Reduced microRNA-150 is associated with poor survival in pulmonary arterial hypertension

Identification of circulating microRNA-126-3p as a new biomarker for coronary artery calcification

Objective

Several circulating microRNAs, including microRNA-126-3p, have been identified as diagnostic and prognostic biomarker of cardiovascular disease. However, whether microRNA-126-3p is an independent risk predictor for coronary artery calcification is unclear.

Methods

In this prospective single-center study, we collected blood samples from coronary artery atherosclerosis patients (n = 54), patients with coronary artery calcification (n = 33) and controls (n = 56). Total RNA was extracted from plasma and blood cells with TRIzol reagents. The microRNA-126-3p level was determined via quantitative real-time polymerase chain reaction (RT-PCR).

Results

MicroRNA-126-3p levels were significantly increased in patients with coronary artery calcification than in coronary artery atherosclerosis patients or controls. The highest expression of microRNA-126-3p was observed in patients with moderate calcification who were diagnosed with Grade 2 calcification by coronary angiography. Age, microRNA-126-3p expression in veins, hypertension and diabetes significantly influence the occurrence of coronary artery calcification, among which diabetes and venous microRNA-126-3p expression were found to be independent risk factors for coronary artery calcification.

Conclusions

Taken together, the data in this study suggest that circulating microRNA-126-3p may be a novel noninvasive biomarker for coronary artery calcification. Regulating microRNA-126-3p expression may be an effective and promising strategy for the diagnosis and treatment of cardiovascular diseases, especially coronary artery calcification.

Orai1/STIMs modulators in pulmonary vascular diseases

Calcium (Ca2+) is a secondary messenger that regulates various cellular processes. However, Ca2+ mishandling could lead to pathological conditions. Orai1 is a Ca2+channel contributing to the store-operated calcium entry (SOCE) and plays a critical role in Ca2+ homeostasis in several cell types. Dysregulation of Orai1 contributed to severe combined immune deficiency syndrome, some cancers, pulmonary arterial hypertension (PAH), and other cardiorespiratory diseases. During its activation process, Orai1 is mainly regulated by stromal interacting molecule (STIM) proteins, especially STIM1; however, many other regulatory partners have also been recently described. Increasing knowledge about these regulatory partners provides a better view of the downstream signalling pathways of SOCE and offers an excellent opportunity to decipher Orai1 dysregulation in these diseases. These proteins participate in other cellular functions, making them attractive therapeutic targets. This review mainly focuses on Orai1 regulatory partners in the physiological and pathological conditions of the pulmonary circulation and inflammation.

Two prospective, multicenter studies for the identification of biomarker signatures for early detection of pulmonary hypertension (PH): The CIPHER and CIPHER-MRI studies

A blood test identifying patients at increased risk of pulmonary hypertension (PH) could streamline the investigative pathway. The prospective, multicenter CIPHER study aimed to develop a microRNA-based signature for detecting PH in breathless patients and enrolled adults with a high suspicion of PH who had undergone right heart catheterization (RHC). The CIPHER-MRI study was added to assess the performance of this CIPHER signature in a population with low probability of having PH who underwent cardiac magnetic resonance imaging (cMRI) instead of RHC. The microRNA signature was developed using a penalized linear regression (LASSO) model. Data were modeled both with and without N-terminal pro-brain natriuretic peptide (NT-proBNP). Signature performance was assessed against predefined thresholds (lower 98.7% CI bound of ≥0.73 for sensitivity and ≥0.53 for specificity, based on a meta-analysis of echocardiographic data), using RHC as the true diagnosis. Overall, 926 CIPHER participants were screened and 888 were included in the analysis. Of 688 RHC-confirmed PH cases, approximately 40% were already receiving PH treatment. Fifty microRNA (from 311 investigated) were algorithmically selected to be included in the signature. Sensitivity [97.5% CI] of the signature was 0.85 [0.80-0.89] for microRNA-alone and 0.90 [0.86-0.93] for microRNA+NT-proBNP, and the corresponding specificities were 0.33 [0.24-0.44] and 0.28 [0.20-0.39]. Of 80 CIPHER-MRI participants with evaluable data, 7 were considered PH-positive by cMRI whereas 52 were considered PH-positive by the microRNA signature. Due to low specificity, the CIPHER miRNA-based signature for PH (either with or without NT-proBNP in model) did not meet the prespecified diagnostic threshold for the primary analysis.

CVD phenotyping in oncologic disorders: cardio-miRNAs as a potential target to improve individual outcomes in revers cardio-oncology

With the increase of aging population and prevalence of obesity, the incidence of cardiovascular disease (CVD) and cancer has also presented an increasing tendency. These two different diseases, which share some common risk factors. Relevant studies in the field of reversing Cardio-Oncology have shown that the phenotype of CVD has a significant adverse effect on tumor prognosis, which is mainly manifested by a positive correlation between CVD and malignant progression of concomitant tumors. This distal crosstalk and the link between different diseases makes us aware of the importance of diagnosis, prediction, management and personalized treatment of systemic diseases. The circulatory system bridges the interaction between CVD and cancer, which suggests that we need to fully consider the systemic and holistic characteristics of these two diseases in the process of clinical treatment. The circulating exosome-miRNAs has been intrinsically associated with CVD -related regulation, which has become one of the focuses on clinical and basic research (as biomarker). The changes in the expression profiles of cardiovascular disease-associated miRNAs (Cardio-miRNAs) may adversely affect concomitant tumors. In this article, we sorted and screened CVD and tumor-related miRNA data based on literature, then summarized their commonalities and characteristics (several important pathways), and further discussed the conclusions of Cardio-Oncology related experimental studies. We take a holistic approach to considering CVD as a risk factor for tumor malignancy, which provides an in-depth analysis of the various regulatory mechanisms or pathways involved in the dual attribute miRNAs (Cardio-/Onco-miRNAs). These mechanisms will be key to revealing the systemic effects of CVD on tumors and highlight the holistic nature of different diseases. Therefore, the Cardio-miRNAs should be given great attention from researchers in the field of CVD and tumors, which might become new targets for tumor treatment. Meanwhile, based on the principles of precision medicine (such as the predictive preventive personalized medicine, 3PM) and reverse Cardio-oncology to better improve individual outcomes, we should consider developing personalized medicine and systemic therapy for cancer from the perspective of protecting cardiovascular function.

MicroRNAs and their regulators: Potential therapeutic targets in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a complex and progressive disease characterized by pulmonary arterial remodeling. Despite that current combination therapy has shown improvement in morbidity and mortality, a better deciphering of the underlying pathological mechanisms and novel therapeutic targets is urgently needed to combat PAH. MicroRNA, the critical element in post-transcription mechanisms, mediates cellular functions mainly by tuning downstream target gene expression. Meanwhile, upstream regulators can regulate miRNAs in synthesis, transcription, and function. In vivo and in vitro studies have suggested that miRNAs and their regulators are involved in PAH. However, the miRNA-related regulatory mechanisms governing pulmonary vascular remodeling and right ventricular dysfunction remain elusive. Hence, this review summarized the controversial roles of miRNAs in PAH pathogenesis, focused on different miRNA-upstream regulators, including transcription factors, regulatory networks, and environmental stimuli, and finally proposed the prospects and challenges for the therapeutic application of miRNAs and their regulators in PAH treatment.

miRNAs orchestration of cardiovascular diseases - Particular emphasis on diagnosis, and progression

MicroRNAs (miRNAs; miRs) are small non-coding ribonucleic acids sequences vital in regulating gene expression. They are significant in many biological and pathological processes and are even detectable in various body fluids such as serum, plasma, and urine. Research has demonstrated that the irregularity of miRNA in multiplying cardiac cells is linked to developmental deformities in the heart's structure. It has also shown that miRNAs are crucial in diagnosing and progressing several cardiovascular diseases (CVDs). The review covers the function of miRNAs in the pathophysiology of CVD. Additionally, the review provides an overview of the potential role of miRNAs as disease-specific diagnostic and prognostic biomarkers for human CVD, as well as their biological implications in CVD.

SPRR1A is a key downstream effector of MiR-150 during both maladaptive cardiac remodeling in mice and human cardiac fibroblast activation

MicroRNA-150 (miR-150) is conserved between rodents and humans, is significantly downregulated during heart failure (HF), and correlates with patient outcomes. We previously reported that miR-150 is protective during myocardial infarction (MI) in part by decreasing cardiomyocyte (CM) apoptosis and that proapoptotic small proline-rich protein 1a (Sprr1a) is a direct CM target of miR-150. We also showed that Sprr1a knockdown in mice improves cardiac dysfunction and fibrosis post-MI and that Sprr1a is upregulated in pathological mouse cardiac fibroblasts (CFs) from ischemic myocardium. However, the direct functional relationship between miR-150 and SPRR1A during both post-MI remodeling in mice and human CF (HCF) activation was not established. Here, using a novel miR-150 knockout;Sprr1a-hypomorphic (Sprr1a^hypo/hypo) mouse model, we demonstrate that Sprr1a knockdown blunts adverse post-MI effects caused by miR-150 loss. Moreover, HCF studies reveal that SPRR1A is upregulated in hypoxia/reoxygenation-treated HCFs and is downregulated in HCFs exposed to the cardioprotective β-blocker carvedilol, which is inversely associated with miR-150 expression. Significantly, we show that the protective roles of miR-150 in HCFs are directly mediated by functional repression of profibrotic SPRR1A. These findings delineate a pivotal functional interaction between miR-150 and SPRR1A as a novel regulatory mechanism pertinent to CF activation and ischemic HF.

Cytokines as prognostic biomarkers in pulmonary arterial hypertension

BACKGROUND

Risk stratification and assessment of disease progression in patients with pulmonary arterial hypertension (PAH) are challenged by the lack of accurate disease-specific and prognostic biomarkers. To date, brain natriuretic peptide (BNP) and/or its N-terminal fragment (NT-proBNP) are the only markers for right ventricular dysfunction used in clinical practice, in association with echocardiographic and invasive haemodynamic variables to predict outcome in patients with PAH.

METHODS

This study was designed to identify an easily measurable biomarker panel in the serum of 80 well-phenotyped PAH patients with idiopathic, heritable or drug-induced PAH at baseline and at first follow-up. The prognostic value of identified cytokines of interest was secondly analysed in an external validation cohort of 125 PAH patients.

RESULTS

Among the 20 biomarkers studied with the multiplex Ella platform, we identified a three-biomarker panel composed of β-NGF, CXCL9 and TRAIL that were independently associated with prognosis both at the time of PAH diagnosis and at the first follow-up after initiation of PAH therapy. β-NGF and CXCL9 were predictors of death or transplantation, whereas high levels of TRAIL were associated with a better prognosis. Furthermore, the prognostic value of the three cytokines was more powerful for predicting survival than usual non-invasive variables (New York Heart Association Functional Class, 6-min walk distance and BNP/NT-proBNP). The results were validated in a fully independent external validation cohort.

CONCLUSION

The monitoring of β-NGF, CXCL9 and TRAIL levels in serum should be considered in the management and treatment of patients with PAH to objectively guide therapeutic options.

Circulatory miR-411-5p as a Novel Prognostic Biomarker for Major Adverse Cardiovascular Events in Patients with Atrial Fibrillation

The risk stratification of patients with atrial fibrillation (AF) for subsequent cardiovascular events could help in guiding prevention strategies. In this study, we aimed at investigating circulating microRNAs as prognostic biomarkers for major adverse cardiovascular events (MACE) in AF patients. We conducted a three-stage nested case-control study within the framework of a prospective registry, including 347 AF patients. First, total small RNA-sequencing was performed in 26 patients (13 cases with MACE) and the differential expression of microRNAs was analyzed. Seven candidate microRNAs with promising results in a subgroup analysis on cardiovascular death were selected and measured via using RT-qPCR in 97 patients (42 cases with cardiovascular death). To further validate our findings and investigate broader clinical applicability, we analyzed the same microRNAs in a subsequent nested case-control study of 102 patients (37 cases with early MACE) by using Cox regression. In the microRNA discovery cohort (n = 26), we detected 184 well-expressed microRNAs in circulation without overt differential expression between the cases and controls. A subgroup analysis on cardiovascular death revealed 26 microRNAs that were differentially expressed at a significance level < 0.05 (three of which with an FDR-adjusted p-value <0.05). We, therefore, proceeded with a nested case-control approach (n = 97) focusing on patients with cardiovascular death and selected, in total, seven microRNAs for further RT-qPCR analysis. One microRNA, miR-411-5p, was significantly associated with cardiovascular death (adjusted HR (95% CI): 1.95 (1.04-3.67)). Further validation (n = 102) in patients who developed early MACE showed similar results (adjusted HR (95% CI) 2.35 (1.17-4.73)). In conclusion, circulating miR-411-5p could be a valuable prognostic biomarker for MACE in AF patients.

Transcription factors in the pathogenesis of pulmonary arterial hypertension-Current knowledge and therapeutic potential

Pulmonary arterial hypertension (PAH) is a disease characterized by elevated pulmonary vascular resistance and pulmonary artery pressure. Mortality remains high in severe cases despite significant advances in management and pharmacotherapy. Since currently approved PAH therapies are unable to significantly reverse pathological vessel remodeling, novel disease-modifying, targeted therapeutics are needed. Pathogenetically, PAH is characterized by vessel wall cell dysfunction with consecutive remodeling of the pulmonary vasculature and the right heart. Transcription factors (TFs) regulate the process of transcribing DNA into RNA and, in the pulmonary circulation, control the response of pulmonary vascular cells to macro- and microenvironmental stimuli. Often, TFs form complex protein interaction networks with other TFs or co-factors to allow for fine-tuning of gene expression. Therefore, identification of the underlying molecular mechanisms of TF (dys-)function is essential to develop tailored modulation strategies in PAH. This current review provides a compendium-style overview of TFs and TF complexes associated with PAH pathogenesis and highlights their potential as targets for vasculoregenerative or reverse remodeling therapies.

MiR-150 blunts cardiac dysfunction in mice with cardiomyocyte loss of β1-adrenergic receptor/β-arrestin signaling and controls a unique transcriptome

The β₁-adrenergic receptor (β₁AR) is found primarily in hearts (mainly in cardiomyocytes [CMs]) and β-arrestin-mediated β₁AR signaling elicits cardioprotection through CM survival. We showed that microRNA-150 (miR-150) is upregulated by β-arrestin-mediated β₁AR signaling and that CM miR-150 inhibits maladaptive remodeling post-myocardial infarction. Here, we investigate whether miR-150 rescues cardiac dysfunction in mice bearing CM-specific abrogation of β-arrestin-mediated β₁AR signaling. Using CM-specific transgenic (TG) mice expressing a mutant β₁AR (G protein-coupled receptor kinase [GRK]^-β₁AR that exhibits impairment in β-arrestin-mediated β₁AR signaling), we first generate a novel double TG mouse line overexpressing miR-150. We demonstrate that miR-150 is sufficient to improve cardiac dysfunction in CM-specific GRK^-β₁AR TG mice following chronic catecholamine stimulation. Our genome-wide circular RNA, long noncoding RNA (lncRNA), and mRNA profiling analyses unveil a subset of cardiac ncRNAs and genes as heretofore unrecognized mechanisms for beneficial actions of β₁AR/β-arrestin signaling or miR-150. We further show that lncRNA Gm41664 and GDAP1L1 are direct novel upstream and downstream regulators of miR-150. Lastly, CM protective actions of miR-150 are attributed to repressing pro-apoptotic GDAP1L1 and are mitigated by pro-apoptotic Gm41664. Our findings support the idea that miR-150 contributes significantly to β₁AR/β-arrestin-mediated cardioprotection by regulating unique ncRNA and gene signatures in CMs.

Biomarker-based approach to determine etiology and severity of pulmonary hypertension: Focus on microRNA

Pulmonary arterial hypertension (PAH) is characterized by remodeling of the pulmonary arteries, and defined by elevated pulmonary arterial pressure, measured during right heart catheterization. There are three main challenges to the diagnostic and therapeutic process of patients with PAH. First, it is difficult to differentiate particular PAH etiology. Second, invasive diagnostic is required to precisely determine the severity of PAH, and thus to qualify patients for an appropriate treatment. Third, the results of treatment of PAH are unpredictable and remain unsatisfactory. MicroRNAs (miRNAs) are small non-coding RNAs that regulate post transcriptional gene-expression. Their role as a prognostic, and diagnostic biomarkers in many different diseases have been studied in recent years. MiRNAs are promising novel biomarkers in PAH due to their activity in various molecular pathways and processes underlying PAH. Lack of biomarkers to differentiate between particular PAH etiology and evaluate the severity of PAH, as well as paucity of therapeutic targets in PAH open a new field for the possibility to use miRNAs in these applications. In our article, we discuss the potential of miRNAs use as diagnostic tools, prognostic biomarkers and therapeutic targets in PAH.

Emerging Roles of Micrornas in Veterinary Cardiology

Simple Summary

MicroRNAs are promising novel biomarkers for the diagnosis and prognosis of cardiovascular diseases. These molecules are defined as a class of short-sequence non-coding RNAs that influence the expression of numerous genes. The growing understanding of cardiac biology contributed to recognising specific abnormal microRNA expression when diseases are present, which makes them potential biomarkers and therapeutical targets. Recent studies have analysed and discussed microRNA expression in cardiac diseases, such as myxomatous mitral valve disease, which are prevalent in our animal companions. This review summarises the most relevant microRNAs related to cardiovascular diseases in dogs and cats. In addition, it describes microRNA’s basic biology and function and discusses their potential as circulating biomarkers for diagnosis, prognosis and monitorisation of treatment, as well as their limitations. Although current studies describe microRNA expression in veterinary cardiology, further work is warranted before they are implemented in the clinical setting.

Abstract

Over the last years, the importance of microRNAs (miRNAs) has increasingly been recognised. Each miRNA is a short sequence of non-coding RNA that influences countless genes’ expression and, thereby, contributes to several physiological pathways and diseases. It has been demonstrated that miRNAs participate in the development of many cardiovascular diseases (CVDs). This review synopsises the most recent studies emphasising miRNA’s influence in several CVDs affecting dogs and cats. It provides a concise outline of miRNA’s biology and function, the diagnostic potential of circulating miRNAs as biomarkers, and their role in different CVDs. It also discusses known and future roles for miRNAs as potential clinical biomarkers and therapeutic targets. So, this review gives a comprehensive outline of the most relevant miRNAs related to CVDs in Veterinary Medicine.

Circulating Microparticles Are Differentially Increased in Lowlanders and Highlanders with High Altitude Induced Pulmonary Hypertension during the Cold Season

The role of microparticles (MPs) and cold in high altitude pulmonary hypertension (HAPH) remains unexplored. We investigated the impact of long-term cold exposure on the pulmonary circulation in lowlanders and high-altitude natives and the role of MPs. Pulmonary hemodynamics were evaluated using Doppler echocardiography at the end of the colder and warmer seasons. We further examined the miRNA content of MPs isolated from the study participants and studied their effects on human pulmonary artery smooth muscle (hPASMCs) and endothelial cells (hPAECs). Long-term exposure to cold environment was associated with an enhanced pulmonary artery pressure in highlanders. Plasma levels of CD62E-positive and CD68-positive MPs increased in response to cold in lowlanders and HAPH highlanders. The miRNA-210 expression contained in MPs differentially changed in response to cold in lowlanders and highlanders. MPs isolated from lowlanders and highlanders increased proliferation and reduced apoptosis of hPASMCs. Further, MPs isolated from warm-exposed HAPH highlanders and cold-exposed highlanders exerted the most pronounced effects on VEGF expression in hPAECs. We demonstrated that prolonged exposure to cold is associated with elevated pulmonary artery pressures, which are most pronounced in high-altitude residents. Further, the numbers of circulating MPs are differentially increased in lowlanders and HAPH highlanders during the colder season.

MiR-150 Attenuates Maladaptive Cardiac Remodeling Mediated by Long Noncoding RNA MIAT and Directly Represses Profibrotic Hoxa4

BACKGROUND

MicroRNA-150 (miR-150) plays a protective role in heart failure (HF). Long noncoding RNA, myocardial infarction-associated transcript (MIAT) regulates miR-150 function in vitro by direct interaction. Concurrent with miR-150 downregulation, MIAT is upregulated in failing hearts, and gain-of-function single-nucleotide polymorphisms in MIAT are associated with increased risk of myocardial infarction (MI) in humans. Despite the correlative relationship between MIAT and miR-150 in HF, their in vivo functional relationship has never been established, and molecular mechanisms by which these 2 noncoding RNAs regulate cardiac protection remain elusive.

METHODS

We use MIAT KO (knockout), Hoxa4 (homeobox a4) KO, MIAT TG (transgenic), and miR-150 TG mice. We also develop DTG (double TG) mice overexpressing MIAT and miR-150. We then use a mouse model of MI followed by cardiac functional, structural, and mechanistic studies by echocardiography, immunohistochemistry, transcriptome profiling, Western blotting, and quantitative real-time reverse transcription-polymerase chain reaction. Moreover, we perform expression analyses in hearts from patients with HF. Lastly, we investigate cardiac fibroblast activation using primary adult human cardiac fibroblasts and in vitro assays to define the conserved MIAT/miR-150/HOXA4 axis.

RESULTS

Using novel mouse models, we demonstrate that genetic overexpression of MIAT worsens cardiac remodeling, while genetic deletion of MIAT protects hearts against MI. Importantly, miR-150 overexpression attenuates the detrimental post-MI effects caused by MIAT. Genome-wide transcriptomic analysis of MIAT null mouse hearts identifies Hoxa4 as a novel downstream target of the MIAT/miR-150 axis. Hoxa4 is upregulated in cardiac fibroblasts isolated from ischemic myocardium and subjected to hypoxia/reoxygenation. HOXA4 is also upregulated in patients with HF. Moreover, Hoxa4 deficiency in mice protects the heart from MI. Lastly, protective actions of cardiac fibroblast miR-150 are partially attributed to the direct and functional repression of profibrotic Hoxa4.

CONCLUSIONS

Our findings delineate a pivotal functional interaction among MIAT, miR-150, and Hoxa4 as a novel regulatory mechanism pertinent to ischemic HF.

MicroRNAs in Pulmonary Hypertension, from Pathogenesis to Diagnosis and Treatment

Pulmonary hypertension (PH) is a fatal and untreatable disease, ultimately leading to right heart failure and eventually death. microRNAs are small, non-coding endogenous RNA molecules that can regulate gene expression and influence various biological processes. Changes in microRNA expression levels contribute to various cardiovascular disorders, and microRNAs have been shown to play a critical role in PH pathogenesis. In recent years, numerous studies have explored the role of microRNAs in PH, focusing on the expression profiles of microRNAs and their signaling pathways in pulmonary artery smooth muscle cells (PASMCs) or pulmonary artery endothelial cells (PAECs), PH models, and PH patients. Moreover, certain microRNAs, such as miR-150 and miR-26a, have been identified as good candidates of diagnosis biomarkers for PH. However, there are still several challenges for microRNAs as biomarkers, including difficulty in normalization, specificity in PH, and a lack of longitudinal and big sample-sized studies. Furthermore, microRNA target drugs are potential therapeutic agents for PH treatment, which have been demonstrated in PH models and in humans. Nonetheless, synthetic microRNA mimics or antagonists are susceptible to several common defects, such as low drug efficacy, inefficient drug delivery, potential toxicity and especially, off-target effects. Therefore, finding clinically safe and effective microRNA drugs remains a great challenge, and further breakthrough is urgently needed.

MiRNAs in Systemic Sclerosis Patients with Pulmonary Arterial Hypertension: Markers and Effectors

Background: Pulmonary arterial hypertension (PAH) is a major cause of death in systemic sclerosis (SSc). Early detection may improve patient outcomes. Methods: We searched for circulating miRNAs that would constitute biomarkers in SSc patients with PAH (SSc-PAH). We compared miRNA levels and laboratory parameters while evaluating miRNA levels in white blood cells (WBCs) and myofibroblasts. Results: Our study found: 1) miR-26 and miR-let-7d levels were significantly lower in SSc-PAH (n = 12) versus SSc without PAH (SSc-noPAH) patients (n = 25); 2) a positive correlation between miR-26 and miR-let-7d and complement-C3; 3) GO-annotations of genes that are miR-26/miR-let-7d targets and that are expressed in myofibroblast cells, suggesting that these miRNAs regulate the TGF-β-pathway; 4) reduced levels of both miRNAs accompanied fibroblast differentiation to myofibroblasts, while macitentan (endothelin receptor-antagonist) increased the levels. WBCs of SSc-noPAH and SSc-PAH patients contained equal amounts of miR-26/miR-let-7d. During the study, an echocardiograph that predicted PAH development, showed increased pulmonary artery pressure in three SSc-noPAH patients. At study initiation, those patients and an additional SSc-noPAH patient, who eventually developed PAH, had miR-let-7d/miR-26 levels similar to those of SSc-PAH patients. This implies that reduced miR-let-7d/miR-26 levels might be an early indication of PAH. Conclusions: miR-26 and miR-let-7d may be serological markers for SSc-PAH. The results of our study suggest their involvement in myofibroblast differentiation and complement pathway activation, both of which are active in PAH development.

MicroRNA-663 prevents monocrotaline-induced pulmonary arterial hypertension by targeting TGF-β1/smad2/3 signaling

OBJECTIVE

Pulmonary vascular remodeling due to excessive growth factor production and pulmonary artery smooth muscle cells (PASMCs) proliferation is the hallmark feature of pulmonary arterial hypertension (PAH). Recent studies suggest that miR-663 is a potent modulator for tumorigenesis and atherosclerosis. However, whether miR-663 involves in pulmonary vascular remodeling is still unclear.

METHODS AND RESULTS

By using quantitative RT-PCR, we found that miR-663 was highly expressed in normal human PASMCs. In contrast, circulating level of miR-663 dramatically reduced in PAH patients. In addition, in situ hybridization showed that expression of miR-663 was decreased in pulmonary vasculature of PAH patients. Furthermore, MTT and cell scratch-wound assay showed that transfection of miR-663 mimics significantly inhibited platelet derived growth factor (PDGF)-induced PASMCs proliferation and migration, while knockdown of miR-663 expression enhanced these effects. Mechanistically, dual-luciferase reporter assay revealed that miR-663 directly targets the 3'UTR of TGF-β1. Moreover, western blots and ELISA results showed that miR-663 decreased PDGF-induced TGF-β1 expression and secretion, which in turn suppressed the downstream smad2/3 phosphorylation and collagen I expression. Finally, intratracheal instillation of adeno-miR-663 efficiently inhibited the development of pulmonary vascular remodeling and right ventricular hypertrophy in monocrotaline (MCT)-induced PAH rat models.

CONCLUSION

These results indicate that miR-663 is a potential biomarker for PAH. MiR-663 decreases PDGF-BB-induced PASMCs proliferation and prevents pulmonary vascular remodeling and right ventricular hypertrophy in MCT-PAH by targeting TGF-β1/smad2/3 signaling. These findings suggest that miR-663 may represent as an attractive approach for the diagnosis and treatment for PAH.

An Overview of miRNAs Involved in PASMC Phenotypic Switching in Pulmonary Hypertension

Pulmonary hypertension (PH) is occult, with no distinctive clinical manifestations and a poor prognosis. Pulmonary vascular remodelling is an important pathological feature in which pulmonary artery smooth muscle cells (PASMCs) phenotypic switching plays a crucial role. MicroRNAs (miRNAs) are a class of evolutionarily highly conserved single-stranded small noncoding RNAs. An increasing number of studies have shown that miRNAs play an important role in the occurrence and development of PH by regulating PASMCs phenotypic switching, which is expected to be a potential target for the prevention and treatment of PH. miRNAs such as miR-221, miR-15b, miR-96, miR-24, miR-23a, miR-9, miR-214, and miR-20a can promote PASMCs phenotypic switching, while such as miR-21, miR-132, miR-449, miR-206, miR-124, miR-30c, miR-140, and the miR-17~92 cluster can inhibit it. The article reviews the research progress on growth factor-related miRNAs and hypoxia-related miRNAs that mediate PASMCs phenotypic switching in PH.

miR-29a-3p/THBS2 Axis Regulates PAH-Induced Cardiac Fibrosis

Pulmonary artery hypertension (PAH) pathology involves extracellular matrix (ECM) remodeling in cardiac tissues, thus promoting cardiac fibrosis progression. miR-29a-3p reportedly inhibits lung progression and liver fibrosis by regulating ECM protein expression; however, its role in PAH-induced fibrosis remains unclear. In this study, we aimed to investigate the role of miR-29a-3p in cardiac fibrosis progression in PAH and its influence on ECM protein thrombospondin-2 (THBS2) expression. The diagnostic and prognostic values of miR-29a-3p and THBS2 in PAH were evaluated. The expressions and effects of miR-29a-3p and THBS2 were assessed in cell culture, monocrotaline-induced PAH mouse model, and patients with PAH. The levels of circulating miR-29a-3p and THBS2 in patients and mice with PAH decreased and increased, respectively. miR-29a-3p directly targets THBS2 and regulates THBS2 expression via a direct anti-fibrotic effect on PAH-induced cardiac fibrosis. The circulating levels of miR-29a-3p and THBS2 were correlated with PAH diagnostic parameters, suggesting their independent prognostic value. miR-29a-3p targeted THBS2 expression via a direct anti-fibrotic effect on PAH-induced cardiac fibrosis, indicating miR-29a-3p acts as a messenger with promising therapeutic effects.

Circulating extracellular vesicles delivering beneficial cargo as key players in exercise effects

Exercise has been recognized as an effective preventive and therapeutic approach for numerous diseases. This review addresses the potential role of circulating extracellular vesicles (EV) cargo that is modulated by physical activity. EV transport and deliver beneficial molecules to adjacent and distant tissues as a whole-body phenomenon, resulting in a healthier global status. Several candidate EV molecules, especially miRNAs, are summarized here as mediators of the beneficial effects of exercise, using different modalities, frequencies, volumes, and intensities. The following are among the candidate miRNAs: miR-21, miR-146, miR-486, miR-148a-3p, miR-223-3p, miR-142-3p, and miR-191a-5p. We highlight the relationship between EV cargo modifications, their targets and pathway interactions, in clinical outcomes, for example, on cardiovascular or immune diseases. This review brings an innovative perspective providing evidence for an intricate biological basis of the relationship between EV cargo and exercise-induced benefits on several diseases. Moreover, specific changes on circulating EV content might potentially be used as biomarkers of exercise efficacy.

Cardiomyocyte microRNA-150 confers cardiac protection and directly represses pro-apoptotic small proline-rich protein 1A

MicroRNA-150 (miR-150) is downregulated in patients with multiple cardiovascular diseases and in diverse mouse models of heart failure (HF). miR-150 is significantly associated with HF severity and outcome in humans. We previously reported that miR-150 is activated by β-blocker carvedilol (Carv) and plays a protective role in the heart using a systemic miR-150 KO mouse model. However, mechanisms that regulate cell-specific miR-150 expression and function in HF are unknown. Here, we demonstrate that potentially novel conditional cardiomyocyte–specific (CM-specific) miR-150 KO (miR-150 cKO) in mice worsens maladaptive cardiac remodeling after myocardial infarction (MI). Genome-wide transcriptomic analysis in miR-150 cKO mouse hearts identifies small proline–rich protein 1a (Sprr1a) as a potentially novel target of miR-150. Our studies further reveal that Sprr1a expression is upregulated in CMs isolated from ischemic myocardium and subjected to simulated ischemia/reperfusion, while its expression is downregulated in hearts and CMs by Carv. We also show that left ventricular SPRR1A is upregulated in patients with HF and that Sprr1a knockdown in mice prevents maladaptive post-MI remodeling. Lastly, protective roles of CM miR-150 are, in part, attributed to the direct and functional repression of proapoptotic Sprr1a. Our findings suggest a crucial role for the miR-150/SPRR1A axis in regulating CM function post-MI.

Circulating Plasma miRNA and Clinical/Hemodynamic Characteristics Provide Additional Predictive Information About Acute Pulmonary Thromboembolism, Chronic Thromboembolic Pulmonary Hypertension and Idiopathic Pulmonary Hypertension

Idiopathic pulmonary artery hypertension (IPAH), chronic thromboembolic pulmonary hypertension (CTEPH), and acute pulmonary embolism (APTE) are life-threatening cardiopulmonary diseases without specific surgical or medical treatment. Although APTE, CTEPH and IPAH are different pulmonary vascular diseases in terms of clinical presentation, prevalence, pathophysiology and prognosis, the identification of their circulating microRNA (miRNAs) might help in recognizing differences in their outcome evolution and clinical forms. The aim of this study was to describe the APTE, CTEPH, and IPAH-associated miRNAs and to predict their target genes. The target genes of the key differentially expressed miRNAs were analyzed, and functional enrichment analyses were carried out. The miRNAs were detected using RT-PCR. Finally, we incorporated plasma circulating miRNAs in baseline and clinical characteristics of the patients to detect differences between APTE and CTEPH in time of evolution, and differences between CTEPH and IPAH in diseases form. We found five top circulating plasma miRNAs in common with APTE, CTEPH and IPAH assembled in one conglomerate. Among them, miR-let-7i-5p expression was upregulated in APTE and IPAH, while miRNA-320a was upregulated in CTEP and IPAH. The network construction for target genes showed 11 genes regulated by let-7i-5p and 20 genes regulated by miR-320a, all of them regulators of pulmonary arterial adventitial fibroblasts, pulmonary artery endothelial cell, and pulmonary artery smooth muscle cells. AR (androgen receptor), a target gene of hsa-let-7i-5p and has-miR-320a, was enriched in pathways in cancer, whereas PRKCA (Protein Kinase C Alpha), also a target gene of hsa-let-7i-5p and has-miR-320a, was enriched in KEGG pathways, such as pathways in cancer, glioma, and PI3K-Akt signaling pathway. We inferred that CTEPH might be the consequence of abnormal remodeling in APTE, while unbalance between the hyperproliferative and apoptosis-resistant phenotype of pulmonary arterial adventitial fibroblasts, pulmonary artery endothelial cell and pulmonary artery smooth muscle cells in pulmonary artery confer differences in IPAH and CTEPH diseases form. We concluded that the incorporation of plasma circulating let-7i-5p and miRNA-320a in baseline and clinical characteristics of the patients reinforces differences between APTE and CTEPH in outcome evolution, as well as differences between CTEPH and IPAH in diseases form.

MicroRNA-17 as a potential diagnostic biomarker in pulmonary arterial hypertension

Objective

This study aimed to detect circulating microRNA (miR)-17 and miR-20a levels in patients with pulmonary arterial hypertension (PAH), and to investigate whether circulating miR-17 levels are associated with PAH.

Methods

Thirty-five PAH patients and 20 healthy controls were enrolled in the study. Circulating miR-17 and miR-20a levels were measured using real-time PCR analysis.

Results

miR-17 levels were significantly increased in PAH patients compared with healthy controls. They were also higher in PAH patients at World Health Organization functional class (WHO FC) III–IV than WHO FC I–II PAH patients. There was no significant difference in miR-20a levels between PAH patients and controls. miR-17 had a high area under the corresponding receiver operating characteristic curve. Further, we found that circulating miR-17 levels correlated with the 6-minute walk distance, mean pulmonary artery pressure, and mean right atrial pressure in PAH patients.

Conclusion

Circulating miR-17 levels may be associated with human PAH. Therefore, miR-17 could be used as a diagnostic index and prognostic factor for PAH patients.

Role of Krüppel-like factors in pulmonary arterial hypertension

Pulmonary arterial hypertension is a rare but deadly disease with a complex pathogenesis. Recent evidence demonstrates that Krüppel-like factors, a diverse family of transcription factors, are involved in several key disease processes such as the phenotypic transition of endothelial cells and smooth muscle cells. Importantly, manipulation of certain Krüppel-like factors enables protection or attenuation against pulmonary arterial hypertension in both animal models and preliminary human studies. In this review, we discuss how Krüppel-like factors, in particular Krüppel-like factors 2, 4 and 5 contribute to the pathological phenomena seen in pulmonary arterial hypertension and how associated signaling and microRNA pathways may be suitable targets for new therapies.

Plasma exosomal miR-596: a novel biomarker predicts survival in patients with idiopathic pulmonary artery hypertension

Objective

To determine if plasma exosomal microRNAs (miRNAs) can predict survival in patients with idiopathic pulmonary arterial hypertension (IPAH).

Methods

The study enrolled patients with IPAH that underwent right heart catheterization. Plasma was collected and exosomal miRNAs were extracted. Exosomes were evaluated using transmission electron microscopy, Western blot analysis and particle size distribution analysis. MiRNAs were evaluated using a miRNA microarray and validated using real-time polymerase chain reaction.

Results

This study included 12 patients with IPAH in the study group and 48 patients with IPAH in the validation group. The mean ± SD follow-up duration was 60.3 ± 35.4 months in the overall cohort. The levels of miR-596 were higher in the nonsurvivors compared with the survivors. The levels of miR-596 significantly correlated with survival time, mean right atrial pressure, pulmonary vascular resistance (PVR) and cardiac index. High levels of miR-596 and PVR were significantly associated with poor overall survival. Multivariate analysis demonstrated that exosomal miR-596 (hazard ratio [HR] = 2.119; 95% confidence interval [CI] 1.402, 3.203) and PVR (HR = 1.146; 95% CI 1.010, 1.300) were independent predictors of survival.

Conclusions

High levels of plasma exosomal miR-596 were significantly associated with disease severity and poor prognosis of patients with IPAH.

Exosomal miR-211 contributes to pulmonary hypertension via attenuating CaMK1/PPAR-γaxis

AIM

Exsomes play a significant role in increasing pathophysiological processes by delivering their content. Recently, a variety of studies have showed exosomal microRNAs (miRNAs) are involved in pulmonary hypertension (PH) notably. In this study, we found that exosomal miR-211 was overexpressed in hypoxia-induced PH rats but its intrinsic regulation was unclear. Therefore, our aim was to reveal the underlying mechanism which overexpressed exosomal miR-211 targeted in the development of PH.

METHODS

18 male SD rats were randomly divided into normoxia and hypoxia group, housed in normal or hypoxic chamber for 3 weeks respectively. Then, mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance(PVR), right ventricular hypertrophy index(RV/(LV + S)), the percentage of medial wall area (WA%) and the percentage of medial wall thickness (WT%) were measured. Expression of miR-211 in exosomes was detected by qRT-PCR. Expression of Ca2+/calmodulin-dependent kinase1(CaMK1)and peroxisome proliferator-activated receptors-γ(PPAR-γ)in lung tissue were detected by Western blot(WB); After miR-211 overexpressed exosomes were injected to rats through caudal vein, mPAP, PVR, RV/(LV + S), WA% and WT% were also measured. Sequentially, hypoxia rats were injected with lentivirus riched in miR-211 inhibitor via tail vein, and PH-related indicators were measured. In vitro, after miR-211 was positively or negatively regulated in pulmonary arterial smooth muscle cell (PASMC) by plasmid transfection, proliferation of PASMC was detected by CCK8, as well as the expression of CaMK1 and PPAR- γ. Further, the relationship between CaMK1 and miR-211 was verified by Dual-Luciferase assay. And the regulatory relationship of CaMK1/PPAR- γ aixs was demonstrated in PASMC.

RESULTS

Evident increases of mPAP, PVR, RVHI, WT% and WA% were observed with hypoxia administration. And the concentration of plasma exosomes in hypoxia rats was increased and positively correlated with the above indexes. miR-211 in exosomes of PH was upregulated while the expression of CaMK1 and PPAR-γ decreased in lung tissues. Further, injection of exosomes overexpressed with miR-211 demonstrated that exosomal miR-211 aggravated PH while inhibition of miR-211 attenuated PH in rats. In vitro, overexpression of miR-211 promoted the proliferation of PASMC and inhibited expression of CaMK1 and PPAR-γ in PASMC. And Dual-luciferase assay demonstrated that CaMK1 was a downstream gene of miR-211. Plasmid transfection experiments indicated that CaMK1 can promote PPAR-γ expression.

CONCLUSION

Exosomal miR-211 promoted PH via inhibiting CaMK1/PPAR-γ axis, promoting PASMC proliferation in rats.

miR-150-PTPMT1-cardiolipin signaling in pulmonary arterial hypertension

Circulating levels of endothelial miR-150 are reduced in pulmonary arterial hypertension (PAH) and act as an independent predictor of patient survival, but links between endothelial miR-150 and vascular dysfunction are not well understood. We studied the effects of endothelial miR-150 supplementation and inhibition in PAH mice and cells from patients with idiopathic PAH. The role of selected mediators of miR-150 identified by RNA sequencing was evaluated in vitro and in vivo. Endothelium-targeted miR-150 delivery prevented the disease in Sugen/hypoxia mice, while endothelial knockdown of miR-150 had adverse effects. miR-150 target genes revealed significant associations with PAH pathways, including proliferation, inflammation, and phospholipid signaling, with PTEN-like mitochondrial phosphatase (PTPMT1) most markedly altered. PTPMT1 reduced inflammation and apoptosis and improved mitochondrial function in human pulmonary endothelial cells and blood-derived endothelial colony-forming cells from idiopathic PAH. Beneficial effects of miR-150 in vitro and in vivo were linked with PTPMT1-dependent biosynthesis of mitochondrial phospholipid cardiolipin and reduced expression of pro-apoptotic, pro-inflammatory, and pro-fibrotic genes, including c-MYB, NOTCH3, transforming growth factor β (TGF-β), and Col1a1. In conclusion, we are the first to show that miR-150 supplementation attenuates pulmonary endothelial damage induced by vascular stresses and may be considered as a potential therapeutic strategy in PAH.

Identification of Hub Genes Associated with Hypertension and Their Interaction with miRNA Based on Weighted Gene Coexpression Network Analysis (WGCNA) Analysis

Background

Hypertension is one of the most widespread health conditions in the world, and the molecular mechanism of it is still unclear. In this study, we identified the hub genes (hub miRNA genes) associated with hypertension and explored the relationship between hypertension miRNA-gene by constructing a mRNA co-expression network and a miRNA co-expression network, which can help to reveal the mechanism and predict the prognosis of hypertension progression.

Material/Methods

Based on gene expression profile data of hypertensive samples from the Gene Expression Omnibus database, WGCNA was used to detect hypertension-related biomarkers and key mRNA and miRNA modules. Then, DAVID was used to perform gene-annotation enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) and miRPath were used for pathway analysis of mRNA and miRNAs genes.

Results

We identified 3 key modules relating to hypertension, 2 mRNA modules named M_saddlebrown and M_greenyellow and 1 miRNA module named M_salmon. In addition, 12 hub genes (RPL21, RPS28, LOC442727/PTGAP10, LOC100129599/RPS29P14, TBXAS1, FCER1G, CFP, FURIN, PECAM1, IGSF6, NCF1C, and LOC285296/UNC93B3) and 7 hub miRNAs (hsa-miR-1268a/b, hsa-miR-513c-3p, hsa-miR-4799-5p, hsa-miR-296-3p, hsa-miR-5195-5p, hsa-miR-219-2-3p, and hsa-miR-548d-5p) relating to hypertension were identified. HIF-1 signaling pathway and insulin signaling pathway were closely related to the 3 key modules. We also discovered 4 miRNAs (hsa-miR-548am-3p, hsa-miR-513c-3p, hsa-miR-182-5p, and hsa-miR-548d-5p) and 6 genes (IGF1R, GSK3B, FOXO1, PRKAR2B, HIF1A, and PIK3R1) were the core nodes in the hypertension-related miRNA-gene network, and hsa-miR-548am-3p was at the center of the network.

Conclusions

These findings will help improve the understanding of the pathogenesis of hypertension, and the discovered genes can serve as signatures for early diagnosis of hypertension.

Comprehensive Analyses of miRNA-mRNA Network and Potential Drugs in Idiopathic Pulmonary Arterial Hypertension

Introduction

Idiopathic pulmonary arterial hypertension (IPAH) is a severe cardiopulmonary disease with a relatively low survival rate. Moreover, the pathogenesis of IPAH has not been fully recognized. Thus, comprehensive analyses of miRNA-mRNA network and potential drugs in IPAH are urgent requirements.

Methods

Microarray datasets of mRNA and microRNA (miRNA) in IPAH were searched and downloaded from Gene Expression Omnibus (GEO). Differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMIs) were identified. Then, the DEMI-DEG network was conducted with associated comprehensive analyses including Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and protein-protein interaction (PPI) network analysis, while potential drugs targeting hub genes were investigated using L1000 platform.

Results

30 DEGs and 6 DEMIs were identified in the lung tissue of IPAH. GO and KEGG pathway analyses revealed that these DEGs were mostly enriched in antimicrobial humoral response and African trypanosomiasis, respectively. The DEMI-DEG network was conducted subsequently with 4 DEMIs (hsa-miR-34b-5p, hsa-miR-26b-5p, hsa-miR-205-5p, and hsa-miR-199a-3p) and 16 DEGs, among which 5 DEGs (AQP9, SPP1, END1, VCAM1, and SAA1) were included in the top 10 hub genes of the PPI network. Nimodipine was identified with the highest CMap connectivity score in L1000 platform.

Conclusion

Our study conducted a miRNA-mRNA network and identified 4 miRNAs as well as 5 mRNAs which may play important roles in the pathogenesis of IPAH. Moreover, we provided a new insight for future therapies by predicting potential drugs targeting hub genes.

Extracellular vesicles: novel communicators in lung diseases

The lung is the organ with the highest vascular density in the human body. It is therefore perceivable that the endothelium of the lung contributes significantly to the circulation of extracellular vesicles (EVs), which include exosomes, microvesicles, and apoptotic bodies. In addition to the endothelium, EVs may arise from alveolar macrophages, fibroblasts and epithelial cells. Because EVs harbor cargo molecules, such as miRNA, mRNA, and proteins, these intercellular communicators provide important insight into the health and disease condition of donor cells and may serve as useful biomarkers of lung disease processes. This comprehensive review focuses on what is currently known about the role of EVs as markers and mediators of lung pathologies including COPD, pulmonary hypertension, asthma, lung cancer and ALI/ARDS. We also explore the role EVs can potentially serve as therapeutics for these lung diseases when released from healthy progenitor cells, such as mesenchymal stem cells.

MiR-18a-5p contributes to enhanced proliferation and migration of PASMCs via targeting Notch2 in pulmonary arterial hypertension

AIM

This study is undertaken to investigate the role and molecular mechanisms of miR-18a-5p in regulating pulmonary arterial hypertension (PAH) pathogenesis.

METHODS

Gene expression and protein levels were determined by qRT-PCR and western blot, respectively; Cell counting kti-8 and Transwell migration assays were used to determine the biological functions of miR-18a-5p in pulmonary arterial smooth muscle cells (PASMCs); bioinformatics analysis, luciferase reporter assays were used to elucidate the mechanisms of miR-18a-5p.

RESULTS

MiR-18a-5p was up-regulated in the clinical samples from PAH patients. PASMCs treated with hypoxia exhibited enhanced proliferative ability and upregulated miR-18a-5p expression. Knockdown of miR-18a-5p attenuated hypoxia-induced hyper-proliferation and enhanced migratory potential of PASMCs; while miR-18a-5p overexpression promoted PASMC proliferation and migration. Further mechanistic studies showed that Notch2 was a direct target of miR-18a-5p and was repressed by miR-18a-5p overexpression. The rescue studies indicated that Notch2 overexpression counteracted the enhanced proliferation and migration induced by miR-18a-5p mimics in PASMCs. Similarly, Notch2 overexpression also block the effects caused by hypoxia in PASMCs. Moreover, Notch2 expression was down-regulated in the PAH patients and was negatively correlated with miR-18a-5p expression. In vivo animal studies further revealed the up-regulation of miR-18a-5p and the down-regulation of Notch2 in the PAH rats.

CONCLUSIONS

Collectively, this study identified the up-regulated miR-18a-5p in the PAH patients; our data suggest that miR-18a-5p contributes to the enhanced proliferation and migration of PASMCs via repressing Notch2 expression.

The application of 'omics' to pulmonary arterial hypertension

Recent genome-wide analyses of rare and common sequence variations have brought greater clarity to the genetic architecture of pulmonary arterial hypertension and implicated novel genes in disease development. Transcriptional signatures have been reported in whole lung tissue, pulmonary vascular cells and peripheral circulating cells. High-throughput platforms for plasma proteomics and metabolomics have identified novel biomarkers associated with clinical outcomes and provided molecular instruments for risk assessment. There are methodological challenges to integrating these datasets, coupled to statistical power limitations inherent to the study of a rare disease, but the expectation is that this approach will reveal novel druggable targets and biomarkers that will open the way to personalized medicine. Here, we review the current state-of-the-art and future promise of 'omics' in the field of translational medicine in pulmonary arterial hypertension. LINKED ARTICLES: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.1/issuetoc.

Long noncoding RNA MALAT1 contributes to pregnancy-induced hypertension development by enhancing oxidative stress and inflammation through the regulation of the miR-150-5p/ET-1 axis

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been identified previously in the pathogenesis of hypertension and some gestational diseases. However, the biological functions of MALAT1 in pregnancy-induced hypertension (PIH) are still poorly understood. Herein, we aim to explore the functional relevance of MALAT1 in PIH and to explain the potential underlying mechanisms. We found that the levels of ET-1 and MALAT1 were upregulated and that of miR-150-5p were downregulated in the serum of pregnant women with PIH and the aortic endothelial cells (ECs) of reduced uterine perfusion pressure (RUPP)-induced rat models. In aortic ECs, MALAT1 could competitively bind to miR-150-5p to upregulate the expression of ET-1. The MALAT1/miR-150-5p/ET-1 axis regulated the expression of endothelin B receptor (ETBR) in aortic ECs leading to oxidative stress imbalance and increased the release of proinflammatory cytokines (IL-18 and IL-1β), which concurrently activated the NF-κB pathway to regulate the ETBR expression and to stimulate smooth muscle cell (SMC) contraction. Furthermore, silencing MALAT1 could alleviate the hypertensive symptoms of RUPP-induced rat models. Taken conjointly, the upregulation of MALAT1 can reduce the expression of ET-1 by competitively binding to miR-150-5p, which enhances the expression of ETBR via the activation of the NF-κB pathway in SMCs, thus exacerbating the hypertensive symptoms in the RUPP-induced rat models.

Prognostic impact of red blood cell distribution width in pulmonary hypertension patients: A systematic review and meta-analysis

Elevated red blood cell distribution width (RDW) may correlate with a worse prognosis in pulmonary hypertension (PH), though results to date are inconsistent. The goal of this study is to detect the impact of RDW on the prognosis of PH.PubMed and EMBASE databases were searched from their inception to July 22, 2019 for relevant publications reporting the relationship between RDW and the prognosis of PH. A meta-analysis was performed, and the heterogeneity across the included studies was evaluated using I and Q statistics. We conducted sensitivity and subgroup analyses to detect sources of heterogeneity. In addition, potential publication bias was evaluated by Begg's and Egger's tests.In total, 1236 publications were retrieved, and 7 eligible publications with 666 PH patients were included in our meta-analysis. The results suggested that increased RDW can predict worse prognosis in PH (hazard ratio (HR) = 1.27, 95% confidence interval (CI) 1.11-1.45). According to subgroup analysis, study design, region, various endpoints, time of follow-up, and patient age were not sources of heterogeneity. In addition, RDW showed prognostic value in retrospective studies (HR = 1.32, 95%CI 1.15-1.51) but not in prospective studies (HR = 1.14, 95%CI 0.78-1.67). Additionally, RDW may serve as a predictive biomarker of PH in Europe (HR = 1.33, 95%CI 1.18-1.49) but not in Asia (HR = 1.20, 95%CI 0.90-1.58). Further analysis indicated that the prognostic value of RDW was influenced by patient age (>44 years: HR = 1.34, 95%CI 1.17-1.55; ≤44 years: HR = 1.20, 95%CI 0.90-1.58) and follow-up (<3 years, HR = 1.36, 95%CI 0.53-3.47; ≥3 years, HR = 1.29, 95%CI 1.14-1.45).RDW provides important prognostic information for PH patients, and this measure may be used to optimize patient management and guide clinical treatment.PROSPERO registration number: CRD42019122636.

Trans-Right-Ventricle and Transpulmonary MicroRNA Gradients in Human Pulmonary Arterial Hypertension

OBJECTIVES

We investigated whether concentrations of circulating microRNAs differ across the hypertensive right ventricle and pulmonary circulation, and correlate with hemodynamic/echocardiographic variables in patients with pulmonary arterial hypertension versus nonpulmonary arterial hypertension controls.

DESIGN

Prospective blood collection during cardiac catheterization from the superior vena cava, pulmonary artery, and ascending aorta in 12 children with pulmonary arterial hypertension and nine matched nonpulmonary arterial hypertension controls, followed by an unbiased quantitative polymerase chain reaction array screen for 754 microRNAs in plasma.

SETTING

Children's hospital at a medical school.

PATIENTS

Twelve pulmonary arterial hypertension patients included as follows: idiopathic pulmonary arterial hypertension (5), pulmonary arterial hypertension (2), pulmonary arterial hypertension-repaired congenital heart disease (4), portopulmonary pulmonary hypertension (1). Nine nonpulmonary arterial hypertension controls included as follows: mild/moderate left ventricular outflow tract obstruction (7), mediastinal teratoma (1), portal vein stenosis (1).

INTERVENTIONS

Standard pulmonary arterial hypertension treatment.

MEASUREMENTS AND MAIN RESULTS

Analysis of differential concentrations (false discovery rate < 0.05) revealed two trans-right-ventricle microRNA gradients (pulmonary artery vs superior vena cava): miR-193a-5p (step-up in pulmonary arterial hypertension and step-down in control) and miR-423-5p (step-down in pulmonary arterial hypertension and step-up in control) and two transpulmonary microRNA gradients (ascending aorta vs pulmonary artery): miR-26b-5p (step-down only in control) and miR-331-3p (step-up only in pulmonary arterial hypertension). Between-group comparison revealed miR-29a-3p, miR-26a-5p, miR-590-5p, and miR-200c-3p as upregulated in pulmonary arterial hypertension-superior vena cava and miR-99a-5p as downregulated in pulmonary arterial hypertension-pulmonary artery. The differential microRNA-concentrations correlated with prognostic hemodynamic variables (pulmonary vascular resistance, tricuspid annular plane systolic excursion, etc.).

CONCLUSIONS

We identified for the first time in human disease (pulmonary arterial hypertension) trans-right-ventricle and transpulmonary microRNA gradients in blood plasma. Several of these microRNAs regulate transcripts that drive cardiac remodeling and pulmonary arterial hypertension and are now emerging as epigenetic pulmonary arterial hypertension biomarkers and targets for therapy.

Genetic ablation of bone marrow beta-adrenergic receptors in mice modulates miRNA-transcriptome networks of neuroinflammation in the paraventricular nucleus

Elucidating molecular pathways regulating neuroimmune communication is critical for therapeutic interventions in conditions characterized by overactive immune responses and dysfunctional autonomic nervous system. We generated a bone marrow-specific adrenergic beta 1 and beta 2 knockout mouse chimera (AdrB1.B2 KO) to determine how sympathetic drive to the bone affects transcripts and miRNAs in the hypothalamic paraventricular nucleus (PVN). This model has previously exhibited a dampened systemic immune response and decreased blood pressure compared with control animals. Reduced sympathetic responsiveness of the bone marrow hematopoietic cells of AdrB1.B2 KO chimera led to suppression of transcriptional networks that included leukocyte cell adhesion and migration and T cell-activation and recruitment. Transcriptome responses related to IL-17a signaling and the renin-angiotensin system were also suppressed in the PVN. Based on the transcriptome response, we next computationally predicted miRNAs in the PVN that may underscore the reduced sympathetic responsiveness of the bone marrow cells. These included miR-27b-3p, miR-150, miR-223-3p, and miR-326. Using real-time PCR, we measured a downregulation in the expression of miR-150-5p, miR-205-5p, miR-223-3p, miR-375-5p, miR-499a-5p, miR-27b-3p, let-7a-5p, and miR-21a-5p in the PVN of AdrB1.B2 KO chimera, confirming computational predictions that these miRNAs are associated with reduced neuro-immune responses and the loss of sympathetic responsiveness in the bone marrow. Intriguingly, directional responses of the miRNA corresponded to mRNAs, suggesting complex temporal or circuit-dependent posttranscriptional control of gene expression in the PVN. This study identifies molecular pathways involved in neural-immune interactions that may act as targets of therapeutic intervention for a dysfunctional autonomic nervous system.

Mitochondria in the Pulmonary Vasculature in Health and Disease: Oxygen-Sensing, Metabolism, and Dynamics

In lung vascular cells, mitochondria serve a canonical metabolic role, governing energy homeostasis. In addition, mitochondria exist in dynamic networks, which serve noncanonical functions, including regulation of redox signaling, cell cycle, apoptosis, and mitochondrial quality control. Mitochondria in pulmonary artery smooth muscle cells (PASMC) are oxygen sensors and initiate hypoxic pulmonary vasoconstriction. Acquired dysfunction of mitochondrial metabolism and dynamics contribute to a cancer-like phenotype in pulmonary arterial hypertension (PAH). Acquired mitochondrial abnormalities, such as increased pyruvate dehydrogenase kinase (PDK) and pyruvate kinase muscle isoform 2 (PKM2) expression, which increase uncoupled glycolysis (the Warburg phenomenon), are implicated in PAH. Warburg metabolism sustains energy homeostasis by the inhibition of oxidative metabolism that reduces mitochondrial apoptosis, allowing unchecked cell accumulation. Warburg metabolism is initiated by the induction of a pseudohypoxic state, in which DNA methyltransferase (DNMT)-mediated changes in redox signaling cause normoxic activation of HIF-1α and increase PDK expression. Furthermore, mitochondrial division is coordinated with nuclear division through a process called mitotic fission. Increased mitotic fission in PAH, driven by increased fission and reduced fusion favors rapid cell cycle progression and apoptosis resistance. Downregulation of the mitochondrial calcium uniporter complex (MCUC) occurs in PAH and is one potential unifying mechanism linking Warburg metabolism and mitochondrial fission. Mitochondrial metabolic and dynamic disorders combine to promote the hyperproliferative, apoptosis-resistant, phenotype in PAH PASMC, endothelial cells, and fibroblasts. Understanding the molecular mechanism regulating mitochondrial metabolism and dynamics has permitted identification of new biomarkers, nuclear and CT imaging modalities, and new therapeutic targets for PAH. © 2020 American Physiological Society. Compr Physiol 10:713-765, 2020.

Therapeutic potential of KLF2-induced exosomal microRNAs in pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a severe disorder of lung vasculature that causes right heart failure. Homoeostatic effects of flow-activated transcription factor Krüppel-like factor 2 (KLF2) are compromised in PAH. Here, we show that KLF2-induced exosomal microRNAs, miR-181a-5p and miR-324-5p act together to attenuate pulmonary vascular remodelling and that their actions are mediated by Notch4 and ETS1 and other key regulators of vascular homoeostasis. Expressions of KLF2, miR-181a-5p and miR-324-5p are reduced, while levels of their target genes are elevated in pre-clinical PAH, idiopathic PAH and heritable PAH with missense p.H288Y KLF2 mutation. Therapeutic supplementation of miR-181a-5p and miR-324-5p reduces proliferative and angiogenic responses in patient-derived cells and attenuates disease progression in PAH mice. This study shows that reduced KLF2 signalling is a common feature of human PAH and highlights the potential therapeutic role of KLF2-regulated exosomal miRNAs in PAH and other diseases associated with vascular remodelling.

MicroRNA and Cardiovascular Diseases

Cardiovascular diseases are one of the most common causes of death in both developing and developed countries worldwide. Even though there have been improvements in primary prevention, the prevalence of cardiovascular diseases continues to increase in recent years. Hence, it is crucial to both investigate the molecular pathophysiology of cardiovascular diseases in-depth and find novel biomarkers regarding the early and proper prevention and diagnosis of these diseases. MicroRNAs, or miRNAs, are endogenous, conserved, single-stranded non-coding RNAs of 21-25 nucleotides in length. miRNAs have important roles in various cellular events such as embryogenesis, proliferation, vasculogenesis, apoptosis, cell growth, differentiation, and tumorigenesis. They also have potential roles in the cardiovascular system, including angiogenesis, cardiac cell contractility, control of lipid metabolism, plaque formation, the arrangement of cardiac rhythm, and cardiac cell growth. Circulating miRNAs are promising novel biomarkers for purposes of the diagnosis and prognosis of cardiovascular diseases. Cell or tissue specificity, stability in serum or plasma, resistance to degradative factors such as freeze-thaw cycles or enzymes in the blood, and fast-release kinetics, provide the potential for miRNAs to be surrogate markers for the early and accurate diagnosis of disease and for predicting middle- or long-term prognosis. Moreover, it may be a logical approach to combine miRNAs with traditional biomarkers to improve risk stratification and long-term prognosis. In addition to their efficacy in both diagnosis and prognosis, miRNA-based therapeutics may be beneficial for treating cardiovascular diseases using novel platforms and computational tools and in combination with traditional methods of analysis. microRNAs are promising, novel therapeutic agents, which can affect multiple genes using different signaling pathways. miRNAs therapeutic modulation techniques have been used in the settings of atherosclerosis, acute myocardial infarction, restenosis, vascular remodeling, arrhythmias, hypertrophy and fibrosis, angiogenesis and cardiogenesis, aortic aneurysm, pulmonary hypertension, and ischemic injury. This review presents detailed information about miRNAs regarding structure and biogenesis, stages of synthesis and functions, expression profiles in serum/plasma of living organisms, diagnostic and prognostic potential as novel biomarkers, and therapeutic applications in various diseases.

Screening strategies for pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is rare and, if untreated, has a median survival of 2-3 years. Pulmonary arterial hypertension may be idiopathic (IPAH) but is frequently associated with other conditions. Despite increased awareness, therapeutic advances, and improved outcomes, the time from symptom onset to diagnosis remains unchanged. The commonest symptoms of PAH (breathlessness and fatigue) are non-specific and clinical signs are usually subtle, frequently preventing early diagnosis where therapies may be more effective. The failure to improve the time to diagnosis largely reflects an inability to identify patients at increased risk of PAH using current approaches. To date, strategies to improve the time to diagnosis have focused on screening patients with a high prevalence [systemic sclerosis (10%), patients with portal hypertension assessed for liver transplantation (2-6%), carriers of mutations of the gene encoding bone morphogenetic protein receptor type II, and first-degree relatives of patients with heritable PAH]. In systemic sclerosis, screening algorithms have demonstrated that patients can be identified earlier, however, current approaches are resource intensive. Until, recently, it has not been considered possible to screen populations for rare conditions such as IPAH (prevalence 5-15/million/year). However, there is interest in the use of artificial intelligence approaches in medicine and the application of diagnostic algorithms to large healthcare data sets, to identify patients at risk of rare conditions. In this article, we review current approaches and challenges in screening for PAH and explore novel population-based approaches to improve detection.

Hypoxia-induced Pulmonary Hypertension in Different Mouse Strains: Relation to Transcriptome

Patients with pulmonary arterial hypertension (PAH) can harbor mutations in several genes, most commonly in BMPR2. However, disease penetrance in patients with BMPR2 mutations is low. In addition, most patients do not carry known PAH gene mutations, suggesting that other factors determine susceptibility to PAH. To begin to identify additional genomic factors contributing to PAH pathogenesis, we exposed 32 mouse strains to chronic hypoxia. We found that the PL/J strain has extremely high right ventricular systolic pressure (RVSP; 86.58 mm Hg) but minimal lung remodeling. To identify potential genomic factors contributing to the high RVSP, RNAseq analysis of PL/J lung mRNAs and microRNAs (miRNAs) after hypoxia was performed, and it demonstrated that 4 of 43 upregulated miRNAs in the Dlk1-Dio3 imprinting region are predicted to target T cell marker mRNAs. These target mRNAs, as well as the numbers of T cells were downregulated. In addition, C5a and its receptor, C5AR1, were increased. Analysis of Rho-associated protein kinase (Rock) 2 mRNA expression, in the RhoA/Rock pathway, demonstrated a significant increase in PL/J. Inhibition of Rock2 ameliorated a portion of the elevated RVSP. In addition, we identified miR-150-5p as a potential regulator of Rock2 expression. In conclusion, we identified two possible pathways contributing to the hypoxia pulmonary hypertension phenotype of extreme RVSP elevation: aberrant T cell expression driven by hypoxia-induced miRNAs and increased expression of C5a and C5AR1. We suggest that the PL/J mouse will be a good model for seeking mechanism(s) of RVSP elevation in hypoxia-induced PAH.

Overexpression of miR-150 Inhibits the NF-κB Signal Pathway in Intervertebral Disc Degeneration through Targeting P2X7

Objective: To elaborate the mechanism of miR-150 in the regulation of the NF-κB signal pathway in intervertebral disc degeneration (IDD) by targeting P2X7. Methods: The degenerative and normal intervertebral disc tissues were collected to detect the expressions of miR-150 and P2X7. Nucleus pulposus cells were transfected and divided into different groups. Cell apoptosis was determined by flow cytometry and TUNEL staining. The expressions of IL-6, TNF-α, MMP-3, MMP-13, Cox-2, iNOS, collagen II and aggrecan, as well as NF-κB-associated proteins were measured by qRT-PCR and Western blotting. Furthermore, IDD rat models were established to validate the role of miR-150 in vivo.Results: miR-150 was down-regulated but P2X7 was up-regulated in the degenerative intravertebral disc tissues. The apoptosis of nucleus pulposus cells in the IL-1β-induced group with the transfection of miR-150 mimic and siP2X7 was significantly decreased, with reduced levels of IL-6, TNF-α, MMP-3, MMP-13, Cox-2 and iNOS, increased levels of collagen II and aggrecan, as well as decreased P2X7, p-p65/p65 and cleaved caspase-3. However, the above factors showed an opposite tendency after treatment with miR-150 inhibitor. Furthermore, the P2X7 siRNA transfection could reverse the effects caused by miR-150 inhibitor. Simultaneously, pcDNA P2X7 transfection also inhibited the function of miR-150 mimic in IL-1β-induced nucleus pulposus cells. In vivoexperiments further verified the protective role of miR-150 in IDD rats. Conclusion: miR-150 may alleviate the degeneration of the intervertebral disc partially since it could restrict the NF-κB pathway by targeting P2X7, and thereby inhibiting IL-1β-induced matrix catabolism, inflammatory responses and apoptosis of the nucleus pulposus cells.

Precision medicine: The future of diagnostic approach to pulmonary hypertension?

Pulmonary hypertension (PH) is a common finding that can result from many different pathological conditions. Depending on the etiology, treatment may be quite different, but early diagnosis and correct classification of PH is difficult. With an aging population and recently suggested decreased pulmonary arterial pressure threshold defining PH, we are facing even more diagnostic uncertainties. A new approach to patients' phenotyping is needed. Here we present available data and future perspectives on employing an in-depth analysis of the omics cascade to allow an earlier and more reliable diagnosis and classification of PH. Indeed, with the help of super-fast computing, it became possible to simultaneously consider the levels of thousands of potential biomarkers to find patterns specific for clinically suspected disease. The omics cascade is an invaluable source of information. However, while the genome can be perceived as providing possibilities, transcriptome-as carving them this is metabolome that may tell us 'what is really going on' in an individual living organism. Metabolomics research requires blinded search for characteristic patterns of discreet changes in the levels of detectable metabolites. Since as many as 40,000 various substances are produced as a 'side effect of staying alive', metabolite profiling can be compared to fishing up for organized signals in a universe of chaos. Although difficult, such search for metabolic patterns that might lead to replacing the term biomarker by metabolic fingerprinting in the area of pulmonary circulation has already begun.

Clinical value of non-coding RNAs in cardiovascular, pulmonary, and muscle diseases

Although a majority of the mammalian genome is transcribed to RNA, mounting evidence indicates that only a minor proportion of these transcriptional products are actually translated into proteins. Since the discovery of the first non-coding RNA (ncRNA) in the 1980s, the field has gone on to recognize ncRNAs as important molecular regulators of RNA activity and protein function, knowledge of which has stimulated the expansion of a scientific field that quests to understand the role of ncRNAs in cellular physiology, tissue homeostasis, and human disease. Although our knowledge of these molecules has significantly improved over the years, we have limited understanding of their precise functions, protein interacting partners, and tissue-specific activities. Adding to this complexity, it remains unknown exactly how many ncRNAs there are in existence. The increased use of high-throughput transcriptomics techniques has rapidly expanded the list of ncRNAs, which now includes classical ncRNAs (e.g., ribosomal RNAs and transfer RNAs), microRNAs, and long ncRNAs. In addition, splicing by-products of protein-coding genes and ncRNAs, so-called circular RNAs, are now being investigated. Because there is substantial heterogeneity in the functions of ncRNAs, we have summarized the present state of knowledge regarding the functions of ncRNAs in heart, lungs, and skeletal muscle. This review highlights the pathophysiologic relevance of these ncRNAs in the context of human cardiovascular, pulmonary, and muscle diseases.

Machine learning-based microarray analyses indicate low-expression genes might collectively influence PAH disease

Accurately predicting and testing the types of Pulmonary arterial hypertension (PAH) of each patient using cost-effective microarray-based expression data and machine learning algorithms could greatly help either identifying the most targeting medicine or adopting other therapeutic measures that could correct/restore defective genetic signaling at the early stage. Furthermore, the prediction model construction processes can also help identifying highly informative genes controlling PAH, leading to enhanced understanding of the disease etiology and molecular pathways. In this study, we used several different gene filtering methods based on microarray expression data obtained from a high-quality patient PAH dataset. Following that, we proposed a novel feature selection and refinement algorithm in conjunction with well-known machine learning methods to identify a small set of highly informative genes. Results indicated that clusters of small-expression genes could be extremely informative at predicting and differentiating different forms of PAH. Additionally, our proposed novel feature refinement algorithm could lead to significant enhancement in model performance. To summarize, integrated with state-of-the-art machine learning and novel feature refining algorithms, the most accurate models could provide near-perfect classification accuracies using very few (close to ten) low-expression genes.

Pulmonary arterial hypertension (PAH) is a serious and progressive disease, with only a roughly 50% of 5-year survival rate even with best available therapies. Accurately detecting/differentiating different forms of PAH and developing drugs that could directly target at genes involved in PAH pathogenesis are essential. We proposed a computational approach using low-cost microarray data collected from a clinical trial and had accurately predicted each PAH group. In particular, we considered the fact that there might exist some low-expression genes that were usually discarded by researchers but might function collectively and significantly controlling the disease in each case. Therefore, we had developed different filtering algorithms that intentionally selected those low-expression genes for constructing prediction model. Using a few highly informative low-expression genes that had never been extensively investigated before, our systematic approach had produced models that could offer prefect accuracy in predicting PAH. Additionally, our analysis also found that the composition of gene factors controlling the PAH etiology under each form are quite different from each other.