Stem cells for amyotrophic lateral sclerosis modeling and therapy: Myth or fact?

Micro-RNAs Shuttled by Extracellular Vesicles Secreted from Mesenchymal Stem Cells Dampen Astrocyte Pathological Activation and Support Neuroprotection in In-Vitro Models of ALS

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with no effective cure. Astrocytes display a toxic phenotype in ALS and contribute to motoneuron (MN) degeneration. Modulating astrocytes' neurotoxicity can reduce MN death. Our previous studies showed the beneficial effect of mesenchymal stem cell (MSC) administration in SOD1^G93A ALS mice, but the mechanisms are still unclear. We postulated that the effects could be mediated by extracellular vesicles (EVs) secreted by MSCs. We investigated, by immunohistochemical, molecular, and in vitro functional analyses, the activity of MSC-derived EVs on the pathological phenotype and neurotoxicity of astrocytes isolated from the spinal cord of symptomatic SOD1^G93A mice and human astrocytes (iAstrocytes) differentiated from inducible neural progenitor cells (iNPCs) of ALS patients. In vitro EV exposure rescued mouse and human ALS astrocytes' neurotoxicity towards MNs. EVs significantly dampened the pathological phenotype and neuroinflammation in SOD1^G93A astrocytes. In iAstrocytes, exposure to EVs increased the antioxidant factor Nrf2 and reduced reactive oxygen species. We previously found nine miRNAs upregulated in MSC-derived EVs. Here, the transfection of SOD1^G93A astrocytes with single miRNA mimics reduced astrocytes' activation and the expression of neuroinflammatory factors. Moreover, miR-466q and miR-467f mimics downregulate Mapk11, while miR-466m-5p and miR-466i-3p mimics promote the nuclear translocation of Nrf2. In iAstrocytes, transfection with miR-29b-3p mimic upregulated NQO1 antioxidant activity and reduced neurotoxicity towards MNs. MSC-derived EVs modulate astrocytes' reactive phenotype and neurotoxicity through anti-inflammatory and antioxidant-shuttled miRNAs, thus representing a therapeutic strategy in ALS.

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.

Intravenous infusion of mesenchymal stem cells delays disease progression in the SOD1G93A transgenic amyotrophic lateral sclerosis rat model

ALS is a devastating neurodegenerative disease with few curative strategies. Both sporadic and familial ALS display common clinical features that show progressive paralysis. The pathogenesis remains unclear, but disruption of the blood-spinal cord barrier (BSCB) may contribute to the degeneration of motor neurons. Thus, restoration of the disrupted BSCB and neuroprotection for degenerating motor neurons could be therapeutic targets. We tested the hypothesis that an intravenous infusion of MSCs would delay disease progression through the preservation of BSCB function and increased expression of a neurotrophic factor, neurturin, in SOD1G93A ALS rats. When the open-field locomotor function was under 16 on the Basso, Beattie, and Bresnahan (BBB) scoring scale, the rats were randomized into two groups; one received an intravenous infusion of MSCs, while the other received vehicle alone. Locomotor function was recorded using BBB scoring and rotarod testing. Histological analyses, quantitative reverse transcription-polymerase chain reaction (qRT-PCR), were performed. The MSC group exhibited reduced deterioration of locomotor activity compared to the vehicle group, which displayed progressive deterioration of hind limb function. We observed the protection of motor neuron loss and preservation of microvasculature using Evans blue leakage and immunohistochemical analyses in the MSC group. Confocal microscopy revealed infused green fluorescent protein+ (GFP+) MSCs in the spinal cord, and the GFP gene was detected by nested PCR. Neurturin expression levels were significantly higher in the MSC group. Thus, restoration of the BSCB and the protection of motor neurons might be contributing mechanisms to delay disease progression in SOD1G93A ALS rats.

From Multi-Omics Approaches to Precision Medicine in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating and fatal neurodegenerative disorder, caused by the degeneration of upper and lower motor neurons for which there is no truly effective cure. The lack of successful treatments can be well explained by the complex and heterogeneous nature of ALS, with patients displaying widely distinct clinical features and progression patterns, and distinct molecular mechanisms underlying the phenotypic heterogeneity. Thus, stratifying ALS patients into consistent and clinically relevant subgroups can be of great value for the development of new precision diagnostics and targeted therapeutics for ALS patients. In the last years, the use and integration of high-throughput "omics" approaches have dramatically changed our thinking about ALS, improving our understanding of the complex molecular architecture of ALS, distinguishing distinct patient subtypes and providing a rational foundation for the discovery of biomarkers and new individualized treatments. In this review, we discuss the most significant contributions of omics technologies in unraveling the biological heterogeneity of ALS, highlighting how these approaches are revealing diagnostic, prognostic and therapeutic targets for future personalized interventions.

Dynamics of host and graft after cell sheet transplantation: Basic study for the application of amyotrophic lateral sclerosis

Stem cells offer great hope for the therapy of neurological disorders. Using a human artificial chromosome (HAC), we generated modified mesenchymal stem cells (MSCs), termed HAC-MSC that express 3 growth factors and 2 marker proteins including luciferase, and previously demonstrated that intrathecal administration of HAC-MSCs extended the lifespan in a mouse model of amyotrophic lateral sclerosis (ALS). However, donor cells disappeared rapidly after transplantation. To overcome this poor survival, we transplanted the HAC-MSCs as a sheet structure which retained the extracellular matrix. We investigated, here, whether cell sheet showed a longer survival than intrathecal administration. Also, the therapeutic effects on ALS model mice were examined. In vivo imaging showed that luciferase signals increased immediately after transplantation up to 7 days, and these signals were sustained for up to 14 days. In contrast, following intrathecal administration, signals were drastically decreased by day 3. Moreover, cell sheet transplantation successfully prolonged the survival of donor HAC-MSCs. Cell sheet transplantation increased the level of p-Akt at the graft area. Pathologically, none of the donor cells differentiated into neurons, astrocytes or microglial cells. When the cell sheet was transplanted into ALS model mice, there was an encouraging trend in the delayed onset of symptoms and increased lifespan. If each group was subdivided into rapid and slow progressors based on cut-off values for respective median survival, the survival of rapid progressors differed significantly between groups (treated vs. sham-operated = 145.4 ± 1.4 vs. 139.2 ± 1.2). The effect of HAC-MSC sheet transplantation still has a temporally narrow therapeutic window. Further improvement could be achieved by optimization of the transplantation conditions, e.g. co-transplantation of HAC-MSCs with endothelial progenitor cells.

Morpho-Functional Characteristics of Bone Marrow Multipotent Mesenchymal Stromal Cells after Activation or Inhibition of Epidermal Growth Factor and Toll-Like Receptors or Treatment with DNA Intercalator Cisplatin

This study is aimed to reveal morphological and functional changes in multipotent mesenchymal stromal cells (MSCs) isolated from the rat bone marrow after: (i) activation of Toll-like receptors (TLRs) with teichoic acid (TA), (ii) impact on epidermal growth factor (EGF) receptors with activator EGF or inhibitor Herceptin, and (iii) treatment with DNA intercalator Cisplatin. According to our results, TA and EGF cause an increase in the synthesis of glycosaminoglycans, c-Myc content, and protein in the MSC cytoplasm. It was observed that the cell population in G0 phase decreased and the cell population in G1 phase increased, when compared with control. At the same time, the cell population with a higher nuclear-cytoplasmic ratio (NCR) in S and G2 phases also increased. This indicates the manifestation of the MSC mesenchymal phenotype, exhibiting indirect metabolic signs of the regenerative potential increase. In other experiments, Herceptin was shown to suppress only the stemness signs of MSCs, while Cisplatin seriously affected cell viability in general, reducing synthetic and proliferative activities and causing cell morphology disturbances. © 2018 International Society for Advancement of Cytometry.

Pericytes Extend Survival of ALS SOD1 Mice and Induce the Expression of Antioxidant Enzymes in the Murine Model and in IPSCs Derived Neuronal Cells from an ALS Patient

Amyotrophic Lateral Sclerosis (ALS) is one of the most common adult-onset motor neuron disease causing a progressive, rapid and irreversible degeneration of motor neurons in the cortex, brain stem and spinal cord. No effective treatment is available and cell therapy clinical trials are currently being tested in ALS affected patients. It is well known that in ALS patients, approximately 50% of pericytes from the spinal cord barrier are lost. In the central nervous system, pericytes act in the formation and maintenance of the blood-brain barrier, a natural defense that slows the progression of symptoms in neurodegenerative diseases. Here we evaluated, for the first time, the therapeutic effect of human pericytes in vivo in SOD1 mice and in vitro in motor neurons and other neuronal cells derived from one ALS patient. Pericytes and mesenchymal stromal cells (MSCs) were derived from the same adipose tissue sample and were administered to SOD1 mice intraperitoneally. The effect of the two treatments was compared. Treatment with pericytes extended significantly animals survival in SOD1 males, but not in females that usually have a milder phenotype with higher survival rates. No significant differences were observed in the survival of mice treated with MSCs. Gene expression analysis in brain and spinal cord of end-stage animals showed that treatment with pericytes can stimulate the host antioxidant system. Additionally, pericytes induced the expression of SOD1 and CAT in motor neurons and other neuronal cells derived from one ALS patient carrying a mutation in FUS. Overall, treatment with pericytes was more effective than treatment with MSCs. Our results encourage further investigations and suggest that pericytes may be a good option for ALS treatment in the future. Graphical Abstract ᅟ.

Multiple intracerebroventricular injections of human umbilical cord mesenchymal stem cells delay motor neurons loss but not disease progression of SOD1G93A mice

Stem cell therapy is considered a promising approach in the treatment of amyotrophic lateral sclerosis (ALS) and mesenchymal stem cells (MSCs) seem to be the most effective in ALS animal models. The umbilical cord (UC) is a source of highly proliferating fetal MSCs, more easily collectable than other MSCs. Recently we demonstrated that human (h) UC-MSCs, double labeled with fluorescent nanoparticles and Hoechst-33258 and transplanted intracerebroventricularly (ICV) into SOD1G93A transgenic mice, partially migrated into the spinal cord after a single injection. This prompted us to assess the effect of repeated ICV injections of hUC-MSCs on disease progression in SOD1G93A mice. Although no transplanted cells migrated to the spinal cord, a partial but significant protection of motor neurons (MNs) was found in the lumbar spinal cord of hUC-MSCs-treated SOD1G93A mice, accompanied by a shift from a pro-inflammatory (IL-6, IL-1β) to anti-inflammatory (IL-4, IL-10) and neuroprotective (IGF-1) environment in the lumbar spinal cord, probably linked to the activation of p-Akt survival pathway in both motor neurons and reactive astrocytes. However, this treatment neither prevented the muscle denervation nor delayed the disease progression of mice, emphasizing the growing evidence that protecting the motor neuron perikarya is not sufficient to delay the ALS progression.

The use of mesenchymal stem cells (MSCs) for amyotrophic lateral sclerosis (ALS) therapy – a perspective on cell biological mechanisms

Recent clinical trials of mesenchymal stem cells (MSCs) transplantation have demonstrated procedural safety and clinical proof of principle with a modest indication of benefit in patients with amyotrophic lateral sclerosis (ALS). While replacement therapy remained unrealistic, the clinical efficacy of this therapeutic option could be potentially enhanced if we could better decipher the mechanisms underlying some of the beneficial effects of transplanted cells, and work toward augmenting or combining these in a strategic manner. Novel ways whereby MSCs could act in modifying disease progression should also be explored. In this review, I discuss the known, emerging and postulated mechanisms of action underlying effects that transplanted MSCs may exert to promote motor neuron survival and/or to encourage regeneration in ALS. I shall also speculate on how transplanted cells may alter the diseased environment so as to minimize non-neuron cell autonomous damages by immune cells and astrocytes.

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.

Immunomodulatory oligonucleotide IMT504: Effects on mesenchymal stem cells as a first-in-class immunoprotective/immunoregenerative therapy

The immune responses of humans and animals to insults (i.e., infections, traumas, tumoral transformation and radiation) are based on an intricate network of cells and chemical messengers. Abnormally high inflammation immediately after insult or abnormally prolonged pro-inflammatory stimuli bringing about chronic inflammation can lead to life-threatening or severely debilitating diseases. Mesenchymal stem cell (MSC) transplant has proved to be an effective therapy in preclinical studies which evaluated a vast diversity of inflammatory conditions. MSCs lead to resolution of inflammation, preparation for regeneration and actual regeneration, and then ultimate return to normal baseline or homeostasis. However, in clinical trials of transplanted MSCs, the expectations of great medical benefit have not yet been fulfilled. As a practical alternative to MSC transplant, a synthetic drug with the capacity to boost endogenous MSC expansion and/or activation may also be effective. Regarding this, IMT504, the prototype of a major class of immunomodulatory oligonucleotides, induces in vivo expansion of MSCs, resulting in a marked improvement in preclinical models of neuropathic pain, osteoporosis, diabetes and sepsis. IMT504 is easily manufactured and has an excellent preclinical safety record. In the small number of patients studied thus far, IMT504 has been well-tolerated, even at very high dosage. Further clinical investigation is necessary to demonstrate the utility of IMT504 for resolution of inflammation and regeneration in a broad array of human diseases that would likely benefit from an immunoprotective/immunoregenerative therapy.

Advances in Stem Cell Research- A Ray of Hope in Better Diagnosis and Prognosis in Neurodegenerative Diseases

Neurodegeneration and neurodegenerative disorders have been a global health issue affecting the aging population worldwide. Recent advances in stem cell biology have changed the current face of neurodegenerative disease modeling, diagnosis, and transplantation therapeutics. Stem cells also serve the purpose of a simple in-vitro tool for screening therapeutic drugs and chemicals. We present the application of stem cells and induced pluripotent stem cells (iPSCs) in the field of neurodegeneration and address the issues of diagnosis, modeling, and therapeutic transplantation strategies for the most prevalent neurodegenerative disorders. We have discussed the progress made in the last decade and have largely focused on the various applications of stem cells in the neurodegenerative research arena.

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.

Neuromuscular disorders: genes, genetic counseling and therapeutic trials

Neuromuscular disorders (NMD) are a heterogeneous group of genetic conditions, with autosomal dominant, recessive, or X-linked inheritance. They are characterized by progressive muscle degeneration and weakness. Here, we are presenting our major contributions to the field during the past 30 years. We have mapped and identified several novel genes responsible for NMD. Genotype-phenotype correlations studies enhanced our comprehension on the effect of gene mutations on related proteins and their impact on clinical findings. The search for modifier factors allowed the identification of a novel "protective"; variant which may have important implication on therapeutic developments. Molecular diagnosis was introduced in the 1980s and new technologies have been incorporated since then. Next generation sequencing greatly improved our capacity to identify disease-causing mutations with important benefits for research and prevention through genetic counseling of patients' families. Stem cells researches, from and for patients, have been used as tools to study human genetic diseases mechanisms and for therapies development. The clinical effect of preclinical trials in mice and canine models for muscular dystrophies are under investigation. Finally, the integration of our researches and genetic services with our post-graduation program resulted in a significant output of new geneticists, spreading out this expertise to our large country.

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

BACKGROUND

Published studies seeking to improve survival in amyotrophic lateral sclerosis (ALS) have poor results in humans, although there are several studies in animal models with positive results.

METHODS

We conducted a systematic review and meta-analysis of studies that were published between March 2009 and March 2015 on stem cell therapy and survival in animal models and patients with ALS. A total of 714 articles were identified, and from these, we selected preclinical in vivo studies and retrospective clinical studies.

RESULTS AND CONCLUSIONS

A meta-analysis confirmed the efficacy of stem cell therapy in improving survival in preclinical trials, where a mean difference of 9.79 days (95% confidence interval: 4.45 - 15.14) in lifespan favored stem cell therapy. In contrast, the number of clinical studies is still insufficient to assess their effectiveness, and these studies only demonstrate the absence of serious adverse events. However, even this conclusion should be interpreted with caution because clinical studies are retrospective and heterogeneous and have an unsatisfactory quality.

Clinical Trials in a Dish: The Potential of Pluripotent Stem Cells to Develop Therapies for Neurodegenerative Diseases

Neurodegenerative diseases are a leading cause of death. No disease-modifying therapies are available, and preclinical animal model data have routinely failed to translate into success for therapeutics. Induced pluripotent stem cell (iPSC) biology holds great promise for human in vitro disease modeling because these cells can give rise to any cell in the human brain and display phenotypes specific to neurodegenerative diseases previously identified in postmortem and clinical samples. Here, we explore the potential and caveats of iPSC technology as a platform for drug development and screening, and the future potential to use large cohorts of disease-bearing iPSCs to perform clinical trials in a dish.