与成纤维细胞共培养的肺泡Ⅱ型上皮细胞的生物学特性

建立胎鼠肺泡Ⅱ型上皮细胞（AECⅡ）与肺成纤维细胞（LF）共培养模型,观察与LF共培养下AECⅡ的生物学特性。倒置相差显微镜观察AECⅡ形态和基本生长情况：RT-PCR和流式细胞术分别检测肺泡表面活性蛋白-C（SP-C）、水通道蛋白5（AQPS）mRNA及蛋白质表达;流式细胞术检测细胞周期及Ki67表达。结果显示,与LF共培养时,AECⅡ能较好地保留其细胞形态。SP-C mRNA及其蛋白质表达明显增加,而AQP5mRNA及其蛋白质表达则明显减少;LF促进AECⅡ增殖,使G2／M、S期细胞及表达Ki67^＋细胞的比率明显增多。结果提示,AECⅡ与LF共培养时,能更好地保留其细胞形态、分化及增殖特性。     

γ-分泌酶抑制剂阻断Notch信号通路对BMSCs向肺泡上皮细胞分化的影响

为探讨γ-分泌酶抑制剂(DAPT)阻断Notch信号通路对BMSCs分化肺泡上皮细胞过程中的影响。本研究采用BMSCs与MLE-12非接触共培养,并在共培养中加入DAPT,实验分3组:空白对照组、共培养组、DAPT共培养组。共培养10 d后用光镜观察BMSCs的形态结构变化,Western blotting和RT-qPCR检测Notch信号通路相关基因Notch1,Ⅱ型肺泡上皮细胞特异性表面活性蛋白(surfactant protein C,SPC)、Ⅰ型肺泡上皮细胞标志水通道蛋白(aquaporin 5,AQP5)的表达。结果表明共培养10 d后的BMSCs变为似铺路石样上皮细胞形态;和空白对照组相比,共培养组、DAPT共培养组中Notch1、SPC、AQP5蛋白及mRNA表达升高(p0.05);与共培养组相比,DAPT共培养组中Notch1、SPC、AQP5蛋白及mRNA的表达减少(p0.05)。因此推测BMSCs在MLE-12诱导下可以定向分化为肺泡上皮细胞,且分化的过程中Notch信号通路被激活,DAPT阻断Notch信号通路能抑制BMSCs分化为肺泡上皮细胞。     

过表达TPX2对人宫颈癌Hela细胞增殖和周期的影响及机制

该文的目的是研究过表达Xklp2靶蛋白(targeting protein for Xklp2,TPX2)对人宫颈癌Hela细胞体外增殖和细胞周期的影响及相关机制。构建TPX2过表达慢病毒载体(LV11-TPX2)及阴性对照(LV11-NC),选取稳定感染过表达慢病毒载体(LV11-TPX2)的Hela细胞作为实验组,将稳定感染(LV11-NC)的Hela细胞作为阴性对照组。未感染病毒的人宫颈癌Hela细胞作为空白对照组(CON)。CCK-8法及克隆形成实验检测各组Hela细胞体外增殖能力,FCM法检测各组Hela细胞的细胞周期分布变化。Western blot检测TPX2通路中Aurora A、eg5、P53蛋白质及增殖和细胞周期相关蛋白Ki67、CyclinB2、PCNA的水平。结果显示:与空白对照组及阴性对照组比较,LV11-TPX2感染组Hela细胞增殖能力明显增强(P0.05);LV11-TPX2组形成的克隆数目明显多于阴性对照组及空白对照组(P0.05)。LV11-TPX2组S期及G_2/M期细胞所占比例明显增加(P0.05)。LV11-TPX2感染组Hela细胞中Aurora A、eg5、Ki67、CyclinB2、PCNA蛋白质水平明显上调(P0.05),P53蛋白质明显下调(P0.05)。以上结果表明,TPX2基因过表达能促进宫颈癌细胞的增殖,S期及G_2/M期细胞所占比例明显增加,可能与其下调P53蛋白质水平及上调Aurora A、eg5、Ki67、CyclinB2、PCNA蛋白水平有关。     

UBE2T基因对结直肠细胞增殖和凋亡的影响

目的:探讨人类泛素结合酶E2T(Ubiquitin-conjugating enzyme E2T,UBE2T)基因对结肠细胞增殖和凋亡的影响。方法:体外培养人正常结直肠粘膜细胞FHC,采用将UBE2T基因慢病毒质粒转染至FHC细胞48 h后,通过MTT法检测细胞增殖情况,western blotting检测细胞中增殖相关蛋白UBE2T蛋白、Ki67、促凋亡蛋白Bax和抗凋亡蛋白Bcl-2的表达,流式细胞术检测细胞凋亡率。结果:与转染空质粒的FHC细胞相比,UBE2T基因慢病毒质粒转染FHC细胞48 h后,细胞增殖能力显著上调(P0.05),UBE2T蛋白明显增加,Ki67的表达明显增加(P0.05),细胞凋亡率显著降低(P0.05),且Bax的表达明显下调而Bcl-2的表达上调(P0.05)。结论:UBE2T基因能够促进正常结肠粘膜细胞的增殖,并抑制其凋亡。     

不同浓度TGF-β1对肺泡II型细胞系MLE-12表型及功能的影响

探讨不同浓度及不同时间点TGF-β1对肺泡II型上皮细胞（AECII）表型及功能的影响。小鼠肺泡II型细胞系MLE-12,随机分为：对照组（0ng／mL）、低浓度组（0．1ng／mL）、中浓度组（1ng／mL）和高浓度组（10ng／mL）。应用细胞免疫荧光双标法及荧光定量PCR法观察各组12,24,48,72h细胞形态变化、AECII标记（肺表面活性物质蛋白B,SP—B）及成纤维细胞标记（成纤维细胞特异性蛋白1,FSP—1）蛋白及mRNA的表达情况。结果表明,随着TGF—β1干预时间的延长及浓度的升高,AECII逐渐由鹅卵石样变成纺锤体形状,获得成纤维细胞样外观。蛋白水平,AECII标记SP-B表达逐渐减弱,成纤维细胞标记FSP-1表达逐渐增强,48h中浓度组及24h高浓度组两者可见明显的共表达,同时,其SP-BmRNA表达较同时间对照组下调,而FSP1 mRNA表达较同时间对照组上调。低浓度组各时间点上述表现不明显。TGF—β1促使AECII向成纤维细胞转化（EMT）,且具有时间及浓度依赖性。     

尿激酶型纤溶酶原激活物的表达与毛囊细胞增殖关系的研究

为了研究毛囊外根鞘(outer root sheath,ORS)细胞尿激酶型纤溶酶原激活物(urokinase plasmino-gen activator,uPA)的表达与其细胞周期的关系,并探讨uPA对毛囊生长的调控作用,本文应用流式细胞仪对不同代龄的ORS细胞的细胞周期进行了 检测,并用免疫细胞化学和RT-PCR手段对相应代龄ORS细胞的uPA mRNA及蛋白质的表达进行了检测。结果显示,原代ORS细胞增殖旺盛,而3代ORS细胞增殖水平显著下降,增殖旺盛的ORS细胞uPA mRNA及蛋白表达较强,而增殖缓慢的ORS细胞uPA mRNA及蛋白的表达明显下降或不表达。说明ORS细胞的增殖水平与其uPA mRNA及蛋白的表达密切相关,uPA在毛囊生长早期的表达可以促进毛囊细胞增殖,利于毛囊发育。     

CHFR,PARP-1基因对B细胞淋巴瘤Raji细胞增殖和凋亡的影响（英文）

目的:探讨CHFR与聚(ADP-核糖)聚合酶1(PARP-1)基因对B细胞淋巴瘤Raji细胞增殖和凋亡的影响。方法:用5-Aza-d C处理Raji细胞,后通过qRT-PCR检测CHFR的mRNA表达水平,western blot评估CHFR、PARP-1的蛋白表达。经CHFR慢病毒转染Raji细胞后,用qRT-PCR和western blot评估RAJI细胞中的CHFR、PARP-1变化。通过CCK-8法测定细胞的增殖情况,流式细胞术检测细胞周期的变化。结果:与对照组相比,经5-Aza-d C处理Raji组的CHFR mRNA表达显著上调(P0.01),PARP-1mRNA水平和蛋白表达水平明显降低(P0.05)。与对照组相比,Sh RNA组CHFR的mRNA表达显着下调(均P0.01),PARP-1mRNA和蛋白表达水平升高(P0.05)。CCK结果显示CHFR Sh RNA组细胞活力明显低于对照组(P0.05)。流式细胞术结果显示CHFR沉默后细胞凋亡率降低(P0.05)。结论:CHFR可能通过PARP-1调控B淋巴细胞的增殖和凋亡。     

吸烟大鼠肺脏AQP4 和MUC5AC 的表达及其与 一氧化氮的关系

目的:研究烟草烟雾吸入对大鼠肺组织水通道蛋白4(AQP4)和粘蛋白5AC(MUC5AC)表达的影响及其与支气管肺泡灌洗液内一氧化氮代谢物水平的关系,探讨氧化应激对肺部水转运和粘液分泌的影响。方法:免疫组化法观察AQP4在肺组织内的表达,平均光密度法比较模型组和空白组大鼠AQP4的表达差异;半定量RT-PCR法检测肺组织内AQP4及MUC5AC mRNA的表达水平;硝酸还原酶法测定各组大鼠支气管肺泡灌洗液内一氧化氮代谢产物的浓度,分析模型组AQP4、MUC5AC mRNA的表达水平与支气管肺泡灌洗液内一氧化氮代谢物浓度之间的相关关系。结果:AQP4在空白对照组呈强阳性染色,在模型组呈弱阳性染色,两者平均光密度值有显著差异(P<0.05)。模型组动物肺组织AQP4 mRNA的表达降低,MUC5AC mRNA的表达升高,与空白组比较均有显著差异(P<0.05),模型组动物支气管肺泡灌洗液内一氧化氮代谢产物的浓度与肺组织AQP4 mRNA表达水平呈负相关,相关系数r=-0.798(,P<0.05),与MUC5AC mRNA的表达水平呈正相关,相关系数r=0.857(,P<0.05)。结论:吸烟可导致肺组织AQP4表达下降进而影响气道内水的转运。一氧化氮可能参与了烟雾吸入动物模型中AQP4与MUC5AC基因表达的调控。     

维甲酸对高氧暴露下原代培养的胎鼠肺泡II型上皮细胞和成纤维细胞增殖与凋亡的影响

探讨高氧暴露对原代培养的胎鼠肺泡II型上皮细胞(AECII)、成纤维细胞(LFs)增殖和凋亡的影响以及维甲酸(RA)的保护作用机制。通过建立高氧暴露原代培养的胎鼠AECII和LFs模型,以RA作为干预方式,采用流式细胞术(膜联蛋白V-PI双标记)检测AECII和LFs凋亡,West-ern印迹检测AECII增殖细胞核抗原(PCNA)、p53及caspase-3表达和LFsPCNA表达。结果发现:(1)与空气对照比较,高氧暴露12h,膜联蛋白V( )PI(-)和膜联蛋白V( )PI( )标记AECII数均显著升高(14.41±1.15vs2.80±0.19,P<0.01;61.07±3.06vs1.49±0.11,P<0.01);RA对空气暴露下AECII坏死、凋亡无明显影响,但明显下调高氧暴露下膜联蛋白V( )PI(-)和膜联蛋白V( )PI( )标记AECII数(8.04±0.79vs14.41±1.15,P<0.01;27.57±2.32vs61.07±3.06,P<0.01)。(2)高氧、RA对LFs坏死、凋亡无明显影响。(3)高氧暴露12h,明显降低AECIIPCNA表达(P<0.01),显著提高其p53(P<0.01)和caspase-3活性片段(P<0.01)表达;RA显著上调高氧暴露下AECIIPCNA表达(P<0.01),下调其p53和caspase-3活化片段表达(P<0.01)。(4)高氧、RA对LFsPCNA表达无明显影响。由此提示,高氧暴露,导致AECII大量凋亡、坏死,增殖受到抑制,同时,LFs所受影响较小,两种细胞对高氧暴露的差异性行为可能是导致未成熟肺组织异常重构的重要原因;RA通过降低AECII凋亡、坏死从而对高氧肺损伤具有保护作用。     

miR-125b-5p对人血管瘤内皮细胞HemES增殖和凋亡的影响及其机制

目的: 研究miR-125b-5p 对人血管瘤内皮细胞HemECs增殖、凋亡的影响。方法: RT-qPCR检测人血管瘤内皮细胞HemECs及其旁系组织细胞中miR-125b-5p与MCL-1 mRNA的表达;选取HemECs细胞分为对照组、miR-NC组、miR-125b-5p mimic组、miR-125b-5p inhibitor组、pc-MCL-1组、miR-125b-5p+ pc-MCL-1组,每组设9复孔。将100 nmol · L^-1 的miR-NC、miR-125b-5p mimic、miR-125b-5p inhibitor 、pc-MCL-1质粒分别或联合转染进入HemECs细胞。MTT法检测HemECs细胞增殖;流式细胞术检测HemECs细胞凋亡; 双荧光素酶报告检测靶向关系;蛋白印迹法检测Ki67、PCNA、cleaved caspase-3、Bax、Bcl-2、p-p70s6k/ p70s6k、p-AKT/AKT、p-mTOR/ mTOR蛋白相对表达水平。结果: 通过比较miR-125b-5p在血管瘤组织和细胞中的表达水平,选择下调效果比较明显的HemECs细胞系进行后续实验。与对照组相比,miR-125b-5p mimic组HemECs细胞增殖及Ki67和PCNA表达明显减少(P＜0.01),细胞凋亡率及cleaved Caspase-3、Bax表达明显升高、Bcl-2表达明显降低(P＜0.01),p-AKT/AKT、p-mTOR/mTOR、p-p70S6K/p70S6K表达明显下调(P＜0.01);miR-125b-5p inhibitor组HemECs细胞增殖及Ki67和PCNA表达明显增加(P＜0.01),细胞凋亡率及cleaved Caspase-3、Bax表达明显降低、Bcl-2表达升高(P＜0.05,P＜ 0.01)。miR-125b-5p靶向下调MCL-1。与miR-125b-5p mimic组相比,miR-125b-5p+ pc-MCL-1组HemECs细胞增殖及Ki67和PCNA表达明显增加(P＜0.01),细胞凋亡率及cleaved Caspase-3、Bax表达明显降低、Bcl-2表达明显升高(P＜0.01), p-AKT/AKT、p-mTOR/mTOR、p-p70S6K/p70S6K表达明显上调(P＜0.01)。结论: miR-125b-5p抑制人血管瘤内皮细胞增殖、诱导细胞凋亡,其机制可能与靶向下调MCL-1表达,抑制AKT / mTOR通路激活等有关。     

补骨脂素对前列腺癌LNCaP-AI细胞增殖和周期调控及雌激素受体β表达的影响

目的探讨补骨脂素对前列腺癌LNCaP-AI细胞增殖的影响,并初步探索其可能的作用机制。 方法不同浓度补骨脂素处理体外培养的前列腺癌LNCaP-AI细胞,采用CCK-8法检测各组的细胞增殖变化,Western blot法检测各组细胞Ki67蛋白表达,流式细胞术检测各组细胞周期的变化,实时定量RT-PCR法检测各组细胞雌激素受体β（ERβ）mRNA的表达。组间均数比较均采用单因素方差分析。 结果CCK-8检测结果显示,补骨脂素对LNCaP-AI细胞增殖的抑制呈浓度—时间依赖性增强。Western blot法、流式细胞术和实时定量RT-PCR检测结果分别显示,不同浓度补骨脂素（30,50,100 μg/ml）处理48 h后,随着药物浓度的增加,LNCaP-AI细胞的Ki67蛋白表达明显降低,分别为27.82±0.55、25.27±0.62、23.93±0.50和22.54?±0.59（F = 28.59,P < 0.01）;G1期分别为72.14±0.5、74.57±1.22、78.12±0.92、79.36±0.49和80.6?±1.42（F = 38.26,P < 0.01）;G2期分别为27.57±0.5、23.2±1.39、16.41±1.23、12.23±1.3和7.47±1.03（F = 216.63,P < 0.01）细胞均随之增多,而S期细胞则随之减少,分别为0.29±0.07、2.23?±0.32、5.47±0.44、8.41±0.95和11.93±0.57（F = 153.58,P?< 0.01）;ERβ mRNA的表达量明显升高,分别为1±0 、2.197±0.225、4.573±0.346和6.590±0.334（F?= 264.09,P < 0.01）。 结论补骨脂素具有抑制前列腺癌LNCaP-AI细胞增殖和Ki67表达的作用,其机制可能与其将细胞阻滞于G1、G2期和上调ERβ mRNA的表达有关。     

Expression of SP-C and Ki67 in lungs of preterm infants dying from respiratory distress syndrome

This study aimed at exploring the expression of Surfactant protein-C (SP-C) and Ki67 in autopsy lung tissues of premature infants dying from respiratory distress syndrome (RDS) who were exposed to mechanical ventilation and elevated oxygen concentrations. The possible influence of pulmonary surfactant (PS) on the expression of SP-C and Ki67 was also investigated. Thirty preterm infants were selected who were histologically and clinically diagnosed as RDS. Preterm infants with RDS were divided into 4 groups, according to the time of death: infants ventilated for 1–3 days, 4–8 days, 9–16 days and >6 days. Five premature infants died within 1 day after delivery for non- pulmonary reasons served as controls. The expression of SP-C and Ki67 in lungs was detected by immunohistochemistry. Compared with the control group, the expression of SP-C and Ki67 in RDS infants decreased significantly after 1–3 days of ventilation, but increased after 4 days and reached peak value after 9–16 days. No significant difference in the expression of SP-C and Ki67 was found between infants treated with PS and those without. Thus our results suggest SP-C and Ki67 may have participated in the pulmonary pathological process in ventilated/oxygen treated preterm infants with RDS, and exogenous surfactant had no effect on the expression of SP-C and Ki67 in the lungs of ventilated/oxygen treated preterm infants with RDS.Key words: respiratory distress syndrome, surfactant protein-C, Ki67, preterm.     

Regulation of human pulmonary surfactant protein gene expression by 1alpha,25-dihydroxyvitamin D3

1alpha,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] has been reported to stimulate lung maturity, alveolar type II cell differentiation, and pulmonary surfactant synthesis in rat lung. We hypothesized that 1,25(OH)(2)D(3) stimulates expression of surfactant protein-A (SP-A), SP-B, and SP-C in human fetal lung and type II cells. We found that immunoreactive vitamin D receptor was detectable in fetal lung tissue and type II cells only when incubated with 1,25(OH)(2)D(3). 1,25(OH)(2)D(3) significantly decreased SP-A mRNA in human fetal lung tissue but did not significantly decrease SP-A protein in the tissue. In type II cells, 1,25(OH)(2)D(3) alone had no significant effect on SP-A mRNA or protein levels but reduced SP-A mRNA and protein in a dose-dependent manner when the cells were incubated with cAMP. SP-A mRNA levels in NCI-H441 cells, a nonciliated bronchiolar epithelial (Clara) cell line, were decreased in a dose-dependent manner in the absence or presence of cAMP. 1,25(OH)(2)D(3) had no significant effect on SP-B mRNA levels in lung tissue but increased SP-B mRNA and protein levels in type II cells incubated in the absence or presence of cAMP. Expression of SP-C mRNA was unaffected by 1,25(OH)(2)D(3) in lung tissue incubated +/- cAMP. These results suggest that regulation of surfactant protein gene expression in human lung and type II cells by 1,25(OH)(2)D(3) is not coordinated; 1,25(OH)(2)D(3) decreases SP-A mRNA and protein levels in both fetal lung tissue and type II cells, increases SP-B mRNA and protein levels only in type II cells, and has no effect on SP-C mRNA levels.     

Effects of hypoxia and hypercapnia on surfactant protein expression proliferation and apoptosis in A549 alveolar epithelial cells

During lung injury alveolar epithelial cells are directly exposed to changes in PO(2) and PCO(2). Integrity of alveolar epithelial type II cells (AECII) is critical in lung injury but the effect of hypoxia and hypercapnia on AECII function, viability and proliferation has not been clearly investigated. Aim of the present work was to determine the direct effect of hypoxia and hypercapnia on surfactant protein expression, proliferation and apoptosis of lung epithelial cells in vitro. A549 alveolar epithelia cells were subjected to hypoxia (1%O(2)-5% CO(2)) or hypercapnia (21% O(2-) 15% CO(2)) and expression of surfactant protein C was measured and compared to normal conditions (21% O(2)- 5% CO(2)). Cell cycle progression and apoptosis were measured by flow cytometric analysis. RESULTS: A549 alveolar epithelial cells produce surfactant proteins, including surfactant protein C, when cultured under normal conditions, which is reduced under hypoxic conditions. Specifically, pro-SpC expression is moderately decreased after 8 h of culture in hypoxia, and is completely attenuated after 48 h. Hypercapnia decreases pro-SpC expression only after 48 h of exposure. Stimulation with TNF-alpha partly reverses pSPC decrease observed under hypoxic and hypercapnic conditions. Hypoxic culture of A549 cells results in progressive arrest of cells in the G1 phase of the cell cycle and increased apoptosis first observed 4 h following exposure and peaking at 24 h. In contrast hypercapnia has no significant effect on alveolar epithelial cell proliferation or apoptosis. CONCLUSIONS: Taken together we can conclude that hypoxia rapidly and severely affects AECII function and viability while hypercapnia has an inhibitory effect on pro-SpC production only after prolonged exposure.     

PKA and Epac cooperate to augment bradykinin-induced interleukin-8 release from human airway smooth muscle cells

Background

Platelet-derived growth factor A (PDGF-A) signals solely through PDGF-Rα, and is required for fibroblast proliferation and transdifferentiation (fibroblast to myofibroblast conversion) during alveolar development, because pdgfa-null mice lack both myofibroblasts and alveoli. However, these PDGF-A-mediated mechanisms remain incompletely defined. At postnatal days 4 and 12 (P4 and P12), using mouse lung fibroblasts, we examined (a) how PDGF-Rα correlates with ki67 (proliferation marker) or alpha-smooth muscle actin (αSMA, myofibroblast marker) expression, and (b) whether PDGF-A directly affects αSMA or modifies stimulation by transforming growth factor beta (TGFβ).

Methods

Using flow cytometry we examined PDGF-Rα, αSMA and Ki67 in mice which express green fluorescent protein (GFP) as a marker for PDGF-Rα expression. Using real-time RT-PCR we quantified αSMA mRNA in cultured Mlg neonatal mouse lung fibroblasts after treatment with PDGF-A, and/or TGFβ.

Results

The intensity of GFP-fluorescence enabled us to distinguish three groups of fibroblasts which exhibited absent, lower, or higher levels of PDGF-Rα. At P4, more of the higher than lower PDGF-Rα + fibroblasts contained Ki67 (Ki67+), and Ki67+ fibroblasts predominated in the αSMA + but not the αSMA- population. By P12, Ki67+ fibroblasts comprised a minority in both the PDGF-Rα + and αSMA+ populations. At P4, most Ki67+ fibroblasts were PDGF-Rα + and αSMA- whereas at P12, most Ki67+ fibroblasts were PDGF-Rα- and αSMA-. More of the PDGF-Rα + than - fibroblasts contained αSMA at both P4 and P12. In the lung, proximate αSMA was more abundant around nuclei in cells expressing high than low levels of PDGF-Rα at both P4 and P12. Nuclear SMAD 2/3 declined from P4 to P12 in PDGF-Rα-, but not in PDGF-Rα + cells. In Mlg fibroblasts, αSMA mRNA increased after exposure to TGFβ, but declined after treatment with PDGF-A.

Conclusion

During both septal eruption (P4) and elongation (P12), alveolar PDGF-Rα may enhance the propensity of fibroblasts to transdifferentiate rather than directly stimulate αSMA, which preferentially localizes to non-proliferating fibroblasts. In accordance, PDGF-Rα more dominantly influences fibroblast proliferation at P4 than at P12. In the lung, TGFβ may overshadow the antagonistic effects of PDGF-A/PDGF-Rα signaling, enhancing αSMA-abundance in PDGF-Rα-expressing fibroblasts.     

Cellular kinetics and modeling of bronchioalveolar stem cell response during lung regeneration

Organ regeneration in mammals is hypothesized to require a functional pool of stem or progenitor cells, but the role of these cells in lung regeneration is unknown. Whereas postnatal regeneration of alveolar tissue has been attributed to type II alveolar epithelial cells (AECII), we reasoned that bronchioalveolar stem cells (BASCs) have the potential to contribute substantially to this process. To test this hypothesis, unilateral pneumonectomy (PNX) was performed on adult female C57/BL6 mice to stimulate compensatory lung regrowth. The density of BASCs and AECII, and morphometric and physiological measurements, were recorded on days 1, 3, 7, 14, 28, and 45 after surgery. Vital capacity was restored by day 7 after PNX. BASC numbers increased by day 3, peaked to 220% of controls (P<0.05) by day 14, and then returned to baseline after active lung regrowth was complete, whereas AECII cell densities increased to 124% of baseline (N/S). Proliferation studies revealed significant BrdU uptake in BASCs and AECII within the first 7 days after PNX. Quantitative analysis using a systems biology model was used to evaluate the potential contribution of BASCs and AECII. The model demonstrated that BASC proliferation and differentiation contributes between 0 and 25% of compensatory alveolar epithelial (type I and II cell) regrowth, demonstrating that regeneration requires a substantial contribution from AECII. The observed cell kinetic profiles can be reconciled using a dual-compartment (BASC and AECII) proliferation model assuming a linear hierarchy of BASCs, AECII, and AECI cells to achieve lung regrowth.     

LATS1过表达对肺癌A549细胞增殖及周期的影响

通过过表达手段上调大肿瘤抑制因子1（1arge tumor suppressor gene 1,LATS1）基因在A549细胞中的表达,研究LATS1对A549细胞生长和细胞周期调控的作用。构建过表达LATS1基因的慢病毒载体,转染A549N胞株,采用RT-PCR和蛋白质印迹法检测转染后A549细胞中LATS1、YAPmRNA和蛋白的表达效率;流式细胞术检测细胞凋亡、周期情况：CCK-8检测细胞的增殖水平变化。结果发现,过表达LATS1慢病毒载体转染A549细胞株后,LATS1mRNA及蛋白表达水平高于未处理组及转染空载体组,YAPmRNA及蛋白表达水平低于未处理组及转染空载体组;过表达LATS1慢病毒转染后,A549细胞增殖率从第五天开始低于对照组（P〈0．05）,过表达组细胞G1期比例明显增高（P〈0．05）,凋亡率明显增加（P〈0．05）,差异均有统计学意义。以上结果提示,LATS1可通过下调YAP的表达水平促进A549细胞的凋亡,诱导G1期阻滞,降低细胞的增殖能力。