Lycopene supplementation prevents smoke-induced changes in p53, p53 phosphorylation, cell proliferation, and apoptosis in the gastric mucosa of ferrets

Cigarette smoking increases the risk for gastric cancer. Higher intakes or blood levels of lycopene are associated with a decreased risk of gastric cancer. However, the biological mechanisms by which lycopene may protect against gastric carcinogenesis are poorly understood. We evaluated the effects of lycopene supplementation on smoke-induced changes in protein levels of p53, p53 target genes (p21(Waf1/Cip1) and Bax-1), cell proliferation, and apoptosis in the gastric mucosa of ferrets. Ferrets were assigned to cigarette smoke exposure or to no exposure and to no, low-dose, or high-dose lycopene supplementation (2 x 3 factorial design) for 9 wk. Lycopene concentrations were significantly elevated in a dose-dependent manner in the gastric mucosa of ferrets supplemented with lycopene alone, but were markedly reduced in ferrets supplemented with lycopene and exposed to smoke. Although ferrets were given lycopene containing 95% all-trans isomers, cis isomers were the predominant forms in the gastric mucosa. Total p53 and phosphorylated p53 levels were greater in ferrets exposed to smoke alone than in all other groups. Levels were approximately 300 and 500% of the controls, respectively. However, smoke-elevated total p53 and phosphorylated p53 were markedly attenuated by both doses of lycopene. p21(Waf1/Cip1), Bax-1, and cleaved caspase 3 were substantially decreased, whereas cyclin D1 and proliferating cellular nuclear antigen (PCNA) were increased in ferrets exposed to smoke alone. Lycopene prevented smoke-induced changes in p21(Waf1/Cip1), Bax-1, cleaved caspase 3, cyclin D1, and PCNA in a dose-dependent fashion. These data indicate that lycopene may prevent smoke exposure-induced changes in p53, p53 phosphorylation, p53 target genes, cell proliferation, and apoptosis in the gastric mucosa of ferrets.     

香烟烟雾提取物对MIN6细胞JNK及p38MAPK表达影响

目的 探讨体外香烟烟雾提取物（CSE）对胰岛MIN6细胞形态及活力的影响,及对胞内丝裂原活化蛋白激酶（MAPKs）信号转导通路ERK、JNK、p38MAPK表达的影响。方法 体外培养MIN6细胞至生长对数期后,设不同浓度CSE（20、50、100和200 μg/mL）实验组,同时设对照组,48 h后,镜下观察MIN6细胞形态学改变,并应用CCK-8法检测CSE对MIN6细胞的增殖抑制率;同时应用蛋白印迹法（WB）检测细胞内ERK、JNK、p38MAPK蛋白及磷酸化程度。结果 与对照组比较,100和200 μg/mL剂量下的细胞形态出现明显异常,胞核固缩,细胞呈梭形样改变;与对照组比较,MIN6细胞活力出现下降,20、50、100、200 μg/mL各组细胞活力分别为（97.32±2.67）%、（94.67±5.33）%、（87.71±12.3）%和（74.23±25.8）%;与对照组相比,ERK、JNK、p38MAPK蛋白表达变化不大,但随着CSE剂量的增加,p-JNK和p-p38MAPK磷酸化程度明显增加（与对照组相比,P<0.05）,并呈一定的剂量-效应关系。结论 CSE能够导致MIN6细胞形态异常、抑制其细胞增殖活力,其机制可能与JNK和p38MAPK信号通路的激活相关。     

矽肺患者巨噬细胞培养上清通过p38MAPK对人胚肺成纤维细胞增殖的影响

目的 探讨矽肺患者巨噬细胞(AM)培养上清是否通过激活p38丝裂原活化蛋白激酶(p38MAPK)信号转导通路促进人胚肺成纤维细胞(HELF)的增殖作用,进而参与矽肺纤维化的发生发展过程.方法 以支气管肺泡灌洗法收集矽肺患者AM,在体外用含有SiO2(50 μg/ml)的DMEM培养基和不含SiO2的DMEM培养基培养18h,然后收集培养的AM上清液.用组织贴块法获取培养HELF,与AM上清液共同孵育,将HELF分为空白对照组、AM组、SiO2+AM组、SB203580+SiO2+AM组,用噻唑蓝(MTT)法和流式细胞仪法分别检测各组HELF的增殖情况和细胞周期.结果 SiO2+AM组细胞的平均吸光度值为0.48±0.03,与空白对照组(0.29±0.01)、AM组(0.38±0.02)、SB203580+SiO2+AM组(0.33±0.03)的差异有统计学意义(P<0.05);SiO2+AM组细胞增殖指数为18.12±0.82,与空白对照组(9.24±0.48)、AM组(14.76±0.43)、SB203580+SiO2+AM组(11.71±0.70)的差异有统计学意义(P<0.05).SB203580+SiO2+AM组的细胞吸光度值和细胞增殖指数均明显降低.结论 经SiO2刺激的矽肺患者AM培养上清通过激活p38MAPK信号转导通路可以促进HELF增殖.     

Epicatechin Gallate Induces Cell Death via p53 Activation and Stimulation of p38 and JNK in Human Colon Cancer SW480 Cells

The tea flavonoid epicatechin gallate (ECG) exhibits a wide range of biological activities. In this study, the in vitro anticancer effects of ECG on SW480 colon cancer cell line was investigated by analyzing the cell cycle, apoptosis, key proteins involved in cellular survival/proliferation, namely AKT/phosphatidylinositol-3-kinase (PI3K) and mitogen-activated protein kinases (MAPKs), and the role of p53 in these processes. ECG induced cell cycle arrest at the G0/G1-S phase border associated with the stimulation of p21, p-p53, and p53 and the suppression of cyclins D1 and B1. Exposure of SW480 cells to ECG also led to apoptosis as determined by time-dependent changes in caspase-3 activity, MAPKs [extracellular regulated kinase (ERK), p38, and c-jun amino-terminal kinase (JNK)], p21 and p53 activation, and AKT inhibition. The presence of pifithrin, an inhibitor of p53 function, blocked ECG-induced apoptosis as was manifested by restored cell viability and caspase-3 activity to control values and reestablished the balance among Bcl-2 anti- and proapoptotic protein levels. Interestingly, ECG also inhibited p53 protein and RNA degradation, contributing to the stabilization of p53. In addition, JNK and p38 have been identified as necessary for ECG-induced apoptosis, upon activation by p53. The results suggest that the activation of the p53-p38/JNK cascade is required for ECG-induced cell death in SW480 cells.     

Exposing ferrets to cigarette smoke and a pharmacological dose of beta-carotene supplementation enhance in vitro retinoic acid catabolism in lungs via induction of cytochrome P450 enzymes

In our previous studies, we found lower levels of retinoic acid (RA) in the lungs of ferrets exposed to cigarette smoke and/or a pharmacological dose of beta-carotene. To determine whether this is involved in excessive catabolism of RA via cytochrome P450 (CYP) induction, we carried out in vitro incubations of RA with the lung microsomal fractions of ferrets with or without CYP inhibitors and antibodies against CYP. The polar metabolites (4-oxo-RA and 18-hydroxy-RA) of RA metabolism after the incubation were analyzed by HPLC. Expressions of CYP (1A1, 1A2, 2E1 and 3A1) were examined using Western blot analysis. Incubation of various concentrations of RA with the lung microsomal fraction from ferrets exposed to cigarette smoke, a pharmacological dose of beta-carotene or their combination dose-dependently increased the levels of 4-oxo-RA and 18-hydroxy-RA compared with that of the control ferrets. At all RA concentrations, this increase was the greatest in lung tissue from the combined treatment group. Furthermore, this enhanced RA catabolism was substantially (approximately 80%) inhibited by nonspecific CYP inhibitors (disulfiram and liarozole), but was partially (approximately 50%) inhibited by resveratrol (CYP1A1 inhibitor), alpha-naphthoflavone (CYP1A2 inhibitor) and antibodies against CYP1A1 and CYP1A2. Cigarette smoke exposure and/or pharmacological doses of beta-carotene increased levels of CYP1A1 and 1A2 by three- to sixfold but not levels of 2E1 and 3A1 in ferret lung tissue. These findings suggest that low levels of RA in the lung of ferrets exposed to cigarette smoke and/or pharmacological doses of beta-carotene may be caused by the enhanced RA catabolism via induction of CYP, CYP1A1 and CYP1A2 in particular, which provides a possible explanation for enhanced lung carcinogenesis seen with pharmacological doses of beta-carotene supplementation in cigarette smokers.     

p38MAPK及核因子-κB在百草枯致大鼠肺损伤中的变化

目的观察急性百草枯（PQ）中毒大鼠肺组织中p38丝裂原活化蛋白激酶（p38MAPK）及核因子．κB（NF-κB）的变化，探讨褪黑素（MT）的治疗效果。方法将128只SD大鼠随机分为染毒组60只、治疗组60只和对照组8只，对染毒组以生理盐水稀释PQ50mg／kg，一次性灌胃；治疗组PQ灌胃后的大鼠以MT10mg／kg腹腔注射，每日1次；对照组生理盐水一次性灌胃。于不同处理后1、3、7及14d时分别测定大鼠血清中丙二醛（MDA）含量；电泳迁移率改变分析法（EMSA）检测大鼠肺组织中NF—κB活性；Westernblot检测磷酸化p38MAPK蛋白水平，同时观察大鼠肺组织病理变化。结果染毒组大鼠血清MDA浓度在1、3及7d分别为（4．45±1．23）、（3．77±1．12）及（2．84±0．96）nmol／ml，较对照组明显升高，差异有统计学意义（P〈0．01）；治疗组MDA浓度1、3及7d分别为（2．68±0．85）、（1．97±0．74）和（1．53±0．62）nmol／ml，较染毒组明显降低，差异有统计学意义（P=0.05）。染毒组大鼠肺组织磷酸化p38MAPK蛋白水平及NF-κB活性在各时间点均明显高于对照组，差异有统计学意义（P〈0．01）。经MT治疗后磷酸化p38MAPK蛋白水平及NF—κB活性均明显降低，差异有统计学意义（P〈0．05）。治疗组大鼠肺组织病理改变较染毒组明显减轻。结论磷酸化p38MAPK及NF—κB活性在百草枯所致大鼠肺组织中明显增高；MT能降低磷酸化p38MAPK蛋白水平，抑制NF—κB的活化，减轻染毒大鼠肺组织损伤。     

Hypergravity induces phosphorylation of p53 at serine 15, but not an expression of p53-downstream genes

We investigated the p53 signaling pathway induced by hypergravity in the human glioblastoma cell line A172. Hypergravity (20 x g) induced the accumulation of p53 and the phosphorylation of p53 at Ser-15. The phosphorylation of p53 with hypergravity was not inhibited by wortmannin, the PI3-kinase inhibitor. This indicated that the p53 signal pathway induced by hypergravity is different from other p53 signal pathways, such as that of the DNA damage signal. Hypergravity did not induce an expression of the genes Waf-1 or Bax, located downstream from p53. We also examined the expression of genes with hypergravity by using a DNA microarray containing oligo DNA from 30,000 human genes. Hypergravity (20 x g, 6 h) did induce the expression of some genes concerned with the cell signaling pathway and cytoskeleton of the cell, but not any of the p53-downstream genes. DNA microarray revealed the induction of many genes to enable the cells to adapt to the hypergravity environment.     

p53、p21waf1和增殖细胞核抗原诊断肺癌的评估

目的　评价p53、p21waf1和增殖细胞核抗原(PCNA)蛋白表达对肺癌的诊断价值。方法　采用免疫组化法检测114例肺癌和89例肺良性疾病组织标本p53、p21waf1和PCNA蛋白表达状况，计算三项指标及其组合诊断肺癌的各项参数。结果　(1)肺癌p53、p21waf1及PCNA表达阳性率分别为47.37%、75.44%和80.70%，明显高于肺良性疾病组织(P＜0.001)。其OR值分别为39.15,5.75和6.76。(2)p53、p21waf1及PCNA蛋白表达与肺癌TNM分期无关。不同病理类型p53和p21waf1蛋白表达也无差异，但鳞癌PCNA表达阳性率高于小细胞癌。(3)p53诊断肺癌的阳性似然比为21.08，高于p21waf1和PCNA，但灵敏度较低。(4)PCNA诊断鳞癌的Youden指数为0.5146，显著高于小细胞癌。但其阳性似然比为2.29，仍低于p53。(5)p53和PCNA平行试验的灵敏度为89.47%,特异度为60.67%,其综合评价参数最高。结论　(1)肺癌p53、p21waf1和PCNA表达均上调，三者与肺癌均有很强联系。(2)p53是一项很好的肺癌诊断单项指标。p53和PCNA平行试验诊断肺癌的综合价值较高。     

Beta-carotene, retinol and retinyl ester concentrations in serum and selected tissues of ferrets fed beta-carotene.

The concentrations of beta-carotene, retinol and retinyl esters in serum and selected tissues of ferrets fed diets supplemented with beta-carotene (80 micrograms/g wet diet) for 3 wk were determined. The initial concentration of serum beta-carotene was 0.011 +/- 0.006 mumol/L (mean +/- SEM); at the end of the experimental period it was 5.75 +/- 1.60 mumol/L. No significant differences in serum retinol and total retinyl esters were observed between beta-carotene-fed and control ferrets that had been fed an unsupplemented diet. The predominant retinyl esters in serum were retinyl stearate (53%) and retinyl palmitate (35%). Of the tissues analyzed after beta-carotene feeding, the liver contained the highest concentration of beta-carotene (78.8 +/- 18.8 nmol/g). Other tissues that contained beta-carotene in amounts ranging from 17 to 20 nmol/g were adrenals, small intestine, stomach and colon; lesser amounts (6.9 nmol/g) were found in kidneys. Amounts ranging from 1.2 to 2.3 nmol/g were found in muscle, bladder, adipose tissue, lungs and skin; only 0.37 and 0.34 nmol/g were present in brain and eyes, respectively. Thus, like humans, ferrets have the capacity to absorb intact beta-carotene and to store this compound in tissues, especially the liver. However, compared with humans, ferrets have elevated concentrations of retinyl esters in serum, liver and other tissues.     

FXR,a Key Regulator of Lipid Metabolism,Is Inhibited by ER Stress-Mediated Activation of JNK and p38 MAPK in Large Yellow Croakers (Larimichthys crocea) Fed High Fat Diets

High-fat diets induced abnormal lipid accumulation in the liver of cultured fish that caused body damage and diseases. The purpose of this research was to investigate the role and mechanism of farnesoid X receptor (FXR) in regulating lipid metabolism and to determine how high-fat diets affect FXR expression in large yellow croakers. The results showed that ligand-meditated FXR-activation could prevent abnormal lipid accumulation in the liver and hepatocytes of large yellow croakers. FXR activation increased the expression of lipid catabolism-related genes while decreasing the expression of lipogenesis-related genes. Further investigation found that the promoter activity of proliferator-activated receptor α (PPARα) could be increased by croaker FXR. Through the influence of SHP on LXR, FXR indirectly decreased the promoter activity of sterol regulatory element binding protein 1 (SREBP1) in large yellow croakers. Furthermore, the findings revealed that endoplasmic reticulum (ER)-stress-induced-activation of JNK and P38 MAPK participated in the reduction of FXR induced by high-fat diets. Then, hepatocyte nuclear factor 1α (HNF1α) was confirmed to be an FXR regulator in large yellow croaker, and it was reduced by high-fat diets and ER stress. In addition, co-expression of c-Jun with HNF1α inhibited the effect of HNF1α on FXR promoter, and suppression of P38 MAPK could relieve the HNF1α expression reduction caused by ER stress activation. In summary, the present study showed that FXR mediated lipid metabolism can prevent abnormal lipid accumulation through regulating PPARα and SREBP1 in large yellow croakers, while high-fat diets can suppress FXR expression by ER stress mediated-activation of JNK and P38 MAPK pathways. This research could benefit the study of FXR functions in vertebrate evolution and the development of therapy or preventative methods for nutrition-related disorders.     

Serum cholesterol, beta-carotene, and risk of lung cancer.

This paper hypothesizes that beta-carotene mediates the association between low serum cholesterol and increased risk of lung cancer, predicts that the association should be greater in population strata with low intake of beta-carotene than in those with high intake if the hypothesis is correct, and investigates this prediction with data from a 24-year cohort study of 1,960 middle-aged employed men. In the total cohort, serum cholesterol was not related to risk of lung cancer. The relative risk associated with a difference of -1.0 mmol per liter in serum cholesterol was 1.01 (95% confidence interval of 0.80-1.27) after adjustment for cigarette smoking, age, and intake of beta-carotene. In contrast, however, when the study group was restricted to men with intake of beta-carotene less than 5,000 (N = 929) or less than 3,000 IU per day (N = 272), comparable relative risks were 1.10 and 1.21, respectively. Although the 95% confidence intervals for these relative risks were broad and included unity, the result is consistent with expectation. We conclude that the hypothesis warrants further investigation.     

Dietary carotenoids,serum beta-carotene,and retinol and risk of lung cancer in the alpha-tocopherol,beta-carotene cohort study

Findings from several beta-carotene supplementation trials were unexpected and conflicted with most observational studies. Carotenoids other than beta-carotene are found in a variety of fruits and vegetables and may play a role in this important malignancy, but previous findings regarding the five major carotenoids are inconsistent. The authors analyzed the associations between dietary beta-carotene, beta-carotene, lutein/zeaxanthin, lycopene, beta-cryptoxanthin, vitamin A, serum beta-carotene, and serum retinol and the lung cancer risk in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort of male smokers conducted in southwestern Finland between 1985 and 1993. Of the 27,084 male smokers aged 50-69 years who completed the 276-food item dietary questionnaire at baseline, 1,644 developed lung cancer during up to 14 years of follow-up. Cox proportional hazards models were used to estimate relative risks and 95% confidence intervals. Consumption of fruits and vegetables was associated with a lower lung cancer risk (relative risk = 0.73, 95% confidence interval: 0.62, 0.86, highest vs. lowest quintile). Lower risks of lung cancer were observed for the highest versus the lowest quintiles of lycopene (28%), lutein/zeaxanthin (17%), beta-cryptoxanthin (15%), total carotenoids (16%), serum beta-carotene (19%), and serum retinol (27%). These findings suggest that high fruit and vegetable consumption, particularly a diet rich in carotenoids, tomatoes, and tomato-based products, may reduce the risk of lung cancer.     

脑胶质瘤中p16与p53及增殖细胞核抗原蛋白的表达和意义

目的探讨p16与p53及增殖细胞核抗原(PCNA)在人脑胶质瘤中的表达及意义。方法用免疫组织化学手段检测114例不同级别脑胶质瘤组织中p16和p53、PCNA蛋白的表达,并其与肿瘤不同级别的关系。结果p16蛋白表达缺失在Ⅲ级(65.6%)、Ⅳ级(91.3%)脑胶质瘤中显著高于Ⅰ~Ⅱ级的缺失(33.3%)(P<0.01);p53蛋白表达在Ⅲ级(68.8%)、Ⅳ级(89.1%)脑胶质瘤中显著高于Ⅰ~Ⅱ级的表达(27.8%)(P<0.01);PCNA蛋白的表达在Ⅲ级(56.3%)、Ⅳ级(84.8%)脑胶质瘤中的表达强度显著高于Ⅰ~Ⅱ级(16.7%)的表达强度(P<0.01)。结论p16和p53、PCNA蛋白表达异常可用以判断人脑胶质瘤的生物学行为。     

血清中VEGF、Survivin、p53在肺痛中的表达及相关性

目的:探讨VEGF(血管内皮生长因子)、Survivin(生存素)、p53在肺癌中的表达及与肺癌临床病理关系及相关性.方法:采用抗人VEGF单克隆抗体、夹心ELISA法分别检测85例肺癌和35例良性肺疾病患者血清中VEGF、Sur-vivin、p53的表达情况.结果:与对照组比较,肺癌组VEGF、Survivin、p53蛋白水平均增高,差异具有显著性(P＜0.01),血清中VEGF、Survivin、r63的表达与患者的年龄、性别、分化程度、病理类型无明显相关(P＞0.05),而与淋巴结转移和分期显著相关(P＜0.05).血清中VEGF的表达与p53和survivin显著相关,联合检测可以提高诊断的灵敏度.结论:血清中VEGF、Survivin、p53可作为肺癌转移和判断分期的一个良好指标,联检可提高诊断效率.     

p53和p27在肺癌组织中的表达及其临床意义

目的 检测肺癌组织中p53和p27蛋白的表达情况,以探讨其相关的临床意义.方法 选择2011年12月至2012年12月收治的肺癌患者组织标本100例,另选取同期肺部良性病变切除的正常肺组织40例作为正常对照.采用免疫组织化学法检测p53和p27蛋白的表达.结果 p53蛋白在正常肺组织中的阳性表达率为27.5％(11/40),显著低于肺癌组织中的66.0％(66/100),差异有统计学意义(P＜0.05),而p27蛋白在正常肺组织中的阳性表达率为87.5％(35/40),显著高于肺癌组织中的41.0％(41/100),差异有统计学意义(P＜0.05).肺癌组织中p53和p27蛋白的表达与患者的性别、肿瘤组织类型无显著相关性(P＞0.05),而在不同临床分期存在显著相关性(P＜0.05).Spearman相关性分析显示肺癌组织中p53和p27蛋白的表达呈显著负相关(r=-0.516,P＜0.05).结论 p53和p27蛋白的异常表达可能参与了肺癌的发生、发展过程,二者的联合检测有可能成为肺癌诊断以及预后评估的新分子标记物.     

Effects of dietary taurocholate, fat and protein on the storage and metabolism of dietary beta-carotene and alpha-tocopherol in ferrets

Dietary factors affecting tissue storage of beta-carotene (BC), alpha-tocopherol (alpha-T), and retinol (ROL) in mammals include taurocholate, protein, and fat. Few studies have examined the effects of these factors on the storage of BC, retinyl esters, and alpha-T in a mammalian system that is similar to humans. The main objective of the study was to investigate the effects of taurocholate (TC), fat, and protein on the absorption and metabolism of BC and alpha-T in ferret tissues. Three 4-week experiments were conducted using groups of 5-6 ferrets per treatment. All diets contained 0.2% BC. In Experiment 1, taurocholate was fed at concentrations of 0, 0.5, or 1%. Effects of two concentrations of dietary fat (6 and 23%) and three concentrations of protein (10, 20, and 40%) were also studied in Experiments 2 and 3, respectively. Tissues were analyzed for BC, retinoids, and alpha-T by high-pressure liquid chromatography (HPLC). Taurocholate enhanced hepatic and plasma concentrations of BC (2.3- to 3-fold), retinyl palmitate [(RP) 3.2- to 9.5-fold], retinyl stearate [(RS) 2.9- to 6- fold], and hepatic alpha-T (6- to 13- fold) at p < 0.05. High-fat diets elevated hepatic BC, RP, RS, and retinyl linoleate (RL) concentrations (2- to 3.6-fold, p < 0.05). In contrast, high-protein diets lowered hepatic RL 1.8-fold and alpha-T 8-fold (p < 0.05). Our results indicate the importance of taurocholate, fat, and protein in achieving adequate levels of vitamins A and E in mammals.     

p38MAPK及Caspase3在LNG诱导人子宫肌瘤细胞凋亡中的作用

目的 探讨p38MAPK及Caspase3在高浓度左炔诺孕酮(LNG)诱导体外培养人子宫肌瘤细胞(UtLMC)凋亡过程中的作用.方法 原代培养UtLMC传代后,加入不同浓度LNG,流式细胞术测定其对细胞凋亡率的影响,并以AO/EB双染法区分早、晚期凋亡细胞和坏死细胞;Western blot测定p38MAPK、Caspase3在LNG诱导细胞凋亡中的活性变化.结果 流式细胞术分析,加药组细胞凋亡率随LNG浓度的增加而逐渐升高,与对照组相比有显著性差异(t值分别为8.458、25.582、58.415、127.390,均P<0.05);AO/EB双染后发现,对照组无明显凋亡细胞,10μg/mL LNG作用UtLMC后,早期凋亡细胞多于阴性对照组,随着LNG剂量的增加,晚期凋亡细胞也逐渐增多,核浓聚、偏位,被染成桔红色;在10μg/mL以上LNG诱导UtLMC凋亡中,p38MAPK磷酸化水平升高(t值分别为96.278、165.878,均P<0.05),Caspase3被明显激活(t值分别为31.527、53.190,均P<0.05).结论 高浓度LNG诱导UtLMC凋亡的机制涉及多途径、多靶点,可能与直接激活p38MAPK信号通路,诱导Caspase3活化有关.