Comp Biochem Physiol C Toxicol Pharmacol
September 2010
Sessile organisms may experience chronic exposure to copper that is released into the marine environment from antifoulants and stormwater runoff. We have identified the site of damage caused by copper to the symbiotic cnidarian, Zoanthus robustus (Anthozoa, Hexacorallia). External changes to the zoanthids were apparent when compared with controls.
View Article and Find Full Text PDFA series of biaxial V-shaped, shape-persistent molecules has been synthesised by stepwise coupling of phenylene ethynylene arms to an oxadiazole bending unit. Studies of their thermotropic nematic phases point to phase biaxiality.
View Article and Find Full Text PDFHuman skin fibroblasts efficiently internalize the matrikine decorin by receptor-mediated endocytosis, however, very little is known about its intracellular trafficking routes up to lysosomal degradation. In an in vitro system measuring uptake and degradation of [(35)S]sulfate-labeled decorin, endocytosis was blocked by 46% when clathrin assembly/disassembly was inhibited using chlorpromazine. Pharmacological inhibition of EGF receptor signaling caused 34% reduction of decorin uptake, whereas inhibition of the IGF receptor had no effect.
View Article and Find Full Text PDFEur Phys J E Soft Matter
December 2006
Three homologous achiral five-ring bent-core mesogens are presented where 4-chlororesorcinol is the central core and the aromatic rings are linked by ester groups. These compounds form smectic phases with a tilted arrangement of the molecules (tilt angle approximately 45 degrees). On cooling the isotropic liquid this phase adopts a fan-like texture which shows for two homologues at relatively high electric fields ( 25-35 V microm(-1)) an antiferroelectric electro-optical response based on the collective rotation of the molecules around their long axes.
View Article and Find Full Text PDFA novel class of bent-core molecules with oligo(siloxane) or carbosilane units at both ends was synthesized and the self-organization of these molecules was investigated by polarizing microscopy, DSC, X-ray scattering, dielectric and electrooptical methods. Depending on the size of the silicon-containing segments, smectic and columnar liquid crystalline phases are formed. Most smectic phases are low birefringent and composed of macroscopic domains of opposite handedness (dark conglomerate phases).
View Article and Find Full Text PDFThree mesogenic dimers have been synthesized in which a five-ring bent-core moiety is connected with different calamitic units flexible spacers. The mesophase behavior of the dimers have been investigated by polarizing microscopy, differential scanning calorimetry, X-ray diffraction on oriented samples and by dielectric and electro-optical measurements. We found that two dimers exhibit a dimorphism columnar-nematic whereas the third one forms a columnar phase only.
View Article and Find Full Text PDFA combination of negative ion nano-electrospray ionization Fourier-transform ion cyclotron resonance and quadrupole time-of-flight mass spectrometry was applied to analysis of oversulfation in glycosaminoglycan oligosaccharides of the chondroitin sulfate type from bovine aorta. Taking advantage of the high-resolution and high mass accuracy provided by the FT-ICR instrument, a direct compositional assignment of all species present in the mixture can be obtained. An oligosaccharide fraction containing mainly hexasaccharides exhibited different levels of sulfation, indicated by the presence of species with regular sulfation pattern as well as oversulfated oligosaccharides with one additional sulfate group.
View Article and Find Full Text PDFThe influence of the direction of ester linkage groups on the structural and electronic properties of five-ring banana-shaped molecules with a central 1,3-phenylene unit has been investigated including hexyloxy and dodecyloxy terminal chains. DFT studies on the B3LYP/6-31G(d) level were performed on the conformational behaviour of the ten isomers in a systematic way. The one- and two-fold potential energy scans show that the flexibility of the wings significantly depends on the orientation of the carboxyl linkage groups.
View Article and Find Full Text PDFThe small leucine-rich proteoglycan (SLRP) decorin is efficiently internalized by a variety of cultured cells. A 51-kDa protein has previously been described as a receptor mediating endocytosis of decorin and of the structurally related SLRP biglycan. Recent findings suggest that endocytosis of SLRPs may also be mediated by additional receptors.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
May 2005
Linear dielectric relaxation studies performed on two isotropic liquids composed of the molecules of the same moment of inertia and a quite different polarity: C10H21-O-Ph-COO-Ph-CN (the dipole moment of about 5 D) and C10H21-O-Ph-OOC-Ph-CN (2.5 D) showed that, at given temperature, the relaxation times corresponding to the rotation around the short axis of the two kinds of molecules coincide to each other, regardless the polarity of the molecules and their abilities to accomplish dipolar aggregation. The studies allow one to estimate the lifetime of the intermolecular aggregates due to the dipolar interactions in liquids as no longer than 0.
View Article and Find Full Text PDFIn vivo cells exist in a three-dimensional environment generated and maintained by multiple cell-cell and cell-matrix interactions. Proteoglycans, like decorin, affect these complex interactions. Thus, we sought to investigate the role of decorin in a three-dimensional environment where the matrix was generated over time by decorin-deficient fibroblasts in the presence of L-ascorbic acid 2-phosphate.
View Article and Find Full Text PDFThe small dermatan sulfate proteoglycan decorin is involved in the regulation of collagen fibrillogenesis, cell adhesion and migration, and growth factor signaling. In a progeroid patient carrying two point mutations in beta4 galactosyltransferase I (beta4GalT-7) only 50% of the decorin core protein molecules are substituted with glycosaminoglycan chains. We expressed decorin, as well as wild-type and mutant alleles of beta4GalT-7 in galactosyltransferase-deficient CHO618 cells.
View Article and Find Full Text PDFScientificWorldJournal
November 2004
Bisdermican (PG760) is a large, heterodimeric, dermatan sulfate proteoglycan found in selected basement membranes, smooth muscle cell layers, and different extracellular matrices. Age-dependent and developmentally regulated alterations in glycosaminoglycan structure and quantity have been shown to be functionally relevant for a number of physiological and pathological processes. Bisdermican was purified from human skin fibroblast cultures of different age and confluency.
View Article and Find Full Text PDFSmall leucine-rich proteoglycans play important roles in the organization of the extracellular matrix as well as for the regulation of cell behavior; two biological processes that are essential for angiogenesis. We investigated consequences of the targeted ablation of decorin (DCN), biglycan (BGN) and fibromodulin (FMOD) genes on inflammation-induced angiogenesis in the cornea. In wild-type mice, DCN was localized exclusively to the corneal stroma, while FMOD and BGN were more prominently expressed in epithelial cells.
View Article and Find Full Text PDFThe small leucine-rich proteoglycan biglycan (BGN) is abundantly expressed in mesenchymal tissues. Its expression level is related to the phenotypic differentiation of cells. A dysregulation in BGN expression occurs under several pathological conditions, including glomerulonephritis, mesothelioma, pancreatic cancer and a mouse model of osteoporosis.
View Article and Find Full Text PDFThe small leucine-rich proteoglycan decorin can bind via its core protein to different types of collagens such as type I and type VI. To test whether decorin can act as a bridging molecule between these collagens, the binding properties of wild-type decorin, two full-length decorin species with single amino acid substitutions (DCN E180K, DCN E180Q), which previously showed reduced binding to collagen type I fibrils, and a truncated form of decorin (DCN Q153) to the these collagens were investigated. In a solid phase assay dissociation constants for wild-type decorin bound to methylated, therefore monomeric, triple helical type I collagen were in the order of 10(-10) m, while dissociation constants for fibrillar type I collagen were approximately 10(-9) m.
View Article and Find Full Text PDFA novel approach in glycosaminoglycomics, based on sheathless on-line capillary electrophoresis/nanoelectrospray ionization-quadrupole time of flight-mass spectrometry (CE/nanoESI-QTOF-MS) and tandem MS of extended chondroitin sulfate/dermatan (CS/DS) oligosaccharide chains is described. The methodology required the construction of a new sheathless CE/nanoESI-QTOF-MS configuration, its implementation and optimization for the high sensitivity analysis of CS/DS oligosaccharide mixtures from conditioned culture medium of decorin transfected human embryonic kidney (HEK) 293 cells. Under newly established sheathless on-line CE/(-)nanoESI conditions for glycosaminoglycan (GAG) ionization and MS detection, single CS/DS oligosaccharide components of extended chain length and increased sulfation degree were identified.
View Article and Find Full Text PDFObjective: Previous studies have shown that decorin and biglycan account for over 70% of the proteoglycans (PGs) synthesized by human peritoneal mesothelial cells (HPMCs). Since these PGs are involved in the control of cell growth, cell differentiation, and matrix assembly, we investigated their turnover in cultured HPMCs.
Methods: Confluent HPMCs were metabolically labeled with [35S]-sulfate and the labeled products isolated from the cell medium and the cell layer characterized by sensitivity to bacterial eliminases.
Decorin, a small multifunctional proteoglycan, is expressed by sprouting endothelial cells (ECs) during inflammation-induced angiogenesis in vivo and by human ECs co-cultured with fibroblasts in a collagen lattice. To investigate how decorin is induced, human EA.hy 926 ECs and/or human umbilical vein ECs were treated with interleukin (IL)-10 and IL-6.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
February 2004
Mesogenic compounds belonging to the two well-known -cyanophenyl, and -isothiocyanatophenyl homologous series, which distinctly differ in the molecular polarity (-C identical with N, 5D; -N=C=S, 2.5D), show an essential difference in the pretransitional dielectric behavior in the vicinity of the isotropic to nematic (I-N) phase transition. Taking into account the results presented in Phys.
View Article and Find Full Text PDFObjective: Endothelin-1 concentrations are increased in patients with increased mean pulmonary arterial pressure, pulmonary blood flow, and pulmonary vascular resistance. However, endothelin-1 concentrations have not been well characterized in patients with congenital heart disease and normal pulmonary vascular resistance. In particular, it is unclear whether pressure or flow is the key regulator of endothelin- 1 in this setting.
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