Introduction

Colorectal cancer (CRC) poses a significant global health threat, with high incidence rates and a major impact on public health. Despite screening and diagnostic advances, CRC claimed 2,520 lives in Belgium in 2021. Colonoscopy helps identify and remove polyps, reducing CRC risk. However, post-colonoscopy CRC (PCCRC) cases still occur, influenced by factors like inadequate bowel preparation and short withdrawal time. Understanding these factors is vital for enhancing CRC screening and prevention. Utilizing a POWERBI dashboard can aid in collecting data on screening colonoscopies, including key performance indicators like withdrawal time and adenoma detection ratio (ADR).

Aims & Methods

This study aimed to create a comprehensive dashboard for analyzing PCCRC at our center. Secondary goals included identifying factors contributing to PCCRC in our patient population. We designed an integrated dashboard and analyzed coded data from electronic patient records, including colonoscopy findings matched with histopathological data. A retrospective analysis identified patients with PCCRC and factors possibly contributing to its development. Each case underwent detailed manual review. Colonoscopy indications analyzed were positive iFOBT, surveillance and screening.

Results

The dashboard was developed by a data analyst under the guidance of the clinical nurse specialist in endoscopy and the gastroenterologists in our center. The initial version of this dashboard consisted of the following data: demographics and comorbidities of the patients, number of colonoscopies and their indications, adenoma detection ratio per endoscopist, histopathology data coupled with the data from the endoscopy report, BBPS and withdrawal time. Using diagrams, an easy overview of the current available data is readily visualised.
From the 13200 screening colonoscopies performed between June 2019 and april 2024, 274 (2.08%) CRC's were detected. 16/274 (5.84%) were PCCRC (9 males and 7 females), including 1 patient with Lynch syndrome, 1 Crohn’s disease, and 1 signet ring cell carcinoma. The detected carcinomas were located in the ascending colon (1), hepatic flexure (2), transverse colon (1),cecum (5), sigmoid (5) and rectum (2). The median time to the detection of a PCCRC was 23 months (range 5 - 38). The mean age of individuals diagnosed with PCCRC was 70 years (range 37 – 88). The median withdrawal time at the index colonoscopy was 8.5 minutes (range 3 - 54). The Boston Bowel Preparation Score (BBPS) was utilized to assess bowel preparation quality of the index colonoscopy, with a median score of 9 (range 3 - 9). The median ADR in our center is 46.2%. Three patients died of PCCRC.

Conclusion

We identified and analysed PCCRC and interval cancers by using a newly developed dashboard. This dashboard extracts real-time coded data from patient files and allows for retrospective, real-time and ongoing monitoring. By using this tool as an audit, healthcare providers can take targeted actions to improve the quality of colonoscopies and aim to reduce the incidence of PCCRC. In the future, expansion of this dashboard should allow to extract data allowing for comparing groups and analyse risk factors associated with PCCRC and interval cancer. Ideally, a dashboard should be considered to be integrated in all endoscopy reporting systems providing real-time data on endoscopist’s performance and patient outcomes.

References

1. Burr NE, Derbyshire E, Taylor J, et al.. Variation in post-colonoscopy colorectal cancer across colonoscopy providers in English National Health Service: population based cohort study. BMJ 2019;367:l6090. 10.1136/bmj.l6090
2. Rutter, M. D., Beintaris, I., Valori, R., Chiu, H. M., Corley, D. A., Cuatrecasas, M., Dekker, E., Forsberg, A., Gore-Booth, J., Haug, U., Kaminski, M. F., Matsuda, T., Meijer, G. A., Morris, E., Plumb, A. A., Rabeneck, L., Robertson, D. J., Schoen, R. E., Singh, H., Tinmouth, J., … Sanduleanu, S. (2018). World Endoscopy Organization Consensus Statements on Post-Colonoscopy and Post-Imaging Colorectal Cancer. Gastroenterology, 155(3), 909–925.e3. https://doi.org/10.1053/j.gastro.2018.05.038
3. Post-colonoscopy colorectal cancer (PCCRC) rates vary considerably depending on the method used to calculate them: a retrospective observational population-based study of PCCRC in the English National Health Service.

Introduction

Despite approval of several therapeutic approaches for the treatment of IBD, current treatments do not extend clinical response beyond the 40% ‘therapeutic ceiling’ and many patients do not achieve clinical remission.
The aryl hydrocarbon receptor (AhR) is a cytosolic ligand-dependent transcription factor that is expressed in many cell types. Activation of the receptor regulates many pathophysiological functions, including immune homeostasis and barrier integrity. AQ312 is a potent and selective AhR agonist undergoing preclinical development for the treatment of IBD.

Aims & Methods

The aim of the work was to determine the potency of AQ312 and evaluate the effects of AQ312 in preclinical animal models of IBD.
Cellular potency of AQ312 was determined using the human, mouse and rat AhR/ARNT reporter gene assay and compared to reference AhR agonists (Indigo Biosciences). The pharmacokinetics of AQ312 were measured in rats after acute administration (P.O.). Acute colitis was induced in C57Bl/6 mice by administration of DSS in the drinking water. Chronic colitis was induced in SCID mice by transfer of CD4+ T cells obtained from spleens of Balb/c mice. AQ312 was administered perorally (P.O.) at 1mg/kg, daily (d-7 to d9 in DSS and d0-d48 T cell transfer). Body weight was monitored throughout the study whilst colon weight and length, and inflammatory cells (flow cytometry) and cytokines (Luminex) in the colon were determined at necropsy. In addition, expression of cytochrome P450 1A1 (CYP1A1) was determined in colon tissue by RT-PCR to demonstrate AhR activation.

Results

AQ312 was a selective and potent activator of AhR, with similar potency for human, mouse and rat receptors (EC50 of 4.3, 2.1 and 3.9nM respectively). In rats, a single dose of AQ312 was rapidly cleared (T_0.5=1h) with little systemic exposure after 4h. Induction of acute or chronic experimental colitis in mice led to marked colon edema, immune cell infiltration and increased production of inflammatory cytokines. These effects were significantly reduced after per oral treatment with AQ312.

Conclusion

AQ312 is a potent and selective small molecule AhR agonist that is rapidly cleared in rodents. The molecule has demonstrated therapeutic benefit in 2 models of experimental colitis. AQ312 has the potential to be the ‘best in class’ AhR agonist for the treatment of IBD.

Introduction

Inflammatory Bowel Diseases (IBD) are chronic inflammatory disorders characterized by alterations of acute relapses and remission. The past decades have brought substantial advances in the pharmacological management of IBD by a wide range of medicines. However, the sustained efficacy of the currently available anti-inflammatory therapies is still far from optimal. Therefore, the development of novel therapies represents a major unmet clinical need in this field. Recently, the enrichment of the coagulation pathway genes and among these, Plasminogen activator inhibitor 1 (PAI-1) was described in IBD, whereas PAI-1 emerged as a link between the epithelium and inflammation. Moreover, the genetic deletion of PAI-1 prevented the severity of experimental colitis in mice.

Aims & Methods

Based on these, we aimed to develop and test novel PAI-1 inhibitors for the treatment of IBD.
The novel, amino acid-based PAI-1 inhibitor, LDN-071 was synthesized by the A³SMO^® platform. The inhibitory potential and cytotoxicity effects of the peptide were determined by in vitro assays. Acute and chronic colitis was induced in mice with DSS and 10 mg/bwkg LDN-071 was administered per os. The changes of body weight, spleen weight, and colon length were measured. Haematoxylin eosin (HE) and Periodic acid-Schiff (PAS) staining were performed for histology. ELISA and qRT-PCR measurements were applied to analyze the cytokine expressions. Hydroxyproline assay was used to quantify the mucosal collagen deposition. In vivo, the toxicity of LDN-071 was determined in mice. Human colon organoid and fibroblast (FB) cell cultures were generated from IBD patients and the effects of LDN-071 were observed.

Results

LDN-071 significantly inhibited PAI-1 in vitro without decreasing the cell viability in a concentration range of 1µM-1mM. In the acute mice model, the administration of 10 mg/bwkg LDN-071 in the DSS-treated mice prevented the body weight loss, the development of bloody diarrhea, the decrease of colon length, and the increase of the spleen weight, which were displayed by the DSS+vehicle-treated animals. The histological analysis of the colon revealed that DSS treatment induced severe transmural inflammation, ulceration, loss of crypt structures, and goblet cell depletion. Importantly, all these parameters were significantly ameliorated by the administration of 10 mg/bwkg LDN-071 in the acute and chronic models as well. Additionally, mucosal gene and protein expressions of TNF-α, IL-1β, and IL-6 were significantly decreased by PAI-1 inhibition in the acute phase. Besides, the LDN-071 treatment significantly reduced the inflammation, epithelial erosion, and fibrosis caused by chronic administration of DSS. However, the collagen deposition was significantly lower in the PAI-1-inhibited DSS mice. Importantly, no signs of toxicity were observed in mice exposed to 100 mg/bwkg LDN-071 for 7 days. In our in vitro models, the PAI-1 inhibition reduced the protein level and gene expression of pro-inflammatory cytokines in human colon organoid of IBD patient. Moreover, the gene expression of fibrosis-related genes significantly decreased after the LDN-071 treatment in IBD patients-derived human FB cell culture.

Conclusion

Our results showed that LDN-071, a novel amino acid-based inhibitor of PAI-1, significantly ameliorated the severity of acute and chronic colitis in mice. However, the LDN-071 reduced the expression of inflammation- and fibrosis-related genes and proteins in vitro human models. We propose that the inhibition of PAI-1 could be a potential novel therapeutic strategy in IBD.

Disclosure

LDN-071 PAI-1 inhibitor is owned by Ladon Therapeutics Ltd.

Introduction

SARS-CoV-2 exhibits an extra-pulmonary tropism, with up to 70% of COVID-19 patients experiencing at least one gastrointestinal (GI) symptom. Persistent viral presence has been observed in intestinal biopsies months after the virus has been cleared from the respiratory tract, which has been implicated in the development of long COVID symptoms. Despite these observations, the dynamics of SARS-CoV-2 infection within the intestine, as well as its potential to act as a viral reservoir and source of ongoing pathogenesis, remain largely unknown.

Aims & Methods

We recently established a robust mouse model to study the dynamics of intestinal SARS-CoV-2 infection by exposing the distal ileum of mice through ventral laparotomy and administering the virus directly into the lumen.

Results

In wild-type (WT) C57Bl/6 mice, after perfusion, viral RNA was detected throughout the GI tract at 7 days post infection (dpi), not only at the site of initial infection, but also in other regions such as the esophagus, stomach, duodenum, jejunum, colon, and rectum. Moreover, viral RNA was also found in extra-intestinal sites, including the salivary gland, liver, and brain. In Stat1^-/- mice with impaired type I, II, and III interferon signaling, the levels of viral RNA as well as nucleocapsid antigens in the GI tract were 10 to 100 times higher than those in WT mice. Virus also successfully disseminated to systemic organs such as the heart, lung, kidney, brain, and spleen. Viral shedding in feces was observed from 3 to 7 dpi in Stat1^-/- mice but not WT mice. Notably, rapid secretory diarrhea was observed in these mice, marking the first instance of diarrhea induced by SARS-CoV-2 infection in a mouse model. Additional studies are ongoing to further characterize these findings, including the assessment of the timing of viral replication, titration of infectious viruses, detailed histological analysis, and immunological profiling.

Conclusion

These results emphasize the usefulness of this mouse model in exploring the mechanisms underlying the impact of SARS-CoV-2 on the intestines locally and systemically. The study also underscores the critical role of interferon signaling in restricting intra-intestinal replication and preventing the virus from spreading to other organs. This has important clinical implications, particularly for individuals taking JAK inhibitor medications, which could affect the interferon response and potentially increase susceptibility to more severe outcomes from SARS-CoV-2 infection.

Disclosure

M.S.D. is a consultant for Inbios, Vir Biotechnology, Ocugen, Topspin Therapeutics, GlaxoSmithKline, Moderna, and Immunome. The Diamond laboratory has received unrelated funding support in sponsored research agreements from Vir Biotechnology, Emergent BioSolutions, and Moderna.

Clinical Case Summary

Introduction: Ulcerative colitis (UC) is a chronic inflammatory disease characterized by remitting and relapsing patterns, necessitating multifaceted therapeutic interventions, among which mesalazine, or 5-aminosalicylic acid (5-ASA), is prominently utilized. Despite its typically favorable tolerability profile, mesalazine may occasionally precipitate severe adverse events, such as myocarditis.
Case presentation: A 46-year-old male recently diagnosed with UC presented with a moderate UC flare-up and was initiated on 5-ASA therapy upon admission.
Within a span of two days following initiation of oral therapy, he developed acute chest pain, palpitations, dyspnea, and desaturation, necessitating intensive care due to cardiogenic shock.
Paraclinical assessments revealed elevated troponin levels, along with electrocardiographic and echocardiographic abnormalities, including left ventricular dysfunction and reduced ejection fraction.
Discontinuation of mesalazine resulted in symptom improvement and reduction of cardiac markers. Subsequent evaluations demonstrated a recovery in cardiac function, establishing a causal relationship between myocarditis and the administration of 5-ASA. Consequently, a therapeutic switch to mercaptopurine was instituted.
Conclusion: This case underscores the infrequent yet significant hazard of mesalazine-triggered myocarditis, emphasizing the critical necessity for vigilant patient monitoring during this therapy and prompt consideration of alternative therapeutic options in the presence of severe cardiac complications.

Introduction

Maintaining the mucus layer is crucial in the innate immune system, and MCU2 is a significant component of the mucus layer in the intestinal tract. Urolithin A (Uro A) is a gut microbiota-derived metabolite from ellagic acid, commonly found in pomegranates and raspberries. Recently, it has been described that the administration of Uro A enhances barrier function via the tight junction. However, the intestinal protective effect via mucin production has yet to be elucidated.

Aims & Methods

This study aimed to elucidate the effect of Uro A on mucin synthesis in the colon and to investigate the underlying molecular mechanisms. First, in vivo experiments were performed using wild-type mice (C57BL/6), NF-E2-related factor 2 (Nrf2) deficient mice, and wild-type mice treated with an aryl hydrocarbon receptor (AhR) antagonist. After Uro A administration, gut microbiota composition was analyzed, and short-chain fatty acid concentration was also measured. Next, in vitro assays using mucin-producing cells (LS174T) were conducted to assess mucus production upon Uro A treatment.

Results

The thickness of the MUC2-positive mucus layer in the Uro A group was significantly increased compared with that in the control group (p<0.01). MUC2 protein levels in the colonic mucosal epithelium were significantly higher in the Uro A group than in the control group (p=0.041). In Nrf2 deficient mice, Uro A treatment did not increase MUC2 protein levels in the colonic epithelium (p=0.309). Similarly, in mice treated intraperitoneally with an AhR antagonist, MUC2 protein levels did not increase in the colonic epithelium after treatment with Uro A (p=0.222). In experiments using Fluorescein isothiocyanate- Dextran, Uro A administration suppressed the mucosal permeability. Meanwhile, Uro A administration did not significantly upregulate tight junction protein expression in the epithelium. Hence, increased intestinal mucus appears to suppress leaky gut by a mechanism distinct from upregulating tight junction protein. After the treatment with Uro A, short-chain fatty acid-producing bacteria such as family S24_7, and genus Ruminococcus significantly increased. In addition, the propionic acid concentrations in stools were significantly increased after UroA administration. The treatment of Uro A was also beneficial for dextran sulfate sodium (DSS)-induced colitis in the mice model. The Uro A group showed a marked reduction in the disease activity index (DAI) after DSS administration (p=0.033), and in the control group, the intestinal length was significantly shortened (p=0.018). Hematoxylin and eosin staining of tissue sections showed that inflammatory cell infiltration and destruction of gland duct structures were mild in the Uro A group. In vitro data using LS174T cells demonstrated that the MUC2 mRNA level and the MUC2 protein levels in LS174T cells significantly increased after Uro A administration (p=0.02 and p<0.01, respectively). Fluorescence immunostaining showed that the strength of MUC2 fluorescence in LS174T cells after treatment with Uro A was significantly higher than that in the control group. In addition, MUC2 fluorescence expression did not increase after treatment with an Nrf 2 inhibitor. Similarly, MUC2 fluorescence did not increase after treatment with AhR antagonist.

Conclusion

Uro A promoted the up-regulation of MUC2 synthesis through the AhR and Nrf2 pathway, leading to the enhancement of the mucosal barrier function and the inhibition of the development of murine colitis. These findings involve alternating the intestinal microbiota and SCFA.

Disclosure

Tomohisa Takagi received collaborative research funds from Mitsubishi Tanabe Pharma Corporation and PreMedica, Inc. Yuji Naito received scholarship funds from EA Pharma Co., Ltd.; a collaboration research fund from Taiyo Kagaku Co., Ltd.

Introduction

G-protein coupled receptor-119 (GPR119) agonism is known to modulate non-alcoholic fatty liver disease physiology. However, due to off-target effects, challenges remain for successful GPR119 agonist pharmacotherapy.
Designing a non-systemic drug candidate that locally targets gut-located receptors for incretin secretion is suggested as a safer approach to minimise conventional side effects. This strategy may potentially limit the direct action on pancreatic β-cells; however, chronic use may lead to beneficial outcomes.
We developed a novel small-molecule agent as an oleoyl-lysophosphatidylinositol derivative that stimulates intestinal glucagon-like peptide-1 (GLP-1) secretion by coupling with gut receptors at the orthosteric site.

Aims & Methods

The present study was designed to investigate the chronic impact of novel GPR119 agonist agent ps297 alone and in combination with Sitagliptin on liver health in high-fat diet (HFD)-induced obese mice.
Five-week-old healthy male C57BL6/J mice were fed with HFD for 20 weeks. Normal control mice were maintained on a standard chow diet. A dose-escalation protocol was followed during the treatment phase. Oral administration of the test compound commenced with an initial dose of 10 mg/kg/day for the first week, followed by weekly dose escalations of 10 mg/kg for the subsequent ten weeks until reaching a maximum dose concentration of 90 mg/kg/day. Sitagliptin was gavaged at a fixed dose of 20 mg/kg/day. Vehicle control mice received an equal volume of 0.25% carboxymethyl cellulose in water.
After ten weeks of treatment, blood samples were collected from each 4-hour fasted mice. Biochemical parameters including plasma glucose, triglycerides (TG), cholesterol (CHO), alanine aminotransferase (ALT), and aspartate transaminase (AST) were analysed using an automated analyser. Plasmatic concentrations of metabolic hormones were determined in a multiplex assay platform. Hepatic TG, CHO, and hydroxyproline concentrations were determined in frozen liver tissue samples by colourimetric assay. Liver histology was studied in tissue stored in 10% neutral buffered formalin. Hepatic ballooning was assessed in hematoxylin and eosin-stained sections, imaged using a slide scanner.

Results

Ten-week co-administration of compound ps297 with sitagliptin resulted in higher plasmatic GLP-1 levels compared to the HFD control arm, which led to a significant (p<0.05) reduction in fasting plasma glucose levels in this group. Moreover, combination group exhibited a significant reduction in liver weights (p<0.0001), plasma CHO (p<0.05), ALT (p<0.0001), and AST (p<0.01) levels. Furthermore, combination treatment showed a significant reduction in hepatic TG (p<0.0001) and CHO (p<0.001) concentrations compared to the HFD control group. Elevated hepatic hydroxyproline levels in HFD control mice were attenuated by combination treatment. Additionally, the hepatic ballooning score was found to be significantly reduced in the combination treatment mice.

Conclusion

Sitagliptin combination of ps297, improved glucose homeostasis in HFD-fed obese mice. Additionally, a prominent improvement in liver health status was observed in this group, as evident by reductions in liver weight, plasma liver enzymes, hepatic TG and CHO, and hydroxyproline levels. These findings were further supported by liver histological examination. The overall findings suggest the pharmacological potential of the GPR119 agonist compound ps297 in combination with gliptins to alleviate fatty liver disease, warranting further molecular investigation in disease-specific animal models.

References

Paternoster S, Simpson PV, Kokh E, Kizilkaya HS, Rosenkilde MM, Mancera RL, Keating DJ, Massi M, Falasca M. Pharmacological and structure-activity relationship studies of oleoyl-lysophosphatidylinositol synthetic mimetics. Pharmacol. Res. 172 (2021) 105822.

Bahirat UA, Shenoy RR, Talwar R, Goel RJ, Nemmani KVS. Co-administration of APD668, a G protein-coupled receptor 119 agonist and linagliptin, a DPPIV inhibitor, prevents progression of steatohepatitis in mice fed on a high trans-fat diet. Biochem Biophys Res Commun 495 (2018) 1608-1613

Disclosure

MF and MM are inventors of a patent related to oleoyl-LPI mimetics. Curtin University received funding from Little Green Pharma Pty Ltd. to support MF to conduct the submitted work. LW is a paid employee of Little Green Pharma Pty Ltd. No other relationships or activities that could appear to have influenced the submitted work.