Adrenomedullin regulated by miRNA-574-3p protects premature infants with bronchopulmonary dysplasia

The vascular phenotype of BPD: new basic science insights-new precision medicine approaches

Bronchopulmonary dysplasia (BPD) is the most common complication of preterm birth. Up to 1/3 of children with BPD develop pulmonary hypertension (PH). PH increases mortality, the risk of adverse neurodevelopmental outcome and lacks effective treatment. Current vasodilator therapies address symptoms, but not the underlying arrested vascular development. Recent insights into placental biology and novel technological advances enabling the study of normal and impaired lung development at the single cell level support the concept of a vascular phenotype of BPD. Dysregulation of growth factor pathways results in depletion and dysfunction of putative distal pulmonary endothelial progenitor cells including Cap1, Cap2, and endothelial colony-forming cells (ECFCs), a subset of vascular progenitor cells with self-renewal and de novo angiogenic capacity. Preclinical data demonstrate effectiveness of ECFCs and ECFC-derived particles including extracellular vesicles (EVs) in promoting lung vascular growth and reversing PH, but the mechanism is unknown. The lack of engraftment suggests a paracrine mode of action mediated by EVs that contain miRNA. Aberrant miRNA signaling contributes to arrested pulmonary vascular development, hence using EV- and miRNA-based therapies is a promising strategy to prevent the development of BPD-PH. More needs to be learned about disrupted pathways, timing of intervention, and mode of delivery. IMPACT: Single-cell RNA sequencing studies provide new in-depth view of developmental endothelial depletion underlying BPD-PH. Aberrant miRNA expression is a major cause of arrested pulmonary development. EV- and miRNA-based therapies are very promising therapeutic strategies to improve prognosis in BPD-PH.

miR-3202 inhibits bronchopulmonary dysplasia-mediated apoptosis and oxidative stress in bronchial epithelial cells via targeting RAG1

BACKGROUND

BPD is a refractory disease affecting preterm infants with alveolar dysplasia and declined pulmonary function. However, the molecular mechanism underlying BPD is largely unknown. To explore the pathogenic mechanism of BPD and to facilitate better diagnosis and treatment of this disease.

METHOD

The DEMs and DEGs in BPD vs. Control samples from the miRNA expression data in GSE108754 and mRNA expression data in the GSE108755 were screened, followed by the construction of the miRNA-mRNA regulatory network. DEGs PPI network and hub DEGs analysis were constructed by using the STRING database and Cytoscape software. Functional and pathway enrichment analyses were then performed for these DEGs and DEMs based on the ClusterProfiler package in the R and the miRWalk database. The k-mean algorithm is used to perform clustering analysis of DEGs. Cellular experiments (flow cytometry, western blot, RT-PCR, dual-luciferase reporter assay) were used to validate the results of bioinformatics.

RESULTS

We obtained 20 DEMs and 262 DEGs. A 15 DEMs-11 DEGs regulatory network was constructed. miR-3202-RAG1 is a core sub-network. Hyperoxia induced a cell model of BPD. The upregulation of RAG1 and downregulation of miR-3202 were observed in BPD cells. Furthermore, siRNA targeting RAG1 was transfected into BEAS-2B cells to inhibit its expression and miR-3202 mimics was transfected into the cells to increase its expression. Inhibition of RAG1 and elevation of miR-3202 inhibit cell apoptosis and reduce ROS level caused by hyperoxia. A double-luciferase reporter assay revealed that miR-3202 directly targets RAG1.

CONCLUSION

The miRNA-3202/RAG1 axis contributes into BPD-induced cell apoptosis and ROS production. The present study provides a probable target for the treatment of BPD.

miRNA Signatures in Bronchopulmonary Dysplasia: Implications for Biomarkers, Pathogenesis, and Therapeutic Options

Bronchopulmonary dysplasia (BPD) is a chronic lung disease in premature infants characterized by alveolar dysplasia, vascular simplification and dysmorphic vascular development. Supplemental oxygen and mechanical ventilation commonly used as life-saving measures in premature infants may cause BPD. microRNAs (miRNAs), a class of small, non-coding RNAs, regulate target gene expression mainly through post-transcriptional repression. miRNAs play important roles in modulating oxidative stress, proliferation, apoptosis, senescence, inflammatory responses, and angiogenesis. These cellular processes play pivotal roles in the pathogenesis of BPD. Accumulating evidence demonstrates that miRNAs are dysregulated in the lung of premature infants with BPD, and in animal models of this disease, suggesting contributing roles of dysregulated miRNAs in the development of BPD. Therefore, miRNAs are considered promising biomarker candidates and therapeutic agents for this disease. In this review, we discuss how dysregulated miRNAs and their modulation alter cellular processes involved in BPD. We then focus on therapeutic approaches targeting miRNAs for BPD. This review provides an overview of miRNAs as biomarkers, and highlights potential pathogenic roles, and therapeutic strategies for BPD using miRNAs.

Grimm S, Coarfa C, Theis F, Simon LM, Shivanna B. Leveraging Integrated RNA Sequencing to Decipher Adrenomedullin's Protective Mechanisms in Experimental Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic lung disease commonly affecting premature infants, with limited therapeutic options and increased long-term consequences. Adrenomedullin (Adm), a proangiogenic peptide hormone, has been found to protect rodents against experimental BPD. This study aims to elucidate the molecular and cellular mechanisms through which Adm influences BPD pathogenesis using a lipopolysaccharide (LPS)-induced model of experimental BPD in mice. Bulk RNA sequencing of Adm-sufficient (wild-type or Adm+/+) and Adm-haplodeficient (Adm+/-) mice lungs, integrated with single-cell RNA sequencing data, revealed distinct gene expression patterns and cell type alterations associated with Adm deficiency and LPS exposure. Notably, computational integration with cell atlas data revealed that Adm-haplodeficient mouse lungs exhibited gene expression signatures characteristic of increased inflammation, natural killer (NK) cell frequency, and decreased endothelial cell and type II pneumocyte frequency. Furthermore, in silico human BPD patient data analysis supported our cell type frequency finding, highlighting elevated NK cells in BPD infants. These results underscore the protective role of Adm in experimental BPD and emphasize that it is a potential therapeutic target for BPD infants with an inflammatory phenotype.

Macrophage Polarizations in the Placenta and Lung are Associated with Bronchopulmonary Dysplasia

The intricate interplay between macrophage polarization and placenta vascular dysfunction has garnered increasing attention in the context of placental inflammatory diseases. This study delves into the complex relationship between macrophage polarization within the placenta and its potential impact on the development of vascular dysfunction and inflammatory conditions. The placenta, a crucial organ in fetal development, relies on a finely tuned balance of immune responses for proper functioning. Disruptions in this delicate equilibrium can lead to pathological conditions, including inflammatory diseases affecting the fetus and newborn infant. We explored the interconnectedness between placental macrophage polarization and its relevance to lung macrophages, particularly in the context of early life lung development. Bronchopulmonary dysplasia (BPD), the most common chronic lung disease of prematurity, has been associated with abnormal immune responses, and understanding the role of macrophages in this context is pivotal. The investigation aims to shed light on how alterations in placental macrophage polarization may contribute to lung macrophage behavior and, consequently, influence the development of BPD. By unraveling the intricate mechanisms linking macrophage polarization, placental dysfunction and BPD, this research seeks to provide insights that could pave the way for targeted therapeutic interventions. The findings may offer novel perspectives on preventing and managing placental and lung-related pathologies, ultimately contributing to improved maternal and neonatal health outcomes.

Pulmonary phenotypes of bronchopulmonary dysplasia in the preterm infant

Bronchopulmonary dysplasia (BPD) remains the most common complication of premature birth, imposing a significant and potentially life-long burden on patients and their families. Despite advances in our understanding of the mechanisms that contribute to patterns of lung injury and dysfunctional repair, current therapeutic strategies remain non-specific with limited success. Contemporary definitions of BPD continue to rely on clinician prescribed respiratory support requirements at specific time points. While these criteria may be helpful in broadly identifying infants at higher risk of adverse outcomes, they do not offer any precise information regarding the degree to which each compartment of the lung is affected. In this review we will outline the different pulmonary phenotypes of BPD and discuss important features in the pathogenesis, clinical presentation, and management of these frequently overlapping scenarios.

Involvement of miR-495 overexpression in the pathogenesis of bronchopulmonary dysplasia in preterm infants via the targeting of NEDD4L-ENaC pathway

Background

Bronchopulmonary dysplasia (BPD) is a severe pulmonary complication causing morbidity and mortality in preterm infants. A key histopathological feature of BPD is late lung growth retardation, in which the process of alveolarization is hindered and the mechanism of which is unclear. Emerging evidence indicates that microRNAs (miRNAs) promote the development of BPD via the inhibition of their target genes. MiR-495 has been reported to be involved in various lung diseases. However, the physiological function of miR-495 in BPD has not yet been fully understood.

Methods

Differentially expressed miRNAs in peripheral blood of patients with BPD were compared with those of normal controls. A dual-luciferase reporter assay was performed to identify the target genes of miR-495. A BPD neonatal rat model was established by injecting lipopolysaccharide (LPS) in the amniotic sac of pregnant rats. The morphology of the lungs was observed using hematoxylin and eosin (HE) staining. The expression of miR-495, neural precursor cell expressed developmentally down-regulated 4-like (NEDD4L), and epithelial Na⁺ channel (ENaC) was tested using quantitative reverse transcription-polymerase chain reaction (qRT-PCR), Western blot analysis, and immunofluorescent (IF) staining.

Results

The expression of miR-495 was significantly increased in the peripheral blood samples of premature infants with BPD and verified using qRT-PCR. NEDD4L was proven to be the target gene of miR-495. Additionally, miR-495 expression was also increased in the lungs of rat pups with BPD at postnatal day (P) 3 compared with the control group. qRT-PCR and Western blot results showed that NEDD4L expression was decreased while ENaC expression was increased at the transcriptional and translational levels. IF staining results showed that NEDD4L level was decreased while ENaC level was increased in the LPS-induced BPD rat model, which was consistent with abnormal changes in alveolar structure.

Conclusions

The aberrant overexpression of miR-495 may contribute to the development of BPD by targeting NEDD4L-ENaC pathway, implying an imbalance in lung fluid clearance.

LncRNA SNHG6 accelerates hyperoxia-induced lung cell injury via regulating miR-335 to activate KLF5/NF-κB pathway

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a common chronic lung disease in premature infants, and its pathogenesis has not been clarified. Long non-coding RNAs (lncRNA) have important functions in cell bioactivity. However, their role in developmental lung disease remains unclear.

OBJECTIVE

The aim of this study was to demonstrate the role of lncRNA SNHG6 (SNHG6) in BPD and its underlying mechanisms.

METHODS

The blood of patients with BPD were collected, and BPD model of BEAS-2B cells was established by hyperoxia method. SNHG6, miR-335 and KLF5 mRNA expression were detected by RT-qPCR. Western blot was conducted to measure the levels of apoptosis-related proteins' expression and NF-κB pathway related proteins. BEAS-2B cell viability and apoptosis were assessed by CCK-8 and flow cytometry, respectively. Assay Kit was applied to detect ROS, MDA and SOD levels, respectively. ELISA was performed to assess the levels of inflammatory factors. The binding site of miR-335 with SNHG6 or KLF5 were predicted by using DIANA or TargetScan, and which was verified by double luciferase reporter assay.

RESULTS

Firstly, SNHG6 was highly expressed and miR-335 was lowly expressed in BPD model, SNHG6 knockdown and miR-335 mimics both alleviated hyperoxia-induced lung cell injury, and SNHG6 targeted miR-335. Subsequently, KLF5 was targeted by miR-335, and KLF5 promoted lung cell injury via activating NF-κB pathway. Furthermore, SNHG6 mediated lung cell injury via regulating the miR-335/KLF5/NF-κB pathway.

CONCLUSION

Our research confirmed that SNHG6 mediated hyperoxia-induced lung cell injury via regulating the miR-335/KLF5/NF-κB pathway. These findings suggest that SNHG6 serves as promising targets for the treatment of newborns with BPD.

Inhibition of miR-21 improves pulmonary vascular responses in bronchopulmonary dysplasia by targeting the DDAH1/ADMA/NO pathway

miR-21 has been confirmed to be overexpressed in neonatal rat lungs with hyperoxia-mediated bronchopulmonary dysplasia (BPD). The specific function of miR-21 in BPD is still unclear. We established the hyperoxia-induced BPD rat model in vivo and the hyperoxia-induced pulmonary microvascular endothelial cells (PMVECs) model in vitro. Transwell assay was utilized to detect the migratory capability of PMVECs. Tube formation assay was utilized to measure angiogenesis ability. ELISA was utilized to test nitric oxide (NO) production and the intracellular and extracellular Asymmetric Dimethylarginine (ADMA) concentration. Furthermore, the interaction between miR-21 and dimethylarginine dimethylaminohydrolase 1 (DDAH1) was evaluated using luciferase reporter assay. We found that miR-21 expression in PMVECs was increased by hyperoxia stimulation. Inhibition of miR-21 improved the migratory and angiogenic activities of PMVECs and overexpression of miR-21 exerted the opposite effects. Furthermore, knockdown of miR-21 increased NO production and decreased intracellular and extracellular ADMA concentration in hyperoxia-treated PMVECs. Next we proved that miR-21 could bind to DDAH1 and negatively regulate its expression. Rescues assays showed that DDAH1 knockdown reversed the effects of miR-21 depletion on hyperoxia-mediated PMVEC functions, NO production, and ADMA concentration. Importantly, miR-21 downregulation restored alveolarization and vascular density in BPD rats. This study demonstrates that inhibition of miR-21 improves pulmonary vascular responses in BPD by targeting the DDAH1/ADMA/NO pathway.

Insight Into the Roles of Non-coding RNA in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic lung disease most commonly occurring in premature infants, and its pathological manifestations are alveolar hypoplasia and dysregulation of pulmonary vasculature development. The effective treatment for BPD has not yet been established. Non-coding RNAs, including microRNAs and long non-coding RNAs do not encode proteins, but can perform its biological functions at the RNA level. Non-coding RNAs play an important role in the incidence and development of BPD by regulating the expression of genes related to proliferation, apoptosis, angiogenesis, inflammation and other cell activities of alveolar epithelial cells and vascular endothelial cells. Here we summarize the role of non-coding RNAs in BPD, which provides possible molecular marker and therapeutic target for the diagnosis and treatment of BPD.

He-Jie-Shen-Shi Decoction as an Adjuvant Therapy on Severe Coronavirus Disease 2019: A Retrospective Cohort and Potential Mechanistic Study

Combination therapy using Western and traditional Chinese medicines has shown notable effects on coronavirus disease 2019 (COVID-19). The He-Jie-Shen-Shi decoction (HJSS), composed of Bupleurum chinense DC., Scutellaria baicalensis Georgi, Pinellia ternata (Thunb.) Makino, Glycyrrhiza uralensis Fisch. ex DC., and nine other herbs, has been used to treat severe COVID-19 in clinical practice. The aim of this study was to compare the clinical efficacies of HJSS combination therapy and Western monotherapy against severe COVID-19 and to study the potential action mechanism of HJSS. From February 2020 to March 2020, 81 patients with severe COVID-19 in Wuhan Tongji Hospital were selected for retrospective cohort study. Network pharmacology was conducted to predict the possible mechanism of HJSS on COVID-19-related acute respiratory distress syndrome (ARDS). Targets of active components in HJSS were screened using the Traditional Chinese Medicine Systems Pharmacology (TCMSP) and PharmMapper databases. The targets of COVID-19 and ARDS were obtained from GeneCards and Online Mendelian Inheritance in Man databases. The key targets of HJSS in COVID-19 and ARDS were obtained based on the protein–protein interaction network (PPI). Kyoto Encyclopedia of Genes and Genomes analysis (KEGG) was conducted to predict the pathways related to the targets of HJSS in COVID-19 and ARDS. A “herb-ingredient-target-pathway” network was established using Cytoscape 3.2.7. Results showed that the duration of the negative conversion time of nucleic acid was shorter in patients who received HJSS combination therapy. HJSS combination therapy also relieved fever in patients with severe COVID-19. Network pharmacology analysis identified interleukin (IL) 6, tumor necrosis factor (TNF), vascular endothelial growth factor A (VEGFA), catalase (CAT), mitogen-activated protein kinase (MAPK) 1, tumor protein p53 (TP53), CC-chemokine ligand (CCL2), MAPK3, prostaglandin-endoperoxide synthase 2 (PTGS2), and IL1B as the key targets of HJSS in COVID-19-related ARDS. KEGG analysis suggested that HJSS improved COVID-19-related ARDS by regulating hypoxia-inducible factor (HIF)-1, NOD-like receptor, TNF, T cell receptor, sphingolipid, PI3K-Akt, toll-like receptor, VEGF, FoxO, and MAPK signaling pathways. In conclusion, HJSS can be used as an adjuvant therapy on severe COVID-19. The therapeutic mechanisms may be involved in inhibiting viral replication, inflammatory response, and oxidative stress and alleviating lung injury. Further studies are required to confirm its clinical efficacies and action mechanisms.

Long non-coding RNA Rian protects against experimental bronchopulmonary dysplasia by sponging miR-421

Bronchopulmonary dysplasia (BPD) is a frequent complication characterized by accelerated lung alveolarization in newborns. Long non-coding RNAs (lncRNAs) and microRNAs (miRs) are regarded as essential regulators in various diseases, including BPD. However, the detailed mechanism of the functions of RNA imprinted and accumulated in nucleus (Rian) lncRNA in the progression of BPD have remained elusive. The aim of the present study was to illustrate the interaction between miR-421 and Rian in BPD models and MLE-12 cells. The ability of Rian to protect neonatal lungs from hyperoxia-induced lung damage was examined. A mouse model of BPD and a hyperoxia-stimulated MLE-12 cell damage model were generated and treated with specific plasmid/mimics for the overexpression of Rian/miR-421. The interaction between miR-421 and Rian was predicted and verified using StarBase and a dual-luciferase reporter assay, respectively. The expression levels of miR-421 or Rian in both tissues and the MLE-12 alveolar epithelial cell line were assessed using reverse transcription-quantitative (RT-q)PCR. As parameters of alveolarization, the mean linear intercept (MLI), radial alveolar count (RAC) and the lung weight/body weight (LW/BW) ratio were measured. Furthermore, RT-qPCR was used to measure mRNA levels of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) in the lung tissue of mice, and ELISAs were performed to determine the levels of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) in the supernatant of MLE-12 cells. Cell growth and apoptosis were evaluated using an MTT assay and flow cytometry, respectively. Furthermore, caspase-3 activity was assessed using a caspase-3 activity detection kit. Prediction with StarBase and the dual-luciferase reporter assay revealed that miR-421 directly targeted Rian. RT-qPCR analysis confirmed that Rian was downregulated and miR-421 was upregulated in lung tissues of the mouse model of BPD and in hyperoxia-induced MLE-12 cells. However, the expression of miR-421 was decreased by Rian-overexpression, an effect that was reversed by miR-421 mimics. In addition, BPD was alleviated by Rian-plasmid, as confirmed by the enhanced RAC and reduced MLI and LW/BW ratio. The present results also indicated that Rian-plasmid inhibited the secretion of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) in BPD mouse serum and hyperoxia-induced MLE-12 cells. In addition, Rian-plasmid eliminated the effect of hyperoxia to inhibit cell viability and induce apoptosis in MLE-12 cells. However, all of these effects of Rian were markedly reversed by miR-421 mimics. The present results indicated that Rian may attenuate hyperoxic damage in neonatal lungs and may serve as a novel molecular target for BPD treatment.

Long Non-coding RNA TUG1 Modulates Expression of Elastin to Relieve Bronchopulmonary Dysplasia via Sponging miR-29a-3p

Objective: Multiple studies have highlighted that long non-coding RNAs (lncRNAs) may exert paramount roles in relieving bronchopulmonary dysplasia (BPD). The aim of our investigation is to probe the role and mechanism of lncRNA taurine upregulated gene 1 (TUG1) in BPD. Methods: The current mouse model of BPD was simulated by induction of hyperoxia, and hyperoxia-induced mouse type II alveolar epithelial (MLE-12) (MLE-12) cells were established as a cellular model. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to determine relative expressions of TUG1, miR-29a-3p, and elastin (ELN). We assessed cell apoptosis by TdT-mediated dUTP-biotin nick-end labeling (TUNEL) staining. Western blot was used for detection of apoptosis-related proteins. Moreover, cell viability was tested by cell counting kit-8 (CCK-8) assay. Inflammatory factors were measured by enzyme-linked immunosorbent assay (ELISA). Dual-luciferase reporter (DLR) assay was employed to confirm relationship between genes. Results: Upregulation of miR-29a-3p was found in lung tissues of BPD mice compared with lung tissues without BPD, while downregulations of TUG1 and ELN were discovered in BPD tissues in comparison with tissues without BPD. Increasing TUG1 was shown to alleviate lung injury of BPD mice and promote proliferation of hyperoxia-induced MLE-12 cells. Meanwhile, TUG1 inhibited inflammatory response and cell apoptosis in lung tissues of BPD mice and hyperoxia-induced MLE-12 cells. miR-29a-3p was targeted by TUG1 and negatively modulated by TUG1. ELN was inversely regulated by miR-29a-3p. Meantime, suppressive effects of TUG1 on apoptosis and inflammation were reversed by decreasing ELN or increasing miR-29a-3p in hyperoxia-induced MLE-12 cells. Conclusion: lncRNA TUG1 relieved BPD through regulating the miR-29a-3p/ELN axis, which provided a therapeutic option to prevent or ameliorate BPD.