The potential of mecciRNA in hepatic stellate cell to regulate progression of nonalcoholic hepatitis

Circular RNAs modulate cell death in cardiovascular diseases

Cardiovascular diseases (CVDs) remain a global health challenge, with programmed cell death (PCD) mechanisms like apoptosis and necroptosis playing key roles in the progression. Circular RNAs (circRNAs) have recently been recognized as crucial regulators of gene expression, especially in modulating PCD. In current researches, circRNA regulation of apoptosis is the most studied area, followed by autophagy and ferroptosis. Notably, the regulatory role of circRNAs in pyroptosis and necroptosis has also begun to attract attention. From a mechanistic perspective, circRNAs influence cellular processes through several modes of action, including miRNA sponging, protein interactions, and polypeptide translation. Manipulating circRNAs and their downstream targets through inhibition or overexpression offers versatile therapeutic options for CVD treatment. Continued investigation into circRNA-mediated mechanisms may enhance our understanding of CVD pathophysiology and underscore their potential as novel and promising therapeutic targets.

Circ_0089761 accelerates colorectal cancer metastasis and immune escape via miR-27b-3p/PD-L1 axis

Circular RNAs have been implicated as critical regulators in the initiation and progression of colorectal cancer (CRC). This study was intended to elucidate the functional significance of the circ_0089761/miR-27b-3p/programmed cell death ligand 1 (PD-L1) axis in CRC. Our findings indicated that circ_0089761 expression was significantly elevated in CRC tissues and cell lines. Furthermore, the high expression of circ_0089761 was correlated with TNM stage and tumor size. Silencing circ_0089761 inhibited CRC cell proliferation, migration, and invasion, and increased apoptosis. Mechanistically, circ_0089761 facilitated its biological function by binding to miR-27b-3p to upregulate PD-L1 expression in CRC. Coculture experiments confirmed that low expression of circ_0089761 impeded CD8 + T cell apoptosis and depletion, activated CD8 + T cell function, and increased secretion of the immune effector cytokines IFN-γ, TNF-α, perforin, and granzyme-B. MiR-27b-3p inhibition or PD-L1 overexpression partially impeded CD8 + T cell function. The circ_0089761/miR-27b-3p/PD-L1 axis is postulated to exert pivotal functions in the mechanistic progression of CRC. Furthermore, it holds promising prospects as a feasible biomarker and therapeutic target for CRC.

Unraveling the crosstalk: circRNAs and the wnt signaling pathway in cancers of the digestive system

Circular RNA (circRNA) is a unique type of noncoding RNA molecule characterized by its closed-loop structure. Functionally versatile, circRNAs play pivotal roles in gene expression regulation, protein activity modulation, and participation in cell signaling processes. In the context of cancers of the digestive system, the Wnt signaling pathway holds particular significance. Anomalous activation of the Wnt pathway serves as a primary catalyst for the development of colorectal cancer. Extensive research underscores the notable participation of circRNAs associated with the Wnt pathway in the progression of digestive system tumors. These circRNAs exhibit pronounced dysregulation across esophageal cancer, gastric cancer, liver cancer, colorectal cancer, pancreatic cancer, and cholangiocarcinoma. Furthermore, the altered expression of circRNAs linked to the Wnt pathway correlates with prognostic factors in digestive system tumors. Additionally, circRNAs related to the Wnt pathway showcase potential as diagnostic, therapeutic, and prognostic markers within the realm of digestive system tumors. This comprehensive review outlines the interplay between circRNAs and the Wnt signaling pathway in cancers of the digestive system. It seeks to provide a comprehensive perspective on their association while delving into ongoing research that explores the clinical applications of circRNAs associated with the Wnt pathway.

CircRNA_001373 promotes liver fibrosis by regulating autophagy activation in hepatic stellate cells via the miR-142a-5p/Becn1 axis

The purpose of this study was to investigate the regulatory role and underlying mechanisms of circRNA_001373 in the hepatic stellate cell (HSC) activation. Quantitative real-time polymerase chain reaction was used to detect the expression of circRNA_001373, miR-142a-5p and Becn1. The viability of JS-1 cells was measured by Cell Counting Kit-8. The targeting relationship between miR-142a-5p and CircRNA_001373, as well as between miR-142a-5p and Becn1 was predicted using CircInteractome and TargetScan databases, respectively, and validated by dual-luciferase reporter assay. Western blot was utilized to determine the expression levels of proteins related to autophagy and the activation if HSCs in JS-1 cells. After activation by platelet-derived growth factor-BB, an increase was observed in the expression of collagen I and α-smooth muscle actin proteins. The expression of CircRNA_001373 was up-regulated in the activated HSCs. Knockdown of CircRNA_001373 significantly inhibited cell viability and activation of JS-1 cells, as well as autophagy in the activated HSCs. CircRNA_001373 could sponge miR-142a-5p in the activated HSCs, which in turn elevated the Becn1 expression. Concurrent knockdown of both CircRNA_001373 and miR-142a-5p reversed the inhibitory effects of the knockdown of CircRNA_001373 alone on cell viability and autophagy in activated JS-1 cells. CircRNA_ 001373 promotes cell viability and autophagy as well as the activation of JS-1 cells by regulating the miR-142a-5p/Becn1 axis.

Identification and bioinformatic analysis of CircRNAs in the plasma of patients with very severe chronic obstructive pulmonary disease

BACKGROUND

The differential expression of circular RNAs (circRNAs) in individuals with very severe chronic obstructive pulmonary disease (COPD) and healthy individuals was screened using microarray technology. The related functions and mechanisms were analyzed using bioinformatic methods to explore the potential of target circRNAs as biomarkers of COPD and provide insights for future pathogenesis.

PATIENTS AND METHODS

Thirty patients with very severe COPD and thirty healthy controls were diagnosed at The Second People's Hospital of Hefei from September 2021 to September 2022. The differential expression of circRNAs was compared and analyzed using a gene microarray and verified using quantitative real-time polymerase chain reaction (qRT-PCR) technology.

RESULTS

A total of 90 upregulated and 29 downregulated circRNAs were screened in patients with very severe COPD and compared with those in healthy controls. qRT-PCR analysis showed that hsa_circ_0062683 of patients with very severe COPD was significantly upregulated, and hsa_circ_0089763 and hsa_circ_0008882 were significantly downregulated. By constructing the circRNA-miRNA interaction network, it was found that hsa-miR-612, hsa-miR-593-5p, hsa-miR-765, and hsa-miR-103a-2-5p are the miRNAs regulated by more differentially expressed circRNAs (DEcircRNAs). DEcircRNAs may participate in the development of COPD through hypoxia or regulation of various immune cells.

CONCLUSION

Plasma circRNAs may play a helpful role in the diagnosis and assessment of COPD and be valuable disease biomarkers.

Overview of CircRNAs Roles and Mechanisms in Liver Fibrosis

Liver fibrosis represents the reversible pathological process with the feature of the over-accumulation of extracellular matrix (ECM) proteins within the liver, which results in the deposition of fibrotic tissues and liver dysfunction. Circular noncoding RNAs (CircRNAs) have the characteristic closed loop structures, which show high resistance to exonuclease RNase, making them far more stable and recalcitrant against degradation. CircRNAs increase target gene levels by playing the role of a microRNA (miRNA) sponge. Further, they combine with proteins or play the role of RNA scaffolds or translate proteins to modulate different biological processes. Recent studies have indicated that CircRNAs play an important role in the occurrence and progression of liver fibrosis and may be the potential diagnostic and prognostic markers for liver fibrosis. This review summarizes the CircRNAs roles and explores their underlying mechanisms, with a special focus on some of the latest research into key CircRNAs related to regulating liver fibrosis. Results in this work may inspire fruitful research directions and applications of CircRNAs in the management of liver fibrosis. Additionally, our findings lay a critical theoretical foundation for applying CircRNAs in diagnosing and treating liver fibrosis.

Differential Analysis of Key Proteins Related to Fibrosis and Inflammation in Soluble Egg Antigen of Schistosoma mansoni at Different Infection Times

Schistosomiasis is a major global health problem. Schistosomes secrete antigens into the host tissue that bind to chemokines or inhibit immune cell receptors, regulating the immune responses to allow schistosome development. However, the detailed mechanism of chronic schistosome infection-induced liver fibrosis, including the relationship between secreted soluble egg antigen (SEA) and hepatic stellate cell (HSC) activation, is still unknown. We used mass spectrometry to identify the SEA protein sequences from different infection weeks. In the 10th and 12th infection weeks, we focused on the SEA components and screened out the special protein components, particularly fibrosis- and inflammation-related protein sequences. Our results have identified heat shock proteins, phosphorylation-associated enzymes, or kinases, such as Sm16, GSTA3, GPCRs, EF1-α, MMP7, and other proteins linked to schistosome-induced liver fibrosis. After sorting, we found many special proteins related to fibrosis and inflammation, but studies proving their association with schistosomiasis infection are limited. Follow-up studies on MICOS, MATE1, 14-3-3 epsilon, and CDCP1 are needed. We treated the LX-2 cells with the SEA from the 8th, 10th, and 12th infection weeks to test HSC activation. In a trans-well cell model in which PBMCs and HSCs were co-cultured, the SEA could significantly induce TGF-β secretion, especially from the 12th week of infection. Our data also showed that TGF-β secreted by PBMC after the SEA treatment activates LX-2 and upregulates hepatic fibrotic markers α-SMA and collagen 1. Based on these results, the CUB domain-containing protein 1 (CDCP1) screened at the 12th infection week could be investigated further. This study clarifies the trend of immune mechanism variation in the different stages of schistosome infection. However, how egg-induced immune response transformation causes liver tissue fibrosis needs to be studied further.

Regulatory Functions and Mechanisms of Circular RNAs in Hepatic Stellate Cell Activation and Liver Fibrosis

Chronic liver injury induces the activation of hepatic stellate cells (HSCs) into myofibroblasts, which produce excessive amounts of extracellular matrix (ECM), resulting in tissue fibrosis. If the injury persists, these fibrous scars could be permanent and disrupt liver architecture and function. Currently, effective anti-fibrotic therapies are lacking; hence, understanding molecular mechanisms that control HSC activation could hold a key to the development of new treatments. Recently, emerging studies have revealed roles of circular RNAs (circRNAs), a class of non-coding RNAs that was initially assumed to be the result of splicing errors, as new regulators in HSC activation. These circRNAs can modulate the activity of microRNAs (miRNAs) and their interacting protein partners involved in regulating fibrogenic signaling cascades. In this review, we will summarize the current knowledge of this class of non-coding RNAs for their molecular function in HSC activation and liver fibrosis progression.

Transforming growth factor-β signaling: From tissue fibrosis to therapeutic opportunities

Fibrosis refers to the excessive deposition of extracellular matrix components in the processes of wound repair or tissue regeneration after tissue damage. Fibrosis occurs in various organs such as lung, heart, liver, and kidney tissues, resulting in the failure of organ structural integrity and its functional impairment. It has long been thought to be relentlessly progressive and irreversible process, but both preclinical models and clinical trials in multiorgans have shown that fibrosis is a highly dynamic process. Transforming growth factor-beta (TGF-β) is a superfamily of related growth factors. Many studies have described that activation of profibrotic TGF-β signaling promotes infiltration and/or proliferation of preexisting fibroblasts, generation of myofibroblasts, extracellular matrix deposition, and inhibition of collagenolysis, which leads to fibrosis in the pathological milieu. This review describes the effect of TGF-β signaling in fibrotic-associate lung, heart, liver, and kidney tissues, followed by a detailed discussion of canonical and non-canonical TGF-β signaling pathway. In addition, this review also discusses therapeutic options by using natural products and chemical agents, for targeting tissue fibrosis via modulating TGF-β signaling to provide a more specific concept-driven therapy strategy for multiorgan fibrosis.