一日龄高原牦牛肺泡组织结构特征

目的 探讨1日(d)龄高原牦牛肺泡组织结构特点及其与高原低氧适应性的关系. 方法 1d龄高原牦牛和1d龄平原黄牛各5头,HE染色、光镜、透射电镜观察和形态测量学分析. 结果 1d龄高原牦牛肺泡较同日龄平原黄牛扩张充分,肺组织中有大量类似肺泡囊的囊状结构,囊内可见大量 "芽"状结构,同日龄平原黄牛肺组织中少见此种结构;高原牦牛肺泡中Ⅱ型肺泡细胞数量较多,肺泡腔内可见大量排出的板层小体.高原牦牛单位面积内的肺泡数(MAN)较1d龄平原黄牛少(P<0.05),但单个肺泡的面积(MSAA)、肺泡隔厚度(MAST)和单位面积内的肺泡面积(SA)均大于平原黄牛的相应值(P<0.05);高原牦牛气-血屏障的算术平均厚度较平原黄牛大(P<0.05),但气-血屏障调和平均厚度两者差异不显著(P>0.05). 结论 1d龄高原牦牛的肺泡发育较平原黄牛完善.高原牦牛肺泡数将以"芽生"的形式快速增加.高原牦牛出生时肺泡相对完善的发育和肺泡数的快速增加以及肺泡隔相对较厚且厚薄不均等组织学特点是高原牦牛能很好适应高原低氧环境的组织学基础.     

肺泡表面活性物质系统的变化与成人呼吸窘迫综合征

可引起成人呼吸窘迫综合征(Adult Respiratory Distress Syndrome,ARDS)的原因是多方面的,始动机制不完全一样,但总的说来,ARDS的发生和发展是肺微循环障碍,毛细血管-肺泡膜受损和肺泡表面活性物质缺失的结果。 肺泡表面活性物质(Pulmonary Surfactant,PS)系统的变化与肺部疾病的关系日愈受到重视。Avery等(1959)发现患呼吸窘迫综合征新生儿的肺浸出液表面张力增加是肺泡表面披复物变化的结果;Tyler(1964)和Kikkawa(1965)先后用电镜显示出肺泡表面活性层和肺泡上皮细胞内嗜锇酸包含体变化与新生儿呼吸窘迫综征发生的关系,揭示了PS系     

大鼠肺泡结构的立体计量研究

应用立体计量方法,对5只正常大鼠(Wistar系,雌性)肺泡结构进行了定量研究。得出:1)双侧肺脏肺泡总数(Na)为(15.78±2.57)×10~6个;2)双侧肺泡总内表面积(Sa)4232.4±702.9cm~2;3)肺泡毛细血管床容积(Vc)0.42+O.09cm~3/左右肺;4)肺泡毛细血管床内表面积(Sc):3525.05±569.91cm~2/左右肺;5)血气屏障厚度:算术平均(Tat)0.54±O.13μm;调和平均(Tht)0.21±0.09um:6)肺泡Ⅰ、Ⅱ型上皮细胞、肺泡毛细血管内皮细胞的总体积(×lO~(-2)cm~3)分别为:8.71±1.7,5.12±1.6,10.53±O.1;7)肺泡毛细血管床内粒细胞、血小板的总体积(×10~(-2)cm~3)分别为:1.85±1;0.35±0.24。     

肥大细胞与弥漫性肺间质纤维化

肺间质是指肺泡间的泡隔和小叶间、支气管及肺血管周围的结缔组织,其中以肺泡间隔为主。正常肺泡间隔内的细胞成分有:成纤维细胞(Fb)、肌纤维母细     

蛋白激酶C与肺泡巨噬细胞的功能调节

蛋白激酶C(PKC)是一个由多种具有不同生物特性的同工酶组成的蛋白质家族.肺泡巨噬细胞中至少有9种PKC同工酶分布.PKC通道参与调节肺泡巨噬细胞(AM)的吞噬、粘附、趋化,及分泌各种细胞因子、氧自由基等免疫功能.     

高脂饮食兔肺泡巨噬细胞［Ca2+］i及ACE活性变化

目的： 了解高脂饮食对兔肺泡巨噬细胞胞浆游离钙浓度(［Ca²⁺］_i)及血管紧张素Ⅰ转换酶 (ACE) 活性的影响，探索哮喘与高脂饮食相关的可能机制。方法: 高胆固醇饮食法建立高脂兔模型(ｎ=6)，8周后离体支气管肺泡灌洗；Fura2/am测定肺泡巨噬细胞［Ca²⁺］_i,紫外法检测ACE活性。结果: 高脂组肺泡巨噬细胞［Ca²⁺］_i显著高于正常组 (P＜0.01)；其支气管肺泡灌洗液(BALF)及肺泡巨噬细胞上清液中ACE活性显著高于正常组 (均P＜0.01)；高脂组BALF中肺泡巨噬细胞数、肺泡巨噬细胞［Ca²⁺］_i 及肺泡巨噬细胞培养上清液ACE活性均与血清总胆固醇含量呈正相关，r分别为0.851、0.840、0.847(均P＜0.05)。结论: 高脂饮食导致兔肺泡巨噬细胞活化，活性增高的肺泡巨噬细胞处于易激状态。     

不同毒力结核分枝杆菌感染小鼠对肺泡巨噬细胞的凋亡率及其时相性变化的影响

目的:探讨不同毒力结核分枝杆菌感染小鼠肺泡巨噬细胞的凋亡率及其时相性变化。方法:不同毒力结核分枝杆菌悬液分别经小鼠尾静脉注射、复制及鉴定各组小鼠感染模型,各组小鼠感染模型复制成功后第1、3、5、7、9、11、13、15天,进行肺泡灌洗,收集小鼠肺泡灌洗液,获取感染小鼠肺泡巨噬细胞,以激光共聚焦显微镜技术检测及鉴定结核分枝杆菌感染小鼠肺泡巨噬细胞,流式细胞术检测上述各时间点、各组感染小鼠肺泡巨噬细胞的凋亡率,比较各组感染小鼠肺泡巨噬细胞凋亡率的时相性变化。结果:激光共聚焦显微镜检测结果显示,结核分枝杆菌国际标准强毒株H37Rv株和卡介苗菌株(BCG)均被小鼠肺泡巨噬细胞大量吞噬。流式细胞技术检测结果显示:结核分枝杆菌国际标准强毒株H37Rv株感染小鼠模型组和卡介苗菌株(BCG)感染小鼠模型组,在小鼠感染模型复制成功后1～9天,小鼠肺泡巨噬细胞的凋亡率逐渐升高,9天时两组小鼠肺泡巨噬细胞的凋亡率均达最高,随着时间的延长,两组小鼠肺泡巨噬细胞的凋亡率呈现逐渐降低趋势。结核分枝杆菌国际标准强毒株H37Rv株感染小鼠组,感染小鼠的肺泡巨噬细胞的凋亡率明显高于卡介苗菌株(BCG)感染小鼠组,差异有统计学意义(P<0.05)。结论:感染小鼠的肺泡巨噬细胞的凋亡率与结核分枝杆菌的毒力强弱呈正相关。     

急性间质性肺炎2例尸检病理分析

目的探讨急性间质性肺炎(acute interstitial pneumo-nia,AIP)的临床特点、病理学特征、诊断、治疗及预后。方法对2例因急性呼吸衰竭而死亡的患者进行系统病理解剖,观察死因。结果 2例尸检肺组织均可见弥漫的肺泡损伤,纤维增生,肺泡隔增宽;肺泡腔内广泛的透明膜形成,并见水肿液;肺泡腔内见息肉样机化物。结合临床特点、影像学结果诊断为AIP。结论 AIP是一种原因不明、爆发性起病、并快速进展为呼吸衰竭的特发性间质性肺炎(idiopathic inter-stitial pneumonia,IIP)。组织病理学改变为弥漫性肺泡损伤(diffuse alveolar damage,DAD)机化期改变,透明膜的形成是其明显特征。胸部影像学表现为双侧弥漫网状、细结节及磨玻璃样阴影。AIP的诊断需要结合临床及影像学资料。AIP病死率较高,早期诊断尤为重要。     

实验性糖尿病肺形态学及氧自由基研究

目的:了解早期糖尿病肺形态学及氧化应激的变化。方法:应用体视学方法对四氧嘧啶诱导的糖尿病28d大鼠肺进行定量研究、观察超微结构变化并测定血清和肺组织的超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量。结果:糖尿病大鼠肺泡体密度和平均截线长度减少,肺泡壁体密度、肺泡表面积密度、肺泡数密度、肺泡面数密度和肺泡比表面增加。糖尿病大鼠Ⅱ型肺泡细胞粗面内质网扩张,其体密度、面密度、平均截面积和平均周长增加,而比表面减少。肺上皮和毛细血管基底膜增厚。糖尿病大鼠血清SOD活性下降,MDA含量增加;肺组织MDA含量明显升高。结论:糖尿病早期大鼠肺已发生形态学变化且受到氧化应激的危害,提示肺脏是糖尿病损害的"靶器官"之一。     

高浓度氧对早产鼠肺发育影响的动态研究

目的为探讨高浓度氧对早产儿肺泡发育影响的动态变化规律.方法以暴露于高氧环境中早产鼠为研究对象,分别采用光镜和透色电镜技术,观察不同吸氧时间肺重量与体重比、肺组织形态学及Ⅱ型肺泡上皮细胞(AEC-Ⅱ)超微结构变化.结果 1)肺重量/体重:于吸氧7d和14d,实验组明显低于对照组(P<0.01);2)肺形态学:吸高氧7d即开始出现肺泡化障碍,14d肺泡体积明显增大、肺泡融合、数目减少,21d时正常的肺泡结构几乎消失;3)AEC-Ⅱ的超微结构:暴露高氧1d即出现线粒体(Mi)肿胀,3d板层小体(LB)开始排空,7d细胞核发生异常改变,14～21d,逐渐出现Mi嵴消失,LB空泡变性,细胞核溶解、固缩.结论吸入高浓度氧早期即可损伤AEC-Ⅱ,继之影响肺泡发育成熟,且随吸氧时间的延长,损伤逐渐加重.     

Endothelial Colony-Forming Cells Do Not Participate to Fibrogenesis in a Bleomycin-Induced Pulmonary Fibrosis Model in Nude Mice

Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease characterized by fibroblast proliferation, extracellular matrix deposition, destruction of pulmonary alveolar architecture and vascular remodeling. Apart pirfenidone or nintendanib that only slow down the fibrotic process, there is no curative treatment other than lung transplantation. Because cell therapy approaches have been proposed in IPF, we hypothesized that injection of endothelial colony-forming cells (ECFCs), the vasculogenic subtype of endothelial progenitor cells, could modulate fibrosis in a Nude mouse model of bleomycin induced-pulmonary fibrosis. Mice were injected with ECFCs isolated from cord blood and from peripheral blood of adult IPF patients at two time-points: during the development of the fibrosis or once the fibrosis was constituted. We assessed morbidity, weight variation, collagen deposition, lung imaging by microCT, Fulton score and microvascular density. Neither ECFCs isolated from cord blood nor from IPF patients were able to modulate fibrosis or vascular density during fibrogenesis or when fibrosis was constituted. These findings indicate that human ECFCs do not promote an adaptive regenerative response in the lung upon fibrosis or angiogenic process in the setting of bleomycin-induced pulmonary fibrosis in Nude mice.     

The role of dimethylarginine dimethylaminohydrolase in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive, dysregulated response to alveolar injury that culminates in compromised lung function from excess extracellular matrix production. Associated with high morbidity and mortality, IPF is generally refractory to current pharmacological therapies. We examined fibrotic lungs from mice and from patients with IPF and detected increased expression of dimethylarginine dimethylaminohydrolases (DDAHs)--key enzymes that metabolize asymmetric dimethylarginine (ADMA), which is an endogenous inhibitor of nitric oxide synthase, to form l-citrulline and dimethylamine. DDAHs are up-regulated in primary alveolar epithelial type II cells from these mice and patients where they are colocalized with inducible nitric oxide synthase. In cultured alveolar epithelial type II cells from bleomycin-induced fibrotic mouse lungs, inhibition of DDAH suppressed proliferation and induced apoptosis in an ADMA-dependent manner. In addition, DDAH inhibition reduced collagen production by fibroblasts in an ADMA-independent but transforming growth factor/SMAD-dependent manner. In mice with bleomycin-induced pulmonary fibrosis, the DDAH inhibitor L-291 reduced collagen deposition and normalized lung function. In bleomycin-induced fibrosis, inducible nitric oxide synthase inhibition decreased fibrosis, but an even stronger reduction was observed after inhibition of DDAH. Thus, DDAH inhibition reduces fibroblast-induced collagen deposition in an ADMA-independent manner and reduces abnormal epithelial proliferation in an ADMA-dependent manner, offering a possible therapeutic avenue for attenuation of pulmonary fibrosis.     

Extracellular matrix powder protects against bleomycin-induced pulmonary fibrosis

Pulmonary fibrosis refers to a group of lung diseases characterized by inflammation, fibroblast proliferation, and excessive collagen deposition. Although the mechanisms underlying pulmonary fibrosis are poorly understood, current evidence suggests that epithelial injury contributes to the development of fibrosis. Regenerative medicine approaches using extracellular matrix (ECM) scaffolds have been shown to promote site-specific tissue remodeling. This led to the hypothesis that particulate ECM would promote normal tissue repair and attenuate bleomycin-induced pulmonary fibrosis. C57BL/6 mice were treated intratracheally with bleomycin or saline with or without a particulate form of ECM scaffold from porcine urinary bladder matrix (UBM-ECM) or enzymatically digested UBM-ECM. Mice were sacrificed 5 and 14 days after exposure. Compared to control mice, bleomycin-exposed mice had similar increases in inflammation in the bronchoalveolar lavage fluid regardless of UBM-ECM treatment. However, 14 days after exposure, lung histology and collagen levels revealed that mice treated with bleomycin and the particulate or digested UBM-ECM had negligible fibrosis, whereas mice given only bleomycin had marked fibrosis. Administration of the particulate UBM-ECM 24 h after bleomycin exposure also significantly protected against pulmonary injury. In vitro epithelial cell migration and wound healing assays revealed that particulate UBM-ECM promoted epithelial cell chemotaxis and migration. This suggests that promotion of epithelial wound repair may be one mechanism in which UBM-ECM limits pulmonary fibrosis.     

The role of high mobility group box1 in pulmonary fibrosis

High mobility group box1 protein (HMGB1) was originally discovered as a nuclear binding protein, and is known to play an important role in acute lung injury. However, the role of HMGB1 in pulmonary fibrosis has not been addressed. Therefore, we measured the HMGB1 levels in serum and bronchoalveolar lavage fluids (BALF) from patients with idiopathic pulmonary fibrosis (IPF), nonspecific interstitial pneumonia, interstitial pneumonia associated with collagen vascular diseases, and hypersensitivity pneumonitis (HP) by enzyme-linked immunosorbent assay. We also assessed the HMGB1 expression in bleomycin-induced pulmonary fibrosis in mice, and examined the effect of anti-HMGB1 antibody and ethyl pyluvate, which inhibits the HMGB1 secretion from alveolar macrophages. In addition, we examined the effect of HMGB1 on fibroblast proliferation, apoptosis, and collagen synthesis in vitro. Serum HMGB1 levels were not significantly increased in interstitial lung diseases compared with control subjects. BALF HMGB1 levels were significantly increased in IPF and HP compared with control subjects. HMGB1 protein was predominantly detected in inflammatory cells and hyperplasic epithelial cells in IPF. In bleomycin-induced pulmonary fibrosis in mice, HMGB1 protein was predominantly up-regulated in bronchiolar epithelial cells at early phase and in alveolar epithelial and inflammatory cells in fibrotic lesions at later phase. Intraperitoneal injection of anti-HMGB1 antibody or ethyl pyluvate significantly attenuated lung inflammation and fibrosis in this model. HMGB1 significantly induced proliferation, but not apoptosis or collagen synthesis on cultured fibroblasts. HMGB1 may be a promising target against pulmonary fibrosis as well as acute lung injury.     

Discoidin domain receptor 1 contributes to the survival of lung fibroblast in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF), characterized by fibroblast proliferation and accumulation of extracellular matrix, including collagen, is a chronic progressive disorder that results in lung remodeling and fibrosis. However, the cellular mechanisms that may make fibroblasts resistant to apoptosis have not been completely elucidated. Discoidin domain receptor 1 (DDR1), a receptor tyrosine kinase whose ligand is collagen, is expressed in vivo and contributes in vitro to leukocyte differentiation and nuclear factor (NF)-kappaB activation, which may play an important role in fibroblast survival. In this study, we examined in vivo and in vitro DDR1 expression and its role in cell survival using fibroblasts obtained from IPF and non-IPF patients. Immunohistochemically, fibroblasts present in fibroblastic foci expressed endogenous DDR1. The DDR1 expression level was significantly higher in fibroblasts from IPF patients, and the predominant isoform was DDR1b. In IPF patients, DDR1 activation in fibroblasts inhibited Fas ligand-induced apoptosis and resulted in NF-kappaB nuclear translocation. Suppression of DDR1 expression in fibroblasts by siRNA abolished these effects, and an NF-kappaB inhibitor abrogated the anti-apoptotic effect of DDR1 activation. We propose that DDR1 contributes to fibroblast survival in the tissue microenvironment of IPF and that DDR1 up-regulation may occur in other fibroproliferative lung diseases as well.     

Increased production and immunohistochemical localization of transforming growth factor-beta in idiopathic pulmonary fibrosis

Transforming growth factor-beta (TGF-beta) can regulate cell growth and differentiation as well as production of extracellular matrix proteins. Elevated production of TGF-beta has been associated with human and rodent chronic inflammatory and fibrotic diseases. Using immunohistochemical staining, we have examined lung sections of patients with advanced idiopathic pulmonary fibrosis (IPF), a disease characterized by chronic inflammation and fibrosis and demonstrated a marked and consistent increase in TGF-beta production in epithelial cells and macrophages when compared to patients with nonspecific inflammation and those with no inflammation or fibrosis. In patients with advanced IPF, intracellular staining with anti-LC (1-30) TGF-beta antibody was seen prominently in bronchiolar epithelial cells. In addition, epithelial cells of honeycomb cysts and hyperplastic type II pneumocytes stained intensely. Anti-CC (1-30) TGF-beta antibody, which reacts with extracellular TGF-beta, was localized in the lamina propria of bronchioles and in subepithelial regions of honeycomb cysts in areas of dense fibroconnective tissue deposition. The close association of subepithelial TGF-beta to the intracellular form in advanced IPF suggests that TGF-beta was produced and secreted primarily by epithelial cells. Because of the well-known effects of TGF-beta on extracellular matrix formation and on epithelial cell differentiation, the increased production of TGF-beta in advanced IPF may be pathogenic to the pulmonary fibrotic and regenerative responses seen in this disease.     

MRP14 is elevated in the bronchoalveolar lavage fluid of fibrosing interstitial lung diseases

Pulmonary fibrosis is defined by an overgrowth of fibroblasts and extracellular matrix deposition, and results in respiratory dysfunction that is often fatal. It is the end stage in many chronic inflammatory interstitial lung diseases (ILD) such as sarcoidosis and idiopathic pulmonary fibrosis (IPF). The myeloid‐related proteins (MRPs) belong to the S100 family of calcium‐binding proteins and are highly expressed by neutrophils, macrophages and epithelial cells during chronic inflammation. MRP14 stimulates fibroblast proliferation in vitro and is expressed in granulomas from sarcoidosis patients. We hypothesized that MRP14 may be a biomarker for fibrotic interstitial lung diseases. The objective of this study was to investigate whether levels of MRP14 in the bronchoalveolar lavage fluid (BALF) of patients with sarcoidosis and IPF correlate with clinical parameters. We used an enzyme‐linked immunosorbent assay (ELISA) to measure MRP14 in BALF of 74 sarcoidosis patients, 54 IPF patients and 19 controls. Mean BALF levels of MRP14 were elevated significantly in IPF (P < 0·001) and sarcoidosis (P < 0·05) patients compared to controls. MRP14 levels were associated linearly with sarcoidosis disease severity based on chest radiographic stage. Moreover, BALF MRP14 levels were correlated inversely with diffusion capacity and forced vital capacity in sarcoidosis patients. In IPF patients, a correlation with BALF neutrophil percentage was found. In conclusion, BALF MRP14 levels are elevated in IPF and sarcoidosis and are associated with disease severity in sarcoidosis. The results support the need for further studies into the role of MRP14 in the pathogenesis of lung fibrosis.     

Reduced expression of cyclooxygenase (COX) in idiopathic pulmonary fibrosis and sarcoidosis

AIMS: To test the hypothesis that cyclooxygenase (COX)-1 or COX-2 expression is defective in lungs in idiopathic pulmonary fibrosis (IPF) and to characterize the cellular distribution. IPF is a progressive inflammatory lung disorder with an adverse prognosis. Previous work has shown that prostaglandin E2 (PGE2) regulates collagen deposition and fibroblast proliferation and a defect in COX regulation may contribute to the fibrosis that occurs in IPF. METHODS: Immunohistochemistry was utilized to determine COX immunoreactivity in lung sections from 25 IPF, six sarcoidosis and 14 control subjects. RESULTS: COX-1 and COX-2 expression in bronchiolar epithelial cells was significantly lower in IPF and sarcoidosis than in controls. No significant difference was found in COX-2 expression between macrophages in IPF and control sections, but COX-2 was reduced in macrophages in sarcoidosis compared with controls. CONCLUSIONS: These studies confirm COX-2 loss in bronchial epithelial cells but not macrophages in IPF, and show for the first time reduced constitutive COX-1 expression in epithelial cells and macrophages. Similar abnormalities were observed in sarcoidosis.     

Extracellular glutathione suppresses human lung fibroblast proliferation

Alveolar epithelial lining fluid glutathione (GSH) is markedly decreased in patients with idiopathic pulmonary fibrosis (IPF). Because patients with IPF have exaggerated numbers of fibroblasts in their lower respiratory tract, we hypothesized that GSH can suppress lung fibroblast proliferation. To verify this hypothesis, we examined the ability of GSH to suppress human lung fibroblast (ATCC; HFL-1) proliferation in vitro in the presence of either IPF bronchoalveolar lavage fluid (BAL) or calf serum (CS). Both CS at a concentration of 10% and IPF BAL markedly increased fibroblast proliferation when compared to cells grown without CS or IPF BAL (10% CS = 93 +/- 4%, P less than 0.001; IPF BAL = 47 +/- 4%, P less than 0.001). In the presence of physiologic concentrations of GSH (0 to 500 microM), both CS- and IPF BAL-mediated fibroblast proliferation were markedly reduced, with 500 microM GSH inducing complete inhibition. Interestingly, glutathione disulfide (GSSH) and S-methylglutathione did not suppress proliferation, whereas various sulfhydryl-containing molecules (cysteine, N-acetylcysteine, 2-mercaptoethanol, and low concentrations of dithiothreitol) induced an inhibition of fibroblast proliferation similar to that observed with GSH. Most of the suppressive effect of GSH was mediated at the cell level since incubation of fibroblasts with 500 microM GSH for 1 h completely blocked the ability of the cells to subsequently proliferate in the presence of untreated 10% CS. Treatment of CS with 500 microM GSH for 1 h followed by removal of GSH by molecular sieve chromatography had no detectable effect on fibroblast proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)