Regulation of vascular smooth muscle cell calcification by syndecan-4/FGF-2/PKCα signaling and cross-talk with TGFβ

Aims: Vascular calcification is a major cause of morbidity and mortality. Fibroblast growth factor-2 (FGF-2) plays an instructive role in osteogenesis and bone development, but its role in vascular calcification was unknown. Therefore, we investigated the involvement of FGF-2 in vascular calcification and determined the mechanism by which it regulates this process. Methods and Results: We demonstrate that FGF-2 expression is increased in vascular smooth muscle cells (VSMCs) induced to deposit a mineralized matrix by incubation with β-glycerophosphate. FGF-2 is also localized to sites of calcification within human atherosclerotic plaques. The expression of syndecan-4, a heparan sulfate proteoglycan which regulates FGF-2 signaling, is also increased in mineralizing VSMCs and co-localizes with FGF-2 in human calcified atherosclerotic plaques. Exogenous FGF-2 inhibits VSMC mineralization, and this inhibition is reduced when syndecan-4 expression is knocked-down using siRNA. Biochemical inhibition of FGFR signaling using a pan FGFR inhibitor (BGJ398) or knocking-down syndecan-4 expression in VSMCs using siRNA increases VSMC mineralization. These increases are prevented by inhibiting transforming growth factor-β (TGFβ) signaling with SB431542, suggesting cross-talk between FGF-2 and TGFβ signaling is crucial for the regulation of VSMC mineralization. Syndecan-4 can also regulate FGF-2 signaling directly via protein kinase Cα (PKCα) activation. Biochemical inhibition of PKCα activity using Gö6976, or siRNA-mediated suppression of PKCα expression increases VSMC mineralization; this increase is also prevented with SB431542. Finally, the ability of FGF-2 to inhibit VSMC mineralization is reduced when PKCα expression is knocked-down. Conclusion: This is the first demonstration that syndecan-4 promotes FGF-2 signaling, and in turn, suppresses VSMC mineralization by down-regulating TGFβ signaling. Our discoveries that FGF-2 and syndecan-4 expression is increased in mineralizing VSMCs and that PKCα regulates FGF-2 and TGFβ signaling in VSMCs suggests that the syndecan-4/FGF-2/TGFβ signaling axis could represent a new therapeutic target for vascular calcification

The optical properties of evaporated gold in the vacuum ultraviolet from 300 Å to 2 000 Å

The reflectance and optical constants of evaporated gold films were measured in the vacuum ultraviolet from 300 Å to 2 000 Å. The optical constants were determined from reflectance measurements made at various angles of incidence. In contrast to aluminium, gold shows little change in reflectance after deposition in vacuum and during exposure to air. Due to interference, semitransparent films of about 150 Å on glass show the highest reflectance at most wavelengths in the vacuum ultraviolet.On a mesuré les facteurs de réflexion de couches d'or, obtenues par évaporation, dans l'ultraviolet de 300 à 2 000 Å. On a déduit les constantes optiques des mesures de facteur de réflexion effectuées pour différents angles d'incidence. Contrairement à ce qui se passe pour l'aluminium, le facteur de réflexion de couches d'or préparées sous vide varie peu au cours de leur exposition à l'air. Des couches semi transparentes, d'une épaisseur voisine de 150 Å, présentent des maximums de réflexion, dus à des phénomènes d'interférence, pour de nombreuses longueurs d'onde de l'ultraviolet lointain

Comparative quantification of the surfaceome of human multipotent mesenchymal progenitor cells

SummaryMesenchymal progenitor cells have great therapeutic potential, yet incomplete characterization of their cell-surface interface limits their clinical exploitation. We have employed subcellular fractionation with quantitative discovery proteomics to define the cell-surface interface proteome of human bone marrow mesenchymal stromal/stem cells (MSCs) and human umbilical cord perivascular cells (HUCPVCs). We compared cell-surface-enriched fractions from MSCs and HUCPVCs (three donors each) with adult mesenchymal fibroblasts using eight-channel isobaric-tagging mass spectrometry, yielding relative quantification on >6,000 proteins with high confidence. This approach identified 186 upregulated mesenchymal progenitor biomarkers. Validation of 10 of these markers, including ROR2, EPHA2, and PLXNA2, confirmed upregulated expression in mesenchymal progenitor populations and distinct roles in progenitor cell proliferation, migration, and differentiation. Our approach has delivered a cell-surface proteome repository that now enables improved selection and characterization of human mesenchymal progenitor populations

Molecular diagnosis of Pneumocystis pneumonia in dogs

Pneumocystis pneumonia (PCP) is a life-threatening fungal disease that can occur in dogs. The aim of this study was to provide a preliminary genetic characterisation of Pneumocystis carinii f. sp. 'canis' (P. canis) in dogs and thereby develop a reliable molecular protocol to definitively diagnose canine PCP. We investigated P. canis in a variety of lung specimens from dogs with confirmed or strongly suspected PCP (Group 1, n = 16), dogs with non-PCP lower respiratory tract problems (Group 2, n = 65) and dogs not suspected of having PCP or other lower respiratory diseases (Group 3, n = 11). Presence of Pneumocystis DNA was determined by nested PCR of the large and small mitochondrial subunit rRNA loci and by a real-time quantitative polymerase chain reaction (qPCR) assay developed using a new set of primers. Molecular results were correlated with the presence of Pneumocystis morphotypes detected in cytological/histological prepa rations. Pneumocystis DNA was amplified from 13/16 PCP-suspected dogs (Group 1) and from 4/76 dogs of control Groups 2 and 3 (combined). The latter four dogs were thought to have been colonized by P. canis. Comparison of C-T values in 'infected' versus 'colonized' dogs was consistent with this notion, with a distinct difference in molecular burden between groups (C-T <= 26 versus C-T range (26 < C-T < 35), respectively). Phylogenetic analyses showed that P. canis is specifically 'canine' associated, being separated from other mammalian Pneumocystis species, thereby confirming the accuracy of qPCR amplicon for Pneumocystis in dogs. Using qPCR, Pneumocystis DNA can be detected in specimens from the respiratory tract and a C-T value can be interpreted to distinguish infection versus colonization

SOFT X-RAY ABSORPTION AND EMISSION SPECTRA AND THE ELECTRONIC STRUCTURE OF THE Ba2 YCu3 O7-x SUPERCONDUCTOR

Nous présentons des spectres d'émission dans les X mous, du Ba2YCu3O7-x supraconducteur, excité par des faisceaux d'électrons, ainsi que les spectres du rendement total de photoélectrons du même materiau excité par des photons d'énergie comprise entre 20 et 600 eV. Nous confirmons, par la mesure de ce rendement, que le cuivre a une valence +2 dans ce composé. L'émission de rayons X mous fourni, par l'étude du spectre N4,5 du barium, du spectre M4,5 de l'yttrium et du spectre K de l'oxygène, une mesure de la densité d'états partielle de type p (p-PDOS) localisée sur chacun des sites atomiques respectifs. Dans chaque cas cette densité d'états est très petite à l'énergie de Fermi, et a un premier pic situé entre 3.5 et 4 eV en dessous du niveau de Fermi. L'étude du spectre K de l'oxygène confirme l'interprétation selon laquelle les structures observées dans les mesures de photoémission sont associées aux orbitales 2p de l'oxygène. Enfin nous n'avons observé aucun changement entre les spectres enregistré au dessus ou au dessous de la température critique Tc.We present e-beam excited soft x-ray emission spectra and total photoelectron yield spectra in the 20-600 eV photon energy range for the Ba2YCu3O7-x superconductor. We confirm the 2+ valency of Cu in the compound by total yield measurements. In soft x-ray emission, the N4.5 spectrum of Ba, the M4,5 spectrum of Y, and the K spectrum of O provide measures of the p-type partial density of states (p-PDOS) localized on the respective atomic sites. In each case the p-PDOS is very small at the Fermi energy with the first peak in the p-PDOS lying 3.5 to 4 eV below the Fermi energy. The K spectra of O confîrm the interpretation that the structure observed in the photoemission measurements are associated with the O 2p orbitals. Finally no changes are observed between spectra taken above and below Tc

Impact of Cultivation Legacies on Rehabilitation Seedings and Native Species Re-Establishment in Great Basin Shrublands

Little is known about how cultivation legacies affect the outcome of rehabilitation seedings in the Great Basin, even though both frequently co-occur on the same lands. Similarly, there is little known about how these legacies affect native species re-establishment into these seedings. We examined these legacy effects by comparing areas historically cultivated and seeded to adjacent areas that were seeded but never cultivated, for density of seeded crested wheatgrass (Agropyron cristatum [L.] Gaertn.) and native perennial grasses, vegetation cover, and ground cover. At half of the sites, historically cultivated areas had lower crested wheatgrass density (P<0.05), and only one site had a higher density of crested wheatgrass (P<0.05). Likewise, the native shrub Wyoming big sagebrush (Artemisia tridentata Nutt. subsp. wyomingensis Beetle & Young) had lower cover (P<0.05) in historically cultivated areas at half the sites. Sandberg bluegrass (Poa secunda J. Presl.) density was consistently lower in historically cultivated areas relative to those seeded-only. At sites where black greasewood (Sarcobatus vermiculatus [Hook.] Torr.) and bottlebrush squirreltail (Elymus elymoides [Raf.] Swezey) were encountered, there was either no difference or a higher density and cover within historically cultivated areas (P<0.05). Likewise, cover of exotic forbs, especially halogeton (Halogeton glomeratus [M. Bieb.] C. A. Mey.), was either not different or higher in historically cultivated areas (P<0.05). Bare ground was greater in historically cultivated areas at three sites (P<0.05). These results suggest that cultivation legacies can affect seeding success and re-establishment of native vegetation, and therefore should not be overlooked when selecting research sites or planning land treatments that include seeding and or management to achieve greater native species diversity.The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information