Hiroyuki Yukawa

Osaka Medical College, Takatuki, Ōsaka, Japan

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Publications (8)26.6 Total impact

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    ABSTRACT: Fibroblast growth factor (FGF)-2 is a potent neurotrophic and angiogenic peptide. To examine possible protective effects of FGF-2 gene expression against transient focal cerebral ischemia in rats, a replication defective, recombinant adenovirus vector expressing FGF-2, was injected intraventricularly 2 hours after middle cerebral artery occlusion (MCAO). The treatment group showed significant recovery compared with the vehicle-treated groups in terms of serial neurologic severity scores over the 35 days after MCAO. Further, 2,3,5-triphenyltetrazolium chloride staining showed that FGF-2 gene transfer decreased infarct volume by 44% as compared with that in the vehicle-treated groups at 2 days after MCAO. The same tendency of gene transfer effects on infarct volume was confirmed at 35 days after MCAO with hematoxylin/eosin staining. Enzyme-linked immunosorbent assay revealed that FGF-2 concentration was increased significantly at 2 days after MCAO, not only in cerebrospinal fluid but also in cerebral substance in the lesioned and treated animals. These results suggested that FGF-2 gene transfer using these adenoviral vectors might be a useful modality for the treatment of occlusive cerebrovascular disease even after the onset of stroke.
    Journal of Cerebral Blood Flow & Metabolism 12/2004; 24(11):1205-13. DOI:10.1097/01.WCB.0000136525.75839.41 · 5.41 Impact Factor
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    ABSTRACT: We constructed two replication-deficient recombinant adenovirus vectors coding human basic fibroblast growth factor (bFGF), one with and one without the interleukin-2 (IL-2) secretory signal sequence and examined their neurotrophic effects on primary neuronal cells in vitro. The primary neuronal cells were successfully infected at a high efficiency with the adenovirus vectors. bFGF protein was detected in the culture medium of the neurons infected with both these vectors. The cells infected with the bFGF-expressing adenovirus containing the IL-2 signal sequence showed 2- to 10-fold higher levels of secretion levels than cells infected with the native bFGF-expressing adenovirus alone. Both bFGF-expressing vectors augmented the survival of primary neuronal cells in an in vitro culture, compared with a mock infection or control virus infection. Notably, the cells infected with the bFGF-expressing adenovirus containing the IL-2 signal sequence were markedly enhanced cell survival in the early phase of the culture, compared with the control cells and even those infected with the bFGF-expressing adenovirus without the IL-2 signal sequence. However, in the late phase of neuronal culture, neither viral vector could support the cell survival. In contrast the co-infection of the bFGF-expressing vector with a Bcl-xL-expressing vector was extremely effective on neuronal survival.
    Neuroreport 07/2000; 11(9):2001-6. DOI:10.1097/00001756-200006260-00039 · 1.52 Impact Factor
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    ABSTRACT: Cerebral ischemic disease often causes morbidity and mortality, while the induction of new blood vessels is expected to provide a therapeutic effect in this occlusive cerebrovascular disease. In this study, we utilized two replication-deficient adenoviral vectors containing cDNA from basic fibroblast growth factor (bFGF), a well-known angiogenic factor, and examined whether biological angiogenic activity of adenovirally gene-transferred bFGF could be observed in the rat brain. One vector contained native cDNA from bFGF without the secretory signal sequence and the other contained the same cDNA fused with an interleukin-2 secretory signal sequence. After ventricular administration of these viral vectors, gene-transferred cells demonstrated a high immunoreactivity against the anti-bFGF antibody and a remarkably high concentration of bFGF was detected in the cerebrospinal fluid. A semiquantitative analysis of angiogenic activity revealed that bFGF gene transfer induced angiogenesis in normal rat brains, with a more pronounced angiogenic effect seen with the vector of a secreted form than with the vector without a secretory signal sequence. These results suggest that bFGF gene transfer using these adenoviral vectors might be useful for the treatment of ischemic cerebrovascular disease.
    Gene Therapy 07/2000; 7(11):942-9. DOI:10.1038/sj.gt.3301182 · 3.10 Impact Factor
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    ABSTRACT: The purpose of current study was to determine the step at which dietary selenium (Se) regulates the transcriptional expression of the gene for Se-glutathione peroxidase (Se-GPx) in rat brain and transplanted glioma tissue. Wistar rats were fed a Se-free diet or the same diet supplemented with 0.5, 2.0, and 4.0 mg Se/kg as sodium selenite for at least 3 wk. Then, the rats were transplanted with C6 rat glioma cells into the right frontal lobe parenchyma. All rats were observed for 30 d, then tumor and contralateral brain tissue were excised and divided into three portions for purification of selenium content, for the assay of Se concentration, Se-GPx activity, and for Se-GPx mRNA. Se concentration and Se-GPx activity are increased with Se supplementation both in tumor tissue and contralateral brain tissue, and Se concentration in tumor is higher than that in contralateral brain tissue at each dietary Se content. Se-GPx mRNA of brain and tumor were probed with fragments from a rat Se-GPx cDNA in Northern blot analysis. There was significant differences of Se-GPx mRNA transcription in brain tumor tissue among each dietary group of the Se content, and the steady-state level of Se-GPx mRNA was markedly reduced by Se deficiency. These results suggest that dietary Se exerts its augmenting effect on Se-GPx gene transcription.
    Biological Trace Element Research 01/2000; 73(1):67-76. DOI:10.1385/BTER:73:1:67 · 1.75 Impact Factor
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    ABSTRACT: The proliferation of vascular smooth muscle cells (VSMCs) is a common feature associated with vascular proliferative disorders such as atherosclerosis and restenosis after balloon angioplasty. We examined the antiproliferative effects of recombinant replication-competent herpes simplex virus (HSV), hrR3, to proliferative VSMCs both in vitro and in vivo. Early passages of Sprague-Dawley rat VSMCs were infected with hrR3 at a low multiplicity of infection (0.01 to 1.0) to examine the in vitro cytotoxic activity of this recombinant HSV to VSMCs in a proliferative state. Sprague-Dawley rats underwent balloon dilatation injury of the left carotid artery to induce neointimal formation. The injured carotid arteries were infected with hrR3 five days after balloon injury. Two weeks after injury, the left carotid arteries were fixed, and the areas of the neointimal and medial layers were analyzed microscopically. Because the reporter Escherichia coli lacZ gene in hrR3 is expressed only in infected cells in which the virus is actively replicating, virus replication was confirmed by X-gal staining. A morphometric analysis revealed that there were significant differences in the intima/media ratio between the HSV-treated group and mock-infected group (0. 354+/-0.068 and 1.08+/-0.055, respectively). In the histological study (X-gal staining), positive X-gal staining was observed chiefly in the VSMCs in the medial layer just beneath the internal elastic lamina, indicating active viral replication. Virus-mediated cytocidal therapy using recombinant HSV vector is a promising modality for the treatment of the restenosis after balloon angioplasty.
    Stroke 12/1999; 30(11):2431-8; discussion 2438-9. DOI:10.1161/01.STR.30.11.2431 · 5.72 Impact Factor
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    ABSTRACT: Bcl-xL is a Bcl-2-related gene that regulates programmed cell death in a bcl-2-independent fashion. It is expressed in tissues containing long-surviving postmitotic cells, such as neurons in adult brains. To investigate the possibility of gene therapy for transferring this anti-apoptotic gene into the neuron for the treatment of vascular occlusive or neurodegenerative diseases, we examined the effect of a replication-deficient recombinant adenovirus vector coding human Bcl-xL gene on the augmentation of the survival of primarily-cultured rat neuronal cells in vitro. Immunoblot analysis revealed that primarily-cultured neuronal cells were successfully infected and transferred with this gene by recombinant adenovirus vector with high transduction efficiency. Bcl-xL gene transfer to the primarily-cultured neurons could prevent these cells from cell death.
    Neuroscience Letters 09/1999; 270(3):177-80. DOI:10.1016/S0304-3940(99)00499-1 · 2.03 Impact Factor
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    ABSTRACT: Basic fibroblast growth factor (FGF-2) and high affinity FGF receptor (FGFR) have been detected in the nucleus as well as the cytoplasm of many human gliomas, and are known to stimulate cellular proliferation and angiogenesis in the tumors. To investigate the effects of inactivation of FGFR on the growth of malignant gliomas, we constructed a replication-deficient recombinant adenovirus vector encoding a truncated form of chicken FGFR1 (AxCA delta FR). AxCA delta FR-infected cells were confirmed to express truncated FGFR protein by immunoblotting and FGF-2-dependent clonogenicity of NIH3T3 cells was suppressed by infection with this virus vector. Then human malignant glioma cell lines U-251MG and T98G, both of which have been reported to express FGF-2 and FGFR, were infected with AxCA delta FR. These infected cells showed nuclear as well as cytoplasmic expression of a truncated FGFR protein. Proliferation rate and the ability to form colonies in soft agar of the cells infected with this virus vector were significantly suppressed compared with those of uninfected and lacZ-expressing adenovirus-infected cells. Moreover, intratumoral injection of AxCA delta FR significantly suppressed the subcutaneous tumor growth of the glioma cells in nude mice. We concluded that inactivation of the cytoplasmic and nuclear FGFR using this truncated FGFR-expressing adenovirus vector can inhibit the growth of malignant gliomas both in vitro and in vivo.
    Journal of Neuro-Oncology 02/1999; 44(3):195-203. DOI:10.1023/A:1006355014351 · 3.07 Impact Factor
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    ABSTRACT: Vascular smooth muscle cell (VSMC) proliferation associated with arterial injury causes restenosis, which remains to be resolved in cardiovascular and ischemic cerebrovascular disease, especially after balloon angioplasty. Fibroblast growth factor (FGF) is a potent mitogen and a trophic factor for a variety of cells, including VSMCs. We constructed a replication-deficient adenovirus vector, designated AxCA delta FR, coding a truncated form of fibroblast growth factor receptor-1 (FGFR-1) gene lacking the intracellular domain to interrupt receptor-mediated FGF signaling, and examined its effect on the proliferation of primary-cultured rat VSMCs. We transferred the truncated form of the FGFR-1 gene to the VSMCs and confirmed its expression and localization in infected cells by Western blotting and immunofluorescence study. The VSMCs infected with AxCA delta FR degenerated and the proliferation of these cells was suppressed markedly by the infection with this virus in vitro. Our results suggest that the receptor-mediated signal of FGFs has an important role in VSMC proliferation and gene transfer of a truncated form of FGFR using adenoviral vector may be useful for the treatment of the diseases caused by excessive proliferation of VSMCs like restenosis after percutaneous transluminal angioplasty or carotid endoarterectomy.
    Atherosclerosis 12/1998; 141(1):125-32. DOI:10.1016/S0021-9150(98)00162-2 · 3.99 Impact Factor

Publication Stats

124 Citations
26.60 Total Impact Points


  • 2004
    • Osaka Medical College
      • Department of Neurosurgery
      Takatuki, Ōsaka, Japan
  • 2000
    • Shinshu University
      • Department of Ophthalmology
      Shonai, Nagano, Japan
  • 1999–2000
    • Kyoto University
      • Department of Neurosurgery
      Kioto, Kyōto, Japan