Erratum: [Corrigendum] Downregulated caveolin­1 expression serves a potential role in coronary artery spasm by inducing nitric oxide production in vitro.

[This corrects the article DOI: 10.3892/etm.2018.6646.].

The redox activity of polychlorinated biphenyl quinone metabolite orchestrates its pro-atherosclerosis effect via CAV1 phosphorylation.

Further investigations are required to prove that polychlorinated biphenyls (PCBs) exposure is a cardiovascular disease risk factor. Unlike previous studies that attributed the atherogenic effect of PCBs to aryl hydrocarbon receptor activation, we illustrated a new mechanism involved in the redox reactivity of PCBs. We discover the redox reactivity of quinone moiety is the primary factor for PCB29-pQ-induced proinflammatory response, which highly depends on the status of caveolin 1 (CAV1) phosphorylation. PCB29-pQ-mediated CAV1 phosphorylation disrupts endothelial nitric oxide synthase, toll-like receptor 4, and reduces interleukin-1 receptor-associated kinase 1 binding with CAV1. Phosphorylated proteomics analysis indicated that PCB29-pQ treatment significantly enriched phosphorylated peptides in protein binding functions, inflammation, and apoptosis signaling. Meanwhile, apolipoprotein E knockout (ApoE-/-) mice exposed to PCB29-pQ had increased atherosclerotic plaques compared to the vehicle group, while this effect was significantly reduced in ApoE-/-/CAV1-/- double knockout mice. Thus, we hypothesis CAV1 is a platform for proinflammatory cascades induced by PCB29-pQ on atherosclerotic processes. Together, these findings confirm that the redox activity of PCB metabolite plays a role in the etiology of atherosclerosis.

Optimal antiplatelet therapy for patients after antiplatelet therapy induced gastrointestinal bleeding: timing.

Adjusting antiplatelet strategies after antiplatelet-associated gastrointestinal bleeding (GIB) is a complex clinical challenge. To assess the risk of outcomes at different times of resumption of antiplatelet therapy in an attempt to find the optimal time to resume therapy. The study analyzed consecutive patients with antiplatelet-associated GIB from Beijing Friendship Hospital Information System between October 2019 and June 2022. The primary outcomes were recurrent bleeding, major adverse cardiovascular and cerebrovascular events (MACE), and all-cause death. Multivariate-adjusted Cox proportional hazards models were used to evaluate the risks of these outcomes. The receiver operating characteristic curve was used to find the optimal time to resume treatment. Of the 617 patients with GIB after antiplatelet therapy successfully followed up, the median follow-up was 246 (interquartile range: 120-466) days, most patients (87.36%) interrupted therapy after GIB and 45.22% resumed within 90 days, of which 35.13% resumed within 7 days and 64.87% resumed after 7 days. Resumption therapy had a low risk of recurrent bleeding (uninterrupted as a reference: HR 0.32, 95% CI 0.15-0.67, p = 0.003), MACE (no resumption as a reference: HR 0.66, 95% CI 0.45-0.98, p = 0.037), and all-cause death (no resumption as a reference: HR 0.18, 95% CI 0.08-0.40, p < 0.001). And resuming therapy within 7 days had a lower risk of MACE (HR 0.18, 95% CI 0.08-0.44, p < 0.001) than after 7 days without a significantly higher risk of re-bleeding. The optimal time point for resuming therapy in this study was 8.5 days. Resuming antiplatelet therapy after GIB provides better clinical benefits compared to discontinued and uninterrupted therapy, especially compared with resuming after 7 days, resuming within 7 days is associated with a lower risk of MACE and a less significant increased risk of recurrent bleeding, leading to a higher net clinical benefit. China Clinical Trial Registration: ChiCTR2200064063.

QRS score: A simple marker to quantify the extent of myocardial scarring in patients with chronic total arterial occlusion.

Background: Chronic total occlusion (CTO) is a critical and unique subgroup of coronary lesions. This study aimed to investigate the correlation between the Selvester QRS score and late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMRI) in quantifying myocardial scarring to provide a simple and feasible method for treating CTO. Methods: The medical records of 134 patients with absolute CTO who underwent coronary angiography between May 1, 2014 and December 30, 2017 were retrospectively reviewed. All patients were grouped according to the CTO location (right coronary artery [RCA] CTO, left artery descending [LAD] CTO, left circumflex [LCX] CTO, and multivessel CTO groups). The degree of myocardial scarring was determined according to the Selvester QRS score and using the LGE-CMRI. All patients were followed up for at least 12 months. Results: Among the 62 CTO patients, 55 had occlusion of a single vessel and seven had occlusion of multiple vessels, of which 27 (43.55%) were in the RCA CTO group, 16 (25.81%) in the LAD CTO group, 12 (19.35%) in the LCX CTO group, and 7 (11.29%) in the multivessel CTO group. The area under the receiver operating characteristic curve for the QRS score that was used to determine the degree of myocardial scarring was 0.806, with a sensitivity and specificity of 94.7% and 42.1%, respectively. The Selvester QRS score and LGE-CMRI measures of scar size were correlated in the RCA CTO, LCX CTO, and multivessel CTO groups (r = 0.466, 0.593, and 0.775, respectively). Conclusion: The Selvester QRS score was feasible for detecting myocardial scarring in patients with CTO.

Comparison of Clinical Outcomes Between Ticagrelor and Clopidogrel in Elderly Patients Undergoing Percutaneous Coronary Intervention: A Cohort Study.

Background: Age is a strong predictor of adverse outcomes due both to a higher risk of bleeding and ischemia. The purpose of this study was to evaluate the safety and efficacy of ticagrelor in elderly patients. Methods: Patients ≥75 years of age admitted to our center from January, 2015 to December, 2019 who had undergone percutaneous coronary intervention (PCI) and received dual antiplatelet therapy (DAPT) were included in our study. Eligible patients were divided into clopidogrel and ticagrelor groups according to the P2Y12 receptor inhibitor and were followed up for 1 year. The primary safety endpoint was types 2, 3, and 5 bleeding, as defined by Bleeding Academic Research Consortium (BARC), and the primary efficacy endpoint was combined major adverse cardiovascular and cerebrovascular events (MACCEs). A Cox proportional hazard model and propensity score matching were used to correct confounding factors. Results: Of 1505 patients enrolled in this study, 442 were assigned to ticagrelor group and 1063 were assigned to clopidogrel group. The incidence of BARC 2, 3, and 5 bleeding (HR, 2.304; 95% CI, 1.540-3.447), and any bleeding (HR, 2.476; 95% CI, 1.802-3.403) in ticagrelor group was significantly higher than clopidogrel group. There were no significant difference between the two groups with respect to BARC 3 and 5 bleeding (HR, 1.566; 95% CI, 0.767-3.198) and MACCEs (HR, 0.957; 95% CI, 0.702-1.305). Conclusion: Compared with clopidogrel, DAPT with ticagrelor significantly increased the risk of BARC 2, 3, and 5 bleeding without reducing MACCEs in elderly patients who underwent PCI. Trial Registration: The study was retrospectively registered in clinicaltrials.gov (NCT04999293).

Evaluation of Early Biomarkers of Atherosclerosis Associated with Polychlorinated Biphenyl Exposure: An in Vitro and in Vivo Study.

BACKGROUND: Miscellaneous cardiovascular risk factors have been defined, but the contribution of environmental pollutants exposure on cardiovascular disease (CVD) remains underappreciated. OBJECTIVE: We investigated the potential impact of typical environmental pollutant exposure on atherogenesis and its underlying mechanisms. METHODS: We used human umbilical vein endothelial cells (HUVECs) and apolipoprotein E knockout (ApoE-/-) mice to investigate how 2,3,5-trichloro-6-phenyl-[1,4]-benzoquinone (PCB29-pQ, a toxic polychlorinated biphenyl metabolite) affects atherogenesis and identified early biomarkers of CVD associated with PCB29-pQ exposures. Then, we used long noncoding RNAs (lncRNAs) HDAC7-AS1-overexpressing ApoE-/- mice and apolipoprotein E/caveolin 1 double-knockout (ApoE-/-/CAV1-/-) mice to address the role of these early biomarkers in PCB29-pQ-induced atherogenesis. Plasma samples from patients with coronary heart disease (CHD) were also used to confirm our findings. RESULTS: Our data indicate that lncRNA HDAC7-AS1 bound to MIR-7-5p via argonaute 2 in PCB29-pQ-challenged HUVECs. Our mRNA sequencing assay identified transforming growth factor-ß2 (TGF-ß2) as a possible target gene of MIR-7-5p; HDAC7-AS1 sponged MIR-7-5p and inhibited the binding of TGF-ß2 to MIR-7-5p. The effect of PCB29-pQ-induced endothelial injury, vascular inflammation, development of plaques, and atherogenesis in ApoE-/- mice was greater with MIR-7-5p-mediated TGF-ß2 inhibition, whereas HDAC7-AS1-overexpressing ApoE-/- mice and ApoE-/-/CAV1-/- mice showed the opposite effect. Consistently, plasma levels of HDAC7-AS1 and MIR-7-5p were found to be significantly associated individuals diagnosed with CHD. DISCUSSIONS: These findings demonstrated that a mechanism-based, integrated-omics approach enabled the identification of potentially clinically relevant diagnostic indicators and therapeutic targets of CHD mediated by environmental contaminants using in vitro and in vivo models of HUVECs and ApoE-/- and ApoE-/-/CAV1-/- mice. https://doi.org/10.1289/EHP9833.

GALNT4 primes monocytes adhesion and transmigration by regulating O-Glycosylation of PSGL-1 in atherosclerosis.

Atherosclerosis is a major underlying cause of cardiovascular disease. Genome wide association studies have predicted that GalNAc-T4 (GALNT4), which responsible for initiating step of mucin-type O-glycosylation, plays a causal role in the susceptibility to cardiovascular diseases, whereas the precise mechanism remains obscure. Thus, we sought to determine the role and mechanism of GALNT4 in atherosclerosis. Firstly, we found the expression of GALNT4 and protein O-glycosylation were both increased in plaque as atherosclerosis progressed in ApoE-/- mice by immunohistochemistry. And the expression of GALNT4 was also increased in human monocytes treated with ACS (acute coronary syndrome) sera and subjected to LPS and ox-LDL in vitro. Moreover, silencing expression of GALNT4 by shRNA lentivirus alleviated atherosclerotic plaque formation and monocyte/macrophage infiltration in ApoE-/- mice. Functional investigations demonstrate that GALNT4 knockdown inhibited P-selectin-induced activation of ß2 integrin on the surface of monocytes, decreased monocytes adhesion under flow condition with P-selectin stimulation, as well as suppressed monocytes transmigration triggered by monocyte chemotactic protein- 1(MCP-1). In contrast, GALNT4 overexpression enhanced monocytes adhesion and transmigration. Furthermore, Vicia Villosa Lectin (VVL) pull down and PSGL-1 immunoprecipitation assays showed that GALNT4 overexpression increased O-Glycosylation of PSGL-1 and P-selectin induce phosphorylation of Akt/mTOR and IκBα/NFκB on monocytes. Conversely, knockdown of GALNT4 decreased VVL binding and attenuated the activation of Akt/mTOR and IκBα/NFκB. Additionally, mTOR inhibitor rapamycin blocked these effects of GALNT4 overexpression on monocytes. Collectively, GALNT4 catalyzed PSGL-1 O-glycosylation that involved in P-selectin induced monocytes adhesion and transmigration via Akt/mTOR and NFκB pathway. Thus, GALNT4 may be a potential therapeutic target for atherosclerosis.

TLR4-Myd88 pathway upregulated caveolin-1 expression contributes to coronary artery spasm.

AIM: To study the role of toll-like receptors 4-myeloid differentiation factor 88 (TLR4-Myd88) dependent caveolin-1 (Cav-1) expression modulation in coronary artery spasm (CAS) and explore the underlying pathogenic mechanisms. METHODS AND RESULTS: Lipopolysaccharide (LPS) and acetylcholine (Ach) were used to develop the in vitro and in vivo models mimicking the physiological CAS microenvironment. LPS-induced upregulation of Cav-1 expression in mouse coronary and aorta endothelial cells was shown by western blot and immunofluorescence (IF) staining (p < 0.01). Caveolin-1-knockout (Cav-1-/-) mice had reduced aortic inflammation after LPS challenge, and fewer ST segment changes were observed through electrocardiogram (ECG) monitoring compared to wild type mice after LPS and ACh administration. In vitro, pretreating human umbilical vein endothelial cells (HUVECs) with siCav-1 to knock down Cav-1 expression reduced the endothelial inflammation following LPS challenge. SiCav-1 also partially reversed the attenuated Ca2+ concentration after LPS and ACh administration compared to the control group, which was evaluated by fluorescent molecular probing for Ca2+ alternation monitoring (p < 0.05). TLR4 and Myd88 downregulation by siRNA partially blocked the increased Cav-1 mRNA and protein expressions following LPS treatment, as well as partially reversed the decreased NO production evaluated by nitrate reductase method and the impaired Ca2+ concentration of endothelial cells induced by LPS and ACh. CONCLUSION: These findings suggested that Cav-1, which was upregulated by TLR4-Myd88, served as an important modulator of CAS microenvironment establishment in vivo and in vitro, making it a potential pharmacologic target for the treatment of vasospasm via reduced endothelial cell inflammation.

Elevated Wnt2 and Wnt4 activate NF-κB signaling to promote cardiac fibrosis by cooperation of Fzd4/2 and LRP6 following myocardial infarction.

BACKGROUND: Acute myocardial infarction (AMI)-induced excessive myocardial fibrosis exaggerates cardiac dysfunction. However, serum Wnt2 or Wnt4 level in AMI patients, and the roles in cardiac fibrosis are largely unkown. METHODS: AMI and non-AMI patients were enrolled to examine serum Wnt2 and Wnt4 levels by ELISA analysis. The AMI patients were followed-up for one year. MI mouse model was built by ligation of left anterior descending branch (LAD). FINDINGS: Serum Wnt2 or Wnt4 level was increased in patients with AMI, and the elevated Wnt2 and Wnt4 were correlated to adverse outcome of these patients. Knockdown of Wnt2 and Wnt4 significantly attenuated myocardial remodeling and cardiac dysfunction following experimental MI. In vitro, hypoxia enhanced the secretion and expression of Wnt2 and Wnt4 in neonatal rat cardiac myocytes (NRCMs) or fibroblasts (NRCFs). Mechanistically, the elevated Wnt2 or Wnt4 activated ß-catenin /NF-κB signaling to promote pro-fibrotic effects in cultured NRCFs. In addition, Wnt2 or Wnt4 upregulated the expression of these Wnt co-receptors, frizzled (Fzd) 2, Fzd4 and (low-density lipoprotein receptor-related protein 6 (LRP6). Further analysis revealed that Wnt2 or Wnt4 activated ß-catenin /NF-κB by the co-operation of Fzd4 or Fzd2 and LRP6 signaling, respectively. INTERPRETATION: Elevated Wnt2 and Wnt4 activate ß-catenin/NF-κB signaling to promote cardiac fibrosis by cooperation of Fzd4/2 and LRP6 in fibroblasts, which contributes to adverse outcome of patients with AMI, suggesting that systemic inhibition of Wnt2 and Wnt4 may improve cardiac dysfunction after MI.

Clinical Outcomes of Concomitant Use of Proton Pump Inhibitors and Dual Antiplatelet Therapy: A Systematic Review and Meta-Analysis.

Background: The safety and efficacy associated with the use of proton pump inhibitors (PPIs) by patients with coronary artery disease receiving dual antiplatelet therapy (DAPT) remain unclear. Methods: The evaluated outcomes included combined major adverse cardiovascular events (MACEs), myocardial infarction (MI), all-cause mortality, and gastrointestinal (GI) bleeding. A random effects meta-analysis, stratified by study design, was performed and heterogeneity was assessed using the I2 statistic. Results: In total, 6 randomized controlled trials (RCTs) (6930 patients) and 16 observational studies (183,546 patients) were included. Analysis of RCTs showed that there were no significant differences in the incidences of MACEs (risk ratio [RR] = 0.89 [95% confidence interval (CI) = 0.75-1.05]), MI (RR = 0.93 [95% CI = 0.76-1.15]), and all-cause mortality (RR = 0.79 [95% CI = 0.50-1.23]) in the PPI groups vs. the non-PPI groups. Pooled data from observational studies revealed an inconsistent association between the use of each PPI subtype and the increased risks of MACEs during clopidogrel treatment. There was no increased risk of MACEs or all-cause mortality associated with the use of PPIs (as a class) and other P2Y12 inhibitors. Both the RCTs and observational studies revealed that the use of PPIs significantly reduced the risks of GI bleeding. Conclusion: The use of PPIs was associated with a reduced risk of GI bleeding in patients treated with DAPT after percutaneous coronary intervention or acute coronary syndrome. There was no clear evidence of an association between the use of PPIs and adverse cardiovascular events. Clinical Trial Registration: identifier [CRD42020190315].

Deficiency of tenascin-C attenuated cardiac injury by inactivating TLR4/NLRP3/caspase-1 pathway after myocardial infarction.

Inflammation and pyroptosis play a deleterious role in cardiac dysfunction after myocardial infarction (MI). NLRP3/caspase-1 is a well-established axis in pyroptosis and inflammation. In this study, we examined the effects of TN-C on pyroptosis through NLRP3 is unclear. We constructed 18 TN-C-knockout and 38 WT male mice model and divided into WT sham (n = 16), WT MI (n = 22), TNKO sham (n = 6), TNKO MI (n = 12). Elisa, immunostaining, TTC, qPCR, CCK8, flow cytometry, and western blot, echocardiographic, TUNEL staining technologies were applied. Here, we found a positive correlation between TN-C and NLRP3 in heart tissue via the GEPIA database (r = 0.52, p < 0.05). The findings indicate that TN-C was elevated and peaked on the fifth day after MI. TN-C deficiency alleviated cardiac dysfunction (LVEF, FS, LVIDd, and LVIDs) and cardiomyocyte death. Though the intracellular levels of pyroptosis-related cytokine caspase-1, cleaved caspase-1, NLRP3, IL-18, IL-1ß were upregulated both in MI and H2O2 stimulation, knockout of TN-C resisted such injury and alleviated cardiac pyroptosis, which further decreased IL-6, TNF-α, MCP-1 expression. TN-C knockdown inhibited TLR4 expression, reduces the release of downstream factors by inactivating the TLR4/NF-kB pathway, while protects the cardiomyocytes. And TLR4 inhibitor TAK-242 significantly reduced NLRP3 expression levels after MI. We demonstrated for the first time a direct link between MI-induced TN-C upregulation and caspase-1-dependent cardiomyocyte pyroptosis, a process mediated, at least in part, by TLR4/NF-kB/NLRP3 and IL-18, IL-1ß signaling pathways. These findings provide new insights into the role of TN-C in post-MI cardiomyocytes' pyroptosis and inflammation.

Evaluation of Therapeutic Agents Targeting the Pathogenesis of Coronary Artery Spasm: A Mini Review.

Coronary artery spasm (CAS) plays an important role in the pathogenesis of ischemic heart disease. The clinical manifestations of CAS include variant angina, myocardial infarction and sudden death. Although endothelial dysfunction and hyperreactivity of vascular smooth muscle cells have been associated with CAS, the underlying mechanisms remain unclear. Thus, there is a long way to go to truly understand the pathogenesis of CAS to formulate effective treatments. This article discusses the pathophysiological mechanisms as well as downstream molecular pathways of CAS, with a focus on potential therapeutic targets.

The P-selectin and PSGL-1 axis accelerates atherosclerosis via activation of dendritic cells by the TLR4 signaling pathway.

P-selectin and dendritic cells (DCs) are associated with atherosclerosis. However, their interactions in this setting are undefined. Herein, we investigated the role of P-selectin and its receptor P-selectin glycoprotein ligand (PSGL)-1 on atherosclerosis via activation of DCs. In the current study, a total of 34 patients with ST elevation myocardial infarction (STEMI) and 34 healthy control subjects were enrolled. Serum concentration of P-selectin was higher and the myeloid DC/plasmacytoid DC (mDC/pDC) ratio was lower in STEMI patients than in normal individuals. Interestingly, in STEMI patients, P-selectin was decreased and the mDC/pDC ratio was increased at 5-7 days after successful percutaneous coronary intervention, as compared with values on admission. Serum P-selectin was inversely correlated with the mDC/pDC ratio. Moreover, ApoE-/-P-/- and ApoE-/-PSGL-1-/- mice developed small atherosclerotic plaques after feeding of a western diet for 12 weeks and DC infiltration was significantly reduced. P-selectin stimulation markedly induced phenotypic maturation, enhanced secretion of inflammatory cytokines, communication with T cells, and the adhesion and migration of DCs. In vivo, DC maturation was significantly attenuated in P-selectin and PSGL1 knockout mice under hypercholesterolemic and inflammatory conditions. These effects were associated with the activation of myeloid differentiation primary response 88 (MYD88)-dependent and MyD88-independent Toll-like receptor 4 (TLR4) signaling pathways. Taken together, binding of P-selectin to PSGL-1 on DCs contributes to atherosclerosis progression via DC activation via the TLR4 signaling pathway.

Differences in the cargos and functions of exosomes derived from six cardiac cell types: a systematic review.

Exosomes are bilayer membrane vesicles with cargos that contain a variety of surface proteins, markers, lipids, nucleic acids, and noncoding RNAs. Exosomes from different cardiac cells participate in the processes of cell migration, proliferation, apoptosis, hypertrophy, and regeneration, as well as angiogenesis and enhanced cardiac function, which accelerate cardiac repair. In this article, we mainly focused on the exosomes from six main types of cardiac cells, i.e., fibroblasts, cardiomyocytes, endothelial cells, cardiac progenitor cells, adipocytes, and cardiac telocytes. This may be the first article to describe the commonalities and differences in regard to the function and underlying mechanisms of exosomes among six cardiac cell types in cardiovascular disease.

A Peptide Analogue of Selectin Ligands Attenuated Atherosclerosis by Inhibiting Monocyte Activation.

BACKGROUND: Circulating monocytes play a critical role in the pathogenesis of atherosclerosis. Monocyte homing to sites of atherosclerosis is primarily initiated by selectin. Thus, blockade of the interaction of selectins and their ligands holds a significant role in monocyte homing which might be a potential approach to treat atherosclerosis. Here, we investigated the efficacy of a novel peptide analogue of selectin ligands IELLQAR in atherosclerosis. METHODS AND RESULTS: In this study, we firstly measured the effect of the IELLQAR selectin-binding peptide on the inhibition of binding of selectins to monocytes by flow cytometry, which exhibited a dose-dependent inhibitory effect on the binding of the P-, E-, and L-selectins to monocytes, especially the inhibition of P-selectin binding to human peripheral blood monocytes (PBMCs) (half maximal inhibitory concentration (IC50~5 µM)) and THP-1 cells (IC50~10 µM). Furthermore, IELLQAR inhibited P-selectin-induced activation of CD11b on the surface of monocytes and decreased adhesion of monocytes to the endothelium. ApoE-/- mice with or without IELLQAR (1 or 3 mg/kg) fed a Western-type diet (WTD) or which had disturbed blood flow-induced shear stress underwent partial left carotid artery ligation (PLCA) to induce atherosclerosis. In the WTD- and PLCA-induced atherosclerosis models, atherosclerotic plaque formation and monocyte/macrophage infiltration of the arterial wall both decreased in ApoE-/- mice treated with the IELLQAR peptide. Our results also revealed that IELLQAR inhibited the differentiation of monocytes into macrophages through P-selectin-dependent activation of the nuclear factor- (NF-) κB and mammalian target of rapamycin (mTOR) pathways. CONCLUSION: Collectively, our results demonstrated that IELLQAR, a peptide analogue of selectin ligands, inhibited selectin binding to monocytes, which led to subsequent attenuation of atherosclerosis via inhibition of monocyte activation. Hence, use of the IELLQAR peptide provides a new approach and represents a promising candidate for the treatment of atherosclerosis in the early stage of disease.

Downregulated caveolin-1 expression serves a potential role in coronary artery spasm by inducing nitric oxide production in vitro.

The present study aimed to investigate the effects of downregulated caveolin-1 (Cav-1) expression on nitric oxide (NO) production in lipopolysaccharide (LPS)-damaged primary human umbilical vein endothelial cells (HUVECs) in a model of coronary artery spasm (CAS) microenvironment induced by acetylcholine (ACh) treatment. Small interfering RNA (siRNA)-mediated Cav-1 downregulation in HUVECs was confirmed by western blotting. The cell viability and superoxide dismutase (SOD) inhibition in HUVECs incubated with LPS (0, 10, 25, 50, 75 and 100 µg/ml) were measured by cell counting kit-8 assay and a SOD kit, respectively. Intracellular Ca2+ [(Ca2+)i] in Fluo4-acetoxymethyl ester-loaded cells was detected by fluorescence microscopy. NO levels in the cell culture supernatants were measured by the nitrate reductase method. The results indicated that transfection with Cav-1 siRNA, in particular siCav-1 (2), downregulated the Cav-1 protein expression. LPS at a dose of 75 µg/ml induced a significant decrease in HUVECs/si-NC and HUVECs/siCav-1 viability compared with the other concentrations of LPS. Compared with the effects of untreated cells, SOD inhibition in HUVECs/si-NC and HUVECs/siCav-1 was significantly decreased by LPS (75 µg/ml). In addition, ACh stimulation caused a greater increase in [Ca2+]i in HUVECs/si-NC as compared with LPS-treated HUVECs/si-NC. ACh stimulation also induced significantly higher NO levels in LPS-treated HUVECs/siCav-1 compared with LPS-treated HUVECs/si-NC cells (P<0.05). In conclusion, the downregulated Cav-1 expression served a key role in NO production in the in vitro model of CAS induced by ACh stimulation of LPS-damaged HUVECs.

Effects of different doses of granulocyte colony-stimulating factor mobilization therapy on ischemic cardiomyopathy.

G-CSF mobilization might be beneficial to ICM, but the relationship between effect/safety and the dosage of G-CSF remains unclear. In this study, 24 pigs were used to build ICM models and were randomized into four groups. Four weeks later, different dosages of G-CSF were given daily by subcutaneous injection for 5 days. Another 4 weeks later, all the animals were sacrificed. Electrocardiography, coronary arteriography, left ventriculography, transthoracic echocardiography, cardiac MRI, and SPECT, histopathologic analysis, and immunohistochemistry techniques were used to evaluate left ventricular function and myocardial infarct size. Four weeks after G-CSF treatment, pigs in middle-dose G-CSF group exhibited obvious improvements of left ventricular remodeling and function. Moderate G-CSF mobilization ameliorated the regional contractility of ICM, preserved myocardial viability, and reduced myocardial infarct size. More neovascularization and fewer apoptotic myocardial cells were observed in the ischemic region of the heart in middle-dose group. Expression of vWF, VEGF and MCP-1 were up-regulated, and Akt1 was activated in high- and middle-dose groups. Moreover, CRP, TNF-α and S-100 were elevated after high-dose G-CSF mobilization. Middle-dose G-CSF mobilization therapy is an effective and safe treatment for ICM, and probably acts via a mechanism involving promoting neovascularization, inhibiting cardiac fibrosis and anti-apoptosis.

Selectins modify dendritic cells during atherosclerosis.

Dendritic cells (DCs) are professional antigen-presenting cells (APC) that facilitate the development and progression of atherosclerosis. However, DCs also function as novel "switches" between immune activation and immune tolerance and represent a heterogeneous hematopoietic lineage, with cell subsets in different tissues that show a differential morphology, phenotype, and function. Regulatory DCs, depending on their immature state, can be induced by immunosuppressive modulation, which plays an important part in the maintenance of immunologic tolerance via suppression of the immune response. In this review, we describe the current understanding of the generation of regulatory DCs. The novel role of selectins in the modification of DCs in atherosclerosis is also discussed.

L-selectin Promotes the Maturation of Dendritic Cells via Up-regulation the Expression of TLR4 in vitro.

The relationship between dendritic cells (DCs) and L-selectin in the progress of atherosclerosis is unclear. Here, we used L-selectin co-cultured with DCs to investigate the effect of L-selectin on the maturation of DCs in vitro Monocytes derived DCs were isolated and cultured from human peripheral blood. After being stimulated with L-selectin and/or its antagonist for 24-48 hours, the feather of cells was observed by the electron microscope. The expression of mature antigens CD1a, CD80, CD83, and CD86 were investigated by flow cytometric analysis (FACS). RT-PCR and FACS were used to detect the mRNA and protein expression of Toll-like receptor 4(TLR-4). We found that only the cells of giving L-selectin have the mature special feature for irregular shapes. DCs which were stimulated by L-selectin have a larger number of expressing CD1a, CD80, CD83, and CD86 compared with non-stimulated and cultured with L-selectin antagonist. The transcript levels of TLR4 were significantly higher after L-selectin and lipopolysaccharide (LPS) stimulated. And the antagonist of L-selectin can deeply decrease the expression of CD1a, CD80, CD83, and CD86 on DCs appeared to coincide with the level of TLR4 transcription. The results demonstrate L-selectin can promote the maturation of DCs via up-regulation the expression of TLR4.

Subcutaneous injection of dendritic cells aggravates atherosclerosis in ApoE­knockout mice by activation of TLR4.

Dendritic cells (DCs) are specialized antigen­presenting cells which are important in immune diseases, in particular atherosclerosis, a chronic inflammatory disease, however their role in atherosclerosis­associated immunity is unclear. To evaluate the role of DCs in atherosclerosis, exogenous bone marrow­derived DCs were transferred into ApoE­/­ mice in the present study. The extent of disease was measured in the aorta and was compared with mice treated with phosphate­buffered saline (PBS) or left untreated and fed a western diet. Mice receiving exogenous DCs demonstrated significantly larger atherosclerotic lesions compared with the mice treated with PBS, with increasing numbers of mature DCs in circulation and enhanced DC infiltration into plaque lesions, in addition to activation of circulating inflammatory components and atherosclerotic lesions. Furthermore, it was demonstrated that exogenous DCs upregulated the expression of Toll­like receptor 4 (TLR4) on DCs, which may be an important mechanism to activate DCs and aggravate atherosclerosis. Therefore the present study concluded that exogenous DCs may induce maturation of endogenous DCs via upregulation of TLR4, further increasing the inflammatory response and accelerating atherosclerosis.