Effect of Anagliptin on Vascular Injury in the Femoral Artery of Type 2 Diabetic Rats.

Patients with diabetes mellitus (DM) often experience complications such as peripheral arterial disease (PAD), which is thought to be caused by vascular damage resulting from increased oxidative stress. Dipeptidyl peptidase-4 inhibitors have been reported to reduce oxidative stress, although the exact mechanism remains unclear. This study aimed to investigate the impact of long-term (6 weeks) anagliptin treatment at a dose of 200 mg/kg/d against oxidative stress in the femoral artery of Otsuka Long-Evans Tokushima Fatty (OLETF) rats using a well-established animal model for type 2 DM. Serum toxic advanced glycation end-products concentrations and blood glucose levels after glucose loading were significantly elevated in OLETF rats compared to Long-Evans Tokushima Otsuka (LETO) rats but were significantly suppressed by anagliptin administration. Plasma glucagon-like peptide-1 concentrations after glucose loading were significantly increased in anagliptin-treated rats. Superoxide production and reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity in femoral arteries were significantly increased in OLETF rats compared to LETO rats but were significantly decreased by anagliptin administration. The expressions of NADPH oxidase components (p22phox in the intima region and p22phox and gp91phox in the media region) in the femoral artery were significantly increased in OLETF rats compared to LETO rats but were significantly suppressed by anagliptin administration. Furthermore, the femoral artery showed increased wall thickness in OLETF rats compared to LETO rats, but anagliptin administration reduced the thickening. This study suggests that long-term anagliptin administration can reduce oxidative stress in femoral arteries and improve vascular injury.

Iatrogenic Carotid Artery Pseudoaneurym: Successful Treatment With Percutaneous Thrombin Injection.

This report demonstrates the successful treatment of a carotid artery pseudoaneurysm using percutaneous thrombin injection. The patient, a 62-year-old woman with multiple comorbidities, experienced a pseudoaneurysm following an unintentional carotid artery puncture during a failed attempt to place a triple lumen catheter in the right jugular vein. Percutaneous thrombin injection was chosen as the treatment method, with Doppler ultrasound monitoring. Follow-up examinations showed no signs of recurrence, and the patient was discharged after nine days without complications.

Tartary buckwheat protein-derived peptide AFYRW alleviates H2O2-induced vascular injury via the PI3K/AKT/NF-κB pathway.

Tartary buckwheat protein-derived peptide (Ala-Phe-Tyr-Arg-Trp, AFYRW) is a natural active peptide that hampers the atherosclerosis process, but the underlying role of AFYRW in angiogenesis remains unknown. Here, we present a system-based study to evaluate the effects of AFYRW on H2O2-induced vascular injury in human umbilical vein endothelial cells (HUVECs). HUVECs were co-incubated with H2O2 for 2 h in the vascular injury model, and AFYRW was added 24 h in advance to investigate the protective mechanism of vascular injury. We identified that AFYRW inhibits oxidative stress, cell migration, cell invasion, and angiogenesis in H2O2-treated HUVECs. In addition, we found H2O2-induced upregulation of phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), phosphorylation of nuclear factor-κB (NF-κB) p65 and nuclear translocation of NF-κB decreased by AFYRW. Taken together, AFYRW attenuated H2O2-induced vascular injury through the PI3K/AKT/NF-κB pathway. Thereby, AFYRW may serve as a therapeutic option for vascular injuries.

Paeonol Promotes Reendothelialization After Vascular Injury Through Activation of c-Myc/VEGFR2 Signaling Pathway.

Purpose: Dysfunction of endothelium is associated with multiple pathological vascular diseases. However, how to regulate reendothelialization after vascular injury is not well defined. This study aims to determine whether and how Paeonol controls reendothelialization following artery injury. Methods: The endothelium of murine carotid artery was denuded by catheter guide wires injury. H&E staining and IF staining were performed to determine whether Paeonol is critical for reendothelialization. BRDU Incorporation Assay, Boyden Chamber Migration Assay, Tube Formation Assay, and Spheroid Sprouting Assay were used to investigate whether Paeonol is involved in regulating proliferation and migration of endothelial cells. The underlying mechanism of how Paeonol regulates reendothelialization was determined by Molecular docking simulation and CO-IP Assay. Results: Paeonol treatment significantly inhibits neointima formation in carotid artery ligation model by promoting proliferation and migration of endothelial cells. Mechanistically, Paeonol enhances c-Myc expression, consequently interacts with VEGFR2 results in activating VEGF signaling pathway, and eventually promotes reendothelialization after vascular injury. Conclusion: Our data demonstrated that Paeonol plays a critical role in regulating vascular reendothelialization, which may be therapeutically used for treatment of pathological vascular diseases.

Serum levels of angiotensin-converting enzyme 2 in children with Kawasaki disease.

Kawasaki disease (KD) has replaced rheumatic fever as the main cause of acquired heart disease in Japanese, American, and Chinese children. Polymorphisms in angiotensin-converting enzyme may be associated with susceptibility to KD, but the association of angiotensin-converting enzyme 2 (ACE2) with vascular endothelial injury in KD and the possibility for prognosis of vascular injury in KD by evaluating changes in serum ACE2 have not yet been assessed. Thus, this study aimed to investigate ACE2 levels in patients with KD to further explore the relationship between ACE2 and vascular injury in KD. Blood samples were collected from 49 children with KD before intravenous immunoglobulin treatment and 28 healthy children in the same period as the control group. Clinical data were collected from the patients and serum ACE2 levels of all participants were measured using an enzyme-linked immunosorbent assay. Serum ACE2 levels were significantly higher in the KD group than in the control group, and were negatively correlated with platelet levels in patients with KD. Serum ACE2 levels are related to the pathogenesis of KD and may be used as a potential serum marker for KD diagnosis.

Patient Preferences for Pharmaceutical and Device-Based Treatments for Uncontrolled Hypertension: Discrete Choice Experiment.

BACKGROUND: Discrete choice experiment is a survey method used to understand how individuals make decisions and to quantify the relative importance of features. Using discrete choice experiment methods, we quantified patient benefit-risk preferences for hypertension treatments, including pharmaceutical and interventional treatments, like renal denervation. METHODS: Respondents from the United States with physician-confirmed uncontrolled hypertension selected between treatments involving a procedure or pills, using a structured survey. Treatment features included interventional, noninterventional, or no hypertension treatment; number of daily blood pressure (BP) pills; expected reduction in office systolic BP; duration of effect; and risks of drug side effects, access site pain, or vascular injury. The results of a random-parameters logit model were used to estimate the importance of each treatment attribute. RESULTS: Among 400 patients completing the survey between 2020 and 2021, demographics included: 52% women, mean age 59.2±13.0 years, systolic BP 155.1±12.3 mm Hg, and 1.8±0.9 prescribed antihypertensive medications. Reduction in office systolic BP was the most important treatment attribute. The remaining attributes, in decreasing order, were duration of effect, whether treatment was interventional, number of daily pills, risk of vascular injury, and risk of drug side effects. Risk of access site pain did not influence choice. In general, respondents preferred noninterventional over interventional treatments, yet only a 2.3 mm Hg reduction in office systolic BP was required to offset this preference. Small reductions in office systolic BP would offset risks of vascular injury or drug side effects. At least a 20% risk of vascular injury or drug side effects would be tolerated in exchange for improved BP. CONCLUSIONS: Reduction in systolic BP was identified as the most important driver of patient treatment preference, while treatment-related risks had less influence. The results indicate that respondents would accept interventional treatments in exchange for modest reductions in systolic BP compared with those observed in renal denervation trials.

Galangin inhibits neointima formation induced by vascular injury via regulating the PI3K/AKT/mTOR pathway.

Aims: The proliferation and migration of vascular smooth muscle cells (VSMCs) play vital roles in the pathological process of neointima formation after vascular injury. Galangin, an extract of the ginger plant galangal, is involved in numerous biological activities, including inhibiting the proliferation and migration of tumor cells, but its effect on VSMCs is unknown. This study focused on the role and mechanism of galangin in the neointima formation induced by vascular injury. Methods and results: In this study, we found that galangin restrained the PDGF-BB-induced proliferation, migration and phenotypic switching of VSMCs in a concentration-dependent manner. In vivo, we established a model of carotid artery balloon injury in rats, followed by intragastric administration of galangin (40 mg kg-1 day-1 or 80 mg kg-1 day-1) for 14 or 28 consecutive days. Then, the degree of neointima hyperplasia was evaluated by H&E staining, and the level of relevant protein expression was assessed by immunofluorescence and western blotting. In vitro, we isolated and grew primary rat aortic smooth muscle cells, which were treated with PDGF-BB and different doses of galangin, and then CCK-8 assay, wound healing assay, transwell assay, western blotting and immunofluorescence assays were performed. We found that galangin significantly inhibited PDGF-BB-induced proliferation, migration, and phenotypic switching of VSMCs and promoted autophagy in VSMCs in vitro, and galangin significantly inhibited neointimal hyperplasia after the common carotid artery balloon injury in rats. In terms of mechanisms, galangin inhibited the PI3K/AKT/mTOR pathway, thereby suppressing VSMC's switch from a contractile to a synthetic phenotype, inhibiting VSMC proliferation, migration and phenotypic switching and upregulating the Beclin1 protein expression levels and the ratio of LC3BII/I, promoting VSMC autophagy, and thereby inhibiting neointimal hyperplasia after vascular injury. Conclusion: Our study suggests that galangin inhibits neointimal hyperplasia after vascular injury by inhibiting smooth muscle cell proliferation, migration and phenotypic switching and by promoting autophagy, and that galangin may be a promising drug for the prevention and treatment of vascular restenosis after PCI.

Dantrolene reduces platelet-derived growth factor (PDGF)-induced vascular smooth muscle cell proliferation and neointimal formation following vascular injury in mice.

Dantrolene is a ryanodine receptor blocker that is used clinically for treatment of malignant hyperthermia. This study was conducted using murine aortic vascular smooth muscle cells (MOVAS) and a mouse arterial injury model to investigate the inhibitory effect of dantrolene on smooth muscle cell proliferation and migration. We investigated whether dantrolene suppressed platelet-derived growth factor (PDGF)-induced vascular smooth muscle cell proliferation and migration in vitro. The effect of dantrolene on smooth muscle phenotype was evaluated using immunostaining. In addition, smooth muscle cell proliferation and phenotype switching were tested by applying dantrolene around blood vessels using a mouse arterial injury model. Dantrolene inhibited PDGF-induced cell proliferation and migration of MOVAS. Dantrolene also inhibited the switch from contractile to synthetic phenotype both in vitro and in vivo. Dantrolene is effective at inhibiting vascular smooth muscle cell proliferation, migration, and neointimal formation following arterial injury in mice.

Liraglutide alleviates vascular injury in diabetic rabbits with lower limb vascular stenosis through regulation of RCAN1.

OBJECTIVE: The aim of the present study is to explore the possible mechanism that may have ameliorative effect of liraglutide (Lira) on diabetic lower extremity vascular stenosis. MATERIALS AND METHODS: A diabetic rabbit model of lower extremity stenosis was established and treated with Lira. The intimal hyperplasia of the lower extremity and the oxidative stress level of vascular tissue were observed and examined. Vascular smooth muscle cells (VSMCs) induced by high glucose (HG) were treated with Lira, and RCAN1 overexpressing plasmid was constructed to transfect VCMCs. RESULTS: Lira treatment showed its association in significantly improving the hyperplasia of the intima, the level of oxidative stress, and the level of homeostasis model assessment of insulin resistance (HOMA-IR) in rabbits induced by diabetes and lower limb stenosis. In addition, Lira treatment reduced the elevated expression of RCAN1 in vascular tissues induced by diabetes. Not only could Lira treatment inhibit the increase of ROS level, proliferation and migration of VSMCs induced by HG, but reduce the expression of PCNA, MMP-9 and collagen I induced by HG. Overexpression of RCAN1 in VSMCs counteracted the effect of Lira, suggesting that Lira affected the proliferation and migration of VSMCs by regulating RCAN1. CONCLUSIONS: Our findings have important implications for Lira to exert beneficial outcomes in reducing excessive neointimal formation after lower extremity vascular injury in diabetic rabbits via the regulation of RCAN1.

17R/S-Benzo-RvD1, a synthetic resolvin D1 analogue, attenuates neointimal hyperplasia in a rat model of acute vascular injury.

BACKGROUND: Persistent inflammation following vascular injury drives neointimal hyperplasia (NIH). Specialized lipid mediators (SPM) mediate resolution which attenuates inflammation and downstream NIH. We investigated the effects of a synthetic analogue of resolvin D1 (RvD1) on vascular cells and in a model of rat carotid angioplasty. METHODS: Human venous VSMC and endothelial cells (EC) were employed in migration, cell shape, toxicity, proliferation and p65 nuclear translocation assays. Murine RAW 264.7 cells were utilized to test the effect of pro-resolving compounds on phagocytic activity. A model of rat carotid angioplasty was used to evaluate the effects of 17R/S-benzo-RvD1 (benzo-RvD1) and 17R-RvD1 applied to the adventitia via 25% Pluronic gel. Immunostaining was utilized to examine Ki67 expression and leukocyte recruitment. Morphometric analysis was performed on arteries harvested 14 days after injury. RESULTS: Exposure to benzo-RvD1 attenuated PDGF- stimulated VSMC migration across a range of concentrations (0.1-100 nM), similar to that observed with 17R-RvD1. Pre-treatment with either Benzo-RvD1 or 17R-RvD1 (10, 100nM) attenuated PDGF-BB-induced VSMC cytoskeletal changes to nearly baseline dimensions. Benzo-RvD1 demonstrated modest anti-proliferative activity on VSMC and EC at various concentrations, without significant cytotoxicity. Benzo-RvD1 (10nM) inhibited p65 nuclear translocation in cytokine-stimulated EC by 21% (p<0.05), similar to 17R-RvD1. Consistent with pro-resolving activities of other SPM, both 17R-RvD1 and benzo-RvD1 increased the phagocytic activity of RAW 264.7 cells against S. Aureus and Zymosan particles. There were no significant differences in Ki-67 or CD45 staining observed on day 3 after angioplasty. Periadventitial treatment with benzo-RvD1 reduced carotid neointimal area at 14 days compared to control (0.08 mm2 v. 0.18 mm2; p<0.05), with similar efficacy to 17R-RvD1. CONCLUSIONS: 17R/S-benzo-RvD1 and 17R-RvD1 exhibit similar pro-resolving and anti-migratory activity in cell-based assays, and both compounds attenuated NIH following acute arterial injury in rats. Further studies of the mechanisms of resolution following vascular injury, and the translational potential of SPM analogues, are indicated.

Metformin prevents methylglyoxal-induced apoptosis by suppressing oxidative stress in vitro and in vivo.

Methylglyoxal (MGO) is an active metabolite of glucose and plays a prominent role in the pathogenesis of diabetic vascular complications, including endothelial cell apoptosis induced by oxidative stress. Metformin (MET), a widely prescribed antidiabetic agent, appears to reduce excessive reactive oxygen species (ROS) generation and limit cell apoptosis. However, the molecular mechanisms underlying this process are still not fully elucidated. We reported here that MET prevents MGO-induced apoptosis by suppressing oxidative stress in vitro and in vivo. Protein expression and protein phosphorylation were investigated using western blotting, ELISA, and immunohistochemical staining, respectively. Cell viability and apoptosis were assessed by the MTT assay, TUNEL staining, and Annexin V-FITC and propidium iodide double staining. ROS generation and mitochondrial membrane potential (MMP) were measured with fluorescent probes. Our results revealed that MET prevented MGO-induced HUVEC apoptosis, inhibited apoptosis-associated biochemical changes such as loss of MMP, the elevation of the Bax/Bcl-2 ratio, and activation of cleaved caspase-3, and attenuated MGO-induced mitochondrial morphological alterations in a dose-dependent manner. MET pretreatment also significantly suppressed MGO-stimulated ROS production, increased signaling through the ROS-mediated PI3K/Akt and Nrf2/HO-1 pathways, and markedly elevated the levels of its downstream antioxidants. Finally, similar results were obtained in vivo, and we demonstrated that MET prevented MGO-induced oxidative damage, apoptosis, and inflammation. As expected, MET reversed MGO-induced downregulation of Nrf2 and p-Akt. In addition, a PI3K inhibitor (LY-294002) and a Nrf2 inhibitor (ML385) observably attenuated the protective effects of MET on MGO-induced apoptosis and ROS generation by inhibiting the Nrf2/HO-1 pathways, while a ROS scavenger (NAC) and a permeability transition pores inhibitor (CsA) completely reversed these effects. Collectively, these findings broaden our understanding of the mechanism by which MET regulates apoptosis induced by MGO under oxidative stress conditions, with important implications regarding the potential application of MET for the treatment of diabetic vascular complications.

An Unusual Cause of Internal Carotid Artery Dissection: Mobile Phone Misuse.

The use of mobile phones has become an indispensable part of our lives, especially due to widespread use of the internet. We report the case of a 38-year-old male patient who developed internal carotid artery dissection after talking on the phone between her left shoulder and ear by laterally flexing the neck for 20 minutes. In addition to many positive effects of technology that facilitate the daily life, the development of neurological deficits may be observed with widespread use of mobile phones. Misuse of mobile phone should be considered in patients with carotid artery dissection.

Role of PDE10A in vascular smooth muscle cell hyperplasia and pathological vascular remodelling.

AIMS: Intimal hyperplasia is a common feature of vascular remodelling disorders. Accumulation of synthetic smooth muscle cell (SMC)-like cells is the main underlying cause. Current therapeutic approaches including drug-eluting stents are not perfect due to the toxicity on endothelial cells and novel therapeutic strategies are needed. Our preliminary screening for dysregulated cyclic nucleotide phosphodiesterases (PDEs) in growing SMCs revealed the alteration of PDE10A expression. Herein, we investigated the function of PDE10A in SMC proliferation and intimal hyperplasia both in vitro and in vivo. METHODS AND RESULTS: RT-qPCR, immunoblot, and in situ proximity ligation assay were performed to determine PDE10A expression in synthetic SMCs and injured vessels. We found that PDE10A mRNA and/or protein levels are up-regulated in cultured SMCs upon growth stimulation, as well as in intimal cells in injured mouse femoral arteries. To determine the cellular functions of PDE10A, we focused on its role in SMC proliferation. The anti-mitogenic effects of PDE10A on SMCs were evaluated via cell counting, BrdU incorporation, and flow cytometry. We found that PDE10A deficiency or inhibition arrested the SMC cell cycle at G1-phase with a reduction of cyclin D1. The anti-mitotic effect of PDE10A inhibition was dependent on cGMP-dependent protein kinase Iα (PKGIα), involving C-natriuretic peptide (CNP) and particulate guanylate cyclase natriuretic peptide receptor 2 (NPR2). In addition, the effects of genetic depletion and pharmacological inhibition of PDE10A on neointimal formation were examined in a mouse model of femoral artery wire injury. Both PDE10A knockout and inhibition decreased injury-induced intimal thickening in femoral arteries by at least 50%. Moreover, PDE10A inhibition decreased ex vivo remodelling of cultured human saphenous vein segments. CONCLUSIONS: Our findings indicate that PDE10A contributes to SMC proliferation and intimal hyperplasia at least partially via antagonizing CNP/NPR2/cGMP/PKG1α signalling and suggest that PDE10A may be a novel drug target for treating vascular occlusive disease.

Reparo de lesão vascular não letal causada por tamanduá-bandeira (Myrmecophaga tridactyla) no Brasil / Repair of non-lethal vascular injury caused by giant anteater (Myrmecophaga tridactyla) in Brazil

Resumo O tamanduá-bandeira é um mamífero encontrado na América Central e na América do Sul. Esse animal possui garras que podem chegar a 6,5 cm de comprimento, utilizadas para escavar formigueiros e obter alimento, além de servir para sua defesa. Relatamos o caso de paciente masculino de 52 anos, com histórico de epilepsia, que foi levado desacordado ao pronto-socorro, devido a lesões no seu braço direito causadas por um tamanduá. Frente à suspeita de trauma vascular, o paciente foi submetido a exploração cirúrgica, que evidenciou uma lesão combinada de vasos braquiais, submetida a reparo. Apresentou boa evolução do quadro, recebendo alta hospitalar no segundo dia de pós-operatório e, no seguimento ambulatorial, evoluiu sem sequelas neurológicas ou vasculares.

Abstract The giant anteater is a mammal found in Central and South America. These animals have claws that can reach 6.5 centimeters in length, which they use to dig anthills to obtain food and for defense. We report the case of a 52-year-old male patient with a history of epilepsy who was taken unconscious to the emergency room due to injuries to his right arm caused by an anteater. He underwent surgical exploration to investigate suspected vascular trauma, revealing a combined (arterial and venous) injury of the brachial vessels, which were repaired. He recovered well and was discharged on the second postoperative day. During outpatient follow-up he continued to improve, with no neurological or vascular sequelae.

Aralia armata (Wall.) Seem Improves Intimal Hyperplasia after Vascular Injury by Downregulating the Wnt3α/Dvl-1/ß-Catenin Pathway.

The aim of the study is to examine the mechanism of Aralia armata (Wall.) Seem (AAS) in improving intimal hyperplasia after vascular injury in rats. Rats with femoral artery injury were randomly divided into three groups: the model group, AAS low-dose group (40 mg/kg), and AAS high-dose group (80 mg/kg). The sham operation group was used as a control group. HE staining was used to observe the changes in femoral artery vessels. Immunohistochemistry was adopted to detect α-SMA, PCNA, GSK-3ß, and ß-catenin proteins in femoral artery tissue. The CCK-8 test and wound healing assay were employed to analyze the effect of AAS on proliferation and migration of vascular smooth muscle cells (VSMCs) cultured in vitro. Western blotting (WB) and polymerase chain reaction (PCR) assays were used to evaluate the molecular mechanism. AAS reduced the stenosis of blood vessels and the protein expressions of α-SMA, PCNA, GSK-3ß, and ß-catenin compared to the model group. In addition, AAS (0-15 µg/mL) effectively inhibited the proliferation and migration of VSMCs. Moreover, the results of WB and PCR showed that AAS could inhibit the activation of ß-catenin induced by 15% FBS and significantly decrease the expression levels of Wnt3α, Dvl-1, GSK-3ß, ß-catenin, and cyclin D1 in the upstream and downstream of the pathway. AAS could effectively inhibit the proliferation and migration of neointima after vascular injury in rats by regulating the Wnt/ß-catenin signaling pathway.

Salt-Inducible Kinase 3 Promotes Vascular Smooth Muscle Cell Proliferation and Arterial Restenosis by Regulating AKT and PKA-CREB Signaling.

Objective: Arterial restenosis is the pathological narrowing of arteries after endovascular procedures, and it is an adverse event that causes patients to experience recurrent occlusive symptoms. Following angioplasty, vascular smooth muscle cells (SMCs) change their phenotype, migrate, and proliferate, resulting in neointima formation, a hallmark of arterial restenosis. SIKs (salt-inducible kinases) are a subfamily of the AMP-activated protein kinase family that play a critical role in metabolic diseases including hepatic lipogenesis and glucose metabolism. Their role in vascular pathological remodeling, however, has not been explored. In this study, we aimed to understand the role and regulation of SIK3 in vascular SMC migration, proliferation, and neointima formation. Approach and Results: We observed that SIK3 expression was low in contractile aortic SMCs but high in proliferating SMCs. It was also highly induced by growth medium in vitro and in neointimal lesions in vivo. Inactivation of SIKs significantly attenuated vascular SMC proliferation and up-regulated p21CIP1 and p27KIP1. SIK inhibition also suppressed SMC migration and modulated actin polymerization. Importantly, we found that inhibition of SIKs reduced neointima formation and vascular inflammation in a femoral artery wire injury model. In mechanistic studies, we demonstrated that inactivation of SIKs mainly suppressed SMC proliferation by down-regulating AKT (protein kinase B) and PKA (protein kinase A)-CREB (cAMP response element-binding protein) signaling. CRTC3 (CREB-regulated transcriptional coactivator 3) signaling likely contributed to SIK inactivation-mediated antiproliferative effects. Conclusions: These findings suggest that SIK3 may play a critical role in regulating SMC proliferation, migration, and arterial restenosis. This study provides insights into SIK inhibition as a potential therapeutic strategy for treating restenosis in patients with peripheral arterial disease.

Valsartan Prevented Neointimal Hyperplasia and Inhibited SRSF1 Expression and the TLR4-iNOS-ERK-AT1 Receptor Pathway in the Balloon-injured Rat Aorta.

Valsartan has the potential to attenuate neointimal hyperplasia and to suppress the inflammatory response. This study aimed to evaluate the role of valsartan in neointimal hyperplasia and the toll-like receptor 4 (TLR4)-nitric oxide synthase (NOS) pathway in the balloon-injured rat aorta.Forty-eight Wistar rats were randomly allocated to three groups: sham control (control), balloon-injured group (surgery), and balloon-injured+valsartan-treated group (valsartan). Rats were killed at 14 and 28 days after balloon-injury, and then the aortic tissues were collected for morphometric analysis as well as for measurements of the mRNA or protein expression of angiotensin II, angiotensin II type 1 (AT1) receptor, angiotensin II type 2 (AT2) receptor, TLR4, endothelial nitric oxide synthase (eNOS), inducible NOS (iNOS), serine/arginine-rich splicing factor 1(SRSF1) and extracellular signal regulated kinase (ERK). Valsartan at a dose of 20 mg/kg/day markedly decreased neointimal hyperplasia in the aorta of balloon-injured rats, and significantly reduced the mRNA or protein expression of TLR4, AT1 receptor, SRSF1 and phosphorylated-ERK (p-ERK) as well as the aortic levels of iNOS (all p < 0.05). Moreover, valsartan increased the eNOS level and AT2 receptor mRNA and protein expression levels (all p < 0.05). Valsartan prevented neointimal hyperplasia and inhibited SRSF1 expression and the TLR4-iNOS-ERK-AT1 receptor pathway in the balloon-injured rat aorta.

Roles of vascular endothelial and smooth muscle cells in the vasculoprotective effect of insulin in a mouse model of restenosis.

BACKGROUND: Insulin exerts vasculoprotective effects on endothelial cells (ECs) and growth-promoting effects on vascular smooth muscle cells (SMCs) in vitro, and suppresses neointimal growth in vivo. Here we determined the role of ECs and SMCs in the effect of insulin on neointimal growth. METHODS: Mice with transgene CreERT2 under the control of EC-specific Tie2 (Tie2-Cre) or SMC-specific smooth muscle myosin heavy chain promoter/enhancer (SMMHC-Cre) or littermate controls were crossbred with mice carrying a loxP-flanked insulin receptor (IR) gene. After CreERT2-loxP-mediated recombination was induced by tamoxifen injection, mice received insulin pellet or sham (control) implantation, and underwent femoral artery wire injury. Femoral arteries were collected for morphological analysis 28 days after wire injury. RESULTS: Tamoxifen-treated Tie2-Cre+ mice showed lower IR expression in ECs, but not in SMCs, than Tie2-Cre- mice. Insulin treatment reduced neointimal area after arterial injury in Tie2-Cre- mice, but had no effect in Tie2-Cre+ mice. Tamoxifen-treated SMMHC-Cre+ mice showed lower IR expression in SMCs, but not in ECs, than SMMHC-Cre- mice. Insulin treatment reduced neointimal area in SMMHC-Cre- mice, whereas unexpectedly, it failed to inhibit neointima formation in SMMHC-Cre+ mice. CONCLUSION: Insulin action in both ECs and SMCs is required for the "anti-restenotic" effect of insulin in vivo.

Current progress on the mechanisms of hyperhomocysteinemia-induced vascular injury and use of natural polyphenol compounds.

Cardiovascular disease is one of the most common diseases in the elderly population, and its incidence has rapidly increased with the prolongation of life expectancy. Hyperhomocysteinemia is an independent risk factor for various cardiovascular diseases, including atherosclerosis, and damage to vascular function plays an initial role in its pathogenesis. This review presents the latest knowledge on the mechanisms of vascular injury caused by hyperhomocysteinemia, including oxidative stress, endoplasmic reticulum stress, protein N-homocysteinization, and epigenetic modification, and discusses the therapeutic targets of natural polyphenols. Studies have shown that natural polyphenols in plants can reduce homocysteine levels and regulate DNA methylation by acting on oxidative stress and endoplasmic reticulum stress-related signaling pathways, thus improving hyperhomocysteinemia-induced vascular injury. Natural polyphenols obtained via daily diet are safer and have more practical significance in the prevention and treatment of chronic diseases than traditional drugs.

Melatonin attenuates restenosis after vascular injury in diabetic rats through activation of the Nrf2 signaling pathway.

Diabetes is a major risk factor for the development of cardiovascular disease. Diabetic patients have a higher incidence of restenosis following endovascular therapy than non-diabetic patients. Melatonin is primarily synthesized and secreted by the pineal gland and plays an important protective anti-inflammatory and antioxidant role in a variety of cardiovascular diseases. However, no studies to date have evaluated the underlying effects and molecular mechanisms of melatonin on diabetes-related restenosis. Herein, we used an in vivo model of diabetes-related restenosis and an in vitro model of high glucose-cultured vascular smooth muscle cells to investigate the anti-restenosis effect and signaling mechanisms induced by melatonin treatment. The present study provides the first evidence that melatonin attenuates restenosis following vascular injury in diabetic rats. We further investigated the underlying molecular mechanisms both in vivo and in vitro. The data suggest that the Nrf2 signaling pathway is an important molecular target for melatonin-mediated inhibition of diabetes-related restenosis after vascular injury. These findings indicate that melatonin may represent a potential candidate for the prevention or treatment of vascular diseases and restenosis following endovascular therapy, especially in diabetic patients.