1-S06-1
ヒト胚性または誘導性多能性幹細胞を用いた不整脈の診断と治療への再生医療技術の適用性の探求
Exploring the applicability of regenerative medicine technology using human embryonic or induced pluripotent stem cells to the diagnosis and treatment of arrhythmia
〇三明淳一朗1
JunichiroMiake1
1鳥取大学医学部病態解析医学講座 薬理学・薬物療法学分野
1Division of Pharmacology, Department of Pathophysiology and Therapeutic Science Faculty of Medicine, Tottori University
Diagnosis and treatment of arrhythmia are not sufficiently supported by present medical care. Therefore, we studied the applicability of human embryonic (ESC) or induced pluripotent stem cells (iPSC) to the diagnosis and treatment of arrhythmia. In the study on the diagnosis of arrhythmia, we established disease-specific iPSCs from a patient with long QT syndrome type 1 (LQTS1) and confirmed electrophysiological properties of LQTS1 after the cardiac differentiation. Computer simulation of the sympathetic activation state revealed the occurrence of early afterdepolarizations, the cause of sudden cardiac death in LQTS. In the study on the treatment of arrhythmia, we selectively obtained pacemaker-, Purkinje-, ventricular myocyte-like cells from cells differentiated from human ESCs/iPSCs using HCN4 and Mlc2v genes as labeling genes. When implanted to a rat model with atrioventricular block, the pacemaker-like cells successfully functioned as a pacemaker with an ability to respond to sympathetic stimulation. In conclusion, the application of human ESCs/iPSCs to the diagnosis of arrhythmia is promising and that to the treatment of arrhythmia is feasible.
1-S06-2
骨髄由来細胞の遊走性および標的化を応用した神経疾患への分子治療戦略
The strategy of molecular therapy for neuronal diseases with the application of cell migration and targeting
〇寺島智也1
TomoyaTerashima1
1滋賀医科大学医学部生化学・分子生物学講座 再生修復医学部門
1Shiga Univ. Med. Sci., Dept. Stem Cell Biol. and Regenerative Med.
In neuronal diseases, it is difficult to provide the satisfactory outcome only by stem cell transplantation because their pathogenesis is complex. Therefore, it should be developed a novel therapy considering the pathophysiology. We focused on migration of bone marrow-derived cell (BMDC)s to pathological lesion step by step with disease progression. We devised to apply this phenomenon, namely cell migration and targeting, to therapeutic strategy.
As application of cell migration, bone marrow transplantation was performed for the treatment of ALS mice. BMDCs migrated to the spinal cord and delayed disease progression, and this effect was enhanced by stem cell factor. Furthermore, we show other strategies with mesenchymal stem cells expressing growth factors transduced by human artificial chromosome vectors and with BMDCs as gene delivery carrier to target tissues.
As application of cell targeting, we have identified tissue specific peptides for dorsal root ganglion, microglia or astrocytes. And their peptides were incorporated into viral vectors or the complexes with therapeutic oligonucleotides to develop a novel therapy.
The combination of cell migration and targeting is a very useful tool for novel molecular therapy of neuronal diseases. This strategy is expected to have high therapeutic potential because therapeutic genes are targeted to specific cells and rescue cells gradually accumulate in pathological lesion as much as diseases progress.
1-S06-3
iPS細胞由来骨格筋幹細胞を用いた筋ジストロフィーに対する細胞移植治療の開発
Development of cell therapy for muscular dystrophy by iPSC-derived muscle stem cell
〇櫻井英俊1、趙明明1、竹中菜々1、佐藤優江1、高山了1,2、田積充年1,2、池谷真1、堀田秋津1、伊東佑太3、関口清俊4
HidetoshiSakurai1, MingmingZhao1, NanaTakenaka1, MasaeSato1, SatoruTakayama1,2, AtsutoshiTazumi1,2, MakotoIkeya1, AkitsuHotta1, YutaIto3, KiyotoshiSekiguchi4
1京都大学iPS細胞研究所、2旭化成㈱、3名古屋学院大学リハビリテーション科学部、4大阪大学蛋白質研究所
1CiRA, Kyoto Univ., 2ASAHI KASEI, 3Faculty Reha Sci., Nagoya Gakuin Univ., 4Institute Protein Res., Osaka Univ.
Cell therapy is one of desired method for treating intractable muscular diseases, such as Duchenne muscular dystrophy (DMD). Here, we demonstrated the effective stepwise differentiation method from human iPSCs to engraftable muscle stem cells without transgene induction. We induced myotome-like population that is identified as Myf5 positive cells, which showed highly myogenic differentiation potential in vitro. Gene expression profile of purified Myf5+ cells demonstrated that the expression of Pax7 was significantly increased in Myf5+ cells at the late stage of differentiation. To assess the regeneration potential, we transplanted the Myf5+ cells at the late stage of differentiation into immunodeficient DMD-model mice. The Myf5+ cells could be engrafted in more than one hundred of host myofibers and regenerate the diseased muscles with producing dystrophin. Finally, we confirmed the recovery of muscle function after transplantation. Taken together, we demonstrate that the transplantation of the human iPSC-derived muscle stem cells with step-wise differentiation can be effective for DMD with amelioration of muscle function.
1-S06-4
iPS細胞由来細胞を用いた腎臓・内分泌領域創薬の新展開
Novel therapeutic strategy for kidney and endocrine diseases using iPS cell technology
〇人見浩史1
HirofumiHitomi1
1関西医科大学医学部iPS・幹細胞再生医学講座
1Dept. iPS Stem Cell Regenerative Medicine, Kansai Medical Univ.
The differentiation of induced pluripotent stem cells (iPSCs), which have unlimited self-renewal capability and the potential to differentiate into any cell type in the body, provides promising cell sources for regenerative medicine. The somatic cell types differentiated from these stem cells have the potential for clinical applications, including cell therapy and drug screening. In this symposium, I will briefly summarize our novel therapeutic strategy for kidney and endocrine diseases using iPS cell technology.
Firstly, I will present our recent findings about cell therapy for renal anemia. The production of erythropoietin (EPO), a principal hormone for the hematopoietic system, by the kidneys is reduced in patients with chronic kidney disease (CKD), eventually resulting in severe anemia. Although recombinant human EPO treatment improves anemia in patients with CKD, returning to full red blood cell production without fluctuations does not always occur. Although vigorous efforts have been made to generate multiple somatic cell types from stem cells, the directed differentiation of EPO-producing cells (EPO cells) from iPSCs has not yet been achieved. Recently, we established a method to generate EPO-producing cells from human iPSCs (hiPSCs) by modifying previously reported hepatic differentiation protocols. These cells showed increased EPO expression and secretion in response to low oxygen conditions. The EPO protein secreted from hiPSC-derived EPO-producing (hiPSC-EPO) cells induced the erythropoietic differentiation of human umbilical cord blood progenitor cells in vitro. Furthermore, transplantation of hiPSC-EPO cells into mice with CKD induced by adenine treatment improved renal anemia. Thus, hiPSC-EPO cells may be a useful tool for clarifying the mechanisms of EPO production and may be useful as a therapeutic strategy for treating renal anemia.
Secondly, I will mention about drug screening and evaluation for renal anemia. It has been reported that EPO production is regulated by oxygen concentrations through hypoxia-inducible factors and their regulators, prolyl hydroxylase domain-containing enzymes (PHDs). Several PHD inhibitors are currently in clinical trials for treatment of renal anemia. Interestingly, our recent findings showed that a PHD inhibitor augmented EPO production only in hiPSC-EPO cells, but not HepG2 cells, which are an immortalized human hepatoma cell line and are widely used to investigate EPO production. These findings suggest that hiPSC-EPO cells may provide a good model for screening PHD inhibitors for their effects on renal anemia.
Finally, I will brief summarize recent topics about cell therapy for endocrine disease using iPS cell technology.