Chaperone protein BiP binds to Ire1 and dissociates in response to endoplasmic reticulum (ER) stress. However, it remains unclear how the signal transducer Ire1 senses ER stress and is subsequently activated. The crystal structure of the core stress-sensing region (CSSR) of yeast Ire1 luminal domain led to the controversial suggestion that the molecule can bind to unfolded proteins. We demonstrate that, upon ER stress, Ire1 clusters and actually interacts with unfolded proteins. Ire1 mutations that affect these phenomena reveal that Ire1 is activated via two steps, both of which are ER stress regulated, albeit in different ways. In the first step, BiP dissociation from Ire1 leads to its cluster formation. In the second step, direct interaction of unfolded proteins with the CSSR orients the cytosolic effector domains of clustered Ire1 molecules.

The efficient asymmetric total synthesis of (-)-oseltamivir, an antiviral reagent, has been accomplished by using two "one-pot" reaction sequences, with excellent overall yield (60 %) and only one required purification by column chromatography. The first one-pot reaction sequence consists of a diphenylprolinol silyl ether mediated asymmetric Michael reaction, a domino Michael reaction/Horner-Wadsworth-Emmons reaction combined with retro-aldol/Horner-Wadsworth-Emmons reaction and retro Michael reactions, a thiol Michael reaction, and a base-catalyzed isomerization. Six reactions can be successfully conducted in the second one-pot reaction sequence; these are deprotection of a tert-butyl ester and its conversion into an acyl chloride then an acyl azide, Curtius rearrangement, amide formation, reduction of a nitro group into an amine, and a retro Michael reaction of a thiol moiety. A column-free synthesis of (-)-oseltamivir has also been established.

Abstract. Signaling molecules produced by osteocytes have been proposed to serve as soluble factors that contribute to bone remodeling, as well as to homeostasis of other organs. However, to the best of our knowledge, there are currently no studies investigating the role of osteocyte-secreted exosomes. In the present study, ablation of osteocytes in mice [osteocyte-less (OL)] was used to examine the microRNA (miRNA) levels of plasma-circulating exosomes. In order to investigate the function of osteocyte-secreted exosomes, exosomes derived from MLO-Y4 cells were extracted and their miRNA expression levels were examined using miRNA array analysis and deep sequencing. Comparison of miRNA expression levels between plasma exosomes from OL mouse plasma and MLO-Y4-derived exosomes revealed that decreases in the number of miRNAs from exosomes circulating in the OL mouse plasma may be caused by a decrease in secretion of exosomes from osteocytes. These results suggest that osteocytes secrete exosomes containing characterized miRNAs and then circulate in the blood, and may thus transfer their components, including miRNAs, to recipient cells where they function as signaling molecules in other organs and/or tissues to regulate biological responses.

Granulocyte colony-stimulating factor (G-CSF) is widely used for peripheral blood stem/progenitor mobilization. G-CSF causes low-grade fever that is ameliorated by nonsteroidal anti-inflammatory drugs (NSAIDs), suggesting the activation of arachidonic acid (AA) cascade. How G-CSF regulated this reaction was assessed. G-CSF treatment in mice resulted in fever, which was canceled in prostaglandin E synthase (mPGES-1)-deficient mice. Mobilization efficiency was twice as high in chimeric mice lacking mPGES-1, specifically in hematopoietic cells, suggesting that prostaglandin E (PGE) from hematopoietic cells modulated the bone marrow (BM) microenvironment. Neutrophils from steady-state BM constitutively expressed mPGES-1 and significantly enhanced PGE production in vitro by β-adrenergic stimulation, but not by G-CSF, which was inhibited by an NSAID. Although neutrophils expressed all β-adrenergic receptors, only β3-agonist induced this phenomenon. Liquid chromatography-tandem mass spectrometry traced β-agonist-induced PGE synthesis from exogenous deuterium-labeled AA. Spontaneous PGE production was highly efficient in Gr-1 neutrophils among BM cells from G-CSF-treated mice. In addition to these in vitro data, the in vivo depletion of Gr-1 neutrophils disrupted G-CSF-induced fever. Furthermore, sympathetic denervation eliminated both neutrophil priming for PGE production and fever during G-CSF treatment. Thus, sympathetic tone-primed BM neutrophils were identified as one of the major PGE producers. PGE upregulated osteopontin, specifically in preosteoblasts, to retain progenitors in the BM via EP4 receptor. Thus, the sympathetic nervous system regulated neutrophils as an indispensable PGE source to modulate BM microenvironment and body temperature. This study provided a novel mechanistic insight into the communication of the nervous system, BM niche components, and hematopoietic cells.

A great deal of attention has been paid both in the scientific literature and the general media to the high potential risk of a worldwide spread of avian H5N1 influenza virus, the death rate of which is over 50 %.[1] Indeed, should this virus acquire the ability to become capable of spreading easily and directly from human to human it could very possibly cause a disastrous pandemic. (À)-Oseltamivir phosphate (Tamiflu), a neuraminidase inhibitor used in the treatment of both type A and type B human influenza, [2] is one of the most promising therapeutics, and many nations have plans to stock a significant amount of this compound in case of a possible influenza outbreak. Moreover, the recent emergence of Tamiflu-resistant virus strains has prompted the chemical community to develop medicines effective against the mutated virus.[3] To meet these demands, intensive efforts have been devoted to the development of efficient preparations of this life-saving drug [1,2,4] and of its derivatives. For our synthesis of Tamiflu, we set the following objectives, because meeting these requirements would allow a large amount to be prepared in a short time and at low cost: 1) The number of synthetic reactions should be not more than ten, and the number of separate operations should be as few as possible.2) The overall yield should be over 50 %. 3) Only inexpensive reagents should be employed. Preparing a molecule of this complexity, possessing three contiguous chiral centers, in no more than ten synthetic reactions in over 50 % overall yield is a very challenging goal. Even if each individual reaction of a sequence proceeds in 90 % yield-an excellent yield in organic synthesis-the overall yield falls to 35 % after ten reactions (0.9 10 = 0.35). The best yield yet achieved for the total synthesis of Tamiflu is approximately 35 %. [4b, d] Moreover, in order to supply Tamiflu to developing countries where influenza might spread, production costs should be kept low. This requires that only inexpensive reagents be used. Although several syntheses of Tamiflu have been reported, previous methods do not meet all these requirements, and developing a method which does so remains a great challenge for the chemical community.One-pot operations are effective for carrying out several transformations and forming several bonds in a single pot, while at the same time cutting out several purification steps, minimizing chemical waste generation, and saving time. To simplify the synthesis we investigated the preparation of Tamiflu by a small number of one-pot operations. Our strategy was to construct a key, fully functionalized ethyl cyclohexenecarboxylate intermediate in a single-pot operation as the first step; after this, the remainder of the synthesis consists simply of functional group manipulations, also carried out in one-pot operations.The first key reaction relied on organocatalysis, a relatively new, rapidly developing technology in synthetic organic chemistry.[5] Diphenylprolinol silyl ether 4, [6] which was developed independently by ou...

Fibroblast growth factor-23 (FGF23) hormone is produced by bone-embedded osteocytes and regulates phosphate homeostasis in kidneys. We found that granulocyte colony-stimulating factor (G-CSF) administration in mice induced a rapid and tremendous increase in FGF23 mRNA in bone marrow (BM) cells. This increase mainly originated from CD45-Ter119+CD71+ erythroblasts. FGF23 protein in BM extracellular fluid was markedly increased during G-CSF-induced hematopoietic progenitor cell (HPC) mobilization but remained stable in the blood with no change in the phosphate level. Consistent with the BM hypoxia induced by G-CSF, low oxygen concentration induced FGF23 release from human erythroblast HUDEP-2 cells in vitro. The mobilization efficiency by G-CSF was drastically decreased in both FGF23-/- and chimeric mice with FGF23 deficiency only in hematopoietic cells but increased in osteocyte-specific FGF23-/- mice. This suggests that erythroblast-derived, but not bone-derived, FGF23 is required to release HPCs from BM to circulation. Mechanistically, FGF23 did not influence CXCL12 binding to CXCR4 on progenitors but interfered with their transwell migration toward CXCL12, which was canceled by FGF receptor inhibitors. These results suggest that BM erythroblasts facilitate G-CSF-induced HPC mobilization via FGF23 production as an intrinsic suppressor of chemoattraction.

Polarized infrared (IR) reflectance measurements were performed on polyoxymethylene (POM) prepared by the extrusion method, and an abnormally high reflectance of ∼90% was observed along the extruded direction in the 1000 cm−1–900 cm−1 region. High reflectivity was found in samples made by the conventional injection molding. However, the response of the extrusion sample was higher than that of the injection sample, which can be attributed to the Reststrahlen band. The relative permittivity calculated from the polarized reflection spectrum of the extruded direction shows a notably deep negative region in this high reflectance frequency. Using x rays, by differential scanning calorimetry, and by field emission scanning electron microscopy characterization, the difference in crystallinity and morphology from the extrusion and the injection molding plate was investigated, and the difference in IR optical response was discussed. The conventional IR band assignment of POM was also discussed.

Quantitative structural analysis by conventional X-ray diffraction and anomalous X-ray scattering coupled with the reverse Monte-Carlo simulation technique has been carried out, in order to characterize the atomicscale structure of rust formed on the surface of Fe, Fe-2 %Cr, Fe-3 %Ni and Fe-1.6 %Cu alloys and a weathering steel. Rust samples were prepared by filtering corrosion products formed on the surface of these alloys in salt water. X-ray diffraction patterns showed that main components of the rust consist of ferric oxyhydroxides such as g-FeOOH. Radial distribution functions obtained from both conventional X-ray diffraction and anomalous X-ray scattering clearly indicated that the fundamental local unit structure in the rust is the octahedral FeO 6 , although it is likely to be distorted. Realistic atomic arrangements in the rust were estimated by fitting of the ordinary and environmental interference functions calculated using the reverse Monte-Carlo simulation technique. These results provided that the network structure consists of the FeO 6 octahedral units and its distortion depend upon the composition of samples. These facts suggest that alloying elements in the rust, which themselves are corroded, play an important role in forming the atomic-scale structure of the rust.KEY WORDS: X-ray diffraction; reverse Monte-Carlo simulation; iron based alloys; weathering steel; rust; corrosion; atomic structure.alloys, containing chromium, nickel or copper, and weathering steel in salt water, because a few percents of these alloying elements are known to be added to iron based alloys in order to improve corrosion protection of steel. It has also been the focusing point of this work to reveal the network structure consisting of FeO 6 octahedral units and its distortion from the ideal case found in a typical ferric oxyhydroxide of g-FeOOH. This includes how the alloying elements affect on the structure of rust formed on the surface of various iron based alloys and steel. Experimental SamplesSamples of iron, iron-2.0 mass% chromium, iron-3.0 mass% nickel and iron-1.6 mass% copper alloys were prepared from pure iron, chromium and nickel by vacuum induction melting. 12) These samples were hereafter referred to as Fe, Fe-2 %Cr, Fe-3 %Ni and Fe-1.6 %Cu, respectively. A commercial weathering steel referred to as WS, of which the chemical composition is 0.10% C, 0.050% Si, 0.50% Mn, 0.096 % P, 0.016 % S, 0.15 % Ni and 0.56 % Cr in mass%, was also utilized. The iron based alloys and steel were shaped to10 mm square sheets of 1 mm in thickness. They were leached in artificial seawater with 2.5 mass% NaCl, 1.1 mass% MgCl 2 , 0.4 mass% Na 2 SO 4 and 0.07 mass% KCl at room temperature for about 15 days, so as to form colloidal corrosion products, from which powder rust samples were obtained by filtering. The structures of the corrosion products were almost independent of leaching time. Measurements And analysisConventional X-ray diffraction experiments were carried out using Cu Ka radiation, in order to identify constituents...