Mimura J.,Hirosaki University |
Kosaka K.,Nagase and Co. |
Maruyama A.,Hirosaki University |
Satoh T.,Iwate University |
And 5 more authors.
Journal of Biochemistry | Year: 2011
Nerve growth factor (NGF) is a neurotrophic factor that plays an important role in neuronal cell development and survival. Carnosic acid (CA), a hydrophobic constituent of the herb rosemary, induces NGF production in human T98G glioblastoma cells, but the mechanism through which it works remains unknown. In the present study, we found a redox-sensitive transcription factor, Nrf2, which coordinates the expression of cytoprotective phase 2 genes, also participates in CA-inducible NGF expression. In T98G cells, CA caused NGF gene induction in a dose- and time-dependent manner without altering NGF mRNA stability. Simultaneously, CA increased Nrf2 nuclear accumulation and activated expression of prototypical Nrf2 target genes such as haem oxygenase 1 (HO-1) and thioredoxin reductase 1 (TXNRD1). Knockdown of endogenous Nrf2 by Nrf2-specific siRNA significantly reduced constitutive and CA-inducible NGF gene expression. In addition, NGF gene expression was enhanced by knockdown of Keap1, an Nrf2 inhibitor, in the absence of CA. Furthermore, CA induced NGF expression in normal human astrocytes in an Nrf2-dependent manner. These results highlight a role of Nrf2 in NGF gene expression in astroglial cells. © The Authors 2011. Source
Rezaie T.,Sanford Burnham Institute for Medical Research |
McKercher S.R.,Sanford Burnham Institute for Medical Research |
Kosaka K.,Nagase and Co. |
Seki M.,Sanford Burnham Institute for Medical Research |
And 10 more authors.
Investigative Ophthalmology and Visual Science | Year: 2012
Purpose. The herb rosemary has been reported to have antioxidant and anti-inflammatory activity. We have previously shown that carnosic acid (CA), present in rosemary extract, crosses the blood-brain barrier to exert neuroprotective effects by upregulating endogenous antioxidant enzymes via the Nrf2 transcriptional pathway. Here we investigated the antioxidant and neuroprotective activity of CA in retinal cell lines exposed to oxidative stress and in a rat model of light-induced retinal degeneration (LIRD). Methods. Retina-derived cell lines ARPE-19 and 661W treated with hydrogen peroxide were used as in vitro models for testing the protective activity of CA. For in vivo testing, dark-adapted rats were given intraperitoneal injections of CA prior to exposure to white light to assess protection of the photoreceptor cells. Retinal damage was assessed by measuring outer nuclear layer thickness and by electroretinogram (ERG). Results. In vitro, CA significantly protected retina-derived cell lines (ARPE-19 and 661W) against H2O2-induced toxicity. CA induced antioxidant phase 2 enzymes and reduced formation of hyperoxidized peroxiredoxin (Prx)2. Similarly, we found that CA protected retinas in vivo from LIRD, producing significant improvement in outer nuclear layer thickness and ERG activity. Conclusions. These findings suggest that CA may potentially have clinical application to diseases affecting the outer retina, including age-related macular degeneration and retinitis pigmentosa, in which oxidative stress is thought to contribute to disease progression. © 2012 The Association for Research in Vision and Ophthalmology, Inc. Source
Meng P.,Hirosaki University |
Yoshida H.,Hirosaki University |
Tanji K.,Hirosaki University |
Matsumiya T.,Hirosaki University |
And 11 more authors.
Neuroscience Research | Year: 2015
Amyloid-beta (Aβ) peptides, Aβ 1-42 (Aβ42) and Aβ43 in particular, cause neurotoxicity and cell death in the brain of Alzheimer's disease (AD) at higher concentrations. Carnosic acid (CA), a phenolic diterpene compound in the labiate herbs rosemary and sage, serves as an activator for neuroprotective and neurotrophic functions in brain cells. We investigated the effect of CA on apoptosis induced by Aβ42 or Aβ43 in cultured SH-SY5Y human neuroblastoma cells. Treatment of the cells with Aβ42 or Aβ43 (monomer, 10. μM each) induced apoptosis, which was confirmed by the cleavage of poly-(ADP-ribose) polymerase (PARP) and apoptosis-inducing factor (AIF). Concurrently, the Aβ treatment induced the activation of caspase (Casp) cascades including an effector Casp (Casp3) and initiator Casps (Casp4, Casp8 and Casp9). Pretreatment of the cells with CA (10. μM) partially attenuated the apoptosis induced by Aβ42 or Aβ43. CA pretreatment also reduced the cellular oligomers of Aβ42 and Aβ43. These results suggest that CA suppressed the activation of Casp cascades by reducing the intracellular oligomerization of exogenous Aβ42/43 monomer. The ingestion of an adequate amount of CA may have a potential in the prevention of Aβ-mediated diseases, particularly AD. © 2014 Elsevier Ireland Ltd and the Japan Neuroscience Society. Source
Sota M.,University of Idaho |
Sota M.,Nagase and Co. |
Yano H.,University of Idaho |
M Hughes J.,University of Idaho |
And 5 more authors.
ISME Journal | Year: 2010
The ability of bacterial plasmids to adapt to novel hosts and thereby shift their host range is key to their long-term persistence in bacterial communities. Promiscuous plasmids of the incompatibility group P (IncP)-1 can colonize a wide range of hosts, but it is not known if and how they can contract, shift or further expand their host range. To understand the evolutionary mechanisms of host range shifts of IncP-1β plasmids, an IncP-1Β mini-replicon was experimentally evolved in four hosts in which it was initially unstable. After 1000 generations in serial batch cultures under antibiotic selection for plasmid maintenance (kanamycin resistance), the stability of the mini-plasmid dramatically improved in all coevolved hosts. However, only plasmids evolved in Shewanella oneidensis showed improved stability in the ancestor, indicating that adaptive mutations had occurred in the plasmid itself. Complete genome sequence analysis of nine independently evolved plasmids showed seven unique plasmid genotypes that had various kinds of single mutations at one locus, namely, the N-terminal region of the replication initiation protein TrfA. Such parallel evolution indicates that this region was under strong selection. In five of the seven evolved plasmids, these trfA mutations resulted in a significantly higher plasmid copy number. Evolved plasmids were found to be stable in four other naive hosts, but could no longer replicate in Pseudomonas aeruginosa. This study shows that plasmids can specialize to a novel host through trade-offs between improved stability in the new host and the ability to replicate in a previously permissive host. © 2010 International Society for Microbial Ecology All rights reserved. Source
Ichinose H.,Japan National Food Research Institute |
Araki Y.,Mie University |
Michikawa M.,Japan National Food Research Institute |
Harazono K.,Nagase and Co. |
And 3 more authors.
Applied and Environmental Microbiology | Year: 2012
We cloned two glycoside hydrolase family 74 genes, the sav_1856 gene and the sav_2574 gene, from streptomyces avermitilis nbrc14893 and characterized the resultant recombinant proteins. The sav_1856 gene product (saGH74a) consisted of a catalytic domain and a family 2 carbohydrate-binding module at the c terminus, while the sav_2574 gene product (sagh74b) consisted of only a catalytic domain. Sagh74a and sagh74b were expressed successfully and had molecular masses of 92 and 78 kda, respectively. Both recombinant proteins were xyloglucanases. SaGH74a had optimal activity at 60°c and ph 5.5, while sagh74b had optimal activity at 55°c and ph 6.0. SaGH74a was stable over a broad ph range (pH 4.5 to 9.0), whereas sagh74b was stable over a relatively narrow ph range (pH 6.0 to 6.5). Analysis of the hydrolysis products of tamarind xyloglucan and xyloglucan-derived oligosaccharides indicated that sagh74a was endo-processive, while sagh74b was a typical endo-enzyme. The c terminus of sagh74a, which was annotated as a carbohydrate-binding module, bound to β-1,4-linked glucan-containing soluble polysaccharides such as hydroxyethyl cellulose, barley glucan, and xyloglucan. © 2012, American Society for Microbiology. Source