Plant-Derived Products for Treatment of Vascular Intima Hyperplasia Selectively Inhibit Vascular Smooth Muscle Cell Functions

Schisandrin inhibits VSMCs proliferation and migration by arresting cell cycle and targeting JAK2 to regulating the JAK2/STAT3 pathway

Abnormal proliferation, migration, and foam cell formation of Vascular smooth muscle cells (VSMCs) each play a role in the development of atherosclerosis (AS). Schisandrin (Sch) is the active lignan ingredient with broad-spectrum pharmacological effects. However, the role of Sch in the AS process is not clear. Therefore, this study was proposed to explore the therapeutic effect and potential mechanism of Sch on VSMCs. Ox-LDL was selected to create an atherosclerosis injury environment for VSMCs and macrophages. The MTT assay, Oil red O staining, wound healing, transwell experiments and ELISA were used to investigate the phenotype effects of Sch. Network pharmacology, molecular docking, flow cytometry, and western blot were used to investigate the underlying mechanisms of Sch on AS progression. Our findings implied that Sch treatment inhibited the proliferation and migration of VSMCs, and suppressed the ROS production and inflammatory cytokines up-regulation of VSMCs and macrophages. Moreover, Sch reduced lipid uptake and foam cell formation through downregulating LOX-1. Mechanistically, we found that Sch can inhibit the activation of JAK2/STAT3 signaling by targeting JAK2, and arrest cell cycle in GO/G1 phase. In summary, Sch can inhibit VSMCs proliferation and migration by arresting cell cycle and targeting JAK2 to regulating the JAK2/STAT3 pathway. Sch may serve as a potential drug for patients with AS.

Nemopilema nomurai jellyfish venom attenuates phenotypic modulation of PDGF BB-induced vascular smooth muscle cells and κ-carrageenan-induced rat tail thrombosis

Jellyfish venoms have long been recognized as a potentially rich source of natural bioactive compounds with pharmacological potential for the creation of innovative drugs. Our previous study demonstrated that Nemopilema nomurai jellyfish venom (NnV) has a chymotrypsin-like serine protease with fibrinolytic activity in vitro. Therefore, the present study aims to investigate the potential effect of NnV on cell migration, proliferation, and differentiation of vascular smooth muscle cells (VSMC; A7r5 cells) involved in the probable mechanism pathways. We also determined its anti-thrombotic effect through κ-carrageenan-induced Sprague-Dawley (SD) rat tail thrombus model. NnV inhibits on Platelet-derived growth factor (PDGF)-BB-stimulated A7r5 cells migration and proliferation by decreasing matrix metalloproteinase 2 (MMP-2) level and phosphorylation of ERK and Akt in a dose-dependent manner, but not p38. Furthermore, NnV regulates the phenotype transition of differentiation in PDGF-BB-stimulated A7r5 cells via ɑ-SMA and calponin in a dose-dependent manner. In an in vivo study, NnV treatment demonstrated clear anti-thrombotic activity in a dose-dependent manner, which was associated with decreased thrombus formation and length in κ-carrageenan-induced SD rat tail. These findings suggested that NnV has a novel fibrinolytic enzyme that can be used to prevent and/or treat thrombosis-related cardiovascular disorders.

Extracellular vesicles produced by human-induced pluripotent stem cell-derived endothelial cells can prevent arterial stenosis in mice via autophagy regulation

Intravascular transplantation of human-induced pluripotent stem cells (hiPSCs) demonstrated a significant therapeutic effect in the treatment of restenosis by the paracrine function of extracellular vesicles (EVs). However, the risk of tumorigenicity and poor cell survival limits its clinical applications. In this study, we for the first time applied a highly efficient and robust three-dimensional (3D) protocol for hiPSC differentiation into endothelial cells (ECs) with subsequent isolation of EVs from the derived hiPSC-EC (ECs differentiated from hiPSCs), and validated their therapeutic effect in intimal hyperplasia (IH) models. We found that intravenously (iv) injected EVs could accumulate on the carotid artery endothelium and significantly alleviate the intimal thickening induced by the carotid artery ligation. To elucidate the mechanism of this endothelial protection, we performed miRNA expression profiling and found out that among the most conserved endothelial miRNAs, miR-126 was the most abundant in hiPSC-EC-produced EVs (hiPSC-EC-EV). MiR-126 depletion from hiPSC-EC-EV can hinder its protective effect on human umbilical vein endothelial cells (HUVECs) in an inflammatory process. A variety of functional in vitro studies revealed that miR-126 was able to prevent endothelial apoptosis after inflammatory stimulation, as well as promote EC migration and tube formation through autophagy upregulation. The latter was supported by in vivo studies demonstrating that treatment with hiPSC-EC-EV can upregulate autophagy in mouse carotid artery ECs, thereby preventing IH and modulating vascular homeostasis via remodeling of the vascular intima. Our findings suggest a regulatory mechanism for the therapeutic effect on arterial restenosis by autophagy regulation, and provide a potential strategy for clinical treatment of the disease.

Scaffold Engineering with Flavone-Modified Biomimetic Architecture for Vascular Tissue Engineering Applications

BACKGROUND

Vascular intimal hyperplasia (IH) is one of the key challenges in the clinical application of small-diameter vascular grafts. Current tissue engineering strategies focus on vascularization and antithrombotics, yet few approaches have been developed to treat IH. Here, we designed a tissue-engineered vascular scaffold with portulaca flavonoid (PTF) composition and biomimetic architecture.

METHOD

By electrospinning, PTF is integrated with biodegradable poly(ε-caprolactone) (PCL) into a bionic vascular scaffold. The structure and functions of the scaffolds were evaluated based on material characterization and cellular biocompatibility. Human vascular smooth muscle cells (HVSMCs) were cultured on scaffolds for up to 14 days.

RESULTS

The incorporation of PTF and preparation parameters during fabrication influences the morphology of the scaffold, including fibre diameter, structure, and orientation. Compared to the PCL scaffold, the scaffolds integrated with bioactive PTF show better hydrophilicity and degradability. HVSMCs seeded on the scaffold alongside the fibres exhibit fusiform-like shapes, indicating that the scaffold can provide contact guidance for cell morphology alterations. This study demonstrates that the PCL/PTF (9.1%) scaffold inhibits the excessive proliferation of HVSMCs without causing cytotoxicity.

CONCLUSION

The study provides insights into the problem of restenosis caused by IH. This engineered vascular scaffold with complex function and preparation is expected to be applied as a substitute for small-diameter vascular grafts.

Molecular Action of Hydroxytyrosol in Attenuation of Intimal Hyperplasia: A Scoping Review

Objective: Hydroxytyrosol (HT), a polyphenol of olive plant is well known for its antioxidant, anti-inflammatory and anti-atherogenic properties. The aim of this systematic search is to highlight the scientific evidence evaluating molecular efficiency of HT in halting the progression of intimal hyperplasia (IH), which is a clinical condition arises from endothelial inflammation.

Methods: A systematic search was performed through PubMed, Web of Science and Scopus, based on pre-set keywords which are Hydroxytyrosol OR 3,4-dihydroxyphenylethanol, AND Intimal hyperplasia OR Neointimal hyperplasia OR Endothelial OR Smooth muscles. Eighteen in vitro and three in vitro and in vivo studies were selected based on a pre-set inclusion and exclusion criteria.

Results: Based on evidence gathered, HT was found to upregulate PI3K/AKT/mTOR pathways and supresses inflammatory factors and mediators such as IL-1β, IL-6, E-selectin, P-selectin, VCAM-1, and ICAM-1 in endothelial vascularization and functioning. Two studies revealed HT disrupted vascular smooth muscle cells (SMC) cell cycle by dephosphorylating ERK1/2 and AKT pathways. Therefore, HT was proven to promote endothelization and inhibit vascular SMCs migration thus hampering IH development. However, none of these studies described the effect of HT collectively in both vascular endothelial cells (EC) and SMCs in IH ex vivo model.

Conclusions: Evidence from this concise review provides an insight on HT regulation of molecular pathways in reendothelization and inhibition of VSMCs migration. Henceforth, we propose effect of HT on IH prevention could be further elucidated through in vivo and ex vivo model.

Propolis ameliorates restenosis in hypercholesterolemia rabbits with carotid balloon injury by inhibiting lipid accumulation, oxidative stress, and TLR4/NF-κB pathway

Neointima formation and atherosclerosis are the main complications after the endovascular intervention and vascular surgery, and there are no effective drugs. Propolis is a kind of resin substance produced by honeybees and has numerous health-beneficial effects. In this study, we evaluated the effects of propolis (125 and 250 mg·kg^-1 ·day^-1 , 6 weeks) on carotid restenosis in hypercholesterolemia rabbits. Propolis significantly ameliorated the degree of carotid restenosis, inhibited neointima hyperplasia, reduced serum lipids profile, and enhanced the anti-oxidative activities in hypercholesterolemia rabbits. Furthermore, propolis reduced the plasma levels of C-reactive protein, interleukin-6, and tumor necrosis factor-α (TNF-α), and inhibited the expression of CD68, TLR4, NF-κB p65, MMP-9, and TNF-α in the carotid arteries. The results indicate that propolis has a protective effect on carotid restenosis in rabbits, which is associated with regulating blood lipids, inhibiting oxidative stress and inflammation, and its anti-inflammatory activity may be related to inhibit TLR4-mediated NF-κB signaling pathway. PRACTICAL APPLICATIONS: Restenosis is a primary challenge in angioplasty and atherosclerotic treatment. Hyperlipidemia can induce inflammation and accelerate the formation of restenosis. Recently, natural products have been widely used to prevent intimal hyperplasia of common cardiovascular diseases. Propolis is currently a popular functional food, but the role of propolis on carotid restenosis after angioplasty and its underlying mechanism remains unclear. This study showed that propolis inhibits the effect of carotid restenosis in hypercholesterolemia rabbits. The results of this study may provide a basis for propolis to prevent and treat vascular restenosis.

Glossogyne tenuifolia Attenuates Proliferation and Migration of Vascular Smooth Muscle Cells

The proliferation and migration of vascular smooth muscle cells (VSMCs) are essential in the pathogenesis of various vascular diseases, such as atherosclerosis and restenosis. Among the mediators of VSMC during atherosclerosis development, platelet-derived growth factor (PDGF)-BB is a potent mitogen for VSMCs and greatly contributes to the intimal accumulation of VSMCs. Glossogyne tenuifolia (GT, Xiang-Ru) is a traditional antipyretic and hepatoprotective herb from Penghu Island, Taiwan. This study evaluated the inhibitory effect of GT ethanol extract (GTE) and GT water extract (GTW) on proliferative and migratory activities in PDGF-BB-induced VSMCs. The experimental results demonstrated that GTE significantly inhibited the PDGF-BB-stimulated VSMC proliferation and migration, as shown by MTT, wound healing, and Boyden chamber assays. GTE was found to have a much more potent inhibitory activity than GTW. Based on the Western blot analysis, GTE significantly blocked the PDGF-BB-induced phosphorylation of NF-κB and mitogen-activated protein kinase (MAPK) pathways, including extracellular signal-regulated kinase (ERK), p38, and JNK, in VSMCs. In addition, GTE retarded the PDGF-BB-mediated migration through the suppression of matrix metalloproteinase (MMP)-2 and MMP-9 expression in VSMCs. Three main ingredients of GT-chlorogenic acid, luteolin-7-glucoside, and luteolin-all showed significant anti-proliferative effects on PDGF-BB-induced VSMCs. As a whole, our findings indicated that GTE has the potential to be a therapeutic agent to prevent or treat restenosis or atherosclerosis.

The Effects of Pro-Inflammatory and Anti-Inflammatory Agents for the Suppression of Intimal Hyperplasia: An Evidence-Based Review

Anti-atherogenic therapy is crucial in halting the progression of inflammation-induced intimal hyperplasia. The aim of this concise review was to methodically assess the recent findings of the different approaches, mainly on the recruitment of chemokines and/or cytokine and its effects in combating the intimal hyperplasia caused by various risk factors. Pubmed and Scopus databases were searched, followed by article selection based on pre-set inclusion and exclusion criteria. The combination of keywords used were monocyte chemoattractant protein-1 OR MCP-1 OR TNF-alpha OR TNF-α AND hyperplasia OR intimal hyperplasia OR neointimal hyperplasia AND in vitro. These keywords combination was incorporated in the study and had successfully identified 77 articles, with 22 articles were acquired from Pubmed, whereas 55 articles were obtained from Scopus. However, after title screening, only twelve articles meet the requirements of defined inclusion criteria. We classified the data into 4 different approaches, i.e., utilisation of natural product, genetic manipulation and protein inhibition, targeted drugs in clinical setting, and chemokine and cytokines induction. Most of the articles are working on genetic manipulation targeted on specific pathway to inhibit the pro-inflammatory factors expression. We also found that the utilisation of chemokine- and cytokine-related treatments are emerging throughout the years. However, there is no study utilising the combination of approaches that might give a better outcome in combating intimal hyperplasia. Hopefully, this concise review will provide an insight regarding the usage of different novel approaches in halting the progression of intimal hyperplasia, which serves as a key factor for the development of atherosclerosis in cardiovascular disease.

Ruxolitinib attenuates intimal hyperplasia via inhibiting JAK2/STAT3 signaling pathway activation induced by PDGF-BB in vascular smooth muscle cells

BACKGROUND

Cardiovascular diseases are associated with proliferation and phenotypic switch. Platelet-derived growth factor-BB (PDGF-BB) is a major initiating factor for proliferative vascular diseases, such as neointimal lesion formation, restenosis after angioplasty, and atherosclerosis. Ruxolitinib, a potent Janus kinase (JAK) 1 and 2 inhibitor, has been reported to significantly block the proliferation-related signaling pathway of JAK2/signal transducers and activators of transcription 3 (STAT3) and harbor a broad spectrum of anti-cancer activities, including proliferation inhibition, apoptosis induction, and anti-inflammation. However, the role of ruxolitinib in regulating PDGF-BB-induced VSMC proliferation remains to be elucidated. Thus, this study investigates the role of ruxolitinib in regulating PDGF-BB-induced VSMC proliferation and its underlying mechanisms.

METHODS

In vivo, the medial thickness of the carotid artery was evaluated using a mouse carotid ligation model, ruxolitinib was administered orally to the mice every other day, and the mice were euthanized on day 28 to evaluate the therapeutic effects of ruxolitinib. Cell proliferation markers were measured using real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blotting. In vitro, VSMCs were treated with ruxolitinib with or without PDGF-BB at an indicated time and concentration. Cell proliferation and apoptosis were measured using Cell Counting Kit-8 assay, MTS assays and flow cytometry. The JAK2/STAT3 signaling pathway involved in the effects of ruxolitinib on VSMCs was detected by western blotting with the specific pathway inhibitor AG490.

RESULTS

In vivo, ruxolitinib significantly decreased the ratio-of-intima ratio (I/M ratio) by inhibiting the expression of PCNA and cyclinD1 (p <0.05). In vitro, ruxolitinib inhibited PDGF-BB-induced VSMC proliferation compared with the PDGF-BB treatment group (p <0.05). In addition, ruxolitinib inhibited the PDGF-BB-induced activation of the JAK2/STAT3 signaling pathway and decreased the expression of proliferation related-proteins cyclinD1 and PCNA in VSMCs (p <0.05).

CONCLUSION

Our findings suggest that ruxolitinib inhibits VSMC proliferation in vivo and in vitro by suppressing the activation of the JAK2/STAT3 signaling pathway. Therefore, ruxolitinib has a therapeutic potential for proliferative vascular diseases.

Inhibition of ERK or Akt ameliorates intimal hyperplasia via up-regulation of Cx37 and down-regulation of Cx43 in balloon injury rat model

Background

Connexins (Cxs) are reported to participate in atherosclerosis associated intimal hyperplasia (IH), while their function involved in the balloon injury (BI) induced IH and restenosis is less reported.

Methods

Forty-eight male Sprague-Dawley rats were randomly assigned to not injured (NI) group and BI group, which were further administrated with ERK-inhibitor U0216 and Akt-inhibitor MIK2206. Western blot and RT-PCR were utilized to detect the expression of Cx30, Cx37, Cx40, and Cx43 at 6 hours, 24 hours, 7 days, and 14 days post-surgery. H&E staining and related intima area, media area, and luminal area measurement were applied to indicate neointima formation and IH. ERK and Akt phosphorylation levels and proliferating cell nuclear antigen (PCNA) immunostaining were also detected.

Results

Among the four Cxs detected, Cx37 showed down-regulated, and Cx43 showed up-regulated temporal expression pattern in BI rats with confirmed neointima formation. Up-regulated p-ERK (P<0.01) and p-Akt (P<0.01) can be detected in BI rats compared with NI rats. Meanwhile, U0216 and MIK2206 can significantly reduce Cx43 expression and increase CX37 expression accompanied with reduced neointima formation and PCNA staining (P<0.05 or P<0.01) in BI rats.

Conclusions

ERK or Akt inhibition can alleviate BI-induced IH via up-regulation of Cx37 and down-regulation of Cx43.

Ameliorative Effects and Cellular Aspects of Phytoconstituents in Atherosclerosis

Atherosclerosis is a cardiovascular disease that involves vessels through the development of fatty streaks and plaques. Plant-based compounds can help treat or prevent atherosclerosis by affecting various factors that are involved in the disease. The present review discusses our current knowledge of the major cellular and molecular mechanisms of phytotherapeutics for the treatment of atherosclerosis. Numerous studies have evaluated the antiatherosclerotic activity of phytoconstituents to provide preliminary evidence of efficacy, but only a few studies have delineated the underlying molecular mechanisms. Plant-derived phytotherapeutics primarily targets abnormal levels of lipoproteins, endothelial dysfunction, smooth muscle cell migration, foam cell development, and atheromatous plaque formation. Nonetheless, the principal mechanisms that are responsible for their therapeutic actions remain unclear. Further pharmacological studies are needed to elucidate the underlying molecular mechanisms of the antiatherosclerotic response to these phytoconstituents.

Hybrid electrospun rapamycin-loaded small-diameter decellularized vascular grafts effectively inhibit intimal hyperplasia

For the surgical treatment of coronary artery disease, renal artery stenosis and other peripheral vascular diseases, there is significant demand for small diameter (inner diameter <6 mm) vascular grafts. However, autologous grafts are not always available when the substitute vascular grafts are severely diseased. In our previous work, hybrid small-diameter vascular grafts were successfully fabricated by combining electrospun polycaprolactone (PCL) and decellularized rat aorta (DRA). However, histological assessments of these grafts revealed the development of intimal hyperplasia, indicating potential negative impacts on the long-term patency of these grafts. To address this challenge, PCL nanofibers blended with rapamycin (RM) were electrospun outside the decellularized vascular graft to fabricate a RM-loaded hybrid tissue-engineered vascular graft (RM-HTEV), endowing the graft with a drug delivery function to prevent intimal hyperplasia. RM-HTEV possessed superior mechanical properties compared to DRA and exhibited a sustained drug release profile. To evaluate the applicability of RM-HTEV in vivo, abdominal aorta transplantation was performed on rats. Doppler sonography showed that the grafts were functional for up to 8 weeks in vivo. Moreover, histological analysis of explanted grafts 12 weeks postimplantation demonstrated that RM-HTEV significantly decreased neo-intimal hyperplasia compared with HTEV, without impairing reendothelialization and M2 macrophage polarization. Overall, RM-HTEV represents a promising strategy for developing small-diameter vascular grafts with great clinical translational potential. STATEMENT OF SIGNIFICANCE: In this study, a new type of rapamycin-loaded hybrid tissue-engineered vascular graft (RM-HTEV) was fabricated using electrospinning technology. The unique hybrid bi-layer structure endowed the RM-HTEV with multi-functionality: the exterior rapamycin-loaded electrospun PCL nanofibrous layer enhanced the mechanical properties of the graft and possessed drug releasing property; the interior decellularized aorta layer with porous structure could facilitate cell proliferation and migration. In in vivo implantation experiment, RM-HTEV exhibited satisfying long-term patency rate and significantly inhibited intimal hyperplasia without impairing re-endothelialization and M2 macrophage polarization. This strategy is expected to be a promising strategy for developing bioactive small-diameter vascular grafts with great clinical translational potential.