Faculty Profiles - SAKAMOTO Hirotaka

MISC - SAKAMOTO Hirotaka

Division display 81 - 100 of about 113 ／ All the affair displays >>

Behavior of host and graft cells in the early remodeling process of rotator cuff defects in a transgenic animal model

Yoshio Iwata, Toru Morihara, Hisakazu Tachiiri, Yoshiteru Kajikawa, Atsuhiko Yoshida, Yuji Arai, Daisaku Tokunaga, Hirotaka Sakamoto, Ken-ichi Matsuda, Masao Kurokawa, Mitsuhiro Kawata, Toshikazu Kubo

JOURNAL OF SHOULDER AND ELBOW SURGERY 17 ( 1 ) 101S - 107S 2008.1

Language：English Publisher：MOSBY-ELSEVIER

Autologous tissue graft is one of the treatment options for a large rotator cuff defect. To develop appropriate strategies for enhanced solid graft integration at the bone-tendon interface and tendon-tendon interface, clarifying the fate of the graft and host cells that contribute to repair and remodeling is necessary. We have developed a new grafting model using green fluorescent protein-transgenic rats and wild-type rats to simulate autologous transplantation for examining the behavior of the host and graft cells in the remodeling process after tendon grafting. We found that the host cells commenced proliferation in the graft at 1 day after grafting. The host cells infiltrated into the graft from the subacromial synovium, proximal tendon, and bone-tendon insertion. The number of graft-derived cells decreased with time. Our result clearly demonstrated that host cells, rather than graft cells, were essential for rotator cuff remodeling after tendon grafting for rotator cuff defect.

DOI： 10.1016/j.jse.2007.07.008

Web of Science

researchmap

Mode of action and functional significance of estrogen-inducing dendritic growth, spinogenesis, and synaptogenesis in the developing purkinje cell

Katsunori Sasahara, Hanako Shikimi, Shogo Haraguchi, Hirotaka Sakamoto, Shin-ichiro Honda, Nobuhiro Harada, Kazuyoshi Tsutsui

JOURNAL OF NEUROSCIENCE 27 ( 28 ) 7408 - 7417 2007.7

Language：English Publisher：SOC NEUROSCIENCE

Neurosteroids are synthesized de novo from cholesterol in the brain. To understand neurosteroid action in the brain, data on the regio- and temporal-specific synthesis of neurosteroids are needed. Recently, we identified the Purkinje cell as an active neurosteroidogenic cell. In rodents, this neuron actively produces several neurosteroids including estradiol during neonatal life, when cerebellar neuronal circuit formation occurs. Estradiol may be involved in cerebellar neuronal circuit formation through promoting neuronal growth and neuronal synaptic contact, because the Purkinje cell expresses estrogen receptor-beta (ER beta). To test this hypothesis, in this study we examined the effects of estradiol on dendritic growth, spinogenesis, and synaptogenesis in the Purkinje cell using neonatal wild-type (WT) mice or cytochrome P450 aromatase knock-out (ArKO) mice. Administration of estradiol to neonatal WT or ArKO mice increased dendritic growth, spinogenesis, and synaptogenesis in the Purkinje cell. In contrast, WT mice treated with tamoxifen, an ER antagonist, or ArKO mice exhibited decreased Purkinje dendritic growth, spinogenesis, and synaptogenesis at the same neonatal period. To elucidate the mode of action of estradiol, we further examined the expression of brain-derived neurotrophic factor ( BDNF) in response to estrogen actions in the neonate. Estrogen administration to neonatal WT or ArKO mice increased the BDNF level in the cerebellum, whereas tamoxifen decreased the BDNF level in WT mice similar to ArKO mice. BDNF administration to tamoxifen-treated WT mice increased Purkinje dendritic growth. These results indicate that estradiol induces dendritic growth, spinogenesis, and synaptogenesis in the developing Purkinje cell via BDNF action during neonatal life.

DOI： 10.1523/JNEUROSCI.0710-07.2007

Web of Science

researchmap

GFP chimeric models exhibited a biphasic pattern of mesenchymal cell invasion in tendon healing

Yoshiteru Kajikawa, Toru Morihara, Nobuyoshi Watanabe, Hirotaka Sakamoto, Ken-Ichi Matsuda, Masashi Kobayash, Yasushi Oshima, Atsuhiko Yoshida, Mitsuhiro Kawata, Toshikazu Kubo

JOURNAL OF CELLULAR PHYSIOLOGY 210 ( 3 ) 684 - 691 2007.3

Language：English Publisher：WILEY-LISS

The healing of an injured musculoskeletal system requires an influx of mesenchymal cells that can differentiate into osteoblasts, fibroblasts, chondroblasts, and skeletal myoblasts. However, whether these mesenchymal cells arise from the circulation (bone marrow) or the injured tissues themselves has been controversial. To reveal the spatiotemporal characteristics of the reparative mesenchymal cells, we investigated the healing process after patellar tendon injury using two types of green fluorescent protein (GFP) chimeric rats; one expressing GFP in the circulating cells, and the other expressing it in the patellar tendon. We analyzed the behavior of GFP-positive cells after experimental tendon injury in both chimeric rats to clarify the origin of reparative cells. At 24 h after the injury, the wound contained circulation-derived cells but not tendon-derived cells. Tendon-derived cells first appeared in the wounded area at 3 days after the injury, and had significantly increased in number with time and had maintained a high level of proliferative activity until 7 days after the injury, whereas the circulation-derived cells had decreased in number and had been replaced by the tendon-derived cells. These findings suggest that circulation-derived and tendon-derived cells contribute to the healing of tendons in different periods as part of a biphasic process.

DOI： 10.1002/jcp.20876

Web of Science

researchmap

Intervertebral disc regeneration using platelet-rich plasma and biodegradable gelatin hydrogel microspheres

Masateru Nagae, Takumi Ikeda, Yasuo Mikami, Hitoshi Hase, Hitoshi Ozawa, Ken-Ichi Matsuda, Hirotaka Sakamot, Yasuhiko Tabata, Mitsuhiro Kawata, Toshikazu Kubo

TISSUE ENGINEERING 13 ( 1 ) 147 - 158 2007.1

Language：English Publisher：MARY ANN LIEBERT INC

This study evaluated the regenerative effects of platelet-rich plasma (PRP) for the degenerated intervertebral disc (IVD) in vivo. After induction of IVD degeneration in rabbits, we prepared PRP by centrifuging blood obtained from these rabbits. These PRP were injected into the nucleus pulposus (NP) of the degenerated IVDs after impregnation into gelatin hydrogel microspheres that can immobilize PRP growth factors physiochemically and release them in a sustained manner with the degradation of the microspheres. As controls, microspheres impregnated with phosphate-buffered saline (PBS) and PRP without microspheres were similarly injected. Histologically, notable progress in IVD degeneration with time courses was observed in the PBS control, PRP-only, and sham groups. In contrast, progress was remarkably suppressed over the 8-week period in the PRP group. Moreover, in immunohistochemistry, intense immunostaining for proteoglycan in the NP and inner layer of the annulus fibrosus was observed 8 weeks after administration of PRP-impregnated microspheres. Almost all microspheres were indistinct 8 weeks after the injection, and there were no apparent side effects in this study. Our results suggest that the combined administration of PRP and gelatin hydrogel microspheres into the IVD may be a promising therapeutic modality for IVD degeneration.

DOI： 10.1089/ten.2006.0042

Web of Science

researchmap

内分泌学的PTSDストレスモデルはバソプレッシン系にも影響する

吉井崇喜, 坂本浩隆, 川崎展, 小澤一史, 尾仲達史, 上田陽一, 福居顯二, 河田光博

日本内分泌学会雑誌 82 ( 2 ) 368 - 368 2006.9

The vasopressin dynamism is altered by PTSD model stress

Takanobu Yoshii, Hirotaka Sakamoto, Makoto Kawasaki, Hitoshi Ozawa, Yoichi Ueta, Kenji Fukui, Mitsuhiro Kawata

FRONTIERS IN NEUROENDOCRINOLOGY 27 ( 1 ) 46 - 46 2006.5

Distribution of gastrin releasing peptide in the rat lumbar spinal cord is sexually dimorphic and regulated by androgen

Hirotaka Sakamoto, Mitsuhiro Kawata

FRONTIERS IN NEUROENDOCRINOLOGY 27 ( 1 ) 146 - 146 2006.5

Intrauterine proximity to male fetuses affects the morphology of the sexually dimorphic nucleus of the preoptic area in the adult rat brain

M Pei, K Matsuda, H Sakamoto, M Kawata

EUROPEAN JOURNAL OF NEUROSCIENCE 23 ( 5 ) 1234 - 1240 2006.3

Language：English Publisher：BLACKWELL PUBLISHING

Previous studies on polytocous rodents have revealed that the fetal intrauterine position influences its later anatomy, physiology, reproductive performance and behavior. To investigate whether the position of a fetus in the uterus modifies the development of the brain, we examined whether the structure of the sexually dimorphic nucleus of the preoptic area (SDN-POA) of rat brains accorded to their intrauterine positions. Brain sections of adult rats gestated between two male fetuses (2M) and between two female fetuses (2F) in the uterus were analysed for their immunoreactivity to calbindin-D28k, which is a marker of the SDN-POA. The SDN-POA volume of the 2M adult males was greater than that of the 2F adult males, whereas the SDN-POA volume of the 2M and 2F adult females showed no significant difference. This result indicated that contiguous male fetuses have a masculinizing effect on the SDN-POA volume of the male. To further examine whether the increment of SDN-POA volume in adulthood was due to exposure to elevated steroid hormones during fetal life, concentrations of testosterone and 17 beta-estradiol in the brain were measured with 2M and 2F fetuses during gestation, respectively. On gestation day 21, the concentrations of testosterone and 17 beta-estradiol in the brain were significantly higher in the 2M male rats as compared with the 2F male rats. The results suggested that there was a relationship between the fetal intrauterine position, hormone transfer from adjacent fetuses and the SDN-POA volume in adult rat brains.

DOI： 10.1111/j.1460-9568.2006.04661.x

Web of Science

researchmap

Effects of single-prolonged stress on dendritic arborization of neurons in the central and basolateral amygdala

Honghai Cui, Hirotaka Sakamoto, Mitsuhiro Kawata

NEUROSCIENCE RESEARCH 55 S180 - S180 2006

多血小板血漿含浸ゼラチンハイドロゲル粒子の椎間板内投与による椎間板再生効果の組織学的検討 Reviewed

長江将輝, 池田巧, 三上靖夫, 長谷斉, 小澤一史, 松田賢一, 坂本浩隆, 田畑泰彦, 久保俊一, 河田光博

第111 回日本解剖学会総会・全国学術集会（2006.3.29－31. 相模原） 2006

PTSD model stress changes the vasopressin dynamism

Yoshii Takanobu, Hirotaka Sakamoto, Makoto Kawasaki, Hitoshi Ozawa, Yoichi Ueta, Kenji Fukui, Mitsuhiro Kawata

NEUROSCIENCE RESEARCH 55 S91 - S91 2006

発達期の小脳プルキンエ細胞における25-Dxの発現 ― プルキンエ細胞が合成するプロゲステロンの作用機構 ―

筒井和義ら, 番目

生体の科学 56:296–302 2006

Dendritic growth, spinogenesis and synaptogenesis in response to neurosteroids in the developing Purkinje cell

Kazuyoshi Tsutsui, Hirotaka Sakamoto, Katsunori Sasahara, Hanako Shikimi, Kazuyoshi Ukena, Mitsuhiro Kawata

NEUROSCIENCE RESEARCH 55 S27 - S27 2006

IIA-21 GFP骨髄キメラを用いた腱修復における未分化間葉系細胞の起源の解析(技術,一般演題発表,第46回日本組織細胞化学会総会・学術集会)

梶川佳照, 坂本浩隆, 松田賢一, 渡邉信佳, 大島康史, 吉田敦彦, 久保俊一, 河田光博

日本組織細胞化学会総会プログラムおよび抄録集 ( 46 ) 90 - 90 2005

Expression and localization of 25-Dx, a membrane-associated putative progesterone-binding protein, in the developing Purkinje cell

H Sakamoto, K Ukena, H Takemori, M Okamoto, M Kawata, K Tsutsui

NEUROSCIENCE 126 ( 2 ) 325 - 334 2004

Language：English Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Neurosteroids are synthesized de novo in the brain and the cerebellar Purkinje cell is a major site for neurosteroid formation. We have demonstrated that the rat Purkinje cell actively produces progesterone de novo from cholesterol only during neonatal life and progesterone promotes dendritic growth, spinogenesis and synaptogenesis via its nuclear receptor in this neuron. On the other hand, 25-Dx, a putative membrane progesterone receptor, has been identified in the rat liver. In this study, we therefore investigated the expression and localization of 25-Dx in the Purkinje cell to understand the mode of progesterone actions in this neuron. Reverse transcription-PCR and Western immunoblot analyses revealed the expressions of 25-Dx mRNA and 25-Dx-like protein in the rat cerebellum, which increased during neonatal life. By immunocytochemistry, the expression of 25-Dx-like protein was localized in the Purkinje cell and external granule cell layer. At the ultrastructural level, we further found that 25-Dx-like immunoreactivity was associated with membrane structures of the endoplasmic reticulum and Golgi apparatus in the Purkinje cell. These results indicate that the Purkinje cell expresses the putative membrane progesterone receptor, 25-Dx during neonatal life. Progesterone may promote dendritic growth, spinogenesis and synaptogenesis via 25-Dx as well as its nuclear receptor in the Purkinje cell in the neonate. (C) 2004 IBRO. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.neuroscience.2004.04.003

Web of Science

researchmap

ANALYSIS OF THE ROLE OF ESTROGEN IN THE GROWTH OF CEREBELLAR PURKINJE CELLS USING AROMATASE-DEFICIENT MICE

SHIKIMI Hanako, SAKAMOTO Hirotaka, UKENA Kazuyoshi, HARADA Nobuhiro, TSUTSUI Kazuyoshi

( 18 ) 15 - 15 2003.8

Neonatal expression of progesterone receptor isoforms in the cerebellar Purkinje cell in rats

H Sakamoto, H Shikimi, K Ukena, K Tsutsui

NEUROSCIENCE LETTERS 343 ( 3 ) 163 - 166 2003.6

Language：English Publisher：ELSEVIER SCI IRELAND LTD

The cerebellar Purkinje cell (PC) is a typical site for neurosteroid formation. Progesterone synthesized de novo in developing PCs participates in the promotion of dendritic growth, spinogenesis and synaptogenesis in this neuron and such organizing actions may contribute to the formation of the cerebellar neuronal circuit during rat neonatal life. Progesterone receptors (PR) occur as two isoforms (PR-A and PR-B) derived from a single gene. To clarify the mode of organizing actions of progesterone, therefore, we examined the expression of these PR isoforms in the rat cerebellum during development. Western immunoblot analysis revealed that both PR isoforms were expressed highly in the cerebellum during neonatal life and the expression decreased thereafter. PR-like immunoreactivity was localized primarily in PCs in the neonatal cerebellum. Thus, progesterone may act directly on PCs via PR isoforms to promote its dendritic growth, spinogenesis and synaptogenesis. (C) 2003 Elsevier Science Ireland Ltd. All rights reserved.

DOI： 10.1016/S0304-9340(03)000362-8

Web of Science

researchmap

エストロゲンが誘導する小脳プルキンエ細胞の発達:アロマターゼノックアウトによる解析

SHOKUMI HANAKO, SAKAMOTO HIROTAKA, UKIANA KAZUYOSHI, HARADA NOBUHIRO, TSUTSUI KAZUYOSHI

日本比較内分泌学会大会及びシンポジウムプログラム・講演要旨 28th 25 2003

ENDCRINE DISRUPTING CHEMICALS PROMOTE PURKINJE DENDRITIC GROWTH DURING CEREBELLAR CORTICAL FORMATION(Endocrinology,Abstracts of papers presented at the 74^<th> Annual Meeting of the Zoological Society of Japan) :

Shikimi Hanako, Sakamoto Hirotaka, Mezaki Yukio, Ukena Kazuyoshi, Tsutsui Kazuyoshi

Zoological science 20 ( 12 ) 1601 - 1601 2003

EXPRESSION AND LOCALIZATION OF THE PUTATIVE MEMBRANE PROGESTERONE RECEPTOR 25-DX IN THE DEVELOPING PURKINJE CELL(Endocrinology,Abstracts of papers presented at the 74^<th> Annual Meeting of the Zoological Society of Japan) :

Tsutsui Kazuyoshi, Sakamoto Hirotaka, Shikimi Hanako, Ukena Kazuyoshi, Takemori Hiroshi, Okamoto Mitsuhiro, Kawata Mitsuhiro

Zoological science 20 ( 12 ) 1606 - 1606 2003

　 PREV - NEXT 　

< SAKAMOTO Hirotaka >

MISC - SAKAMOTO Hirotaka