Self-expanding intracranial drug-eluting stent system in patients with symptomatic intracranial atherosclerotic stenosis: initial experience and midterm angiographic follow-up

BACKGROUND

Symptomatic intracranial atherosclerotic stenosis (ICAS) is a major cause of ischemic stroke worldwide. In patients undergoing endovascular treatment for ICAS, in-stent restenosis (ISR) is associated with ischemic stroke recurrence.

OBJECTIVE

Intracranial drug-eluting self-expanding stent systems (COMETIU; Sinomed Neurovita Technology Inc., CHN) are new devices for treating ICAS. This study evaluated the perioperative experience and medium-term outcomes of COMETIU in 16 patients.

METHODS

We prospectively analyzed 16 patients with ICAS (≥ 70% stenosis) who underwent intravascular therapy between September 4, 2022, and February 1, 2023. The primary outcome was the incidence of ISR at 6 months postoperatively. The secondary efficacy outcomes were device and technical success rates. The secondary safety outcomes included stroke or death within 30 days after the procedure and the cumulative annual rate of recurrent ischemic stroke in the target-vessel territory from 31 days to 6 months and 1 year.

RESULTS

A total of 16 patients with 16 intracranial atherosclerotic lesions were treated with 16 COMETIUs. All procedures were performed under general anesthesia with 100% device and technical success rates, with no cases of periprocedural stroke or death. The mean radiographic follow-up duration was at least 6 months postoperatively, and all patients presented for radiographic and clinical follow-up. There were no reported ischemic or hemorrhagic strokes. Angiographic follow-up for all patients revealed no cases of ISR.

CONCLUSION

COMETIU is safe and effective for treating ICAS, with minimal risk during the procedure and a low rate of ISR during medium-term follow-up.

Comparison of the safety and efficacy of Neuroform Atlas stent deployed via Gateway balloon catheter and microcatheter for the treatment of intracranial stenosis

OBJECTIVE

This study aimed to compare the safety and efficacy of the Atlas stent released by the Gateway catheter and microcatheter in the treatment of intracranial stenosis (IS).

METHODS

The primary efficacy and safety outcomes were the in-stent restenosis (ISR) rate and post-procedural stroke or death within one month.

RESULTS

Atlas stents were deployed using the Gateway catheter and microcatheter in 19 (57.6 %) and 14 (42.4 %) procedures, respectively. Follow-up imaging data were available for 26 patients; the incidence of ISR was 15.4 %, and the ISR rate was higher, though not significantly, in the microcatheter group than in the Gateway group (30.0% vs. 6.25 %, P = .39). Clinical follow-up data were available for 30 patients; the post-procedural stroke rate was 3.3 % within one month and 13.3 % from one month to one year. The post-procedural stroke rate within one month was higher, though not significantly, in the microcatheter group than in the Gateway group (7.7% vs. 0 %, P = .43). The Gateway group had a significantly lower rate of post-procedural stroke in the same territory than that of the microcatheter group (0% vs. 30.8 %, P = .026). A higher incidence of residual stenosis <30 % was found in the non-ISR group than in the ISR group (72.2% vs. 0 %, P = .014).

CONCLUSIONS

This study provides preliminary evidence that the Atlas stent is safe and effective for IS treatment. The use of the Gateway catheter to deliver the Atlas stent appears to be safer than using microcatheter. The incidence of ISR may be related to the degree of the residual stenosis.

Effect of Drug-Coated Balloon Versus Stent Angioplasty in Patients With Symptomatic Intracranial Atherosclerotic Stenosis

BACKGROUND AND OBJECTIVES

Drug-coated balloons (DCBs) have exhibited promising results in coronary and peripheral artery diseases, but conclusive evidence is lacking in intracranial vasculature. We assessed the safety and efficacy of DCBs vs stent angioplasty for symptomatic intracranial atherosclerotic stenosis (sICAS) and initially identified patients who might have benefited most from DCB treatment.

METHODS

A single-center, retrospective cohort study was conducted from June 2021 to May 2022 with 154 patients with sICAS divided into 2 treatment groups: a DCB group (with or without remedial stenting, n = 47) and a stent group (n = 107). The treatment outcomes were compared using 1:2 propensity score matching. The primary safety end point was perioperative stroke or mortality, and the primary efficacy end point was the rate of target vessel restenosis at 12 months. The degree of luminal change was analyzed as a subgroup, defined as the difference between the degree of stenosis at follow-up and immediately after intervention.

RESULTS

One hundred eighteen patients were enrolled using propensity score matching, with 43 patients in the DCB group and 75 in the stent group. The incidence of perioperative adverse events was 2.3% in the DCB group and 8.0% in the stent group (P = .420). At a median follow-up of 12 months, the incidence of restenosis (11.9% [5/43] vs 28.0% [21/75], P = .045) and the median degree of stenosis (30% [20%, 44%] vs 30% [30%, 70%], P = .009, CI [0-0.01, 0.2]) were significantly lower in the DCB group than in the stent group. DCB angioplasty effectively prevented adverse events in the target vessel area and significantly reduced the degree of luminal change in the M1 segment of the middle cerebral artery (0 [0, 15%] vs 10% [0, 50%], P = .016).

CONCLUSION

DCB angioplasty might be a safe and effective alternative to stent angioplasty to treat sICAS, particularly among patients with M1 segment of the middle cerebral artery stenosis.

Inhibition effect of copper-bearing metals on arterial neointimal hyperplasia via the AKT/Nrf2/ARE pathway in vitro and in vivo

In-stent restenosis can be caused by the activation, proliferation and migration of vascular smooth muscle cells (VSMCs), which affects long-term efficacy of interventional therapy. Copper (Cu) has been proved to accelerate the endothelialization and reduce thrombosis formation, but little is known about its inhibition effect on the excessive proliferation of VSMCs. In this study, 316L-Cu stainless steel and L605-Cu cobalt-based alloy with varying Cu content were fabricated and their effects on surface property, blood compatibility and VSMCs were studied in vitro and in vivo. CCK-8 assay and EdU assay indicated that the Cu-bearing metals had obvious inhibitory effect on proliferation of VSMCs. Blood clotting and hemolysis tests showed that the Cu-bearing metals had good blood compatibility. The inhibition effect of the Cu-bearing metals on migration of cells was detected by Transwell assay. Further studies showed that Cu-bearing metals significantly decreased the mRNA expressions of bFGF, PDGF-B, HGF, Nrf2, GCLC, GCLM, NQO1 and HO1. The phosphorylation of AKT and Nrf2 protein expressions in VSMCs were significantly decreased by Cu-bearing metals. Furthermore, it was also found that SC79 and TBHQ treatments could recover the protein expressions of phospho-AKT and Nrf2, and their downstream proteins as well. Moreover, 316L-Cu stent proved its inhibitory action on the proliferation of VSMCs in vivo. In sum, the results demonstrated that the Cu-bearing metals possessed apparent inhibitory effect on proliferation and migration of VSMCs via regulating the AKT/Nrf2/ARE pathway, showing the Cu-bearing metals as promising stent materials for long-term efficacy of implantation.

Endovascular treatment of symptomatic severe intracranial atherosclerotic stenosis with a novel intracranial dedicated drug-eluting stent: a more effective treatment approach

Background

Endovascular treatment of severe intracranial atherosclerotic stenosis (ICAS) using coronary drug-eluting stents (DESs) significantly reduces the risk of in-stent restenosis (ISR) and stroke recurrence. However, there are few reports regarding the treatment of ICAS with intracranial dedicated DES. Herein, we present our experience with the feasibility, safety, and medium-term follow-up outcomes of a novel intracranial DES, named NOVA stent, in patients with symptomatic severe ICAS (≥70%).

Methods

From December 2021 to May 2022, patients with symptomatic severe ICAS who underwent implantation of the NOVA stent in our institution were retrospectively analyzed for procedural results, perioperative complications, imaging and clinical follow-up outcomes.

Results

Twenty-four patients, 16 (66.7%) with anterior circulation lesions and 8 (33.3%) with posterior circulation lesions, were enrolled. All patients with intracranial ICA (n = 6), middle cerebral artery (n = 10), basilar artery (n = 3), intracranial vertebral artery (n = 3), and the vertebrobasilar junction (n = 2) stenosis were treated successfully using NOVA stents. The severity of stenosis ranged from 75 to 96% (mean 85.9%) before treatment and this was reduced to 0 to 20% (mean 8.6%) immediately after stent placement. Symptomatic distal embolism occurred in one case; however, there were no other perioperative complications. The mean follow-up duration was 12.2 ± 1.06 months. No symptomatic ischemic events occurred during follow-up. Follow-up cerebral angiography was performed in 22 of 24 patients (91.7%), and significant ISR occurred in one patient (4.2%).

Conclusion

Our results demonstrate that implantation of the novel intracranial DES NOVA in severe ICAS is feasible, safe, and effective in selected cases, reducing the incidence of ISR, and showing excellent midterm clinical outcomes, providing a promising option for ICAS treatment.

First-in-human experience of sirolimus coated balloon for symptomatic intracranial artery stenosis

BACKGROUND

The drug coated balloon is a promising endovascular therapy for intracranial atherosclerosis (ICAS), potentially combining the advantages of primary angioplasty and antiproliferative drugs. Previous studies have focused on the paclitaxel coated balloon, revealing promising outcomes in the treatment of ICAS, while concerns about the neurotoxicity of paclitaxel were reported. Sirolimus was shown to have less neurotoxicity in the canine cerebral vasculature. The feasibility and safety of a sirolimus coated balloon (SCB) for ICAS have never been evaluated in humans. We assessed the first-in-human feasibility and safety of SCBs for treating symptomatic patients with severe ICAS.

METHODS

This prospective, open label, single arm cohort study was designed to enroll patients with transient ischemic attacks or non-disabling, non-perforator territory ischemic stroke caused by severe ICAS (70-99%) and following at least 3 weeks after the onset of ischemic symptoms. The primary outcome was stroke or death within 30 days. All patients were followed up to detect restenosis at 6 months.

RESULTS

A total of 60 eligible patients were enrolled with an average age of 59.4±10.8 years. The technical success rate of SCBs for ICAS was 100%. Seven patients (11.7%) required stenting because of flow limited dissections or elastic retraction. Three patients (5.0%) had 30 day strokes, including two ischemic strokes and one hemorrhagic stroke. An additional three patients had recurrent stroke or death during follow-up. Ten patients had restenosis but only two had symptoms.

CONCLUSIONS

SCBs may be feasible and safe in selected patients with symptomatic ICAS, with high grade stenosis (70-99%). Further studies are warranted.

Tanshinone IIA: a Chinese herbal ingredient for the treatment of atherosclerosis

Tanshinone IIA (Tan IIA) is a fat-soluble compound extracted from Salvia miltiorrhiza, which has a protective effect against atherosclerosis (AS). Tan IIA can inhibit oxidative stress and inflammatory damage of vascular endothelial cells (VECs) and improve endothelial cell dysfunction. Tan IIA also has a good protective effect on vascular smooth muscle cells (VSMCs). It can reduce vascular stenosis by inhibiting the proliferation and migration of vascular smooth muscle cells (VSMCs), and improve the stability of the fibrous cap of atherosclerotic plaque by inhibiting apoptosis and inflammation of VSMCs. In addition, Tan IIA inhibits the inflammatory response of macrophages and the formation of foam cells in atherosclerotic plaques. In summary, Tan IIA improves AS through a complex pathway. We propose to further study the specific molecular targets of Tan IIA using systems biology methods, so as to fundamentally elucidate the mechanism of Tan IIA. It is worth mentioning that there is a lack of high-quality evidence-based medical data on Tan IIA treatment of AS. We recommend that a randomized controlled clinical trial be conducted to evaluate the exact efficacy of Tan IIA in improving AS. Finally, sodium tanshinone IIA sulfonate (STS) can cause adverse drug reactions in some patients, which needs our attention.

Poly(l-lactide)/polycaprolactone based multifunctional coating to deliver paclitaxel/VEGF and control the degradation rate of magnesium alloy stent

Despite significant advancements made in cardiovascular stents, restenosis, thrombosis, biocompatibility, and clinical complications remain a matter of concern. Herein, we report a biodegradable Mg alloy stent with a dual effect of the drug (Paclitaxel) and growth factor (VEGF) release. To mitigate the fast degradation of Mg alloy, inorganic and organic coatings were formed on the alloy surface. The optimized hierarchal sequence of the coating was the first layer consisting of magnesium fluoride, followed by poly(l-lactide) and hydroxyapatite coating, and finally sealed by a polycaprolactone layer (MgC). PLLA and HAp were used to increase the adhesion strength and biocompatibility of the coating. Paclitaxel and VEGF were loaded in the final PCL layer (Mg-C/PTX-VEGF). As compared to bare Mg alloy (28 % weight loss), our MgC system showed (3.1 % weight loss) successful decrease in the degradation rate. Further, the in vitro biocompatibility illustrated the highly biocompatible nature of our drug and growth factor-loaded system. The in vivo results displayed that the drug loading decreased the inflammation and neointimal hyperplasia as indicated by the α-SMA and CD-68 antibody staining. The growth factor helped in the endothelialization which was established by the FLKI and ICAM antibody staining of the tissue.

Nox1-based NADPH oxidase regulates the Par protein complex activity to control cell polarization

Cell migration is essential for many biological and pathological processes. Establishing cell polarity with a trailing edge and forming a single lamellipodium at the leading edge of the cell is crucial for efficient directional cell migration and is a hallmark of mesenchymal cell motility. Lamellipodia formation is regulated by spatial-temporal activation of the small GTPases Rac and Cdc42 at the front edge, and RhoA at the rear end. At a molecular level, partitioning-defective (Par) protein complex comprising Par3, Par6, and atypical Protein Kinase (aPKC isoforms ζ and λ/ι) regulates front-rear axis polarization. At the front edge, integrin clustering activates Cdc42, prompting the formation of Par3/Par6/aPKC complexes to modulate MTOC positioning and microtubule stabilization. Consequently, the Par3/Par6/aPKC complex recruits Rac1-GEF Tiam to activate Rac1, leading to lamellipodium formation. At the rear end, RhoA-ROCK phosphorylates Par3 disrupting its interaction with Tiam and inactivating Rac1. RhoA activity at the rear end allows the formation of focal adhesions and stress fibers necessary to generate the traction forces that allow cell movement. Nox1-based NADPH oxidase is necessary for PDGF-induced migration in vitro and in vivo for many cell types, including fibroblasts and smooth muscle cells. Here, we report that Nox1-deficient cells failed to acquire a normal front-to-rear polarity, polarize MTOC, and form a single lamellipodium. Instead, these cells form multiple protrusions that accumulate Par3 and active Tiam. The exogenous addition of H2O2 rescues this phenotype and is associated with the hyperactivation of Par3, Tiam, and Rac1. Mechanistically, Nox1 deficiency induces the inactivation of PP2A phosphatase, leading to increased activation of aPKC. These results were validated in Nox1y/- primary mouse aortic smooth muscle cells (MASMCs), which also showed PP2A inactivation after PDGF-BB stimulation consistent with exacerbated activation of aPKC. Moreover, we evaluated the physiological relevance of this signaling pathway using a femoral artery wire injury model to generate neointimal hyperplasia. Nox1y/- mice showed increased staining for the inactive form of PP2A and increased signal for active aPKC, suggesting that PP2A and aPKC activities might contribute to reducing neointima formation observed in the arteries of Nox1y/- mice.

Evaluation of safety and efficacy of rapamycin-eluting balloon in patients with intracranial atherosclerotic stenosis: a cohort study

OBJECTIVE

The safety and efficacy of drug-eluting balloon on the treatment of intracranial atherosclerotic stenosis (ICAS) remain unclear. Here, we present our observation in a cohort study on the safety and efficacy of rapamycin-eluting balloon for patients with ICAS.

METHODS

A total of 80 ICAS patients with stenosis degree of 70-99% were included. All patients were treated with rapamycin-eluting balloon and were followed up for 12 months after operation.

RESULTS

All patients were successfully treated, where the mean stenosis severity reduced from 85.1 ± 7.6 to 6 ± 4.9%. 8 patients experienced immediate post-operational complications. Two patients passed away during the first month of the follow-up period. Recurrent ischemic syndrome and angiographic restenosis only appeared 7 days after operation. During later follow-up period, none of the patients had clinical angiographic restenosis or needed target vessel revascularization.

CONCLUSION

Our data suggest that intracranial stenting with rapamycin-eluting balloon seems to be safe and effective, although more clinical data are needed to support this notion.

Bves maintains vascular smooth muscle cell contractile phenotype and protects against transplant vasculopathy via Dusp1-dependent p38MAPK and ERK1/2 signaling

BACKGROUND AND AIMS

Vascular smooth muscle cell (VSMC) plasticity is tightly associated with the pathological process of vasculopathy. Blood vessel epicardial substance (Bves) has emerged as an important regulator of intracardiac vasculogenesis and organ homeostasis. However, the involvement and role of Bves in VSMC plasticity and neointimal lesion development remain unclear.

METHODS

We used an in vivo rat model of graft arteriosclerosis and in vitro PDGF-treated VSMCs and identified the novel VSMC contractile phenotype-related gene Bves using a transcriptomic analysis and literature search. In vitro knockdown and overexpression approaches were used to investigate the mechanisms underlying VSMC phenotypic plasticity. In vivo, VSMC-specific Bves overexpression in rat aortic grafts was generated to assess the physiological function of Bves in neointimal lesion development.

RESULTS

Here, we found that Bves expression was negatively regulated in aortic allografts in vivo and PDGF-treated VSMCs in vitro. The genetic knockdown of Bves dramatically inhibited, whereas Bves overexpression markedly promoted, the VSMC contractile phenotype. Furthermore, RNA sequencing unraveled a positive correlation between Bves and dual-specificity protein phosphatase 1 (Dusp1) expression in VSMCs. We found that Bves knockdown restrained Dusp1 expression, but enhanced p38MAPK and ERK1/2 activation, resulting in the loss of the VSMC contractile phenotype. In vivo, an analysis of a rat graft model confirmed that VSMC-specific Bves and Dusp1 overexpression in aortic allografts significantly attenuated neointimal lesion formation.

CONCLUSIONS

Bves maintains the VSMC contractile phenotype through Dusp1-dependent p38MAPK and ERK1/2 signaling, and protects against neointimal formation, underscoring the important role of Bves in preventing transplant vasculopathy.

Comparison of Drug-Eluting Stent With Bare-Metal Stent in Patients With Symptomatic High-grade Intracranial Atherosclerotic Stenosis: A Randomized Clinical Trial

Importance

In-stent restenosis (ISR) is the primary reason for stroke recurrence after intracranial stenting in patients who were treated with a standard bare-metal stent (BMS). Whether a drug-eluting stent (DES) could reduce the risk of ISR in intracranial atherosclerotic stenosis (ICAS) remains unclear.

Objective

To investigate whether a DES can reduce the risk of ISR and stroke recurrence in patients with symptomatic high-grade ICAS.

Design, Settings, and Participants

A prospective, multicenter, open-label randomized clinical trial with blinded outcome assessment was conducted from April 27, 2015, to November 16, 2018, at 16 medical centers in China with a high volume of intracranial stenting. Patients with symptomatic high-grade ICAS were enrolled, randomized, and followed up for 1 year. Intention-to-treat data analysis was performed from April 1 to May 22, 2021.

Interventions

Patients were randomly assigned to receive DES (NOVA intracranial sirolimus-eluting stent system) or BMS (Apollo intracranial stent system) treatment in a 1:1 ratio.

Main Outcomes and Measures

The primary efficacy end point was ISR within 1 year after the procedure, which was defined as stenosis that was greater than 50% of the luminal diameter within or immediately adjacent to (within 5 mm) the implanted stent. The primary safety end point was any stroke or death within 30 days after the procedure.

Results

A total of 263 participants (194 men [73.8%]; median [IQR] age, 58 [52-65] years) were included in the analysis, with 132 participants randomly assigned to the DES group and 131 to the BMS group. The 1-year ISR rate was lower in the DES group than in the BMS group (10 [9.5%] vs 32 [30.2%]; odds ratio, 0.24; 95% CI, 0.11-0.52; P < .001). The DES group also had a significantly lower ischemic stroke recurrence rate from day 31 to 1 year (1 [0.8%] vs 9 [6.9%]; hazard ratio, 0.10; 95% CI, 0.01-0.80; P = .03). No significant difference in the rate of any stroke or death within 30 days was observed between the DES and BMS groups (10 [7.6%] vs 7 [5.3%]; odds ratio, 1.45; 95% CI, 0.54-3.94; P = .46).

Conclusions and Relevance

This trial found that, compared with BMSs, DESs reduced the risks of ISR and ischemic stroke recurrence in patients with symptomatic high-grade ICAS. Further investigation into the safety and efficacy of DESs is warranted.

Trial Registration

ClinicalTrials.gov Identifier: NCT02578069.

A Computational Framework Examining the Mechanical Behaviour of Bare and Polymer-Covered Self-Expanding Laser-Cut Stents

PURPOSE

Polymer covered stents have demonstrated promising clinical outcomes with improved patency rates compared to traditional bare-metal stents. However, little is known on the mechanical implication of stent covering. This study aims to provide insight into the role of a polymeric cover on the biomechanical performance of self-expanding laser-cut stents through a combined experimental-computational approach.

METHODS

Experimental bench top tests were conducted on bare and covered versions of a commercial stent to evaluate the radial, axial and bending response. In parallel, a computational framework with a novel covering strategy was developed that accurately predicts stent mechanical performance. Different stent geometries and polymer materials were also considered to further improve understanding on covered stent mechanics.

RESULTS

Results show that stent covering causes increased initial axial stiffness and up to 60% greater radial resistive force at small crimp diameters as the cover folds and self-contacts. The incorporation of a cover allows stent designs without interconnecting struts, thereby providing improved flexibility without compromising radial force. It was also shown that use of a stiffer PET polymeric covering material caused significant alterations to the radial and axial response, with the initial axial stiffness increasing six-fold and the maximum radial resistive force increasing four-fold compared to a PTFE-PU covered stent.

CONCLUSION

This study demonstrates that stent covering has a substantial effect on the overall stent mechanical performance and highlights the importance of considering the mechanical properties of the combined cover and stent.

H3K4 Methyltransferase Smyd3 Mediates Vascular Smooth Muscle Cell Proliferation, Migration, and Neointima Formation

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MIA SH3 Domain ER Export Factor 3 Deficiency Prevents Neointimal Formation by Restoring BAT-Like PVAT and Decreasing VSMC Proliferation and Migration

Abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) and excessive accumulation of dysfunctional PVAT are hallmarks of pathogenesis after angioplasty. Recent genome-wide association studies reveal that single-nucleotide polymorphism (SNP) in MIA3 is associated with atherosclerosis-relevant VSMC phenotypes. However, the role of MIA3 in the vascular remodeling response to injury remains unknown. Here, we found that expression of MIA3 is increased in proliferative VSMCs and knockdown of MIA3 reduces VSMCs proliferation, migration, and inflammation, whereas MIA3 overexpression promoted VSMC migration and proliferation. Moreover, knockdown of MIA3 ameliorates femoral artery wire injury-induced neointimal hyperplasia and increases brown-like perivascular adipocytes. Collectively, the data suggest that MIA3 deficiency prevents neointimal formation by decreasing VSMC proliferation, migration, and inflammation and maintaining BAT-like perivascular adipocytes in PVAT during injury-induced vascular remodeling, which provide a potential therapeutic target for preventing neointimal hyperplasia in proliferative vascular diseases.

Behaviour of Vascular Smooth Muscle Cells on Amine Plasma-Coated Materials with Various Chemical Structures and Morphologies

Amine-coated biodegradable materials based on synthetic polymers have a great potential for tissue remodeling and regeneration because of their excellent processability and bioactivity. In the present study, we have investigated the influence of various chemical compositions of amine plasma polymer (PP) coatings and the influence of the substrate morphology, represented by polystyrene culture dishes and polycaprolactone nanofibers (PCL NFs), on the behavior of vascular smooth muscle cells (VSMCs). Although all amine-PP coatings improved the initial adhesion of VSMCs, 7-day long cultivation revealed a clear preference for the coating containing about 15 at.% of nitrogen (CPA-33). The CPA-33 coating demonstrated the ideal combination of good water stability, a sufficient amine group content, and favorable surface wettability and morphology. The nanostructured morphology of amine-PP-coated PCL NFs successfully slowed the proliferation rate of VSMCs, which is essential in preventing restenosis of vascular replacements in vivo. At the same time, CPA-33-coated PCL NFs supported the continuous proliferation of VSMCs during 7-day long cultivation, with no significant increase in cytokine secretion by RAW 264.7 macrophages. The CPA-33 coating deposited on biodegradable PCL NFs therefore seems to be a promising material for manufacturing small-diameter vascular grafts, which are still lacking on the current market.

Initial Experience With the Next-Generation Resolute Onyx Zotarolimus-Eluting Stent in Symptomatic Intracranial Atherosclerotic Disease

Background and Purpose: Intracranial atherosclerotic disease (ICAD) is a common cause of stroke worldwide. Although there are different endovascular options for the treatment of symptomatic ICAD (sICAD), it is still controversial. Herein, we aim to study the safety and efficacy of a new generation of drug-eluting balloon-mounted stent (DES); Resolute (R) onyx DES in the treatment of sICAD.

Methods: A prospectively maintained neuroendovascular procedures database in a high-volume comprehensive stroke center was reviewed from October 2019 through January 2020. Patients were included if they had sICAD (≥70% stenosis), failed medical management, and underwent intracranial stenting with R-onyx DES. Technical success was defined as the ability to deploy the device at the desired location and achievement of <30% residual stenosis. The primary outcome was the occurrence of complications within 72 h of the procedure (strokes, ischemic or hemorrhagic; and mortality). Secondary outcomes included rates of symptomatic and angiographic recurrence within 6 months of the procedure.

Results: A total of 18 consecutive patients (mean age, 66.6 years; 44.4% were females and 94.4% were Hispanic) were eligible for the analysis. Indication for treatment was recurrent strokes in 13 and recurrent transient ischemic attack (TIA) in 5. A total of 22 symptomatic lesions with a mean baseline stenosis percent (84.9 ± 9.6) were treated using 23 R-onyx DES in 19 procedures. All procedures were done under general anesthesia with 100% technical success, and no reported periprocedural strokes or death. Among 13 patients who had clinical follow-up, 1 (7.7%) patient had TIA. There were no reported ischemic or hemorrhagic strokes. Angiographic follow-up for 9 (50%) patients showed no in-stent restenosis.

Conclusion: The use of R-onyx DES in the treatment of sICAD is safe with high technical success rates. Large prospective multicenter trials with long-term follow-up are warranted.

Role of FOXM1 in vascular smooth muscle cell survival and neointima formation following vascular injury

Background

Accelerated smooth muscle cell (SMC) proliferation is the primary cause of intimal hyperplasia (IH) following vascular interventions. Forkhead Box M1 (FOXM1) is considered a proliferation-associated transcription factor. However, the presence and role of FOXM1 in IH following vascular injury have not been determined.

Objective

We examined the expression of FOXM1 in balloon-injured rat carotid arteries and investigated the effect of FOXM1 inhibition in SMCs and on the development of IH.

Methods and results

FOXM1 was detected by immunofluorescent staining in balloon-injured rat carotid arteries where we observed an upregulation at day 7, 14, and 28 compared to uninjured controls. Immunofluorescence staining revealed FOXM1 coincided with proliferating cell nuclear antigen (PCNA). FOXM1 was also detectable in human carotid plaque samples. Western blot showed an upregulation of FOXM1 protein in serum-stimulated SMCs. Inhibition of FOXM1 using siRNA or chemical inhibition led to the induction of apoptosis as measured by flow cytometry and western blot for cleaved caspase 3. Perturbations in survival signaling were measured by western blot following FOXM1 inhibition, which showed a decrease in phosphorylated AKT and β-catenin. The chemical inhibitor thiostrepton was delivered by intraperitoneal injection in rats that underwent balloon injury and led to reduced intimal thickening compared to DMSO controls.

Conclusions

FOXM1 is an important molecular mediator of IH that contributes to the proliferation and survival of SMCs following vascular injury.

A novel role of VEPH1 in regulating AoSMC phenotypic switching

Abdominal aortic aneurysm (AAA) is a potentially lethal disease featured by focal dilatation in the aorta. The transition of vascular smooth muscle cells (SMCs) from a contractile/differentiated to a synthetic/dedifferentiated phenotype is considered to contribute to AAA formation and expansion. Our previous gene microarray data showed that Ventricular Zone Expressed PH Domain Containing 1 (VEPH1) expression increased in angiotensin II (Ang II)-infused aortic tissues. This study was thus performed to further explore the role of VEPH1. Herein, we first demonstrate that VEPH1 increases in the SMCs of Ang II-treated abdominal aortas. As in vivo, Ang II also upregulated VEPH1 expression in cultured hAoSMCs. The dedifferentiation of human aortic SMCs (hAoSMCs) was induced by a 24-hr stimulation of Ang II (1 μM)-the expression of contractile SMC markers, MYH11 and α-smooth muscle actin (α-SMA) decreased and that of synthetic markers, proliferating cell nuclear antigen and Vimentin increased. Inhibition of VEPH1 prevented Ang II-induced pathological dedifferentiation of hAoSMCs as indicated by the restored expression of MYH11 and α-SMA. In contrast, the forced overexpression of VEPH1 aggravated Ang II's effects. Furthermore, we demonstrated that VEPH1 and transforming growth factor-β1 (TGF-β1), a key regulator responsible for vascular SMC differentiation, negatively regulated each other's transcription. In contrast to VEPH1 silencing, its overexpression inhibited recombinant TGF-β1-induced increases in MYH11 and α-SMA and suppressed Smad3 phosphorylation and nuclear accumulation. Collectively, our study demonstrates that VEPH1 elevation promotes the synthetic phenotype switching of AoSMCs and suppressed the TGF-β1/Smad3 signaling pathway. Identification of VEPH1 as a pathogenic molecule for AAA formation provides novel insights into this disease.

Potential function of microRNAs in thoracic aortic aneurysm and thoracic aortic dissection pathogenesis

Thoracic aortic aneurysm (TAA) and thoracic aortic dissection (TAD) are aortic diseases known as 'silent killers'. While TAA is characterized by an enlargement of at least half of the normal aortic diameter, TAD is characterized by progressive pseudo‑lumen formation, which results in the gradual separation of the aortic wall layers. In the present study, a total of 28 serum samples from nine patients with TAA, nine patients with TAD and ten healthy individuals were studied. The aim of the present study was to investigate the expression profiles of hsa‑microRNA(miR)‑143‑3p and hsa‑miR‑22‑3p in TAA and TAD in order to identify candidate miRNAs that are responsible for the pathogenesis of the diseases. Following the detection of target mRNAs from candidate miRNAs by bioinformatic tools, the expression profiles of target mRNAs were analyzed. A quantitative polymerase chain reaction was performed to detect Kirsten rat sarcoma viral oncogene homolog (KRAS), mitogen‑activated protein kinase (MAPK) 7, MAPK14 and transgelin (TAGLN) mRNA expression profiles. The results of the comparison with control group demonstrated that the increase in the expression levels of hsa‑miR‑143‑3p (P=0.017) and hsa‑miR‑22 (P=0.03) candidate miRNAs were statistically significant in the TAA group, but not in the TAD group. The expression of KRAS and MAPK7 mRNAs decreased in the two groups compared with the control group. The level of expression of MAPK14 decreased in the TAD group, but increased in the TAA group compared with the control group. TAGLN mRNA expression level increased in the two groups. The statistically significant difference in the expression of hsa‑miR‑143‑3p suggests that hsa‑miR‑143‑3p may be a potential biomarker for TAA, as the expression of the target mRNAs KRAS and MAPK7 decreased and the miRNA‑mRNA association was negatively correlated. These miRNAs and their associated genes may serve important functions in TAA formation, the altered expression of which may be important in the pathogenesis of TAA.

Neointimal tissue characterization after implantation of drug-eluting stents by optical coherence tomography: quantitative analysis of optical density

Normalized optical density (NOD) measured by optical coherence tomography represents neointimal maturity after coronary stent implantation and is correlated with morphologic information provided by both light and electron microscopy. We aimed to test the hypothesis that even second generation drug-eluting stents (DESs) are problematic in terms of neointimal maturity. We implanted bare-metal stents (BMS: n = 14), everolimus-eluting stents (EESs: n = 15) or zotarolimus-eluting stents (ZESs: n = 12) at 41 sites in 32 patients with stable coronary artery disease. OCT was performed at up to 12 months of follow-up, and the average optical density of neointima covering struts was evaluated. NOD was calculated as the optical density of stent-strut covering tissue divided by the optical density of the struts. We also measured circulating CD34+ /CD133+ /CD45low cells, and serum levels of stromal cell-derived factor (SDF)-1, interleukin (IL)-8 and matrix metalloproteinase (MMP)-9 at baseline and follow-up. NOD was lower in the EES (0.70 ± 0.06) group than in the BMS (0.76 ± 0.07, P < 0.05) and ZES (0.76 ± 0.06, P < 0.05) groups. The mean neointimal area (R = 0.33, P < 0.05) and mean neointimal thickness (R = 0.37, P < 0.05) were correlated with NOD. Although NOD was not correlated with percent changes in circulating endothelial progenitor cells, and the levels of SDF-1 and IL-8, it was negatively correlated with the change in MMP-9 level (R = - 0.51, P < 0.01). Neointimal maturity might be lower at EES sites than BMS or ZES sites. This might lead to impaired neointimal tissue growth and matrix degradation. These results suggest a specific pathophysiology after DES implantation.

Amlodipine induces vasodilation via Akt2/Sp1-activated miR-21 in smooth muscle cells

BACKGROUND AND PURPOSE

The calcium antagonist amlodipine exerts important cardioprotective effects by modulating smooth muscle and endothelial functions. However, the mechanisms underlying these effects are incompletely understood.

EXPERIMENTAL APPROACH

Western blotting was used to compare the expression of key genes involved in vascular smooth muscle cell (VSMC) phenotype conversion. Recombinant adeno-associated virus system was used to regulate miRNA expression in rats via tail vein. Bioinformatics was used to predict the transcriptional regulation of miR-21 upstream followed by biochemical validation using quantitative real-time polymerase chain reaction, ChIP-qPCR and EMSA assays.

KEY RESULTS

Only the calcium antagonist amlodipine, and no other type of anti-hypertensive drug, induced miR-21 overexpression in plasma and aortic vessels in the animal model. Real-time PCR and luciferase assays showed that amlodipine induced miR-21 overexpression in vascular smooth muscle cells. Western blot and immunofluorescence assays demonstrated that amlodipine activated Akt2, rather than Akt1, followed by activation of transcription factor Sp1, which regulated VSMC phenotype conversion via binding to the miR-21 promoter. Furthermore, bioinformatic analyses and luciferase assays demonstrated that amlodipine activated miR-21 transcription at the -2034/-2027 Sp1-binding site, which was further demonstrated by ChIP-qPCR and EMSA assays. Consistently, small-interfering RNA-mediated knockdown of Akt2 and Sp1 significantly attenuated the effects of amlodipine on miR-21 expression in smooth muscle cells.

CONCLUSION AND IMPLICATIONS

These results indicate that amlodipine induces smooth muscle cell differentiation via miR-21, which is regulated by p-Akt2 and Sp1 nuclear translocation, thereby providing a novel target for cardiovascular diseases.

MicroRNA-451 inhibits vascular smooth muscle cell migration and intimal hyperplasia after vascular injury via Ywhaz/p38 MAPK pathway

Increasing evidence has indicated that intimal hyperplasia is a common event in the pathophysiology of many vascular diseases including atherosclerosis (AS). Recently, deregulated microRNAs (miRNAs) have been reported to be associated with the pathophysiology of AS. However, the biological function and regulatory mechanisms of miRNAs in intimal hyperplasia in AS remain largely unclear. The aim of this study was to investigate the effects of miRNAs on intimal hyperplasia and reveal the underlying mechanisms of their effects. Firstly, the model of rat vascular injury was successfully constructed in vivo. Then, the miRNAs expression profiles were analyzed by miRNA microarray. It was observed that miR-451 was significantly downregulated in injury carotid arteries. Subsequently, we investigated miR-451 function and found that upregulation of miR-451 by agomir-451 improves intimal thickening in rats following vascular injury. It was also observed that miR-451 was downregulated in the VSMCs following platelet-derived growth factor type BB (PDGF-BB) stimulation. The upregulation of miR-451 attenuated PDGF-BB-induced VSMCs injury, as evidenced by inhibition of proliferation, invasion and migration. Besides, overexpression of miR-451 blocked the activation of p38 MAPK signaling pathway in PDGF-BB treated VSMCs, as demonstrated by the downregulation of phosphorylated (p-) p38. In addition, Ywhaz, a positive regulator of p38 MAPK signaling pathway, was found to be a direct target of miR-451 in the VSMCs and this was validated using a luciferase reporter assay. Overexpression of Ywhaz partially abolished the inhibitory effects of miR-451 overexpression on PDGF-BB induced VSMCs injury. Collectively, these findings indicated that miR-451 protected intimal hyperplasia and PDGF-BB-induced VSMCs injury by Ywhaz/p38 MAPK pathway, and miR-451 may be considered as a potential therapeutic target in the treatment of AS.

Comparison between paclitaxel-coated balloon and standard uncoated balloon in the treatment of femoropopliteal long lesions in diabetics

Atherosclerotic diseases may include femoropopliteal artery stenosis or occlusion. Percutaneous transluminal angioplasty (PTA) is an effective and minimally invasive treatment strategy for atherosclerotic femoropopliteal artery stenosis/occlusion disease. Balloon angioplasty is a widely used technique in the management of occlusive disease in almost all arterial segments.We enrolled 111 diabetics with long femoropopliteal lesions, among which 54 received PTA with paclitaxel-coated balloon (the Paclitaxel group), and 57 with standard balloon catheters (the Control group).The primary outcome was set as angiographic late lumen loss (LLL) within 6 months; the secondary angiographic outcome was binary restenosis. Clinical outcomes included Rutherford clarification, ankle-brachial index (ABI) and rate of clinically driven target lesion revascularization (TLR). Two groups had similar basal clinical features, angiographic and procedural characteristics. Compared to controls, the Paclitaxel group had a significantly lower 6-month LLL rate, 12-month binary restenosis rate, 12-month TLR, lower Rutherford grades at 3 and 6 months, and higher ABI at 3 months. For all factors which might influence outcomes, fasting blood glucose was negatively correlated with ABI; the blood urea nitrogen (BUN) was positively related with the Rutherford clarification grades. In addition, the coronary heart disease (CHD) and smoking histories were positively correlated with residual stenosis after treatment.Collectively, the paclitaxel-coated balloon angioplasty can yield more favorable angiographic and clinical outcomes than standard uncoated balloon angioplasty, even in the more challenging lesions (the long and occlusive femoropopliteal lesions) in diabetics, when it had a similar safety profile to the traditional balloon. Blood glucose, BUN, CHD, and smoking imply poor curative effects.

Efficacy and safety of drug-eluting stent for the intracranial atherosclerotic disease: A systematic review and meta-analysis

Drug-eluting stent (DES) is a potential endovascular treatment for patients with symptomatic intracranial atherosclerotic disease (sICAD). However, evidence regarding the treatment of ICAD with DES is lacking. We systematically searched Pubmed, Embase, Cochrane database (before 2017-12-21) for literature reporting the application of DES in the treatment of sICAD. The main outcomes were as follows: the incidence of any stroke or death within 30 days (perioperative complications), ischemic stroke in the territory of the qualifying artery beyond 30 days (long-term complications), in-stent restenosis rate (ISR) and symptomatic ISR during follow-up. Those studies with mean stenosis rate greater than 70% and less than 70% were defined as severe and moderate stenosis group, respectively. The random effect model was used to pool the data. Of 518 articles, 13 studies were eligible and included in our analysis (N = 336 patients with 364 lesions). After the implantation of DES, perioperative complications (mortality = 0) occurred in 6.0% (95%CI 2.0%-11.9%), long-term complications occurred in 2.2% (95%CI 0.7%-4.5%), ISR rate was 4.1% (95%CI 1.6%-7.7%) and the symptomatic ISR rate was only 0.5% (95%CI 0-2.2%). In addition, subgroup analysis showed that the perioperative complication rate in severe stenosis group [10.6% (95%CI 6.5%-15.7%)] was significantly (p < 0.01) higher than that in moderate stenosis group [1.0% (95%CI 0.3%-3.5%)]. In summary, endovascular DES implantation is a relatively safe and effective method compared with stents or medical management group in SAMMPRIS and VISSIT trials. However, a higher preoperative stenosis rate may imply a higher risk of perioperative complications. Further studies are needed.

The role of monocyte subpopulations in vascular injury following partial and transient depletion

The innate immunity system plays a critical role in vascular repair and restenosis development. Liposomes encapsulating bisphosphonates (LipBPs), but not free BPs, suppress neointima formation following vascular injury mediated in part by monocytes. The objective of this study was to elucidate the role of monocyte subpopulations on vascular healing following LipBP treatment. The potency- and dose-dependent treatment effect of clodronate (CLOD) and alendronate (ALN) liposomes on restenosis inhibition, total monocyte depletion, and monocytes subpopulation was studied. Rats subjected to carotid injury were treated by a single IV injection of LipBPs at the time of injury. Low- and high-dose LipALN treatment (3 and 10 mg/kg, respectively) resulted in a dose-dependent effect on restenosis development after 30 days. Both doses of LipALN resulted in a dose-dependent inhibition of restenosis, but only high dose of LipALN depleted monocytes (-60.1 ± 4.4%, 48 h post injury). Although LipCLOD treatment (at an equivalent potency to 3 mg/kg alendronate) significantly reduced monocyte levels (72.1 ± 6%), no restenosis inhibition was observed. The major finding of this study is the correlation found between monocyte subclasses and restenosis inhibition. Non-classical monocyte (NCM) levels were found higher in LipALN-treated rats, but lower in LipCLOD-treated rats, 24 h after injury and treatment. We suggest that the inhibition of circulating monocyte subpopulations is the predominant mechanism by which LipBPs prevent restenosis. The effect of LipBP treatment on the monocyte subpopulation correlates with the dose and potency of LipBPs.

Monocyte-mediated drug delivery systems for the treatment of cardiovascular diseases

Major advances have been achieved in understanding the mechanisms and risk factors leading to cardiovascular disorders and consequently developing new therapies. A strong inflammatory response occurs with a substantial recruitment of innate immunity cells in atherosclerosis, myocardial infarction, and restenosis. Monocytes and macrophages are key players in the healing process that ensues following injury. In the inflamed arterial wall, monocytes, and monocyte-derived macrophages have specific functions in the initiation and resolution of inflammation, principally through phagocytosis, and the release of inflammatory cytokines and reactive oxygen species. In this review, we will focus on delivery systems, mainly nanoparticles, for modulating circulating monocytes/monocyte-derived macrophages. We review the different strategies of depletion or modulation of circulating monocytes and monocyte subtypes, using polymeric nanoparticles and liposomes for the therapy of myocardial infarction and restenosis. We will further discuss the strategies of exploiting circulating monocytes for biological targeting of nanocarrier-based drug delivery systems for therapeutic and diagnostic applications.

Notoginsenoside R1 inhibits vascular smooth muscle cell proliferation, migration and neointimal hyperplasia through PI3K/Akt signaling

Restenosis caused by neointimal hyperplasia significantly decreases long-term efficacy of percutaneous transluminal angioplasty (PTA), stenting, and by-pass surgery for managing coronary and peripheral arterial diseases. A major cause of pathological neointima formation is abnormal vascular smooth muscle cell (VSMC) proliferation and migration. Notoginsenoside R1 (NGR1) is a novel saponin that is derived from Panax notoginseng and has reported cardioprotective, neuroprotective and anti-inflammatory effects. However, its role in modulating VSMC neointima formation remains unexplored. Herein, we report that NGR1 inhibits serum-induced VSMC proliferation and migration by regulating VSMC actin cytoskeleton dynamics. Using a mouse femoral artery endothelium denudation model, we further demonstrate that systemic administration of NGR1 had a potent therapeutic effect in mice, significantly reducing neointimal hyperplasia following acute vessel injury. Mechanistically, we show that NGR1’s mode of action is through inhibiting the activation of phosphatidylinositol 3-kinase (PI3K)/Akt signaling. Taken together, this study identified NGR1 as a potential therapeutic agent for combating restenosis after PTA in cardiovascular diseases.

Exogenous SERP1 attenuates restenosis by restoring GLP-1 receptor activity in diabetic rats following vascular injury

The activity of glucagon-like peptide 1 (GLP-1R) is essential for preventing restenosis following vascular injury; however, the mechanism of dysfunctional GLP-1R glycosylation and ways to enhance the activity of GLP-1R on vascular surfaces in diabetic patients are poorly understood. In the present study, we investigated the N-glycosylation level and role of stress-associated endoplasmic reticulum protein 1 (SERP1) in preventing restenosis following carotid injury in diabetic rats. Our results showed that N-glycosylation levels in both rat aortic endothelial cells (RAOECs) and rat vascular smooth muscle cells (VSMCs) decreased gradually following glucose treatment in a concentration dependant manner. Furthermore, co-immunoprecipitation (Co-IP) analyses indicated that SERP1 could interact with GLP-1R in RAOECs and VSMCs. Moreover, SERP1 enhanced GLP-1R N-glycosylation and increased the production of phosphorylated endothelial nitric oxide synthase (eNOS) as well as proliferation of RAOECs. SERP1 also increased phosphorylated adenosine monophosphate activated protein kinase (AMPK) and decreased the migration of VSMCs. Importantly, intima media thickness (IMT) and neointimal hyperplasia were alleviated in the carotid artery of diabetic rats injected with SERP1 following balloon injury. We also found an increase in re-endothelialization and a decrease in VSMC proliferation in the carotid artery of diabetic rats injected with SERP1. In summary, the remarkable effects of SERP1 on reducing restenosis following vascular injury may contribute to future advancements in the treatment of diabetic vascular complications.

Mobilization of progenitor cells and assessment of vessel healing after second generation drug-eluting stenting by optical coherence tomography

Background

Bone marrow-derived progenitor cells likely contribute to both endothelial- and smooth muscle cell-dependent healing responses in stent-injured vessel sites. This study aimed to assess mobilization of progenitor cells and vessel healing after zotarolimus-eluting (ZES) and everolimus-eluting (EES) stents.

Methods and results

In 63 patients undergoing coronary stent implantation, we measured circulating CD34 + CD133 + CD45low cells and serum levels of biomarkers relevant to stem cell mobilization. In 31 patients of them, we assessed vessel healing within the stented segment using optical coherence tomography (OCT) imaging. The CD34 + CD133 + CD45low cells increased 68 ± 59% 7 days after bare metal stent (BMS), 10 ± 53% after ZES (P < 0.01 vs BMS), 3 ± 49% after EES (P < 0.001 vs BMS), compared with baseline. Percent change in CD34 + CD133 + CD45low cells was positively correlated with that in stromal cell-derived factor (SDF)-1α (R = 0.29, P = 0.034). Percentage of uncovered struts was higher in the EES group (14.4 ± 17.3%), compared with the BMS (0.7 ± 1.3, P < 0.01) and ZES (0.4 ± 0.5, P < 0.01) groups. The change in CD34 + CD133 + CD45low cells showed positive correlation with OCT-quantified mean neointimal area (R = 0.48, P < 0.01). Finally, circulating mononuclear cells obtained from 5 healthy volunteers were isolated to determine the effect of sirolimus, zotarolimus and everolimus on vascular cell differentiation. The differentiation of mononuclear cells into endothelial-like cells was dose-dependently suppressed by sirolimus, zotarolimus, and everolimus.

Conclusions

Mobilization of progenitor cells was suppressed, and differentiation of mononuclear cells into endothelial-like cells was inhibited, in association with increased number of uncovered stent struts, even after second generation drug-eluting stenting. These data suggest that new approaches are necessary to enhance stent healing.

Comprehensive gene and microRNA expression profiling on cardiovascular system in zebrafish co-exposured of SiNPs and MeHg

Air pollution has been shown to increase cardiovascular diseases. However, little attention has been paid to the combined effects of PM and air pollutants on the cardiovascular system. To explore this, a high-throughput sequencing technology was used to determine combined effects of silica nanoparticles (SiNPs) and MeHg in zebrafish. Our study demonstrated that SiNPs and MeHg co-exposure could cause significant changes in mRNA and miRNA expression patterns in zebrafish. The differentially expressed (DE) genes in profiles 17 and 26 of STC analysis suggest that SiNPs and MeHg co-exposure had more proinflammatory and cardiovascular toxicity in zebrafish than single exposure. Major gene functions associated with cardiovascular system in the co-exposed zebrafish were discerned from the dynamic-gene-network, including stxbp1a, celf4, ahr1b and bai2. In addition, the prominently expressed pathway of cardiac muscle contraction was targeted by 3 DE miRNAs identified by the miRNA-pathway-network (dre-miR-7147, dre-miR-26a and dre-miR-375), which included 23 DE genes. This study presents a global view of the combined SiNPs and MeHg toxicity on the dynamic expression of both mRNAs and miRNAs in zebrafish, and could serve as fundamental research clues for future studies, especially on cardiovascular system toxicity.

Surface modification of endovascular stents with rosuvastatin and heparin-loaded biodegradable nanofibers by electrospinning

This study describes the development of drug-loaded nanofibrous scaffolds as a nanocoating for endovascular stents for the local and sustained delivery of rosuvastatin (Ros) and heparin (Hep) to injured artery walls after endovascular procedures via the electrospinning process.

PURPOSE

The proposed hybrid covered stents can promote re-endothelialization; improve endothelial function; reduce inflammatory reaction; inhibit neointimal hyperplasia of the injured artery wall, due to well-known pleiotropic actions of Ros; and prevent adverse events such as in-stent restenosis (ISR) and stent thrombosis (ST), through the antithrombotic action of Hep.

METHODS

Biodegradable nanofibers were prepared by dissolving cellulose acetate (AC) and Ros in N,N-dimethylacetamide (DMAc) and acetone-based solvents. The polymeric solution was electrospun (e-spun) into drug-loaded AC nanofibers onto three different commercially available stents (Co-Cr stent, Ni-Ti stent, and stainless steel stent), resulting in nonwoven matrices of submicron-sized fibers. Accordingly, Hep solution was further used for fibrous coating onto the engineered Ros-loaded stent. The functional encapsulation of Ros and Hep drugs into polymeric scaffolds further underwent physicochemical analysis. Morphological characterization took place via scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses, while scaffolds' wettability properties were obtained by contact angle (CA) measurements.

RESULTS

The morphology of the drug-loaded AC nanofibers was smooth, with an average diameter of 200-800 nm, and after CA measurement, we concluded to the superhydrophobic nature of the engineered scaffolds. In vitro release rates of the pharmaceutical drugs were determined using a high-performance liquid chromatography assay, which showed that after the initial burst, drug release was controlled slowly by the degradation of the polymeric materials.

CONCLUSION

These results imply that AC nanofibers encapsulated with Ros and Hep drugs have great potential in the development of endovascular grafts with anti-thrombogenic properties that can accelerate the re-endothelialization, reduce the neointimal hyperplasia and inflammatory reaction, and improve the endothelial function.

Epigallocatechin-3-gallate attenuates neointimal hyperplasia in a rat model of carotid artery injury by inhibition of high mobility group box 1 expression

Epigallocatechin-3-gallate (EGCG) is a kind of polyphenol compound, called catechin, and is extracted from green tea. EGCG has a wide range of biological activities. The present study aimed to evaluate the effect of EGCG on neointimal hyperplasia in a rat model of carotid artery balloon injury and to explore the molecular mechanisms involved. Various experiments were performed to assess the effects of EGCG on thickening of neointima, expression levels of high mobility group box 1 protein (HMGB1) and receptor of advanced glycation end products (RAGE), the inflammatory response, oxidative stress and activation of nuclear factor (NF)-κB. Results demonstrated that EGCG decreased the intimal area and the ratio of intimal area/medial area compared with the balloon injury group. The expression levels of HMGB1 and RAGE induced by balloon injury were markedly inhibited by EGCG treatment. Furthermore, the inflammatory response and oxidative stress damage, which have close correlations with HMGB1, were restrained by EGCG. Finally, EGCG treatment markedly inhibited NF-κB activation. The present data provided evidence that EGCG attenuates neointimal hyperplasia in a model of carotid artery balloon injury, which indicated that EGCG may serve as a potential drug for restenosis in clinics.

miRNA‑504 inhibits p53‑dependent vascular smooth muscle cell apoptosis and may prevent aneurysm formation

Abdominal aortic aneurysm (AAA) is a common disease that is associated with the proliferation and apoptosis of vascular smooth muscle cells (VSMCs). VSMCs are regulated by microRNAs (miRNA). The aim of the present study was to identify miRNA sequences that regulate aortic SMCs during AAA. miRNA-504 was identified using a miRNA PCR array and by reverse transcription-quantitative polymerase chain reaction analysis, and its expression levels were observed to be downregulated in the aortic cells derived from patients with AAA when compared with controls. Transfection of SMCs with pMSCV-miRNA-504 vector was performed, and cell proliferation and the expression levels of proliferating cell nuclear antigen (PCNA), replication factor C subunit 4 (RFC4), B-cell lymphoma-2 (Bcl-2) and caspase-3/9 were measured by western blotting. The mechanisms underlying the effects of miRNA-504 was then analyzed. The results demonstrated that overexpression of miRNA-504 significantly upregulated the expression levels of PCNA, RFC4 and Bcl-2, while caspase-3/9 expression was significantly inhibited when compared with non-targeting controls. In addition, miRNA-504 overexpression was observed to promote the proliferation of SMCs. The expression level of the tumor suppressor, p53, which is known to be a direct target of miRNA-504, was inhibited following transfection of SMCs with pMSCV-miRNA-504. In addition, the expression of the downstream targets of p53, p21 and Bcl-like protein-4, were significantly reduced following overexpression of miRNA-504. These results revealed the anti-apoptotic role of miRNA-504 in SMCs derived from patients with AAA via direct targeting of p53.

Inhibition effect of tacrolimus and platelet-derived growth factor-BB on restenosis after vascular intimal injury

Excessive proliferation and migration of vascular smooth muscle cells(VSMCs) and delayed proliferation and migration of endothelial cells(ECs) were the main cause of restenosis after endovascular interventional therapy. Since tacrolimus has proved to be more sensitive to inhibiting VSMCs' proliferation,and platelet-derived growth factor-BB(PDGF-BB) benefitted ECs' and VSMCs' proliferation, this study was aimed to identify combined effect of tacrolimus and PDGF-BB, investigate any mechanisms underneath and demonstrate combined effect of two drugs in vivo. As the results showed we confirmed differential effect of PDGF-BB and tacrolimus on ECs and VSMCs. On the concentration level of 2-5μg/ml tacrolimus plus 10ng/ml PDGF-BB, combination of drugs could effectively promote ECs proliferation and migration, and meanwhile inhibit VSMCs proliferation and migration, and the inhibition of p-mTOR's expression within VSMCs played an important role in this differentiated effect. Raising concentration level of PDGF-BB would weaken inhibitory effect of tacrolimus on both kinds of cell. For injured intima, the mix solution of two drugs could promote intima healing and suppress excessive intimal hyperplasia.

Association between plasma BMP-2 and in-stent restenosis in patients with coronary artery disease

OBJECTIVE

This study aimed to assess the association between plasma bone morphogenetic protein-2 (BMP-2) level and in-stent restenosis in patients with coronary artery disease.

METHODS

A total of 96 patients who underwent percutaneous coronary intervention (PCI) and were followed up after PCI were enrolled in this study. 47 patients diagnosed with in-stent restenosis (ISR) were recruited to ISR group and 49 patients without ISR were recruited to Control group according to the results of coronary angiography (CAG). Baseline characteristic data were collected, and plasma BMP-2 level was evaluated. The results were analyzed using logistic regression.

RESULTS

There were 47 patients in the ISR group and 49 patients in the Control group. Plasma levels of BMP-2 were higher in the ISR group than in the non-ISR group [20.96 (18.44, 27.05) pg/ml vs. 29.53 (25.03, 34.07) pg/ml, P<0.01]. Furthermore, the ISR group had significantly longer stent lengths and lower stent diameters than the Control group (P<0.01 and P<0.01, respectively). In multivariate analysis, BMP-2 level, diabetes, stent length and stent diameter were independently associated with ISR [odds ratio (OR)=1.11, 95% confidence interval (CI)=1.03-1.18, P<0.01; OR=4.75, 95% CI=(1.44-15.61), P=0.01; OR=1.06, 95% CI=(1.02-1.11), P<0.01; and OR=0.15, 95% CI=(0.02-0.95), P=0.04, respectively].

CONCLUSIONS

Increased BMP-2 levels were independently associated with ISR in patients with coronary artery disease. Plasma BMP-2 may be useful in predicting ISR.

Distinct gene expression profiles associated with Notch ligands Delta-like 4 and Jagged1 in plaque material from peripheral artery disease patients: a pilot study

Background

The lack of early diagnosis, progression markers and effective pharmacological treatment has dramatic unfavourable effects on clinical outcomes in patients with peripheral artery disease (PAD). Addressing these issues will require dissecting the molecular mechanisms underlying this disease. We sought to characterize the Notch signaling and atherosclerosis relevant markers in lesions from femoral arteries of symptomatic PAD patients.

Methods

Plaque material from the common femoral, superficial femoral or popliteal arteries of 20 patients was removed by directional atherectomy. RNA was obtained from 9 out of 20 samples and analysed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR).

Results

We detected expression of Notch ligands Delta-like 4 (Dll4) and Jagged1 (Jag1), of Notch target genes Hes1, Hey1, Hey2, HeyL and of markers of plaque inflammation and stability such as vascular cell adhesion molecule 1 (VCAM1), smooth muscle 22 (SM22), cyclooxygenase 2 (COX2), Bcl2, CD68 and miRNAs 21-5p, 125a-5p, 126-5p,146-5p, 155-5p, 424-5p. We found an “inflamed plaque” gene expression profile characterized by high Dll4 associated to medium/high CD68, COX2, VCAM1, Hes1, miR126-5p, miR146a-5p, miR155-5p, miR424-5p and low Jag1, SM22, Bcl2, Hey2, HeyL, miR125a-5p (2/9 patients) and a “stable plaque” profile characterized by high Jag1 associated to medium/high Hey2, HeyL, SM22, Bcl2, miR125a and low Dll4, CD68, COX2, VCAM1, miR126-5p, miR146a-5p, miR155-5p, miR424-5p (3/9 patients). The remaining patients (4/9) showed a plaque profile with intermediate characteristics.

Conclusions

This study reveals the existence of a gene signature associated to Notch activation by specific ligands that could be predictive of PAD progression.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-017-1199-3) contains supplementary material, which is available to authorized users.

RNA-Eluting Surfaces for the Modulation of Gene Expression as A Novel Stent Concept

Presently, a new era of drug-eluting stents is continuing to improve late adverse effects such as thrombosis after coronary stent implantation in atherosclerotic vessels. The application of gene expression–modulating stents releasing specific small interfering RNAs (siRNAs) or messenger RNAs (mRNAs) to the vascular wall might have the potential to improve the regeneration of the vessel wall and to inhibit adverse effects as a new promising therapeutic strategy. Different poly (lactic-co-glycolic acid) (PLGA) resomers for their ability as an siRNA delivery carrier against intercellular adhesion molecule (ICAM)-1 with a depot effect were tested. Biodegradability, hemocompatibility, and high cell viability were found in all PLGAs. We generated PLGA coatings with incorporated siRNA that were able to transfect EA.hy926 and human vascular endothelial cells. Transfected EA.hy926 showed significant siICAM-1 knockdown. Furthermore, co-transfection of siRNA and enhanced green fluorescent protein (eGFP) mRNA led to the expression of eGFP as well as to the siRNA transfection. Using our PLGA and siRNA multilayers, we reached high transfection efficiencies in EA.hy926 cells until day six and long-lasting transfection until day 20. Our results indicate that siRNA and mRNA nanoparticles incorporated in PLGA films have the potential for the modulation of gene expression after stent implantation to achieve accelerated regeneration of endothelial cells and to reduce the risk of restenosis.