miR‑155‑5p downregulation inhibits epithelial‑to‑mesenchymal transition by targeting SIRT1 in human nasal epithelial cells

The role of histone deacetylases in inflammatory respiratory diseases: an update

INTRODUCTION

Histone deacetylases (HDACs) catalyze the removal of acetyl groups from lysine residues of histones and other proteins, generally leading to a closed chromosomal configuration and transcriptional repression. Different HDACs have distinct substrate specificities and functions in different biological processes. Accumulating evidence indicates that HDACs play a key role in the pathogenesis of multiple respiratory diseases.

AREAS COVERED

After an extensive search of the PubMed database, Web of Science and ClinicalTrials.gov, covering the period from 1992 to 2024, this review summarizes recent advances in understanding the role of HDACs in inflammatory respiratory diseases, including allergic rhinitis (AR), chronic rhinosinusitis (CRS), asthma and chronic obstructive pulmonary disease (COPD). We also examine recent progress on the efficacy and potential use of histone deacetylase inhibitors (HDACi) for the treatment of these diseases.

EXPERT OPINION

Available data indicate that HDACs play an important role in the development of common inflammatory respiratory diseases, and HDACi have shown promise as treatments for these diseases. However, the exact roles and underlying mechanisms of specific HDACs in disease pathogenesis require further study. Additional work is necessary to develop novel potent HDACi with high isoform selectivity.

Andrographis modulates cisplatin resistance in lung cancer via miR-155-5p/SIRT1 axis

Andrographis (Andro) has been identified as an anti-cancer herbal. This study was to explore its underlying regulatory routes regarding cisplatin (DDP) resistance in lung cancer. The impacts of Andro on cell viability in lung cancer cells and normal cells BEAS-2B were validated using CCK8 tests. Then, cell viability and apoptosis analysis was performed in the cells after DDP, Andro, or combined treatment. RT-qPCR was applied for evaluating miR-155-5p and SIRT1 mRNA expressions, while western blot was for evaluating SIRT1 protein expressions. Binding sites between SIRT1 and miR-155-5p were predicted on TargetScan and were confirmed using luciferase reporter assays. Xenograft animal models were established for in vivo validation of the regulatory function of Andro in lung cancer. Andro decreased the cell viability in lung cancer cells but not normal cells BEAS-2B. The combined treatment with DDP and Andro induced the lowest viability and highest apoptosis in both A549 and A549/DDP cells. MiR-155-5p expression was suppressed, and SIRT was promoted by the Andro treatment, while overexpression of miR-155-5p reversed effects of Andro in cells, which was further counteracted by SIRT1 activation. SIRT1 was verified to be a target of miR-155-5p in A549/DDP cells. Moreover, Andro synergized with DDP in mice with lung cancer via miR-155-5p/SIRT1. Andro modulates cisplatin resistance in lung cancer via miR-155-5p/SIRT1 axis.

Epithelial cell dysfunction in chronic rhinosinusitis: the epithelial-mesenchymal transition

INTRODUCTION

Epithelial-mesenchymal transition (EMT) is a type of epithelial cell dysfunction, which is widely present in the nasal mucosa of patients with chronic rhinosinusitis (CRS), especially CRS with nasal polyps, and contributes to pathogenesis of the disease. EMT is mediated via complex mechanisms associated with multiple signaling pathways.

AREAS COVERED

We have summarized the underlying mechanisms and signaling pathways promoting EMT in CRS. Strategies or drugs/agents targeting the genes and pathways related to the regulation of EMT are also discussed for their potential use in the treatment of CRS and asthma. A literature search of studies published in English from 2000 to 2023 was conducted using the PubMed database, employing CRS, EMT, signaling, mechanisms, targeting agents/drugs, as individual or combinations of search terms.

EXPERT OPINION

EMT in nasal epithelium not only leads to epithelial cell dysfunction but also plays an important role in nasal tissue remodeling in CRS. A comprehensive understanding of the mechanisms underlying EMT and the development of drugs/agents targeting these mechanisms may provide new treatment strategies for CRS.

Insights into the epigenetics of chronic rhinosinusitis with and without nasal polyps: a systematic review

Background

Epigenetics facilitates insights on the impact of host environment on the genesis of chronic rhinosinusitis (CRS) through modulations of host gene expression and activity. Epigenetic mechanisms such as DNA methylation cause reversible but heritable changes in gene expression over generations of progeny, without altering the DNA base-pair sequences. These studies offer a critical understanding of the environment-induced changes that result in host predisposition to disease and may help in developing novel biomarkers and therapeutics. The goal of this systematic review is to summarize the current evidence on epigenetics of CRS with a focus on chronic rhinosinusitis with nasal polyps (CRSwNP) and highlight gaps that merit further research.

Methods

A systematic review of the English language literature was performed to identify investigations related to epigenetic studies in subjects with CRS.

Results

The review identified 65 studies. These have focused on DNA methylation and non-coding RNAs, with only a few on histone deacetylation, alternative polyadenylation, and chromatin accessibility. Studies include those investigating in vivo and in vitro changes or both. Studies also include animal models of CRS. Almost all have been conducted in Asia. The genome-wide studies of DNA methylation found differences in global methylation between CRSwNP and controls, while others specifically found significant differences in methylation of the CpG sites of the thymic stromal lymphopoietin (TSLP), IL-8, and PLAT. In addition, DNA methyltransferase inhibitors and histone deacetylase inhibitors were studied as potential therapeutic agents. Majority of the studies investigating non-coding RNAs focused on micro-RNAs (miRNA) and found differences in global expression of miRNA levels. These studies also revealed some previously known as well as novel targets and pathways such as tumor necrosis factor alpha, TGF beta-1, IL-10, EGR2, aryl hydrocarbon receptor, PI3K/AKT pathway, mucin secretion, and vascular permeability. Overall, the studies have found a dysregulation in pathways/genes involving inflammation, immune regulation, tissue remodeling, structural proteins, mucin secretion, arachidonic acid metabolism, and transcription.

Conclusions

Epigenetic studies in CRS subjects suggest that there is likely a major impact of the environment. However, these are association studies and do not directly imply pathogenesis. Longitudinal studies in geographically and racially diverse population cohorts are necessary to quantify genetic vs. environmental risks for CRSwNP and CRS without nasal polyps and assess heritability risk, as well as develop novel biomarkers and therapeutic agents.

Research advances in roles of microRNAs in nasal polyp

MicroRNAs (miRNAs), a subset of endogenous RNAs highly conservative with short chains, play key regulatory role in the biological relevant events of the cells. Exosomes are extracellular vesicles like the plasma membrane components being able to deliver information molecules such as miRNA between cells and to regulate the fate of the target cells. The progression of chronic rhinosinusitis with nasal polyps (CRSwNP) is closely associated with significant alterations of miRNA levels in both cells and exosomes. RNA-binding proteins (RBPs) have been acknowledged to play important roles in intracellular miRNA transport to exosomes, and specific membrane proteins such as caveolin-1 critically involved in HNRNPA1 -mediated transport of miRNA to exosomes. Aberrant alteration in endogenous miRNA levels significantly contributes to the process of airway remodeling in the nasal tissue and to the occurrence and progression of inflammatory responses in CRSwNP. Exogenous miRNAs delivered via exosomes has also been shown to play an important role in activating macrophages or in regulating vascular permeability in the CRSwNP.This paper highlights the mechanism of RBP-mediated delivery of miRNAs to exosomes and the important contribution of endogenous miRNAs to the development of CRSwNP in response to inflammation and airway remodeling. Finally, we discuss the future research directions for regulation of the miRNAs to CRSwNP.Delivery of exogenous miRNAs by exosomes alters the endogenous miRNAs content in nasal mucosal epithelial cells or in associated inflammatory cells in the CRSwNP, and altered endogenous miRNAs affects the inflammatory response and airway remodeling, which then regulates the occurrence and progression of CRSwNP.RBPs and associated membrane proteins such as caveolin-1 may play a crucial role in the entry of exogenous miRNA into exosomes.

TIM-4 in macrophages contributes to nasal polyp formation through the TGF-β1–mediated epithelial to mesenchymal transition in nasal epithelial cells

Chronic rhinosinusitis with nasal polyps (CRSwNP) is caused by prolonged inflammation of the paranasal sinus mucosa. The epithelial to mesenchymal transition (EMT) is involved in the occurrence and development of CRSwNP. The T-cell immunoglobulin domain and the mucin domain 4 (TIM-4) is closely related to chronic inflammation, but its mechanism in CRSwNP is poorly understood. In our study, we found that TIM-4 was increased in the sinonasal mucosa of CRSwNP patients and, especially, in macrophages. TIM-4 was positively correlated with α-SMA but negatively correlated with E-cadherin in CRS. Moreover, we confirmed that TIM-4 was positively correlated with the clinical parameters of the Lund-Mackay and Lund-Kennedy scores. In the NP mouse model, administration of TIM-4 neutralizing antibody significantly reduced the polypoid lesions and inhibited the EMT process. TIM-4 activation by stimulating with tissue extracts of CRSwNP led to a significant increase of TGF-β1 expression in macrophages in vitro. Furthermore, coculture of macrophages and human nasal epithelial cells (hNECs) results suggested that the overexpression of TIM-4 in macrophages made a contribution to the EMT process in hNECs. Mechanistically, TIM-4 upregulated TGF-β1 expression in macrophages via the ROS/p38 MAPK/Egr-1 pathway. In conclusion, TIM-4 contributes to the EMT process and aggravates the development of CRSwNP by facilitating the production of TGF-β1 in macrophages. Inhibition of TIM-4 expression suppresses nasal polyp formation, which might provide a new therapeutic approach for CRSwNP.

The Role of Small Extracellular Vesicles and MicroRNAs in the Diagnosis and Treatment of Allergic Rhinitis and Nasal Polyps

Allergic rhinitis and nasal polyps are common otorhinolaryngological diseases. Small extracellular vesicles and microRNAs have recently become major research topics of interest due to their key regulatory roles in cancer, inflammation, and various diseases. Although very detailed and in-depth studies on the pathogenesis and pathophysiology of allergic rhinitis and nasal polyps have been conducted, few studies have assessed the regulatory effects of exosomes and microRNAs on allergic rhinitis and nasal polyps. This paper reviews the studies on small extracellular vesicles and microRNAs in allergic rhinitis and nasal polyps conducted in recent years and focuses on the regulation of small extracellular vesicles and microRNAs in allergic rhinitis and nasal polyps with the aim of providing insights for the future diagnosis and treatment of allergic rhinitis and nasal polyps.

Identification of lncRNA Biomarkers and LINC01198 Promotes Progression of Chronic Rhinosinusitis with Nasal Polyps through Sponge miR-6776-5p

Background

Chronic sinusitis (CRS) was a chronic inflammation that originated in the nasal mucosa and affected the health of most people around the world. Chronic rhinosinusitis with nasal polyps (CRSwNP) was one kind of chronic sinusitis. Emerging research had suggested that long noncoding RNAs (lncRNAs) played vital parts in inflammatories and inflammation development.

Methods

We acquired GEO data to analyze the differential expression between the miRNA, immune genes, TF, and lncRNA data in CRSWNP and the corresponding control tissues. Bioinformatic analysis by coexpression of endogenous RNA network and competitive way enrichment, analysis, and forecasting functions of these noncoding RNA. The different pathway expressions in CRSwNP patients were confirmed using GSVA to analyze the differentially expressed immune genes and TF data sets in CRSwNP patients. The differential immune gene and transcription factor data set in CRSwNP perform functional notes and protein-protein interaction (PPI) network structure. We predicted the potential genes and RNAs related to CRSWNP by constructing a ceRNA network. In addition, we also used 19 hub immune genes to predict the potential drugs of CRSWNP. lncRNA biomarkers in CRSwNP were identified by lncRNAs LASSO regression. The CIBERSORT algorithm was used to contrast the divergence in immune infiltrations between CRSwNP and usual inferior turbinate organizations in 22 immunocyte subgroups.

Results

We identified a total of 48 miRNAs, 304 lncRNAs, 92 TFs, and 525 immune genes as CRSwNP-specific RNAs. GO and KEGG pathways both analyzed differentially expressed immune genes and transcription factor data sets. We predicted the potential genes GNG7, TUSC8, LINC01198, and has-miR-6776-5p by constructing ceRNA and PPI networks. At the same time, we found that the above genes were involved in two important pathways: chemokine signal path and PI3K/AKT signal path. In addition, we predicted 5 small molecule drugs to treat CRSwNP by analyzing 19 central immune genes, namely, danazol, ikarugamycin, semustine, cefamandole, and molindone. Finally, we identified 5 biomarkers in CRSwNP, namely, LINC01198, LINC01094, LINC01798, LINC01829, and LINC01320.

Conclusions

We had identified CRSwNP-related miRNAs, lncRNAs, TFs, and immune genes, which may be making use of latent therapeutic target for CRSwNP. At the same time, we identified 5 lncRNA biomarkers in CRSwNP. The results of this study showed that LINC01198 promoted the progression of CRSwNPs through spongy miR-6776-5p. Our studies provide a new way for further analyses of the pathogenesis of CRSwNP.

Inhibition of miRNA-155 Alleviates High Glucose-Induced Podocyte Inflammation by Targeting SIRT1 in Diabetic Mice

OBJECTIVE

Microinflammation plays a crucial role in podocyte dysfunction in diabetic nephropathy, but its regulatory mechanism is still unclear. This study is aimed at discussing the mechanisms underlying the effect of miRNA-155 on podocyte injury to determine its potential as a therapeutic target.

METHODS

Cultured immortalized mouse podocytes and diabetic KK-Ay mice models were treated with a miR-155 inhibitor. Western blotting, real-time PCR, ELISA, immunofluorescence, and Luciferase reporter assay were used to analyze markers of inflammation cytokines and podocyte injury.

RESULTS

miRNA-155 was found to be highly expressed in serum and kidney tissue of mice with diabetic nephropathy and in cultured podocytes, accompanied by elevated levels of inflammatory factors. Inhibition of miRNA-155 can reduce proteinuria and ACR levels, diminish the secretion of inflammatory molecules, improve kidney function, inhibit podocyte foot fusion, and reverse renal pathological changes in diabetic nephropathy mice. Overexpression of miRNA-155 in vitro can increase inflammatory molecule production in podocytes and aggravates podocyte injury, while miRNA-155 inhibition suppresses inflammatory molecule production in podocytes and reduces podocyte injury. A luciferase assay confirmed that miRNA-155 could selectively bind to 3'-UTR of SIRT1, resulting in decreased SIRT1 expression. In addition, SIRT1 siRNA could offset SIRT1 upregulation and enhance inflammatory factor secretion in podocytes, induced by the miRNA-155 inhibitor.

CONCLUSIONS

These findings strongly support the hypothesis that miRNA-155 inhibits podocyte inflammation and reduces podocyte injury through SIRT1 silencing. miRNA-155 suppression therapy may be useful for the management of diabetic nephropathy.