Masaki Kodaira

Generation of induced pluripotent stem cells from human terminally differentiated circulating T cells.

A manuscript has appeared online demonstrating isolation of iPSCs from peripheral blood, including a single line that showed evidence for both TCR-β and TCR-γ rearrangement by PCR (Kunisato, A., Wakatsuki, M., Shinba, H., Ota, T., Ishida, I., and Nagao, K. [2010]. Direct generation of induced pluripotent stem cells from human non-mobilized blood. Stem Cells Dev., in press. Published online May 24, 2010. 10.1089/scd.2010.0063).

Endothelin‐1 Induces Myofibrillar Disarray and Contractile Vector Variability in Hypertrophic Cardiomyopathy–Induced Pluripotent Stem Cell–Derived Cardiomyocytes

Background Despite the accumulating genetic and molecular investigations into hypertrophic cardiomyopathy (HCM), it remains unclear how this condition develops and worsens pathologically and clinically in terms of the genetic–environmental interactions. Establishing a human disease model for HCM would help to elucidate these disease mechanisms; however, cardiomyocytes from patients are not easily obtained for basic research. Patient‐specific induced pluripotent stem cells (iPSCs) potentially hold much promise for deciphering the pathogenesis of HCM. The purpose of this study is to elucidate the interactions between genetic backgrounds and environmental factors involved in the disease progression of HCM. Methods and Results We generated iPSCs from 3 patients with HCM and 3 healthy control subjects, and cardiomyocytes were differentiated. The HCM pathological phenotypes were characterized based on morphological properties and high‐speed video imaging. The differences between control and HCM iPSC‐derived cardiomyocytes were mild under baseline conditions in pathological features. To identify candidate disease‐promoting environmental factors, the cardiomyocytes were stimulated by several cardiomyocyte hypertrophy‐promoting factors. Interestingly, endothelin‐1 strongly induced pathological phenotypes such as cardiomyocyte hypertrophy and intracellular myofibrillar disarray in the HCM iPSC‐derived cardiomyocytes. We then reproduced these phenotypes in neonatal cardiomyocytes from the heterozygous Mybpc3‐targeted knock in mice. High‐speed video imaging with motion vector prediction depicted physiological contractile dynamics in the iPSC‐derived cardiomyocytes, which revealed that self‐beating HCM iPSC‐derived single cardiomyocytes stimulated by endothelin‐1 showed variable contractile directions. Conclusions Interactions between the patients genetic backgrounds and the environmental factor endothelin‐1 promote the HCM pathological phenotype and contractile variability in the HCM iPSC‐derived cardiomyocytes.

Relationships between Traumatic Symptoms and Environmental Damage Conditions among Children 8 Months after the 2011 Japan Earthquake and Tsunami

Background To evaluate relationships between traumatic symptoms and environmental damage conditions among children who survived the 2011 Great East Japan Earthquake and Tsunami. Methods The subjects were 12,524 children in kindergartens, elementary schools, and junior high schools in Ishinomaki City, Miyagi Prefecture, Japan. The Post Traumatic Stress Symptoms for Children 15 items (PTSSC-15), a self-completion questionnaire on traumatic symptoms, was distributed to the children and a questionnaire regarding environmental damage conditions affecting the children was distributed to their teachers. Of 12,524 questionnaires distributed, an effective response was obtained from 11,692 (93.3%). Results The PTSSC-15 score was significantly higher in females than in males among 4th to 6th grade students in elementary schools and among junior high school students. In terms of traumatic symptoms and environmental damage conditions, with the exception of kindergartners, children who had their houses damaged or experienced separation from family members had a significantly higher PTSSC-15 score than children who did not experience environmental damage. Except for kindergartners and 4th- to 6th-grade elementary school students, children who experienced evacuation had a significantly higher PTSSC-15 score. Conclusions This study demonstrated relationships between traumatic symptoms and environmental damage conditions in children who had suffered from the disaster. Factors examined in studying the relationship between environmental damage conditions and traumatic symptoms were gender, age, house damage, evacuation experience, and bereavement experience. It was critical not only to examine the traumatic symptoms of the children but also to collect accurate information about environmental damage conditions.

Impaired respiratory function in MELAS‐induced pluripotent stem cells with high heteroplasmy levels

Mitochondrial diseases are heterogeneous disorders, caused by mitochondrial dysfunction. Mitochondria are not regulated solely by nuclear genomic DNA but by mitochondrial DNA. It is difficult to develop effective therapies for mitochondrial disease because of the lack of mitochondrial disease models. Mitochondrial myopathy, encephalomyopathy, lactic acidosis, and stroke‐like episodes (MELAS) is one of the major mitochondrial diseases. The aim of this study was to generate MELAS‐specific induced pluripotent stem cells (iPSCs) and to demonstrate that MELAS‐iPSCs can be models for mitochondrial disease. We successfully established iPSCs from the primary MELAS‐fibroblasts carrying 77.7% of m.3243A>G heteroplasmy. MELAS‐iPSC lines ranged from 3.6% to 99.4% of m.3243A>G heteroplasmy levels. The enzymatic activities of mitochondrial respiratory complexes indicated that MELAS‐iPSC‐derived fibroblasts with high heteroplasmy levels showed a deficiency of complex I activity but MELAS‐iPSC‐derived fibroblasts with low heteroplasmy levels showed normal complex I activity. Our data indicate that MELAS‐iPSCs can be models for MELAS but we should carefully select MELAS‐iPSCs with appropriate heteroplasmy levels and respiratory functions for mitochondrial disease modeling.

Sleep Duration among Children 8 Months after the 2011 Japan Earthquake and Tsunami

Background To elucidate relationships between disaster damage conditions and sleep duration among children who survived the 2011 Japan earthquake and tsunami. Methods The subjects comprised 12,524 children in kindergartens, elementary schools, and junior high schools in Ishinomaki City, Miyagi Prefecture, Japan. The Post Traumatic Stress Symptoms for Children 15 items (PTSSC-15), a self-completion questionnaire on traumatic symptoms, and a sleep questionnaire were distributed to them. A questionnaire regarding disaster damage conditions of the children’s homes was distributed to their teachers. Of 12,524, an effective response was obtained from 11,692 (93.3%). Results Relationships between sleep duration and traumatic symptoms were displayed low correlations. Children with house damage and/or evacuation experiences slept for a significantly shorter time than children without these experiences. Conclusion It is critical not only to examine traumatic symptoms in children but also to collect sleep duration and disaster damage conditions following natural disasters.

G-CSF supports long-term muscle regeneration in mouse models of muscular dystrophy

Duchenne muscular dystrophy (DMD) is a chronic and life-threatening disease that is initially supported by muscle regeneration but eventually shows satellite cell exhaustion and muscular dysfunction. The life-long maintenance of skeletal muscle homoeostasis requires the satellite stem cell pool to be preserved. Asymmetric cell division plays a pivotal role in the maintenance of the satellite cell pool. Here we show that granulocyte colony-stimulating factor receptor (G-CSFR) is asymmetrically expressed in activated satellite cells. G-CSF positively affects the satellite cell population during multiple stages of differentiation in ex vivo cultured fibres. G-CSF could be important in developing an effective therapy for DMD based on its potential to modulate the supply of multiple stages of regenerated myocytes. This study shows that the G-CSF-G-CSFR axis is fundamentally important for long-term muscle regeneration, functional maintenance and lifespan extension in mouse models of DMD with varying severities.

Generation and characterization of functional cardiomyocytes derived from human T cell-derived induced pluripotent stem cells.

Induced pluripotent stem cells (iPSCs) have been proposed as novel cell sources for genetic disease models and revolutionary clinical therapies. Accordingly, human iPSC-derived cardiomyocytes are potential cell sources for cardiomyocyte transplantation therapy. We previously developed a novel generation method for human peripheral T cell-derived iPSCs (TiPSCs) that uses a minimally invasive approach to obtain patient cells. However, it remained unknown whether TiPSCs with genomic rearrangements in the T cell receptor (TCR) gene could differentiate into functional cardiomyocyte in vitro. To address this issue, we investigated the morphology, gene expression pattern, and electrophysiological properties of TiPSC-derived cardiomyocytes differentiated by floating culture. RT-PCR analysis and immunohistochemistry showed that the TiPSC-derived cardiomyocytes properly express cardiomyocyte markers and ion channels, and show the typical cardiomyocyte morphology. Multiple electrode arrays with application of ion channel inhibitors also revealed normal electrophysiological responses in the TiPSC-derived cardiomyocytes in terms of beating rate and the field potential waveform. In this report, we showed that TiPSCs successfully differentiated into cardiomyocytes with morphology, gene expression patterns, and electrophysiological features typical of native cardiomyocytes. TiPSCs-derived cardiomyocytes obtained from patients by a minimally invasive technique could therefore become disease models for understanding the mechanisms of cardiac disease and cell sources for revolutionary cardiomyocyte therapies.

Posttraumatic Symptoms in Elementary and Junior High School Children after the 2011 Japan Earthquake and Tsunami: Symptom Severity and Recovery Vary by Age and Sex

OBJECTIVES To measure psychiatric symptoms exhibited by children in Ishinomaki City, Japan, an area severely damaged by the 2011 earthquake and tsunami, at 8 and 20 months post-tsunami to investigate differences in symptom severity and recovery rate by age, sex, and degree of trauma experienced. STUDY DESIGN Prospective data were collected from children in elementary school (5th and 6th grades) and junior high school (8th and 9th grades). Students completed the Post-Traumatic Stress Symptoms for Children-15 (PTSSC-15) survey. Trauma severity was scored according to experiences of bereavement, home damage, and evacuation. In total, 3795 PTSSC-15 surveys were analyzed, yielding total scores, post-traumatic stress disorder (PTSD) factor subscores, and depression factor subscores, which were analyzed according to grade group, sex, and degree of trauma (trauma dose). RESULTS In the elementary school children, mean total PTSSC-15 score, PTSD factor score, and depression factor score were significantly improved at 20 months post-tsunami compared with 8 months (P < .0001 for all), whereas there were no significant improvements in the junior high school children. In females of the older group, the depression factor score at 20 months post-tsunami was significantly higher than at 8 months (P < .01). CONCLUSIONS Elementary school and junior high school children living near the epicenter of the 2011 Japan earthquake and tsunami exhibited marked differences in PTSD and depressive symptoms. The mental health status of elementary school children improved, whereas that of junior high school children did not.

Poor performance on the Iowa gambling task in children with obsessive-compulsive disorder

BackgroundSeveral lines of evidence implicate orbitofrontal cortex dysfunction in the pathophysiology of obsessive-compulsive disorder (OCD). The purpose of this study was to investigate neuropsychological dysfunction of the orbitofrontal cortex in children with OCD.MethodsThe Iowa Gambling Task (IGT), which reflects orbitofrontal cortex function, and the Wisconsin Card Sorting Test (WCST), which is associated with functioning of the dorsolateral prefrontal cortex, were administered to 22 children with OCD and 22 healthy controls matched for gender, age, and intelligence.ResultsOCD patients displayed poor performance on the IGT. In contrast, performance on the WCST was not impaired in OCD patients compared to controls.ConclusionsThese findings are in line with previous studies demonstrating that OCD in childhood is associated with a dysfunction of orbitofrontal-striatal-thalamic circuitry.

Analysis of changes in traumatic symptoms and daily life activity of children affected by the 2011 Japan earthquake and tsunami over time.

Background On March 11, 2011, Japan was struck by a massive earthquake and tsunami. The tsunami caused tremendous damage and traumatized a number of people, including children. This study aimed to compare traumatic symptoms and daily life activity among children 20 months after the 2011 Great East Japan Earthquake and Tsunami with those observed after 8 months. Methods The study comprised two groups. The first comprised 12,524 kindergarten, elementary school, and junior high school children in Ishinomaki City, Miyagi Prefecture, Japan, who were evaluated 8 months after the disaster. The second comprised 10,597 children from the same place who were evaluated 20 months after the disaster. The Post Traumatic Stress Symptoms for Children 15 items (PTSSC-15), a self-completion questionnaire on traumatic symptoms, and a questionnaire on childrens daily life were distributed to the children. An effective response was obtained from 11,639 (92.9%, 8 months after) and 10,597 (86.9%, 20 months after) children. Results The PTSSC-15 score was significantly higher in junior high school girls than in boys. The PTSSC-15 score was significantly higher in 4th–6th grade girls than in boys after 8 months. Elementary and junior high school children evaluated after 20 months had a significantly lower PTSSC-15 score than those evaluated after 8 months. The number of children having breakfast was significantly higher after 8 months than that after 20 months. In both the groups, children of all grades who had breakfast had a significantly lower PTSSC-15 score than those who did not have breakfast. Conclusions We conclude that traumatic symptoms and daily life activity of children who survived the earthquake and tsunami improved over time.