Artery Vascular Smooth Muscle Cells Research Articles

Specification of CNS macrophage subsets occurs postnatally in defined niches.

All tissue-resident macrophages of the central nervous system (CNS)-including parenchymal microglia, as well as CNS-associated macrophages (CAMs1) such as meningeal and perivascular macrophages2-7-are part of the CNS endogenous innate immune system that acts as the first line of defence during infections or trauma2,8-10. It has been suggested that microglia and all subsets of CAMs are derived from prenatal cellular sources in the yolk sac that were defined as early erythromyeloid progenitors11-15. However, the precise ontogenetic relationships, the underlying transcriptional programs and the molecular signals that drive the development of distinct CAM subsets in situ are poorly understood. Here we show, using fate-mapping systems, single-cell profiling and cell-specific mutants, that only meningeal macrophages and microglia share a common prenatal progenitor. By contrast, perivascular macrophages originate from perinatal meningeal macrophages only after birth in an integrin-dependent manner. The establishment of perivascular macrophages critically requires the presence of arterial vascular smooth muscle cells. Together, our data reveal a precisely timed process in distinct anatomical niches for the establishment of macrophagesubsetsin the CNS.

Noncanonical HIPPO/MST Signaling via BUB3 and FOXO Drives Pulmonary Vascular Cell Growth and Survival.

The MSTs (mammalian Ste20-like kinases) 1/2 are members of the HIPPO pathway that act as growth suppressors in adult proliferative diseases. Pulmonary arterial hypertension (PAH) manifests by increased proliferation and survival of pulmonary vascular cells in small PAs, pulmonary vascular remodeling, and the rise of pulmonary arterial pressure. The role of MST1/2 in PAH is currently unknown. To investigate the roles and mechanisms of the action of MST1 and MST2 in PAH. Using early-passage pulmonary vascular cells from PAH and nondiseased lungs and mice with smooth muscle-specific tamoxifen-inducible Mst1/2 knockdown, we found that, in contrast to canonical antiproliferative/proapoptotic roles, MST1/2 act as proproliferative/prosurvival molecules in human PAH pulmonary arterial vascular smooth muscle cells and pulmonary arterial adventitial fibroblasts and support established pulmonary vascular remodeling and pulmonary hypertension in mice with SU5416/hypoxia-induced pulmonary hypertension. By using unbiased proteomic analysis, gain- and loss-of function approaches, and pharmacological inhibition of MST1/2 kinase activity by XMU-MP-1, we next evaluated mechanisms of regulation and function of MST1/2 in PAH pulmonary vascular cells. We found that, in PAH pulmonary arterial adventitial fibroblasts, the proproliferative function of MST1/2 is caused by IL-6-dependent MST1/2 overexpression, which induces PSMC6-dependent downregulation of forkhead homeobox type O 3 and hyperproliferation. In PAH pulmonary arterial vascular smooth muscle cells, MST1/2 acted via forming a disease-specific interaction with BUB3 and supported ECM (extracellular matrix)- and USP10-dependent BUB3 accumulation, upregulation of Akt-mTORC1, cell proliferation, and survival. Supporting our in vitro observations, smooth muscle-specific Mst1/2 knockdown halted upregulation of Akt-mTORC1 in small muscular PAs of mice with SU5416/hypoxia-induced pulmonary hypertension. Together, this study describes a novel proproliferative/prosurvival role of MST1/2 in PAH pulmonary vasculature, provides a novel mechanistic link from MST1/2 via BUB3 and forkhead homeobox type O to the abnormal proliferation and survival of pulmonary arterial vascular smooth muscle cells and pulmonary arterial adventitial fibroblasts, remodeling and pulmonary hypertension, and suggests new target pathways for therapeutic intervention.

Expression of the microRNA‑30 family in pulmonary arterial hypertension and the role of microRNA‑30d‑5p in the regulation of pulmonary arterial smooth muscle cell toxicity and apoptosis

The biological processes of pulmonary artery vascular smooth muscle cells (PA-SMCs) and pulmonary artery endothelial cells in pulmonary arterial hypertension (PAH) are generally abnormal, with increased levels of proliferation and reduced levels of apoptosis. Although microRNAs (miRNAs/miRs) participate in a number of biological processes in a variety of diseases, such as tumors and infections, studies on the association between miRNAs and PAH are limited. In the present study, blood samples were collected from 6 patients with patent ductus arteriosus. The experimental group included 3 patients with severe PAH, while the control group included 3 patients without PAH. Microarray technology was used to detect the presence of any associated miRNAs. Moreover, a rat PAH model was established via left lung resection followed by monocrotaline injection, involving a total of 8 rats in the PAH group and 8 untreated rat in the control group. Reverse transcription-quantitative PCR was performed to verify the expression levels of the miR-30 family in the animal model. miR-30d-5p mimics and anti-miR-30d-5p were transfected into primary cultured PA-SMCs. Levels of cytotoxicity and cell apoptosis were examined, and Notch-3 expression levels were studied using western blotting. The results of the present study demonstrated that miR-30d-5p expression was downregulated in both patient blood and animal models of the PAH group compared with control groups. In primary cultured PA-SMCs, overexpression of miR-30d-5p attenuated the platelet-derived growth factor-induced toxicity of PA-SMCs, while knockdown of miR-30d-5p resulted in the increased toxicity of PA-SMCs compared with control group. The apoptosis rate of PA-SMCs increased with the overexpression of miR-30d-5p compared with control group. Moreover, the expression levels of Notch-3 in the miR-30d-5p group were significantly reduced compared with the anti-miR-30d-5p and miR-NC groups. In total, 10 circulating miRNAs that may be associated with PAH were discovered in the present study. Moreover, the expression of the miR-30 family was verified in animal models in vivo, and seven miRNAs in this family were discovered that may be associated with PAH. Additionally, miR-30d-5p was downregulated in both patients with PAH and animal models compared with control groups. Thus, the results of the present study demonstrated that the regulatory mechanism underlying PA-SMCs may be via the Notch-3 signaling pathway.

Abstract 12968: mitoTEMPO Improves Expression of Pulmonary Artery Soluble Guanylate Cyclase β1 and Lowers Exercise Associated Elevations in Pulmonary Artery Pressures in a Rat Model of Combined Pre- and Post-Capillary Pulmonary Hypertension

Introduction: Exercise induced pulmonary hypertension (EIPH) portends worse prognosis compared to isolated resting PH. Exercise increases mitochondrial reactive oxygen species (mROS) production in peripheral blood mononuclear cells of patients with heart failure. Metabolic syndrome related mROS contribute to EIPH by decreasing the expression of the vasodilatory enzyme soluble guanylate cyclase (sGC) via downregulating an sGC transcription factor, namely nuclear factor Y alpha (NFYA; Satoh et al in press). Hypothesis: mROS scavenging with mitoTEMPO will restore sGC expression and ameliorate EIPH in a rat model of combined pre-and post-capillary pulmonary hypertension (CpcPH). Methods: Obese ZSF1 rats treated with sugen were used to model CpcPH. Half received mitoTEMPO (2mM) for 2 weeks. CpcPH rats treated with vehicle and lean ZSF1 rats served as controls (n=6/group). Hemodynamics were evaluated at rest and during treadmill exercise. Cardiac function was assessed using Doppler-echocardiography. We cultured pulmonary artery vascular smooth muscle cells (PAVSMCs) from lean rats in palmitate, glucose and insulin (PGI) containing media to simulate the metabolic syndrome milieu. Cells were treated with vehicle or mitoTEMPO. Expression of sGCβ1 and NFYA in pulmonary arteries of animals and in cultured cells was quantified by Western Blot. Data were analyzed with repeated measures two-way ANOVA. Results: MitoTEMPO significantly improved EIPH by reducing pulmonary vascular resistance (fig1A), significantly improved right ventricular function (fig1B) and significantly restored NFYA/sGCβ1 expression in pulmonary arteries (fig1C) and PAVSMCs of rats with CpcPH (fig1D). MitoTEMPO significantly blunted PGI-induced downregulation of NFYA and sGCβ1 in PAVSMCs from lean rats (fig1E). Conclusions: Mitochondria targeted antioxidants can improve EIPH in CpcPH by restoring NFYA/sGCβ1 expression, identifying a potential therapeutic target for CpcPH.

Small interfering RNA-induced silencing lncRNA PVT1 inhibits atherosclerosis via inactivating the MAPK/NF-κB pathway.

Atherosclerosis (AS) is a chronic disease of the arterial wall. The role of lncRNAs in AS has been acknowledged. This study investigated the role of lncRNA plasmacytoma variant translocation 1 (PVT1) in AS via the MAPK/NF-κB pathway. Serum samples were collected from AS and non-AS patients. Serum levels of PVT1, CRP, IL-6, IL-1β, and TNF-α were determined. AS mouse model was established and transfected with si-PVT1. Levels of TG, TC, HDL, LDL, MAPK, NF-κB, MMP-2, MMP-9, TIMP-1, and macrophage content were detected. Human arterial vascular smooth muscle cells (HA-VSMCs) induced by 50 mg/mL oxLDL were transfected with si-PVT1 or oe-PVT1 and added with MAPK inhibitor U0126. Viability, apoptosis, cell cycle, colony formation and DNA replication were assessed. Levels of apoptosis-related proteins were detected. Consequently, PVT1 was highly expressed in AS patients. Silencing PVT1 decreased levels of TG, TC, LDL, IL-6, IL-1β, TNF-α, MMP-2, MMP-9, CRP, TIMP-1, MAPK, and NF-κB, increased HDL, reduced atherosclerotic plaques and macrophage content in mice, inhibited viability, clones and EdU positive rates in HA-VSMCs, but promoted apoptosis and cell cycle arrest. Inhibition of MAPK/NF-κB pathway suppressed proliferation and promoted apoptosis of HA-VSMCs while PVT1 overexpression facilitated AS development. Briefly, silencing PVT1 inhibited AS development by downregulating MAPK/NF-κB pathway.

Loss of GATA4 C-Terminus by p.S335X Mutation Modulates Coronary Artery Vascular Smooth Muscle Cell Phenotype.

Coronary artery disease (CAD) has been the leading cause of morbidity and mortality worldwide, and its pathogenesis is closely related with the proliferation and migration of vascular smooth muscle cell (VSMC). We previously reported a truncated GATA4 protein lacking C-terminus induced by p.S335X mutation in cardiomyocyte from ventricular septal defect (VSD) patients. However, it is still unclear whether GATA4 p.S335X mutation could influence the development of CAD. GATA4 wild-type (WT) and p.S335X mutant (MU) overexpression plasmids were constructed and transfected transiently into rat coronary artery smooth muscle cell (RCSMC) to observe the proliferative and migratory abilities by MTS and wound healing assay, respectively. PCR array was used to preliminarily detect the expression of phenotypic modulation-related genes, and QRT-PCR was then carried out to verify the screened differentially expressed genes (DEGs). The results showed that, when stimulated by fetal bovine serum (10%) for 24 h or tumor necrosis factor-α (10 or 30 ng/ml) for 10 or 24 h, deletion of GATA4 C-terminus by p.S335X mutation in GATA4 enhanced the proliferation of RCSMC, without alteration of the migration capability. Twelve DEGs, including Fas, Hbegf, Itga5, Aimp1, Cxcl1, Il15, Il2rg, Il7, Tnfsf10, Il1r1, Irak1, and Tlr3, were screened and identified as phenotypic modulation-related genes. Our data might be beneficial for further exploration regarding the mechanisms of GATA4 p.S335X mutation on the phenotypic modulation of coronary VSMC.

Mechanisms of vascular smooth muscle cell investment and phenotypic diversification in vascular diseases.

In contrast with the heart, the adult mammalian vasculature retains significant remodelling capacity, dysregulation of which is implicated in disease development. In particular, vascular smooth muscle cells (VSMCs) play major roles in the pathological vascular remodelling characteristic of atherosclerosis, restenosis, aneurysm and pulmonary arterial hypertension. Clonal lineage tracing revealed that the VSMC-contribution to disease results from the hyperproliferation of few pre-existing medial cells and suggested that VSMC-derived cells from the same clone can adopt diverse phenotypes. Studies harnessing the powerful combination of lineage tracing and single-cell transcriptomics have delineated the substantial diversity of VSMC-derived cells in vascular lesions, which are proposed to have both beneficial and detrimental effects on disease severity. Computational analyses further suggest that the pathway from contractile VSMCs in healthy arteries to phenotypically distinct lesional cells consists of multiple, potentially regulatable, steps. A better understanding of how individual steps are controlled could reveal effective therapeutic strategies to minimise VSMC functions that drive pathology whilst maintaining or enhancing their beneficial roles. Here we review current knowledge of VSMC plasticity and highlight important questions that should be addressed to understand how specific stages of VSMC investment and phenotypic diversification are controlled. Implications for developing therapeutic strategies in pathological vascular remodelling are discussed and we explore how cutting-edge approaches could be used to elucidate the molecular mechanisms underlying VSMC regulation.

Loss of Nfat5 promotes lipid accumulation in vascular smooth muscle cells.

The nuclear factor of activated T-cells 5 (NFAT5) is a transcriptional regulator of macrophage activation and T-cell development, which controls stabilizing responses of cells to hypertonic and biomechanical stress. In this study, we detected NFAT5 in the media layer of arteries adjacent to human arteriosclerotic plaques and analyzed its role in vascular smooth muscle cells (VSMCs) known to contribute to arteriosclerosis through the uptake of lipids and transformation into foam cells. Exposure of both human and mouse VSMCs to cholesterol stimulated the nuclear translocation of NFAT5 and increased the expression of the ATP-binding cassette transporter Abca1, required to regulate cholesterol efflux from cells. Loss of Nfat5 promoted cholesterol accumulation in these cells and inhibited the expression of genes involved in the management of oxidative stress or lipid handling, such as Sod1, Plin2, Fabp3, and Ppard. The functional relevance of these observations was subsequently investigated in mice fed a high-fat diet upon induction of a smooth muscle cell-specific genetic ablation of Nfat5 (Nfat5(SMC)-/- ). Under these conditions, Nfat5(SMC)-/- but not Nfat5fl/fl mice developed small, focal lipid-rich lesions in the aorta after 14 and 25weeks, which were formed by intracellular lipid droplets deposited in the sub-intimal VSMCs layer. While known for being activated by external stimuli, NFAT5 was found to mediate the expression of VSMC genes associated with the handling of lipids in response to a cholesterol-rich environment. Failure of this protective function may promote the formation of lipid-laden arterial VSMCs and pro-atherogenic vascular responses.

Role of Long Non-Coding RNAs in Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is a debilitating condition of the pulmonary circulatory system that occurs in patients of all ages and if untreated, eventually leads to right heart failure and death. Despite existing medical treatment options that improve survival and quality of life, the disease remains incurable. Thus, there is an urgent need to develop novel therapies to treat this disease. Emerging evidence suggests that long non-coding RNAs (lncRNAs) play critical roles in pulmonary vascular remodeling and PAH. LncRNAs are implicated in pulmonary arterial endothelial dysfunction by modulating endothelial cell proliferation, angiogenesis, endothelial mesenchymal transition, and metabolism. LncRNAs are also involved in inducing different pulmonary arterial vascular smooth muscle cell phenotypes, such as cell proliferation, apoptosis, migration, regulation of the phenotypic switching, and cell cycle. LncRNAs are essential regulators of gene expression that affect various diseases at the chromatin, transcriptional, post-translational, and even post-translational levels. Here, we focus on the role of LncRNAs and their molecular mechanisms in the pathogenesis of PAH. We also discuss the current research challenge and potential biomarker and therapeutic potentials of lncRNAs in PAH.

Antrodia cinnamomea ameliorates neointimal formation by inhibiting inflammatory cell infiltration through downregulation of adhesion molecule expression in vitro and in vivo

The increased vascular inflammation is a key event in the development of atherosclerotic lesions. Antrodia cinnamomea has been shown to promote anticancerogenic activity through decreasing inflammation. However, the potential role of A. cinnamomea in cardiovascular diseases remains unexplored. Herein, using carotid arterial ligation models, we found that ethanol extract from A. cinnamomea (EEAC) significantly inhibited neointimal hyperplasia in a dose-dependent manner, accompanied with the reduced expression of activated p65 and inflammatory cytokines. We also show that EEAC ameliorated TNF-α-induced phosphorylation of p65 and pro-inflammatory cytokine expression in both vascular smooth muscle cells (VSMCs) and macrophages in vitro. Mechanistically, EEAC suppressed expression levels of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM-1) in VSMCs, which attenuates the ability of monocytes/macrophages adhesion to VSMCs. Furthermore, the expression level of these adhesion molecules and infiltration of monocytes/macrophages were also decreased in neointimal VSMCs of arteries pretreated with EEAC. Altogether, our results reveal a novel function of A. cinnamomea in suppressing vascular inflammation upon ligation injury during neointimal formation, likely through inhibition of inflammatory cell infiltration via downregulating the adhesion molecules in VSMCs. Thus, A. cinnamomea may offer a pharmacological therapy to slow down disease progression in patients with vascular injury.

Bioactive Compounds From Coptidis Rhizoma Alleviate Pulmonary Arterial Hypertension by Inhibiting Pulmonary Artery Smooth Muscle Cells' Proliferation and Migration.

Pulmonary arterial hypertension (PAH) is a devastating disorder characterized by excessive proliferation and vasoconstriction of small pulmonary artery vascular smooth muscle cells (PASMCs). Coptidis rhizoma (CR) because of the complexity of the components, the underlying pharmacological role and mechanism of it on PAH remains unknown. In this article, the network pharmacological analysis was used to screen the main active constituents of CR and the molecular targets that these constituents act on. Then, we evaluated the importance of berberine and quercetin (biologically active components of CR) on the proliferation and migration of PASMCs and vascular remodeling in experimental models of PAH. Our results showed that berberine and quercetin effectively inhibited the proliferation and migration of hypoxia-induced PASMCs in a manner likely to be mediated by the suppression of MAPK1, NADPH oxidase 4 (NOX4), and cytochrome P450 1B1 (CYP1B1) expression. Furthermore, berberine and quercetin treatment attenuates pulmonary hypertension, reduces right ventricular hypertrophy, and improves pulmonary artery remodeling in monocrotaline-induced pulmonary hypertension in rat models. In conclusion, this research demonstrates CR might be a promising treatment option for PAH, and the network pharmacology approach can be an effective tool to reveal the potential mechanisms of Chinese herbal medicine.

Dehydration results in a reduction in the expression and function of AT 1 R and V 1 R in resistance‐sized arteries

In the body, the state of dehydration occurs where there is a deficit of water compared to that which is required to function properly. Water transportation is crucial and carried out via aquaporins (AQPs) located throughout the body and as a response to dehydration events, hormones such as angiotensin II (Ang II) and arginine-vasopressin (AVP) are secreted to induce various normal physiological functions via a hormone-specific receptor and associated-receptor activation found in vascular smooth muscle cells (VSMCs). Consequently, dehydration results with overall blood vessel constriction and thickening of the blood, ultimately leading to heart strain and increased blood pressure. Currently, the effect of dehydration on both the angiotensin II receptor type 1 (AT1R) and vasopressin receptor (V1R) expressed in resistance-sized artery VSMCs is unclear. C57BL/6J male mice were deprived of water for 48 hours before analyzing AT1R and V1R expression and function in freshly isolated mesenteric arteries, compared to controls. Dehydration for 48 hours results in a reduction in AT1R and V1R message and protein expression as well as a reduction in angiotensin- and arginine vasopressin (AVP)-induced vasoconstriction in pressurized mesenteric arteries. These data suggest that AT1R and V1R function is reduced in resistance-sized mesenteric arteries as a response to an elevation in plasma vasopressin and angiotensin II that occurs after dehydration.

Hsa_circ_0054633 regulates PDGF-BB-induced proliferation, migration and oxidative stress of vascular smooth muscle cells through miR-107/TXNIP axis

IntroductionHsa_circ_0054633 has been found to be elevated in the blood of coronary artery disease (CAD) patients. However, the molecular mechanism and the role of hsa_circ_0054633 in the pathogenesis of CAD have not been reported in detail.Material and methodsThe expression of hsa_circ_0054633, microRNA (miR)-107 and thioredoxin-interacting protein (TXNIP) mRNA was measured using quantitative real-time polymerase chain reaction. Human artery vascular smooth muscle cell (HA-VSMC) proliferation, cell cycle, and migration were detected by cell counting kit-8 assay, flow cytometry and transwell assay, respectively. The generation of reactive oxygen species (ROS) was analyzed by dichlorofluorescein diacetate (DCFH-DA) assay. Western blot was utilized to determine the levels of proliferating cell nuclear antigen (PCNA), cyclin D1, matrix metallopeptidase 9 (MMP-9), Mn-superoxide dismutase (SOD2) and TXNIP protein. The interaction between miR-107 and hsa_circ_0054633 or TXNIP was confirmed by dual-luciferase reporter, RNA immunoprecipitation assay or pull-down assay.ResultsHsa_circ_0054633 was elevated in the plasma of CAD patients, and might be a potential blood biomarker for CAD prediction. Hsa_circ_0054633 silencing reversed PDGF-BB-induced promotion on HA-VSMC proliferation, cell cycle, migration and ROS production. MiR-107 directly interacted with hsa_circ_0054633 and TXNIP, and hsa_circ_0054633 regulated TXNIP expression by sponging miR-107. Besides, rescue assay indicated that the action of hsa_circ_0054633 silencing on PDGF-BB-treated HA-VSMCs could be attenuated by miR-107 inhibition or TXNIP overexpression, respectively.ConclusionsHsa_circ_0054633 knockdown protected HA-VSMCs against PDGF-BB-induced dysfunction through regulating miR-107/TXNIP axis, suggesting a potential therapeutic target for coronary atherosclerosis.

Coenzyme Q10 inhibits intracranial aneurysm formation and progression in a mouse model.

The aim of this study was to investigate the effect of coenzyme Q10 (CoQ10), a commonly used nutritional supplement, on intracranial aneurysm (IA) initiation and progression in a mouse model, as well as the mechanism. Hydrogen peroxide (H2O2) was used to treat mouse-derived vascular smooth muscle cells (VSMCs) to induce oxidative injury, followed by incubation with CoQ10. In the mouse IA model established by elastase injection, CoQ10 was orally administered at 10 mg/kg every other day for 14 days, during which the incidence of IA, rupture rate, symptom-free survival, and systolic blood pressure were recorded. CoQ10 promoted the expression of nuclear factor erythroid 2-related factor 2 and antioxidant enzymes. In H2O2-treated VSMCs, reactive oxygen species and cell apoptosis were reduced by CoQ10. In IA mice, CoQ10 treatment decreased the rupture rate of IA, improved the symptom-free survival, and reduced systolic blood pressure. Macrophage infiltration and expression of pro-inflammatory cytokines in the cerebral arteries were mitigated by CoQ10 treatment. CoQ10 is effective in reducing oxidative stress in VSMCs, thereby attenuating IA formation and rupture in mice. CoQ10 also alleviates inflammation and restores normal phenotypes of VSMCs in the cerebral arteries. Our data suggest that CoQ10 is a potentially effective drug for managing IA. To investigate the effect of CoQ10, a commonly used nutritional supplement, on IA initiation and progression in a mouse model, as well as the mechanism. CoQ10 promoted the expression of Nrf2 and antioxidant enzymes. In H2O2-treated VSMCs, ROS and cell apoptosis were reduced by CoQ10. CoQ10 is effective in reducing oxidative stress in VSMCs, thereby attenuating IA formation and rupture in mice.

Lysosome (Dys)function in Atherosclerosis—A Big Weight on the Shoulders of a Small Organelle

Atherosclerosis is a progressive insidious chronic disease that underlies most of the cardiovascular pathologies, including myocardial infarction and ischemic stroke. The malfunctioning of the lysosomal compartment has a central role in the etiology and pathogenesis of atherosclerosis. Lysosomes are the degradative organelles of mammalian cells and process endogenous and exogenous substrates in a very efficient manner. Dysfunction of these organelles and consequent inefficient degradation of modified low-density lipoproteins (LDL) and apoptotic cells in atherosclerotic lesions have, therefore, numerous deleterious consequences for cellular homeostasis and disease progression. Lysosome dysfunction has been mostly studied in the context of the inherited lysosomal storage disorders (LSDs). However, over the last years it has become increasingly evident that the consequences of this phenomenon are more far-reaching, also influencing the progression of multiple acquired human pathologies, such as neurodegenerative diseases, cancer, and cardiovascular diseases (CVDs). During the formation of atherosclerotic plaques, the lysosomal compartment of the various cells constituting the arterial wall is under severe stress, due to the tremendous amounts of lipoproteins being processed by these cells. The uncontrolled uptake of modified lipoproteins by arterial phagocytic cells, namely macrophages and vascular smooth muscle cells (VSMCs), is the initial step that triggers the pathogenic cascade culminating in the formation of atheroma. These cells become pathogenic “foam cells,” which are characterized by dysfunctional lipid-laden lysosomes. Here, we summarize the current knowledge regarding the origin and impact of the malfunctioning of the lysosomal compartment in plaque cells. We further analyze how the field of LSD research may contribute with some insights to the study of CVDs, particularly how therapeutic approaches that target the lysosomes in LSDs could be applied to hamper atherosclerosis progression and associated mortality.

PRDX2 Protects Against Atherosclerosis by Regulating the Phenotype and Function of the Vascular Smooth Muscle Cell.

Peroxiredoxin 2 (PRDX2), an inhibitor of reactive oxygen species (ROS), is potentially involved in the progression of atherosclerosis (AS). The aim of this study was to explore the role and mechanism of PRDX2 in AS. The expression of PRDX2 was evaluated in 14 human carotid artery tissues with or without AS. The results showed that the positive reaction of PRDX2 was observed in the carotid artery vascular smooth muscle cells (CAVSMCs). To assess the mechanism by which PRDX2 may function in AS, the CAVSMCs were transfected with pEX4-PRDX2 and si-PRDX2. The catalase, hydrogen peroxide (H2O2) scavenger, was used to further confirm that PRDX2-induced inhibitory effects might be mediated through reducing ROS levels. Phenotype alteration and functional testing included transcription testing, immunostaining, and expression studies. The drug of MAPK signaling pathway inhibitors SB203580, SP600125, and PD98059 was used to evaluate the underlying mechanism. In this study, we found that the protein level of PRDX2 and the level of H2O2 were higher in the human AS carotid artery tissues than in the normal carotid artery tissues, accompanied with the activation of MAPK signaling pathway. The up-regulation of PRDX2 in the CAVSMCs significantly decreased the expression of ROS, collagen type I (COL I), collagen type III (COL III), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) and inhibited the proliferation, migration, and transformation of the CAVSMCs. The up-regulation of PRDX2 reversed the effect of the CAVSMCs treated with tumor necrosis factor-α (TNF-α). In addition, PRDX2 down-regulation promoted the protein levels of p-p38, p-JNK, and p-ERK, which was confirmed in relevant MAPK inhibitor treatment experiments. Our results suggest a protective role of PRDX2, as a scavenger of ROS, in AS progression through inhibiting the VSMC phenotype alteration and function via MAPK signaling pathway.

Potential Target miR-455 Delaying Arterial Stenosis Progression Through PTEN.

Background: Vascular smooth muscle cells (VSMC) underwent phenotypic switching upon stimulation signals, and this is the prerequisite for their proliferation and migration. Previous work revealed that miR-455 may be involved in vascular stenosis. Thus, this study aimed to explore potential targets and mechanisms underlying the dynamics of miR-455 in vascular stenosis.Methods: miR-455 and PTEN expression levels were studied in normal and stenosis tissue, as well as in VSMC in proliferation model. Manipulating miR-455 expression levels was achieved by transfection of either miR-455 mimic or inhibitor, and its effect on cell proliferation was studied by CCK-8 assay. Its effect on gene expression was studied by RT-qPCR and western blot. The expression regulation mechanism was studied by luciferase reporter system. Finally, the effect of miR-455 on regulating vascular stenosis was studied using a rat balloon-injured carotid artery stenosis model.Results: High expression levels of miR-455 were detected in both stenosis arterial tissues and VSMC proliferation models. In contrast, the expression levels of PTEN were downregulated in these systems. miR-455 transfected VSMC showed higher levels of proliferation and decreased levels of PTEN. Potential binding sites between miR-455 and PTEN 3′UTR were predicted and confirmed. NF-kB p65 was found to bind directly on miR-455 promoter region and regulate its transcription. The progression of arterial stenosis could be delayed by introducing miR-455 antagomir.Conclusions: The p65/miR-455/PTEN signaling pathway plays a crucial role in regulating VSMC proliferation and vascular stenosis. This indicated that miR-455 is a novel target that would help improve treatment outcomes in patients suffering from vascular stenosis.

The pericyte: A critical cell in the pathogenesis of CADASIL.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary small vessel disease presenting with migraine, mood and cognitive disorders, focal neurological deficits, recurrent ischemic attacks, lacunar infarcts and brain white matter changes. As they age, CADASIL patients invariably develop cognitive impairment and subcortical dementia. CADASIL is caused by missense mutations in the NOTCH3 gene resulting in a profound cerebral vasculopathy affecting primarily arterial vascular smooth muscle cells, which target the microcirculation and perfusion. Based on a thorough review of morphological lesions in arteries, veins, and capillaries in CADASIL, we surmise that arteriolar and capillary pericyte damage or deficiency appears a key feature in the pathogenesis of the disease. This may affect critical pericyte-endothelial interactions causing stroke injury and vasomotor disturbances. Changes in microvascular permeability due to perhaps localized blood-brain barrier alterations and pericyte secretory dysfunction likely contribute to delayed neuronal as well as glial cell death. Moreover, pericyte-mediated cerebral venous insufficiency may explain white matter lesions and the dilatation of Virchow-Robin perivascular spaces typical of CADASIL. The postulated central role of the pericyte offers some novel approaches to the study and treatment of CADASIL and enable elucidation of other forms of cerebral small vessel diseases and subcortical vascular dementia.

Uterine decidual niche modulates the progressive dedifferentiation of spiral artery vascular smooth muscle cells during human pregnancy†.

Uterine spiral artery (SPA) remodeling is a crucial event during pregnancy to provide enough blood supply to maternal-fetal interface and meet the demands of the growing fetus. Along this process, the dynamic change and the fate of spiral artery vascular smooth muscle cells (SPA-VSMCs) have long been debatable. In the present study, we analyzed the cell features of SPA-VSMCs at different stages of vascular remodeling in human early pregnancy, and we demonstrated the progressively morphological change of SPA-VSMCs at un-remodeled (Un-Rem), remodeling, and fully remodeled (Fully-Rem) stages, indicating the extravillous trophoblast (EVT)-independent and EVT-dependent phases of SPA-VSMC dedifferentiation. In vitro experiments in VSMC cell line revealed the efficient roles of decidual stromal cells, decidual natural killer cells (dNK), decidual macrophages, and EVTs in inducing VSMCs dedifferentiation. Importantly, the potential transformation of VSMC toward CD56+ dNKs was displayed by immunofluorescence-DNA in-situ hybridization-proximity ligation and chromatin immunoprecipitation assays for H3K4dime modification in the myosin heavy chain 11 (MYH11) promoter region. The findings clearly illustrate a cascade regulation of the progressive dedifferentiation of SPA-VSMCs by multiple cell types in uterine decidual niche and provide new evidences to reveal the destination of SPA-VSMCs during vascular remodeling.

Metabolic syndrome contributes to the pulmonary arterial dysfunction in pulmonary hypertension in heart failure with preserved ejection fraction

Abstract Background Many Heart Failure with preserved Ejection Fraction (HFpEF) patients have metabolic syndrome and develop Exercise Induced Pulmonary Hypertension (EIPH). The pathogenesis of EIPH in HFpEF remains unclear as there is no rodent model. As the SGLT2 inhibitor Empagliflozin improves clinical outcome in patients with type 2 diabetes and cardiovascular risk, we tested its effect on EIPH in a novel rat model of HFpEF. Methods Obese ZSF1 (HFpEF model) with leptin receptor mutation have metabolic syndrome and received the VEGF-inhibitor SU5416 to stimulate PH (Obese + Sugen). Half also received Empagliflozin (0.2 mg/kg/day) in drinking water from 8 to 22 weeks old. Lean ZSF1 lacking the mutation served as controls. During treadmill exercise, right/left ventricle (RV/LV) hemodynamics were evaluated via catheters. Pulmonary artery vascular smooth muscle cells (PAVSMC) prepared from normal or diabetic patients were cultured in standard media, or with Palmitate acid, Glucose and Insulin (PGI) to induce metabolic stress. Flow cytometry was used to evaluate reactive oxygen species (ROS) in mitochondria (Mitosox) or cytoplasm (CellROX). Results Relative to Lean, Obese + Sugen had increased body weight and HgA1C (Fig. 1A). Relative to Lean and at rest, Obese + Sugen showed mildly elevated RVSP and LVEDP. After exercise, LVSP and LVEDP rose similarly in Lean and Obese + Sugen. However, after exercise, Obese + Sugen showed a markedly greater increase in RVSP and exercise intolerance consistent with EIPH (Fig. 1B). In MR imaging of PA, Lean showed dobutamine (5 μg/kg/min)-induced PA dilation, which was not seen in Obese + Sugen (Fig. 1C). Protein levels of sGCβ1 (key regulator of PA relaxation) and its transcription factor (NFYA) both were decreased in PA from Obese + Sugen relative to Lean (Fig. 1D). Obese + Sugen + SGLT2 inhibitor treated rats showed marked improvements metabolic syndrome (body weight, HgA1c), exercise induced increase in RVSP, PA response to dobutamine, and increased NFYA and sGCβ1 expression (Fig. 1A–D). We observed greater ROS-induced DNA damage (8-OHdG staining) (Fig. 1E) and mitochondrial complex I, III, and IV activity in Obese + Sugen PA that was normalized in Obese + Sugen + SGLT2 inhibitor (Fig. 1F), suggesting a role of ROS in EIPH. Control human PAVSMC treated with PGI media showed elevated cytoplasmic and mitochondrial ROS, associated with increased mitochondrial complex I, III, IV and V activity (Fig. 1F, G). PGI media also accelerated the degradation of NFYA RNA and protein level in a manner mimicked by H2O2, and prevented by catalase/SOD (Fig. 1H, I), suggesting PGI-induced ROS enhanced NFYA degradation. Diabetic human PAVSMCs cultured in normal media resembled PGI-treated normal cells with respect to sGCb1 and NFYA expression, and in response to catalase/SOD (Fig. 1H, I). Conclusions In this PH-HFpEF model, metabolic syndrome contributes to PA dysfunction and EIPH through mitochondrial dysfunction and enhanced ROS, which were improved by Empagliflozin treatment. Figure 1 Funding Acknowledgement Type of funding source: None