Dysregulation of microRNA-214 and PTEN contributes to the pathogenesis of hypoxic pulmonary hypertension

MFN2-dependent mitochondrial dysfunction contributes to Relm-β-induced pulmonary arterial hypertension via USP18/Twist1/miR-214 pathway

Induction of resistin-like molecule β (Relm-β) and mitofusin 2 (MFN2) mediated aberrant mitochondrial fission have been found to be involved in the pathogenesis of pulmonary arterial hypertension (PAH). However, the molecular mechanisms underlying Relm-β regulation of MFN2 therefore mitochondrial fission remain unclear. This study aims to address these issues. Primary cultured PASMCs and monocrotaline (MCT)-induced PAH rats were applied in this study. The results showed that Relm-β promoted cells proliferation in PASMCs, this was accompanied with the upregulation of USP18, Twist1 and miR-214, and downregulation of MFN2. We found that Relm-β increased USP18 expression which in turn raised Twist1 by suppressing its proteasome degradation. Elevation of Twist1 increased miR-214 expression and then reduced MFN2 expression and mitochondrial fragmentation leading to PASMCs proliferation. In vivo study, we confirmed that Relm-β was elevated in MCT-induced PAH rat model, and USP18/Twist1/miR-214/MFN2 axis was altered similar as in vitro. Targeting this cascade by Relm-β receptor inhibitor Calhex231, proteasome inhibitor MG-132, Twist1 inhibitor Harmine or miR-214 antagomiR prevented the development of pulmonary vascular remodeling and therefore PAH in MCT-treated rats. In conclusion, we demonstrate that Relm-β promotes PASMCs proliferation and vascular remodeling by activating USP18/Twist1/miR-214 dependent MFN2 reduction and mitochondrial fission, suggesting that this signaling pathway might be a promising target for management of PAH.

MicroRNAs as promising drug delivery target to ameliorate chronic obstructive pulmonary disease using nano-carriers: a comprehensive review

Chronic obstructive pulmonary disease (COPD) is a deteriorating condition triggered by various factors, such as smoking, free radicals, and air pollution. This worsening disease is characterized by narrowing and thickening of airways, painful cough, and dyspnea. In COPD, numerous genes as well as microRNA (miRNA) play a significant role in the pathogenesis of the disease. Many in vivo and in vitro studies suggest that upregulation or suppression of certain miRNAs are effective treatment options for COPD. They have been proven to be more beneficial than the current symptomatic treatments, such as bronchodilators and corticosteroids. MiRNAs play a crucial role in immune cell development and regulate inflammatory responses in various tissues. MiRNA treatment thus allows for precision therapy with improved outcomes. Nanoparticle drug delivery systems such as polymeric nanoparticles, inorganic nanoparticles, dendrimers, polymeric micelles, and liposomes are an efficient method to ensure the biodistribution of the miRNAs to the target site. Identification of the right nanoparticle depending on the requirements and compatibility is essential for achieving maximum therapeutic effect. In this review, we offer a thorough comprehension of the pathology and genetics of COPD and the significance of miRNAs concerning various pathologies of the lung, as potential targets for treating the disease. The present review offers the latest insights into the nanoparticle drug delivery systems that can efficiently carry and deliver miRNA or antagomirs to the specific target site and hence help in effective management of COPD.

miR-221-3p is upregulated in acute pulmonary embolism complicated with pulmonary hypertension and promotes pulmonary arterial smooth muscle cells proliferation and migration by inhibiting PTEN

Pulmonary arterial smooth muscle cells (PASMCs) functions are associated with the pathogenesis of pulmonary hypertension (PH) which is a life-threatening complication of acute pulmonary embolism (APE). This study sought to explore the expression pattern of microRNA (miR)-221-3p in APE-PH patients and its role in PASMCs proliferation and migration. The clinical data and venous blood of APE-PH patients were collected. The expression levels of miR-221-3p and phosphatase and tensin homolog (PTEN) in serum were determined, followed by receiver operator characteristic curve analysis of miR-221-3p diagnostic efficacy. PASMCs were transfected with miR-221-3p mimics and PTEN-overexpressed vector, followed by assessment of cell viability, proliferation, and migration through cell counting kit-8, 5-ethynyl-2'-deoxyuridine, Transwell, and wound healing assays. The binding between miR-221-3p and PTEN 3'UTR region was testified by the dual-luciferase assay. miR-221 was upregulated in the serum of APE-PH patients and presented with good diagnostic efficacy with 1.155 cutoff value, 66.25% sensitivity, and 67.50% specificity. miR-221 was negatively correlated with PTEN in APE-PH patients. miR-221 overexpression facilitated PASMCs proliferation and migration in vitro. miR-221-3p bound to PTEN 3'UTR region to decrease PTEN protein levels. PTEN overexpression abolished the promotive role of miR-221-3p in PASMCs. Overall, miR-221-3p targeted PTEN to facilitate PASMC proliferation and migration.

Research progress on the role of p53 in pulmonary arterial hypertension

PURPOSE OF REVIEW

Pulmonary arterial hypertension (PAH) is a devastating disease characterized by increased pulmonary vascular resistance and pulmonary arterial pressure. At present, the definitive pathology of PAH has not been elucidated and its effective treatment remains lacking. Despite PAHs having multiple pathogeneses, the cancer-like characteristics of cells have been considered the main reason for PAH progression.

RECENT FINDINGS

p53 protein, an important tumor suppressor, regulates a multitude of gene expressions to maintain normal cellular functions and suppress the progression of malignant tumors. Recently, p53 has been found to exert multiple biological effects on cardiovascular diseases. Since PAH shares similar metabolic features with cancer cells, the regulatory roles of p53 in PAH are mainly the induction of cell cycle, inhibition of cell proliferation, and promotion of apoptosis.

SUMMARY

This paper summarized the advanced findings on the molecular mechanisms and regulatory functions of p53 in PAH, aiming to reveal the potential therapeutic targets for PAH.

Association of Fetal Lung Development Disorders with Adult Diseases: A Comprehensive Review

Fetal lung development is a crucial and complex process that lays the groundwork for postnatal respiratory health. However, disruptions in this delicate developmental journey can lead to fetal lung development disorders, impacting neonatal outcomes and potentially influencing health outcomes well into adulthood. Recent research has shed light on the intriguing association between fetal lung development disorders and the development of adult diseases. Understanding these links can provide valuable insights into the developmental origins of health and disease, paving the way for targeted preventive measures and clinical interventions. This review article aims to comprehensively explore the association of fetal lung development disorders with adult diseases. We delve into the stages of fetal lung development, examining key factors influencing fetal lung maturation. Subsequently, we investigate specific fetal lung development disorders, such as respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), congenital diaphragmatic hernia (CDH), and other abnormalities. Furthermore, we explore the potential mechanisms underlying these associations, considering the role of epigenetic modifications, transgenerational effects, and intrauterine environmental factors. Additionally, we examine the epidemiological evidence and clinical findings linking fetal lung development disorders to adult respiratory diseases, including asthma, chronic obstructive pulmonary disease (COPD), and other respiratory ailments. This review provides valuable insights for healthcare professionals and researchers, guiding future investigations and shaping strategies for preventive interventions and long-term care.

Role of thioredoxin in chronic obstructive pulmonary disease (COPD): a promising future target

INTRODUCTION

Thioredoxin (Trx) is a secretory protein that acts as an antioxidant, redox regulator, anti-allergic, and anti-inflammatory molecule. It has been used to treat dermatitis and inflammation of the digestive tract. In the lungs, Trx has a significant anti-inflammatory impact. On the other hand, Chronic Obstructive Pulmonary Disease (COPD) is one of the significant causes of death in the developed world, with a tremendous individual and socioeconomic impact. Despite new initiatives and endless treatment trials, COPD incidence and death will likely escalate in the coming decades.

AREAS COVERED

COPD is a chronic inflammatory disease impacting the airways, lung parenchyma, and pulmonary vasculature. Oxidative stress and protease-antiprotease imbalances are thought to be involved in the process. The most popular respiratory inflammatory and allergic disorders therapies are corticosteroids and β-receptor agonists. These medications are helpful but have some drawbacks, such as infection and immunosuppression; thus, addressing Trx signalling treatments may be a viable COPD treatment approach. This review shall cover the pathophysiology of COPD, the pharmacognosy of anti-COPD drugs, including the assets and liabilities of each, and the role and mechanism of Trx in COPD treatment.

EXPERT OPINION

Limited research has targeted the thioredoxin system as an anti-COPD drug. Spectating the increase in the mortality rates of COPD, this review article would be an interesting one to research.

Critical miRNAs in regulating pulmonary hypertension: A focus on Signaling pathways and therapeutic Targets

Pulmonary hypertension (PH) is complex disease as a result of obstructive pulmonary arterial remodeling, which in turn results in elevated pulmonary arterial pressure (PAP) and subsequent right ventricular heart failure, eventually leading to premature death. However, there is still a lack of a diagnostic blood-based biomarker and therapeutic target for PH. Because of the difficulty of diagnosis, new and more easily accessible prevention and treatment strategy are being explored. New target and diagnosis biomarkers should also allow for early diagnosis. In biology, miRNAs are short endogenous RNA molecules that are not coding. It is known that miRNAs can regulate gene expression and affect a variety of biological processes. Besides, miRNAs have been proven to be a crucial factor in PH pathogenesis. miRNAs have various effects on pulmonary vascular remodeling and are expressed differentially in various pulmonary vascular cells. Nowadays, it has been shown to be critical in the functions of different miRNAs in the pathogenesis of PH. Therefore, clarifying the mechanism of miRNAs regulating pulmonary vascular remodeling is of great importance to explore new therapeutic targets of PH and improve the survival qualify and time of patients. This review is focused on the role, mechanism, and potential therapeutic targets of miRNAs in PH and puts forward possible clinical treatment strategies.

The key roles of non-coding RNAs in the pathophysiology of hypertension

Hypertension is a multifactorial condition in which several genetic and environmental elements contribute. Recent investigations have revealed contribution of non-coding region of the transcriptome in this trait. CDKN2B-AS1, AK098656, MEG3, H19, PAXIP1-AS1, TUG1, GAS5, CASC2 and CPS1-IT are among long non-coding RNAs participating in the pathophysiology of hypertension. Several miRNAs have also been found to be implicated in this disorder. miR-296, miR-637, miR-296, miR-637, hsa-miR-361-5p, miR-122-5p, miR-199a-3p, miR-208a-3p, miR-423-5p, miR-223-5p and miR-140-5p are among dysregulated miRNAs in this condition whose application as diagnostic biomarkers for hypertension has been evaluated. Finally, hsa-circ-0005870, hsa_circ_0037911 and hsa_circ_0014243 are examples of dysregulated circular RNAs in hypertensive patients. In the current review, we describe the role of these non-coding RNAs in the pathophysiology of hypertension.

PTEN: An Emerging Potential Target for Therapeutic Intervention in Respiratory Diseases

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a potent tumor suppressor that regulates several key cellular processes, including proliferation, survival, genomic integrity, migration, and invasion, via PI3K-dependent and independent mechanisms. A subtle decrease in PTEN levels or catalytic activity is implicated not only in cancer but also in a wide spectrum of other diseases, including various respiratory diseases. A systemic overview of the advances in the molecular and cellular mechanisms of PTEN involved in the initiation and progression of respiratory diseases may offer novel targets for the development of effective therapeutics for the treatment of respiratory diseases. In the present review, we highlight the novel findings emerging from current research on the role of PTEN expression and regulation in airway pathological conditions such as asthma/allergic airway inflammation, pulmonary hypertension (PAH), chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), and other acute lung injuries (ALI). Moreover, we discuss the clinical implications of PTEN alteration and recently suggested therapeutic possibilities for restoration of PTEN expression and function in respiratory diseases.

Non-Coding RNA Networks in Pulmonary Hypertension

Non-coding RNAs (ncRNAs) are involved in various cellular processes. There are several ncRNA classes, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). The detailed roles of these molecules in pulmonary hypertension (PH) remain unclear. We systematically collected and reviewed reports describing the functions of ncRNAs (miRNAs, lncRNAs, and circRNAs) in PH through database retrieval and manual literature reading. The characteristics of identified articles, especially the experimental methods, were carefully reviewed. Furthermore, regulatory networks were constructed using ncRNAs and their interacting RNAs or genes. These data were extracted from studies on pulmonary arterial smooth muscle cells, pulmonary artery endothelial cells, and pulmonary artery fibroblasts. We included 14 lncRNAs, 1 circRNA, 74 miRNAs, and 110 mRNAs in the constructed networks. Using these networks, herein, we describe the current knowledge on the role of ncRNAs in PH. Moreover, these networks actively provide an improved understanding of the roles of ncRNAs in PH. The results of this study are crucial for the clinical application of ncRNAs.

RNA Methylations in Cardiovascular Diseases, Molecular Structure, Biological Functions and Regulatory Roles in Cardiovascular Diseases

Cardiovascular diseases (CVDs) are the leading cause of morbidity and mortality in the world. Despite considerable progress in the diagnosis, treatment and prognosis of CVDs, new diagnostic biomarkers and new therapeutic measures are urgently needed to reduce the mortality of CVDs and improve the therapeutic effect. RNA methylations regulate almost all aspects of RNA processing, such as RNA nuclear export, translation, splicing and non-coding RNA processing. In view of the importance of RNA methylations in the pathogenesis of diseases, this work reviews the molecular structures, biological functions of five kinds of RNA methylations (m6A, m5C, m1a, m6am and m7G) and their effects on CVDs, including pulmonary hypertension, hypertension, vascular calcification, cardiac hypertrophy, heart failure. In CVDs, m6A “writers” catalyze the installation of m6A on RNAs, while “erasers” remove these modifications. Finally, the “readers” of m6A further influence the mRNA splicing, nuclear export, translation and degradation. M5C, m1A, m6Am and m7G are new types of RNA methylations, their roles in CVDs need to be further explored. RNA methylations have become a new research hotspot and the roles in CVDs is gradually emerging, the review of the molecular characteristics, biological functions and effects of RNA methylation on CVDs will contribute to the elucidation of the pathological mechanisms of CVDs and the discovery of new diagnostic markers and therapeutic targets of CVDs.

Rs884225 polymorphism is associated with primary hypertension by compromising interaction between epithelial growth factor receptor (EGFR) and miR-214

Genetic variations in the 3′UTR of mRNAs as well as sequences of microRNAs (miRNAs) and long non‐coding RNAs (lncRNAs) can affect gene expression by interfering with the binding between them. In this study, we investigated the role of the following polymorphisms in the risk of hypertension: the 774T > C (rs17337023) polymorphism located in the EGFR 3’ untranslated region (3’UTR), the rs884225 polymorphism located in the sequence of miR‐214, and the single nucleotide polymorphisms (SNPs) rs325797437, rs344501106, rs81286029 and rs318656749 located in the promoter of lncRNA MEG3. Taqman genotyping assays and haplotype analysis tools were used to measure the MEG3 haplotypes and the rs17337023 and rs884225 polymorphisms genotypes. The relationship between MEG3, miR‐214 and EGFR was validated using computational analysis and luciferase assays. Unlike other polymorphisms, only patients grouped according to their rs884225 genotypes exhibited varied EGFR mRNA and protein levels, which indicated that the rs884225 genotype is associated with the expression of EGFR mRNA and protein levels. MiR‐214 was confirmed to bind to MEG3 and 3’UTR of EGFR by showing that the transfection of exogenous miR‐214 significantly down‐regulated the luciferase activity of A549 and H460 cells transfected with wild‐type MEG3 or wild‐type EGFR 3’ UTR. Additionally, MEG3 overexpression inhibited miR‐214 expression while elevating the EGFR mRNA and protein expressions. Meanwhile, MEG3 down‐regulation demonstrated an opposite result, thus establishing the MEG3/miR‐214/EGRF signalling pathway. Our study confirmed that the T > C substitution of rs884225 polymorphism located in miR‐214 binding site in the 3’UTR of EGFR is associated with increased risk of primary hypertension.

Micro-RNA Analysis in Pulmonary Arterial Hypertension: Current Knowledge and Challenges

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The role of miRNAs in PAH is fast expanding, and it is increasingly difficult to identify which molecules have the highest translational potential.

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This review discusses the challenges in miRNA analysis and interpretation in PAH and highlights 4 promising miRNAs in this field.

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Additional pre-clinical studies and clinical trials are urgently needed to bring miRNAs from the bench to the bedside soon.

Pulmonary arterial hypertension (PAH) is a rare, chronic disease of the pulmonary vasculature that is associated with poor outcomes. Its pathogenesis is multifactorial and includes micro-RNA (miRNA) deregulation. The understanding of the role of miRNAs in PAH is expanding quickly, and it is increasingly difficult to identify which miRNAs have the highest translational potential. This review summarizes the current knowledge of miRNA expression in PAH, discusses the challenges in miRNA analysis and interpretation, and highlights 4 promising miRNAs in this field (miR-29, miR-124, miR-140, and miR-204).

miR-214 Protects Against Uric Acid-Induced Endothelial Cell Apoptosis

Background: Uric acid (UA) has been reported to be an important risk factor for cardiovascular diseases and can cause endothelial cell apoptosis through unclear mechanisms. Accumulating evidence has demonstrated that miR-214 plays a pivotal role in the pathogenesis of cardiovascular diseases. This study was to investigate the role of miR-214 in UA-induced endothelial cell apoptosis and the underlying mechanism.

Material and methods: We enrolled 30 patients with hyperuricemia and 32 healthy controls and analyzed the levels of miR-214 in the serum of the participants. Then mouse aorta endothelial cells (MAECs) were treated with UA to induce cell apoptosis. An miR-214 mimic and a specific COX-2 inhibitor (NS398) were used to confirm the roles of these molecules in mediating UA-induced MAEC apoptosis or COX-2/PGE₂ cascade activation.

Results: A significant reduction in circulating miR-214 in the hyperuricemia patients compared with the healthy controls, along with a negative correlation with UA levels was observed. In the MAECs, UA treatment strikingly increased apoptosis as shown by the upregulation of BAX and cleaved Caspase-3 and the increased number of apoptotic cells. Interestingly, the expression of COX-2 was also upregulated at both the protein and mRNA levels during UA-induced cell apoptosis. In addition, an miR-214 mimic blocked UA-induced MAEC apoptosis, COX-2 induction and PGE₂ secretion. The inhibition of COX-2 markedly ameliorated UA-induced apoptotic response and PGE₂ production in MAECs. Luciferase activity assays further confirmed that COX-2 is a target gene of miR-214 in endothelial cells.

Conclusion: We concluded that miR-214 could alleviate UA-induced MAEC apoptosis possibly by inhibiting the COX-2/PGE₂ cascade.

Identifying potential functional lncRNAs in metabolic syndrome by constructing a lncRNA-miRNA-mRNA network

The metabolic syndrome (MS) is a cluster of interrelated risk factors including diabetes mellitus, abdominal obesity, high cholesterol, and hypertension, which can significantly increase mortality and disability. Accumulating evidence suggest that long non-coding RNAs (lncRNAs) are involved in the pathogenesis of human metabolic diseases. However, little is known about the regulatory role of lncRNAs in MS. In this work, we proposed a method for identifying potential MS-associated lncRNAs by constructing an lncRNA-miRNA-mRNA network (LMMN). Firstly, we constructed LMMN by integrating MS-associated genes, miRNA-mRNA interactions, miRNA-lncRNA interactions and mRNA/miRNA expression profiles in patients with MS. Then, we predicted potential MS-associated lncRNAs based on the topological properties of LMMN. As a result, we identified XIST as the most important lncRNA in LMMN. Furthermore, we focused on XIST/miR-214-3p and mir-181a-5p/PTEN axis and validated their expression in MS using real-time quantitative polymerase chain reaction (RT-qPCR). The RT-qPCR results showed that the expression of XIST and PTEN was significantly decreased (P < 0.05) while the expression of miR-214-3p was significantly increased (P < 0.05) in peripheral blood mononuclear cells (PBMCs) of patients with MS, compared with healthy controls. In addition, correlation analysis showed that XIST was negatively correlated with serum C peptide and PTEN was positively correlated with BMI of MS patients. Our findings provided new evidence for further exploring the regulatory role of XIST and other lncRNAs in MS.

Puerarin attenuates hypoxia-resulted damages in neural stem cells by up-regulating microRNA-214

Puerarin has been reported to be useful in protection against hypoxia-induced injury. In our current study, we attempted to explore the protective effects of puerarin against hypoxia-caused damages in neural stem cells (NSCs). Additionally, the relative molecular underpinning studies preliminarily proceeded. NSCs were pre-incubated with puerarin before the hypoxic stimulus. MicroRNA-214 (miR-214) inhibitor was transfected into NSCs. Subsequently, the viability of NSCs was assessed by CCK-8 assay. Flow cytometry was employed to detect apoptotic cells after staining. qRT-PCR was performed to quantify miR-214. Western blot was applied for analyzing the expression of apoptosis-relative proteins and regulators. We found that puerarin alleviated hypoxia-induced apoptosis and maintained cell viability. Hypoxia-evoked up-regulation of miR-214 was further enhanced by puerarin. By contrast, miR-214-deficient NSCs showed the reduction in cell viability and the facilitation in apoptosis progress after pre-treatment with puerarin and stimulation in a hypoxia circumstance. Additionally, puerarin restored the phosphorylation of relative regulators, which was originally blunted by hypoxia. However, puerarin did not evidently restore the phosphorylation for response to hypoxia in miR-214-silenced NSCs. In conclusion, puerarin might be applied as a novel agent to ameliorate hypoxia-evoked damages in NSCs. Molecularly, miR-214 might be implicated in the protective roles of puerarin.

Pulmonary hypertension and chronic lung disease: where are we headed?

Pulmonary hypertension related to chronic lung disease, mainly represented by COPD and idiopathic pulmonary fibrosis, is associated with a worse outcome when compared with patients only affected by parenchymal lung disease. At present, no therapies are available to reverse or slow down the pathological process of this condition and most of the clinical trials conducted to date have had no clinically significant impact. Nevertheless, the importance of chronic lung diseases is always more widely recognised and, along with its increasing incidence, associated pulmonary hypertension is also expected to be growing in frequency and as a health burden worldwide. Therefore, it is desirable to develop useful and reliable tools to obtain an early diagnosis and to monitor and follow-up this condition, while new insights in the therapeutic approach are explored.

Hypoxia Promotes Vascular Smooth Muscle Cell Proliferation through microRNA-Mediated Suppression of Cyclin-Dependent Kinase Inhibitors

Regulation of vascular smooth muscle cell (VSMC) proliferation is essential to maintain vascular homeostasis. Hypoxia induces abnormal proliferation of VSMCs and causes vascular proliferative disorders, such as pulmonary hypertension and atherosclerosis. As several cyclin/cyclin-dependent kinase (CDK) complexes and CDK inhibitors (CKIs) control cell proliferation, in this study, we investigated CKIs involved in the hypoxia-induced proliferation process of human primary pulmonary artery smooth muscle cells to understand the underlying molecular mechanism. We demonstrated that p15, p16, and p21 are downregulated in pulmonary artery smooth muscle cells when exposed to hypoxia. In addition, we identified novel hypoxia-induced microRNAs (hypoxamiRs) including miR-497, miR-1268a, and miR-665 that are upregulated under hypoxia and post-transcriptionally regulate p15, p16, and p21 genes, respectively, by directly targeting their 3'UTRs. These miRNAs promoted the proliferation of VSMCs, and their inhibition decreased VSMC proliferation even in hypoxic conditions. Overall, this study revealed that miRNA-mediated regulatory mechanism of CKIs is essential for hypoxia-induced proliferation of VSMCs. These findings provide insights for a better understanding of the pathogenesis of vascular proliferative disorders.

The roles of microRNAs in the pathogenesis of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by a progressive and irreversible airflow obstruction, with an abnormal lung function. The etiology of COPD correlates with complex interactions between environmental and genetic determinants. However, the exact pathogenesis of COPD is obscure although it involves multiple aspects including oxidative stress, imbalance between proteolytic and anti-proteolytic activity, immunity and inflammation, apoptosis, and repair and destruction in both airways and lungs. Many genes have been demonstrated to be involved in those pathogenic processes of this disease in patients exposed to harmful environmental factors. Previous reports have investigated promising microRNAs (miRNAs) to disclose the molecular mechanisms for COPD development induced by different environmental exposure and genetic predisposition encounter, and find some potential miRNA biomarkers for early diagnosis and treatment targets of COPD. In this review, we summarized the expression profiles of the reported miRNAs from studies of COPD associated with environmental risk factors including cigarette smoking and air pollution exposures, and provided an overview of roles of those miRNAs in the pathogenesis of the disease. We also highlighted the potential utility and limitations of miRNAs serving as diagnostic biomarkers and therapeutic targets for COPD.

Epigenetic Regulation and Its Therapeutic Potential in Pulmonary Hypertension

Recent advances in epigenetics have made a tremendous impact on our knowledge of biological phenomena and the environmental stressors on complex diseases. Understanding the mechanism of epigenetic reprogramming during the occurrence of pulmonary hypertension (PH) is important for advanced studies and clinical therapy. In this article, we review the discovery of novel epigenetic mechanisms associated with PH including DNA methylation, histone modification, and noncoding RNA interference. In addition, we highlight the role of epigenetic mechanisms in adult PAH resulting from undesirable perinatal environments-Extrauterine growth restriction (EUGR) and Intrauterine growth retardation (IUGR). Lastly, we give a comprehensive summary for the remaining challenges and discuss future methods of epigenetic targeted therapy for pulmonary hypertension.

miR-190a-5p participates in the regulation of hypoxia-induced pulmonary hypertension by targeting KLF15 and can serve as a biomarker of diagnosis and prognosis in chronic obstructive pulmonary disease complicated with pulmonary hypertension

PURPOSE

miR-190a-5p expression alters dynamically in response to hypoxia. However, the role of miR-190a-5p expression in hypoxia-induced pulmonary hypertension (PH) remains unclear. We sought to correlate the miR-190a-5p expression levels with the severity, diagnosis, and prognosis of PH in relation to chronic obstructive pulmonary disease (COPD-PH). Additionally, we evaluated the effect of miR-190a-5p through in vitro experiments on human pulmonary endothelial cells (HPECs) that were exposed to hypoxia and in vivo experiments using an animal model of hypoxia-induced PH.

METHODS

Circulating miR-190a-5p levels were measured from 73 patients with PH and 32 healthy controls through quantitative real-time PCR. The levels of miR-190a-5p and the expression of Krüppel-like factor 15 (KLF15) were analyzed in HPECs that were exposed to hypoxia, and the effects of antagomir-190a-5p in mice with chronic hypoxia-induced PH were tested. Target gene analysis was performed by Western blot and luciferase assay.

RESULTS

The miR-190a-5p level was significantly higher in patients with COPD-PH than in the healthy controls. Higher miR-190a-5p levels were associated with a greater severity of COPD-PH. In vitro experiments on HPECs showed that exposure to hypoxia increased the miR-190a-5p levels significantly. KLF15 was validated as a target of miR-190a-5p. Transfection with miR-190a-5p mimicked inhibition of KLF15 expression in HPECs. In the mouse model of PH, antagomir-190a-5p reduced right ventricular systolic pressure and enhanced the KLF15 expression levels in lung tissue.

CONCLUSION

miR-190a-5p regulates hypoxia-induced PH by targeting KLF15. The circulating levels of miR-190a-5p correlate with the severity of COPD-PH, thereby confirming the diagnostic and prognostic value of this parameter in COPD-PH.