Expression and clinical significance of PAK4 in non-small cell lung cancer

AIM: To investigate the expression and clinical significance of PAK4 in the cell lines and tissues of non-small cell lung cancer (NSCLC). METHODS: PAK4 expression in human bronchial epithelial (HBE) cells, NSCLC cell lines, NSCLC tissues and adjacent non-tumor tissues were assessed by immunohistochemistry, real-time PCR and Western blot. Prognostic value of PAK4 expression was evaluated by Kaplan-Meier analysis and Cox regression. RESULTS: PAK4 was over-expressed in the NSCLC cell lines at both mRNA and protein levels compared with HBE cells (P<0.05). PAK4 was over-expressed in the NSCLC tissues at both mRNA and protein levels compared with adjacent non-tumor tissues (P<0.05). PAK4 was over-expressed in the metastatic NSCLC tissues compared with the primary NSCLC tissues (P<0.05). Higher PAK4 staining scores were positively correlated with differentiation, lymph node metastasis, distant metastasis, and clinical stage. Kaplan-Meier analysis and log-rank test showed that overall survival was significantly different between the patients with up-regulated PAK4 and the patients with down-regulated PAK4(P<0.05). PAK4 over-expression was associated with NSCLC progression.CONCLUSION: Increased PAK4 expression was associated with tumor invasion, metastasis and prognosis in the patients with NSCLC. PAK4 is an important prognostic marker and potential therapeutic target in NSCLC.     

Protective effect of BNDF on vascular endothelial cells with H2O2-induced oxidative injury

AIM: To study the protective effect of brain-derived neurotrophic factor (BDNF) on vascular endothelial cells with H₂O₂-induced oxidative injury. METHODS: Human umbilical vein endothelial cells (HUVECs) were cultured in vitro, and the oxidation injury model of HUVECs was established by treatment with H₂O₂. The oxidatively injured HUVECs were cultured with different concentrations (1, 10 and 100 μg/L) of BDNF. At the same time, the control group (no injury), PBS treatment after H₂O₂ injury group and TrkB inhibitor group (with 100 μg/L BDNF and 1: 1 000 TrkB inhibitor) were also set up. The viability of the HUVECs was detected by MTT assay. The levels of LDH, MDA, SOD and GSH were measured. The releases of NO, ET-1 and ICAM-1 were analyzed by ELISA. The changes of ROS production and cell apoptosis were evaluated by flow cytometry. The protein levels of TrkB, p-TrkB, cleaved caspase-3, Bcl-2 and Bax were determined by Western blot. RESULTS: Compared with uninjured control group, in H₂O₂ oxidative injury plus PBS treatment group, the viability of the cells was decreased significantly, the LDH and MDA levels were increased significantly and the activities of SOD and GSH were decreased significantly. The NO secretion was decreased, and the ET-1 and ICAM-1 concentrations were increased significantly. The ROS content and apoptotic rate were increased significantly. The protein levels of cleaved caspase-3 and Bax were increased but Bcl-2 protein expression was decreased significantly. Compared with PBS treatment group, in H₂O₂-injured HUVECs treated with different concentrations of BDNF, the cell viability was gradually increased, the LDH and MDA levels were decreased and the activities of SOD and GSH were increased gradually. The secretion of NO was increased but ET-1 and ICAM-1 were decreased gradually. The ROS content and apoptotic rate were decreased significantly. The TrkB and p-TrkB levels were significantly increased significantly, the protein expression of cleaved-caspase 3 and Bax was decreased gradually and the Bcl-2 protein expression increased gradually. The role of BDNF was inhibited by TrkB inhibitor. CONCLUSION: BDNF protects HUVECs from oxidative injury by binding with TrkB to activate the BDNF-TrkB signaling pathways.     

Effects of myosin light chain kinase on regulation of endothelial barrier function

Myosin light chain kinase (MLCK) activates the regulatory light chain of myosin II, and the phosphorylated myosin light chain leads to actomyosin contractile activity, as well as the cell contraction and increasing intercellular gap, which finally results in endothelial barrier dysfunction. MLCK-dependent hyperpermeability occurs in response to multiple cell signaling molecules and signaling pathways, including Ca²⁺, Src, PKC, NO, cGMP and mitogen activated protein kinases (MAPK). In this review, different mechanisms of endothelial hyperpermeability mediated by MLCK are discussed.     

花生黄曲霉抗性与类受体蛋白激酶的相关性分析

LRR类受体激酶RH4基因在花生黄曲霉敏感品种发育种子的种皮中上调表达.基于这类受体激酶多由于序列的变异导致抗性的变异,笔者将数据库中花生抗黄曲霉和敏感品种相似基因编码的蛋白进行序列比较分析,发现抗性品种与敏感品种的类似蛋白序列有很大差别.用荧光定量PCR方法对抗性品种KB153与敏感品种JH1012发育中不同时期的果...     

METFORMIN短期内对蛋鸡体AMPK活性的影响

选用日龄、体重及产蛋率相近的产蛋高峰期的新罗曼蛋鸡20只,按两两配对的原则,分为2个处理组,每个处理5个重复,每个重复2只鸡;其中实验组蛋鸡日粮中含有0．8％浓度的Metformin;配对组蛋鸡采食日粮除不合Metformin外,日粮成分与实验组相同,并按实验组前1d的采食量供给;正式实验期为5d。实验组与配对组相比,实验组蚤鸡肝脏中AMPK活性提高了24．82％（P〈0．3）,而卵巢中AMPK活性仅提高了10．13％（P〈0．6）;实验组蛋鸡肝脏中TG下降了13．61％（P〈0．1）;血清中VLDL—C含量下降了12．66％（P〈0．6）,同时在直径分别为2,1,0．5cm的卵泡中,卵黄胆固醇含量分别下降了9．18％（P〈0．01）,9．72％（P〈0．01）,17．04％（P〈0．05）。实验结果表明Metformin提高了蛋鸡体内AMPK的活性,并降低了蛋鸡体内脂质的合成及卵黄中胆固醇的含量。     

肾上腺髓质素对大鼠心肌成纤维细胞胶原合成的影响

目的:观察肾上腺髓质素(ADM)对大鼠心肌成纤维细胞(FBC)胶原合成的影响,并探讨其可能的作用机制。方法:用差速贴壁分离法获得心肌成纤维细胞为材料,用放射免疫法测定细胞培养上清液中I及III型前胶原末端肽(PINP、PCIII)的含量。结果:①ADM呈浓度依赖性抑制FBC的PINP、PCIII分泌;②在AngII存在的情况下,PKA抑制剂能完全阻断ADM抑制细胞PINP、PCIII分泌的作用;③在基础状态和AngII刺激下,PKC及酪氨酸蛋白激酶抑制剂均能增强ADM作用。结论;①ADM能够抑制FBC胶原合成;②ADM抑制FBC胶原合成是通过PKA途径介导。     

表面张力法研究表面活性剂和肌酸激酶相互作用

】本文利用表面张力法研究了十二烷基硫酸钠（ＳＤＳ）和溴化十二烷基三甲铵（Ｃ１２ＮＭ３）与肌酸激酶（Ｃ．Ｋ．）的相互作用。结果表明，当ＳＤＳ为０．０５ｍＭ时，ＳＤＳ开始“明显”和Ｃ．Ｋ．结合。在溶液的ｐＨ＜６．０（Ｃ．Ｋ．的等电点）时，于０．２～１．２ｍＭ的浓度范围内，ＳＤＳ可引起Ｃ．Ｋ．的沉淀。在溶液的ｐＨ＞８．０时，于０．６～４．５ｍＭ的浓度范围内，Ｃ１２ＮＭ３可引起Ｃ．Ｋ．沉淀。Ｃ．Ｋ．和ＳＤＳ的结合量随溶液ｐＨ和ＳＤＳ浓度的增加而增加     

细胞分裂素与细胞的分裂增殖

细胞分裂素对细胞的分裂增殖起着重要的调节作用,在细胞周期中的G1/S期,细胞分裂素促进D型细胞周期蛋白CycD的表达;在G2/M期,其作用与CDK的磷酸化有关。植物通过体内细胞分裂素的代谢影响细胞分裂素水平,调节植物生长发育调控基因,影响植物的根尖、茎尖等器官的生长发育。     

酵母穿梭表达质粒pGBKT7-hCK2α＇的构建

目的：用人蛋白激酶CK2α’(hCK2α’)cDNA片段构建酵母双杂交体系中“诱饵”载体。方法；通过PCR扩增已构建成功的重组质粒pThCKA’获得人CK2α’亚基编码区cDNA，将PstⅠ／NdeⅠ双酶切的PCR产物连接到同样酶切的“诱饵”载体pGBKT7，转化感受态细胞DH5α获得转化子．琼脂糖凝胶电泳初步筛选转化子，将阳性克隆进行限制性内切酶酶切与DNA测序的方法鉴定。将DNA测序验证的pGBKT7-hCK2α’转染感受态酵母株AH109．Westernblot签定hCK2α’蛋白表达．检测表达产物对报道基因的激活作用及对酵母株AH109的毒性。结果：限制性酶切结果表明，插入片段和重组质粒的大小与理论值推测值相符。重组质粒pGBKT7-hCK2α’转染的酵母株AH109中能够表达hCK2α’蛋白，pGBKT7-hCK2α’无自主激活报道基因的能力及对酵母的生长无毒性。结论：pGBKT7-hCK2α’酵母双杂“诱饵”载体构建获得成功，可应用于酵母双杂交体系。     

甘蓝两种SRK短截蛋白的体外表达及其与THL1作用检测

 为探明S–位点受体激酶（SRK）上与类硫氧还蛋白1（THL1）作用的氨基酸区域以及两者间作用方式,依据SRK_E1上功能域分布构建了两种SRK_E1短截体原核表达质粒pGEX-SRK_E1A和pGEX-SRK_E1B,分别在大肠杆菌BL21中获得了可溶性表达。通过体外孵育检测蛋白质相互作用的方法对SRK_E1A、SRK_E1B与THL1相互作用进行了检测,结果表明SRK_E1A和SRK_E1B均可与THL1结合,明确了THL1与SRK相互作用并不依赖于SRK激酶活性。两类SRK等位序列间比对结果表明Cys在两类SRK间的保守性存在明显差异,推测两类SRK材料亲和性的差异可能与Cys保守性不同有关。