MiR-342 attenuates lipopolysaccharide-induced acute lung injury via inhibiting MAPK1 expression

Protective Effects and Mechanisms of Luteolin against Acute Respiratory Distress Syndrome: Network Pharmacology and In vivo and In vitro Studies

BACKGROUND

Acute Respiratory Distress Syndrome (ARDS) is an acute life-threatening disease, and luteolin has the potential to become a therapeutic agent for ARDS. However, its mechanism of action has not yet been clarified.

OBJECTIVE

The present study explored the potential effects and mechanisms of luteolin in the treatment of ARDS through network pharmacology analysis and verified them through biological experiments.

METHODS

The potential targets of luteolin and ARDS were obtained from online databases. Functional enrichment and protein-protein interaction (PPI) analyses were performed to explore the underlying molecular mechanisms and to identify hub targets. Molecular docking was used to verify the relationship between luteolin and target proteins. Finally, the effects of luteolin on key signaling pathways and biological processes were verified by in vitro and in vivo experiments.

RESULTS

A total of 146 luteolin- and 496 ARDS-related targets were extracted from public databases. The network pharmacological analysis suggested that luteolin could inhibit ARDS through the following potential therapeutic targets: AKT1, RELA, and NFKBIA. Inflammatory and oxidative stress responses were the main biological processes involved, with the AKT/NF-κB signaling pathway being the key signaling pathway targeted by luteolin for the treatment of ARDS. Molecular docking analysis indicated that luteolin had a good binding affinity to AKT1, RELA, and NFKBIA. The in vitro and in vivo experiments revealed that luteolin could regulate the inflammatory response and oxidative stress in the treatment of ARDS by inhibiting the AKT/NF- κB signaling pathway.

CONCLUSION

Luteolin could reduce the production of reactive oxygen species and inflammatory factors by inhibiting the AKT/NF-κB signaling pathway, thus reducing apoptosis and attenuating ARDS.

miRNA transcriptomics analysis shows miR-483-5p and miR-503-5p targeted miRNA in extracellular vesicles from severe acute pancreatitis-associated lung injury patients

AIM

This study sought to identify potential biomarkers and miRNA-mRNA networks within extracellular vesicles (EVs) for detecting severe acute pancreatitis-associated lung injury (SAPALI).

METHODS

Blood-derived EVs were isolated, and their miRNA transcriptomic profiles were comprehensively analyzed using miRBase v.21 database along with miRDeep2 tool to predict novel miRNAs. DEGseq R package was deployed for the identification of differentially expressed miRNAs (DEMs). Protein-protein interaction (PPI) networks were assembled using STRING and Cytoscape. A lung injury model was established using Lipopolysaccharide (LPS)-induced BEAS-2B cells, chosen for their respiratory epithelial origin and pertinent association with lung injury. The expression levels of targeted miRNA and associated proteins, TLR4, NF-κB mRNA were quantified via RT-PCR and Western Blot. Levels of IL-6, IL-1β, TNF-α, and ROS were measured using designated kits. Dual-luciferase reporter assay was conducted to examine the interaction between miRNA and proteins.

RESULTS

The comparisons between the SAPALI and the control group revealed 10 DEM, including miR-503-5p and miR-483-5p. The cytoHubba plugin in Cytoscape identified three principal miRNA-mRNA interactions: miR-483-5p with PTK2 and HDAC2; miR-28-5p with MAPK1, TP53BP1, SEMA3A; and miR-503-5p with PPP1CB, SEMA6D, EPHB2, UNC5B. The SAPALI model exhibited elevated miR-503-5p, HDAC2 and inflammatory markers, with a decline UNC5B, miR-483-5p and miR-28-5p. Transfection with miR-503-5p and miR-483-5p inhibitors increased the levels of their supposed binding proteins but not miR-28-5p inhibitor. The Dual-luciferase reporter gene assay identified the interaction of miR-503-5p with UNC5B, and miR-483-5p with HDAC2, but not miR-28-5p with TP53BP1.

CONCLUSIONS

Our study maps miRNA-mRNA interactions in SAPALI, identifying miR-503-5p and miR-483-5p as critical regulatory miRNAs.

Exploration of the Pharmacological Mechanism of Bufei Nashen Pill in Treating Chronic Obstructive Pulmonary Disease Using Network Pharmacology Integrated Molecular Docking

Objective: Based on network pharmacological analysis and molecular docking verification, the therapeutic mechanism of Bufei Nashen Pill (BFNSP) in treating chronic obstructive pulmonary disease (COPD) is discussed. Methods: First, the active ingredients and therapeutic targets of BFNSP were determined based on literature and the Chinese medicine system pharmacology database. Relevant targets of COPD were determined using GeneCard, Therapeutic Target Database and Online Mendelian Inheritance in Man (OMIM). The con-targets of BFNSP and COPD were then obtained through the Veen platform, which were implemented in Cytoscape to build “Drug-Ingredients-Potential Target network.” Target gene function enrichment analysis and signal pathway analysis were performed based on STRING database, Database for Annotation, Visualization, and Integrated Discovery, and Kyoto Encyclopedia of Genes and Genomes Pathway database. Finally, SYBYL 2.2.1 software was used to finish docking. Results: In the Drug-Ingredients-Potential Targets network, 172 active ingredients and 183 potential targets were found. Enrichment analysis showed that potential targets mainly involve biological functions such as inflammation, reactive oxygen, and immunity. Molecular docking showed that the active ingredients of BFNSP had preferential interaction with interleukin 6, mitogen-activated protein kinase 1, SRC, epidermal growth factor receptor, and matrix metalloproteinase-9. Conclusion: BFNSP can be used to treat COPD by the regulation of inflammation, immunity, and hypoxia tolerance.

Transcriptomic and physiological responses of contrasting maize genotypes to drought stress

Drought is a significant environmental stress factor that adversely affects maize productivity. However, many details regarding the molecular mechanisms of maize against drought are still unclear. In this study, leaf transcriptomics and physiological traits of two maize genotypes with differing drought resistance were analyzed. Transcriptome sequencing identified 8985 and 7305 differentially expressed genes (DEGs) in SD902 and SD609, respectively. Functional analysis suggested that numerous genes are highly involved in oxidative defense, protein modification, photosynthesis, phytohormone response, MAPK signaling, and transcription factors (TFs). Compared to SD902, SD609 had a higher expression of DEGs related to antioxidant enzymes, photosynthetic electron transport, heat shock proteins, and indole-3-acetic acid (IAA) signaling under drought conditions, which might contribute to its tolerance mechanisms to drought. Stress-induced TFs may play a crucial regulatory role in genotypic differences. Moreover, the physiological changes and gene expression abundance determined using quantitative reverse transcription polymerase chain reaction were consistent with the RNA sequencing data. The study results suggest that the higher drought tolerance of SD609 than SD902 can be attributed to stronger stress defense capabilities, IAA signal transduction, and more stable photosynthesis. Our findings provide new insights into the molecular mechanisms of maize against drought stress, and the candidate genes identified may be used in breeding drought-tolerant maize cultivars.

Knockdown of circ_0001679 alleviates lipopolysaccharide-induced MLE-12 lung cell injury by regulating the miR-338-3p/ mitogen-activated protein kinase 1 axis

The upregulation of circ_0001679 was reported in lipopolysaccharide (LPS)-induced lung injury mouse model, but its functional roles and mechanisms in LPS-induced lung injury remain to be investigated. In this study, we aimed to explore the potential role of circ_0001679 in septic acute lung injury. We initially established an in vitro lung cell injury model using LPS-treated MLE-12 cells. siRNAs targeting circRNA_0001679 were employed to stably knock down circRNA_0001679, followed by functional assays to investigate the effect of circRNA_0001679 silencing. The levels of inflammatory cytokines such as IL-6, IL-β and TNF-α (Tumor necrosis factor-α) were detected by ELISA (Enzyme-linked immunosorbent assay). Meanwhile, protein levels of Bcl-2, cleaved-caspase 3, Bax, and MAPK1 (Mitogen-Activated Protein Kinase 1) proteins expression level were measured by Western blot. We found that Circ_0001679 was upregulated in LPS-induced MLE-12 cells, and silencing circ_0001679 attenuated the growth inhibition and suppressed apoptosis induced by LPS. Circ_0001679 knockdown also lowered levels of IL-6, IL-β and TNF-α, and prevent the activation of cleaved-caspase 3 protein. We further revealed that circ_0001679 functioned as a sponge of miR-338-3p to negatively regulate miR-338-3p activity. miR-338-3p downregulated its downstream target MAPK1, while the upregulation of circ_0001679 maintained a high-level expression of MAPK1 by suppressing miR-338-3p. Collectively, our study indicates that circ_0001679/miR-338-3p/MAPK1 axis may play an important role in the pathogenesis of acute lung injury (ALI).

The molecular mechanism of Ligusticum wallichii for improving idiopathic pulmonary fibrosis: A network pharmacology and molecular docking study

BACKGROUND

At present, there was no evidence that any drugs other than lung transplantation can effectively treat Idiopathic Pulmonary Fibrosis (IPF). Ligusticum wallichii, or Chinese name Chuan xiong has been widely used in different fibrosis fields. Our aim is to use network pharmacology and molecular docking to explore the pharmacological mechanism of the Traditional Chinese medicine (TCM) Ligusticum wallichii to improve IPF.

MATERIALS AND METHODS

The main chemical components and targets of Ligusticum wallichii were obtained from TCMSP, Swiss Target Prediction and Phammapper databases, and the targets were uniformly regulated in the Uniprot protein database after the combination. The main targets of IPF were obtained through Gencards, OMIM, TTD and DRUGBANK databases, and protein interaction analysis was carried out by using String to build PPI network. Metascape platform was used to analyze its involved biological processes and pathways, and Cytoscape3.8.2 software was used to construct "component-IPF target-pathway" network. And molecular docking verification was conducted through Auto Dock software.

RESULTS

The active ingredients of Ligusticum wallichii were Myricanone, Wallichilide, Perlolyrine, Senkyunone, Mandenol, Sitosterol and FA. The core targets for it to improve IPF were MAPK1, MAPK14, SRC, BCL2L1, MDM2, PTGS2, TGFB2, F2, MMP2, MMP9, and so on. The molecular docking verification showed that the molecular docking affinity of the core active compounds in Ligusticum wallichii (Myricanone, wallichilide, Perlolyrine) was <0 with MAPK1, MAPK14, and SRC. Perlolyrine has the strongest molecular docking ability, and its docking ability with SRC (-6.59 kJ/mol) is particularly prominent. Its biological pathway to improve IPF was mainly acted on the pathways in cancer, proteoglycans in cancer, and endocrine resistance, etc.

CONCLUSIONS

This study preliminarily identified the various molecular targets and multiple pathways of Ligusticum wallichii to improve IPF.

LncRNA KCNQ1OT1 (potassium voltage-gated channel subfamily Q member 1 opposite strand/antisense transcript 1) aggravates acute kidney injury by activating p38/NF-κB pathway via miR-212-3p/MAPK1 (mitogen-activated protein kinase 1) axis in sepsis

Acute kidney injury (AKI), a common complication of sepsis, is characterized by a rapid loss of renal excretory function. A variety of etiologies and pathophysiological processes may contribute to AKI. Previously, mitogen-activated protein kinase 1 (MAPK1) was reported to regulate cellular processes in various sepsis-associated diseases. The current study aimed to further explore the biological function and regulatory mechanism of MAPK1 in sepsis-induced AKI. In our study, MAPK1 exhibited high expression in the serum of AKI patients. Functionally, knockdown of MAPK1 suppressed inflammatory response, cell apoptosis in response of lipopolysaccharide (LPS) induction in HK-2 cells. Moreover, MAPK1 deficiency alleviated renal inflammation, renal dysfunction, and renal injury in vivo. Mechanistically, MAPK1 could activate the downstream p38/NF-κB pathway. Moreover, long noncoding RNA potassium voltage-gated channel subfamily Q member 1 opposite strand/antisense transcript 1 (KCNQ1OT1) was identified to serve as a competing endogenous RNA for miR-212-3p to regulate MAPK1. Finally, rescue assays indicated that the inhibitory effect of KCNQ1OT1 knockdown on inflammatory response, cell apoptosis, and p38/NF-κB pathway was reversed by MAPK1 overexpression in HK-2 cells. In conclusion, KCNQ1OT1 aggravates acute kidney injury by activating p38/NF-κB pathway via miR-212-3p/MAPK1 axis in sepsis. Therefore, KCNQ1OT may serve as a potential biomarker for the prognosis and diagnosis of AKI patients.

Piper Kadsura Extract Inhibits miR-155 to Protect Lipopolysaccharide-Induced Acute Lung Injury

Acute lung injury (ALI) is a common and critical disease encountered in clinical practice. When the disease progresses to a more serious stage, it is called acute respiratory distress syndrome and is associated with a high mortality rate. However, there is a lack of specific drugs for treating this disease; therefore, it is very important to find safe and effective drugs for treatment. Piper kadsura (P. kadsura), part of the of the vin family Piperaceae, has a capability to dispel wind and dampness and its n-butanol extract can provide protection against inflammatory responses, such as inflammatory infiltration and hyperplasia of synovial tissue of joints. In order to explore the therapeutic effect of P. kadsura extract on ALI, we treated HPAEpiC cells with different doses of its extract. We found that after treatment using low-medium and high-dose P. kadsura extract, the optical density value was decreased in HPAEpiC cells as induced by lipopolysaccharide (LPS). In addition, the following were statistically and significantly decreased in a dose-dependent (P < 0.05): the apoptosis rate, cleaved-caspase3 expression, the expression levels of TNF-α, IL-6, and miR-155. However, procaspase 3 increased the expression of miR-155, which can promote LPS-induced apoptosis and the release of inflammatory factors in HPAEpiC cells. The overexpressed miR-155 can weaken the protection conferred by P. kadsura extract on ALI. These results suggest that P. kadsura extract may play a protective role against ALI induced by LPS by decreasing the expression of miR-155.

miR-150 and SRPK1 regulate AKT3 expression to participate in LPS-induced inflammatory response

miR-150 was found to target the 3'-untranslated regions of AKT3, and the AKT pathway was affected by SR protein kinase 1 (SRPK1). However, the expression and significance of miR-150, AKT3 and SRPK1 in acute lung injury (ALI) were not clear. Here, we found that the expression of miR-150 was significantly reduced, while the expression of AKT3 and SRPK1 were markedly increased in LPS-treated A549, THP-1 and RAW 264.7 cells. miR-150 significantly decreased levels of pro-inflammatory cytokines IL-1β, IL-6 and TNF-α, reduced the expression of AKT3, but had no impact on SRPK1 expression compared with the control group in LPS-treated A549, THP-1 and RAW 264.7 cells. AKT3 silencing only reduced the production of pro-inflammatory cytokines and showed no effect on miR-150 and SRPK1 expression. Finally, we observed that miR-150 mimics and/or silencing of SRPK1 decreased the expression of AKT3 mRNA. Besides, over-expression of miR-150 or silencing of SRPK1 also reduced the expression of AKT3 protein, which exhibited the lowest level in the miR-150 mimics plus si-SRPK1 group. However, si-SRPK1 had no effect on miR-150 level. In conclusion, miR-150 and SRPK1 separately and cooperatively participate into inflammatory responses in ALI through regulating AKT3 pathway. Increased miR-150 and silenced SRPK1 may be a novel potential factor for preventing and treating more inflammatory lung diseases.

[Mechanism and material basis of Lianhua Qingwen capsule for improving clinical cure rate of COVID-19: a study based on network pharmacology and molecular docking technology]

OBJECTIVE

To explore the potential targets, signal pathways and biological functions that mediate the effect of Lianhua Qingwen capsule in improving clinical cure rate of COVID-19 in light of network pharmacology and molecular docking technology.

METHODS

TCMSP, Target, Prediction, CooLGeN, GeneCards, DAVID and other databases were searched for the active components and their target proteins from 13 herbs including Forsythia, Honeysuckle and roasted Ephedra used in Lianhua Qingwen capsule. The common target proteins, signal pathways and biological functions shared by these components and the clinical manifestations of COVID-19 (fever, cough, and fatigue) were identified to construct the network consisting of the component drugs in Lianhua Qingwen capsule, the active ingredients of, their targets of action, and the biological functions involved using Gephi software.

RESULTS

A total 160 active components including MOL000522, and MOL003283, MOL003365, MOL003006, MOL003014 in 13 component drugs in Lianhua Qingwen capsule produced therapeutic effects against COVID-19 through 57 target proteins including MAPK1, IL6, HSP90AA1, TNF, and CCL2, involving 35 signaling pathways including NOD-like receptor signaling pathway and Toll-like receptor signaling pathway. The results of molecular docking showed that 83 chemical components had total scores no less than 5.0 for docking with 12 target proteins (including MAPK1, IL6, and HSP90AA1) with high binding activities to form stable conformations. The binding of MOL000522, MOL004989, and MOL003330 with MAPK1; MOL001495 and MOL001494 with NLRP3; MOL004908, MOL004863 and MOL004806 with HSP90AA1; MOL001749 with TLR9; and MOL001495 with AKT1 all had total scores exceeding 9.0.

CONCLUSIONS

Lianhua Qingwen capsule contains multiple effective ingredients to improve clinical cure rate of COVID-19, and its therapeutic effect is mediated by multiple protein targets, signal pathways and biological functions.

MicroRNA-320c inhibits articular chondrocytes proliferation and induces apoptosis by targeting mitogen-activated protein kinase 1 (MAPK1)

AIM

To clarify the interaction of microRNA-320c (miR-320c) and mitogen-activated protein kinase 1 (MAPK1), and to investigate the effects of miR-320c on articular chondroctye proliferation and apoptosis.

METHODS

Lentiviral expression vectors were constructed and dual luciferase assays containing MAPK1 3'-untranslated regions (3'-UTRs) were performed. Small hairpin RNA (shRNA) was utilized to modulate MAPK1 expression. The messenger RNA and protein expression levels were determined by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting respectively. Cell Counting Kit-8 and flow cytometry were conducted to detect the proliferation and apoptosis of Human Chondrocyte-articular (HC-a) cells. Besides that, the influences of miR-320c and MAPK1 on MAPK pathway activation were also evaluated.

RESULTS

Our data identified MAPK1 as a direct target gene of miR-320c, and miR-320c can negatively regulate MAPK1 expression by directly binding to MAPK1 3'-UTR in HC-a cells. Further functional study displayed that miR-320c overexpression and MAPK1 shRNA significantly suppressed the proliferation of HC-a cells and promoted cell apoptosis. Meanwhile, MAPK1 shRNA could attenuate miR-320c inhibitor promotive effects on HC-a cell proliferation and reverse its inhibitory effect on cell apoptosis. MAPK1 overexpression could rescue the inhibitory effect of miR-320c on HC-a cell proliferation, and weaken the accelerating effect of miR-320c on cell apoptosis. However, neither miR-320c or MAPK1 shRNA regulate the expression of c-JUN, JNK and c-Fos.

CONCLUSION

miR-320c inhibits articular chondrocyte proliferation and induces apoptosis by targeting MAPK1, suggesting that miR-320c perhaps participates in the pathogenesis of osteoarthritis and acts as a potential target for the therapeutic treatment of osteoarthritis.

Traditional Chinese medicine network pharmacology study on exploring the mechanism of Xuebijing Injection in the treatment of coronavirus disease 2019

As a representative drug for the treatment of severe community-acquired pneumonia and sepsis, Xuebijing (XBJ) injection is also one of the recommended drugs for the prevention and treatment of coronavirus disease 2019 (COVID-19), but its treatment mechanism for COVID-19 is still unclear. Therefore, this study aims to explore the potential mechanism of XBJ injection in the treatment of COVID-19 employing network pharmacology and molecular docking methods. The corresponding target genes of 45 main active ingredients in XBJ injection and COVID-19 were obtained by using multiple database retrieval and literature mining. 102 overlapping targets of them were screened as the core targets for analysis. Then built the PPI network, TCM-compound-target-disease, and disease-target-pathway networks with the help of Cytoscape 3.6.1 software. After that, utilized DAVID to perform gene ontology (GO) function enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis to predict the action mechanism of overlapping targets. Finally, by applying molecular docking technology, all compounds were docked with COVID-19 3 CL protease(3CLpro), spike protein (S protein), and angiotensin-converting enzyme II (ACE2). The results indicated that quercetin, luteolin, apigenin and other compounds in XBJ injection could affect TNF, MAPK1, IL6 and other overlapping targets. Meanwhile, anhydrosafflor yellow B (AHSYB), salvianolic acid B (SAB), and rutin could combine with COVID-19 crucial proteins, and then played the role of anti-inflammatory, antiviral and immune response to treat COVID-19. This study revealed the multiple active components, multiple targets, and multiple pathways of XBJ injection in the treatment of COVID-19, which provided a new perspective for the study of the mechanism of traditional Chinese medicine (TCM) in the treatment of COVID-19.

Network Pharmacology Integrated Molecular Docking Reveals the Anti-COVID-19 Mechanism of Xingnaojing Injection

In the process of fighting against COVID-19 in China, Xingnaojing injection has been recommended for its clinical treatment, but the information about its active components and mechanism is still lacking. Therefore, in this work, using network pharmacology and molecular docking, we studied the active components of Xingnaojing injection having anti-COVID-19 properties. Using the DL parameter, TCMSP and CNKI databases were used to screen the active components of the Xingnaojing injection. Then, the SwissTargetPrediction webserver was used to collect the corresponding gene targets, and the gene targets related to COVID-19 were searched in the Genecards database. The DAVID database was used to enrich the function of gene targets, and the KOBAS3.0 database for the annotation of related KEGG pathways. The “components–targets–pathways” network of Xingnaojing injection was constructed with Cytoscape 3.6.1 software. The protein–protein interaction networks were analyzed using the String database. Specific proteins, SARS-COV-2 3 Cl, ACE2, and the active components were imported into Discovery Studio 2016 Client for molecular docking studies. From the Xingnaojing injection, a total of 58 active components, including Divanillalaceton and Q27139023, were screened. These were linked to 53 gene targets including mitogen-activated protein kinase 1 (MAPK1), tumor necrosis factorTNF, epidermal growth factor receptor, MAPK3, and 196 signaling pathways related to COVID-19, such as apoptosis, C-type lectin receptor signaling pathway, and hypoxia-inducible factor 1 signaling pathway. Furthermore, molecular docking studies were performed to study potential binding between the key targets and selected active components. Xingnaojing injection exhibits anti-COVID-19 effects via multiple components, multiple targets, and multiple pathways. These results set a scientific basis for further elucidation of the anti-COVID-19 mechanism of Xingnaojing injection.

The novel circ_0028171/miR-218-5p/IKBKB axis promotes osteosarcoma cancer progression

Background

Recently, it has been demonstrated that circular RNA (circRNA) contributes to the production and progression in human cancer. However, the specific function and underlying mechanism of circ_0028171 in osteosarcoma (OS) still remain largely unclear and require to be investigated.

Methods

In our study, we confirmed differentially expressed circRNAs by microarray analysis in normal bone cells vs. OS cell lines. The expression of circ-0028171 in OS was measured by qRT-PCR. Nuclear-cytoplasmic fractionation was employed to identify the localization of circ-0028171, and RNase R and actinomycin D treatment were used to prove its circular characteristic. In vitro experiments, such as CCK-8 method, cell count, cell colony formation, transwell migration and invasion assays, and in vivo tumor models were adopted to evaluate the effect of circ_0028171. Further, luciferase reporter, RIP and RNA pull-down assays were conducted to confirm the binding sites of circ_0028171 with miR-218-5p.

Results

We found that circ_0028171 displayed a remarkably higher expression in both OS tissues and cell lines. Circ_0028171 mainly located in the cytoplasm as a stable cyclic transcript. Knockdown of circ_0028171 suppressed OS tumor growth in vitro and in vivo, while up-regulated circ_0028171 remarkably enhanced cell proliferation, migration and invasion abilities in OS. Several mechanistic experiments revealed that circ_0028171 served as a sponge of miR-218-5p to increase IKBKB expression.

Conclusions

our research reveals that circ_0028171 might promote the malignant behavior of OS tissues through miR-218-5p/IKBKB axis, which could be a potential novel marker for early diagnosis of OS.

FoxF1 protects rats from paraquat-evoked lung injury following HDAC2 inhibition via the microRNA-342/KLF5/IκB/NF-κB p65 axis

PURPOSE

Forkhead box f1 (FoxF1), a transcription factor, was implicated in lung development. However, the molecular mechanism of FoxF1 in lung injury, specifically in injury caused by paraquat (PQ), one of the most frequently used herbicides, is unknown. Accordingly, we performed this study to investigate whether FoxF1 attenuates PQ-induced lung injury and to determine the possible mechanism.

METHODS

We used PQ-treated Beas-2B cells to measure the expression of FoxF1. Later, ChIP-qPCR was applied to detect the levels of histone acetylation in cells, followed by the validation of the relationship between histone deacetylase-2 (HDAC2) and FoxF1. Subsequently, the correlation between FoxF1 and microRNA (miR)-342 and the downstream mechanism of miR-342 were evaluated by bioinformatics analysis. The apoptosis and the content of reactive oxygen species (ROS) in PQ-treated cells were detected to evaluate the roles of HDAC2, FoxF1 and miR-342 in vitro. Finally, a rat model was developed to evaluate the effects of HDAC2, miR-342 and Krüppel-like factor 5 (KLF5) on PQ-induced lung injury in vivo.

RESULTS

PQ treatment significantly enhanced FoxF1 promoter deacetylation, thereby inhibiting FoxF1 expression. After inhibition of HDAC2 activity, apoptosis and oxidative stress induced by PQ were significantly reversed. Nevertheless, further inhibition of miR-342 or overexpression of KLF5 promoted apoptosis and oxidative stress induced by PQ, and IκB/NF-κB p65 signaling was significantly activated after PQ treatment.

CONCLUSION

PQ treatment inhibited miR-342 expression by promoting HDAC2-induced deacetylation of the FoxF1 promoter, thereby promoting KLF5 expression and the IκB/NF-κB p65 signaling activation, and finally exacerbating PQ-induced lung injury in rats.