Exposure of human renal proximal tubular cells to glucose leads to accumulation of type IV collagen and fibronectin by decreased degradation

Exposure of human renal proximal tubular cells to glucose leads to accumutation of type IV collagen and fibronectin by decreased degradation. Thickening and reduplication of the tubular basement membrane has been reported as an early event in diabetic nephropathy. In the current study we examined the effects of elevated D-glucose concentrations on human proximal tubular (HPTC) type IV collagen and fibronectin turnover. Incubation of confluent growth arrested HPTC with 25mM D-glucose led to accumulation of both type IV collagen and fibronectin. This effect was maximal at 48 hours and represented a sevenfold increase for fibronectin (N = 4, P = 0.04), and a threefold increase for type IV collagen (N = 3, P = 0.03) over cells exposed to 5mM D-glucose controls. This increase was not dependent on new gene transcription for either protein. Tissue inhibitor of metalloproteinases (TIMP 1 + TIMP 2) were induced following addition of 25mM D-glucose, but not when cells were exposed to 5mM D-glucose. Twenty-four hours after the addition of 25mM D-glucose there was an eightfold increase in TIMP 1 (P = 0.009, N = 4), and a tenfold increase in TIMP 2 levels (P = 0.003, N = 4), over the control values for both inhibitors. The increase in both TIMP 1 and TIMP 2 in response to 25mM D-glucose was abrogated in a dose dependent manner by the aldose reductase inhibitor sorbinil. Gelatin-substrate gel zymography showed increased activity of gelatinase A, but not of gelatinase B in response to the addition of 25mM D-glucose to HPTC. The induction of gelatinase A was accompanied by increased gelatinase A mRNA expression, which was inhibited both by protein kinase C (PKC) depletion using PMA pre-treatment, and by the addition of a PKC inhibitor. These data demonstrate that the glucose-induced accumulation of type IV collagen and fibronectin is unrelated to increased gene transcription, but may involve alterations in the degradative pathway of these basement membrane constituents. Furthermore, the data demonstrate that glucose may simultaneously activate two intracellular pathways (the polyol pathway and a PKC dependent activation pathway), which are involved in mediating separate, complementary effects on cell function

Deep GALEX Imaging of the HST/COSMOS Field: A First Look at the Morphology of z~0.7 Star-forming Galaxies

We present a study of the morphological nature of redshift z~0.7 star-forming galaxies using a combination of HST/ACS, GALEX and ground-based images of the COSMOS field. Our sample consists of 8,146 galaxies, 5,777 of which are detected in the GALEX near-ultraviolet band down to a limiting magnitude of 25.5 (AB). We make use of the UV to estimate star formation rates, correcting for the effect of dust using the UV-slope, and compute, from the ACS F814W images, the C,A,S,G,M20 morphological parameters for all objects in our sample. We observe a morphological bimodality in the galaxy population and show that it has a strong correspondence with the FUV - g color bimodality. We conclude that UV-optical color predominantly evolves concurrently with morphology. We observe many of the most star-forming galaxies to have morphologies approaching that of early-type galaxies, and interpret this as evidence that strong starburst events are linked to bulge growth and constitute a process through which galaxies can be brought from the blue to the red sequence while simultaneously modifying their morphology accordingly. We conclude that the red sequence has continued growing at z~<0.7. We also observe z~0.7 galaxies to have physical properties similar to that of local galaxies, except for higher star formation rates. Whence we infer that the dimming of star-forming galaxies is responsible for most of the evolution in the star formation rate density of the Universe since that redshift, although our data are also consistent with a mild number evolution. [abridged]Comment: 29 pages including 22 figures. Accepted for publication in ApJS COSMOS Special Issue. A copy of the paper with high resolution figures is available at http://www.astro.columbia.edu/~michel/galex_cosmos_paper.pd

Revision and Update of the Consensus Definitions of Invasive Fungal Disease From the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium.

BACKGROUND: Invasive fungal diseases (IFDs) remain important causes of morbidity and mortality. The consensus definitions of the Infectious Diseases Group of the European Organization for Research and Treatment of Cancer and the Mycoses Study Group have been of immense value to researchers who conduct clinical trials of antifungals, assess diagnostic tests, and undertake epidemiologic studies. However, their utility has not extended beyond patients with cancer or recipients of stem cell or solid organ transplants. With newer diagnostic techniques available, it was clear that an update of these definitions was essential. METHODS: To achieve this, 10 working groups looked closely at imaging, laboratory diagnosis, and special populations at risk of IFD. A final version of the manuscript was agreed upon after the groups' findings were presented at a scientific symposium and after a 3-month period for public comment. There were several rounds of discussion before a final version of the manuscript was approved. RESULTS: There is no change in the classifications of "proven," "probable," and "possible" IFD, although the definition of "probable" has been expanded and the scope of the category "possible" has been diminished. The category of proven IFD can apply to any patient, regardless of whether the patient is immunocompromised. The probable and possible categories are proposed for immunocompromised patients only, except for endemic mycoses. CONCLUSIONS: These updated definitions of IFDs should prove applicable in clinical, diagnostic, and epidemiologic research of a broader range of patients at high-risk

Crossing the Dripline to 11N Using Elastic Resonance Scattering

The level structure of the unbound nucleus 11N has been studied by 10C+p elastic resonance scattering in inverse geometry with the LISE3 spectrometer at GANIL, using a 10C beam with an energy of 9.0 MeV/u. An additional measurement was done at the A1200 spectrometer at MSU. The excitation function above the 10C+p threshold has been determined up to 5 MeV. A potential-model analysis revealed three resonance states at energies 1.27 (+0.18-0.05) MeV (Gamma=1.44 +-0.2 MeV), 2.01(+0.15-0.05) MeV, (Gamma=0.84 +-$0.2 MeV) and 3.75(+-0.05) MeV, (Gamma=0.60 +-0.05 MeV) with the spin-parity assignments I(pi) =1/2+, 1/2- and 5/2+, respectively. Hence, 11N is shown to have a ground state parity inversion completely analogous to its mirror partner, 11Be. A narrow resonance in the excitation function at 4.33 (+-0.05) MeV was also observed and assigned spin-parity 3/2-.Comment: 14 pages, 9 figures, twocolumn Accepted for publication in PR

Multiple dose-dependent roles for Sox2 in the patterning and differentiation of anterior foregut endoderm

Sox2 is expressed in developing foregut endoderm, with highest levels in the future esophagus and anterior stomach. By contrast, Nkx2.1 (Titf1) is expressed ventrally, in the future trachea. In humans, heterozygosity for SOX2 is associated with anopthalmiaesophageal-genital syndrome (OMIM 600992), a condition including esophageal atresia (EA) and tracheoesophageal fistula (TEF), in which the trachea and esophagus fail to separate. Mouse embryos heterozygous for the null allele, Sox2EGFP, appear normal. However, further reductions in Sox2, using Sox2LP and Sox2COND hypomorphic alleles, result in multiple abnormalities. Approximately 60% of Sox2EGFP/COND embryos have EA with distal TEF in which Sox2 is undetectable by immunohistochemistry or western blot. The mutant esophagus morphologically resembles the trachea, with ectopic expression of Nkx2.1, a columnar, ciliated epithelium, and very few p63+ basal cells. By contrast, the abnormal foregut of Nkx2.1-null embryos expresses elevated Sox2 and p63, suggesting reciprocal regulation of Sox2 and Nkx2.1 during early dorsal/ventral foregut patterning. Organ culture experiments further suggest that FGF signaling from the ventral mesenchyme regulates Sox2 expression in the endoderm. In the 40% Sox2EGFP/COND embryos in which Sox2 levels are ~18% of wild type there is no TEF. However, the esophagus is still abnormal, with luminal mucus-producing cells, fewer p63+ cells, and ectopic expression of genes normally expressed in glandular stomach and intestine. In all hypomorphic embryos the forestomach has an abnormal phenotype, with reduced keratinization, ectopic mucus cells and columnar epithelium. These findings suggest that Sox2 plays a second role in establishing the boundary between the keratinized, squamous esophagus/forestomach and glandular hindstomach

FGF Signaling Pathway in the Developing Chick Lung: Expression and Inhibition Studies

Background: Fibroblast growth factors (FGF) are essential key players during embryonic development. Through their specific cognate receptors (FGFR) they activate intracellular cascades, finely regulated by modulators such as Sprouty. Several FGF ligands (FGF1, 2, 7, 9, 10 and 18) signaling through the four known FGFRs, have been implicated in lung morphogenesis. Although much is known about mammalian lung, so far, the avian model has not been explored for lung studies. Methodology/Principal Findings: In this study we provide the first description of fgf10, fgfr1-4 and spry2 expression patterns in early stages of chick lung development by in situ hybridization and observe that they are expressed similarly to their mammalian counterparts. Furthermore, aiming to determine a role for FGF signaling in chick lung development, in vitro FGFR inhibition studies were performed. Lung explants treated with an FGF receptor antagonist (SU5402) presented an impairment of secondary branch formation after 48 h of culture; moreover, abnormal lung growth with a cystic appearance of secondary bronchi and reduction of the mesenchymal tissue was observed. Branching and morphometric analysis of lung explants confirmed that FGFR inhibition impaired branching morphogenesis and induced a significant reduction of the mesenchyme. Conclusions/Significance: This work demonstrates that FGFRs are essential for the epithelial-mesenchymal interactions tha

GATA6 Activates Wnt Signaling in Pancreatic Cancer by Negatively Regulating the Wnt Antagonist Dickkopf-1

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease characterized by late diagnosis and treatment resistance. Recurrent genetic alterations in defined genes in association with perturbations of developmental cell signaling pathways have been associated with PDAC development and progression. Here, we show that GATA6 contributes to pancreatic carcinogenesis during the temporal progression of pancreatic intraepithelial neoplasia by virtue of Wnt pathway activation. GATA6 is recurrently amplified by both quantitative-PCR and fluorescent in-situ hybridization in human pancreatic intraepithelial neoplasia and in PDAC tissues, and GATA6 copy number is significantly correlated with overall patient survival. Forced overexpression of GATA6 in cancer cell lines enhanced cell proliferation and colony formation in soft agar in vitro and growth in vivo, as well as increased Wnt signaling. By contrast siRNA mediated knockdown of GATA6 led to corresponding decreases in these same parameters. The effects of GATA6 were found to be due to its ability to bind DNA, as forced overexpression of a DNA-binding mutant of GATA6 had no effects on cell growth in vitro or in vivo, nor did they affect Wnt signaling levels in these same cells. A microarray analysis revealed the Wnt antagonist Dickopf-1 (DKK1) as a dysregulated gene in association with GATA6 knockdown, and direct binding of GATA6 to the DKK1 promoter was confirmed by chromatin immunoprecipitation and electrophoretic mobility shift assays. Transient transfection of GATA6, but not mutant GATA6, into cancer cell lines led to decreased DKK1 mRNA expression and secretion of DKK1 protein into culture media. Forced overexpression of DKK1 antagonized the effects of GATA6 on Wnt signaling in pancreatic cancer cells. These findings illustrate that one mechanism by which GATA6 promotes pancreatic carcinogenesis is by virtue of its activation of canonical Wnt signaling via regulation of DKK1

The varied roles of nuclear receptors during vertebrate embryonic development

Nuclear receptors comprise a superfamily of sequence-specific transcription factors whose members have diverse roles during development. This review will summarize the developmental roles of selected members of the nuclear receptor superfamily

Genome-Wide Analyses of Nkx2-1 Binding to Transcriptional Target Genes Uncover Novel Regulatory Patterns Conserved in Lung Development and Tumors

The homeodomain transcription factor Nkx2-1 is essential for normal lung development and homeostasis. In lung tumors, it is considered a lineage survival oncogene and prognostic factor depending on its expression levels. The target genes directly bound by Nkx2-1, that could be the primary effectors of its functions in the different cellular contexts where it is expressed, are mostly unknown. In embryonic day 11.5 (E11.5) mouse lung, epithelial cells expressing Nkx2-1 are predominantly expanding, and in E19.5 prenatal lungs, Nkx2-1-expressing cells are predominantly differentiating in preparation for birth. To evaluate Nkx2-1 regulated networks in these two cell contexts, we analyzed genome-wide binding of Nkx2-1 to DNA regulatory regions by chromatin immunoprecipitation followed by tiling array analysis, and intersected these data to expression data sets. We further determined expression patterns of Nkx2-1 developmental target genes in human lung tumors and correlated their expression levels to that of endogenous NKX2-1. In these studies we uncovered differential Nkx2-1 regulated networks in early and late lung development, and a direct function of Nkx2-1 in regulation of the cell cycle by controlling the expression of proliferation-related genes. New targets, validated in Nkx2-1 shRNA transduced cell lines, include E2f3, Cyclin B1, Cyclin B2, and c-Met. Expression levels of Nkx2-1 direct target genes identified in mouse development significantly correlate or anti-correlate to the levels of endogenous NKX2-1 in a dosage-dependent manner in multiple human lung tumor expression data sets, supporting alternative roles for Nkx2-1 as a transcriptional activator or repressor, and direct regulator of cell cycle progression in development and tumors