Notoginsenoside R1 upregulates miR-221-3p expression to alleviate ox-LDL-induced apoptosis, inflammation, and oxidative stress by inhibiting the TLR4/NF-κB pathway in HUVECs.

Atherosclerosis (AS) is a common vascular disease, which can cause apoptosis of vascular endothelial cells. Notoginsenoside R1 (NGR1) is considered an anti-AS drug. MicroRNAs (miRNAs) are believed to play a vital role in cell apoptosis and angiogenesis. This study aimed to explore the mechanism of NGR1 for treating AS through miRNAs. Flow cytometry was used to detect the apoptosis rate. The levels of inflammatory cytokines interleukin (IL)-6 and IL-1ß were detected using ELISA. Reactive oxygen species (ROS) and malondialdehyde (MDA) levels were measured using corresponding assay kits. Quantitative real-time polymerase chain reaction (qRT-PCR) assay was performed to detect miR-221-3p expression. Dual-luciferase reporter and RNA immunoprecipitation assays were carried out to examine the relationship between miR-221-3p and toll-like receptors 4 (TLR4). Also, western blot analysis was performed to determine the levels of TLR4 and nuclear factor kappa B (NF-κB) signaling pathway-related proteins. Oxidized low-density lipoprotein (ox-LDL) induced human umbilical vein endothelial cells (HUVECs) apoptosis, inflammation, and oxidative stress. NGR1 alleviated the negative effect of ox-LDL through promoting the expression of miR-221-3p in HUVECs. TLR4 was a target of miR-221-3p, and its overexpression could reverse the inhibition effects of miR-221-3p on apoptosis, inflammation, and oxidative stress. NGR1 improved miR-221-3p expression to inhibit the activation of the TLR4/NF-κB pathway in ox-LDL-treated HUVECs. NGR1 decreased ox-LDL-induced HUVECs apoptosis, inflammation, and oxidative stress through increasing miR-221-3p expression, thereby inhibiting the activation of the TLR4/NF-κB pathway. This study of the mechanism of NGR1 provided a more theoretical basis for the treatment of AS.

Notoginsenoside R1 upregulates miR-221-3p expression to alleviate ox-LDL-induced apoptosis, inflammation, and oxidative stress by inhibiting the TLR4/NF-κB pathway in HUVECs

Atherosclerosis (AS) is a common vascular disease, which can cause apoptosis of vascular endothelial cells. Notoginsenoside R1 (NGR1) is considered an anti-AS drug. MicroRNAs (miRNAs) are believed to play a vital role in cell apoptosis and angiogenesis. This study aimed to explore the mechanism of NGR1 for treating AS through miRNAs. Flow cytometry was used to detect the apoptosis rate. The levels of inflammatory cytokines interleukin (IL)-6 and IL-1β were detected using ELISA. Reactive oxygen species (ROS) and malondialdehyde (MDA) levels were measured using corresponding assay kits. Quantitative real-time polymerase chain reaction (qRT-PCR) assay was performed to detect miR-221-3p expression. Dual-luciferase reporter and RNA immunoprecipitation assays were carried out to examine the relationship between miR-221-3p and toll-like receptors 4 (TLR4). Also, western blot analysis was performed to determine the levels of TLR4 and nuclear factor kappa B (NF-κB) signaling pathway-related proteins. Oxidized low-density lipoprotein (ox-LDL) induced human umbilical vein endothelial cells (HUVECs) apoptosis, inflammation, and oxidative stress. NGR1 alleviated the negative effect of ox-LDL through promoting the expression of miR-221-3p in HUVECs. TLR4 was a target of miR-221-3p, and its overexpression could reverse the inhibition effects of miR-221-3p on apoptosis, inflammation, and oxidative stress. NGR1 improved miR-221-3p expression to inhibit the activation of the TLR4/NF-κB pathway in ox-LDL-treated HUVECs. NGR1 decreased ox-LDL-induced HUVECs apoptosis, inflammation, and oxidative stress through increasing miR-221-3p expression, thereby inhibiting the activation of the TLR4/NF-κB pathway. This study of the mechanism of NGR1 provided a more theoretical basis for the treatment of AS.

C1q/TNF-related protein-9 attenuates atherosclerosis through AMPK-NLRP3 inflammasome singling pathway.

BACKGROUNDS: C1q tumor necrosis factor-related protein 9 (CTRP9) has been suggested to exert an atheroprotective effect by modulating the inflammation, foam cell formation, endothelia and smooth muscle cell function via Adenosine Monophosphate Activated Protein Kinase (AMPK) pathway. On the other hand, the NLR Family Pyrin Domain Containing 3 (NLRP3) inflammasome plays an critical role in the atherosclerosis development, which is regulated by the AMPK. However, whether the CTRP9 affects the activity of NLRP3 inflammasome during the atherosclerosis development remains unclear, which would be elucidated in the current study. METHODS: The macrophage cells were stimulated with the oxidized low-density lipoprotein (ox-LDL) and also treated with the recombinant CTRP9 in the meantime. The activation of NLRP3 inflammasome was determined by measuring the releasing of IL-1ß and caspase-1 p10 via ELISA and western blot, respectively. Then the AMPK was inhibited in macrophages by Dorsomorphin. Finally, the CTRP9-AMPK-NLRP3 inflammasome pathway was validated in the mouse model of atherosclerosis. RESULTS: The CTRP9 could down-regulate the expression of NLRP3 protein and also the activity of NLRP3 inflammasome in the ox-LDL activated macrophages. Inhibiting the AMPK significantly restored the activities of NLRP3 inflammasome. In the apolipoprotein E-deficient mice, lentiviral expression of CTRP9 could suppress the atherosclerosis development, which could be abolished by AMPK inhibition. CONCLUSION: Our data here indicated that the CTRP9 showed atheroprotective function via CTRP9-AMPK- NLRP3 inflammasome pathway.

Polymer-Infiltrated Aligned Carbon Nanotube Fibers by in situ Polymerization.

Carbon nanotube-polymer composite fibers are obtained by infiltration of a monomer liquid into aligned carbon nanotube aerogel fibers with subsequent in situ polymerization. The monomer, methyl methacrylate (MMA), was infiltrated into the aerogel fibers of multi-walled carbon nanotubes (MWNTs) at room temperature and subsequently polymerized at 50 °C into poly(methyl methacrylate) (PMMA). Cross-sections of the PMMA/MWNT composite fibers showed that the PMMA filled the spaces of the nanotube fibers and bound the nanotubes together. PMMA in the composite fibers exhibited local order. The resultant composite fibers with 15 wt.-% nanotube loading exhibited a 16-fold and a 49-fold increase in tensile strength and Young's modulus, respectively, compared to the control PMMA.

Hierarchical silicon etched structures for controlled hydrophobicity/superhydrophobicity.

Silicon surface hydrophobicity has been varied by using silane treatments on silicon pyramid surfaces generated by KOH anisotropic etching. Results demonstrated that by altering the surface hydrophobicity, the apparent contact angle changed in accord with the Wenzel equation for surface structures with inclined side walls. Hierarchical structures were also constructed from Si pyramids where nanostructures were added by Au-assisted electroless HF/H2O2 etching. Surface hydrophobicity and superhydrophobicity were achieved by surface modification with a variety of silanes. Stability of the Cassie state of superhydrophobicity is described with respect to the Laplace pressure as indicated by the water droplet meniscus in contact with the hierarchical structures. The contact angle hysteresis observed is also discussed with respect to water/substrate adhesion.

Biomimetic creation of hierarchical surface structures by combining colloidal self-assembly and Au sputter deposition.

Surfaces of hexagonally packed silica spheres have been functionalized with silanes containing different hydrocarbon or fluorocarbon chains. The resulting chemical and physical structures were studied to establish the effect of surface hydrophobicity on the measured contact angles on the rough surfaces. The results were used to assess the effects of surface modifications on the parameters in the Cassie equation. To achieve superhydrophobicity via a biomimetic approach, we created two-scale structures by first forming hexagonally packed SiO2 spheres, followed by Au deposition on the spheres and heat treatment to form Au nanoparticles on sphere surfaces. Contact angles over 160 degrees were achieved. This work provides improved understanding of the effect of the surface roughness and solid surface fraction on superhydrophobicity.

Electrowetting of aligned carbon nanotube films.

Electrowetting is one approach to reducing the interfacial tension between a solid and a liquid. In this method, an electrical potential is applied across the solid/liquid interface which modifies the wetting properties of the liquid on the solid without changing the composition of the solid and liquid phases. Electrowetting of aligned carbon nanotube (CNT) films is investigated by the sessile drop method by dispensing deionized (DI) water or 0.03 M NaCl droplets (contacted by Au wire) onto aligned CNT films assembled on a copper substrate. The results demonstrate that electrowetting can greatly reduce the hydrophobicity of the aligned CNTs; the contact angle saturation for DI water and 0.03 M NaCl droplets occurs at 98 and 50 degrees , respectively. The combined effects of the geometrical roughness and the electrical potential on the contact angle are briefly discussed and modeled. Such a strategy may be invoked to controllably reduce the interfacial tension between carbon nanotubes (CNTs) and polymer precursors when infiltrating the monomers into the prealigned nanotube films.

Monitoring carbon nanotube growth by formation of nanotube stacks and investigation of the diffusion-controlled kinetics.

A novel method is presented to monitor carbon nanotube (CNT) growth by formation of CNT stacks. By this process, CNT growth kinetics are investigated for densely packed CNT films in the gas-diffusion-controlled regime. CNT stacks are fabricated by water-assisted selective etching and the cyclic introduction of ethylene into the chemical vapor deposition (CVD) reactor. Formation of the CNT stacks allows monitoring of the CNT growth evolution, thereby providing insight into the growth kinetics. A parabolic increase of CNT length versus time is observed, indicating a gas-diffusion-controlled growth mode. The densely packed, well-aligned CNT films act as porous barrier layers to the diffusion of ethylene precursor to the catalyst nanoparticles, since these films form via a base-growth mode under the conditions invoked in our system. By adjustment of CNT growth time and temperature, a quantitative time-evolution analysis is performed to investigate the CNT growth model and extract the gas precursor mass transfer coefficient in the CNT films. The self-diffusion of gases in the densely packed CNT films is found to be Knudsen diffusion with a diffusion coefficient on the order of 10(-4) cm(2)/s.

Well-aligned open-ended carbon nanotube architectures: an approach for device assembly.

To circumvent the high carbon nanotube (CNT) growth temperature and poor adhesion with the substrates that currently plague CNT implementation, we proposed using CNT transfer technology enabled by open-ended CNTs. The process is featured with separation of CNT growth and CNT device assembly. Field emission testing of the as-assembled CNT devices is in good agreement with the Fowler-Nordheim (FN) equation, with a field enhancement factor of 4,540. This novel technique shows promising applications for positioning CNTs on temperature-sensitive substrates and for the fabrication of field emitters, electrical interconnects, and thermal management structures in microelectronics packaging.

Aligned carbon nanotube stacks by water-assisted selective etching.

Well-aligned, high-purity carbon nanotube (CNT) stacks of up to 10 layers fabricated in one batch process have been formed by water-assisted selective etching of carbon atoms. Etching takes place at the CNT caps as well as at the interface between CNTs and metal catalyst particles. This simple process generates high-purity CNTs and opens the CNT ends by removing the nanotube caps. High-resolution transmission electron microscopy indicates that the process does not damage CNT wall structures. A mechanism for stacked growth of CNT layers is proposed.

Superhydrophobicity on two-tier rough surfaces fabricated by controlled growth of aligned carbon nanotube arrays coated with fluorocarbon.

Considerable effort has been expended on theoretical studies of superhydrophobic surfaces with two-tier (micro and nano) roughness, but experimental studies are few due to the difficulties in fabricating such surfaces in a controllable way. The objective of this work is to experimentally study the wetting and hydrophobicity of water droplets on two-tier rough surfaces for comparison with theoretical analyses. To compare wetting on micropatterned silicon surfaces with wetting on nanoscale roughness surfaces, two model systems are fabricated: carbon nanotube arrays on silicon wafers and carbon nanotube arrays on carbon nanotube films. All surfaces are coated with 20 nm thick fluorocarbon films to obtain low surface energies. The results show that the microstructural characteristics must be optimized to achieve stable superhydrophobicity on microscale rough surfaces. However, the presence of nanoscale roughness allows a much broader range of surface design criteria, decreases the contact angle hysteresis to less than 1 degrees , and establishes stable and robust superhydrophobicity, although nanoscale roughness could not increase the apparent contact angle significantly if the microscale roughness dominates.