PAR1 and PAR4 exert opposite effects on tumor growth and metastasis of esophageal squamous cell carcinoma via STAT3 and NF-κB signaling pathways

New insight into the agonism of protease-activated receptors as an immunotherapeutic strategy

The activation and mobilization of immune cells play a crucial role in immunotherapy. Existing therapeutic interventions, such as cytokines administration, aim to enhance immune cell activity. However, these approaches usually result in modest effectiveness and toxic side effects, thereby restricting their clinical application. Protease-activated receptors (PARs), a subfamily of G protein-coupled receptors, actively participate in the immune system by directly activating immune cells. The activation of PARs by proteases or synthetic ligands can modulate immune cell behavior, signaling, and responses to treat immune-related diseases, suggesting the significance of PARs agonism in immunotherapy. However, the agonism of PARs in therapeutical applications remains rarely discussed, since it has been traditionally considered that PARs activation facilitates disease progressions. This review aims to comprehensively summarize the activation, rather than inhibition, of PARs in immune-related physiological responses and diseases. Additionally, we will discuss the emerging immunotherapeutic potential of PARs agonism, providing a new strategic direction for PARs-mediated immunotherapy.

MicroRNA-26a alleviates tubulointerstitial fibrosis in diabetic kidney disease by targeting PAR4

Our previous study found that miR-26a alleviates aldosterone-induced tubulointerstitial fibrosis (TIF). However, the effect of miR-26a on TIF in diabetic kidney disease (DKD) remains unclear. This study clarifies the role and possible mechanism of exogenous miR-26a in controlling the progression of TIF in DKD models. Firstly, we showed that miR-26a was markedly decreased in type 2 diabetic db/db mice and mouse tubular epithelial cells (mTECs) treated with high glucose (HG, 30 mM) using RT-qPCR. We then used adeno-associated virus carrying miR-26a and adenovirus miR-26a to enhance the expression of miR-26a in vivo and in vitro. Overexpressing miR-26a alleviated the TIF in db/db mice and the extracellular matrix (ECM) deposition in HG-stimulated mTECs. These protective effects were caused by reducing expression of protease-activated receptor 4 (PAR4), which involved in multiple pro-fibrotic pathways. The rescue of PAR4 expression reversed the anti-fibrosis activity of miR-26a. We conclude that miR-26a alleviates TIF in DKD models by directly targeting PAR4, which may provide a novel molecular strategy for DKD therapy.

Fecal microbiota transplantation improves intestinal inflammation in mice with ulcerative colitis by modulating intestinal flora composition and down-regulating NF-kB signaling pathway

Ulcerative colitis (UC) is a chronic inflammatory disease of the intestine. It is characterized with recurrent. The pathogenesis is mainly associated with environmental factors, genetic susceptibility, dysbiosis of the intestinal flora and autoimmunity. The role of intestinal flora disorders in the pathogenesis and progression of UC is becoming increasingly prominent. More and more studies have confirmed that fecal microbiota transplantation (FMT) could reshape the composition of UC intestinal flora and it is expected to be a new strategy for UC treatment. In this study, we used 2% Dextran sulfate sodium (DSS) for 7 days to induce acute colitis model in mice, and interfere with FMT and Enterotoxigenic Escherichia coli (ETEC). ELISA and immunohistochemistry were applied to detect the concentration and expression of NF-κB p65, STAT3 and IL-6. 16SrRNA high-throughput sequencing was performed to explore the composition of intestinal flora. The aim was to study the treatment effect of FMT on UC mice and explore its potential mechanism by observing the changes of intestinal flora composition and diversity, and its relationship with NF-κB p65, STAT3 and IL-6 expression. We conclude that FMT could improve intestinal flora disorder in mice with ulcerative colitis, regulate NF-κB signaling pathway, and significantly reduce intestinal inflammation in UC mice.

The role of the tumor microenvironment in colorectal cancer and the potential therapeutic approaches

BACKGROUND

Colorectal cancer (CRC) with a high prevalence is recognized as the fourth most common cause of cancer-related death globally. Over the past decade, there has been growing interest in the network of tumor cells, stromal cells, immune cells, blood vessel cells, and fibroblasts that comprise the tumor microenvironment (TME) to identify new therapeutic interventions.

METHODS

Databases, such as Google Scholar, PubMed, and Scopus, were searched to provide an overview of the recent research progress related to targeting the TME as a novel therapeutic approach.

RESULTS

Tumor microenvironment as a result of the cross talk between these cells may result in either advantages or disadvantages in tumor development and metastasis, affecting the signals and responses from the surrounding cells. Whilst chemotherapy has led to an improvement in CRC patients' survival, the metastatic aspect of the disease remains difficult to avoid.

CONCLUSIONS

The present review emphasizes the structure and function of the TME, alterations in the TME, its role in the incidence and progression of CRC, the effects on tumor development and metastasis, and also the potential of its alterations as therapeutic targets. It should be noted that providing novel studies in this field of research might help us to achieve practical therapeutic strategies based on their interaction.