Efficacy of Stem Cell Therapy in Amyotrophic Lateral Sclerosis: A Systematic Review and Meta-Analysis

Perinatal Tissue-Derived Stem Cells: An Emerging Therapeutic Strategy for Challenging Neurodegenerative Diseases

Over the past 20 years, stem cell therapy has been considered a promising option for treating numerous disorders, in particular, neurodegenerative disorders. Stem cells exert neuroprotective and neurodegenerative benefits through different mechanisms, such as the secretion of neurotrophic factors, cell replacement, the activation of endogenous stem cells, and decreased neuroinflammation. Several sources of stem cells have been proposed for transplantation and the restoration of damaged tissue. Over recent decades, intensive research has focused on gestational stem cells considered a novel resource for cell transplantation therapy. The present review provides an update on the recent preclinical/clinical applications of gestational stem cells for the treatment of protein-misfolding diseases including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD) and amyotrophic lateral sclerosis (ALS). However, further studies should be encouraged to translate this promising therapeutic approach into the clinical setting.

Assessment of Immunological Potential of Glial Restricted Progenitor Graft In Vivo-Is Immunosuppression Mandatory?

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease, causing motor neuron and skeletal muscle loss and death. One of the promising therapeutic approaches is stem cell graft application into the brain; however, an immune reaction against it creates serious limitations. This study aimed to research the efficiency of glial restricted progenitors (GRPs) grafted into murine CNS (central nervous system) in healthy models and the SOD1G93A ALS disease model. The cellular grafts were administered in semiallogenic and allogeneic settings. To investigate the models of immune reaction against grafted GRPs, we applied three immunosuppressive/immunomodulatory regimens: preimplantation factor (PiF); Tacrolimus; and CTLA-4, MR1 co-stimulatory blockade. We tracked the cells with bioluminescence imaging (BLI) in vivo to study their survival. The immune response character was evaluated with brain tissue assays and multiplex ELISA in serum and cerebrospinal fluid (CSF). The application of immunosuppressive drugs is disputable when considering cellular transplants into the immune-privileged site/brain. However, our data revealed that semiallogenic GRP graft might survive inside murine CNS without the necessity to apply any immunomodulation or immunosuppression, whereas, in the situation of allogeneic mouse setting, the combination of CTLA-4, MR1 blockade can be considered as the best immunosuppressive option.

Improved survival in amyotrophic lateral sclerosis patients following autologous bone marrow mononuclear cell therapy: a long term 10-year retrospective study

Background:

Promising results from previous studies using cell therapy have paved the way for an innovative treatment option for amyotrophic lateral sclerosis (ALS). There is considerable evidence of immune and inflammatory abnormalities in ALS. Bone marrow mononuclear cells (BMMNCs) possess immunomodulatory properties and could contribute to slowing of disease progression.

Objective:

Aim of our study was to evaluate the long-term effect of autologous BMMNCs combined with standard treatment on survival duration in a large population and to evaluate effect of type of onset and hormonal status on survival duration in the intervention group.

Methods:

This controlled, retrospective study spanned over 10 years, 5 months; included 216 patients with probable or definite ALS, 150 in intervention group receiving autologous BMMNCs and standard treatment, and 66 in control group receiving only standard treatment. The estimated survival duration of control group and intervention group was computed and compared using Kaplan Meier analysis. Survival duration of patients with different types of onset and hormonal status was compared within the intervention group.

Results:

None of the patients reported any major adverse events related to cell administration or the procedure. Kaplan Meier analysis estimated survival duration in the intervention group to be 91.7 months while 49.7 months in the control group (p = 0.008). Within the intervention group, estimated survival was significantly higher (p = 0.013) in patients with limb onset (102.3 months) vs. bulbar onset (49.9 months); premenopausal women (93.1 months) vs. postmenopausal women (57.6 months) (p = 0.002); and preandropausal men (153.7 months) vs. postandropausal males (56.5 months) (p = 0.006).

Conclusion:

Cell therapy using autologous BMMNCs along with standard treatment offers a promising and safe option for ALS with the potential of long term beneficial effect and increased survival. Limb onset patients, premenopausal women and men ≤ 40 years of age demonstrated better treatment efficacy.

Multiple doses of cell therapy and neurorehabilitation in amyotrophic lateral sclerosis: A case report

Cell therapy, along with intensive rehabilitation has been shown to significantly improve outcomes in amyotrophic lateral sclerosis (ALS), in addition to standard therapy. We present a 40-years-old male ALS patient, suffering for the past four years, who underwent multiple doses of cell therapy at our institution. Along with riluzole treatment and lithium co-administration, his treatment involved multiple intrathecal transplants of autologous bone marrow-derived mononuclear cells, followed by multidisciplinary neurorehabilitation. The outcome measures of ALSFunctional Rating Scale Revised score remained stable, and importantly, Six Minute Walk Test distance improved from 475.2 m to 580.8 m, over a span of 16 months. Improved outcomes are indicative of slowing down of disease progression. Multiple doses of intrathecal autologous cell therapy along with rehabilitation and lithium, in addition to standard riluzole treatment is a novel approach for decelerating disease progression and qualitatively improving living conditions for ALS patients and their caregivers.

Regenerative Cell-Based Therapies: Cutting Edge, Bleeding Edge, and Off the Edge

With the emergence of cell-based therapies as viable treatment options readily accessible to patients, the scientific community and public have raised concerns regarding consumer accessibility and regulation enforcement. Opposing viewpoints regarding regulation have emerged, and efforts to maintain the balance between promoting scientific innovation and ensuring public safety has proved challenging. To further complicate matters, there is contradictory information regarding the clinical safety and efficacy of cell-based treatments. Herein, we outline the FDA's regulatory framework for cell-based therapies and describe what we term the cutting edge, bleeding edge, and off the edge interventions. We conclude with a new classification system for regenerative cell-based therapies intended to further aid in delineating between the clinically and scientifically sound therapies to those that compel further scientific investigation.

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 exists. Current treatment approaches largely focus on relieving symptoms to improve the quality of life of those affected. The therapeutic potential of cell-based therapies in ALS/MND has not been fully evaluated, given the paucity of high-quality clinical trials. Based on data from preclinical studies, cell-based therapy is a promising treatment for ALS/MND. This review was first published in 2015 when the first clinical trials of cell-based therapies were still in progress. We undertook this update to incorporate evidence now available from randomised controlled trials (RCTs).

OBJECTIVES

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

SEARCH METHODS

On 31 July 2019, 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 included RCTs that assigned people with ALS/MND to receive cell-based therapy versus a placebo or no additional treatment. Co-interventions were allowed, provided that they were given to each group equally.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology.

MAIN RESULTS

Two RCTs involving 112 participants were eligible for inclusion in this review. One study compared autologous bone marrow-mesenchymal stem cells (BM-MSC) plus riluzole versus control (riluzole only), while the other study compared combined intramuscular and intrathecal administration of autologous mesenchymal stem cells secreting neurotrophic factors (MSC-NTF) to placebo. The latter study was reported as an abstract and provided no numerical data. Both studies were funded by biotechnology companies. The only study that contributed to the outcome data in the review involved 64 participants, comparing BM-MSC plus riluzole versus control (riluzole only). It reported outcomes after four to six months. It had a low risk of selection bias, detection bias and reporting bias, but a high risk of performance bias and attrition bias. The certainty of evidence was low for all major efficacy outcomes, with imprecision as the main downgrading factor, because the range of plausible estimates, as shown by the 95% confidence intervals (CIs), encompassed a range that would likely result in different clinical decisions. Functional impairment, expressed as the mean change in the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) score from baseline to six months after cell injection was slightly reduced (better) in the BM-MSC group compared to the control group (mean difference (MD) 3.38, 95% CI 1.22 to 5.54; 1 RCT, 56 participants; low-certainty evidence). ALSFRS-R has a range from 48 (normal) to 0 (maximally impaired); a change of 4 or more points is considered clinically important. The trial did not report outcomes at 12 months. There was no clear difference between the BM-MSC and the no treatment group in change in respiratory function (per cent predicted forced vital capacity; FVC%; MD -0.53, 95% CI -5.37 to 4.31; 1 RCT, 56 participants; low-certainty evidence); overall survival at six months (risk ratio (RR) 1.07, 95% CI 0.94 to 1.22; 1 RCT, 64 participants; low-certainty evidence); risk of total adverse events (RR 0.86, 95% CI 0.62 to 1.19; 1 RCT, 64 participants; low-certainty evidence) or serious adverse events (RR 0.47, 95% CI 0.13 to 1.72; 1 RCT, 64 participants; low-certainty evidence). The study did not measure muscle strength.

AUTHORS' CONCLUSIONS

Currently, there is a lack of high-certainty evidence to guide practice on the use of cell-based therapy to treat ALS/MND. Uncertainties remain as to whether this mode of therapy is capable of restoring muscle function, slowing disease progression, and improving survival in people with ALS/MND. Although one RCT provided low-certainty evidence that BM-MSC may slightly reduce functional impairment measured on the ALSFRS-R after four to six months, this was a small phase II trial that cannot be used to establish efficacy. We need large, prospective RCTs with long-term follow-up to establish the efficacy and safety 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 are to determine the appropriate cell source, phenotype, dose and method 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.

Stem Cells and Other Emerging Agents as Innovative "Drugs" in Neurodegenerative Diseases: Benefits and Limitations

The brain has a limited process of repair/regeneration linked to the restricted and localized activity of neuronal stem cells. Consequently, it shows a reduced capacity to counteract the age-related loss of neural and glial cells and to repair the consequent injuries/lesions of nervous system. This progressively determines nervous dysfunction and onset/progression of neurodegenerative diseases, which represent a serious social (and economic) problem of our populations. Thus, the research of efficient treatments is encouraged. Stem cell therapy might represent a solution. Today, it, indeed, represents the object of intensive research with the hope of using it, in a near future, as effective therapy for these diseases and preventive treatment in susceptible individuals. Here, we report and discuss the data of the recent studies on this field, underling the obstacles and benefits. We also illustrate alternative measures of intervention, which represent another parallel aim for the care of neurodegenerative pathology-affected individuals. Thus, the road for delaying or retarding these diseases appears hard and long, but the advances might be different.

Ethics of clinical research in patients with ALS: is there a risk of exploitation?

Amyotrophic lateral sclerosis is the most common degenerative disease of the motor neuron network. Due to its inevitably fatal outcome, numerous attempts have been made to ameliorate its course. The emergence of every new technology has spurred research to see if it might benefit patients with ALS (PALS). This paper suggests a detailed road map to be followed when performing clinical research in PALS to satisfy the ethics requirements of the Declaration of Helsinki, expressed using the terminology of Beauchamp and Childress. The ethics principles that need to be satisfied are arranged in a hierarchical manner, each having to be satisfied before the next is approached: Justice; Beneficence, Nonmaleficence, Professional-Patient Relationship, and Respect for Autonomy. Study participants' autonomy can be respected only when all other principles have been addressed before PALS are approached to participate. Five 'red flags' are identified, which, if present, might indicate a risk that PALS may be exploited. PALS who are contemplating new treatments or clinical trials and their families will be assured that their best interests are the only ones that matter whenever adherence to established ethics principles and avoidance of known pitfalls are made explicit.

Three-Dimensional Organoid System Transplantation Technologies in Future Treatment of Central Nervous System Diseases

In recent years, scientists have made great achievements in understanding the development of human brain and elucidating critical elements of stepwise spatiotemporal control strategies in neural stem cell specification lineage, which facilitates successful induction of neural organoid in vitro including the cerebral cortex, cerebellar, neural tube, hippocampus cortex, pituitary, and optic cup. Besides, emerging researches on neural organogenesis promote the application of 3D organoid system transplantation in treating central nervous system (CNS) diseases. Present review will categorize current researches on organogenesis into three approaches: (a) stepwise, direct organization of region-specific or population-enriched neural organoid; (b) assemble and direct distinct organ-specific progenitor cells or stem cells to form specific morphogenesis organoid; and (c) assemble embryoid bodies for induction of multilayer organoid. However, the majority of these researches focus on elucidating cellular and molecular mechanisms involving in brain organogenesis or disease development and only a few of them conducted for treating diseases. In this work, we will compare three approaches and also analyze their possible indications for diseases in future treatment on the basis of their distinct characteristics.

Protein aggregation, misfolding and consequential human neurodegenerative diseases

Proteins are major components of the biological functions in a cell. Biology demands that a protein must fold into its stable three-dimensional structure to become functional. In an unfavorable cellular environment, protein may get misfolded resulting in its aggregation. These conformational disorders are directly related to the tissue damage resulting in cellular dysfunction giving rise to different diseases. This way, several neurodegenerative diseases such as Alzheimer, Parkinson Huntington diseases and amyotrophic lateral sclerosis are caused. Misfolding of the protein is prevented by innate molecular chaperones of different classes. It is envisaged that work on this line is likely to translate the knowledge into the development of possible strategies for early diagnosis and efficient management of such related human diseases. The present review deals with the human neurodegenerative diseases caused due to the protein misfolding highlighting pathomechanisms and therapeutic intervention.

Relationship between Clinical Parameters and Brain Structure in Sporadic Amyotrophic Lateral Sclerosis Patients According to Onset Type: A Voxel-Based Morphometric Study

Background and purpose

Amyotrophic lateral sclerosis (ALS) is a rapidly progressing, phenotypically heterogeneous neurodegenerative disease affecting mainly the motor neuron system. The present voxel-based morphometry (VBM) study investigated whether patterns of brain atrophy differ among sporadic ALS subtypes.

Material and methods

Sporadic ALS patients (n = 62) with normal cognition and age-matched healthy controls (n = 57) were included in the study. ALS patients were divided into limb- and bulbar-onset groups according to clinical manifestations at symptom onset (n = 48 and 14, respectively). Clinical measures were ALS Functional Rating Scale-Revised (ALSFRS-R) score, disease duration, and forced vital capacity (FVC). Patterns of brain atrophy between ALS subgroups were compared by VBM.

Results

In limb-onset ALS patients, atrophy was largely confined to the motor cortex and adjacent pre- and postcentral regions. However, in the bulbar-onset group, affected regions were more widespread and included these same areas but also extended to the bilateral frontotemporal and left superior temporal and supramarginal gyri, and multiple regression analysis revealed that their ALSFRS-R scores were associated with extensive loss of gray matter while FVC was related to atrophy in subcortical regions of the left superior temporal gyrus. In limb-onset ALS patients, disease duration was related to the degree of atrophy in the motor and adjacent areas.

Conclusion

Sporadic ALS subtypes show different patterns of brain atrophy. Neural networks related to limb and bulbar motor functions in each ALS subtype may underlie their distinct patterns of cerebral atrophy. That is, more extensive cortical and subcortical atrophy is correlated with greater ALSFRS-R severity and shorter disease duration in the bulbar-onset subtype and may explain the poor prognosis of these patients.