Rat Carotid Artery Research Articles

Acupuncture attenuates cognitive impairment, oxidative stress and NF-κB activation in cerebral multi-infarct rats.

Patients with multiple infarct dementia (MID) have subtle deficits that commonly go unnoticed, and are at risk of developing Alzheimer's disease. Oxidative stress induced by ischaemic injury results in intracellular calcium accumulation and neuronal apoptosis, leading to cognitive impairment by triggering various cellular signal transduction pathways. Several studies have suggested that NF-κB in the presence of p53 has a pro-apoptotic function in various models, but the mechanism is unclear. The aim of this study was to investigate whether acupuncture could protect cognitive function against cerebral multi-infarction (CMi) induced oxidative stress by inhibiting the activation of NF-κB and its target gene p53. An animal model of CMi was established by injecting homologous blood emboli into the right internal carotid artery of male Wistar rats. After 2 weeks of acupuncture treatment, cognitive function was detected by novel object recognition. Electron spin resonance and Fluo-3 fuorescence imaging were used to test the generation of ROS and intracellular calcium accumulation, respectively. Expression of NF-κB and p53 was examined by Western blot analysis and immunofluorescence. CMi induced spatial learning and memory impairment, overproduction of intracellular hydroxyl radicals, and elevations of Ca2+, which were ameliorated by verum acupuncture treatment. Acupuncture inhibited activation of NF-κB and its downstream target gene p53. These findings suggest that acupuncture could protect cognitive function against oxidative stress induced by CMi, which is partially associated with suppression of NF-κB-p53 activation.

LncRNA GAS5 regulates vascular smooth muscle cell cycle arrest and apoptosis via p53 pathway

Vascular remodeling is a pathological process following cardiovascular intervention. Vascular smooth muscle cells (VSMC) play a critical role in the vascular remodeling. Long noncoding RNAs (lncRNA) are a class of gene regulators functioning through various mechanisms in physiological and pathological conditions. By using cultured VSMC and rat carotid artery balloon injury model, we found that lncRNA growth arrest specific 5 (GAS5) serves as a negative regulator for VSMC survival in vascular remodeling. By manipulating GAS5 expression via adenoviral overexpression or short hairpin RNA knockdown, we found that GAS5 suppresses VSMC proliferation while promoting cell cycle arrest and inducing cell apoptosis. Mechanistically, GAS5 directly binds to p53 and p300, stabilizes p53-p300 interaction, and thus regulates VSMC cell survival via induction of p53-downstream target genes. Importantly, local delivery of GAS5 via adenoviral vector suppresses balloon injury-induced neointima formation along with an increased expression of p53 and apoptosis in neointimal SMCs. Our study demonstrated for the first time that GAS5 negatively impacts VSMC survival via activation the p53 pathway during vascular remodeling.

Effect of Equol on Vasocontractions in Rat Carotid Arteries Treated with High Insulin.

Previous research has indicated that high insulin affects vascular function. Equol is an active metabolite of daidzein, an isoflavone produced from soy by intestinal microbial flora, with beneficial effects on the vascular system. This study investigated whether equol was beneficial for vascular function under high insulin conditions. Using organ culture techniques, rat carotid arteries were treated for 23 ± 1 h with a vehicle, high insulin (100 nM), or equol (100 µM) plus high insulin (100 nM). Vascular isometric forces were measured by the organ bath technique. In each endothelium-intact ring, the contractions induced by high-K+, noradrenaline, or by serotonin (5-HT) were similar for the vehicle, insulin, and equol + insulin treatments. Contractions induced by a selective 5-HT2A receptor agonist (TCB2) increased with insulin treatment (vs. vehicle), but less so with equol + insulin. Under basal conditions, a selective 5-HT2B receptor agonist (BW723C86) did not induce contraction; following precontraction by a thromboxane analog, it induced contraction but not relaxation. These responses were similar across the three treatments. Acetylcholine-induced relaxations were also similar for the three treatments. In the endothelium-denuded preparations, 5-HT-induced contraction was augmented with insulin treatment (vs. vehicle) but less so by equol + insulin treatment. These differences in 5-HT-induced contractions were eliminated by iberiotoxin, a large-conductance calcium-activated K+ channel (BKCa) inhibitor. These results suggest that equol exerts a preventive effect on the enhancement of 5-HT-induced contraction by high insulin (possibly mediated by the 5-HT2A receptor), and that these effects may be attributed to the activation of BKCa channels in vascular smooth muscle.

Potentiation of the hypoxic preconditioning effect by antihypoxants

The development of effective methods to increase the organism resistance to hypoxia is an important task of current medicine. One of such methods is preconditioning, as a result of which, a potent mobilization of the adaptive organism abilities occurs under a preconditioning factor action.
 Aim. To study the possibility of potentiating of the hypoxic preconditioning effect with help of antihypoxants.
 Methods. Evaluation of the effectiveness of combined preconditioning (antihypoxants + moderate hypobaric hypoxia) was performed on experimental models of acute hypoxia with hypercapnia, acute hypobaric hypoxia in mice, and bilateral occlusion of the common carotid arteries in rats. Investigated antihypoxants are amtizol, hypoxen, cobazole, metaprot, mexidol, mildronate, substances under the codes VM-606, pQ-4 and pQ-1104.
 Results. PreC with use of amtizol at dose 25 mg/kg, cobazole at dose 30 mg/kg, VM-606, pQ-4 and pQ-1104 at doses 50 mg/kg in combination with moderate hypoxia increased the lifespan of mice in acute hypoxia with hypercapniamodel and acute hypobaric hypoxia from 57 to 170%. Combined preconditioning with amtizol, cobazole and pQ-4 significantly increased the survival rate of rats in cerebral ischemia, amtizol and pQ-4 reduced neurological deficiency in the post ischemic period as well.
 Conclusion. Antitipoxants as amtizol, cobazole, VM-606, pQ-4, pQ-1104 potentiate the hypoxic preconditioning effect on acute hypoxia with hypercapnia, acute hypobaric hypoxia and occlusion of the common carotid arteries models, the most significant effect was noted for amtizol and pQ-4. Signal role in the adaptation induction to hypoxia and ischemia by combined preconditioning with use of antihypoxants hypoxia-inducible factor HIF-1α can play.

PC238. TBK1 as a Promising Druggable Target to Interrupt Interferon γ Atherogenic Signals and to Prevent or to Treat Obstructive Vascular Disease

Interferon γ is a recognized culprit of atherogenesis. Blockade of interferon γ signaling in endothelial and smooth muscle cells should positively affect intimal hyperplasia. Expression of signal transducer and activator of transcription 1 (STAT1), the key transcriptional regulator of interferon γ signaling, is regulated by autocrine interferon β. In turn, interferon β is downstream to the noncanonical IκB kinase TANK-binding kinase 1 (TBK1; Fig 1). We checked whether TBK1 inhibition, using the clinically safe drug amlexanox as well as another inhibitor, MRT67307, reduces STAT1 expression and interferon γ signaling in vascular cells. Human coronary artery endothelial and smooth muscle cells were treated with poly I:C (100 μg/mL), a double-stranded RNA mimetic that stimulates TBK1 phosphorylation, or with human recombinant interferon γ (500 U/mL). Cells were pretreated with amlexanox (50-100 μM) for 1 hour or 24 to 48 hours before poly I:C or interferon γ, respectively, and harvested for RNA and protein isolation at 1 hour, 7 hours, and 24 hours after treatment. Samples were analyzed by Western blot and reverse transcription quantitative polymerase chain reaction. Treatment of endothelial and smooth muscle cells with poly I:C for 1 hour was optimal to induce TBK1 phosphorylation. Poly I:C upregulated interferon γ and STAT1 messenger RNA levels in both cell types. Phosphorylated TBK1 levels were increased by mere addition of amlexanox, consistent with its mechanism of action. Preincubation with amlexanox decreased basal STAT1 expression and inhibited poly I:C-induced upregulation of interferon γ and STAT1 messenger RNA, confirmed at the protein level for STAT1. Importantly, pretreatment of cells with amlexanox for 24 hours to 48 hours blunted the upregulation of the interferon γ-dependent gene IDO (Fig 2). Altogether our data validate the critical role of TBK1 in mediating interferon γ atherogenic signaling and set the basis for the pursuit of TBK1 inhibitors as novel therapies to prevent and to treat obstructive vascular disease. Future studies are aimed at checking the effectiveness of amlexanox in curbing intimal hyperplasia in a rat carotid artery model of post-balloon angioplasty stenosis and in a canine model of vein interposition graft failure.Fig 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Sildenafil Reduces Neointimal Hyperplasia after Angioplasty and Inhibits Platelet Aggregation via Activation of cGMP-dependent Protein Kinase

Sildenafil is known to reduce cardiac hypertrophy through cGMP-dependent protein kinase (cGK) activation. Studies have demonstrated that cGK has a central switching role in modulating vascular smooth muscle cell (VSMC) phenotype in response to vascular injury. Here, we aimed to examine the effects of cGK activation by sildenafil on neointimal formation and platelet aggregation. After vascular injury, neointimal hyperplasia in rat carotid arteries was significantly reduced in the sildenafil-treated group. This effect of sildenafil was accompanied by the reduction of viability and migration of VSMCs. Further experiments showed that the increased cGK activity by sildenafil inhibited platelet-derived growth factor-induced phenotype change of VSMCs from a contractile form to a synthetic one. Conversely, the use of cGK inhibitor or gene transfer of dominant-negative cGK reversed the effects of sildenafil, increasing viability of VSMCs and neointimal formation. Interestingly, sildenafil significantly inhibited platelet aggregation induced by ADP or thrombin. This effect was reversed by cGK inhibitor, suggesting that sildenafil inhibits platelet aggregation via cGK pathway. This study demonstrated that sildenafil inhibited neointimal formation and platelet aggregation via cGK pathway. These results suggest that sildenafil could be a promising candidate for drug-eluting stents for the prevention of both restenosis and stent thrombosis.

A Middle Cerebral Artery Occlusion Technique for Inducing Post-stroke Depression in Rats.

Post-stroke depression (PSD) is the most recurrent of all psychiatric complications resulting from an ischemic stroke. A greater majority (about 60%) of all ischemic stroke patients suffer from PSD, a disorder considered to be an ischemic stroke-related precursor for increased death and degradation in health. The pathophysiology of PSD is still obscure. To study the mechanism of development and occurrence of PSD further, and to find out a therapy, we attempted to develop a new protocol that requires occluding the middle cerebral artery (MCA) via the internal carotid artery (ICA) in rats. This protocol describes a model of PSD induced in rats through the middle cerebral artery occlusion (MCAO). Also used in the experiment are the Porsolt forced swim test and the sucrose preference test to confirm and evaluate the depressive mood of the rats under investigation. Rather than inserting the catheter through the external carotid artery (ECA), as stipulated for the original procedure, this MCAO technique has the monofilament passing directly through the ICA. This MCAO technique was developed a few years ago and leads to a reduction in mortality and variability. It is generally accepted that the criteria used are preferred in the selection of biological models. The data obtained with this protocol show that this model of MCAO could be a way of inducing PSD in rats and could potentially lead to the understanding of the pathophysiology and the future development of new drugs and other neuroprotective agents.

Biodegrading highly porous elastomeric graft regenerates muscular and innervated carotid artery-Comparative study with vein graft.

This study aims to investigate the superiorities of fast degrading elastomeric poly(glycerol sebacate) (PGS)/polycaprolactone (PCL) grafts over autologous vein grafts in the reconstruction of carotid artery, thus providing more suitable vascular grafts for carotid artery replacement. We fabricated small arterial grafts from microporous tubes of PGS reinforced with PCL nanofibers on the outer surface. As control, autologous jugular veins were harvested as vein grafts. Both types of grafts were interpositioned in rat carotid arteries and evaluated at 1year postoperatively. PGS/PCL grafts remodelled into "neoarteries" (regenerated arteries) with smooth and even vessel wall approximate to native carotid arteries. In contrast, dilated vessel cavity and thickening vessel wall presented in neoarteries remoulded from vein. Histologically, neoarteries from both groups mimic arterial tissue architecture with a confluent endothelium and media and adventita-like layers, whereas PGS/PCL neoarteries presented well-organized muscular component and elastic fibres, which contributed more flexibility and elasticity. Different from vein grafts, PGS/PCL neoarteries acquired reinnervation and displayed apparent vascular function of contraction and relaxation, as was confirmed with responsiveness to various vasoactivators, which suggests that vascular cells within neoarteries express functional phenotypes and potential of autonomic reactivity that carotid arteries owned. To conclude, according to the requirement of strong flexibility, innervation from sympathetic and parasympathetic nerves which can response the carbon dioxide and blood pressure, the muscular remodelling and innervation possessed promising possibility of clinical application.

Chronological Change of Vascular Reactivity to cGMP Generators in the Balloon-Injured Rat Carotid Artery

Background/Aims: Soluble guanylate cyclase (sGC) exists as reduced, oxidized, and heme-free forms. Currently, it is unclear whether endovascular mechanical stenosis has an impact on vascular tone control by drugs targeting sGC, namely cGMP generators. Methods: Pharmacological responses to acidified sodium nitrite (reduced sGC stimulant) and BAY 60-2770 (oxidized/heme-free sGC stimulant) were studied in balloon-injured rat carotid arteries at several time points. In addition, sGC expression was detected by immunohistochemistry. Results: At 1 day after injury, acidified sodium nitrite-induced relaxation was attenuated in the injured artery, whereas BAY 60-2770-induced relaxation was augmented. Similar attenuation of response to acidified sodium nitrite was seen at 7 and 14 days after injury. On the other hand, the augmentation of response to BAY 60-2770 disappeared at 7 and 14 days after injury. At 1 day after injury, the immunohistochemical expression pattern of sGC in the smooth muscle layer of the injured artery was not different from that of the uninjured artery. However, in the injured artery, the intensity of sGC staining was weak at 7 and 14 days after injury. Conclusion: Balloon injury alters vascular responsiveness to cGMP generators, which seems to be associated with the form and/or expression of sGC.

Protective Role of RNA Helicase DEAD-Box Protein 5 in Smooth Muscle Cell Proliferation and Vascular Remodeling.

RNA helicases, highly conserved enzymes, are currently believed to be not only involved in RNA modulation, but also in other biological processes. We recently reported that RNA helicase DDX (DEAD-box protein)-5 is required for maintaining the homeostasis of vascular smooth muscle cells (SMCs). However, the expression and function of RNA helicase in vascular physiology and disease is unknown. To investigate the role of RNA helicase in vascular diseases. We showed here that DDX-5 was the most abundant DEAD-box protein expressed in human and rodent artery, which mainly located in SMCs. It was demonstrated that DDX-5 levels were reduced in cytokine-stimulated SMCs and vascular lesions. DDX-5 knocking down or deficiency increased SMC proliferation and migration, whereas overexpression of DDX-5 prevented aberrant proliferation and migration of SMCs. Mechanistic studies revealed transcription factor GATA (GATA-binding protein)-6 as a novel downstream target of DDX-5, which directly interacted with GATA-6 and protected it from MDM (mouse double minute)-2-mediated degradation. Our ChIP assay identified a previously unreported binding of p27Kip1 promoter to GATA-6. DDX-5 increased the recruitment of GATA-6 to p27Kip1 promoter, which enhanced p27Kip1 expression and maintained SMC quiescence. Finally, we showed exacerbated neointima formation in DDX-5 SMC-deficient mice after femoral artery injury, whereas overexpression of DDX-5 potently inhibited vascular remodeling in balloon-injured rat carotid artery. These findings provide the first evidence for a role of RNA helicase DDX-5 in the protection against SMC proliferation, migration, and neointimal hyperplasia. Our data extend the fundamental role of RNA helicase beyond RNA modulation, which provides the basic information for new therapeutic strategies for vascular diseases.

Oligonucleotide Microarrays Identified Potential Regulatory Genes Related to Early Outward Arterial Remodeling Induced by Tissue Plasminogen Activator.

Constrictive vascular remodeling limiting blood flow, as well as compensatory outward remodeling, has been observed in many cardiovascular diseases; however, the underlying mechanisms regulating the remodeling response of the vessels remain unclear. Plasminogen activators (PA) are involved in many of the processes of vascular remodeling. We have shown previously that increased levels of tissue-type PA (tPA) contributes to outward vascular remodeling. To elucidate the mechanisms involved in the induction of outward remodeling we characterized changes in the expression profiles of 8799 genes in injured rat carotid arteries 1 and 4 days after recombinant tPA treatment compared to vehicle. Periadventitial tPA significantly increased lumen size and vessel area, encompassed by the external elastic lamina, at both one and 4 days after treatment. Among 41 differentially expressed known genes 1 day after tPA application, five genes were involved in gene transcription, five genes were related to the regulation of vascular tone [for example, thromboxane A2 receptor (D32080) or non-selective-type endothelin receptor (S65355)], and eight genes were identified as participating in vascular innervation [for example, calpain (D14478) or neural cell adhesion molecule L1 (X59149)]. Four days after injury in tPA-treated arteries, four genes, regulating vascular tone, were differentially expressed. Thus, tPA promotes outward arterial remodeling after injury, at least in part, by regulating expression of genes in the vessel wall related to function of the nervous system and vascular tone.

Inhibitory effects of scoparone from chestnut inner shell on platelet-derived growth factor-BB-induced vascular smooth muscle cell migration and vascular neointima hyperplasia.

Compounds of the inner shell of chestnut (Castanea crenata) have diverse biological activities, including anti-cancer and anti-oxidant activities. Here we explored the effects of an extract of chestnut inner shells and of its bioactive component scoparone on vascular smooth muscle cell migration and vessel damage. The ethanol extract of chestnut inner shells, containing 11 major compounds, inhibited platelet-derived growth factor (PDGF)-BB-induced migration of rat aortic smooth muscle cells (RASMCs). Among these compounds, scoparone (6,7-dimethoxycoumarin) suppressed RASMC migration and wound healing in response to PDGF-BB but did not affect RASMC proliferation. In RASMCs, scoparone inhibited the PDGF-BB-induced rat aortic sprout outgrowth and attenuated the PDGF-BB-mediated increase in phosphorylation of mitogen-activated protein kinases (MAPKs), p38 MAPK and extracellular signal-regulated kinase 1/2. The in vivo administration of scoparone resulted in the attenuation of neointima formation in balloon-injured carotid arteries of rats. These findings demonstrate that scoparone, found in chestnut inner shells, may inhibit cell migration through suppression of the phosphorylation of MAPKs in PDGF-BB-treated RASMCs, probably contributing to the reduction of neointimal hyperplasia induced after vascular injury. Therefore, scoparone and chestnut inner shell may be a potential agent or functional food, respectively, for the prevention of vascular disorders such as vascular restenosis or atherosclerosis. © 2019 Society of Chemical Industry.

Antithrombotic Activity of a Novel Diazepino[1,2-α] Benzimidazole Derivative on Arterial Thrombosis Model in Rats without Concomitant Pathology and in Rats with Experimental Myocardial Infarction.

Antithrombotic activity of a novel tricyclic derivative of diazepino[1,2-α]benzimidazole (DAB-15) was examined on the model of arterial thrombosis developed in rats without concomitant pathology and in rats with experimental myocardial infarction. DAB-15 demonstrated high antithrombotic efficacy in modeled thrombosis of carotid artery in rats without the concomitant pathology surpassing that of the reference drugs acetylsalicylic acid and clopidogrel by 5.1 and 4.8 times, respectively. In rats with experimental noncoronary myocardial infarction, DAB-15 increased the thrombus formation time by 86.2% in comparison with experimental control level in non-treated rats with similar myocardial infarction.

Gamma‐mangostin of Garcinia mangostana peels ameliorates hyperglycemia in synergism of insulin

Type II diabetes mellitus is diagnosed because of obese having high sugar, high salt and high fat in diet, and is a heterogeneous group of disorders characterized by hyperglycemia due to an absolute or relative deficit in insulin synthesis or action. Mangostins, isolated from Garcinia mangostana peels, contain various isoforms α, β and γ, however, the medicinal values of γ‐mangostin particular in anti‐diabetic as an alternative medicine or folk medicine remain to be explored. This study attempted to investigate hypoglycemic efficacy of γ‐mangostin through execution in cellular and mouse levels. In vitro, the vascular smooth cells isolated from the external carotid artery of SD rat and FL83B mouse hepatocytes were applied to determine the cytotoxicity and glucose uptake. The cell viability data showed that 0.5 μM, 2.5 μM and 5 μM γ‐mangostin had non‐toxicticity in both cell types. The hypoglycemic effectiveness of 5 μM γ‐mangostin treatment was greater than those of 0.5 and 2.5 μM γ‐mangostin during two hours test of two cell types. Compared with 10−7 M insulin, the potency of γ‐mangostin plus insulin in synergistic glucose uptake reached plateau within 90 min. Furthermore, the hypoglycemic efficacy of oral administration 0.1, 0.2 and 0.4 mg γ‐mangostin was similar to 0.2 U insulin intraperitoneal injection and oral 50 mg/kg metformin for 120 min of oral glucose tolerance test (OGTT) in diet‐induced diabetic ICR mice. The hypoglycemic ability of oral 0.4 mg γ‐mangostin was more effective than that of 12 mg/kg Acarbose for 180 min in oral starch tolerance test. Diabetic ICR mice were daily fed 0.2 mg γ‐mangostin, 0.4 mg γ‐mangostin and vehicle for 4 weeks, the data revealed that γ‐mangostin caused the lowing blood glucose at fasting level and OGTT. Taken altogether, γ‐mangostin plays an insulin sensitizer to dampen the hyperglycemia with non‐ cytotoxicity in cell line tested.Support or Funding InformationMinistry of Science and Technology (107‐2813‐C‐259‐061‐B), Taiwan.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Dioscin inhibits intimal hyperplasia in rat carotid artery balloon injury model through inhibition of the MAPK-FoxM1 pathway

Vascular smooth muscle cell (VSMC) proliferation and migration are crucial events in the pathological course of atherosclerosis and restenosis after percutaneous coronary intervention (PCI). Dioscin has been shown to exhibit powerful cardiovascular protective effects and potent therapeutic potential in cancer owing to the inhibition of cell proliferation and migration. However, its effects on arterial wall hypertrophy-related diseases caused by VSMC proliferation and migration remain unclear. In this study, we investigated the effects of dioscin on intimal hyperplasia after balloon injury in vivo, its effects on VSMC proliferation and migration in vitro, and the mechanisms underlying these effects. Results showed that dioscin treatment significantly inhibited VSMC proliferation and intimal thickening after balloon injury. In cultured VSMCs, treatment with dioscin significantly decreased fetal bovine serum or platelet-derived growth factor-induced cell proliferation and migration. Moreover, dioscin inhibited the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and expression of Forkhead box M1 (FoxM1) and its downstream target genes. FoxM1 knockdown with shRNA partially counteracted the inhibitory effects of dioscin on cell proliferation and migration. In conclusion, we demonstrated that dioscin attenuated neointima formation in response to balloon injury by suppressing VSMC proliferation and migration through MAPK-FoxM1 pathway. Our data suggested that dioscin might be a potential therapeutic agent for atherosclerosis and restenosis after PCI.

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.

Oscillating flow promotes inflammation through the TLR2–TAK1–IKK2 signalling pathway in human umbilical vein endothelial cell (HUVECs)

BackgroundOscillatory shear stress (OSS) occurs in areas where atherosclerosis is prevalent. Toll-like receptor 2 (TLR2) has been associated with mechanical-stress-mediated activation of signalling pathways that may lead to inflammation, apoptosis, and atherosclerosis. Nonetheless, the mechanism underlying the connection between TLR2 and OSS is not fully understood. The purpose of this study was to investigate the link between OSS and TLR2 in human umbilical vein endothelial cell (HUVECs). MethodsMonolayer endothelial cells were stimulated or not stimulated by OSS. Protein expression was determined by western blotting and immunofluorescent staining. Endothelial function was assessed by using dihydroethidium assay, RT-PCR, immunofluorescent staining and western blotting. The carotid artery of rats was ligated for 1 week, and a section exposed to OSS was excised and analysed. ResultsIn vitro, the expression of TLR2 in HUVECs was activated by OSS. Additionally, OSS increased apoptosis, inflammatory changes, and oxidative stress in HUVECs, and these effects were reversed by down-regulation the expression of TLR2. We proved that OSS regulates the inflammatory response of endothelial cells through the TLR2–TAK1–IKK2 pathway. In the rats with carotid artery ligation, TLR2, TAK1 and phospho-IKK2 amounts increased at the site of OSS. SignificanceAccording to our results, the OSS-mediated HUVECs injury may be associated with an increase in TLR2 expression. Accordingly, strategies designed to reduce TLR2 expression or inhibit TLR2 activation may be an effective approach to reduce the incidence of atherosclerosis.

MicroRNA-24 attenuates vascular remodeling in diabetic rats through PI3K/Akt signaling pathway

Background and aimsThe vascular remodeling plays a crucial role in pathogenesis of diabetic cardiovascular complications. In this study, we intended to explore the effects and potential mechanisms of microRNA-24 (miR-24) on vascular remodeling under diabetic conditions. Methods and ResultsMiR-24 recombinant adenovirus (Ad-miR-24-GFP) was used to induce miR-24 overexpression either in carotid arteries or high glucose (HG)-induced vascular smooth muscle cells (VSMCs). Cell proliferation was analyzed using CCK-8 method. Cell migration was examined using wound-healing and transwell assay. mRNA and protein expressions of critical factors were, respectively, measured by real-time PCR and western blot as follows: qRT-PCR for the levels of miR-24, PIK3R1; western blot for the protein levels of PI3K (p85α), Akt, p-Akt, mTOR, p-mTOR, 4E-BP1, p-4E-BP1, p70s6k, p-p70s6k, MMP 2, MMP 9, collagen Ⅰ, as well as collagen Ⅲ. Carotid arteries in diabetic rats suffered balloon injury were harvested and examined by HE, immunohistochemical and Masson trichrome staining.The expression of miR-24 was decreased in HG-stimulated VSMCs and balloon-injured carotid arteries of diabetic rats, accompanied by increased mRNA expression of PIK3R1. The up-regulation of miR-24 suppressed VSMCs proliferation, migration, collagen deposition not only induced by HG in vitro, but also in balloon-injured diabetic rats, which were related to inactivation of PI3K/Akt signaling pathway. ConclusionThe up-regulation of miR-24 significantly attenuated vascular remodeling both in balloon-injured diabetic rats and HG-stimulated VSMCs via suppression of proliferation, migration and collagen deposition by acting on PIK3R1 gene that modulated the PI3K/Akt/mTOR axes.

Effects of Bemiparin Sodium Versus Dabigatran Etexilate After Anastomosis in Rat Carotid Arteries on the Development of Neointima and Thrombolytic Efficacy

Revascularization before infarct development after cerebral ischemia may affect morbidity. The success of revascularization can be less than expected because of spontaneous thrombosis or restenosis with intimal hyperplasia. The aim of this study was to compare dabigatran etexilate, a direct thrombin inhibitor, with bemiparin sodium, a second-generation low-molecular-weight heparin, after carotid artery anastomosis. This study used 24 randomly selected Sprague-Dawley rats. The rats were separated into 3 equal groups: group 1 (control group); group 2 (dabigatran group), in which dabigatran 10 mg/kg was orally administered for 7 days; and group 3 (bemiparin group), in which bemiparin 250 IU/kg was subcutaneously administered for 7 days. The right-side carotid artery of rats was used for anastomosis and the left-side carotid artery was used for the control. The carotid artery was explored and transected. Anastomosis was applied using 10/0 polypropylene sutures. After 7 days of treatment, the right and left carotid arteries were removed. Lumen diameter, lumen area, tunica media thickness, edema, vessel wall injury, intimal hyperplasia, thrombus, and inflammation were evaluated in tissue biopsy specimens. Bemiparin used after anastomosis caused less thickening of tunica media and reduced intimal hyperplasia but did not decrease lumen diameter and area. Dabigatran increased edema and inflammation but did not prevent intimal hyperplasia. Bemiparin reduced intimal hyperplasia and prevented thrombosis angiogenesis, but dabigatran did not prevent intimal hyperplasia, and its anticoagulation effect was more than the antithrombotic effect.

Mass Spectrometric Imaging Reveals Temporal and Spatial Dynamics of Bioactive Lipids in Arteries Undergoing Restenosis.

Restenosis, or renarrowing of the arterial lumen, is a common recurrent disease following balloon angioplasty and stenting treatments for cardiovascular disease. A major technical barrier for deciphering restenotic mechanisms is the dynamic, spatial profiling of bioactive lipids in the arterial wall, especially in small animals. Here, applying matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI), we conducted the first lipidomic study of temporal-spatial profiling in a small animal model of angioplasty-induced restenosis. Cross sections were collected 3, 7, and 14 days after balloon angioplasty of rat carotid arteries. MALDI-MSI analyses showed that diacylglycerols (DAGs), signaling lipids associated with restenosis, and lysophosphatidylcholines (LysoPCs), whose function was uncharacterized in restenosis, dramatically increased at postangioplasty day 7 and day 14 in the neointimal layer of balloon-injured arteries compared to uninjured controls. In contrast, sphingomyelins (SMs) did not increase, but rather decreased at day 3, day 7, and day 14 in injured arteries versus the uninjured control arteries. These results revealed previously unexplored distinct temporal-spatial lipid dynamics in the restenotic arterial wall. Additionally, we employed time-of-flight secondary ion mass spectrometry (TOF-SIMS) tandem MS imaging for both molecular identification and imaging at high spatial resolution. These imaging modalities provide powerful tools for unraveling novel mechanisms of restenosis involving lipids or small signaling molecules.