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Ohguchi K.,Gifu International Institute of Biotechnology | Itoh T.,Gifu International Institute of Biotechnology | Akao Y.,Gifu International Institute of Biotechnology | Inoue H.,Nara Women's University | And 2 more authors.
British Journal of Dermatology | Year: 2010

SummaryBackground SIRT1, an NAD +-dependent histone/protein deacetylase, controls a broad range of cellular functions. Objectives We examined if SIRT1 is involved in the regulation of matrix metalloproteinase (MMP) expression in human dermal fibroblasts. Methods We studied the effect of inhibition of SIRT1 by specific inhibitor and small interfering RNA (siRNA) on MMP-1 and MMP-3 expression in human dermal fibroblasts. Results Treatment with a potent and selective inhibitor of SIRT1, EX-527, increased the basal expression levels of MMP-1 and MMP-3 proteins. Knockdown of endogenous SIRT1 by siRNA led to increased expression of MMP-1 and MMP-3 at both mRNA and protein levels. SIRT1 knockdown also upregulated MMP protein induction caused by an inflammatory cytokine, interleukin (IL)-1β. Moreover, treatment with a SIRT1 activator, resveratrol, significantly suppressed IL-1β-mediated induction of MMP-1, which was attenuated by pretreatment with EX-527. Finally, MMP-1 promoter activity was increased by EX-527 in cells treated with or without IL-1β. Conclusions Our findings suggest that SIRT1 exerts a negative regulatory role in the production of MMP-1 and MMP-3 in human dermal fibroblasts. © 2010 British Association of Dermatologists.

Kojima K.,Gifu University | Kojima K.,Gifu International Institute of Biotechnology | Fujita Y.,Gifu International Institute of Biotechnology | Nozawa Y.,Gifu International Institute of Biotechnology | And 3 more authors.
Prostate | Year: 2010

BACKGROUND Patients with hormone-refractory prostate cancer are treated with taxane drugs, but eventually become drug resistant. We aimed to elucidate the molecular mechanisms underlying paclitaxel resistance of hormone-refractory prostate cancer with a special focus on the roles of miR-34a and SIRT1. METHODS Paclitaxel-resistant cells (PC3PR) were generated from hormone-refractory PC3 cells. The expression levels of mRNA and miRNA were determined by reverse transcriptase PCR and those of protein were by Western blot analysis. Transfection of miRNA precursor or siRNA was performed using the liposome-mediated method. RESULTS MiR-34a over-expression and SIRT1 knockdown attenuated paclitaxel resistance of PC3PR cells. MiR-34a expression was reduced in PC3PR cells compared with PC3 cells, while the expression levels of HuR and Bcl2 as well as SIRT1 were elevated in PC3PR cells. Luciferase reporter assays revealed that both SIRT1 3′-UTR and promoter activities were higher in PC3PR cells than in PC3 cells. Introduction of miR-34a precursor into PC3PR cells resulted in decreases in HuR, Bcl2, and SIRT1 expression and inhibition of the SIRT1 3′-UTR activity. HuR knockdown reduced SIRT1 and Bcl2 expression. These results suggest that miR-34a not only directly but also indirectly via regulating HuR expression acts on the 3′-UTR of SIRT1 and Bcl2 mRNAs, thereby controlling their expression. Thus, in PC3PR cells, reduced expression of miR-34a confers paclitaxel resistance via up-regulating SIRT1 and Bcl2 expression. CONCLUSIONS MiR-34a and its downstream targets SIRT1 and Bcl2 play important roles in the development of paclitaxel resistance, all of which can be useful biomarkers and promising therapeutic targets for the drug resistance in hormone-refractory prostate cancer. © 2010 Wiley-Liss, Inc.

Iio A.,Gifu International Institute of Biotechnology | Nakagawa Y.,Aichi University | Hirata I.,Aichi University | Naoe T.,Nagoya University | And 2 more authors.
Molecular Cancer | Year: 2010

In a variety of cancers, altered patterns of microRNA (miRNA) expression are reported and may affect the cell cycle and cell survival. Recent studies suggest that the expression level of miRNAs that act as tumor suppressors is frequently reduced in cancers because of chromosome deletions, epigenetical changes, aberrant transcription and disturbances in miRNA processing. miR-143 and -145, which are located approximately 1.3 kb from each other at chromosome 5q33, are highly expressed in several tissues, but down-regulated in most cancers. However, the mechanism of this down-regulation has not been investigated in detail. Here, we show that both miRNAs were expressed well under the same control program in human tissues, but were down-regulated equally in the most of the cancer cell lines tested. Then we identified the host gene encoding both miRNAs. The transcripts of this gene were approximately 11, 7.5, and 5.5 kb long; and the expression of these transcripts was coordinated with that of its resident miRNAs and down-regulated in the cancer cell lines tested as well as in colorectal cancer tissue samples. These data demonstrate that the host gene can function as a primary miRNA transcript and suggest that the down-regulation of host gene expression caused the low-expression of its encoded microRNAs-143 and -145 in human cancer cell lines and in cancer tissues.© 2010 Iio et al; licensee BioMed Central Ltd.

Naoi M.,Gifu International Institute of Biotechnology | Maruyama W.,National Research Center for Geriatrics and Gerontology | Inaba-Hasegawa K.,Gifu International Institute of Biotechnology | Akao Y.,Gifu University
International Review of Neurobiology | Year: 2011

In Parkinson's disease, type B monoamine oxidase (MAO-B) is proposed to play an important role in the pathogenesis through production of reactive oxygen species and neurotoxins from protoxicants, such as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. In addition, inhibitors of MAO-B protect neurons in the cellular and animal models of Parkinson's and Alzheimer's diseases. However, the role of type A MAO (MAO-A) in neuronal death and neuroprotection by MAO-B inhibitors has been scarcely elucidated. This chapter presents our recent results on the involvement of MAO-A in the activation of mitochondrial death signal pathway and in the induction of prosurvival genes to prevent cell death with MAO-B inhibitors. The roles of MAO-A in the regulation of neuronal survival and death are discussed in concern to find a novel strategy to protect neurons in age-associated neurodegenerative disorders and depression. © 2011 Elsevier Inc.

Akao Y.,Gifu University | Noguchi S.,Gifu University | Iio A.,Gifu International Institute of Biotechnology | Kojima K.,Gifu International Institute of Biotechnology | And 2 more authors.
Cancer Letters | Year: 2011

MiR-34a was identified as one of the down-regulated micro-RNAs (miRs) in human colorectal cancer 5-fluorouracil (5-FU)-resistant DLD-1 cells compared with those in the parental DLD-1 cells. Exposure to 5-FU at 30μM activated phosphoinositide 3-kinase (PI3K)/Akt signaling markedly from 12. h up to 48. h in the 5-FU-resistant cells compared with that in the parental cells and resulted in an overt difference in growth at those times. Furthermore, the expression of miR-34a in the 5-FU-resistant cells was sustained at a low-level, whereas it was up-regulated in the parental cells after the 5-FU treatment. Sirt1, which is one of the target genes for miR-34a and related to drug-resistance, was strikingly up-regulated in the 5-FU-resistant cells. The ectopic expression of miR-34a in the 5-FU-resistant cells inhibited growth, as in the parental cells, and attenuated the resistance to 5-FU through the down-regulation of Sirt1 and E2F3. Moreover, the silencing of Sirt1 significantly canceled the resistance to 5-FU in the 5-FU-resistant cells. These findings suggest that miR-34a targeting the Sirt1 and E2F3 genes could negatively regulate, at least in part, the resistance to 5-FU in human colorectal cancer DLD-1 cells. © 2010 Elsevier Ireland Ltd.

Akao Y.,Gifu University | Iio A.,Gifu International Institute of Biotechnology | Itoh T.,Gifu International Institute of Biotechnology | Noguchi S.,Gifu University | And 3 more authors.
Molecular Therapy | Year: 2011

Microvesicles (MVs) and exosomes, which are shed from cells as a cell-to-cell communication tool, are possible vehicles for navigating RNA molecules to body tissues. It is considered that intravenous injection of such MVs or exosomes from patients would not cause severe not-self and toxic reactions. Previously, we found that macrophages take up liposome-entrapped RNA molecules, some of which remain undegraded in the cells. Here, we demonstrate that transfected RNA molecules in human monocytic leukemia THP-1 cells were shed from THP-1 macrophages as contents in MVs during incubation in serum-free medium, which shedding was shown by biochemical analyses such as quantitative reverse transcription (qRT)-PCR, expression of TSG101 (a membrane-associated exosomal protein), and immunoelectron microscopic study. More chemically modified RNA molecules (miR-143BPs) entrapped by MVs (MV-miR-143BPs) were secreted from THP-1 macrophages after miR-143BP transfection compared with the amount after transfection with nonmodified miR-143 transfection. Furthermore, we show that the THP-1 macrophages, which were transfected with the miR-143BP ex vivo, secreted MV-miR-143BPs in xenografted nude mice after intravenous injection, because miR-143 levels were significantly increased in the serum, tumor, and kidney of the host animals. These data suggest that some of the transfected miR-143BPs were secreted from THP-1 macrophages as MV-RNAs both in vitro and in vivo. © The American Society of Gene & Cell Therapy.

Maruyama W.,National Research Center for Geriatrics and Gerontology | Naoi M.,Gifu International Institute of Biotechnology | Naoi M.,Aichi Gakuin University
Journal of Neural Transmission | Year: 2013

Neuroprotection has been proposed in neurodegenerative disorders, such as Parkinson's and Alzheimer's diseases, to delay or halt disease progression or reverse neuronal deterioration. The inhibitors of type B monoamine oxidase (MAO), rasagiline and (-)deprenyl, prevent neuronal loss in cellular and animal models of neurodegenerative disorders by intervening in the death signal pathway in mitochondria. In addition, rasagiline and (-)deprenyl increase the expression of anti-apoptotic Bcl-2 protein family and neurotrophic factors. Neurotrophic factors, especially glial cell line-derived neurotrophic factor (GDNF) and brain-derived derived neurotrophic factor (BDNF), are required not only for growth and maintenance of developing neurons, but also for function and plasticity of distinct population of adult neurons. GDNF and BDNF have been reported to reduce Parkinson and Alzheimer's diseases, respectively. GDNF protects the nigra-striatal dopamine neurons in animal models of Parkinson's disease, and its administration has been tried as a disease-modifying therapy for parkinsonian patients. However, the results of clinical trials have not been fully conclusive and more practical ways to enhance GDNF levels in the targeted neurons are essentially required for future clinical application. Rasagiline and (-)deprenyl induced preferentially GDNF and BDNF in cellular and non-human primate experiments, and (-)deprenyl increased BDNF level in the cerebrospinal fluid of parkinsonian patients. In this paper, we review the induction of GDNF and BDNF by these MAO inhibitors as a strategy of neuroprotective therapy. The induction of prosurvival genes is discussed in relation to a possible disease-modifying therapy with MAO inhibitors in neurodegenerative disorders. © 2012 Springer-Verlag.

Itoh T.,Gifu International Institute of Biotechnology | Takeda S.,Keio University | Akao Y.,Gifu International Institute of Biotechnology | Akao Y.,Gifu University
Journal of Biological Chemistry | Year: 2010

MicroRNAs (miRs) represent a class of endogenous ∼18-25 nucleotide RNAs that regulate gene expression through translational repression by binding to a target mRNA. These miRs regulate several biological functions, such as cell growth, cell differentiation, carcinogenesis, and so on. In a previous report, we have indicated that miR-141 and -200a act as preosteoblast differentiation modulators. In the present study, using microRNA array and in silico analyses, we found that miR-208 is closely involved in preosteoblast differentiation by partially regulating the expression of Ets1 (V-ets erythroblastosis virus E26 oncogene homolog 1), which transactivates osteopontin, runt-related transcription factor 2, parathyroid hormone-related protein, and type I procollagen. Furthermore, the enforced expression of mature miR-208 in murine preosteoblast in MC3T3-E1 cells or primary osteoblast cells remarkably attenuated BMP-2-induced preosteoblast differentiation. In addition, we determined that Ets1 is a target gene of miR-208 by using a sensor luciferase reporter assay. Taken together, these results suggest that the down-regulation of miR-208 in BMP-2-stimulated osteoblast differentiation is an important part of the regulatory machinery involved in early osteogenesis. © 2010 by The American Society for Biochemistry and Molecular Biology, Inc.

Naoi M.,Gifu International Institute of Biotechnology | Naoi M.,Aichi Gakuin University | Maruyama W.,National Research Center for Geriatrics and Gerontology | Yi H.,Gifu International Institute of Biotechnology
Journal of Neural Transmission | Year: 2013

Rasagiline protects neuronal cells from cell death caused by various lines of insults. Its neuroprotective function is due to suppression of mitochondrial apoptosis signaling and induction of neuroprotective genes, including Bcl-2 and neurotrophic factors. Rasagiline inhibits the mitochondrial membrane permeabilization, an initial stage in apoptosis, but the mechanism has been elusive. In this paper, it was investigated how rasagiline regulates mitochondrial death cascade in apoptosis induced in SH-SY5Y cells by PK11195, a ligand of the outer membrane translocator protein of 18 kDa. Rasagiline prevented release of cytochrome c (Cyt-c), and the following caspase 3 activation, ATP depletion and apoptosis, but did not inhibit the mitochondrial membrane potential collapse, in contrast to Bcl-2 overexpression. Rasagiline stabilized the mitochondrial contact site and suppressed Cyt-c release into cytoplasm, which should be the critical point for the regulation of apoptosis. Monoamine oxidase was not associated with anti-apoptotic activity of rasagiline in PK11195-induced apoptosis. © 2013 Springer-Verlag Wien.

Inaba-Hasegawa K.,Gifu International Institute of Biotechnology | Akao Y.,Gifu University | Maruyama W.,National Research Center for Geriatrics and Gerontology | Naoi M.,Gifu International Institute of Biotechnology
Journal of Neural Transmission | Year: 2012

Rasagiline and (-)deprenyl (selegiline), irreversible type B monoamine oxidase (MAO-B) inhibitors, protect neuronal cells through gene induction of pro-survival Bcl-2 and neurotrophic factors in the cellular models of neurodegenerative disorders. In this paper, the role of MAO in the up-regulation of neuroprotective Bcl-2 gene by these inhibitors was studied using type A MAO (MAO-A) expressing wild SH-SY5Y cells and the transfectionenforced MAO-B overexpressed cells. Rasagiline and (-)deprenyl, and also befloxatone, a reversible MAO-A inhibitor, increased Bcl-2 mRNA and protein in SH-SY5Y cells. Silencing MAO-A expression with short interfering (si) RNA suppressed Bcl-2 induction by rasagiline, but not by (-)deprenyl. MAO-B overexpression inhibited Bcl-2 induction by rasagiline and befloxatone, but did not affect that by (-)deprenyl, suggesting the different mechanisms behind Bcl-2 gene induction by theseMAO-B inhibitors. The novel role of MAO-A in Bcl-2 induction by rasagiline is discussed with regard to the molecular mechanism underlying neuroprotection by the MAO inhibitors. © Springer-Verlag 2011.

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