High Density Lipoprotein (HDL) Promotes Glucose Uptake in Adipocytes and Glycogen Synthesis in Muscle Cells

Background: High density lipoprotein (HDL) was reported to decrease plasma glucose and promote insulin secretion in type 2 diabetes patients. This investigation was designed to determine the effects and mechanisms of HDL on glucose uptake in adipocytes and glycogen synthesis in muscle cells. Methods and Results: Actions of HDL on glucose uptake and GLUT4 translocation were assessed with 1- [ 3 H]-2deoxyglucose and plasma membrane lawn, respectively, in 3T3-L1 adipocytes. Glycogen analysis was performed with amyloglucosidase and glucose oxidase-peroxidase methods in normal and palmitate-treated L6 cells. Small interfering RNA was used to observe role of scavenger receptor type I (SR-BI) in glucose uptake of HDL. Corresponding signaling molecules were detected by immunoblotting. HDL stimulated glucose uptake in a time- and concentration-dependent manner in 3T3-L1 adipocytes. GLUT4 translocation was significantly increased by HDL. Glycogen deposition got enhanced in L6 muscle cells paralleling with elevated glycogen synthase kinase3 (GSK3) phosphorylation. Meanwhile, increased phosphorylations of Akt-Ser473 and AMP activated protein kinase (AMPK) a were detected in 3T3-L1 adipocytes. Glucose uptake and Akt-Ser473 activation but not AMPK-a were diminished in SR-BI knock-down 3T3-L1 cells. Conclusions: HDL stimulates glucose uptake in 3T3-L1 adipocytes through enhancing GLUT4 translocation by mechanisms involving PI3K/Akt via SR-BI and AMPK signaling pathways, and increases glycogen deposition in L6 muscle cells throug

How (not) to increase older adults’ tendency to anthropomorphise in serious games

<div><p>Among elderly, the use of serious games steadily increases. Research shows that anthropomorphising digital agents (i.e., ascribing human characteristics to them) has positive short-term consequences on interactions with digital agents. However, whether these effects can also be observed over a long-term period and in a real-life setting is unknown. In two studies, we investigated the important long-term consequences of anthropomorphism among older adults (age > 50) to increase involvement in serious games. Participants read either a story that highly anthropomorphized the digital agent of a training game, or a low anthropomorphism story about that agent. To investigate long-term effect, they played the training game for three weeks, and gaming data was assessed (number of games played, time of playing, points gained). While on the short-term, the anthropomorphic story increased the humanness of the agent (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0199948#sec002" target="_blank">Study 1</a>), no long-term effects where found (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0199948#sec007" target="_blank">Study 2</a>). Furthermore, an anthropomorphic story had no influence on the gaming outcome. Our results inform app developers about which techniques are useful to humanise digital agents.</p></div

t-values, x²-values, and p-values of the control variables of Study 2.

<p>t-values, x²-values, and p-values of the control variables of Study 2.</p

R code and model statistics for the mixed effects models.

<p>The r² was for the whole model, and the rest of the statistics were for the fixed effect of story version.</p

Means, standard deviations, and score-range for all dependent variables of Study 2.

<p>Means, standard deviations, and score-range for all dependent variables of Study 2.</p

Self-assembly of pH-sensitive fluorinated peptide dendron functionalized dextran nanoparticles for on-demand intracellular drug delivery.

In this study, the amphiphilic fluorinated peptide dendrons functionalized dextran (FPD-HZN-Dex) via an acid-sensitive hydrazone linkage was successfully designed and prepared for the first time. We demonstrated a spontaneous self-assembly of amphiphilic FPD-HZN-Dex into the well-defined nanoparticles with the core-shell architecture in aqueous media, which is attributed to the efficient amphiphilic functionalization of dextran by the hydrophobic fluorinated peptide dendrons. The spherical morphology, uniform particle size and good storage stability of the prepared FPD-HZN-Dex nanoparticles were characterized by dynamic light scattering and transmission electron microscopy, respectively. In vitro drug release studies showed a controlled and pH dependent hydrophobic drug release profile. The cell viability assays show excellent biocompatibility of the FPD-HZN-Dex nanoparticles for both normal cells and tumor cells. Moreover, the FPD-HZN-Dex self-assembled systems based on pH-sensitive hydrazone linkage also can serve as stimulus bioresponsive carriers for on-demand intracellular drug delivery. These self-assembled nanoparticles exhibit a stimulus-induced response to endo/lysosome pH (pH 5.0) that causes their disassembly over time, enabling controlled release of encapsulated DOX. This work has unveiled a unique non-covalent interaction useful for engineering amphiphilic dendrons or dendrimers self-assembled systems.The European Commission Research and Innovation (PIRSES-GA-2011-295218