The Molecular Mechanisms and Function of miR-15a/16 Dysregulation in Fibrotic Diseases

Metformin inhibits subretinal fibrosis by activating Klotho by miR-126-5p

Subretinal fibrosis is a main cause of visual loss in patients with neovascular age-related macular degeneration (nAMD), for whom there has been a lack of effective medication. Metformin can improve inflammation and angiogenesis in eye diseases. This study aimed to investigate the mechanism by which metformin inhibits subretinal fibrosis. A subretinal fibrosis cell model was induced by treating human retinal pigment epithelial cells (ARPE-19) with TGF-β1, a subretinal fibrosis mouse model was induced by a laser, and both cells and mice were treated with metformin. Cell proliferation, migration, and invasion were detected by CCK-8, scratch, and Transwell assays. Western blotting and immunofluorescence were used to evaluate protein expression levels, and RT‒qPCR was used to detect gene expression levels. HE and Masson staining were used to observe the morphological changes in retinal and choroidal tissues. Metformin treatment inhibited the TGF-β1-induced proliferation, migration, invasion and epithelial‒mesenchymal transition (EMT) of ARPE-19 cells and effectively ameliorated laser-induced subretinal fibrosis in mice. Mechanistically, metformin inhibits the expression of miR-126-5p, promotes Klotho synthesis, slows the progression of subretinal fibrosis, and miR-126-5p targets and negatively regulates Klotho. Metformin activates Klotho by inhibiting miR-126-5p, thereby reversing TGF-β1-induced ARPE-19 cell EMT and improving laser-induced subretinal fibrosis in mice.

The Effects of Extracellular Vesicles Derived from Hydatid Cyst Fluid on the Expression of microRNAs Involved in Liver Fibrosis

INTRODUCTION

Hydatidosis is a zoonotic neglected disease caused by the larval stage of Echinococcus granulosus. Evidence suggests a communication between hydatid cyst (HC) and hosts via extracellular vesicles (EVs). However, a little is known about the communication between EVs derived from HC fluid (HCF) and host cells. The current study aimed to investigate the effect of HCF derived EVs on expression of fibrotic and anti-fibrotic miRNAs in THP-1 cell line.

METHODS

In the current study, EVs were isolated using ultracentrifugation from wild-infected sheep HCF and characterized by western blot, electron microscope, and size distribution analysis. The effects of EVs on the expression levels of microRNAs (mir-16, mir-29a, and mir-155) involved in liver fibrosis were investigated using quantitative real-time PCR (qRT-PCR), 3 and 24 h after incubation.

RESULTS

Western blot analyses confirmed the expression of CD63 marker, while Calnexin and CD81 were absent in EVs samples. The SEM and morphology revealed round shape vesicles. The DLS analysis showed average size distribution 130.6 nm diameter. The expression levels of mir-16 and mir-29a were significantly upregulated after 3 h for 8.66 and 3.420, respectively, while they were significantly downregulated after 24 h for 3.853 and 1.859, respectively.

CONCLUSION

The main mechanism of the communication between EVs derived from HCF and their host remains unclear. Our results suggest that HC may modulate the expression of miRNAs, involved in liver fibrosis via EVs.

Diagnostic and Prognostic Significance of miRNA-15a-5p, 16-5p, and 92a-3p in Arrhythmogenic Right Ventricular Cardiomyopathy

BACKGROUND

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) presents diagnostic challenges and significant clinical burden due to life-threatening ventricular arrhythmias, compounded by the limited ability to predict patient prognosis using current clinical parameters. MicroRNAs (miRNAs) offer potential as markers in cardiac diseases, including ARVC, providing insights into disease pathogenesis, identification, and prognosis. However, current diagnostic criteria lack sensitivity and specificity, highlighting the need for novel markers like miRNAs to better understand ARVC's complex pathophysiological mechanisms.

OBJECTIVE

This multi-site study assessed circulating miRNA expression in ARVC patients, stratified by five-year event-free survival risk, to explore their potential as a marker for improving ARVC diagnosis and prognosis.

METHODS

Blood samples from 102 ARVC patients, 24 Brugada Syndrome (BrS) patients, and 22 healthy controls were analyzed for the expression of 20 miRNAs using TaqMan quantitative real-time PCR, ARVC patients were stratified by five-year event-free survival risk. Six candidate miRNAs were selected for further analysis, and machine learning algorithms were applied for classification and risk stratification based on miRNA profiles. Additionally, genotyping and functional annotation of miRNA targets were performed.

RESULTS

Six miRNAs exhibited differential expression between high and low-risk ARVC patients. MiR-15a-5p, miR-16-5p, and miR-92a-3p demonstrated the best performance in risk stratification. MiR-15a-5p also displayed higher expression in patients with adverse cardiac events. Comparative analysis with BrS patients and healthy controls consistently demonstrated increased expression of these miRNAs in ARVC.

CONCLUSION

This study highlights miRNAs' potential to enhance the diagnosis disease progression, and clinical outcomes of ARVC, supporting further research to improve patient care.

Non-coding RNAs as key regulators of Gasdermin-D mediated pyroptosis in cancer therapy

Pyroptosis is an inflammatory programed cell death process that plays a crucial role in cancer therapeutic, while Gasdermin-D is a critical effector protein for pyroptosis execution. This review discusses the intricate interactions between Gasdermin-D and some non-coding RNAs (lncRNA, miRNA, siRNA) and their potential application in the regulation of pyroptosis as an anticancer therapy. Correspondingly, these ncRNAs significantly implicate in Gasdermin-D expression and function regarding the pyroptosis pathway. Functioning as competing endogenous RNAs (ceRNAs), these ncRNAs might regulate Gasdermin-D at the molecular level, underlying fatal cell death caused by cancer and tumor propagation. Therefore, these interactions appeal to therapeutics, offering new avenues for cancer treatment. It address this research gap by discussing the possible roles of ncRNAs as mediators of gasdermin-D regulation. It suggest therapeutic strategies based on the current research findings to ensure the interchange between the ideal pyroptosis and cancer cell death.

Noxa inhibits oncogenesis through ZNF519 in gastric cancer and is suppressed by hsa-miR-200b-3p

While Phorbol-12-myristate-13-acetate-induced protein 1 (Noxa/PMAIP1) assumes a pivotal role in numerous tumors, its clinical implications and underlying mechanisms of gastric cancer (GC) are yet enigmatic. In this investigation, our primary objective was to scrutinize the clinical relevance and potential mechanisms of Noxa in gastric cancer. Immunohistochemical analysis was conducted on tissue microarrays comprising samples from a meticulously characterized cohort of 84 gastric cancer patients, accompanied by follow-up data, to assess the expression of Noxa. Additionally, Noxa expression levels in gastric cancer clinical samples and cell lines were measured through quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis. The effect of Noxa expression on the prognosis of patients with gastric cancer was evaluated using Kaplan-Meier survival. Further insight into the role of Noxa in driving gastric cancer progression was gained through an array of experimental techniques, including cell viability assays (CCK8), plate cloning assays, transwell assays, scratch assays, and real-time cell analysis (RTCA). Potential upstream microRNAs (miRNAs) that might modulate Noxa were identified through rigorous bioinformatics analysis, substantiated by luciferase reporter assays and Western blot experiments. Additionally, we utilized RNA sequencing, qRT-PCR, and Western blot to identify proteins binding to Noxa and potential downstream target. Finally, we utilized BALB/c nude mice to explore the role of Noxa in vivo. Our investigation unveiled a marked downregulation of Noxa expression in gastric cancer and underscored its significance as a pivotal prognostic factor influencing overall survival (OS). Noxa overexpression exerted a substantial inhibitory effect on the proliferation, migration and invasion of GC cells. Bioinformatic analysis and dual luciferase reporter assays unveiled the capacity of hsa-miR-200b-3p to interact with the 3'-UTR of Noxa mRNA, thereby orchestrating a downregulation of Noxa expression in vitro, consequently promoting tumor progression in GC. Our transcriptome analysis, coupled with mechanistic validation, elucidated a role for Noxa in modulating the expression of ZNF519 in the Mitophagy-animal pathway. The depletion of ZNF519 effectively reversed the oncogenic attributes induced by Noxa. Upregulation of Noxa expression suppressed the tumorigenesis of GC in vivo. The current investigation sheds light on the pivotal role of the hsa-miR-200b-3p/Noxa/ZNF519 axis in elucidating the pathogenesis of gastric cancer, offering a promising avenue for targeted therapeutic interventions in the management of this challenging malignancy.