TGF-β receptor I inhibitor may restrict the induction of EMT in inflamed intestinal epithelial cells

Long non-coding RNAs as pathophysiological regulators, therapeutic targets and novel extracellular vesicle biomarkers for the diagnosis of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic relapsing disease of the gastrointestinal (GI) system that includes two groups, Crohn's disease (CD) and ulcerative colitis (UC). To cope with these two classes of IBD, the investigation of pathogenic mechanisms and the discovery of new diagnostic and therapeutic approaches are crucial. Long non-coding RNAs (lncRNAs) which are non-coding RNAs with a length of longer than 200 nucleotides have indicated significant association with the pathology of IBD and strong potential to be used as accurate biomarkers in diagnosing and predicting responses to the IBD treatment. In the current review, we aim to investigate the role of lncRNAs in the pathology and development of IBD. We first describe recent advances in research on dysregulated lncRNAs in the pathogenesis of IBD from the perspective of epithelial barrier function, intestinal immunity, mitochondrial function, and intestinal autophagy. Then, we highlight the possible translational role of lncRNAs as therapeutic targets, diagnostic biomarkers, and predictors of therapeutic response in colon tissues and plasma samples. Finally, we discuss the potential of extracellular vesicles and their lncRNA cargo in the pathophysiology, diagnosis, and treatment of IBD.

Effect of atractylenolide III on zearalenone-induced Snail1-mediated epithelial-mesenchymal transition in porcine intestinal epithelium

BACKGROUND

The intestinal epithelium performs essential physiological functions, such as nutrient absorption, and acts as a barrier to prevent the entry of harmful substances. Mycotoxins are prevalent contaminants found in animal feed that exert harmful effects on the health of livestock. Zearalenone (ZEA) is produced by the Fusarium genus and induces gastrointestinal dysfunction and disrupts the health and immune system of animals. Here, we evaluated the molecular mechanisms that regulate the effects of ZEA on the porcine intestinal epithelium.

RESULTS

Treatment of IPEC-J2 cells with ZEA decreased the expression of E-cadherin and increased the expression of Snai1 and Vimentin, which induced Snail1-mediated epithelial-to-mesenchymal transition (EMT). In addition, ZEA induces Snail-mediated EMT through the activation of TGF-β signaling. The treatment of IPEC-J2 cells with atractylenolide III, which were exposed to ZEA, alleviated EMT.

CONCLUSIONS

Our findings provide insights into the molecular mechanisms of ZEA toxicity in porcine intestinal epithelial cells and ways to mitigate it.

Expression profiles of the lncRNA antisense GAS5-AS1 in colon biopsies from pediatric inflammatory bowel disease patients and its role in regulating sense transcript GAS5

The long non-coding RNA (lncRNA) growth arrest-specific transcript 5 (GAS5) level was demonstrated as involved in pediatric inflammatory bowel disease (IBD) pathogenesis. Since its antisense transcript GAS5-AS1 has never been investigated in IBD, this study aims to detect whether GAS5-AS1 and GAS5 levels are related to IBD clinical parameters and investigate their correlation in vitro. Twenty-six IBD pediatric patients were enrolled; paired inflamed and non-inflamed intestinal biopsies were collected. We evaluated GAS5 and GAS5-AS1 levels by real-time PCR. The role of GAS5 and GAS5-AS1 was assessed in vitro by transient silencing in THP1-derived macrophages. GAS5-AS1 and GAS5 levels were associated with patients' clinical parameters; GAS5-AS1 expression was downregulated in inflamed tissues and inversely correlated with disease activity. A positive correlation between GAS5-AS1 and GAS5 levels was observed in non-inflamed biopsies. On THP1-derived macrophages, a reduced amount of both GAS5-AS1 and GAS5 was observed; accordingly, matrix metalloproteinase (MMP) 9 was increased. After GAS5-AS1 silencing, a downregulation of GAS5 was found, whereas no effect was detected on GAS5-AS1 after GAS5 silencing.    Conclusion: This study provided for the first time new insights into the potential role of GAS5-AS1 in IBD. GAS5-AS1 modulates GAS5 levels in vitro and may serve as a potential IBD diagnostic biomarker. What is Known: • GAS5 is involved in regulating intestinal MMP-2 and MMP-9 in pediatric patients with IBD; • GAS5-AS1 has never been investigated in the context of IBD; • GAS5-AS1 regulates the expression of GAS5, increasing its stability in tissues and in vitro cell models of cancer. What is New: • GAS5-AS1 correlated with GAS5 and IBD clinical parameters; • GAS5-AS1 can modulate GAS5 levels in macrophages; • GAS5-AS1 may serve as potential IBD diagnostic biomarker.

Dendritic cells: the yin and yang in disease progression

Dendritic cells (DCs) are antigen presenting cells that link innate and adaptive immunity. DCs have been historically considered as the most effective and potent cell population to capture, process and present antigens to activate naïve T cells and originate favorable immune responses in many diseases, such as cancer. However, in the last decades, it has been observed that DCs not only promote beneficial responses, but also drive the initiation and progression of some pathologies, including inflammatory bowel disease (IBD). In line with those notions, different therapeutic approaches have been tested to enhance or impair the concentration and role of the different DC subsets. The blockade of inhibitory pathways to promote DCs or DC-based vaccines have been successfully assessed in cancer, whereas the targeting of DCs to inhibit their functionality has proved to be favorable in IBD. In this review, we (a) described the general role of DCs, (b) explained the DC subsets and their role in immunogenicity, (c) analyzed the role of DCs in cancer and therapeutic approaches to promote immunogenic DCs and (d) analyzed the role of DCs in IBD and therapeutic approaches to reduced DC-induced inflammation. Therefore, we aimed to highlight the "yin-yang" role of DCs to improve the understand of this type of cells in disease progression.

Role of the epithelial barrier in intestinal fibrosis associated with inflammatory bowel disease: relevance of the epithelial-to mesenchymal transition

In inflammatory bowel disease (IBD), chronic inflammation in the gastrointestinal tract can lead to tissue damage and remodelling, which can ultimately result in fibrosis. Prolonged injury and inflammation can trigger the activation of fibroblasts and extracellular matrix (ECM) components. As fibrosis progresses, the tissue becomes increasingly stiff and less functional, which can lead to complications such as intestinal strictures, obstructive symptoms, and eventually, organ dysfunction. Epithelial cells play a key role in fibrosis, as they secrete cytokines and growth factors that promote fibroblast activation and ECM deposition. Additionally, epithelial cells can undergo a process called epithelial-mesenchymal transition, in which they acquire a more mesenchymal-like phenotype and contribute directly to fibroblast activation and ECM deposition. Overall, the interactions between epithelial cells, immune cells, and fibroblasts play a critical role in the development and progression of fibrosis in IBD. Understanding these complex interactions may provide new targets for therapeutic interventions to prevent or treat fibrosis in IBD. In this review, we have collected and discussed the recent literature highlighting the contribution of epithelial cells to the pathogenesis of the fibrotic complications of IBD, including evidence of EMT, the epigenetic control of the EMT, the potential influence of the intestinal microbiome in EMT, and the possible therapeutic strategies to target EMT. Finally we discuss the pro-fibrotic interactions epithelial-immune cells and epithelial-fibroblasts cells.