No abstract

Recently, we isolated a subset of glycolipoproteins from Panax ginseng, that we designated gintonin, and demonstrated that it induced [Ca2+]i transients in cells via G protein-coupled receptor (GPCR) signaling pathway(s). However, active components responsible for Ca2+ mobilization and the corresponding receptor(s) were unknown. Active component(s) for [Ca2+]i transients of gintonin were analyzed by liquid chromatography-electrospray ionization-tandem mass spectrometry and ion-mobility mass spectrometry, respectively. The corresponding receptor(s)were investigated through gene expression assays. We found that gintonin contains LPA C18:2 and other LPAs. Proteomic analysis showed that ginseng major latex-like protein and ribonuclease-like storage proteins are protein components of gintonin. Gintonin induced [Ca2+]i transients in B103 rat neuroblastoma cells transfected with human LPA receptors with high affinity in order of LPA2 >LPA5 > LPA1 > LPA3 > LPA4. The LPA1/LPA3 receptor antagonist Ki16425 blocked gintonin action in cells expressing LPA1 or LPA3. Mutations of binding sites in the LPA3 receptor attenuated gintonin action. Gintonin acted via pertussis toxin (PTX)-sensitive and -insensitive G protein-phospholipase C (PLC)-inositol 1,4,5-trisphosphate (IP3)-Ca2+ pathways. However, gintonin had no effects on other receptors examined. In human umbilical vein endothelial cells (HUVECs) gintonin stimulated cell proliferation and migration. Gintonin stimulated ERK1/2 phosphorylation. PTX blocked gintonin-mediated migration and ERK1/2 phosphorylation. In PC12 cells gintonin induced morphological changes, which were blocked by Rho kinase inhibitorY-27632. Gintonin contains GPCR ligand LPAs in complexes with ginseng proteins and could be useful in the development of drugs targeting LPA receptors.

Thin (0.5 to 1 microm) layers of nonaligned or quasi-aligned hollow ZnO fibers were prepared by sputtering ZnO onto sacrificial templates comprising polyvinyl-acetate (PVAc) fibers deposited by electrospinning on silicon or alumina substrates. Subsequently, the ZnO/PVAc composite fibers were calcined to remove the organic components and crystallize the ZnO overlayer, resulting in hollow fibers comprising nanocrystalline ZnO shells with an average grain size of 23 nm. The inner diameter of the hollow fibers ranged between 100 and 400 nm and their wall thickness varied from 100 to 40 nm from top to bottom. The electronic transport and gas sensing properties were examined using DC conductivity and AC impedance spectroscopy measurements under exposure to residual concentrations (2-10 ppm) of NO(2) in air at elevated temperatures (200-400 degrees C). The inner and outer surface regions of the hollow ZnO fibers were depleted of mobile charge carriers, presumably due to electron localization at O(-) adions, constricting the current to flow through their less resistive cores. The overall impedance comprised interfacial and bulk contributions. Both contributions increased upon exposure to electronegative gases such as NO(2) but the bulk contribution was more sensitive than the interfacial one. The hollow ZnO fibers were much more sensitive compared to reference ZnO thin film specimens, displaying even larger sensitivity enhancement than the 2-fold increase in their surface to volume ratio. The quasi-aligned fibers were more sensitive than their nonaligned counterparts.

Supersized pores: A new mesoporous metal–organic framework that is mainly composed of Tb3+ ions and tripodal carboxylate ligands has cages of 3.9 and 4.7 nm in diameter (see picture). The evacuated framework is robust and can accommodate gases or ferrocene molecules, as verified by gas‐sorption measurements and luminescence studies.

Ginseng has been used as a general tonic agent to invigorate human body. In the present study, we isolated novel glycolipoproteins from ginseng that activate Ca 2+ -activated Cl -channel (CaCC) in Xenopus oocytes and transiently increase intracellular free Ca 2+ concentration ([Ca 2+ ] i ) in mouse Ehrlich ascites tumor cells. We named the active ingredients as gintonin. Gintonin exists in at least six different forms. The native molecular weight of gintonin is about 67 kDa but its apparent molecular weight is about 13 kDa, indicating that gintonin might be a pentamer. Gintonin is rich in hydrophobic amino acids. Its main carbohydrates are glucose and glucosamine. Its lipid components are linoleic, palmitic, oleic, and stearic acids. Gintonin actions were blocked by U73122, a phospholipase C inhibitor, 2-aminoethxydiphenyl borate, an inositol 1,4,5-trisphosphate receptor antagonist, or bis (o-aminophenoxy) ethane-N,N,N0,N0-tetracetic acid acetoxymethyl ester, a membrane permeable Ca 2+ chelator. In the present study, we for the fi rst time isolated novel gintonin and showed the signaling pathways on gintonin-mediated CaCC activations and transient increase of [Ca 2+ ] i . Since [Ca 2+ ] i as a second messenger plays a pivotal role in the regulation of diverse Ca 2+ -dependent intracellular signal pathways, gintonin-mediated regulations of [Ca 2+ ] i might contribute to biological actions of ginseng.

Ginseng extracts show cognition-enhancing effects in Alzheimer's disease (AD) patients. However, little is known about the active components and molecular mechanisms of how ginseng exerts its effects. Recently, we isolated a novel lysophosphatidic acid (LPA) receptor-activating ligand from ginseng, gintonin. AD is caused by amyloid-β protein (Aβ) accumulation. Aβ is derived from amyloid-β protein precursors (AβPPs) through the amyloidogenic pathway. In contrast, non-amyloidogenic pathways produce beneficial, soluble AβPPα (sAβPPα). Here, we describe our investigations of the effect of gintonin on sAβPPα release, Aβ formation, Swedish-AβPP transfection-mediated neurotoxicity in SH-SY5Y neuroblastoma cells, and Aβ-induced neuropathy in mice. Gintonin promoted sAβPPα release in a concentration- and time-dependent manner. Gintonin action was also blocked by the Ca2+ chelator BAPTA, α-secretase inhibitor TAPI-2, and protein-trafficking inhibitor brefeldin. Gintonin decreased Aβ1-42 release and attenuated Aβ1-40-induced cytotoxicity in SH-SY5Y cells. Gintonin also rescued Aβ1-40-induced cognitive dysfunction in mice. Moreover, in a transgenic mouse AD model, long-term oral administration of gintonin attenuated amyloid plaque deposition as well as short- and long-term memory impairment. In the present study, we demonstrated that gintonin mediated the promotion of non-amyloidogenic processing to stimulate sAβPPα release to restore brain function in mice with AD. Gintonin could be a useful agent for AD prevention or therapy.

For the efficient cytoplasmic delivery of siRNA, we designed a chimeric capsid protein composed of a capsid shell, integrin targeting peptide, and p19 RNA binding protein. This recombinant protein assembled into a macromolecular container-like structure with capsid shell and provided a nanocarrier for siRNA delivery. Our capsid nanocarriers had dual affinity both for siRNA within the interior and integin receptors on the exterior, and the capsid shell structure allowed the encapsulated siRNAs to be protected from the external nucleases, leading to the enhanced stability of siRNA in serum conditions. The capsid nanocarriers could complex with siRNA in a size-dependent and sequence-independent manner and showed the pH-dependent complexing/dissocation behaviors with siRNA. Moreover, RGD peptides on the exterior surface of the capsid shell enabled the capsid nanocarriers to deliver siRNA into the cytosol of the target cells. Here, we demonstrated the superior efficiency of our siRNA/capsid nanocarrier complexes in RFP gene silencing, compared to untreated cells. These results provide an alternative approach to enhancing the stability of siRNA as well as to achieving targeted siRNA delivery.

The mammalian Y chromosome has unique characteristics compared with the autosomes or X chromosomes. Here we report the finished sequence of the chimpanzee Y chromosome (PTRY), including 271 kb of the Y-specific pseudoautosomal region 1 and 12.7 Mb of the male-specific region of the Y chromosome. Greater sequence divergence between the human Y chromosome (HSAY) and PTRY (1.78%) than between their respective whole genomes (1.23%) confirmed the accelerated evolutionary rate of the Y chromosome. Each of the 19 PTRY protein-coding genes analyzed had at least one nonsynonymous substitution, and 11 genes had higher nonsynonymous substitution rates than synonymous ones, suggesting relaxation of selective constraint, positive selection or both. We also identified lineage-specific changes, including deletion of a 200-kb fragment from the pericentromeric region of HSAY, expansion of young Alu families in HSAY and accumulation of young L1 elements and long terminal repeat retrotransposons in PTRY. Reconstruction of the common ancestral Y chromosome reflects the dynamic changes in our genomes in the 5-6 million years since speciation.