[Show abstract][Hide abstract] ABSTRACT: The developing dorsomedial telencephalon includes the medial pallium, which goes on to form the hippocampus. Generating a reliable source of human hippocampal tissue is an important step for cell-based research into hippocampus-related diseases. Here we show the generation of functional hippocampal granule- and pyramidal-like neurons from self-organizing dorsomedial telencephalic tissue using human embryonic stem cells (hESCs). First, we develop a hESC culture method that utilizes bone morphogenetic protein (BMP) and Wnt signalling to induce choroid plexus, the most dorsomedial portion of the telencephalon. Then, we find that titrating BMP and Wnt exposure allowed the self-organization of medial pallium tissues. Following long-term dissociation culture, these dorsomedial telencephalic tissues give rise to Zbtb20(+)/Prox1(+) granule neurons and Zbtb20(+)/KA1(+) pyramidal neurons, both of which were electrically functional with network formation. Thus, we have developed an in vitro model that recapitulates human hippocampus development, allowing the generation of functional hippocampal granule- and pyramidal-like neurons.
Preview · Article · Nov 2015 · Nature Communications
[Show abstract][Hide abstract] ABSTRACT: Background:
To evaluate the in vivo function of human dopaminergic (DA) neurons, Parkinson's disease (PD) model rats made by the hemi-lateral injection of 6-hydroxydopamine (6-OHDA) are widely used as host animals. In the case of such xeno-transplantation, however, immunosuppression is needed for good survival of the grafted cells.
In order to determine whether human mature neurons can survive in X-linked severe combined immunodeficiency (X-SCID) rats without immunosuppression, we grafted human embryonic stem cell (ESC)-derived DA neurons into the striatum of X-SCID rats. We next treated the X-SCID rats with 6-OHDA and grafted mouse fetal DA neurons or human induced pluripotent stem cell (iPSC)-derived DA neurons to examine whether these rats can be used as PD model rats.
X-SCID rats did not elicit immune responses against human ESC-derived DA neurons and consequently resulted in good survival of the cells without immunosuppression. Furthermore, 6-OHDA-lesioned X-SCID rats exhibited rotational behavior, which was recovered by grafting mouse fetal DA neurons or human iPSC-derived DA neurons.
Comparison with existing methods:
Immunosuppression by drugs such as Cyclosporine A requires daily injection, which is stressful for rats and moreover may cause renal or hepatic failure. Furthermore, blood levels of the drug may not be stable, which weakens the reliability of the data.
Our results provide a more accessible and reliable method to evaluate the in vivo function of human DA neurons, potentially offering a pre-clinical study for the application of pluripotent stem cells.
No preview · Article · Feb 2015 · Journal of Neuroscience Methods
[Show abstract][Hide abstract] ABSTRACT: Objective: Navigation of the guiding catheter (GC) is important in performing neuroendovascular therapy, as the GC may often disturb blood flow of the parent artery. In the present study, we aimed to examine the risk factors of mechanical vasospasm (mVS) of the parent artery during neuroendovascular therapy.Methods: We assessed a total of 64 consecutive cases who underwent coil embolization for unruptured intracranial aneurysms. mVS was defined as a stenotic change of the parent artery of > 25% after navigating GC.Results: mVS was observed in 24 cases (38%), and in 5 cases the GCs were changed to smaller sizes. The vasospastic changes in all the cases improved after changing the position of GC or the GC itself. Young age, female gender, and absence of hypertensive history were significantly associated with mVS. However, body mass index, adjunctive technique of coil embolization, and presence of hyper-intense lesions on diffusion weighted images were not associated with mVS.Conclusions: We suggest that care should be taken when navigating the GCs in patients with young age, female gender, and the absence of a history of hypertension in terms of the occurrence of mVS.
[Show abstract][Hide abstract] ABSTRACT: Survivors of pediatric brain tumors are often affected by late effects, such as motility disturbance of limb(s), seizure, ocular/visual impairment, endocrine abnormality, and higher brain dysfunction, resulting from the disease and its treatment. Appropriate provision of supportive care will require understanding the effects of these experiences on survivors' health-related quality of life (HRQOL).
The aim of this study was to identify the relationships between late effects and specific aspects of the HRQOL of pediatric brain tumor survivors.
We distributed questionnaires for measuring HRQOL to 138 survivors and their parents at 8 hospitals and 1 clinic in Japan and simultaneously surveyed late effects using information provided by the survivors' attending physicians. We compared the HRQOL of survivors with and survivors without specific late effects.
A total of 106 survivors and their parents returned the questionnaires to the researchers. The HRQOL of survivors 18 years or older was negatively affected by all 5 late effects, indicating that their higher impairment was associated with diminished HRQOL. The HRQOL of survivors aged 12 to 17 years was negatively affected by 2 late effects (ocular/visual impairment and motility disturbance of the limbs). A part of the HRQOL subdomain (motor and cognitive functioning) of survivors aged 12 to 17 years was positively related to ocular/visual impairment.
Five late effects influenced the HRQOL of pediatric brain tumor survivors.
Nurses and other health professionals should provide specific care designed to support aspects of HRQOL affected by late effects. For example, survivors with ocular/visual impairment may be expected to require additional emotional support, and those with seizures or endocrine abnormalities may be expected to require additional support for sleep disorders.
[Show abstract][Hide abstract] ABSTRACT: Human induced pluripotent stem cells (iPSCs) can provide a promising source of midbrain dopaminergic (DA) neurons for cell replacement therapy for Parkinson's disease. However, iPSC-derived donor cells inevitably contain tumorigenic or inappropriate cells. Here, we show that human iPSC-derived DA progenitor cells can be efficiently isolated by cell sorting using a floor plate marker, CORIN. We induced DA neurons using scalable culture conditions on human laminin fragment, and the sorted CORIN(+) cells expressed the midbrain DA progenitor markers, FOXA2 and LMX1A. When transplanted into 6-OHDA-lesioned rats, the CORIN(+) cells survived and differentiated into midbrain DA neurons in vivo, resulting in significant improvement of the motor behavior, without tumor formation. In particular, the CORIN(+) cells in a NURR1(+) cell-dominant stage exhibited the best survival and function as DA neurons. Our method is a favorable strategy in terms of scalability, safety, and efficiency and may be advantageous for clinical application.
Full-text · Article · Mar 2014 · Stem Cell Reports
[Show abstract][Hide abstract] ABSTRACT: In order to apply human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) to regenerative medicine, the cells should be produced under restricted conditions conforming to GMP guidelines. Since the conventional culture system has some issues that need to be addressed to achieve this goal, we developed a novel culture system. We found that recombinant laminin-511 E8 fragments are useful matrices for maintaining hESCs and hiPSCs when used in combination with a completely xeno-free (Xf) medium, StemFit™. Using this system, hESCs and hiPSCs can be easily and stably passaged by dissociating the cells into single cells for long periods, without any karyotype abnormalities. Human iPSCs could be generated under feeder-free (Ff) and Xf culture systems from human primary fibroblasts and blood cells, and they possessed differentiation abilities. These results indicate that hiPSCs can be generated and maintained under this novel Ff and Xf culture system.
Full-text · Article · Jan 2014 · Scientific Reports
[Show abstract][Hide abstract] ABSTRACT: The aim of stem cell therapy for Parkinson's disease (PD) is to reconstruct local synapse formation and/or induce the release of dopamine and cytokines from grafted cells in the putamen. Fetal ventral-midbrain cells are reported to relieve the neurological symptoms of PD patients. However, not only embryonic stem cells (ESCs), but also induced pluripotent stem cells (iPSCs) are expected to provide an alternative donor cell population because of their capacity for self-renewal and pluripotency. A protocol to generate dopaminergic (DA) neurons from ESCs and iPSCs has been developed, and human ESCs were proven to function in the brain of rat and monkey PD models. The next step will be the isolation of DA neurons as a donor cell population for a safe and efficient transplantation.
[Show abstract][Hide abstract] ABSTRACT: We examined the gene expression and DNA methylation of 49 human induced pluripotent stem cells (hiPSCs) and 10 human embryonic stem cells and found overlapped variations in gene expression and DNA methylation in the two types of human pluripotent stem cell lines. Comparisons of the in vitro neural differentiation of 40 hiPSCs and 10 human embryonic stem cells showed that seven hiPSC clones retained a significant number of undifferentiated cells even after neural differentiation culture and formed teratoma when transplanted into mouse brains. These differentiation-defective hiPSC clones were marked by higher expression levels of several genes, including those expressed from long terminal repeats of specific human endogenous retroviruses. These data demonstrated a subset of hiPSC lines that have aberrant gene expression and defective potential in neural differentiation, which need to be identified and eliminated before applications in regenerative medicine.
Preview · Article · Nov 2013 · Proceedings of the National Academy of Sciences
[Show abstract][Hide abstract] ABSTRACT: Surgical intervention is expected to improve the quality of life in patients with intractable epilepsy by providing adequate seizure control. Although many previous studies showed various rates of seizure freedom, definite conclusions have not yet been made regarding outcomes. In order to clarify the long-term postoperative outcome for a period up to 10 years, a retrospective review of our patients was performed longitudinally by using the survival analysis method. The postoperative state of epilepsy in 76 patients who underwent resection surgery was assessed based on Engel's criteria. In addition, Kaplan-Meier survival analysis was used to calculate the probability of seizure freedom. In this patient group, abnormal lesion were detected by MRI in 70 out of 76 cases, and the ictal onset zone was finally identified within temporal lobe in 51 cases. The most favorable outcome, defined as Engel Class Ia, was observed in 26 (37%), 24 (40%), and 18 (41%) cases at 2, 5, and 10 years after surgery, respectively. The Kaplan-Meier survival curve in the overall group estimated the probability of seizure freedom as 75% (95% confidence interval [CI] 70-80%), 67% (62-72%), and 51% (45-57%) at 2, 5, and 10 years follow up, respectively. Half of all seizure recurrences occurred within the first 2 postoperative years. In this study, we showed that long-term favorable outcome of seizure control following resection surgery can be achieved in more than half of the patients.
No preview · Article · Oct 2013 · Neurologia medico-chirurgica
[Show abstract][Hide abstract] ABSTRACT: Induced pluripotent stem cells (iPSCs) provide the potential for autologous transplantation using cells derived from a patient's own cells. However, the immunogenicity of iPSCs or their derivatives has been a matter of controversy, and up to now there has been no direct comparison of autologous and allogeneic transplantation in the brains of humans or nonhuman primates. Here, using nonhuman primates, we found that the autologous transplantation of iPSC-derived neurons elicited only a minimal immune response in the brain. In contrast, the allografts caused an acquired immune response with the activation of microglia (IBA-1(+)/MHC class II(+)) and the infiltration of leukocytes (CD45(+)/CD3(+)). Consequently, a higher number of dopaminergic neurons survived in the autografts. Our results suggest that the autologous transplantation of iPSC-derived neural cells is advantageous for minimizing the immune response in the brain compared with allogeneic grafts.
Full-text · Article · Oct 2013 · Stem Cell Reports
[Show abstract][Hide abstract] ABSTRACT: Our work and the study of Bilican et al. highlight the need for complementary assays to detect subtle phenotypic differences between control and mutant induced pluripotent stem cell lines.
No preview · Article · Jun 2013 · Science translational medicine
[Show abstract][Hide abstract] ABSTRACT: We herein report three cases of gonadotroph adenoma in men (36-72 years of age) presenting with visual impairment and suprasellar masses measuring approximately 20 to 30 mm in diameter. Endocrinological examinations were normal, except for slightly increased follicle stimulating hormone (FSH) levels in two cases. Based on the tentative diagnosis of non-functioning pituitary adenoma, transsphenoidal surgery was performed, which revealed that the tumors consisted of FSH- and LH-positive cells. As gonadotroph adenoma is very common among patients with clinically silent pituitary adenoma, it should be diagnosed using pathological examinations.
No preview · Article · Jun 2013 · Internal Medicine
[Show abstract][Hide abstract] ABSTRACT: Pluripotent stem cells are promising potential sources for cell replacement therapy and are useful research tools for exploring disease mechanisms. Neural cells are one of the cell types that have been most efficiently differentiated through several established protocols. This chapter describes the feeder-free floating aggregation culture system for the induction of dopaminergic neurons. This method is simple and highly efficient for the production of dopaminergic neurons. It has several advantages for application in clinical usage in comparison to the other protocols using either feeder cells or Matrigel.
Full-text · Article · May 2013 · Methods in molecular biology (Clifton, N.J.)
[Show abstract][Hide abstract] ABSTRACT: Aim:
The aim of this study was to determine the correlation between the growth hormone (GH)-insulin-like growth factor-I (IGF-I) axis and glucose intolerance in acromegaly during the early postoperative period.
Subjects and methods:
The study included 20 patients with acromegaly caused by GH-secreting pituitary adenoma who received transsphenoidal surgery in our hospital. Glucose tolerance was evaluated with oral glucose tolerance tests (OGTTs) performed during pre- and early postoperative periods (9 [7-18] days after surgery). Homeostasis model assessment of insulin resistance (HOMA-IR) and insulinogenic index (IGI) were calculated, and correlation analyses were performed between these values and the GH-IGF-I axis. Patients were divided according to postoperative changes of the axis, and glucose tolerance was compared between the groups.
In preoperative OGTTs, nine patients had impaired glucose tolerance and two had diabetes mellitus patterns. Postoperatively, significant reduction was observed both in fasting plasma glucose levels (p<0.01) and in HOMA-IR (p<0.01), whereas IGI showed no significant change. HOMA-IR was significantly correlated with serum IGF-I levels both before (r=0.83, p<0.01) and after (r=0.57, p<0.01) surgery, although it was not correlated with serum GH levels. Patients who achieved more than 50% postoperative reduction in serum IGF-I levels showed significant improvement in OGTTs results (p<0.05).
In patients with acromegaly, serum IGF-I levels, but not GH levels, were significantly correlated with insulin resistance. Early postoperative improvement of glucose tolerance is observed in patients who achieved postoperative reduction in serum IGF-I levels.
No preview · Article · May 2013 · Journal of endocrinological investigation
[Show abstract][Hide abstract] ABSTRACT: Animals that possess regenerative abilities are widespread in the animal kingdom. Hydra,
planarian, zebrafish, newt and axolotl are known prominent species, and the cellular aspects
of the stem cell system for regeneration are well elucidated. However, few animals can be
used to investigate the molecular basis of neuronal regeneration, in spite of the presence of
prominent regenerative animals, as mentioned above. Planarians, for instance, can regenerate
a functional brain after amputation in a few days, even from non-brain tissue. Newts can
regenerate several tissues and organs (i.e., lens, limbs, jaws, hearts and tails) with recovery of
function and physiology after injury or tissue removal. These animals achieve regeneration
of missing nervous system utilizing stem cells. However, it is difficult to regenerate
nervous system in mammalians, including human beings, although these animals possess
neural stem cells. Therefore, regenerative animals provide unique opportunities to investigate
the generation and utilization of stem cells to repair lost or injured tissue in non-regenerative
animals. On the other hand, the successful derivation of neural cells from human embryonic
stem cells (ESCs) and induced pluripotent stem cells (iPSCs) under in vitro conditions
provides a new experimental strategy for clinical translation. In other words, although human
beings lack regenerative abilities, the new clinical strategy of “regenerative medicine,”
including cell-transplantation therapy, has been developed to recover lost neural functions by
using stem cells. This research field has become a greatly advancing scientific field worldwide. In this chapter, we focus on the molecular systems of generation of functional dopaminergic
(DA) neurons in vivo and/or in vitro in regenerative and non-regenerative animals. The first
topic investigates how regenerative animals recruit new DA neurons from stem cells after
injury. The second topic explores how to generate DA neurons from mammalian ESCs and
iPSCs under in vitro conditions. The third topic evaluates clinical applications for human neural
disease, especially Parkinson’s disease.
[Show abstract][Hide abstract] ABSTRACT: Cell replacement therapy using embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) is a promising strategy for the treatment of neurologic diseases such as Parkinson’s disease (PD). However, a limiting factor for effective cell transplantation is the low survival rate of grafted cells, especially neurons. In this study, we modified the host environment and investigated whether the simultaneous administration of soluble factors can improve the survival and differentiation of murine iPSC-derived dopaminergic (DA) neurons in host brains. With the goal of applying this technology in clinical settings in the near future, we selected drugs that were already approved for clinical use. The drugs included two commonly used anticonvulsants, valproic acid (VPA) and zonisamide (ZNS), and estradiol (E2), also known as biologically active estrogen. Following neural induction of murine iPSCs, we collected neural progenitor cells by sorting PSA-NCAM+ cells, then treated the PSA-NCAM+ cells with drugs for four days. An immunofluorescence study revealed that 0.01 mM and 0.1 mM of VPA and 10 nM of E2 increased the percentage of tyrosine hydroxylase+ (TH: a DA neuron marker) cells in vitro. Furthermore, 0.1 mM of VPA increased the percentage of TH+ cells that simultaneously express the midbrain markers FOXA2 and NURR1. Next, in order to determine the effects of the drugs in vivo, the iPSC-derived NPCs were transplanted into the striata of intact SD rats. The animals received intraperitoneal injections of one of the drugs for four weeks, then were subjected to an immunofluorescence study. VPA administration (150 mg/kg/daily) increased the number of NeuN+ postmitotic neurons and TH+ DA neurons in the grafts. Furthermore, VPA (150 mg/kg/daily) and ZNS (30 mg/kg/daily) increased the number of TH+FOXA2+ midbrain DA neurons. These results suggest that the systemic administration of VPA and ZNS may improve the efficiency of cell replacement therapy using iPSCs to treat PD.
Preview · Article · Feb 2013 · Frontiers in Cellular Neuroscience