Search

The imbalance between osteogenic and adipogenic differentiation of Bone marrow-derived mesenchymal stem cells (BMSCs) is involved in the occurrence and development of osteoporosis (OP). Previous studies have indicated the potential of phosphatase and actin regulator 1 (Phactr1) in regulating osteogenic and adipogenic differentiation of BMSCs. The present study aims to investigate the function and mechanism of Phactr1 in regulating osteogenic and adipogenic differentiation of BMSCs. Herein, the expression of Phactr1 in bone and adipose tissue of OP rats was determined by immunohistochemical. BMSCs were subjected to osteogenic and adipogenic differentiation, and transfected with Phactr1 overexpression lentivirus, small interference RNA (siRNA) and KD025 (selective ROCK2 inhibitor). The relationship between Phactr1 and ROCK2 was detected by Co-IP experiment. The expression of Phactr1, Runx2, C/EBPα, RhoA and ROCK2 was detected by Western blot. Calcium nodule and lipid droplets were determined by alizarin red and Oil red O staining. Interestingly, Phactr1 increased in both bone and adipose tissue of OP rats. During osteogenic differentiation, Phactr1 decreased and active RhoA, ROCK2 increased, while overexpression Phactr1 inhibits the increase of Runx2. Phactr1 increased and active RhoA decreased, ROCK2 did not changed during adipogenic differentiation. While, Knockdown Phactr1 inhibits the increase of C/EBPα. Phactr1 and ROCK2 were combined in osteogenic differentiation, but not in adipogenic differentiation. By using KD025, the decrease of Phactr1 and increase of Runx2 were inhibited respectively in osteogenic differentiation. Meanwhile, when ROCK2 was inhibited, Phactr1, C/EBPα were significantly increased in adipogenic differentiation. These findings indicated that Phactr1 negatively regulates bone mass by inhibiting osteogenesis and promoting adipogenesis of BMSCs by activating RhoA/ROCK2. [ABSTRACT FROM AUTHOR]

A study was conducted on novel light-emitting devices based on various pyridine-containing conjugated polymers and copolymers in various device configurations. The high electron affinity of pyridine-based polymers enhances stability and electron transport properties of the polymers. Bilayer devices exhibited better efficiency and brightness than single layer devices because of charge confinement and exciplex emission at the PVK/emitting polymer interface.

Evaluation of fish stock status is a key step for fisheries management. Tuna Regional Fisheries Management Organizations (t-RFMOs) are moving towards management strategy evaluation (MSE), a process that combines science and policy and depends on technical aspects, developed by scientists, designed to meet management objectives established by managers and other stakeholders. In the Indian Ocean, the current management advice for swordfish (Xiphias gladius) is based on an ensemble of 24 models considering four areas of uncertainty about the stock dynamics. There is an ongoing MSE process for swordfish, and this paper describes the methodology being applied for the conditioning of the operating model (OM), including model selection and validation. In the MSE, nine sources of uncertainty were considered, each being characterized by 2–3 levels. A partial factorial design was employed to reduce the number of models from a full factorial design to those needed to encompass the overall uncertainty. A selection and validation process was carried out, filtering models that converged, showed good predictive skills, and provided plausible estimates. Overall, the estimated spawning stock biomass (SSB) relative to SSB at maximum sustainable yield (MSY), and fishing mortality (F) relative to FMSY encompasses the estimates of the stock assessment ensemble at the most optimist area of the distribution. The MSE for swordfish is an ongoing process that is expected to provide more robust management advice in the future. Further developments to the OM can still occur, but the methods presented herein can be applied to this, or other species, MSE processes. [ABSTRACT FROM AUTHOR]

Abstract Background The endothelial cell dysfunction observed in preeclampsia (PE) may be induced by CD40/CD40L signaling. This study investigated the role of CD40/CD40L in the pathogenesis of PE by comparing the effect of maternal serum obtained from healthy pregnant women and PE patients on HUVEC cell growth, apoptosis and CD40/CD40L expression. Methods Maternal serum was obtained from 20 patients with PE (PE group) as well as 20 healthy pregnant women (control group). The human umbilical endothelial cell line, CRL1730, was cultured in the presence of maternal serum for 24, 48, and 72 h after which cell growth and apoptosis were assessed by MTT and flow cytometry analysis, respectively. CD40/CD40L expression was determined using flow cytometry and RT-PCR analyses. Results As compared to CRL1730 cells treated with control sera, those treated with PE sera had altered morphology, decreased cell growth, increased apoptosis and greater CD40/CD40L protein and mRNA expression. Stimulation of CD40/CD40L protein and mRNA expression by PE sera was greatest at 24 h. Conclusions PE sera may induce endothelial cell damage possibly through increased CD40/CD40L expression in early-onset PE. Further studies are necessary to determine the factor(s) in PE sera responsible for the observed changes in endothelial cell viability.