Temporal and spatial distribution of ciliogenesis in the tracheobronchial airways of mice

Little is known about ciliogenesis as it proceeds through the entire airway tree, from the trachea to the terminal bronchioles, especially during the postnatal period. The purpose of this study was to define the spatial and temporal (prenatal and postnatal) pattern of normal cilia development in the mouse. Three airway generations representing the entire airway tree were examined: trachea, lobar bronchi, and terminal bronchiole. Ciliated cells in lung lobe whole mounts were labeled with a fluorescent dye for confocal microscopy, and ciliated cell surface density was measured for each airway generation and age. The same samples were examined by scanning electron microscopy to verify the appearance of ciliated cells among the differentiating epithelium of the airways. Ciliated cells were first detected in the trachea and lobar bronchi at 16 days gestational age (DGA) and in the terminal bronchioles at 18 DGA. Ciliated cell surface density increased with prenatal and postnatal age at all airway levels. However, the ciliated cell surface density of the trachea and lobar bronchi was always greater compared with the terminal bronchiole. In conclusion, the study revealed that in developing tracheobronchial airways of the mouse: 1) Ciliogenesis differs temporally and spatially by airway generation; 2) Ciliated cell surface density increases with age in all airway generations, but density decreases in a proximal to distal direction; and 3) A significant portion of ciliogenesis continues after birth. This study provides a healthy basis for investigations of neonatal pulmonary disease or pollutant toxicity affecting cilia and its functions.     

Endogenous IL-11 is pro-inflammatory in acute methylated bovine serum albumin/interleukin-1-induced (mBSA/IL-1)arthritis

OBJECTIVE: To evaluate the role of interleukin-11 (IL-11) in acute mBSA/IL-1-induced inflammatory arthritis. METHODS: IL-11 was administered via intra-articular (IA) injection into knee joints of C57BL/6 mice and joint histology was assessed. The mitogenic response to IL-11 was measured in wild-type (WT) synovial fibroblasts. IL-1 was used as a comparator in both the studies. The severity of acute methylated bovine serum albumin (mBSA)/IL-1 arthritis was determined in WT and IL-11 receptor null (IL-11Ra1-/-) mice. In parallel experiments, a neutralising antibody to IL-11 was administered to WT mice throughout this model. RESULTS: IA injections of IL-11 resulted in mild-to-moderate joint inflammation which was less than that due to IA IL-1. IL-11 had a dose-dependent mitogenic effect on WT synovial fibroblasts (P<0.01). mBSA/IL-1 acute arthritis was reduced in IL-11Ra1-/- versus WT mice (histological arthritis score: 10.1+/-0.5 versus 12.8+/-0.7, respectively; P=0.01). Administration of an IL-11 neutralising antibody to WT mice reduced mBSA/IL-1 acute arthritis scores compared to control antibody (10.6+/-0.7 versus 13.3+/-0.6, respectively; P=0.02). CONCLUSIONS: These data demonstrate that endogenous IL-11 exerts relatively mild but consistent pro-inflammatory effects in acute inflammatory arthritis.     

Combined radioimmunotherapy and chemotherapy of breast tumors with Y-90-labeled anti-Her2 and anti-CEA antibodies with taxol

Because breast cancer cells often express either Her2/neu or carcinoembryonic antigen (CEA) or both, these tumor markers are good targets for radioimmunotherapy using Y-90-labeled antibodies. We performed studies on nude mice bearing xenografts from MCF7, a cell line that has low Her2 and CEA expression, to more accurately reflect the more usual situation in breast cancer. Although uptake of In-111 anti-CEA into tumors was lower than that for In-111-labeled anti-Her2, radioimmunotherapy (RIT) with Y-90 anti-CEA was equivalent to that of Y-90 anti-Her2. When either Y-90 antibody was combined with a split-dose treatment with Taxol, the antitumor effect was greater than with either agent alone. When Y-90 anti-CEA was combined with a single dose of Taxol, the results were equivalent to the split-dose regimen. RIT plus cold Herceptin had no additional effects on tumor size reduction over RIT alone. When animals were first treated with Y-90 anti-Her2 and imaged 1-2 weeks later with In-111 anti-CEA or anti-Her2, tumor uptake was higher for anti-CEA and improved over tumor uptake with no prior RIT. These results suggest that a split dose of RIT with anti-Her2 antibody followed by anti-CEA antibody would be more effective than a single dose of either. This prediction was partially confirmed in a controlled study comparing single- vs split-dose anti-Her2 RIT followed by either anti-Her2 or anti-CEA RIT. These studies suggest that combined RIT and Taxol therapy are suitable in breast cancers expressing either low amounts of Her2 or CEA, thus expanding the number of eligible patients for combined therapies. They further suggest that split-dose RIT using different combinations of Y-90-labeled antibodies is effective in antitumor therapy.     

Expression of heat shock proteins and heat shock protein messenger ribonucleic acid in human prostate carcinoma in vitro and in tumors in vivo

Heat shock proteins (HSPs) are thought to play a role in the development of cancer and to modulate tumor response to cytotoxic therapy. In this study, we have examined the expression of hsf and HSP genes in normal human prostate epithelial cells and a range of prostate carcinoma cell lines derived from human tumors. We have observed elevated expressions of HSF1, HSP60, and HSP70 in the aggressively malignant cell lines PC-3, DU-145, and CA-HPV-10. Elevated HSP expression in cancer cell lines appeared to be regulated at the post-messenger ribonucleic acid (mRNA) levels, as indicated by gene chip microarray studies, which indicated little difference in heat shock factor (HSF) or HSP mRNA expression between the normal and malignant prostate cell lines. When we compared the expression patterns of constitutive HSP genes between PC-3 prostate carcinoma cells growing as monolayers in vitro and as tumor xenografts growing in nude mice in vivo, we found a marked reduction in expression of a wide spectrum of the HSPs in PC-3 tumors. This decreased HSP expression pattern in tumors may underlie the increased sensitivity to heat shock of PC-3 tumors. However, the induction by heat shock of HSP genes was not markedly altered by growth in the tumor microenvironment, and HSP40, HSP70, and HSP110 were expressed abundantly after stress in each growth condition. Our experiments indicate therefore that HSF and HSP levels are elevated in the more highly malignant prostate carcinoma cells and also show the dominant nature of the heat shock-induced gene expression, leading to abundant HSP induction in vitro or in vivo.     

Molecular mechanisms of survival and apoptosis in RAW 264.7 macrophages under oxidative stress

Organisms living in an aerobic environment are continuously exposed to reactive oxygen species (ROS). Apoptosis of cells can be induced by ROS and cells also develop negative feedback mechanisms to limit ROS induced cell death. In this study, RAW264.7 murine macrophage cells were treated with H₂O₂ and cDNA microarray technique was used to produce gene expression profiles. We found that H₂O₂ treatment caused up-regulation of stress, survival and apoptosis related genes, and down-regulation of growth and cell cycle promoting genes. Numerous genes of metabolism pathways showed special expression patterns under oxidative stress: glycolysis and lipid synthesis related genes were down-regulated whereas the genes of lipid catabolism and protein synthesis were up-regulated. We also identified several signaling molecules as ROS-responsive, including p53, Akt, NF- B, ERK, JNK, p38, PKC and INF- . They played important roles in the process of apoptosis or cell survival. Finally, an interactive pathway involved in cellular response to oxidative stress was proposed to provide some insight into the molecular events of apoptosis induced by ROS and the feedback mechanisms involved in cell survival.Y. Zhang and C.C. Fong contributed equally to this work.     

SpecAlign--processing and alignment of mass spectra datasets

SUMMARY: Pre-processing of chromatographic profile or mass spectral data is an important aspect of many types of proteomics and biomarker discovery experiments. Here we present a graphical computational tool, SpecAlign, that enables simultaneous visualization and manipulation of multiple datasets. SpecAlign not only provides all common processing functions, but also uniquely implements an algorithm that enables the complete alignment of each mass spectrum within a loaded dataset. We demonstrate its utility by aligning two datasets each containing six spectra; one set was acquired prior to instrument calibration and the other following calibration. AVAILABILITY: The software is free of charge and available for download from http://ptcl.chem.ox.ac.uk/~jwong/specalign. Supports Windows operating systems including Windows 9X/NT/2000/XP.     

Evaluation of Streptomyces sp. strain g10 for suppression of Fusarium wilt and rhizosphere colonization in pot-grown banana plantlets

Streptomyces sp. strain g10 exhibited strong antagonism towards Fusarium oxysporum f.sp. cubense (Foc) races 1, 2 and 4 in plate assays by producing extracellular antifungal metabolites. Treating the planting hole and roots of 4-week-old tissue-culture-derived Novaria banana plantlets with strain g10 suspension (10⁸ cfu/ml), significantly (P<0.05) reduced wilt severity when the plantlets were inoculated with 10⁴ spores/ml Foc race 4. The final disease severity index for leaf symptom (LSI) and rhizome discoloration (RDI) was reduced about 47 and 53%, respectively, in strain g10-treated plantlets compared to untreated plantlets. Reduction in disease incidence was not significant (P<0.05) when plantlets were inoculated with a higher concentration (10⁶ spores/ml) of Foc race 4. Rhizosphere population of strain g10 showed significant (P=0.05) increase of more than 2-fold at the end of the 3rd week compared to the 2nd week after soil amendment with the antagonist. Although the level dropped, the rhizosphere population at the end of the 6th week was still nearly 2-fold higher than the level detected after 2 weeks. In contrast, the root-free population declined significantly (P=0.05), nearly 4-fold after 6 weeks when compared to the level detected after 2 weeks. Neither growth-inhibiting nor growth-stimulating effects were observed in plantlets grown in strain g10-amended soil.     

Emerging views on integrin signaling via Rac1 during invasin-promoted bacterial uptake

Enteropathogenic Yersinia species encode invasin, which promotes uptake into host cells by binding beta1 integrins. Invasin may cluster integrin heterodimers extracellularly and cause the integrin alpha and beta chains to splay apart in the cytoplasm. Cdc42 signaling is not essential for Yersinia uptake, whereas invasin crucially triggers Rac1-mediated signals that enable internalization. The signals linking invasin-mediated adhesion to Rac1 activation are not clear, but a novel kinase may release it from RhoGDI so that Rac1 can be activated, for example by Dock180. Rac1 may act via Arp2/3, phosphatidylinositol 4,5-bisphosphate and capping-proteins in the formation of nascent phagosomes during Yersinia uptake.