TNF-α elicits phenotypic and functional alterations of vascular smooth muscle cells by miR-155-5p-dependent down-regulation of cGMP-dependent kinase 1

Immunoproteasomal Inhibition With ONX-0914 Attenuates Atherosclerosis and Reduces White Adipose Tissue Mass and Metabolic Syndrome in Mice

BACKGROUND

Atherosclerosis is the major underlying pathology of cardiovascular disease and is driven by dyslipidemia and inflammation. Inhibition of the immunoproteasome, a proteasome variant that is predominantly expressed by immune cells and plays an important role in antigen presentation, has been shown to have immunosuppressive effects.

METHODS

We assessed the effect of ONX-0914, an inhibitor of the immunoproteasomal catalytic subunits LMP7 (proteasome subunit β5i/large multifunctional peptidase 7) and LMP2 (proteasome subunit β1i/large multifunctional peptidase 2), on atherosclerosis and metabolism in LDLr-/- and APOE*3-Leiden.CETP mice.

RESULTS

ONX-0914 treatment significantly reduced atherosclerosis, reduced dendritic cell and macrophage levels and their activation, as well as the levels of antigen-experienced T cells during early plaque formation, and Th1 cells in advanced atherosclerosis in young and aged mice in various immune compartments. Additionally, ONX-0914 treatment led to a strong reduction in white adipose tissue mass and adipocyte progenitors, which coincided with neutrophil and macrophage accumulation in white adipose tissue. ONX-0914 reduced intestinal triglyceride uptake and gastric emptying, likely contributing to the reduction in white adipose tissue mass, as ONX-0914 did not increase energy expenditure or reduce total food intake. Concomitant with the reduction in white adipose tissue mass upon ONX-0914 treatment, we observed improvements in markers of metabolic syndrome, including lowered plasma triglyceride levels, insulin levels, and fasting blood glucose.

CONCLUSIONS

We propose that immunoproteasomal inhibition reduces 3 major causes underlying cardiovascular disease, dyslipidemia, metabolic syndrome, and inflammation and is a new target in drug development for atherosclerosis treatment.

Extracellular vesicles in atherosclerosis and vascular calcification: the versatile non-coding RNAs from endothelial cells and vascular smooth muscle cells

Atherosclerosis (AS) is characterized by the accumulation of lipids, fibrous elements, and calcification in the innermost layers of arteries. Vascular calcification (VC), the deposition of calcium and phosphate within the arterial wall, is an important characteristic of AS natural history. However, medial arterial calcification (MAC) differs from intimal calcification and cannot simply be explained as the consequence of AS. Endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) are directly involved in AS and VC processes. Understanding the communication between ECs and VSMCs is critical in revealing mechanisms underlying AS and VC. Extracellular vesicles (EVs) are found as intercellular messengers in kinds of physiological processes and pathological progression. Non-coding RNAs (ncRNAs) encapsulated in EVs are involved in AS and VC, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). The effects of ncRNAs have not been comprehensively understood, especially encapsulated in EVs. Some ncRNAs have demonstrated significant roles in AS and VC, but it remains unclear the functions of the majority ncRNAs detected in EVs. In this review, we summarize ncRNAs encapsulated in EC-EVs and VSMC-EVs, and the signaling pathways that are involved in AS and VC.

MiR-155-5p Attenuates Vascular Smooth Muscle Cell Oxidative Stress and Migration via Inhibiting BACH1 Expression

The malfunction of vascular smooth muscle cells (VSMCs) is an initiating factor in the pathogenesis of pathological vascular remodeling, including hypertension-related vascular lesions. MicroRNAs (miRNAs) have been implicated in the pathogenesis of VSMC proliferation and migration in numerous cases of cardiovascular remodeling. The evidence for the regulatory role of miR-155-5p in the development of the cardiovascular system has been emerging. However, it was previously unclear whether miR-155-5p participated in the migration of VSMCs under hypertensive conditions. Thus, we aimed to define the exact role and action of miR-155-5p in VSMC migration by hypertension. Here, we detected that the level of miR-155-5p was lower in primary VSMCs from spontaneously hypertensive rats (SHRs). Its overexpression attenuated, while its depletion accelerated, the migration and oxidative damage of VSMCs from SHRs. Our dual-luciferase reporter assay showed that miRNA-155-5p directly targeted the 3'-untranslated region (3'-UTR) of BTB and CNC homology 1 (BACH1). The miR-155-5p mimic inhibited BACH1 upregulation in SHR VSMCs. By contrast, the deletion of miR-155-5p further elevated the upregulation of BACH1 in SHR-derived VSMCs. Importantly, the overexpression of miR-155-5p and knockdown of BACH1 had synergistic effects on the inhibition of VSMCs in hypertension. Collectively, miR-155-5p attenuates VSMC migration and ameliorates vascular remodeling in SHRs, via suppressing BACH1 expression.

MicroRNA regulation of phenotypic transformations in vascular smooth muscle: relevance to vascular remodeling

Alterations in the vascular smooth muscle cells (VSMC) phenotype play a critical role in the pathogenesis of several cardiovascular diseases, including hypertension, atherosclerosis, and restenosis after angioplasty. MicroRNAs (miRNAs) are a class of endogenous noncoding RNAs (approximately 19-25 nucleotides in length) that function as regulators in various physiological and pathophysiological events. Recent studies have suggested that aberrant miRNAs' expression might underlie VSMC phenotypic transformation, appearing to regulate the phenotypic transformations of VSMCs by targeting specific genes that either participate in the maintenance of the contractile phenotype or contribute to the transformation to alternate phenotypes, and affecting atherosclerosis, hypertension, and coronary artery disease by altering VSMC proliferation, migration, differentiation, inflammation, calcification, oxidative stress, and apoptosis, suggesting an important regulatory role in vascular remodeling for maintaining vascular homeostasis. This review outlines recent progress in the discovery of miRNAs and elucidation of their mechanisms of action and functions in VSMC phenotypic regulation. Importantly, as the literature supports roles for miRNAs in modulating vascular remodeling and for maintaining vascular homeostasis, this area of research will likely provide new insights into clinical diagnosis and prognosis and ultimately facilitate the identification of novel therapeutic targets.

Colchicine Protects against Ethanol-Induced Senescence and Senescence-Associated Secretory Phenotype in Endothelial Cells

Inflammaging is a potential risk factor for cardiovascular diseases. It results in the development of thrombosis and atherosclerosis. The accumulation of senescent cells in vessels causes vascular inflammaging and contributes to plaque formation and rupture. In addition to being an acquired risk factor for cardiovascular diseases, ethanol can induce inflammation and senescence, both of which have been implicated in cardiovascular diseases. In the current study, we used colchicine to abate the cellular damaging effects of ethanol on endothelial cells. Colchicine prevented senescence and averted oxidative stress in endothelial cells exposed to ethanol. It lowered the relative protein expression of aging and senescence marker P21 and restored expression of the DNA repair proteins KU70/KU80. Colchicine inhibited the activation of nuclear factor kappa B (NFκ-B) and mitogen activated protein kinases (MAPKs) in ethanol-treated endothelial cells. It reduced ethanol-induced senescence-associated secretory phenotype. In summary, we show that colchicine ameliorated the ethanol-caused molecular events, resulting in attenuated senescence and senescence-associated secretory phenotype in endothelial cells.

Progress in research on the role of exosomal miRNAs in the diagnosis and treatment of cardiovascular diseases

Cardiovascular diseases are the most common diseases threatening the health of the elderly, and the incidence and mortality rates associated with cardiovascular diseases remain high and are increasing gradually. Studies on the treatment and prevention of cardiovascular diseases are underway. Currently, several research groups are studying the role of exosomes and biomolecules incorporated by exosomes in the prevention, diagnosis, and treatment of clinical diseases, including cardiovascular diseases. Now, based on the results of published studies, this review discusses the characteristics, separation, extraction, and identification of exosomes, specifically the role of exosomal miRNAs in atherosclerosis, myocardial injury and infarction, heart failure, aortic dissection, myocardial fibrosis, ischemic reperfusion, atrial fibrillation, and other diseases. We believe that the observations noted in this article will aid in the prevention, diagnosis, and treatment of cardiovascular diseases.

GJD Modulates Cardiac/Vascular Inflammation and Decreases Blood Pressure in Hypertensive Rats

Gedan Jiangya decoction (GJD) (aqueous ethanol extract), a traditional Chinese medicine formula which contain six botanical drugs (Uncaria rhynchophylla (Miq.) Miq., Salvia miltiorrhiza Bunge, Pueraria lobata (Willd.) Ohwi, Eucommia ulmoides Oliv., Prunella vulgaris L., and Achyranthes bidentata Blume) was designed to treat hypertension; however, the underlying mechanism of action is unclear. This study aimed to determine the mechanisms of action of GJD in the treatment of hypertension in spontaneously hypertensive rats (SHR). Male SHRs were randomly divided into five groups: GJD doses were low (1.36 g/kg/d), medium (2.72 g/kg/d), and high (5.44 g/kg/d), captopril (13.5 mg/kg/d), and SHR groups, with Wistar-Kyoto rats (WKY) serving as the control. Every rat was gavaged once a day. The ALC-NIBP, a noninvasive blood pressure device, measured systolic (SBP) and diastolic (DBP) blood pressures. Six weeks following treatment, all rats were anesthetized. The blood samples were obtained from the abdominal aorta and then serum isolated to assess endothelin-1 and angiotensin II, interleukin-1beta, interleukin-6, and TNF-alpha. The left ventricular and thoracic aortas were taken for HE staining, immunohistochemistry, RT-qPCR, and western blot examination. Following GJD therapy, SBP and DBP were significantly lowered, as were serum levels of endothelin-1 and angiotensin II. The thickness of the left ventricular and thoracic aorta walls reduced, as did type I collagen, type III collagen, and alpha-SMA expression in the left ventricular and aortic tissues. The GJD treatment significantly reduced serum levels of the inflammatory markers interleukin-1beta, interleukin-6, and TNF-alpha. Furthermore, interleukin-1 beta, interleukin-6, TNF-alpha, TAK1, and NF-κB/p65 levels were significantly reduced in left ventricular and aortic tissues, whereas IkB-alpha levels were significantly elevated. GJD has a dose-dependent effect on all parameters. In conclusion, GJD has been shown to lower blood pressure, improve cardiovascular remodeling, and reduce inflammation via regulating NF-κB in SHRs.

Therapeutic potential of traditional Chinese medicine in atherosclerosis: A review

Atherosclerosis is the onset of endothelial cell damage and is characterized by abnormal accumulation of fibrinogen and lipid in large and middle arteries. Recent researches indicate that traditional Chinese medicine including Notoginseng Radix et Rhizoma, Astragali Radix, Salviae Miltiorrhizae Radix et Rhizoma, Ginseng Radix et Rhizoma, Fructus Crataegi, Glycyrrhizae Radix et Rhizoma, Polygoni Multiflori Radix, Fructus Lycii, and Coptidis Rhizoma have therapeutic effects on atherosclerosis. Furthermore, the pharmacological roles of these kinds of traditional Chinese medicine in atherosclerosis refer to endothelial function influences, cell proliferation and migration, platelet aggregation, thrombus formation, oxidative stress, inflammation, angiogenesis, apoptosis, autophagy, lipid metabolism, and the gut microbiome. Traditional Chinese medicine may serve as potential and effective anti-atherosclerosis drugs. However, a critical study has shown that Notoginseng Radix et Rhizoma may also have toxic effects including pustules, fever, and elevate circulating neutrophil count. Further high-quality studies are still required to determine the clinical safety and efficacy of traditional Chinese medicine and its active ingredients.

The gut-cardiovascular connection: new era for cardiovascular therapy

Our gut microbiome is constituted by trillions of microorganisms including bacteria, archaea and eukaryotic microbes. Nowadays, gut microbiome has been gradually recognized as a new organ system that systemically and biochemically interact with the host. Accumulating evidence suggests that the imbalanced gut microbiome contributes to the dysregulation of immune system and the disruption of cardiovascular homeostasis. Specific microbiome profiles and altered intestinal permeability are often observed in the pathophysiology of cardiovascular diseases. Gut-derived metabolites, toxins, peptides and immune cell-derived cytokines play pivotal roles in the induction of inflammation and the pathogenesis of dysfunction of heart and vasculature. Impaired crosstalk between gut microbiome and multiple organ systems, such as gut-vascular, heart-gut, gut-liver and brain-gut axes, are associated with higher cardiovascular risks. Medications and strategies that restore healthy gut microbiome might therefore represent novel therapeutic options to lower the incidence of cardiovascular and metabolic disorders.

Cytokines as therapeutic targets for cardio- and cerebrovascular diseases

Despite major advances in prevention and treatment, cardiac and cerebral atherothrombotic complications still account for substantial morbidity and mortality worldwide. In this context, inflammation is involved in the chronic process leading atherosclerotic plaque formation and its complications, as well as in the maladaptive response to acute ischemic events. For this reason, modulation of inflammation is nowadays seen as a promising therapeutic strategy to counteract the burden of cardio- and cerebrovascular disease. Being produced and recognized by both inflammatory and vascular cells, the complex network of cytokines holds key functions in the crosstalk of these two systems and orchestrates the progression of atherothrombosis. By binding to membrane receptors, these soluble mediators trigger specific intracellular signaling pathways eventually leading to the activation of transcription factors and a deep modulation of cell function. Both stimulatory and inhibitory cytokines have been described and progressively reported as markers of disease or interesting therapeutic targets in the cardiovascular field. Nevertheless, cytokine inhibition is burdened by harmful side effects that will most likely prevent its chronic use in favor of acute administrations in well-selected subjects at high risk. Here, we summarize the current state of knowledge regarding the modulatory role of cytokines on atherosclerosis, myocardial infarction, and stroke. Then, we discuss evidence from clinical trials specifically targeting cytokines and the potential implication of these advances into daily clinical practice.

Rare Causes of Arterial Hypertension and Thoracic Aortic Aneurysms-A Case-Based Review

Thoracic aortic aneurysms may result in dissection with fatal consequences if undetected. A young male patient with no relevant familial history, after having been investigated for hypertension, was diagnosed with an ascending aortic aneurysm involving the aortic root and the proximal tubular segment, associated with a septal atrial defect. The patient underwent a Bentall surgery protocol without complications. Clinical examination revealed dorso-lumbar scoliosis and no other signs of underlying connective tissue disease. Microscopic examination revealed strikingly severe medial degeneration of the aorta, with areas of deep disorganization of the medial musculo-elastic structural units and mucoid material deposition. Genetic testing found a variant of unknown significance the PRKG1 gene encoding the protein kinase cGMP-dependent 1, which is important in blood pressure regulation. There may be genetic links between high blood pressure and thoracic aortic aneurysm determinants. Hypertension was found in FBN1 gene mutations encoding fibrillin and in PRKG1 mutations. Possible mechanisms involving the renin-angiotensin system, the role of oxidative stress, osteopontin, epigenetic modifications and other genes are reviewed. Close follow-up and strict hypertension control are required to reduce the risk of dissection. Hypertension, scoliosis and other extra-aortic signs suggesting a connective tissue disease are possible clues for diagnosis.

Downregulation of Soluble Guanylate Cyclase and Protein Kinase G With Upregulated ROCK2 in the Pulmonary Artery Leads to Thromboxane A2 Sensitization in Monocrotaline-Induced Pulmonary Hypertensive Rats

Thromboxane A2 (TXA2) promotes various physiological responses including pulmonary artery (PA) contraction, and pathophysiological implications have been suggested in cardiovascular diseases including pulmonary hypertension. Here, we investigated the role of TXA2 receptor (TP)-mediated signaling in the pathophysiology of pulmonary arterial hypertension (PAH). The sensitivity of PA to the contractile agonist could be set by relaxing signals such as the nitric oxide (NO), soluble guanylate cyclase (sGC), and cGMP-dependent kinase (PKG) pathways. Changes in the TP agonist (U46619)-induced PA contraction and its modulation by NO/cGMP signaling were analyzed in a monocrotaline-induced PAH rat model (PAH-MCT). In the myograph study, PA from PAH-MCT showed higher responsiveness to U46619, that is decreased EC50. Immunoblot analysis revealed a lower expression of eNOS, sGC, and PKG, while there was a higher expression of RhoA-dependent kinase 2 (ROCK2) in the PA from PAH-MCT than in the control. In PAH-MCT, the higher sensitivity to U46619 was reversed by 8-Br-cGMP, a membrane-permeable cGMP analog, but not by the NO donor, sodium nitroprusside (SNP 30 μM). In contrast, in the control PA, inhibition of sGC by its inhibitor (1H- [1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ), 10 μM) lowered the threshold of U46619-induced contraction. In the presence of ODQ, SNP treatment had no effect whereas the addition of 8-Br-cGMP lowered the sensitivity to U46619. The inhibition of ROCK by Y-27632 attenuated the sensitivity to U46619 in both control and PAH-MCT. The study suggests that the attenuation of NO/cGMP signaling and the upregulation of ROCK2 increase the sensitivity to TXA2 in the PAH animal, which might have pathophysiological implications in patients with PAH.

Extreme Diversity of the Human Vascular Mesenchymal Cell Landscape

Background Human mesenchymal cells are culprit factors in vascular (patho)physiology and are hallmarked by phenotypic and functional heterogeneity. At present, they are subdivided by classic umbrella terms, such as "fibroblasts," "myofibroblasts," "smooth muscle cells," "fibrocytes," "mesangial cells," and "pericytes." However, a discriminative marker-based subclassification has to date not been established. Methods and Results As a first effort toward a classification scheme, a systematic literature search was performed to identify the most commonly used phenotypical and functional protein markers for characterizing and classifying vascular mesenchymal cell subpopulation(s). We next applied immunohistochemistry and immunofluorescence to inventory the expression pattern of identified markers on human aorta specimens representing early, intermediate, and end stages of human atherosclerotic disease. Included markers comprise markers for mesenchymal lineage (vimentin, FSP-1 [fibroblast-specific protein-1]/S100A4, cluster of differentiation (CD) 90/thymocyte differentiation antigen 1, and FAP [fibroblast activation protein]), contractile/non-contractile phenotype (α-smooth muscle actin, smooth muscle myosin heavy chain, and nonmuscle myosin heavy chain), and auxiliary contractile markers (h1-Calponin, h-Caldesmon, Desmin, SM22α [smooth muscle protein 22α], non-muscle myosin heavy chain, smooth muscle myosin heavy chain, Smoothelin-B, α-Tropomyosin, and Telokin) or adhesion proteins (Paxillin and Vinculin). Vimentin classified as the most inclusive lineage marker. Subset markers did not separate along classic lines of smooth muscle cell, myofibroblast, or fibroblast, but showed clear temporal and spatial diversity. Strong indications were found for presence of stem cells/Endothelial-to-Mesenchymal cell Transition and fibrocytes in specific aspects of the human atherosclerotic process. Conclusions This systematic evaluation shows a highly diverse and dynamic landscape for the human vascular mesenchymal cell population that is not captured by the classic nomenclature. Our observations stress the need for a consensus multiparameter subclass designation along the lines of the cluster of differentiation classification for leucocytes.

Indoxyl sulfate promotes osteogenic differentiation of vascular smooth muscle cells by miR-155-5p-dependent downregulation of matrix Gla protein via ROS/NF-κB signaling

Vascular calcification (VC) is a major risk factor for increasing cardiovascular morbidity and mortality in patients with chronic kidney disease (CKD). Indoxyl sulfate (IS), a representative uremic toxin, is closely associated with VC in CKD patients. Matrix Gla protein (MGP) plays pivotal role in VC as a calcification inhibitor. The aim of this work was to explore whether MGP was involved in IS-induced VC. Here, we demonstrated the role of MGP in the IS-induced osteogenic differentiation of human aortic smooth muscle cells (HASMCs). The methods included Von Kossa staining, immunohistochemistry, Alizarin Red staining, quantitative real-time PCR and western blotting. MGP was decreased in calcified arteries both in CKD patients and rats. In vitro, IS suppressed MGP expression in HASMCs by activating ROS/NF-κB signaling in parallel with osteogenic differentiation, which was mitigated by inhibiting ROS and NF-κB with diphenyleneiodonium and Bay11-7082. Further investigation showed that IS induced NF-κB-responsive microRNA (miR)-155-5p mediating MGP downregulation. Overexpression of miR-155-5p with mimics aggravated IS-induced MGP reduction and osteogenic differentiation. In contrast, these conditions were diminished by silencing miR-155-5p. We demonstrate that IS promotes the HASMCs phenotype switch by suppressing MGP expression via ROS/NF-κB/miR-155-5p signaling and provide a new insight for the pathogenesis of IS-induced VC.

The Effects of Pro-Inflammatory and Anti-Inflammatory Agents for the Suppression of Intimal Hyperplasia: An Evidence-Based Review

Anti-atherogenic therapy is crucial in halting the progression of inflammation-induced intimal hyperplasia. The aim of this concise review was to methodically assess the recent findings of the different approaches, mainly on the recruitment of chemokines and/or cytokine and its effects in combating the intimal hyperplasia caused by various risk factors. Pubmed and Scopus databases were searched, followed by article selection based on pre-set inclusion and exclusion criteria. The combination of keywords used were monocyte chemoattractant protein-1 OR MCP-1 OR TNF-alpha OR TNF-α AND hyperplasia OR intimal hyperplasia OR neointimal hyperplasia AND in vitro. These keywords combination was incorporated in the study and had successfully identified 77 articles, with 22 articles were acquired from Pubmed, whereas 55 articles were obtained from Scopus. However, after title screening, only twelve articles meet the requirements of defined inclusion criteria. We classified the data into 4 different approaches, i.e., utilisation of natural product, genetic manipulation and protein inhibition, targeted drugs in clinical setting, and chemokine and cytokines induction. Most of the articles are working on genetic manipulation targeted on specific pathway to inhibit the pro-inflammatory factors expression. We also found that the utilisation of chemokine- and cytokine-related treatments are emerging throughout the years. However, there is no study utilising the combination of approaches that might give a better outcome in combating intimal hyperplasia. Hopefully, this concise review will provide an insight regarding the usage of different novel approaches in halting the progression of intimal hyperplasia, which serves as a key factor for the development of atherosclerosis in cardiovascular disease.

Discovery of Novel Pyrazolo[3,4-b] Pyridine Derivatives with Dual Activities of Vascular Remodeling Inhibition and Vasodilation for the Treatment of Pulmonary Arterial Hypertension

Current pulmonary arterial hypertension (PAH) therapeutic strategies mainly focus on vascular relaxation with less emphasis on vascular remodeling, which results in poor prognosis. Hence, dual pathway regulators with vasodilation effect via soluble guanylate cyclase (sGC) stimulation and vascular remodeling regulation effect by AMP-activated protein kinase (AMPK) inhibition provide more advantages and potentialities. Herein, we designed and synthesized a series of novel pyrazolo[3,4-b] pyridine derivatives based on sGC stimulator and AMPK inhibitor scaffolds. In vitro, 2 exhibited moderate vasodilation activity and higher proliferation and migration suppressive effects compared to riociguat. In vivo, 2 significantly decreased right ventricular systolic pressure (RVSP), attenuated pulmonary artery medial thickness (PAMT), and right ventricular hypertrophy (RVH) in hypoxia-induced PAH rat models (i.g.). Given the unique advantages of significant vascular remodeling inhibition and moderate vascular relaxation based on the dual pathway regulation, we proposed 2 as a promising lead for anti-PAH drug discovery.

Circulating miRNAs Associated with Dysregulated Vascular and Trophoblast Function as Target-Based Diagnostic Biomarkers for Preeclampsia

Preeclampsia (PE) is a pregnancy-specific disorder associated with hypertension and proteinuria. Since there is no proven method to treat PE, early prediction and accurate diagnosis are essential for appropriate management of the disease. Thus, reliable biomarkers for diagnosing PE need to be identified and evaluated. We analyzed serum-soluble factors and miRNAs in 92 patients with PE and an equal number of healthy controls to identify new useful biomarkers for PE. Serum miR-31-5p, miR-155-5p, and miR-214-3p levels were significantly elevated in these patients and highly correlated with clinical symptoms of hypertension and proteinuria, whereas the miR-1290-3p level was decreased. The increased miRNAs were upregulated in an NF-κB-dependent manner and suppressed endothelial nitric oxide synthase (eNOS) and placental growth factor (PlGF) expression. The level of each miRNA had greater than 90% diagnostic accuracy, which was further increased by analyzing its ratio relative to that of miR-1290-3p. Taken together, the ratios of miR-31-5p, miR-155-5p, or miR-214-3p to miR-1290-3p may serve as reliable diagnostic or prognostic tools for PE, thereby providing evidence that these miRNAs are promising mechanism-based targets for designing therapeutic and preventive strategies for the clinical management of PE.

Angiotensin-converting enzyme 2 augments the effects of endothelial progenitor cells-exosomes on vascular smooth muscle cell phenotype transition

Phenotype transition of vascular smooth muscle cells (VSMCs) is implicated in vascular diseases. Angiotensin-converting enzyme 2 (ACE2) is a perspective cardiovascular target due to its ability of converting angiotensin (Ang II) to Ang (1-7). Our group recently showed that ACE2 can regulate the function of endothelial progenitor cell-derived exosomes (EPC-EXs). Here, we investigate whether ACE2 could affect the role of EPC-EXs on phenotype transition of VSMCs. After co-incubation with EXs released from EPC overexpressed ACE2 (EPC-EXs^ACE2), the ACE2 level and Ang II/Ang (1-7), proliferation/migration, phenotype gene, cytokine and NF-κB level on VSMCs were assessed. To determine the EX uptake route, VSMCs were pretreated with inhibitors. We found that (1) EPC-EXs and EPC-EXs^ACE2 were uptaken by VSMCs dominantly through caveolin-dependent endocytosis. (2) EPC-EXs^ACE2 remarkably increased the ACE2 level and decreased Ang II/Ang (1-7) in VSMCs activated by Ang II, whereas EPC-EXs^ACE2 pretreated by proteinase A blocked this effect. (3) EPC-EXs^ACE2 had better effects than EPC-EXs on reducing proliferation/migration activities and cytokine (MCP-1, TNF-α) secretion of Ang II-activated VSMCs. (4) EPC-EXs attenuated Ang II-induced VSMC synthetic phenotype change as evidenced by upregulated expressions of calponin and a-SMA and downregulated expressions of CRBP-1 and MYH10, associated with a decreased NF-κB level. EPC-EXs^ACE2 augmented these effects, which were attenuated by ACE2 inhibitor (DX600). In conclusion, EPC-EXs^ACE2 reduced Ang II-induced VSMC phenotype change by conveying functional ACE2 to downregulate the activated NF-κB pathway.

Emerging Roles for Neuropilin-2 in Cardiovascular Disease

Cardiovascular disease, the leading cause of death worldwide, is predominantly associated with atherosclerosis. Atherosclerosis is a chronic inflammatory disease characterised by the narrowing of large to medium-sized arteries due to a build-up of plaque. Atherosclerotic plaque is comprised of lipids, extracellular matrix, and several cell types, including endothelial, immune, and vascular smooth muscle cells. Such narrowing of the blood vessels can itself restrict blood flow to vital organs but most severe clinical complications, including heart attacks and strokes, occur when lesions rupture, triggering the blood to clot and obstructing blood flow further down the vascular tree. To circumvent such obstructions, percutaneous coronary intervention or bypass grafts are often required; however, re-occlusion of the treated artery frequently occurs. Neuropilins (NRPs), a multifunctional family of cell surface co-receptors, are expressed by endothelial, immune, and vascular smooth muscle cells and are regulators of numerous signalling pathways within the vasculature. Here, we review recent studies implicating NRP2 in the development of occlusive vascular diseases and discuss how NRP2 could be targeted for therapeutic intervention.

Human Umbilical Cord Mesenchymal Stem Cells Attenuate Abdominal Aortic Aneurysm Progression in Sprague-Dawley Rats: Implication of Vascular Smooth Muscle Cell Phenotypic Modulation

Abdominal aortic aneurysm (AAA) is life-threatening, for which efficient nonsurgical treatment strategy has not been available so far. Several previous studies investigating the therapeutic effect of mesenchymal stem cells (MSCs) in AAA indicated that MSCs could inhibit aneurysmal inflammatory responses and extracellular matrix destruction, and suppress aneurysm occurrence and expansion. Vascular smooth muscle cell (VSMC) phenotypic plasticity is reported to be predisposed in AAA initiation and progression. However, little is known about the effect of MSCs on VSMC phenotypic modulation in AAA. In this study, we investigate the therapeutic efficacy of umbilical cord mesenchymal stem cells (UC-MSCs) in elastase-induced AAA model and evaluate the effect of UC-MSC on VSMC phenotypic regulation. We demonstrate that the intravenous injection of UC-MSC attenuates elastase-induced aneurysmal expansion, reduces elastin degradation and fragmentation, inhibits MMPs and TNF-α expression, and preserves and/or restores VSMC contractile phenotype in AAA. Taken together, these results highlight the therapeutic and VSMC phenotypic modulation effects of UC-MSC in AAA progression, which further indicates the potential of applying UC-MSC as an alternative treatment candidate for AAA.

TiO2-Based Nanotopographical Cues Attenuate the Restenotic Phenotype in Primary Human Vascular Endothelial and Smooth Muscle Cells

Coronary and peripheral stents are implants that are inserted into blocked arteries to restore blood flow. After stent deployment, the denudation of the endothelial cell (EC) layer and the resulting inflammatory cascade can lead to restenosis, the renarrowing of the vessel wall due to the hyperproliferation and excessive matrix secretion of smooth muscle cells (SMCs). Despite advances in drug-eluting stents (DES), restenosis remains a clinical challenge and can require repeat revascularizations. In this study, we investigated how vascular cell phenotype can be modulated by nanotopographical cues on the stent surface, with the goal of developing an alternative strategy to DES for decreasing restenosis. We fabricated TiO2 nanotubes and demonstrated that this topography can decrease SMC surface coverage without affecting endothelialization. In addition, to our knowledge, this is the first study reporting that TiO2 nanotube topography dampens the response to inflammatory cytokine stimulation in both endothelial and smooth muscle cells. We observed that compared to flat titanium surfaces, nanotube surfaces attenuated tumor necrosis factor alpha (TNFα)-induced vascular cell adhesion molecule-1 (VCAM-1) expression in ECs by 1.8-fold and decreased TNFα-induced SMC growth by 42%. Further, we found that the resulting cellular phenotype is sensitive to changes in nanotube diameter and that 90 nm diameter nanotubes leads to the greatest magnitude in cell response compared to 30 or 50 nm nanotubes.

Triiodothyronine Reduces Vascular Dysfunction Associated with Hypertension by Attenuating Protein Kinase G/Vasodilator-Stimulated Phosphoprotein Signaling

Vascular dysfunction associated with hypertension comprises hypercontractility and impaired vasodilation. We have previously demonstrated that triiodothyronine (T3), the active form of thyroid hormone, has vasodilatory effects acting through rapid onset mechanisms. In the present study, we examined whether T3 mitigates vascular dysfunction associated with hypertension. To test the direct effects of T3 in hypertensive vessels, aortas from female Dahl salt-sensitive (Dahl SS) rats fed a high-salt diet (8% NaCl, HS group) and their age-matched controls fed a standard low-salt diet (0.3% NaCl, LS group) for 16 weeks were isolated and used in ex vivo vascular reactivity studies. We confirmed that the HS group exhibited a higher systolic blood pressure in comparison with the control LS group and displayed aortic remodeling. Aortas from both groups were pretreated with T3 (0.1 μM) for 30 minutes at 37°C in a 5% CO₂ incubator before functional vascular studies. T3 treatment significantly attenuated hypercontractility and improved impaired endothelium-dependent vasodilation in aortas from the HS group. These vascular improvements in response to T3 were accompanied by increased phosphorylation of vasodilator-stimulated phosphoprotein (VASP) at serine 239, a vasodilatory factor of the cGMP-dependent protein kinase (PKG)/VASP signaling pathway in vascular smooth muscle cells. Moreover, increased production of reactive oxygen species in aortas from the HS group were significantly reduced by T3, suggesting a potential antioxidant effect of T3 in the vasculature. These results demonstrate that T3 can mitigate hypertension-related vascular dysfunction through the VASP signaling pathway and by reducing vascular ROS production. SIGNIFICANCE STATEMENT: This study demonstrates that triiodothyronine (T3) directly acts on vascular tone and has a beneficial effect in hypertension-induced vascular dysfunction. T3 augmented vasodilation and diminished vasoconstriction in blood vessels from hypertensive rats in association with activation of the protein kinase G/vasodilator-stimulated phosphoprotein signaling pathway that activates vascular relaxation and exerted an antioxidant effect. Collectively, these results show that T3 is a potential vasoprotective agent with rapid action on hypertension-related vascular dysfunction.

The Role of Epigenetics in Placental Development and the Etiology of Preeclampsia

In this review, we comprehensively present the function of epigenetic regulations in normal placental development as well as in a prominent disease of placental origin, preeclampsia (PE). We describe current progress concerning the impact of DNA methylation, non-coding RNA (with a special emphasis on long non-coding RNA (lncRNA) and microRNA (miRNA)) and more marginally histone post-translational modifications, in the processes leading to normal and abnormal placental function. We also explore the potential use of epigenetic marks circulating in the maternal blood flow as putative biomarkers able to prognosticate the onset of PE, as well as classifying it according to its severity. The correlation between epigenetic marks and impacts on gene expression is systematically evaluated for the different epigenetic marks analyzed.

Ginsenoside Re inhibits PDGF-BB-induced VSMC proliferation via the eNOS/NO/cGMP pathway

Ginsenoside Re (GS-Re), which is a major monomeric member of the ginseng trialcohol saponin family, is one of the main active components of ginseng and plays an important role in protecting the cardiovascular system. Here, we report a novel function by which GS-Re regulates the eNOS/NO/cGMP pathway, which affects the platelet-derived growth factor-BB (PDGF-BB)-induced proliferation of vascular smooth muscle cells (VSMCs). GS-Re inhibited PDGF-BB-induced VSMC proliferation in a concentration-dependent manner without cytotoxicity, and the endothelial nitric oxide synthase (eNOS) inhibitor NG-nitro-L-arginine methyl ester (L-NAME) antagonized the antiproliferative effect of GS-Re. The flow cytometry analysis suggested that GS-Re regulates VSMC proliferation by influencing the cell cycle transition from G0/G1 to S phase and decreasing the expression of G0/G1-specific regulatory proteins, including proliferating cell nuclear antigen (PCNA), cyclin D1, and CDK4, in PDGF-BB-treated VSMCs, consequently upregulating the protein expression of p21. After GS-Re treatment, the levels of nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) and the phos-eNOS ^Ser1177/eNOS protein ratio were obviously increased. In addition, treatment with L-NAME blocked the eNOS/NO/cGMP signaling pathway, and the protein levels of PCNA, cyclin D1, and CDK4 were markedly increased in GS-Re-treated VSMCs, while p21 expression was decreased in PDGF-BB-induced VSMCs. Overall, these findings reveal that GS-Re can inhibit the proliferation of VSMCs through G0/G1 cell cycle arrest, which is closely related to eNOS/NO/cGMP pathway activation. The present results provide basic pharmacological evidence of the potential prevention and treatment of cardiovascular diseases by GS-Re.

NF-κB-responsive miR-155 induces functional impairment of vascular smooth muscle cells by downregulating soluble guanylyl cyclase

Vascular smooth muscle cells (VSMCs) play an important role in maintaining vascular function. Inflammation-mediated VSMC dysfunction leads to atherosclerotic intimal hyperplasia and preeclamptic hypertension; however, the underlying mechanisms are not clearly understood. We analyzed the expression levels of microRNA-155 (miR-155) in cultured VSMCs, mouse vessels, and clinical specimens and then assessed its role in VSMC function. Treatment with tumor necrosis factor-α (TNF-α) elevated miR-155 biogenesis in cultured VSMCs and vessel segments, which was prevented by NF-κB inhibition. MiR-155 expression was also increased in high-fat diet-fed ApoE^−/− mice and in patients with atherosclerosis and preeclampsia. The miR-155 levels were inversely correlated with soluble guanylyl cyclase β1 (sGCβ1) expression and nitric oxide (NO)-dependent cGMP production through targeting the sGCβ1 transcript. TNF-α-induced miR-155 caused VSMC phenotypic switching, which was confirmed by the downregulation of VSMC-specific marker genes, suppression of cell proliferation and migration, alterations in cell morphology, and NO-induced vasorelaxation. These events were mitigated by miR-155 inhibition. Moreover, TNF-α did not cause VSMC phenotypic modulation and limit NO-induced vasodilation in aortic vessels of miR-155^−/− mice. These findings suggest that NF-κB-induced miR-155 impairs the VSMC contractile phenotype and NO-mediated vasorelaxation by downregulating sGCβ1 expression. These data suggest that NF-κB-responsive miR-155 is a novel negative regulator of VSMC functions by impairing the sGC/cGMP pathway, which is essential for maintaining the VSMC contractile phenotype and vasorelaxation, offering a new therapeutic target for the treatment of atherosclerosis and preeclampsia.

The overexpression of a microRNA molecule adversely affects the functioning of vascular smooth muscle cells (VSMCs) and may contribute to the development of artherosclerosis and preeclampsia. The interactions between VSMCs and the cells lining blood vessels (endothelium) are crucial for maintaining the healthy phenotype and relaxation of blood vessels. Disruption to these interactions via inflammation, for example, can trigger serious vascular diseases. Young-Myeong Kim at Kangwon National University, Chungcheon, South Korea, and co-workers demonstrated that expression levels of a microRNA-155 are elevated in patients with artherosclerosis and preeclampsia, while an enzyme found in VSMCs called soluble guanylyl cyclase is considerably reduced. Using human and mice tissues, the team showed that miR-155 impairs the contractile phenotype and relaxation of VSMCs by reducing guanylyl cyclase expression. Their findings may inform new therapies for vascular diseases.

The microRNAs Regulating Vascular Smooth Muscle Cell Proliferation: A Minireview

Vascular smooth muscle cell (VSMC) proliferation plays a critical role in atherosclerosis. At the beginning of the pathologic process of atherosclerosis, irregular VSMC proliferation promotes plaque formation, but in advanced plaques VSMCs are beneficial, promoting the stability and preventing rupture of the fibrous cap. Recent studies have demonstrated that microRNAs (miRNAs) expressed in the vascular system are involved in the control of VSMC proliferation. This review summarizes recent findings on the miRNAs in the regulation of VSMC proliferation, including miRNAs that exhibit the inhibition or promotion of VSMC proliferation, and their targets mediating the regulation of VSMC proliferation. Up to now, most of the studies were performed only in cultured VSMC. While the modulation of miRNAs is emerging as a promising strategy for the regulation of VSMC proliferation, most of the effects of miRNAs and their targets in vivo require further investigation.