Expression of c-erbB receptors and ligands in the bronchial epithelium of asthmatic subjects.

BACKGROUND: The c-erbB family of receptor tyrosine kinases act in a combinatorial fashion to regulate cell behavior. Disturbances in this system have been associated with neoplastic and inflammatory diseases. OBJECTIVES: Although expression of the epidermal growth factor receptor (EGFR; c-erbB1) is increased in the bronchial epithelium in asthma, there is no information on expression of other members of the c-erbB receptor and ligand family that can modulate EGFR function. METHODS: Immunohistochemistry was used to compare expression of EGFR, c-erbB2, c-erbB3, epidermal growth factor, heparin-binding epidermal growth factor-like growth factor, and transforming growth factor alpha in bronchial biopsy specimens from normal and asthmatic subjects. Scrape-wounded monolayers of 16HBE 14o(-) cells were used as an in vitro model of damage and repair. Changes in EGFR, c-erbB2, and c-erbB3 distribution were measured by means of immunocytochemistry, whereas tyrosine phosphorylation was measured by means of immunoprecipitation and Western blotting. RESULTS: Although epithelial staining for the EGFR was significantly increased in asthmatic epithelium (P <.001), there was no difference in staining for the other receptors and ligands studied. In scrape-wounded epithelial monolayers, tyrosine phosphorylation of EGFR, c-erbB2, and c-erbB3 occurred immediately after damage; however, only EGFR showed a change in expression in response to damage. CONCLUSIONS: Even though EGFR levels are increased in asthma, this is not linked to changes in expression of its activating ligands or other c-erbB receptors. Because bronchial epithelial cells respond to physical damage through activation of several c-erbB family members, the shift in favor of increased EGFR levels in asthma may lead to altered epithelial function by influencing the number and type of heterodimeric signaling complexes, assuming sufficient ligand availability.     

Expression of Wnt ligands and Frizzled receptors in colonic mucosa and in colon carcinoma.

AIMS: Signalling through the Wnt pathway is integrally associated with colon carcinogenesis. Although activating mutations in the genes for adenomatous polyposis coli (APC) and beta-catenin are clearly associated with colon cancer, less is understood about the role of the upstream secreted ligands (Wnts) and their receptors (frizzled, Fz) in this process. In other systems, increased Wnt signalling has been shown to alter the expression of components of this pathway. This study was designed to test the hypothesis that colon cancer is characterised by aberrant expression of specific Wnt genes and Fz receptors. METHODS: The expression of Wnt genes was assessed by in situ, antisense RNA hybridisation in paraffin wax embedded samples of normal and malignant human colon tissues with probes specific for the individual Wnt genes. The expression of Fz1 and Fz2 was determined by immunoperoxidase based antibody staining on human tissues. RESULTS: Changes in the expression of some ligands and receptors were seen in colon cancer. For example, Wnt2 mRNA was detected in colon cancer but was undetectable in normal colonic mucosa. Differential expression of Wnt5a in normal mucosa was also noted, with increased expression at the base of the crypts compared with the luminal villi and slightly increased expression in colon cancer. Wnt7a exhibited minimal expression in both normal and malignant colon tissues, whereas other Wnt ligands including Wnts 1, 4, 5b, 6, 7b, and 10b were expressed equally and strongly in both normal and malignant colon tissues. In defining cellular responses and phenotype, the type and distribution of Fz receptors may be as important as the pattern of Wnt ligand expression. No expression of Fz receptor 1 and 2 was seen in normal colonic mucosa and in well differentiated tumours. However, poorly differentiated tumours exhibited a high degree of Fz receptor expression, especially at the margin of cellular invasion. CONCLUSIONS: These data indicate that the expression of members of the Wnt signal transduction pathway, distinct from APC and beta-catenin, is integrally associated with the process of colon carcinogenesis. Wnt2, and possibly Wnt5a, may be involved in the progression from normal mucosa to cancer and the expression of Fz1/2 receptors may be involved in processes associated with tumour invasion. Altered expression of these Wnts and Fz receptors may prove useful as prognostic or diagnostic markers for patients with colon cancer.     

哮喘支气管黏膜中类胰蛋白酶的表达增强

目的 观察含类胰蛋白酶的肥大细胞在豚鼠支气管黏膜的表达和分布特征。方法 Dunkin Hartley豚鼠随机分为哮喘组(A组)和生理盐水组(B组)。用100m/mL卵蛋白进行致敏,并于致敏后第5周行抗原特异性支气管激发试验。激发后2h取各组豚鼠支气管组织标本,免疫组化染色以抗人类胰蛋白酶(Tryptase)单克隆抗体(AAl)为一抗,过氧化物酶标记的绵羊抗鼠IgG为二抗,并用联苯二胺(Diaminobenzidine,DAB)显色。仅选择阳性染色细胞进行计数。结果 鼠抗人Trvptase单克隆抗体即可识别人支气管Tryptase又可识别豚鼠支气管Tryptase。哮喘支气管组织中Tryptase阳性细胞数明显多于正常支气管组织。相似地,支气管激发试验后的豚鼠支气管组织中的肥大细胞数要比生理盐水吸入组多出2．0倍以上。结论 抗人Tryptase单克隆抗体可以用于识别豚鼠支气管的肥大细胞。哮喘者和激发试验阳性的豚鼠支气管肺组织中的Tryptase阳性肥大细胞数明显多于正常支气管组织,表明肥大细胞在支气管哮喘发病机制中可能起重要作用。     

Age dynamics of cell populations and mast cell density in human bronchial mucosa

Using the quantitative analysis of mast cell number and granularity, some regularities of their age-associated dynamics were established. In suckling babies and in early childhood the mast cells are small and contain a moderate amount of secretory granules with no signs of degranulation. Henceforth they become larger and are functioning asynchronously. Mast cell number increases up to the age of 16 years. After 36 years mast cell prevalence and their secretory granule content are reduced.     

Interaction between the human NK receptors and their ligands

NK cells are physiologically important in a number of contexts: mediating immunity against viruses, intracellular bacteria and parasites, and in anti-tumour immune responses. Moreover, in addition to these overtly immune protective functions, NK cells also mediate a variety of homeostatic functions, particularly in the regulation of haematopoesis and they may have an important role to play in the maintenance and development of placentation; certainly NK cells are a major component of the lymphocyte population of the decidua. The behaviour of the NK cell in these various situations is regulated by a large number of distinct receptors that transmit positive and negative signals. The balance of these signals determines whether the NK cell does nothing or is activated to proliferate, kill or secrete a wide range of cytokines and chemokines. In this review the structure and function of a number of molecules found on the NK cell surface are discussed, particular emphasis being placed on the molecular details of the recognition of target cell classical class I HLA molecules by Killer cell Immunoglobulin-like Receptors (KIR) and the binding of the non-classical class I molecule HLA-E to the heterodimer formed by the association of CD94 with various members of the NKG2 proteins.     

Expression and regulation of vascular endothelial growth factor ligands and receptors during menstruation and post-menstrual repair of human endometrium

Regeneration and growth of the human endometrium after shedding of the functional layer during menstruation depends on an adequate angiogenic response. We analysed the mRNA expression levels of all known vascular endothelial growth factor (VEGF) ligands and receptors in human endometrium collected in the menstrual and proliferative phases of the menstrual cycle. In addition, we evaluated the expression of VEGF-A, VEGF-R2 and NRP-1 at the protein level. Two periods of elevated mRNA expression of ligands and receptors were observed, separated by a distinct drop at cycle days (CDs) 9 and 10. Immunohistochemical staining showed that VEGF and VEGF-R2 were expressed in epithelial, stromal and endothelial cells. NRP-1 was mainly confined to stroma and blood vessels; only in late-proliferative endometrium, epithelial staining was also observed. Except for endothelial VEGF-R2 expression in CDs 6-8, there were no significant differences in the expression of VEGF, VEGF-R2 or NRP-1 in any of the cell compartments. In contrast, VEGF release by cultured human endometrium explants decreased during the proliferative phase. This output was significantly reduced in menstrual and early-proliferative endometrium by estradiol (E2) treatment. Western blot analysis indicated that part of the VEGF-A was trapped in the extracellular matrix (ECM). Changes in VEGF ligands and receptors were associated with elevated expression of the hypoxia markers HIF1alpha and CA-IX in the menstrual and early proliferative phases. HIF1alpha was also detected in late-proliferative phase endometrium. Our findings indicate that VEGF-A exerts its actions mostly during the first half of the proliferative phase. Furthermore, VEGF-A production appears to be triggered by hypoxia in the menstrual phase and subsequently suppressed by estrogen during the late proliferative phase.     

The ultrastructural heterogeneity of potentially preneoplastic lesions in the human bronchial mucosa

170 consecutive biopsies from the bronchial tree were subjected to ultrastructural analysis. 62 were identified as preneoplastic lesions: of these, 7 as goblet cell hyperplasia, 20 as basal cell hyperplasia, 17 as combined goblet and basal cell hyperplasia, 10 as epidermoid metaplasia, and 8 as dysplasia. The ultrastructural features of these lesions are described. According to these results, preneoplastic lesions of the human bronchial mucosa are composed of heterogeneous populations that display mixed or combined morphologic features signaling abnormal differentiation patterns at this stage. The findings are tentatively correlated with bronchial carcinoma cell heterogeneity and histogenesis.     

Expression profile of Eph receptors and ephrin ligands in human skin and downregulation of EphA1 in nonmelanoma skin cancer.

Eph receptors and ephrin ligands represent the largest family of receptor tyrosine kinases. Beyond their well-defined meaning in developmental processes, these molecules also have important functions in adult human tissues and cancer. However, the Eph/ephrin expression profile in human skin is only marginally studied. We therefore investigated the mRNA expression of 21 Eph receptors and ephrin ligands in adult human skin in comparison to 13 other adult human tissues using quantitative real-time RT-PCR. In addition, immunohistochemistry was established for some members (EphA1, EphA2 and EphA7) to confirm the results of the RT-PCR and to identify the expressing cells in the skin. We found all investigated family members expressed in human skin, but at highly varying levels. EphA1, EphB3 and ephrin-A3 turned out to be most prominently expressed in skin compared to other adult human tissues. EphA1 was exclusively expressed in the epidermis. We therefore investigated the expression of EphA1 in nonmelanoma skin cancers derived from the epidermis (56 basal cell carcinomas and 32 squamous cell carcinomas). As demonstrated by immunohistochemistry, both skin cancers displayed a significant downregulation of EphA1 compared to the normal epidermis. In squamous cell carcinoma, the EphA1 downregulation was associated with increased tumor thickness, although this was not significant. Our results indicate that Eph receptors and ephrin ligands are widely expressed in the adult human skin, particularly in the epidermis, and may play an important role in skin homeostasis. EphA1 seems to be a marker of the differentiated normal epidermis and its downregulation in nonmelanoma skin cancer may contribute to carcinogenesis of these very frequent human tumors. EphA1 represents a new potential prognostic marker and therapeutic target in nonmelanoma skin cancer.     

Concentrations of temafloxacin in serum and bronchial mucosa

The bronchial mucosal concentrations of temafloxacin hydrochloride were determined in specimens obtained at fibreoptic bronchoscopy and compared with simultaneous serum concentrations. The 18 patients studied were given an oral dose of 400 mg b.i.d. for three days to achieve steady state levels. The mean serum concentration was 6.9 mg/l (SD 2.5 mg/l) and the mean bronchial mucosal concentration 12.2 mg/kg (SD 4 mg/kg). The mucosal levels exceeded those required to inhibit most of the common respiratory pathogens, includingStreptococcus pneumoniae andPseudomonas aeruginosa. These data support the use of temafloxacin for therapy of bronchial infections.     

Abnormal cilia in the bronchial mucosa

Summary Atypical cilia in the bronchial mucosa of non-smoking women and in guinea-pig lungs were studied by the electron microscope. In human cases, numerous compound cilia were observed in the main bronchi. The largest one contained about 40 axial filament complexes in a ciliary shaft. Occasionally, atypical basal bodies were also seen.In the experimental model in guinea-pigs, 50% oxygen at one atmospheric pressure damaged the bronchial surface and resulted in degeneration and reduction of cilia and pellicular structures. The injury was not sufficiently severe to initiate adaptation and reparative mechanisms in the bronchial mucosa, and rapid renewal of the surface structures was found.The human cases were associated with bronchogenic carcinoma but the experimental model suggested that atypical cilia were not always related to pulmonary carcinogenesis.     

Expression and function of toll-like receptors in human basophils

We investigated the expression and function of a panel of Toll-like receptors (TLRs) in human basophils. Basophil preparations constitutively expressed TLR2, TLR4, TLR9 and TLR10 mRNAs (TLR4 > TLR2 > TLR9, TLR10). Although TLR mRNA expression in basophils was generally less prominent compared with those in neutrophils and monocytes, basophils expressed significantly higher levels of TLR2 and TLR4 mRNA than eosinophils. Various TLR ligands (Pam3Cys-Ser-Lys4, poly I:C, lipopolysaccharide, R-848, CpG DNA) were tested, but none affected the expression level of adhesion molecule CD11b or the viability of freshly purified basophils. On the other hand, when basophils were pretreated with interferon-gamma before stimulation with TLR ligands, only the TLR4 ligand, lipopolysaccharide, upregulated CD11b expression. However, the surface levels of TLR2 and TLR4 on the interferon-gamma-treated basophils showed no obvious changes. These results suggest that TLR4 on basophils may be involved in the pathogenesis of infection-induced exacerbation of allergic inflammation by modulating basophil functions.     

类风湿关节炎患者外周血单个核细胞Notch及其配体表达

为研究Notch信号途径在类风湿关节炎(RA)发病机制中的作用,选取活动期RA患者,采用流式细胞术结合细胞表面及细胞内染色技术检测外周血单个核细胞Notch受体及配体表达情况,并与正常对照进行比较。结果发现,活动期RA患者外周血T细胞Notch2、Notch3及Notch4表达较正常人明显增加,Notch1分子表达均较少,二者未见差异。其中表达Notch分子的细胞以CD4+T细胞为主。二者B细胞Notch1、Notch2、Notch3及Notch4的表达均较低,之间未见明显差异。RA患者单核细胞Jagged1分子表达明显增加,而Delta1表达降低。结果提示活动期RA患者外周血单个核细胞中不同群体细胞存在Notch及其配体表达水平的改变。     

Intracellular keratins in normal and pathological bronchial mucosa

Summary The distribution of intracellular keratins was investigated in normal bronchial epithelium and in several morphologically distinct forms of respiratory tract carcinomas. This study was performed with two different experimentally produced antisera against normal human stratum corneum keratin and against keratin protein of MW 67000 dalton, using indirect immunofluorescence and immunoperoxidase methods on tissue sections and cell suspensions.In normal bronchial epithelium, the basal cells were strongly labelled by both antisera. The ciliated columnar cells appeared devoid of cytokeratins in tissue sections but were strongly labelled with both antisera in cell suspensions. The goblet cells remained negative in every case. In squamous metaplasia of the bronchus, all epithelial cells were unevenly stained with both antisera.Among tumours, only the squamous cell carcinomas were strongly labelled by both antisera. Primary lung adenocarcinoma appeared weakly positive, whereas metastatic lung carcinomas, undifferentiated lung carcinomas, oat cell tumours, carcinoid tumours were negative.The immunocytochemical determination of keratins appears to be of value in the study of normal and abnormal epithelial differentiation, in the diagnosis of poorly differentiated carcinomas and in their distinction from metastatic tumours of the lung.