MiR-339 inhibits proliferation of pulmonary artery smooth muscle cell by targeting FGF signaling

Comprehensive characterization of small noncoding RNA profiles in hypoxia-induced pulmonary hypertension (HPH) rat tissues

Hypoxia-induced pulmonary hypertension (HPH) is a fatal cardiovascular disease characterized by an elevation in pulmonary artery pressure, resulting in right ventricular dysfunction and eventual heart failure. Exploring the pathogenesis of HPH is crucial, and small noncoding RNAs (sncRNAs) are gaining recognition as potential regulators of cellular responses to hypoxia. In this study, we conducted a comprehensive analysis of sncRNA profiles in eight tissues of male HPH rats using high-throughput sequencing. Our study unveiled several sncRNAs, with the brain, kidney, and spleen exhibiting the highest abundance of microRNA (miRNA), tRNA-derived small RNA (tDR), and small nucleolar RNA (snoRNA), respectively. Moreover, we identified numerous tissue-specific and hypoxia-responsive sncRNAs, particularly miRNAs and tDRs. Interestingly, we observed arm switching in miRNAs under hypoxic conditions and a significant increase in the abundance of 5' tRNA-halves among the total tDRs during hypoxia. Overall, our study provides a comprehensive characterization of the sncRNA profiles in HPH rats.

MicroRNA miR-627-5p restrains pulmonary artery smooth muscle cell dysfunction by targeting MAP 2 K4 and PI3K/AKT signaling

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is characterized by pulmonary vascular remodeling, which can be caused by abnormal proliferation and migration of pulmonary artery smooth muscle cells (PASMCs). Several microRNAs were demonstrated to regulate the PASMC dysfunction. Our study intends to evaluate whether miR-627-5p affects cigarette smoke extract (CSE)-induced aberrant biological behaviors of PASMCs.

METHODS

PASMCs was treated with CSE to create the in vitro cellular model of COPD. The viability and LDH release of PASMCs was detected by CCK-8 assay and LDH release assay. MiR-627-5p and MAP 2 K4 expression in CSE (2%)-treated PASMCs was detected by qRT-PCR. PASMC proliferation was observed under a microscope, and PASMC migration was assessed by Transwell migration assays. The binding of miR-627-5p on MAP 2 K4 was verified by dual-luciferase reporter assay. Protein levels of MAP2K4 and the PI3K/AKT signaling markers were examined by western blotting.

RESULTS

The viability of PASMCs treated with 2% CSE reached a peak. CSE dose-dependently downregulated miR-627-5p expression in PASMCs. MiR-627-5p overexpression attenuated the CSE-induced abnormal proliferation and migration of PASMCs. However, MAP2K4 overexpression antagonized the effects of miR-627-5p on PASMC dysfunction. Importantly, miR-627-5p inhibited CSE-stimulated activation of the PI3K/AKT pathway via downregulating MAP2K4.

CONCLUSION

MiR-627-5p improves CSE-induced abnormal proliferation and migration of PASMCs by inhibiting MAP2K4 expression and the PI3K/AKT pathway.

New developments in the biology of fibroblast growth factors

The fibroblast growth factor (FGF) family is composed of 18 secreted signaling proteins consisting of canonical FGFs and endocrine FGFs that activate four receptor tyrosine kinases (FGFRs 1-4) and four intracellular proteins (intracellular FGFs or iFGFs) that primarily function to regulate the activity of voltage-gated sodium channels and other molecules. The canonical FGFs, endocrine FGFs, and iFGFs have been reviewed extensively by us and others. In this review, we briefly summarize past reviews and then focus on new developments in the FGF field since our last review in 2015. Some of the highlights in the past 6 years include the use of optogenetic tools, viral vectors, and inducible transgenes to experimentally modulate FGF signaling, the clinical use of small molecule FGFR inhibitors, an expanded understanding of endocrine FGF signaling, functions for FGF signaling in stem cell pluripotency and differentiation, roles for FGF signaling in tissue homeostasis and regeneration, a continuing elaboration of mechanisms of FGF signaling in development, and an expanding appreciation of roles for FGF signaling in neuropsychiatric diseases. This article is categorized under: Cardiovascular Diseases > Molecular and Cellular Physiology Neurological Diseases > Molecular and Cellular Physiology Congenital Diseases > Stem Cells and Development Cancer > Stem Cells and Development.

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.

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.

MiR-339 and galectin-3: diagnostic value in patients with airway obstruction after lung transplantation

Respiratory complications can be the cause of graft dysfunction after lung transplantation (LTx). MicroRNAs are small regulatory molecules-potential biomarkers of respiratory diseases and post-transplant complications. Galectin-3 is highly expressed in fibrosis of transplanted solid organs. The aim was to evaluate the expression of plasma miR-339 and galectin-3 concentrations in lung recipients including with airway obstruction after LTx. The study included 57 lung recipients (34 men and 23 women aged 10 to 74 years) were followed up to 5 years after LTx. The plasma microRNAs were detected by real-time PCR; galectin-3 levels were measured by ELISA. During follow-up in 30 recipients, post-transplant complications were detected: 12 (40.0%) cases of airway obstruction. The levels of miR-339 and galectin-3 were significantly higher in recipients with airway obstruction compare with 27 (47.3%) recipients without any complications (P = 0.036 and P = 0.014, resp.). Increasing miR-339 (above the 0.02 fold change) and galectin-3 (above the 11.7 ng/ml) threshold plasma levels in lung recipients is associated with high risk (RR = 7.14 ± 0.97 [95% CI 1.05-48.60], P = 0.045) of airway obstruction after LTx. A measurement of miR-339 expression in combination with galectin-3 level might be perspective to identify recipients at risk of airway obstruction after LTx.

Novel molecular insights and public omics data in pulmonary hypertension

Pulmonary hypertension is a rare disease with high morbidity and mortality which mainly affects women of reproductive age. Despite recent advances in understanding the pathogenesis of pulmonary hypertension, the high heterogeneity in the presentation of the disease among different patients makes it difficult to make an accurate diagnosis and to apply this knowledge to effective treatments. Therefore, new studies are required to focus on translational and personalized medicine to overcome the lack of specificity and efficacy of current management. Here, we review the majority of public databases storing 'omics' data of pulmonary hypertension studies, from animal models to human patients. Moreover, we review some of the new molecular mechanisms involved in the pathogenesis of pulmonary hypertension, including non-coding RNAs and the application of 'omics' data to understand this pathology, hoping that these new approaches will provide insights to guide the way to personalized diagnosis and treatment.

CAR (CARSKNKDC) Peptide Modified ReNcell-Derived Extracellular Vesicles as a Novel Therapeutic Agent for Targeted Pulmonary Hypertension Therapy

In recent years, mesenchymal stem cells (MSCs)–derived extracellular vesicles (EVs) are emerging as a potential therapeutic agent for pulmonary hypertension (PH). However, the full realization of MSCs-derived EVs therapy has been hampered by the absence of standardization in MSCs culture and the challenges of industrial scale-up. The study was to exploit an alternative replacement for MSCs using currently commercialized stem cell lines for effective targeted PH therapy. ReNcell VM—a human neural stem cell line—has been utilized here as a reliable and easily adoptable source of EVs. We first demonstrated that ReNcell-derived EVs (ReNcell-EVs) pretreatment effectively prevented Su/Hx (SU5416/hypoxia)-induced PH in mice. Then for targeted therapy, we conjugated ReNcell-EVs with CAR (CARSKNKDC) peptide (CAR-EVs)—a peptide identified to specifically target hypertensive pulmonary arteries, by bio-orthogonal chemistry. Intravenous administration of CAR-EVs selectively targeted hypertensive pulmonary artery lesions especially pulmonary artery smooth muscle cells. Moreover, compared with unmodified ReNcell-EVs, CAR-EVs treatment significantly improved therapeutic effect in reversing Su/Hx-induced PH in mice. Mechanistically, ReNcell-EVs inhibited hypoxia-induced proliferation, migration, and phenotype switch of pulmonary artery smooth muscle cells, at least in part, via the delivery of its endogenous highly expressed miRNAs, let-7b-5p, miR-92b-3p, and miR-100-5p. In addition, we also found that ReNcell-EVs inhibited hypoxia-induced cell apoptosis and endothelial-mesenchymal transition in human microvascular endothelial cells. Taken together, our results provide an alternative to MSCs-derived EVs–based PH therapy via using ReNcell as a reliable source of EVs. Particularly, our CAR-conjugated EVs may serve as a novel drug carrier that enhances the specificity and efficiency of drug delivery for effective PH-targeted therapy.

Identification of a Plasma Microrna Signature as Biomarker of Subaneurysmal Aortic Dilation in Patients with High Cardiovascular Risk

Patients with subaneurysmal aortic dilation (SAD; 25–29 mm diameter) are likely to progress to true abdominal aortic aneurysm (AAA). Despite these patients having a higher risk of all-cause mortality than subjects with aortic size <24 mm, early diagnostic biomarkers are lacking. MicroRNAs (miRs) are well-recognized potential biomarkers due to their differential expression in different tissues and their stability in blood. We have investigated whether a plasma miRs profile could identify the presence of SAD in high cardiovascular risk patients. Using qRT-PCR arrays in plasma samples, we determined miRs differentially expressed between SAD patients and patients with normal aortic diameter. We then selected 12 miRs to be investigated as biomarkers by construction of ROC curves. A total of 82 significantly differentially expressed miRs were found by qPCR array, and 12 were validated by qRT-PCR. ROC curve analyses showed that seven selected miRs (miR-28-3p, miR-29a-3p, miR-93-3p, miR-150-5p, miR-338-3p, miR-339-3p, and miR-378a-3p) could be valuable biomarkers for distinguishing SAD patients. MiR-339-3p showed the best sensitivity and specificity, even after combination with other miRs. Decreased miR-339-3p expression was associated with increased aortic abdominal diameter. MiR-339-3p, alone or in combination with other miRs, could be used for SAD screening in high cardiovascular risk patients, helping to the early diagnosis of asymptomatic AAA.

Targeting Bronchopulmonary Dysplasia-Associated Pulmonary Hypertension (BPD-PH): Potential Role of the FGF Signaling Pathway in the Development of the Pulmonary Vascular System

More than 50 years after the first description of Bronchopulmonary dysplasia (BPD) by Northway, this chronic lung disease affecting many preterm infants is still poorly understood. Additonally, approximately 40% of preterm infants suffering from severe BPD also suffer from Bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH), leading to a significant increase in total morbidity and mortality. Until today, there is no curative therapy for both BPD and BPD-PH available. It has become increasingly evident that growth factors are playing a central role in normal and pathologic development of the pulmonary vasculature. Thus, this review aims to summarize the recent evidence in our understanding of BPD-PH from a basic scientific point of view, focusing on the potential role of Fibroblast Growth Factor (FGF)/FGF10 signaling pathway contributing to disease development, progression and resolution.

Beyond the genome: challenges and potential for epigenetics-driven therapeutic approaches in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a devastating disease of the cardiopulmonary system caused by the narrowing of the pulmonary arteries, leading to increased vascular resistance and pressure. This leads to right ventricle remodeling, dysfunction, and eventually, death. While conventional therapies have largely focused on targeting vasodilation, other pathological features of PAH including aberrant inflammation, mitochondrial dynamics, cell proliferation, and migration have not been well explored. Thus, despite some recent improvements in PAH treatment, the life expectancy and quality of life for patients with PAH remains poor. Showing many similarities to cancers, PAH is characterized by increased pulmonary arterial smooth muscle cell proliferation, decreased apoptotic signaling pathways, and changes in metabolism. The recent successes of therapies targeting epigenetic modifiers for the treatment of cancer has prompted epigenetic research in PAH, revealing many new potential therapeutic targets. In this minireview we discuss the emergence of epigenetic dysregulation in PAH and highlight epigenetic-targeting compounds that may be effective for the treatment of PAH.

MicroRNA Nanotherapeutics for Lung Targeting. Insights into Pulmonary Hypertension

In this review, the potential future role of microRNA-based therapies and their specific application in lung diseases is reported with special attention to pulmonary hypertension. Current limitations of these therapies will be pointed out in order to address the challenges that they need to face to reach clinical applications. In this context, the encapsulation of microRNA-based therapies in nanovectors has shown improvements as compared to chemically modified microRNAs toward enhanced stability, efficacy, reduced side effects, and local administration. All these concepts will contextualize in this review the recent achievements and expectations reported for the treatment of pulmonary hypertension.

Pathobiology of pulmonary artery hypertension: role of long non-coding RNAs

Pulmonary arterial hypertension (PAH) is a disease with complex pathobiology, significant morbidity and mortality, and remains without a cure. It is characterized by vascular remodelling associated with uncontrolled proliferation of pulmonary artery smooth muscle cells, endothelial cell proliferation and dysfunction, and endothelial-to-mesenchymal transition, leading to narrowing of the vascular lumen, increased vascular resistance and pulmonary arterial pressure, which inevitably results in right heart failure and death. There are multiple molecules and signalling pathways that are involved in the vascular remodelling, including non-coding RNAs, i.e. microRNAs and long non-coding RNAs (lncRNAs). It is only in recent years that the role of lncRNAs in the pathobiology of pulmonary vascular remodelling and right ventricular dysfunction is being vigorously investigated. In this review, we have summarized the current state of knowledge about the role of lncRNAs as key drivers and gatekeepers in regulating major cellular and molecular trafficking involved in the pathogenesis of PAH. In addition, we have discussed the limitations and challenges in translating lncRNA research in vivo and in therapeutic applications of lncRNAs in PAH.

Targeting epigenetic mechanisms as an emerging therapeutic strategy in pulmonary hypertension disease

Pulmonary arterial hypertension (PAH) is a multifactorial cardiopulmonary disease characterized by an elevation of pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR), which can lead to right ventricular (RV) failure, multi-organ dysfunction, and ultimately to premature death. Despite the advances in molecular biology, the mechanisms underlying pulmonary hypertension (PH) remain unclear. Nowadays, there is no curative treatment for treating PH. Therefore, it is crucial to identify novel, specific therapeutic targets and to offer more effective treatments against the progression of PH. Increasing amounts of evidence suggest that epigenetic modification may play a critical role in the pathogenesis of PAH. In the presented paper, we provide an overview of the epigenetic mechanisms specifically, DNA methylation, histone acetylation, histone methylation, and ncRNAs. As the recent identification of new pharmacological drugs targeting these epigenetic mechanisms has opened new therapeutic avenues, we also discuss the importance of epigenetic-based therapies in the context of PH.

MicroRNA‑132 mediates proliferation and migration of pulmonary smooth muscle cells via targeting PTEN

Pulmonary arterial hypertension (PAH) is a severe and progressive disease characterized by the remodeling of small pulmonary arteries. The aberrant proliferation of pulmonary arterial smooth muscle cells (PASMCs) is the primary feature of PAH. MicroRNA (miR)‑132 has been demonstrated to inhibit the proliferation of vascular smooth muscle cells and repress neointimal formation. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a direct target of miR‑132 that has been revealed to be involved in the development of PAH. However, the role of miR‑132 in PAH remains unclear. The present study demonstrated that miR‑132 expression was upregulated in monocrotaline‑induced PAH rats and platelet‑derived growth factor‑induced PASMCs. In addition, treatment of PASMCs with miR‑132 mimics inhibited their proliferation, whereas miR‑132 inhibition exhibited the opposite effects. Furthermore, miR‑132 mimics promoted cell migration and maintained the PASMC contractile phenotype. Finally, the expression levels of PTEN were significantly decreased in PAH and PASMCs treated with miR‑132 mimics. Taken collectively, the data suggested that miR‑132 regulated PASMC function via PTEN and that it may be used as a potential target for the treatment of PAH.

PDGFBB promotes proliferation and migration via regulating miR-1181/STAT3 axis in human pulmonary arterial smooth muscle cells

Platelet-derived growth factor (PDGF) can induce hyperproliferation of pulmonary artery smooth muscle cells (PASMCs), which is a key causative factor to the occurrence and progression of pulmonary arterial hypertension (PAH). We previously identified that miR-1181 is significantly downregulated by PDGFBB in human PASMCs. In this work, we further explore the function of miR-1181 and underlying regulatory mechanisms in PDGF-induced PASMCs. First, the expression pattern of miR-1181 was characterized under PDGFBB treatment, and PDGF receptor/PKCβ signaling was found to repress miR-1181 expression. Then, gain- and loss-of-function experiments were respectively conducted and revealed the prominent role of miR-1181 in inhibiting PASMC proliferation and migration. Flow cytometry analysis suggested that miR-1181 regulated the PASMC proliferation through influencing the cell cycle transition from G0/G1 to S phase. Moreover, we exhibited that miR-1181 targeting STAT3 formed a regulatory axis to modulate PASMC proliferation. Finally, serum miR-1181 expression was also observed to be reduced in adult and newborn patients with PAH. Overall, this study provides novel findings that the miR-1181/STAT3 axis mediated PDGFBB-induced dysfunction in human PASMCs, implying a potential use of miR-1181 as a therapeutic and diagnostic candidate for the vascular remodeling diseases.

MiR-339 inhibits proliferation of pulmonary artery smooth muscle cell by targeting FGF signaling

Pulmonary artery hypertension (PAH) is a fatal disorder. Recent studies suggest that microRNA (miRNA) plays an important role in regulating proliferation of pulmonary artery smooth muscle cells (PASMC), which underlies the pathology of PAH. However, the exact mechanism of action of miRNAs remains elusive. In this study, we found that miR‐339 was highly expressed in the cardiovascular system and was downregulated by a group of cytokines and growth factors, especially PDGF‐BB and FGF2. Functional analyses revealed that miR‐339 can inhibit proliferation of PASMC. Also, miR‐339 inhibited FGF2‐induced proliferation, but had no effect on proliferation induced by PDGF‐BB. The fibroblast growth factor receptor substrate 2 (FRS2) was identified as a potential direct target of miR‐339. Consistent with the actions of miR‐339, knockdown of FRS2 only inhibited FGF2‐ but not PDGF‐BB‐induced proliferation of PASMC. In addition, our results showed that inhibition of ERK and PI3K abrogated the downregulation of miR‐339 induced by PDGF‐BB. Finally, miR‐339 expression was found to be decreased in the pulmonary arteries of rats with MCT‐induced PAH. Our study is the first report on the biological role of miR‐339 in regulating proliferation of PASMC by targeting FGF signaling, providing new mechanistic insights into PASMC proliferation and pathogenesis of PAH.