Alterations in metabolome and lipidome in patients with in-stent restenosis.

CONTEXT: In-stent restenosis (ISR) can lead to blood flow obstruction, insufficient blood supply to the brain, and may even result in serious complications such as stroke. Endothelial cell hyperproliferation and thrombosis are the primary etiologies, frequently resulting in alterations in intravascular metabolism. However, the metabolic changes related to this process are still undermined. OBJECTIVE: We tried to characterize the serum metabolome of patients with ISR and those with non-restenosis (NR) using metabolomics and lipidomics, exploring the key metabolic pathways of this pathological phenomenon. RESULTS: We observed that the cysteine and methionine pathways, which are associated with cell growth and oxidative homeostasis, showed the greatest increase in the ISR group compared to the NR group. Within this pathway, the levels of N-formyl-l-methionine and L-methionine significantly increased in the ISR group, along with elevated levels of downstream metabolites such as 2-ketobutyric acid, pyruvate, and taurocholate. Additionally, an increase in phosphatidylcholine (PC) and phosphatidylserine (PS), as well as a decrease in triacylglycerol in the ISR group, indicated active lipid metabolism in these patients, which could be a significant factor contributing to the recurrence of blood clots after stent placement. Importantly, phenol sulfate and PS(38:4) were identified as potential biomarkers for distinguishing ISR, with an area under the curve of more than 0.85. CONCLUSIONS: Our study revealed significant metabolic alterations in patients with ISR, particularly in the cysteine and methionine pathways, with phenol sulfate and PS(38:4) showing promise for ISR identification.

Linarin Ameliorates Restenosis After Vascular Injury in Type 2 Diabetes Mellitus via Regulating ADAM10-Mediated Notch Signaling Pathway.

Vascular lesions frequently arise as complication in patients diagnosed with diabetes mellitus (DM). Presently, percutaneous coronary intervention (PCI) and antithrombotic therapy serve as primary treatments. However, in-stent restenosis persists as a challenging clinical issue following PCI, lacking sustained and effective treatment. Linarin (LN) exhibits diverse pharmacological activities and is regarded as a potential drug for treating various diseases, including DM. But its specific role in restenosis after vascular injury in DM patients remains unclear. A rat model of diabetes-related restenosis was established to evaluate the role of LN on neointimal hyperplasia. Vascular smooth muscle cells (VSMCs) stimulated by high glucose (HG, 30 mM) underwent LN treatment. Additionally, an overexpression plasmid of A disintegrin and metalloproteinases (ADAM10) was constructed to transfect VSMCs. We employed CCK-8, Brdu, wound-healing scratch, and transwell migration assays to evaluate the proliferation and migration of VSMCs. Furthermore, western blot and immunofluorescence assays were utilized to investigate the expressions of ADAM10 and the downstream Notch signaling pathway in vivo and in vitro models. LN notably alleviated intimal hyperplasia after vascular injury in DM rats and reduced the protein expression of ADAM10, alongside its downstream Notch1 signaling pathway-related proteins (Notch1, NICD and Hes1) in rat carotid artery tissues. LN effectively suppressed the proliferation and migration of VSMCs induced by HG, downregulating the protein expression of ADAM10, Notch1, NICD and Hes1. Moreover, our findings indicated that ADAM10 overexpression significantly reversed LN's effects on proliferation, migration, and the expression of Notch1 signaling pathway-related proteins in HG-treated VSMCs. LN demonstrates potential therapeutic efficacy in addressing restenosis after diabetic-related vascular injury, with the ADAM10 mediated Notch signaling pathway playing a pivotal role.

Platelet bioenergetic profiling uncovers a metabolic pattern of high dependency on mitochondrial fatty acid oxidation in type 2 diabetic patients who developed in-stent restenosis.

Although platelet bioenergetic dysfunction is evident early in the pathogenesis of diabetic macrovascular complications, the bioenergetic characteristics in type 2 diabetic patients who developed coronary in-stent restenosis (ISR) and their effects on platelet function remain unclear. Here, we performed platelet bioenergetic profiling to characterize the bioenergetic alterations in 28 type 2 diabetic patients with ISR compared with 28 type 2 diabetic patients without ISR (non-ISR) and 28 healthy individuals. Generally, platelets from type 2 diabetic patients with ISR exhibited a specific bioenergetic alteration characterized by high dependency on fatty acid (FA) oxidation, which subsequently induced complex III deficiency, causing decreased mitochondrial respiration, increased mitochondrial oxidant production, and low efficiency of mitochondrial ATP generation. This pattern of bioenergetic dysfunction showed close relationships with both α-granule and dense granule secretion as measured by surface P-selectin expression, ATP release, and profiles of granule cargo proteins in platelet releasates. Importantly, ex vivo reproduction of high dependency on FA oxidation by exposing non-ISR platelets to its agonist mimicked the bioenergetic dysfunction observed in ISR platelets and enhanced platelet secretion, whereas pharmaceutical inhibition of FA oxidation normalized the respiratory and redox states of ISR platelets and diminished platelet secretion. Further, causal mediation analyses identified a strong association between high dependency on FA oxidation and increased angiographical severity of ISR, which was significantly mediated by the status of platelet secretion. Our findings, for the first time, uncover a pattern of bioenergetic dysfunction in ISR and enhance current understanding of the mechanistic link of high dependency on FA oxidation to platelet abnormalities in the context of diabetes.

Detoxification and Activating Blood Circulation Decoction Promotes Reendothelialization of Damaged Blood Vessels via VEGF Signaling Pathway Activation by miRNA-126.

The occurrence of in-stent restenosis (ISR) poses a significant challenge for percutaneous coronary intervention (PCI). Thus, the promotion of vascular reendothelialization is essential to inhibit endothelial proliferation. In this study, we clarified the mechanism by which Detoxification and Activating Blood Circulation Decoction (DABCD) promotes vascular reendothelialization to avoid ISR by miRNA-126-mediated modulation of the vascular endothelial growth factor (VEGF) signaling pathway. A rat model of post-PCI restenosis was established by balloon injury. The injured aortic segment was collected 14 and 28 d after model establishment. Our findings indicate that on the 14th and 28th days following balloon injury, DABCD reduced intimal hyperplasia and inflammation and promoted vascular reendothelialization. Additionally, DABCD markedly increased nitric oxide (NO) expression and significantly decreased ET-1 production in rat serum. DABCD also increased the mRNA level of endothelial nitric oxide synthase (eNOS) and the protein expression of VEGF, p-Akt, and p-extracellular signal-regulated kinase (ERK)1/2 in vascular tissue. Unexpectedly, the expression of miR-126a-5p mRNA was significantly lower in the aortic tissue of balloon-injured rats than in the aortic tissue of control rats, and higher miR-126a-5p levels were observed in the DABCD groups. The results of this study indicated that the vascular reendothelialization effect of DABCD on arterial intimal injury is associated with the inhibition of neointimal formation and the enhancement of vascular endothelial activity. More specifically, the effects of DABCD were mediated, at least in part, through miR-126-mediated VEGF signaling pathway activation.

miRNA­92a inhibits vascular smooth muscle cell phenotypic modulation and may help prevent in­stent restenosis.

The modulation of vascular smooth muscle cell (VSMC) phenotype during cellular proliferation and migration may represent a potential therapeutic approach for vascular intimal hyperplasia prevention. However, the precise role of this process in VSMC biology and remodeling remains unclear. In the present study, western blotting, PCR, MTT and Transwell assays were used to analyze related protein and mRNA expression, cell viability and cell migration, respectively. It was demonstrated that miR­92a modulated VSMCs into a synthetic phenotype via the Kruppel­like factor 4 (KLF4) pathway. Targeting microRNA (miRNA/miR)­92a in VSMCs using a KLF4 inhibitor suppressed the synthetic phenotype and inhibited VSMC proliferation and migration. To further confirm this finding, the expression levels of miR­92a were measured in patients undergoing coronary artery intervention. The serum miR­92a expression levels were significantly higher in patients with in­stent restenosis (ISR) compared with those in patients without ISR, whereas KLF4 expression was significantly reduced in the non­ISR group. Bioinformatic analysis and promoter­luciferase reporter assays were used to examine the regulatory mechanisms underlying KLF4 expression. KLF4 was demonstrated to be transcriptionally upregulated by miR­92a in VSMCs. miRNA transfection was also performed to regulate the level of miR­92a expression. miR­92a overexpression inhibited VSMC proliferation and migration, and also increased the mRNA and protein expression levels of certain differentiated VSMC­related genes. Finally, miR­92a inhibition promoted the proliferation and migration of VSMCs, which could be reversed using a KLF4 inhibitor. Collectively, these results indicated that the local delivery of a KLF4 inhibitor may act as a novel therapeutic option for the prevention of ISR.

Vascular Smooth Muscle Cells Phenotypic Switching in Cardiovascular Diseases.

Vascular smooth muscle cells (VSMCs), the major cell type in the arterial vessel wall, have a contractile phenotype that maintains the normal vessel structure and function under physiological conditions. In response to stress or vascular injury, contractile VSMCs can switch to a less differentiated state (synthetic phenotype) to acquire the proliferative, migratory, and synthetic capabilities for tissue reparation. Imbalances in VSMCs phenotypic switching can result in a variety of cardiovascular diseases, including atherosclerosis, in-stent restenosis, aortic aneurysms, and vascular calcification. It is very important to identify the molecular mechanisms regulating VSMCs phenotypic switching to prevent and treat cardiovascular diseases with high morbidity and mortality. However, the key molecular mechanisms and signaling pathways participating in VSMCs phenotypic switching have still not been fully elucidated despite long-term efforts by cardiovascular researchers. In this review, we provide an updated summary of the recent studies and systematic knowledge of VSMCs phenotypic switching in atherosclerosis, in-stent restenosis, aortic aneurysms, and vascular calcification, which may help guide future research and provide novel insights into the prevention and treatment of related diseases.

Predicting Cardiovascular Stent Complications Using Self-Reporting Biosensors for Noninvasive Detection of Disease.

Self-reporting implantable medical devices are the future of cardiovascular healthcare. Cardiovascular complications such as blocked arteries that lead to the majority of heart attacks and strokes are frequently treated with inert metal stents that reopen affected vessels. Stents frequently re-block after deployment due to a wound response called in-stent restenosis (ISR). Herein, an implantable miniaturized sensor and telemetry system are developed that can detect this process, discern the different cell types associated with ISR, distinguish sub plaque components as demonstrated with ex vivo samples, and differentiate blood from blood clot, all on a silicon substrate making it suitable for integration onto a vascular stent. This work shows that microfabricated sensors can provide clinically relevant information in settings closer to physiological conditions than previous work with cultured cells.

Correlations between vitronectin, miR-520, and miR-34 in patients with stenosis of coronary arteries.

BACKGROUND: In-stent restenosis usually occurs by platelet activation, neointima formation, VSMC migration, and proliferation in the position of the vessel stent. The monocytes have a magnificent role in neointimal hyperplasia since these cells recruit to the site of vessel injury through chemokines and other secretion proteins. This study is focused on the investigation of vitronectin, miR-193, miR-34, and miR-520 expression levels in PBMCs isolated from stenosed patients. METHODS: A total of sixty subjects undergoing coronary artery angiography containing patients with stent no restenosis (n = 20), in-stent restenosis (n = 20), and healthy participants (n = 20) participated in the study. The vitronectin, miR-193, miR-34, and miR-520 expression levels were measured by the RT-qPCR technique. Data were analyzed by SPSS software. RESULTS: The vitronectin, miR-34, and miR-520 expression levels changed significantly in patients with vessel in-stent restenosis (p = 0.02, p = 0.02, and p = 0.01, respectively). Furthermore, there were inverse correlations between the expression levels of vitronectin gene and miR-34 (r = - 0.44, p = 0.04) as well as miR-520 (r = - 0.5, p=0.01). CONCLUSIONS: The molecular events in the vessel stenosis may be affected by targeting vitronectin with miR-520 and miR-34.

miR-126 contributes to the epigenetic signature of diabetic vascular smooth muscle and enhances antirestenosis effects of Kv1.3 blockers.

OBJECTIVES: Restenosis after vessel angioplasty due to dedifferentiation of the vascular smooth muscle cells (VSMCs) limits the success of surgical treatment of vascular occlusions. Type 2 diabetes (T2DM) has a major impact on restenosis, with patients exhibiting more aggressive forms of vascular disease and poorer outcomes after surgery. Kv1.3 channels are critical players in VSMC proliferation. Kv1.3 blockers inhibit VSMCs MEK/ERK signalling and prevent vessel restenosis. We hypothesize that dysregulation of microRNAs (miR) play critical roles in adverse remodelling, contributing to Kv1.3 blockers efficacy in T2DM VSMCs. METHODS AND RESULTS: We used clinically relevant in vivo models of vascular risk factors (VRF) and vessels and VSMCs from T2DM patients. RESUKTS: Human T2DM vessels showed increased remodelling, and changes persisted in culture, with augmented VSMCs migration and proliferation. Moreover, there were downregulation of PI3K/AKT/mTOR and upregulation of MEK/ERK pathways, with increased miR-126 expression. The inhibitory effects of Kv1.3 blockers on remodelling were significantly enhanced in T2DM VSMCs and in VRF model. Finally, miR-126 overexpression confered "diabetic" phenotype to non-T2DM VSMCs by downregulating PI3K/AKT axis. CONCLUSIONS: miR-126 plays crucial roles in T2DM VSMC metabolic memory through activation of MEK/ERK pathway, enhancing the efficacy of Kv1.3 blockers in the prevention of restenosis in T2DM patients.

Plasma Small Extracellular Vesicle-Carried miRNA-501-5p Promotes Vascular Smooth Muscle Cell Phenotypic Modulation-Mediated In-Stent Restenosis.

Vascular smooth muscle cell (VSMC) phenotypic modulation plays an important role in the occurrence and development of in-stent restenosis (ISR), the underlying mechanism of which remains a key issue needing to be urgently addressed. This study is designed to investigate the role of plasma small extracellular vesicles (sEV) in VSMC phenotypic modulation. sEV were isolated from the plasma of patients with ISR (ISR-sEV) or not (Ctl-sEV) 1 year after coronary stent implantation using differential ultracentrifugation. Plasma sEV in ISR patients are elevated markedly and decrease the expression of VSMC contractile markers α-SMA and calponin and increase VSMC proliferation. miRNA sequencing and qRT-PCR validation identified that miRNA-501-5p was the highest expressed miRNA in the plasma ISR-sEV compared with Ctl-sEV. Then, we found that sEV-carried miRNA-501-5p level was significantly higher in ISR patients, and the level of plasma sEV-carried miRNA-501-5p linearly correlated with the degree of restenosis (R 2 = 0.62). Moreover, miRNA-501-5p inhibition significantly increased the expression of VSMC contractile markers α-SMA and calponin and suppressed VSMC proliferation and migration; in vivo inhibition of miRNA-501-5p could also blunt carotid artery balloon injury induced VSMC phenotypic modulation in rats. Mechanically, miRNA-501-5p promoted plasma sEV-induced VSMC proliferation by targeting Smad3. Notably, endothelial cells might be the major origins of miRNA-501-5p. Collectively, these findings showed that plasma sEV-carried miRNA-501-5p promotes VSMC phenotypic modulation-mediated ISR through targeting Smad3.

Modulated molecular markers of restenosis and thrombosis byin-vitrovascular cells exposed to bioresorbable scaffolds.

Drug-eluting bioresorbable vascular scaffolds (BVSs) have emerged as a potential breakthrough for the treatment of coronary artery stenosis, providing mechanical support and drug delivery followed by complete resorption. Restenosis and thrombosis remain the primary limitations in clinical use. The study aimed to identify potential markers of restenosis and thrombosis analyzing the vascular wall cell transcriptomic profile modulation triggered by BVS at different values of shear stress (SS). Human coronary artery endothelial cells and smooth muscle cells were cultured under SS (1 and 20 dyne cm-2) for 6 h without and with application of BVS and everolimus 600 nM. Cell RNA-Seq and bioinformatics analysis identified modulated genes by direct comparison of SS conditions and Gene Ontology (GO). The results of different experimental conditions and GO analysis highlighted the modulation of specific genes as semaphorin 3E, mesenchyme homeobox 2, bone morphogenetic protein 4, (heme oxygenase 1) and selectin E, with different roles in pathological evolution of disease. Transcriptomic analysis of dynamic vascular cell cultures identifies candidate genes related to pro-restenotic and pro-thrombotic mechanisms in anin-vitrosetting of BVS, which are not adequately contrasted by everolimus addition.

The CTGF gene -945 G/C polymorphism is associated with target lesion revascularization for in-stent restenosis.

BACKGROUND AND AIMS: Previous studies have shown that transforming growth factor ß (TGF-ß) and vascular endothelial growth factor A (VEGF-A) pathways are involved in the in-stent restenosis (ISR) process. The present study aimed to assess the relationship between single-nucleotide polymorphisms (SNPs) in genes encoding downstream proteins of TGF-ß and VEGF-A pathways and the risk of target lesion revascularization (TLR) for in-stent restenosis. METHODS: A total of 657 patients (with 781 treated lesions) who underwent percutaneous coronary intervention (PCI) with stent implantation at our center between 2007 and 2012 and completed a 4-year follow-up for clinically-driven TLR, were included. SNPs in CTGF (rs6918698), TGFBR2 (rs2228048), SMAD3 (rs17293632), KDR (rs2071559), CCL2 (rs1024610) were genotyped using TaqMan assay. RESULTS: Major allele carriers of CTGF gene -945 G/C polymorphism (rs6918698) were significantly less likely to underwent clinically-driven TLR during follow-up than minor allele carriers. After adjustment for clinical, angiographic, and procedural covariates, CTGF polymorphism was significantly associated with TLR, and minor allele (C) carriers had nearly two times higher risk of developing ISR requiring TLR (HR of 1.93, 95%CI 1.15-3.24) compared to patients with major (GG) genotype. No significant relationship was found between other analyzed polymorphisms and cumulative incidence of TLR at 4-years. CONCLUSIONS: Our results suggest that functional -945 G/C polymorphism in the gene encoding connective tissue growth factor is associated with the need for TLR in patients who underwent PCI for stable coronary artery disease.

The multiple roles of chemokines in the mechanisms of stent biocompatibility.

While the advent of drug-eluting stents has been clinically effective in substantially reducing the rates of major stent-related adverse events compared with bare metal stents, vascular biological problems such as neointimal hyperplasia, delayed re-endothelialization, late stent thrombosis are not eliminated and, increasingly, neoatherosclerosis is the underlying mechanism for very late stent failure. Further understanding regarding the mechanisms underlying the biological responses to stent deployment is therefore required so that new and improved therapies can be developed. This review will discuss the accumulating evidence that the chemokines, small inflammatory proteins, play a role in each key biological process of stent biocompatibility. It will address the chemokine system in its specialized roles in regulating the multiple facets of vascular biocompatibility including neointimal hyperplasia, endothelial progenitor cell (EPC) mobilization and re-endothelialization after vascular injury, platelet activation and thrombosis, as well as neoatherosclerosis. The evidence in this review suggests that chemokine-targeting strategies may be effective in controlling the pathobiological processes that lead to stent failure. Preclinical studies provide evidence that inhibition of specific chemokines and/or broad-spectrum inhibition of the CC-chemokine class prevents neointimal hyperplasia, reduces thrombosis and suppresses the development of neoatherosclerosis. In contrast, however, to these apparent deleterious effects of chemokines on stent biocompatibility, the CXC chemokine, CXCL12, is essential for the mobilization and recruitment of EPCs that make important contributions to re-endothelialization post-stent deployment. This suggests that future chemokine inhibition strategies would need to be correctly targeted so that all key stent biocompatibility areas could be addressed, without compromising important adaptive biological responses.

Prostaglandin E2 (PGE2) synthesis pathway is involved in coronary artery stenosis and restenosis.

The inflammatory events related to prostaglandins may play an important role in the progression of vessel stenosis. The aim of this study was to investigate the monocyte PTGES and 15-PGDH gene expression levels and the serum 13,14-dihyro-15-keto-PGF2α value involved in PGE2 metabolism in patients with coronary artery stenosis and restenosis. Moreover, the effects of miR-520, miR-1297 and miR-34 were studied on the gene expression levels. A total of sixty subjects referred for coronary angiography including healthy controls (stenosis <5%), subjects with stent no restenosis) SNR, stenosis <5%) and subjects in stent restenosis (ISR, restenosis >70%) were participated in the study. The gene expression levels and the serum 13,14-dihyro-15-keto- PGF2α value were measured by RT-qPCR and ELISA techniques, respectively. Moreover, the effects of miRNAs on the gene expression levels were investigated by the monocyte transfection of miR/PEI complexes. The PTGES and 15-PGDH gene expression levels and serum 13,14-dihyro-15-keto- PGF2α value increased significantly (P <0.05). Based on the miR-520 and miR-34 expression levels, the miR/PEI transfection studies were confirmed significantly the gene expression changes. The monocyte PGE2 synthesis pathway is actively considered in the SNR and ISR patients and might be related to miR-34 and miR-520 functions.

H2S attenuates oxidative stress via Nrf2/NF-κB signaling to regulate restenosis after percutaneous transluminal angioplasty.

Restenosis after angioplasty of peripheral arteries is a clinical problem involving oxidative stress. Hydrogen sulfide (H2S) participates in oxidative stress regulation and activates nuclear factor erythroid 2-related factor 2 (Nrf2). This study investigated the effect of H2S and Nrf2 on restenosis-induced arterial injury. Using an in vivo rat model of restenosis, we investigated whether H2S inhibits restenosis after percutaneous transluminal angioplasty (PTA) and the oxidative stress-related mechanisms implicated therein. The involvement of Nrf2 was explored using Nrf2-shRNA. Neointimal formation and the deposition of elastic fibers were assessed histologically. Inflammatory cytokine secretion and the expression of proteins associated with oxidative stress and inflammation were evaluated. The artery of rats subjected to restenosis showed increased arterial intimal thickness, with prominent elastic fiber deposition. Sodium hydrosulfide (NaHS), an H2S donor, counteracted these changes in vivo. Restenosis caused a decrease in anti-oxidative stress signaling. This phenomenon was inhibited by NaHS, but Nrf2-shRNA counteracted the effects of NaHS. In terms of inflammation, inflammatory cytokines were upregulated, whereas NaHS suppressed the induced inflammatory reaction. Similarly, Nrf2 downregulation blocked the effect of NaHS. In vitro studies using aortic endothelial and vascular smooth muscle cells isolated from experimental animals showed consistent results as those of in vivo studies, and the participation of the nuclear factor-kappa B signaling pathway was demonstrated. Collectively, H2S played a role in regulating post-PTA restenosis by alleviating oxidative stress, modulating anti-oxidant defense, and targeting Nrf2-related pathways via nuclear factor-kappa B signaling.

Circulating miRNA-23b and miRNA-143 Are Potential Biomarkers for In-Stent Restenosis.

In-stent restenosis (ISR) is one of the main complications in patients undergoing percutaneous coronary angioplasty, and microRNAs participate in the contractile-to-synthetic phenotypic switch of vascular smooth muscle cells, a hallmark of restenosis development. MicroRNAs (miRNAs) can be released into circulation from injured tissues, enticing a potential role as noninvasive biomarkers. We aimed to evaluate circulating levels of miRNA-23b, miRNA-143, and miRNA-145 as diagnostic markers of ISR. 142 patients with coronary artery disease undergoing successful angioplasty and a follow-up angiography were included. Subjects were classified according to the degree of obstruction at the angioplasty site into cases (≥50%) or controls (<50%). Total RNA was isolated from plasma to quantify circulating miRNAs levels, and the ROC curves were constructed. Among circulating miRNAs assessed, miRNA-23b and miRNA-143 were significantly lower in cases (miRNA-23b: 18.4x10-5 and miRNA-143: 13.7x10-5) than controls (miRNA-23b: 5.2x10-5, p < 0.0001; miRNA-143: 4.0x10-5, p < 0.0001). Plasma levels of miRNA-145 showed no significant differences. The analysis of the ROC curves showed an area under the curve for miRNA-23b of 0.71 (95% CI: 0.62-0.80, p < 0.0001) and 0.69 for miRNA-143 (95% CI: 0.60-0.78; p < 0.0001). Our data suggest that plasma levels of miRNA-23b and miRNA-143 could be useful as noninvasive biomarkers of ISR.

Honokiol-mesoporous Silica Nanoparticles Inhibit Vascular Restenosis via the Suppression of TGF-ß Signaling Pathway.

INTRODUCTION: The main pathological mechanism of restenosis after percutaneous coronary intervention (PCI) is intimal hyperplasia, which is mainly caused by proliferation and migration of vascular smooth muscle cells (VSMCs). Our previous study found that honokiol (HNK), a small-molecule polyphenol, can inhibit neointimal hyperplasia after balloon injury, but its specific mechanism is still unclear. Moreover, poor water solubility as well as low bioavailability of honokiol has limited its practical use. METHODS: We used mesoporous silica nanoparticles (MSNPs) as a standard substance to encapsulate HNK and then assemble into honokiol-mesoporous silica nanoparticles, and we investigated the effect of these nanoparticles on the process of restenosis after common carotid artery injury in rats. RESULTS: We report a promising delivery system that loads HNK into MSNPs and finally assembles it into a nanocomposite particle. These HNK-MSNPs not merely inhibited proliferation and migration of VSMCs by reducing phosphorylation of Smad3, but also showed a higher suppression of intimal thickening than the free-honokiol-treated group in a rat model of balloon injury. CONCLUSION: To sum up, this drug delivery system supplies a potent nano-platform for improving the biological effects of HNK and provides a promising strategy for preventing vascular restenosis.

A potential strategy for in-stent restenosis: Inhibition of migration and proliferation of vascular smooth muscle cells by Cu ion.

The in-stent restenosis (ISR) often happens after the implantation of metal stents, including both bare metal stents (BMSs) and drug-eluting stents (DESs). Drug release from DESs could reduce significantly the occurrence of ISR but also suppress the revascularization and cause thrombosis. In this study, the effect of Cu ion in a range of 0 to 500 µM on the migration and proliferation of rat aortic smooth muscle cells (RASMCs) was investigated by a series of in vitro experiments including wound-healing assay, cell viability assay and flow cytometric analysis. It has been found that the critical concentration of Cu ion should be at least 250 µM in order to significantly inhibit the migration of RASMCs and the proliferation of RASMCs were impeded by every dose of Cu ion used in this study. In addition, the protein level of caspase-3 was upregulated by 250 µM and 500 µM Cu2+ exposure, which might be the main reason for RASMCs apoptosis. Thus, it is proposed that ISR might be prevented by the constant release of Cu ion.

COX and PTGDS Gene Expression Levels in PGD2 Synthesis Pathway are Correlated with miR-520 in Patients with Vessel Restenosis.

BACKGROUND: The vessel restenosis is related to the inflammatory events in subendothelial space. It is proposed that the inflammatory agents affect the prostaglandin synthesis pathway. In this study, we investigated the COX-1, COX-2, PTGDS and miRNA-520a-5p expression levels and the serum 15-Deoxy-Δ12,14-PGJ2 metabolite values in patients with the stenosed and re-stenosed vessels. Furthermore, the associations between genes and miR-520 were evaluated in the monocyte transfection studies. METHODS: The subjects (n=60) were included three groups; healthy subjects (control (stenosis < 5%), stent no restenosis (SNR, restenosis < 5%) and in-stent restenosis (ISR, restenosis > 70%)). The miRNA and gene expression levels were measured by RT-qPCR technique. 15-Deoxy-Δ12,14-PGJ2 values were measured by the ELISA technique. The miR-520 was transfected into myocytes using PEI polymer. RESULTS: The monocyte COX-1, COX-2 and PTGDS gene expression levels and the serum 15-Deoxy- Δ12,14-PGJ2 values increased significantly in the patients. Furthermore, the miR-520 correlated conversely with the COX-1, and PTGDS gene expression levels. CONCLUSION: The results showed that the PGD2 synthesis pathway is active in the patients and, miR- 520 may be involved in the function of this pathway.

Preventing treatment failures in coronary artery disease: what can we learn from the biology of in-stent restenosis, vein graft failure, and internal thoracic arteries?

Coronary artery disease (CAD) remains one of the most important causes of morbidity and mortality worldwide, and the availability of percutaneous or surgical revascularization procedures significantly improves survival. However, both strategies are daunted by complications which limit long-term effectiveness. In-stent restenosis (ISR) is a major drawback for intracoronary stenting, while graft failure is the limiting factor for coronary artery bypass graft surgery (CABG), especially using veins. Conversely, internal thoracic artery (ITA) is known to maintain long-term patency in CABG. Understanding the biology and pathophysiology of ISR and vein graft failure (VGF) and mechanisms behind ITA resistance to failure is crucial to combat these complications in CAD treatment. This review intends to provide an overview of the biological mechanisms underlying stent and VGF and of the potential therapeutic strategy to prevent these complications. Interestingly, despite being different modalities of revascularization, mechanisms of failure of stent and saphenous vein grafts are very similar from the biological standpoint.