線虫 Caenorhabditis elegans 生殖巣形成 : リーダー細胞の移動停止機構の研究

関西学院大

Cryopreservation of Induced Pluripotent Stem Cell-Derived Dopaminergic Neurospheres for Clinical Application

[Background:] Pluripotent stem cell (PSC)-derived dopaminergic (DA) neurons are an expected source of cell therapy for Parkinson’s disease. The transplantation of cell aggregates or neurospheres, instead of a single cell suspension has several advantages, such as keeping the 3D structure of the donor cells and ease of handling. For this PSC-based therapy to become a widely available treatment, cryopreservation of the final product is critical in the manufacturing process. However, cryopreserving cell aggregates is more complicated than cryopreserving single cell suspensions. Previous studies showed poor survival of the DA neurons after the transplantation of cryopreserved fetal ventral-mesencephalic tissues. [Objective:] To achieve the cryopreservation of induced pluripotent stem cell (iPSC)-derived DA neurospheres toward clinical application. [Methods:] We cryopreserved iPSC-derived DA neurospheres in various clinically applicable cryopreservation media and freezing protocols and assessed viability and neurite extension. We evaluated the population and neuronal function of cryopreserved cells by the selected method in vitro. We also injected the cells into 6-hydroxydopamine (6-OHDA) lesioned rats, and assessed their survival, maturation and function in vivo. [Results:] The iPSC-derived DA neurospheres cryopreserved by Proton Freezer in the cryopreservation medium Bambanker hRM (BBK) showed favorable viability after thawing and had equivalent expression of DA-specific markers, dopamine secretion, and electrophysiological activity as fresh spheres. When transplanted into 6-OHDA-lesioned rats, the cryopreserved cells survived and differentiated into mature DA neurons, resulting in improved abnormal rotational behavior. [Conclusion:] These results show that the combination of BBK and Proton Freezer is suitable for the cryopreservation of iPSC-derived DA neurospheres

The BED finger domain protein MIG-39 halts migration of distal tip cells in Caenorhabditis elegans

AbstractOrgans are often formed by the extension and branching of epithelial tubes. An appropriate termination of epithelial tube extension is important for generating organs of the proper size and morphology. However, the mechanism by which epithelial tubes terminate their extension is mostly unknown. Here we show that the BED-finger domain protein MIG-39 acts to stop epithelial tube extension in Caenorhabditis elegans. The gonadal leader cells, called distal tip cells (DTCs), migrate in a U-shaped pattern during larval development and stop migrating at the young adult stage, generating a gonad with anterior and posterior U-shaped arms. In mig-39 mutants, however, DTCs overshot their normal stopping position. MIG-39 promoted the deceleration of DTCs, leading to the proper timing and positioning of the cessation of DTC migration. Among three Rac GTPase genes, mutations in ced-10 and rac-2 enhanced the overshoot of anterior DTCs, while they suppressed that of posterior DTCs of mig-39 mutants. On the other hand, the mutation in mig-2 suppressed both the anterior and posterior DTC defects of mig-39. Genetic analyses suggested that MIG-39 acts in parallel with Rac GTPases in stopping DTC migration. We propose a model in which the anterior and posterior DTCs respond in an opposite manner to the levels of Rac activities in the cessation of DTC migration

Viral delivery of L1CAM promotes axonal extensions by embryonic cerebral grafts in mouse brain

遺伝子治療によるホスト脳の環境最適化が細胞移植効果を高める --ホスト脳へのL1CAMの強制発現によるマウス胎仔脳移植片の軸索伸長促進効果--. 京都大学プレスリリース. 2023-03-24.Combining cell transplantation and gene therapy to enhance axonal outgrowth in the central nervous system. 京都大学プレスリリース. 2023-04-06.Cell replacement therapy is expected as a new and more radical treatment against brain damage. We previously reported that transplanted human cerebral organoids extend their axons along the corticospinal tract in rodent brains. The axons reached the spinal cord but were still sparse. Therefore, this study optimized the host brain environment by the adeno-associated virus (AAV)-mediated expression of axon guidance proteins in mouse brain. Among netrin-1, SEMA3, and L1CAM, only L1CAM significantly promoted the axonal extension of mouse embryonic brain tissue-derived grafts. L1CAM was also expressed by donor neurons, and this promotion was exerted in a haptotactic manner by their homophilic binding. Primary cortical neurons cocultured on L1CAM-expressing HEK-293 cells supported this mechanism. These results suggest that optimizing the host environment by the AAV-mediated expression of axon guidance molecules enhances the effect of cell replacement therapy

MHC matching improves engraftment of iPSC-derived neurons in non-human primates.

The banking of human leukocyte antigen (HLA)-homozygous-induced pluripotent stem cells (iPSCs) is considered a future clinical strategy for HLA-matched cell transplantation to reduce immunological graft rejection. Here we show the efficacy of major histocompatibility complex (MHC)-matched allogeneic neural cell grafting in the brain, which is considered a less immune-responsive tissue, using iPSCs derived from an MHC homozygous cynomolgus macaque. Positron emission tomography imaging reveals neuroinflammation associated with an immune response against MHC-mismatched grafted cells. Immunohistological analyses reveal that MHC-matching reduces the immune response by suppressing the accumulation of microglia (Iba-1+) and lymphocytes (CD45+) into the grafts. Consequently, MHC-matching increases the survival of grafted dopamine neurons (tyrosine hydroxylase: TH+). The effect of an immunosuppressant, Tacrolimus, is also confirmed in the same experimental setting. Our results demonstrate the rationale for MHC-matching in neural cell grafting to the brain and its feasibility in a clinical setting.Major histocompatibility complex (MHC) matching improves graft survival rates after organ transplantation. Here the authors show that in macaques, MHC-matched iPSC-derived neurons provide better engraftment in the brain, with a lower immune response and higher survival of the transplanted neurons

ヒト人工多能性幹細胞由来中脳ドーパミン神経の霊長類パーキンソン病モデル脳への生着

京都大学0048新制・課程博士博士(医学)甲第17099号医博第3707号新制||医||994(附属図書館)29829京都大学大学院医学研究科医学専攻(主査)教授 髙橋 良輔, 教授 福山 秀直, 教授 中辻 憲夫学位規則第4条第1項該当Doctor of Medical ScienceKyoto UniversityDA

Isolation of Human Induced Pluripotent Stem Cell-Derived Dopaminergic Progenitors by Cell Sorting for Successful Transplantation

Daisuke Doi, Bumpei Samata, Mitsuko Katsukawa, Tetsuhiro Kikuchi, Asuka Morizane, Yuichi Ono, Kiyotoshi Sekiguchi, Masato Nakagawa, Malin Parmar, and Jun Takahashi, "Isolation of Human Induced Pluripotent Stem Cell-Derived Dopaminergic Progenitors by Cell Sorting for Successful Transplantation", Stem Cell Reports, 2, 3, 337-350, Cell Press, 201

Pre-clinical study of induced pluripotent stem cell-derived dopaminergic progenitor cells for Parkinson’s disease

臨床用iPS細胞を用いたパーキンソン病治療の非臨床研究を実施 --ヒトiPS細胞由来のドパミン神経前駆細胞の安全性と有効性を確認--. 京都大学プレスリリース. 2020-07-20.Induced pluripotent stem cell (iPSC)-derived dopaminergic (DA) neurons are an expected source for cell-based therapies for Parkinson’s disease (PD). The regulatory criteria for the clinical application of these therapies, however, have not been established. Here we show the results of our pre-clinical study, in which we evaluate the safety and efficacy of dopaminergic progenitors (DAPs) derived from a clinical-grade human iPSC line. We confirm the characteristics of DAPs by in vitro analyses. We also verify that the DAP population include no residual undifferentiated iPSCs or early neural stem cells and have no genetic aberration in cancer-related genes. Furthermore, in vivo studies using immunodeficient mice reveal no tumorigenicity or toxicity of the cells. When the DAPs are transplanted into the striatum of 6-OHDA-lesioned rats, the animals show behavioral improvement. Based on these results, we started a clinical trial to treat PD patients in 2018

Purification of functional human ES and iPSC-derived midbrain dopaminergic progenitors using LRTM1

Human induced pluripotent stem cells (iPSCs) can provide a promising source of midbrain dopaminergic (mDA) neurons for cell replacement therapy for Parkinson's disease (PD). However, iPSC-derived donor cells inevitably contain tumorigenic or inappropriate cells. To eliminate these unwanted cells, cell sorting using antibodies for specific markers such as CORIN or ALCAM has been developed, but neither marker is specific for ventral midbrain. Here we employ a double selection strategy for cells expressing both CORIN and LMX1A::GFP, and report a cell surface marker to enrich mDA progenitors, LRTM1. When transplanted into 6-OHDA-lesioned rats, human iPSC-derived LRTM1 + cells survive and differentiate into mDA neurons in vivo, resulting in a significant improvement in motor behaviour without tumour formation. In addition, there was marked survival of mDA neurons following transplantation of LRTM1 + cells into the brain of an MPTP-treated monkey. Thus, LRTM1 may provide a tool for efficient and safe cell therapy for PD patients