一般口演（Oral）

Oral Stem Cells, iPS Cells, Reprogramming 一般口演幹細胞、iPS細胞、リプログラミング

7月28日（日）8:45～9:00　第8会場（朱鷺メッセ　3F　303+304） 4O-08m1-1 ヒト神経細胞でのプレセニリン/γ-セクレターゼ生理機能を解析する幹細胞ツールの開発 Hirotaka Watanabe（渡部博貴），Zhi Zhou（周智），Kent Imaizumi（今泉研人），Hideyuki Okano（岡野栄之）慶應義塾大学医学部・生理学教室 Alzheimer's disease (AD) is characterized neuropathologically by the presence of amyloid plaques and neurofibrillary tangles as well as the loss of synapses and neurons. Mutations in the amyloid precursor protein (APP) and presenilin (PS) have been linked to familial forms of AD (FAD), accounting for approximately ~2% of AD patients. In particular, more than 200 distinct mutations in the PS genes have the majority of all identified causative mutations in FAD, highlighting an importance of PS mutation in the AD pathogenesis probably by affecting γ-secretase proteolytic activity, which then leads to an increase of more toxic β-amyloid (Aβ) peptides, especially Aβ42 or longer forms. Despite extensive investigations of pathogenic mechanism of PS mutations thus far, normal physiological functions of PS in mature neurons, especially human neurons, remain to be determined. However, detailed examination of PS physiological roles in mature neurons is often hampered by experimental hurdles, since simple PS knockout impairs Notch signaling pathway lethally during neural development. In this study, to investigate whether PS1 plays essential physiological roles in human cortical mature neurons, we generated PS1 conditional knockout (cKO) induced pluripotent stem cells (iPSCs) by CRISPR/Cas9 system, in which PS1 can be ablated selectively under an introduction of Cre recombinase. We then differentiated the PS1 cKO iPSCs into human cortical neurons in vitro, and ablated PS1 proteins by infection of lentivirus expressing Cre. Whereas no gross morphological alteration was observed between PS1-null neurons and PS1-intact control neurons, Aβ generation was robustly reduced in PS1-null neurons, along with a concomitant accumulation of APP-CTFs. Using this novel stem cell-based tool, we would discuss important physiological PS1 functions in human mature neurons, dysfunction of which could possibly underlie AD pathogenesis.		7月28日（日）9:00～9:15　第8会場（朱鷺メッセ　3F　303+304） 4O-08m1-2 Modelling Schizophrenia in a Dish: A Stem Cell Approach Annie Kathuria（Kathuria Annie）¹，Kara Elise Lopez Lengowski（Lengowski Kara Elise）^2,3，Brad Watmuff（Watmuff Brad）^1,2,3，Rakesh Karmacharya（Karmacharya Rakesh）^1,2,3 ¹HARVARD MEDICAL SCHOOL ²Broad Institute of MIT and Harvard ³Massachusetts General Hospital (MGH) Center for Genomic Medicine (CGM) Schizophrenia (SCZD) is a crippling neurological disorder with a world-wide prevalence of 1%. Cognitive impairments is the most important predictor of functional outcomes in patients with schizophrenia. However, efficacious treatment of cognitive deficits in psychotic disorders remains a significant challenge in clinical practice. Even though, antipsychotic medications provide symptom relief by reducing hallucinations, they do not improve the cognitive deficits that is the core feature in schizophrenia. There is an urgent need for new therapeutic approaches that target the neurobiology of cognitive impairments. Our research focuses on developing stem cell-based models to study the molecular and cellular basis of schizophrenia using iPSCs (Induced pluripotent stem cells) generated from patients. We have derived nine control and schizophrenia lines from eighteen donors, nine each. To better understand the development the of telencephalon, we made cerebral organoids from these lines. Six month old in-vitro cerebral organoids were compared using, total RNA sequencing, immunohistochemistry and, electrophysiology. Preliminary data, revealed that the neurodevelopmental pathways involved in synaptogenesis are aberrant in schizophrenia cerebral organoids. This was further confirmed as schizophrenia cerebral organoids showed no electrical activity when stimulated while the control organoids showed electrical activity. Thus, this suggests that there is dysfunction in the connectivity of these mini brains.

7月28日（日）9:15～9:30　第8会場（朱鷺メッセ　3F　303+304） 4O-08m1-3 FGF8によるヒトES/iPS細胞由来大脳皮質ニューロンの前後軸制御 Kent Imaizumi（今泉研人），Hideyuki Okano（岡野栄之）慶應大医生理 The cerebral cortex is subdivided into distinct areas that have particular functions. The rostrocaudal (R-C) gradient of fibroblast growth factor 8 (FGF8) signaling defines this areal identity during neural development. However, the mechanism of areal patterning has mostly been studied in mouse models, and it is unclear whether the findings can be applied to human cerebral cortex development. In this study, we recapitulated cortical R-C patterning in human embryonic stem cell (ESC) and induced pluripotent stem cell (iPSC) cultures. Modulation of FGF8 signaling appropriately regulated the expression of R-C markers, and the correlation analysis with human in vivo fetal brain transcriptome showed that FGF8 treatment conferred rostral (the sensorimotor cortex) identity on ESC/iPSC-derived cells, whereas these cells retained caudal (the temporal lobe) identity in the absence of FGF8. Our data suggest that the areal patterning can be precisely controlled in human ESC/iPSC cultures. Moreover, the area-specific forebrain phenotypes of ALS2-associated amyotrophic lateral sclerosis (ALS) were reproduced in vitro by using this system. We here present the first evidence of modeling the upper motor neuron phenotypes of ALS in vitro and our results represent an important step in the study of ALS. Finally, we will show preliminary results of the recapitulation of the FGF8-driven R-C axis formation in ESC/iPSC-derived cerebral organoids, and will discuss the mechanism underlying the precise establishment of the R-C axis within these organoids.		7月28日（日）9:30～9:45　第8会場（朱鷺メッセ　3F　303+304） 4O-08m1-4 脳梗塞患者より単離した小脳由来幹細胞は機能的な神経に分化し得る Mikiya Beppu（別府幹也）¹，Takayuki Nakagomi（中込隆之）²，Toshinori Takagi（高木俊範）¹，Akiko Doi（土居亜紀子）²，Tomohiro Matsuyama（松山知弘）²，Shinichi Yoshimura（吉村紳一）¹ ¹兵庫医科大学　脳神経外科 ²兵庫医科大学　神経再生部門 Introduction: Despite the availability of effective reperfusion therapies, only a few proved to be beneficial to the patients after stroke, owing to their limited time window. We have previously demonstrated that adult brain pericytes develop the stemness following ischemia and that these ischemia-induced multipotent stem cells (iSCs) can self-propagate and differentiate into mature neural cells, including neurons. More recently, we showed that putative iSCs were present within post-stroke human cerebral tissues. The current study aimed to establish iSCs from cerebellar infarction of two patients and examine their characteristics. Methods: We isolated iSCs from post-stroke human cerebellum, examined their characteristics by polymerase chain reaction and immunocytochemistry, and compared their traits with those of others by microarray and flow cytometry analyses. Furthermore, we investigated whether cerebellar-iSCs (cl-iSCs) have the multipotency to differentiate into functional neurons. Electrophysiological properties were analyzed using multi-electrode arrays. Results: The isolated cl-iSCs exhibited multipotency and differentiated into electrophysiologically functional neurons. Neurogenic potential was confirmed in single-cell suspensions. Highly similar gene expression patterns were observed between pericytes and iSCs, and a strong lineage resemblance between cl-iSCs and cerebral ischemia-induced multi-potent stem cells (cr-iSCs) was revealed, although cl-iSCs expressed certain cerebellum-specific genes. Conclusions: Putative iSCs are present in post-stroke cerebellum and possess region-specific traits, suggesting that cl-iSCs have the potential to regenerate functional neurons following an ischemic stroke.