Spinal cord injury is a very serious, complex, and life changing injury for which today's medicine still does not have an efficient treatment. It is only possible to mitigate the consequences of this injury and the pathological processes associated with it. Neural stem cell transplantation has immunosuppressive effects in the pathology of spinal cord injury and promotes regeneration. mTOR kinase is a member of the crucial intracellular PI3K/Akt/mTOR signalling pathway, making it a suitable target for therapeutic intervention and immunosuppressants such as rapamycin. mTOR signalling is important for neural stem cells and in the pathology of spinal cord injury. The aim of this study was to investigate the role of the mTOR pathway in differentiation of stem cells into neuronal phenotype. Rapamycin was applied to in vitro culture of neural progenitors. Immunocytochemistry and immunoblotting techniques were used to study the effect of this inhibition on the cell phenotype and on the activity of the mTOR pathway. Using the rat model of spinal cord injury in vivo, immunohistochemistry and immunoblotting techniques were used to evaluate the impact of rapamycin inhibition on the mTOR pathway, autophagy, and cytokine production by cells in the damaged tissue. The results show that the mTOR pathway plays role...

Due to their underlying genetic complexity, chromosomal disorders such as Down syndrome (DS), which is caused by trisomy 21, have long been understudied and continue to lack effective treatments. With over 200 genes on the extra chromosome, even the specific cell pathologies and pathways impacted in DS are not known, and it has not been considered a viable target for the burgeoning field of gene therapy. Recently, our lab demonstrated that the natural mechanism of dosage compensation can be harnessed to silence the trisomic chromosome in pluripotent cells. Using an inducible XIST transgene allows us to study the effects of trisomy in a tightly controlled system by comparing the same cells with either two or three active copies of chromosome 21. In addition, it raises the prospect that insertion of a single gene into a trisomic chromosome could potentially be developed in the future for “chromosome therapy”. This thesis aims to utilize this inducible system for dosage compensation to study the neurodevelopmental effects of trisomy 21 in vitro, and to answer basic epigenetic questions critical to the viability of chromosome silencing as a therapeutic approach. Foremost, for XIST to have any prospect as a therapeutic, and to strengthen its experimental utility, it must be able to initiate chromosome silencing beyond its natural context of pluripotency. Here I demonstrate that, contrary to the current literature, XIST is capable of initiating chromosome silencing in differentiated cells and producing fully dosage compensated DS neurons. Additionally, I show that silencing of the trisomic chromosome in neural stem cells enhances their terminal differentiation to neurons, and transcriptome analysis provides evidence of a specific pathway involved. Separate experiments utilize novel three-dimensional organoid technology and transcriptome analysis to model DS neurodevelopment in relation to isogenic euploid cells. Overall, this work demonstrates that dosage compensation provides a powerful experimental tool to examine early DS neurodevelopment, and establishes that XIST function does not require pluripotency, thereby overcoming a perceived obstacle to the potential of XIST as a therapeutic strategy for trisomy.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18870号 / 医博第3981号 / 新制||医||1008(附属図書館) / 31821 / 京都大学大学院医学研究科医学専攻 / (主査)教授 萩原 正敏, 教授 瀬原 淳子, 教授 中畑 龍俊 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・論文博士 / 博士(医科学) / 乙第12971号 / 論医科博第2号 / 新制||医科||5(附属図書館) / 32409 / 新制||医科||5 / 横浜市立大学大学院国際総合科学研究科バイオ科学専攻 / (主査)教授 長船 健二, 教授 中畑 龍俊, 教授 髙折 晃史 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

This research was originally published in The Journal of Biological Chemistry. May Nakajima-Koyama, Joonseong Lee, Sho Ohta, Takuya Yamamoto, and Eisuke Nishida. Induction of Pluripotency in Astrocytes through a Neural Stem Cell-Like State. The Journal of Biological Chemistry, 290(52), 31173-31188, 2015. © The American Society for Biochemistry and Molecular Biology / 京都大学 / 0048 / 新制・論文博士 / 博士(生命科学) / 乙第13027号 / 論生博第13号 / 新制||生||47(附属図書館) / 32955 / 京都大学大学院生命科学研究科統合生命科学専攻 / (主査)教授 西田 栄介, 教授 米原 伸, 教授 上村 匡 / 学位規則第4条第2項該当 / Doctor of Philosophy in Life Sciences / Kyoto University / DFAM

Final publication is available at http://www.cell.com/cell-stem-cell/abstract/S1934-5909(13)00012-X / 京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19622号 / 医博第4129号 / 新制||医||1015(附属図書館) / 32658 / 京都大学大学院医学研究科医学専攻 / (主査)教授 高橋 淳, 教授 伊佐 正, 教授 YOUSSEFIAN Shohab / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19967号 / 医博第4157号 / 新制||医||1017(附属図書館) / 33063 / 京都大学大学院医学研究科医学専攻 / (主査)教授 篠原 隆司, 教授 斎藤 通紀, 教授 山下 潤 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(生命科学) / 甲第20743号 / 生博第384号 / 新制||生||51(附属図書館) / 京都大学大学院生命科学研究科統合生命科学専攻 / (主査)教授 西田 栄介, 教授 米原 伸, 教授 松本 智裕 / 学位規則第4条第1項該当 / Doctor of Philosophy in Life Sciences / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20978号 / 医博第4324号 / 新制||医||1026(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 井上 治久, 教授 木村 剛, 教授 瀬原 淳子 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第13194号 / 論医博第2158号 / 新制||医||1030(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 柳田 素子, 教授 横出 正之, 教授 川口 義弥 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM