筋強直性ジストロフィー1型における脳卒中に関する危険因子の臨床的特徴

Objective: Myotonic dystrophy type 1 (DM1) is a rare autosomal dominant disorder with highly variable phenotypic expression. Some patients have diabetes mellitus, dyslipidemia, and/or arrhythmias, which are risk factors for stroke. However, the mechanism of stroke is poorly understood in patients with DM1. We studied the characteristics of risk-factor profiles for stroke associated with DM1. Patients and methods: We studied 77 patients with DM1 (45 men and 32 women) on the basis of the patients’ clinical histories and laboratory and genetic examination results. Results: The analysis showed that 26 patients (34%) had dyslipidemia, and 16 (21%) had diabetes. Arrhythmias were diagnosed in 46 patients (61%), including 11 (14%) with atrial fibrillation and 9 (12%) with conduction defects. Echocardiographic abnormalities were found in 28 patients (37%). Eight patients (11%) met the criteria for metabolic syndrome. We identified 2 patients (2.6%) with ischemic stroke caused by cardiogenic embolism among 77 patients with DM1. One had paroxysmal atrial fibrillation and sick sinus syndrome, and the other had cardiac dysfunction with an ejection-fraction of 35% and dyslipidemia. Both patients had highly expanded numbers of CTG repeats (1000 and 1500). Conclusion: To our knowledge, this is the first study to report a comprehensive analysis of risk-factor profiles for stroke in patients with DM1. Stroke is a relatively rare, but severe complication of DM1. Our results indicate that it is important to manage risk factors for stroke, especially cardiac involvement and arrhythmias.博士（医学）・乙第1392号・平成29年3月15日Copyright: © 2016 Sugie M, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

C9orf72由来のプロリン : アルギニンポリペプチドは細胞骨格とメカニカルストレス応答を制御する

Proline:arginine (PR) poly-dipeptides from the GGGGCC repeat expansion in C9orf72 have cytotoxicity and bind intermediate filaments (IFs). However, it remains unknown how PR poly-dipeptides affect cytoskeletal organization and focal adhesion (FA) formation. Here, we show that changes to the cytoskeleton and FA by PR poly-dipeptides result in the alteration of cell stiffness and mechanical stress response. PR poly-dipeptides increased the junctions and branches of the IF network and increased cell stiffness. They also changed the distribution of actin filaments and increased the size of FA and intracellular calcium concentration. PR poly-dipeptides or an inhibitor of IF organization prevented cell detachment. Furthermore, PR poly-dipeptides induced upregulation of mechanical stress response factors and led to a maladaptive response to cyclic stretch. These results suggest that the effects of PR poly-dipeptides on mechanical properties and mechanical stress response may serve as a pathogenesis of C9orf72-related neurodegeneration.博士（医学）・甲第846号・令和4年9月28日Copyright © 2022 Shiota, Nagata, Kikuchi, Nanaura, Matsubayashi, Nakanishi,Kobashigawa, Isozumi, Kiriyama, Nagayama, Sugie, Yamashiro and Mori. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms

C9orf72-derived arginine-rich poly-dipeptides impede phase modifiers

Nuclear import receptors (NIRs) not only transport RNA-binding proteins (RBPs) but also modify phase transitions of RBPs by recognizing nuclear localization signals (NLSs). Toxic arginine-rich poly-dipeptides from C9orf72 interact with NIRs and cause nucleocytoplasmic transport deficit. However, the molecular basis for the toxicity of arginine-rich poly-dipeptides toward NIRs function as phase modifiers of RBPs remains unidentified. Here we show that arginine-rich poly-dipeptides impede the ability of NIRs to modify phase transitions of RBPs. Isothermal titration calorimetry and size-exclusion chromatography revealed that proline:arginine (PR) poly-dipeptides tightly bind karyopherin-β2 (Kapβ2) at 1:1 ratio. The nuclear magnetic resonances of Kapβ2 perturbed by PR poly-dipeptides partially overlapped with those perturbed by the designed NLS peptide, suggesting that PR poly-dipeptides target the NLS binding site of Kapβ2. The findings offer mechanistic insights into how phase transitions of RBPs are disabled in C9orf72-related neurodegeneration

A Nationwide Survey on Danon Disease in Japan

Danon disease, an X-linked dominant cardioskeletal myopathy, is caused by primary deficiency of lysosome-associated membrane protein-2 (LAMP-2). To clarify the clinicopathological features and management, we performed the first nationwide, questionnaire-based survey on Danon disease in Japan. A total of 39 patients (17 males, 22 females) from 20 families were identified in the analysis. All patients had cardiomyopathy. Of the 21 patients who died, 20 (95%) died of cardiac failure or sudden cardiac arrest. Most patients had hypertrophic cardiomyopathy. Wolf⁻Parkinson⁻White syndrome was present at a comparatively high incidence (54% in males, 22% in females). Only one female patient received a heart transplant, which is the most effective therapy. Histopathologically, all male patients showed autophagic vacuoles with sarcolemmal features in muscle. Half of the probands showed de novo mutations. Male patients showed completely absent LAMP-2 expression in muscle. In contrast, female patients showed decreased LAMP-2 expression, which is suggested to reflect LAMP-2 haploinsufficiency due to a heterozygous null mutation. In conclusion, Danon disease is an extremely rare muscular disorder in Japan. Cardiomyopathy is the most significant prognostic factor and the main cause of death. Our findings suggest that the present survey can extend our understanding of the clinical features of this rare disease

C9orf72-derived arginine-rich poly-dipeptides impede phase modifiers

Nuclear import receptors (NIRs) not only transport RNA-binding proteins (RBPs) but also modify phase transitions of RBPs by recognizing nuclear localization signals (NLSs). Toxic arginine-rich poly-dipeptides from C9orf72 interact with NIRs and cause nucleocytoplasmic transport deficit. However, the molecular basis for the toxicity of arginine-rich poly-dipeptides toward NIRs function as phase modifiers of RBPs remains unidentified. Here we show that arginine-rich poly-dipeptides impede the ability of NIRs to modify phase transitions of RBPs. Isothermal titration calorimetry and size-exclusion chromatography revealed that proline:arginine (PR) poly-dipeptides tightly bind karyopherin-β2 (Kapβ2) at 1:1 ratio. The nuclear magnetic resonances of Kapβ2 perturbed by PR poly-dipeptides partially overlapped with those perturbed by the designed NLS peptide, suggesting that PR poly-dipeptides target the NLS binding site of Kapβ2. The findings offer mechanistic insights into how phase transitions of RBPs are disabled in C9orf72-related neurodegeneration

ヒト多能性幹細胞を用いた脳幹オルガノイドの開発

The brainstem is a posterior region of the brain, composed of three parts, midbrain, pons, and medulla oblongata. It is critical in controlling heartbeat, blood pressure, and respiration, all of which are life-sustaining functions, and therefore, damages to or disorders of the brainstem can be lethal. Brain organoids derived from human pluripotent stem cells (hPSCs) recapitulate the course of human brain development and are expected to be useful for medical research on central nervous system disorders. However, existing organoid models are limited in the extent hPSCs recapitulate human brain development and hence are not able to fully elucidate the diseases affecting various components of the brain such as brainstem. Here, we developed a method to generate human brainstem organoids (hBSOs), containing midbrain/hindbrain progenitors, noradrenergic and cholinergic neurons, dopaminergic neurons, and neural crest lineage cells. Single-cell RNA sequence (scRNA-seq) analysis, together with evidence from proteomics and electrophysiology, revealed that the cellular population in these organoids was similar to that of the human brainstem, which raises the possibility of making use of hBSOs in investigating central nervous system disorders affecting brainstem and in efficient drug screenings.博士（医学）・乙第1479号・令和2年12月24日Copyright © 2020 Eura, Matsui, Luginbühl, Matsubayashi, Nanaura, Shiota, Kinugawa, Iguchi, Kiriyama, Zheng, Kouno, Lan, Kongpracha, Wiriyasermkul, Sakaguchi, Nagata, Komeda, Morikawa, Kitayoshi, Jong, Kobashigawa, Nakanishi, Hasegawa, Saito, Shiromizu, Nishimura, Kasai, Takeda, Kobayashi, Inagaki, Tanaka, Makinodan, Kishimoto, Kuniyasu, Nagamori, Muotri, Shin, Sugie and Mori. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY https://creativecommons.org/licenses/by/4.0/). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms

Brainstem Organoids From Human Pluripotent Stem Cells.

The brainstem is a posterior region of the brain, composed of three parts, midbrain, pons, and medulla oblongata. It is critical in controlling heartbeat, blood pressure, and respiration, all of which are life-sustaining functions, and therefore, damages to or disorders of the brainstem can be lethal. Brain organoids derived from human pluripotent stem cells (hPSCs) recapitulate the course of human brain development and are expected to be useful for medical research on central nervous system disorders. However, existing organoid models are limited in the extent hPSCs recapitulate human brain development and hence are not able to fully elucidate the diseases affecting various components of the brain such as brainstem. Here, we developed a method to generate human brainstem organoids (hBSOs), containing midbrain/hindbrain progenitors, noradrenergic and cholinergic neurons, dopaminergic neurons, and neural crest lineage cells. Single-cell RNA sequence (scRNA-seq) analysis, together with evidence from proteomics and electrophysiology, revealed that the cellular population in these organoids was similar to that of the human brainstem, which raises the possibility of making use of hBSOs in investigating central nervous system disorders affecting brainstem and in efficient drug screenings