RhoC、Rho-GDIα在肺癌细胞系中过

目的分析RhoC及其调节蛋白GDP解离抑制因子α（Guanine dissociation inhibitor,GDIα）在肺癌细胞中的表达及其与肺癌细胞转移能力间的关系。方法应用Western blot、RT-PCR分别检测正常支气管上皮细胞、不同的肺癌细胞系中的RhoC、Rho-GDIα蛋白及mRNA的表达。结果RhoC、Rho-GDIα在人支气管上皮细胞、肺腺癌细胞系、肺巨细胞癌细胞系均有表达,免疫荧光显示均表达于细胞浆。RhoC、Rho-GDIα在肺癌中的表达高于人支气管上皮细胞。在高转移能力的肺巨细胞癌亚系BEI RhoC、Rho-GDIα的表达均高于低转移能力的肺巨细胞癌亚系LH7。结论RhoC、RhoGDIα在肺癌细胞系中过表达并与转移能力相关。     

金黄色葡萄球菌所致肺部感染的耐药特点及其Panton—Valentine杀白细胞素基因的携带状况分析

目的分析金黄色葡萄球菌所致肺部感染的耐药性特点及其Panton—Valentine杀白细胞素基因的携带状况。方法回顾性调查了温州医学院第一附属医院2005年1月至2006年1月医院感染的金黄色葡萄球菌所致肺部感染患者132例,对其体外药敏试验进行分析;并利用多重PCR检测其PVL基因,应用多位点基因序列分型（multilocus sequence typing,MLST）技术对PVL基因阳性的菌株进行序列分型。耐甲氧西林金黄色葡萄球菌（methicillin-resistant Staphylococcus aureus,MRSA）的SCCmec基因分型采用多重聚合酶链反应。结果致肺部感染的132株金黄色葡萄球菌的耐药现象较为严重,仅对万古霉素、呋喃妥因及复方新诺明等药物的敏感率较高;其中经多重PCR筛选出10株携带PVL基因的金葡菌,全部为MRSA菌株,3株为ST239-SCCⅢ,2株为ST398-SCCmecⅢ,2株为ST398-SCCmecⅣ,ST25-SCCmecⅢ、ST59-SCCmecⅠ和ST88-SCCmecⅢ各1株。结论肺部感染的金黄色葡萄球菌对多种抗生素耐药,呈多重耐药性;其携带PVL基因占一定比例。     

Enhancing Glutathione Synthesis can Decrease Zinc-Mediated Toxicity

Zinc toxicity has been linked to cellular glutathione: A decrease in glutathione is followed by an increase in zinc-mediated toxicity. The question arises whether an increase in glutathione synthesis might decrease zinc-mediated cytotoxicity. We incubated five cell lines (hepatoma and lung-derived) with zinc chloride and 2 mmol/l N-acetyl-l-cysteine (NAC) to support glutathione synthesis. In all but one hepatic cell line, the glutathione content was increased by NAC as compared to the d-enantiomere NADC, whereas NADC did not increase GSH content as compared to not treated controls. In both alveolar epithelial cell lines, an increase in zinc tolerance was observed due to NAC as compared to NADC. In native fibroblast-like and the hepatoma cell lines, no changes in zinc tolerance were found due to NAC. In the fibroblast-like cells, zinc tolerance was increased due to NAC only after cellular glutathione had been previously decreased (by lowered cysteine concentrations in the medium). Enhancing glutathione synthesis can antagonize zinc-mediated toxicity in the alveolar epithelial cell lines, whereas some other characteristics than glutathione synthesis might be more important in other cell types. Furthermore, NAC acted as a GSH precursor only at cysteine medium concentrations of 10 μmol/l or below and therefore might be described as a poor cysteine repletor for glutathione synthesis. This work is dedicated to Peter Eyer on the occasion of his 65th birthday.     

Role for mitogen-activated protein kinase p38 alpha in lung epithelial branching morphogenesis

In the early stages of lung development, the endoderm undergoes extensive and stereotypic branching morphogenesis. During this process, a simple epithelial bud develops into a complex tree-like system of tubes specialized for the transport and exchange of gas with blood. The endodermal cells in the distal tips of the developing lung express a special set of genes, have a higher proliferation rate than proximal part, undergo shape change and initiate branching morphogenesis. In this study, we found that of the four p38 genes, only p38α mRNA is localized specifically to the distal endoderm suggesting a role in the regulation of budding morphogenesis. Chemical inhibitors specific for the p38α and p38β isoforms suppress budding of embryonic mouse lung explants and isolated endoderm in vitro. Specific knockdown of p38α in cultured lung endoderm using shRNA also inhibited budding morphogenesis, consistent with the chemical inhibition of the p38 signaling pathway. Disruption of p38α did not affect proliferation or expression of the distal cell markers, Sox9 and Erm. However, the amount of E-cadherin protein increased significantly and ectopic expression of E-cadherin also impaired budding of endoderm in vitro. These results suggest that p38α modulates epithelial cell-cell interactions and possibly cell rearrangement during branching morphogenesis. This study provides the first evidence that p38α is involved in the morphogenesis of an epithelial organ.     

Hyperosmotic stress up-regulates the expression of major vault protein in SW620 human colon cancer cells

The major vault protein (MVP) is the major constituent of the vault particle, the largest ribonuclear protein complex described to date and is identical to lung resistance-related protein (LRP). Although MVP is also expressed in several normal tissues, little is known about its physiological role. MVP played a protective role against some xenobiotics and other stresses. We thus investigated the effect of osmotic stress on MVP expression by treating human colon cancer SW620 cells with sucrose or NaCl. The expression level of both MVP protein and MVP mRNA was increased by the osmostress. Sucrose or sodium chloride could also enhance MVP promoter activity. Inhibition of p38 MAPK in SW620 cells by SB203580 inhibited the expression of MVP under hyperosmotic stress. These findings suggested that osmotic stress up-regulated the MVP expression through p38 MAPK pathway. Down-regulation of MVP expression by MVP interfering RNA (RNAi) in SW620 cells increased the sensitivity of the cells to hyperosmotic stress and enhanced apoptosis. Furthermore, MVP RNAi prevented the osmotic stress-induced, time-dependent increase in phosphorylated Akt. These findings suggest that the PI3K/Akt pathway might be implicated in the cytoprotective effect of MVP.Our data demonstrate that exposure of cells to hyperosmotic stress induces MVP that might play an important role in the protection of the cells from the adverse effects of osmotic stress.     

Effects of 6-month daily supplementation with oral beta-carotene in combination or not with benzo[a]pyrene on cell-cycle markers in the lung of ferrets

Epidemiological studies have demonstrated that people who eat more fruits and vegetables (rich in carotenoids) and people who have higher serum beta-carotene (BC) levels have a lower risk of cancer, particularly lung cancer. However, the two main human intervention studies of BC supplementation (the ATBC and the CARET trials) revealed an increased risk of lung cancer among smokers and asbestos workers. Previous studies carried out in the ferret have reported that BC effects are related to dose. Here, we treated ferrets with two concentrations of oral BC (0.8 and 3.2 mg/kg body weight per day) for 6 months, using BC in a formulation also containing dl-alpha-tocopherol and ascorbyl palmitate. The effect of the smoke-derived carcinogenic agent benzo[a]pyrene (BP), with or without low-dose BC, was also analysed. We determined the protein levels and mRNA expression levels of activator protein 1 (c-Jun and c-Fos), c-Myc, cyclin D1, proliferating cellular nuclear antigen and retinoic acid receptor beta. We did not find higher levels of cell proliferation markers in the lung of ferrets treated with BC or signals of squamous metaplasia lesions either. On the other hand, although no evident signals of pulmonary carcinogenesis were observed in animals exposed to BP, BC supplementation in these animals may prevent against excess cell proliferation, since this reestablishes Jun protein and cyclin D1 mRNA levels in the lung of BP-exposed animals. In summary, these results show that the combination of BC with alpha-tocopherol and ascorbyl palmitate does not induce pro-oxidant effects in the lung of ferrets.     

实验性腹膜炎肺损伤时大黄的保护作用

目的探讨大黄对实验性腹膜炎时肺损伤的保护作用.方法用酵母多糖A腹腔注射制备大鼠急性腹膜炎模型,诱发肺脏损伤.将SD大鼠随机分为4组:(1)正常组,(2)模型组,(3)大黄实验组,(4)抗生素实验组(氨苄西林组).测定肺组织匀浆中丙二醛(MDA)、黄嘌呤氧化酶(XOD)、谷光甘肽(GSH)和血清内毒素水平,并进行血气分析及外周血WBC计数.结果大黄组内毒素、肺组织匀浆中MDA和XOD,以及白细胞计数均明显低于模型组(P＜0.05),而还原GSH变化不明显.结论大黄可能通过降低外周及门静脉血内毒素水平,抑制脂质过氧化和加强自由基的清除,从而减轻实验性腹膜炎引起的肺损伤.     

实验性腹膜炎时内毒素血症及肺脏的变化

目的探讨实验性腹膜炎时,内毒素与肺损伤的变化.方法用酵母多糖A腹腔注射制备大鼠急性实验性腹膜炎模型,随机分为模型组和对照组;观察实验性腹膜炎时,肺损伤变化.结果模型组内毒素、肺匀浆脂质过氧化物,以及白细胞计数均明显增高;而还原谷胱甘肽(GSH)明显降低,与对照组比差异有显著性(P＜0.05).结论实验性腹膜炎时,内毒素的形成、细菌因子的释放及脂质过化与肺损害有一定的联系.     

Physical interaction between Tbx6 and mespb is indispensable for the activation of bowline expression during Xenopus somitogenesis

Crk is a member of a family of adaptor proteins that are involved in intracellular signal pathways altering cell adhesion, proliferation, and migration. Increased expression of Crk has been described in lung cancer and associated with increased tumor invasiveness. MicroRNAs (miRNAs) are a family of small non-coding RNAs (approximately 21–25 nt long) that are capable of targeting genes for either degradation of mRNA or inhibition of translation. Crk is a predicted putative target gene for miR-126. Over-expression of miR126 in a lung cancer cell line resulted in a decrease in Crk protein without any alteration in the associated mRNA. These lung cancer cells exhibit a decrease in adhesion, migration, and invasion. Decreased cancer cell invasion was also evident following targeted knockdown of Crk. MiR-126 alters lung cancer cell phenotype by inhibiting adhesion, migration, and invasion and the effects on invasion may be partially mediated through Crk regulation.     

肺癌的超声像、超声引导下穿刺活检及纤支镜检、酶组织化学,超微结构的研究

为了探讨超声对肺癌诊断的可行性价值,研究对象包括20例患者,20例可疑病例,均采用超声像,超声引导下穿刺活检和纤支镜检,常规病理检查,酶组织化学检查和电镜观察,结果超声诊断肺癌可以确认肺部肿块的存在,并可以观察肿瘤的大小,形态及内部结构,B超引导下活检可应用于周围型肺部肿块以及患者不宜行纤支镜检或镜检失败的某些中心型肺部肿块,肺癌组织酶组织化学活性反应为（NOS、LDH,CCO,ACP）的活性增高,SDH的活性降低,呈“四高、一是低”的特点,其超微结构示肺组织结构破坏,肺癌组织细胞结构不清,提示：超声像有助于发现肺部肿块,B超引导下活检是安全,快速,简便可行的有效手段,酶组织化学检查及电镜观察对肺癌的鉴别诊断有意义。