Research Projects -
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Inhibition of cell-to-cell propagation of alpha-synuclein aggregation by glial cells and its involvement in neuropathology in Parkinson's disease.
Grant number：23K06928 2023.04 - 2026.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
宮崎 育子, 浅沼 幹人
Authorship：Principal investigator
Grant amount：\4550000 （ Direct expense: \3500000 、 Indirect expense：\1050000 ）
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食品容器より溶出されるエポキシ樹脂への妊娠・授乳期曝露により惹起される自閉スペクトラム症様の産仔早期脳発達のメカニズムの解明
2022.11 - 2023.10
岡山医学研究助成 2022年
宮崎育子
Authorship：Principal investigator
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Studies of neurodegenerative processes and alpha-synuclein expression focusing on regional specificity of astrocytes.
Grant number：19K07993 2019.04 - 2022.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C) Grant-in-Aid for Scientific Research (C)
Miyazaki Ikuko
Authorship：Principal investigator
Grant amount：\4420000 （ Direct expense: \3400000 、 Indirect expense：\1020000 ）
In this study, we revealed that mesencephalic astrocyte-microglia interaction promoted a pesticide rotenone-induced dopaminergic neurotoxicity. In addition, we demonstrated that mesencephalic astrocytes upregulated alpha-synuclein expression in the dopaminergic neurons. We examined secreted molecules from rotenone-treated mesencephalic astrocyte and microglia co-culture by LC-MS/MS analysis. It is demonstrated increase in the inflammatory molecules and decrease in the antioxidants and a protein which inhibits alpha-synuclein aggregation and cell-to-cell propagation. In rotenone-injected parkinsonian mice, we observed alpha-synuclein aggregation and neurodegeneration not only in the central nervous system but also peripheral enteric nervous system. However, change in the alpha-synuclein expression and neurodegeneration are not parallel in some brain region. These results suggest some factors in addition to alpha-synuclein aggregation are involved in region-specific neurodegeneration.
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Grant number：16K09673 2016.04 - 2019.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C) Grant-in-Aid for Scientific Research (C)
Miyazaki Ikuko
Authorship：Principal investigator
Grant amount：\4550000 （ Direct expense: \3500000 、 Indirect expense：\1050000 ）
In this study, we revealed that astrocyte-conditioned media from low-dose rotenone-treated mesencephalic, but not striatal, astrocytes produced dopaminergic neuron-specific neurotoxicity, and that endogenous dopamine and its oxidation play an important role in mesencephalic astrocyte-mediated dopaminergic neurodegeneration. In addition, we demonstrated that reduction of antioxidative molecule metallothionein (MT) in enteric glial cells after rotenone-exposure induced enteric neurotoxicity. Oral administration of coffee components, caffeic acid and chlorogenic acid, upregulated MT expression both in the striatal astrocytes and enteric glial cells, and inhibited degeneration of central dopaminergic and peripheral enteric neurons in rotenone-treated mice. These results suggest possible involvement of brain region-specific glial dysfunction in neurotoxicity induced by environmental toxin rotenone.
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アストロサイトにおけるNFAT関連分子の部位特異的誘導がもたらす神経変性
2014
岡山医学振興会研究助成
宮崎育子
Authorship：Principal investigator
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アストロサイトにおけるオートファジーに着目した環境毒誘発パーキンソニズムの病態解析
2014
山陽放送学術文化財団研究助成
宮崎育子
Authorship：Principal investigator
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Grant number：25461279 2013.04 - 2016.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C) Grant-in-Aid for Scientific Research (C)
MIYAZAKI IKUKO, ASANUMA MASATO
Authorship：Principal investigator
Grant amount：\4940000 （ Direct expense: \3800000 、 Indirect expense：\1140000 ）
In this study, we revealed that subcutaneous administration of rotenone caused progressive neurodegeneration in the olfactory bulb and myenteric plexus of ascending colon, in addition to the nigrostriatal pathway, but not in the thoracic cord. Rotenone treatment also induced increases in the number of astrocytes in a time- and region-specific manner. These results suggested that neurodegeneration after rotenone exposure was region-specific, but did not spread retrogradely from the peripheral tissue to nigrostriatal pathway, and that glial activation could be related to rotenone-induced neurotoxicity. Using primary cultured cells, we showed that rotenone induced activation of NFAT, secretion of inflammatory cytokines, and decreased metallothionein release in/from rotenone-treated mesencephalic astrocytes, which caused dopaminergic neurotoxicity. These results suggest possible involvement of glial dysfunction in dopaminergic neurotoxicity induced by environmental toxin rotenone.
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Systemic neurodegeneration and involvement of astroglial cells in Parkinson's disease.
Grant number：22590934 2010 - 2012
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C) Grant-in-Aid for Scientific Research (C)
MIYAZAKI Ikuko, ASANUMA Masato, NAKAMURA Kazufumi
Authorship：Principal investigator
Grant amount：\4420000 （ Direct expense: \3400000 、 Indirect expense：\1020000 ）
In this study, we revealed that GFAP-positive glial cells were distributed along the myenteric plexus in the ileum and ascending colon of rotenone-chronically treated rats, preceding central dopaminergic neurodegeneration, suggesting possible involvement of enteric glial cells in rotenone-induced cytotoxicity of enteric neuronal cells which precedes neurodegeneration in central nervous system. Using primary cultured cells, we also proposed a possible involvement of some molecules secreted from rotenone-treated mesencephalic astroglia in rotenone-induced dopaminergic neurotoxicity, and revealed that metallothionein could protect dopaminergic neurons against rotenone toxicity.
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ドパミン神経選択的障害因子ドパミンキノンによる神経障害に対するアストログリアの抗酸化機構の役割に関する研究
2008
(財)川崎医学・医療福祉学振興会教育研究助成
宮崎育子
Authorship：Principal investigator
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ドパミンキノン神経障害を含む脳内酸化ストレスに対するアストログリアの抗酸化機構の解析
2008
岡山医学振興会研究助成
宮崎育子
Authorship：Principal investigator
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シナプス小胞外の遊離ドパミンによるドパミン神経障害とその保護に関わる分子の探索
Grant number：18700364 2006 - 2007
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B) Grant-in-Aid for Young Scientists (B)
宮崎 育子
Authorship：Principal investigator
Grant amount：\3500000 （ Direct expense: \3500000 ）
1.内在性キノン消去系分子の検索
小胞外ドパミン(DA)過剰モデル細胞においてキノン還元酵素NQO1が増加しており,DA神経毒6-OHDAによる片側パーキンソン病(PD)モデルマウスの線条体では,NQO1が増加し,NQOI遺伝子の転写因子Nrf2の神経細胞での活性化ならびにDAキノン(DAQ)消去にはたらくグルタチオン(GSH)の合成基質のアストログリアでの取り込み部位の発現増加がみられることを組織学的に確認できた.
2.内在性キノン消去系分子のキノン毒性に対する保護効果
DA系神経細胞CATH.aへの過剰DA添加あるいはメタンフェタミン(METH)添加による小胞外過剰DA状態でのキノン結合蛋白キノプロテイン(QP:DAQ生成の指標)の増加と細胞障害性が,NQO1の賦活薬BHAの前処置により抑制できることを明らかにした.また,昨年度の検索でDAQを消去することがわかった内在性キノン消去分子の金属結合蛋白メタロチオネイン1(MT1)のキノン毒性への効果について検討した.CATH.a細胞への過剰DA添加によるQP増加ならびに細胞死は,MT1を誘導す亜鉛添加により抑制できた.
3.内土性キノン消去系分子ノックダンによるドパミン神経障害増悪の検討
昨年度,DAQを酸化させるチロシナーゼの欠損マヴスの線条体では,METH投与によるDATの脱落が野生型に比べて著明に増悪することを報告したが,CATH.a細胞へのチロシナーゼ阻害薬添加によりMETH神経毒性が増悪することも確認できた.また,DAQを無毒化することが明らかになった中枢神経作用薬の投与により,大脳基底核のGSH量が増加し,PDモデル障害側黒質でのDA神経の脱落および障害側線条体でのL-DOPA連日投与によるQPの著増が抑制された.さらに,片側PDモデルの障害側のDA神経障害は,野生型に比べMT1ノックアウトマウスでより顕著であった.
DAQ消去にはたらくGSH,NQO1,Nrf2,チロシナーゼ,MT1などのシステイン基含有分子およびこれらの発現を高める薬剤が,小胞外遊離DAによるDA神経毒性に対して保護的にはたらくことを明らかにできた. -
パミン神経特異的酸化ストレスとしてのドパミンキノンを指標にした非ステロイド性消炎鎮痛薬のドパミン神経保護効果のプロファイリング
2006
カテコールアミンと神経疾患研究会研究助成
宮崎育子
Authorship：Principal investigator
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パーキンソン病のL-DOPA投与による副作用発現とグリアのドパミン取込みとの連関
Grant number：15790450 2003 - 2004
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B) Grant-in-Aid for Young Scientists (B)
宮崎 育子
Authorship：Principal investigator
Grant amount：\3200000 （ Direct expense: \3200000 ）
昨年度,ラット胎児中脳あるいは線条体からの初代培養アストロサイトにおいてドパミンD1,D3,D4,D5レセプターおよびドパミントランスポーター(DAT)が発現しており,L-DOPA投与によりパーキンソン病(PD)モデル傷害側のアストロサイトでのドパミンの取り込みおよびDATの発現増加が認められることを明らかにした.本年度は,初代培養アストロサイトにおけるドパミンの取り込み,L-DOPAからのドパミン産生能,PDモデル脳のミクログリアにおけるドパミン取り込みについて検討した.
1.ドパミン神経障害時の培養アストロサイトでのドパミンの取込み動態の変化
線条体からのニューロン・アストロサイト混合初代培養系に6-OHDAあるいはLPSで前処置を行い,さらにドパミンを添加しドパミン神経障害を惹起させると,アストロサイトへのドパミンの取り込みがみられ,DATの発現が増加することを蛍光二重染色により明らかにした.さらに,このときアストロサイト細胞内においてドパミンが増加することを高速液体クロマトグラフィーにより検出した.
2.培養アストロサイトにおけるL-DOPAからのドパミン産生機構
線条体からの初代培養アストロサイトにおいて,DOPA脱炭酸酵素およびL型中性アミノ酸トランスポーターが発現していることをWestern blot法により確認した.このことから,L-DOPAはアストロサイトに取り込まれ,ドパミンに変換されている可能性が考えられる.
3.パーキンソン病モデル脳のミクログリアにおけるドパミン取り込み
6-OHDA注入による片側PDモデルラットにL-DOPAを1週間連日投与し,最終投与3時間後の脳凍結切片を用いてドパミンとOX-42(ミクログリアマーカー)の蛍光二重染色を行った.PDモデル傷害側線条体でミクログリアの著しい増殖がみられたが,ミクログリアへのドパミンの取り込みは認められなかった. -
腸管粘膜バリアの破綻に着目した末梢先行型パーキンソン病の神経変性機構の解明
Grant number：24K10620 2024.04 - 2027.03
日本学術振興会 科学研究費助成事業 基盤研究(C)
浅沼 幹人, 宮崎 育子
Grant amount：\4680000 （ Direct expense: \3600000 、 Indirect expense：\1080000 ）
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扁平上皮特異的金属結合タンパク質を利用した口腔癌遺伝子治療に向けての基盤構築
Grant number：23K09323 2023.04 - 2026.03
日本学術振興会 科学研究費助成事業 基盤研究(C)
十川 紀夫, 十川 千春, 宮崎 育子, 村上 聡
Authorship：Coinvestigator(s)
Grant amount：\4680000 （ Direct expense: \3600000 、 Indirect expense：\1080000 ）
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バイオマテリアルin vitro安全性評価のためのgPAD-オルガノイドシステムの開発
Grant number：23K11926 2023.04 - 2026.03
日本学術振興会 科学研究費助成事業 基盤研究(C)
十川 千春, 十川 紀夫, 宮崎 育子, 中野 敬介, 塚本 壮輔
Authorship：Coinvestigator(s)
Grant amount：\4550000 （ Direct expense: \3500000 、 Indirect expense：\1050000 ）
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グリア機能不全に着目した環境毒誘発パーキンソン病における腸管神経変性機構の解明
Grant number：21K07415 2021.04 - 2024.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C) Grant-in-Aid for Scientific Research (C)
浅沼 幹人, 宮崎 育子
Authorship：Coinvestigator(s)
Grant amount：\4160000 （ Direct expense: \3200000 、 Indirect expense：\960000 ）
パーキンソン病発症の環境毒であるロテノン曝露による腸管の免疫細胞を含む細胞環境の変化，炎症反応や酸化ストレスと腸管グリア機能不全との関係を検討し，腸管グリア機能不全ひいては腸管先行性神経変性をもたらす機構を明らかにするために，環境毒ロテノン持続皮下投与パーキンソン病モデルマウスの腸管関連リンパ組織(GALT)，粘膜下・筋間神経叢における腸管免疫細胞（樹状細胞，細胞障害性/細胞保護性マクロファージ，腸管リンパ球），炎症関連分子，消化管粘膜バリアの細胞組織学的変化を検討した．C57BLマウスへの浸透圧ミニポンプを用いた低用量ロテノン(2.5 mg/kg/day) 4週間慢性皮下投与により，黒質ドパミン神経の変性脱落のみならず，回腸筋間神経叢，アストロサイト様グリア細胞の脱落が認められ，腸管粘膜上皮tight junction (ZO-1)の脆弱化，組織損傷時に核外に移行し細胞外へ放出され炎症惹起に働くdamage-associated molecular patterns (DAMPs)であるHigh mobility group box-1 (HMGB1)の粘膜上皮の核膜管腔側から核外への著明な集積が認められた．また，ロテノン暴露腸管初代培養系において腸管グリア細胞共存下でのみ惹起される腸管神経細胞死が，アストロサイト様グリア細胞での抗酸化分子メタロチオネインの発現を増加させるポリフェノール類により抑制された．これらの結果は，腸管神経障害には腸管粘膜バリア機能の破綻，炎症反応，グリア細胞の機能障害が関与することを示唆している．
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Basic construction for medical treatment of oral cancer by controlling of metal-binding protein expression utilizing optogenetics
Grant number：20K10151 2020.04 - 2023.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C) Grant-in-Aid for Scientific Research (C)
十川 紀夫, 今村 泰弘, 十川 千春, 宮崎 育子, 村上 聡, 荒 敏昭
Authorship：Coinvestigator(s)
Grant amount：\4420000 （ Direct expense: \3400000 、 Indirect expense：\1020000 ）
メタロチオネイン(MT)は，生体内で亜鉛と結合し，生体亜鉛濃度の恒常性維持，および調節に関わっている低分子量の金属結合タンパク質である。 亜鉛は，多くの酵素において活性中心をなす金属であり，また，転写因子の機能発現においても重要であることから，亜鉛の細胞内調節は癌の発症，増殖および転移に関与している可能性が示唆されている。しかし，亜鉛が癌細胞増殖に関与する機序の詳細は未だ明らかになっていない。
2020年度の検討により，HSC-4においてMT-4遺伝子発現が亜鉛代謝に関与している可能性を示唆する結果が得られたことから，2021年度は2020年度末に策定した研究推進方策に従い，既構築したMT-4発現ベクターを亜鉛感受性が異なるヒト舌癌細胞HSC-4およびヒト歯肉癌細胞Cas9－22に遺伝子導入し，その結果として認められる亜鉛トランスポーター遺伝子の発現変動を，real time RT-PCR法にて比較・検討した。
その結果，両細胞において，細胞質内外に亜鉛を移動させる亜鉛トランスポーター(ZnTおよびZIP)のいくつかの遺伝子が，亜鉛添加およびMT-4導入による発現変動を示したが，これら遺伝子の発現変動を総括すると，亜鉛添加およびMT-4遺伝子導入によりZIP2, ZIP4およびZIP10の発現減少とZnT9の発現増加が誘導されるとの結果が得られた。これまでの両細胞における細胞増殖に対する影響と併せ考えると，これら亜鉛トランスポーターの発現変動がMT-4や亜鉛を介した細胞増殖に関与している可能性が強く示唆された。 -
Genetic analysis of developmental dyslexia in Japanese speakers
Grant number：19K07802 2019.04 - 2022.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C) Grant-in-Aid for Scientific Research (C)
OKA Makio
Authorship：Coinvestigator(s)
Grant amount：\2470000 （ Direct expense: \1900000 、 Indirect expense：\570000 ）
We investigated the presence of gene mutations that cause pathogenesis in Japanese speakers with developmental dyslexia (DD). The subjects were 3 families with DD children, one of which was a large family with 5 DD children out of 11 siblings. SNP array (Illumina Infinium Asian Screening Array-24 v1.0) was performed on 48 children including 28 typical developmental children. As a result, in a large family, SNPs in exons and introns, which are genes related to Nance-Holan syndrome (NHS gene) present in Xp22.13, were found in 7 boys of 11 siblings and their mother.
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Foundation of medical treatment for tongue cancer by the regulation of metal-binding protein
Grant number：17K11689 2017.04 - 2020.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C) Grant-in-Aid for Scientific Research (C)
Sogawa Norio
Authorship：Coinvestigator(s)
Grant amount：\4550000 （ Direct expense: \3500000 、 Indirect expense：\1050000 ）
In order to construct a foundation of medical treatment for tongue cancer, it was investigated the influence of the regulation of MT-4 expression on cancer cell growth, an intracellular zinc ion regulating protein expressed specifically in squamous epithelium. Moreover, it was explored the inducers of MT-4 gene expression and intracellular interacted factor with MT-4 protein.
As the results, it was revealed that the zinc sensitivity was associated with cell proliferation of cancer, and zinc sensitive cancer cells decreased the cell proliferation by MT-4 gene introduction. Moreover, it was suggested that MT-4 gene expression was induced by glucocorticoids and MT-4 was related with gene expression by itself. -
Development of neuroprotective therapy for amyotrophic lateral sclerosis using serotonergic reagent
Grant number：24659431 2012.04 - 2015.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research Grant-in-Aid for Challenging Exploratory Research
ASANUMA Masato, MIYAZAKI Ikuko
Authorship：Coinvestigator(s)
Grant amount：\3770000 （ Direct expense: \2900000 、 Indirect expense：\870000 ）
We examined neuroprotective effects of serotonin-1A receptor agonist 8-OH-DPAT on progressive motor neuron degeneration in amyotrophic lateral sclerosis (ALS) model mice and in primary culture cells. The pre-treatments of 8-OH-DPAT prior to onset of motor symptoms delayed disease onset. The chronic post-treatments of the drug after the onset significantly inhibited disease progression and showed protective effects on motor neuron loss in the cervical and lumber spinal cords in the ALS models. Furthermore, we revealed that the neuroprotective effects are based, in part, on expression and release of metallothionein in/from astrocytes via serotonin-1A receptors and sequent activation of transcription factor Nrf2.
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A new regulative mechanism for monoamine transporter expression in plasma membrane : The participation of histamine H3 receptor
Grant number：22592065 2010 - 2012
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
SOGAWA Norio, OHYAMA Kazumi, SOGAWA Chiharu, MIYAZAKI Ikuko, KITAYAMA Shigeo
Grant amount：\4420000 （ Direct expense: \3400000 、 Indirect expense：\1020000 ）
To study the participation of histamine H3 receptor (H3R) on the transition of monoamine transporters into plasma membrane which is necessary to exert their function as transporters, we investigated the relation between H3R and noradrenaline transporter (NET) expression by using coexpressing cell system for both H3R and NET. The results which obtained from this experiment were suggested that there was a mechanism by which H3R inhibited the NET expression into the plasma membrane by binding to NET and making it fit tightly in the cell.
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Grant number：21591082 2009 - 2011
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C) Grant-in-Aid for Scientific Research (C)
ASANUMA Masato, MIYAZAKI Ikuko
Authorship：Coinvestigator(s)
Grant amount：\4420000 （ Direct expense: \3400000 、 Indirect expense：\1020000 ）
We revealed that induction and sequent release of glutathione or metallothionein in astroglia play an antioxidative protective role against neurotoxicity induced by dopamine neuron-specific oxidative stress in this study. Using neuron-astroglia coculture and parkinsonian model mice, we also proposed a possible therapeutic strategy for Parkinson's disease that a serotonin receptor agonist can protect dopamine neurons via activation of dopamine quinone-sensing molecules in astroglia.
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Studies on dopamine neuron-specific dmenerative factor dopamine quinone in the pathogenesis of Parkinson's disease.
Grant number：17590878 2005 - 2007
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C) Grant-in-Aid for Scientific Research (C)
ASANUMA Masato, MIYAZAKI Ikuko
Authorship：Coinvestigator(s)
Grant amount：\3700000 （ Direct expense: \3400000 、 Indirect expense：\300000 ）
To clarify the possible roles of dopamine neuron-specific degenerative factor dopamine quinone in the pathogenesis of Parkinson's disease and to investigate therapeutic application of the dopamine quinone-regulating agents, we performed following experiments using dopaminergic neuronal cultured cells and hemi-parkinsonian model mice.
1. Screening of interacting molecules with dopamine or dopamine quinone
By electron spin resonance method using in vitro dopamine quinone generating system, we identified metallothionein-1, some dopamine agonists and certain drug as dopamine quinone-interacting molecules.
2. Dopamine quinone-induced toxicity in cultured neuronal cells and effects of regulation of quinone-quenching system
In dopaminergic CATH.a cells, dopamine quinone generated from excess free dopamine exerts neurotoxic effects. However, the dopamine-quinone-induced neurotoxicity was prevented by quenching of dopamine quinone, e.g. quinone reductase inducer, metallothionein inducer and a drug which enhances up-take of the substrate of glutathione synthesis in astroglial cells.
3. Changes in quinone-quenching system and effects of its regulation in parkinsonian animal models
Several molecules of quinone-quenching system were activated in the lesioned striatum of hemi-parkinsonian mice. The drug, which interacts with dopamine quinone, enhanced astroglial proliferation, up-take of glutathione substrate in astroglial cells, and increased glutathione levels in the striatum. Furthermore, the drug ameliorated dopaminergic neuronal loss in the substantia nigra and inhibited repeated L-DOPA injections-induced elevation of protein-bound quinone (quinoprotein) in the striatum. Repeated L-DOPA administration markedly elevated striatal quinoprotein levels and reduced the dopaminergic nerve terminals specifically on the lesioned side in metallothionein-knockout parkinsonian mice, suggesting that intrinsic cysteine-rich molecule metallothionein protects against L-DOPA-induced dopamine quinone neurotoxicity in parkinsonian mice by its quinone-quenching property.
These experimental results suggest a therapeutic potency of dopamine quinone-quenching agents for the patients of Parkinson's disease, and clarify that neuro-glial interaction on up-take of the substrate of glutathione synthesis plays a role in neuroprotective strategies against progressive dopaminergic neurodegeneration. -
Studies on tyrosinase-producing cell transplantation into parkinsonian models.
Grant number：14570596 2002 - 2004
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C) Grant-in-Aid for Scientific Research (C)
ASANUMA Masato, MIYAZAKI Ikuko
Authorship：Coinvestigator(s)
Grant amount：\3200000 （ Direct expense: \3200000 ）
To investigate the possible effects of tyrosinase-producing cell transplantation in parkinsonian models, we performed intrastriatal transplantation of melanocytes or melanoma cells, as tyrosinase-producing cells, into hemi-parkinsonian model animals, as follows :
1.Transplantation of melanoma cells into the striatum of parkinsonian models
Intrastriatal transplantation of B16-F1 melanoma cells, as tyrosinase-producing cells, into hemi-parkinsonian rats lesioned by 6-OHDA markedly ameliorated apomorphine-induced rotation behavior towards contralateral side up to 40 days after the transplantation of melanoma cells, coinciding with expression of dopamine-positive signals around survived transplant.
2.Primary cultured melanocvtes from the back of newborn mice
We established the procedure of primary culture for melanocytes from the back of newborn C57BL mice, which showed higher tyrosinase activity than melanocytes from albino mice.
3.Transplantation of primary_cultured melanocytes into the striatum of parkinsonian models
The transplantation of primary cultured melanocytes from the back of newborn black mice into the lesioned striatum of hemi-parkinsonian mice markedly and continuously ameliorated the apomorphine-induced contralateral rotation behavior up to 3 months after the melanocyte transplantation. In the transplanted group with melanocytes, the striatal transplant melanocytes survived coinciding with dopamine- and tyrosinase-positive signals along the transplant in the striatum 3 months after the transplantation.
4.Primary cultured melanocytes from the adult mice
We tried to establish the culture of melanocytes from the back skin of adult C57BL mice for future auto-transplantation of melanocytes into parkinsonian models, but failed to do it because of contamination of the folliculi.
5.Distribution of tyrosinase-positive cells in the brain of parkinsonian models
Tyrosinase constitutively expressed mainly on oligodendrocytes in the corpus callosum, striatum and substantia nigra. In the parkinsonian model mice, tyrosinase-positive oligodendrocytes increased in the striatum, whereas it decreased in the substantia nigra.
These experimental results suggest a therapeutic potency of tyrosinase-producing cells such as melanocytes which may complement tyrosine hydroxylase when dopaminergic neurons are degenerated in Parkinson's disease, and may normalize L-DOPA-induced abnormal dopamine turnover