Silencing of long non-coding RNA KCNQ1OT1 alleviates LPS-induced lung injury by regulating the miR-370-3p/FOXM1 axis in childhood pneumonia

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.

The Clinical Significance and the Potential Regulatory Mechanism of the LncRNA OIP5-AS1 in Paediatric Severe Community-Acquired Pneumonia Blood Through the MiR-150-5p/PDCD4 Axis

BACKGROUND

This study aimed to elucidate the clinical significance and regulatory mechanism of the long non-coding RNA OIP5-AS1 in severe community-acquired pneumonia (SCAP) among paediatric patients.

METHODS

qRT-PCR was used to assess the mRNA levels of OIP5-AS1. ROC curve analysis was used to assess the diagnostic significance of OIP5-AS1. Short-term prognostic significance was evaluated through Kaplan-Meier survival. An in vitro cell model was developed using LPS-induced MRC-5 cells. CCK-8, flow cytometry, and ELISA were conducted to measure cell viability, apoptosis, and inflammatory factor levels. The association between miR-150-5p and PDCD4 was confirmed through DLR assays.

RESULTS

Elevated OIP5-AS1 were observed in paediatric patients with SCAP, which enabled effective differentiation from healthy individuals. High expression of OIP5-AS1 correlated with reduced survival rates. OIP5-AS1 knockdown attenuated cell viability suppression and the promotion of apoptosis and inflammatory factors induced by LPS. However, this attenuation was reversed by reduced levels of miR-150-5p. miR-150-5p was identified as a target of PDCD4 and OIP5-AS1.

CONCLUSION

Increased OIP5-AS1 levels show potential as a valuable diagnostic and prognostic biomarker for paediatric patients with SCAP. This study illustrates its role in regulating cell viability, apoptosis, and the inflammatory response via the miR-150-5p/PDCD4 axis, acting as a ceRNA.

A review on the role of KCNQ1OT1 lncRNA in human disorders

KCNQ1OT1 is an lncRNA located within KCNQ1 gene on chromosome 11p15.5. This lncRNAs participates in the pathogenesis of a diversity of cancers as well as non-cancerous conditions. In most types of cancers, KCNQ1OT1 is regarded as an oncogene. In a wide array of cancers, high level of KCNQ1OT1 is associated with lower overall survival time. This lncRNA has been found to adsorb a variety of miRNAs, namely miR-15a, miR-211-5p, hsa-miR-107, miR-145, miR-34a, miR-204-5p, miR-129-5p, miR-372-3p, miR-491-5p, miR-153, miR-185-5p, miR-124-3p, miR-211-5p, miR-149, miR-148a-3p, miR-140-5p, miR-125b-5p, miR-9, miR-329-3p, miR-760, miR-296-5p, miR-3666 and miR-129-5p, thus regulating the downstream targets of these miRNAs. In this manuscript, our attention is on this lncRNA and its biomolecular roles in human cancers and other disorders. KCNQ1OT1 plays significant roles in the tumorigenesis and may function as a prospective target for cancer therapy.

Circ_0026579 knockdown ameliorates lipopolysaccharide-induced human lung fibroblast cell injury by regulating CXCR1 via miR-370-3p

Pneumonia is an inflammatory disease in lower respiratory tracts and its development involves the regulation of RNAs. Circular RNAs are a class of RNA subgroups that can mediate the progression of pneumonia. However, the molecular mechanism of circ_0026579 in regulating pneumonia occurrence remains unclear. The study is designed to reveal the role of circ_0026579 in lipopolysaccharide (LPS)-induced human lung fibroblast cell injury and the underlying mechanism. The expression levels of circ_0026579, miR-370-3p and C-X-C motif chemokine receptor 1 (CXCR1) were detected by quantitative real-time polymerase chain reaction or by western blotting. The production of tumour necrosis factor-α, interleukin (IL)-1β and IL-6 was assessed by enzyme-linked immunosorbent assays. Malondialdehyde and superoxide dismutase levels were analysed using commercial kits. Cell viability, proliferation and apoptosis were analysed by cell counting kit-8 assay, 5-Ethynyl-2'-deoxyuridine assay and flow cytometry analysis, respectively. The binding relationship between miR-370-3p and circ_0026579 or CXCR1 was identified by dual-luciferase reporter assay, RNA immunoprecipitation assay and RNA pull-down assay. Circ_0026579 and CXCR1 expression were significantly upregulated, whereas miR-370-3p was downregulated in the serum of pneumonia patients. LPS treatment induced inflammatory response, oxidative stress and cell apoptosis and inhibited cell proliferation in MRC-5 cells; however, these effects were reversed after circ_0026579 depletion. In terms of the mechanism, circ_0026579 acted as a miR-370-3p sponge, and miR-370-3p combined with CXCR1. Additionally, circ_0026579 depletion ameliorated LPS-induced MRC-5 cell disorder by increasing miR-370-3p expression. CXCR1 overexpression also relieved the miR-370-3p-mediated effects in LPS-treated MRC-5 cells. Further, circ_0026579 induced CXCR1 expression by interacting with miR-370-3p. Circ_0026579 absence ameliorated MRC-5 cell dysfunction induced by LPS through the regulation of the miR-370-3p/CXCR1 axis.

Sinomenine attenuates lipopolysaccharide-induced inflammation and apoptosis of WI-38 cells by reducing glutathione S-transferase M1 expression

Pediatric pneumonia is an infectious lung disease with high morbidity and mortality. Sinomenine, an alkaloid extracted from Caulis Sinomenii, exerts anti-inflammatory and anti-apoptotic activities. Lipopolysaccharide (LPS) is widely used for the establishment of an inflammatory model. This research aimed to explore the influences of sinomenine on LPS-caused inflammatory injuries in fetal lung WI-38 cells. WI-38 cells were treated with LPS to establish a cellular model of pediatric pneumonia. Cell viability was evaluated using CCK-8 assay. Apoptosis was evaluated using TUNEL staining and caspase-3 activity assays. Inflammatory cytokines and NF-κB p65 phosphorylation levels were measured by Enzyme-Linked Immunosorbent Assay. Glutathione S-transferase M1 (GSTM1) expression was detected by western blotting. Results showed that LPS reduced WI-38 cell viability, and sinomenine protected cells against LPS-induced viability reduction. Sinomenine concentration-dependently attenuated LPS-induced inflammation by reducing TNF-α, IL-1β and MCP-1, and increasing IL-10 levels. Sinomenine mitigated LPS-induced apoptosis. GSTM1 was screened by matching the targets of sinomenine and pediatric pneumonia. GSTM1 was upregulated in LPS-treated WI-38 cells, and this effect was attenuated after sinomenine treatment. GSTM1 was upstream of NF-κB pathway. Overexpression of GSTM1 reversed the suppressive functions of sinomenine on LPS-stimulated inflammation and apoptosis. Overall, sinomenine attenuates inflammation and apoptosis in WI-38 cells stimulated by LPS via inhibiting GSTM1 expression, indicating the therapeutic potential of sinomenine in pediatric pneumonia.

Combination therapy with budesonide and acetylcysteine alleviates LPS-induced acute lung injury via the miR-381/NLRP3 molecular axis

BACKGROUND

Acute lung injury (ALI) usually has a high morbidity and mortality rate, but the current treatment is relatively scarce. Both budesonide (Bud) and N-acetylcysteine (NAC) exhibit protective effects in ALI, so we further investigated whether they have a synergistic effect on ALI when used together.

METHODS

Establishment of a rat model of ALI with Lipopolysaccharide (LPS). Bud and NAC were administered by nebulized inhalation alone or in combination. Subsequently, HE staining was performed to observe the pathological changes in lungs of rat. Evans blue staining was implemented to assess alveolar permeability, and the pulmonary edema was assessed by measuring the ratio of wet to dry weight of the lung. Moreover, a TUNEL kit was served to test apoptosis in lung tissues. Western blot and immunohistochemistry were analyzed for expression of scorch-related proteins and NLRP3 in lung tissue, respectively. ELISA was implemented to detect inflammatory factor levels in BALF. and RT-qPCR was utilized to assess the expression level of miR-381. After stable transfection of miR-381 inhibitor or OE-NLRP3 in BEAS-2B treated with LPS, Bud and NAC, miR-381 expression was assessed by RT-qPCR, scorch death-related protein expression was measured by western blot, cell proliferation/viability was assayed by CCK-8, apoptosis was measured by flow cytometry, and ELISA was implemented to assess inflammatory factor levels. Furthermore, the Dual-luciferase assay was used to verify the targeting relationship.

RESULTS

Bud and NAC treatment alone or in combination with nebulized inhalation attenuated the increased alveolar permeability, pulmonary edema, inflammatory response and scorching in LPS-induced ALI rats, and combined treatment with Bud and NAC was the most effective. In addition, combined treatment with Bud and NAC upregulated miR-381 expression and inhibited NLRP3 expression in cellular models and LPS-induced ALI rats. Transfection of the miR-381 inhibitor and OE-NLRP3 partially reversed the protective effects of Bud and NAC combination treatment on BEAS-2B cell proliferation inhibition, apoptosis, focal death and the inflammatory response.

CONCLUSION

Combined Bud and NAC nebulization therapy alleviates LPS-induced ALI by modulating the miR-381/NLRP3 molecular axis.

Long non coding RNAs reveal important pathways in childhood asthma: a future perspective

Asthma is a long-term inflammatory disease of the airways of the lungs refers changes that occur in conjunction with, or as a result of, chronic airway inflammation. Airway remodeling the subsequent of inflammation constitutes cellular and extracellular matrix changes in the wall airways, epithelial-to-mesenchymal-transition and airway smooth muscle cell proliferation. Diseases often begin in childhood and despite extensive research, causative pathogenic mechanisms still remain unclear. Transcriptome analysis of childhood asthma reveals distinct gene expression profiles of Long noncoding RNAs which have been reported to play a central regulatory role in various aspects of pathogenesis, clinical course and treatment of asthma. We briefly review current understanding of lnc-RNA dysregulation in children with asthma, focusing on their complex role in the inflammation, cell proliferation and remodeling of airway to guide future researches. We found that the lnc-RNAs increases activity of several oncogenes such c-Myc, Akt, and ERK and various signaling pathways such as MAPK (PI3K, Ras, JNK and p38), NF-κB and Wnt and crosstalk between these pathways by TGFβ, β-catenin, ERK and SKP2. Moreover, two different signal transduction pathways, Wnt and Notch1, can be activated by two lnc-RNAs through sponging the same miRNA for exacerbation cell proliferation.

Long noncoding RNA signatures in intrauterine infection/inflammation-induced lung injury: an integrative bioinformatics study

BACKGROUND

Intrauterine infection/inflammation can result in fetal and neonatal lung injury. However, the biological mechanisms of intrauterine infection/inflammation on fetal and neonatal lung injury and development are poorly known. To date, there are no reliable biomarkers for improving intrauterine infection/inflammation-induced lung injury.

METHODS

An animal model of intrauterine infection/inflammation-induced lung injury was established with pregnant Sprague-Dawley rats inoculated with Escherichia coli suspension. The intrauterine inflammatory status was assessed through the histological examination of the placenta and uterus. A serial of histological examinations of the fetal and neonatal rats lung tissues were performed. The fetal and neonatal rat lung tissues were harvested for next generation sequencing at embryonic day 17 and postnatal day 3, respectively. Differentially expressed mRNAs and lncRNAs were identified by conducting high-throughput sequencing technique. The target genes of identified differentially expressed lncRNAs were analyzed. Homology analyses for important differentially expressed lncRNAs were performed.

RESULTS

The histopathological results showed inflammatory infiltration, impaired alveolar vesicular structure, less alveolar numbers, and thickened alveolar septa in fetal and neonatal rat lung tissues. Transmission electron micrographs revealed inflammatory cellular swelling associated with diffuse alveolar damage and less surfactant-storing lamellar bodies in alveolar epithelial type II cells. As compared with the control group, there were 432 differentially expressed lncRNAs at embryonic day 17 and 125 differentially expressed lncRNAs at postnatal day 3 in the intrauterine infection group. The distribution, expression level, and function of these lncRNAs were shown in the rat genome. LncRNA TCONS_00009865, lncRNA TCONS_00030049, lncRNA TCONS_00081686, lncRNA TCONS_00091647, lncRNA TCONS_00175309, lncRNA TCONS_00255085, lncRNA TCONS_00277162, and lncRNA TCONS_00157962 may play an important role in intrauterine infection/inflammation-induced lung injury. Fifty homologous sequences in Homo sapiens were also identified.

CONCLUSIONS

This study provides genome-wide identification of novel lncRNAs which may serve as potential diagnostic biomarkers and therapeutic targets for intrauterine infection/inflammation-induced lung injury.

Circ_0035292 knockdown alleviates lipopolysaccharide (LPS)-induced WI-38 cell apoptosis and inflammatory injury

BACKGROUND

Circular RNAs have emerged as important regulators in the pathogenesis of human diseases, including infantile pneumonia (IP). In this study, we aimed to explore the effects of circ_0035292 on lipopolysaccharide (LPS)-treated Wistsar Institute (WI)-38 cells.

METHODS

Quantitative real-time polymerase chain reaction and western blot were executed to detect the levels of circ_0035292, microRNA-370-3p (miR-370-3p) and transducin β-like 1X related protein 1 (TBL1XR1). Cell counting kit-8, 5-ethynyl-2'-deoxyuridine, and flow cytometry assessed cell proliferation and apoptosis. Concentrations of inflammatory factors were examined with enzyme linked immunosorbent assay kits. Dual-luciferase reporter assay and RNA immunoprecipitation were adopted to analyze binding between miR-370-3p and circ_0035292 or TBL1XR1.

RESULTS

Circ_0035292 level was increased in IP patients and LPS-triggered WI-38 cells. Circ_0035292 knockdown rescued LPS-mediated WI-38 cell proliferation suppression and WI-38 cell apoptosis and inflammation promotion. Circ_0035292 interacted with miR-370-3p and miR-370-3p directly targeted TBL1XR1. Moreover, miR-370-3p overexpression alleviated LPS-induced WI-38 cell apoptosis and inflammatory injury, which was abrogated via TBL1XR1 upregulation. Circ_0035292 absence inhibited the NF-κB pathway.

CONCLUSION

Knockdown of circ_0035292 rescued LPS-triggered WI-38 cell injury via miR-370-3p/TBL1XR1 axis and NF-κB pathway.

FOXM1: Functional Roles of FOXM1 in Non-Malignant Diseases

Forkhead box (FOX) proteins are a wing-like helix family of transcription factors in the DNA-binding region. By mediating the activation and inhibition of transcription and interactions with all kinds of transcriptional co-regulators (MuvB complexes, STAT3, β-catenin, etc.), they play significant roles in carbohydrate and fat metabolism, biological aging and immune regulation, development, and diseases in mammals. Recent studies have focused on translating these essential findings into clinical applications in order to improve quality of life, investigating areas such as diabetes, inflammation, and pulmonary fibrosis, and increase human lifespan. Early studies have shown that forkhead box M1 (FOXM1) functions as a key gene in pathological processes in multiple diseases by regulating genes related to proliferation, the cell cycle, migration, and apoptosis and genes related to diagnosis, therapy, and injury repair. Although FOXM1 has long been studied in relation to human diseases, its role needs to be elaborated on. FOXM1 expression is involved in the development or repair of multiple diseases, including pulmonary fibrosis, pneumonia, diabetes, liver injury repair, adrenal lesions, vascular diseases, brain diseases, arthritis, myasthenia gravis, and psoriasis. The complex mechanisms involve multiple signaling pathways, such as WNT/β-catenin, STAT3/FOXM1/GLUT1, c-Myc/FOXM1, FOXM1/SIRT4/NF-κB, and FOXM1/SEMA3C/NRP2/Hedgehog. This paper reviews the key roles and functions of FOXM1 in kidney, vascular, lung, brain, bone, heart, skin, and blood vessel diseases to elucidate the role of FOXM1 in the development and progression of human non-malignant diseases and makes suggestions for further research.

Protective role of FBXL19 in Streptococcus pneumoniae-induced lung injury in pneumonia immature mice

OBJECTIVE

Streptococcus pneumoniae (Spn) is a common pathogen for pediatric pneumonia and leads to severe lung injury. This study is conducted to analyze the role of F-box and leucine rich repeat protein 19 (FBXL19) in Spn-induced lung injury in immature mice.

METHODS

Immature mice were infected with Spn to record the survival rates and bacterial loads in bronchoalveolar lavage fluid. Levels of FBXL19 and FOXM1 in lung tissues were determined via real-time quantitative polymerase chain reaction or Western blotting. After the interference of FBXL19, its impacts on lung inflammatory injury were appraised by the lung wet/dry weight ratio, myeloperoxidase activity, hematoxylin and eosin staining, and enzyme-linked immunosorbent assay. The binding of FBXL19 to forkhead box M1 (FOXM1) in mouse lung epithelial cells was determined. After MG132 treatment, the protein and ubiquitination levels of FOXM1 were measured. The functional rescue experiments were performed to analyze the role of FOXM1 in FBXL19-regulated lung injury.

RESULTS

FBXL19 was downregulated while FOXM1 was upregulated in lung tissues of Spn-infected immature mice. Overexpression of FBXL19 reduced the degree of lung injury and inflammation. FBXL19 can bind to FOXM1 to reduce its protein level via ubiquitination degradation. MG132 reduced the ubiquitination and increased the protein level of FOXM1. Overexpression of FOXM1 reversed the protective role of FBXL19 overexpression in lung injury of Spn immature mice.

CONCLUSION

FBXL19 was downregulated by Spn and FBXL19 overexpression alleviated lung injury by inducing ubiquitination and degradation of FOXM1 in Spn immature mice.

Role of M2 macrophages-derived extracellular vesicles in IL-1β-stimulated chondrocyte proliferation and inflammatory responses

M2 macrophages-derived extracellular vesicles (M2-EVs) serve as a tool for the delivery of miRNAs and play an anti-inflammatory role in diseases. This study sought to explore the role of (M2-EVs) in the proliferation and inflammatory responses of IL-1β-stimulated chondrocytes. M2 macrophages were induced and characterized, followed by isolation and characterization of M2-EVs. Chondrocytes were treated with 10 ng/mL IL-1β and co-cultured with M2 macrophages transfected with Cy3-labeled miR-370-3p. Cell viability, TNF (tumor necrosis factor)-α, IL(Interleukin)-18, IL-10, miR-370-3p, and sex-determining region Y-related high-mobility-group box transcription factor 11 (SOX11) mRNA were determined via cell counting assay kit, colony formation, ELISA, and qRT-PCR. The binding relationship between miR-370-3p and SOX11 was testified via the dual-luciferase assay. The functional rescue experiment was designed to confirm the role of SOX11. M2-EVs improved chondrocyte viability and colony formation, lowered TNF-α and IL-18, and elevated IL-10. M2-EVs delivered miR-370-3p into chondrocytes to upregulate miR-370-3p. Upregulation of miR-370-3p in M2-EVs enhanced the protective role of M2-EVs in chondrocytes. miR-370-3p inhibited SOX11 transcription. SOX11 overexpression attenuated the protective role of M2-EVs in chondrocytes. Overall, our findings suggested that M2-EVs promote proliferation and suppress inflammatory responses in IL-1β-stimulated chondrocytes via the miR-370-3p/SOX11 axis.

Abnormal expression of lncRNA CASC9 in pneumonia children with respiratory failure and its feasible value for the clinical diagnosis of patients

lncRNA CASC9 expression was involved in a variety of diseases and exerted a protective role against inflammation and sepsis-induced injury. However, the role of CASC9 in severe pneumonia remains unclear. This study aimed to explore the potential diagnostic role of lncRNA CASC9 in severe pneumonia. The CASC9 expression levels were measured by RT-qPCR. The receiver operating characteristic curve (ROC) was conducted to evaluate the clinical diagnostic value of CASC9 in severe pneumonia. LPS-induced human lung fibroblast MRC-5 was used to establish the pneumonia model and then transfected with CASC9 overexpression vectors to evaluate the influence of CASC9 on cell viability and apoptosis. The inflammatory cytokines IL-1β, TNF-α, IL-6 levels were detected using a commercial enzyme-linked immunosorbent assay (ELISA). Pearson correlation analysis was used to explore the correlation between CASC9 expression and clinical data. The relative expression of CASC9 was downregulated in serum samples of severe pneumonia patients. The low expression of CASC9 in severe pneumonia was negatively correlated with several clinical data. The CASC9 had the relatively high area under ROC curve (AUC) values for distinguishing severe pneumonia from pneumonia children and healthy control. The elevated expression of CASC9 accelerated cell viability and diminished apoptosis in LPS-induced MRC-5 cells. The CASC9 expression was decreased in serum samples of severe pneumonia, and upregulation of CASC9 facilitated LPS-induced cell viability and inhibited apoptosis. In summary, CASC9 might be a diagnostic predictor and might act as a crucial regulatory roles in the progression of severe pneumonia.