MiR-122-5p protects against acute lung injury via regulation of DUSP4/ERK signaling in pulmonary microvascular endothelial cells

Pulmonary miRNA expression after polytrauma depends on the surgical invasiveness and displays an anti-inflammatory pattern by the combined inhibition of C5 and CD14

Background

Respiratory failure can be a severe complication after polytrauma. Extensive systemic inflammation due to surgical interventions, as well as exacerbated post-traumatic immune responses influence the occurrence and progression of respiratory failure. This study investigated the effect of different surgical treatment modalities as well as combined inhibition of the complement component C5 and the toll-like receptor molecule CD14 (C5/CD14 inhibition) on the pulmonary microRNA (miRNA) signature after polytrauma, using a translational porcine polytrauma model.

Methods

After induction of general anesthesia, animals were subjected to polytrauma, consisting of blunt chest trauma, bilateral femur fractures, hemorrhagic shock, and liver laceration. One sham group (n=6) and three treatment groups were defined; Early Total Care (ETC, n=8), Damage Control Orthopedics (DCO, n=8), and ETC + C5/CD14 inhibition (n=4). Animals were medically and operatively stabilized, and treated in an ICU setting for 72 h. Lung tissue was sampled, miRNAs were isolated, transcribed, and pooled for qPCR array analyses, followed by validation in the individual animal population. Lastly, mRNA target prediction was performed followed by functional enrichment analyses.

Results

The miRNA arrays identified six significantly deregulated miRNAs in lung tissue. In the DCO group, miR-129, miR-192, miR-194, miR-382, and miR-503 were significantly upregulated compared to the ETC group. The miRNA expression profiles in the ETC + C5/CD14 inhibition group approximated those of the DCO group. Bioinformatic analysis revealed mRNA targets and signaling pathways related to alveolar edema, pulmonary fibrosis, inflammation response, and leukocytes recruitment. Collectively, the DCO group, as well as the ETC + C5/CD14 inhibition group, revealed more anti-inflammatory and regenerative miRNA expression profiles.

Conclusion

This study showed that reduced surgical invasiveness and combining ETC with C5/CD14 inhibition can contribute to the reduction of pulmonary complications.

MicroRNA-1258 suppresses oxidative stress and inflammation in septic acute lung injury through the Pknox1-regulated TGF-β1/SMAD3 cascade

AIM

The study was to clarify the mechanism of miR-1258 targeting Prep1 (pKnox1) to control Transforming Growth Factor β1 (TGF-β1)/SMAD3 pathway in septic Acute Lung Injury (ALI)-induced oxidative stress and inflammation.

METHODS

BEAS-2B cells and C57BL/6 mice were used to make in vitro and in vivo septic ALI models, respectively. miR-1258 expression was checked by RT-qPCR. After transfection in the in vitro experimental model, inflammation, oxidative stress, viability, and apoptosis were observed through ELISA, MTT, and flow cytometry.

RESULTS

In the in vivo model after miR-1258 overexpression treatment, inflammation, oxidative stress, and lung injury were further investigated. The targeting relationship between miR-1258 and Pknox1 was tested. Low miR-1258 was expressed in septic ALI patients, LPS-treated BEAS-2B cells, and mice. Upregulated miR-1258 prevented inflammation, oxidative stress, and apoptosis but enhanced the viability of LPS-treated BEAS-2B cells. The impact of upregulated miR-1258 on LPS-treated BEAS-2B cells was mitigated by inhibiting Pknox1 expression. MiR-1258 overexpression had the alleviating effects on inflammation, oxidative stress, and lung injury of LPS-injured mice through suppressing Pknox1 expression and TGF-β1/SMAD3 cascade activation.

CONCLUSIONS

The study concludes that miR-1258 suppresses oxidative stress and inflammation in septic ALI through the Pknox1-regulated TGF-β1/SMAD3 cascade.

MiR-122-5p as a potential regulator of pulmonary vascular wall cell in idiopathic pulmonary arterial hypertension

MicroRNAs (miRNAs) are versatile regulators of pulmonary arterial remodeling in idiopathic pulmonary arterial hypertension (IPAH). We herein aimed to characterize miRNAs in peripheral blood mononuclear cell (PBMC) and plasma exosomes, and investigate specific miRNA expression in pulmonary artery cells and lung tissues in IPAH. A co-dysregulated miRNA was identified from the miRNA expression profiles of PBMC and plasma exosomes in IPAH. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed the potential function of differentially expressed miRNAs. Real-time quantitative reverse transcription polymerase chain reaction was used to validate the expression of specific miRNAs in hypoxia-induced pulmonary microvascular endothelial cells (PMECs), pulmonary artery smooth muscle cells (PASMCs), pericyte cells (PCs), and lung tissues of patients with IPAH and rats. Finally, the miRNA-mRNA mechanisms of miR-122-5p were predicted. MiR-122-5p was the only co-upregulated miRNA in PBMC and plasma exosomes in patients with IPAH. Functional analysis of differentially expressed miRNAs revealed associations with the GO terms "transcription, DNA-templated," "cytoplasm," and "metal ion binding" in both PBMC and plasma exosomes, KEGG pathway MAPK signaling in PBMC, and KEGG-pathway human papillomavirus infection in plasma exosomes. Hypoxic PMECs and PCs, lung tissue of patients with IPAH, and rats showed increased expression of miR-122-5p, but hypoxic PASMCs showed decreased expression. And miR-122-5p mimics and inhibitor affected cell proliferation. Finally, miR-122-5p was found to potentially target DLAT (in lung tissue) and RIMS1 (in PMECs) in IPAH. According to the dual-luciferase assay, miR-122-5p bound to DLAT or RIMS1. In studies, DLAT imbalance was associated with cell proliferation and migration, RIMS1 is differentially expressed in cancer and correlated with cancer prognosis. Our findings suggest that the miR-122-5p is involved in various biological functions in the adjacent vascular wall cells in IPAH.

miR-122-5p Promotes Peripheral and Central Nervous System Inflammation in a Mouse Model of Intracerebral Hemorrhage via Disruption of the MLLT1/PI3K/AKT Signaling

Intracerebral hemorrhage (ICH) is a recognized central nervous system inflammation complication. Several microRNAs (miRNAs or miRs) have been documented to be vital modulators in peripheral and central nervous system inflammation. Based on whole transcriptome sequencing and bioinformatics analysis, this study aims to reveal the possible molecular mechanisms by which miR-122-5p affects the inflammatory response in the peripheral and central nervous system in a mouse model of ICH. Differentially expressed ICH-related miRNAs were screened. Adeno-associated viral vectors were used to knock down miR-122-5p in mice to evaluate the effect of miR-122-5p on peripheral and central nervous system inflammation. The downstream target gene of miR-122-5p was analyzed. Neurons were isolated from mice and treated with hemin to construct an in vitro model of ICH, followed by transduction with miR-122-5p mimic or combined with oe-MLLT1. The neurons were then co-cultured with microglia BV2 to assess their activation. It was found that miR-122-5p was highly expressed in ICH, and MLLT1 was lowly expressed. In vivo experiments showed that miR-122-5p knockdown decreased neurological deficits, BBB permeability, and inflammation in the peripheral and central nervous system in ICH mice. It involved its binding to MLLT1 and downregulation of the activity of the PI3K/AKT pathway. In vitro data exhibited that miR-122-5p stimulated the generation of inflammatory factors and microglia activation by targeting MLLT1 and inhibiting the PI3K/AKT pathway. Collectively, our work reveals a novel miR-122-5p/MLLT1-mediated regulatory network in ICH that may be a viable target for neuroinflammation alleviation.

Role and mechanism of WNT5A in benzo(a)pyrene-induced acute lung injury and lung function decline

Benzo(a)pyrene was sparsely studied for its early respiratory impairment. The non-canonical ligand WNT5A play a role in pneumonopathy, while its function during benzo(a)pyrene-induced adverse effects were largely unexplored. Individual benzo(a)pyrene, plasma WNT5A, and spirometry 24-hour change for 87 residents from Wuhan-Zhuhai cohort were determined to analyze potential role of WNT5A in benzo(a)pyrene-induced lung function alternation. Normal bronchial epithelial cell lines were employed to verify the role of WNT5A after benzo(a)pyrene treatment. RNA sequencing was adopted to screen for benzo(a)pyrene-related circulating microRNAs and differentially expressed microRNAs between benzo(a)pyrene-induced cells and controls. The most potent microRNA was selected for functional experiments and target gene validation, and their mechanistic link with WNT5A-mediated non-canonical Wnt signaling was characterized through rescue assays. We found significant associations between increased benzo(a)pyrene and reduced 24-hour changes of FEF50% and FEF75%, as well as increased WNT5A. The benzo(a)pyrene-induced inflammation and epithelial-mesenchymal transition in BEAS-2B and 16HBE cells were attenuated by WNT5A silencing. hsa-miR-122-5p was significantly and positively associated with benzo(a)pyrene and elevated after benzo(a)pyrene induction, and exerted its effect by downregulating target gene TP53. Functionally, WNT5A participates in benzo(a)pyrene-induced lung epithelial injury via non-canonical Wnt signaling modulated by hsa-miR-122-5p/TP53 axis, showing great potential as a preventive and therapeutic target.

Integrated Analysis of Non-Coding RNA and mRNA Expression Profiles in Exosomes from Lung Tissue with Sepsis-Induced Acute Lung Injury

Background

Acute lung injury (ALI) is associated with a high mortality rate; however, the underlying molecular mechanisms are poorly understood. The purpose of this study was to investigate the expression profile and related networks of long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and mRNAs in lung tissue exosomes obtained from sepsis-induced ALI.

Methods

A mouse model of sepsis was established using the cecal ligation and puncture method. RNA sequencing was performed using lung tissue exosomes obtained from mice in the sham and CLP groups. Hematoxylin-eosin staining, Western blotting, immunofluorescence, quantitative real-time polymerase chain reaction, and nanoparticle tracking analysis were performed to identify relevant phenotypes, and bioinformatic algorithms were used to evaluate competitive endogenous RNA (ceRNA) networks.

Results

Thirty lncRNA-miRNA-mRNA interactions were identified, including two upregulated lncRNAs, 30 upregulated miRNAs, and two downregulated miRNAs. Based on the expression levels of differentially expressed mRNAs(DEmRNAs), differentially expressed LncRNAs(DELncRNAs), and differentially expressed miRNAs(DEmiRNAs), 30 ceRNA networks were constructed.

Conclusion

Our study revealed, for the first time, the expression profiles of lncRNA, miRNA, and mRNA in exosomes isolated from the lungs of mice with sepsis-induced ALI, and the exosome co-expression network and ceRNA network related to ALI in sepsis.

Inhibition of MicroRNA-122-5p Relieves Myocardial Ischemia-Reperfusion Injury via SOCS1

OBJECTIVE

 Evidence has shown that microRNA (miR)-122-5p is a diagnostic biomarker of acute myocardial infarction. Here, we aimed to uncover the functions of miR-122-5p in the pathological process of myocardial ischemia-reperfusion injury (MI/RI).

METHODS

 An MI/RI model was established by left anterior descending coronary artery ligation in mice. The levels of miR-122-5p, suppressor of cytokine signaling-1 (SOCS1), phosphorylation of Janus kinase 2 (p-JAK2), and signal transducers and activators of transcription (p-STAT3) in the myocardial tissues of mice were measured. Downregulated miR-122-5p or upregulated SOCS1 recombinant adenovirus vectors were injected into mice before MI/RI modeling. The cardiac function, inflammatory response, myocardial infarction area, pathological damage, and cardiomyocyte apoptosis in the myocardial tissues of mice were evaluated. Cardiomyocytes were subjected to hypoxia/reoxygenation (H/R) injury and cardiomyocyte biological function was tested upon transfection of miR-122-5p inhibitor. The target relation between miR-122-5p and SOCS1 was evaluated.

RESULTS

 miR-122-5p expression and p-JAK2 and p-STAT3 expression were high, and SOCS1 expression was low in the myocardial tissues of MI/RI mice. Decreasing miR-122-5p or increasing SOCS1 expression inactivated the JAK2/STAT3 pathway to alleviate MI/RI by improving cardiac function and reducing inflammatory reaction, myocardial infarction area, pathological damage, and cardiomyocyte apoptosis in mice. Silencing of SOCS1 reversed depleted miR-122-5p-induced cardioprotection for MI/RI mice. In vitro experiments revealed that the downregulation of miR-122-5p induced proliferative, migratory, and invasive capabilities of H/R cardiomyocytes while inhibiting apoptosis. Mechanically, SOCS1 was a target gene of miR-122-5p.

CONCLUSION

 Our study summarizes that inhibition of miR-122-5p induces SOCS1 expression, thereby relieving MI/RI in mice.

Inhibition of microRNA-122 alleviates pyroptosis by targeting dual-specificity phosphatase 4 in myocardial ischemia/reperfusion injury

Pyroptosis is a type of programmed cell death that induces myocardial ischemia-reperfusion injury (I/RI), which leads to cardiac dysfunction and even lethal reperfusion injury. MiR-122 is a liver-specific miRNA associated with coronary heart disease, but its role in pyroptosis activation in myocardial I/RI remains unclear. Thus, this study aimed to determine whether miR-122 inhibition exerts myocardial I/RI protection in in vivo and in vitro models. An I/RI model was established in vivo using C57BL/J6 male mice. MiR-122 expression was upregulated in the heart tissues from the I/RI group. Quantitative results of echocardiography parameters showed that miR-122 inhibition improved cardiac function and downregulated interleukin (IL)-1β, IL-18, caspase 1, and caspase 11. However, pretransfection with recombinant adeno-associated virus type 9 encoding a DUSP4-specific siRNA (AAV9-siDUSP4) blocked the protective effects of miR-122 inhibition. A hypoxia/reoxygenation (H/R) model was established to mimic the I/R condition in vitro using H9C2 cells. Results showed that miR-122 inhibition increased superoxide dismutase activity (SOD) and cell viability and decreased malondialdehyde (MDA) level, IL-1β, IL-18, caspase 1, caspase 11, and cell death. These protective effects were abolished by transfection with DUSP4-specific siRNA. In summary, miR-122 expression is upregulated in I/RI, and miR-122 inhibition alleviates I/RI by suppressing pyroptosis through targeting DUSP4. Thus, miR-122 may be a novel therapeutic target for treating myocardial I/RI.

Identification of key microRNAs in exosomes derived from patients with the severe acute pancreatitis

OBJECTIVE

Exosomes have been identified as important carriers of various genetic materials, including microRNAs (miRNAs). Increasing evidence indicates that the course of severe acute pancreatitis (SAP) is associated with miRNAs transported by exosomes. We aimed to identify the signature miRNAs as biomarkers of SAP.

METHODS

We obtained exosomes from the SAP patients' blood. After separation, purification, and identification, we performed high-throughput sequencing and screened the differentially expressed(DE) miRNAs in the exosomes. Bioinformatics analysis was performed to identified the target genes of the miRNAs and the pathways enriched based on Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses, and selected the key miRNAs related to SAP. Total RNA was extracted from patient serum exosomes to detect the expression levels of the selected miRNAs in exosomes of three experimental groups (mild -, moderately severe -, and severe AP) and a control group, using Real-time quantitative polymerase chain reaction (RT-qPCR).

RESULTS

272 DE miRNAs were identified between SAP and control group. Using bioinformatics analysis, we determined that the functions of the target genes were enriched in six signaling pathways including focal adhesion. Based on this, seven candidate signature miRNAs were selected: miR-603, miR-548ad-5p, miR-122-5p, miR-4477a, miR-192-5p, miR-215-5p, and miR-583. The RT-qPCR results of the seven miRNAs in the SAP group were consistent with the sequencing results.

CONCLUSION

Exosome-derived miR-603, miR-548ad-5p, miR-122-5p, miR-4477a, miR-192-5p, miR-215-5p, miR-583 are positively correlated with SAP, which might provide new insights into the pathogenesis of SAP and serve as the biomarkers of SAP.

Exosomal let-7f-5p derived from mineralized osteoblasts promotes the angiogenesis of endothelial cells via the DUSP1/Erk1/2 signaling pathway

Blood vessel formation is the prerequisite for the survival and growth of tissue-engineered bone. Mineralized osteoblasts (MOBs) have been shown to regulate angiogenesis through the secretion of exosomes containing various pro-angiogenic factors. However, whether the mineralized osteoblast-derived exosomes (MOB-Exos) containing let-7f-5p can regulate the angiogenesis of endothelial cells (ECs) is still unknown. In this study, the angiogenic capabilities of ECs respectively treated with MOB-Exos, let-7f-5p mimicked MOB-Exos (miR mimic group), and let-7f-5p inhibited MOB-Exos (miR inhibitor group) were compared through in vitro and in vivo studies. Moreover, the potential mechanism of MOB-Exo let-7f-5p regulating angiogenesis was explored by verifying the role of the Erk1/2 signaling pathway and target gene DUSP1. The results showed that MOB-Exos could significantly promote the angiogenesis of ECs, which could be enhanced by mimicked exosomal let-7f-5p and attenuated by inhibited exosomal let-7f-5p. Let-7f-5p could suppress the luciferase activity of wide-type DUSP1, and the mutation of DUSP1 could abrogate the repressive ability of let-7f-5p. Furthermore, the expression of DUSP1 exhibited a reversed trend to that of pErk1/2. The expression of pErk1/2 was significantly higher in the miR mimic group and lower in the miR inhibitor group than that in the MOB-Exos group, while inhibition of pErk1/2 could partly impair the angiogenic capabilities of ECs. In conclusion, we concluded that exosomal let-7f-5p derived from MOBs could promote the angiogenesis of ECs via activating the DUSP1/Erk1/2 signaling pathway, which might be a promising target for promoting the angiogenesis of tissue-engineered bone.

Fighting Fire with Fire: Exosomes and Acute Pancreatitis-Associated Acute Lung Injury

Acute pancreatitis (AP) is a prevalent clinical condition of the digestive system, with a growing frequency each year. Approximately 20% of patients suffer from severe acute pancreatitis (SAP) with local consequences and multi-organ failure, putting a significant strain on patients' health insurance. According to reports, the lungs are particularly susceptible to SAP. Acute respiratory distress syndrome, a severe type of acute lung injury (ALI), is the primary cause of mortality among AP patients. Controlling the mortality associated with SAP requires an understanding of the etiology of AP-associated ALI, the discovery of biomarkers for the early detection of ALI, and the identification of potentially effective drug treatments. Exosomes are a class of extracellular vesicles with a diameter of 30-150 nm that are actively released into tissue fluids to mediate biological functions. Exosomes are laden with bioactive cargo, such as lipids, proteins, DNA, and RNA. During the initial stages of AP, acinar cell-derived exosomes suppress forkhead box protein O1 expression, resulting in M1 macrophage polarization. Similarly, macrophage-derived exosomes activate inflammatory pathways within endothelium or epithelial cells, promoting an inflammatory cascade response. On the other hand, a part of exosome cargo performs tissue repair and anti-inflammatory actions and inhibits the cytokine storm during AP. Other reviews have detailed the function of exosomes in the development of AP, chronic pancreatitis, and autoimmune pancreatitis. The discoveries involving exosomes at the intersection of AP and acute lung injury (ALI) are reviewed here. Furthermore, we discuss the therapeutic potential of exosomes in AP and associated ALI. With the continuous improvement of technological tools, the research on exosomes has gradually shifted from basic to clinical applications. Several exosome-specific non-coding RNAs and proteins can be used as novel molecular markers to assist in the diagnosis and prognosis of AP and associated ALI.

Distinct miRNAs associated with various clinical presentations of SARS-CoV-2 infection

MicroRNAs (miRNAs) have been shown to play important roles in viral infections, but their associations with SARS-CoV-2 infection remain poorly understood. Here, we detected 85 differentially expressed miRNAs (DE-miRNAs) from 2,336 known and 361 novel miRNAs that were identified in 233 plasma samples from 61 healthy controls and 116 patients with COVID-19 using the high-throughput sequencing and computational analysis. These DE-miRNAs were associated with SASR-CoV-2 infection, disease severity, and viral persistence in the patients with COVID-19, respectively. Gene ontology and KEGG pathway analyses of the DE-miRNAs revealed their connections to viral infections, immune responses, and lung diseases. Finally, we established a machine learning model using the DE-miRNAs between various groups for classification of COVID-19 cases with different clinical presentations. Our findings may help understand the contribution of miRNAs to the pathogenesis of COVID-19 and identify potential biomarkers and molecular targets for diagnosis and treatment of SARS-CoV-2 infection.

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2,336 known and 361 novel miRNAs identified in this study

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85 miRNAs associated with COVID-19

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A panel of miRNAs targeting the viral or cellular genes

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Machine learning using miRNAs for classification of COVID-19

Long noncoding RNA Kcnq1ot1 prompts lipopolysaccharide-induced acute lung injury by microRNA-7a-5p/Rtn3 axis

Background

Long noncoding RNA (lncRNA)-regulated mechanism in acute lung injury (ALI) has attracted special interests in study researches. We planned to disclose whether KCNQ1 overlapping transcript 1 (Kcnq1ot1) is involved in ALI and its mechanism.

Methods

The lipopolysaccharide (LPS)-induced ALI model was established in mice. Kcnq1ot1, microRNA (miR)-7a-5p and Reticulon 3 (Rtn3) levels were measured in lung tissues of mice. The vector that changed Kcnq1ot1, miR-7a-5p and Rtn3 expression was injected into LPS-treated mice, and pathological damage, fibrosis, apoptosis and inflammatory response were subsequently examined in lung tissues. The relation between Kcnq1ot1 and miR-7a-5p, and that between miR-7a-5p and Rtn3 were identified.

Results

Kcnq1ot1 and Rtn3 expression increased while miR-7a-5p expression decreased in LPS-treated mice. Reduced Kcnq1ot1 or elevated miR-7a-5p alleviated pathological damage, fibrosis, apoptosis and inflammatory response in ALI mice, while overexpressed Rtn3 worsened ALI in mice. Downregulation of Rtn3 reversed the exacerbation of miR-7a-5p downregulation in ALI mice. Kcnq1ot1 competitively bound to miR-7a-5p and miR-7a-5p negatively mediated Rtn3 expression.

Conclusion

Our experiments evidence that silencing Kcnq1ot1 upregulates miR-7a-5p to suppress Rtn3 expression, thereby diminishing LPS-induced ALI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-022-00653-8.

Novel Insights Into the Pathogenesis of Diabetic Cardiomyopathy and Pharmacological Strategies

Diabetic cardiomyopathy (DCM) is a severe complication of diabetes developed mainly in poorly controlled patients. In DCM, several clinical manifestations as well as cellular and molecular mechanisms contribute to its phenotype. The production of reactive oxygen species (ROS), chronic low-grade inflammation, mitochondrial dysfunction, autophagic flux inhibition, altered metabolism, dysfunctional insulin signaling, cardiomyocyte hypertrophy, cardiac fibrosis, and increased myocardial cell death are described as the cardinal features involved in the genesis and development of DCM. However, many of these features can be associated with broader cellular processes such as inflammatory signaling, mitochondrial alterations, and autophagic flux inhibition. In this review, these mechanisms are critically discussed, highlighting the latest evidence and their contribution to the pathogenesis of DCM and their potential as pharmacological targets.

DUSP4 alleviates LPS-induced chondrocyte injury in knee osteoarthritis via the MAPK signaling pathway

Knee osteoarthritis (KOA) is characterized by cartilage damage, and the associated pathogenesis is complex. The expression of dual specificity protein phosphatase 4 (DUSP4) is significantly decreased in osteoarthritis (OA); however, the specific role and mechanism underlying DUSP4 in OA are yet to be elucidated. ATDC5 cells were treated with lipopolysaccharide (LPS) to establish the cell injury model. The expression levels of DUSP4 were decreased in OA chondrocytes, demonstrated by reverse transcription-quantitative PCR and western blot analysis. Following overexpression of DUSP4 by cell transfection, Cell Counting Kit-8, ELISA, TUNEL and western blotting assays were used to detect the cell viability, oxidative stress, inflammation and apoptosis levels of LPS-induced ATDC5 cells. Overexpression of DUSP4 inhibited the activation of the MAPK signaling pathway, thereby reducing oxidative stress levels, inflammatory response and apoptosis in the OA cell model. The mechanisms underlying DUSP4 in OA were further explored following the addition of MAPK signaling pathway agonist, phorbol 12-myristate 13-acetate (PMA). The addition of PMA reversed the inhibitory effects of DUSP4 overexpression on oxidative stress, inflammatory response and apoptosis in cells. In summary, DUSP4 alleviated LPS-induced chondrocyte injury in KOA via the MAPK signaling pathway.

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.

A Blood Exosomal miRNA Signature in Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is a diffuse, acute, inflammatory lung disease characterized by a severe respiratory failure. Recognizing and promptly treating ARDS is critical to combat the high mortality associated with the disease. Despite a significant progress in the treatment of ARDS, our ability to identify early patients and predict outcomes remains limited. The development of novel biomarkers is crucial. In this study, we profiled microRNA (miRNA) expression of plasma-derived exosomes in ARDS disease by small RNA sequencing. Sequencing of 8 ARDS patients and 10 healthy subjects (HSs) allowed to identify 12 differentially expressed exosomal miRNAs (adjusted p < 0.05). Pathway analysis of their predicted targets revealed enrichment in several biological processes in agreement with ARDS pathophysiology, such as inflammation, immune cell activation, and fibrosis. By quantitative RT-PCR, we validated the alteration of nine exosomal miRNAs in an independent cohort of 15 ARDS patients and 20 HSs, among which seven present high capability in discriminating ARDS patients from HSs (area under the curve > 0.8) (miR-130a-3p, miR-221-3p, miR-24-3p, miR-98-3p, Let-7d-3p, miR-1273a, and miR-193a-5p). These findings highlight exosomal miRNA dysregulation in the plasma of ARDS patients which provide promising diagnostic biomarkers and open new perspectives for the development of therapeutics.

Inhibition of micro RNA miR-122-5p prevents lipopolysaccharide-induced myocardial injury by inhibiting oxidative stress, inflammation and apoptosis via targeting GIT1

Myocardial injury resulting from sepsis is the leading cause of death worldwide. Micro RNA miR-122-5p is involved in various physiological and pathological processes and is highly expressed in the heart of septic rats. However, its function in sepsis-caused myocardial injury remains elusive. Herein, a rat model of septic myocardial injury was established by intraperitoneal injection of lipopolysaccharide (LPS), and cardiomyocyte H9c2 was exposed to LPS to induce sepsis-related inflammatory injury in vitro. Inhibition of miR-122-5p suppressed LPS-triggered myocardial injury evidenced by decreased heart weight index (HWI), reduced inflammatory cell infiltration and cell rupture, and reduced cardiac marker enzymes cTnI and LDH. MiR-122-5p inhibition inhibited ROS production and enhanced the activities of antioxidant enzymes CAT, SOD and GSH-px in LPS-treated rats and H9c2 cells. MiR-122-5p inhibition reduced the production of pro-inflammatory cytokines TNF-α, IL-6 and IL-1β, and inhibited cell apoptosis along with decreased cleaved-caspase 3 induced by LPS. Moreover, increased GIT1 expression was found following miR-122-5p inhibition. We further verified GIT1 as a target of miR-122-5p, and silencing GIT1 partially reversed the benefits of miR-122-5p loss in LPS-injured H9c2 cells. The HO-1 and NQO-1 expression and Nrf-2 activation were enhanced by miR-122-5p inhibition, which was reversed by GIT1 depletion, indicating the involvement of Nrf-2/HO-1 signaling in regulating miR-122-5p/GIT1-mediated cardioprotection. Taken together, our data suggest that inhibition of miR-122-5p may mitigate sepsis-triggered myocardial injury through inhibiting inflammation, oxidative stress and apoptosis via targeting GIT1, which provides a possible therapeutic target for sepsis.

Recent updates on the role of extracellular vesicles in the pathogenesis of allergic asthma

Asthma is a chronic inflammatory disease of the airway diagnosed with different endotypes and phenotypes, characterized by airway obstruction in response to allergens, bacterial/viral infections, or pollutants. Several cell types such as the airway epithelial cells, mesenchymal stem cells and different immune cells including dendritic cells (DCs), T and B cells and mast cells play an essential role during the pathobiology of asthma. Extracellular vesicles (EVs) are membranous nanovesicles produced by every cell type that facilitates intercellular communications. EVs contain heterogeneous cargos that primarily depend on the composition or cell type of origin and they can alter the physiological state of the target cells. EVs encompass a wide variety of proteins including Tetraspanins, MHC classes I and II, co-stimulatory molecules, nucleic acids such as RNA, miRNA, piRNA, circRNA, and lipids like ceramides and sphingolipids. Recent literature indicates that EVs play a pivotal role in the pathophysiology of allergic asthma and may potentially be used as a novel biomarker to determine endotypes and phenotypes in severe asthmatics. Based on the prior reports, we speculate that regulation of EVs biogenesis and release might be under the control of circadian rhythms. Thus, circadian rhythms may influence the composition of the EVs, which alter the microenvironment that results in the induction of an immune-inflammatory response to various environmental insults or allergens such as air pollutants, ozone, diesel exhaust particles, pollens, outdoor molds, environmental tobacco smoke, etc. In this mini-review, we summarize the recent updates on the novel role of EVs in the pathogenesis of asthma, and highlight the link between circadian rhythms and EVs that may be important to identify molecular mechanisms to target during the pathogenesis of chronic inflammatory lung disease such as asthma.

Transcriptome sequencing reveals differential expression of circRNAs in sepsis induced acute respiratory distress syndrome

circRNAs play important roles in regulating gene expression at both transcriptional and post transcriptional levels and involve in a variety of human diseases. But up to now, it is still unclear whether circRNAs are involved in the occurrence and development of sepsis induced acute respiratory distress syndrome (ARDS). In the present research, we collected lung tissues of sepsis induced ARDS patients (n = 3) and brain dead patients without ARDS (n = 3). From the results of genome-wide sequencing, a total of 272 significantly up-regulated and 231 significantly down-regulated circRNAs were obtained. Combining the previous sequencing results in the plasma of ARDS patients, 11 up-regulated and 3 down-regulated circRNAs simultaneously in plasma and lung tissues were identified. Pathway enrichment analysis showed that the co differentially expressed circRNAs might be involved in the regulation of ECM-receptor interaction and adherens junction etc. In conclusion, these data indicates that circRNAs may involve in the progression of sepsis induced ARDS.

MiR-122-5p Mitigates Inflammation, Reactive Oxygen Species and SH-SY5Y Apoptosis by Targeting CPEB1 After Spinal Cord Injury Via the PI3K/AKT Signaling Pathway

Spinal cord injury (SCI) is a threatening disease that lead to severe motor and sensory deficits. Previous research has revealed that miRNAs are involved in the pathogenesis of a variety of diseases. However, whether miR-122-5p was involved in SCI was rarely investigated. In our study, we intended to probe role of miR-122-5p in the regulation of inflammatory response, reactive oxygen species (ROS) and SH-SY5Y apoptosis. We found miR-122-5p was downregulated in SCI mouse model and LPS-induced SH-SY5Y cells. Moreover, miR-122-5p overexpression alleviated inflammatory response, ROS and SH-SY5Y apoptosis in SCI mice. In addition, miR-122-5p elevation also mitigated SCI in LPS-induced SH-SY5Y cells. Additionally, cytoplasmic polyadenylation element binding protein 1 (CPEB1) was verified to be a target of miR-122-5p. CPEB1 expression was upregulated in SCI mouse model and LPS-induced SH-SY5Y cells. CPEB1 expression was negatively related to miR-122-5p expression. Moreover, CPEB1 activated the PI3K/AKT signaling pathway in SH-SY5Y cells. Finally, CPEB1 elevation recovered the suppressive effect on inflammatory response, ROS and SH-SY5Y apoptosis in LPS-treated SH-SY5Y cells mediated by miR-122-5p upregulation and through the PI3K/AKT signaling pathway.