Irie M.,Rikkyo University |
Fukaminato T.,Hokkaido University |
Matsuda K.,Kyoto University |
Kobatake S.,Osaka City University
Chemical Reviews | Year: 2014
Chemical bond rearrangement during the phototransformation induces electronic as well as geometrical structure changes of the molecules. The molecular structure changes can be applied to various photonic devices. The electronic structure changes can be applied to optical memory media and various photoswitching devices. On the other hand, the geometrical structure changes can be applied to light-driven actuators and others. The photochromic diarylethene was serendipitously discovered during the course of study on photoresponsive polymers a quarter of a century ago. Various types of polymers having photoisomerizable chromophores, such as spiropyran, azobenzene, or stilbene, in the side or main chains, have been prepared in an attempt to change their conformation by photoirradiation.
Tanaka T.,Osaka City University
Current pharmaceutical design | Year: 2013
Tumor cells frequently promote the dysregulation of the cell cycle and escape from apoptotic cell death triggered by a number of cellular stresses. Programmed proteolytic degradation of regulatory proteins via the ubiquitin-proteasome pathway is crucial for homeostasis of numerous biological processes. Disruption of this system is one of the factors that promote aberrant cell-proliferation. The small ubiquitin-like protein, NEDD8, has been identified as a fundamental regulator of the activity of the E3 ubiquitin ligases called the SCF complex (consisting of Skp-1, cullin, and F-box protein) or CRL (cullin-RING ubiquitin ligase) which control a final step in ubiquitination of diverse substrates associated with cancer biology. The ubiquitin ligase activity of the SCF complex requires NEDD8 to covalently bind to cullins. To a large extent, exploring the negative regulation system of the NEDD8 pathway is expected to lead to the development of novel anticancer targets. This review focuses on the NEDD8 negative regulation system including chemical compounds such as MLN4924 and protein molecules (e.g. COP9 signalosome, CAND1, inactive mutant of Ubc12 and NUB1/NUB1L) and clarifies possible strategies for targeting the NEDD8 cascade in cancer cells.
Shinoda S.,Osaka City University |
Shinoda S.,Japan Science and Technology Agency
Chemical Society Reviews | Year: 2013
Structural dynamism plays important roles in artificial and biological systems, because it controls structures and functions of various molecules and assemblies. In this review, molecular recognition and self-assembling behavior of dynamic armed cyclen-metal complexes are discussed at the molecular and supramolecular levels. These metal complexes provide useful platforms for molecular receptors, supramolecules, and molecular assemblies that can respond rapidly to guest molecules and environments. Since armed cyclens have many structural and geometrical variations, they form a wide variety of metal complexes having specific sensing and signaling functions. The Lewis acidity of the metal cations plays an essential role in anion binding and in hydrolytic catalysis of phosphate esters. Characteristic luminescence and magnetic properties of lanthanides also enable techniques for effective bio-imaging. They also serve as chiral building blocks for self-assembled architectures, which offer chirality integration effective for chirality sensing and signaling at the supramolecular level. © 2013 The Royal Society of Chemistry.
Kawada N.,Osaka City University
Hepatology Research | Year: 2011
Molecular analysis of hepatic fibrogenesis has progressed with respect to both fibrosis progression and regression by using cell biological, molecular biological and (epi)genetic approaches. Recent researches have revealed sources of collagen-producing cells other than hepatic stellate cells in the liver, and the involvement of the innate immune system and oxidative stress in the fibrotic process has attracted new attention. Together with these advancements in basic knowledge on the cellular and molecular biology of hepatic fibrosis, clinical researches have linked the clarification of the relationship between progression of the fibrosis stage and therapeutic efficacy for chronic viral hepatitis and non-alcoholic steatohepatitis and validation of the regression of advanced fibrosis, even cirrhosis, of appropriate therapies using modern medicines. Furthermore, non-invasive assessment of liver fibrosis using an ultrasound-based modality has become a focus in the clinical diagnosis of liver fibrosis instead of liver biopsy. Taken together, liver fibrosis research has been evolving both basically and clinically in the past three decades. © 2011 The Japan Society of Hepatology.
Vinogradov A.,Osaka City University
Scripta Materialia | Year: 2010
The acoustic emission (AE) method is proposed for the assessment of shear band velocity in metallic glasses. The shear band velocity is discussed in light of analysis of real-time AE transient events which occur during inhomogeneous plastic flow. It is estimated that the velocity of shear events triggering shear bands should be at least as high as 1-10 m s-1 to be detected by AE transducers. © 2010 Acta Materialia Inc.