Therapies in muscular dystrophy: current concepts and future prospects

In the fast moving field of muscular dystrophy, therapeutic matters are now high on the agenda. Despite little progress made in the understanding of the exact pathogenesis, hopes have been raised with the advent of molecular medicine applied to such disorders. A constellation of techniques or therapeutic solutions are now available, but very few have reached the clinical stage. Gene therapy, cell therapy and pharmacological therapy look more promising, but their clinical application may still take years. We review the various alternatives and suggest that some of them might be used in combination.     

The allure of stem cell therapy for muscular dystrophy

Duchenne muscular dystrophy (DMD) is a lethal muscle disease for which an effective treatment is urgently needed. The use of stem cells to produce normal muscle cells to replace the missing dystrophin protein has attracted much attention. Claims of success using stem cell treatment in animal models of human muscle diseases require careful evaluation and are not necessarily easily extrapolated to the clinical situation. Recent studies in the dystrophic dog model have been claimed to show that injected mesangioblasts, stem cells derived from blood vessels, reduce the severity of the disease. However, the authors' interpretation of the results did not consider that benefits might arise from the concomitant use of immunosuppressive drugs alone.     

Induced pluripotent stem cell technology for spinal cord injury: a promising alternative therapy

Spinal cord injury has long been a prominent challenge in the trauma repair process. Spinal cord injury is a research hotspot by virtue of its difficulty to treat and its escalating morbidity. Furthermore, spinal cord injury has a long period of disease progression and leads to complications that exert a lot of mental and economic pressure on patients. There are currently a large number of therapeutic strategies for treating spinal cord injury, which range from pharmacological and surgical methods to cell therapy and rehabilitation training. All of these strategies have positive effects in the course of spinal cord injury treatment. This review mainly discusses the problems regarding stem cell therapy for spinal cord injury, including the characteristics and action modes of all relevant cell types. Induced pluripotent stem cells, which represent a special kind of stem cell population, have gained impetus in cell therapy development because of a range of advantages. Induced pluripotent stem cells can be developed into the precursor cells of each neural cell type at the site of spinal cord injury, and have great potential for application in spinal cord injury therapy.     

Modeling Alzheimer's disease with human induced pluripotent stem (iPS) cells

In the last decade, induced pluripotent stem (iPS) cells have revolutionized the utility of human in vitro models of neurological disease. The iPS-derived and differentiated cells allow researchers to study the impact of a distinct cell type in health and disease as well as performing therapeutic drug screens on a human genetic background. In particular, clinical trials for Alzheimer's disease (AD) have been failing. Two of the potential reasons are first, the species gap involved in proceeding from initial discoveries in rodent models to human studies, and second, an unsatisfying patient stratification, meaning subgrouping patients based on the disease severity due to the lack of phenotypic and genetic markers. iPS cells overcome this obstacles and will improve our understanding of disease subtypes in AD. They allow researchers conducting in depth characterization of neural cells from both familial and sporadic AD patients as well as preclinical screens on human cells.In this review, we briefly outline the status quo of iPS cell research in neurological diseases along with the general advantages and pitfalls of these models. We summarize how genome-editing techniques such as CRISPR/Cas9 will allow researchers to reduce the problem of genomic variability inherent to human studies, followed by recent iPS cell studies relevant to AD. We then focus on current techniques for the differentiation of iPS cells into neural cell types that are relevant to AD research. Finally, we discuss how the generation of three-dimensional cell culture systems will be important for understanding AD phenotypes in a complex cellular milieu, and how both two- and three-dimensional iPS cell models can provide platforms for drug discovery and translational studies into the treatment of AD.     

Cardiomyopathy of Duchenne muscular dystrophy: current understanding and future directions

Duchenne muscular dystrophy (DMD) is the most common and severe form of muscular dystrophy and occurs in 1 in 3500 male births. Improved survival due to improvements in clinical care of the musculoskeletal and respiratory systems has led to an increased incidence of cardiomyopathy. Cardiac-related deaths are now seen in approximately 20% of DMD patients. Our current understanding of DMD cardiomyopathy has increased significantly over the past 10 years, but further research is required to improve cardiac treatment and outcomes in DMD. This review provides a summary of the current literature and discussion of potential new therapies for DMD cardiomyopathy.     

Stem cell based cell therapy for muscular dystrophy]

Stem cell-based cell therapy is one of attractive therapeutic approaches to muscular dystrophy. In transplantation into dystrophic skeletal muscle, muscle satellite cells and musclE side population (SP) cells are good candidates as sources of stem cells. We purified mouse satellite cells from adult C57B16 mice by FACS using a monoclonal antibody, SM/C-2.6, which can specifically recognize quiescent satellite cells. DNA micro-array analysis on both quiescent and activated satellite cells allowed us to distinguish novel quiescent satellite cell-specific genes. These genes may encode molecules that keep satellite cells in a dormant and undifferentiated state. We transplanted purified muscle satellite cells transduced with lentivirus vector, and found these cells were effectively incorporated into dystrophin-deficient skeletal muscle and expressed transduced dystrophin. We also identified a novel side population (SP) cells in uninjured and regenerating skeletal muscle. The majority of muscle-SP cells in uninjured stage showed endothelial cell-like properties. CD31 negative/CD45 negative SP cells were a minor population in normal conditions, but actively proliferate during muscle regeneration. Co-transplantation experiments showed that the SP cells synergistically promoted muscle regeneration with satellite cells. It is indispensable to study molecular basis of muscle stem cells and muscle regeneration to achieve effective stem cell-based cell therapy on muscular dystrophy.     

Current status and future prospects of stem cell therapy in Alzheimer's disease

Alzheimer's disease is a common progressive neurodegenerative disorder, pathologically characterized by the presence of β-amyloid plaques and neurofibrillary tangles. Current treatment approaches using drugs only alleviate the symptoms without curing the disease, which is a serious issue and influences the quality of life of the patients and their caregivers. In recent years, stem cell technology has provided new insights into the treatment of neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Currently, the main sources of stem cells include neural stem cells, embryonic stem cells, mesenchymal stem cells, and induced pluripotent stem cells. In this review, we discuss the pathophysiology and general treatment of Alzheimer's disease, and the current state of stem cell transplantation in the treatment of Alzheimer's disease. We also assess future challenges in the clinical application and drug development of stem cell transplantation as a treatment for Alzheimer's disease.     

Induced pluripotent stem cell-derived neural stem cell therapies for spinal cord injury

The greatest challenge to successful treatment of spinal cord injury is the limited regenerative capacity of the central nervous system and its inability to replace lost neurons and severed axons following injury. Neural stem cell grafts derived from fetal central nervous system tissue or embryonic stem cells have shown therapeutic promise by differentiation into neurons and glia that have the potential to form functional neuronal relays across injured spinal cord segments. However, implementation of fetal-derived or embryonic stem cell-derived neural stem cell therapies for patients with spinal cord injury raises ethical concerns. Induced pluripotent stem cells can be generated from adult somatic cells and differentiated into neural stem cells suitable for therapeutic use, thereby providing an ethical source of implantable cells that can be made in an autologous fashion to avoid problems of immune rejection. This review discusses the therapeutic potential of human induced pluripotent stem cell-derived neural stem cell transplantation for treatment of spinal cord injury, as well as addressing potential mechanisms, future perspectives and challenges.     

Review: Induced pluripotent stem cell models of frontotemporal dementia

The increasing prevalence of dementia in the ageing population combined with the lack of treatments and the burden on national health care systems globally make dementia a public health priority. Despite the plethora of important research findings published over the past two decades, the mechanisms underlying dementia are still poorly understood and the progress in pharmacological interventions is limited. Recent advances in cellular reprogramming and genome engineering technologies offer an unprecedented new paradigm in disease modeling. Induced pluripotent stem cells (iPSCs) have enabled the study of patient‐derived neurons in vitro, a significant progress in the field of dementia research. The first studies using iPSCs to model dementia have recently emerged, holding promise for elucidating disease pathogenic mechanisms and accelerating drug discovery. In this review, we summarize the major findings of iPSC‐based studies in frontotemporal dementia (FTD) and FTD overlapping with amyotrophic lateral sclerosis (FTD/ALS). We also discuss some of the main challenges in the use of iPSCs to model complex, late‐onset neurodegenerative diseases such as dementias.     

The genetic background of Parkinson's disease: current progress and future prospects

Almost two decades of genetic research in Parkinson's disease (PD) have remarkably increased our knowledge regarding the genetic basis of PD with numerous genes and genetic loci having been found to cause familial PD or affect the risk for PD. Approximately 5–10% of PD patients have monogenic forms of the disease, exhibiting a classical Mendelian type of inheritance, however, the majority PD cases are sporadic, probably caused by a combination of genetic and environmental risk factors. Nowadays, six genes, alpha synuclein, LRRK2, VPS35, Parkin, PINK1 and DJ‐1, have definitely been associated with an autosomal dominant or recessive PD mode of inheritance. The advent of genome‐wide association studies (GWAS) and the implementation of new technologies, like next generation sequencing (NGS) and exome sequencing has undoubtedly greatly aided the identification on novel risk variants for sporadic PD. In this review, we will summarize the current progress and future prospects in the field of PD genetics.     

Induced pluripotent stem cells for disease modeling,cell therapy and drug discovery in genetic autonomic disorders: a review

Clinical Autonomic Research - The autonomic nervous system (ANS) regulates all organs in the body independent of consciousness, and is thus essential for maintaining homeostasis of the entire...     

Spinal muscular atrophy: recent advances and future prospects

Spinal muscular atrophies (SMA) are characterized by degeneration of lower motor neurons associated with muscle paralysis and atrophy. Childhood SMA is a frequent recessive autosomal disorder and represents one of the most common genetic causes of death in childhood. Mutations of the SMN1 gene are responsible for SMA. The knowledge of the genetic basis of SMA, a better understanding of SMN function, and the recent generation of SMA mouse models represent major advances in the field of SMA. These are starting points towards understanding the pathophysiology of SMA and developing therapeutic strategies for this devastating neurodegenerative disease, for which no curative treatment is known so far.     

Gene therapy for duchenne muscular dystrophy: expectations and challenges

Duchenne muscular dystrophy is a debilitating X-linked disease with limited treatment options. We examined the possibility of moving forward with gene therapy, an approach that demonstrates promise for treating Duchenne muscular dystrophy. Gene therapy is not limited to replacement of defective genes but also includes strategies using surrogate genes with alternative but effective means of improving cellular function or repairing gene mutations. The first viral-mediated gene transfer for any muscle disease was carried out at Columbus Children's Research Institute and Ohio State University for limb girdle muscular dystrophy type 2D, and the first viral-mediated trial of gene transfer for Duchenne muscular dystrophy is under way at the same institutions. These studies, consisting of intramuscular injection of virus into a single muscle, are limited in scope and represent phase 1 clinical trials with safety as the primary end point. These initial clinical studies lay the foundation for future studies, providing important information about dosing, immunogenicity, and viral serotype in humans. This article highlights the challenges and potential pitfalls as the field advances this treatment modality to clinical reality.     

Hematopoietic stem cell transplantation for multiple sclerosis: current status and future challenges

PURPOSE OF REVIEW: This article reviews recent advances in clinical trials of hematopoietic stem cell transplantation as a therapy for multiple sclerosis, and progress in exploring the potential for neural repair of hematopoietic-derived precursors. RECENT FINDINGS: Important recent findings are that hematopoietic stem cell transplantation can completely suppress the inflammatory component of multiple sclerosis, hematopoietic stem cells can migrate into the central nervous systems of rodents and humans, and can differentiate into cells expressing neural and glial markers. Hematopoietic stem cells also have neural and myelin repair potential. The heterogeneity of transplant regimens, the selection of patients at different stages of disease in clinical trials, and the limited duration of follow-up all currently preclude the evaluation of the long-term clinical benefits of hematopoietic stem cell transplantation for multiple sclerosis. SUMMARY: Hematopoietic stem cell transplantation is an experimental treatment that shows strong effects on the inflammatory component of multiple sclerosis. On the basis of experience acquired from initial pilot studies, controlled clinical trials are now being designed to verify long-term clinical efficacy. Selecting patients at high risk in the earlier stages of the disease that is dominated by inflammation, and monitoring objectively disease activity by magnetic resonance imaging will be critically important in these studies. Recent advances on the migratory potential and on the differentiation plasticity of hematopoietic stem cells have opened new opportunities for remyelination and axonal repair strategies for multiple sclerosis.     

Infrastructure for new drug development to treat muscular dystrophy: current status of patient registration (remudy)

Clinical trials for new therapeutic strategies are now being planned for Duchenne and Becker muscular dystrophies (DMD/BMD); however, many challenges exist in the planning and conduction of a clinical trial for rare diseases. The epidemiological data, total number of patients, natural history, and clinical outcome measures are unclear. Adequate numbers of patients are needed to achieve significant results in clinical trials. As solutions to these problems, patient registries are an important infrastructure worldwide, especially in the case of rare diseases such as DMD/BMD. In Europe, TREAT-NMD, a clinical research network for neuromuscular disorders, developeda global database for dystrophinopathy patients. We developed a national registry of Japanese DMD/BMD patients in collaboration with TREAT-NMD. The database includes clinical and molecular genetic data as well as all required items for the TREAT-NMD global patient registry. As of July 2011, 750 patients were registered in the database. The purpose of this registry is the effective recruitment of eligible patients for clinical trials, and it may also provide timely information to individual patients about upcoming trials. This registry data also provides more detailed knowledge about natural history, epidemiology, and clinical care. In recent years, drug development has become dramatically globalized, and global clinical trials (GCTs) are being conducted in Japan. It is appropriate, particularly with regard to orphan diseases, to include Japanese patients in GCTs to increase evidence for evaluation, because such large-scale trials would be difficult to conduct solely within Japan. GCTs enable the synchronization of clinical drug development in Japan with that in Western countries, minimizing drug approval delays.     

胶质瘤干细胞研究的现状与未来

脑肿瘤（主要是胶质瘤）干细胞（brain tumor stem cells，BTSCs）的研究始于2002年Ignatova等的研究，当时称神经干细胞样的细胞（neural stem—like cells）。Singh等于2003、2004年通过体内外系统实验证明，这类细胞是直接生成肿瘤细胞的细胞，称癌干细胞（cancer stem cells），也有学者称脑肿瘤始动细胞（brain tumor initiating cells），[第一段]     

脐带间充质干细胞治疗Duchenne型肌营养不良3例报告

Due to their relative abundance,stable biological properties and excellent reproductive activity,umbilical cord mesenchymal stem cells have previously been utilized for the treatment of Duchenne muscular dystrophy,which is a muscular atrophy disease.Three patients who were clinically and pathologically diagnosed with Duchenne muscular dystrophy were transplanted with umbilical cord mesenchymal stem cells by intravenous infusion,in combination with multi-point intramuscular injection.They were followed up for 12 months after cell transplantation.Results showed that clinical symptoms significantly improved,daily living activity and muscle strength were enhanced,the sero-enzyme,electromyogram,and MRI scans showed improvement,and dystrophin was expressed in the muscle cell membrane.Hematoxylin-eosin staining of a muscle biopsy revealed that muscle fibers were well arranged,fibrous degeneration was alleviated,and fat infiltration was improved.These pieces of evidence suggest that umbilical cord mesenchymal stem cell transplantation can be considered as a new regimen for Duchenne muscular dystrophy.