Introduction

Aims & Methods

Results

Conclusion

Introduction

Acute pancreatitis (AP) is one of the most common diseases in gastroenterology. Nevertheless, neither the etiology nor the pathophysiology of the disease are fully understood and causal treatment options are not available. Recently we demonstrated that Heparanase (Hpa) is adversely involved in the pathogenesis of AP and inhibition of this enzyme largely ameliorates the manifestation of the disease. Moreover, a pioneer study demonstrated that Aspirin has inhibitory effect on Hpa. Additional compound which possesses mild pancreato-protective effect against AP, is Trehalose, a common disaccharide. The mechanisms underlying these beneficial effects are unknown and we assume that Hpa inhibition is involved in this process. Therefore, we hypothesize that combination of Aspirin and Trehalose may exert pancreato-protective effect more than each drug alone. Recently, we synthesized a new compound termed Aspirlose which is the product of chemical coupling between Aspirin with the sugar Trehalose.

Aims & Methods

Aim: Developing a new compound for the treatment of AP which combines Trehalose with Aspirin that will be administered either pre to AP development in subject predispose to the disease or aftermath.
Methods: AP was induced by cerulein in Heparanase-overexpressing transgenic mice (Hpa-Tg) and their wild-type (WT) BALB/c mice, with or without either Aspirin, Trehalose or Aspirlose. The animals sacrificed 24h after the induction of the disease and the severity of AP evaluated by the serum pancreatic enzymes amylase and lipase, histological alterations and inflammation parameters.

Results

Cerulein-induced AP in WT mice resulted with significant rises of amylase and lipase along disruption of ultra-structure of pancreatic tissue as well as enhancement of inflammatory pathways and biomarkers. All these deleterious responses were more profound in Hpa-Tg animals. Pretreatment with either Aspirin or Trehalose reduced inflammatory response along remarkable reduction in amylase and lipase in both mice groups. Noteworthy, Pre-administration of Aspirlose ameliorated AP more efficiently than each drug alone.

Conclusion

Combination of Trehalose with Aspirin is more effective in mitigating AP than each drug alone. The newly synthesized compound Aspirlose is well tolerated and effective against AP in both WT and Hpa-Tg mice. Aspirlose may composes a novel therapeutic maneuver for the treatment of this common orphan disease.

Introduction

The intestinal epithelium serves as a site for digestion and absorption of the nutrients and dietary factors, while forming the selective barrier to separate the body’s internal environment from the external luminal environment. The intestinal barrier is established by a combination of several mechanisms, including the mucous layer, antimicrobial peptides, and the intercellular tight junction (TJ)⁽¹⁾. The TJ structure is a multiprotein complex composed of both transmembrane proteins such as claudins and occludin, and cytosolic plaque proteins such as zonula occludens and cingulin, and regulates the paracellular passage of macromolecules, ions, and water. Our and other research groups have shown that the regulation of the intestinal TJ barrier is closely related to intestinal microbial metabolism^(2-4), however, the precise underlying mechanisms are still unclear.

Aims & Methods

The aim of this study was to investigate the role of intestinal microflora in the regulation of the colonic TJ barrier using mice and Caco-2 and MDCKII epithelial cells. In particular, we focused on the molecular mechanisms of n-butyrate-mediated expression of claudin-23. To investigate the effect of intestinal microflora on the TJ expression, RNA sequencing analysis was performed in the colonic tissues from germ-free (GF) and specific pathogen-free (SPF) mice. Claudin-23 expression was also examined in the colon of experimental colitis mice. Human intestinal Caco-2 cells were treated with various microbial metabolites and components including n-butyrate. The TJ barrier function was assessed by measuring the transepithelial resistance (TER) and FITC-dextran (FD) permeability. Claudin-23 expression and transcriptional activity were examined by qRT-PCR, immunoblot, immunofluorescence, and luciferase reporter analyses. The siRNA targeting SP1 and the selective inhibitor of AMPK were used in combination in some experiments. To investigate the role of claudin-23 in the epithelial barrier function, TER and FD permeability were measured in MDCKII epithelial cells stably expressing human claudin-23.

Results

Among several TJ molecules, the claudin-23 mRNA was lower in the colon of GF mice than that of the SPF mice. Claudin-23 mRNA expression was higher in the lower intestinal segments, such as ileum, cecum, and colon, compared with those in the duodenum and jejunum. Claudin-23 expression in the colitis mice was downregulated compared to the normal mice. n-butyrate, but not other microbial metabolites or components, upregulated the claudin-23 expression at both mRNA and protein levels in intestinal Caco-2 cells. N-butyrate enhanced the intestinal TJ barrier integrity, indicated by increased TER and decreased FD permeability. Luciferase reporter assay showed that n-butyrate increased the claudin-23 transcriptional activity. The SP1 siRNA and AMPK inhibitor reduced the n-butyrate-mediated claudin-23 expression and promoter activity. Exogenously expressed claudin-23 localized to the junctional region of MDCKII cells, but did not affect the TER and FD permeability.

Conclusion

Claudin-23 expression in the mouse colon is regulated by a microbial metabolite, n-butyrate. Our results suggest that the transcription factor, SP1, and the AMPK pathway are involved in its transcriptional regulation. Although the precise role of claudin-23 in the intestine is still unclear, the n-butyrate-mediated claudin-23 expression may contribute to the intestinal homeostasis.

References

(1) Suzuki T. Anim Sci J. 2020;91(1):e13357.
(2) Isayama K et al. Exp Cell Res. 2023;425(2):113528.
(3) Yokoo K et al. FASEB J. 2021;35(11):e21854.
(4) Tinh NTT et al. Foods. 2021;10(2):240.

Introduction

Barrett’s mucosal neoplasia can be endoscopically cured with minimal risk of lymph node metastasis while submucosally invasive neoplasia poses higher risk and usually requires surgery. Endoscopic optical diagnosis is often challenging to differentiate between the two. We aim to develop an artificial intelligence (AI) system using a deep neural network to stage Barrett’s neoplasia into mucosal (LGD, HGD, pT1a) and submucosally invasive (pT1b) lesions.

Aims & Methods

A VGG16-based deep neural network was used for the staging AI system. The model was trained with 69 images which were carefully selected from 79,159 frame images with histological ground truth. As a pre-trained model for training, the model from initial Barrett’s detection and delineation system was used, which was trained for 1,090,171 images from 161 Barrett's patients¹. We tested staging AI on pre-recorded images and its performance was compared to two experts who regularly perform Barrett's endoscopic resections.

Results

68 neoplastic images (white light, enhanced imaging, near focused/magnification) were used. 43 were mucosal (2 LGD, 31 HGD, 10 pT1a) and 25 were submucosal (6 pT1bSM1 and 19 pT1bSM2/3). The sensitivity, specificity and accuracy of AI were 80%, 84% and 82% while that of experts were 74%, 78% and 76% with no statistical difference (p=0.507).

Conclusion

This suggests that the staging AI system is good at differentiating submucosal neoplasia and it can perform as well as experts. It has the potential to help guide expert clinicians to decide if endoscopic resection of Barrett's neoplasia can be curative while helping non-expert to achieve more yield in targeted biopsy. However, more work is still needed to further refine and validate this staging AI model.

References

1. Mohamed Abdelrahim, Masahiro Saiko, Naoto Maeda, Ejaz Hossain, Asma Alkandari, Sharmila Subramaniam, Adolfo Parra-Blanco, Andres Sanchez-Yague, Emmanuel Coron, Alessandro Repici, Pradeep Bhandari, Development and Validation of Artificial Neural Networks Model for Detection of Barrett’s Neoplasia, a Multicenter Pragmatic Non-Randomized Trial, Gastrointestinal Endoscopy (2022)

Introduction

Gastric emptying (GE) of liquids and solids is differentially regulated. GE of liquids follows an exponential kinetic and mainly depends on fundic tone, GE of solids requires trituration by antral contractions for passage through the adequately opened pylorus into the duodenum. Adler et al. showed that liquid GE was more often delayed in systemic sclerosis patients compared with GE of solids (Rheumatology 2022), but knowledge on the association between GE of solids and liquids in dyspeptic patients, in general, is limited.

Aims & Methods

To investigate this association and the correlation of GE times with symptoms, we compared results of breath tests using 13C-acetate (13C-ABT, GE-liquids) and 13C-octanoic acid (13C-OBT, GE-solids) in consecutive dyspeptic patients undergoing both tests (Keller et al. UEG J 2021). Normal ranges at our institution for 13C-ABT are 20-35 min (T lag-liquids), for 13C-OBT 50-150 min (T ½-solids). All patients additionally answered the gastroparesis cardinal symptom index questionnaire (GCSI, Revicki APT 2003).

Results

302 patients were included (230 women, age 45.9 (31.7-59.5) yrs, median(IQR)). Median T lag-liquids was 25 (20-35) min, median T ½-solids 78 (60-104) min. T lag-liquids and T ½-solids were weakly associated (R=0.165, p=0.002). Both were indirectly correlated with age (R=-0.280, p<0.0001 and R=-0.179, p=0.0009, resp), and similar in men and women. Concordant results for both tests were achieved in 172 subjects (57.6%): Both were normal in 161 (53.3%), both showed accelerated GE in 10 (3.3%) and both delayed GE in 3 (1%) subjects. Discrepant results were observed in 128 subjects (42.4%), in the vast majority of these, one of the tests was normal, but in 7 subjects (2.3%), GE was accelerated in one test, delayed in the other. 67 patients (22.2%) had delayed GE in at least one of the tests. Only in this subgroup, GE time correlated significantly with GCSI (R=0.242, p=0.024), in particular with the nausea/vomiting subscale (p=0.009).

Conclusion

In a large group of dyspeptic patients, more than 45% had disturbances of liquid and/or solid GE. In less than 5% of the total group both tests were found to be either accelerated or delayed in the same patient. Instead, measurements of liquid and solid GE often differred. In patients with delayed GE in at least one of the tests, severity of gastroparesis symptoms was associated with GE time. Thus, measurements of liquid and solid GE may be complementary and identify patients with different pathomechanism leading to GE disturbances and symptoms.

Introduction

Colorectal cancer is one of the most common types of cancer worldwide. The majority of patients are operable at the time of diagnosis. One of the most severe surgical complications is anastomotic leakage (AL). The incidence of AL depends on where the anastomosis is located (1-2% for ileocolic anastomoses, increasing to 10-15% of anastomoses to the rectum). AL leads to prolonged hospital stay, decreased quality of life, increased risk of cancer recurrence, and increased mortality.
Experimental studies have shown that certain bacteria can contribute to the development of AL.
In Denmark, people aged 50-74 years are offered free of charge screening for colorectal cancer. They collect a stool sample at home to be analyzed for the presence for blood (a fecal immunochemistry sample). It is possible to extract bacterial DNA from the fecal sample, to characterize the gut microbiome at the time of sampling.

Aims & Methods

The objective of the study was to use third-generation sequencing methods to analyze screening fecal samples in a cohort of colorectal cancer patients, and to characterize and compare the gut microbiome between patients with or without postoperative AL.
Fecal samples sent to the Colorectal Cancer Screening Program that tested positive for blood, from 2016-2018, were place in a biobank and stored at -80 ⁰C. By combining the biobank with data from the Danish Colorectal Cancer Group, we identified 18 patients who had surgery for colonic or rectal cancer in the period and suffered a postoperative AL (AL group). We matched these patients in a 1:2-ratio, with 36 patients without AL (Control group). We analyzed the 16S ribosomal RNA genes in the screening fecal samples with third-generation sequencing (Oxford Nanopore Technologies).

Results

The data are preliminary, as the data analysis has not yet been completed.
The AL-group and Control group were similar on basic demographic parameters (age, gender, type of resection, smoker status and ASA classification). The gut microbiome composition was significant different in the two groups, based on the two main components of a principal coordinate analysis (PCoA) chart (PERMANOVA, p-value = 0.01).
The Bacteroidota phylum was more abundant in the Control group (p < 0.05). On the order level, Campylobacterales and Bacteroidales were more abundant in the Control group (p < 0.001). On family level, Campylobacteraceae were more abundant in the Control group (p < 0.001), whereas Burkholderiaceae were abundant in the AL-group (p < 0.001). The AL-group also had more Ralstonia and Burkholderia at genus level (p < 0.001), whereas the Control group had more Campylobacter and Oridobacter genera (p < 0.001).

Conclusion

The preoperative gut microbiome composition in colorectal patients with subsequent anastomotic leakage were significantly different from the control group without anastomotic leakage. Campylobacter and Oridobacter seem protective against AL, whereas Ralstonia and Burkholderia seem harmful. We are awaiting further analysis for the species level.
Further studies should focus on validating our results, including changes in the gut microbiome prior to surgery - for instance the impact of bowel preparation – and on estimating the predictive value of our findings.