Long non-coding RNA SNHG5 suppresses the development of acute respiratory distress syndrome by targeting miR-205/COMMD1 axis

Clinical Significance of Long Non-Coding RNA SNHG5 in the Diagnosis and Prognosis of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is preventable and requires early screening. The study aimed to examine the clinical values of long non-coding RNA (lncRNA) SNHG5 in COPD diagnosis and prognosis. Out of 160 COPD patients, 80 were in the stable stage and 80 were in the acute exacerbation of COPD stage (AECOPD). SNHG5 expression was detected via qRT-PCR. The survival analysis was conducted using Cox regression analysis and K-M curve. SNHG5 levels significantly reduced in both stable COPD and AECOPD groups compared with the control group, with AECOPD group recording the lowest values. SNHG5 levels were negatively correlated with GOLD stage. Serum SNHG5 can differentiate stable COPD patients from healthy individuals (AUC = 0.805), and can screen AECOPD from stable ones (AUC = 0.910). SNHG5 negatively influenced the release of inflammatory cytokines. For AECOPD patients, those with severe cough and wheezing dyspnea symptoms exhibited the lowest values of SNUG5. Among the 80 AECOPD patients, 16 cases died in the one-year follow-up, all of whom had low levels of SNHG5. SNHG5 levels independently influenced survival outcomes, patients with low SNHG5 levels had a poor prognosis. Thus, lncRNA SNHG5, which is downregulated in patients with COPD (especially AECOPD), can potentially protect against AECOPD and serve as a novel prognostic biomarker for AECOPD.

The long non-coding RNA mir155hg promotes NLRP3-inflammasome activation and oxidative stress response in acute lung injury by targeting miR-450b-5p to regulate HIF-1α

BACKGROUND

Acute lung injury (ALI) can cause multiple organ dysfunction and a high mortality rate. Inflammatory responses, oxidative stress, and immune damage contribute to their pathogenic mechanisms. We studied the role of the newly discovered lncRNA, Lncmir155hg, in ALI.

METHODS

The levels of Lncmir155hg and miR-450b-5p from mice with ALI were detected via polymerase chain reaction analysis (qRT-PCR) and Fluorescence in situ hybridization (FISH). Pathological changes of lung were detected by HE (hematoxylin and eosin) staining, and HIF-1α, NOD-like receptor 3 (NLRP3) and caspase-1 protein changes were detected by immunohistochemistry. MLE-12 cells proliferation was detected by Cell-Counting Kit 8 analysis, and reactive oxygen species (ROS) was detected via flow cytometry. NLRP3, apoptosis-associated speck-like protein (ASC), and caspase-1 were measured via western blotting, and enzyme-linked immunosorbent assays detected the expression of Inflammatory factors. Lncmir155hg, miR-450b-5p, miR-450b-5p, and HIF-1α targets were predicted using LncTar and miRWalk and confirmed in dual-luciferase reporter assays.

RESULTS

In mice with ALI and MLE-12 cells induced by lipopolysaccharide (LPS), Lncmir155hg was high-expressed and miR-450b-5p was low-expressed. sh-Lncmir155hg reduced the damage of lung tissue, the production of inflammatory cytokines and oxidative stress reaction induced by LPS，miR-450b-5p reverses the effect of Lncmir155hg in mice. sh-Lncmir155hg decreased the protein levels of HIF-1α, NLRP3 and caspase-1 in LPS-induced lung tissues. sh-Lncmir155hg + miR-450b-5p inhibitor transfection reversed the effect of sh-Lncmir155hg on the expression of HIF-1α, NLRP3 and caspase-1. Lncmir155hg knockdown induced proliferation and inhibited NLRP3-inflammasome activation and oxidative stress in MLE-12 cells of ALI. miR-450b-5p was identified to have binding with Lncmir155hg, and inhibition of miR-450b-5p eliminated the effect of si-Lncmir155hg in MLE-12 cells of ALI. More importantly, miR-450b-5p was directly combined with HIF-1α, miR-450b-5p mimic promoted proliferation and inhibited activation of inflammasome associated proteins and reaction of oxidative stress, and HIF-1α overexpression abolished these effects.

CONCLUSION

Lncmir155hg aggravated ALI via the miR-450b-5p/HIF-1α axis.

Exploring the translational landscape of the long noncoding RNA transcriptome in acute respiratory distress syndrome: it is a long way to the top

Acute respiratory distress syndrome (ARDS) poses a significant and widespread public health challenge. Extensive research conducted in recent decades has considerably improved our understanding of the disease pathophysiology. Nevertheless, ARDS continues to rank among the leading causes of mortality in intensive care units and its management remains a formidable task, primarily due to its remarkable heterogeneity. As a consequence, the syndrome is underdiagnosed, prognostication has important gaps and selection of the appropriate therapeutic approach is laborious. In recent years, the noncoding transcriptome has emerged as a new area of attention for researchers interested in biomarker development. Numerous studies have confirmed the potential of long noncoding RNAs (lncRNAs), transcripts with little or no coding information, as noninvasive tools for diagnosis, prognosis and prediction of the therapeutic response across a broad spectrum of ailments, including respiratory conditions. This article aims to provide a comprehensive overview of lncRNAs with specific emphasis on their role as biomarkers. We review current knowledge on the circulating lncRNAs as potential markers that can be used to enhance decision making in ARDS management. Additionally, we address the primary limitations and outline the steps that will be essential for integration of the use of lncRNAs in clinical laboratories. Our ultimate objective is to provide a framework for the implementation of lncRNAs in the management of ARDS.

CircARF3 Mitigates Allergic Rhinitis through Targeting microRNA-205-5p/Sirtuin 5 Axis

INTRODUCTION

Circular RNAs (circRNAs) are essential in the progression of allergic rhinitis (AR). The purpose of this research was to examine the role of circRNA ADP-ribosylation factor 3 (circARF3) in the pathogenesis of AR.

METHODS

To generate an animal model of AR, mice were treated with house dust mite (HDM), and mice nasal epithelial cells (NEpCs) were treated with IL-4/IL-13 to imitate the inflammatory damage of AR in vitro. Sanger sequencing, qRT-PCR, and RNAse R digestion assays all validated the circularization structure of circARF3. The levels of circARF3, miR-205-5p, and sirtuin 5 (SIRT5) were determined by qRT-PCR or Western blotting. Luciferase reporter, RNA immunoprecipitation, and pull-down experiments were used to investigate the regulatory network. Flow cytometry was used to investigate the rate of cell apoptosis, and Western blotting was used to determine the levels of apoptotic-related proteins (cleaved caspase 3, cleaved polyadenosine-diphosphate-ribose polymerase) and HMGB1, TLR4, and MyD88. Enzyme-linked immunosorbent assay was used to assess the inflammatory response. Hematoxylin-eosin staining and TUNEL were used to detect the histology of injury and apoptosis of nasal mucosa tissues.

RESULTS

CircARF3 and SIRT5 levels were reduced in HDM-treated animals and IL-4/IL-13-treated NEpCs, while miR-205-5p expression was increased. CircARF3 was generated by back-splicing exons 3-5 with a stable circular shape. CircARF3 overexpression mitigated IL-4/IL-13-induced apoptosis in NEpCs by inhibiting miR-205-5p. SIRT5 upregulation attenuated IL-4/IL-13-induced inflammatory injury in NEpCs, and SIRT5 knockdown induced opposite effects. miR-205-5p silencing reversed the effects of SIRT5 knockdown on IL-4/IL-13-induced inflammatory injury. Furthermore, circARF3 overexpression alleviated histological abnormalities, apoptosis, inflammatory response, and HMGB1/TLR4 signaling activation in HDM-treated animals.

CONCLUSION

CircARF3 inhibited cell apoptosis and inflammation via the miR-205-5p/SIRT5 axis in IL-4/IL-13-treated NEpCs and HDM-treated mice.

Extracellular Vesicles, New Players in Sepsis and Acute Respiratory Distress Syndrome

Sepsis refers to a complex syndrome associated with physiological, pathological, and biochemical abnormalities resulted from infection. Sepsis is the major cause of acute respiratory distress syndrome (ARDS). Extracellular vesicles (EVs) are serving as new messengers to mediate cell-cell communication in vivo. Non-coding RNAs, proteins and metabolites encapsulated by EVs could result in either pro-inflammatory or anti-inflammatory effects in the recipient cells. Pathogens or host cells derived EVs play an important role in pathogens infection during the occurrence and development of sepsis and ARDS. Additionally, we summarize the potential application for EVs in diagnosis, prevention and treatment for sepsis and ARDS.

Long non-coding RNA LINC01194 promotes the inflammatory response and apoptosis of LPS-treated MLE 12 cells through the miR-203a-3p /MIP-2 axis

Acute lung injury (ALI) induced by bacteria LPS is characterized by the upregulation of the apoptosis rate of tissue cells and aggravation of inflammatory response. Although many studies have focused on the pathogenesis of this disease, its mechanism remains unknown. This study examined the regulatory role of long non-coding RNA (lncRNA) LINC01194 in the progression of ALI through various bioinformatics analyses and experimental work, including ELISA assay, dual-luciferase reporter assay, biotinylated RNA pull-down assay, and western blot analysis. The result showed that the LINC01194 was overexpressed in the ALI-induced mice model. We observed a significant upregulation of LINC01194 in LPS-treated Mouse lung epithelial type II cells (MLE-12 cells) after 24 hrs of induction. Bioinformatics analysis, Elisa assay, qRT-PCR analysis, Biotinylated RNA pull-down assay, apoptosis test, and western blot analysis demonstrated that the LINC01194 could act as a miR-203a-3p sponge to activate the inflammatory response in LPS-induced ALI model through post-transcriptional upregulation of MIP-2. We showed that LINC01194 regulates the inflammatory response and apoptosis of LPS-induced mice and MLE-12 cells via the miR-203a-3p/MIP-2 axis. LINC01194 could be a potential biomarker for early diagnosis and the treatment of ALI.

Long non-coding RNA (lncRNA): A potential therapeutic target in acute lung injury

Acute Lung Injury (ALI) and its severe form Acute Respiratory Distress Syndrome (ARDS) are the major cause of ICU death worldwide. ALI/ARDS is characterized by severe hypoxemia and inflammation that leads to poor lung compliance. Despite many advances in understanding and management, ALI/ARDS is still causing significant morbidity and mortality. Long non-coding RNA (lncRNA) is a fast-growing topic in lung inflammation and injury. lncRNA is a class of non-coding RNA having a length of more than 200 nucleotides. It has been a center of research for understanding the pathophysiology of various diseases in the past few years. Multiple studies have shown that lncRNAs are abundant in acute lung injury/injuries in mouse models and cell lines. By targeting these long non-coding RNAs, many investigators have demonstrated the alleviation of ALI in various mouse models. Therefore, lncRNAs show great promise as a therapeutic target in ALI. This review provides the current state of knowledge about the relationship between lncRNAs in various biological processes in acute lung injury and its use as a potential therapeutic target.