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High stroma content, as measured by tumor-stroma ratio (TSR), is generally a negative prognostic parameter for epithelial cancers, including sporadic colorectal cancer (sCRC). Inflammatory bowel disease patients have higher risk for colorectal cancer than the background population. Evidence suggests that this colitis-associated colorectal cancer (CAC) is more aggressive and occurs at younger age than sCRC. CAC also differs from sCRC in oncogenesis and prognosis. This study tests the hypothesis that TSR in CAC tumors correlates with survival. Age at CAC diagnosis relative to TSR was also explored. TSR was quantified in 36 CAC cases. In routine hematoxylin–eosin staining, the amount of stroma was estimated in categorical steps of 10% increments per image field. The area with highest amount of stroma and tumor tissue at all quadrants of the visual field boundary was scored for TSR. For statistical analysis, tumors were divided into stroma-high (> 50%) or stroma-low (≤ 50%). Of all cases, 22 were stroma-high and 14 were stroma-low. Five-year survival in the stroma-high group was 32% (n = 22), compared to 71% (n = 14) in the stroma-low group (p = 0.049). High stroma content was more frequent if cancer diagnosis was before 60 years of age (17/23) compared to after 60 years of age (5/13). Despite differences in oncogenesis and tumor biology in CAC compared to sCRC, high stroma content also predicts worse outcome in CAC and is particularly common in younger patients.

Studying the pathogenesis of human-adapted microorganisms is challenging, since small animal models often fail to recapitulate human physiology. Hence, the comprehensive genetic and regulatory circuits driving the infection process of principal human pathogens such as Shigella flexneri remain to be defined. We combined large-scale Shigella infections of enteroids and colonoids with transposon-directed insertion sequencing and Bayesian statistical modeling to address infection bottlenecks, thereby establishing the comprehensive genome-wide map of Shigella genes required to infect human intestinal epithelium. This revealed the Shigella virulence effectors essential for epithelial cell colonization across geometries and intestinal segments, identified over 100 chromosomal genes involved in the process and uncovered a post-transcriptional mechanism whereby tRNA-modification enzymes and differential codon usage exert global control of a bacterial virulence program. Our findings provide a broadly applicable framework for combining advanced organotypic tissue culture with functional genomics and computational tools to map human–microorganism interactions at scale.

Despite their relatedness, Salmonella and Shigella enteropathogens differ in infectious dose, pathogenesis, and disease kinetics. The prototype strains Salmonella enterica serovar Typhimurium (Salmonella) and Shigella flexneri (Shigella) use Type-3-secretion-systems (T3SSs) to colonize intestinal epithelial cells (IECs). However, they have evolved unique sets of T3SS effectors and accessory virulence factors. A synthesis of how these differences impact the temporal progression of infection in non-transformed human epithelia is missing. Here, we followed Salmonella and Shigella infections of human enteroids and colonoids by time-lapse imaging to pinpoint virulence factor modules that shape the divergent epithelial colonization strategies. By an apical targeting module that integrates flagella and the SPI-4-encoded adhesin system with T3SS-1, Salmonella accomplishes appreciable numbers of apical IEC invasion events. These are promptly counteracted by IEC death, thus fostering a polyclonal iterative epithelial colonization strategy. The lack of a corresponding apical targeting module in Shigella makes this pathogen reliant on external factors, for example, preexisting damage, for rare apical access to the intraepithelial environment. However, Shigella compensates for this ineptness by an intraepithelial expansion module reliant on the tight coupling of OspC3-dependent temporal delay of cell death and IcsA-mediated mobility. This module enables intraepithelial Shigella to evade the IEC death response just long enough to expand laterally, thus fostering an essentially monoclonal colonization strategy. Taken together, the study reveals how a small set of virulence factors shapes divergent epithelial colonization strategies by related enterobacteria.

Introduction

Understanding meal-induced changes of gut hormones, gastric motility, and appetite is crucial for developing therapies for obesity. We investigated glucose-dependent insulinotropic peptide (GIP), glucagon-like peptide-1 (GLP-1), ghrelin, and motilin influences on gastric motility and appetite, to compare healthy individuals and people with obesity.

Methods

Subjects (healthy n = 41; obesity n = 32) consumed a 270-kcal meal and a wireless motility capsule. GIP, active GLP-1, acyl-ghrelin, and motilin were measured by electrochemiluminescence. MotiliGI and GIMS software were used for motility analysis, while visual analog scoring measured appetite.

Results

Gastric emptying was more rapid in people with obesity than in healthy individuals (p < 0.01). Gastric emptying time was negatively associated with motility index and hunger contractions (p < 0.01, p < 0.05) in healthy individuals, but not in individuals with obesity. In controls, gastric motility index correlated positively with acyl-ghrelin (p < 0.01) and motilin (p < 0.0001), and negatively with GIP (p < 0.05), but not aGLP-1. In people with obesity, no gut hormones correlated with the motility index. In both groups, GIP and aGLP-1 correlated with decreased hunger (p < 0.0001, p = 0.001) and (p < 0.0001, p < 0.05), along with increased satiety in controls (p < 0.0001, p = 0.001) and people with obesity (p = 0.049, p = 0.01). Acyl-ghrelin correlated positively with hunger (p < 0.0001) and negatively with satiety (p = 0.049) in controls, but not in obesity. Motilin was neither associated with hunger nor satiety.

Conclusion

In the gastric phase, people with obesity show rapid gastric emptying with altered hormone and motility meal responses. In healthy individuals, GIP promotes satiety, and ghrelin and motilin promote hunger through actions on motility. Like GIP, GLP-1 promotes satiety along with trending suppression of gastric motility.

Pathogen invasion of intestinal epithelial cells (IECs) is a key gut infection event. The dynamics of this process in intact epithelia and the factors governing IEC susceptibility remain underexplored. We present a resource for live-cell infection imaging in human enteroid-/colonoid-derived IEC layers across maturation states and in the presence or absence of soluble mucus production. Utilization of this resource shows how human IEC maturation fortifies the apical surface against invasion by Salmonella Typhimurium (S.Tm). Immature IEC layers appear permissive to S.Tm invasion, but maturation toward an enterocyte/colonocyte phenotype reduces the susceptibility by up to 10-fold. This shift couples to downregulated expression of actin regulatory proteins exploited by the pathogen, an increased dependence on the S.Tm effector SipA, and the build-up of the apical IEC glycocalyx linked to surface-attached mucins like MUC13 and nullifiable by StcE-enzyme treatment. This underscores how the maturation state of human IECs governs susceptibility to bacterial invasion.

Background

High intake of whole grains has consistently been associated with reduced risk of obesity, coronary artery disease, and type 2 diabetes. Dietary interventions have shown beneficial metabolic effects of whole grains, but the metabolic response varies with different types of cereals.

Objectives

We evaluate the metabolic effects of substituting refined wheat with wholegrain rye foods within a complex diet, examining the day-long postprandial response of glucose-dependent insulinotropic peptide (GIP), glucagon-like peptide-1 (GLP-1), ghrelin, glucose, and inflammatory biomarkers in individuals with overweight and obesity.

Methods

Twenty-nine healthy adults with body mass index of 32 ± 9 kg/m² were randomly assigned to 3 intervention days, separated by 1-wk washout. Participants adhered to a hypocaloric diet rich in wholegrain rye for 1 intervention and refined wheat for the second intervention and were randomly assigned to either diet for the third intervention with continuous blood sampling.

Results

No differences in GIP, GLP-1, or ghrelin levels were found between the diets when measured throughout the whole intervention day. GIP total area under the curve after the rye-based lunch was 31% (P < 0.05) lower compared with the wheat-based lunch, and ghrelin concentrations were 29% (P < 0.05) lower after the rye-based dinner. Baseline Homeostatic Model Assessment for Insulin Resistance-adjusted model showed 61% (P = 0.015) lower whole-day GLP-1 and 40% (P = 0.03) lower GIP after the rye-based diet. Day-long glucose incremental area under the curve was 30% (P < 0.001) lower after the rye-based diet, and glycemic variability was measured as SD reduced (−0.13 mmol/L, P = 0.04). The rye-based diet compared with refined wheat induced higher glycoprotein N-acetylation A, as measured by z-scores (0.36, P = 0.014).

Conclusions

Overall, no day-long differences in gut hormone levels were observed, but the wholegrain rye-based compared with refined wheat-based dinner showed lower postprandial ghrelin concentrations. The rye-based diet improved day-long glycemic control in individuals with overweight and obesity. Observations of diet-induced inflammation after whole-grain rye intake warrant further investigation.

Trial registration number

This study was registered at Clinical Trials Registry of clinicaltrials.gov (NCT05004584): https://clinicaltrials.gov/study/NCT05004584?locStr=Gothenburg,%20Sweden&country=Sweden&state=V%C3%A4stra%20G%C3%B6taland%20County&city=Gothenburg&distance=50&term=appetite&aggFilters=status:com&rank=1

AIM: Acyl ghrelin increases cardiac output (CO) in heart failure with reduced ejection fraction (HFrEF). This could impair the right ventricular-pulmonary arterial coupling (RVPAC), both through an increased venous return and right ventricular afterload. We aim to investigate if acyl ghrelin increases CO with or without worsening the right-sided haemodynamics in HFrEF assessed by RVPAC.

METHODS AND RESULTS: The Karolinska Acyl ghrelin Trial was a randomized double-blind placebo-controlled trial of acyl ghrelin versus placebo (120-min intravenous infusion) in HFrEF. RVPAC was assessed echocardiographically at baseline and 120 min. ANOVA was used for difference in change between acyl ghrelin versus placebo, adjusted for baseline values. Of the 30 randomized patients, 22 had available RVPAC (acyl ghrelin n = 12, placebo n = 10). Despite a 15% increase in CO in the acyl ghrelin group (from 4.0 (3.5-4.6) to 4.6 (3.9-6.1) L/min, P = 0.003), RVPAC remained unchanged; 5.9 (5.3-7.6) to 6.3 (4.8-7.5) mm·(m/s)^-1 , P = 0.372, while RVPAC was reduced in the placebo group, 5.2 (4.3-6.4) to 4.8 (4.2-5.8) mm·(m/s)^-1 , P = 0.035. Comparing change between groups, CO increased in the acyl ghrelin group versus placebo (P = 0.036) while RVPAC and the right ventricular pressure gradient remained unchanged.

CONCLUSION: Treatment with acyl ghrelin increases CO while preserving or even improving RVPAC in HFrEF, possibly due to increased contractility, reduced PVR and/or reduced left sided filling pressures. These potential effects strengthen the role of acyl ghrelin therapy in HFrEF with right ventricular failure.

Background and Aims

Ghrelin is an endogenous appetite-stimulating peptide hormone with potential cardiovascular benefits. Effects of acylated (activated) ghrelin were assessed in patients with heart failure and reduced ejection fraction (HFrEF) and in ex vivo mouse cardiomyocytes.

Methods and results

In a randomized placebo-controlled double-blind trial, 31 patients with chronic HFrEF were randomized to synthetic human acyl ghrelin (0.1 µg/kg/min) or placebo intravenously over 120 min. The primary outcome was change in cardiac output (CO). Isolated mouse cardiomyocytes were treated with acyl ghrelin and fractional shortening and calcium transients were assessed. Acyl ghrelin but not placebo increased cardiac output (acyl ghrelin: 4.08 ± 1.15 to 5.23 ± 1.98 L/min; placebo: 4.26 ± 1.23 to 4.11 ± 1.99 L/min, P < 0.001). Acyl ghrelin caused a significant increase in stroke volume and nominal increases in left ventricular ejection fraction and segmental longitudinal strain and tricuspid annular plane systolic excursion. There were no effects on blood pressure, arrhythmias, or ischaemia. Heart rate decreased nominally (acyl ghrelin: 71 ± 11 to 67 ± 11  b.p.m.; placebo 69 ± 8 to 68 ± 10  b.p.m.). In cardiomyocytes, acyl ghrelin increased fractional shortening, did not affect cellular Ca²⁺ transients, and reduced troponin I phosphorylation. The increase in fractional shortening and reduction in troponin I phosphorylation was blocked by the acyl ghrelin antagonist D-Lys 3.

Conclusion

In patients with HFrEF, acyl ghrelin increased cardiac output without causing hypotension, tachycardia, arrhythmia, or ischaemia. In isolated cardiomyocytes, acyl ghrelin increased contractility independently of preload and afterload and without Ca²⁺ mobilization, which may explain the lack of clinical side effects. Ghrelin treatment should be explored in additional randomized trials.

BACKGROUND: Inflammatory bowel disease (IBD; mainly ulcerative colitis and Crohn's disease) is associated with the development of colorectal cancer (CRC) referred to as colitis-associated colorectal cancer (CAC). In inflammatory flares of IBD, the production of luminal nitric oxide (NO) increases due to the increased inducible nitric oxide synthase (iNOS) activity in inflamed tissue. It is believed that iNOS parallels pro-inflammatory interleukin-1β (IL-1β). How these biomarkers relate to CAC pathogenesis or survival is unknown.

AIM: The primary aim of this study was to investigate iNOS and IL-1β immunoreactivity in CAC tumors in comparison with CRC and normal colonic mucosa, and the secondary aim was to determine if immunoreactivity correlates with 5-year survival of CAC.

METHODS: Immunohistochemistry was performed on tissue sections as follows: CAC (n = 59); sporadic CRC (sCRC) (n = 12); colonic mucosa >2 cm outside sCRC margin (normal mucosa) (n = 22); paracancerous IBD (pIBD) (n = 12). The expression of iNOS and IL-1β was quantified separately for epithelium and stroma. Data were evaluated using the Mann-Whitney U-test and the log-rank test for 5-year Kaplan-Meier survival curves. Results were compared with online mRNA databases.

RESULTS: Immunoreactivity occurred predominantly in epithelial cells and to lesser extent in stroma. Compared with normal mucosa, immunoreactivity for iNOS (P < 0.01) and IL-1β (P < 0.005) was higher in CAC epithelium. In CAC stroma, iNOS immunoreactivity was lower than normal mucosa (P < 0.001), whereas IL-1β was higher (P < 0.05). Immunoreactivity differences of iNOS or IL-1β among CAC patients failed to correlate with 5-year survival. These findings were supported by online mRNA databases.

CONCLUSION: Consistent with high NO production in IBD, there is more iNOS in CAC epithelium, albeit not in stroma. This immunoreactivity difference exists for IL-1β in both epithelium and stroma. The intervention of arginine or iNOS activity for CAC chemotherapy is not straightforward.