GRK2 negatively regulates glycogen synthesis in mouse liver FL83B cells

G-protein-coupled receptor (GPCR) kinases (GRKs) are serine/threonine kinases that desensitize agonist-occupied classical GPCRs. Although the insulin receptor (IR) is a tyrosine kinase receptor, the IR also couples to G-proteins and utilizes G-protein signaling components. The present study was designed to test the hypothesis that GRK2 negatively regulates IR signaling. FL83B cells, derived from mouse liver, were treated with insulin and membrane translocation of GRK2 was determined using immunofluoresecence and Western blotting. Insulin caused an increase in the translocation of GRK-2 from cytosol to the plasma membrane. To determine the role of GRK2 in IR signaling, GRK2 was selectively down-regulated ( approximately by 90%) in FL83B cells using a small interfering RNA technique. Basal as well as insulin-induced glycogen synthesis (measured by d-[U-(14)C]glucose incorporation) was increased in GRK2-deficient cells compared with control cells. Similarly, GRK2 deficiency increased the basal and insulin-stimulated phosphorylation of Ser(21) in glycogen synthase kinase-3alpha. Insulin-induced tyrosine phosphorylation of the IR was similar in control and GRK2-deficient cells. Basal and insulin-stimulated phosphorylation of Tyr(612) in insulin receptor subunit 1 was significantly increased while phosphorylation of Ser(307) was decreased in GRK2-deficient FL83B cells compared with control cells. Chronic insulin treatment (24 h) in control cells caused an increase in GRK2 (56%) and a decrease in IR (50%) expression associated with the absence of an increase in glycogen synthesis, suggesting impairment of IR function. However, chronic insulin treatment (24 h) did not decrease IR expression or impair IR effects on glycogen synthesis in GRK2-deficient cells. We conclude that (i) GRK2 negatively regulates basal and insulin-stimulated glycogen synthesis via a post-IR signaling mechanism, and (ii) GRK2 may contribute to reduced IR expression and function during chronic insulin exposure.     

Determining antibody stability: creation of solid-liquid interfacial effects within a high shear environment

The purpose of this study was to assess the stability of protein formulations using a device designed to generate defined, quantifiable levels of shear in the presence of a solid-liquid interface. The device, based on a rotating disk, produced shear strain rates of up to 3.4 x 10(4) s(-1) (at 250 rps) and was designed to exclude air-liquid interfaces and enable temperature to be controlled. Computational fluid dynamics (CFD) was used to study the fluid flow patterns within the device and to determine the shear strain rate (s(-1)) at a range of disk speeds. The device was then used to study the effect on a monoclonal IgG4 of high levels of shear at the solid-liquid interface. Monomeric antibody concentration and aggregation of the protein in solution were monitored by gel permeation HPLC and turbidity at 350 nm. High shear strain rates were found to cause significant levels of protein aggregation and precipitation with reduction of protein monomer following first-order kinetics. Monomer reduction rate was determined for a range of disk speeds and found to have a nonlinear relationship with shear strain rate, indicating the importance of identifying and minimizing such environments during processing.     

An Ultrahigh Narrowband Absorber Close to the Information Communication Window

Plasmonics - In this paper, we demonstrate a plasmonic ultrahigh narrowband perfect absorber, which realizes an absorption intensity of up to 99.99% in the near-infrared electromagnetic spectrum...     

Blockchain based secure,efficient and coordinated energy trading and data sharing between electric vehicles

Cluster Computing - In this study, a secure and coordinated blockchain based energy trading system for Electric Vehicles (EVs) is presented. The major goals of this study are to provide secure and...     

Antioxidant,antibacterial, and catalytic performance of biosynthesized silver nanoparticles of Rhus javanica,Rumex hastatus,and Callistemon viminalis

Rhus javanica (Anacardiaceae) containing abundant glucopyranosidal constituents, is traditionally used to treat gastric and duodenal ulcer, dysentery, and diarrhea. Rumex hastatus (Polygonaceae) widely distributed in Pakistan, has traditional importance in treating wound healing, jaundice, rheumatism, and skin diseases. Callistemon viminalis (Myrtaceae), a rich source of essential oils, saponins, triterpenoids, phloroglucinols, and flavonoids is used in industries, perfumes, nutrition, and cosmetics. Taking the importance of the subject plants, this study is designed to synthesize silver nanoparticles via aqueous extracts of R. javanica (RJAgNPs), R. hastatus (RHAgNPs), and C. viminalis (CVAgNPs). Synthesis, surface, and sizes of silver nanoparticles (AgNPs) were confirmed using spectroscopic techniques including ultraviolet–visible (UV–Vis), Fourier transform-infrared (FT-IR), and scanning electron microscopy (SEM). AgNPs were produced in ratios 1:15, 1:16, and 1:9 and inferred via appearance of a sharp surface plasmon resonance (SPR) absorption peak (400–435 nm), which represented well-defined, stable, and spherical AgNPs. From SEM analysis, the sizes of RJAgNPs, RHAgNPs, and CVAgNPs were found to be 67 nm, 61 nm, and 55 nm, respectively. The synthesized AgNPs exhibited potential free radical scavenging, antibacterial, and catalytic properties in degradation of dyes including Congo red, methylene blue, methyl orange, rhodamine B, ortho and para-nitrophenols, and several food colours. Hence, the subject AgNPs in the current study might display promising role in drug development and remediation of environmental/industrial effluents.     

Treatment of a bifurcation lesion at the anastomosis of a vein graft by true 'Y' stenting

We describe the treatment of a bifurcation lesion at the anastomosis of a vein graft by 'true Y' stenting which preserved both antegrade and retrograde flow away from the graft.     

The complete nucleotide sequence of wild rice (Oryza nivara) chloroplast genome: first genome wide comparative sequence analysis of wild and cultivated rice

We determined the complete nucleotide sequence of the chloroplast genome of wild rice, Oryza nivara and compared it with the corresponding published sequence of relative cultivated rice, Oryza sativa. The genome was 134,494 bp long with a large single-copy region of 80,544 bp, a small single-copy region of 12,346 bp and two inverted repeats of 20,802 bp each. The overall A+T content was 61.0%. The O. nivara chloroplast genome encoded identical functional genes to O. sativa in the same order along the genome. On the other hand, detailed analysis revealed 57 insertion, 61 deletion and 159 base substitution events in the entire chloroplast genome of O. nivara. Among substitutions, transversions were much higher than transitions with the former even more frequent than the latter in the coding region. Most of the insertions/deletions were single-base but a few large length mutations were also detected. The frequency of insertion/deletion events was more in the coding region within inverted repeats. In contrast, a very few substitution events were identified in the coding region. Polymorphism was observed among rice cultivars at loci of large insertion/deletion events. This is the first report describing comparative and genome wide chloroplast analysis between a wild and cultivated crop.     

Isolation of ginkgolides A, B, C, J and bilobalide from G. biloba extracts

Ginkgolides A, B, C and J, together with bilobalide, are unique terpenoid components of the Ginkgo biloba tree. Due to similar chemical properties, their separation is quite tedious. We have developed an efficient and rapid protocol for separation of individual ginkgolides and bilobalide from G. biloba extracts. The procedure takes advantage of enhanced susceptibility of ginkgolides B and C to benzylation and the ease of separation of these products from ginkgolides A and J which do not react. The protocol is applicable to the previously reported enriched extracts prepared from G. biloba leaves. A single chromatographic step prior to benzylation provides bilobalide and mixture of ginkgolides A, B, C, and J. After benzylation, the individual ginkgolides are separated by chromatography.     

Antidote-mediated control of an anticoagulant aptamer in vivo

Patient safety and treatment outcome could be improved if physicians could rapidly control the activity of therapeutic agents in their patients. Antidote control is the safest way to regulate drug activity, because unlike rapidly clearing drugs, control of the drug activity is independent of underlying patient physiology and co-morbidities. Until recently, however, there was no general method to discover antidote-controlled drugs. Here we demonstrate that the activity and side effects of a specific class of drugs, called aptamers, can be controlled by matched antidotes in vivo. The drug, an anticoagulant aptamer, systemically induces anticoagulation in pigs and inhibits thrombosis in murine models. The antidote rapidly reverses anticoagulation engendered by the drug, and prevents drug-induced bleeding in surgically challenged animals. These results demonstrate that rationally designed drug-antidote pairs can be generated to provide control over drug activities in animals.