Effect of Counter Electrode in Electroformation of Giant Vesicles
Electroformation of cell-sized lipid membrane vesicles (giant vesicles, GVs), from egg yolk phosphatidylcholine, was examined varying the shape of the counter electrode. Instead of a planar ITO (indium tin oxide) electrode commonly used, platinum wire mesh was employed as a counter electrode facing lipid deposit on a planar formation electrode. The modification did not significantly alter GV formation, and many GVs of 30–50 μm, some as large as 100 μm, formed as with the standard setup, indicating that a counter electrode does not have to be a complete plane. When the counter electrode was reduced to a set of two parallel platinum wires, GV formation deteriorated. Some GVs formed, but only in close proximity to the counter electrode. Lower electric voltage with this setup no longer yielded GVs. Instead, a large onion-like multilamellar structure was observed. The deteriorated GV formation and the formation of a multilamellar structure seemed to indicate the weakened effect of the electric field on lipid deposit due to insufficient coverage with a small counter electrode. Irregular membranous objects formed by spontaneous swelling of lipid without electric voltage gradually turned into multilamellar structure upon following application of voltage. No particular enhancement of GV formation was observed when lipid deposit on a wire formation electrode was used in combination with a large planar counter electrode.
RNF186 impairs insulin sensitivity by inducing ER stress in mouse primary hepatocytes.
RING finger 186 (RNF186) is involved in the process of endoplasmic reticulum (ER)-stress-mediated apoptosis and inflammation of different cell types, such as HeLa cells and colon epithelial cells. However, the physiological and functional roles of RNF186 in peripheral tissues remain largely unknown. In the current study, we investigate the physiological function of RNF186 in the regulation of ER stress with respect to its biological roles in regulating insulin sensitivity in mouse primary hepatocytes. RNF186 expression is induced in the livers of diabetic, obese and diet-induced obese (DIO) mice. Mouse primary hepatocytes were isolated and treated with Ad-RNF186 or Ad-GFP. The results suggest that overexpression of RNF186 increases the protein levels of the ER stress sensors inositol requiring kinase 1 (IRE1) and C/EBP homologous protein (CHOP) protein, as well as the phosphorylation level of eukaryotic initiation factor 2α (eIF2α), in mouse primary hepatocytes. This effect impedes the action of insulin through c-Jun N-terminal kinase (JNK)-mediated phosphorylation of insulin receptor substrate 1 (IRS1). Furthermore, overexpression of RNF186 also significantly increases the levels of proinflammatory cytokines, including TNFα, IL-6 and MCP1. In addition, tauroursodeoxycholic acid (TUDCA), an ER stress inhibitor, alleviates the expression of ER stress markers induced by RNF186 overexpression. Taken together, the results of the present study show that overexpression of RNF186 induces ER stress and impairs insulin signalling in mouse primary hepatocytes, suggesting that RNF186 merits further investigation as a potential therapeutic target for treatment of insulin-resistance-associated metabolic diseases.
Microwave source with enhanced radiation power based on orbitron MASERs
We have proposed the design of high power microwave source in a vacuum tube based on the theory of negative mass instability. The proposed source does not operate based on a slow-wave structure but instead makes use of accelerated charged particles. In our structure, an electron emitter injects the charged particles into to the cavity. Emitted particles move around the anode, which leads to electron acceleration and emission of electromagnetic waves with a specific frequency. In this paper, we have enhanced the output power and frequency of microwave source by variation of particles initial energy and the number of anodes incorporating their specific arrangement and applied voltages. Working at room temperature, compactness, wide bandwidth, and tunability of output frequency are among the advantages of the proposed source.