3,648 research outputs found
Extracellular Matrix Heterogeneity Regulates Three-Dimensional Morphologies of Breast Adenocarcinoma Cell Invasion
Plasticity and reciprocity of breast cancer cells to various extracellular matrice (ECMs) are three-dimensionally analyzed in quantitative way in a novel and powerful microfluidic in vitro platform. This successfully demonstrates the metastatic potential of cancer cells and their effective strategies of ECM proteolytic remodeling and morphological change, while interacting with other cells and invading into heterogeneous ECMs.International Research & Development Program (Grant 2009-00631)National Research Foundation of Korea (Basic Science Research Program Grant 2012-022481
Lipocalin 2 is protective against E. coli pneumonia
<p>Abstract</p> <p>Background</p> <p>Lipocalin 2 is a bacteriostatic protein that binds the siderophore enterobactin, an iron-chelating molecule produced by <it>Escherichia coli </it>(<it>E. coli</it>) that is required for bacterial growth. Infection of the lungs by <it>E. coli </it>is rare despite a frequent exposure to this commensal bacterium. Lipocalin 2 is an effector molecule of the innate immune system and could therefore play a role in hindering growth of <it>E. coli </it>in the lungs.</p> <p>Methods</p> <p>Lipocalin 2 knock-out and wild type mice were infected with two strains of <it>E. coli</it>. The lungs were removed 48 hours post-infection and examined for lipocalin 2 and MMP9 (a myeloid marker protein) by immunohistochemical staining and western blotting. Bacterial numbers were assessed in the lungs of the mice at 2 and 5 days after infection and mortality of the mice was monitored over a five-day period. The effect of administering ferrichrome (an iron source that cannot be bound by lipocalin 2) along with E.coli was also examined.</p> <p>Results</p> <p>Intratracheal installation of <it>E. coli </it>in mice resulted in strong induction of lipocalin 2 expression in bronchial epithelium and alveolar type II pneumocytes. Migration of myeloid cells to the site of infection also contributed to an increased lipocalin 2 level in the lungs. Significant higher bacterial numbers were observed in the lungs of lipocalin 2 knock-out mice on days 2 and 5 after infection with <it>E. coli </it>(p < 0.05). In addition, a higher number of <it>E. coli </it>was found in the spleen of surviving lipocalin 2 knock-out mice on day 5 post-infection than in the corresponding wild-type mice (p < 0.05). The protective effect against <it>E. coli </it>infection in wild type mice could be counteracted by the siderophore ferrichrome, indicating that the protective effect of lipocalin 2 depends on its ability to sequester iron.</p> <p>Conclusions</p> <p>Lipocalin 2 is important for protection of airways against infection by <it>E. coli</it>.</p
Loss of the integrin-activating transmembrane protein Fam38A (Piezo1) promotes a switch to a reduced integrin-dependent mode of cell migration
Lung cancer is one of the most common fatal diseases in the developed world. The disease is rarely cured by currently available therapies, with an overall survival rate of ∼10%. Characterizing novel proteins that offer crucial insights into the processes of lung tumour invasion and metastasis may therefore provide much-needed prognostic markers, and influence therapeutic strategies. Aberrant function of the integrin family of heterodimeric cell surface receptors is a common theme in cancer--investigation into novel integrin activity regulators may offer crucial insights into the processes of tumour invasion and metastasis and may reveal insights into potential therapeutic targets. We previously described that depletion of the novel multi-transmembrane domain protein Fam38A, located at the endoplasmic reticulum (ER), inactivates endogenous beta1 integrin affinity, reducing cell adhesion. We now show that depletion of Fam38A, also now known as Piezo1, causes anchorage independence and a switch to a reduced integrin-dependent mode of cell migration/invasion, a novel phenotype for this integrin-regulating protein. Normal lung epithelial cells show increased rates of migration by 2D time-lapse microscopy and increased capacity to invade into matrigel, despite having decreased integrin affinity. We confirm greatly depleted Fam38A expression in small cell lung cancer (SCLC) lines where a form of reduced integrin-dependent migration, i.e. amoeboid migration, is a known phenotype. We propose that loss of Fam38A expression may cause increased cell migration and metastasis in lung tumours
Trends in Winter Warm Spells in the Central England Temperature Record
An important impact of climate change on agriculture and the sustainability of ecosystems is the increase of extended warm spells during winter. We apply crossing theory to the central England temperature time series of winter daily maximum temperatures to quantify how increased occurrence of higher temperatures translates into more frequent, longer-lasting, and more intense winter warm spells. We find since the late 1800s an overall two- to threefold increase in the frequency and duration of winter warm spells. A winter warm spell of 5 days in duration with daytime maxima above 13°C has a return period that was often over 5 years but now is consistently below 4 years. Weeklong warm intervals that return on average every 5 years now consistently exceed ~13°C. The observed changes in the temporal pattern of environmental variability will affect the phenology of ecological processes and the structure and functioning of ecosystems
Interstitial cell migration: integrin-dependent and alternative adhesion mechanisms
Adhesion and migration are integrated cell functions that build, maintain and remodel the multicellular organism. In migrating cells, integrins are the main transmembrane receptors that provide dynamic interactions between extracellular ligands and actin cytoskeleton and signalling machineries. In parallel to integrins, other adhesion systems mediate adhesion and cytoskeletal coupling to the extracellular matrix (ECM). These include multifunctional cell surface receptors (syndecans and CD44) and discoidin domain receptors, which together coordinate ligand binding with direct or indirect cytoskeletal coupling and intracellular signalling. We review the way that the different adhesion systems for ECM components impact cell migration in two- and three-dimensional migration models. We further discuss the hierarchy of these concurrent adhesion systems, their specific tasks in cell migration and their contribution to migration in three-dimensional multi-ligand tissue environments
Global data for ecology and epidemiology: a novel algorithm for temporal Fourier processing MODIS data
Background. Remotely-sensed environmental data from earth-orbiting satellites are increasingly used to model the distribution and abundance of both plant and animal species, especially those of economic or conservation importance. Time series of data from the MODerate-resolution Imaging Spectroradiometer (MODIS) sensors on-board NASA's Terra and Aqua satellites offer the potential to capture environmental thermal and vegetation seasonality, through temporal Fourier analysis, more accurately than was previously possible using the NOAA Advanced Very High Resolution Radiometer (AVHRR) sensor data. MODIS data are composited over 8- or 16-day time intervals that pose unique problems for temporal Fourier analysis. Applying standard techniques to MODIS data can introduce errors of up to 30% in the estimation of the amplitudes and phases of the Fourier harmonics. Methodology/Principal Findings. We present a novel spline-based algorithm that overcomes the processing problems of composited MODIS data. The algorithm is tested on artificial data generated using randomly selected values of both amplitudes and phases, and provides an accurate estimate of the input variables under all conditions. The algorithm was then applied to produce layers that capture the seasonality in MODIS data for the period from 2001 to 2005. Conclusions/Significance. Global temporal Fourier processed images of 1 km MODIS data for Middle Infrared Reflectance, day- and night-time Land Surface Temperature (LST), Normalised Difference Vegetation Index (NDVI), and Enhanced Vegetation Index (EVI) are presented for ecological and epidemiological applications. The finer spatial and temporal resolution, combined with the greater geolocational and spectral accuracy of the MODIS instruments, compared with previous multi-temporal data sets, mean that these data may be used with greater confidence in species' distribution modelling
Eruptive papules during efalizumab (anti-CD11a) therapy of psoriasis vulgaris: a case series
BACKGROUND: Newer biological therapies for moderate-to-severe psoriasis are being used more frequently, but unexpected effects may occur. CASE PRESENTATIONS: We present a group of 15 patients who developed inflammatory papules while on efalizumab therapy (Raptiva, Genentech Inc, anti-CD11a). Immunohistochemistry showed that there were increased CD11b(+), CD11c(+ )and iNOS(+ )cells (myeloid leukocytes) in the papules, with relatively few CD3(+ )T cells. While efalizumab caused a decreased expression of CD11a on T cells, other circulating leukocytes from patients receiving this therapy often showed increased CD11b and CD11c. In the setting of an additional stimulus such as skin trauma, this may predispose to increased trafficking into the skin using these alternative β2 integrins. In addition, there may be impaired immune synapse formation, limiting the development of these lesions to small papules. There is little evidence for these papular lesions being "allergic" in nature as there are few eosinophils on biopsy, and they respond to minimal or no therapy even if efalizumab is continued. CONCLUSION: We hypothesize that these papules may represent a unique type of "mechanistic" inflammatory reaction, seen only in the context of drug-induced CD11a blockade, and not during the natural disease process
Attachment of HeLa cells during early G1 phase
Both growth factor directed and integrin dependent signal transduction were shown to take place directly after completion of mitosis. The local activation of these signal transduction cascades was investigated in early G1 cells. Interestingly, various key signal transduction proteins were found in blebs at the cell membrane within 30 min after mitosis. These membrane blebs appeared in round, mitotic-like cells and disappeared rapidly during spreading of the cells in G1 phase. In addition to tyrosine-phosphorylated proteins, the blebs contained also phosphorylated FAK and phosphorylated MAP kinase. The formation of membrane blebs in round, mitotic cells before cell spreading is not specific for mitotic cells, because similar features were observed in trypsinized cells. Just before cell spreading also these cells exhibited membrane blebs containing active signal transduction proteins. Inhibition of signal transduction did not affect membrane bleb formation, suggesting that the membrane blebs were formed independent of signal transduction
Reelin Is Involved in Transforming Growth Factor-β1-Induced Cell Migration in Esophageal Carcinoma Cells
Reelin (RELN), which is a glycoprotein secreted by Cajal-Retzius cells of the developing cerebral cortex, plays an important role in neuronal migration, but its role in cell migration and cancer metastasis is largely unclear. Here, we showed that cell motility was significantly increased in KYSE-510 cells by TGF-β1 treatment. Moreover, TGF-β1 decreased RELN mRNA expression and overexpression of Reelin at least partly reversed TGF-β1-induced cell migration in KYSE-30 cells. Furthermore, this negative regulation of Reelin expression by TGF-β1 was through Snail, one transcription factor which was induced by TGF-β1 in KYSE-510 cells. RELN promoter activity was reduced in parallel with the induction of Snail after TGF-β1 treatment and Snail suppressed both RELN promoter activity and expression through binding to E-box sequences in the RELN promoter region in ESCC cells. Knockdown of RELN induced cell migration in KYSE-510 cells, together with the increase of mesenchymal markers expression. Taken together, Reelin is an essential negative regulator in the TGF-β1-induced cell migration process, and is suppressed by TGF-β pathway at the transcriptional level through Snail regulation. Therefore, the correlation of Reelin and TGF-β pathway was critical in cancer metastasis, and Reelin could be one potential anti-metastasis target in future clinical practice
Threshold effect of foreign direct investment on environmental degradation
The aim of this paper is to investigate the threshold effect of foreign direct investment (FDI) on environmental degradation. In empirical analysis, FDI and environmental degradation are jointly determined under the given threshold variable and other exogenous variables. Using carbon dioxide (CO2) emissions per capita as a proxy for environmental degradation, the results show that increasing FDI worsens CO2 emissions after a threshold level of corruption has been reached. Our results demonstrate that increasing FDI will increase CO2 emissions when the degree of corruptibility is relatively high. The study suggests that further FDI and improved environmental quality are competing rather than compatible objectives in high-corruption countries and are compatible rather than competing objectives in low-corruption countries. Higher trade liberalization in low-corruption countries could contribute to negative environmental consequences because of the increased output or economic activity which results from increased trade. The robustness estimation confirms the evidence that pollution and economic development increase together up to a certain income level, after which the trend reverses.info:eu-repo/semantics/publishedVersio
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