inflammatory effects of FKB were demonstrated through drug affinity responsive target stability assay and cellular thermal shift assay, revealing its binding affinity to TLR2. By inhibiting the activation of the TLR2/NF-κB signaling pathway, FKB effectively prevented DSS-induced IBD and exhibited promising potential as a therapeutic candidate for IBD treatment.

Gut bacteria exacerbates TNBS-induced colitis and kidney injury through oxidative stress

Gut microbiota has been implicated in the initiation and progression of various diseases; however, the underlying mechanisms remain elusive and effective therapeutic strategies are scarce. In this study, we investigated the role and mechanisms of gut microbiota in TNBS-induced colitis and its associated kidney injury while evaluating the potential of dietary protein as a therapeutic intervention. The intrarectal administration of TNBS induced colitis in mice, concurrently with kidney damage. Interestingly, this effect was absent when TNBS was administered intraperitoneally, indicating a potential role of gut microbiota. Depletion of gut bacteria with antibiotics significantly attenuated the severity of TNBS-induced inflammation, oxidative damage, and tissue injury in the colon and kidneys. Mechanistic investigations using cultured colon epithelial cells and bone-marrow macrophages unveiled that TNBS induced cell oxidation, inflammation and injury, which was amplified by the bacterial component LPS and mitigated by thiol antioxidants. Importantly, in vivo administration of thiol-rich whey protein entirely prevented TNBS-induced colonic and kidney injury. Our findings suggest that gut bacteria significantly contribute to the initiation and progression of colitis and associated kidney injury, potentially through mechanisms involving LPS-induced exaggeration of oxidative cellular damage. Furthermore, our research highlights the potential of dietary thiol antioxidants as preventive and therapeutic interventions.

Tolerogenic dendritic cell-mediated regulatory T cell differentiation by Chinese herbal formulation attenuates colitis progression

IntroductionUlcerative colitis (UC) is a chronic inflammatory disease characterized by loss of immune tolerance to luminal antigens and progressive intestinal tissue injury. Thus, the re-establishment of immune tolerance is crucial for suppressing aberrant immune responses and UC progression. ObjectivesThis study aimed to investigate the mechanisms underlying the action of CDD-2103 and its bioactive compounds in mediating immune regulation in mouse models of colitis. MethodsTwo experimental colitis models, chronic 2,4,6-trinitrobenzene sulfonic acid (TNBS)- and T-cell transfer-induced Rag1-/- mice, were used to determine the effects of CDD-2103 on colitis progression. Single-cell transcriptome analysis was used to profile the immune landscape and its interactions after CDD-2103 treatment. Liquid chromatography-mass spectrometry (LC-MS) was used to analyze the major components interacting with lymphoid cells. A primary cell co-culture system was used to confirm the effects of bioactive component. ResultsCDD-2103 dose-dependently suppresses the progression of colitis induced by chemicals or T cell transplantation in Rag1-/- mice. The effect of CDD-2103 is primarily attributable to an increase in the de novo generation of regulatory T cells (Tregs) in the lamina propria (LP). Single-cell transcriptomic analysis revealed that CDD-2103 treatment increased the number of tolerogenic dendritic cells (DCs). Mechanistically, CDD-2103 promoted tolerogenic DCs accumulation and function by upregulating several genes in the electron transport chain related to oxidative phosphorylation, leading to increased differentiation of Tregs. Further LC-MS analysis identified several compounds in CDD-2103, particularly those distributed within the mesenteric lymph nodes of mice. Subsequent studies revealed that palmatine and berberine promoted tolerogenic bone marrow-derived dendritic cells (BMDC)-mediated Treg differentiation. ConclusionOverall, our study demonstrated that the clinically beneficial effect of CDD-2103 in the treatment of UC is based on the induction of immune tolerance. In addition, this study supports berberine and palmatine as potential chemical entities in CDD-2103 that modulate immune tolerance.

Knockdown of TOP2A suppresses IL-17 signaling pathway and alleviates the progression of ulcerative colitis.

Ulcerative colitis (UC) is a chronic inflammatory disease of the colonic mucosa, with a gradually increasing incidence. Therefore, it is necessary to actively seek targets for the treatment of UC. Common differentially expressed genes (DEGs) were screened from two microarray data sets related to UC. Protein-protein interaction network was constructed to find the hub genes. The UC mouse model and cell model were induced by dextran sulfate sodium (DSS). The pathological changes of colon tissue were observed by hematoxylin-eosin staining. Immunohistochemistry and immunofluorescence were performed to detect the expressions of Ki67 and Claudin-1. The performance of mice was observed by disease activity index (DAI). The effect of TOP2A on proliferation, inflammation, oxidative stress, and interleukin-17 (IL-17) signaling pathway in UC model was measured by cell counting kit-8, enzyme-linked immunosorbent assay, and western blot. Through bioinformatics analysis, 295 common DEGs were screened, and the hub gene TOP2A was selected. In UC model, there was obvious inflammatory cell infiltration in the colon and less goblet cells, while si-TOP2A lessened it. More Ki67 positive cells and less Claudin-1 positive cells were observed in UC model mice. Furthermore, knockdown of TOP2A increased the body weight and colon length of UC mice, while the DAI was decreased. Through in vivo and in vitro experiments, knockdown of TOP2A also inhibited inflammation and IL-17 signaling pathway, and promoted proliferation in DSS-induced NCM460 cells. Knockdown of TOP2A alleviated the progression of UC by suppressing inflammation and inhibited IL-17 signaling pathway.

M1 intestinal macrophages-derived exosomes promote colitis progression and mucosal barrier injury.

This work aimed to investigate the role of M1 intestinal macrophages-derived exosomes (M1-Exo) in colitis and its mechanism. M1 polarization of intestinal macrophages was induced in vitro, and their exosomes were extracted and identified. Thereafter, the DSS-induced colitis mouse model was built. Each mouse was given intraperitoneal injection of exosomes, and then mouse weight and DAI were dynamically monitored. In addition, the levels of cytokines were detected by ELISA. After treatment with the TLR4 inhibitor Resatorvid, the effects of M1 macrophages-derived exosomes were observed. Besides, the mouse intestinal epithelial cells were cultured in vitro for observing function of M1-Exo. M1-exo aggravated the colitis and tissue inflammation in mice, activated the TLR4 signal, and destroyed the mucosal barrier. But M0 macrophages-derived exosomes (M0-Exo) did not have the above effects. Resatorvid treatment antagonized the roles of M1-exo. Moreover, as confirmed by cellular experiments in vitro, M1-exo destroyed mucosal barrier. M1-exo serve as the pro-inflammatory mediator, which can promote mouse colitis progression by activating TLR4 signal.

The Natural History of Patients With Pre-Existing and De Novo Inflammatory Bowel Disease After Solid Organ Transplantation: EITOS Study of GETECCU.

Limited data are available on the outcome of inflammatory bowel disease (IBD) in patients with solid organ transplantation (SOT). We describe the natural history of pre-existing IBD and de novo IBD after SOT. This was a retrospective, multicenter study that included patients with pre-existing IBD at the time of SOT and patients with de novo IBD after SOT. The primary outcome was IBD progression, defined by escalation of medical treatment, surgical therapy, or hospitalization due to refractory IBD. Risk factors were identified using multivariate Cox proportional hazard analysis. A total of 177 patients (106 pre-existing IBD and 71 de novo IBD) were included. Most patients with pre-existing IBD (92.5%) were in remission before SOT. During follow-up, 32% of patients with pre-existing IBD had disease progression, with a median time between SOT and IBD progression of 2.2 (interquartile range, 1.3-4.6) years. In the de novo cohort, 55% of patients had disease progression with a median time to flare of 1.9 (interquartile range, 0.8-3.9) years after diagnosis. In the pre-existing IBD cohort, active IBD at the time of SOT (hazard ratio, 1.80; 95% confidence interval, 1.14-2.84; P = .012) and the presence of extraintestinal manifestations (hazard ratio, 3.10; 95% confidence interval, 1.47-6.54; P = .003) were predictive factors for IBD progression. One-third of patients with pre-existing IBD and about half of patients with de novo IBD have disease progression after SOT. Active IBD at the time of SOT and the presence of extraintestinal manifestations were identified as risk factors for IBD progression.

Abstract 6885: Investigating a novel role of DCLK1 isoforms in colitis and colitis associated colon cancer

Abstract Chronic intestinal inflammation in patients diagnosed with inflammatory bowel disease (IBD) significantly increases their risk of colorectal cancer (CRC). Despite the rising global frequency of IBD, the precise mechanisms that regulate the transition from IBD to colon cancer are poorly understood. Doublecortin-like kinase 1 (DCLK1) is a protein with two major isoforms, DCLK1-L and DCLK1-S. Previous studies have shown that hypermethylation of the DCLK-1α promoter encoding DCLK1-L, particularly in colorectal cancer, allows switching to the DCLK1-S isoform that confers an invasive tumor phenotype. The DCLK1-L is a tuft cell marker that protects against colitis by sensing and eliminating gut pathogenic infection through various mechanisms. On the contrary, the role of DCLK1-S in colitis and colitis-associated cancer has not been thoroughly investigated. Studies from our lab have identified a marked elevation of DCLK1-S in tissue samples of IBD patients. We also recently discovered that DCLK1-S is predominantly expressed in Ly6G+; MHCII- neutrophils, which coincide with elevated levels of inflammation and tissue damage in the colon. To further understand the role of DCLK1 isoforms in driving the progression of colitis to colon cancer, we bred Dclk1fl/fl mice with MRP8-Cre-ires/GFP mice to generate Dclk1fl/fl;MRP8-Cre+/- that eliminates DCLK1-L upon tamoxifen injection resulting in sustained expression of DCLK1-S in the granulocytes especially neutrophils. When infected with Citrobacter rodentium (CR), MRP8;Dclk1−/− mice compared to MRP8;Dclk1+/− or WT mice developed more severe colitis. We have also discovered a novel interaction between DCLK1-S and MMP13 in an unbiased docking study that correlated with significant co-localization of DCLK1-S with MMP13 in the colons of CR-infected mice. Employing a knock-in mice over-expressing the DCLK1-S +19 under the CAG promoter, the DCLK1-MMP13 co-localization correlated with severe ulceration and colitis with loss of crypts and immune cell infiltration including Ly6G+ neutrophils. Studies are underway to see if the severity of colitis in MRP8;Dclk1−/− mice translates into enhanced tumorigenesis and to see if potential interaction between DCLK1-S and MMP13 could provide a plausible mechanism of colitis progression to colon cancer through ECM remodeling and tissue damage. Citation Format: Kafayat Aderonke Yusuf, Badal C. Roy, Shrikant Anant, Shahid Umar. Investigating a novel role of DCLK1 isoforms in colitis and colitis associated colon cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6885.

Linking Periodontitis with Inflammatory Bowel Disease through the Oral-Gut Axis: The Potential Role of Porphyromonas gingivalis.

Periodontitis and inflammatory bowel disease (IBD) are both chronic inflammatory diseases that are characterized by abnormal host immune responses and microbiota dysbiosis. Emerging evidence implies potential associations between periodontitis and IBD. Porphyromonas gingivalis (P. gingivalis), a primary cause of periodontitis, is thought to play a role in the development of IBD through the oral-gut disease axis. However, the precise mechanisms of its involvement remain enigmatic. In this narrative review, we begin with a discussion of the bidirectional relationship between periodontitis and IBD and the involvement of P. gingivalis in each of the two diseases. Further, we summarize the possible routes by which P. gingivalis links periodontitis and IBD through the oral-gut axis, as well as the underlying mechanisms of its involvement in the pathogenesis of IBD. Collectively, P. gingivalis participates in the progression of IBD through gut dysbiosis, impairment of the intestinal barrier, release of inflammatory mediators, and disturbance of the immune response. The above findings may provide new insights for exploring novel biomarkers and potential therapeutic approaches for IBD.