Restenosis Model Research Articles

Association of non-insulin-dependent insulin resistance indices with lower limb artery restenosis after drug-coated balloon angioplasty

BackgroundThis study aimed to investigate the associations between noninsulin-dependent insulin resistance indices (NI-IRIs), including the triglyceride-glucose (TyG) index, TyG-BMI, triglyceride-to-high-density lipoprotein cholesterol ratio (TG/HDL-C), and metabolic score for insulin resistance (METS-IR), as well as the occurrence of restenosis in patients with lower extremity atherosclerotic occlusive disease after drug-coated balloon (DCB) treatment.MethodsThe primary endpoint was restenosis within one year after the procedure, which was defined as ≥ 50% stenosis of the treated artery segment. The association between NI-IRIs and restenosis was assessed via multivariable logistic regression analysis. Restricted cubic spline (RCS) analysis was performed to quantify nonlinearity. The consistency of these associations was confirmed through subgroup and interaction analyses. Additionally, the additional predictive value of NI-IRIs beyond established risk factors for restenosis was evaluated via receiver operating characteristic (ROC) curves, the net reclassification improvement (NRI), and integrated discrimination improvement (IDI) indices.ResultsExcept for the TyG index, the other three NI-IRIs demonstrated nonlinear relationships with the probability of postoperative restenosis. Specifically, TG/HDL-C (inflection point: 1.48, P for nonlinearity: 0.003) exhibited a saturating effect, whereas METS-IR (inflection point: 49.30, P for nonlinearity: 0.017) and TyG-BMI (inflection point: 221.53, P for nonlinearity: 0.039) showed threshold effects. Subgroup analysis revealed that the interactions among the subgroups were not statistically significant. Furthermore, among the four NI-IRIs, the addition of the TG/HDL-C index significantly enhanced the predictive power of the base model for restenosis in ASO patients following DCB angioplasty (AUC values: 0.726 vs. 0.760, P = 0.042). The P values for the NRI and IDI were 0.001 and 0.002, respectively.ConclusionTG/HDL-C showed a saturating effect on restenosis within one year after DCB treatment in ASO patients, and METS-IR and TyG-BMI showed threshold effects. The addition of the TG/HDL-C index significantly improved the predictive ability of the base model for restenosis in ASO patients who underwent DCB angioplasty.

Risk-Prediction Model of Restenosis after Endovascular Treatment for Peripheral Arterial Disease: A Systematic Review and Meta-analysis.

Peripheral artery disease (PAD) patients after endovascular treatment (EVT) have a relatively high restenosis rate. However, this risk can be mitigated through precise risk assessment and individualized self-management intervention plans. Moreover, the number of predictive models for restenosis risk in PAD patients after EVT is gradually increasing, yet these results of study exhibit certain discrepancies, raising uncertainties regarding the quality and applicability in clinical practice and future research. The objective of this study was to systematically evaluate risk-predictive models for restenosis in patients with PAD after EVT. A systematic review and meta-analysis of predictive model construction and validation using observational studies was undertaken. The China National Knowledge Infrastructure, China Science and Technology Journal Database, Wanfang Database, SinoMed, PubMed, Web of Science, Embase, and the Cochrane Library were searched from inception to January 1, 2024. Two researchers independently conducted literature screening and data extraction, encompassing study design, data sources, outcome definition, sample size, predictive factors, model development, and performance. The Prediction Model Risk of Bias Assessment Tool (PROBAST) was used for risk of bias and applicability assessment of the models. A total of 4275 studies were retrieved, ultimately resulting in the inclusion of 7 articles comprising 7 predictive models for restenosis in PAD patients after EVT, with a restenosis incidence ranging from 21.8% to 39.7%. The total sample size of the included models ranged from 137 to 1578 cases, with logistic regression analysis being the most commonly used modeling method. All models were built using R software. Only 2 models underwent external validation, and the reported area under the curve ranged from 0.728 to 0.864. The summary area-under-the-curve statistic was 0.80 (95% confidence interval [CI], 0.74-0.86), with an approximate prediction interval of 0.80 (95% CI, 0.62-0.91) . The number of included predictive factors ranged from 3 to 10, with the most common factors being age, Trans-Atlantic Inter-Society Consensus Ⅱ classification, hypertension, diabetes, high-sensitivity C-reactive protein, and surgical approach. All studies exhibited high risk of bias, primarily attributed to inappropriate sources of data and poor reporting of the analysis domain. Predictive models for restenosis after EVT in PAD patients demonstrate overall good predictive performance but are still in the developmental stage with higher risk of bias. Future studies should follow the TRIPOD statement, focusing on the development of new models with larger samples, rigorous study designs, and multicenter external validation. This systematic review adheres to the PRISMA 2020 statement, offering the most recent systematic assessment of risk prediction models for restenosis following endovascular treatment in peripheral arterial disease.The newly developed PROBAST tool was employed to assess the risk of bias and the applicability of the existing evidence.This review emphasizes the practical utility, limitations of the current evidence, and recommendations for future research, with the goal of providing valuable information for clinicians and patients in their decision-making process, while also supporting the advancement of future research endeavors.

M6A Modification of Profilin-1 in Vascular Smooth Muscle Cells Drives Phenotype Switching and Neointimal Hyperplasia via Activation of the p-ANXA2/STAT3 Pathway.

In-stent restenosis is characterized by a significant reduction in lumen diameter within the stented segment, primarily attributed to excessive proliferation of vascular smooth muscle cells (VSMCs) and neointimal hyperplasia. PFN1 (profilin-1), an actin-sequestering protein extensively studied in amyotrophic lateral sclerosis, remains less explored in neointimal hyperplasia. Utilizing single-cell RNA sequencing alongside data from in-stent restenosis patients and various experimental in-stent restenosis models (swine, rats, and mice), we investigated the role of PFN1 in promoting VSMC phenotype switching and neointimal hyperplasia. Single-cell RNA sequencing of stenotic rat carotid arteries revealed a critical role for PFN1 in neointimal hyperplasia, a finding corroborated in stented swine coronary arteries, in-stent restenosis patients, PFN1SMC-IKO (SMC-specific PFN1 knockout) mice, and PFN1 overexpressed mice. PFN1 deletion was shown to suppress VSMC phenotype switching and neointimal hyperplasia in PFN1SMC-IKO mice subjected to a wire-injured model. To elucidate the observed discordance in PFN1 mRNA and protein levels, we identified that METTL3 (N6-methyladenosine methyltransferase) and YTHDF3 (N6-methyladenosine-specific reader) enhance PFN1 translation efficiency in an N6-methyladenosine-dependent manner, confirmed through experiments involving METTL3 knockout and YTHDF3 knockout mice. Furthermore, PFN1 was mechanistically found to interact with the phosphorylation of ANXA2 (annexin A2) by recruiting Src, promoting the phosphorylation of STAT3, a typical transcription factor known to induce VSMC phenotype switching. This study unveils the significance of PFN1 N6-methyladenosine modification in VSMCs, demonstrating its role in promoting phenotype switching and neointimal hyperplasia through the activation of the p-ANXA2 (phospho-ANXA2)/STAT3 pathway.

The role of inflammation biomarkers in carotid artery stenosis procedures

BackgroundCarotid revascularization procedures, such as carotid endarterectomy (CEA) and carotid artery stenting (CAS), can lead to restenosis. Monitoring restenosis onset through biomarkers is crucial in clinical practice. This study aimed to evaluate inflammation biomarkers in CEA and CAS to determine their predictive value for restenosis risk post-procedure. MethodsA retrospective analysis was conducted on the clinical records of patients with carotid stenosis who underwent CEA or CAS over one year at the Vascular Surgery departments of an interuniversity center. Eligible asymptomatic patients with carotid stenosis (70-99%) underwent revascularization. Differences between pre- and early post-procedural inflammation indices were assessed, and restenosis risk was evaluated using Receiver Operating Curve analysis and logistic regression. ResultsThe cohort comprised 100 patients, 68 undergoing CEA and 32 undergoing CAS. Significant values were observed for inflammation ratios post-CEA: neutrophils to lymphocytes ratio (NLR) (p=0.036), platelets to lymphocytes ratio (PLR) (p=0.009), monocytes to lymphocytes ratio (MLR) (p<0.001), systemic inflammation index (SII) (p=0.024), systemic immune response index (SIRI) (p=0.003), and aggregate inflammation response index (AISI) (p<0.001). At 12-month follow-up, 12% of patients experienced restenosis; 50% were men and 50% women. Women showed a higher restenosis rate (26.1% vs 7.8%). Pre-intervention NLR (OR [95% CI] = 13.38 [1.88 to 95.44], p=0.010) and SIRI (OR [95% CI] = 10.22 [2.65 to 39.43], p=0.001) remained significantly associated with restenosis after adjusting for sex and smoking. ConclusionThe study provided a predictive model for restenosis, identifying pre-intervention NLR and SIRI as independent predictors of restenosis at 12-month follow-up.

Cell-Specific Effects of Insulin in a Murine Model of Restenosis Under Insulin-Sensitive and Insulin-Resistant Conditions.

Restenosis following percutaneous revascularization is a major challenge in patients with insulin resistance and diabetes. Currently, the vascular effects of insulin are not fully understood. In vitro, insulin's effects on endothelial cells (ECs) are beneficial, whereas on vascular smooth muscle cells (SMCs), they are mitogenic. We previously demonstrated a suppressive effect of insulin on neointimal growth under insulin-sensitive conditions that was abolished in insulin-resistant conditions. Here, we aimed to determine the cell-specific effects of insulin on neointimal growth in a model of restenosis under insulin-sensitive and insulin-resistant conditions. Vascular cell-specific insulin receptor (IR)-deficient mice were fed a low-fat diet (LFD) or a high-fat, high-sucrose diet (HFSD) and implanted with an insulin pellet or vehicle prior to femoral artery wire injury. In insulin-sensitive conditions, insulin decreased neointimal growth only in controls. However, under insulin-resistant conditions, insulin had no effect in either control, EC-specific or SMC-specific IR-deficient mice. These data demonstrate that EC and SMC IRs are required for the anti-restenotic effect of insulin in insulin-sensitive conditions and that, in insulin resistance, insulin has no adverse effect on vascular SMCs in vivo.

MicroRNA-127-3p regulates inflammatory response in injury-induced vascular remodeling and cellular senescence in vascular smooth muscle cells through mTor

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Martin-Luther-Universität Halle-Wittenberg Background and Purpose The accumulation of senescent cells in the vasculature contributes to impaired vascular function over the lifetime. Micro RNAs (miRs) are promising therapeutic targets due to their cell-specific functions. Targeting miR-127-3p emerges as an attractive approach to enhance vascular healing and limit angioplasty-related complications. Here, we focus on elucidating the role of miR-127-3p in vascular smooth muscle cells (VSMC) to characterize their role in cellular function and vascular senescence. Methods Utilizing reverse transcription and qRT-PCR we checked expression levels of miR-127-3p in human and murine aortic VSMCs. After overexpression and downregulation via transfection of pre-miR and antagomiR, we evaluated the influence of miR-127-3p on cellular functions such as proliferation and migration of human (non-) replicative senescent VSMCs. Potential targets were selected via target prediction analysis and verified on mRNA and protein levels. Morphological changes were visualized via high-resolution fluorescence microscopy. Senescence marker expression was checked after transfection by qRT-PCR. Results MiR-127-3p is highly upregulated in femoral artery tissue on day 10 after wire-induced injury in C57Bl6 mice, serving as restenosis model (p&amp;lt;0.001) and aged C57BL/6 mice (3 months vs. 22 months, p&amp;lt;0.0001). Replicative senescent human VSMC exhibit increased miR-127-3p expression (p&amp;lt;0.05). In vitro, miR-127-3p overexpression reduces proliferation in senescent (p&amp;lt;0.001) and non-senescent (p&amp;lt;0.01) cells. It hinders migration in non-senescent cells (p&amp;lt;0.0001) but has a reverse effect in senescent cells (p&amp;lt;0.01). Potential targets affecting cellular functions, inflammatory pathways, and cellular aging were identified as mTOR, AXL, and TEAD3 (p&amp;lt;0.05). Transfection of pre-miR leads to increase in cell size and the acquisition of a flattened morphology of human VSMC. P14arf and laminB1, as senescence-associated genes, showed downregulation after overexpression of miR-127-3p on mRNA level (p&amp;lt;0.05). When VSMCs were stimulated with anti-miR-127-3p, increased mRNA levels of p14arf and laminB1 were detected (p&amp;lt;0.05). Conclusion This study identifies miR-127-3p as a contributor to cellular functions including cellular proliferation and migration and seems to have opposing effects in non- and replicative senescent VSMC. Further research is needed to validate miR-127-3p as a therapeutic target for vascular aging and remodeling in vitro and in vivo.

MiR-32-5p as potential key mediator of vascular remodeling enhances cell proliferation of vascular smooth muscle cells

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): University Hospital Halle, Martin-Luther-University Halle-Wittenberg Background and purpose The dysfunctionality of endothelial cells (EC) and smooth muscle cells (SMC) contributes to the progression of vascular remodeling and subsequent cardiovascular pathologies. Several microRNAs (miRNA) have been revealed as key regulators of EC and SMC function, therefore suggesting them as potential targets in the modulation of vascular remodeling. Here, we investigate the potential role of miR-32-5p in vascular cell function and its potential as a therapeutic target in vascular remodeling. Material and Methods Initial screenings by qRT-PCR analysis for miR-32-5p expression were performed in murine femoral artery tissue on day 10 and 21 after wire-induced injury in C57Bl6 mice, serving as restenosis model. MiR-32-5p expression was assessed using qRT-PCR in human vascular endothelial (HVECs) and human vascular smooth muscle cells (HVSMC). The role of miR-32-5p on cellular functions, as migration and proliferation, was determined by performing scratch wound and BrdU assays. Potential miR-32-5p downstream targets were identified from literature and their expression levels upon interference with miR-32-5p evaluated on mRNA and protein levels. Results MiR-32-5p expression was decreased over time in the wire-induced injury model. In vitro, miR-32-5p expression was significantly decreased in replicative senescent HVSMC and HVEC (p&amp;lt;0,05) and relatively higher in HVSMC than in HVEC for all conditions. Under growth conditions an elevated expression of miR-32-5p in HVEC and significantly increased expression in HVSMC was detected (p&amp;lt;0,01). Proliferation in HVSMC increased significantly (p&amp;lt;0,05) by pre-miR-32-5p transfection, but remained unaffected in HVEC. Migration of HVECs and HVSMCs was improved by miR-32-5p and decelerated after antagomiR interference. Systemic literature target research revealed several potential targets in both cell types, of which the following were significantly downregulated in HVSMC after pre-miR transfection including PIK3r3 (p&amp;lt;0,05), KLF4 (p&amp;lt;0,05), CD69 (p&amp;lt;0,01), MAP2K4 (p&amp;lt;0,05) and BCL211 (p&amp;lt;0,01). Additionally, CD69 and KLF4 expression increased significantly either in HVECs (p&amp;lt;0,05). Conclusion Our results suggest that miR-32-5p may be a substantial regulator in HVEC and HVSMC senescence and function and subsequently in vascular remodeling. To fully evaluate its role in the pathogenesis of atherosclerosis and therefore, its therapeutic potential in cardiovascular diseases, further investigations are needed. Additional experiments with the purpose of investigating miR-32-5p-target interactions and apoptotic effects will be performed shortly.

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.

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, 30mM) 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.

Calcitonin Inhibits Phenotypic Switching of Aortic Smooth Muscle Cells and Neointimal Hyperplasia through the AMP-Activated Protein Kinase/Mechanistic Target of Rapamycin Pathway.

Calcitonin (CT) is a peptide hormone secreted by the parafollicular C cells of the thyroid gland, salmon calcitonin was originally extracted from the hind cheek of salmon. Neointimal hyperplasia refers to the excessive proliferation and migration of vascular smooth muscle cells (VSMCs). In this study, a rat model of restenosis was employed to explore the impact of calcitonin on neointima proliferation. Calcitonin was administered via continuous injections for a duration of 14 days postsurgery, and the expression of proteins associated with proliferation, migration, and phenotypic switching was assessed using the vascular smooth muscle cells. Additionally, metabolomic analyses were conducted to shed light on the mechanisms that underlie the role of calcitonin in the development of cardiovascular disease. In our study, we found that calcitonin possesses the capability to dispute the proliferation, migration, and phenotypic transformation of VSMCs induced by platelet-derived growth factor-BB (PDGF-BB) and 15% fetal bovine serum in vitro. Calcitonin has demonstrated a favorable impact on smooth muscle cells, both in vitro and in vivo. More specifically, it has been observed to mitigate phenotypic switching, proliferation, and migration of these cells. Moreover, calcitonin has been identified as a protective factor against phenotypic switching and the formation of neointima, operating through the AMP-activated protein kinase/mechanistic target of rapamycin (mTOR) pathway.

TGF-β1 inhibitor P144 protects against benign restenosis after esophageal stenting through TGF-β1/Smads signaling pathway inhibition

Background and study aimsEsophageal restenosis is a serious complication after esophageal stent placement, which influences the clinical prognosis of stent implantation and the patient's quality of life. TGF-β1/Smads signaling pathway plays an important role in the development of the eosinophilic esophagitis and scar repair after skin trauma. However, the role of TGF-β1/Smads in the development of esophageal restenosis after esophageal stent placement remains unknown. Our study aimed to investigate whether TGF-β1/Smads plays an important role in the development of esophageal restenosis after esophageal stent, and whether the exogenous TGF-β1 inhibitor supplement could ameliorate the esophageal restenosis after esophageal stent. Material and methodsWe established the model of esophageal restenosis after esophageal stenting in rats, and determined the expression levels of TGF-β1/Smads signaling pathway and the relevant markers of fibroblast activation by immunochemistry (IHC), Western Blot and real time qPCR. Those all the indicators were also determined in esophageal fibroblast when exposed to rhTGF-β1 with or without TGF-β1 inhibitor P144. ResultsThe serum level of IL-1β and TNFα were significantly increased in stent implantation group compared to blank control group, and obviously ameliorated when treated with P144. The TGF-β1/Smads signaling pathway and the relevant markers of fibroblast activation were significantly increased in stent implantation group compared to blank control group, and obviously ameliorated when treated with P144. Those all the indicators were significantly increased when exposed to rhTGF-β1, and obviously decreased when treated with P144. ConclusionsTGF-β1 Inhibitor P144 could protect against benign restenosis after esophageal stenting by down-regulating the expression levels of relevant markers of fibroblast activation through TGF-β1/Smads signaling pathway inhibition, and may be used as a novel therapy for benign restenosis after esophageal stenting.

Risk prediction model for in-stent restenosis following PCI: a systematic review.

The morbidity and mortality rates of coronary heart disease are significant, with PCI being the primary treatment. The high incidence of ISR following PCI poses a challenge to its effectiveness. Currently, there are numerous studies on ISR risk prediction models after PCI, but the quality varies and there is still a lack of systematic evaluation and analysis. To systematically retrieve and evaluate the risk prediction models for ISR after PCI. A comprehensive search was conducted across 9 databases from inception to March 1, 2024. The screening of literature and extraction of data were independently carried out by two investigators, utilizing the checklist for critical appraisal and data extraction for systematic reviews of prediction modeling studies (CHARMS). Additionally, the risk of bias and applicability were evaluated using the Prediction Model Risk of Bias Assessment Tool (PROBAST). A total of 17 studies with 29 models were included, with a sample size of 175-10,004 cases, and the incidence of outcome events was 5.79%-58.86%. The area under the receiver operating characteristic curve was 0.530-0.953. The top 5 predictors with high frequency were diabetes, number of diseased vessels, age, LDL-C and stent diameter. Bias risk assessment into the research of the risk of higher bias the applicability of the four study better. The overall risk of bias in the current ISR risk prediction model post-PCI is deemed high. Moving forward, it is imperative to enhance study design and specify the reporting process, optimize and validate the model, and enhance its performance.

Histological Features of In-Stent Restenosis after Iliac Vein Thrombus Removal and Stent Placement in a Goat Model

PurposeTo establish an animal model for in-stent restenosis (ISR) after postthrombotic iliac vein stent placement and characterize histopathological changes in tissue within the stented vein. Materials and MethodsIliac vein thrombosis was induced using balloon occlusion and thrombin injection in 8 male Boer goats. Mechanical thrombectomy and iliac vein stent placement were performed 3 days after thrombosis induction. Restenosis was evaluated by venography and optical coherence tomography (OCT) at 1 and 8 weeks after stent placement, and stent specimens were taken for pathological examination after the animals were euthanized. ResultsThrombosis induction was successful in all 8 goats, with >80% iliac vein occlusion. After thrombus removal, OCT revealed considerable venous intimal thickening and a small number of mural thrombi. Neointimal hyperplasia with thrombus formation was observed in all goats 1 week after stent implantation; the degree of ISR was 15%–33%. At 8 weeks, the degree of ISR was 21%–32% in 3 goats, and stent occlusion was observed in 1 goat. At 1 week, the neointima predominantly consisted of fresh thrombi. At 8 weeks, proliferplastic fibrotic tissue and smooth muscle cells (SMCs) were predominant, and the stent surfaces were endothelialized in 2 of 3 goats and partially endothelialized in 1 goat. ConclusionsIn the goat model, postthrombotic neointimal hyperplasia in the venous stent may result from time-dependent thrombus formation and organization, accompanied by migration and proliferation of SMCs, causing ISR. These results provide a basis to further explore the mechanism of venous ISR and promote the development of venous stents that reduce neointimal hyperplasia.

Gallic Acid Inhibits Proliferation and Migration of Smooth Muscle Cells in a Pig In-Stent Restenosis Model.

In-stent restenosis (ISR) develops primarily due to neointimal hyperplasia. Gallic acid (GA) has anti-inflammatory, antioxidant, and cardioprotective effects. This study sought to investigate the effects of GA on neointimal hyperplasia and proliferation and migration of vascular smooth muscle cells (VSMCs) in a pig ISR model. In vitro proliferation and migration experiments were confirmed, after VSMCs were treated with platelet-derived growth factor (PDGF-BB) and GA (100 µM) using a 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT) assay and a scratch wound assay for 24 hours and 48 hours. A bare metal stent (BMS) was implanted in the pig coronary artery to induce ISR with overdilation (1.1-1.2:1), and GA (10 mg/kg/day) was administered for 4 weeks. At the 4-week follow-up, optical coherence tomography (OCT) and histopathological analyses were performed. GA decreased the proliferation of VSMCs by PDGF-BB for 24 hours (89.24±24.56% vs. 170.04±19.98%, p<0.001) and 48 hours (124.87±7.35% vs. 187.64±4.83%, p<0.001). GA inhibited the migration of VSMCs induced by PDGF-BB for 24 hours (26.73±2.38% vs. 65.38±9.73%, p<0.001) and 48 hours (32.96±3.04% vs. 77.04±10.07%, p<0.001). Using OCT, % neointimal hyperplasia was shown to have significantly decreased in the GA group compared with control vehicle group (28.25±10.07% vs. 37.60±10.84%, p<0.001). GA effectively reduced neointimal hyperplasia by inhibiting the proliferation and migration of VSMCs in a pig ISR model. GA could be a potential treatment strategy for reducing ISR after stent implantation.

Predictive model for In-stent restenosis following DES Implantation- first –in-literature score from India

Predictive model for In-stent restenosis following DES Implantation- first –in-literature score from India

Preliminary Investigation on Efficacy and Safety of Substance P-Coated Stent for Promoting Re-Endothelialization: A Porcine Coronary Artery Restenosis Model.

Current polymer-based drug-eluting stents (DESs) have fundamental issues about inflammation and delayed re-endothelializaton of the vessel wall. Substance-P (SP), which plays an important role in inflammation and endothelial cells, has not yet been applied to coronary stents. Therefore, this study compares poly lactic-co-glycolic acid (PLGA)-based everolimus-eluting stents (PLGA-EESs) versus 2-methacryloyloxyethyl phosphorylcholine (MPC)-based SP-eluting stents (MPC-SPs) in in-vitro and in-vivo models. The morphology of the stent surface and peptide/drug release kinetics from stents were evaluated. The in-vitro proliferative effect of SP released from MPC-SP is evaluated using human umbilical vein endothelial cell. Finally, the safety and efficacy of the stent are evaluated after inserting it into a pig's coronary artery. Similar to PLGA-EES, MPC-SP had a uniform surface morphology with very thin coating layer thickness (2.074μm). MPC-SP showed sustained drug release of SP for over 2weeks. Endothelial cell proliferation was significantly increased in groups treated with SP (n = 3) compared with the control (n = 3) and those with everolimus (n = 3) (SP: 118.9 ± 7.61% vs. everolimus: 64.3 ± 12.37% vs. the control: 100 ± 6.64%, p < 0.05). In the animal study, the percent stenosis was higher in MPC-SP group (n = 7) compared to PLGA-EES group (n = 7) (MPC-SP: 28.6 ± 10.7% vs. PLGA-EES: 16.7 ± 6.3%, p < 0.05). MPC-SP group showed, however, lower inflammation (MPC-SP: 0.3 ± 0.26 vs. PLGA-EES: 1.2 ± 0.48, p < 0.05) and fibrin deposition (MPC-SP: 1.0 ± 0.73 vs. PLGA-EES: 1.5 ± 0.59, p < 0.05) around the stent strut. MPC-SP showed more increased expression of cluster of differentiation 31, suggesting enhanced re-endothelialization. Compared to PLGA-EES, MPC-SP demonstrated more decreased inflammation of the vascular wall and enhanced re-endothelialization and stent coverage. Hence, MPC-SP has the potential therapeutic benefits for the treatment of coronary artery disease by solving limitations of currently available DESs.

Abstract 17002: Platelet-Derived Purified Exosome Product to Treat In-Stent Restenosis Porcine Model

Introduction: Patients with coronary artery disease (CAD) not amenable to revascularization are reported to have a 3-year mortality &gt;14%. Advances in treatment modalities including medical management, rotational atherectomy, balloon lithotripsy, and drug-eluting stents work for focal disease but poorly treat diffuse CAD. In a porcine model of in-stent restenosis, we here evaluated whether a pro-angiogenic platelet-derived exosome product (PEP) could be delivered into the perivascular space to foster collateral vessel formation. Methods/Results: Cobalt chromium stents were placed and were oversized by 1 mm in the left anterior descending (LAD) and posterior descending arteries (PDA) of sus scrofa domesticus pigs. In-stent restenosis was angiographically visualized at the 2-month timepoint, with hemodynamic significance documented with fractional flow reserve (FFR) of &lt;0.8. To document feasibility of PEP delivery into the perivascular space, exosomes were labeled with a far-red fluorescent tag and delivered into the perivascular bed. Here, the Bullfrog® micro-infusion catheter was positioned either in the great cardiac vein or the middle cardiac vein and PEP was delivered with the microneedle pointed towards the LAD or the PDA. Biodistribution demonstrated exosome retention and uptake around cardiac veins. Using the Bullfrog® technique, PEP was delivered in the perivascular space adjacent to areas of significant coronary stenosis. Initial results 1-month post-treatment demonstrated improved FFR of treated stenotic vessels (from 0.68 to 0.85), while untreated vessels demonstrate no change from previous FFR measurement (from 0.79 to 0.78). Conclusions: Here, exosome-mediated angiogenesis in the perivascular space improved coronary blood flow, distal to areas of stenosis. In patients with diffuse CAD, delivery of biotherapy in cardiac veins running anatomically parallel to stenosed epicardial arteries provides a novel therapeutic opportunity to supplement the existing armamentarium of therapies available for in-stent restenosis.

Abstract P3046: The Effect Of MicroRNA-367-3p And MicroRNA-148a-3p On Vascular Endothelial Cells In Context Of Senescence And Infarct Healing

To improve the healing after myocardial infarction (MI), a well-coordinated angiogenic response is necessary. MicroRNAs (miRNAs) were identified as regulators of angiogenesis, however, strategies to improve angiogenesis by targeting miRNAs are challenging. Here, we evaluate miRNA-367-3p and 148a-3p as novel miRNA candidates regarding their therapeutic potential toward neovascularization after MI. Following expression analysis of the respective miRNAs in human vascular endothelial cells (EC) and mice tissue, their contribution to EC function after either pre- or anti-miR transfection was assessed. Further, potential targets were identified and studied on mRNA and protein level. Initial screenings show that miRNA-148a-3p and miRNA-367-3p are differently expressed in both a restenosis model via wire-induced injury and aged mice tissue (p&lt;0.05). Under growth conditions, miRNA-148a-3p expression was upregulated in ECs. In senescent ECs, miRNA-367-3p shows a significant 50-fold upregulation of its expression (p&lt;0.01); miRNA-148a-3p is also overexpressed in senescent ECs (p&lt;0.01). Hypoxia increases the effect observed in senescence (p&lt;0.05). Downregulation of either miRNA-367-3p or miRNA 148a-3p leads to an improvement in migration capacity (p&lt;0.0001) and proliferation of ECs (p&lt;0.0001). Systematic target research in silico identified DKK3 as potential target of miRNA-367-3p and DDX6 as potential target of miRNA-148a-3p. Downregulation of either miRNA-148a-3p or miRNA-367-3p verified these predictions by significantly upregulating DKK3 respectively DDX6. In further experiments, we study the dysfunctional effect of miRNA-148a-3p on vascular endothelial cells by targeting DDX6 as well as the anti-angiogenic impact of miRNA-367-3p by targeting DKK3. Summarizing different expression levels of miRNA-367-3p and miRNA-148a-3p exerted distinct effects on EC function, especially in senescent cells and under hypoxic conditions. Our experimental data regarding cellular function show that these miRNAs are involved in the angiogenetic response and hold the potential to serve as therapeutic targets. In future experiments, we will evaluate the miRNA potential on MI healing in vivo.

Effect of down-regulation of let-7c/g on triggering a double-negative feedback loop and promoting restenosis.

Excessive proliferation and migration of vascular smooth muscle cells (VSMCs) are the main causes of restenosis (RS) in diabetic lower extremity arterial disease (LEAD). However, the relevant pathogenic mechanisms are poorly understood. In this study, we introduced a "two-step injury protocol" rat RS model, which started with the induction of atherosclerosis (AS) and was followed by percutaneous transluminal angioplasty (PTA). Hematoxylin-eosin (HE) staining and immunohistochemistry staining were used to verify the form of RS. Two-step transfection was performed, with the first transfection of Lin28a followed by a second transfection of let-7c and let-7g, to explore the possible mechanism by which Lin28a exerted effects. 5-ethynyl-2΄-deoxyuridine (EdU) and Transwell assay were performed to evaluate the ability of proliferation and migration of VSMCs. Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) were performed to detect the expression of Lin28a protein and let-7 family members. Using a combination of in vitro and in vivo experiments, we discovered that let-7c, let-7g, and microRNA98 (miR98) were downstream targets of Lin28a. More importantly, decreased expression of let-7c/let-7g increased Lin28a, leading to further inhibition of let-7c/let-7g. We also found an increased level of let-7d in the RS pathological condition, suggesting that it may function as a protective regulator of the Lin28a/let-7 loop by inhibiting the proliferation and migration of VSMCs. These findings indicated the presence of a double-negative feedback loop consisting of Lin28a and let-7c/let-7g, which may be responsible for the vicious behavior of VSMCs in RS.

Modeling of main arteries restenosis in experimental cardiology

Abstract Funding Acknowledgements Type of funding sources: None. Purpose To perform the model of main arteries restenosis and to study the arterial hemodynamics using the original device for modeling of intra-arterial circulation. Materials and methods We used an original device developed by us for modeling of intra-arterial circulation. The main part of the device is a prototype of human arterial vessel - rotameter glass tube 365 mm length, with inlet diameter more than outlet (20 mm vs 16.5 mm). An aqueous solution of glycerin is introduced inside closed system had the same viscosity as the human blood. Flexible silicone tubes are connected with rotameter and electric pump with various modes of work (imitation of pulse waves in regular rhythm (RR), extrasystoles (ES), atrial fibrillation (AF)). We hermetically installed in the rotameter imitation of arterial stent – metal construction with spiral oriented parts 68 mm long. Plastic diaphragms 15 mm long with stenosis of the internal lumen of 50%, 70%, and 90% were alternatively put inside the tube to study intra-arterial hemodynamics. 5 mm long silk thread was alternately installed inside the tube, an intravascular piezoelectric crystal pressure sensor connected to an oscilloscope was injected with a dye - clerical ink. Results When imitating AF after the long pause the speed of fluid flow through the diaphragms increased in comparison with the RR with the pendency: if longer pause was than more speed increased. So, with a stenosis of 50%: the speed with a RR was 2.09 m/s, with AF after the pause &amp;lt;1 s speed was 3.36 m/s, AF after the pause &amp;gt;1, but &amp;lt;2 s speed was 4.97 m/s, AF after the pause &amp;gt;2 s speed was 5.88 m/s; with 70% stenosis: the speed with a RR was 3.24 m/s with AF after the pause &amp;lt;1 s speed was 3.96 m/s, AF after the pause &amp;gt;1, but &amp;lt;2 s speed was 5.87 m/s, AF after the pause &amp;gt;2 s speed was 7.83 m/s; with 90% stenosis, the speed at RR 8.96 m/s, with AF after the pause &amp;lt;1 s speed was 9.46 m/s, AF after the pause &amp;gt;1, but &amp;lt;2 s speed was 11.17 m/s, AF after the pause &amp;gt;2 s speed was 13.45 m/s. The pressure measured by piezoelectrical probe increased proportionally to the speed. We observed the appearance of reflected, standing waves in the edge zones of the diaphragm and stent and a turbulent flow of liquid behind the diaphragm and stent. Conclusion These changes in hemodynamics are characterized by proposed concept of "hydraulic shock". Intense mechanical effect of the pressure waves after the long pauses between cardio cycles in AF in the marginal zones of the diaphragm and intra-arterial stent can cause the further growth, progression of atherosclerosis and restenosis in arterial vessels.