Introduction

Inflammatory bowel disease (IBD) constitutes a group of chronic and relapsing idiopathic inflammatory disorder of the intestine that includes Crohn’s disease (CD) and ulcerative colitis (UC). Both diseases characterized by a cyclical nature alternating between active and quiescent states, that markedly diminish physical functioning and quality of life in patients. Our previous study have indicated that exercise of moderate intensity can be recommended as the alternative therapy in prevention and healing of experimental colitis in obese mice.

Aims & Methods

The intestinal alkaline phosphatase (IAP) is an important apical brush border enzyme, released from cells walls during stressful events maintains tight junction and barrier integrity It remains unknown, whether IAP treatment besides its protective action against colitis, can influence the gene expression of proinflammatory genes in adipose tissue, liver and skeletal muscle of obese mice forced to exercise on treadmill. In this study two major series of C57BL/6 male mice were fed ad libitum high fat diet (HFD, 70% energy from fat, series A) or standard diet (SD,10% energy from fat, series B) (Altromin, Lage, Germany) for 12 weeks and subjected to forced treadmill exercise (15 min/day, 6 wks., Panlab, Harvard Apparatus, MA, USA) with or without the intragastric treatment with AP (200 U/day) and trinitrobenzene sulfonic acid (TNBS) colitis was induced. Following colitis, the colonic blood flow (CBF) was examined by Laser Doppler flowmetry, the disease activity index (DAI) as well as histology of intestinal mucosa were determined. The biopsy samples of abdominal fat, liver and skeletal muscle were excised, and shock frozen in liquid nitrogen for determination of the gene expression of antioxidative enzymes SOD, GPx and fat biomarkers leptin and adiponectin as well as proinflammatory biomarkers IL-1β, IL-6, TNF-α, HIF-1α and iNOS by qPCR.

Results

In obese mice the DAI was significantly increased and a significant fall in CBF as compared with sedentary SD fed mice (P<0.05). Treadmill exercise exacerbated the DAI activity in obese mice and decreased CBF vs. SD fed mice (P< 0.05), and this effect was significantly inhibited by treatment with IAP (P< 0.05). In fat tissue and liver of obese mice, the adiponectin mRNA expression was downregulated, while the mRNA leptin expression being upregulated (p<0.05), and this ratio in expression of these factors was restored by IAP. In the skeletal muscle, the mRNA expression ratio of adiponectin to leptin remained unchanged. The SOD and GPx mRNA expression was unchanged in the liver, while the mRNA expression of proinflammatory markers HIF-1α, TNF-α and IL-1β was significantly increased (P< 0.05) in all tissues collected from the high fat diet fed mice forced to exercise as compared to SD animals. The treatment with IAP significantly reduced the expression of these markers in liver, skeletal muscle, and adipose abdominal tissue.(p<0.05).

Conclusion

We conclude that forced treadmill exercise not only exacerbates the severity of colonic damage and diminishes the colonic blood flow in obese mice but also exerts deleterious effect as manifested by the increased expression of local proinflammatory biomarkers in fat, liver, and skeletal muscle. IAP downregulates gene expression of proinflammatory biomarkers and deserves an attention as may exert the multi-organ protective activity in the treatment of IBD in humans. Supported by National Science Centre (NCN) within the framework of project grant (UMO-2015/19/B/NZ4/03130) and grant from UJCM, No.: N41/DBS/000783.

Introduction

Inflammatory bowel disease (IBD), encompassing ulcerative colitis and Crohn’s disease, is characterized by chronic intestinal inflammation linked to dysbiosis and impaired bile acid (BA) metabolism. Recent studies have underscored the pivotal role of the gut microbiota–BA axis in modulating intestinal immunity [1]. Disruptions in this axis, particularly reduced microbial conversion of primary to secondary BAs, have been implicated in the pathogenesis of IBD [2–4]. Probiotic interventions have emerged as promising strategies to restore microbial balance and modulate BA profiles. Some probiotic bacteria express enzymes that can modify bile acids thereby influencing BA receptor signaling pathways such as GPBAR1, FXR and receptors that have recently been identified as BA-binding receptors, such as RORγt [4–6]. Building upon this framework, our previous research demonstrated that specific microbial-derived BAs, notably 3-oxo-DCA, act as dual agonists for GPBAR1 and inverse agonists for RORγt, leading to reduced Th17-mediated inflammation in murine models of colitis [7]. These findings suggest that targeted modulation of the gut microbiota–BA axis via probiotic formulations could offer therapeutic benefits in IBD management.

Aims & Methods

To investigate the therapeutic potential of a novel multi-strain probiotic formulation in reducing colitis. For this purpose, we employed murine models of colitis induced in male C57BL/6 mice. In the acute colitis model, disease was induced by administering a 2% dextran sulfate sodium (DSS) solution in drinking water for 9 days. Chronic colitis was induced using three cycles of 1.5% DSS administration (1 week) followed by 15 days of water to mimic the exacerbation-remission phases of human IBD. The new probiotic formulation, named Vivomixx neo9®, was administered daily by gavage at 50 × 10^9 CFU/kg. Vivomixx neo9® included nine bacterial strains: Bifidobacterium animalis subsp. lactis, Bifidobacterium breve, Lactobacillus acidophilus, Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus rhamnosus (two distinct bacterial strains), Lactobacillus lactis, and Streptococcus thermophilus. Vivomixx®, a commercial probiotic, served as the control.

Results

Our data demonstrated that treatment with both probiotic strains effectively mitigated disease severity in both acute and chronic murine models of colitis. Furthermore, the novel probiotic formulation notably ameliorated colonic mucosal injury at both macroscopic and microscopic levels and decreased fibrosis indices. DSS administration induced severe gut dysbiosis, reflected by substantial alterations in intestinal microbiota composition and disrupted BA profiles. Specifically, fecal BA analysis revealed a pronounced dysregulation characterized by diminished secondary BA levels and an elevated primary-to-secondary BA ratio. Probiotic treatment effectively reversed these dysbiotic changes, restoring fecal BA profiles comparable to those observed in naive mice. Of particular interest, the novel multi-strain probiotic enhanced the generation of oxo- and allo-BA derivatives, recognized as dual agonists for GPBAR1 and inverse agonists for RORγt, regulators of innate and adaptive immune responses.

Conclusion

Our findings indicate that Vivomixx neo9® significantly reduces colitis severity through modulation of intestinal microbiota composition and normalization of fecal bile acid profiles. These results underscore the therapeutic promise of targeting microbiota–bile acid interplay as a supplementary approach in the clinical management of IBD.

References

[1] Pan Y, Zhang H, Li M, He T, Guo S, Zhu L, et al. Novel approaches in IBD therapy: targeting the gut microbiota-bile acid axis. Gut Microbes 2024;16:2356284. https://doi.org/10.1080/19490976.2024.2356284.
[2] Bai SH, Chandnani A, Cao S. Bile Acids in Inflammatory Bowel Disease: From Pathophysiology to Treatment. Biomedicines 2024;12. https://doi.org/10.3390/biomedicines12122910.
[3] Lavelle A, Sokol H. Gut microbiota-derived metabolites as key actors in inflammatory bowel disease. Nat Rev Gastroenterol Hepatol 2020;17:223–37. https://doi.org/10.1038/s41575-019-0258-z.
[4] Biagioli M, Marchianò S, Carino A, Di Giorgio C, Santucci L, Distrutti E, et al. Bile Acids Activated Receptors in Inflammatory Bowel Disease. Cells 2021;10:1281. https://doi.org/10.3390/cells10061281.
[5] Fiorucci S, Carino A, Baldoni M, Santucci L, Costanzi E, Graziosi L, et al. Bile Acid Signaling in Inflammatory Bowel Diseases. Dig Dis Sci 2021;66:674–93. https://doi.org/10.1007/s10620-020-06715-3.
[6] Paik D, Yao L, Zhang Y, Bae S, D’Agostino GD, Zhang M, et al. Human gut bacteria produce Τ(Η)17-modulating bile acid metabolites. Nature 2022;603:907–12. https://doi.org/10.1038/s41586-022-04480-z.
[7] Biagioli M, Di Giorgio C, Massa C, Marchianò S, Bellini R, Bordoni M, et al. Microbial-derived bile acid reverses inflammation in IBD via GPBAR1 agonism and RORγt inverse agonism. Biomed Pharmacother 2024;181:117731. https://doi.org/10.1016/j.biopha.2024.117731.

Introduction

Inflammatory bowel disease (IBD), comprising of Crohn’s disease and Ulcerative Colitis (UC), is a debilitating inflammatory disease of the gastrointestinal tract with no known cause. Although extensive work has linked numerous genetic loci to IBD, most of these associations remain poorly understood. In addition, some studies have associated IBD to metabolic diseases such as diabetes and non-alcoholic fatty liver disease (NAFLD), although the precise molecular and pathophysiological mechanisms underlying these associations are unknown.

Aims & Methods

The central objective of this study was to understand the molecular mechanisms underlying the associations between IBD and obesity related metabolic diseases. To address this research question, we used multiple mouse models of colitis (dextran sodium sulfate or DSS), DSS and Azoxymethane induced colitis associated colon cancer and Helicobacter hepaticus infection induced colitis in Il-10-/- mice) and high fat diet (HFD) and genetic models of obesity and obesity associated metabolic diseases. In addition, for mechanistic studies, we used chimeric mice generated through bone marrow transplantation as well as conditional knockout mouse models. Lastly, we employed CRISPR/Cas9 edited cells in vitro to understand the molecular mechanism.

Results

Employing multiple murine models of colitis, colitis-associated colon cancer (CAC) and obesity associated metabolic diseases, we have identified DUPD1, a phosphatase of unknown function, that links IBD with metabolic diseases. Specifically, Dupd1^-/-mice are protected from dextran sodium sulfate (DSS) and Helicobacter hepaticus induced colitis, and DSS/azoxymethane (AOM) induced CAC. Dupd1^-/- mice also exhibited protection against high fat diet (HFD) induced obesity and fatty liver disease and glucose intolerance. DUPD1 is highly expressed in the skeletal muscle. Indeed, using skeletal muscle specific conditional DUPD1 knockout mice (Dupd1^fl/flMyf6^Cre), we show that DUPD1 exerts its colitogenic effects from the skeletal muscle through modulation of autophagy, a pathway whose dysfunction is known to play a role in IBD. Importantly, a dual specificity phosphatase inhibitor (NSC-663284) inhibited DUPD1 enzyme activity and reduced DSS-induced colitis in wild type mice but not in Dupd1^-/-mice.

Conclusion

Our study identifies Dupd1 as a central gene that links IBD and obesity-associated metabolic diseases and suggests that it is a new therapeutic target in IBD, and obesity associated metabolic diseases.

Disclosure

Nothing to declare.

Introduction

Inflammatory bowel disease (IBD) is a complex chronic and relapsing inflammatory disorder of the gastrointestinal tract with unclear pathogenesis. Accumulating evidence suggests food emulsifiers as a risk factor for the development of IBD. It is indicated that food emulsifiers carboxymethylcellulose (CMC) can alter gut microbiota and promote intestinal inflammation in IBD under normal diet. Since high-fat diet is the main life scenario for CMC use, little is known about the effect of CMC on colitis model in different high-fat diet.

Aims & Methods

C57/BL6 mice (3-5 weeks old) were randomly divided into three high-fat diet (HFD) groups, which only differed by fat composition (40 %), derived from corn oil (HCO, n-6 polyunsaturated fatty acids), olive oil (HOO, monounsaturated fatty acids) and milk fat (HMF, saturated fatty acids), and exposed to CMC (1.0% w/v) in drinking water for 4 weeks before the establishment of dextran sulfate sodium (DSS) induced acute colitis mice model. Colon inflammation severity was evaluated using survival rate, HE staining, colon length, body weight change and DAI score. Ki67 and TUNEL assays were performed to detect proliferation and apoptosis.

Results

Compared with the CMC+DSS group, the HMF+CMC+DSS group markedly increased survival rate (P=0.013), colon length (P=0.027) and body weight (day4, day5, day6 and day7, P<0.05, respectively), and relieved DAI score (day4 and day6, P<0.05, respectively) and histological damage (P<0.0001). The HOO+CMC+DSS group seemly had no significant difference from the CMC+DSS group. In contrast, the HCO+CMC+DSS group developed more aggressive colitis with increased DAI score (day5, P<0.01) and decreased body weight (day1, day2, day5 and day6, P<0.05, respectively). In terms of maintaining homeostasis of the intestinal barrier, the HMF+CMC+DSS group showed the highest Ki67 (P=0.012, P=0.0002 P=0.042, respectively) and TUNEL positive cells (P=0.324, P<0.0001, P<0.0001, respectively) compared with the CMC+DSS, HOO+CMC+DSS or HCO+CMC+DSS group. Between CMC+DSS and HOO+CMC+DSS or HCO+CMC+DSS group, there was no difference in Ki67 positive cells, while TUNEL positive cells significantly decreased (P=0.002, P=0.008, respectively).

Conclusion

The function of CMC on DSS colitis varies in different high-fat. Unexpectedly, CMC protects against the development of high-milk-fat related colitis by maintaining homeostasis of proliferation and apoptosis.

References

The function of CMC on DSS colitis varies in different high-fat. Unexpectedly, CMC protects against the development of high-milk-fat related colitis by maintaining homeostasis of proliferation and apoptosis.

Disclosure

none

Introduction

Inflammatory bowel disease (IBD) represents a cluster of chronic systemic intestinal disturbances that comprise Crohn’s disease (CD) and ulcerative colitis. It has been shown that the transcription factor peroxisome proliferator activated receptor-gamma (PPAR-α) exerts its anti-inflammatory action by negatively influencing the expression and activity of inflammatory transcription factor called NF-kb. In the absence of (PPAR-α) gene, IBD pathologies are exacerbated. (1) We have previously shown that the polyphenolic extract from maqui fruit decreased reactive oxygen species (ROS) in a dose-dependent manner and its administration in an experimental animal model of CD significatively ameliorated the clinical course of the disease and intestinal inflammation.

Aims & Methods

We explored whether maqui extract had an anti-inflammatory role through modulating PPAR-α expression in epithelial cells and macrophage cells from colon tissue. Male Balb/c mice 12-14 weeks old which were exposed to 2,4,6-trinitrobenzene sulfonic acid (TNBS) via intracolonic administration and were randomly assigned in 4 groups (n=6) as follows: i) Control Group (EtOH 50%) ii) Crohn’s Disease Group (100 mg/kg of TNBS plus EtOH 50%), iii) Curative Group (maqui at 50mg/kg for 4 days after TNBS induction), iv) Preventive Group (maqui at 50mg/kg 7 days prior TNBS and 4 days after induction).

Results

In the epithelial cells, TNBS induced a slight decrease of PPAR-α expression when we compared with the control group. Notably, this difference did not reach statistical significance. The administration of maqui extract did not alter epithelial PPAR-α level. Similar PPAR-α staining intensity and expression was showed either for curative or preventive groups remained like the control group.
In terms of specific macrophage PPAR-α levels, a stronger positive staining and intensity was observed in the CD mice when compared to the controls. However, this difference was not significant. Similarly, an increase in PPAR-α staining intensity and PPAR-α positive macrophages was also observed in mice that received curative maqui treatment, whereas colons from mice receiving maqui extract as a preventive treatment yielded a significative PPAR-α staining.

Conclusion

Maqui extract treatment elicit an anti-inflammatory action by increasing the expression of PPAR-α in immune cells during the earlier phase of the disease. These data support the preventive effect of polyphenols from maqui extract and its potential antiinflammatory effect in IBD.

References

1. Leng F, Yin H, Qin S, Zhang K, Guan Y, Fang R, et al. NLRP6 self-assembles into a linear molecular platform following LPS binding and ATP stimulation. Sci Rep. 2020;10(1):1–10.

Introduction

The intestinal epithelium is the most regenerative tissue in the human body and an essential interface between the microbial ecosystem and the underlying mucosa, orchestrating both immune-mediated and metabolic functions. Mitochondrial signaling and metabolism controls the phenotype and function of intestinal epithelial cells (IECs) and mitochondrial perturbation is associated with chronic inflammation. We hypothesize that disruption of microbial-metabolic circuits and impaired metabolic flexibility of IECs contribute to the initiation and progression of tissue injury underlying chronic inflammation.

Aims & Methods

To address the role of mitochondrial impairment in epithelial homeostasis, conditional deletion of Heat shock protein 60 (Hsp60) was induced in the epithelium of Hsp60^Δ/ΔIEC and Hsp60^Δ/ΔIEC;Il10^-/- mice under specific pathogen free and germfree conditions. Blinded histological analysis was used to assess metabolic inury and tissue inflammation. Additional 16S rRNA and shallow shotgun sequencing as well as metaproteomic analysis were performed to identify microbiome changes at the compositional and functional levels. Nanostring analysis and single-cell RNA sequencing (scRNA-seq) were used to identify epithelial cell population-specific transcriptional responses and to validate these gene signatures in resected tissues from Crohn’s disease patients.

Results

Hsp60 deletion in IECs leads to the disruption of mitochondrial metabolism and the development of irregular crypt architecture, referred to as metabolic injury. Tissue lesions and IBD-related colitis are accelerated in Hsp60^Δ/ΔIEC;Il10^-/- mice. Germfree mice are protected from injury and inflammation, demonstrating a causal contribution of bacteria to metabolic injury. Mitochondrial perturbation in Hsp60^Δ/ΔIEC mice is associated with microbial dysbiosis, including an increased abundance of Bacteroides spp., which are maintained during sustained inflammation in Hsp60^Δ/ΔIEC;Il10^-/- mice. Consistently, B. caecimuris triggers tissue aberration in monocolonized-Hsp60^Δ/ΔIEC mice, supporting its deleterious role in tissue homeostasis. Furthermore, metaproteomic analysis revealed a metabolic adaptation of B. caecimuris in response to tissue injury. Importantly, the clinical relevance of Bacteroides spp. is confirmed in a combined analysis of three IBD cohorts (N=560 patients). Transcriptional profiling of the epithelium identified a gene signature in injury-associated sub-populations, including Ido1, Nos2 and Duox2. Remarkably, the identified metabolic injury gene signature discriminates inflamed (N=196) versus non-inflamed (N=147) mucosa in CD patients, thus validating the human relevance of epithelial mitochondrial disruption in IBD.

Conclusion

Bacterial presence is a key driver of intestinal injury and metabolic injury associates with dysbiotic changes, notably expansion of Bacteroides spp. and their metabolic adaptation. Furthermore, mitochondrial perturbation induces a metabolic injury signature, which differentiates inflamed versus non-inflamed mucosa in IBD patients, strengthening the hypothesis of unresolved metabolic injury as a novel concept in the pathogenesis of intestinal inflammation.