A multifunctional shuttling protein nucleolin is a macrophage receptor for apoptotic cells

Early apoptotic Jurkat T cells undergo capping of CD43, and its polylactosaminyl saccharide chains serve as ligands for phagocytosis by macrophages. This suggests the presence of a polylactosaminoglycan-binding receptor on macrophages. Here we show that this receptor is nucleolin, a multifunctional shuttling protein present in nucleus, cytoplasm, and on the surface of some types of cells. Nucleolin was detected at the surface of macrophages, and anti-nucleolin antibody inhibited the binding of the early apoptotic cells to macrophages. Nucleolin-transfected HEK293 cells expressed nucleolin on the cell surface and bound the early apoptotic cells but not phosphatidylserine-exposing late apoptotic cells. This binding was inhibited by anti-nucleolin antibody, by polylactosamine-containing oligosaccharides, and by anti-CD43 antibody. Deletion of the antibody binding region of nucleolin resulted in loss of the apoptotic cell-binding ability. Moreover, truncated recombinant nucleolin in solution containing this region blocked the apoptotic cell binding to macrophages, and the blocking effect was cancelled by the oligosaccharides. These results indicate that nucleolin is a macrophage receptor for apoptotic cells.     

Characterization of the heme environmental structure of cytoglobin,a fourth globin in humans

Cytoglobin (Cgb) represents a fourth member of the globin superfamily in mammals, but its function is unknown. Site-directed mutagenesis, in which six histidine residues were replaced with alanine, was carried out, and the results indicate that the imidazoles of His81 (E7) and His113 (F8) bind to the heme iron as axial ligands in the hexacoordinate and the low-spin state. The optical absorption, resonance Raman, and IR spectral results are consistent with this conclusion. The redox potential measurements revealed an E' of 20 mV (vs NHE) in the ferric/ferrous couple, indicating that the imidazole ligands of His81 and His113 are electronically neutral. On the basis of the nu(Fe-CO) and nu(C-O) values in the resonance Raman and infrared spectra of the ferrous-CO complexes of Cgb and its mutants, it was found that CO binds to the ferrous iron after the His81 imidazole is dissociated, and three conformers are present in the resultant CO coordination structure. Two are in closed conformations of the heme pocket, in which the bound CO ligand interacts with the dissociated His81 imidazole, while the third is in an open conformation. The nu(Fe-O2) in the resonance Raman spectra of oxy Cgb can be observed at 572 cm(-1), suggesting a polar heme environment. These structural properties of the heme pocket of Cgb are discussed with respect to its proposed in vivo oxygen storage function.     

Angelica keiskei extract improves insulin resistance and hypertriglyceridemia in rats fed a high-fructose drink

Angelica keiskei is a traditional herb peculiar to Japan and abundantly contains vitamins, dietary fiber and such polyphenols as chalcone. We investigated in the present study the effect of A. keiskei on insulin resistance and hypertriglyceridemia in fructose-drinking rats as a model for the metabolic syndrome. Male Wistar rats were given a 15% fructose solution as drinking water for 11 weeks. Fructose significantly increased the levels of serum insulin and triglyceride (TG) compared with the control level. Treatment with an ethanol extract of A. keiskei (AE) significantly reduced the levels of blood glucose (-16.5%), serum insulin (-47.3%), HOMA-R (-56.4%) and TG (-24.2%). A hepatic gene analysis showed that fructose reduced the expression of the genes related to fatty acid β-oxidation and high-density lipoprotein (HDL) production. Treatment with AE enhanced the expression of the acyl-CoA oxidase 1 (ACO1), medium-chain acyl-CoA dehydrogenase (MCAD), ATP-binding membrane cassette transporter A1 (ABCA1) and apolipoprotein A1 (Apo-A1) genes. These results suggest that AE improved the insulin resistance and hypertriglyceridemia of the fructose-drinking rats.     

Preischemic infusion of alpha-human atrial natriuretic peptide elicits myoprotective effects against ischemia reperfusion in isolated rat hearts

In order to study the role of membrane proteins in bilirubin (BR) binding phenomenon, selective removal of membrane proteins was carried out using various reagents, namely, ethylenediamine tetraacetic acid (EDTA), sodium hydroxide (NaOH), 3,5-diiodosalicylic acid, lithium salt (LIS), dimethylmaleic anhydride (DMMA), sodium iodide (NaI), o-phenanthroline-cupric sulfate (CuP) and phenanthroline-cupric sulfate containing 2-mercaptoethanol (CuP-mercaptoethanol). Effects of these treatments on the conformation and BR binding properties of the membrane were studied using circular dichroism (CD) spectroscopy as well as estimation of membrane-bound BR by diazotised-color reaction. Though a significant amount of protein (ranging from 23–69%) was lost from the membranes upon these treatments, only a small decrease (3–13%) was observed in BR binding, being maximum with NaOH-treated membranes. However, DMMA and NaI treatments produced a little increase in BR binding. Conformation of the membrane was retained to a significant extent as indicated by far-UV CD spectra upon these treatments except in DMMA and NaI treatments which resulted in the perturbation in CD spectra. Taken together, these results suggest that membrane proteins play little role in BR binding, rather act as barriers in BR binding phenomenon.     

Numerically evaluated functional equivalence between chaotic dynamics in neural networks and cellular automata under totalistic rules

Chaotic dynamics in a recurrent neural network model and in two-dimensional cellular automata, where both have finite but large degrees of freedom, are investigated from the viewpoint of harnessing chaos and are applied to motion control to indicate that both have potential capabilities for complex function control by simple rule(s). An important point is that chaotic dynamics generated in these two systems give us autonomous complex pattern dynamics itinerating through intermediate state points between embedded patterns (attractors) in high-dimensional state space. An application of these chaotic dynamics to complex controlling is proposed based on an idea that with the use of simple adaptive switching between a weakly chaotic regime and a strongly chaotic regime, complex problems can be solved. As an actual example, a two-dimensional maze, where it should be noted that the spatial structure of the maze is one of typical ill-posed problems, is solved with the use of chaos in both systems. Our computer simulations show that the success rate over 300 trials is much better, at least, than that of a random number generator. Our functional simulations indicate that both systems are almost equivalent from the viewpoint of functional aspects based on our idea, harnessing of chaos.     

Lignin is linked to ethyl-carbamate formation in ume (Prunus mume) liqueur

Ethyl carbamate concentrations in oak barrel-aged ume (Prunus mume) liqueurs were measured, and possible explanations for elevated levels were examined. The average concentration was 0.30 mg/L, significantly higher than in ume liqueurs not aged in oak (0.08 mg/L). Oak powder extracts were prepared from both untoasted and toasted oak powder by extraction with aqueous ethanol, and these were used to make ume liqueurs. Relative to a no-oak control, the ethyl carbamate concentrations were 3.8 and 11 times higher in the ume liqueur made with the untoasted and toasted oak powder extracts respectively. The extracts were loaded onto a C18 column, washed with water, and eluted with methanol. The (13)C-NMR spectra for the main constituents of the methanol elution fractions were consistent with those for lignin or fragments thereof. The methanol fractions were added to ume liqueur which was stored for 3 months. Relative to a control, the ethyl carbamate concentrations in the 3-month old liqueurs were found to be 1.2 and 4.6 higher for the untoasted oak-powder and the toasted oak-powder respectively. Ethyl carbamate was formed when lignin was added to a 40% aqueous ethanol solution that contained potassium cyanide. These observations suggest that lignin or fragments thereof promote the formation of ethyl carbamate.     

Migration and immunological reaction after the administration of αGalCer-pulsed antigen-presenting cells into the submucosa of patients with head and neck cancer

Background  

Antigen-presenting cells (APCs) play a crucial role in the induction of immune responses. However, the optimal administration route of tumor-specific APCs for inducing effective immunological responses via cancer immunotherapy remains to be elucidated. Human NKT cells are known to have strong anti-tumor activities and are activated by the specific ligand, namely, α-galactosylceramide (αGalCer).     

Discovery of potent, selective, and orally bioavailable quinoline-based dipeptidyl peptidase IV inhibitors targeting Lys554

Dipeptidyl peptidase IV (DPP-4) inhibition is a validated therapeutic option for type 2 diabetes, exhibiting multiple antidiabetic effects with little or no risk of hypoglycemia. In our studies involving non-covalent DPP-4 inhibitors, a novel series of quinoline-based inhibitors were designed based on the co-crystal structure of isoquinolone 2 in complex with DPP-4 to target the side chain of Lys554. Synthesis and evaluation of designed compounds revealed 1-[3-(aminomethyl)-4-(4-methylphenyl)-2-(2-methylpropyl)quinolin-6-yl]piperazine-2,5-dione (1) as a potent, selective, and orally active DPP-4 inhibitor (IC??=1.3 nM) with long-lasting ex vivo activity in dogs and excellent antihyperglycemic effects in rats. A docking study of compound 1 revealed a hydrogen-bonding interaction with the side chain of Lys554, suggesting this residue as a potential target site useful for enhancing DPP-4 inhibition.     

The generation of tumor-specific in vivo protective immunity in the tumor mass from mice rendered tolerant to tumor antigens

Summary C3H/He mice were inoculated i.v. with 10⁶ heavily X-irradiated syngeneic X5563 plasmacytoma cells 3 times at 4 day intervals. When these mice received an appropriate immunization procedure consisting of i. d. inoculation of viable tumor cells plus the surgical resection of the tumor which enables i.v. nonpresensitized mice to produce anti-X5563 immunity, they failed to develop tumor-specific immunity. This was demonstrated by the abrogation in potential of spleen and lymph node cells to generate in vivo protective immunity. In contrast, the tumor mass from X5563 tumor-bearing mice which had received the i.v. presensitization contained comparable anti-X5563 tumor neutralizing activity to that obtained from the tumor mass from nonpresensitized, X5563 tumor-bearing mice. Such an in vivo protective immunity was revealed to be mediated by tumor-specific T cells. These results demonstrate the differential generation and antitumor capability of tumor infiltrating T cells and T cells in lymphoid organs from mice which are in the tumor-specific tolerant state. The results are discussed in the context of potential utilization of tumor infiltrating in vivo protective T cells to enhance the local tumor-specific immunity in tumor-specific tolerant mice.This work was supported by Special Project Research-Cancer Bioscience from the Ministry of Education, Science and Culture