63 research outputs found
Atmospheric polycyclic aromatic hydrocarbons in rural and urban areas of northern China
Different Effects of Angiotensin II and Angiotensin-(1-7) on Vascular Smooth Muscle Cell Proliferation and Migration
Background: Angiotensin (Ang) II and Ang-(1-7) are two of the bioactive peptides of the rennin-angiotensin system. Ang II is involved in the development of cardiovascular disease, such as hypertension and atherosclerosis, while Ang-(1-7) shows cardiovascular protection in contrast to Ang II. Methodology/Principal Findings: In this study, we investigated effects of Ang II and Ang-(1-7) on vascular smooth muscle cell (SMC) proliferation and migration, which are critical in the formation of atherosclerotic lesions. Treatment with Ang II resulted in an increase of SMC proliferation, whereas Ang-(1-7) alone had no effects. However, preincubation with Ang-(1-7) inhibited Ang II-induced SMC proliferation. Ang II promoted SMC migration, and this effect was abolished by pretreatment with Ang-(1-7). The stimulatory effects of Ang II on SMC proliferation and migration were blocked by the Ang II receptor antagonist lorsartan, while the inhibitory effects of Ang-(1-7) were abolished by the Ang-(1-7) receptor antagonist A-799. Ang II treatment caused activation of ERK1/2 mediated signaling, and this was inhibited by preincubation of SMCs with Ang-(1-7). Conclusion: These results suggest that Ang-(1-7) inhibits Ang II-induced SMC proliferation and migration, at least in part, through negative modulation of Ang II induced ERK1/2 activity.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000281153500009&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Multidisciplinary SciencesSCI(E)36ARTICLE8null
Functional Impact of Heterogeneous Nuclear Ribonucleoprotein A2/B1 in Smooth Muscle Differentiation from Stem Cells and Embryonic Arteriogenesis
Heterogeneous nuclear ribonucleoproteins (hnRNPs) play various roles in transcriptional and post-transcriptional modulation of gene expression. However, it remains unclear if hnRNPs are associated with smooth muscle cell (SMC) differentiation from stem cells and embryonic arteriogenesis. In this study, mouse embryonic stem (ES) cells were cultivated on collagen IV-coated plates and smooth muscle differentiation medium. We found that hnRNPA2/B1 gene and protein expression was significantly up-regulated following 3–7 days of cell differentiation. hnRNPA2/B1 knockdown resulted in down-regulation of specific smooth muscle markers and transcription factors, whereas enforced expression of hnRNPA2/B1 enhanced the expression of these genes. Moreover, we demonstrated by using luciferase and chromatin immunoprecipitation assays that hnRNPA2/B1 could transcriptionally regulate SMC gene expression through direct binding to promoters of Smαa and Sm22α genes. We further demonstrated that chromobox protein homolog gene 3, a previously identified SMC differentiation regulatory nuclear protein, is required for hnRNPA2/B1-mediated SMC differentiation gene expression. Importantly, specifically designed Hnrnpa2/b1 morpholinos for in vivo knockdown could inhibit the migration and differentiation of neural crest cells into SMCs in chick embryos. This resulted in the maldevelopment of branchial arch arteries and increased embryo lethality at a later developmental stage. Our findings demonstrated that hnRNPA2/B1 plays a functional role in SMC differentiation from stem cells in vitro and embryonic branchial arch artery development. This indicates that hnRNPA2/B1 is a potential modulating target for deriving SMCs from stem cells and cardiovascular regenerative medicine
Study on Properties of Waste Concrete Powder by Thermal Treatment and Application in Mortar
Waste concrete must be crushed, screened, and ground in order to produce high-quality recycled aggregate. In this treatment process, 15–30% waste concrete powder (<0.125 mm) can be generated. Hydration activity and the reuse of waste concrete powders (WCPs) were studied in this work, and the results illustrated that the particle size changed after a series of thermal treatments at temperatures from 400 ℃ to 800 ℃. The particle size of waste concrete powder decreased by 700 ℃ thermal treatment, and by 600 ℃ thermal treatment, it increased. More active elements appeared in WCP heated by 800 ℃. Nevertheless, the activity index (AI) of WCP, measured by the ratio of mechanical strengths between mortar with a 30% replacement of the cement with WCP and normal mortar without WCP, indicated that the WCP by 700 ℃ thermal treatment had an optimal AI value, which meant WCP treated at 700 ℃ could be used in mortar or concrete as an admixture
Non-Rigid Vehicle-Borne LiDAR-Assisted Aerotriangulation
VLS (Vehicle-borne Laser Scanning) can easily scan the road surface in the close range with high density. UAV (Unmanned Aerial Vehicle) can capture a wider range of ground images. Due to the complementary features of platforms of VLS and UAV, combining the two methods becomes a more effective method of data acquisition. In this paper, a non-rigid method for the aerotriangulation of UAV images assisted by a vehicle-borne light detection and ranging (LiDAR) point cloud is proposed, which greatly reduces the number of control points and improves the automation. We convert the LiDAR point cloud-assisted aerotriangulation into a registration problem between two point clouds, which does not require complicated feature extraction and match between point cloud and images. Compared with the iterative closest point (ICP) algorithm, this method can address the non-rigid image distortion with a more rigorous adjustment model and a higher accuracy of aerotriangulation. The experimental results show that the constraint of the LiDAR point cloud ensures the high accuracy of the aerotriangulation, even in the absence of control points. The root-mean-square error (RMSE) of the checkpoints on the x, y, and z axes are 0.118 m, 0.163 m, and 0.084m, respectively, which verifies the reliability of the proposed method. As a necessary condition for joint mapping, the research based on VLS and UAV images in uncontrolled circumstances will greatly improve the efficiency of joint mapping and reduce its cost
Ang-(1-7) inhibits Ang II-induced ERK1/2 phosphorylation.
<p>(A) Representative Western blotting results, showing bands for phosphorylated ERK1/2 (p-ERK1/2) and total ERK1/2. (B) Quantification of band intensity of Western blots. Data shown are mean ± SEM of 3 experiments.</p
Antagonists abrogate the effects of Ang II and Ang-(1-7) on SMC proliferation.
<p>Data shown are mean ± SEM of cell numbers at day 4 from 4 experiments, each with triplicate wells per condition.</p
Ang-(1-7) inhibits the stimulating effect of Ang II on SMC migration.
<p>Data shown are mean ± SEM of migration distance from 4 experiments, each with triplicate wells per condition.</p
Ang-(1-7) inhibits Ang II-induced SMC proliferation.
<p>Data shown are mean ± SEM of cell numbers at day 4 from 4 experiments, each with triplicate wells per condition.</p
- …