Retracted: Larvicidal activity of 4-hydroxycoumarin derivatives against Aedes aegypti

Context: Apoptotic neuronal cell death plays an important role in Parkinson’s disease (PD), a progressive neurodegenerative disorder. Luteolin, a flavonoid, has been shown to possess various pharmacological properties including strong antioxidant capacity.

Objective: This study investigated the neuroprotective effect of luteolin against cytotoxicity induced by 6-hydroxy-dopamine (6-OHDA) (250 µM) in rat pheochromocytoma (PC12) cell line.

Materials and methods: The neuroprotective effect of luteolin against 6-OHDA-induced cytotoxicity in PC12 was evaluated by using cell viability test, nuclear staining and flow cytometry. In addition, the apoptotic role of luteolin was unveiled by monitoring mRNA expression of proapoptotic and anti-apoptotic genes.

Results: Pretreatment with luteolin (3.13, 6.25, 12.5, 25 or 50 µM) could markedly attenuate 6-OHDA-induced PC12 cell viability loss in a concentration-dependent manner. Cell morphologic analysis and nuclear staining assays showed that luteolin (3.13, 12.5 or 50 µM) protected the cells from 6-OHDA-induced damage. As shown in the flow cytometry assay, the increased apoptotic rate induced by 6-OHDA could be significantly (p < 0.001) suppressed by luteolin (12.5 or 50 µM) pretreatment. The protection of luteolin (50 µM) against 6-OHDA-induced cell damage was shown to be through suppressing the over-expression of Bax gene (p < 0.01), inhibiting the reduction of Bcl-2 gene expression (p < 0.05) and markedly depressing the enhanced Bax/Bcl-2 ratio. Luteolin also downregulated the gene expression level of p53.

Discussion and conclusion: Luteolin has protective effects against 6-OHDA-induced cell apoptosis and might be a potential nutritional supplement which could be used to prevent neurodegenerative diseases such as PD.     

Luteolin inhibits apoptosis and improves cardiomyocyte contractile function through the PI3K/Akt pathway in simulated ischemia/reperfusion

Luteolin, a naturally occurring polyphenol flavonoid, has demonstrated to exert myocardial protection effects. However, the mechanisms have not been fully elucidated. In the present study, we investigated whether luteolin pretreatment was associated with cardioprotection in a rat ischemia/reperfusion (I/R) model. Luteolin significantly not only restored contractility of the left ventricle, but also reduced the infarct size and lactate dehydrogenase leakage during I/R. In addition, luteolin pretreatment significantly improved cardiomyocyte shortening amplitude, decreased the apoptotic rate, upregulated Bcl-2 expression, downregulated Bax expression and raised the Bcl-2/Bax ratio under a simulated ischemia/reperfusion (SI/R) condition. Moreover, luteolin pretreatment increased protein kinase B (Akt) phosphorylation, phospholamban phosphorylation and the expression of sarcoplasmic reticulum calcium ATPase following SI/R. The phosphoinositide 3-kinase (PI3K)/Akt pathway is one of the most important intracellular survival signal pathways. To determine whether luteolin-induced cardioprotection was mediated by the PI3K/Akt pathway, we utilized the PI3K inhibitor LY294002. Inhibition of Akt activity markedly abolished luteolin-induced positive contraction and inhibition of apoptosis in SI/R cardiomyocytes. These results showed that luteolin inhibits apoptosis and improves cardiomyocyte contractile function at least partly through the PI3K/Akt pathway in SI/R.     

Assessment of luteolin isolated from Eclipta alba leaves in animal models of epilepsy

Context: Eclipta alba (Linn) Hassk. (Asteraceae) has been reported to be a nerve tonic and has been used to treat epilepsy in folk medicine.

Objective: The present study isolates and characterizes luteolin from E. alba and evaluates its antiepileptic potential in chemically induced acute and chronic models in mice.

Materials and methods: The methanol extract (16.85% w/w) of E. alba leaves was subjected to fractionation for isolation of luteolin. In acute pentylenetetrazole (PTZ) model, luteolin (5, 10, 20?mg/kg, i.p.) was administered 30?min prior to PTZ injection (100?mg/kg) in Swiss albino mice. Kindling was induced by chronic administration of PTZ (35?mg/kg) on every alternate day (48 days). Luteolin was investigated on the course of kindling development and oxidative stress markers [reduced glutathione (GSH) and malondialdehyde (MDA)] in kindled mice.

Results: Single-dose pretreatment with luteolin (10 and 20?mg/kg, i.p.) was found to be effective in an acute PTZ model (100% protection from mortality) and it did not exhibit any effect on motor coordination at the same doses. PTZ-induced kindling was significantly (p?p?p?Discussion and conclusion: The results of the present study demonstrated that luteolin had an anticonvulsant effect in an acute PTZ model. Luteolin exhibited and inhibitory effect on the course of kindling and associated oxidative stress and hence could be a potential molecule in the treatment of epilepsy.     

Luteolin ameliorates dextran sulfate sodium-induced colitis in mice possibly through activation of the Nrf2 signaling pathway

BackgroundLuteolin has a reputation for being a safe and effective natural antioxidant that has strong radical scavenging and cell protective properties. The role of oxidative stress in inflammatory bowel disease (IBD) has been well established and is increasingly highlighted. Thus, we studied the protective effect of luteolin administration in a mouse model of experimental colitis.MethodsExperimental acute colitis was induced by administering 3% dextran sulfate sodium (DSS) in the drinking water of mice for 7 days. The disease activity index (DAI); colon length; histological assessment; mRNA levels of nuclear factor-erythroid 2-related factor 2 (Nrf2), tumor necrosis factor (TNF-α), interleukin-6 (IL-6), heme oxygenase-1 (HO-1), and NADP(H): quinone oxidoreductase 1 (NQO-1); protein expression of Nrf2 and inducible nitric oxide synthase (iNOS); colon malondialdehyde (MDA) levels; and the activity levels of colonic superoxide dismutase (SOD) and catalase (CAT) were examined.ResultsLuteolin (20 and 50 mg/kg) significantly attenuated the DAI, colon shortening and histological damage. In addition, luteolin administration effectively decreased the expression of inflammatory mediators, such as iNOS, TNF-α and IL-6. Luteolin also decreased the colonic content of MDA. The activities of colonic SOD and CAT and the levels of Nrf2 and its downstream targets, HO-1 and NQO1, were elevated by luteolin treatment.ConclusionThese observations indicate that luteolin may suppress experimental colitis through the Nrf2 signaling pathway.     

Antitumor activity of luteolin in human colon cancer SW620 cells is mediated by the ERK/FOXO3a signaling pathway

The aim of this study was to investigate the mechanism of the anticancer activity of luteolin in metastatic human colon cancer SW620 cells. Luteolin dose-dependently reduced the viability and proliferation of SW620 cells and increased the expression of antioxidant enzymes. The expression of antiapoptotic protein Bcl-2 decreased whereas the expression of proapoptotic proteins Bax and caspase-3 increased by luteolin treatment, resulting in increased poly (ADP-ribose) polymerase (PARP) cleavage and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positivity. Luteolin also increased the expression of autophagic proteins Beclin-1, autophagy-related protein 5 (Atg5) and microtubule-associated protein 1A/1B-light chain 3 beta-I/II (LC3B-I/II), while the usage of 3-methyladenine suggested a prosurvival role of autophagy. Moreover, treatment with luteolin induced reversal of the epithelial-mesenchymal transition process through the suppression of the wingless-related integration site protein (Wnt)/β-catenin pathway. The cytotoxic activity of luteolin coincided with the activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and forkhead box O3a (FOXO3a). Treatment with the mitogen-activated protein kinase kinase (MEK) inhibitor PD0325901 inhibited ERK-dependent FOXO3a phosphorylation, resulting in increased FOXO3a expression and apoptosis, with the suppression of autophagy. The results of the current study suggest the antitumor activity of luteolin in SW620 cells through the ERK/FOXO3a-dependent mechanism, as well as its antimetastatic potential.     

Luteolin improves contractile function and attenuates apoptosis following ischemia-reperfusion in adult rat cardiomyocytes

Luteolin occurs in a variety of plants and possesses antioxidant and anti-inflammatory properties. However, its role in protection against ischemia-reperfusion injury in Sprague-Dawley rats has not been elucidated. In the present study, we tested the contractile function of left ventricular cardiomyocytes with different concentrations of luteolin: 0.5, 1.5, 2.5 and 5.0 μg/ml after simulated. We investigated the direct effect of luteolin against necrosis and apoptosis following ischemia-reperfusion in cardiomyocytes. We further observed the function of isolated hearts subjected to ischemia-reperfusion with or without 10.0 μg/ml luteolin pretreatment. Following 24h incubation with or without luteolin, adult rat cardiomyocytes were subjected to 3h of ischemia followed by 2h of reperfusion for contractile function and necrosis (trypan blue exclusion and lactate dehydrogenase release) or 18 h of reperfusion for apoptosis studies. The cardiomyocyte shortening amplitude depended on different concentrations of luteolin, increasing significantly at 2.5 μg/ml luteolin (P<0.01). Necrosis and apoptosis were reduced by luteolin at 2.5 μg/ml. In addition, the expression of Bcl-2 was upregulated by luteolin and the ratio of Bax to Bcl-2 was decreased. Luteolin inhibited the activation of Caspase3 after ischemia-reperfusion in cardiomyocytes. Furthermore, luteolin at 10.0 μg/ml improved ischemia-reperfusion induced myocardial function, by improving heart rate, +dp/dt(max) and -dp/dt(max), and also limiting the decline of left ventricular systolic pressure (LVSP) and elevation of left ventricular end-diastolic pressure (LVEDP) to some extent. Our results demonstrated that luteolin prevents ischemia-reperfusion injury by reducing necrosis and apoptosis in rat cardiomyocytes.     

藏药蕨麻对原代培养小鼠肝细胞酒精损伤保护作用研究

目的 研究藏药蕨麻对原代培养酒精损伤肝细胞的保护作用。方法 原代肝细胞经分离纯化培养后,MTT法评价藏药蕨麻对酒精损伤肝细胞存活率的影响;荧光染色法测定藏药蕨麻对酒精损伤肝细胞活性氧物质(ROS)含量、细胞内钙离子浓度的影响;流式细胞仪检测藏药蕨麻对酒精损伤肝细胞凋亡的影响;免疫印迹法检测藏药蕨麻对Bcl-2和Bax表达的影响。结果 经酒精损伤后,肝细胞存活率降低;细胞内ROS含量和钙离子浓度增高;凋亡抑制基因Bcl-2减弱、促凋亡基因Bax表达增强。藏药蕨麻可明显提高细胞存活率;降低细胞内ROS含量和钙离子浓度;改善凋亡情况,增强Bcl-2表达,抑制Bax表达,且作用呈剂量依赖性。结论 藏药蕨麻对原代培养小鼠肝细胞酒精损伤具有一定的保护作用。     

右美托咪定通过lncRNA H19介导香烟提取物诱导的肺泡巨噬细胞效应研究

目的探索右美托咪定(Dexmedetomidine,DEX)通过长链非编码RNA(long noncoding RNA,lncRNA)H19对香烟烟雾提取物(cigarette smoke extract,CSE)诱导的RAW264.7巨噬细胞活力、凋亡和自噬的影响。方法制备CSE及CSE干预巨噬细胞模型,运用体外细胞培养,DEX以不同浓度(2、4和8μmol/L)作用于CSE诱导的巨噬细胞,采用MTT法检测细胞存活率,流式细胞术检测模型细胞的凋亡率,采用蛋白质印迹法(Western blot)检测细胞中凋亡相关蛋白Bax和Bcl-2及自噬相关蛋白LC3Ⅱ和ATG7表达情况,实时荧光定量PCR(qRT-PCR)检测H19表达水平;为了进一步验证DEX对CSE诱导的巨噬细胞增殖、凋亡和自噬影响,运用双酶切法构建pcDNA3.1-H19表达载体。结果一定剂量的DEX可明显拮抗CSE诱导的巨噬细胞活力下降作用(P<0.05),具有浓度依赖性;DEX抑制CSE诱导的巨噬细胞凋亡,且细胞中凋亡蛋白Bax明显下调(P<0.05),抗凋亡蛋白Bcl-2上调(P<0.05),自噬相关蛋白LC3Ⅱ和ATG7表达上调(P<0.05),H19表达下调(P<0.05);成功构建pcDNA3.1-H19表达载体,DEX作用于CSE诱导的巨噬细胞,细胞活力明显降低(P<0.05),且细胞中凋亡蛋白Bax上调(P<0.05),抗凋亡蛋白Bcl-2下调(P<0.05),自噬相关蛋白LC3Ⅱ和ATG7表达下调(P<0.05)。结论DEX抑制H19表达,增强CSE诱导的巨噬细胞活力,抑制细胞凋亡和自噬。     

葛根异黄酮对MPP~+诱导的PC12细胞凋亡的保护作用

目的探讨葛根异黄酮(Total isoflavones from puerarialobata,TIP)对甲基-苯基-吡啶离子(1-methyl-4-phenylpyr-idinium,MPP+)诱导的PC12细胞凋亡的保护作用及其机制。方法用不同浓度TIP预处理体外培养的PC12细胞后,加入MPP+诱导多巴胺能神经损伤模型,用MTT法检测PC12细胞活力,采用实时定量RT-PCR检测Bcl-2和BaxmRNA的表达水平。结果MPP+处理48~96 h,细胞活力较空白对照组降低,阴性对照组Bax 2-ΔΔCt升高,而Bcl-22-ΔΔCt降低,差异具有统计学意义(P<0.05)。与阴性对照组比较,葛根异黄酮组Bax 2-ΔΔCt降低,而Bcl-2 2-ΔΔCt升高,差异具有统计学意义(P<0.05)。结论葛根异黄酮对MPP+诱导的PC12细胞凋亡具有抑制作用,下调Bax和上调Bcl-2 mRNA表达可能是其作用的机制之一。     

Luteolin protects osteoblastic MC3T3-E1 cells from antimycin A-induced cytotoxicity through the improved mitochondrial function and activation of PI3K/Akt/CREB

Luteolin is a flavonoid found in many herbal extracts including celery, green pepper, parsley, perilla leaf and seeds, and chamomile. Antimycin A (AMA) is an inhibitor of the mitochondrial electron transport chain. In the present study, the protective effect of luteolin on AMA-induced cell damage was investigated in osteoblastic MC3T3-E1 cells. Luteolin significantly increased the viability of MC3T3-E1 cells in the presence of AMA and the effect of luteolin in increasing cell viability was completely prevented by the presence of LY294002, Akt inhibitor, or auranofin, suggesting that the effect of luteolin might be partly mediated from PI3K, Akt, and thioredoxin reductase. Pre-treatment with luteolin prior to AMA exposure significantly prevented mitochondrial membrane potential dissipation, ATP loss, inactivation of complex I and IV, ROS production, inactivation of thioredoxin reductase, intracellular calcium elevation, and cytochrome c release induced by AMA. Moreover, luteolin increased activities of PI3K (phosphoinositide 3-kinase) and Akt (protein kinase B), and CREB (cAMP-response element-binding protein) phosphorylation inhibited by AMA treatment. Collectively, these results suggest that luteolin protects MC3T3-E1 cells from AMA-induced cell damage through the improved mitochondrial function and activation of PI3K/Akt/CREB.     

Synergism of simvastatin with losartan prevents angiotensin II‐induced cardiomyocyte apoptosis in vitro

Objectives Increasing evidence suggests that cardiomyocyte apoptosis has an important role in the transition from compensatory cardiac remodelling to heart failure. The synergistic effect of statins (3‐hydroxy‐3‐methylglutaryl‐coenzyme A reductase inhibitors) and angiotensin II (Ang II) type 1 receptor antagonists reduces the incidence of cardiovascular events. However, the anti‐apoptotic potential of the synergism between losartan and simvastatin in heart failure remains unexplored. Here, we demonstrate that Ang II‐induced apoptosis is prevented by losartan and simvastatin in neonatal cardiomyocytes. Methods The in‐vitro cardiomyocyte apoptosis model was established by co‐culturing neonate rat cardiomyocytes with Ang II. Cell viability was analysed by the MTT assay. Cell apoptosis was evaluated using fluorescence microscopy and flow cytometry. Apoptosis‐related proteins Bax and Bcl‐2 expressions were measured by flow cytometry detection. Key findings Incubation with 10^?7 m Ang II for 48 h increased cardiomyocyte apoptosis and decreased cell viability. Losartan (10^?5 m ) and simvastatin (10^?5 m ), either alone or in combination, significantly decreased Ang II‐induced cardiomyocyte apoptosis and increased cell viability. The q values calculated by the probability sum test were 1.31 for cardiomyocyte apoptosis and 1.21 for cell viability. Ang II induced a significant increase in Bax protein expression, whereas Bcl‐2 protein expression was decreased. Losartan alone or in combination with simvastatin blocked the increased Bax expression and increased Bcl‐2 expression. However, simvastatin had no such effect. Conclusions Our data provide the first evidence that synergism of simvastatin with losartan prevents angiotensin II‐induced cardiomyocyte apoptosis in vitro. Synergism between simvastatin and losartan may provide a new therapeutic approach to the prevention of cardiac remodelling.     

Matrine induces apoptosis in angiotensin II-stimulated hyperplasia of cardiac fibroblasts: effects on Bcl-2/Bax expression and caspase-3 activation

The present study was designed to assess the effect of matrine, an active component of Chinese traditional medicine, on angiotensin II (Ang II)-induced hyperplastic growth of cardiac fibroblasts in vitro. Cardiac fibroblasts were prepared from hearts of neonatal Kunming mice by collagenase disruption. Cultured cardiac fibroblasts were either not treated, treated with 0.1 microM Ang II, or matrine (2.0 approximately 4.0 mM) plus Ang II for 12-72 hr. Cell morphology was monitored under an inverted phase contrast microscope. Number of cells was counted with a haemocytometer. Cell apoptosis was determined by propidium iodide/Hoechst 33342 staining and flow cytometry. The cleaved caspase-3 fragment expression, anti-apoptotic Bcl-2 and pro-apoptotic Bax protein expressions were also studied. The results show that Ang II stimulation resulted in hyperplastic growth of cardiac fibroblasts. Matrine significantly, dose and time dependently inhibited Ang II-induced cell proliferation. Matrine addition to the culture medium led to most cells being arrested in the G1 phase of the cell cycle, the fraction of cells in S phase was markedly decreased compared to control and Ang II alone groups. Cell apoptosis in matrine treatment group was markedly increased, accompanied by down-regulation in Bcl-2/Bax ratio and up-regulation in cleaved caspase-3 activity. These results suggest that matrine can induce apoptosis and thereby inhibit Ang II-induced hyperplasic growth of cardiac fibroblasts. The regulations of matrine on Bcl-2/Bax expression and caspase-3 activation may be the pro-apoptotic mechanisms involved.     

Salvianolic acid A inhibits angiotensin II-induced proliferation of human umbilical vein endothelial cells by attenuating the production of ROS

Aim:

To investigate the action of salvianolic acid A (SalA) on angiotensin II (Ang II)-induced proliferation of human umbilical vein endothelial cells (HUVECs) and the possible signaling pathways mediating this action.

Methods:

Cell proliferation was examined with MTT assay. The expression levels of Src phosphorylation (phospho-Src), Akt phosphorylation (phospho-Akt), and NADPH oxidase 4 (Nox4) in HUVECs were determined by Western blot. The production of reactive oxygen species (ROS) was estimated using fluorescence-activated cell sorting (FACS).

Results:

SalA (6.25–50 μmol/L) did not affect the viability of HUVECs. Treatment of HUVECs with Ang II (1 μmol/L) markedly increased the cell viability; pretreatment of HUVECs with SalA (12.5, 25 and 50 μmol/L) prevented Ang II-induced increase of the cell viability in a concentration-dependent manner. Treatment of HUVECs with Ang II (1 μmol/L) markedly up-regulated the protein expression levels of phospho-Src, phospho-Akt (473) and Nox4; pretreatment of HUVECs with SalA (12.5, 25 and 50 μmol/L) blocked all the effects in a concentration-dependent manner. Treatment of HUVECs with Ang II (1 μmol/L) dramatically increased ROS production in HUVECs; pretreatment of HUVECs with SalA (12.5, 25 and 50 μmol/L) blocked the ROS production in a concentration-dependent manner.

Conclusion:

SalA inhibits Ang II-induced proliferation of HUVECs via reducing the expression levels of phospho-Src and phospho-Akt (473), thereby attenuating the production of ROS.     

7-羟乙基白杨素对高原脑水肿的作用机制初探

目的 研究7-羟乙基白杨素（7-HEC）对高原脑水肿（HACE）的可能作用机制。方法 建立大鼠高原脑水肿模型,测定大鼠脑组织中超氧化物歧化酶（SOD）的活性及丙二醛（MDA）的含量,采用蛋白质印迹法检测细胞凋亡、周期及自噬相关蛋白的表达水平,探究7-HEC对高原脑水肿的保护作用及其机制。结果 与对照组相比,缺氧模型组大鼠脑组织中MDA含量显著上调,SOD活力显著下调,周期蛋白CyclinD1、CyclinE1、CDK6、CDK2,凋亡蛋白Bcl-2、PARP,自噬蛋白LC3-B相对表达下调,凋亡蛋白Bax,自噬蛋白P62的相对表达上调,差异均具有统计学意义（P<0.05）;与缺氧模型组相比,7-HEC给药组MDA含量下调,SOD活力显著上调,周期蛋白CyclinD1、CyclinE1、CDK6、CDK2,凋亡蛋白Bcl-2、PARP,自噬蛋白LC3-B的相对表达上调,凋亡蛋白Bax,自噬蛋白P62的相对表达下调,差异均具有统计学意义（P<0.05）。结论 7-HEC对高原脑水肿具有一定的保护作用,其机制可能与调控细胞周期、自噬、凋亡以及氧化应激等通路有关。     

Liposomal Induction of a Heat-stable Macrophage Priming Factor to Induce Nitric Oxide in Response to LPS

Purpose. The effects of liposomes on nitric oxide (NO) production from mouse peritoneal macrophages following intraperitoneal injection of liposomes were investigated. Methods. Mouse peritoneal macrophages were collected following intraperitoneal injection of liposomes and cultured with and without lipopolysaccharide (LPS). Peritoneal washing fluid was also collected from the mice injected with liposomes. NO production was evaluated by measuring the concentration of nitrite in the macrophage culture supernatant by Griess reagent. Results. NO production stimulated by LPS was observed in peritoneal macrophages obtained from the liposome-treated mice, but liposomes did not activate macrophages directly to induce NO in response to LPS. NO production was higher in the liposomes composed of phospha-tidylcholine than that of negatively charged liposomes composed of phosphatidylserine. Peritoneal washing fluid obtained from mice injected with liposomes has a capacity to induce NO production in the macrophages from naive mice. This capacity was not diminished by heat-treatment at 100°C for 5 min. Conclusions. Peritoneal macrophages were activated to produce NO in response to LPS following intraperitoneal injection of liposomes. They did not activate macrophages directly, and the induction of heat-stable macrophage priming factor, but not cytokines, is suggested.     

姜黄素通过调控miR-7641/PTPN14分子轴抑制乳腺癌发展进程的分子机制研究

目的 探讨姜黄素通过调控miR-7641/PTPN14分子轴抑制乳腺癌发展进程的分子机制。方法 采用实时荧光定量PCR（qRT-PCR）检测乳腺癌患者癌组织及细胞系中miR-7641表达情况;使用Kaplan-Meier方法作乳腺癌患者生存曲线;采用不同浓度的姜黄素处理细胞,或转染miR-7641 mimic、Anti-miR-7641及pcDNA-PTPN14载体,采用qRT-PCR检测miR-7641表达情况,MTT实验及克隆形成实验检测细胞增殖能力,Transwell小室法检测细胞迁移及侵袭,western blotting检测Ki67、pcDNA、CyclinD1、Bax、Bcl-2、caspase-3、caspase-8蛋白表达水平,采用双荧光素酶报告基因系统检测miR-7641与PTPN14靶向调控关系。结果 与癌旁组织或乳腺正常上皮细胞比较,miR-7641在乳腺癌患者癌组织及乳腺癌细胞系中高表达（P<0.01、0.001）,且miR-7641能够明显促进乳腺癌细胞的增殖、迁移及侵袭（P<0.05、0.01、0.001）,并促进Ki67、pcDNA、CyclinD1、Bcl-2蛋白表达,抑制Bax、caspase-3、caspase-8蛋白表达;miR-7641与PTPN14 3''-UTR靶向结合,姜黄素通过miR-7641/PTPN14分子轴抑制乳腺癌细胞的增殖、迁移及侵袭（P<0.01、0.001）,并抑制Ki67、pcDNA、CyclinD1、Bax蛋白表达,促进Bcl-2、caspase-3、caspase-8蛋白表达。结论 姜黄素可通过下调miR-7641促进PTPN14表达,进而抑制乳腺癌细胞的增殖、迁移及侵袭。     

Protective effects of luteolin against lipopolysaccharide-induced acute lung injury involves inhibition of MEK/ERK and PI3K/Akt pathways in neutrophils

Aim:

To investigate whether luteolin, the major polyphenolic components of Lonicera japonica, has beneficial effects against lipopolysaccharide (LPS)-induced acute lung injury (ALI) and to determine whether the protective mechanism involves anti-inflammatory effects on neutrophils.

Methods:

ALI was induced with intratracheal instillation of LPS in mice. The level of ALI was determined by measuring the cell count and protein content in bronchoalveolar lavage (BAL) fluid. Neutrophils were stimulated with formyl-Met-Leu-Phe (fMLP) or LPS in vitro. Chemotaxis and superoxide anion generation were measured to evaluate neutrophil activation. The potential involvement of intracellular signaling molecules in regulating neutrophil activation was analyzed by using Western blot.

Results:

LPS induced ALI in mice, as evidenced with leukocyte infiltration and protein leakage into the lungs. Luteolin attenuated LPS-induced leukocyte infiltration and protein extravasation. In cell studies, luteolin attenuated the fMLP-induced neutrophil chemotaxis and respiratory burst (IC₅₀ 0.2±0.1 μmol/L and 2.2±0.8 μmol/L, respectively), but had a negligible effect on superoxide anion generation during phorbol myristate acetate stimulation. Furthermore luteolin effectively blocked MAPK/ERK kinase 1/2 (MEK), extracellular signal-regulated kinase (ERK), and Akt phosphorylation in fMLP- and LPS-stimulated neutrophils.

Conclusion:

These results indicate that luteolin has beneficial effects against LPS-induced ALI in mice, and the attenuation of neutrophil chemotaxis and respiratory burst by luteolin involves the blockade of MEK-, ERK-, and Akt-related signaling cascades.     

Class A scavenger receptor deficiency augments angiotensin II-induced vascular remodeling

Class A scavenger receptor (SR-A) is a multifunctional molecule that participates in macrophage-mediated inflammation. Here we evaluated the role of SR-A in angiotensin II (Ang II)-induced hypertensive vascular remodeling. Chronic infusion of Ang II leads to an increased systolic blood pressure both in SR-A knockout (SR-A^−/−) and wild type (SR-A^+/+) mice with no significant difference between these two groups. SR-A^−/− hypertensive mice, however, exhibited a marked augmentation of arterial wall thickening and vascular cell proliferation compared with SR-A^+/+ hypertensive mice. M1 macrophage markers were increased whereas M2 macrophage markers were decreased in vascular tissues of SR-A^−/− mice. Co-culture experiments revealed that more pro-inflammatory cytokines like TNF-α were produced by SR-A^−/− peritoneal macrophages leading to a stronger proliferation of primary vascular smooth muscle cells in vitro. In addition, SR-A^−/− macrophages were more prone to lipopolysaccharide-induced M1 differentiation while resisting interleukin-4-induced M2 differentiation. Importantly, transplantation of SR-A^−/− bone marrow into SR-A^+/+ mice significantly augmented Ang II-induced vascular remodeling. These results show that SR-A is critical for Ang II-induced vascular remodeling by regulating macrophage polarization. Therefore, SR-A may be a useful therapeutic target for the intervention of hypertensive vascular remodeling.     

Interaction Between Polyalkylcyanoacrylate Nanoparticles and Peritoneal Macrophages: MTT Metabolism,NET Reduction,and NO Production

Purpose. The nature of interactions between macrophages and drug carriers is of primordial importance either in the design of more effective therapeutic strategies for macrophage-associated pathogenesis or in establishing new approaches for pharmacological action avoiding macrophages. Methods. Polyalkylcyanoacrylate nanoparticles (PMCA, PECA, PBCA and PIBCA nanoparticles) were assayed for their toxicity on peritoneal resident and thioglycolate-elicited macrophages. Cellular viability was assessed by MTT tetrazolium salt assay, oxidative burst by NBT reduction and NO production by nitrite evaluation. Results. The nanoparticles tested led to cellular morphological modifications and induced toxicity in both types of macrophages in culture. The polyalkylcyanoacrylate nanoparticles uptake by peritoneal macrophages caused an increase in respiratory burst, as assessed by the NBT reduction assay, and induced the release of soluble toxic factors to the culture medium. The association of LPS with the PMCA nanoparticles significantly stimulated the production of nitric oxide (NO) by resident macrophages. In contrast, the association of PBCA nanoparticles with LPS does not increase the nitrite production as compared with LPS alone, which may be due to a different physico-chemical interaction between LPS and the two types of polymers. Conclusions. In cultured mice peritoneal macrophages, nanoparticles of PACA induce the production of oxygen reactive products, which cause changes in the cell metabolism of both resident and elicited macrophages. PMCA nanoparticles in association with LPS significantly increase the expression of the inducible isoform of nitric oxide synthase, leading to the release of large amount of NO, which may be highly cytotoxic to the cultured cells in the presence of peroxide generated from the oxidative burst.