Expression profiling of microRNAs in lipopolysaccharide-induced acute lung injury after hypothermia treatment

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.

Mechanism of chlorogenic acid reducing lipopolysaccharideinduced acute lung injury in mice by regulating miR223/NLRP3 axis

OBJECTIVES

Chlorogenic acid has various physiological activities such as antibacterial, anti-inflammatory, and antiviral activities. Studies have shown that chlorogenic acid can alleviate the inflammatory response of mice with acute lung injury (ALI), but the specific mechanism is still unclear. This study aims to investigate whether chlorogenic acid attenuates lipopolysaccharide (LPS)-induced ALI in mice by regulating the microRNA-223 (miR-223)/nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) axis.

METHODS

SPF grade BALBc male mice were randomly divided into a control group, a model group, a chlorogenic acid group, a chlorogenic acid+miR-223 negative control (miR-223 NC) group, and a chlorogenic acid+miR-223 inhibitor (miR-223 antagomir) group, 10 mice in each group. Except the control group, the other groups were instilled with 4 mg/kg LPS through the airway to establish the ALI mouse model. After the modeling, the mice in the chlorogenic acid group were continuously given chlorogenic acid (100 mg/kg) by gavage for 7 d. The chlorogenic acid+miR-223 NC group and the chlorogenic acid+miR-223 antagomir group were given 100 mg/kg chlorogenic acid by gavage every day, and then were injected with 10 μL of miR-223 NC (0.5 nmol/μL) and miR-223 antagomir (0.5 nmol/μL) respectively for 7 consecutive days.The control group and the model group were replaced with normal saline. The lung tissues of mice were taken to measure the ratios of lung wet to dry weight (W/D). The bronchoalveolar lavage fluid of mice was collected to measure the levels of TNF-α, IL-6, and IL-1β by ELISA kit and to count the number of eosinophils (EOS), lymphocytes, neutrophils under light microscope. After HE staining, the pathological changes of lung tissues were observed and lung injury was scored. qRT-PCR method were used to determine the expression levels of miR-223 in lung tissues. Western blotting was used to determine the expression levels of NLRP3 protein in mouse lung tissues. Luciferase reporter assay was used to analyze the targeting relationship of miR-223 to NLRP3.

RESULTS

Compared with the control group, the lung W/D value, the lung injury score and the level of inflammatory factors in the bronchoalveolar lavage fluid were significantly increased in the model group (all P<0.05); the infiltration of inflammatory cells in the lung tissue was severe; the alveolar space was significantly increased; the alveolar wall was significantly thickened; the number of EOS, lymphocytes, and neutrophils in the bronchoalveolar lavage fluid was significantly increased (all P<0.05); the expression levels of miR-223 in lung tissue were significantly decreased (P<0.05); and the protein expression levels of NLRP3 were significantly increased (P<0.05). Compared with the model group, the W/D value of lungs, lung injury score, and levels of inflammatory factors in bronchoalveolar lavage fluid were significantly decreased in the chlorogenic acid group, the chlorogenic acid+miR-223 NC group, and the chlorogenic acid+miR-223 antagomir group (all P<0.05); lung tissues damage was alleviated; the numbers of EOS, lymphocytes, and neutrophils in bronchoalveolar lavage fluid were significantly decreased (all P<0.05); the expression levels of miR-223 in lung tissues were significantly increased (P<0.05); and the expression levels of NLRP3 protein were significantly decreased (P<0.05). Compared with the chlorogenic acid group, the lung W/D value, lung injury score, and inflammatory factor levels in the bronchoalveolar lavage fluid were significantly increased in the chlorogenic acid+miR-223 antagomir group (all P<0.05); lung tissue damage was aggravated; the number of EOS, lymphocytes and neutrophils in bronchoalveolar lavage fluid significantly increased (all P<0.05); the expression levels of miR-223 in lung tissues were significantly decreased (P<0.05); and the expression levels of NLRP3 protein were significantly increased (P<0.05). The results of luciferase reporter assay showed that miR-223 had a targeting relationship with NLRP3.

CONCLUSIONS

Chlorogenic acid may increase the level of miR-223, target the inhibition of NLRP3 expression, reduce LPS-induced inflammatory response in ALI mice, and alleviate pathological damage of lung tissues.

Inhibition of miRNA-34a Promotes M2 Macrophage Polarization and Improves LPS-Induced Lung Injury by Targeting Klf4

Acute respiratory distress syndrome (ARDS) is an outcome of an accelerated immune response that starts initially as a defensive measure, however, due to non-canonical signaling, it later proves to be fatal not only to the affected tissue but to the whole organ system. microRNAs are known for playing a decisive role in regulating the expression of genes involved in diverse functions such as lung development, repair, and inflammation. In-silico analyses of clinical data and microRNA databases predicted a probable interaction between miRNA-34a (miR-34a), mitogen-activated protein kinase 1 (ERK), and kruppel like factor 4 (Klf4). Parallel to in silico results, here, we show that intra-tracheal instillation of lipopolysaccharides (LPS) to mice enhanced miR-34a expression in lung macrophages. Inhibition of miR-34a significantly improved lung histology, whereas over-expression of miR-34a worsened the lung injury phenotype. miR-34a over-expression in macrophages were also demonstrated to favour pro-inflammatory M1 phenotype and inhibition of M2 polarization. In a quest to confirm this likely interaction, expression profiles of Klf4 as the putative target were analyzed in different macrophage polarizing conditions. Klf4 expression was found to be prominent in the miR-34a inhibitor-treated group but down-regulated in the miR-34a mimic treated group. Immuno-histopathological analyses of lung tissue from the mice treated with miR-34a inhibitor also showed reduced inflammatory M1 markers as well as enhanced cell proliferation. The present study indicates that miR-34a intensified LPS-induced lung injury and inflammation by regulating Klf4 and macrophage polarization, which may serve as a potential therapeutic target for acute lung injury/ARDS.

Characterization of MicroRNA and Gene Expression Profiles Following Ricin Intoxication

Ricin, derived from the castor bean plant, is a highly potent toxin, classified as a potential bioterror agent. Current methods for early detection of ricin poisoning are limited in selectivity. MicroRNAs (miRNAs), which are naturally occurring, negative gene expression regulators, are known for their tissue specific pattern of expression and their stability in tissues and blood. While various approaches for ricin detection have been investigated, miRNAs remain underexplored. We evaluated the effect of pulmonary exposure to ricin on miRNA expression profiles in mouse lungs and peripheral blood mononuclear cells (PBMCs). Significant changes in lung tissue miRNA expression levels were detected following ricin intoxication, specifically regarding miRNAs known to be involved in innate immunity pathways. Transcriptome analysis of the same lung tissues revealed activation of several immune regulation pathways and immune cell recruitment. Our work contributes to the understanding of the role of miRNAs and gene expression in ricin intoxication.

MicroRNA-653 Inhibits Thymocyte Proliferation and Induces Thymocyte Apoptosis in Mice with Autoimmune Myasthenia Gravis by Downregulating TRIM9

OBJECTIVES

Myasthenia gravis (MG) is an organ-specific autoimmune neuromuscular disorder that occurs as a result of the impairment in neuromuscular junction and autoantibody attack on the postsynaptic receptors. Increasing evidence suggests that microRNAs (miRs) might be involved in the development of MG. Therefore, the present study aimed to investigate the regulatory function of miR-653 on MG and its relationship with tripartite motif 9 (TRIM9).

METHODS

The thymic tissues obtained from MG patients with thymic hyperplasia were prepared for establishing an MG mouse model in BALB/c mice. Afterwards, the miR-653 and TRIM9 expressions were determined in thymic tissues. A dual-luciferase reporter assay was carried out to validate whether miR-653 directly targets TRIM9. Finally, the thymocytes were exposed to mimics or inhibitors of miR-653, or siRNA against TRIM9 with the use of MTT assays and flow cytometry for the verification of the gain or loss function of miR-653 and TRIM9 on viability, cell cycle progression, and apoptosis of thymocytes.

RESULTS

There was a decrease in thymocyte miR-653 and an increase in TRIM9 in thymic tissues of MG mice. miR-653 was found to negatively regulate TRIM9. Overexpression of miR-653 or depletion of TRIM9 resulted in the inhibition of cell viability, suppression of cell cycle progression, and induction of apoptosis rate in thymocytes.

CONCLUSION

The findings from the present study provided evidence that miR-653 impairs proliferation and promotes apoptosis of thymocytes of MG mice by suppressing TRIM9, indicating that miR-653 could be used as potential therapeutic target in the treatment of autoimmune MG.

Essential Oils as Repellents against Arthropods

The development of effective and safe repellents against arthropods is very important, because there are no effective vaccines against arthropod-borne viruses (arboviruses) and parasites. Arboviruses and parasites are transmitted to humans from arthropods, and mosquitoes are the most common arthropods associated with dengue, malaria, and yellow fever. Enormous efforts have been made to develop effective repellents against arthropods, and thus far synthetic repellents have been widely used. However, the use of synthetic repellents has raised several concerns in terms of environmental and human health risks and safety. Thus, plant essential oils (EOs) have been widely used as an alternative to synthetic repellents. In this review, we briefly introduce and summarize recent studies that have investigated EOs as insect repellents. Current technology and research trends to develop effective and safe repellents from plant EOs are also described in this review.