Explore the vast range of titles available.

Heparan and chondroitin sulfate proteoglycans (HSPGs and CSPGs, respectively) regulate numerous cell surface signaling events, with typically opposite effects on cell function. CSPGs inhibit nerve regeneration through receptor protein tyrosine phosphatase sigma (RPTPσ). Here we report that RPTPσ acts bimodally in sensory neuron extension, mediating CSPG inhibition and HSPG growth promotion. Crystallographic analyses of a shared HSPG-CSPG binding site reveal a conformational plasticity that can accommodate diverse glycosaminoglycans with comparable affinities. Heparan sulfate and analogs induced RPTPσ ectodomain oligomerization in solution, which was inhibited by chondroitin sulfate. RPTPσ and HSPGs colocalize in puncta on sensory neurons in culture, whereas CSPGs occupy the extracellular matrix. These results lead to a model where proteoglycans can exert opposing effects on neuronal extension by competing to control the oligomerization of a common receptor.

Heterogeneous uptake of SO.sub.2 on mineral dust is a predominant formation pathway of sulfates, whereas the contribution of photo-induced SO.sub.2 oxidation to sulfates on the dust interfaces still remains unclear. Here, we investigated heterogeneous photochemical reactions of SO.sub.2 on five mineral oxides (SiO.sub.2, kaolinite, Al.sub.2 O.sub.3, MgO, and CaO) without photocatalytic activity. Light enhanced the uptake of SO.sub.2, and its enhancement effects negatively depended on the basicity of mineral oxides. The initial uptake coefficient (γ.sub.0,BET) and the steady-state uptake coefficient (γ.sub.s,BET) of SO.sub.2 positively relied on light intensity, relative humidity (RH), and O.sub.2 content, while they exhibited a negative relationship with the initial SO.sub.2 concentration. Rapid sulfate formation during photo-induced heterogeneous reactions of SO.sub.2 with all mineral oxides was confirmed to be ubiquitous, and H.sub.2 O and O.sub.2 played key roles in the conversion of SO.sub.2 to sulfates. In particular, triplet states of SO.sub.2 (.sup.3 SO.sub.2) were suggested to be the trigger for photochemical sulfate formation. Atmospheric implications supported a potential contribution of interfacial SO.sub.2 photochemistry on non-photoactive mineral dust to atmospheric sulfate sources.

SO.sub.2 and NO.sub.2 are the critical precursors in forming sulfate and nitrate in ambient particles. We studied the mechanism of sulfate and nitrate formation during the co-uptake of NO.sub.2 and SO.sub.2 into NaCl droplets at different RHs under irradiation and dark conditions. A significant formation of nitrate attributable to NO.sub.2 hydrolysis was observed during the NO.sub.2 uptake under all conditions, and its formation rate increases with decreasing RH. The averaged NO.sub.2 uptake coefficient, γNO2, from the unary uptake of NO.sub.2 into NaCl droplets under dark conditions is 1.6 x 10.sup.-5, 1.9 x 10.sup.-5, and 3.0 x 10.sup.-5 at 80 %, 70 %, and 60 % RH, respectively. Chloride photolysis and nitrate photolysis play a crucial role in sulfate formation during the co-uptake. Nitrate photolysis generates reactive species (e.g., OH radicals, NO.sub.2, and N(III)) that directly react with S(IV) to produce sulfate. The OH radicals generated from nitrate photolysis can also react with chloride ions to form reactive chlorine species and then sulfate. To parameterize the role of nitrate photolysis and chloride photolysis in forming sulfate, the SO.sub.2 uptake coefficient, γSO2, as a function of the nitrate photolysis rate, PNO3- (jNO3- x [NO3-]), and chloride photolysis rate, PCl- (jCl- x [Cl.sup.- ]), was derived as γSO2 = 0.41 x PNO3- + 0.34 x PCl-. Our findings open up new perspectives on the formation of secondary aerosol from the combined effect of nitrate photolysis and chlorine chemistry.

Background The quality of colonoscopy is significantly influenced by the effectiveness of bowel preparation. In this study, we aimed to evaluate the efficacy, safety, and tolerability of bowel cleansing between a new oral sulfate solution (OSS) and standard polyethylene glycol electrolyte powder (PEG). Methods This single center, randomized, superiority study recruited 679 outpatients who were assigned to either the new OSS group (Group A) or standard PEG group (Group B). The quality of bowel cleansing was evaluated using the Boston Bowel Preparation Scale (BBPS) and compared between the two groups. Furthermore, data pertaining to the duration of bowel preparation, patient tolerability, and the occurrence of adverse events were also analyzed. Results According to BBPS scores, group A demonstrated significantly higher bowel preparation cleanliness than group B. Additionally, group A achieved superior bowel cleansing, as evidenced by a greater proportion of patients with BBPS scores ≥ 8 compared to group B (75.3% vs. 55.2%, P  < 0.05). No severe adverse events were reported during examinations in either group. Conclusions The magnesium sulfate, sodium sulfate, and potassium sulfate concentrated oral solution is a novel, safe, and effective bowel preparation for colonoscopy. Trial registration This study was registered in the Chinese Clinical Trial Registry on 20/02/2024 (clinical trial registration number: ChiCTR2400081004).

The durability of C[sub.3]S-C[sub.3]A paste with varied C[sub.3]A content (0%, 5%, 10%, and 20%) against sulfate attack at various attack ages (3 d, 7 d, 28 d, and 180 d) was investigated in this study through the examinations of corrosion product composition, Ca/Si and Al/Si of calcium-(aluminum)-silicate-hydrate (C-(A)-S-H) gel, formation and evolution of microstructure, migration and transformation of Al containing phase products, and pore structure. The results indicated that sulfate attack can promote the hydration reaction in C[sub.3]S-C[sub.3]A paste, thus accelerating the production of C-(A)-S-H gel in the paste. With the increase of C[sub.3]A content, the acceleration effect becomes more significant. In addition, sulfate attack led to the dealumination and decalcification of C-(A)-S-H gel, resulting in the reduction of the gelling power of C-(A)-S-H gel. The degree of dealumination and decalcification of C-(A)-S-H gel increases with the increase of C3A content. At the same time, free Al and Ca promote the formation of expansive products such as ettringite and gypsum. Finally, under the action of sulfate, the pore characterization of C[sub.3]S-C[sub.3]A paste deteriorated, showing a decrease in specific surface area, cumulative pore volume and average pore diameter.

Extracellular vesicle (EV)-mediated intercellular transfer of signaling proteins and nucleic acids has recently been implicated in the development of cancer and other pathological conditions; however, the mechanism of EV uptake and how this may be targeted remain as important questions. Here, we provide evidence that heparan sulfate (HS) proteoglycans (PGs; HSPGs) function as internalizing receptors of cancer cell-derived EVs with exosome-like characteristics. Internalized exosomes colocalized with cell-surface HSPGs of the syndecan and glypican type, and exosome uptake was specifically inhibited by free HS chains, whereas closely related chondroitin sulfate had no effect. By using several cell mutants, we provide genetic evidence of a receptor function of HSPG in exosome uptake, which was dependent on intact HS, specifically on the 2-O and N-sulfation groups. Further, enzymatic depletion of cell-surface HSPG or pharmacological inhibition of endogenous PG biosynthesis by xyloside significantly attenuated exosome uptake. We provide biochemical evidence that HSPGs are sorted to and associate with exosomes; however, exosome-associated HSPGs appear to have no direct role in exosome internalization. On a functional level, exosome-induced ERK1/2 signaling activation was attenuated in PG-deficient mutant cells as well as in WT cells treated with xyloside. Importantly, exosome-mediated stimulation of cancer cell migration was significantly reduced in PG-deficient mutant cells, or by treatment of WT cells with heparin or xyloside. We conclude that cancer cell-derived exosomes use HSPGs for their internalization and functional activity, which significantly extends the emerging role of HSPGs as key receptors of macromolecular cargo.

A subset of monoclonal anti-DNA autoantibodies enters a variety of living cells. Here, we aimed to identify the endocytic receptors recognized by an internalizing anti-nucleic acid autoantibody, the 3D8 single-chain variable fragment (scFv). We found that cell surface binding and internalization of 3D8 scFv were inhibited markedly in soluble heparan sulfate (HS)/chondroitin sulfate (CS)-deficient or -removed cells and in the presence of soluble HS and CS. 3D8 scFv colocalized intracellularly with either HS proteoglycans (HSPGs) or CSPGs in HeLa cells. 3D8 scFv was co-endocytosed and co-precipitated with representative individual HSPG and CSPG molecules: syndecan-2 (a transmembrane HSPG), glypican-3 (a glycosylphosphatidylinositol (GPI)-anchored HSPG); CD44 (a transmembrane CSPG); and brevican (a GPI-anchored CSPG). Collected data indicate that 3D8 scFv binds to the negatively charged sugar chains of both HSPGs and CSPGs and is then internalized along with these molecules, irrespective of how these proteoglycans are associated with the cell membrane. This is the first study to show that anti-DNA antibodies enter cells via both HSPGs and CSPGs simultaneously. The data may aid understanding of endocytic receptors that bind anti-DNA autoantibodies. The study also provides insight into potential cell membrane targets for macromolecular delivery.

New 4-(benzoxazol-2-yl)phenyl 3-((3-chloro-1,4-naphthoquinon-2-yl)amino)phenyl sulfate was synthesized via the SuFEx click reaction between fluorosulfate-containing 1,4-naphthoquinone and 2-(4-hydroxyphenyl)benzoxazole. 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) was used as an organic base, while triethylamine was inactive in this reaction.

Glycosaminoglycans (GAGs) are natural, linear and negatively charged heteropolysaccharides which are incident in every mammalian tissue. They consist of repeating disaccharide units, which are composed of either sulfated or non-sulfated monosaccharides. Depending on tissue types, GAGs exhibit structural heterogeneity such as the position and degree of sulfation or within their disaccharide units composition being heparin, heparan sulfate, chondroitine sulfate, dermatan sulfate, keratan sulfate, and hyaluronic acid. They are covalently linked to a core protein (proteoglycans) or as free chains (hyaluronan). GAGs affect cell properties and functions either by direct interaction with cell receptors or by sequestration of growth factors. These evidences of divert biological roles of GAGs make their characterization at cell and tissue levels of importance. Thus, non-invasive techniques are interesting to investigate, to qualitatively and quantitatively characterize GAGs in vitro in order to use them as diagnostic biomarkers and/or as therapeutic targets in several human diseases including cancer. Infrared and Raman microspectroscopies and imaging are sensitive enough to differentiate and classify GAG types and subtypes in spite of their close molecular structures. Spectroscopic markers characteristic of reference GAG molecules were identified. Beyond these investigations of the standard GAG spectral signature, infrared and Raman spectral signatures of GAG were searched in complex biological systems like cells. The aim of the present review is to describe the implementation of these complementary vibrational spectroscopy techniques, and to discuss their potentials, advantages and disadvantages for GAG analysis. In addition, this review presents new data as we show for the first time GAG infrared and Raman spectral signatures from conditioned media and live cells, respectively.