Integrin αV mediated activation of myofibroblast via mechanoparacrine of transforming growth factor ß1 in promoting fibrous scar formation after myocardial infarction.

BACKGROUND: Myocardial infarction (MI) dramatically changes the mechanical stress, which is intensified by the fibrotic remodeling. Integrins, especially the αV subunit, mediate mechanical signal and mechanoparacrine of transforming growth factor ß1 (TGF-ß1) in various organ fibrosis by activating CFs into myofibroblasts (MFBs). We investigated a possible role of integrin αV mediated mechanoparacrine of TGF-ß1 in MFBs activation for fibrous reparation in mice with MI. METHODS: Heart samples from MI, sham, or MI plus cilengitide (14 mg/kg, specific integrin αV inhibitor) treated mice, underwent functional and morphological assessments by echocardiography, and histochemistry on 7, 14 and 28 days post-surgery. The mechanical and ultrastructural changes of the fibrous scar were further evaluated by atomic mechanics microscope (AFM), immunofluorescence, second harmonic generation (SHG) imaging, polarized light and scanning electron microscope, respectively. Hydroxyproline assay was used for total collagen content, and western blot for protein expression profile examination. Fibroblast bioactivities, including cell shape, number, Smad2/3 signal and expression of extracellular matrix (ECM) related proteins, were further evaluated by microscopic observation and immunofluorescence in polyacrylamide (PA) hydrogel with adjustable stiffness, which was re-explored in fibroblast cultured on stiff matrix after silencing of integrin αV. The content of total and free TGF-ß1 was tested by enzyme-linked immunosorbent assay (ELISA) in both infarcted tissue and cell samples. RESULT: Increased stiffness with heterogeneity synchronized with integrin αV and alpha smooth muscle actin (α-SMA) positive MFBs accumulation in those less mature fibrous areas. Cilengitide abruptly reduced collagen content and disrupted collagen alignment, which also decreased TGF-ß1 bioavailability, Smad2/3 phosphorylation, and α-SMA expression in the fibrous area. Accordingly, fibroblast on stiff but not soft matrix exhibited obvious MFB phenotype, as evidenced by enlarged cell, hyperproliferation, well-developed α-SMA fibers, and elevated ECM related proteins, while silencing of integrin αV almost abolished this switch via attenuating paracrine of TGF-ß1 and nuclear translocation of Smad2/3. CONCLUSION: This study illustrated that increased tissue stiffness activates CFs into MFBs by integrin αV mediated mechanoparacrine of TGF-ß1, especially in immature scar area, which ultimately promotes fibrous scar maturation.

[Research progress on chemical constituents and pharmacological studies on root bark of Lycium barbarum].

Lycii Cortex, the dry root bark of Lycium barbarum(Solanaceae), is rich in chemical compositions with unique structures, such as organic acids, lipids, alkaloids, cyclopeptides and other components, and plays an important role in traditional Chinese medicine. It has the effect of cooling blood and removing steam, clearing lung and reducing fire. It is mainly used in the treatment of hot flashes due to Yin deficiency, hectic fever with night sweat, cough, hemoptysis and internal heat and diabetes. Modern pharmacological studies have shown that the crude extract or monomer of Lycii Cortex has a variety of pharmacological activities, such as hypoglycemic, hypotensive, hypolipidemic, antibacterial, and antiviral effects. In this paper, the chemical constituents and pharmacological effects of Cortex Lycii were reviewed in order to further clarify its effective substances, promote the development of medical undertakings, and ensure the "Healthy China" plan.

[A new 9,19-cycloartane glycoside from Asplenium ruprechtii].

Chemical constituents of water extracts of Asplenium ruprechtii were investigated. Five compounds were isolated by silica gel, Sephadex LH-20 gel column chromatographies and preparative HPLC, and their structures were identified by various spectral analyses as aspleniumside G(1), trans-p-coumaric acid(2), trans-p-coumaric acid 4-O-ß-D-glucoside(3), cis-p-coumaric acid 4-O-ß-D-glucoside(4), and(E)-ferulic acid-4-O-ß-D-glucoside(5). Among them, compound 1 is a new 9,19-cycloartane glycoside.

HPLC coupled with quadrupole time of flight tandem mass spectrometry for analysis of glycosylated components from the fresh flowers of two congeneric species: Robinia hispida L. and Robinia pseudoacacia L.

Developing methods for the systematic and rapid identification of the chemical compositions of fresh plant tissues has long attracted the attention of phytochemists and pharmacologists. In the present study, based on highly efficient sample pretreatment and high-throughput analysis of high-performance liquid chromatography coupled with quadrupole time of flight tandem mass spectrometry data using molecular networks, a method was developed for systematically analyzing the chemical constituents of the fresh flowers of Robinia hispida L. and Robina pseudoacacia L., two congeneric ornamental species that lack prior consideration. A total of 44 glycosylated structures were characterized. And on the basis of establishing of the fragmentation pathways of 11 known flavonoid glycosides, together with the molecular networking analysis, 18 other ions of flavonoid glycosides in five classes were clustered. Moreover, 15 soyasaponins/triterpenoid glycosides were tentatively identified by comparison of their tandem mass spectrometry characteristic ions with those reported in the literature or the online Global Natural Product Social Molecular Networking database. The water extracts were separated by flash chromatography, which resulted in the discovery of one new compound, named rohispidascopolin, along with five known entities. The pharmacological targets were predicted by SwissTargetPrediction.

Structural Determination of a New Cycloartane Glycoside from Asplenium ruprechtii.

We characterized a new cycloartane glycoside, herein known as aspleniumside F (1), along with five known compounds as kaempferol-3-O-[(6-O-(E)-feruloyl)-ß-D-glucopyranosyl]-(1→2)-ß-D-galacopyranoside (2), quercetin-3-O-[(6-O-(E)-feruloyl)-ß-D-glucopyranosyl]-(1→2)-ß-D-glucopyranoside (3), kaempferol-3-O-[(6-O-(E)-caffeoyl)-ß-D-glucopyranosyl]-(1→2)-ß-D-glucopyranoside (4), kaempferol-3-O-[(6-O-(E)-caffeoyl)-ß-D-glucopyranosyl]-(1→2)-ß-D-glucopyranosyl-7-O-ß-D-glucopyranoside (5), and kaempferol-3-O-[(6-O-p-coumaroyl)-ß-D-glucopyranosyl]-(1→2)-ß-D-glucopyranosyl-7-O-ß-D-glucopyranoside (6), from Asplenium ruprechtii Sa. Kurata, a folk medicine widely used to treat Thromboangiitis obliterans in China, Japan, and Korea. Based on spectroscopic, mainly 1D-, 2D-NMR and (+)-HR-ESI-MS, analyses as well as through comparisons with previous reports, its chemical structure was determined as 3ß,24,30-tri-ß-D-glucopyranosyl-23,25-dihydroxycycloartane (= (23R,24R)-3ß,24-bis-(ß-D-glucopyranosyloxy)-23,25-dihydroxy-9ß-9,19-cyclolanostan-29-yl ß-D-glucopyranoside). According to the 1 H coupling constant of anomeric protons and co-TLC of the acid hydrolysate with D-glucose, all three glycoside groups in 1 were revealed as ß-D-glucopyranosyl. Furthermore, SOD-like antioxidant activity evaluation via IC50 of 12.43, 6.78, 9.12, 6.94 and 4.85 µM revealed that compounds 2-6 had bioactivity.

Plasmon-induced efficiency enhancement on dye-sensitized solar cell by a 3D TNW-AuNP layer.

A new 3D TNW-AuNP plasmonic electrode consists of antireflective (AR) TiO2 nanowires (TNWs) (∼600 nm thickness) serving as light-harvesting antennae coupling with Au nanoparticles (NPs). A huge red-shift of 55 nm is observed in surface plasmon spectra for the Au (11 nm) plasmonic electrode that has 11 nm size Au NPs, whereby (111) lattice planes have a specific bonding with the TiO2 (101) planes. Remarkable red-shift is mainly attributed to the localized electric field improvement resulting from the plasmonic coupling effect between the Au NPs and the Au-TiO2 hybrids. After TiCl4 treatment, this favorable Au (11 nm) nanostructure takes advantage of harvesting photons to increase the conversion efficiency of dye-sensitized solar cells (DSSCs) from 6.25% to 9.73%.

Thermally induced percolational transition and thermal stability of silver nanowire networks studied by THz spectroscopy.

Great demand toward flexible optoelectronic devices finds metal nanowires (NWs) the most promising flexible transparent conducting material with superior mechanical properties. However, ultrathin metal nanowires suffer from relatively poor thermal stability and sheet conductance, attributed to the poor adhesivity of the ohmic contact between nanowires. Thermal heating and annealing at 200 °C increase the conductivity of the metal network, but prolonged annealing accelerates the breakage of NWs near the NW junction and the formation of Ag droplets. In this study, the thermal stability of silver NW (AgNW) films is investigated through the in situ measurements of sheet resistance and terahertz (THz) conductivity. With the improved ohmic contact at the NW junctions by heating, a characteristic transition from the subpercolative to percolative network is observed by in situ THz spectroscopy. It is found that stamp-transferred graphene incorporated with a near-percolative AgNW network can dramatically enhance the thermal stability of the graphene-AgNW (GAgNW) hybrid film. In both in situ measurements, little variation of physical parameters in GAgNW film is observed for up to 3 h of annealing. The presented results offer the potential of graphene-incorporated metal nanowire film as a highly conductive electrode that also has high thermal stability and excellent transparency for next-generation electronics and optoelectronics on flexible substrates.

Chain-network anatase/TiO2 (B) thin film with improved photocatalytic efficiency.

A 3-dimensional chain-network anatase/TiO2 (B) was obtained via the basic hydrothermal treatment of a sandwich Ti/TiO2/Ti film on a glass substrate that was prepared from 16 nm anatase TiO2 nanoparticles. The Ti film was converted to the TiO2 (B) phase in a Teflon vessel containing a 10 M NaOH aqueous solution that was encapsulated in a stainless-steel autoclave and heated at 130 °C for 2 h. The TiO2 (B) then served as a binder layer that enabled the formation of pearl-necklace chains made of anatase TiO2 nanoparticles, and these chain-like structures thoroughly interpenetrated into the textured layer. Decomposition tests using methylene blue indicated that the chain-network anatase/TiO2 (B) mixed-phase film had a photocatalytic half-life that was 0.84 and 0.69 times shorter than those of as-prepared anatase TiO2 and P25, respectively. In addition, the intensity of the room temperature photoluminescence spectra of anatase TiO2 was 2.55-fold higher than that of the chain-network anatase/TiO2 (B). We thus conclude that the remarkable photocatalytic activity of the chain-network anatase/TiO2 (B) is attributed to the chain-network structural characteristics and a synergistic effect of the matching band gap potentials, which increases the transfer of photogenerated electrons and reduces electron-hole recombination.

Hydrothermally processed TiO2 nanowire electrodes with antireflective and electrochromic properties.

Dual functionalities of antireflective and electrochromic properties-based anatase TiO(2) nanowire devices with a high-porosity cross-linked geometry directly grown onto transparent conductive glass was achieved for the first time through a simple one-step hydrothermal process under mild alkali conditions. Devices fashioned from these TiO(2) nanowires were found to display enhanced optical transparency in the visible range, better color contrast, and faster color-switching time in comparison to devices made from nanoparticles. These improvements can be attributed to the low refractive index and high porosity of the TiO(2) nanowires and their larger accessible surface area for Li(+) intercalation and deintercalation, leading to enhanced capabilities for transparent electrochromic smart windows.