Balloon-injured Carotid Arteries Research Articles

Matrix-Binding, N-Cadherin-Targeting Chimeric Peptide Inhibits Intimal Thickening but Not Endothelial Repair in Balloon-Injured Carotid Arteries.

Treatment of occluded vessels can involve angioplasty, stenting, and bypass grafting, which can be limited by restenosis and thrombosis. Drug-eluting stents attenuate restenosis, but the current drugs used are cytotoxic, causing smooth muscle cell (SMC) and endothelial cell (EC) death that may lead to late thrombosis. N-cadherin is a junctional protein expressed by SMCs, which promotes directional SMC migration contributing to restenosis. We propose that engaging N-cadherin with mimetic peptides can act as a cell type-selective therapeutic strategy to inhibit polarization and directional migration of SMCs without negatively impacting ECs. We designed a novel N-cadherin-targeting chimeric peptide with a histidine-alanine-valine cadherin-binding motif, combined with a fibronectin-binding motif from Staphylococcus aureus. This peptide was tested in SMC and EC culture assays of migration, viability, and apoptosis. Rat carotid arteries were balloon injured and treated with the N-cadherin peptide. Treating scratch-wounded SMCs with the N-cadherin-targeting peptide inhibited migration and reduced polarization of wound-edge cells. The peptide colocalized with fibronectin. Importantly, EC junction, permeability, or migration was not impacted by peptide treatment in vitro. We also demonstrated that the chimeric peptide persisted for 24 hours after transient delivery in the balloon-injured rat carotid artery. Treatment with the N-cadherin-targeting chimeric peptide reduced intimal thickening in balloon-injured rat carotid arteries at 1 and 2 weeks after injury. Reendothelialization of injured vessels after 2 weeks was unimpaired by peptide treatment. These studies show that an N-cadherin-binding and fibronectin-binding chimeric peptide is effective in inhibiting SMC migration in vitro and in vivo and limiting neointimal hyperplasia after balloon angioplasty without affecting EC repair. These results establish the potential of an advantageous SMC-selective strategy for antirestenosis therapy.

Abstract 496: Inhibition Of Tirna-gly-gcc Ameliorates Neointimal Formation Via Cbx3-mediated Vascular Smooth Muscle Cells Phenotypic Switching

Introduction: Vascular smooth muscle cells (VSMCs) are the main component of blood vessels and synthetic VSMCs play an essential role in vascular diseases. tRNA-derived fragments (tRFs) are a new class of non-coding RNAs involved in a variety of pathological processes, but their biological functions and mechanisms in VSMCs phenotype transition and vascular intimal hyperplasia are unclear. Hypothesis: We assessed the hypothesis that tRFs play important role in VSMCs phenotype transition, regulation of tRFs could ameliorates neointimal formation. Methods: Differential expression profiles of tRFs from different phenotype of VSMCs was acquired using small-RNA sequence. The expression of tiRNA-Gly-GCC was confirmed in VSMCs, vascular tissues and plasma from healthy and atherosclerosis using quantitative real-time PCR and RNA fluorescence in situ hybridization. Gain-and loss- of function were performed using mimics and inhibitors to investigate the role of tiRNA-Gly-GCC in VSMCs phenotypic transition and neointimal formation after vascular injury. Dual-luciferase reporter gene and rescue experiments were performed to demonstrate the relationship between tiRNA-Gly-GCC and CBX3. Results: tiRNA-Gly-GCC is upregulated in synthetic VSMCs, atherosclerotic arteries, plasma and the balloon injured carotid artery of rats. Functionally, the inhibition of tiRNA-Gly-GCC represses VSMCs proliferation, migration, and reversed dedifferentiation, whereas the overexpression of tiRNA-Gly- GCC have contrary effects. Mechanistically, tiRNA-Gly-GCC performs these functions on VSMCs via downregulating the expression of CBX3. Finally, the inhibition of tiRNA-Gly-GCC could ameliorate neointimal formation after vascular injury in vivo . Conclusions: In conclusion, tiRNA-Gly-GCC is a mediator of VSMCs phenotypic switching by targeting CBX3, inhibition of tiRNA-Gly-GCC suppresses neointimal formation.

Inhibition of tiRNA-Gly-GCC ameliorates neointimal formation via CBX3-mediated VSMCs phenotypic switching.

tRNA-derived fragments (tRFs) are a new class of non-coding RNAs involved in a variety of pathological processes, but their biological functions and mechanisms in human aortic smooth muscle cells (HASMCs) phenotype transition and vascular intimal hyperplasia are unclear. tiRNA-Gly-GCC is upregulated in synthetic HASMCs, atherosclerotic arteries, plasma, and the balloon injured carotid artery of rats. Functionally, the inhibition of tiRNA-Gly-GCC represses HASMCs proliferation, migration, and reversed dedifferentiation, whereas the overexpression of tiRNA- Gly-GCC have contrary effects. Mechanistically, tiRNA-Gly-GCC performs these functions on HASMCs via downregulating chromobox protein homolog 3 (CBX3). Finally, the inhibition of tiRNA-Gly-GCC could ameliorate neointimal formation after vascular injury in vivo. tiRNA-Gly-GCC is a mediator of HASMCs phenotypic switching by targeting CBX3 and inhibition of tiRNA-Gly-GCC suppresses neointimal formation.

Sophocarpine Alleviates Injury-Induced Intima Hyperplasia of Carotid Arteries by Suppressing Inflammation in a Rat Model.

Introduction: Balloon angioplasty is a commonly applied procedure for treating atherosclerotic vascular diseases. However, the maintenance of long-term lumen patency is relatively difficult due to the occurrence of restenosis. Previous research has shown that the occurrence of vascular wall inflammation is associated with higher rates of restenosis. Sophocarpine (SPC) can exert various therapeutic effects such as anti-oxidation, anti-inflammation, anti-tumor, antivirus and immune regulation. This study aimed to investigate whether SPC can alleviate intimal hyperplasia following balloon injury in a rat carotid artery model. Methods: Twenty Sprague–Dawley rats were randomly assigned to four groups: (i) control, (ii) balloon injury, (iii) balloon injury followed by saline injection, and (iv) balloon injury followed by SPC administration. Each group contained five rats. A high-pressure balloon of 3 mm × 20 mm was placed in the carotid artery. The balloon was inflated to a pressure of 8 atmospheres to carry out rat carotid artery balloon injury model. The areas of neointimal and media were determined by Verhoeff_Van Gieson staining, and the intima-to-media (I:M) ratios were subsequently evaluated. After that, the protein levels of IL-6, IL-1β, MCP-1, NF-κB, TNF-α, VCAM-1, ICAM-1 and eNOS were measured. Results: The ratio of I:M was remarkably higher in the balloon injury group than in the control group (p < 0.01). SPC could significantly decrease the ratio of I:M compared with the balloon injury group (p < 0.01). Besides, the protein levels of IL-6, IL-1β, MCP-1, NF-κB, TNF-α, ICAM-1 and VCAM-1 were increased in rat carotid arteries exposed to balloon injury (p < 0.01), and treatment with SPC could attenuate these effects (p < 0.05). Furthermore, balloon injury inhibited the protein expression of eNOS (p < 0.01), and SPC could elevate its level (p < 0.05). Conclusions: SPC could alleviate an intimal hyperplasia in balloon-injured carotid artery, and the mechanisms underlying this protective effect might be due to its inhibitory potency against inflammation signals. Our study also implies the potential applicability of SPC in treating restenosis after balloon angioplasty.

Chrysin boosts KLF2 expression through suppression of endothelial cell-derived exosomal microRNA-92a in the model of atheroprotection.

Atherosclerosis and its related clinical complications are the leading cause of death. MicroRNA (miR)-92a in the inflammatory endothelial dysfunction leads to atherosclerosis. Krüppel-like factor 2 (KLF2) is required for vascular integrity and endothelial function maintenance. Flavonoids possess many biological properties. This study investigated the vascular protective effects of chrysin in balloon-injured carotid arteries. Exosomes were extracted from human coronary artery endothelial cell (HCAEC) culture media. Herb flavonoids and chrysin were the treatments in these atheroprotective models. Western blotting and real-time PCRs were performed. In situ hybridization, immunohistochemistry, and immunofluorescence analyses were employed. MiR-92a increased after balloon injury and was present in HCAEC culture media. Chrysin was treated, and significantly attenuated the miR-92a levels after balloon injury, and similar results were obtained in HCAEC cultures in vitro. Balloon injury-induced miR-92a expression, and attenuated KLF2 expression. Chrysin increased the KLF2 but reduced exosomal miR-92a secretion. The addition of chrysin and antagomir-92a, neointimal formation was reduced by 44.8 and 49.0% compared with balloon injury after 14days, respectively. Chrysin upregulated KLF2 expression in atheroprotection and attenuated endothelial cell-derived miR-92a-containing exosomes. The suppressive effect of miR-92a suggests that chrysin plays an atheroprotective role. Proposed pathway for human coronary artery endothelial cell (HCAEC)-derived exosomes induced by chrysin to suppress microRNA (miR)-92a expression and counteract the inhibitory effect of miR-92a on KLF2 expression in HCAECs. This provides an outline of the critical role of the herbal flavonoid chrysin, which may serve as a valuable therapeutic supplement for atheroprotection.

Nkx2-3 induces autophagy inhibiting proliferation and migration of vascular smooth muscle cells via AMPK/mTOR signaling pathway.

Vascular remodeling and restenosis are common complications after percutaneous coronary intervention. Excessive proliferation and migration of vascular smooth muscle cells (VSMCs) play important roles in intimal hyperplasia-induced vascular restenosis. NK2 Homeobox 3 (Nkx2-3), a critical member of Nkx family, is involved in tissue differentiation and organ development. However, the role of Nkx2-3 in VSMCs proliferation and migration remains unknown. In this study, we used carotid balloon injury model and platelet-derived growth factor-BB (PDGF)-treated VSMCs as in vivo and in vitro experimental models. EdU assay and CCK-8 assay were used to detect cell proliferation. Migration was measured by scratch test. Hematoxylin and eosin staining and immunohistochemistry staining were used to evaluate the intimal hyperplasia. The autophagy level was detected by fluorescent mRFP-GFP-LC3 in vitro and by transmission electron microscopy in vivo. It was shown that Nkx2-3 was upregulated both in balloon injured carotid arteries and PDGF-stimulated VSMCs. Adenovirus-mediated Nkx2-3 overexpression inhibited intimal hyperplasia after balloon injury, and suppressed VSMCs proliferation and migration induced by PDGF. Conversely, silencing of Nkx2-3 by small interfering RNA exaggerated proliferation and migration of VSMCs. Furthermore, we found that Nkx2-3 enhanced autophagy level, while the autophagy inhibitor 3-MA eliminated the inhibitory effect of Nkx2-3 on VSMCs proliferation and migration both in vivo and in vitro. Moreover, Nkx2-3 promoted autophagy in VSMCs by activating the AMP-activated protein kinase/mammalian target of rapamycin (AMPK/mTOR) signaling pathway. These results demonstrated for the first time that Nkx2-3 inhibited VSMCs proliferation and migration through AMPK/mTOR-mediated autophagy.

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.

Metformin attenuates carotid neointimal hyperplasia by modulating the vascular smooth muscle cell phenotype transformation through upregulation of TET2, Nur77 and calponin

Metformin is a drug used to treat type 2 diabetes based on its effectiveness as well as cardiovascular safety. Metformin has been shown to modulate proliferation and migration of vascular smooth muscle cells (VSMCs), but the underlying mechanisms of the effect of metformin on VSMC function remains unclear. We found that metformin inhibits VSMC proliferation and migration and upregulates the expression of nuclear receptor subfamily 4 group A member 1 (Nur77), ten-eleven translocation 2 (TET2), and calponin in vitro. In the carotid artery balloon injury model of rats, metformin effectively prevented neointimal hyperplasia in the carotid artery, including neointimal thickness, increased neointimal area, and the neointimal area/medial area ratio. It also reduced the number of proliferating cell nuclear antigen (PCNA)+ cells and increased the expression of Nur77, calponin and alpha-smooth muscle actin (?-SMA). These results show that metformin attenuates neointimal hyperplasia in balloon-injured carotid arteries via increased expression of TET2, Nur77 and calponin, and reduced expression of matrix metallopeptidase 9 (MMP-9).

Dihydroartemisinin ameliorates balloon injury-induced neointimal formation through suppressing autophagy in vascular smooth muscle cells.

The present study was designed to investigate the therapeutic effects of injection of dihydroartemisinin (DHA) into the balloon-injured carotid arteries on balloon injury-induced neointimal formation and to explore whether autophagy is involved in the action of DHA. Percutaneous transluminal balloon angioplasty was performed in Sprague-Dawley rats to induce neointimal formation, immediately after which DHA (100μmol/l×1ml) and/or Rapamycin (1mg/100μl), were injected into the balloon-injured carotid arteries. After 14days, the serum samples and carotid artery tissues were harvested for analysis. Rat aortic vascular smooth muscle cells (VSMCs) were pretreated with DMSO (vehicle), DHA (1, 10, and 100μmol/l), or 3-methyladenine (3-MA; 10mM) for 1h and then stimulated with platelet-derived growth factor-BB (PDGF-BB; 10ng/ml) for another 24h. Animal experiments showed that DHA attenuated the balloon injury-induced neointimal formation, inflammation and VSMC phenotypic transition by inhibiting the balloon injury-induced autophagy activation. In vitro results showed that DHA attenuated the PDGF-BB-induced VSMC phenotypic transition, proliferation, and migration by inhibiting the PDGF-BB-induced autophagy activation. Taken together, DHA ameliorates balloon injury-induced neointimal formation through suppressing autophagy. This study provides insights into the development of a drug-eluting stent using DHA.

Sophocarpine prevents cigarette smoke-induced restenosis in rat carotid arteries after angioplasty.

Cigarette smoking is one of the main predisposing factors for atherosclerosis, which can lead to vascular inflammation. Emerging research has demonstrated that the rate of restenosis is increased following angioplasty in smokers. Sophocarpine, one of the Sophora alkaloids, can play the antiinflammatory role in cells. This study aimed to assess whether sophocarpine can alleviate the restenosis induced by cigarette smoke in rats post-angioplasty. Fifteen male Sprague-Dawley rats were randomized into three groups (control group, smoking group, smoking and injected with sophocarpine group). An established balloon-induced carotid artery injury was performed to all the groups. For the balloon-injured carotid arteries, Verhoeff-Van Gieson stain was used to detect the area of neointima and media. Then the ratio of neointima to media (I/M ratio) was calculated. For the contralateral carotid arteries, the level of MAP kinase kinase 3 (MKK3), MAP kinase kinase 6 (MKK6), Phospho-MKK3/6, p38, Phospho-p38, interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were measured. The I/M ratio of smoking group is larger than that of control group. However, sophocarpine could dramatically reduce the I/M ratio compared to smoking group. Cigarette smoke could induce the expression of Phospho-MKK3/6, Phospho-p38, IL-1β and TNF-α, and treatment with sophocarpine could inhibit such effects. The levels of MKK3, MKK6 and p38 were not under the influence of cigarette smoke or sophocarpine. Sophocarpine could alleviate the cigarette smoke-induced restenosis in rat carotid arteries after balloon injury and the mechanism of its protective effect might be the inhibition of the inflammatory reaction. This also implies sophocarpine has the potential therapeutic applicability in preventing restenosis after angioplasty in smokers.

Identification and Functional Validation of the miRNAs and their Targets, which are Essential to the Induction of Neointimal Hyperplasia

Angioplasty and stent procedures for widening the narrowed artery of atherosclerosis can cause restenosis by damaging endothelial cells. The main reason for this phenomenon is the migration and proliferation of vascular smooth muscle cells toward the intimal layer, which is called neointimal hyperplasia. After the function of miRNA, which is cell‐specific and fine‐tunes the translation of several mRNA targets, was known, several studies have identified miRNAs that affect arterial restenosis to overcome the limits of the previous drugs. However, most of the studies focused on one miRNA each. Therefore, it is necessary to ensure which of the individually studied miRNAs play a more important role at the beginning of restenosis. We should also ensure that there are any unknown miRNAs associated with restenosis regulation. In this study, we used the rat balloon injured carotid artery model to identify the entire differentially expressed (DE)‐miRNAs and DE‐mRNAs in the early stages of restenosis, through small RNA sequencing and total RNA sequencing, respectively. Among the DE‐miRNAs which show the same results in small RNA sequencing and RT‐qPCR, we focus on the rat, human conserved miRNAs with the largest change in expression (&gt; 5 fold). The conserved DE‐miRNAs included previously well‐known miRNAs, such as miR‐221 and miR‐21, but also miRNAs, which show more change in expression but still unknown. By performing in vivo and in vitro functional assays, we were able to identify several undiscovered miRNAs that are effective in the cellular functions associated with the suppression of neointimal hyperplasia. Next, among the DE‐mRNAs identified by total RNA sequencing, we selected the predicted targets of the miRNAs through the target prediction databases (Targetscan, miRDB, miRmap). Also, we selected mRNAs functionally in context with the miRNAs by using the Gene Ontology (GO) term of the expected targets. We used RT‐qPCR to double‐check the changes in expression of these filtered targets and to confirm whether these predicted targets are actual targets for miRNAs. For the mRNA with the greatest variation, we performed luciferase assay to check whether the mRNA is a direct target of the miRNA. Additional functional assays were used to determine whether the target mRNA plays a central role in the progression of the neointimal hyperplasia.In summary, we identified entire miRNAs and their target mRNAs that are important for restenosis control. Through this study, we expect to utilize diverse miRNAs for the diagnosis and therapy of restenosis.Support or Funding InformationThis study was supported by the grant from the National Research Foundation of Korea (2018029571)

TSPO ligands prevent the proliferation of vascular smooth muscle cells and attenuate neointima formation through AMPK activation.

Abnormal growth of the intimal layer of blood vessels (neointima formation) contributes to the progression of atherosclerosis and in-stent restenosis. Recent evidence shows that the 18-kDa translocator protein (TSPO), a mitochondrial membrane protein, is involved in diverse cardiovascular diseases. In this study we investigated the role of endogenous TSPO in neointima formation after angioplasty in vitro and in vivo. We established a vascular injury model in vitro by using platelet-derived growth factor-BB (PDGF-BB) to stimulate rat thoracic aortic smooth muscle cells (A10 cells). We found that treatment with PDGF-BB (1–20 ng/mL) dose-dependently increased TSPO expression in A10 cells, which was blocked in the presence of PKC inhibitor or MAPK inhibitor. Overexpression of TSPO significantly promoted the proliferation and migration in A10 cells, whereas downregulation of TSPO expression by siRNA or treatment with TSPO ligands PK11195 or Ro5-4864 (104 nM) produced the opposite effects. Furthermore, we found that PK11195 (10−104 nM) dose-dependently activated AMPK in A10 cells. PK11195-induced inhibition on the proliferation and migration of PDGF-BB-treated A10 cells were abolished by compound C (an AMPK-specific inhibitor, 103 nM). In rats with balloon-injured carotid arteries, TSPO expression was markedly upregulated in the carotid arteries. Administration of PK11195 (3 mg/kg every 3 days, ip), starting from the initial balloon injury and lasting for 2 weeks, greatly attenuated carotid neointima formation by suppressing balloon injury-induced phenotype switching of VSMCs (increased α-SMA expression). These results suggest that TSPO is a vascular injury-response molecule that promotes VSMC proliferation and migration and is responsible for the neointima formation after vascular injury, which provides a novel therapeutic target for various cardiovascular diseases including atherosclerosis and restenosis.

MicroRNA-24 inhibits the oxidative stress induced by vascular injury by activating the Nrf2/Ho-1 signaling pathway

Background and aimsThe process of endothelial repair in diabetic patients after stent implantation was significantly delayed compared with that in non-diabetic patients, and oxidative stress is increasingly considered to be relevant to the pathogenesis of diabetic endothelial repair. However, the mechanisms linking diabetes and reendothelialization after vascular injury have not been fully elucidated. The aim of this study was to evaluate the effect of microRNA-24 (miR-24) up-regulation in delayed endothelial repair caused by oxidative stress after balloon injury in diabetic rats. MethodsIn vitro, vascular smooth muscle cells (VSMCs) isolated from the thoracic aorta were stimulated with high glucose (HG) after miR-24 recombinant adenovirus (Ad-miR-24-GFP) transfection for 3 days. In vivo, diabetic rats induced using high-fat diet (HFD) and low-dose streptozotocin (30 mg/kg) underwent carotid artery balloon injury followed by Ad-miR-24-GFP transfection for 20 min. ResultsThe expression of miR-24 was decreased in HG-stimulated VSMCs and balloon-injured carotid arteries of diabetic rats, which was accompanied by increased expression of Ogt and Keap1 and decreased expression of Nrf2 and Ho-1. Up-regulation of miR-24 suppressed VSMC oxidative stress induced by HG in vitro, and miR-24 up-regulation promoted reendothelialization in balloon-injured diabetic rats. The underlying mechanism was related to the activation of the Nrf2/Ho-1 signaling pathway, which subsequently suppressed intracellular reactive oxidative species (ROS) production and malondialdehyde (MDA) and NADPH oxidase (Nox) activity, and to the restoration of Sod and Gsh-px activation. ConclusionsThe up-regulation of miR-24 significantly promoted endothelial repair after balloon injury through inhibition of oxidative stress by activating the Nrf2/Ho-1 signaling pathway.

ALDH1A3 Regulations of Matricellular Proteins Promote Vascular Smooth Muscle Cell Proliferation.

SummaryVascular smooth muscle cell (VSMC) proliferation promotes intimal hyperplasia (IH) in occluding vascular diseases. Here we identified a positive role of ALDH1A3 (an aldehyde dehydrogenase) in this pro-IH process. The expression of ALDH1A3, but not that of 18 other isoforms of the ALDH family, was substantially increased in cytokine-stimulated VSMCs. PDGF(BB) stimulated VSMC total ALDH activity and proliferation, whereas ALDH1A3 silencing abolished this effect. ALDH1A3 silencing also diminished the expression of two matricellular proteins (TNC1 and ESM1), revealing a previously unrecognized ALDH1A3 function. Loss-of-function experiments demonstrated that TNC1 and ESM1 mediated ALDH1A3's pro-proliferative function via activation of AKT/mTOR and/or MEK/ERK pathways. Furthermore, ALDH inhibition with disulfiram blocked VSMC proliferation/migration in vitro and decreased TNC1 and ESM1 and IH in angioplasty-injured rat carotid arteries. Thus, ALDH1A3 promotes VSMC proliferation at least partially through TNC1/ESM1 upregulation; dampening excessive ALDH1A3 activity represents a potential approach to IH mitigation.

Cell-Specific Effects of GATA (GATA Zinc Finger Transcription Factor Family)-6 in Vascular Smooth Muscle and Endothelial Cells on Vascular Injury Neointimal Formation.

Objective- Transcription factor GATA (GATA zinc finger transcription factor family)-6 is highly expressed in vessels and rapidly downregulated in balloon-injured carotid arteries and viral delivery of GATA-6 to the vessels limited the neointimal formation, however, little is known about its cell-specific regulation of in vivo vascular smooth muscle cell (VSMC) phenotypic state contributing to neointimal formation. This study aims to determine the role of vascular cell-specific GATA-6 in ligation- or injury-induced neointimal hyperplasia in vivo. Approach and Results- Endothelial cell and VSMC-specific GATA-6 deletion mice are generated, and the results indicate that endothelial cell-specific GATA-6 deletion mice exhibit significant decrease of VSMC proliferation and attenuation of neointimal formation after artery ligation and injury compared with the wild-type littermate control mice. PDGF (platelet-derived growth factor)-B is identified as a direct target gene, and endothelial cell-GATA-6-PDGF-B pathway regulates VSMC proliferation and migration in a paracrine manner which controls the neointimal formation. In contrast, VSMC-specific GATA-6 deletion promotes injury-induced VSMC transformation from contractile to proliferative synthetic phenotype leading to increased neointimal formation. CCN (cysteine-rich 61/connective tissue growth factor/nephroblastoma overexpressed family)-5 is identified as a novel target gene, and VSMC-specific CCN-5 overexpression in mice reverses the VSMC-GATA-6 deletion-mediated increased cell proliferation and migration and finally attenuates the neointimal formation. Conclusions- This study gives us a direct in vivo evidence of GATA-6 cell lineage-specific regulation of PDGF-B and CCN-5 on VSMC phenotypic state, proliferation and migration contributing to neointimal formation, which advances our understanding of in vivo neointimal hyperplasia, meanwhile also provides opportunities for future therapeutic interventions.

Inhibitory effects of scoparone from chestnut inner shell on platelet-derived growth factor-BB-induced vascular smooth muscle cell migration and vascular neointima hyperplasia.

Compounds of the inner shell of chestnut (Castanea crenata) have diverse biological activities, including anti-cancer and anti-oxidant activities. Here we explored the effects of an extract of chestnut inner shells and of its bioactive component scoparone on vascular smooth muscle cell migration and vessel damage. The ethanol extract of chestnut inner shells, containing 11 major compounds, inhibited platelet-derived growth factor (PDGF)-BB-induced migration of rat aortic smooth muscle cells (RASMCs). Among these compounds, scoparone (6,7-dimethoxycoumarin) suppressed RASMC migration and wound healing in response to PDGF-BB but did not affect RASMC proliferation. In RASMCs, scoparone inhibited the PDGF-BB-induced rat aortic sprout outgrowth and attenuated the PDGF-BB-mediated increase in phosphorylation of mitogen-activated protein kinases (MAPKs), p38 MAPK and extracellular signal-regulated kinase 1/2. The in vivo administration of scoparone resulted in the attenuation of neointima formation in balloon-injured carotid arteries of rats. These findings demonstrate that scoparone, found in chestnut inner shells, may inhibit cell migration through suppression of the phosphorylation of MAPKs in PDGF-BB-treated RASMCs, probably contributing to the reduction of neointimal hyperplasia induced after vascular injury. Therefore, scoparone and chestnut inner shell may be a potential agent or functional food, respectively, for the prevention of vascular disorders such as vascular restenosis or atherosclerosis. © 2019 Society of Chemical Industry.

MicroRNA-24 attenuates vascular remodeling in diabetic rats through PI3K/Akt signaling pathway

Background and aimsThe vascular remodeling plays a crucial role in pathogenesis of diabetic cardiovascular complications. In this study, we intended to explore the effects and potential mechanisms of microRNA-24 (miR-24) on vascular remodeling under diabetic conditions. Methods and ResultsMiR-24 recombinant adenovirus (Ad-miR-24-GFP) was used to induce miR-24 overexpression either in carotid arteries or high glucose (HG)-induced vascular smooth muscle cells (VSMCs). Cell proliferation was analyzed using CCK-8 method. Cell migration was examined using wound-healing and transwell assay. mRNA and protein expressions of critical factors were, respectively, measured by real-time PCR and western blot as follows: qRT-PCR for the levels of miR-24, PIK3R1; western blot for the protein levels of PI3K (p85α), Akt, p-Akt, mTOR, p-mTOR, 4E-BP1, p-4E-BP1, p70s6k, p-p70s6k, MMP 2, MMP 9, collagen Ⅰ, as well as collagen Ⅲ. Carotid arteries in diabetic rats suffered balloon injury were harvested and examined by HE, immunohistochemical and Masson trichrome staining.The expression of miR-24 was decreased in HG-stimulated VSMCs and balloon-injured carotid arteries of diabetic rats, accompanied by increased mRNA expression of PIK3R1. The up-regulation of miR-24 suppressed VSMCs proliferation, migration, collagen deposition not only induced by HG in vitro, but also in balloon-injured diabetic rats, which were related to inactivation of PI3K/Akt signaling pathway. ConclusionThe up-regulation of miR-24 significantly attenuated vascular remodeling both in balloon-injured diabetic rats and HG-stimulated VSMCs via suppression of proliferation, migration and collagen deposition by acting on PIK3R1 gene that modulated the PI3K/Akt/mTOR axes.

LncRNA CRNDE regulates the proliferation and migration of vascular smooth muscle cells.

Restenosis after angioplasty or stent is a major clinical problem. While long noncoding RNAs (lncRNAs) are implicated in a variety of diseases, their role in restenosis is not well understood. This study aims to investigate how dysregulated lncRNAs and messenger RNAs (mRNAs) contribute to restenosis. By microarray analysis, we identified 202 lncRNAs and 625 mRNAs (fold change > 2.0, p < 0.05) differentially expressed between the balloon-injured carotid artery and uninjured carotid artery in the rats. Among differentially expressed lncRNAs, LncRNA CRNDE had the highest fold change and the change was validated by reverse transcription polymerase chain reaction. We found that LncRNA CRNDE was significantly upregulated in injured rat carotid artery and vascular smooth muscle cells (VSMCs) stimulated by platelet-derived growth factor-BB (PDGF-BB). Knockdown of LncRNA CRNDE by small interference RNA significantly inhibited PDGF-BB stimulated proliferation and migration of VSMCs. Moreover, knockdown of LncRNA CRNDE attenuated PDGF-BB-induced phenotypic change of VSMCs. Taken together, our study reveals a novel mechanoresponsive LncRNA CRNDE which may be a therapeutic target for restenosis.

Molecular Ultrasound Monitoring of Early Artery Injury After Carotid Balloon Angioplasty.

Cardiovascular intervention is a common treatment procedure for many cardiovascular diseases. But restenosis often occurs after these procedures, greatly discounting their long-term therapeutic effects. Early detection of endothelial denudation is helpful for the diagnosis and prevention of restenosis. Here, we fabricated targeted microbubbles by conjugating anti-collagen IV antibodies to the surface of biotinylated microbubbles (MBColIV) and applied them for ultrasound molecular imaging of endothelial injury at early stage. Our results showed that the MBColIV, with a typical multi-peak particle distribution, was successfully constructed, which was confirmed by Alexa Fluor® 555-labeled secondary antibody. Ex vivo adhesion of microbubbles revealed that MBColIV can effectively and specially bind to the surface of balloon-injured carotid artery. The in vivo animal experiments showed ultrasound molecular imaging signals from carotid artery-injured rats administrated with MBColIV were significantly higher than those administrated with isotype control microbubbles. Histological staining of the left carotid common artery revealed that collagen IV was obviously exposed after endothelium denudation in balloon-injured artery. In conclusion, our current study provides an effective approach to detect vascular injury at the early stage and a potential platform for image-guided therapy to vascular injury.

Catalpol Ameliorates Neointimal Hyperplasia in Diabetic Rats.

Catalpol, an iridoid glycoside, is an isolated natural product of Rehmannia glutinosa, which has been reported to have antidiabetic properties. This study investigated the vascular protective effects of catalpol in hyperglycemic rats with balloon-injured carotid arteries. Balloon injury stress led to the upregulation of monocyte chemoattractant protein-1 expression in rats with streptozotocin-induced diabetes. Western blotting and real-time PCR were performed. In situ hybridization, immunohistochemistry, and confocal analyses were employed. Monocyte chemoattractant protein-1 levels were increased through streptozotocin induction or balloon injury. After treatment with catalpol, the neointimal hyperplasia area was reduced 2 weeks after balloon injury in hyperglycemic rats. Real-time PCR and immunohistochemical analysis demonstrated reduced levels of monocyte chemoattractant protein-1 2 weeks after the balloon injury. Monocyte chemoattractant protein-1 expression was significantly increased in balloon-injured rats compared with the control groups. Thus, treatment with catalpol affected monocyte chemoattractant protein-1 expression. This study demonstrated that catalpol downregulated monocyte chemoattractant protein-1 expression in carotid arteries and ameliorated neointimal hyperplasia in hyperglycemic rats. The suppressive effect of monocyte chemoattractant protein-1 suggests that it plays a key role in neointimal hyperplasia. The results imply that catalpol is potentially effective for preventing hyperglycemia-related ischemic cardiac diseases.