Tomohiro Yamauchi
Hokkaido University
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Publication
Featured researches published by Tomohiro Yamauchi.
PLOS ONE | 2015
Tomohiro Yamauchi; Yasumasa Kuroda; Takahiro Morita; Hideo Shichinohe; Kiyohiro Houkin; Mari Dezawa; Satoshi Kuroda
Objective Bone marrow stromal cells (BMSCs) are heterogeneous and their therapeutic effect is pleiotropic. Multilineage-differentiating stress enduring (Muse) cells are recently identified to comprise several percentages of BMSCs, being able to differentiate into triploblastic lineages including neuronal cells and act as tissue repair cells. This study was aimed to clarify how Muse and non-Muse cells in BMSCs contribute to functional recovery after ischemic stroke. Methods Human BMSCs were separated into stage specific embryonic antigen-3-positive Muse cells and -negative non-Muse cells. Immunodeficient mice were subjected to permanent middle cerebral artery occlusion and received transplantation of vehicle, Muse, non-Muse or BMSCs (2.5×104 cells) into the ipsilateral striatum 7 days later. Results Motor function recovery in BMSC and non-Muse groups became apparent at 21 days after transplantation, but reached the plateau thereafter. In Muse group, functional recovery was not observed for up to 28 days post-transplantation, but became apparent at 35 days post-transplantation. On immunohistochemistry, only Muse cells were integrated into peri-infarct cortex and differentiate into Tuj-1- and NeuN-expressing cells, while negligible number of BMSCs and non-Muse cells remained in the peri-infarct area at 42 days post-transplantation. Conclusions These findings strongly suggest that Muse cells and non-Muse cells may contribute differently to tissue regeneration and functional recovery. Muse cells may be more responsible for replacement of the lost neurons through their integration into the peri-infarct cortex and spontaneous differentiation into neuronal marker-positive cells. Non-Muse cells do not remain in the host brain and may exhibit trophic effects rather than cell replacement.
Neurorehabilitation and Neural Repair | 2015
Hideo Shichinohe; Takeshi Ishihara; Koji Takahashi; Yoshikazu Tanaka; Michiyuki Miyamoto; Tomohiro Yamauchi; Hisayasu Saito; Hiroshi Takemoto; Kiyohiro Houkin; Satoshi Kuroda
Background. Transplantation of bone marrow stromal cells (BMSCs) may contribute to functional recovery after stroke. This study was designed to clarify their mechanisms, trophic effects of neurotrophic factors, and neural differentiation. Methods. Mouse neurons exposed to glutamate were cocultured with mouse BMSCs. Either neutralizing antibodies against brain-derived neurotrophic factor (BDNF) or nerve growth factor (NGF) or Trk inhibitor K252a was added to explore the mechanism of their protective effects. Fluorescence in situ hybridization (FISH) was used to assess BDNF or NGF mRNA expression in BMSCs. The mice were subjected to permanent focal ischemia, and 7 days later, either BMSCs or the vehicle was stereotactically transplanted into the ipsilateral striatum. The mouse brains were processed for FISH and immunostaining 2 or 4 weeks after transplantation. Results. BMSCs significantly ameliorated glutamate-induced neuronal death. Treatment with anti-BDNF antibody significantly reduced their protective effects. FISH analysis showed that the majority of BMSCs expressed BDNF and NGF mRNA in vitro. BMSC transplantation significantly improved the survival of neurons in peri-infarct areas. FISH analysis revealed that approximately half of BMSCs expressed BDNF and NGF mRNA 2 weeks after transplantation; however, the percentage of BDNF and NGF mRNA-positive cells decreased thereafter. Instead, the percentage of microtubule-associated protein 2–positive BMSCs gradually increased during 4 weeks after transplantation. Conclusions. These findings strongly suggest that BDNF may be a key factor underlying the trophic effects of BMSCs. BMSCs might exhibit the trophic effect in the early stage of cell therapy and the phenotypic change toward neural cells thereafter.
Surgical Neurology | 2008
Toshiya Osanai; Satoshi Kuroda; Naoki Nakayama; Tomohiro Yamauchi; Kiyohiro Houkin; Yoshinobu Iwasaki
BACKGROUND In moyamoya disease, intracranial bleeding is known to occur because of the rupture of saccular aneurysms in the circle of Willis or because of the rupture of dilated, fragile moyamoya vessels. The former causes subarachnoid hemorrhage (SAH), and the latter causes intracerebral or intraventricular hemorrhage. CASE DESCRIPTION In this report, we describe the case of a 34-year-old woman with moyamoya disease who suddenly developed headache and jacksonian seizure. Plain computed tomographic scans on admission revealed SAH localized over the left frontal cortex. The patient was diagnosed with moyamoya disease on cerebral angiography. However, no aneurysm was found on cerebral angiography. Positron emission tomography showed the reduction of CBF and its reactivity to acetazolamide and the elevation of CBV in the left hemisphere. She underwent STA to MCA anastomosis and indirect synangiosis. Intraoperative observations revealed that the pial arterioles were markedly dilated on the brain surface. The CBF in the left hemisphere significantly improved after surgery. The patient has experienced no further episode of cerebral ischemia or intracranial bleeding. CONCLUSIONS Subarachnoid hemorrhage of unknown cause is quite rare in moyamoya disease. Based on the findings in the present case, the dilated collateral arteries on the brain surface may rupture and cause SAH over the cerebral cortex, which is the third cause of intracranial bleeding in patients with persistent cerebral ischemia due to moyamoya disease.
Journal of Korean Neurosurgical Society | 2013
Chang Il Ju; Kazutoshi Hida; Tomohiro Yamauchi; Kiyohiro Houkin
A 61-year-old woman with a very rare case of totally ossified large thoracic spinal metaplastic meningioma, showing progressing myelopathy is presented. Computed tomographic images showed a large totally ossfied intradural round mass occupying the spinal canal on T9-10 level. Magnetic resonance imaging revealed a large T9-10 intradural extramedullary mass that was hypointense to spinal cord on T1- and T2-weighted sequences, partial enhancement was apparent after Gadolinium administration. The spinal cord was severely compressed and displaced toward the right at the level of T9-10. Surgical removal of the tumor was successfully accomplished via the posterior midline approach and the histological diagnosis verified an ossified metaplastic meningioma. The clinical neurological symptoms of patient were improved postoperatively. In this article we discuss the surgical and pathological aspects of rare case of spinal totally ossified metaplastic meningioma.
Stem Cells International | 2018
Michiyuki Miyamoto; Kentaro Nakamura; Hideo Shichinohe; Tomohiro Yamauchi; Masaki Ito; Hisayasu Saito; Masahito Kawabori; Toshiya Osanai; Tasuku Sasaki; Kiyohiro Houkin; Satoshi Kuroda
Bone marrow stromal cell (BMSC) transplantation has the therapeutic potential for ischemic stroke. However, it is unclear which delivery routes would yield both safety and maximal therapeutic benefits. We assessed whether a novel recombinant peptide (RCP) sponge, that resembles human collagen, could act as a less invasive and beneficial scaffold in cell therapy for ischemic stroke. BMSCs from green fluorescent protein-transgenic rats were cultured and Sprague–Dawley rats were subjected to permanent middle cerebral artery occlusion (MCAo). A BMSC-RCP sponge construct was transplanted onto the ipsilateral intact neocortex 7 days after MCAo. A BMSC suspension or vehicle was transplanted into the ipsilateral striatum. Rat motor function was serially evaluated and histological analysis was performed 5 weeks after transplantation. The results showed that BMSCs could proliferate well in the RCP sponge and the BMSC-RCP sponge significantly promoted functional recovery, compared with the vehicle group. Histological analysis revealed that the RCP sponge provoked few inflammatory reactions in the host brain. Moreover, some BMSCs migrated to the peri-infarct area and differentiated into neurons in the BMSC-RCP sponge group. These findings suggest that the RCP sponge may be a promising candidate for animal protein-free scaffolds in cell therapy for ischemic stroke in humans.
Spinal Surgery | 2011
Shunsuke Yano; Kazutoshi Hida; Takeshi Aoyama; Motoyuki Iwasaki; Tomohiro Yamauchi; Minoru Akino; Hisatoshi Saitou
頚椎前方固定術における固定隣接椎間障害の画像的因子解析 矢野俊介 飛
Acta Neurobiologiae Experimentalis | 2013
Hideo Shichinohe; Tomohiro Yamauchi; Hisayasu Saito; Kiyohiro Houkin; Satoshi Kuroda
Translational Stroke Research | 2014
Tomohiro Yamauchi; Hisayasu Saito; Masaki Ito; Hideo Shichinohe; Kiyohiro Houkin; Satoshi Kuroda
Stroke | 2014
Tomohiro Yamauchi; Satoshi Kuroda; Hisayasu Saito; Hideo Shichinohe; Kiyohiro Houkin
Stroke | 2014
Michiyuki Miyamoto; Satoshi Kuroda; Kentaro Nakamura; Tomohiro Yamauchi; Masaki Ito; Hisayasu Saito; Hideo Shichinohe; Tasuku Sasaki; Kiyohiro Houkin