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<p><b>Background</b>Oxidized low-density lipoprotein (ox-LDL)-induced oxidative stress and endothelial apoptosis are essential for atherosclerosis. Our previous study has shown that ox-LDL-induced apoptosis is mediated by the protein kinase RNA-like endoplasmic reticulum kinase (PERK)/eukaryotic translation initiation factor 2α-subunit (eIF2α)/CCAAT/enhancer-binding protein homologous protein (CHOP) endoplasmic reticulum (ER) stress pathway in endothelial cells. Statins are cholesterol-lowering drugs that exert pleiotropic effects including suppression of oxidative stress. This study aimed to explore the roles of simvastatin on ox-LDL-induced ER stress and apoptosis in endothelial cells.</p><p><b>Methods</b>Human umbilical vein endothelial cells (HUVECs) were treated with simvastatin (0.1, 0.5, or 2.5 μmol/L) or DEVD-CHO (selective inhibitor of caspase-3, 100 μmol/L) for 1 h before the addition of ox-LDL (100 μg/ml) and then incubated for 24 h, and untreated cells were used as a control group. Apoptosis, expression of PERK, phosphorylation of eIF2α, CHOP mRNA level, and caspase-3 activity were measured. Comparisons among multiple groups were performed with one-way analysis of variance (ANOVA) followed by post hoc pairwise comparisons using Tukey's tests. A value of P < 0.05 was considered statistically significant.</p><p><b>Results</b>Exposure of HUVECs to ox-LDL resulted in a significant increase in apoptosis (31.9% vs. 4.9%, P < 0.05). Simvastatin (0.1, 0.5, and 2.5 μmol/L) led to a suppression of ox-LDL-induced apoptosis (28.0%, 24.7%, and 13.8%, F = 15.039, all P < 0.05, compared with control group). Ox-LDL significantly increased the expression of PERK (499.5%, P < 0.05) and phosphorylation of eIF2α (451.6%, P < 0.05), if both of which in the control groups were considered as 100%. Simvastatin treatment (0.1, 0.5, and 2.5 μmol/L) blunted ox-LDL-induced expression of PERK (407.8%, 339.1%, and 187.5%, F = 10.121, all P < 0.05, compared with control group) and phosphorylation of eIF2α (407.8%, 339.1%, 187.5%, F = 11.430, all P < 0.05, compared with control group). In contrast, DEVD-CHO treatment had no significant effect on ox-LDL-induced expression of PERK (486.4%) and phosphorylation of eIF2α (418.8%). Exposure of HUVECs to ox-LDL also markedly induced caspase-3 activity together with increased CHOP mRNA level; these effects were inhibited by simvastatin treatment.</p><p><b>Conclusions</b>This study suggested that simvastatin could inhibit ox-LDL-induced ER stress and apoptosis in vascular endothelial cells.</p>
Assuntos
Humanos , Apoptose , Células Cultivadas , Estresse do Retículo Endoplasmático , Células Endoteliais da Veia Umbilical Humana , Metabolismo , Lipoproteínas LDL , Farmacologia , Oligopeptídeos , Farmacologia , Sinvastatina , FarmacologiaRESUMO
<p><b>OBJECTIVE</b>A new technique of transthoracic lung ultrasonography (TLS) has emerged and demonstrated promising results in acute heart failure diagnosis at an early stage. However, the diagnostic value of ultrasound lung comets (ULCs) for acute heart failure (AHF) performed in busy emergency department (ED) is uncertain. The present meta-analysis aimed to assess the diagnostic efficiency of ULCs in AHF.</p><p><b>METHODS</b>We conducted a search on online journal databases to collect the data on TLS performed for diagnosing AHF published up to the end of July 2017. The sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and summary receiver operating characteristic (SROC) curve were calculated. The post-test probability of AHF was calculated by using Bayes analysis.</p><p><b>RESULTS</b>We enrolled a total of 15 studies involving 3,309 patients. The value of sensitivity, specificity, PLR, NLR, DOR, area under the SROC curve, and Q* index was 85%, 91%, 8.94, 0.14, 67.24, 0.9587, and 0.9026, respectively. We detected significant heterogeneity among included studies, and therefore, all these results were analyzed under the random-effect model. We also explored possible sources of heterogeneity among the studies by using meta-regression analysis. Results suggest that the time interval between patient's admission to bedside TLS examination was closely related to TLS accuracy.</p><p><b>CONCLUSION</b>This meta-analysis demonstrated that detecting ULCs is a convenient bedside tool and has high accuracy for early AHF diagnosis in ED. TLS could be recommended to be applied for early diagnosis of AHF in ED.</p>
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<p><b>OBJECTIVE</b>PERK/eIF2α/CHOP is a major signaling pathway mediating endoplasmic reticulum (ER) stress related with atherosclerosis. Oxidized LDL (ox-LDL) also induces endothelial apoptosis and plays a vital role in the initiation and progression of atherosclerosis. The present study was conducted to explore the regulatory effect of ox-LDL on PERK/eIF2α/CHOP signaling pathway in vascular endothelial cells.</p><p><b>METHODS</b>The effects of ox-LDL on PERK and p-eIF2α protein expression of primary human umbilical vein endothelial cells (HUVECs) were investigated by Western blot analysis. PERK gene silencing and selective eIF2α phosphatase inhibitor, salubrinal were used to inhibit the process of ox-LDL induced endothelial cell apoptosis, caspase-3 activity, and CHOP mRNA level.</p><p><b>RESULTS</b>Ox-LDL treatment significantly increased the expression of PERK, PERK-mediated inactivation of eIF2α phosphorylation, and the expression of CHOP, as well as the caspase-3 activity and apoptosis. The effects of ox-LDL were markedly decreased by knocking down PERK with stable transduction of lentiviral shRNA or by selective eIF2α phosphatase inhibitor, salubrinal.</p><p><b>CONCLUSION</b>This study provides the first evidence that ox-LDL induces apoptosis in vascular endothelial cells mediated largely via the PERK/eIF2α/CHOP ER-stress pathway. It adds new insights into the molecular mechanisms underlying the pathogenesis and progression of atherosclerosis.</p>
Assuntos
Humanos , Apoptose , Estresse do Retículo Endoplasmático , Fator de Iniciação 2 em Eucariotos , Genética , Metabolismo , Células Endoteliais da Veia Umbilical Humana , Metabolismo , Lipoproteínas LDL , Genética , Metabolismo , Transdução de Sinais , Fator de Transcrição CHOP , Genética , Metabolismo , eIF-2 Quinase , Genética , MetabolismoRESUMO
Objective To investigate the protective effects of Ulinastatin (UTI) and 1, 6 fructose diphosphate (FDP) on cerebral ischemia-reperfusion injury, and to discuss the protective mechanisms of UT1 and FDP on cerebral ischemia-repeffusion injury. Method Rabbit ischemia-repeffusion injury models were prepared by"four arteries occlusion". All rabbits were divided into four groups (n=6): control group, UTI (10 U/kg) group, FDP (200 mg/kg) group, UTI+ FDP group. Salt water, UTI, FDP and UTI + FDP were respectively used immediately after ischemia-reperfusion. Plasmic MDA and GSH-Px were measured at 30 minutes, 1 hour, 3 hours and 6 hours after reperfusion. Results The concentrations of plasmic MDA in every group were significantly improved compared with those in control group (P0.05 ), but significant difference could be found after 3 hours (P