Matrix metalloproteinase-9 is necessary for the regulation of smooth muscle cell replication and migration after arterial injury

Blocking Sigmar1 exacerbates methamphetamine-induced hypertension

AIM

Methamphetamine (METH) chronic exposure is an important risk factor for hypertension development. However, the mechanisms behind METH-induced hypertension remain unclear. Therefore, we aimed to reveal the potential mechanisms underlying METH-induced hypertension.

METHODS AND RESULTS

We structured the mouse hypertension model by METH, and observed that METH-treated mice have presented vascular remodeling (large-and small-size arteries) with collagen deposit around the vessel and increasing blood pressure (BP) and Sigma1 receptor (Sigmar1) in vascular tissue. We hypothesized that Sigmar1 is crucial in METH-induced hypertension and vascular remodeling. Sigmar1 knockout (KO) mice and antagonist (BD1047) pretreated mice exposed to METH for six-week showed higher BP and more collagen deposited around vessels than wild-type (WT) mice exposed to METH for six-week, in contrast, mice pretreated with Sigmar1 agonist (PRE-084) had unchanged BP and perivascular collagen despite the six-week METH exposure. Furthermore, we found that METH exposure induced vascular smooth muscle cells (VSMCs) and mesenchymal stem cells to differentiate into the myofibroblast-like cell and secrete collagen into surrounding vessels. Mechanically, Sigmar1 can suppress the COL1A1 expression by blocking the classical fibrotic TGF-β/Smad2/3 signaling pathway in METH-exposed VSMCs and mesenchymal stem cells.

CONCLUSION

Our results suggest that Sigmar1 is involved in METH-induced hypertension and vascular fibrosis by blocking the activation of the TGF-β/Smad2/3 signaling pathway. Accordingly, Sigmar1 may be a novel therapeutic target for METH-induced hypertension and vascular fibrosis.

Electrochemical impedance spectroscopy unmasks high-risk atherosclerotic features in human coronary artery disease

Coronary plaque rupture remains the prominent mechanism of myocardial infarction. Accurate identification of rupture-prone plaque may improve clinical management. This study assessed the discriminatory performance of electrochemical impedance spectroscopy (EIS) in human cardiac explants to detect high-risk atherosclerotic features that portend rupture risk. In this single-center, prospective study, n = 26 cardiac explants were collected for EIS interrogation of the three major coronary arteries. Vessels in which advancement of the EIS catheter without iatrogenic plaque disruption was rendered impossible were not assessed. N = 61 vessels underwent EIS measurement and histological analyses. Plaques were dichotomized according to previously established high rupture-risk parameter thresholds. Diagnostic performance was determined via receiver operating characteristic areas-under-the-curve (AUC). Necrotic cores were identified in n = 19 vessels (median area 1.53 mm2) with a median fibrous cap thickness of 62 μm. Impedance was significantly greater in plaques with necrotic core area ≥1.75 mm2 versus <1.75 mm2 (19.8 ± 4.4 kΩ vs. 7.2 ± 1.0 kΩ, p = .019), fibrous cap thickness ≤65 μm versus >65 μm (19.1 ± 3.5 kΩ vs. 6.5 ± 0.9 kΩ, p = .004), and ≥20 macrophages per 0.3 mm-diameter high-power field (HPF) versus <20 macrophages per HPF (19.8 ± 4.1 kΩ vs. 10.2 ± 0.9 kΩ, p = .002). Impedance identified necrotic core area ≥1.75 mm2, fibrous cap thickness ≤65 μm, and ≥20 macrophages per HPF with AUCs of 0.889 (95% CI: 0.716-1.000) (p = .013), 0.852 (0.646-1.000) (p = .025), and 0.835 (0.577-1.000) (p = .028), respectively. Further, phase delay discriminated severe stenosis (≥70%) with an AUC of 0.767 (0.573-0.962) (p = .035). EIS discriminates high-risk atherosclerotic features that portend plaque rupture in human coronary artery disease and may serve as a complementary modality for angiography-guided atherosclerosis evaluation.

Local vascular Klotho mediates diabetes-induced atherosclerosis via ERK1/2 and PI3-kinase-dependent signaling pathways

BACKGROUND AND AIMS

Diabetes is one of the major causes of cardiovascular disease (CVD). As high as 29 % of patients with diabetes develop atherosclerosis. Vascular Smooth Muscle Cells (VSMCs) are a key mediator in the pathogenesis of atherosclerosis, generating pro-inflammatory and proliferative characteristics in atherosclerotic lesions.

METHODS

We used human atherosclerotic samples, developed diabetes-induced atherosclerotic mice, and generated loss of function and gain of function in Klotho human aortic smooth muscle cells to investigate the function of Klotho in atherosclerosis.

RESULTS

We found that Klotho expression is decreased in smooth muscle actin-positive cells in patients with diabetes and atherosclerosis. Consistent with human data, we found that Apoe knockout mice with streptozotocin-induced diabetes fed on a high-fat diet showed decreased expression of Klotho in SMCs. Additionally, these mice showed increased expression of TGF-β, MMP9, phosphorylation of ERK and Akt. Further, we utilized primary Human Aortic Smooth Muscle Cells (HASMCs) with d-glucose under dose-response and in time-dependent conditions to study the role of Klotho in these cells. Klotho gain of function and loss of function studies showed that Klotho inversely regulated the expression of atherosclerotic markers TGF-β, MMP2, MMP9, and Fractalkine. Further, High Glucose (HG) induced Akt, and ERK1/2 phosphorylation were enhanced or mitigated by endogenous Klotho deficiency or its overexpression respectively. PI3K/Akt and MAPK/ERK inhibition partially abolished the HG-induced upregulation of TGF-β, MMP2, MMP9, and Fractalkine. Additionally, Klotho knockdown increased the proliferation of HASMCs and enhanced α-SMA and TGF-β expression.

CONCLUSIONS

Taken together, these results indicate that local vascular Klotho is involved in diabetes-induced atherosclerosis, which is via PI3K/Akt and ERK1/2-dependent signaling pathways.

Inositol 1,4,5-Trisphosphate Receptors Regulate Vascular Smooth Muscle Cell Proliferation and Neointima Formation in Mice

BACKGROUND

Vascular smooth muscle cell (VSMC) proliferation is involved in many types of arterial diseases, including neointima hyperplasia, in which Ca2+ has been recognized as a key player. However, the physiological role of Ca2+ release via inositol 1,4,5-trisphosphate receptors (IP3Rs) from endoplasmic reticulum in regulating VSMC proliferation has not been well determined.

METHODS AND RESULTS

Both in vitro cell culture models and in vivo mouse models were generated to investigate the role of IP3Rs in regulating VSMC proliferation. Expression of all 3 IP3R subtypes was increased in cultured VSMCs upon platelet-derived growth factor-BB and FBS stimulation as well as in the left carotid artery undergoing intimal thickening after vascular occlusion. Genetic ablation of all 3 IP3R subtypes abolished endoplasmic reticulum Ca2+ release in cultured VSMCs, significantly reduced cell proliferation induced by platelet-derived growth factor-BB and FBS stimulation, and also decreased cell migration of VSMCs. Furthermore, smooth muscle-specific deletion of all IP3R subtypes in adult mice dramatically attenuated neointima formation induced by left carotid artery ligation, accompanied by significant decreases in cell proliferation and matrix metalloproteinase-9 expression in injured vessels. Mechanistically, IP3R-mediated Ca2+ release may activate cAMP response element-binding protein, a key player in controlling VSMC proliferation, via Ca2+/calmodulin-dependent protein kinase II and Akt. Loss of IP3Rs suppressed cAMP response element-binding protein phosphorylation at Ser133 in both cultured VSMCs and injured vessels, whereas application of Ca2+ permeable ionophore, ionomycin, can reverse cAMP response element-binding protein phosphorylation in IP3R triple knockout VSMCs.

CONCLUSIONS

Our results demonstrated an essential role of IP3R-mediated Ca2+ release from endoplasmic reticulum in regulating cAMP response element-binding protein activation, VSMC proliferation, and neointima formation in mouse arteries.

Matrix metallopeptidase 9 contributes to the beginning of plaque and is a potential biomarker for the early identification of atherosclerosis in asymptomatic patients with diabetes

Aims

To determine the roles of matrix metallopeptidase-9 (MMP9) on human coronary artery smooth muscle cells (HCASMCs) in vitro, early beginning of atherosclerosis in vivo in diabetic mice, and drug naïve patients with diabetes.

Methods

Active human MMP9 (act-hMMP9) was added to HCASMCs and the expressions of MCP-1, ICAM-1, and VCAM-1 were measured. Act-hMMP9 (n=16) or placebo (n=15) was administered to diabetic KK.Cg-Ay/J (KK) mice. Carotid artery inflammation and atherosclerosis measurements were made at 2 and 10 weeks after treatment. An observational study of newly diagnosed drug naïve patients with type 2 diabetes mellitus (T2DM n=234) and healthy matched controls (n=41) was performed and patients had ultrasound of carotid arteries and some had coronary computed tomography angiogram for the assessment of atherosclerosis. Serum MMP9 was measured and its correlation with carotid artery or coronary artery plaques was determined.

Results

In vitro, act-hMMP9 increased gene and protein expressions of MCP-1, ICAM-1, VCAM-1, and enhanced macrophage adhesion. Exogenous act-hMMP9 increased inflammation and initiated atherosclerosis in KK mice at 2 and 10 weeks: increased vessel wall thickness, lipid accumulation, and Galectin-3+ macrophage infiltration into the carotid arteries. In newly diagnosed T2DM patients, serum MMP9 correlated with carotid artery plaque size with a possible threshold cutoff point. In addition, serum MMP9 correlated with number of mixed plaques and grade of lumen stenosis in coronary arteries of patients with drug naïve T2DM.

Conclusion

MMP9 may contribute to the initiation of atherosclerosis and may be a potential biomarker for the early identification of atherosclerosis in patients with diabetes.

Clinical trial registration

https://clinicaltrials.gov, identifier NCT04424706.

Immunomodulatory activities and biomedical applications of melittin and its recent advances

Melittin (MLT), a peptide containing 26 amino acids, is a key constituent of bee venom. It comprises ∼40%-60% of the venom's dry weight and is the main pricing index for bee venom, being the causative factor of pain. The unique properties of MLT extracted from bee venom have made it a very valuable active ingredient in the pharmaceutical industry as this cationic and amphipathic peptide has propitious effects on human health in diverse biological processes. It has the ability to strongly impact the membranes of cells and display hemolytic activity with anticancer characteristics. However, the clinical application of MLT has been limited by its severe hemolytic activity, which poses a challenge for therapeutic use. By employing more efficient mechanisms, such as modifying the MLT sequence, genetic engineering, and nano-delivery systems, it is anticipated that the limitations posed by MLT can be overcome, thereby enabling its wider application in therapeutic contexts. This review has outlined recent advancements in MLT's nano-delivery systems and genetically engineered cells expressing MLT and provided an overview of where the MLTMLT's platforms are and where they will go in the future with the challenges ahead. The focus is on exploring how these approaches can overcome the limitations associated with MLT's hemolytic activity and improve its selectivity and efficacy in targeting cancer cells. These advancements hold promise for the creation of innovative and enhanced therapeutic approaches based on MLT for the treatment of cancer.

Induced pluripotent stem cell-derived exosomes attenuate vascular remodelling in pulmonary arterial hypertension by targeting HIF-1α and Runx2

AIMS

Pulmonary arterial hypertension (PAH) is characterized by extensive pulmonary arterial remodelling. Although mesenchymal stem cell (MSC)-derived exosomes provide protective effects in PAH, MSCs exhibit limited senescence during in vitro expansion compared with the induced pluripotent stem cells (iPSCs). Moreover, the exact mechanism is not known.

METHODS AND RESULTS

In this study, we used murine iPSCs generated from mouse embryonic fibroblasts with triple factor (Oct4, Klf4, and Sox2) transduction to determine the efficacy and action mechanism of iPSC-derived exosomes (iPSC-Exo) in attenuating PAH in rats with monocrotaline (MCT)-induced pulmonary hypertension. Both early and late iPSC-Exo treatment effectively prevented the wall thickening and muscularization of pulmonary arterioles, improved the right ventricular systolic pressure, and alleviated the right ventricular hypertrophy in MCT-induced PAH rats. Pulmonary artery smooth muscle cells (PASMC) derived from MCT-treated rats (MCT-PASMC) developed more proliferative and pro-migratory phenotypes, which were attenuated by the iPSC-Exo treatment. Moreover, the proliferation and migration of MCT-PASMC were reduced by iPSC-Exo with suppression of PCNA, cyclin D1, MMP-1, and MMP-10, which are mediated via the HIF-1α and P21-activated kinase 1/AKT/Runx2 pathways.

CONCLUSION

IPSC-Exo are effective at reversing pulmonary hypertension by reducing pulmonary vascular remodelling and may provide an iPSC-free therapy for the treatment of PAH.

Current Insights into Tissue Injury of Giant Cell Arteritis: From Acute Inflammatory Responses towards Inappropriate Tissue Remodeling

Giant cell arteritis (GCA) is an autoimmune disease affecting large vessels in patients over 50 years old. It is an exemplary model of a classic inflammatory disorder with IL-6 playing the leading role. The main comorbidities that may appear acutely or chronically are vascular occlusion leading to blindness and thoracic aorta aneurysm formation, respectively. The tissue inflammatory bulk is expressed as acute or chronic delayed-type hypersensitivity reactions, the latter being apparent by giant cell formation. The activated monocytes/macrophages are associated with pronounced Th1 and Th17 responses. B-cells and neutrophils also participate in the inflammatory lesion. However, the exact order of appearance and mechanistic interactions between cells are hindered by the lack of cellular and molecular information from early disease stages and accurate experimental models. Recently, senescent cells and neutrophil extracellular traps have been described in tissue lesions. These structures can remain in tissues for a prolonged period, potentially favoring inflammatory responses and tissue remodeling. In this review, current advances in GCA pathogenesis are discussed in different inflammatory phases. Through the description of these-often overlapping-phases, cells, molecules, and small lipid mediators with pathogenetic potential are described.

Perivascular CLICK-gelatin delivery of thrombospondin-2 small interfering RNA decreases development of intimal hyperplasia after arterial injury

Bypass graft failure occurs in 20%-50% of coronary and lower extremity bypasses within the first-year due to intimal hyperplasia (IH). TSP-2 is a key regulatory protein that has been implicated in the development of IH following vessel injury. In this study, we developed a biodegradable CLICK-chemistry gelatin-based hydrogel to achieve sustained perivascular delivery of TSP-2 siRNA to rat carotid arteries following endothelial denudation injury. At 21 days, perivascular application of TSP-2 siRNA embedded hydrogels significantly downregulated TSP-2 gene expression, cellular proliferation, as well as other associated mediators of IH including MMP-9 and VEGF-R2, ultimately resulting in a significant decrease in IH. Our data illustrates the ability of perivascular CLICK-gelatin delivery of TSP-2 siRNA to mitigate IH following arterial injury.

The contribution of matrix metalloproteinases and their inhibitors to the development, progression, and rupture of abdominal aortic aneurysms

Abdominal aortic aneurysms (AAAs) account for up to 8% of deaths in men aged 65 years and over and 2.2% of women. Patients with AAAs often have atherosclerosis, and intimal atherosclerosis is generally present in AAAs. Accordingly, AAAs are considered a form of atherosclerosis and are frequently referred to as atherosclerotic aneurysms. Pathological observations advocate inflammatory cell infiltration alongside adverse extracellular matrix degradation as key contributing factors to the formation of human atherosclerotic AAAs. Therefore, macrophage production of proteolytic enzymes is deemed responsible for the damaging loss of ECM proteins, especially elastin and fibrillar collagens, which characterise AAA progression and rupture. Matrix metalloproteinases (MMPs) and their regulation by tissue inhibitors metalloproteinases (TIMPs) can orchestrate not only ECM remodelling, but also moderate the proliferation, migration, and apoptosis of resident aortic cells, alongside the recruitment and subsequent behaviour of inflammatory cells. Accordingly, MMPs are thought to play a central regulatory role in the development, progression, and eventual rupture of abdominal aortic aneurysms (AAAs). Together, clinical and animal studies have shed light on the complex and often diverse effects MMPs and TIMPs impart during the development of AAAs. This dichotomy is underlined from evidence utilising broad-spectrum MMP inhibition in animal models and clinical trials which have failed to provide consistent protection from AAA progression, although more encouraging results have been observed through deployment of selective inhibitors. This review provides a summary of the supporting evidence connecting the contribution of individual MMPs to AAA development, progression, and eventual rupture. Topics discussed include structural, functional, and cell-specific diversity of MMP members; evidence from animal models of AAA and comparisons with findings in humans; the dual role of MMPs and the requirement to selectively target individual MMPs; and the advances in identifying aberrant MMP activity. As evidenced, our developing understanding of the multifaceted roles individual MMPs perform during the progression and rupture of AAAs, should motivate clinical trials assessing the therapeutic potential of selective MMP inhibitors, which could restrict AAA-related morbidity and mortality worldwide.

Regulation of cardiovascular health and disease by visceral adipose tissue-derived metabolic hormones

Visceral adipose tissue (VAT) is a metabolic organ known to regulate fat mass, and glucose and nutrient homeostasis. VAT is an active endocrine gland that synthesizes and secretes numerous bioactive mediators called 'adipocytokines/adipokines' into systemic circulation. These adipocytokines act on organs of metabolic importance like the liver and skeletal muscle. Multiple preclinical and in vitro studies showed strong evidence of the roles of adipocytokines in the regulation of metabolic disorders like diabetes, obesity and insulin resistance. Adipocytokines, such as adiponectin and omentin, are anti-inflammatory and have been shown to prevent atherogenesis by increasing nitric oxide (NO) production by the endothelium, suppressing endothelium-derived inflammation and decreasing foam cell formation. By inhibiting differentiation of vascular smooth muscle cells (VSMC) into osteoblasts, adiponectin and omentin prevent vascular calcification. On the other hand, adipocytokines like leptin and resistin induce inflammation and endothelial dysfunction that leads to vasoconstriction. By promoting VSMC migration and proliferation, extracellular matrix degradation and inflammatory polarization of macrophages, leptin and resistin increase the risk of atherosclerotic plaque vulnerability and rupture. Additionally, the plasma concentrations of these adipocytokines alter in ageing, rendering older humans vulnerable to cardiovascular disease. The disturbances in the normal physiological concentrations of these adipocytokines secreted by VAT under pathological conditions impede the normal functions of various organs and affect cardiovascular health. These adipokines could be used for both diagnostic and therapeutic purposes in cardiovascular disease.

Transcription factors: key regulatory targets of vascular smooth muscle cell in atherosclerosis

Atherosclerosis (AS), leading to gradual occlusion of the arterial lumen, refers to the accumulation of lipids and inflammatory debris in the arterial wall. Despite therapeutic advances over past decades including intervention or surgery, atherosclerosis is still the most common cause of cardiovascular diseases and the main mechanism of death and disability worldwide. Vascular smooth muscle cells (VSMCs) play an imperative role in the occurrence of atherosclerosis and throughout the whole stages. In the past, there was a lack of comprehensive understanding of VSMCs, but the development of identification technology, including in vivo single-cell sequencing technology and lineage tracing with the CreERT2-loxP system, suggests that VSMCs have remarkable plasticity and reevaluates well-established concepts about the contribution of VSMCs. Transcription factors, a kind of protein molecule that specifically recognizes and binds DNA upstream promoter regions or distal enhancer DNA elements, play a key role in the transcription initiation of the coding genes and are necessary for RNA polymerase to bind gene promoters. In this review, we highlight that, except for environmental factors, VSMC genes are transcriptionally regulated through complex interactions of multiple conserved cis-regulatory elements and transcription factors. In addition, through a series of transcription-related regulatory processes, VSMCs could undergo phenotypic transformation, proliferation, migration, calcification and apoptosis. Finally, enhancing or inhibiting transcription factors can regulate the development of atherosclerotic lesions, and the downstream molecular mechanism of transcriptional regulation has also been widely studied.

The Role of Matrix Metalloproteinase in Inflammation with a Focus on Infectious Diseases

Matrix metalloproteinases (MMPs) are involved in extracellular matrix remodeling through the degradation of extracellular matrix components and are also involved in the inflammatory response by regulating the pro-inflammatory cytokines TNF-α and IL-1β. Dysregulation in the inflammatory response and changes in the extracellular matrix by MMPs are related to the development of various diseases including lung and cardiovascular diseases. Therefore, numerous studies have been conducted to understand the role of MMPs in disease pathogenesis. MMPs are involved in the pathogenesis of infectious diseases through a dysregulation of the activity and expression of MMPs. In this review, we discuss the role of MMPs in infectious diseases and inflammatory responses. Furthermore, we present the potential of MMPs as therapeutic targets in infectious diseases.

Endothelial Foxp1 Regulates Neointimal Hyperplasia Via Matrix Metalloproteinase-9/Cyclin Dependent Kinase Inhibitor 1B Signal Pathway

Background The endothelium is essential for maintaining vascular physiological homeostasis and the endothelial injury leads to the neointimal hyperplasia because of the excessive proliferation of vascular smooth muscle cells. Endothelial Foxp1 (forkhead box P1) has been shown to control endothelial cell (EC) proliferation and migration in vitro. However, whether EC-Foxp1 participates in neointimal formation in vivo is not clear. Our study aimed to investigate the roles and mechanisms of EC-Foxp1 in neointimal hyperplasia. Methods and Results The wire injury femoral artery neointimal hyperplasia model was performed in Foxp1 EC-specific loss-of-function and gain-of-function mice. EC-Foxp1 deletion mice displayed the increased neointimal formation through elevation of vascular smooth muscle cell proliferation and migration, and the reduction of EC proliferation hence reendothelialization after injury. In contrast, EC-Foxp1 overexpression inhibited the neointimal formation. EC-Foxp1 paracrine regulated vascular smooth muscle cell proliferation and migration via targeting matrix metalloproteinase-9. Also, EC-Foxp1 deletion impaired EC repair through reduction of EC proliferation via increasing cyclin dependent kinase inhibitor 1B expression. Delivery of cyclin dependent kinase inhibitor 1B-siRNA to ECs using RGD (Arg-Gly-Asp)-peptide magnetic nanoparticle normalized the EC-Foxp1 deletion-mediated impaired EC repair and attenuated the neointimal formation. EC-Foxp1 regulates matrix metalloproteinase-9/cyclin dependent kinase inhibitor 1B signaling pathway to control injury induced neointimal formation. Conclusions Our study reveals that targeting EC-Foxp1-matrix metalloproteinase-9/cyclin dependent kinase inhibitor 1B pathway might provide future novel therapeutic interventions for restenosis.

CaMKII Splice Variants in Vascular Smooth Muscle Cells: The Next Step or Redundancy?

Vascular smooth muscle cells (VSMCs) help to maintain the normal physiological contractility of arterial vessels to control blood pressure; they can also contribute to vascular disease such as atherosclerosis. Ca²⁺/calmodulin-dependent kinase II (CaMKII), a multifunctional enzyme with four isoforms and multiple alternative splice variants, contributes to numerous functions within VSMCs. The role of these isoforms has been widely studied across numerous tissue types; however, their functions are still largely unknown within the vasculature. Even more understudied is the role of the different splice variants of each isoform in such signaling pathways. This review evaluates the role of the different CaMKII splice variants in vascular pathological and physiological mechanisms, aiming to show the need for more research to highlight both the deleterious and protective functions of the various splice variants.

The Compatibility of Alisma and Atractylodes Affects the Biological Behaviours of VSMCs by Inhibiting the miR-128-5p/p21 Gene

Objective

The compatibility of Alisma and Atractylodes (AA) has been estimated to exhibit antiatherosclerotic effects, but the mechanism remains unclear. This study aimed to identify the role of AA in oxidized low-density lipoprotein (ox-LDL)-induced vascular smooth muscle cell (VSMC) behaviours and to explore the effects of microRNAs (miRNAs).

Methods

A scratch wound-healing assay was used to detect the migration of VSMCs, and immunocytochemistry and western blotting for SM22ɑ were used to evaluate phenotypic transformation. Bromodeoxyuridine (BrdU) immunocytochemistry and flow cytometry were applied to detect the proliferation of VSMCs. miRNA microarray profiling was performed using Lianchuan biological small RNA sequencing analysis. VSMCs were transfected with the miR-128-5p mimic and inhibitor, and the migration, phenotypic modulation, and proliferation of VSMCs were investigated. The 3'UTR-binding sequence site of miR-128-5p on the p21 gene was predicted and assessed by luciferase assays.

Result

AA and the extracellular regulated protein kinase 1/2 (ERK1/2) blocker U0126 markedly inhibited migration, elevated smooth muscle 22α (SM22α) expression, repressed VSMC proliferation, elevated miR-466f-3p and miR-425-3p expression, and suppressed miR-27a-5p and miR-128-5p expression in ox-LDL-induced VSMCs. miR-128-5p targets the tissue inhibitor of metalloproteinases (TIMPs), silent information regulator 2 (SIRT2), peroxisome proliferator-activated receptor (PPAR), and p21 genes, which are linked to the behaviours of VSMCs. The miR-128-5p mimic promoted the migration and proliferation of VSMCs and suppressed p21, p27, and SM22ɑ expression. The inhibitor increased p21, p27, and SM22ɑ expression and repressed the migration, phenotypic transformation, and proliferation of VSMCs. miR-128-5p directly targeted the 3'UTR-binding sequences of the p21 gene, negatively regulated p21 expression, and supported the proliferation of VSMCs.

Conclusion

Our research showed that the migration, phenotypic transformation, and proliferation of ox-LDL-induced VSMCs were repressed by AA through inhibiting miR-128-5p by targeting the p21 gene, which may provide an effective option for the treatment of atherosclerosis.

The Effect of Chronic Immunosuppressive Regimens Treatment on Aortal Media Morphology and the Balance between Matrix Metalloproteinases (mmp-2 and mmp-9) and Their Inhibitors in the Abdominal Aorta of Rats

Immunosuppressive drugs are widely and chronically used to avoid graft rejection in transplant recipients. However, they are also known to have organotoxic effects and can exert numerous side effects. The aim of this study was to assess whether the chronic treatment of rats with the most commonly used clinical immunosuppressive regimens in organ recipients had an effect on the morphology and function of the aorta. The rats were divided into five groups and each group was chronically treated with different sets of three immunosuppressive drugs (TRG, CRG, MRG, CMG, TMG) for 6 months. The changes were most profound in calcineurin inhibitor-based protocols. TMG protocol treatment was characterized by the most numerous alterations such as morphological changes, changes in the thickness of the tunic media, wider distances between elastic lamellae, an increase in the number of vSMCs and changes in collagen deposition. We concluded that the morphological changes were connected with MMP-2 and MMP-9/TIMP-2 and TIMP-1 imbalances, which was also determined and noticed.

Combination release of chemokines from coated coils to target aneurysm healing

BACKGROUND

Monocyte chemoattractant protein 1 (MCP-1) and osteopontin (OPN) have been identified separately as key mediators of the aneurysm healing process following coil embolization in the rodent model. The ability of protein coated coils to accelerate this process is currently unknown.To create coils coated with both MCP-1 and OPN to target aneurysm healing.

METHODS

We uses a polymer (poly(glycolide-co-caprolactone)) (Rao pharmaceuticals) (CG910) to test whether coils could be dual coated with active proteins with sequential reliable release. Coils were coated with poly-DL-lactic glycolic acid (PLGA), CG910, and subsequently dipped with protein OPN (inner layer for delayed release) and MCP-1 (outer layer for initial release). Release assays were used to measure protein elution from coils over time. To test in vivo feasibility, coated coils were implanted into carotid aneurysms to determine the effect on aneurysm healing.

RESULTS

The in vitro protein release assay demonstrated, a significant amount of OPN and MCP-1 release within 2 days. Using a 200 µg/µL solution of MCP-1 in phosphate-buffered saline, we showed that CG910 coated coils provide effective release of MCP over time. In the carotid aneurysm model, MCP-1 and OPN coated coils significantly increased tissue ingrowth (74% and 80%) compared with PLGA and CG910 coated coils alone (58% and 53%). To determine synergistic impact of dual coating, we measured ingrowth for MCP-1/OPN coils (63%) as well as overlap coefficients for NOX4 and NFκB with CD31.

CONCLUSIONS

This study demonstrates that MCP-1 and OPN coated coils are viable and may promote early aneurysm healing. Dual coated coils may have synergistic benefit given different location of protein interaction measured in vivo. Further work is warranted.

MMP9: A Tough Target for Targeted Therapy for Cancer

Having the capability to proteolyze diverse structural and signaling proteins, matrix metalloproteinase 9 (MMP9), one of the best-studied secretory endopeptidases, has been identified as a crucial mediator of processes closely associated with tumorigenesis, such as the extracellular matrix reorganization, epithelial to mesenchymal transition, cell migration, new blood vessel formation, and immune response. In this review, we present the current state of knowledge on MMP9 and its role in cancer growth in the context of cell adhesion/migration, cancer-related inflammation, and tumor microenvironment formation. We also summarize recent achievements in the development of selective MMP9 inhibitors and the limitations of using them as anticancer drugs.

Assessment of Carotid Plaque Stability Using Contrast-Enhanced Ultrasound and Its Correlation With the Expression of CD147 and MMP-9 in the Plaque

This study aims to investigate the correlation between the enhancement degree of contrast-enhanced ultrasound (CEUS) and the expression of CD147 and MMP-9 in carotid atherosclerotic plaques in patients with carotid endarterectomy and evaluate the diagnostic efficacy of CEUS using pathological results as the gold standard. Thirty-eight patients who underwent carotid endarterectomy (CEA) for carotid stenosis in the Department of Neurovascular Surgery of the Second People’s Hospital of Shenzhen from July 2019 to June 2020 were selected. Preoperatively, two-dimensional (2D) ultrasound scan was performed on all patients to assess the characteristics of the plaque and degree of stenosis, and CEUS was used to evaluate the surface morphology of the plaque and the distribution of neovascularization. Postoperatively, pathological sections and immunohistochemical analysis of CD147 and MMP-9 levels in the plaque were performed on the stripped plaque tissue, and the results were analyzed against the CEUS grading and pathological results. Among the 38 patients, pathological results showed that 10 and 28 were in the stable and vulnerable plaque groups, respectively. There were more smokers in the vulnerable plaque group than in the stable plaque group, with higher intraplaques CD147 and MMP-9. The difference in ultrasound plaque surface morphology grading and CEUS grading between the two groups was statistically significant. There was no significant difference in age, sex, incidence of complications such as hypertension, diabetes, and coronary heart disease between the two groups. CD147 was higher in the CEUS grade IV group than in the grades I (P = 0.040) and II (P = 0.010) groups. MMP-9 was higher in the CEUS grade IV group than in the grade II group (P = 0.017); MMP-9 was higher in the grade III group than in the grade II group (P = 0.015). Intraplaque contrast enhancement intensity was positively correlated with CD147 (r = 0.462, P = 0.003) and MMP-9 (r = 0.382, P = 0.018) levels. There was moderate consistency between the assessment of plaque vulnerability by 2D-ultrasound and by histopathological hematoxylin-eosin (HE) (kappa = 0.457, P > 0.05). 2D diagnosis of vulnerable plaque had a sensitivity of 85.7%, a specificity of 60.0%, a positive predictive value of 85.7%, a negative predictive value of 60.0%, and an accuracy of 78.0%. There was a strong consistency between the assessment of plaque vulnerability by CEUS and histopathological HE (kappa = 0.671, P < 0.01). CEUS had a sensitivity of 89.2%, a specificity of 80.0%, a positive predictive value of 92.6%, a negative predictive value of 72.7%, and an accuracy of 86.8% for the diagnosis of vulnerable plaques; CEUS is a reliable, non-invasive test that can show the distribution of neovascularization within vulnerable plaques, evaluate the vulnerability and risk of intraplaque hemorrhage, with a high consistency with pathological findings. The degree of intraplaque enhancement and the levels of CD147 and MMP-9 in the tissue were positively correlated.

A collagen I derived matricryptin increases aorta vascular wall remodeling after induced thrombosis in mouse

Matricryptins are collagen fragments proteolytically released from the extracellular matrix (ECM) with biological activity that can regulate several processes involved in ECM remodeling. Vessel wall matrix reorganization after lesion is important to the recovery of vascular function. This study aimed to analyze the effect of the peptide p1158/59 (Lindsey, 2015) on thrombosis, neointimal formation, and vascular remodeling of C57BL6 mice abdominal aorta. We used a FeCl₃ induced vascular injury mice model and analyzed thrombus size, neointima formation, gelatinase activities in situ, re-endothelization, and collagen fibers organization on the arterial wall using polarization microscopy. As result, we observed that 2 days after injury the treatment with p1158/59 increased thrombus size and gelatinase activity, vascular lesion and it did not recover the endothelium loss induced by the chemical injury. We also observed that the peptide increased neointima growth and collagen birefringence, indicating collagen fibers reorganization. It also promoted increased re-endothelization and decreased activity of gelatinases 14 days after injury. Thus, we conclude that the peptide p1158/59 impaired the initial thrombosis recovery 2 days after injury but was able to induce vascular ECM remodeling after 14 days, improving vessel re-endothelization, collagen fibers deposition, and organization.

Disparate effects of MMP and TIMP modulation on coronary atherosclerosis and associated myocardial fibrosis

Matrix metalloproteinase (MMP) activity is tightly regulated by the endogenous tissue inhibitors (TIMPs), and dysregulated activity contributes to extracellular matrix remodelling. Accordingly, MMP/TIMP balance is associated with atherosclerotic plaque progression and instability, alongside adverse post-infarction cardiac fibrosis and subsequent heart failure. Here, we demonstrate that prolonged high-fat feeding of apolipoprotein (Apo)e-deficient mice triggered the development of unstable coronary artery atherosclerosis alongside evidence of myocardial infarction and progressive sudden death. Accordingly, the contribution of select MMPs and TIMPs to the progression of both interrelated pathologies was examined in Apoe-deficient mice with concomitant deletion of Mmp7, Mmp9, Mmp12, or Timp1 and relevant wild-type controls after 36-weeks high-fat feeding. Mmp7 deficiency increased incidence of sudden death, while Mmp12 deficiency promoted survival, whereas Mmp9 or Timp1 deficiency had no effect. While all mice harboured coronary disease, atherosclerotic burden was reduced in Mmp7-deficient and Mmp12-deficient mice and increased in Timp1-deficient animals, compared to relevant controls. Significant differences in cardiac fibrosis were only observed in Mmp-7-deficient mice and Timp1-deficient animals, which was associated with reduced capillary number. Adopting therapeutic strategies in Apoe-deficient mice, TIMP-2 adenoviral-overexpression or administration (delayed or throughout) of a non-selective MMP inhibitor (RS-130830) had no effect on coronary atherosclerotic burden or cardiac fibrosis. Taken together, our findings emphasise the divergent roles of MMPs on coronary plaque progression and associated post-MI cardiac fibrosis, highlighting the need for selective therapeutic approaches to target unstable atherosclerosis alongside adverse cardiac remodelling while negating detrimental adverse effects on either pathology, with targeting of MMP-12 seeming a suitable target.

Esculetin: A review of its pharmacology and pharmacokinetics

Esculetin is a natural dihydroxy coumarin; it is mainly extracted from twig skin and the trunk bark of the Chinese herbal medicine Fraxinus rhynchophylla Hance. Emerging evidence suggests that esculetin has a wide range of pharmacological activities. Based on its fundamental properties, including antioxidant, antiinflammatory, antiapoptotic, anticancer, antidiabetic, neuroprotective, and cardiovascular protective activities, as well as antibacterial activity, among others, esculetin is expected to be a therapeutic drug for specific disease indications, such as cancer, diabetes, atherosclerosis, Alzheimer's disease (AD), Parkinson's disease (PD), nonalcoholic fatty liver disease (NAFLD), and other diseases. The oral bioavailability of esculetin was shown by studies to be low. The extensive glucuronidation was described to be the main metabolic pathway of esculetin and C-7 phenolic hydroxyl to be its major metabolic site. With the development of scientific research technology, the pharmacological effects of esculetin are identified and its potential for the treatment of diseases is demonstrated. The underlining mechanisms of action and biological activities as well as the pharmacokinetic data of the analyzed compound reported so far are highlighted in this review with the aim of becoming a proven, and applicable insight and reference for further studies on the utilization of esculetin.

Anti-Atherosclerotic Effect of Gossypetin on Abnormal Vascular Smooth Muscle Cell Proliferation and Migration

Gossypetin (GTIN), known as 3,5,7,8,3′,4′-hexahydroxyflavone, has been demonstrated to exert anti-atherosclerotic potential against apoptotic injury in oxidized low-density lipoprotein-incubated endothelial cells, and atherosclerotic lesions of cholesterol-fed rabbits. However, the effect and underlying mechanism of GTIN on abnormal vascular smooth muscle cells (VSMCs) proliferation and migration, a major event in the pathogenesis of atherosclerosis, is still unknown. In this study, non-cytotoxic doses of GTIN abolished the VSMCs A7r5 proliferation and cell-cycle S phase distribution. The GTIN-arrested G0/G1 phase might be performed by increasing the expressions of phosphorylated p53 and its downstream molecules that inhibit the activation of cyclin E/cyclin-dependent kinase (cdk)-2, blocking retinoblastoma protein (Rb) phosphorylation and the subsequent dissociation of Rb/transcription factor E2F1 complex. In addition, the results indicated that GTIN inhibited VSMCs wound-healing and migratory abilities through reducing matrix metalloproteinase (MMP)-9 activity and expression, as well as down-regulating protein kinase B (PKB)/nuclear factor-kappaB (NF-κB) signaling. GTIN also revealed potential in diminishing reactive oxygen species (ROS) generation. These findings suggested the inhibitory effects of GTIN on VSMCs dysfunction could likely lead to the containment of atherosclerosis and other cardiovascular illness.

Preventive Effect and Mechanism of Crossostephium chinense Extract on Balloon Angioplasty-Induced Neointimal Hyperplasia

Balloon angioplasty-induced neointimal hyperplasia remains a clinical problem that must be resolved. The bioactivities of the Crossostephium chinense extract (CCE) have demonstrated potential in preventing the progression of restenosis. The present study evaluated whether CCE can suppress balloon angioplasty-induced neointima formation and elucidated its possible pharmacological mechanisms. A rat model of carotid arterial balloon angioplasty was established to evaluate the inhibitory effect of CCEs on neointimal hyperplasia. Two cell lines, A10 vascular smooth muscle cells (VSMCs) and RAW264.7 macrophages, were used to investigate the potential regulatory activities and pharmacological mechanisms of CCEs in cell proliferation and migration and in inflammation. Our in vitro results indicated that CCE3, the ethanolic extract of C. chinense, exerted the strongest growth inhibitory and antimigratory effects on VSMCs. CCE3 blocked the activation of focal adhesion kinase, platelet-derived growth factor receptor-β (PDGFRB), and its downstream molecules (AKT and mTOR) and reduced the expression of matrix metalloproteinase-2. In addition, our findings revealed that CCE3 significantly increased the expression of miRNA-132, an inhibitory regulator of inflammation and restenosis, and suppressed the expression of inflammation-related molecules (inducible nitric oxide synthase, cyclooxygenase-2, interleukin- (IL-) 1β, and IL-6). Our in vivo study results indicated that balloon injury-induced neointimal hyperplasia was inhibited by CCE3. CCE3 could reduce neointima formation in balloon-injured arteries, and this effect may be partially attributed to the CCE3-induced suppression of PDGFRB-mediated downstream pathways and inflammation-related molecules.

Mechanisms of Lower Extremity Vein Dysfunction in Chronic Venous Disease and Implications in Management of Varicose Veins

Chronic venous disease (CVD) is a common venous disorder of the lower extremities. CVD can be manifested as varicose veins (VVs), with dilated and tortuous veins, dysfunctional valves and venous reflux. If not adequately treated, VVs could progress to chronic venous insufficiency (CVI) and lead to venous leg ulcer (VLU). Predisposing familial and genetic factors have been implicated in CVD. Additional environmental, behavioral and dietary factors including sedentary lifestyle and obesity may also contribute to CVD. Alterations in the mRNA expression, protein levels and proteolytic activity of matrix metalloproteinases (MMPs) have been detected in VVs and VLU. MMP expression/activity can be modulated by venous hydrostatic pressure, hypoxia, tissue metabolites, and inflammation. MMPs in turn increase proteolysis of different protein substrates in the extracellular matrix particularly collagen and elastin, leading to weakening of the vein wall. MMPs could also promote venous dilation by increasing the release of endothelium-derived vasodilators and activating potassium channels, leading to smooth muscle hyperpolarization and relaxation. Depending on VVs severity, management usually includes compression stockings, sclerotherapy and surgical removal. Venotonics have also been promoted to decrease the progression of VVs. Sulodexide has also shown benefits in VLU and CVI, and recent data suggest that it could improve venous smooth muscle contraction. Other lines of treatment including induction of endogenous tissue inhibitors of metalloproteinases (TIMPs) and administration of exogenous synthetic inhibitors of MMPs are being explored, and could provide alternative strategies in the treatment of CVD.

MMP-9 Deletion Attenuates Arteriovenous Fistula Neointima through Reduced Perioperative Vascular Inflammation

Matrix metalloproteinase 9 (MMP-9) expression is upregulated in vascular inflammation and participates in vascular remodeling, including aneurysm dilatation and arterial neointima development. Neointima at the arteriovenous (AV) fistula anastomosis site primarily causes AV fistula stenosis and failure; however, the effects of MMP-9 on perioperative AV fistula remodeling remain unknown. Therefore, we created AV fistulas (end-to-side anastomosis) in wild-type (WT) and MMP-9 knockout mice with chronic kidney disease to further clarify this. Neointima progressively developed in the AV fistula venous segment of WT mice during the four-week postoperative course, and MMP-9 knockout increased the lumen area and attenuated neointima size by reducing smooth muscle cell and collagen components. Early perioperative AV fistula mRNA sequencing data revealed that inflammation-related gene sets were negatively enriched in AV fistula of MMP-9 knockout mice compared to that in WT mice. qPCR results also showed that inflammatory genes, including tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1), were downregulated. In addition, Western blot results showed that MMP-9 knockout reduced CD44 and RAC-alpha serine/threonine-protein kinase (Akt) and extracellular signal-regulated kinases (ERK) phosphorylation. In vitro, MMP-9 addition enhanced IL-6 and MCP-1 expression in vascular smooth muscle cells, as well as cell migration, which was reversed by an MMP-9 inhibitor. In conclusion, MMP-9 knockout attenuated AV fistula stenosis by reducing perioperative vascular inflammation.

Platelet-Derived Extracellular Vesicles Increase Col8a1 Secretion and Vascular Stiffness in Intimal Injury

The arterial mechanical microenvironment, including stiffness, is a crucial pathophysiological feature of vascular remodeling, such as neointimal hyperplasia after carotid endarterectomy and balloon dilatation surgeries. In this study, we examined changes in neointimal stiffness in a Sprague-Dawley rat carotid artery intimal injury model and revealed that extracellular matrix (ECM) secretion and vascular stiffness were increased. Once the endothelial layer is damaged in vivo, activated platelets adhere to the intima and may secrete platelet-derived extracellular vesicles (pEVs) and communicate with vascular smooth muscle cells (VSMCs). In vitro, pEVs stimulated VSMCs to promote collagen secretion and cell adhesion. MRNA sequencing analysis of a carotid artery intimal injury model showed that ECM factors, including col8a1, col8a2, col12a1, and elastin, were upregulated. Subsequently, ingenuity pathway analysis (IPA) was used to examine the possible signaling pathways involved in the formation of ECM, of which the Akt pathway played a central role. In vitro, pEVs activated Akt signaling through the PIP₃ pathway and induced the production of Col8a1. MicroRNA (miR) sequencing of pEVs released from activated platelets revealed that 14 of the top 30 miRs in pEVs targeted PTEN, which could promote the activation of the Akt pathway. Further research showed that the most abundant miR targeting PTEN was miR-92a-3p, which promoted Col8a1 expression. Interestingly, knockdown of Col8a1 expression in vivo abrogated the increase in carotid artery stiffness and simultaneously increased the degree of neointimal hyperplasia. Our results revealed that pEVs may deliver miR-92a-3p to VSMCs to induce the production and secretion of Col8a1 via the PTEN/PIP3/Akt pathway, subsequently increasing vascular stiffness. Therefore, pEVs and key molecules may be potential therapeutic targets for treating neointimal hyperplasia.

Blood Biomarkers for Monitoring and Prognosis of Large Vessel Vasculitides

PURPOSE OF REVIEW

Large vessel vasculitides (LVVs) are inflammatory conditions of the wall of large-sized arteries, mainly represented by giant cell arteritis (GCA) and Takayasu arteritis (TA). The inflammatory process within the vessel wall can lead to serious consequences such as development of aneurysms, strokes and blindness; therefore, early diagnosis and follow-up of LVV are fundamental. However, the arterial wall is poorly accessible and blood biomarkers are intended to help physicians not only in disease diagnosis but also in monitoring and defining the prognosis of these conditions, thus assisting therapeutic decisions and favouring personalised management. The field is the object of intense research as the identification of reliable biomarkers is likely to shed light on the mechanisms of disease progression and arterial remodelling. In this review, we will discuss the role of blood biomarkers in LVVs in the light of the latest evidence.

RECENT FINDINGS

In clinical practice, the most widely performed laboratory investigations are the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). However, these indices may be within normal limits during disease relapse and they are not reliable in patients receiving interleukin-6 (IL-6) receptor inhibitors. New biomarkers struggle to gain traction in clinical practice and no molecule with good accuracy has been identified to date. IL-6, a pro-inflammatory cytokine that drives CRP synthesis and increases the ESR, is one of the most promising biomarkers in the field. IL-6 analysis is increasingly performed, and serum levels are more sensitive than ESR for active GCA and might reflect persistent inflammation with high risk of relapse in patients on IL-6 receptor inhibitors. A future with biomarkers that reflect different disease features is an important aspiration. Accordingly, intense effort is being made to identify IL-6-independent inflammatory biomarkers, such as S100 proteins, pentraxin-3 and osteopontin. Moreover, metalloproteinases such as MMP2/9 and angiogenic modulators such as VEGF, YLK-40 and angiopoietins are being studied as markers of arterial remodelling. Lastly, biomarkers indicating organ damage may guide prognostic stratification as well as emergency therapeutic decisions: the most promising biomarkers so far identified are NT-proBNP, which reflects myocardial strain; pentraxin-3, which has been associated with recent optic nerve ischemia; and endothelin-1, which is associated with ischaemic complications. Currently, the use of these molecules in clinical practice is limited because of their restricted availability, lack of sufficient studies supporting their validity and associated costs. Further evidence is required to better interpret their biological and clinical value.

Glucagon-like peptide-1 receptor agonist reduces di(2-ethylhexyl) phthalate-induced atherosclerotic processes in vascular smooth muscle cells

Glucagon-like peptide-1 receptor (GLP1R) agonist is an incretin hormone and regulates glucose metabolism. However, phthalates, known as endocrine disruptors, can interfere with hormone homeostasis. In the present study, we aimed to estimate the impact of GLP1R agonist on di(2 ethylhexyl) phthalate (DEHP)-induced atherosclerosis. For this purpose, the effects of GLP1R agonist on various atherogenesis-related cellular processes and pathways were assessed in vascular smooth muscle cells (VSMCs). DEHP-induced cell proliferation and migration were significantly decreased by GLP1R agonist in VSMCs. Protein levels of matrix metalloproteinase (MMP)-2 and MMP-9 were significantly decreased in cells exposed to GLP1R agonist, compared with DEHP-treated cells. Expression levels of intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 were also reduced in GLP1R agonist-treated cells. Similarly, DEHP-associated phosphorylation of protein kinase B and extracellular signal-regulated kinase 1/2 was decreased in GLP1R agonist-treated cells, compared with DEHP-treated cells. Our findings suggest that treatment with GLP1R agonist counteracts the activation of pathways related to atherosclerosis.

Proliferation of Vascular Smooth Muscle Cells under ox-LDL Is Regulated by Alismatis rhizoma Decoction via InhibitingERK1/2 and miR-17∼92a Cluster Activation

Context: Alismatis rhizome decoction (AD) exhibits antiatherosclerotic activities. The activity of AD against vascular smooth muscle cell (VSMC) proliferation remains unclear. Objective. The mechanisms and effects of AD on oxidized low-density lipoprotein (ox-LDL)-induced VSMC proliferation were explored. Materials and methods. The male SD rats were fed with AD (2.56 g/mL) or 0.9% NaCl by oral gavage 4 mL twice daily for 7 d. Then, AD-containing serum (ADcs) was collected. MTS assay was applied to measure the VSMC viability. The proliferation of VSMCs was detected by 5-bromodeoxyuridine (BrdU) immunocytochemistry. The microRNA (miRNA) profiling was performed, and the target genes of miRNAs were searched from the TargetScan 7.2 database. The expressions of matrix metalloproteinases-2/9 (MMP-2/9), cyclin D1/E, cyclin-dependent kinase inhibitor 1B (p27), extracellular regulated protein kinases 1/2 (ERK1/2), and ERK1/2 phosphorylation were examined by western blotting or quantitative reverse transcription PCR. Results. The ox-LDL-induced miR-17-92a expression promoted VSMC proliferation. AD and the ERK1/2 inhibitor U0126 (10 μmol/L) inhibited VSMC proliferation and reduced the overexpression of miR-17∼92a. AD was found to inhibit phosphorylation of ERK1/2 and reduced the expression of MMP-2/9 in VSMCs. The expression of cyclin D1/E was suppressed, and p27 was elevated following treatment with AD as well as ERK1/2 inhibitor. According to the TargetScan 7.2 database, the target genes of miR-17∼92a act on tissue inhibitors of metalloproteinases (TIMPs)-MMPs, p27/21 cyclins, and peroxisome-proliferator-activated receptor α (PPARα) ATP-binding cassette transporter (ABC) A1/G1, which are involved in the process of atherosclerosis. Conclusions. AD inhibits ox-LDL-induced VSMC proliferation via inhibiting ERK1/2 and miR-17∼92a activation. The results provide the multitarget mechanisms for application of AD in the treatment of atherosclerosis. It would be helpful to the treatment of cardiovascular and cerebral diseases.

Carnosine Impedes PDGF-Stimulated Proliferation and Migration of Vascular Smooth Muscle Cells In Vitro and Sprout Outgrowth Ex Vivo

Carnosine, a naturally producing dipeptide, exhibits various beneficial effects. However, the possible role of carnosine in vascular disorders associated with pathological conditions, including proliferation and migration of vascular smooth muscle cells (VSMCs), largely remains unrevealed. Here, we investigated the regulatory role and mechanism of carnosine in platelet-derived growth factor (PDGF)-induced VSMCs. Carnosine inhibited the proliferation of PDGF-induced VSMCs without any cytotoxic effects. Carnosine treatment also induced G1-phase cell cycle arrest by causing a p21WAF1-mediated reduction in the expression of both cyclin-dependent kinases (CDKs) and cyclins in PDGF-treated VSMCs. Carnosine treatment suppressed c-Jun N-terminal kinase (JNK) phosphorylation in PDGF-stimulated signaling. Additionally, carnosine significantly prevented the migration of VSMCs exposed to PDGF. Carnosine abolished matrix metalloproteinase (MMP)-9 activity via reduced transcriptional binding activity of NF-κB, Sp-1, and AP-1 motifs in PDGF-treated VSMCs. Moreover, using aortic assay ex vivo, it was observed that carnosine addition attenuated PDGF-stimulated sprout outgrowth of VSMCs. Taken together, these results demonstrated that carnosine impeded the proliferation and migration of PDGF-stimulated VSMCs by regulating cell cycle machinery, JNK signaling, and transcription factor-mediated MMP-9 activity as well as prevented ex vivo sprout outgrowth of blood vessels. Thus, carnosine may be a potential candidate for preventing vascular proliferative disease.

Identification and validation of four hub genes involved in the plaque deterioration of atherosclerosis

In recent years, intense research has been conducted to explore the diagnostic value of mRNA expression differences in atherosclerosis (AS). Nevertheless, because various technology platforms are applied and sample sizes are small, the results are inconsistent among the studies. We conducted a comprehensive analysis of a total of 161 tissue samples from 4 published studies after evaluating 230 datasets from the Gene Expression Omnibus and ArrayExpress. Adopting the newly published robust rank aggregation approach, combined with Kyoto Encyclopedia of Genes and Genomes pathway analysis, Gene Ontology functional enrichment analysis, and protein-protein interaction network construction, we identified four significantly upregulated genes (CCL4, CCL18, MMP9 and SPP1) for diagnosing AS, even in the advanced stage. Then, we performed gene set enrichment analysis to identify the pathways that were most affected by altered mRNA expression in atherosclerotic plaques. We found that four hub genes cooperatively targeted lipid metabolism and inflammatory immune-related pathways and validated their high expression levels in ruptured plaques by qRT-PCR, western blot analysis and immunohistochemical staining. In summary, our study showed that these genes can be used as interventional targets for plaque progression, and the results suggested we should focus on small changes in these key indicators in the clinical setting.

STRIP2 silencing inhibits vascular smooth muscle cell proliferation and migration via P38-AKT-MMP-2 signaling pathway

STRIP2 (FAM40B) was reported to regulate tumor cell migration. Our study aims to discuss the effect of STRIP2 in mouse aortic smooth muscle cell (MOVAS) proliferation and migration processes, which contributes greatly to atherosclerosis formation. In MOVAS cells, STRIP2 depletion suppressed cell proliferation and migration, which were related to a remarkable decrease in matrix metalloproteinases-2 (MMP-2)/MMP-9 expression. Additionally, P38 mitogen-activated protein kinases and Protein kinase B (AKT) are inactivated while extracellular signal-regulated kinase (ERK1/2) and jun N-terminal kinase (JNK) are activated upon STRIP2 silencing. SB203580 (P38 inhibitor) further reduced AKT phosphorylation (p-AKT) while dehydrocorydaline chloride (Dc; P38 activator) reversed this effect. Furthermore, Dc significantly recovered MMP-2 expression in STRIP2-knockdown cells. As expected, overexpressing STRIP2 exhibited a contrary effect. Dc and AKT activator SC79 reversed the inhibition of cell proliferation and migration induced by STRIP2 silencing. Interestingly, STRIP2 depletion increased vascular endothelial growth factor level significantly. Taken together, STRIP2 contributed to cell proliferation and migration through P38-AKT-MMP-2 signaling in MOVAS cells, indicating the importance of STRIP2 in atherosclerosis.

Downregulation of the transcriptional co-activator PCAF inhibits the proliferation and migration of vascular smooth muscle cells and attenuates NF-κB-mediated inflammatory responses

P300/CBP-associated factor (PCAF) regulates vascular inflammation. This study was to explore the effect of PCAF on the proliferation and migrationof vascular smooth muscle cells (VSMCs) and neointimal hyperplasia in balloon-injured rat carotid artery. Downregulation of PCAF remarkably suppressed VSMCs proliferation and migration induced by lipopolysaccharide, and also significantly inhibit the nuclear translocation of nuclear factor-kappaB p65. Meanwhile, downregulation of PCAF inhibited the mRNA expression of tumor necrosis factor-α and interleukin-6, and also the levels in culture supernatants. Moreover, downregulation of PCAF profoundly reduced the intima area and the ratio of intima area to media area in balloon-injured rat carotid artery. In addition, the expression of PCNA and NF-κB p65 in intima were decreased by downregulation of PCAF. These results highlight that PCAF may be a potential target for prevention and treatment of neointimal hyperplasia and restenosis after angioplasty.

Samul-Tang Regulates Cell Cycle and Migration of Vascular Smooth Muscle Cells against TNF-α Stimulation

Samul-Tang (SMT), consisting of four medicinal herbs, is a well-known herbal prescription treating hematological disorders related symptoms. Our previous study demonstrated that SMT attenuated inflammation of vascular endothelial cells. In condition of retained vascular dysfunction, vascular inflammation is initiated and results in activation of smooth muscle cells (SMCs). Activated SMCs lose control of cell cycle regulation and migrate into intima, resulting in formation of atheroma. Here, we further investigated whether SMT suppresses proliferation and migration of SMCs. SMT showed antiproliferative effects on SMCs by suppressing [³H]-thymidine incorporation against TNF-α stimulation. Underlying mechanisms of antiproliferative effects were found to be resulting from cell cycle regulation. SMT downregulated expression of cyclin D1-CDK4 and cyclin E-CDK2 complexes and upregulated p21^waf1/cip1 and p27^kip1. SMT also suppressed migration of SMCs against TNF-α stimulation. This is thought to have resulted from suppressing MMP2 and MMP9 expressions and ROS production. In summary, SMT attenuates abnormal migration of vascular smooth muscle cells via regulating cell cycle and suppressing MMPs expression and ROS production. Our study suggests that SMT, a traditionally used herbal formula, protects vascular smooth muscle cells and might be used as an antiatherosclerotic drug.

Animal models for studying tumor microenvironment (TME) and resistance to lymphocytic infiltration

In cancer immunotherapy, cytotoxic T or NK cells need to engage cancer cells to initiate the killing. However, in clinical studies and in mouse models, some solid tumors are found with no lymphocytes. It is likely that these tumors will be resistant to all sorts of immunotherapies. Thus, restoring lymphocytic infiltration will be vital to the success of immunotherapies on solid tumors. In order to understand the complex interaction between cancer cells and stromal cells, we propose to establish animal models for studying the tumor microenvironment and to develop and test therapies to restore lymphocytic infiltration of tumors Without lymphocytes infiltrating tumors, all immunotherapies on solid tumors become ineffective.

Variation in expression and activity pattern of mmp2 and mmp9 on different time scales in the regenerating caudal fin of Poecilia latipinna

Alteration in the expression pattern of matrix metalloproteinase (MMP)2 and MMP9 was studied in the regenerating caudal fin of Poecilia latipinna immediately following amputation until the new tissues gained structural integrity. Timed expression pattern of these two MMPs was studied at enzyme, transcript as well as protein levels. Additionally, both the gelatinases were localized in the regenerating caudal fin during three specific stages of regeneration. The results revealed a progressive increase in the expression of MMP2 starting at 1 h post amputation (hpa), indicating its possible role in the remodelling of extracellular matrix early on during caudal-fin regeneration. Nevertheless, a reduction in transcript level expression of MMP2 at 6 hpa and 12 hpa stages, points towards a possible transcriptional regulation, to further moderate its activity. As observed in the case of MMP2, expression of MMP9 too increased from 1 hpa and remained elevated until 5 dpa. However, the active MMP9 revealed its presence only 12 hpa onwards. Moreover, both the gelatinases were localised in the apical epithelial cap and in the progress zone at wound epithelium (1 dpa) and blastema (60 hpa) stages respectively. Further, during early differentiation stage (5 dpa), high intensities of MMP2 and MMP9 were localized in the newly formed actinotrichia as compared with the tissue proximal to it. Based on the results, it could be construed that the controlled up-regulation of MMP2 and MMP9 from 1 hpa until the early differentiation stage ensures a regulated digestion of extracellular matrix, perhaps to facilitate the recruitment, proliferation, morphogenesis and re-patterning of resident stem cells during caudal fin regeneration in P. latipinna.

Treatment of β-thujaplicin counteracts di(2-ethylhexyl)phthalate (DEHP)-exposed vascular smooth muscle activation, inflammation and atherosclerosis progression

The initiation of atherosclerosis involves up-regulation of molecules such as E-selectin, VCAM-1, and ICAM-1. The progression of atherosclerosis is linked to proliferation and migration of vascular smooth muscle cell via MMP-2 and MMP-9 activities. However, the etiology of atherosclerosis concerning plasticizers is unknown. We evaluated β-thujaplicin in preventing the development of atherosclerosis in a model induced by pro-inflammatory cytokines. Moreover, we established a new atherosclerosis model in vascular smooth muscle cells (VSMC) exposed to a common contact plasticizer, di(2-ethylhexyl)phthalate (DEHP). SEVC4-10 endothelial cells were treated with 50% RAW conditioned medium and A7r5 VSMC was treated with the plasticizer, with/without β-thujaplicin (4 or 12 μM). Production of E-selectin, ICAM-1, and VCAM-1 in SEVC4-10 cells as well as MMP-2/MMP-9 (both expression and activity) in VSMC were monitored. Results showed that the conditioned medium induced E-selectin and ICAM were significantly prevented by β-thujaplicin. However, inhibition on the production of VCAM by β-thujaplicin was only seen in a concentration of 12 μM. Both concentrations of β-thujaplicin also significantly prevented DEHP-induced MMP-2 and MMP-9 expression and activities. Evidence uncovers that β-thujaplicin has additional factors in amelioration of atherosclerosis and corroborates that β-thujaplicin is a strong candidate in preventing the initiation and progression of atherosclerosis.

Platelets, inflammation and tissue regeneration

Blood platelets have long been recognised to bring about primary haemostasis with deficiencies in platelet production and function manifesting in bleeding while upregulated function favourises arterial thrombosis. Yet increasing evidence indicates that platelets fulfil a much wider role in health and disease. First, they store and release a wide range of biologically active substances including the panoply of growth factors, chemokines and cytokines released from α-granules. Membrane budding gives rise to microparticles (MPs), another active participant within the blood stream. Platelets are essential for the innate immune response and combat infection (viruses, bacteria, micro-organisms). They help maintain and modulate inflammation and are a major source of pro-inflammatory molecules (e.g. P-selectin, tissue factor, CD40L, metalloproteinases). As well as promoting coagulation, they are active in fibrinolysis; wound healing, angiogenesis and bone formation as well as in maternal tissue and foetal vascular remodelling. Activated platelets and MPs intervene in the propagation of major diseases. They are major players in atherosclerosis and related diseases, pathologies of the central nervous system (Alzheimers disease, multiple sclerosis), cancer and tumour growth. They participate in other tissue-related acquired pathologies such as skin diseases and allergy, rheumatoid arthritis, liver disease; while, paradoxically, autologous platelet-rich plasma and platelet releasate are being used as an aid to promote tissue repair and cellular growth. The above mentioned roles of platelets are now discussed.

Matrix Metalloproteinases, Vascular Remodeling, and Vascular Disease

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that degrade various proteins in the extracellular matrix (ECM). Typically, MMPs have a propeptide sequence, a catalytic metalloproteinase domain with catalytic zinc, a hinge region or linker peptide, and a hemopexin domain. MMPs are commonly classified on the basis of their substrates and the organization of their structural domains into collagenases, gelatinases, stromelysins, matrilysins, membrane-type (MT)-MMPs, and other MMPs. MMPs are secreted by many cells including fibroblasts, vascular smooth muscle (VSM), and leukocytes. MMPs are regulated at the level of mRNA expression and by activation through removal of the propeptide domain from their latent zymogen form. MMPs are often secreted in an inactive proMMP form, which is cleaved to the active form by various proteinases including other MMPs. MMPs degrade various protein substrates in ECM including collagen and elastin. MMPs could also influence endothelial cell function as well as VSM cell migration, proliferation, Ca²⁺ signaling, and contraction. MMPs play a role in vascular tissue remodeling during various biological processes such as angiogenesis, embryogenesis, morphogenesis, and wound repair. Alterations in specific MMPs could influence arterial remodeling and lead to various pathological disorders such as hypertension, preeclampsia, atherosclerosis, aneurysm formation, as well as excessive venous dilation and lower extremity venous disease. MMPs are often regulated by endogenous tissue inhibitors of metalloproteinases (TIMPs), and the MMP/TIMP ratio often determines the extent of ECM protein degradation and tissue remodeling. MMPs may serve as biomarkers and potential therapeutic targets for certain vascular disorders.

Downregulation of Cavin-1 Expression via Increasing Caveolin-1 Degradation Prompts the Proliferation and Migration of Vascular Smooth Muscle Cells in Balloon Injury-Induced Neointimal Hyperplasia

BACKGROUND

Percutaneous coronary intervention has been widely used in the treatment of ischemic heart disease, but vascular restenosis is a main limitation of percutaneous coronary intervention. Our previous work reported that caveolin-1 had a key functional role in intimal hyperplasia, whereas whether Cavin-1 (another important caveolae-related protein) was involved is still unknown. Therefore, we will investigate the effect of Cavin-1 on neointimal formation.

METHODS AND RESULTS

Balloon injury markedly reduced Cavin-1 protein and enhanced ubiquitin protein expression accompanied with neointimal hyperplasia in injured carotid arteries, whereas Cavin-1 mRNA had no change. In cultured vascular smooth muscle cells (VSMCs), Cavin-1 was downregulated after inhibition of protein synthesis by cycloheximide, which was distinctly prevented by pretreatment with proteasome inhibitor MG132 but not by lysosomal inhibitor chloroquine, suggesting that proteasomal degradation resulted in Cavin-1 downregulation. Knockdown of Cavin-1 by local injection of Cavin-1 short hairpin RNA (shRNA) into balloon-injured carotid arteries in vivo promoted neointimal formation. In addition, inhibition or overexpression of Cavin-1 in cultured VSMCs in vitro prompted or suppressed VSMC proliferation and migration via increasing or decreasing extracellular signal-regulated kinase phosphorylation and matrix-degrading metalloproteinases-9 activity, respectively. However, under basic conditions, the effect of Cavin-1 on VSMC migration was stronger than on proliferation. Moreover, our results indicated that Cavin-1 regulated caveolin-1 expression via lysosomal degradation pathway.

CONCLUSIONS

Our study revealed the role and the mechanisms of Cavin-1 downregulation in neointimal formation by promoting VSMC proliferation, migration, and synchronously enhancing caveolin-1 lysosomal degradation. Cavin-1 may be a potential therapeutic target for the treatment of postinjury vascular remodeling.

Matrix Metalloproteinases in Normal Pregnancy and Preeclampsia

Normal pregnancy is associated with marked hemodynamic and uterine changes that allow adequate uteroplacental blood flow and uterine expansion for the growing fetus. These pregnancy-associated changes involve significant uteroplacental and vascular remodeling. Matrix metalloproteinases (MMPs) are important regulators of vascular and uterine remodeling. Increases in MMP-2 and MMP-9 have been implicated in vasodilation, placentation, and uterine expansion during normal pregnancy. The increases in MMPs could be induced by the increased production of estrogen and progesterone during pregnancy. MMP expression/activity may be altered during complications of pregnancy. Decreased vascular MMP-2 and MMP-9 may lead to decreased vasodilation, increased vasoconstriction, hypertensive pregnancy, and preeclampsia. Abnormal expression of uteroplacental integrins, cytokines, and MMPs may lead to decreased maternal tolerance, apoptosis of invasive trophoblast cells, inadequate remodeling of spiral arteries, and reduced uterine perfusion pressure (RUPP). RUPP may cause imbalance between the antiangiogenic factors soluble fms-like tyrosine kinase-1 and soluble endoglin and the proangiogenic vascular endothelial growth factor and placental growth factor, or stimulate the release of inflammatory cytokines, hypoxia-inducible factor, reactive oxygen species, and angiotensin AT1 receptor agonistic autoantibodies. These circulating factors could target MMPs in the extracellular matrix as well as endothelial and vascular smooth muscle cells, causing generalized vascular dysfunction, increased vasoconstriction and hypertension in pregnancy. MMP activity can also be altered by endogenous tissue inhibitors of metalloproteinases (TIMPs) and changes in the MMP/TIMP ratio. In addition to their vascular effects, decreases in expression/activity of MMP-2 and MMP-9 in the uterus could impede uterine growth and expansion and lead to premature labor. Understanding the role of MMPs in uteroplacental and vascular remodeling and function could help design new approaches for prediction and management of preeclampsia and premature labor.

Matrix Metalloproteinase Inhibitors as Investigational and Therapeutic Tools in Unrestrained Tissue Remodeling and Pathological Disorders

Matrix metalloproteinases (MMPs) are zinc-dependent proteolytic enzymes that degrade various proteins in the extracellular matrix (ECM). MMPs may also regulate the activity of membrane receptors and postreceptor signaling mechanisms and thereby affect cell function. The MMP family includes collagenases, gelatinases, stromelysins, matrilysins, membrane-type MMPs, and other MMPs. Inactive proMMPs are cleaved by other MMPs or proteases into active MMPs, which interact with various protein substrates in ECM and cell surface. MMPs regulate important biological processes such as vascular remodeling and angiogenesis and may be involved in the pathogenesis of cardiovascular disorders such as hypertension, atherosclerosis, and aneurysm. The role of MMPs is often assessed by measuring their mRNA expression, protein levels, and proteolytic activity using gel zymography. MMP inhibitors are also used to assess the role of MMPs in different biological processes and pathological conditions. MMP activity is regulated by endogenous tissue inhibitors of metalloproteinases (TIMPs), and the MMP/TIMP balance could determine the net MMP activity, ECM turnover, and tissue remodeling. Also, several synthetic MMP inhibitors have been developed. Synthetic MMP inhibitors include a large number of zinc-binding globulins (ZBGs), in addition to non-ZBGs and mechanism-based inhibitors. MMP inhibitors have been proposed as potential tools in the management of osteoarthritis, cancer, and cardiovascular disorders. However, most MMP inhibitors have broad-spectrum actions on multiple MMPs and could cause undesirable musculoskeletal side effects. Currently, doxycycline is the only MMP inhibitor approved by the Food and Drug Administration. New generation biological and synthetic MMP inhibitors may show greater MMP specificity and fewer side effects and could be useful in targeting specific MMPs, reducing unrestrained tissue remodeling, and the management of MMP-related pathological disorders.

Evidence for the Involvement of Matrix-Degrading Metalloproteinases (MMPs) in Atherosclerosis

Atherosclerosis leads to blockage of arteries, culminating in myocardial infarction, and stroke. The involvement of matrix-degrading metalloproteinases (MMPs) in atherosclerosis is established and many studies have highlighted the importance of various MMPs in this process. MMPs were first implicated in atherosclerosis due to their ability to degrade extracellular matrix components, which can lead to increased plaque instability. However, more recent work has highlighted a multitude of roles for MMPs in addition to breakdown of extracellular matrix proteins. MMPs are now known to be involved in various stages of plaque progression: from initial macrophage infiltration to plaque rupture. This chapter summarizes the development and progression of atherosclerotic plaques and the contribution of MMPs. We provide data from human studies showing the effect of MMP polymorphisms and the expression of MMPs in both the atherosclerotic plaque and within plasma. We also discuss work in animal models of atherosclerosis that show the effect of gain or loss of function of MMPs. Together, the data provided from these studies illustrate that MMPs are ideal targets as both biomarkers and potential drug therapies for atherosclerosis.

Toll-like receptor 2 activation and serum amyloid A regulate smooth muscle cell extracellular matrix

Smooth muscle cells contribute to extracellular matrix remodeling during atherogenesis. De-differentiated, synthetic smooth muscle cells are involved in processes of migration, proliferation and changes in expression of extracellular matrix components, all of which contribute to loss of homeostasis accompanying atherogenesis. Elevated levels of acute phase proteins, including serum amyloid A (SAA), are associated with an increased risk for atherosclerosis. Although infection with periodontal and respiratory pathogens via activation of inflammatory cell Toll-like receptor (TLR)2 has been linked to vascular disease, little is known about smooth muscle cell TLR2 in atherosclerosis. This study addresses the role of SAA and TLR2 activation on smooth muscle cell matrix gene expression and insoluble elastin accumulation. Cultured rat aortic smooth muscle cells were treated with SAA or TLR2 agonists and the effect on expression of matrix metallopeptidase 9 (MMP9) and tropoelastin studied. SAA up-regulated MMP9 expression. Tropoelastin is an MMP9 substrate and decreased tropoelastin levels in SAA-treated cells supported the concept of extracellular matrix remodeling. Interestingly, SAA-induced down-regulation of tropoelastin was not only evident at the protein level but at the level of gene transcription as well. Contributions of proteasomes, nuclear factor κ B and CCAAT/enhancer binding protein β on regulation of MMP9 vs. tropoleastin expression were revealed. Effects on Mmp9 and Eln mRNA expression persisted with long-term SAA treatment, resulting in decreased insoluble elastin accumulation. Interestingly, the SAA effects were TLR2-dependent and TLR2 activation by bacterial ligands also induced MMP9 expression and decreased tropoelastin expression. These data reveal a novel mechanism whereby SAA and/or infection induce changes in vascular elastin consistent with atherosclerosis.

Protection against cerebral infarction by Withaferin A involves inhibition of neuronal apoptosis, activation of PI3K/Akt signaling pathway, and reduced intimal hyperplasia via inhibition of VSMC migration and matrix metalloproteinases

PURPOSE

Stroke is a major public health concern with high rates of morbidity and mortality worldwide. Cerebral ischemia and infarction are commonly associated with stroke. Currently used medications, though effective, are also associated with adverse effects. Development of effective neuroprotective agents with fewer side effects would be of clinical value. We evaluated the effects of Withaferin A (WA), a steroidal lactone derived from the plant Withania somnifera, on experimentally induced cerebral infarction.

MATERIALS AND METHODS

The ability of WA to inhibit neuroapoptosis and modulate vascular smooth muscle cell (VSMC) migration and PI3K/Akt signaling was assessed. Separate groups of Sprague Dawley rats were subjected to cerebral occlusion and reperfused for 24h.

RESULTS

WA treatment (25, 50 or 100mg/kg bodyweight) significantly reduced the infarct area in a carotid ligation model; WA reduced intimal hyperplasia and proliferating cell nuclear antigen (PCNA)-positive cell counts. Western blotting analysis revealed significantly suppressed PI3K/Akt signaling following cerebral ischemia/reperfusion injury. WA supplementation was found to downregulate apoptotic pathway proteins. WA suppressed PTEN and enhanced p-Akt and GSK-3β levels and elevated mTORc1, cyclinD1 and NF-κB p65 expression, suggesting activation of the PI3K/Akt pathway. In vitro studies with PDGF-stimulated A7r5 cells revealed that WA exposure severely downregulated matrix metalloproteinases (MMP)-2 and -9 and inhibited migration of A7r5 cells. Additionally, WA reduced the proliferation of A7r5 cells significantly.

CONCLUSIONS

WA exerted neuroprotective effects by activating the PI3K/Akt pathway, modulating the expression of MMPs, and inhibiting the migration of VSMCs.