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Angiogenesis inhibition treatments are limited and are often too late for advanced gastric cancer (GC) patients, in whom its efficacy is reduced. New molecular biomarkers are needed to optimize therapy regimens. In regard to this framework, circulating miRNAs, with high sensitivity and specificity, could be useful biomarkers of GC. The present longitudinal study was focused on analyzing the expression levels of a blood miRNA signature in a cohort of 40 patients receiving second-line therapy combining Ramucirumab and Paclitaxel, stratified based on their Progression-Free Survival (PFS). Using differential and bioinformatic analysis, miR-205-5p, miR-30e-3p, and miR-23b-3p were selected as possible predictive biomarkers, with the results showing that they were more highly expressed in patients exhibiting longer PFS and that they were involved in modulating angiogenesis. Furthermore, patients with longer PFS showed a progressive and significant decrease in the selected miRNA to minimal levels. The loss of the protective effect and the increased expression of the hypothetical targets, including angiopoietin-2, were then observed. The hypothesis was supported by the inverse correlation found for miR-205-5p and angiopoietin-2. Circulating levels of miR-205-5p were protective (HR = 0.37, p = 0.02) and patients with higher baseline miRNA levels had longer OS (12.47 vs. 9.00 months). Our findings suggest that these three miRNAs may be novel candidates as non-invasive predictive markers of therapy outcomes. [ABSTRACT FROM AUTHOR]

Background/Objectives: KRT23 was recently discovered as an epithelial-specific intermediate filament protein in the type I keratin family. Many studies have underlined keratin's involvement in several biological processes as well as in the pathogenesis of different diseases. Specifically, KRT23 was reported to affect the structural integrity of epithelial cells and to trigger cellular signaling leading to the onset of cancer. The aim of this study is to characterize a novel mechanism based on miR-195-5p/KRT23 in colorectal cancer. Methods: KRT23 mRNA and protein expression were characterized in FFPE sections from patients with CRC. The effects of miR-195-5p on KRT23 expression at the mRNA and protein levels were assessed by transient transfection experiments with mimic and inhibitor molecules. Cell attachment/detachment, migration, invasion, clone formation, and apoptosis were evaluated in human CRC cell lines after miR-195-5p mimic transfection. Results: We identified KRT23 as a putative target of miR-195-5p, a microRNA that we previously demonstrated to be reduced in CRC. We have proved the KRT23 expression deregulation in the tumoral section compared to adjacent normal mucosa in patients with CRC, according to the data derived from the public repository. We proved that the gain of miR-195-5p decreased the KRT23 expression. Conversely, we demonstrated that the inhibition of miR-195-5p led to an increase in KRT23 expression levels. We have demonstrated the in vitro effectiveness of miR-195-5p on CRC progression and that the in vivo intraperitoneal delivery of miR-195-5p mimic lowered colonic KRT23 mRNA and protein expression. Conclusions: These findings highlight a new regulatory mechanism by miR-195-5p in CRC affecting the keratin intermediate filaments and underline the miR-195-5p potential clinical properties. [ABSTRACT FROM AUTHOR]

NOD-like receptors (NLRs) are a family of cytosolic pattern recognition receptors (PRRs) implicated in the innate immune sensing of pathogens and damage signals. NLRs act as sensors in multi-protein complexes called inflammasomes. Inflammasome activity is necessary for the maintenance of intestinal homeostasis, although their aberrant activation contributes to the pathogenesis of several gastrointestinal diseases. In this review, we summarize the main features of the predominant types of inflammasomes involved in gastrointestinal immune responses and their implications in intestinal disease, including Irritable Bowel Syndrome (IBS), Inflammatory Bowel Disease (IBD), celiac disease, and Colorectal Cancer (CRC). In addition, we report therapeutic discoveries that target the inflammasome pathway, highlighting promising novel therapeutic strategies in the treatment of intestinal diseases. Collectively, our understanding of the mechanisms of intestinal inflammasome activation and their interactions with other immune pathways appear to be not fully elucidated. Moreover, the clinical relevance of the efficacy of inflammasome inhibitors has not been evaluated. Despite these limitations, a greater understanding of the effectiveness, specificity, and reliability of pharmacological and natural inhibitors that target inflammasome components could be an opportunity to develop new therapeutic options for the treatment of intestinal disease. [ABSTRACT FROM AUTHOR]

Background. Very low-calorie ketogenic diets (VLCKD) are an effective weight-loss strategy for obese individuals, reducing risks of liver conditions such as non-alcoholic steatohepatitis and fibrosis. Small extracellular vesicles (sEVs) are implicated in liver fibrosis by influencing hepatic cell phenotypes and contributing to liver damage. This study investigates sEVs derived from serum of 60 obese adults categorized into low fibrosis risk (LR) and intermediate/high fibrosis risk (IHR) groups based on FibroScan elastography (FIB E scores, limit value 8 kPa) and all participants underwent an 8-week VLCKD intervention. Methods. The study examines the impact of these sEVs on fibrosis markers, inflammation, and autophagy in a hepatocyte cell line (HEPA-RG) using bioinformatics, RNA sequencing, lipidomics, RT-PCR, and Western blotting before (T0) and after (T1) VLCKD. Results. sEVs from LR patients post-VLCKD reduced fibrosis related gene expression (e.g., ACTA2) and enhanced proteins associated with regeneration and inflammation (e.g., HDAC6). Conversely, sEVs from IHR patients increased fibrosis and inflammation related gene expression (PIK3CB, AKT1, ACTA2) in hepatocytes, raising concerns about VLCKD suitability for IHR patients. IHR sEVs also decreased expression of HDAC10, HDAC6, HDAC3, MMP19, and MMP2, while increasing modulation of p-AKT, α-SMA, and VIM. Conclusion. These findings underscore the critical role of sEVs in regulating inflammation, remodeling, and hepatic stress responses, particularly in IHR patients, and suggest sEVs could complement instrumental evaluations like FibroScan in fibrosis assessment. [ABSTRACT FROM AUTHOR]

Crohn's disease (CD) is a type of inflammatory bowel disease (IBD) affecting the gastrointestinal tract that can also cause extra-intestinal complications. Following exposure to the mRNA vaccine BNT162b2 (Pfizer-BioNTech) encoding the SARS-CoV-2 Spike (S) protein, some patients experienced a lack of response to the biological drug Adalimumab and a recrudescence of the disease. In CD patients in progression, resistant to considered biological therapy, an abnormal increase in intestinal permeability was observed, more often with a modulated expression of different proteins such as Aquaporin 8 (AQP8) and in tight junctions (e.g., ZO-1, Claudin1, Claudin2, Occludin), especially during disease flares. The aim of this study is to investigate how the SARS-CoV-2 vaccine could interfere with IBD therapy and contribute to disease exacerbation. We investigated the role of the SARS-CoV-2 Spike protein, transported by extracellular vesicles (EVs), and the impact of various EVs components, namely, exosomes (EXOs) and microvesicles (MVs), in modulating the expression of molecules involved in the exacerbation of CD, which remains unknown. [ABSTRACT FROM AUTHOR]

Cyclic nucleotide phosphodiesterases (PDEs) consist of a family of enzymes expressed in several types of cells, including inflammatory cells, that play a pivotal role in inflammation. Several studies have demonstrated that the inhibition of PDE4 results in a reduced inflammatory response via PKA and CREB signaling. Hence, PDE4 suppression improves the inflammatory feedback typical of several diseases, such as inflammatory bowel disease (IBD). In our previous studies, we have demonstrated that miR-369-3p regulates inflammatory responses, modulating different aspects of the inflammatory process. The aim of this study was to demonstrate an additional anti-inflammatory effect of miR-369-3p targeting PDE4B, one of the widely expressed isoforms in immune cells. We found that miR-369-3p was able to reduce the expression of PDE4B, elevating the intracellular levels of cAMP. This accumulation increased the expression of PKA and pCREB, mitigating the release of pro-inflammatory cytokines and promoting the release of anti-inflammatory cytokines. To prove that PDE4B is a good therapeutic target in IBD, we also demonstrate that the expression of PDE4B was increased in UC patients compared to healthy controls, affecting the immune infiltrate. PDE4B is considered an important player in inflammatory progression; hence, our results show the ability of miR-369-3p to ameliorate inflammation by targeting PDE4B, supporting its future application as a new therapeutic approach in IBD. [ABSTRACT FROM AUTHOR]

Pinin (PNN) is a desmosome-associated protein that reinforces the organization of keratin intermediate filaments and stabilizes the anchoring of the cytoskeleton network to the lateral surface of the plasma membrane. The aberrant expression of PNN affects the strength of cell adhesion as well as modifies the intracellular signal transduction pathways leading to the onset of CRC. In our previous studies, we characterized the role of miR-195-5p in the regulation of desmosome junctions and in CRC progression. Here, with the aim of investigating additional mechanisms related to the desmosome complex, we identified PNN as a miR-195-5p putative target. Using a public data repository, we found that PNN was a negative prognostic factor and was overexpressed in colon cancer tissues from stage 1 of the disease. Then, we assessed PNN expression in CRC tissue specimens, confirming the overexpression of PNN in tumor sections. The increase in intracellular levels of miR-195-5p revealed a significant decrease in PNN at the mRNA and protein levels. As a consequence of PNN regulation by miR-195-5p, the expression of KRT8 and KRT19, closely connected to PNN, was affected. Finally, we investigated the in vivo effect of miR-195-5p on PNN expression in the colon of AOM/DSS-treated mice. In conclusion, we have revealed a new mechanism driven by miR-195-5p in the regulation of desmosome components, suggesting a potential pharmacological target for CRC therapy. [ABSTRACT FROM AUTHOR]

Desmosomes are essential structures for ensuring tissue functions, and their deregulation is involved in the development of colorectal cancer (CRC). JUP (γ-catenin) is a desmosome adhesion component that also acts as a signaling hub, suggesting its potential involvement in CRC progression. In this context, we recently demonstrated that miR-195-5p regulated JUP and desmosome cadherins expression. In addition, miR-195-5p gain of function indirectly modulated the expression of key effectors of the Wnt pathway involved in JUP-dependent signaling. Here, our purpose was to demonstrate the aberrant expression of miR-195-5p and JUP in CRC patients and to functionally characterize the role of miR-195-5p in the regulation of desmosome function. First, we showed that miR-195-5p was downregulated in CRC tumors compared to adjacent normal tissue. Then, we demonstrated that JUP expression was significantly increased in CRC tissues compared to adjacent normal tissues. The effects of miR-195-5p on CRC progression were assessed using in vitro transient transfection experiments and in vivo miRNA administration. Increased miR-195-5p in colonic epithelial cells strongly inhibits cell proliferation, viability, and invasion via JUP. In vivo gain of function of miR-195-5p reduced the numbers and sizes of tumors and significantly ameliorated the histopathological changes typical of CRC. In conclusion, our findings indicate a potential pharmacological target based on miR-195-5p replacement as a new therapeutic approach in CRC. [ABSTRACT FROM AUTHOR]

Desmosomes play a key role in the regulation of cell adhesion and signaling. Dysregulation of the desmosome complex is associated with the loss of epithelial cell polarity and disorganized tissue architecture typical of colorectal cancer (CRC). The aim of this study was to investigate and characterize the effect of miR-195-5p on desmosomal junction regulation in CRC. In detail, we proposed to investigate the deregulation of miR-195-5p and JUP, a gene target that encodes a desmosome component in CRC patients. JUP closely interacts with desmosomal cadherins, and downstream, it regulates several intracellular transduction factors. We restored the miR-195-5p levels by transient transfection in colonic epithelial cells to examine the effects of miR-195-5p on JUP mRNA and protein expression. The JUP regulation by miR-195-5p, in turn, determined a modulation of desmosome cadherins (Desmoglein 2 and Desmocollin 2). Furthermore, we focused on whether the miR-195-5p gain of function was also able to modulate the expression of key components of Wnt signaling, such as NLK, LEF1 and Cyclin D1. In conclusion, we have identified a novel mechanism controlled by miR-195-5p in the regulation of adhesive junctions, suggesting its potential clinical relevance for future miRNA-based therapy in CRC. [ABSTRACT FROM AUTHOR]