Depression of lncRNA NEAT1 Antagonizes LPS-Evoked Acute Injury and Inflammatory Response in Alveolar Epithelial Cells via HMGB1-RAGE Signaling

LncRNA NEAT1 Inhibits Neuronal Apoptosis and Induces Neuronal Viability of Depressed Rats Via microRNA-320-3p/CRHR1 Axis

Long noncoding RNA nuclear enriched abundant transcript 1 (NEAT1) has been reported to be involved in depression. This study aims to investigate the mechanism of NEAT1/microRNA (miR)-320-3p/Corticotropin-releasing hormone receptor 1 (CRHR1) axis in depressed rats. Rats with depression-like behaviors were prepared by exposing the rats to chronic unpredictable mild stress. Behavioral functions, pathological damage, neuronal apoptosis and monoamine neurotransmitter were examined in depressed rats . Primary hippocampal neurons were injured through simulation with corticosterone(CORT). Cell viability and apoptosis were measured in CORT-Induced hippocampal neurons. The binding relationship between NEAT1 and miR-320-3p and the targeting relationship between miR-320-3p and CRHR1 were detected. Elevated NEAT1, CRHR1 and reduced miR-320-3p exhibited in depressed rats and CORT-treated hippocampal neurons, NEAT1 bound to miR-320-3p to target CRHR1. Silencing NEAT1 or elevating miR-320-3p improved behavioral functions, attenuated pathological damage and apoptosis in the hippocampus, and increased monoamine neurotransmitter in depressed rats. Repression of NEAT1 or promotion of miR-320-3p enhanced viability and suppressed apoptosis of CORT-treated hippocampal neurons. The study highlights that NEAT1 competitively binds to miR-320-3p to up-regulate CRHR1 expression, thereby promoting hippocampal damage of depressed rats.

Psychobiotics Lactiplantibacillus plantarum JYLP-326: Antidepressant-like effects on CUMS-induced depressed mouse model and alleviation of gut microbiota dysbiosis

BACKGROUND

Depression affects a significant portion of the global population and has emerged as one of the most debilitating conditions worldwide. Recent studies have explored the relationship between depression and the microbiota of the intestine, revealing potential avenues for effective treatment.

METHODS

To evaluate the potential alleviation of depression symptoms, we employed a depression C57BL/6 mice model induced by chronic unpredictable mild stress (CUMS). We administered Lactiplantibacillus plantarum JYLP-326 and conducted various animal behavior tests, including the open-field test (OFT), sucrose preference test (SPT), and tail-suspension test (TST). Additionally, we conducted immunohistochemistry staining and analyzed the hippocampal and colon parts of the mice.

RESULTS

The results of the behavior tests indicated that L. plantarum JYLP-326 alleviated spontaneous behavior associated with depression. Moreover, the treatment led to significant improvements in GFAP and Iba1, suggesting its potential neuroprotective effects. Analysis of the hippocampal region indicated that L. plantarum JYLP-326 administration upregulated p-TPH2, TPH2, and 5-HT1AR, while downregulating the expression of pro-inflammatory cytokines IL-1β, IL-6, and TNF-α. In the colon, the treatment inhibited the TLR4-MyD88-NF-κB pathway and increased the levels of occludin and ZO-1, indicating improved intestinal barrier function. Additionally, the probiotic demonstrated a regulatory effect on the HMGB1-RAGE-TLR4 signaling pathway.

CONCLUSIONS

Our findings demonstrate that L. plantarum JYLP-326 exhibits significant antidepressant-like effects in mice, suggesting its potential as a therapeutic approach for depression through the modulation of gut microbiota. However, further investigations and clinical trials are required to validate its safety and efficacy for human use.

Down-regulating lncRNA KCNQ1OT1 relieves type II alveolar epithelial cell apoptosis during one-lung ventilation via modulating miR-129-5p/HMGB1 axis induced pulmonary endothelial glycocalyx

OBJECTIVE

Endothelial glycocalyx (EG) maintains vascular homeostasis and is destroyed after one-lung ventilation (OLV)-induced lung injury. Long noncoding RNAs (lncRNAs) are critically involved in various lung injuries. This study aimed to investigate the role and regulatory mechanism of KCNQ1 overlapping transcript 1 (KCNQ1OT1) in OLV-induced lung injury and LPS-induced type II alveolar epithelial cell (AECII) apoptosis.

METHODS

The rat OLV model was established, and the effects of KCNQ1OT1 on OLV-induced ALI in vivo were explored. Bax and Caspase-3 expression in rat lung tissues was measured by immunochemistry (IHC). AECIIs were isolated from rat lungs and treated with LPS or normal saline (control) for in vitro analysis. The expression of KCNQ1OT1, miR-129-5p, and HMGB1 was measured by quantitative real-time PCR (qRT-PCR) or Western blot (WB). Cell proliferation and apoptosis were examined by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide (MTT) and flow cytometry. The downstream targets of KCNQ1OT1 were predicted by bioinformatics, and the binding relationship between KCNQ1OT1 and miR-129-3p was verified by dual-luciferase reporter assays. The potential target of miR-129-5p was further explored on the Targetscan website and revealed to target HMGB1. Enzyme-linked immunosorbent assay (ELISA) or WB was adopted to determine the levels of IL-1β, TNF-α, MDA, SOD, heparanase (HPA), matrix metalloproteinase 9 (MMP9), heparan sulfate (HS) and syndecan-1 (SDC-1).

RESULTS

KCNQ1OT1 and HMGB1 were up-regulated during OLV-induced lung injury, and their expression was positively correlated. KCNQ1OT1 knockdown reduced OLV-induced pulmonary edema and lung epithelial cell apoptosis, increased vascular permeability, reduced IL-1β, TNF-α, MDA, and SOD levels and glycocalyx markers by targeting miR-129-5p or upregulating HMGB1. Overexpressing KCNQ1OT1 promoted cell apoptosis, reduced cell proliferation, aggravated inflammation and oxidative stress, and up-regulated HMGB1, HPA and MMP9 in LPS-treated AECIIs, while the HMGB1 silencing showed the opposite effects. MiR-129-5p mimics partially eliminated the KCNQ1OT1-induced effects, while recombinant HMGB1 restored the effects of miR-129-5p overexpression on AECIIs. Additionally, KCNQ1OT1 was demonstrated to promote the activation of the p38 MAPK/Akt/ERK signaling pathways in AECIIs via HMGB1.

CONCLUSION

KCNQ1OT1 knockdown alleviated AECII apoptosis and EG damage during OLV by targeting miR-129-5p/HMGB1 to inactivate the p38 MAPK/Akt/ERK signaling. The findings of our study might deepen our understanding of the molecular basis in OLV-induced lung injury and provide clues for the targeted disease management.

Revealing the role of Peg13: A promising therapeutic target for mitigating inflammation in sepsis

To investigate the role of Peg13 in modulating the inflammatory response in sepsis, we established Lipopolysaccharide (LPS)-induced 293T cells and mouse models. Peg13 expression was assessed at various time points after infection using RT-qPCR. The levels of high mobility group box 1 (HMGB1) and interleukin-6 (IL-6) were quantified through ELISA. A total of 44 septic patients and 36 healthy participants were recruited to measure Peg13 and HMGB1 levels in the blood. Peg13 demonstrated significant down-regulation in the supernatant of LPS-induced 293T cells and in the blood of LPS-induced mice. Moreover, the levels of proinflammatory cytokines HMGB1 and IL-6 were elevated in both the supernatant of LPS-induced cell models and blood specimens from LPS-induced murine models, and this elevation could be notably reduced by Peg13 suppression. In a clinical context, Peg13 and HMGB1 levels were higher in septic patients compared to healthy subjects. Peg13 exhibited a negative correlation with HMGB1, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) among septic patients. Peg13 mitigates the inflammatory response by reducing the release of proinflammatory cytokines HMGB1 and IL-6 in sepsis, presenting a potential therapeutic target for alleviating inflammation in sepsis treatment.

Knockdown of lncRNA NEAT1 suppresses streptococcus pneumoniae-induced ferroptosis in alveolar epithelial cells by regulating the Nrf2-GPX4 pathway

OBJECTIVES

Streptococcus pneumoniae (SP) is a major cause of community-acquired pneumonia. Ferroptosis pitches in pneumonia. Long noncoding RNA nuclear paraspeckle assembly transcript 1 (lncRNA NEAT1) regulates ferroptosis in various cells. Therefore, this study probed the mechanism of lncRNA NEAT1 on SP-induced ferroptosis in AECs.

METHODS

Serum lncRNA NEAT1 level in 36 streptococcus pneumonia patients were retrospectively detected, with its correlations with inflammatory factor (TNF-α/IL-1β/IL-6) levels analyzed. Human pulmonary alveolar epithelial cells (HPAEpiC) were transfected with sh-NEAT1 and induced by SP. Cell viability was evaluated by CCK-8. Lactate dehydrogenase (LDH) activity was assessed. Iron content, and levels of TNF-α/IL-1β/IL-6/IL-10/lncRNA NEAT1/lipid peroxidation products [malondialdehyde (MDA)/glutathione (GSH)/reactive oxygen species/(ROS)]/ferroptosis-related proteins [Cyclooxgenase 2 (COX2)/recombinant solute carrier family 7 member 11 (SLC7A11)/total nuclear factor erythroid 2-related factor 2 (Nrf2)/cytoplasmic Nrf2 (C-Nrf2)/nuclear Nrf2 (N-Nrf2)/GPX4)] were determined by kit/ELISA/RT-qPCR/kits/Western blot. Nrf2 nuclear translocation was detected by immunofluorescence assay. On top of lncRNA NEAT1 knockdown, SP-induced HPAEpiC were treated with ML385.

RESULTS

Serum lncRNA NEAT1 level was elevated in streptococcus pneumonia patients, and were positively interrelated with TNF-α/IL-1β/IL-6 levels. SP promoted cell HPAEpiC injury and inflammatory response, and up-regulated lncRNA NEAT1 level. LncRNA NEAT1 knockdown suppressed HPAEpiC injury/inflammatory response (reduced LDH activity and TNF-α/IL-1β/IL-6 levels, elevated IL-10) and suppressed ferroptosis (decreased iron/MDA/ROS contents and COX2 level, increased GSH/SLC7A11), facilitated Nrf2 nuclear translocation, and up-regulated GPX4. Nrf2-GPX4 pathway inhibition annulled NEAT1 knockdown-mediated improvement on SP-induced HPAEpiC ferroptosis/injury/inflammatory response.

CONCLUSIONS

LncRNA NEAT1 knockdown suppressed SP-induced HPAEpiC ferroptosis by activating Nrf2-GPX4 pathway, thereby alleviating cell injury and inflammatory response.

Microarray analysis identifies lncFirre as a potential regulator of obesity-related acute lung injury

AIMS

The inflammatory response in acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is heightened in obesity. The aim of this study was to investigate whether lncRNAs are involved in the effects of obesity on acute lung injury and to find possible effector lncRNAs.

MAIN METHODS

Microarray analysis was used to assess the transcriptional profiles of lncRNAs and mRNAs in lung tissues from normal (CON), high-fat diet induced obese (DIO), and obese ALI mice (DIO-ALI). GO and KEGG analyses were employed to explore the biological functions of differentially expressed genes. A lncRNA-mRNA co-expression network was constructed to identify specific lncRNA. Lung tissues and peripheral blood samples from patients with obesity and healthy lean donors were utilized to confirm the expression characteristics of lncFirre through qRT-PCR. lncFirre was knocked down in MH-S macrophages to explore its function. ELISA and Griess reagent kit were used to detect PGE2 and NO. Flow cytometry was used to detect macrophages polarization.

KEY FINDINGS

There were 475 lncRNAs and 404 mRNAs differentially expressed between DIO and CON, while 1348 lncRNAs and 1349 mRNAs between DIO-ALI and DIO. Obesity increased lncFirre expression in both mice and patients, and PA elevated lncFirre in MH-S. PA exacerbated the inflammation and proinflammatory polarization of MH-S induced by LPS. LncFirre knockdown inhibited the secretion of PGE2 and NO, M1 differentiation while promoted the M2 differentiation in PA and LPS co-challenged MH-S.

SIGNIFICANCE

Interfering with lncFirre effectively inhibit inflammation in MH-S, lncFirre can serve as a promising target for treating obesity-related ALI.

Role of genetically engineered mesenchymal stem cell exosomes and LncRNAs in respiratory diseases treatment

The term acute respiratory disease encompasses a wide range of acute lung diseases, which in recent years have been ranked among the top three deadly diseases in the world. Since conventional treatment methods, including the use of anti-inflammatory drugs, have had no significant effect on the treatment process of these diseases, the attention of the medical community has been drawn to alternative methods. Mesenchymal stem cells (MSC) are multipotential stem/progenitor cells that have extensive immunomodulatory and anti-inflammatory properties and also play a critical role in the microenvironment of injured tissue. MSC secretomes (containing large extracellular vesicles, microvesicles, and exosomes) are a newly introduced option for cell-free therapies that can circumvent the hurdles of cell-based therapies while maintaining the therapeutic role of MSC themselves. The therapeutic capabilities of MSCs have been showed in many acute respiratory diseases, including chronic respiratory disease (CRD), novel coronavirus 2019 (COVID -19), and pneumonia. MSCs offer novel therapeutic approaches for chronic and acute lung diseases due to their anti-inflammatory and immunomodulatory properties. In this review, we summarize the current evidence on the efficacy and safety of MSC-derived products in preclinical models of lung diseases and highlight the biologically active compounds present in the MSC secretome and their mechanisms involved in anti-inflammatory activity and tissue regeneration.

Protective mechanism of quercetin in alleviating sepsis-related acute respiratory distress syndrome based on network pharmacology and in vitro experiments

BACKGROUND

Sepsis-related acute respiratory distress syndrome (ARDS) has a high mortality rate, and no effective treatment is available currently. Quercetin is a natural plant product with many pharmacological activities, such as antioxidative, anti-apoptotic, and anti-inflammatory effects. This study aimed to elucidate the protective mechanism of quercetin against sepsis-related ARDS.

METHODS

In this study, network pharmacology and in vitro experiments were used to investigate the underlying mechanisms of quercetin against sepsis-related ARDS. Core targets and signaling pathways of quercetin against sepsis-related ARDS were screened and were verified by in vitro experiments.

RESULTS

A total of 4,230 targets of quercetin, 360 disease targets of sepsis-related ARDS, and 211 intersection targets were obtained via database screening. Among the 211 intersection targets, interleukin-6 (IL-6), tumor necrosis factor (TNF), albumin (ALB), AKT serine/threonine kinase 1 (AKT1), and interleukin-1β (IL-1β) were identified as the core targets. A Gene Ontology (GO) enrichment analysis revealed 894 genes involved in the inflammatory response, apoptosis regulation, and response to hypoxia. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis identified 106 pathways. After eliminating and generalizing, the hypoxia-inducible factor-1 (HIF-1), TNF, nuclear factor-κB (NF-κB), and nucleotide-binding and oligomerization domain (NOD)-like receptor signaling pathways were identified. Molecular docking revealed that quercetin had good binding activity with the core targets. Moreover, quercetin blocked the HIF-1, TNF, NF-κB, and NOD-like receptor signaling pathways in lipopolysaccharide (LPS)-induced murine alveolar macrophage (MH-S) cells. It also suppressed the inflammatory response, oxidative reactions, and cell apoptosis.

CONCLUSION

Quercetin ameliorates sepsis-related ARDS by binding to its core targets and blocking the HIF-1, TNF, NF-κB, and NOD-like receptor signaling pathways to reduce inflammation, cell apoptosis, and oxidative stress.

A comprehensive review on the emerging role of long non-coding RNAs in the regulation of NF-κB signaling in inflammatory lung diseases

Public health globally faces significant risks from conditions like acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD), and various inflammatory lung disorders. The NF-κB signaling system partially controls lung inflammation, immunological responses, and remodeling. Non-coding RNAs (lncRNAs) are crucial in regulating gene expression. They are increasingly recognized for their involvement in NF-κB signaling and the development of inflammatory lung diseases. Disruption of lncRNA-NF-κB interactions is a potential cause and resolution factor for inflammatory respiratory conditions. This study explores the therapeutic potential of targeting lncRNAs and NF-κB signaling to alleviate inflammation and restore lung function. Understanding the intricate relationship between lncRNAs and NF-κB signaling could offer novel insights into disease mechanisms and identify therapeutic targets. Regulation of lncRNAs and NF-κB signaling holds promise as an effective approach for managing inflammatory lung disorders. This review aims to comprehensively analyze the interaction between lncRNAs and the NF-κB signaling pathway in the context of inflammatory lung diseases. It investigates the functional roles of lncRNAs in modulating NF-κB activity and the resulting inflammatory responses in lung cells, focusing on molecular mechanisms involving upstream regulators, inhibitory proteins, and downstream effectors.

LncRNA NEAT1: A novel regulator associated with the inflammatory response in acute respiratory distress syndrome

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a life-threatening condition with an unfavorable prognosis. As the pathogenesis of ARDS remains unclear, we aimed to identify the core genes associated with ARDS and the mechanisms by which competing endogenous RNAs (ceRNAs) regulate the disease's progression.

METHODS

Three mRNA microarray datasets (GSE17355, GSE48787, and GSE130936), derived from the Gene Expression Omnibus (GEO) database, were selected. Common differentially expressed genes (DEGs) related to acute lung injury (ALI) were identified and subjected to enrichment analysis. Then, hub genes were figured out through the protein-protein interaction (PPI) network and functional analysis, and targeted miRNAs and lncRNAs were predicted. Finally, the ceRNA networks associated with ALI were constructed and validated experimentally.

RESULTS

A total of 155 upregulated and 93 downregulated DEGs were identified in the three datasets. The TNF signaling pathway and IL-17 signaling pathway were the most enriched pathways. Then, eleven DEGs enriched in the IL-17 signaling pathway were selected as the hub genes. Three miRNAs (mmu-mir-155-5p, mmu-mir-21a-5p, and mmu-mir-122-5p), which were located in the lung tissue and predicted to bind the hub genes at the same time, and two lncRNAs (Neat1 and Tug1), which have binding sites for the aforementioned miRNAs, were filtered. With qPCR verification, we identified a ceRNA network composed of NEAT1, miR-21-5p, MMP9, and CXCL5. NEAT1 knockdown promoted the migration and reduced the expression of pro-inflammatory factor and reactive oxygen species (ROS) in lung epithelial cells. We eventually confirmed that NEAT1/miR-21-5p/CXCL5/MMP9 played a pivotal role in regulating the inflammatory response in ALI.

CONCLUSION

The IL-17 signaling pathway is of great importance in the pathogenesis of ARDS. NEAT1/miR-21-5p is involved in the inflammation of ALI by regulating CXCL5 and MMP9.

The Potential Biotherapeutic Targets of Contrast-Induced Acute Kidney Injury

Contrast-induced acute kidney injury (CI-AKI) is manifested by an abrupt decline in kidney function as a consequence of intravascular exposure to contrast media. With the increased applicability of medical imaging and interventional procedures that utilize contrast media for clinical diagnosis, CI-AKI is becoming the leading cause of renal dysfunction. The pathophysiological mechanism associated with CI-AKI involves renal medullary hypoxia, the direct toxicity of contrast agents, oxidative stress, apoptosis, inflammation, and epigenetic regulation. To date, there is no effective therapy for CI-AKI, except for the development of strategies that could reduce the toxicity profiles of contrast media. While most of these strategies have failed, evidence has shown that the proper use of personalized hydration, contrast medium, and high-dose statins may reduce the occurrence of CI-AKI. However, adequate risk predication and attempts to develop preventive strategies can be considered as the key determinants that can help eliminate CI-AKI. Additionally, a deeper understanding of the pathophysiological mechanism of CI-AKI is crucial to uncover molecular targets for the prevention of CI-AKI. This review has taken a step further to solidify the current known molecular mechanisms of CI-AKI and elaborate the biomarkers that are used to detect early-stage CI-AKI. On this foundation, this review will analyze the molecular targets relating to apoptosis, inflammation, oxidative stress, and epigenetics, and, thus, provide a strong rationale for therapeutic intervention in the prevention of CI-AKI.

lncRNA NEAT1 mediates LPS-induced pyroptosis of BEAS-2B cells via targeting miR-26a-5p/ROCK1 axis

Acute lung injury (ALI) is an adverse disease of the respiratory system, and one of its prevalent causes is sepsis induction. Cell pyroptosis facilitates the progression of ALI and lncRNAs play critical roles in ALI. Thus, this research seeks to investigate the specific mechanism of NEAT1 in sepsis-ALI.BEAS-2B cells were exposed to lipopolysaccharide (LPS) to construct a cell model of sepsis-induced ALI. The gene and protein expression were assessed using qRT-PCR and western blot. Cell viability was identified by CCK-8. Cell death was discovered using PI staining. The secretion of IL-1β and IL-18 was examined using ELISA. The interconnections among NEAT1, miR-26a-5p, and ROCK1 were confirmed using starbase, luciferase assay, and RIP.LPS treatment augmented NEAT1 and ROCK1 levels while mitigating miR-26a-5p level in BEAS-2B cells. Additionally, LPS treatment facilitated cell death and cell pyroptosis, whereas NEAT1 silencing could reverse these effects in BEAS-2B cells. Mechanistically, NEAT1 positively mediated ROCK1 expression by targeting miR-26a-5p. Furthermore, miR-26a-5p inhibitor offset NEAT1 depletion-mediated suppressive effects on cell death and cell pyroptosis. ROCK1 upregulation decreased the inhibitory impacts produced by miR-26a-5p overexpression on cell death and cell pyroptosis. Our outcomes demonstrated NEAT1 could reinforce LPS-induced cell death and cell pyroptosis by repressing the miR-26a-5p/ROCK1 axis, thereby worsening ALI caused by sepsis. Our data indicated NEAT1, miR-26a-5p, and ROCK1 might be biomarkers and target genes for relieving sepsis-induced ALI.

Suppression of lncRNA OIP5-AS1 Attenuates Apoptosis and Inflammation, and Promotes Proliferation by Mediating miR-25-3p Expression in Lipopolysaccharide-Induced Myocardial Injury

Purpose

Long non-coding RNAs (LncRNAs) OIP5-AS1 and miR-25-3p play important roles in myocardial injury, whereas their roles in lipopolysaccharide (LPS)-induced myocardial injury remain unknown. The purpose of our study was to investigate the functional mechanisms of OIP5-AS1 and miR-25-3p in LPS-induced myocardial injury.

Methods

Rats and H9C2 cells were treated with LPS to establish the model of myocardial injury in vivo and in vitro, respectively. The expression levels of OIP5-AS1 and miR-25-3p were determined by quantitative reverse transcriptase-polymerase chain reaction. Enzyme-linked immunosorbent assay was performed to measure the serum levels of IL-6 and TNF-α. The relationship between OIP5-AS1 and miR-25-3p/NOX4 was determined by luciferase reporter assay and/or RNA immunoprecipitation assay. The apoptosis rate was detected by flow cytometry, and cell viability was detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. Western blot was performed to detect the protein levels of Bax, Bcl-2, caspase3, c-caspase3, NOX4, and p-NF-κB p65/NF-κB p65.

Results

OIP5-AS1 was up-regulated, and miR-25-3p was down-regulated in myocardial tissues of LPS-induced rats and LPS-treated H9C2 cells. Knockdown of OIP5-AS1 relieved the myocardial injury in LPS-induced rats. Knockdown of OIP5-AS1 also inhibited the inflammation and apoptosis of myocardial cells in vivo, which was subsequently confirmed by in vitro experiments. In addition, OIP5-AS1 targeted miR-25-3p. MiR-25-3p mimics reversed the effects of OIP5-AS1 overexpression on promoting cell apoptosis and inflammation and on inhibiting cell viability. Besides, miR-25-3p mimics blocked the NOX4/NF-κB signalling pathway in LPS-induced H9C2 cells.

Conclusion

Silencing of lncRNA OIP5-AS1 alleviated LPS-induced myocardial injury by regulating miR-25-3p.

Long Noncoding RNA: A Novel Insight into the Pathogenesis of Acute Lung Injury

Acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS), represent an acute stage of lung inflammation where the alveolar epithelium loses its functionality. ALI has a devastating impact on the population as it not only has a high rate of incidence, but also has high rates of morbidity and mortality. Due to the involvement of multiple factors, the pathogenesis of ALI is complex and is not fully understood yet. Long noncoding RNAs (lncRNAs) are a group of non-protein-coding transcripts longer than 200 nucleotides. Growing evidence has shown that lncRNAs have a decisive role in the pathogenesis of ALI. LncRNAs can either promote or hinder the development of ALI in various cell types in the lungs. Mechanistically, current studies have found that lncRNAs play crucial roles in the pathogenesis of ALI via the regulation of small RNAs (e.g., microRNAs) or downstream proteins. Undoubtedly, lncRNAs not only have the potential to reveal the underlying mechanisms of ALI pathogenesis but also serve as diagnostic and therapeutic targets for the therapy of ALI.

miR-22 alleviates sepsis-induced acute kidney injury via targeting the HMGB1/TLR4/NF-κB signaling pathway

BACKGROUND

Acute kidney injury (AKI) is a severe complication of sepsis, and is strongly correlated with MicroRNAs (miRNAs). However, the mechanism of miR-22 on sepsis-induced AKI is not clearly understood. The study aimed to explore the role and mechanism of miR-22 on AKI.

METHODS

The AKI models were established by cecal ligation and puncture (CLP) surgery in SD rats and lipopolysaccharide (LPS) induction in HBZY-1 cells. In AKI rats, the content of serum creatinine (SCr) and blood urea nitrogen (BUN) were detected. Kidney tissues were pathologically examined by H&E and PAS staining. The LPS-induced HBZY-1 cells were transfected with mimics miR-22, si-HMGB1, or oe-HMGB1. miR-22 and HMGB1 expression was detected in vivo and in vitro. In transfected cells, HMGB1/TLR4/NF-κB pathway-related protein expressions were measured by Western blot. The relationship between miR-22 and HMGB1 was assessed by a dual-luciferase gene report. Inflammatory cytokine levels in serum and cells were assessed by ELISA.

RESULTS

In AKI rats, kidney injury was observed, accompanied by the down-regulated miR-122 expression and up-regulated HMBG1 expression. The dual-luciferase report found miR-22-3p could targetly regulate HMBG1. Furthermore, both in vitro and in vivo experiments revealed that the releases of inflammatory cytokine were increased after AKI modeling, but the situation was reversed by mimics miR-22 or si-HMGB1 in vitro. In HBZY-1 cells, mimics miR-22 could suppress LPS-induced overexpression of HMGB1/TLR4/NF-κB signaling pathway-related proteins. However, the oe-HMGB1 addition reversed the effect of mimics miR-22.

CONCLUSION

miR-22 can inhibit the inflammatory response, target the HMGB1, and inhibit the HMGB1/TLR4/NF-kB pathway, to attenuate the sepsis-induced AKI, which indicates that miR-22 may serve as a potential treatment target in sepsis-induced AKI.

Quercetin improves contrast-induced acute kidney injury through the HIF-1α/lncRNA NEAT1/HMGB1 pathway

CONTEXT

The risk of contrast-induced acute kidney injury (CI-AKI) is increasing and the harm is great. Quercetin is the main active component in Abelmoschus manihot (L.) Medik (Malvaceae) and was reported to reduce the expression of HIF-1α.

OBJECTIVE

We investigate whether quercetin improves the CI-AKI through the HIF-1α/lncRNA NEAT1/HMGB1 pathway.

MATERIALS AND METHODS

HK-2 cells were treated with iohexol (200 mg/mL) for 6 h to establish a CI-AKI model. Quercetin (20 μM) was administered to CI-AKI cells cultured in dishes for 24 h. Cell morphology was observed by a fluorescence microscope. MTT and TUNEL assays were used to detect cell survival rate and apoptosis. Relative mRNA levels were measured by qRT-PCR. Protein levels were detected using western blotting. IL-6 and TNF-α protein levels were tested by Elisa assay. Targeting binding sites of HIF-1α and lncRNA NEAT1 were detected by luciferase assay.

RESULTS

The IC₅₀ value of quercetin was 163.25 μM. The expression levels of HIF-1α, lncRNA NEAT1 and HMGB1 were upregulated in the CI-AKI cell model. Quercetin diminished cell injury and apoptosis via inhibiting HIF-1α. Silencing of HIF-1α targeting lncRNA MEAT1 diminished cell injury and apoptosis. Silencing lncRNA NEAT1 has the same effect via suppressing HMGB1 expression. Collectively, quercetin diminished cell injury and apoptosis in CI-AKI cell model via the inhibition of HIF-1α on lncRNA NEAT1/HMGB1 signalling pathway.

DISCUSSION AND CONCLUSIONS

Quercetin diminished cell injury and apoptosis in CI-AKI cell mode via the inhibition of HIF-1α on the lncRNA NEAT1/HMGB1 signalling pathway, offering a potential novel therapeutic target for CI-AKI therapy.

Role of Long Noncoding RNAs in the Regulation of Cellular Immune Response and Inflammatory Diseases

Long noncoding RNAs (lncRNAs) are recently discovered genetic regulatory molecules that regulate immune responses and are closely associated with the occurrence and development of various diseases, including inflammation, in humans and animals. Under specific physiological conditions, lncRNA expression varies at the cell or tissue level, and lncRNAs can bind to specific miRNAs, target mRNAs, and target proteins to participate in certain processes, such as cell differentiation and inflammatory responses, via the corresponding signaling pathways. This review article summarizes the regulatory role of lncRNAs in macrophage polarization, dendritic cell differentiation, T cell differentiation, and endothelial and epithelial inflammation. In addition, it describes the molecular mechanism of lncRNAs in acute kidney injury, hepatitis, inflammatory injury of the lung, osteoarthritis, mastitis, and neuroinflammation to provide a reference for the molecular regulatory network as well as the genetic diagnosis and treatment of inflammatory diseases in humans and animals.

The role of long noncoding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) in immune diseases

The long noncoding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) has been shown to be involved in the pathogenesis of several diseases. Herein, we discuss recent developments and insights into NEAT1 and its contribution to a variety of immune disorders. Our evaluations revealed that NEAT1's function in immune diseases seems to be focused on the modulation of paraspeckle expression and it is primarily associated with the nuclear retention of its mRNA. NEAT1 is also involved in the sequestration of paraspeckle proteins and in affecting the transcriptional expression of specific immune regulators. The expression of NEAT1 may be aberrantly upregulated in several immune pathologies, indicating that it could serve as a potential prognostic biomarker in these conditions. We summarized describing the expression changes and the role of NEAT1 in several immune diseases. We also described the mechanism of its regulation of the immune cell differentiation and function of NEAT1 in different disease.

Baihe Dihuang (Lilium Henryi Baker and Rehmannia Glutinosa) decoction attenuates somatostatin interneurons deficits in prefrontal cortex of depression via miRNA-144-3p mediated GABA synthesis and release

ETHNOPHARMACOLOGICAL RELEVANCE

Baihe Dihuang Decoction is a well-known traditional Chinese medicine prescription (Also known as Lilium Henryi Baker and Rehmannia Glutinosa Decoction, LBRD) composed of Lilium Henryi Baker bulb and raw juice from Rehmannia Glutinosa (Gaertn) DC with the curative efficacy of nourishing yin and clearing heat based on the Chinese herbal medicine theory. It has been used as routine medication in treating depression combined with conventional western medicine in China for years.

AIM OF THE STUDY

LBRD can attenuates GABAergic deficits in the medial prefrontal cortex (mPFC) of depression. This study aimed to investigate the mechanism of antidepressive properties of LBRD in the prefrontal GABAergic interneuron subtypes, including parvalbumin (PV), somatostatin (SST), vasoactive intestinal peptide (VIP)-positive neuron.

MATERIALS AND METHODS

In this project, chronic unpredicted mild stress paradigm was adopted to construct depression model. After treated with LBRD standard decoction and behaviors test, the level of GABA associated miRNA/mRNA and GABAergic subtype-specific markers were detected by qRT-PCR and Western blot. The lncRNAs/miRNAs/GABA regulatory axis was verified by luciferase reporter assay, RNA immunoprecipitation, RNA pull-down assay, and theses changes were measured in LBRD administration with the use of immunofluorescence staining and RNA-fluorescence in situ hybridization.

RESULTS

In the current study, we found that LBRD exhibited high efficacy based on the results of behavioral tests. Meanwhile, LBRD also improved the reduced GABA levels in depression by increasing the expression of lncRNA Neat1 and Malat1, as well as decreasing miRNA-144-3p and miRNA-15b-5p. Moreover, the level of Sst mRNA and protein that were harvested from the mPFC tissues of depression group was significantly lower than those in the control mice. While, these changes can be reverted by LBRD standard decoction administration. Whereas, neither chronic stress nor treatment can change the level of PV and VIP mRNAs and protein expression. In the SST-positive neuron of mPFC tissues, treatment with LBRD standard decoction resulted in the elevation of Gad-67, VGAT, GAT-3 and a reduction of miRNA-144-3p expression.

CONCLUSIONS

These findings suggested that LBRD antidepressant activities may be related to ameliorating the SST-positive neuron deficits via regulating the miRNA-144-3p mediated GABA synthesis and release.

High Mobility Group Proteins in Sepsis

Sepsis, a systemic inflammatory response disease, is the most severe complication of infection and a deadly disease. High mobility group proteins (HMGs) are non-histone nuclear proteins binding nucleosomes and regulate chromosome architecture and gene transcription, which act as a potent pro-inflammatory cytokine involved in the delayed endotoxin lethality and systemic inflammatory response. HMGs increase in serum and tissues during infection, especially in sepsis. A growing number of studies have demonstrated HMGs are not only cytokines which can mediate inflammation, but also potential therapeutic targets in sepsis. To reduce sepsis-related mortality, a better understanding of HMGs is essential. In this review, we described the structure and function of HMGs, summarized the definition, epidemiology and pathophysiology of sepsis, and discussed the HMGs-related mechanisms in sepsis from the perspectives of non-coding RNAs (microRNA, long non-coding RNA, circular RNA), programmed cell death (apoptosis, necroptosis and pyroptosis), drugs and other pathophysiological aspects to provide new targets and ideas for the diagnosis and treatment of sepsis.

Sevoflurane anesthesia ameliorates LPS-induced acute lung injury (ALI) by modulating a novel LncRNA LINC00839/miR-223/NLRP3 axis

Background

Sevoflurane is considered as a lung-protective factor in acute lung injury (ALI), but the underlying molecular mechanism remains largely unknown. The present study identified for the first time that sevoflurane ameliorated lipopolysaccharide (LPS)-induced ALI through regulating a novel long non-coding RNA LINC00839, and uncovered its regulatory mechanism.

Methods

LPS-induced ALI models were established in mice or mouse pulmonary microvascular endothelial cells (MPVECs), and they were administered with sevoflurane. Real-Time quantitative PCR, western blot and bioinformatics analysis were performed to screen the aberrantly expressed long non-coding RNA and the downstream molecules in sevoflurane-treated ALI models, and their roles in the protection effect of sevoflurane were verified by functional recovery experiments.

Results

Sevoflurane relieved LPS-induced lung injury, cell pyroptosis and inflammation in vitro and in vivo. LINC00839 was significantly suppressed by sevoflurane, and overexpression of LINC00839 abrogated the protective effects of sevoflurane on LPS-treated MPVECs. Mechanismly, LINC00839 positively regulated NOD-like receptor protein 3 (NLRP3) via sequestering miR-223. MiR-223 inhibitor reversed the inhibitory effects of LINC00839 knockdown on NLRP3-mediated pyroptosis in LPS-treated MPVECs. Furthermore, both miR-223 ablation and NLRP3 overexpression abrogated the protective effects of sevoflurane on LPS-treated MPVECs.

Conclusion

In general, our work illustrates that sevoflurane regulates the LINC00839/miR-223/NLRP3 axis to ameliorate LPS-induced ALI, which might provide a novel promising candidate for the prevention of ALI.

Tim-3 regulates sepsis-induced immunosuppression by inhibiting the NF-κB signaling pathway in CD4 T cells

Immunosuppression in response to severe sepsis remains a serious human health concern. Evidence of sepsis-induced immunosuppression includes impaired T lymphocyte function, T lymphocyte depletion or exhaustion, increased susceptibility to opportunistic nosocomial infection, and imbalanced cytokine secretion. CD4 T cells play a critical role in cellular and humoral immune responses during sepsis. Here, using an RNA sequencing assay, we found that the expression of T cell-containing immunoglobulin and mucin domain-3 (Tim-3) on CD4 T cells in sepsis-induced immunosuppression patients was significantly elevated. Furthermore, the percentage of Tim-3⁺ CD4 T cells from sepsis patients was correlated with the mortality of sepsis-induced immunosuppression. Conditional deletion of Tim-3 in CD4 T cells and systemic Tim-3 deletion both reduced mortality in response to sepsis in mice by preserving organ function. Tim-3⁺ CD4 T cells exhibited reduced proliferative ability and elevated expression of inhibitory markers compared with Tim-3^-CD4 T cells. Colocalization analyses indicated that HMGB1 was a ligand that binds to Tim-3 on CD4 T cells and that its binding inhibited the NF-κB signaling pathway in Tim-3⁺ CD4 T cells during sepsis-induced immunosuppression. Together, our findings reveal the mechanism of Tim-3 in regulating sepsis-induced immunosuppression and provide a novel therapeutic target for this condition.

Microcrystalline silica particles induce inflammatory response via pyroptosis in primary human respiratory epithelial cells

The mechanism of the sterile inflammatory response in the respiratory tract induced by exposure to sterile particles has not been fully elucidated. The aim of our study is to explore the earlier events in initiating inflammatory response at molecular and cellular level in primary cultured human airway epithelial cells (AEC) exposed to silica particles in order to provide information for earlier diagnosis and prevention of silica particle-induced toxicity as well as possible information on the genesis of silicosis. We isolated primary AEC from three healthy adults and treated them with silica particles at different concentrations for 48 h. We found evidence for silica-induced inflammasome activation by the co-localization of Caspase-1 and NLRP3, as well as increased levels of IL-1β and IL-18. Lactate dehydrogenase and NucGreen analysis proved the occurrence of pyroptosis. High throughput mRNA sequencing showed that the inflammatory response and NF-κB signaling pathways were significantly enriched in gene ontology and Kyoto encyclopedia of genes and genomes analysis, and pyroptosis-related genes were up-regulated. The miR-455-3p and five lncRNAs (LOC105375913, NEAT1, LOC105375181, LOC100506098, and LOC105369370) were verified as key factors related to the mechanism by ceRNA network analysis. LOC105375913 was first discovered to be associated with inflammation in AEC. These data suggest that microcrystalline silica can induce significant inflammation and pyroptosis in human primary AEC through NLRP3 inflammasome pathway and NF-κB signaling pathway at both the gene and protein levels, and the possible mechanism could be miR-455-3p mediated ceRNA hypothesis. Our data provide a method for the studies of the respiratory toxicity of fine particulate matter and the pathogenesis of early silicosis. The miR-455-3p and five lncRNAs related ceRNA network might be the toxicity mechanism of microcrystalline silica particles to AEC.

Long non-coding RNA NEAT1 participates in ventilator-induced lung injury by regulating miR-20b expression

Long non‑coding (lnc)RNA nuclear enriched abundant transcript 1 (NEAT1) has been reported to serve an important role in cancer, but its effects on ventilator‑induced lung injury (VILI) remain unclear. The present study aimed to investigate the role of lncRNA NEAT1 in alveolar macrophages (AMs) on ventilator‑induced lung injury (VILI). Mouse and cell models were established to detect NEAT1 expression, pathological changes in lung tissues, apoptosis of AMs, expression of the M1 phenotype marker, CD86 and M2 phenotype marker, CD206, and the expression levels of interleukin (IL)‑1β, IL‑6, tumor necrosis factor (TNF)‑α and inducible nitric oxide synthase (iNOS). The associations between NEAT1, microRNA (miRNA/miR)‑20b and STAT3 were predicted using StarBase and TargetScan, and verified via the dual‑luciferase reporter and RIP assays. NEAT1 short hairpin RNA and miR‑20b inhibitor were co‑transfected into AMs to assess the effect of NEAT1 and miR‑20b in VILI. The results demonstrated that NEAT1 was highly expressed in lung tissues of VILI mice and cell stretch (CS) treated AMs. Furthermore, NEAT1 knockdown inhibited lung injury and cell apoptosis induced by VILI. Compared with VILI mice or CS‑treated AMs, NEAT1 knockdown accelerated the phenotypic transformation from M1 to M2, and decreased the expression levels of IL‑1β, IL‑6, TNF‑α and iNOS. Notably, miR‑20b was identified as the target of NEAT1, and STAT3 was the target of miR‑20b. NEAT1 knockdown decreased STAT3 protein expression, the effects of which were reversed following transfection with miR‑20b inhibitor. Furthermore, the protective effect of NEAT1 knockdown on VILI was reversed following transfection with miR‑20b inhibitor. Taken together, the results of the present study suggest that NEAT1 knockdown promotes phenotypic transformation of AMs from M1 to M2 and alleviates lung injury and apoptosis of VILI by regulating miR‑20b expression.

Regulatory Role of Non-Coding RNAs on Immune Responses During Sepsis

Sepsis is resulted from a systemic inflammatory response to bacterial, viral, or fungal agents. The induced inflammatory response by these microorganisms can lead to multiple organ system failure with devastating consequences. Recent studies have shown altered expressions of several non-coding RNAs such as long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and circular RNAs (circRNAs) during sepsis. These transcripts have also been found to participate in the pathogenesis of multiple organ system failure through different mechanisms. NEAT1, MALAT1, THRIL, XIST, MIAT and TUG1 are among lncRNAs that participate in the pathoetiology of sepsis-related complications. miR-21, miR-155, miR-15a-5p, miR-494-3p, miR-218, miR-122, miR-208a-5p, miR-328 and miR-218 are examples of miRNAs participating in these complications. Finally, tens of circRNAs such as circC3P1, hsa_circRNA_104484, hsa_circRNA_104670 and circVMA21 and circ-PRKCI have been found to affect pathogenesis of sepsis. In the current review, we describe the role of these three classes of noncoding RNAs in the pathoetiology of sepsis-related complications.

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.

NF-κB-Dependent Snail Expression Promotes Epithelial-Mesenchymal Transition in Mastitis

Simple Summary

Mastitis is a common and important clinical disease in ruminants, resulting in decreased milk production, infertility and delayed conception. If not treated promptly, mastitis may result in fibrotic mastitis. Although epithelial–mesenchymal transition (EMT) is a typical characteristic of fibrotic diseases, the relationship between EMT and mastitis remains largely unknown. NF-κB and Snail are key regulators of the EMT. In the present study, we found that lipopolysaccharide (LPS) induced EMT in primary goat mammary epithelial cells (GMECs). Additionally, the expression of Snail was induced by LPS and was inhibited by the suppression of the TLR4/NF-κB signaling pathway. The knockdown of Snail alleviated LPS-induced EMT and altered the expression of inflammatory cytokines. Finally, we found that the expression of key molecules of the TLR4/NF-κB/Snail signaling pathway was increased in mastitic tissues. This study provides evidence that LPS induces EMT in GMECs through the TLR4/NF-κB/Snail signaling pathway and lays a theoretical foundation for further exploration of the pathological mechanism and treatment of mastitis.

Abstract

Mastitis is a common and important clinical disease in ruminants. This may be associated with inflammatory fibrosis if not treated promptly. Inflammation-derived fibrosis is usually accompanied by epithelial–mesenchymal transition (EMT) in epithelial cells. However, the precise molecular mechanism underlying mastitis-induced fibrosis remains unclear. Nuclear factor kappa-B (NF-κB) and Snail are key regulators of EMT. In this study, primary goat mammary epithelial cells (GMECs) were treated with 10 μg/mL lipopolysaccharide (LPS) for 14 d to mimic the in vivo mastitis environment. After LPS treatment, the GMECs underwent mesenchymal morphological transformation and expressed mesenchymal cell markers. Snail expression was induced by LPS and was inhibited by suppression of the TLR4/NF-κB signaling pathway. Snail knockdown alleviated LPS-induced EMT and altered the expression of inflammatory cytokines. Finally, we found that the expression of key molecules of the TLR4/NF-κB/Snail signaling pathway was increased in mastitis tissues. These results suggest that Snail plays a vital role in LPS-induced EMT in GMECs and that the mechanism is dependent on the activation of the TLR4/NF-κB signaling pathway.

LPS-induced inflammatory response and apoptosis are mediated by Fra-1 upregulation and binding to YKL-40 in A549 cells

Acute respiratory distress syndrome (ARDS) is a multifactorial syndrome that leads to increased morbidity and mortality in infants and children. The identification of novel biomarkers is critical for the treatment of ARDS. The present study aimed to investigate the effects of chitinase-3-like-1 protein (CHI3L1 or YKL-40) in an in vitro model of ARDS and to explore the potential underlying mechanisms. The in vitro model of ARDS was established in A549 alveolar epithelial type II cells, which were treated by lipopolysaccharide (LPS) to induce inflammation. Transfection was performed to alter YKL-40 expression. The mRNA and protein expression of YKL-40 was determined using reverse transcription-quantitative PCR and western blotting, respectively. Cell Counting Kit-8 and TUNEL assays were used to evaluate the cell viability and apoptosis, respectively. The production of cytokines was evaluated using specific ELISA kits. The relationship between YKL-40 and Fos-related antigen 1 (Fra-1) was verified using luciferase reporter and chromatin immunoprecipitation assays. The expression of the apoptotic proteins was detected using western blotting. The expression levels of YKL-40 and Fra-1 were increased in LPS-treated A549 cells. Higher levels of pro-inflammatory cytokines and induction of cell apoptosis were observed in LPS-treated A549 cells compared with the control. YKL-40 knockdown in LPS-treated A549 cells significantly decreased the production of pro-inflammatory cytokines and reduced cell apoptosis, whereas it concomitantly caused upregulation of Bax and downregulation of Bcl-2, cleaved caspase-3 and cleaved caspase-9. In addition, Fra-1 could directly bind to YKL-40 promoter and regulate its expression level. Overexpression of YKL-40 partly decreased the inhibitory effects of Fra-1 knockdown on the inflammatory response and induction of apoptosis. In summary, the findings from the present study indicated that Fra-1 could bind to YKL-40 and regulate its expression, whereas YKL-40 knockdown could further suppress LPS-induced inflammatory response and apoptosis in A549 cells. These data may provide novel evidence on the diagnosis and therapy of ARDS.

miR-942-5p prevents sepsis-induced acute lung injury via targeting TRIM37

MicroRNAs (miRNAs) have been demonstrated to play pivotal roles in the pathogenesis of sepsis-induced acute lung injury (ALI). In this work, we aimed to clarify the potential role and the underlying mechanism of miR-942-5p in a lipopolysaccharide (LPS)-induced A549 cell injury model. The cell injury was evaluated by CCK-8 assay, flow cytometry and enzyme-linked immunosorbent assay (ELISA). The expression levels of miR-942-5p and tripartite motif-containing protein 37 (TRIM37) were measured by real-time PCR and Western blot, and their association was then validated by bioinformatics, luciferase reporter assay and RNA pull-down assay. We found that the expression of miR-942-5p was decreased in LPS-treated A549 cells. Furthermore, LPS treatment suppressed A549 cell viability, promoted apoptosis and increased the levels of inflammatory cytokines. Conversely, overexpression of miR-942-5p increased cell viability, reduced apoptosis and alleviated inflammatory cytokine secretion in the presence of LPS. Moreover, miR-942-5p directly targeted TRIM37 by binding to the 3'-UTR of TRIM37 mRNA. Upregulation of TRIM37 effectively reversed the anti-apoptotic and anti-inflammatory effects of miR-942-5p in LPS-induced A549 cells. Our findings suggested that miR-942-5p protected against LPS-induced cell injury through inhibiting apoptosis and inflammation in A549 cells by negatively regulating TRIM37.

LncRNA NEAT1 aggravates lipopolysaccharide-induced acute lung injury by regulating the miR-98-5p/TLR4 axis

Although long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) was reported to be associated with acute lung injury (ALI), its specific mechanism has not been well studied. Mouse and cell ALI models were constructed by lipopolysaccharide (LPS). Cell viability was evaluated by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide assay. Cell death was evaluated by lactate dehydrogenase release (LDH) detection kit and flow cytometry. The levels of cytokines in lung tissues lysates were detected by quantitative real-time PCR (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). The expression of apoptosis-related markers was detected by Western blot. The relationship between NEAT1, miR-98-5p, and toll-like receptor 4 (TLR4) was determined by bioinformatics prediction, luciferase reporter assay, and RNA immunoprecipitation (RIP) assay. Rescue experiments were performed to determine the role of NEAT1/miR-98-5p/TLR4 in ALI. NEAT1 was significantly upregulated during ALI both in vitro and in vivo. NEAT1 knockdown efficiently attenuated LPS-induced ALI and reduced LPS-induced elevation of cytokines both in vitro and in vivo. NEAT1 negatively regulated miR-98-5p by directly sponging it, and TLR4 was a target of miR-98-5p. MiR-98-5p inhibition or TLR4 overexpression could obviously attenuate the protective effects of NEAT1 knockdown in LPS-treated A549 cells. Our study demonstrated that NEAT1 knockdown alleviated LPS-induced ALI by targeting the miR-98-5p/TLR4 axis.

Exosomal lncRNA Nuclear Paraspeckle Assembly Transcript 1 (NEAT1)contributes to the progression of allergic rhinitis via modulating microRNA-511/Nuclear Receptor Subfamily 4 Group A Member 2 (NR4A2) axis

Allergic rhinitis (AR) is a common chronic disease characterized by inflammation of the nasal mucosa. Long non-coding RNA (LncRNA) has been reported to be involved in the pathogenesis of various diseases. However, the biological roles of lncRNA Nuclear Paraspeckle Assembly Transcript 1 (NEAT1) in AR are still unclear. The mRNA levels of NEAT1, miR-511, and Nuclear Receptor Subfamily 4 Group A Member 2 (NR4A2) were detected by RT-qPCR. The protein levels of exosomal markers were examined by western blot. ELISA was used to assess the levels of GM-CSF, eotaxin-1, and MUC5AC. The cell viability and apoptosis were evaluated by CCK-8 and TUNEL assays. In this study, we found that the NEAT1 level was highly expressed in AR and IL-13-treated HNECs. NEAT1 interference significantly suppressed levels of GM-CSF, eotaxin-1, and MUC5AC and apoptosis rate, but promoted the viability of IL-13-treated human nasal epithelial cells (HNECs). Moreover, exosomes containing NEAT1 induced inflammatory cytokine production and apoptosis, while NEAT1 depletion abrogated these effects. In addition, NEAT1 directly interacted with miR-511, and the inhibition of miR-511 partially restored the inhibitory effects of NEAT1 silencing on inflammatory cytokine, mucus production, and apoptosis in IL-13-stimulated HNECs. Furthermore, miR-511 could bind to the 3ʹUTR of NR4A2, and the inhibition of miR-511 increased levels of inflammatory factors and apoptosis rate, which was counteracted by depleting NR4A2. In conclusion, our data revealed that exosomal NEAT1 contributed to the pathogenesis of AR through the miR-511/NR4A2 axis. These findings might offer novel strategies for the prevention and treatment of AR.

Long Non-Coding RNAs as Biomarkers and Therapeutic Targets in Sepsis

Sepsis, an infection-induced systemic inflammatory disorder, is often accompanied by multiple organ dysfunction syndromes with high incidence and mortality rates, and those who survive are often left with long-term sequelae, bringing great burden to social economy. Therefore, novel approaches to solve this puzzle are urgently needed. Previous studies revealed that long non-coding RNAs (lncRNAs) have exerted significant influences on the process of sepsis. The aim of this review is to summarize our understanding of lncRNAs as potential sepsis-related diagnostic markers and therapeutic targets, and provide new insights into the diagnosis and treatment for sepsis. In this study, we also introduced the current diagnostic markers of sepsis and discussed their limitations, while review the research advances in lncRNAs as promising biomarkers for diagnosis and prognosis of sepsis. Furthermore, the roles of lncRNAs in sepsis-induced organ dysfunction were illustrated in terms of different organ systems. Nevertheless, further studies should be carried out to elucidate underlying molecular mechanisms and pathological process of sepsis.

miR-122-5p downregulation attenuates lipopolysaccharide-induced acute lung injury by targeting IL1RN

MicroRNAs (miRs) and inflammatory cytokines can induce acute lung injury (ALI), which can develop into acute respiratory distress syndrome in severe cases. Previous research has revealed that miR-122-5p participates in the development of ALI, and that its expression is positively associated with ALI. However, the mechanism by which miR-122-5p contributes to ALI remains to be determined. In the current study, TargetScan and dual luciferase reporter gene assays were used to confirm that IL-1 receptor antagonist (IL1RN) was a target of miR-122-5p. Subsequently, by referring to previous literature, a lipopolysaccharide (LPS)-induced ALI cell model was established. A549 cells were transfected with mimic control or miR-122-5p mimics for 24 h, and 10 µg LPS was used to treat the transfected cells for 12 h. The results revealed that miR-122-5p mimics decreased cell viability and promoted apoptosis. Lactate dehydrogenase (LDH) release assays indicated that miR-122-5p mimics increased LDH release. ELISA demonstrated that miR-122-5p mimics promoted TNF-α, IL-1β and IL-6 expression levels. A549 cells were transfected with inhibitor control, miR-122-5p inhibitor, miR-122-5p inhibitor + control-small interfering (si)RNA or miR-122-5p inhibitor + IL1RN-siRNA for 24 h, after which the cells were treated with 10 µg LPS for 12 h. The results revealed that the effects of the miR-122-5p inhibitor were the opposite of those of the miR-122-5p mimic. All the effects of miR-122-5p inhibitor on LPS-treated A549 cells were significantly reversed by IL1RN-siRNA. Overall, the results highlighted miR-122-5p as a potential novel target for the treatment of ALI.

Long non-coding RNA HOTAIR knockdown alleviates lipopolysaccharide-induced acute respiratory distress syndrome and the associated inflammatory response by modulating the microRNA-30a-5p/PDE7A axis

Acute respiratory distress syndrome (ARDS) is a severe pulmonary disease, which can be modulated by certain long non-coding (lnc)RNAs. The present study aimed to investigate the regulatory mechanism of lncRNA HOTAIR in ARDS and the inflammatory response induced by lipopolysaccharide (LPS). The mRNA expression levels of HOTAIR, microRNA (miR)-30a-5p and PDE7A were determined using reverse transcription-quantitative PCR, while a MTT assay was used to assess the viability of the MLE-12 cells and ELISA was used to determine the concentration of different inflammatory factors [tumor necrosis factor (TNF)-α, IL-1β and IL-6]. The interactions between miR-30a-5p and HOTAIR/PDE7A were predicted using TargetScan and StarBase databases and verified using a dual-luciferase reporter assay. The protein expression levels of PDE7A were determined using western blot analysis. Mouse models of LPS-induced ARDS were established to investigate the suppressive effect of HOTAIR knockdown on ARDS in vivo. lncRNA HOTAIR was increased in LPS-treated MLE-12 cells and in a ARDS mouse model. HOTAIR knockdown decreased the concentration of TNF-α, IL-1β and IL-6, and increased cell viability in vitro. miR-30a-5p upregulation decreased TNF-α, IL-1β and IL-6 concentrations, and increased cell viability in vitro. HOTAIR targeted miR-30a-5p and miR-30a-5p targeted PDE7A. miR-30a-5p downregulation and PDE7A upregulation reversed the suppressive effect of HOTAIR knockdown on the concentrations of TNF-α, IL-1β and IL-6, and the positive effect of HOTAIR knockdown on cell viability in vitro. HOTAIR knockdown also attenuated ARDS and the inflammatory response induced by LPS in vivo. The suppression of HOTAIR alleviated ARDS and the inflammatory response induced by LPS by modulating the miR-30a-5p/PDE7A axis. These results provide a potential therapeutic strategy for ARDS.

lncRNA-SNHG14 Plays a Role in Acute Lung Injury Induced by Lipopolysaccharide through Regulating Autophagy via miR-223-3p/Foxo3a

lncRNAs play important roles in lipopolysaccharide- (LPS-) induced acute lung injury. But the mechanism still needs further research. In the present study, we investigate the functional role of the lncRNA-SNHG14/miR-223-3p/Foxo3a pathway in LPS-induced ALI and tried to confirm its regulatory effect on autophagy. Transcriptomic profile changes were identified by RNA-seq in LPS-treated alveolar type II epithelial cells. The expression changes of lncRNA-SNHG14/miR-223-3p/Foxo3a were confirmed using qRT-PCR and west blot. The binding relationship of lncRNA-SNHG14/miR-223-3p/and miR-223-3p/Foxo3a was verified using dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays. Using gain-of-function or loss-of-function approaches, the effect of lncRNA-SNHG14/miR-223-3p/Foxo3a was investigated in LPS-induced acute lung injury mice model and in vitro. Increasing of lncRNA-SNHG14 and Foxo3a with reducing miR-223-3p was found in LPS-treated A549 cells and lung tissue collected from the LPS-induced ALI model. lncRNA-SNHG14 inhibited miR-223-3p but promoted Foxo3a expression as a ceRNA. Artificially changes of lncRNA-SNHG14/miR-223-3p/Foxo3a pathway promoted or protected cell injury from LPS in vivo and in vitro. Autophagy activity could be influenced by lncRNA-SNHG14/miR-223-3p/Foxo3a pathway in cells with or without LPS treatment. In conclusion, aberrant expression changes of lncRNA-SNHG14 participated alveolar type II epithelial cell injury and acute lung injury induced by LPS through regulating autophagy. One underlying mechanism is that lncRNA-SNHG14 regulated autophagy by controlling miR-223-3p/Foxo3a as a ceRNA. It suggested that lncRNA-SNHG14 may serve as a potential therapeutic target for patients with sepsis-induced ALI.

Long non-coding RNA CHRF accelerates LPS-induced acute lung injury through microRNA-146a/Notch1 axis

Background

The present study sought to investigate the regulatory role of the long non-coding RNA (lncRNA) cardiac hypertrophy-related factor (CHRF) in a mouse model of acute lung injury (ALI) and in primary mouse pulmonary microvascular endothelial cells (MPVECs) treated with lipopolysaccharide (LPS).

Methods

C57BL/6 mice were given adenovirus (Ad) sh-CHRF or negative control (NC) before undergoing cecal ligation and perforation. MPVECs transfected with Adsh-CHRF or NC were treated with LPS. Double luciferase assay was used to detect the binding of miR-146a to CHRF or Notch1. Subsequently, MPVECs were co-transfected with miR-146a inhibitor and sh-CHRF for 24 hours, and then treated with LPS.

Results

High expression of CHRF was detected in septic mice. Cecal ligation and perforation induced ALI and apoptosis in mice, whereas, CHRF knockout could inhibit ALI. The protein expression levels of TNF-α, IL-1β and IL-6 in the lung and bronchoalveolar lavage fluid of the CLP group were up-regulated, whereas the expression of IL-4 and IL-10 was down-regulated. CHRF inhibition reduced the production of proinflammatory cytokines in septic mice. The inhibitory effect of CHRF gene knockdown on lung inflammation and apoptosis was confirmed in the septic cell model. Mechanistic investigation showed that CHRF up-regulated the level of Notch1 by sponging miR-146a. Additionally, the low expression of miR-146a reversed the inhibitory effect of CHRF gene knockout on LPS-induced inflammatory response and apoptosis. Together, in vivo and in vitro results demonstrated that CHRF enhanced sepsis-induced ALI by targeting miR-146a and up-regulating Notch1.

Conclusions

CHRF can induce inflammation and apoptosis caused by sepsis by miR-146a/Notch1 axis. Therefore, it may serve as a potential drug target for treating sepsis-induced ALI.

LncRNA NEAT1 regulates MMP-16 by targeting miR-200a/b to aggravate inflammation in asthma

Asthma is a common respiratory disease which is characterized by persistent airway inflammation. Abnormal expression of long non-coding RNAs (lncRNAs) is observed in asthma. However, whether lncRNA nuclear-enriched abundant transcript 1 (NEAT1) regulates asthmatic inflammation and its mechanism still needs to be further investigated. The expression levels of inflammatory factors (tumour necrosis factor (TNF)-α, interleukin (IL)-4, IL-13, and IL-10) were detected using reverse transcription quantitative real-time PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA). MTT and flow cytometry assays were employed to determine cell proliferation and apoptosis, respectively. Dual luciferase reporter assay was performed to verify the relationship between miR-200a/b and MMP-16 or NEAT1. NEAT1 silencing markedly reduced TNF-α, IL-4, and IL-13 levels, while elevated IL-10 expression, suppressed cell proliferation, and promoted cell apoptosis. However, NEAT1 overexpression elicited the opposite effects on cell proliferation and inflammation cytokines secretion. What is more, NEAT1 negatively regulated miR-200a/b expression, and MMP16 was a target gene of miR-200a/b. miR-200a/b overexpression suppressed inflammation, cell proliferation, and enhanced cell apoptosis through regulation of MMP16. Moreover, MMP-16 overexpression or miR-200a/b inhibition abolished the regulatory effect of sh-NEAT1 on cell inflammation and apoptosis in BEAS-2B cells. NEAT1 acted as the role of sponge for miR-200a/b to regulate MMP-16 expression, thereby promoting asthma progression, suggesting that NEAT1 might have great potential as therapeutic target for asthma.

RETRACTED: LncRNA NEAT1 inhibition upregulates miR-16-5p to restrain the progression of sepsis-induced lung injury via suppressing BRD4 in a mouse model

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concern was raised about the reliability of the Western blot results in Figs. 5B and 6B, which appear to have the same eyebrow shaped phenotype as many other publications tabulated here (https://docs.google.com/spreadsheets/d/149EjFXVxpwkBXYJOnOHb6RhAqT4a2llhj9LM60MBffM/edit#gid=0 [docs.google.com]). The journal requested the corresponding author comment on these concerns and provide the raw data. However, the authors were not responsive to the request for comment. Since original data could not be provided, the overall validity of the results could not be confirmed. Therefore, the Editor-in-Chief decided to retract the article.

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.

Knockdown of long non-coding RNA NEAT1 relieves the inflammatory response of spinal cord injury through targeting miR-211-5p/MAPK1 axis

Spinal cord injury (SCI) is a refractory disease often accompanied by inflammation. Long non-coding RNA NEAT1 (lncRNA NEAT1) was reported to be involved in the expression of the inflammasomes, while the regulatory effect of NEAT1 on SCI was poorly investigated. Herein, we carried out further studies on the pathogenesis of SCI. PC-12 cells were incubated with lipopolysaccharide (LPS) to induce inflammation. Western blotting assay was used to measure the protein expression levels. RNA expression levels were analyzed using RT-qPCR. Cell counting kit 8 and flow cytometry assays were used to separately determine the cell viability and apoptosis rate. The targeted relationships were verified by luciferase reporter and RNA pull-down assays. It was found that LPS induced inflammation in the PC-12 cells, leading to significantly higher cell apoptosis rate and lower viability, and the expression level of NEAT1 was elevated by LPS. However, knockdown of NEAT1 partially reversed the effects of LPS. Subsequently, the potential interaction between NEAT1 and miR-211-5p was validated and miR-211-5p inhibitor was further confirmed to antagonize the effects of NEAT knockdown. The downstream target gene of miR-211-5p was predicted and verified to be MAPK1. In addition, overexpression of MAPK1 was proved to antagonize the effects of NEAT1 knockdown. Taken together, the knockdown of NEAT1 remarkably alleviated the inflammation of SCI via miR-211-5p/MAPK1 axis.

Long Noncoding RNA: Regulatory Mechanisms and Therapeutic Potential in Sepsis

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection and is characterized by a hyperinflammatory state accompanied by immunosuppression. Long noncoding RNAs (lncRNAs) are noncoding RNAs longer than 200 nucleotides and have important roles in mediating various biological processes. Recently, lncRNAs were found to exert both promotive and inhibitory immune functions in sepsis, thus participating in sepsis regulation. Additionally, several studies have revealed that lncRNAs are involved in sepsis-induced organ dysfunctions, including cardiovascular dysfunction, acute lung injury, and acute kidney injury. Considering the lack of effective biomarkers for early identification and specific treatment for sepsis, lncRNAs may be promising biomarkers and even targets for sepsis therapies. This review systematically highlights the recent advances regarding the roles of lncRNAs in sepsis and sheds light on their use as potential biomarkers and treatment targets for sepsis.

Whole transcriptome analysis of the differential RNA profiles and associated competing endogenous RNA networks in LPS-induced acute lung injury (ALI)

Acute lung injury (ALI) is a serious inflammation disease usually arises alveolar epithelial membrane dysfunction and even causes death. Therefore, the aims of this study are to screen the differentially expressed lncRNAs, circRNAs, miRNAs, and mRNAs in ALI based on the high-throughput sequencing. The lipopolysaccharide (LPS)-induced ALI mouse model was established, the injury of ALI mouse model was evaluated through histological analysis with hemotoxylin and eosin (H & E) staining assay, dry/wet ratio, infiltrated-immune cells, ET-1 mRNA expression and released-proinflammation factors. Then, expression data of lncRNAs, circRNAs, miRNAs and mRNAs in ALI were acquired using whole-transcriptome sequencing. The differential expression of lncRNAs (DE lncRNAs), circRNAs (DE circRNAs), miRNAs (DE miRNAs) and mRNAs (DE mRNAs) were identified, and the lncRNA-miRNA-mRNA network and circRNA-miRNA-mRNA network were constructed, and the biological function of target genes were annotated based on bioinformatics analysis. In the present study, the LPS-induced ALI mouse model was successfully established. The biological analysis results showed that total 201 DE lncRNAs, 172 DE circRNAs, 62 DE miRNAs, and 3081 DE mRNAs were identified in ALI. The 182 lncRNA-miRNA-mRNA networks and 32 circRNA-miRNA-mRNA networks were constructed were constructed based on the correlation between lncRNAs/circRNAs, miRNAs, mRNAs. The biological function analysis indicated that TNF signaling pathway, chemokine signaling pathway and so on involved in ALI. In the present study, the differential expression coding and non-coding RNAs (ncRNAs) in ALI were identified, and their regulatory networks were constructed. There might provide the potential biomarkers and underlying mechanism for ALI diagnosis and treatment.

Identification and Functional Analysis of Long Non-coding RNAs in Human Pulmonary Microvascular Endothelial Cells Subjected to Cyclic Stretch

Background: Despite decades of intense research, the pathophysiology and pathogenesis of acute respiratory distress syndrome (ARDS) are not adequately elucidated, which hamper the improvement of effective and convincing therapies for ARDS patients. Mechanical ventilation remains to be one of the primary supportive approaches for managing ARDS cases. Nevertheless, mechanical ventilation leads to the induction of further aggravating lung injury which is known as leading to ventilator-induced lung injury (VILI). It has been reported that lncRNAs play important roles in various cellular process through transcriptional, posttranscriptional, translational, and epigenetic regulations. However, to our knowledge, there is no investigation of the expression profile and functions of transcriptome-level endothelium-related lncRNAs in VILI yet. Methods: To screen the differential expression of lncRNAs and mRNAs in Human pulmonary microvascular endothelial cells (HPMECs) subjected to cyclic stretch, we constructed a cellular model of VILI, followed by transcriptome profiling using Affymetrix Human Transcriptome Array 2.0. Bioinformatics analyses, including functional and pathway enrichment analysis, protein-protein interaction network, lncRNA-mRNA coexpression network, and cis-analyses, were performed to reveal the potential functions and underlying mechanisms of differentially expressed lncRNAs. Results: In total, 199 differentially expressed lncRNAs (DELs) and 97 differential expressed mRNAs were screened in HPMECs subjected to 20% cyclic stretch for 2 h. The lncRNA-mRNA coexpression network suggested that DELs mainly enriched in response to hypoxia, response to oxidative stress, inflammatory response, cellular response to hypoxia, and NF-kappa B signaling pathway. LncRNA n335470, n406639, n333984, and n337322 might regulate inflammation and fibrosis induced by cyclic stretch through cis- or trans-acting mechanisms. Conclusion: This study provides the first transcriptomic landscape of differentially expressed lncRNAs in HPMECs subjected to cyclic stretch, which provides novel insights into the molecular mechanisms and potential directions for future basic and clinical research of VILI.

LncRNA SNHG12 downregulates RAGE to attenuate hypoxia-reoxygenation-induced apoptosis in H9c2 cells

Ischemia-reperfusion (I/R) injury causes cardiac dysfunction through several mechanisms including the irregular expression of some long noncoding RNA. However, the role of SNHG12 in myocardial I/R injury remains unclear. Here, we found the increase of the SNHG12 level in hypoxia-reoxygenation (H/R)-injured-H9c2 cells. SNHG12 silencing enhanced the apoptosis of H/R-injured H9c2 cells, while SNHG12 overexpression relieved the cardiomyocyte apoptosis induced by H/R stimulation. Additionally, the suppression of SNHG12 significantly boosted the H/R-induced expression and the production of TNF-α, IL-6, and IL-1β, as well as the activation of NF-κB, which were fully reversed after overexpression of SNHG12. Mechanistically, SNHG12 adversely regulated the production of receptor for advanced glycation end products (RAGE) in H/R-stimulated H9c2 cells. Antibody blocking of RAGE alleviated the apoptosis of H/R-injured H9c2 cells. Collectively, we have determined a valuable mechanism by which the high level of SNHG12 contributes to H9c2 cells against H/R injury through the reduction of RAGE expression.

The receptor for advanced glycation end products mediates dysfunction of airway epithelial barrier in a lipopolysaccharides-induced murine acute lung injury model

BACKGROUND

Airway epithelial cells (AECs) act as the first barrier protecting against invasion of environment agents and maintain integrity of lung structure and function. Dysfunction of airway epithelial barrier has been shown to be involved in ALI/ARDS pathogenesis. Yet, the exact mechanism is still obscure. Our study evaluated whether the receptor for advanced glycation end products (RAGE) mediates impaired airway epithelial barrier in LPS-induced murine ALI model.

METHODS

Male BALB/c mice were subjected to intratracheal instillation of LPS to generate an ALI model. Inhibitors of RAGE, FPS-ZM1 and Azeliragon were respectively given to the mice through intraperitoneal injection. Bronchoalveolar lavage fluid (BALF) and lung tissues were collected for further analysis.

RESULTS

LPS exposure led to markedly increased expression of RAGE and its ligands HMGB1, HSP70, S100b. Treatment of FPS-ZM1 or Azeliragon not only effectively descended the expression of RAGE and its ligands but also attenuated LPS-induced neutrophil-predominant airway inflammation and injury, decreased levels of IL-6, IL-1β and TNF-α in BALF, alleviated increased alveolar-capillary permeability and pulmonary edema. LPS stimulation significantly impaired the integrity of airway epithelium, paralleled with dislocation of adheren junction (AJ) protein E-cadherin at cell-cell contacts and down-expression of both AJ and tight junction (TJ) proteins Claudin-2 and occludin, all of which were dramatically rescued by RAGE inhibition.

CONCLUSION

RAGE signaling mediates airway epithelial barrier dysfunction in a LPS-induced ALI murine model.

LncRNA NEAT1 acts as a key regulator of cell apoptosis and inflammatory response by the miR-944/TRIM37 axis in acute lung injury

Acute lung injury (ALI), a common complication of sepsis, is characterized by the impairment and injury of pulmonary function. The nuclear factor kappa-B (NF-κB) pathway is activated in ALI. Tripartite motif-containing 37 (TRIM37) can activate the NF-κB pathway and is closely associated with inflammation. The purpose of our study is to reveal the role of TRIM37 in ALI. The present study revealed that TRIM37 presented high levels in lung tissues of ALI mice, and knockdown of TRIM37 alleviated lipopolysaccharide (LPS)-induced lung injury, inflammatory response, and cell apoptosis in vivo. In addition, knockdown of TRIM37 inhibited the inflammatory response, and cell apoptosis of LPS-treated WI-38 cells. Mechanistically, miR-944 was identified to bind with and negatively regulate TRIM37. Furthermore, NEAT1 was indicated to act as a competitive endogenous RNA to promote TRIM37 expression by sequestering miR-944. Detailly, NEAT1 bound with miR-944, negatively modulated miR-944 expression, and positively modulated TRIM37 expression. The rescue assays suggested that overexpression of TRIM37 rescued the influence of NEAT1 knockdown on cell apoptosis and inflammatory response. Overall, NEAT1 facilitated cell apoptosis and inflammatory response of WI-38 cells by the miR-944/TRIM37 axis in sepsis-induced ALI, implying that NEAT1 may provide a novel insight for the treatment of sepsis-induced ALI.