Anti-apoptosis endothelial cell-secreted microRNA-195-5p promotes pulmonary arterial smooth muscle cell proliferation and migration in pulmonary arterial hypertension

Panorama of artery endothelial cell dysfunction in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a fatal lung disease characterized by progressive pulmonary vascular remodeling. The initial cause of pulmonary vascular remodeling is the dysfunction of pulmonary arterial endothelial cells (PAECs), manifested by changes in the categorization of cell subtypes, endothelial programmed cell death, such as apoptosis, necroptosis, pyroptosis, ferroptosis, et al., overproliferation, senescence, metabolic reprogramming, endothelial-to-mesenchymal transition, mechanosensitivity, and regulation ability of peripheral cells. Therefore, it is essential to explore the mechanism of endothelial dysfunction in the context of PAH. This review aims to provide a comprehensive understanding of the molecular mechanisms underlying endothelial dysfunction in PAH. We highlight the developmental process of PAECs and changes in PAH and summarise the latest classification of endothelial dysfunction. Our review could offer valuable insights into potential novel EC-specific targets for preventing and treating PAH.

MicroRNA-195-5p Attenuates Pregnancy-Induced Hypertension by Inhibiting Oxidative Stress via OTX1/MAPK Signaling Pathway

Pregnancy-induced hypertension (PIH) is a hypertensive disorder during pregnancy and can induce perinatal death of human infants. MicroRNA (miR)-195-5p was validated to display low expression in severe preeclampsia placentas, but the role of miR-195-5p in pregnancy-induced hypertension (PIH) has not been investigated. The study emphasized on the functions and mechanism of miR-195-5p in PIH. A reduced uterine perfusion pressure (RUPP) rat model was established to mimic PIH in vivo. Adenovirus (Ad)-miR-195-5p agomir and/or Ad-OTX1 were further injected into some model rats. RT-qPCR was conducted to assess the expression of miR-195-5p and orthodenticle homeobox 1 (OTX1) in rat placental tissues, the isolated aortic endothelial cells (AECs), and in serum samples of PIH patients. Western blot analysis was implemented to measure the protein levels of OTX1, VEGFA, and key factors involved in the MAPK signaling pathway. The concentrations of oxidative stress markers (superoxide dismutase, catalase, and lipid hydroperoxide) in AECs and placental tissues of RUPP rats were measured by corresponding kits. The binding relation between miR-195-5p and OTX1 was verified using the dual-luciferase reporter assay. Hematoxylin-eosin staining was conducted to evaluate the pathological features of rat placental tissues. MiR-195-5p was downregulated, while OTX1 was upregulated in rat placental tissues and human serum samples of PIH patients. MiR-195-5p could target OTX1 and inversely regulate OTX1 expression in AECs and rat placental tissues. In addition, miR-195-5p can negatively regulate VEGFA level. Furthermore, miR-195-5p inactivates oxidative stress and the MAPK signaling by downregulating OTX1 in AECs. In vivo experiments revealed that OTX1 overexpression reversed the protective effect of miR-195-5p overexpression on placental damage and oxidative stress. MiR-195-5p alleviates PIH by inhibiting oxidative stress via targeting OTX1 and inactivating MAPK signaling.

MicroRNA153 induces apoptosis by targeting NFATc3 to improve vascular remodeling in pulmonary hypertension

BACKGROUND

The present study aimed to investigate the effect of microRNA153 (miRNA153) on pulmonary hypertension (PH).

METHODS

PH was induced by a single subcutaneous injection of sugen5416 (SU5416) combined with hypoxia exposure for 3 weeks (SuHx) in rats, while pulmonary arterial smooth muscle cells (PASMCs) obtained from rats were exposed to hypoxia to establish an in vitro model. Through observing the characteristic hemodynamic index in rats and by analyzing the physiological function, vascular remodeling and right ventricular hypertrophy were identified. The regulatory effects of miRNA153 on the nuclear factor of activated T cell isoform c3 (NFATc3) were measured by RT-qPCR, western blot, and immunofluorescence. Cell apoptosis was evaluated by flow cytometry.

RESULTS

The miRNA153 expression was reduced and unclear translation of NFATc3 was increased in both the in vivo and in vitro models of PH. In vivo, the pulmonary arterial pressure, right ventricle/(left ventricle + interventricular septum) (RV/(LV+S)), and media vascular thickness were increased in rats with PH; however, all these parameters were suppressed by prophylactic administration of miRNA153agomir. The upregulation of NFATc3 and downregulation of the potassium voltage-gated channel subfamily A member 5 (Kv1.5) were also reversed by transfection with miRNA153agomir. In vitro, miRNA153 increased the level of Kv1.5 in hypoxic PASMCs by targeting NFATc3 and inhibiting their proliferation and apoptosis resistance.

CONCLUSION

Our results confirmed that the therapeutic administration of miRNA153 promotes apoptosis and inhibits the proliferation of PASMCs to ameliorate PH, and that the NFATc3/Kv1.5 channel pathway may be involved in this process.

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.

Epigenetic regulation of programmed cell death in hypoxia-induced pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a severe progressive disease that may cause early right ventricular failure and eventual cardiac failure. The pathogenesis of PAH involves endothelial dysfunction, aberrant proliferation of pulmonary artery smooth muscle cells (PASMCs), and vascular fibrosis. Hypoxia has been shown to induce elevated secretion of vascular endothelial growth factor (VEGF), leading to the development of hypoxic PAH. However, the molecular mechanisms underlying hypoxic PAH remain incompletely understood. Programmed cell death (PCD) is a natural cell death and regulated by certain genes. Emerging evidence suggests that apoptotic resistance contributes to the development of PAH. Moreover, several novel types of PCD, such as autophagy, pyroptosis, and ferroptosis, have been reported to be involved in the development of PAH. Additionally, multiple diverse epigenetic mechanisms including RNA methylation, DNA methylation, histone modification, and the non-coding RNA molecule-mediated processes have been strongly linked to the development of PAH. These epigenetic modifications affect the expression of genes, which produce important changes in cellular biological processes, including PCD. Consequently, a better understanding of the PCD processes and epigenetic modification involved in PAH will provide novel, specific therapeutic strategies for diagnosis and treatment. In this review, we aim to discuss recent advances in epigenetic mechanisms and elucidate the role of epigenetic modifications in regulating PCD in hypoxia-induced PAH.

Unraveling the epigenetic landscape of pulmonary arterial hypertension: implications for personalized medicine development

Pulmonary arterial hypertension (PAH) is a multifactorial disease associated with the remodeling of pulmonary blood vessels. If left unaddressed, PAH can lead to right heart failure and even death. Multiple biological processes, such as smooth muscle proliferation, endothelial dysfunction, inflammation, and resistance to apoptosis, are associated with PAH. Increasing evidence suggests that epigenetic factors play an important role in PAH by regulating the chromatin structure and altering the expression of critical genes. For example, aberrant DNA methylation and histone modifications such as histone acetylation and methylation have been observed in patients with PAH and are linked to vascular remodeling and pulmonary vascular dysfunction. In this review article, we provide a comprehensive overview of the role of key epigenetic targets in PAH pathogenesis, including DNA methyltransferase (DNMT), ten-eleven translocation enzymes (TET), switch-independent 3A (SIN3A), enhancer of zeste homolog 2 (EZH2), histone deacetylase (HDAC), and bromodomain-containing protein 4 (BRD4). Finally, we discuss the potential of multi-omics integration to better understand the molecular signature and profile of PAH patients and how this approach can help identify personalized treatment approaches.

HIV and Drug Use: A Tale of Synergy in Pulmonary Vascular Disease Development

Over the past two decades, with the advent and adoption of highly active anti-retroviral therapy, HIV-1 infection, a once fatal and acute illness, has transformed into a chronic disease with people living with HIV (PWH) experiencing increased rates of cardio-pulmonary vascular diseases including life-threatening pulmonary hypertension. Moreover, the chronic consequences of tobacco, alcohol, and drug use are increasingly seen in older PWH. Drug use, specifically, can have pathologic effects on the cardiovascular health of these individuals. The "double hit" of drug use and HIV may increase the risk of HIV-associated pulmonary arterial hypertension (HIV-PAH) and potentiate right heart failure in this population. This article explores the epidemiology and pathophysiology of PAH associated with HIV and recreational drug use and describes the proposed mechanisms by which HIV and drug use, together, can cause pulmonary vascular remodeling and cardiopulmonary hemodynamic compromise. In addition to detailing the proposed cellular and signaling pathways involved in the development of PAH, this article proposes areas ripe for future research, including the influence of gut dysbiosis and cellular senescence on the pathobiology of HIV-PAH. © 2023 American Physiological Society. Compr Physiol 13:4659-4683, 2023.

Long Non-Coding RNAs Might Regulate Phenotypic Switch of Vascular Smooth Muscle Cells Acting as ceRNA: Implications for In-Stent Restenosis

Coronary in-stent restenosis is a late complication of angioplasty. It is a multifactorial process that involves vascular smooth muscle cells (VSMCs), endothelial cells, and inflammatory and genetic factors. In this study, the transcriptomic landscape of VSMCs’ phenotypic switch process was assessed under stimuli resembling stent injury. Co-cultured contractile VSMCs and endothelial cells were exposed to a bare metal stent and platelet-derived growth factor (PDGF-BB) 20 ng/mL. Migratory capacity (wound healing assay), proliferative capacity, and cell cycle analysis of the VSMCs were performed. RNAseq analysis of contractile vs. proliferative VSMCs was performed. Gene differential expression (DE), identification of new long non-coding RNA candidates (lncRNAs), gene ontology (GO), and pathway enrichment (KEGG) were analyzed. A competing endogenous RNA network was constructed, and significant lncRNA–miRNA–mRNA axes were selected. VSMCs exposed to “stent injury” conditions showed morphologic changes, with proliferative and migratory capacities progressing from G0-G1 cell cycle phase to S and G2-M. RNAseq analysis showed DE of 1099, 509 and 64 differentially expressed mRNAs, lncRNAs, and miRNAs, respectively. GO analysis of DE genes showed significant enrichment in collagen and extracellular matrix organization, regulation of smooth muscle cell proliferation, and collagen biosynthetic process. The main upregulated nodes in the lncRNA-mediated ceRNA network were PVT1 and HIF1-AS2, with downregulation of ACTA2-AS1 and MIR663AHG. The PVT1 ceRNA axis appears to be an attractive target for in-stent restenosis diagnosis and treatment.

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.

Long Non-Coding RNA MEG8 Suppresses Hypoxia-Induced Excessive Proliferation, Migration and Inflammation of Vascular Smooth Muscle Cells by Regulation of the miR-195-5p/RECK Axis

It has been recognized that rebalancing the abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) helps relieve vascular injury. Presently, we aim to investigate whether long non-coding RNA (lncRNA) maternally expressed 8 (MEG8) plays a role in affecting the excessive proliferation and migration of VSMCs following hypoxia stimulation. A percutaneous transluminal angioplasty balloon dilatation catheter was adopted to establish vascular intimal injury, the levels of MEG8 and miR-195-5p in the carotid artery were tested by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Hypoxia was used to stimulate VSMCs, then the cell counting kit-8 (CCK-8) assay, Transnwell assay, and wound healing assay were conducted to evaluate the proliferation, and migration of VSMCs. The protein levels of RECK (reversion inducing cysteine rich protein with kazal motifs), MMP (matrix metalloproteinase) 3/9/13, COX2 (cytochrome c oxidase subunit II), macrophage inflammatory protein (MIP)-1beta, VCAM-1 (vascular cell adhesion molecule 1), ICAM-1 (intercellular adhesion molecule 1), and HIF-1α (hypoxia inducible factor 1 subunit alpha) were determined by western blot or cellular immunofluorescence. As the data showed, MEG8 was down-regulated in the carotid artery after balloon injury in rats and hypoxia-treated VSMCs, and miR-195-5p was overexpressed. Forced MEG8 overexpression or inhibiting miR-195-5p attenuated hypoxia-promoted cell proliferation and migration of VSMCs. In addition, miR-195-5p up-regulation reversed MEG8-mediated effects. Hypoxia hindered the RECK expression while boosted MMP3/9/13 levels, and the effect was markedly reversed with MEG8 up-regulation or miR-195-5p down-regulation. Mechanistically, MEG8 functioned as a competitive endogenous (ceRNA) by sponging miR-195-5p which targeted RECK. Moreover, the HIF-1α inhibitor PX478 prevented hypoxia-induced proliferation, and migration of VSMCs, upregulated MEG8, and restrained miR-195-5p expression. Overall, lncRNA MEG8 participated in hypoxia-induced excessive proliferation, inflammation and migration of VSMCs through the miR-195-5p/RECK axis.

MicroRNA-195-5p Downregulation Inhibits Endothelial Mesenchymal Transition and Myocardial Fibrosis in Diabetic Cardiomyopathy by Targeting Smad7 and Inhibiting Transforming Growth Factor Beta 1-Smads-Snail Pathway

Diabetic cardiomyopathy (DCM) is a complication of diabetes mellitus, which is associated with fibrosis and microRNAs (miRs). This study estimated the mechanism of miR-195-5p in endothelial mesenchymal transition (EndMT) and myocardial fibrosis in DCM. After the establishment of DCM rat models, miR-195-5p was silenced by miR-195-5p antagomir. The cardiac function-related indexes diastolic left ventricular anterior wall (LVAW, d), systolic LVAW (d), diastolic left ventricular posterior wall (LVPW, d), systolic LVPW (d), left ventricular ejection fraction (LVEF), and fractional shortening (FS) were measured and miR-195-5p expression in myocardial tissue was detected. Myocardial fibrosis, collagen deposition, and levels of fibrosis markers were detected. Human umbilical vein endothelial cells (HUVECs) were exposed to high glucose (HG) and miR-195-5p was silenced. The levels of fibrosis proteins, endothelial markers, fibrosis markers, EndMT markers, and transforming growth factor beta 1 (TGF-β1)/Smads pathway-related proteins were measured in HUVECs. The interaction between miR-195-5p and Smad7 was verified. In vivo, miR-195-5p was highly expressed in the myocardium of DCM rats. Diastolic and systolic LVAW, diastolic and systolic LVPW were increased and LVEF and FS were decreased. Inhibition of miR-195-5p reduced cardiac dysfunction, myocardial fibrosis, collagen deposition, and EndMT, promoted CD31 and VE-cadehrin expressions, and inhibited α-SMA and vimentin expressions. In vitro, HG-induced high expression of miR-195-5p and the expression changes of endothelial markers CD31, VE-cadehrin and fibrosis markers α-SMA and vimentin were consistent with those in vivo after silencing miR-195-5p. In mechanism, miR-195-5p downregulation blocked EndMT by inhibiting TGF-β1-smads pathway. Smad7 was the direct target of miR-195-5p and silencing miR-195-5p inhibited EndMT by promoting Smad7 expression. Collectively, silencing miR-195-5p inhibits TGF-β1-smads-snail pathway by targeting Smad7, thus inhibiting EndMT and alleviating myocardial fibrosis in DCM.

Endothelial cells in the pathogenesis of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a devastating disease that involves pulmonary vasoconstriction, small vessel obliteration, large vessel thickening and obstruction, and development of plexiform lesions. PAH vasculopathy leads to progressive increases in pulmonary vascular resistance, right heart failure and, ultimately, premature death. Besides other cell types that are known to be involved in PAH pathogenesis (e.g. smooth muscle cells, fibroblasts and leukocytes), recent studies have demonstrated that endothelial cells (ECs) have a crucial role in the initiation and progression of PAH. The EC-specific role in PAH is multi-faceted and affects numerous pathophysiological processes, including vasoconstriction, inflammation, coagulation, metabolism and oxidative/nitrative stress, as well as cell viability, growth and differentiation. In this review, we describe how EC dysfunction and cell signalling regulate the pathogenesis of PAH. We also highlight areas of research that warrant attention in future studies, and discuss potential molecular signalling pathways in ECs that could be targeted therapeutically in the prevention and treatment of PAH.

Therapeutic effect of and mechanisms underlying the effect of miR-195-5p on subarachnoid hemorrhage-induced vasospasm and brain injury in rats

Objectives

There is much evidence suggesting that inflammation contributes majorly to subarachnoid hemorrhage (SAH)-induced cerebral vasospasm and brain injury. miRNAs have been found to modulate inflammation in several neurological disorders. This study investigated the effect of miR-195-5p on SAH-induced vasospasm and early brain injury in experimental rats.

Methods

Ninety-six Sprague-Dawley male rats were randomly and evenly divided into a control group (no SAH, sham surgery), a SAH only group, a SAH + NC-mimic group, and a SAH + miR-195-5p group. SAH was induced using a single injection of blood into the cisterna magna. Suspensions containing NC-mimic and miR-195-5p were intravenously injected into rat tail 30 mins after SAH was induced. We determined degree of vasospasm by averaging areas of cross-sections the basilar artery 24h after SAH. We measured basilar artery endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κ B), phosphorylated NF-κ B (p-NF-κ B), inhibitor of NF-κ B (Iκ Bα) and phosphorylated-Iκ Bα (p-Iκ Bα). Cell death assay was used to quantify the DNA fragmentation, an indicator of apoptotic cell death, in the cortex, hippocampus, and dentate gyrus. Tumor necrosis factor alpha (TNF-α) levels were measured using sample protein obtained from the cerebral cortex, hippocampus and dentate gyrus.

Results

Prior to fixation by perfusion, there were no significant physiological differences among the control and treatment groups. SAH successfully induced vasospasm and early brain injury. MiR-195-5p attenuated vasospasam-induced changes in morphology, reversed SAH-induced elevation of iNOS, p-NF-κ B, NF-κ B, and p-Iκ Bα and reversed SAH-induced suppression of eNOS in the basilar artery. Cell death assay revealed that MiR-195-5p significantly decreased SAH-induced DNA fragmentation (apoptosis) and restored TNF-α level in the dentate gyrus.

Conclusion

In conclusion, MiRNA-195-5p attenuated SAH-induced vasospasm by up-regulating eNOS, down-regulating iNOS and inhibiting the NF-κ B signaling pathway. It also protected neurons by decreasing SAH-induced apoptosis-related cytokine TNF-α expression in the dentate gyrus. Further study is needed to elucidate the detail mechanism underlying miR-195-5p effect on SAH-induced vasospasm and cerebral injury. We believe that MiR-195-5p can potentially be used to manage SAH-induced cerebral vasospasm and brain injury.

miR-195-5p Regulates the Phenotype Switch of CCSM Cells by Targeting Smad7

INTRODUCTION

Phenotype switch refers to the process in which smooth muscle cells change from contractile type to synthetic type and acquire the ability of proliferation. Phenotypic transformation involves many changes of cell function, such as collagen deposition and fibrosis, which affect the normal erectile function of penis.

AIM

To investigate the role of miR-195-5p in regulating the Phenotype switch of the corpus cavernosum smooth muscle (CCSM) cells.

METHODS

A small mother against decapentaplegic 7(Smad7) virus vector and a miR-195-5p mimics or an si-Smad7 viral vector and a miR-195-5p inhibitor were transfected into CCSM cells. The cells were obtained by primary culture of rat corpus cavernosum smooth muscle tissue. Real-time polymerase chain reaction (PCR) experiments, Western blotting, hematoxylin-eosin (HE) staining, transwell experiments, MTT assays, and flow cytometry were used to detect miR-195-5p, Smad7, phenotype switch markers of CCSM cells and related protein expression, as well as changes in cell morphology, migration, proliferation and apoptosis.

MAIN OUTCOME MEASURE

To study the regulation of miR-195-5p in CCSM cells by overexpression and silencing strategies.

RESULTS

Overexpressed miR-195-5p promoted the transformation of CCSM cells from a contractile type to a synthetic type. Meanwhile, the migration ability and proliferation ability of CCSM cells increased, and the apoptosis rate decreased. The expression-silencing of miR-195-5p gave rise to the opposite effect. The results of the rescue experiment demonstrated that overexpressed Smad7 rescued the inhibitory of the switch of the CCSM cell phenotype from the contractile type to the synthesis type caused by overexpression of miR-195-5p alone. Moreover, the enhancement effect of the migration ability and proliferation ability of CCSM cells was also eliminated, and the apoptosis rate was increased. Silencing miR-195-5p and Smad7 at the same time resulted in the opposite effect.

CONCLUSION

miR-195-5p may regulate the phenotype switch of CCSM cells by targeting Smad7. Zhang J, Zhang X, Zhang J, et al. miR-195-5p Regulates the Phenotype Switch of CCSM Cells by Targeting Smad7. Sex Med 2021;9:100349.

Current perspectives on inhibitory SMAD7 in health and disease

Transforming growth factor β (TGF-β) family members play an extensive role in cellular communication that orchestrates both early development and adult tissue homeostasis. Aberrant TGF-β family signaling is associated with a pathological outcome in numerous diseases, and in-depth understanding of molecular and cellular processes could result in therapeutic benefit for patients. Canonical TGF-β signaling is mediated by receptor-regulated SMADs (R-SMADs), a single co-mediator SMAD (Co-SMAD), and inhibitory SMADs (I-SMADs). SMAD7, one of the I-SMADs, is an essential negative regulator of the pleiotropic TGF-β and bone morphogenetic protein (BMP) signaling pathways. In a negative feedback loop, SMAD7 inhibits TGF-β signaling by providing competition for TGF-β type-1 receptor (TβRI), blocking phosphorylation and activation of SMAD2. Moreover, SMAD7 recruits E3 ubiquitin SMURF ligases to the type I receptor to promote ubiquitin-mediated proteasomal degradation. In addition to its role in TGF-β and BMP signaling, SMAD7 is regulated by and implicated in a variety of other signaling pathways and functions as a mediator of crosstalk. This review is focused on SMAD7, its function in TGF-β and BMP signaling, and its role as a downstream integrator and crosstalk mediator. This crucial signaling molecule is tightly regulated by various mechanisms. We provide an overview of the ways by which SMAD7 is regulated, including noncoding RNAs (ncRNAs) and post-translational modifications (PTMs). Finally, we discuss its role in diseases, such as cancer, fibrosis, and inflammatory bowel disease (IBD).

lncRNA FGD5 antisense RNA 1 upregulates RORA to suppress hypoxic injury of human cardiomyocyte cells by inhibiting oxidative stress and apoptosis via miR‑195

FGD5 antisense RNA 1 (FGD5-AS1) is a long non-coding RNA in acute myocardial infarction (AMI), which is primarily caused by myocardial ischemia-hypoxia. Retinoid acid receptor-related orphan receptor α (RORA) is a key protector in maintaining heart function. However, the roles of FGD5-AS1 and RORA in AMI have not previously been elucidated. The present study investigated the effect and mechanism of FGD5-AS1 and RORA in human cardiomyocyte AC16 cells under hypoxia. Reverse transcription-quantitative PCR and western blotting demonstrated that FGD5-AS1 and RORA were downregulated in the serum of patients with AMI and hypoxia-challenged AC16 cells. Functional experiments were performed via assays, flow cytometry and western blotting. In response to hypoxia, superoxide dismutase (SOD) activity was inhibited, but apoptosis rate and levels of reactive oxygen species and malondialdehyde were promoted in AC16 cells, accompanied by increased Bax and cleaved caspase-3 expression levels, and decreased SOD2 and glutathione peroxidase 1 expression levels. However, hypoxia-induced oxidative stress and apoptosis in AC16 cells were attenuated by ectopic expression of FGD5-AS1 or RORA. Moreover, silencing RORA counteracted the suppressive role of FGD5-AS1 overexpression in hypoxic injury. FGD5-AS1 controlled RORA expression levels via microRNA-195-5p (miR-195), as confirmed by dual-luciferase reporter and RNA pull-down assays. Consistently, miR-195 knockdown suppressed hypoxia-induced oxidative stress and apoptosis in AC16 cells, which was abrogated by downregulating FGD5-AS1 or RORA. In conclusion, FGD5-AS1 modulated hypoxic injury in human cardiomyocytes partially via the miR-195/RORA axis, suggesting FGD5-AS1 as a potential target in interfering with the progression of AMI.

Docosahexaenoic acid inhibits Ca2+ influx and downregulates CaSR by upregulating microRNA-16 in pulmonary artery smooth muscle cells

Docosahexaenoic acid (DHA) is reported to have the potential to ameliorate pulmonary arterial hypertension (PAH), while the specific mechanism is still obscure. This study aims to investigate the function of DHA in pulmonary artery smooth muscle cells (PASMCs) and explore the underlying mechanism. In our study, DHA was used to incubate PASMCs. Cytosolic-free Ca²⁺ concentration ([Ca²⁺ ]cyt) was measured using Fluo-3 AM method. Real-time polymerase chain reaction was used to detect microRNA-16 (miR-16) and calcium-sensing receptor (CaSR) messenger RNA expression levels. CCK-8 assay, BrdU assay, and Transwell assay were employed to detect the effects of DHA on proliferation and migration of PASMCs. CaSR was confirmed as a direct target of miR-16 using dual-luciferase assay, polymerase chain reaction, and Western blot analysis. It was found that DHA significantly inhibited PASMC proliferation and migration and decreased [Ca²⁺ ]cyt. After transfection of miR-16 mimics, proliferation and migration ability of PASMCs were significantly inhibited, whereas opposite effects were observed after miR-16 inhibition. [Ca²⁺ ]cyt was also inhibited by miR-16 transfection. DHA then promoted the expression of miR-16, and the effects of DHA on PASMCs were annulled when miR-16 was inhibited. CaSR was identified as a direct target of miR-16. CaSR was inhibited directly by miR-16 and indirectly by DHA. In conclusion, DHA inhibits the proliferation and migration of PASMCs, and probably ameliorates PAH via regulating miR-16/CaSR axis.

Alginate Oligosaccharide Alleviates Monocrotaline-Induced Pulmonary Hypertension via Anti-Oxidant and Anti-Inflammation Pathways in Rats

Pulmonary arterial hypertension (PAH) is a serious and fatal cardiovascular disorder characterized by increased pulmonary vascular resistance and progressive pulmonary vascular remodeling. The underlying pathological mechanisms of PAH are multi-factorial and multi-cellular. Alginate oligosaccharide (AOS), which is produced by depolymerizing alginate, shows better pharmacological activities and beneficial effects. The present study was undertaken to investigate the effects and potential mechanisms of AOS-mediated alleviation of pulmonary hypertension. Pulmonary hypertension was induced in Sprague-Dawley rats by a single intraperitoneal injection of monocrotaline (MCT; 60 mg/kg). Five weeks after the injection of MCT, AOS (5, 10, and 20 mg·kg^-1·d^-1) was injected intraperitoneally for another three weeks. The results showed that AOS prevented the development of MCT-induced pulmonary hypertension and right ventricular hypertrophy in a dose-dependent manner. AOS treatment also prevented MCT-induced pulmonary vascular remodeling via inhibition of the TGF-β1/p-Smad2 signaling pathway. Furthermore, AOS treatment downregulated the expression of malondialdehyde, nicotinamide adenine dinucleotide phosphate oxidase, and pro-inflammatory cytokines, decreased macrophage infiltration, and upregulated the expression of anti-inflammatory cytokines. These findings indicate that AOS exerts anti-oxidative and anti-inflammatory effects in pulmonary arteries, which may contribute to the alleviation of pulmonary hypertension and pulmonary vascular remodeling.

Extracellular vesicle cross-talk between pulmonary artery smooth muscle cells and endothelium during excessive TGF-β signalling: implications for PAH vascular remodelling

BACKGROUND

Excessive TGF-β signalling has been shown to underlie pulmonary hypertension (PAH). Human pulmonary artery smooth muscle cells (HPASMCs) can release extracellular vesicles (EVs) but their contents and significance have not yet been studied. Here, we aimed to analyse the contents and biological relevance of HPASMC-EVs and their transport to human pulmonary arterial endothelial cells (HPAECs), as well as the potential alteration of these under pathological conditions.

METHODS

We used low-input RNA-Seq to analyse the RNA cargoes sorted into released HPASMC-EVs under basal conditions. We additionally analysed the effects of excessive TGF-β signalling, using TGF-β1 and BMP4, in the transcriptome of HPASMCs and their EVs. We then, for the first time, optimised Cre-loxP technology for its use with primary cells in vitro, directly visualising HPASMC-to-HPAEC communication and protein markers on cells taking up EVs. Furthermore we could analyse alteration of this transport with excessive TGF-β signalling, as well as by other cytokines involved in PAH: IL-1β, TNF-α and VEGFA.

RESULTS

We were able to detect transcripts from 2417 genes in HPASMC-EVs. Surprisingly, among the 759 enriched in HPASMC-EVs compared to their donor cells, we found Zeb1 and 2 TGF-β superfamily ligands, GDF11 and TGF-β3. Moreover, we identified 90 genes differentially expressed in EVs from cells treated with TGF-β1 compared to EVs in basal conditions, including a subset involved in actin and ECM remodelling, among which were bHLHE40 and palladin. Finally, using Cre-loxP technology we showed cell-to-cell transfer and translation of HPASMC-EV Cre mRNA from HPASMC to HPAECs, effectively evidencing communication via EVs. Furthermore, we found increased number of smooth-muscle actin positive cells on HPAECs that took up HPASMC-EVs. The uptake and translation of mRNA was also higher in activated HPAECs, when stimulated with TGF-β1 or IL-1β.

CONCLUSIONS

HPASMC-EVs are enriched in RNA transcripts that encode genes that could contribute to vascular remodelling and EndoMT during development and PAH, and TGF-β1 up-regulates some that could enhance this effects. These EVs are functionally transported, increasingly taken up by activated HPAECs and contribute to EndoMT, suggesting a potential effect of HPASMC-EVs in TGF-β signalling and other related processes during PAH development.

Elevated miR-195-5p expression in deep vein thrombosis and mechanism of action in the regulation of vascular endothelial cell physiology

Deep vein thrombosis (DVT) is one of the most common cardiovascular diseases. The apoptosis of vascular endothelial cells is the most important cause of venous thrombosis. MicroRNAs (miRNAs) play important roles in the regulation of cell apoptosis. miRNA (miR)-195 is upregulated in the blood of patients with DVT, and it was predicted that Bcl-2 is a potential target of miR-195-5p. Therefore, it was hypothesized that miR-195-5p may play an important role in the development of DVT by targeting Bcl-2. The present study aimed to investigate the expression of miR-195-5p in DVT patients, and to explore whether miR-195-5p is involved in the development of DVT by regulating the apoptosis of vascular endothelial cells. The level of miR-195-5p was detected using reverse transcription-quantitative PCR. Dual luciferase reporter assays were used to determine the relationship between Bcl-2 and miR-195-5p. Cell viability was detected using MTT assays, and cell apoptosis was analyzed by flow cytometry. Protein levels of Bcl-2 and Bax were measured by western blotting. The results indicated that miR-195-5p was significantly upregulated in the blood of DVT patients. It was also revealed that Bcl-2 was a direct target of miR-195-5p, and that Bcl-2 was downregulated in the blood of patients with DVT. miR-195-5p downregulation promoted cell viability and inhibited the apoptosis of human umbilical vein endothelial cells (HUVECs). miR-195-5p upregulation inhibited cell viability and increased the apoptosis of HUVECs. All of the observed effects of miR-195-5p upregulation on HUVECs were reversed by raised Bcl-2 expression. In conclusion, miR-195-5p was significantly upregulated in patients with DVT, and it may be involved in the development of DVT by regulating the apoptosis of vascular endothelial cells. Therefore, miR-195-5p may be a potential target for predicting and treating DVT.

Circulating microRNAs in patients with immune thrombocytopenia before and after treatment with thrombopoietin-receptor agonists

MicroRNAs (miRNAs) are small non-coding RNAs involved in the regulation of gene expression. Dysregulated expression of several miRNAs has been found in primary immune thrombocytopenia (ITP) suggesting that miRNAs are likely involved in the pathogenesis of ITP. We aimed to explore the differential expression of miRNAs in patients with ITP before and after starting treatment with thrombopoietin-receptor agonists (TPO-RAs) to clarify their roles in the pathophysiology of ITP, and as potential diagnostic and prognostic markers of this disorder.We performed a profiling study where 179 miRNAs were analyzed in eight ITP patients before and during treatment with TPO-RAs and in eight controls using miRNA PCR panel; 81 miRNAs were differentially expressed in ITP patients compared to controls, and 14 miRNAs showed significant changes during TPO-RA-treatment. Ten miRNAs were selected for validation that was performed in 23 patients and 22 controls using droplet digital PCR. Three miRNAs were found to be differentially expressed in ITP patients before TPO-RA-treatment compared to controls: miR-199a-5p was down-regulated (p = 0.0001), miR-33a-5p (p = 0.0002) and miR-195-5p (p = 0.035) were up-regulated. Treatment with TPO-RAs resulted in changes in six miRNAs including miR-199a-5p (p = 0.001), miR-33a-5p (p = 0.003), miR-382-5p (p = 0.004), miR-92b-3p (p = 0.005), miR-26a-5p (p = 0.008) and miR-221-3p (p = 0.023); while miR-195-5p remained unchanged and significantly higher than in controls, despite the increase in the platelet count, which may indicate its possible role in the pathophysiology of ITP. Regression analysis revealed that pre-treatment levels of miR-199a-5p and miR-221-3p could help to predict platelet response to TPO-RA-treatment. ROC curve analysis showed that the combination of miR-199a-5p and miR-33a-5p could distinguish patients with ITP from controls with AUC of 0.93.This study identifies a number of differentially expressed miRNAs in ITP patients before and after initiation of TPO-RAs with potential roles in the pathophysiology, as well as with a possible utility as diagnostic and prognostic biomarkers. These interesting findings deserve further exploration and validation in future studies.