Pravastatin prevents colitis-associated carcinogenesis by reducing CX3CR1high M2-like fibrocyte counts in the inflamed colon.

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 CX3CR1high macrophages play an essential role in suppressing intestinal inflammation, their function in colitis-related CRC remains unclear. In this study, we found that colonic CX3CR1high 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 CX3CR1high fibrocytes through increased apoptosis, thereby preventing the development of colitis-associated CRC. We next focused statins as drugs targeting CX3CR1high 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 CX3CR1high fibrocyte counts and suppressed colitis-associated CRC. Therefore, CX3CR1high fibrocytes represent a potential target for carcinogenesis-preventing therapy, and statins could be safe therapeutic candidates for IBD.

The Dark Knight: Functional Reprogramming of Neutrophils in the Pathogenesis of Colitis-Associated Cancer.

Neutrophils are the primary myeloid cells that are recruited to inflamed tissues, and they are key players during colitis, being also present within the tumor microenvironment during the initiation and growth of colon cancer. Neutrophils fundamentally serve to protect the host against microorganism invasion, but during cancer development, they can become protumoral and lead to tumor initiation, growth, and eventually, metastasis-hence, playing a dichotomic role for the host. Protumoral neutrophils in cancer patients can be immunosuppressive and serve as markers for disease progression but their characteristics are not fully defined. In this review, we explore the current knowledge on how neutrophils in the gut fluctuate between an inflammatory or immunosuppressive state and how they contribute to tumor development. We describe neutrophils' antitumoral and protumoral effects during inflammatory bowel diseases and highlight their capacity to provoke the advent of inflammation-driven colorectal cancer. We present the functional ambivalence of the neutrophil populations within the colon tumor microenvironment, which can be potentially exploited to establish therapies that will prevent, or even reverse, inflammation-dependent colon cancer incidence in high-risk patients.

A diagnostic dilemma: cytomegalovirus colitis as an uncommon comorbidity in inflammatory bowel disease: a case report.

BACKGROUND: The role of cytomegalovirus infection as an opportunistic pathogen in exacerbating ulcerative colitis and its response to treatment remain a topic of ongoing debate. Clinicians encounter numerous challenges, including the criteria for differentiating between an acute ulcerative colitis flare and true cytomegalovirus colitis, the diagnostic tests for identifying cytomegalovirus colitis, and determining the appropriate timing for initiating antiviral therapy. CASE PRESENTATION: A 28-year-old Syrian female with a seven-year history of pancolitis presented with worsening bloody diarrhea, abdominal pain, and tenesmus despite ongoing treatment with azathioprine, mesalazine, and prednisolone. She experienced a new flare of acute severe ulcerative colitis despite recently completing two induction doses of infliximab (5 mg/kg) initiated four weeks prior for moderate-to-severe ulcerative colitis. She had no prior surgical history. Her symptoms included watery, bloody diarrhea occurring nine to ten times per day, abdominal pain, and tenesmus. Initial laboratory tests indicated anemia, leukocytosis, elevated C-reactive protein (CRP) and fecal calprotectin levels, and positive CMV IgG. Stool cultures, Clostridium difficile toxin, testing for Escherichia coli and Cryptosporidium, and microscopy for ova and parasites were all negative. Sigmoidoscopy revealed numerous prominent erythematous area with spontaneous bleeding. Biopsies demonstrated CMV inclusions confirmed by immunohistochemistry, although prior biopsies were negative. We tapered prednisolone and azathioprine and initiated ganciclovir at 5 mg/kg for ten days, followed by valganciclovir at 450 mg twice daily for three weeks. After one month, she showed marked improvement, with CRP and fecal calprotectin levels returning to normal. She scored one point on the partial Mayo score. The third induction dose of infliximab was administered on schedule, and azathioprine was resumed. CONCLUSION: Concurrent cytomegalovirus infection in patients with inflammatory bowel disease presents a significant clinical challenge due to its associated morbidity and mortality. Diagnosing and managing this condition is particularly difficult, especially regarding the initiation or continuation of immunosuppressive therapies.

Tong-Xie-Yao-Fang induces mitophagy in colonic epithelial cells to inhibit colitis-associated colorectal cancer.

ETHNOPHARMACOLOGICAL RELEVANCE: Based on the core pathogenesis of hepatosplenic disorder and qi transformation disorder in ulcerative colitis, Tong-Xie-Yao-Fang (TXYF) is a classical traditional Chinese medicine commonly used to treat ulcerative colitis. Our study revealed that it has the potential to prevent colitis-associated colorectal cancer, which embodies the academic concept in traditional Chinese medicine of treating the disease before it develops. AIM OF THE STUDY: This study was aimed at evaluating the therapeutic role of TXYF in treating colitis-associated colorectal cancer and exploring its possible underlying mechanisms. MATERIALS AND METHODS: A colitis-associated colorectal cancer model was established in mice using azoxymethane and dextran sulfate sodium salt to examine the therapeutic effect of TXYF. The mouse body weights were observed. Hematoxylin-eosin staining was used to evaluate mouse colon histopathology. Colon cancer cells and colon epithelial cells were used to explore the potential molecular mechanisms. The proliferation and apoptosis of cells were detected by CCK8 and cell colony assays, flow cytometry and western blotting. The epithelial-mesenchymal transition (EMT) and mitophagy markers were examined by immunohistochemistry, western blotting, quantitative real-time PCR and immunofluorescence staining. RESULTS: TXYF inhibited the tumorigenesis of mice with colitis-associated colorectal cancer and the growth of inflammatory colon cells. TXYF induced mitophagy in colon cancer cells through the PTEN-induced putative kinase 1 (PINK1)/Parkin pathway to reverse EMT, which was consistent with the results in mice with colitis-associated colorectal cancer. CONCLUSIONS: The results of the present study demonstrated that TXYF effectively inhibited the progression of colitis-associated colorectal cancer through the PINK1/Parkin pathway, which provides new evidence for prevention strategies for this disease.

Huangqin tang alleviates colitis-associated colorectal cancer via amino acids homeostasisand PI3K/AKT/mtor pathway modulation.

ETHNOPHARMACOLOGICAL RELEVANCE: Huangqin Tang (HQT), a traditional Chinese medicine formula, is commonly used in clinical practice for the treatment of inflammatory bowel diseases. It has been reported that HQT exerts antitumor effects on colitis-associated colorectal cancer (CAC). However, the mechanism by which HQT interferes with the inflammation-to-cancer transformation remains unclear. AIMS OF THE STUDY: The purpose of this study was to dynamically evaluate the efficacy of HQT in alleviating or delaying CAC and to reveal the underlying mechanism. METHODS: We established a mouse model of CAC using azoxymethane combined with 1.5% dextran sodium sulphate. The efficacy of HQT was evaluated based on pathological sections and serum biochemical indices. Subsequently, amino acids (AAs) metabolism analyses were performed using ultra-performance liquid chromatography-tandem mass spectrometry, and the phosphatidylinositol 3 kinase/protein kinase B/mechanistic target of rapamycin (PI3K/AKT/mTOR) pathway was detected by western blotting. RESULTS: The data demonstrated that HQT could alleviate the development of CAC in the animal model. HQT effectively reduced the inflammatory response, particularly interleukin-6 (IL-6), in the inflammation induction stage, as well as in the stages of proliferation initiation and tumorigenesis. During the proliferation initiation and tumorigenesis stages, immunohistochemistry staining showed that the expression of the proliferation marker Ki67 was reduced, while apoptosis was increased in the HQT group. Accordingly, HQT substantially decreased the levels of specific AAs in the colon with CAC, including glutamic acid, glutamine, arginine, and isoleucine. Furthermore, HQT significantly inhibited the activated PI3K/AKT/mTOR pathway, which may contribute to suppression of cell proliferation and enhancement of apoptosis. CONCLUSION: HQT is effective in alleviating and delaying the colon "inflammation-to-cancer". The mechanism of action may involve HQT maintained AAs metabolism homeostasis and regulated PI3K/AKT/mTOR pathway, so as to maintain the balance between proliferation and apoptosis, and then interfere in the occurrence and development of CAC.

Unexplained colonic necrosis in a patient with end-stage kidney disease on chronic hemodialysis: case report and review of uremic colitis.

BACKGROUND: Intestinal necrosis in uremic patients has been reported but is rare. CASE PRESENTATION: A 56-year-old male patient who underwent long-term regular haemodialysis was admitted to the hospital due to involuntary shaking of the limbs and nonsense speech. The patient's symptoms improved after continuous blood purification under heparin anticoagulation, rehydration, sedation, and correction of electrolyte disturbances. However, the patient experienced a sudden onset of abdominal pain and a rapid decrease in blood pressure; high-dose norepinephrine were required to maintain his blood pressure. A plain abdominal radiograph performed at bedside showed intestinal dilation. Colonoscopy revealed inflammation and oedema of the entire colon, with purulent secretions and multiple areas of patchy necrosis. The cause of intestinal ischaemia was not clear. CONCLUSIONS: Although rare, previous causes of uremic colitis have been reported. As the patient developed abdominal pain before the onset of shock and the necrosis was seen on colonoscopy, we suspect that this is a case of fulminant uremic colitis.

Changes in the Expression of Genes Regulating the Response to Hypoxia, Inflammation, Cell Cycle, Apoptosis, and Epithelial Barrier Functioning during Colitis-Associated Colorectal Cancer Depend on Individual Hypoxia Tolerance.

One of the factors contributing to colorectal cancer (CRC) development is inflammation, which is mostly hypoxia-associated. This study aimed to characterize the morphological and molecular biological features of colon tumors in mice that were tolerant and susceptible to hypoxia based on colitis-associated CRC (CAC). Hypoxia tolerance was assessed through a gasping time evaluation in a decompression chamber. One month later, the animals were experimentally modeled for colitis-associated CRC by intraperitoneal azoxymethane administration and three dextran sulfate sodium consumption cycles. The incidence of tumor development in the distal colon in the susceptible to hypoxia mice was two times higher and all tumors (100%) were represented by adenocarcinomas, while in the tolerant mice, only 14% were adenocarcinomas and 86% were glandular intraepithelial neoplasia. The tumor area assessed on serially stepped sections was statistically significantly higher in the susceptible animals. The number of macrophages, CD3-CD19+, CD3+CD4+, and NK cells in tumors did not differ between animals; however, the number of CD3+CD8+ and vimentin+ cells was higher in the susceptible mice. Changes in the expression of genes regulating the response to hypoxia, inflammation, cell cycle, apoptosis, and epithelial barrier functioning in tumors and the peritumoral area depended on the initial mouse's hypoxia tolerance, which should be taken into account for new CAC diagnostics and treatment approaches development.

Decreased Serum Tryptophan and Severe Ulcerative Damage of Colon Mucosa Identify Inflammatory Bowel Disease Patients With High Risk of Cytomegalovirus Colitis.

INTRODUCTION: Patients with inflammatory bowel disease (IBD) are predisposed to the reactivation of viral infections such as cytomegalovirus (CMV). Clinical discrimination of disease flares and colonic CMV reactivation is difficult in patients with established diagnosis of IBD, and there are no reliable noninvasive diagnostic tools yet. Furthermore, the influence of novel therapeutics including biologicals and Janus kinase inhibitors on the risk of CMV colitis is unclear. The goal of this study was to identify risk factors and clinical determinants of CMV colitis that could serve as minimally invasive markers both for active CMV colitis and relapse. METHODS: To this end, a retrospective analysis of 376 patients with suspected or confirmed CMV colitis 2016-2023 was performed. RESULTS: Previous administration of systemic steroids increased the odds of CMV colitis to OR 4.6. Biologicals did not change the incidence of CMV colitis but decreased the OR of a relapse to 0.13. Clinical parameters such as severely bloody diarrhea, intense microscopic ulcerative damage, and decreased serum tryptophan correlated with detection of CMV. Importantly, persistent decrease of tryptophan was observed in patients with CMV relapse. Furthermore, tryptophan degradation through the kynurenine pathway was increased in CMV-positive patients. DISCUSSION: Taken together, we identify decreased serum tryptophan as a novel potential minimally invasive marker to aid identification of IBD patients with active CMV colitis and at high risk for relapse.

Protective function of sclerosing cholangitis on IBD.

OBJECTIVE: There is a strong clinical association between IBD and primary sclerosing cholangitis (PSC), a chronic disease of the liver characterised by biliary inflammation that leads to strictures and fibrosis. Approximately 60%-80% of people with PSC will also develop IBD (PSC-IBD). One hypothesis explaining this association would be that PSC drives IBD. Therefore, our aim was to test this hypothesis and to decipher the underlying mechanism. DESIGN: Colitis severity was analysed in experimental mouse models of colitis and sclerosing cholangitis, and people with IBD and PSC-IBD. Foxp3+ Treg-cell infiltration was assessed by qPCR and flow cytometry. Microbiota profiling was carried out from faecal samples of people with IBD, PSC-IBD and mouse models recapitulating these diseases. Faecal microbiota samples collected from people with IBD and PSC-IBD were transplanted into germ-free mice followed by colitis induction. RESULTS: We show that sclerosing cholangitis attenuated IBD in mouse models. Mechanistically, sclerosing cholangitis causes an altered intestinal microbiota composition, which promotes Foxp3+ Treg-cell expansion, and thereby protects against IBD. Accordingly, sclerosing cholangitis promotes IBD in the absence of Foxp3+ Treg cells. Furthermore, people with PSC-IBD have an increased Foxp3+ expression in the colon and an overall milder IBD severity. Finally, by transplanting faecal microbiota into gnotobiotic mice, we showed that the intestinal microbiota of people with PSC protects against colitis. CONCLUSION: This study shows that PSC attenuates IBD and provides a comprehensive insight into the mechanisms involved in this effect.

Epiploic Appendagitis: Systematic Review of a Distinctive Pathology.

Introduction: Epiploic appendagitis (EA) is an essential cause of abdominal pain that can be confused with more typical causes such as acute diverticulitis and appendicitis. Epiploic appendagitis accounts for 1% of all cases of abdominal pain in adults. The scarcity of information has limited its recognition as an essential nonsurgical cause of acute abdominal pain.Methods: We performed a systematic review of all EA cases published. We searched Scopus, Medline, Web of Science, and Google Scholar to retrieve all available studies from January 2000 to November 2023.Results: 196 case reports and case series were analyzed, with 371 patients with EA included. The mean age at the time of diagnosis was 39 years. Most patients were male (59%). The primary presenting symptoms were pain (100%), tenderness (59.5%), and rebound tenderness (27.4%). The left abdomen was the most common localization of pain (53%). The most frequently identified differential diagnoses were acute appendicitis (26.4%) and acute diverticulitis (16.1%). Most patients (53%) were treated conservatively, and 98 (26.4%) underwent surgical treatment. A significant difference in the choice of treatment was found for signs and symptoms such as rebound tenderness, nausea, anorexia, and diarrhea.Conclusions: Acute EA is an essential clinical condition of rare occurrence that might present a diagnostic challenge, as it can masquerade as another acute abdominal pain etiology. The optimal management of EA is conservative, so a higher recognition by surgeons and emergency physicians is essential to avoid unnecessary surgical interventions and their associated consequences.

ß-hydroxybutyrate restrains colitis-associated tumorigenesis by inhibiting HIF-1α-mediated angiogenesis.

Decreased levels of ß-hydroxybutyrate (BHB), a lipid metabolic intermediate known to slow the progression of colorectal cancer (CRC), have been observed in the colon mucosa of patients with inflammatory bowel diseases (IBD). In particular, patients with recurrent IBD present an increased risk of developing colitis-associated colorectal cancer (CAC). The role and molecular mechanism of BHB in the inflammatory and carcinogenic process of CAC remains unclear. Here, the anti-tumor effect of BHB was investigated in the Azoxymethane (AOM)/Dextran Sulfate Sodium (DSS)-induced CAC model and tumor organoids derivatives. The underlying mechanisms were studied using transcriptome and non-target metabolomic assay and further validated in colon tumor cell lineage CT26 in vitro. The tumor tissues and the nearby non-malignant tissues from colon cancer patients were collected to measure the expression levels of ketogenic enzymes. The exogenous BHB supplement lightened tumor burden and angiogenesis in the CAC model. Notably, transcriptome analysis revealed that BHB effectively decreased the expression of VEGFA in the CAC tumor mucosa. In vitro, BHB directly reduced VEGFA expression in hypoxic-treated CT26 cells by targeting transcriptional factor HIF-1α. Conversely, the deletion of HIF-1α largely reversed the inhibitory effect of BHB on CAC tumorigenesis. Additionally, decreased expression of ketogenesis-related enzymes in tumor tissues were associated with poor survival outcomes in patients with colon cancer. In summary, BHB carries out anti-angiogenic activity in CAC by regulating HIF-1α/VEGFA signaling. These findings emphasize the role of BHB in CAC and may provide novel perspectives for the prevention and treatment of colonic tumors.

Erlotinib suppresses tumorigenesis in a mouse model of colitis-associated cancer.

Colitis-associated cancer (CAC) in inflammatory bowel diseases exhibits more aggressive behavior than sporadic colorectal cancer; however, the molecular mechanisms remain unclear. No definitive preventative agent against CAC is currently established in the clinical setting. We investigated the molecular mechanisms of CAC in the azoxymethane/dextran sulfate sodium (AOM/DSS) mouse model and assessed the antitumor efficacy of erlotinib, a small molecule inhibitor of the epidermal growth factor receptor (EGFR). Erlotinib premixed with AIN-93 G diet at 70 or 140 parts per million (ppm) inhibited tumor multiplicity significantly by 96%, with ∼60% of the treated mice exhibiting zero polyps at 12 weeks. Bulk RNA-sequencing revealed more than a thousand significant gene alterations in the colons of AOM/DSS-treated mice, with KEGG enrichment analysis highlighting 46 signaling pathways in CAC development. Erlotinib altered several signaling pathways and rescued 40 key genes dysregulated in CAC, including those involved in the Hippo and Wnt signaling. These findings suggest that the clinically-used antitumor agent erlotinib might be repurposed for suppression of CAC, and that further studies are warranted on the crosstalk between dysregulated Wnt and EGFR signaling in the corresponding patient population.

Bifidobacterium breve-derived indole-3-lactic acid ameliorates colitis-associated tumorigenesis by directing the differentiation of immature colonic macrophages.

Aim: To elucidate dynamics and functions in colonic macrophage subsets, and their regulation by Bifidobacterium breve (B. breve) and its associated metabolites in the initiation of colitis-associated colorectal cancer (CAC). Methods: Azoxymethane (AOM) and dextran sodium sulfate (DSS) were used to create a CAC model. The tumor-suppressive effect of B. breve and variations of macrophage subsets were evaluated. Intestinal macrophages were ablated to determine their role in the protective effects of B. breve. Efficacious molecules produced by B. breve were identified by non-targeted and targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The molecular mechanism was further verified in murine bone marrow-derived macrophages (BMDMs), macrophages derived from human peripheral blood mononuclear cells (hPBMCs), and demonstrated in CAC mice. Results: B. breve alleviated colitis symptoms, delayed colonic tumorigenesis, and promoted phenotypic differentiation of immature inflammatory macrophages into mature homeostatic macrophages. On the contrary, the ablation of intestinal macrophages largely annulled the protective effects of B. breve. Microbial analysis of colonic contents revealed the enrichment of probiotics and the depletion of potential pathogens following B. breve supplementation. Moreover, indole-3-lactic acid (ILA) was positively correlated with B. breve in CAC mice and highly enriched in the culture supernatant of B. breve. Also, the addition of ILA directly promoted AKT phosphorylation and restricted the pro-inflammatory response of murine BMDMs and macrophages derived from hPBMCs in vitro. The effects of ILA in murine BMDMs and macrophages derived from hPBMCs were abolished by the aryl hydrocarbon receptor (AhR) antagonist CH-223191 or the AKT inhibitor MK-2206. Furthermore, ILA could protect against tumorigenesis by regulating macrophage differentiation in CAC mice; the AhR antagonist largely abrogated the effects of B. breve and ILA in relieving colitis and tumorigenesis. Conclusion: B. breve-mediated tryptophan metabolism ameliorates the precancerous inflammatory intestinal milieu to inhibit tumorigenesis by directing the differentiation of immature colonic macrophages.

Role played by MDSC in colitis-associated colorectal cancer and potential therapeutic strategies.

Colitis-associated colorectal cancer has been a hot topic in public health issues worldwide. Numerous studies have demonstrated the significance of myeloid-derived suppressor cells (MDSCs) in the progression of this ailment, but the specific mechanism of their role in the transformation of inflammation to cancer is unclear, and potential therapies targeting MDSC are also unclear. This paper outlines the possible involvement of MDSC to the development of colitis-associated colorectal cancer. It also explores the immune and other relevant roles played by MDSC, and collates relevant targeted therapies against MDSC. In addition, current targeted therapies for colorectal cancer are analyzed and summarized.

Early administration of Wumei Wan inhibit myeloid-derived suppressor cells via PI3K/Akt pathway and amino acids metabolism to prevent colitis-associated colorectal cancer.

ETHNOPHARMACOLOGICAL RELEVANCE: Wumei Wan (WMW), a traditional Chinese medicine prescription, has been proved to be effective in treating Colitis-associated colorectal cancer (CAC), but it has not been proven to be effective in different stages of CAC. AIM OF THE STUDY: The purpose of our study is to investigate the therapeutic effect and mechanism of WMW on the progression of CAC. MATERIALS AND METHODS: Azioximethane (AOM) and dextran sulfate sodium (DSS) were used to treat mice for the purpose of establishing CAC models. WMW was administered in different stages of CAC. The presentative chemical components in WMW were confirmed by LC-MS/MS under the optimized conditions. The detection of inflammatory cytokines in the serum and colon of mice were estimated by qRT-PCR and ELISA. The changes of T cells and myeloid-derived suppressor cells (MDSCs) in each group were detected by flow cytometry. The metabolic components in serum of mice were detected by UPLC-MS/MS. Expression of genes and proteins were detected by eukaryotic transcriptomics and Western blot to explore the key pathway of WMW in preventing CAC. RESULTS: WMW had significant effect on inhibiting inflammatory responses and tumors during the early development stage of CAC when compared to other times. WMW increased the length of mice's colons, reduced the level of IL-1ß, IL-6, TNF-α in colon tissues, and effectively alleviated colonic inflammation, and improved the pathological damage of colon tissues. WMW could significantly reduce the infiltration of MDSCs in the spleen, increase CD4+ T cells and CD8+ T cells in the spleen of CAC mice, and effectively reform the immune microenvironment in CAC mice. Transcriptomics analysis revealed that 2204 genes had different patterns of overlap in the colon tissues of mice between control group, AOM + DSS group, and early administration of WMW group. And KEGG enrichment analysis showed that PI3K/Akt signaling pathway, ECM-receptor interaction, IL-17 signaling pathway, MAPK signaling pathway, pancreatic secretion, thermogenesis, and Rap1 signaling pathway were all involved. The serum metabolomics results of WMW showed that the metabolic compositions of the control group, AOM + DSS group and the early stage of WMW were different, and 42 differential metabolites with the opposite trends of changes were screened. The metabolic pathways mainly included pyrimidine metabolism, glycine, serine and threonine metabolism, tryptophan metabolism, and purine metabolism. And amino acids and related metabolites may play an important role in WMW prevention of CAC. CONCLUSION: WMW can effectively prevent the occurrence and development of CAC, especially in the initial stage. WMW can reduce the immune infiltration of MDSCs in the early stage. Early intervention of WMW can improve the metabolic disorder caused by AOM + DSS, especially correct the amino acid metabolism. PI3K/Akt signaling pathway was inhabited in early administration of WMW, which can regulate the amplification and function of MDSCs.