Olfactory ensheathing cell neurorestorotherapy for amyotrophic lateral sclerosis patients: benefits from multiple transplantations

Neural Cells for Neurodegenerative Diseases in Clinical Trials

Neurodegenerative diseases (ND) are an entire spectrum of clinical conditions that affect the central and peripheral nervous system. There is no cure currently, with treatment focusing mainly on slowing down progression or symptomatic relief. Cellular therapies with various cell types from different sources are being conducted as clinical trials for several ND diseases. They include neural, mesenchymal and hemopoietic stem cells, and neural cells derived from embryonic stem cells and induced pluripotent stem cells. In this review, we present the list of cellular therapies for ND comprising 33 trials that used neural stem progenitors, 8 that used differentiated neural cells ,and 109 trials that involved non-neural cells in the 7 ND. Encouraging results have been shown in a few early-phase clinical trials that require further investigations in a randomized setting. However, such definitive trials may not be possible given the relative cost of the trials, and in the setting of rare diseases.

Clinical results of neurorestorative cell therapies and therapeutic indications according to cellular bio-proprieties

Cell therapies have been explored to treat patients with nervous diseases for over 20 years. Even though most kinds of cell therapies demonstrated neurorestorative effects in non-randomized clinical trials; the effects of the majority type cells could not be confirmed by randomized controlled trials. In this review, clinical therapeutic results of neurorestorative cell therapies according to cellular bio-proprieties or cellular functions were introduced. Currently it was demonstrated from analysis of this review that some indications of cell therapies were not appropriate, they might be reasons why their neurorestorative effects could not be proved by multicenter, randomized, double blind, placebo-controlled clinical trials. Theoretically if one kind of cell therapy has neurorestorative effects according to its cellular bio-proprieties, it should have appropriate indications. The cell therapies with special bio-properties is promising if the indication selections are appropriate, such as olfactory ensheathing cells for chronic ischemic stroke, and their neurorestorative effects can be confirmed by higher level clinical trials of evidence-based medicine.

Role of curcumin and its nanoformulations in the treatment of neurological diseases through the effects on stem cells

Curcumin from turmeric is a natural phenolic compound with a promising potential to regulate fundamental processes involved in neurological diseases, including inflammation, oxidative stress, protein aggregation, and apoptosis at the molecular level. In this regard, employing nanoformulation can improve curcumin efficiency by reducing its limitations, such as low bioavailability. Besides curcumin, growing data suggest that stem cells are a noteworthy candidate for neurodegenerative disorders therapy due to their anti-inflammatory, anti-oxidative, and neuronal-differentiation properties, which result in neuroprotection. Curcumin and stem cells have similar neurogenic features and can be co-administered in a cell-drug delivery system to achieve better combination therapeutic outcomes for neurological diseases. Based on the evidence, curcumin can induce the neuroprotective activity of stem cells by modulating their related signalling pathways. The present review is about the role of curcumin and its nanoformulations in the improvement of neurological diseases alone and through the effect on different categories of stem cells by discussing the underlying mechanisms to provide a roadmap for future investigations.

Potential of Cellular Therapy for ALS: Current Strategies and Future Prospects

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive upper and lower motor neuron (MN) degeneration with unclear pathology. The worldwide prevalence of ALS is approximately 4.42 per 100,000 populations, and death occurs within 3-5 years after diagnosis. However, no effective therapeutic modality for ALS is currently available. In recent years, cellular therapy has shown considerable therapeutic potential because it exerts immunomodulatory effects and protects the MN circuit. However, the safety and efficacy of cellular therapy in ALS are still under debate. In this review, we summarize the current progress in cellular therapy for ALS. The underlying mechanism, current clinical trials, and the pros and cons of cellular therapy using different types of cell are discussed. In addition, clinical studies of mesenchymal stem cells (MSCs) in ALS are highlighted. The summarized findings of this review can facilitate the future clinical application of precision medicine using cellular therapy in ALS.

Cell Therapy for Neurological Disorders: The Perspective of Promising Cells

Neurological disorders are big public health challenges that are afflicting hundreds of millions of people around the world. Although many conventional pharmacological therapies have been tested in patients, their therapeutic efficacies to alleviate their symptoms and slow down the course of the diseases are usually limited. Cell therapy has attracted the interest of many researchers in the last several decades and has brought new hope for treating neurological disorders. Moreover, numerous studies have shown promising results. However, none of the studies has led to a promising therapy for patients with neurological disorders, despite the ongoing and completed clinical trials. There are many factors that may affect the outcome of cell therapy for neurological disorders due to the complexity of the nervous system, especially cell types for transplantation and the specific disease for treatment. This paper provides a review of the various cell types from humans that may be clinically used for neurological disorders, based on their characteristics and current progress in related studies.

Why is olfactory neuroepithelium?

Currently, most cellular therapeutic effects for nervous diseases cannot be proven in a multicenter, randomized, double-blind placebo-control clinical trials, except for a few kinds of cells such as olfactory ensheathing cells. These cells show significant improvements in functional recovery and quality of life for patients with chronic ischemic stroke. Also, olfactory neuron transplantation has promising neurorestorative effects on patients with vascular dementia. Human olfactory neuroepithelium can spontaneously and sustainably regenerate or produce new olfactory neurons and glial cell types for decades or a lifetime. The neurorestorative mechanisms of olfactory ensheathing cells are well known; however, little is known about the neurorestorative mechanisms of olfactory neurons. Therefore, I hypothesize that the neurorestorative mechanisms of olfactory neurons after transplantation: (1) can well migrate where they are needed and become local functional neurons, as they need to compensate or replace; (2) must be regulated by some special molecular factors to elongate their axons, modulate or direct synapses to correctly recognize and connect the target cells, and integrate functions. Based on olfactory neuroepithelium cells displaying the special characterization, neurorestorative mechanisms, clinical therapeutic achievements, and hypotheses of effective mechanisms, they (olfactory ensheathing cells and olfactory neurons) may be the most efficient instruments of neurorestoration.

What skeletal muscle has to say in amyotrophic lateral sclerosis: Implications for therapy

Amyotrophic lateral sclerosis (ALS) is an adult onset disorder characterized by progressive neuromuscular junction (NMJ) dismantling and degeneration of motor neurons leading to atrophy and paralysis of voluntary muscles responsible for motion and breathing. Except for a minority of patients harbouring genetic mutations, the origin of most ALS cases remains elusive. Peripheral tissues, and particularly skeletal muscle, have lately demonstrated an active contribution to disease pathology attracting a growing interest for these tissues as therapeutic targets in ALS. In this sense, molecular mechanisms essential for cell and tissue homeostasis have been shown to be deregulated in the disease. These include muscle metabolism and mitochondrial activity, RNA processing, tissue-resident stem cell function responsible for muscle regeneration, and proteostasis that regulates muscle mass in adulthood. This review aims to compile scientific evidence that demonstrates the role of skeletal muscle in ALS pathology and serves as reference for development of novel therapeutic strategies targeting this tissue to delay disease onset and progression. LINKED ARTICLES: This article is part of a themed issue on Neurochemistry in Japan. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.6/issuetoc.

Olfactory Ensheathing Cells: A Trojan Horse for Glioma Gene Therapy

BACKGROUND

The olfactory ensheathing cells (OECs) migrate from the peripheral nervous system to the central nervous system (CNS), a critical process for the development of the olfactory system and axonal extension after injury in neural regeneration. Because of their ability to migrate to the injury site and anti-inflammatory properties, OECs were tested against different neurological pathologies, but were never studied in the context of cancer. Here, we evaluated OEC tropism to gliomas and their potential as a "Trojan horse" to deliver therapeutic transgenes through the nasal pathway, their natural route to CNS.

METHODS

OECs were purified from the mouse olfactory bulb and engineered to express a fusion protein between cytosine deaminase and uracil phosphoribosyltransferase (CU), which convert the prodrug 5-fluorocytosine (5-FC) into cytotoxic metabolite 5-fluorouracil, leading to a bystander killing of tumor cells. These cells were injected into the nasal cavity of mice bearing glioblastoma tumors and OEC-mediated gene therapy was monitored by bioluminescence imaging and confirmed with survival and ex vivo histological analysis. All statistical tests were two-sided.

RESULTS

OECs migrated from the nasal pathway to the primary glioma site, tracked infiltrative glioma stemlike cells, and delivered therapeutic transgene, leading to a slower tumor growth and increased mice survival. At day 28, bioluminescence imaging revealed that mice treated with a single injection of OEC-expressing CU and 5-FC had tumor-associated photons (mean [SD]) of 1.08E + 08 [9.7E + 07] vs 4.1E + 08 [2.3E + 08] for control group (P < .001), with a median survival of 41 days vs 34 days, respectively (ratio = 0.8293, 95% confidence interval = 0.4323 to 1.226, P <  .001) (n = 9 mice per group).

CONCLUSIONS

We show for the first time that autologous transplantation of OECs can target and deliver therapeutic transgenes to brain tumors upon intranasal delivery, the natural route of OECs to the CNS, which could be extended to other types of cancer.

Standards of clinical-grade olfactory ensheathing cell culture and quality control (2020 China Version)

Currently, there are many different standards for the quality control of olfactory ensheathing cell (OEC) culture prepared from human olfactory bulb and mucosa. It is challenging to compare the clinical results of OEC treatment from different hospitals. Based on various standards, the Chinese Association of Neurorestoratology (CANR; Preparatory) and China Committee of International Association of Neurorestoratology (IANR-China Committee) organized professional experts in this field to evaluate the data and develop a standard for clinical applications, including donor evaluation, sample collection, cell culture, cell testing, packaging labels, storage, transportation, and quality control of intermediate/finished cell products, as well as training and management procedures for laboratory operators, the use and management of materials and equipment, and routine maintenance of a clean environment. These standards apply to the quality and control of OEC culture using human olfactory bulb and mucosa as the sample source for the member units of the CANR (Preparatory) and IANR-China Committee. It serves as a reference for physicians around the world who perform OEC clinical applications. This standard represents the minimum required standards for quality control when performing clinical-grade OEC cultures in clinical neurorestorative treatments.

Clinical neurorestorative cell therapies: Developmental process, current state and future prospective

Clinical cell therapies (CTs) for neurological diseases and cellular damage have been explored for more than 2 decades. According to the United States Food and Drug Administration, there are 2 types of cell categories for therapy, namely stem cell-derived CT products and mature/functionally differentiated cell-derived CT products. However, regardless of the type of CT used, the majority of reports of clinical CTs from either small sample sizes based on single-center phase 1 or 2 unblinded trials or retrospective clinical studies showed effects on neurological improvement and the ability to either partially or temporarily thwart the deteriorating cellular processes of the neurodegenerative diseases. There have been only a few prospective, multicenter, randomized, double- blind placebo-control clinical trials of CTs so far in this developing novel area that have shown negative results, and more clinical trials are needed. This will expand our knowledge in exploring the type of cells that yield promising results and restore damaged neurological structure and functions of the central nervous system based on higher level evidence-based medical data. In this review, we briefly introduce the developmental process, current state, and future prospective for clinical neurorestorative CT.

Stem cell treatments for amyotrophic lateral sclerosis: a critical overview of early phase trials

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of cortical, brainstem, and spinal motor neurons; it causes progressive muscle weakness and atrophy, respiratory failure, and death. No currently available treatment either stops or reverses this disease. Therapeutics to slow, stop, and reverse ALS are needed. Stem cells may be a viable solution to sustain and nurture diseased motor neurons. Several early-stage clinical trials have been launched to assess the potential of stem cells for ALS treatment. Areas covered: Expert opinion:

AREAS COVERED

This review covers the key advances from early phase clinical trials of stem cell therapy for ALS and identifies promising avenues and key challenges.

EXPERT OPINION

Clinical trials in humans are still in the nascent stages of development. It will be critical to ensure that powered, well-controlled trials are conducted, that optimal treatment windows are identified, and that the ideal cell type, cell dose, and delivery site and method are determined. Several trials have used more invasive procedures, and ethical concerns of sham procedures on patients in the control arm and on their safety should be considered.

Advances in stem cell therapy for amyotrophic lateral sclerosis

INTRODUCTION

Amyotrophic Lateral Sclerosis (ALS) is a progressive, incurable neurodegenerative disease that targets motoneurons. Cell-based therapies have generated widespread interest as a potential therapeutic approach but no conclusive results have yet been reported either from pre-clinical or clinical studies.

AREAS COVERED

This is an integrated review of pre-clinical and clinical studies focused on the development of cell-based therapies for ALS. We analyze the biology of stem cell treatments and results obtained from pre-clinical models of ALS and examine the methods and the results obtained to date from clinical trials. We discuss scientific, clinical, and ethical issues and propose some directions for future studies.

EXPERT OPINION

While data from individual studies are encouraging, stem-cell-based therapies do not yet represent a satisfactory, reliable clinical option. The field will critically benefit from the introduction of well-designed, randomized and reproducible, powered clinical trials. Comparative studies addressing key issues such as the nature, properties, and number of donor cells, the delivery mode and the selection of proper patient populations that may benefit the most from cell-based therapies are now of the essence. Multidisciplinary networks of experts should be established to empower effective translation of research into the clinic.

Various strategies to improve efficacy of stem cell transplantation in multiple sclerosis: Focus on mesenchymal stem cells and neuroprotection

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) which predominantly affect young adults and undergo heavy socioeconomic burdens. Conventional therapeutic modalities for MS mostly downregulate aggressive immune responses and are almost insufficient for management of progressive course of the disease. Mesenchymal stem cells (MSCs), due to both immunomodulatory and neuroprotective properties have been known as practical cells for treatment of neurodegenerative diseases like MS. However, clinical translation of MSCs is associated with some limitations such as short-life engraftment duration, little in vivo trans-differentiation and restricted accessibility into damaged sites. Therefore, laboratory manipulation of MSCs can improve efficacy of MSCs transplantation in MS patients. In this review, we discuss several novel approaches, which can potentially enhance MSCs capabilities for treating MS.

Safety, Feasibility of Intravenous and Intrathecal Injection of Autologous Bone Marrow Derived Mesenchymal Stromal Cells in Patients with Amyotrophic Lateral Sclerosis: An Open Label Phase I Clinical Trial

Objective

Amyotrophic lateral sclerosis (ALS) is the most severe disorder within the spectrum of motor neuron diseases (MND) that has no effective treatment and a progressively fatal outcome. We have conducted two clinical trials to assess the safety and feasibility of intravenous (IV) and intrathecal (IT) injections of bone marrow derived mesenchymal stromal cells (BM-MSCs) in patients with ALS.

Materials and Methods

This is an interventional/experimental study. We enrolled 14 patients that met the following inclusion criteria: definitive diagnosis of sporadic ALS, ALS Functional Rating Scale (ALS-FRS) ≥24, and ≥40% predicted forced vital capacity (FVC). All patients underwent bone marrow (BM) aspiration to obtain an adequate sample for cell isolation and culture. Patients in group 1 (n=6) received an IV and patients in group 2 (n=8) received an IT injection of the cell suspension. All patients in both groups were followed at 24 hours and 2, 4, 6, and 12 months after the injection with ALS-FRS, FVC, laboratory tests, check list of side effects and brain/spinal cord magnetic resonance imaging (MRI). In each group, one patient was lost to follow up one month after cell injection and one patient from IV group died due to severe respiratory insufficiency and infection.

Results

During the follow up there were no reports of adverse events in terms of clinical and laboratory assessments. In MRI, there was not any new abnormal finding. The ALS-FRS score and FVC percentage significantly reduced in all patients from both groups.

Conclusion

This study has shown that IV and IT transplantation of BM-derived stromal cells is safe and feasible (Registration numbers: NCT01759797 and NCT01771640).

Clinical Cell Therapy Guidelines for Neurorestoration (IANR/CANR 2017)

Cell therapy has been shown to be a key clinical therapeutic option for central nervous system diseases or damage. Standardization of clinical cell therapy procedures is an important task for professional associations devoted to cell therapy. The Chinese Branch of the International Association of Neurorestoratology (IANR) completed the first set of guidelines governing the clinical application of neurorestoration in 2011. The IANR and the Chinese Association of Neurorestoratology (CANR) collaborated to propose the current version "Clinical Cell Therapy Guidelines for Neurorestoration (IANR/CANR 2017)". The IANR council board members and CANR committee members approved this proposal on September 1, 2016, and recommend it to clinical practitioners of cellular therapy. These guidelines include items of cell type nomenclature, cell quality control, minimal suggested cell doses, patient-informed consent, indications for undergoing cell therapy, contraindications for undergoing cell therapy, documentation of procedure and therapy, safety evaluation, efficacy evaluation, policy of repeated treatments, do not charge patients for unproven therapies, basic principles of cell therapy, and publishing responsibility.

Neurorestorative effect of olfactory ensheathing cells and Schwann cells by intranasal delivery for patients with ischemic stroke: design of a multicenter randomized double-blinded placebo-controlled clinical study

Introduction:

There have been many clinical studies or trials for patients with ischemic stroke by cell therapy, which includes olfactory ensheathing cell (OEC), mononuclear cell, mesenchymal stromal cell, fetal neural cell or products of varying stem cells, etc. Those cells through different transplanting ways have showed moderate neurorestorative effect in patients with ischemic stroke, but majority were not multicenter randomized, double-blinded, placebo-controlled studies or trials. OEC transplantation has shown a more effective to restore neurological damage in central nervous system (CNS). We hypothesize that OEC through intra-olfactory mucosa transplantation can migrate into the ischemic stroke area around and restore neurological deficit caused from this disaster.

Objective of the study:

This is a multicenter, randomized, double-blinded, placebo- controlled 12 month clinical study of OECs and Schwann cells (SCs) for patients with sub-acute ischemic stroke and chronic ischemic stroke, to test which kind of cell has more neurorestorative effect for patients with ischemic stroke relative to placebo.

Design of the study:

This study is involved two groups of patients with sub-acute ischemic stroke and chronic ischemic stroke. Each group enrolls 30 patients. The experimental intervention consists in using OECs and SCs through intra-olfactory mucosa transplantation in participating patients. This will be compared with using placebo (injecting cell culture medium). Participating patients in groups of sub-acute ischemic stroke and chronic ischemic stroke are randomized in natural order to divide into A, B, or C groups and get one of experimental treatment procedures. Patients, operating physicians, and assessing physicians are left unaware of what cells or medium will be injected to participating patients. All patients will be assessed before treatment and after one month, three months, six months, and one year.

Ethics and dissemination:

The clinical study protocol and consent form were approved by Chinese Association of Neurorestoratology and the ethics committees of the hospitals which joined this clinical study. Findings will be published in peer-reviewed journals.

Cell-based therapies for amyotrophic lateral sclerosis/motor neuron disease

BACKGROUND

Amyotrophic lateral sclerosis (ALS), which is also known as motor neuron disease (MND) is a fatal disease associated with rapidly progressive disability, for which no definitive treatment as yet exists. Current treatment regimens largely focus on relieving symptoms to improve the quality of life of those affected. Based on data from preclinical studies, cell-based therapy is a promising treatment for ALS/MND.

OBJECTIVES

To assess the effects of cell-based therapy for people with ALS/MND, compared with placebo or no additional treatment.

SEARCH METHODS

On 21 June 2016, we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, and Embase. We also searched two clinical trials' registries for ongoing or unpublished studies.

SELECTION CRITERIA

We planned to include randomised controlled trials (RCTs), quasi-RCTs and cluster RCTs that assigned people with ALS/MND to receive cell-based therapy versus a placebo or no additional treatment. Co-interventions were allowable, provided that they were given to each group equally.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology.

MAIN RESULTS

No studies were eligible for inclusion in the review. We identified four ongoing trials.

AUTHORS' CONCLUSIONS

Currently, there is a lack of high-quality evidence to guide practice on the use of cell-based therapy to treat ALS/MND.We need large, prospective RCTs to establish the efficacy of cellular therapy and to determine patient-, disease- and cell treatment-related factors that may influence the outcome of cell-based therapy. The major goals of future research should be to determine the appropriate cell source, phenotype, dose, and route of delivery, as these will be key elements in designing an optimal cell-based therapy programme for people with ALS/MND. Future research should also explore novel treatment strategies, including combinations of cellular therapy and standard or novel neuroprotective agents, to find the best possible approach to prevent or reverse the neurological deficit in ALS/MND, and to prolong survival in this debilitating and fatal condition.

Distributed Features of Vimentin-Containing Neural Precursor Cells in Olfactory Bulb of SOD1G93A Transgenic Mice: a Study about Resource of Endogenous Neural Stem Cells

No any effective treatments can prevent from the motor neuron degeneration in amyotrophic lateral sclerosis (ALS) at present. In order to modulating the endogenous neural precursor cells (NPCs) to repairing the degenerative motor neurons in ALS, we studied the alteration of endogenous vimentin-containing NPCs in olfactory bulb (OB) at the different stages of SOD1 wlid-type and G93A transgenic mice. The results showed that the vimentin-containing cells (VCCs) were mainly distributed in the glomerular layer (Gl), the accessory OB (AOB), the OB core, the granular cell layer (GRO) and the mitral cell layer (MI)+the internal plexiform layer (IPL) of the OB of adult mice. Almost all VCCs in Gl, OB core and GRO were the GFAP positive cells. Almost all VCCs in AOB were the Oligo-2 positive cells. Fewer VCCs in MI+IPL were the NeuN positive cells. VCCs significantly increased in the OB core and Gl of adult OB at the pre-onset, onset and progression stages of ALS-like G93A transgenic disease, particularly in OB core. All increased VCCs were the GFAP positive cells. Our data suggested that there extensively existed the endogenous vimentin-containing NPCs in the OB of adult mice, which was a potential resource of neural stem cells, they could differentiate into astrocyte, oligodendrocyte and neuron cells, were a potential astrocyte neuroregenerative response in adult OB in the ALS-like disease, were a potential pathway to repair the degenerated motor neurons.

Common olfactory ensheathing glial markers in the developing human olfactory system

The in situ immunocytochemical properties of olfactory ensheathing cells (OECs) have been well studied in several small to medium sized animal models including rats, mice, guinea pigs, cats and canines. However, we know very little about the antigenic characteristics of OECs in situ within the adult and developing human olfactory bulb and nerve roots. To address this gap in knowledge we undertook an immunocytochemical analysis of the 11–19 pcw human foetal olfactory system. Human foetal OECs in situ possessed important differences compared to rodents in the expression of key surface markers. P75^NTR was not observed in OECs but was strongly expressed by human foetal Schwann cells and perineurial olfactory nerve fibroblasts surrounding OECs. We define OECs throughout the 11–19 pcw human olfactory system as S100/vimentin/SOX10+ with low expression of GFAP. Our results suggest that P75^NTR is a robust marker that could be utilised with cell sorting techniques to generate enriched OEC cultures by first removing P75^NTR expressing Schwann cells and fibroblasts, and subsequently to isolate OECs after P75^NTR upregulation in vitro. O4 and PSA-NCAM were not found to be suitable surface antigens for OEC purification owing to their ambiguous and heterogeneous expression. Our results highlight the importance of corroborating cell markers when translating cell therapies from animal models to the clinic.

Intraspinal stem cell transplantation for amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder in which the loss of upper and lower motor neurons produces progressive weakness and eventually death. In the decades since the approval of riluzole, the only US Food and Drug Administration-approved medication to moderately slow progression of ALS, no new therapeutics have arisen to alter the course of the disease. This is partly due to our incomplete understanding of the complex pathogenesis of motor neuron degeneration. Stem cells have emerged as an attractive option in treating ALS, because they come armed with equally complex cellular machinery and may modulate the local microenvironment in many ways to rescue diseased motor neurons. Various stem cell types are being evaluated in preclinical and early clinical applications; here, we review the preclinical strategies and advances supporting the recent clinical translation of neural progenitor cell therapy for ALS. Specifically, we focus on the use of spinal cord neural progenitor cells and the pipeline starting from preclinical studies to the designs of phase I and IIa clinical trials involving direct intraspinal transplantation in humans.

The pluralization of the international: Resistance and alter-standardization in regenerative stem cell medicine

The article explores the formation of an international politics of resistance and 'alterstandardization' in regenerative stem cell medicine. The absence of internationally harmonized regulatory frameworks in the clinical stem cell field and the presence of lucrative business opportunities have resulted in the formation of transnational networks adopting alternative research standards and practices. These oppose, as a universal global standard, strict evidence-based medicine clinical research protocols as defined by scientists and regulatory agencies in highly developed countries. The emergence of transnational spaces of alter-standardization is closely linked to scientific advances in rapidly developing countries such as China and India, but calls for more flexible regulatory frameworks, and the legitimization of experimental for-profit applications outside of evidence-based medical care, are emerging increasingly also within more stringently regulated countries, such as the United States and countries in the European Union. We can observe, then, a trend toward the pluralization of the standards, practices, and concepts in the stem cell field.

Intraspinal delivery of bone marrow stromal cell-derived neural stem cells in patients with amyotrophic lateral sclerosis: A safety and feasibility study

BACKGROUND

Stem cells have been used in several studies with different methodologies to treat patients with ALS.

METHODS

In this safety and feasibility study, 11 patients with definite or probable ALS according to El Escorial criteria were selected. 3 patients were excluded due to inadequate bone marrow or safety measures after acquisition of bone marrow. Bone marrow stromal cell-derived neural stem cells were injected in C7-T1 spinal cord under general anesthesia. Patients were followed for 12months after injection with manual muscle testing, ALSFRS-R, quality of life changes, pulmonary function test and electromyography.

RESULTS

None of the patients had perioperative mortality or major morbidity. One patient had temporary deterioration in lower extremities after injection which improved after a few weeks. In the 12months post-injection, only one patient died due to pulmonary embolism. From the remaining 7 patients, all had a stable course after 4months and 5 were stable for the first 8months post-injection and deteriorated afterwards.

DISCUSSION

In this study, intraspinal injection of bone marrow derived neural stem cells appears to be safe. Patients experienced a temporary stabilization for the first few months post-injection and then gradually deteriorated.

Phase I trial of repeated intrathecal autologous bone marrow-derived mesenchymal stromal cells in amyotrophic lateral sclerosis

Stem cell therapy is an emerging alternative therapeutic or disease-modifying strategy for amyotrophic lateral sclerosis (ALS). The aim of this open-label phase I clinical trial was to evaluate the safety of two repeated intrathecal injections of autologous bone marrow (BM)-derived mesenchymal stromal cells (MSCs) in ALS patients. Eight patients with definite or probable ALS were enrolled. After a 3-month lead-in period, autologous MSCs were isolated two times from the BM at an interval of 26 days and were then expanded in vitro for 28 days and suspended in autologous cerebrospinal fluid. Of the 8 patients, 7 received 2 intrathecal injections of autologous MSCs (1 × 10(6) cells per kg) 26 days apart. Clinical or laboratory measurements were recorded to evaluate the safety 12 months after the first MSC injection. The ALS Functional Rating Scale-Revised (ALSFRS-R), the Appel ALS score, and forced vital capacity were used to evaluate the patients' disease status. One patient died before treatment and was withdrawn from the study. With the exception of that patient, no serious adverse events were observed during the 12-month follow-up period. Most of the adverse events were self-limited or subsided after supportive treatment within 4 days. Decline in the ALSFRS-R score was not accelerated during the 6-month follow-up period. Two repeated intrathecal injections of autologous MSCs were safe and feasible throughout the duration of the 12-month follow-up period.

SIGNIFICANCE

Stem cell therapy is an emerging alternative therapeutic or disease-modifying strategy for amyotrophic lateral sclerosis (ALS). To the authors' best knowledge, there are no clinical trials to evaluate the safety of repeated intrathecal injections of autologous bone marrow mesenchymal stromal cells in ALS. After the clinical trial (phase I/II) was conducted, the stem cell (HYNR-CS, NEURONATA-R) was included in the revision of the regulations on orphan drug designation (number 160; December 31, 2013) and approved as a New Drug Application (Department of Cell and Gene Therapy 233; July 30, 2014) by the Korean Food and Drug Administration. The phase II trial is expected to be reported later.

Recent Advances and the Future of Stem Cell Therapies in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis is a progressive neurodegenerative disease of the motor neurons without a known cure. Based on the possibility of cellular neuroprotection and early preclinical results, stem cells have gained widespread enthusiasm as a potential treatment strategy. Preclinical models demonstrate a protective role of engrafted stem cells and provided the basis for human trials carried out using various types of stem cells, as well as a range of cell delivery methods. To date, no trial has demonstrated a clear therapeutic benefit; however, results remain encouraging and are the basis for ongoing studies. In addition, stem cell technology continues to improve, and induced pluripotent stem cells may offer additional therapeutic options in the future. Improved disease models and clinical trials will be essential in order to validate stem cells as a beneficial therapy.

Patient-derived olfactory mucosa for study of the non-neuronal contribution to amyotrophic lateral sclerosis pathology

Amyotrophic lateral sclerosis (ALS) is a degenerative motor neuron disease which currently has no cure. Research using rodent ALS models transgenic for mutant superoxide dismutase 1 (SOD1) has implicated that glial–neuronal interactions play a major role in the destruction of motor neurons, but the generality of this mechanism is not clear as SOD1 mutations only account for less than 2% of all ALS cases. Recently, this hypothesis was backed up by observation of similar effects using astrocytes derived from post-mortem spinal cord tissue of ALS patients which did not carry SOD1 mutations. However, such necropsy samples may not be easy to obtain and may not always yield viable cell cultures. Here, we have analysed olfactory mucosa (OM) cells, which can be easily isolated from living ALS patients. Disease-specific changes observed when ALS OM cells were co-cultured with human spinal cord neurons included decreased neuronal viability, aberrant neuronal morphology and altered glial inflammatory responses. Our results show the potential of OM cells as new cell models for ALS.

Current perspectives in stem cell therapy for spinal cord repair in humans: a review of work from the past 10 years

Spinal cord injury (SCI) and amyotrophic laterals sclerosis (ALS) are devastating neurological conditions that affect individuals worldwide, significantly reducing quality of life, both for patients and their relatives.

OBJECTIVE

The present review aims to summarize the multiple restorative approaches being developed for spinal cord repair, the use of different stem cell types and the current knowledge regarding stem cell therapy.

METHOD

Review of the literature from the past 10 years of human studies using stem cell transplantation as the main therapy, with or without adjuvant therapies.

CONCLUSION

The current review offers an overview of the state of the art regarding spinal cord restoration, and serves as a starting point for future studies.

Concise review: Stem cell therapies for amyotrophic lateral sclerosis: recent advances and prospects for the future

Amyotrophic lateral sclerosis (ALS) is a lethal disease involving the loss of motor neurons. Although the mechanisms responsible for motor neuron degeneration in ALS remain elusive, the development of stem cell-based therapies for the treatment of ALS has gained widespread support. Here, we review the types of stem cells being considered for therapeutic applications in ALS, and emphasize recent preclinical advances that provide supportive rationale for clinical translation. We also discuss early trials from around the world translating cellular therapies to ALS patients, and offer important considerations for future clinical trial design. Although clinical translation is still in its infancy, and additional insight into the mechanisms underlying therapeutic efficacy and the establishment of long-term safety are required, these studies represent an important first step toward the development of effective cellular therapies for the treatment of ALS.

Amyotrophic lateral sclerosis - cell based therapy and novel therapeutic development

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease, characterized by the predominant loss of motor neurons (MNs) in primary motor cortex, the brainstem, and the spinal cord, causing premature death in most cases. Minimal delay of pathological development by available medicine has prompted the search for novel therapeutic treatments to cure ALS. Cell-based therapy has been proposed as an ultimate source for regeneration of MNs. Recent completion of non-autologous fetal spinal stem cell transplant to ALS patients brought renewed hope for further human trials to cure the disease. Autologous somatic stem cell-based human trials are now in track to reveal the outcome of the ongoing trials. Furthermore, induced pluripotent stem cell (iPSC)-based ALS disease drug screen and autologous cell transplant options will broaden therapeutic options. In this review paper, we discuss recent accomplishments in cell transplant treatment for ALS and future options with iPSC technology.

Olfactory ensheathing cell transplantation improves sympathetic skin responses in chronic spinal cord injury

Forty-three patients with chronic spinal cord injury for over 6 months were transplanted with bryonic olfactory ensheathing cells, 2-4 × 10(6), into multiple sites in the injured area under the surgical microscope. The sympathetic skin response in patients was measured with an electromyography/evoked potential instrument 1 day before transplantation and 3-8 weeks after transtion. Spinal nerve function of patients was assessed using the American Spinal Injury Association impairment scale. The sympathetic skin response was elicited in 32 cases before olfactory ensheathing cell transplantation, while it was observed in 34 cases after transplantation. tantly, sympathetic skin response latency decreased significantly and amplitude increased cantly after transplantation. Transplantation of olfactory ensheathing cells also improved American Spinal Injury Association scores for movement, pain and light touch. Our findings indicate that factory ensheathing cell transplantation improves motor, sensory and autonomic nerve functions in patients with chronic spinal cord injury.

Intracranial transplant of olfactory ensheathing cells can protect both upper and lower motor neurons in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal disease that involves the degeneration of cortical and spinal motor neurons. Mutant SOD1(G93A) rats constitute a good animal model for this pathological condition. We have previously demonstrated that transplantation of neonatal olfactory ensheathing cells (OECs) into the dorsal funiculus of the spinal cord of mutant SOD1(G93A) transgenic rats increases the survival of spinal motor neurons and remyelinates the impaired axons through the pyramidal tract. In the present study, we examine whether intracranial cell implantation could also exert a similar effect on cortical motor neurons and on the lower motor neurons in the spinal cord. We injected OECs from the bulb of 7-day-old GFP green rats into the corona radiata of adult SOD1 mutant rats stereotaxically to observe any changes of the upper motor neurons as well as the lower motor neurons. We found that more motor neurons at both the motor cortices and ventral horns of the spinal cord survived in grafted ALS rats than in control rats. Prolonged survival and behavioral tests including a screen test, hind limb extension, rotarod, and gait control showed that the treated animals were better than the control group. This manuscript is published as part of the International Association of Neurorestoratology (IANR) supplement issue of Cell Transplantation.

Preliminary report of multiple cell therapy for patients with multiple system atrophy

The aim of this study is to explore the safety and therapeutic effect of multiple cell transplantations on patients with multiple system atrophy. Ten patients suffering from multiple system atrophy were treated by multiple cell transplantations from August 2005 to March 2011. They were six males and four females, with an average age of 51.90 ± 12.92 years (23-66 years). Multiple cell types were transplanted by intravenous, intrathecal, and intracranial routes; for example, 0.4-0.5 × 10(6)/kg umbilical cord mesenchymal cells by intravenous drip, intrathecal implantation of 2.0 × 10(6) Schwann cells and 2.0-5.0 × 10(6) neural progenitor cells through cerebellar cistern puncture, or 2 × 10(6) olfactory ensheathing cells and 4 × 10(6) neural progenitor cells injected into key points for neural network restoration (KPNNR). The neurological function was assessed before and after treatment with the International Cooperative Ataxia Rating Scale (ICARS) by the World Federation of Neurology and the Unified Multiple System Atrophy Rating Scale (UMSARS). The patients achieved neurological function amelioration after treatment, which included improvements in walking ability, gaits, standing, speech, and muscular tension; the ICARS score decreased from a preoperative 46.30 ± 14.50 points to postoperative 41.90 ± 18.40 points (p = 0.049). The UMSARS score decreased from preoperative 50.00 ± 20.65 points to postoperative 46.56 ± 23.05 points (p = 0.037). Among them, two patients remained stable and underwent a second treatment 0.5-1 year after the first therapy. After treatment, five patients were followed up for more than 6 months. Balance and walking ability improved further in four patients, while one patient remained stable for over 6 months. In conclusion, a strategy of comprehensive cell-based neurorestorative therapy for patients with multiple system atrophy is safe and appears to be beneficial. This manuscript is published as part of the International Association of Neurorestoratology (IANR) supplement issue of Cell Transplantation.

Standard recommendations for the application of Chinese clinical cell therapy for neurorestoration (2012)

Cell therapy has been shown to be a promising alternative therapy for neurorestoration, and more than 30 different types of cells have been shown to possess some capability to restore lost or damaged neurological functions. Chinese physicians have successfully applied cell therapy to many neurological diseases and damages in the clinic and contributed to establish a discipline of neurorestoratology. To standardize the clinical procedures of cell therapy as one of the strategies for treating neurological disorders, the Chinese Branch of the International Association of Neurorestoratology (IANR) and the Preparatory Committee of Chinese Association of Neurorestoratology recently completed the Standard Recommendations (2012) for the Application of Chinese Clinical Cell Therapy for Neurorestoration. We hope these recommendations will guide clinical practice in applying cell therapy for neurorestoration, which will therein offer a reference for both Chinese and other countries' governments to make relevant official regulations. This manuscript is published as part of the International Association of Neurorestoratology (IANR) supplement issue of Cell Transplantation.

Endogenous proliferation after spinal cord injury in animal models

Spinal cord injury (SCI) results in motor and sensory deficits, the severity of which depends on the level and extent of the injury. Animal models for SCI research include transection, contusion, and compression mouse models. In this paper we will discuss the endogenous stem cell response to SCI in animal models. All SCI animal models experience a similar peak of cell proliferation three days after injury; however, each specific type of injury promotes a specific and distinct stem cell response. For example, the transection model results in a strong and localized initial increase of proliferation, while in contusion and compression models, the initial level of proliferation is lower but encompasses the entire rostrocaudal extent of the spinal cord. All injury types result in an increased ependymal proliferation, but only in contusion and compression models is there a significant level of proliferation in the lateral regions of the spinal cord. Finally, the fate of newly generated cells varies from a mainly oligodendrocyte fate in contusion and compression to a mostly astrocyte fate in the transection model. Here we will discuss the potential of endogenous stem/progenitor cell manipulation as a therapeutic tool to treat SCI.

Translating cellular therapies from bench to bedside for amyotrophic lateral sclerosis

The last decade has witnessed an increasing number of biologic (e.g., cell- or viral vector-based) therapeutics supported by preclinical efficacy data for the treatment of afflictions to the CNS. While some international investigators have undertaken preliminary clinical safety studies, published literature indicate varying degrees of rigor with respect to study design and technical approach. To our knowledge, ours is the first group to have systematically generated preclinical validation data for a delivery approach and translated this into a Phase I trial attempting to covalidate the safety of a direct, targeted delivery approach, as well as a cell-based therapeutic. This article discusses the rationale for cell-based therapy in amyotrophic lateral sclerosis and several of the unique considerations encountered during this process.