γ干扰素抑制幼儿支气管上皮细胞MUC5AC表达

本研究主要探讨了IFN-γ在黏蛋白产生中的作用,特别是在儿童支气管上皮细胞中的MUC5AC转录。通过采用人肺黏液表皮样癌细胞系(NCI-H292)和正常人支气管上皮细胞(NHBE),本研究评估了IFN-γ对MUC5AC转录的影响,发现转化生长因子(TGF)-α和双链RNA (polyI:C)诱导的MUC5AC mRNA和蛋白表达被IFN-γ以浓度依赖性方式抑制。IFN-γ对TGF-α和polyI:C诱导的表皮生长因子受体(EGFR)和细胞外信号调节激酶(ERK)的激活作用有限。染色质免疫沉淀实验表明Sp1与位于MUC5AC启动子上的同源序列结合。Sp1抑制剂光神霉素A抑制MUC5AC mRNA,表明Sp 1在MUC5AC诱导中起关键作用,同时IFN-γ阻碍Sp1与MUC5AC启动子的结合。本研究初步表明,IFN-γ可以抑制MUC5AC的表达,干扰Sp1与其靶序列的结合。     

热休克蛋白90参与糖皮质激素及其受体对气道黏蛋白5AC表达调控的机制

目的:探讨热休克蛋白90(HSP90)在糖皮质激素(GC)信号通路中的作用及其对气道黏蛋白(MUC)5AC表达的调控机制。方法:体外培养气道上皮细胞株BEAS-2B,给予HSP90特异性阻断剂格尔德霉素(GA)和地塞米松(DEX)刺激,比较各组MUC5AC的含量,糖皮质激素受体(GR)的核蛋白表达和GR结合活性。结果:与对照组相比,DEX组的MUC5AC mRNA和蛋白水平降低,伴GR核蛋白水平增高(P0.05);与DEX组相比,GA+DEX组MUC5AC mRNA和蛋白水平升高,GR核蛋白水平降低。放射配体结合实验显示,与对照组相比,GA组的受体最大结合容量(Bmax)降低,平衡解离常数(Kd)升高。结论:HSP90可参与GC及GR的抗气道黏液高分泌效应,其抑制剂可阻断上述效应,该效应是通过降低GR的结合活性来调控的。     

人中性粒细胞弹性蛋白酶诱导气道黏液高分 泌细胞模型的建立及其机制的初步研究

目的：以人中性粒细胞弹性蛋白酶(HNE)为诱导因素,研究建立黏蛋白(MUC)5AC和5B高表达的细胞模型,同时对黏蛋白高表达机制进行初步研究。方法：培养人肺腺癌细胞A549,以HNE为刺激因素,EGFR中和抗体、表皮细胞生长因子受体（EGFR）磷酸化阻断剂AG1478为干预因素,分组培养。采用四甲基偶氮唑盐光吸收法（MTT法）检测HNE对细胞活性的影响;逆转录-聚合酶链反应（RT-PCR）检测MUC5AC mRNA、MUC5B mRNA的变化;酶联免疫吸附测定法(ELISA)定量分析MUC5AC和MUC5B蛋白含量的差异;细胞免疫化学以及激光共聚焦技术进一步直观观察MUC5AC、MUC5B、p-EGFR蛋白表达的变化。结果：HNE对A549细胞活力的影响呈剂量依赖性;HNE刺激组的MUC5AC、MUC5B基因转录和蛋白表达水平均明显高于对照组,差异有统计学意义（均P<0.01）;HNE刺激组p-EGFR蛋白表达显著增多,EGFR中和抗体、AG1478能显著降低HNE诱导的MUC5AC高表达,但对MUC5B高表达无干预作用。结论：人肺腺癌细胞A549同时表达MUC5AC和MUC5B,HNE能有效刺激A549细胞高表达MUC5AC和MUC5B,黏蛋白高表达细胞模型的建立为研究气道粘液高分泌疾病提供了实验基础。HNE通过激活EGFR信号转导通路诱导MUC5AC的高表达,但MUC5B高表达机制与之不同,有待进一步研究。     

COX-2/PGE2对TNF-α促进MUC5AC分泌的影响

目的：研究环氧化酶-2（COX-2）/前列腺素（PGE2）在肿瘤坏死因子-α（TNF-α）刺激黏液生成过程中的作用。方法：体外培养的BEAS-2B气道上皮细胞系施以TNF-α刺激,以选择性及非选择性COX-2抑制剂为干预因素,比较各干预组与对照组中COX-2、PGE2水平及黏蛋白（MUC）5AC的含量的差异。结果：COX-2选择性抑制剂NS-398能抑制TNF-α引起的MUC5AC mRNA、MUC5AC蛋白含量增高（P〈0.05）,PGE2、COX-2及cAMP的含量也较刺激组减少,非选择性COX-2抑制剂吲哚美辛对MUC5AC mRNA及蛋白含量的影响不大。结论：在BEAS-2B上皮细胞系中,TNF-α能诱导COX-2/PGE2生成而引起黏蛋白分泌增加。     

粘蛋白1在肿瘤相关信号通路中的作用

粘蛋白1(MUC1)是一种跨膜糖蛋白,正常情况下表达于多种组织、器官上皮细胞近管腔或腺腔面,呈极性分布.研究发现MUC1在70%以上的实体瘤中异常表达,并与肿瘤的发生、发展和转移密切相关.本文综述了肿瘤相关的信号通路,包括Wnt信号通路、酪氨酸激酶通路及细胞核内转录因子等信号通路中,MUC1的影响和功能.提示MUC1是细胞信号网络整合的桥梁和平台.     

基于p38MAPK通路探讨银杏叶提取物对慢性阻塞性肺疾病大鼠气道黏液高分泌及血管重塑的影响

摘要 目的：探讨银杏叶提取物（Ginkgo biloba extract, GBE）通过调控p38MAPK通路对慢性阻塞性肺疾病（chronic obstructive pulmonary disease,COPD）大鼠气道黏液高分泌及肺血管重塑的影响。方法：将90只大鼠随机分为空白对照组、COPD模型组、GBE高剂量组、GBE中剂量组、GBE低剂量组、SB203580组。采用香烟烟雾熏吸联合气道内注入脂多糖（LPS）的方法建立COPD大鼠模型,造模结束后分组给药;通过维多利亚蓝+VG染色观察大鼠肺小动脉病理改变,测量血管壁厚度占血管外径百分比（WT%）、管壁面积占血管面积百分比（WA%）的变化;酶联免疫吸附法（ELISA）检测大鼠肺泡灌洗液（BALF）与血清中TNF-α、TGF-β的表达;实时荧光定量法（RT-PCR）检测肺组织表皮生长因子受体（EGFR）、黏蛋白5AC（MUC5AC）mRNA表达;蛋白质印迹法（Western Blot）检测肺组织EGFR、MUC5AC、p-p38MAPK蛋白的表达。结果：与空白对照组比较,COPD模型组WT%、WA%明显升高（P＜0.05）;与COPD模型组比较,各药物干预组WT%、WA%明显降低（P＜0.05）;COPD模型组大鼠BALF及血清中TNF-α、TGF-β水平较空白对照组明显升高（P＜0.05）,各药物干预组TNF-α、TGF-β水平较COPD模型组明显下降（P＜0.05）;COPD模型组大鼠肺组织EGFR、MUC5AC mRNA与空白对照组相比明显升高（P＜0.05）,各药物干预组大鼠肺组织EGFR、MUC5AC mRNA与COPD模型组相比显著降低（P＜0.05）;COPD模型组大鼠肺组织中EGFR、MUC5AC、p-p38MAPK蛋白的表达与空白对照组相比明显升高（P＜0.05）,各药物干预组大鼠肺组织中EGFR、MUC5AC、p-p38MAPK蛋白的表达与COPD模型组相比明显降低（P＜0.05）,不同GBE剂量干预组中EGFR、MUC5AC、p-p38MAPK蛋白的表达量随着给药剂量增加而减少。结论：GBE能够抑制COPD大鼠气道黏液分泌、改善肺血管重塑,其机制可能与抑制p38MAPK通路有关。     

两种单负链RNA呼吸道病毒——流感病毒和呼吸道合胞病毒感染对粘蛋白1表达调控差异的研究

为进一步了解流感病毒(IFZ)是否像呼吸道合胞病毒(RSV)一样在感染过程中可以上调呼吸道上皮细胞粘蛋白1(MUC1)的表达,进而限制炎症的发展。我们利用qRT-PCR和Western Blot检测两种呼吸道单负链RNA病毒感染人呼吸道上皮细胞系——A549细胞后对MUC1的表达调控。分别利用人喉上皮细胞系——HEp-2细胞系和MDCK细胞系培养并收集RSV和IFZ。相同滴度的两种病毒分别感染A549细胞24h后,分别裂解各组细胞,收集总RNA,应用qRT-PCR检测MUC1mRNA的表达情况;或相同滴度的两种病毒分别感染A549细胞24h和48h后,裂解细胞收集总蛋白,同时收集细胞培养上清,应用Western Blot检测MUC1蛋白的表达情况,应用ELISA检测上清中TNF-α水平。结果显示,虽然两种病毒都能上调TNF-α水平,但只有RSV可以上调呼吸道上皮细胞MUC1表达,并呈剂量效应,而IFZ不能上调呼吸道上皮细胞MUC1的表达。本研究首次探讨两种常见呼吸道单负链RNA病毒感染呼吸道上皮细胞后对MUC1表达调控的差异,初步证实临床上IFZ感染后病情自限性的机制不同于RSV感染,与MUC1的表达上调无关。     

金黄色葡萄球菌肠毒素B诱导人鼻黏膜上皮细胞表达黏蛋白MUC5AC的分子机制

为了观察金黄色葡萄球菌肠毒素B(SEB)对诱导人鼻钻膜上皮细胞分泌粘蛋白MUC5AC的影响,并初步探讨其作用机制,本研究首先在体外培养人鼻黏膜上皮细胞株HNEpC,用不同浓度的SEB孵育细胞0~24 h,ELISA检测培养上清中MUC5AC和转化生长因子-α(TGF-α)的含量;实时定量PCR检测MUC5AC mRNA表达水平;Western blot分析表皮生长因子受体(EGFR)的磷酸化。同时采用肿瘤坏死因子转化酶(TALE)siRNA干扰其表达双察其对TGF-α分泌的影响最后采用TGF-α中和抗体、EGFR抑制剂AG-1478或TALE抑制剂TAPI处理细胞,观察其在介导MUC5AC分泌中的作用。结果显示,1 ng/mL、10 ng/mL和100 ng/mL SEB作用鼻黏膜上皮细胞24 h后,可明显诱导其分泌MUC5AC并表达其mRNA,且其分泌水平随着SEB浓度的增高或时间的延长而逐渐增多。SEB也能诱导鼻黏膜上皮细胞分泌TGF-α,并磷酸化EGFR。给予10μmol/L TALE抑制剂TAPI处理细胞后,TGF-α和MUC5AC分泌水平显著减少,采用TALE siRNA干扰其表达后,TGF-α和MUC5AC也得到了类似结果。采用TGF-α中和抗体预孵育细胞30 min后,可明显抑制EGFR磷酸化。此外,TGF-α和EGFR中和抗体以及AG-1478预处理也可降低MUC5AC分泌。以上结果表明SEB经TALE/TGF-α/EGFR诱导人鼻黏膜上皮细胞表达MUC5AC。     

香烟烟雾暴露对支气管哮喘大鼠肺组织水通道蛋白5表达的影响

目的探讨香烟烟雾暴露对支气管哮喘大鼠肺组织水通道蛋白5(Aquaporin 5,AQP5)和黏蛋白5AC(MUC5AC)表达的影响。方法将30只雄性SD大鼠随机分为3组(n=10),对照组雾化生理盐水,哮喘组采用卵清白蛋白(OVA)致敏并吸入激发制备哮喘模型,哮喘+烟雾暴露组于每日雾化激发OVA前给予香烟烟雾吸入。收集支气管肺泡灌洗液(BALF)进行白细胞计数及分类,测定肺组织病理变化及湿干重比值。实时定量PCR(Realtime PCR)测定AQP5和MUC5AC mRNA的表达,免疫组化法测定AQP5蛋白分布情况,免疫印迹法(Western blot)测定AQP5蛋白的表达,酶联免疫吸附试验(ELISA)测定BALF中MUC5AC的含量。结果①与对照组相比,哮喘组大鼠BALF中白细胞、淋巴细胞、嗜酸粒细胞、中性粒细胞数量明显增加;与哮喘组相比,暴露组大鼠BALF中白细胞、中性粒细胞数量明显增加,差异均有统计学意义(P<0.05)。②与对照组相比,哮喘组和暴露组大鼠肺组织中AQP5表达明显减少,而MUC5AC蛋白含量明显增加;与哮喘组相比,暴露组大鼠肺组织中AQP5明显减少,而MUC5AC蛋白含量明显增加,差异均有统计学意义(P<0.05)。③肺组织中AQP5表达与肺组织BALF中MUC5AC蛋白含量呈负相关(r=-0.852和-0.895,P<0.05)。结论香烟烟雾暴露可导致哮喘大鼠肺组织AQP5表达减少而MUC5AC含量增加,进一步加重哮喘气道炎症和黏液高分泌反应,这可能为哮喘吸烟患者的早期防治提供新思路。     

肺炎支原体P1蛋白的研究进展

肺炎支原体(MP)是引起呼吸系统感染常见的病原微生物,P1蛋白是肺炎支原体上一种与黏附相关的跨膜蛋白,其黏附作用是引发炎症作用的重要原因.目前新发现的一种被称为孤立岛3的P1变异体引起了各学者的广泛关注.另外,还可以利用P1蛋白进行MP感染的实验室诊断.因此,探讨P1蛋白基因结构、致病机制和实验室诊断方法具有重要意义.     

The expression of human FUT1 in HT-29/M3 colon cancer cells instructs the glycosylation of MUC1 and MUC5AC apomucins

Recently, we have reported that in normal gastric epithelium, the expression of gastric apomucins MUC5AC and MUC6 is associated with the specific expression of type 1 and type 2 Lewis antigens, and FUT2 and FUT1 fucosyltransferases, respectively. Until now, there are no data demonstrating the direct implication of specific glycosyltransferases in the specific patterns of apomucin glycosylation.HT29/M3 colon cancer cell line express MUC1, MUC5AC, type 1 Lewis antigens and FUT2 but not type 2 structures and FUT1, as it occurs in the epithelial cells of the gastric superficial epithelium. These cells were transfected with the cDNA of human FUT1, the -1,2-fucosyltransferase responsible for the synthesis of type 2 Lewis antigens, to assess the implication of FUT1 in the glycosylation of MUC1 and MUC5AC.The M3-FUT1 clones obtained express high levels of type 2 Lewis antigens: H type 2 and Ley antigens. Immunoprecipitation of MUC1 and MUC5AC apomucins gives the direct evidence that FUT1 catalyses the addition of -1,2-fucose to these apomucins, supporting the hypothesis that the pattern of apomucin glycosylation is not only instructed by the mucin primary sequence but also by the set of glycosyltransferases expressed in each specific cell type.     

Regulation of MUC5AC mucin secretion by depletion of AQP5 in SPC-A1 cells

Airway mucus is regulated by many inflammatory mediators such as ILs, TNF-alpha, EGF, PGF2alpha, LT, and so on. Recently, the relationship between membrane ion channel and mucus production has been under investigation. The present study aimed to examine whether AQP5 was involved in modulation of mucin expression and secretion in airway submucosal gland cells (SPC-A1). A recombinant plasmid (pShAQP5) containing small hairpin RNA expression cassette targeting AQP5 sequence was constructed. In pShAQP5 transiently transfected cells, ELISA showed MUC5AC synthesis and secretion were increased by 57.9% and 85.3%, respectively, on day 5 after pShAQP5 transfection. While in five stably transfected clones (shAQP5-G1, G2, G3, A2, and A5), the upregulated levels of MUC5AC mRNA were 118%, 165%, 65%, 123%, and 38%, respectively. The elevated levels of MUC5AC synthesis and secretion varied from 59-156% and 33-166%, respectively. This is the first reliable investigation of the regulation of MUC5AC mucin secretion by silencing AQP5. Further study of the regulatory mechanism between AQPs and mucins may provide new strategies for development of novel antihypersecretory drugs in airway diseases.     

Integrin β1 subunit regulates cellular and secreted MUC5AC and MUC5B production in NCI–H292 human lung epithelial cells

The surface of the human respiratory tract is covered with a mucus layer containing mucin 5AC (MUC5AC) and mucin 5B (MUC5B) as the main components. This layer contributes to biological defense by eliminating irritants, but excessive MUC5AC secretion by the airway epithelial cells exacerbates asthma. Therefore, regulating mucin production is important for asthma treatment. In this study, the effects of integrin β1 subunit on MUC5AC and MUC5B production were examined in NCI–H292 human lung cancer epithelial cells. When integrin β1 was overexpressed, cellular and secreted MUC5AC levels were decreased, whereas cellular MUC5B production was increased. Conversely, integrin β1 depletion using siRNA increased cellular and secreted MUC5AC production, but decreased cellular MUC5B production. Further, the activity of extracellular signal-regulated kinase (ERK), which promotes MUC5AC production, was decreased by integrin β1 overexpression and increased by its depletion. These results suggest that integrin β1 suppresses MUC5AC production and promotes MUC5B production by downregulating ERK.     

CTNNAL1 participates in the regulation of mucus overproduction in HDM‐induced asthma mouse model through the YAP‐ROCK2 pathway

Our previous study indicated that adhesion molecule catenin alpha‐like 1(CTNNAL1) is downregulated in airway epithelial cells of asthma patients and asthma animal model but little is known about how the CTNNAL1 affects asthma pathogenesis. To reveal the direct relationship between asthma and CTNNAL1, CTNNAL1‐deficient mouse model in bronchopulmonary tissue was constructed by introducing CTNNAL1‐siRNA sequence using adeno‐associated virus (AAV) as vector. The mouse model of asthma was established by stimulation of house dust mite (HDM). After HDM‐challenged, there was marked airway inflammation, especially mucus hypersecretion in the CTNNAL1‐deficient mice. In addition, the CTNNAL1‐deficient mice exhibited an increase of lung IL‐4 and IL‐13 levels, as well as a significant increase of goblet cell hyperplasia and MUC5AC after HDM exposure. The expression of Yes‐associated protein (YAP), protein that interacted with α‐catenin, was downregulated after CTNNAL1 silencing and was upregulated due to its overexpression. In addition, the interaction between CTNNAL1 and YAP was confirmed by CO‐IP. Besides, inhibition of YAP could decrease the secretion of MUC5AC, IL‐4 and IL‐13 in CTNNAL1‐deficient 16HBE14o‐cells. Above results indicated us that CTNNAL1 regulated mucus hypersecretion through YAP pathway. In addition, the expression of ROCK2 increased when CTNNAL1 was silenced and decreased after YAP silencing, and inhibition of YAP decreased the expression of ROCK2 in CTNNAL1‐deficient HBE cells. Inhibition of ROCK2 decreased MUC5AC expression and IL‐13 secretion. In all, our study demonstrates that CTNNAL1 plays an important role in HDM‐induced asthma, mediating mucus secretion through the YAP‐ROCK2 pathway.     

Bone morphogenetic protein (BMP)1-3 enhances bone repair

Small molecules that exhibit biological activity have contributed to the understanding of the molecular mechanisms of various biological phenomena. 5-Bromodeoxyuridine (BrdU) is a thymidine analogue that modulates various biological phenomena such as cellular differentiation and cellular senescence in cultured mammalian cells. Although BrdU is thought to function through changing chromatin structure and gene expression, its precise molecular mechanisms are not understood. To study the molecular mechanism for the action of BrdU, we have employed the yeast Saccharomycescerevisiae as a model system, and screened multi-copy suppressor genes that confer resistance to BrdU. Our genetic screen has revealed that expression of the N-terminal short fragment of TUP1, and also disruption of HDA1 or HOS1, histone deacetylases that interact with TUP1, conferred resistance to BrdU. These results suggest the implication of the chromatin proteins in the function of BrdU, and would provide novel clues to answer the old question of how BrdU modulates various biological phenomena.     

一个抑制AP-1活性的人类新基因AC3-33的克隆和初步功能研究

Activator protein-1(AP-1)是重要的转录因子, 其活性失调与肿瘤等多种疾病直接相关。本文运用“高通量高内涵细胞筛选技术(high throughput-high content cell-based screening technology)”对650个以未知功能基因为主的人类基因进行AP-1双荧光素酶报告基因筛选(Dual-Luciferase reporter gene screening), 获得了一个可抑制佛波酯(PMA)加离子霉素(Inonmycin)诱导的AP-1活性的人类新基因AC3-33(GenBank中该基因名为C3orf33, No. FLJ31139)。生物信息学分析该基因序列全长1 931 bp, 由6 个外显子和5 个内含子组成, 定位于3q25.31, 从271~1026 有一个编码251 个氨基酸的可读框, 编码一个约29 kDa 的蛋白, 在肾上腺和宫颈等多种组织都有表达。AC3-33 与其他人类已知蛋白质没有明显的同源性, 亚细胞定位于细胞质中, 许多氨基酸序列高度保守。初步实验结果显示AC3-33是一个有重要功能的人类新基因。     

Regional changes in density of serotonin transporter in the brain of 5-HT1A and 5-HT1B knockout mice, and of serotonin innervation in the 5-HT1B knockout

5-HT1A knockout (KO) mice display an anxious-like phenotype, whereas 5-HT1B KOs are over-aggressive. To identify serotoninergic correlates of these altered behaviors, autoradiographic measurements of 5-HT1A and 5-HT1B serotonin (5-HT) receptors and transporter (5-HTT) were obtained using the radioligands [3H]8-OH-DPAT, [125I]cyanopindolol and [3H]citalopram, respectively. By comparison to wild-type, density of 5-HT1B receptors was unchanged throughout brain in 5-HT1A KOs, and that of 5-HT1A receptors in 5-HT1B KOs. In contrast, decreases in density of 5-HTT binding were measured in several brain regions of both genotypes. Moreover, 5-HTT binding density was significantly increased in the amygdalo-hippocampal nucleus and ventral hippocampus of the 5-HT1B KOs. Measurements of 5-HT axon length and number of axon varicosities by quantitative 5-HT immunocytochemistry revealed proportional increases in the density of 5-HT innervation in these two regions of 5-HT1B KOs, whereas none of the decreases in 5-HTT binding sites were associated with any such changes. Several conclusions could be drawn from these results: (i) 5-HT1B receptors do not adapt in 5-HT1A KOs, nor do 5-HT1A receptors in 5-HT1B KOs. (ii) 5-HTT is down-regulated in several brain regions of 5-HT1A and 5-HT1B KO mice. (iii) This down-regulation could contribute to the anxious-like phenotype of the 5-HT1A KOs, by reducing 5-HT clearance in several territories of 5-HT innervation. (iv) The 5-HT hyperinnervation in the amygdalo-hippocampal nucleus and ventral hippocampus of 5-HT1B KOs could play a role in their increased aggressiveness, and might also explain their better performance in some cognitive tests. (v) These increases in density of 5-HT innervation provide the first evidence for a negative control of 5-HT neuron growth mediated by 5-HT1B receptors.