The influence of cigarette smoke on the selected bronchoalveolar cells in experiment

The occurence of lung diseases (obstructive, malignant) resulting from smoking has an increasing tendency. The lung is the primary organ at risk from the effects of inhaled cigarette smoke and smoking has been implicated as a contributing factor to the causation of various respiratory diseases. The aim of presented work was to find out the subchronic effect of the 6-month exposure to cigarette smoke on the selected inflammatory and cytotoxic parameters of bronchoalveolar lavage in W rats and thus to contribute to understanding of the mechanism of action of tobacco smoke and/or path mechanism of lung injury developed after cigarette smoking. In special chamber, the animals smoked 8 standard research 1R1 type of cigarettes per day, except Saturdays and Sundays, during 6 months. The daily concentration of total particulate matter (TPM)/m3 air for two hours per exposure requiring to burn eight cigarettes was 85 mg. Animals were sacrificed after the 6-month exposure and bronchoalveolar lavage (BAL) was performed and selected inflammatory and cytotoxic BAL parameters were examined and compared with the control group. Following BAL parameters were investigated: the total cell and alveolar macrophages (AM) count in BAL, the differential cell count (% of AM, % of polymorphonuclears--PMN, % of lymphocytes--Ly), proportion of immature AM, proportion of bi-nucleated cells--BNC, viability, the phagocytic activity of AM, cytokines TNF-alpha (tumor necrosis factor alpha) and IL-1beta (interleukin-1beta). CONCLUSION: A) The 6-month smoking of eight cigarettes daily significantly changed prevailing number of examined BAL parameters; B) The presence of inflammatory and cytotoxic responses in lung tissue can probably signalize beginning or developing of disease process.     

SiO2对血小板源性生长因子蛋白表达及胶原合成的影响

目的 探讨siO2刺激矽肺患者的肺泡巨噬细胞(AM)及其介导的人胚肺成纤维细胞(HELF)血小板源性生长因子(PDGF)的蛋白表达及胶原合成.方法 收集矽肺患者AM,体外经SiO2刺激3、6、12、18、24、36 h,收集培养上清,用ELISA法检测AM上清中PDGF的蛋白表达,用其表达峰值时的培养上清与HELF共同孵育6、12、18、24、36、48 h,用免疫细胞化学法及Western blot法分别检测HELF及其培养上清中PDGF的蛋白表达情况,用3H-脯氨酸掺入法检测HELF胶原的合成与分泌情况.结果 经SiO2刺激的矽肺患者AM条件上清中PDGF的蛋白表达量在作用24 h时最高(平均吸光度值为0.282±0.019),与同期对照组(平均吸光度值为0.214±0.014)相比,差异有统计学意义(P<0.01). 用AM上清作用于HELF后,HELF细胞内及其培养上清中PDGF的蛋白表达均升高,与对照组比较,HELF培养上清中PDGF蛋白表达于12、18、24、36、48 h时明显增高,HELF中PDGF蛋白表达于18、24、36、48 h时明显增高,差异均有统计学意义(P<0.05).矽肺患者AM培养上清与HELF共同孵育不同时间后,HELF细胞内及培养上清中胶原明显增加.结论 SiO2通过AM的介导影响了HELF中PDGF的蛋白表达与胶原合成及分泌.     

Asbestos fibres and man made mineral fibres: induction and release of tumour necrosis factor-alpha from rat alveolar macrophages.

OBJECTIVES--Mounting evidence suggests that asbestos fibres can stimulate alveolar macrophages to generate the potent inflammatory and fibrogenic mediator, tumour necrosis factor-alpha (TNF-alpha), and that this may play an important part in the onset and development of airway inflammation and lung fibrosis due to asbestos fibre inhalation. Little is known, however, about the ability of other mineral fibres to initiate formation and release of TNF-alpha by alveolar macrophages. Therefore the effects of different fibres (crocidolite, chrysotile A, chrysotile B, two man made mineral fibres (MMVF 21 and MMVF 22), a ceramic fibre (RCF 1), and a silicon carbide whisker fibre (SiCwh)) on formation and release of TNF-alpha by rat alveolar macrophages were examined. METHODS--Cells were isolated and incubated at 37 degrees C with the different fibres, or with culture medium alone (controls), and the amounts of TNF-alpha messenger RNA (mRNA) in the cells and TNF-alpha bioactivity released into the culture medium were measured at different time points. RESULTS--Significantly (P < 0.05 v control) increased amounts of TNF-alpha mRNA were found in cells exposed to crocidolite, chrysotile A, chrysotile B, MMVF 21, RCF 1, or SiCwh for 90 minutes, and significantly (P < 0.05 v control) increased activities of TNF-alpha were found in the medium of macrophages exposed to crocidolite, chrysotile A, chrysotile B, or MMVF 21 for four hours. CONCLUSION--These observations suggest that not only natural mineral fibres but also certain man made mineral fibres are able to induce the formation and release of TNF-alpha by alveolar macrophages in vitro.     

Low dose beta-carotene supplementation of ferrets attenuates smoke-induced lung phosphorylation of JNK, p38 MAPK, and p53 proteins

We demonstrated previously that smoke exposure and/or high-dose beta-carotene supplementation decreases levels of retinoic acid and retinoic acid receptor beta (RARbeta) protein, but increase levels of c-Jun and proliferating cellular nuclear antigen protein in the lungs of ferrets. In contrast, low-dose beta-carotene can prevent the decreased lung retinoic acid and the smoke-induced lung lesions. In the present study, we investigated whether smoke exposure and/or beta-carotene supplementation could affect Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), and p53 in the lungs of ferrets. Ferrets were subjected to cigarette smoke exposure and either a high or low dose of beta-carotene (2 x 3 factorial design) for 6 mo. There were greater protein levels of phosphorylated JNK, p38, and c-Jun, but lower levels of MAPK phophatase-1 (MKP-1) in groups exposed to smoke and/or high dose beta-carotene. Both phosphorylated-p53 and total p53 were substantially increased in the lungs of these groups. In contrast, low-dose beta-carotene greatly attenuated the smoke-induced phosphorylation of JNK, p38, c-Jun, p53, and total p53, accompanied by upregulated MKP-1. Smoke exposure increased MAPK kinase-4 (MKK4) phosphorylation regardless of beta-carotene supplementation. These data indicate that restoration of retinoic acid and MKP-1 by low-dose beta-carotene in the lungs of ferrets may prevent the smoke-induced activation of the JNK-dependent signaling pathway, p38 MAPK, and the associated phosphorylation of p53, thereby lowering the risk of the smoke-related lung lesions. These data provide supportive evidence that the beneficial vs. detrimental effects of beta-carotene supplementation are related to the dosage of beta-carotene administered.     

矽肺肺泡巨噬细胞对人胚肺成纤维细胞Ⅰ型胶原表达的体外研究

目的探讨矽肺患者的肺泡巨噬细胞(AM)是否通过影响肺成纤维细胞(FB)胶原的表达,参与矽肺纤维化的发生发展。方法收集矽肺患者AM,经SiO_2体外刺激18 h收集培养上清,与人胚肺FB共同孵育6、12、18、24、36、48、72 h,用~3H-脯氨酸掺入检测48 h胶原的合成与分泌,免疫细胞化学方法、Western blot方法检测各时间点Ⅰ型胶原表达。结果经SiO_2刺激矽肺患者AM培养上清,可使FB中Ⅰ型胶原的表达增高,实验组48 h细胞内、外3H-脯氨酸掺入值分别为1259.500±73.879、790.500±70.315,免疫细胞化学染色的积分光密度值为0.341±0.011,Western blot条带扫描灰度值为14.218±0.342,均明显高于空白对照组及AM对照组,差异有统计学意义(P<0.05或P<0.01)。结论SiO_2可通过AM介导影响FB中Ⅰ型胶原表达,参与肺纤维化的形成。     

Asbestos effects on superoxide production. An in vitro study of hamster alveolar macrophages

Inhaled asbestos induces accumulation of alveolar macrophages (AM) and polymorphonuclear leukocytes (PMN) in lung. Asbestos-enhanced production of superoxide anion (O2-) by AM and/or PMN may be involved in the pathogenesis of asbestos-induced fibrosis, either through direct effects on collagen synthesis or via mediation of tissue injury and repair. In in vivo experiments, bronchoalveolar lavage (BAL) 3 to 8 weeks following intratracheal asbestos injections showed increases in both PMN and AM, with AM representing 78 to 82% of cells recovered. Inhalation models, generally regarded as more analagous to human exposures, have confirmed AM as the predominant component of the cellular response to inhaled asbestos. In this study, the in vitro effects of asbestos fiber on O2- production by AM have been determined in cell populations derived from the Syrian golden hamster. AM for in vitro study were obtained by BAL. O2- production was monitored as superoxide dismutase (SOD) - inhibitable cytochrome c reduction. Significant rises in O2- release by AM were noted in the presence of 0.4 mg/ml crocidolite (2.53 +/- 0.33 nmole cytochrome c reduced/10(6) cells/30 min, 37 degrees C; controls 1.13 +/- 0.18 nmole; P less than 0.02). Chrysotile induced levels of O2- release in AM which were similar to those evoked by crocidolite.     

Pulmonary clearance and lesions in rats after a single inhalation of ultrafine metallic nickel at dose levels comparable to the threshold limit value.

This study aimed to (1) determine the deposition and clearance rates of ultrafine metallic nickel (Uf-Ni) in rats after a 5 hours single inhalation exposure, and (2) to histopathologically examine the pulmonary lesions induced at dose levels comparable to the Occupational Exposure Limit recommended in Japan (OEL). The exposure concentrations of Uf-Ni for the 3 groups were 0.15 (Low), 1.14 (Medium), and 2.54 (High) mg/m3. Five rats/group were sacrificed at 0 h and 1, 3, 7, 14, and 21 days post exposure. The amount of Ni in the lung accumulated dose-dependently. The half-times for Ni in the lung were estimated as 32 days on average, and were similar to each other regardless of the initial dosage. The histopathologically observed pulmonary lesions induced by a single inhalation of Uf-Ni were, (1) a significant increase in lung weight in the High and Medium groups with time, (2) accumulation of foamy alveolar macrophages (AM), (3) degenerated AM indicating alveolar lipoproteinosis which was aggravated for up to 4 weeks in the High group and (4) acute calcification of the degenerated AM was remarkable. The present results suggest that even a single inhalation of Uf-Ni induces potency of lung lesions at dose levels comparable to the OEL (1 mg/m3 as Ni), or the TWA of ACGIH (1.5 mg/m3 for elemental/metal).     

二氧化硅致肺泡上皮细胞连接蛋白43定位的变化

目的 研究SiO2刺激肺泡巨噬细胞（PAM）上清液对肺泡上皮细胞连接蛋白43（Cx43)定位的影响，以深入探索SiO2抑制肺泡上皮细胞是隙连接通讯（GJIC）的作用水平。方法 不同剂量的SiO2刺激大鼠（SD）PAM培养上清液作用于正常貂肺泡上皮细胞株CCL－64细胞[在体积分数为2％的小牛血清培养基（RPMI 1640）中加体积分数为5％的不同剂量的SiO2刺激PAM的上清液]。采用间接免疫荧光的CCL－64细胞化学法和激光共聚集扫描显微镜（LCSM，Leica TCS SP)进行Cx43定位的测定。结果 正常培养的CCL－64相邻细胞连接处有明亮的斑片状标记， 分布、连接成线；SiO2刺激PAM培养上清液作用的CCL－64细胞连接处标记斑点逐渐减少，Cx43标记斑点出现在胞浆内，呈无特异性定位状态，但随着SiO2剂量的增加，细胞内大多数的Cx43标记斑点向细胞核聚集。结论 SiO2刺激PAM培养上清液可以改变肺泡上皮细胞Cx43的定位。推测SiO2抑制肺泡上皮细胞GJIC功能可能与Cx43的内移有关。     

矽肺肺泡巨噬细胞对肺成纤维细胞基质金属蛋白酶及其组织抑制因子表达的影响

目的 探讨矽肺患者的肺泡巨噬细胞(AM)是否通过影响肺成纤维细胞(FB)基质金属蛋白酶(MMPs)/金属蛋白酶组织抑制因子(TIMPs)系统参与矽肺纤维化的发生发展。方法 收集矽肺患者AM培养上清,与人胚肺FB共同孵育6、12、18、24、36、48 h,用免疫细胞化学的方法检测FB中MMP-1和TIMP-1的表达。结果 未经SiO2刺激的矽肺患者AM培养上清作用于FB 24 h,FB中MMP-1的表达较空白对照组减少(积分光密度值分别为0.103±0.014、0.133±0.023),TIMP-1的表达增多(积分光密度值分别为0.108±0.012、0.065±0.006);经SiO2刺激24 h的矽肺患者AM培养上清作用于FB后,FB中MMP-1的表达量进一步减少(积分光密度值分别为0.062±0.008、0.133±0.023),而TIMP-1的表达量进一步增加(积分光密度值分别为0.143±0.015、0.065±0.006)。结论 SiO2可能通过AM的介导影响了FB中MMP-1/TIMP-1系统的表达,参与了肺纤维化的形成。     

Transport of α-Aminoisobutyric Acid by Alveolar Macrophages Incubated With Cigarette Smoke and Nicotine

Aqueous extracts of cigarette smoke or nicotine at concentrations that did not greatly affect cellular viability, as measured by dye exclusion, markedly reduced the transport of α-aminoisobutyric acid (AIB) by rabbit alveolar macrophages.

Smoke extract was prepared by drawing smoke from three cigarettes (100 mm, nonfilter) into 25 ml of a modified Hanks solution. Aqueous extract of smoke, and nicotine, produced a biphasic effect on AIB transport: a stimulation at low concentrations and an inhibition at higher concentrations. Cell viability, as estimated by dye exclusion, was reduced only 17% by the highest concentration of the smoke extract.

These data suggest that transport of a nonmetabolizable amino acid, ¹⁴C-AIB, is a sensitive and quantitiative assay for examining the influence of air contaminants on membrane permeability.     

Aggregates of ultrafine particles modulate lipid peroxidation and bacterial killing by alveolar macrophages

We hypothesized that aggregates of ultrafine carbon and washed diesel particles impair the ability of alveolar macrophages (AM) to kill bacteria and enhance the AM lipid peroxidation (LPO) of lung surfactant. Rat AM were exposed, 5h, to particles 20 microg/ml. The AM, containing carbon or washed diesel particles, were incubated 2h, with Streptococcus pneumoniae, an American Type Culture Collection (ATCC) strain or clinical isolates. Surviving bacteria were quantified. Surfactant was incubated, 5h, with carbon or washed diesel loaded AM and LPO was measured. The particle load was approximately 1 microg/10(6) AM, representing accepted exposure to ambient particles in Europe. Metal concentrations were 10 to 100 fold higher in washed diesel--than in carbon particles. There was a dose dependent increase in bacterial survival with carbon-loaded macrophages, but not with washed diesel-loaded AM. Clinical isolates had a higher survival rate with carbon-loaded macrophages than the ATCC strain. Surfactant LPO was increased with washed diesel-loaded macrophages (95%) and with carbon-loaded macrophages (55%) compared to controls. High LPO caused by washed diesel-loaded AM reflects their increased oxidative metabolism, probably caused by particle metals. The additional oxygen metabolites maintained bactericidal activity of AM, while corresponding activity was decreased in carbon-loaded AM. Altered functions of AM may explain health problems related to air pollution.     

Alpha-tocopherol and ascorbic acid supplementation reduced acute lung inflammatory response by cigarette smoke in mouse

OBJECTIVE: Short-term cigarette smoke (CS) exposure leads to acute lung inflammation through its influence over oxidants/antioxidants imbalance. Antioxidant vitamins such as ascorbic acid and alpha-tocopherol interact with oxidizing radicals. It is not clear if antioxidant supplementation can reduce inflammatory lung responses. Thus our aim was to analyze the effects of vitamin supplementation on the lungs of mice exposed to six cigarettes per day with histologic, cytological, and biochemical methods. METHODS: C57BL/6 mice were exposed to ambient air (control) or CS from 3, 6, 9, 12, or 15 cigarettes daily for up to 5 d. Mice alveolar macrophages and polymorphonuclear cells were counted in the bronchoalveolar lavage. Groups of CS animals received 50 mg/kg of ascorbic acid daily and/or 50 mg/kg of alpha-tocopherol daily as an oral supplementation (CS+C, CS+E, CS+C+E, respectively) 12 h before CS exposure. Thiobarbituric acid-reactive substances were detected and western blot to nuclear factor-kappaB were performed in lung extracts; metalloprotease-12 and tumor necrosis factor-alpha positive alveolar macrophages were quantified in the lungs processed for immunohistochemistry of the animals exposed to the smoke from six cigarettes daily for 5 d. RESULTS: The number of alveolar macrophages and polymorphonuclear cells in bronchoalveolar lavage (cells x 10(3)/mL) in mice exposed to CS were increased and CS with vitamin supplementation groups presented bronchoalveolar lavage cells similar to those of control. Thiobarbituric acid-reactive substances values were reduced in vitamin supplementation groups when compared with CS and the lower value was found in the CS+C+E group. Metalloprotease-12 and tumor necrosis factor-alpha were more evident in CS as much as nuclear factor-kappaB activation when compared with control and vitamin supplementation groups. CONCLUSION: Our results showed that CS induced acute lung inflammation. The inflammatory process after cigarette exposures was reduced by ascorbic acid, alpha-tocopherol, or more efficiently by both vitamin supplementations.     

矽肺患者肺泡巨噬细胞培养上清对人胚肺成纤维细胞c-myc基因表达的影响

目的 探讨矽肺患者肺泡巨噬细胞(AM)培养上清对人胚肺成纤维细胞(HEFB)c-myc基因表达的影响.方法 AM分为加尘组(SiO2,30μg/ml)和对照组,培养1、2、6、12、24和36 h,收集培养上清.Ⅲ代HEFB用质量分数为0.5%的血清培养液培养48 h使大部分细胞处于静止期后,加人SiO2刺激6 h的AM培养上清(S6组),用反转录一聚合酶链反应(RT-PCR)及Western blot方法观察c-mycmRNA和蛋白的时程变化.然后将各组AM上清与静止状态的HEFB孵育2和7 h,观察c-myc mRNA和蛋白表达的变化.结果 HEFB在静止状态时c-myc mRNA和蛋白的表达为0,在对照组中,培养不同时间的AM上清刺激了c-myc mRNA及蛋白的表达,以AM培养12 h的卜清作用最明显,比值分别为0.749±0.088和0.759±0.101.加尘组中各上清也刺激了c-myc mRNA和蛋白的表达,但作用高峰提前,以SiO2刺激6 h的上清作用最明显,比值分别0.982±0.147和0.978±0.141.与同期对照相比,SiO2刺激1、2和6 h的AM上清诱导mRNA和蛋白表达增多,差异有统计学意义(P＜0.05或P＜0.01).结论 SiO2激活的AM培养上清可促进HEFB c-myc基因的表达.     

维生素C对镍诱导的肺泡巨噬细胞氧化损伤的保护作用

目的:研究维生素C(VC)拮抗Ni2O3的细胞氧化损伤的作用及对大鼠肺泡巨噬细胞iNOS诱导表达的影响。方法:采用体外细胞培养法测定在VC(25,50,100μmol/L)作用下,体外染镍肺泡巨噬细胞的死亡率及活力。同时观察细胞内丙二醛(MDA)、一氧化氮(nitricoxide,NO)和活性氧(ROS)的产生;超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)、诱导型一氧化氮合酶(nitricoxidesynthase,iNOS)活力的变化以及应用RT-PCR法测定iNOSmRNA的表达。结果:在体外染镍肺泡巨噬细胞中加入不同浓度的VC后可降低该细胞的死亡率并提高细胞的活力,可减少MDA、NO和活性氧的产生,降低NOS的活性,提高SOD、GSH-Px、CAT的活性,iNOSmRNA表达也较镍组降低。结论:镍可致细胞脂质过氧化,VC可通过提高抗氧化酶的活性,抑制iNOSmRNA的表达,减少活性氧及NO的产生,拮抗镍对肺泡巨噬细胞的氧化损伤。     

Contrasting roles for reactive oxygen species and nitric oxide in the innate response to pulmonary infection with Streptococcus pneumoniae

The pulmonary innate response to low-dose bacterial challenge requires functioning alveolar macrophages (AM) but also subsequent macrophage apoptosis. To address the role of reactive oxygen species (ROS) and nitric oxide (NO) in AM apoptosis, sub-clinical Streptococcus pneumoniae infection was established in gp91(phox-/-) and inducible NO synthase deficient (iNOS(-/-)) mice. Both AM apoptosis and the number of macrophages containing apoptotic bodies are reduced in iNOS(-/-) as compared to control or gp91(phox-/-) mice. iNOS(-/-) mice recruit neutrophils and generate TNF-alpha to compensate for impaired AM competence but ROS deficiency has no apparent effect on AM function in this model.     

PM_(2.5)对小鼠肺急性损伤的试验研究

目的　研究PM2 5的急性毒效应 ,探讨免疫损伤和氧化损伤在PM2 5对肺损伤过程中的作用。方法　以昆明小鼠为试验对象 ,随机分成空白对照组 ,生理盐水对照组和低剂量、中剂量、高剂量PM2 5组共 5组 ,除空白对照组外 ,其他各组气管滴注染毒 2 4小时后 ,分析支气管肺灌洗液中乳酸脱氢酶 (LDH)、碱性磷酸酶(AKP)、酸性磷酸酶 (ACP)、白蛋白 (ALB)、一氧化氮 (NO)、一氧化氮合酶 (NOS)、丙二醛 (MDA)、超氧化物歧化酶 (SOD)等含量和细胞因子肿瘤坏死因子α(TNF α)、白细胞介素 1(IL - 1)活性 ,以及测定肺巨噬细胞的吞噬功能 ,并观察肺组织病理学改变。结果　空白对照组和生理盐水对照组比较 ,各指标未见明显差异 ;试验组和生理盐水对照组比较 ,肺灌洗液中LDH、AKP、ACP、ALB、NO、NOS、MDA等含量和TNF α、IL 1活性有显著性增高 (P <0 0 5 ) ,SOD含量和肺巨嗜细胞的吞噬功能明显下降 (P <0 0 5 ) ,均呈现出剂量依赖性关系。结论　PM2 5的吸入引起机体的免疫反应和氧化应激反应 ,从而造成对小鼠肺实质细胞和膜性组织的毒作用。     

离体染尘模型中人胚肺成纤维细胞血红素氧合酶-1及热休克蛋白27表达的时间-效应观察

目的观察染尘巨噬细胞(AM)上清液对人胚肺成纤维细胞(HELF)血红素氧合酶-1(HO-1)及热休克蛋白27(HSP27)诱导表达的时间-效应关系。方法经二氧化硅(SiO2)粉尘处理的AM上清液刺激HELF组成离体染尘模型,采用逆转录聚合酶链反应(RT-PCR)技术检测0、2、8、12、16、24 h培养时段的HO-1、HSP27mRNA表达。同时以二氧化钛(TiO2)为对照。结果HO-1、HSP27mRNA相对表达丰度有随时间变化的趋势,且时间因素的作用随着SiO2、TiO2组的不同而有所区别(P<0.05)。结论染尘AM上清液对HELF的HO-1、HSP27表达的诱导具有时间-效应关系,且2种应激蛋白的表达时相不同,两者可能交错对细胞起到保护作用。     

环境细颗粒物亚慢性染毒对大鼠炎症损伤及免疫功能的影响研究

目的建立细颗粒物的亚慢性暴露动物模型,探讨PM2.5对大鼠炎症损伤及免疫功能的影响。方法应用气管滴注建立细颗粒物的亚慢性暴露动物模型;光镜下观察各脏器病理学变化;采用相应的试剂盒测定肺泡灌洗液中的总蛋白和唾液酸水平;ELISA方法检测细胞因子IL-6和TNF-α水平,采用RT-PCR方法检测肺组织中这两种细胞因子的表达水平;收集肺泡巨噬细胞,采用孔雀绿比色法检测巨噬细胞的吞噬功能;取脾脏,采用MTT方法检测淋巴细胞的增殖功能。结果在染毒后的大鼠肺内均观察到异物性肉芽肿形成;在肝脏血窦内观察到有单核吞噬细胞聚集形成肉芽肿的趋势;在肺门淋巴结和肝脏、肾脏血管内观察到明显的吞噬PM2.5的巨噬细胞和游离的PM2.5。总蛋白和唾液酸水平随着暴露时间和剂量升高而增加。在观察的前3个月,染毒组TNF-α表达水平逐渐升高,而在6个月时,TNF-α水平明显降低;IL-6表达水平随着染毒剂量的增加而升高,并呈现明显的剂量-效应关系,染毒3个月后最高,而在6个月后表达水平回落。肺泡巨噬细胞的吞噬功能随着剂量的增加而下降。淋巴细胞增殖功能没有出现显著性变化。结论细颗粒物的亚慢性暴露可以引起机体的持续炎症损伤;细颗粒物对免疫系统的损伤随着剂量和暴露时间的增加而增加,细颗粒物引起的细胞因子网络紊乱会加重免疫系统的损伤;细颗粒物引起巨噬细胞吞噬功能下降,是肺部慢性疾病的致病机制之一。     

SiO2刺激矽肺肺泡巨噬细胞对MMP-9和TIMP-1表达的影响

目的 探讨SiO2对矽肺患者的肺泡巨噬细胞(AM)基质金属蛋白酶-9(MMP-9)及金属蛋白酶组织抑制因子(TIMP)-1表达的影响.方法 收集矽肺患者肺泡AM,体外经SiO2刺激3、6、12、18、24、36 h,分别用明胶酶谱法和免疫细胞化学方法检测AM中TIMP-1、MMP-9蛋白表达和MMP-9活力.结果 实验组AM中6、12、18、24 h MMP-9的蛋白表达增强,在18 h时最高(积分吸光度值为0.386±0.037),与同期对照组相比,差异均有统计学意义(P＜0.05).实验组12、18、24、36h AM中MMP-9活力的表达增强,在24 h最强(吸光度值3.061±0.153),与同期对照组相比,差异均有统计学意义(P＜0.05).实验组与对照组各时间点TIMP-1蛋白表达比较,差异无统计学意义(P＞0.05).结论 体外SiO2刺激矽肺肺泡AM可影响MMP-9蛋白及其活力的表达.