Increased survival and migration of engrafted mesenchymal bone marrow stem cells in 6-hydroxydopamine-lesioned rodents

Mesenchymal Stem Cell Transplantation Ameliorates Ara-C-Induced Motor Deficits in a Mouse Model of Cerebellar Ataxia

This study investigated the therapeutic effects of transplanting human mesenchymal stem cells (hMSCs) into wild-type mice that were intraperitoneally administered cytosine arabinoside (Ara-C) to develop cerebellar ataxia (CA) during the first three postnatal days. hMSCs were intrathecally injected into 10-week-old mice once or thrice at 4-week intervals. Compared to the nontreated mice, the hMSC-treated mice showed improved motor and balance coordination, as measured using the rotarod, open-field, and ataxic scoring assessments, and increased protein levels in Purkinje and cerebellar granule cells, as measured using calbindin and NeuN protein markers. Multiple hMSC injections preserved Ara-C-induced cerebellar neuronal loss and improved cerebellar weight. Furthermore, the hMSC implantation significantly elevated the levels of neurotrophic factors, including brain-derived and glial cell line-derived neurotrophic factors, and suppressed TNF-α-, IL-1β-, and iNOS-mediated proinflammatory responses. Collectively, our results demonstrate that hMSCs exhibit therapeutic potential for Ara-C-induced CA by protecting neurons through the stimulation of neurotrophic factors and inhibition of cerebellar inflammatory responses, which can improve motor behavior and alleviate ataxia-related neuropathology. In summary, this study suggests that hMSC administration, particularly multiple treatments, can effectively treat ataxia-related symptoms with cerebellar toxicity.

Stem Cell-based and Advanced Therapeutic Modalities for Parkinson's Disease: A Risk-effectiveness Patient-centered Analysis

Treatment of Parkinson's disease (PD), the second most prevalent neurodegenerative disorder, is currently considered a challenging issue since it causes substantial disability, poor quality of life, and mortality. Despite remarkable progress in advanced conventional therapeutic interventions, the global burden of the disease has nearly doubled, prompting us to assess the riskeffectiveness of different treatment modalities. Each protocol could be considered as the best alternative treatment depending on the patient's situation. Prescription of levodopa, the most effective available medicine for this disorder, has been associated with many complications, i.e., multiple episodes of "off-time" and treatment resistance. Other medications, which are typically used in combination with levodopa, may have several adverse effects as well. As a result, the therapies that are more in line with human physiology and make the least interference with other pathways are worth investigating. On the other hand, remaining and persistent symptoms after therapy and the lack of effective response to the conventional approaches have raised expectations towards innovative alternative approaches, such as stem cell-based therapy. It is critical to not overlook the unexplored side effects of innovative approaches due to the limited number of research. In this review, we aimed to compare the efficacy and risk of advanced therapies with innovative cell-based and stemcell- based modalities in PD patients. This paper recapitulated the underlying factors/conditions, which could lead us to more practical and established therapeutic outcomes with more advantages and few complications. It could be an initial step to reconsider the therapeutic blueprint for patients with Parkinson's disease.

New Targets and New Technologies in the Treatment of Parkinson’s Disease: A Narrative Review

Parkinson’s disease (PD) is a progressive neurodegenerative disease, whose main neuropathological finding is pars compacta degeneration due to the accumulation of Lewy bodies and Lewy neurites, and subsequent dopamine depletion. This leads to an increase in the activity of the subthalamic nucleus (STN) and the internal globus pallidus (GPi). Understanding functional anatomy is the key to understanding and developing new targets and new technologies that could potentially improve motor and non-motor symptoms in PD. Currently, the classical targets are insufficient to improve the entire wide spectrum of symptoms in PD (especially non-dopaminergic ones) and none are free of the side effects which are not only associated with the procedure, but with the targets themselves. The objective of this narrative review is to show new targets in DBS surgery as well as new technologies that are under study and have shown promising results to date. The aim is to give an overview of these new targets, as well as their limitations, and describe the current studies in this research field in order to review ongoing research that will probably become effective and routine treatments for PD in the near future.

Insights Into the Role of Platelet-Derived Growth Factors: Implications for Parkinson’s Disease Pathogenesis and Treatment

Parkinson’s disease (PD), the second most common neurodegenerative disease after Alzheimer’s disease, commonly occurs in the elderly population, causing a significant medical and economic burden to the aging society worldwide. At present, there are few effective methods that achieve satisfactory clinical results in the treatment of PD. Platelet-derived growth factors (PDGFs) and platelet-derived growth factor receptors (PDGFRs) are important neurotrophic factors that are expressed in various cell types. Their unique structures allow for specific binding that can effectively regulate vital functions in the nervous system. In this review, we summarized the possible mechanisms by which PDGFs/PDGFRs regulate the occurrence and development of PD by affecting oxidative stress, mitochondrial function, protein folding and aggregation, Ca2+ homeostasis, and cell neuroinflammation. These modes of action mainly depend on the type and distribution of PDGFs in different nerve cells. We also summarized the possible clinical applications and prospects for PDGF in the treatment of PD, especially in genetic treatment. Recent advances have shown that PDGFs have contradictory roles within the central nervous system (CNS). Although they exert neuroprotective effects through multiple pathways, they are also associated with the disruption of the blood–brain barrier (BBB). Our recommendations based on our findings include further investigation of the contradictory neurotrophic and neurotoxic effects of the PDGFs acting on the CNS.

Mesenchymal Stem Cell-Derived Extracellular Vesicles and Their Therapeutic Use in Central Nervous System Demyelinating Disorders

Autoimmune demyelinating diseases-including multiple sclerosis, neuromyelitis optica spectrum disorder, anti-myelin oligodendrocyte glycoprotein-associated disease, acute disseminated encephalomyelitis, and glial fibrillary acidic protein (GFAP)-associated meningoencephalomyelitis-are a heterogeneous group of diseases even though their common pathology is characterized by neuroinflammation, loss of myelin, and reactive astrogliosis. The lack of safe pharmacological therapies has purported the notion that cell-based treatments could be introduced to cure these patients. Among stem cells, mesenchymal stem cells (MSCs), obtained from various sources, are considered to be the ones with more interesting features in the context of demyelinating disorders, given that their secretome is fully equipped with an array of anti-inflammatory and neuroprotective molecules, such as mRNAs, miRNAs, lipids, and proteins with multiple functions. In this review, we discuss the potential of cell-free therapeutics utilizing MSC secretome-derived extracellular vesicles-and in particular exosomes-in the treatment of autoimmune demyelinating diseases, and provide an outlook for studies of their future applications.

Preclinical Assessment of Mesenchymal-Stem-Cell-Based Therapies in Spinocerebellar Ataxia Type 3

The low regeneration potential of the central nervous system (CNS) represents a challenge for the development of new therapeutic strategies for neurodegenerative diseases, including spinocerebellar ataxias. Spinocerebellar ataxia type 3 (SCA3)—or Machado–Joseph disease (MJD)—is the most common dominant ataxia, being mainly characterized by motor deficits; however, SCA3/MJD has a complex and heterogeneous pathophysiology, involving many CNS brain regions, contributing to the lack of effective therapies. Mesenchymal stem cells (MSCs) have been proposed as a potential therapeutic tool for CNS disorders. Beyond their differentiation potential, MSCs secrete a broad range of neuroregulatory factors that can promote relevant neuroprotective and immunomodulatory actions in different pathophysiological contexts. The objective of this work was to study the effects of (1) human MSC transplantation and (2) human MSC secretome (CM) administration on disease progression in vivo, using the CMVMJD135 mouse model of SCA3/MJD. Our results showed that a single CM administration was more beneficial than MSC transplantation—particularly in the cerebellum and basal ganglia—while no motor improvement was observed when these cell-based therapeutic approaches were applied in the spinal cord. However, the effects observed were mild and transient, suggesting that continuous or repeated administration would be needed, which should be further tested.

Cell-Based Transplantation versus Cell Homing Approaches for Pulp-Dentin Complex Regeneration

Regenerative dentistry has paved the way for a new era for the replacement of damaged dental tissues. Whether the causative factor is dental caries, trauma, or chemical insult, the loss of the pulp vitality constitutes one of the major health problems worldwide. Two regenerative therapies were introduced for a fully functional pulp-dentin complex regeneration, namely, cell-based (cell transplantation) and cell homing (through revascularization or homing by injection of stem cells in situ or intravenously) therapies, with each demonstrating advantages as well as drawbacks, especially in clinical application. The present review is aimed at elaborating on these two techniques in the treatment of irreversibly inflamed or necrotic pulp, which is aimed at regenerating a fully functional pulp-dentin complex.

Neural Basis of Dental Pulp Stem Cells and its Potential Application in Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disease after Alzheimer's disease. Though significant insights into the molecular-biochemical-cellular-behavioral basis of PD have been understood, there is no appreciable treatment available till date. Current therapies provide symptomatic relief without any influence on the progression of the disease. Stem cell therapy has been vigorously explored to treat PD. In this comprehensive review, we analyze various stem cell candidates for treating PD and discuss the possible mechanisms. We advocate the advantage of using neural crest originated dental pulp stem cells (DPSC) due to their predisposition towards neural differentiation and their potential to regenerate neurons far better than commonly used bone marrow derived mesenchymal stem cells (BM-MSCs). Eventually, we highlight the current challenges in the field and the strategies which may be used for overcoming the impediments.

Mesenchymal stem cells in Parkinson's disease: Motor and nonmotor symptoms in the early posttransplant period

BACKGROUND

Treatment of patients with Parkinson disease (PD) using autologous mesenchymal stem cells (MSCs) is a promising method to influence the pathogenesis of the disease. The aim of this study was to assess the immediate results of the introduction of MSCs on the effectiveness of motor and nonmotor symptoms in patients with PD.

METHODS

MSCs were transplanted to 12 patients with PD through intravenous and tandem (intranasal + intravenous) injections. Effectiveness of the therapy was evaluated 1 and 3 months posttransplantation. Neurological examination of the intensity of motor symptoms was carried out in the morning after a 12 or 24 h break in taking antiparkinsonian drugs, then 1 h after they were taken. The intensity of motor symptoms was assessed with the help of Section III of the Unified PD Rating Scale of the International Society for Movement Disorders (UPDRS). The intensity of nonmotor symptoms was assessed with the help of the following scales: Hamilton Depression Rating Scale, the Pittsburgh Sleep Quality Index, the Epworth Sleepiness Scale, Nonmotor Symptoms Scale, and the 39-item Parkinson's Disease Questionnaire.

RESULTS

We found a statistically significant decrease in the severity of motor and nonmotor symptoms in the study group in the posttransplant period.

CONCLUSION

Positive results allow us to consider MSCs transplantation as a disease-modifying therapeutic strategy in PD. However, this method of PD treatment is not a fully understood process, which requires additional studies and a longer follow-up period to monitor the patients' condition posttransplantation.

Development and Differentiation of Midbrain Dopaminergic Neuron: From Bench to Bedside

Parkinson’s Disease (PD) is a neurodegenerative disorder affecting the motor system. It is primarily due to substantial loss of midbrain dopamine (mDA) neurons in the substantia nigra pars compacta and to decreased innervation to the striatum. Although existing drug therapy available can relieve the symptoms in early-stage PD patients, it cannot reverse the pathogenic progression of PD. Thus, regenerating functional mDA neurons in PD patients may be a cure to the disease. The proof-of-principle clinical trials showed that human fetal graft-derived mDA neurons could restore the release of dopamine neurotransmitters, could reinnervate the striatum, and could alleviate clinical symptoms in PD patients. The invention of human-induced pluripotent stem cells (hiPSCs), autologous source of neural progenitors with less ethical consideration, and risk of graft rejection can now be generated in vitro. This advancement also prompts extensive research to decipher important developmental signaling in differentiation, which is key to successful in vitro production of functional mDA neurons and the enabler of mass manufacturing of the cells required for clinical applications. In this review, we summarize the biology and signaling involved in the development of mDA neurons and the current progress and methodology in driving efficient mDA neuron differentiation from pluripotent stem cells.

Deconstructing Neurogenesis, Transplantation and Genome-Editing as Neural Repair Strategies in Brain Disease

Neural repair in injury and disease presents a pressing unmet need in regenerative medicine. Due to the intrinsically reduced ability of the brain to replace lost and damaged neurons, reversing long-term cognitive and functional impairments poses a unique problem. Over the years, advancements in cellular and molecular understanding of neurogenesis mechanisms coupled with sophistication of biotechnology tools have transformed neural repair into a cross-disciplinary field that integrates discoveries from developmental neurobiology, transplantation and tissue engineering to design disease- and patient-specific remedies aimed at boosting either native rehabilitation or delivering exogenous hypoimmunogenic interventions. Advances in deciphering the blueprint of neural ontogenesis and annotation of the human genome has led to the development of targeted therapeutic opportunities that have the potential of treating the most vulnerable patient populations and whose findings from benchside suggest looming clinical translation. This review discusses how findings from studies of adult neurogenesis have informed development of interventions that target endogenous neural regenerative machineries and how advances in biotechnology, including the use of new gene-editing tools, have made possible the development of promising, complex neural transplant-based strategies. Adopting a multi-pronged strategy that is tailored to underlying neural pathology and that encompasses facilitation of endogenous regeneration, correction of patient’s genomic mutations and delivery of transformed neural precursors and mature disease-relevant neuronal populations to replace injured or lost neural tissue remains no longer a fantasy.

Combination of Human Mesenchymal Stem Cells and Repetitive Transcranial Magnetic Stimulation Enhances Neurological Recovery of 6-Hydroxydopamine Model of Parkinsonian's Disease

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has been in use for the treatment of various neurological diseases, including depression, anxiety, stroke and Parkinson's disease (PD), while its underlying mechanism is stills unclear. This study was undertaken to evaluate the potential synergism of rTMS treatment to the beneficial effect of human mesenchymal stem cells (hMSCs) administration for PD and to clarify the mechanism of action of this therapeutic approach.

METHODS

The neuroprotective effect in nigral dopamine neurons, neurotrophic/growth factors and anti-/pro-inflammatory cytokine regulation, and functional recovery were assessed in the rat 6-hydroxydopamine (6-OHDA) model of PD upon administration of hMSCs and rTMS.

RESULTS

Transplanted hMSCs were identified in the substantia nigra, and striatum. Enhancement of the survival of SN dopamine neurons and the expression of the tyrosine hydroxylase protein were observed in the hMSCs + rTMS compared to that of controls. Combination therapy significantly elevated the expression of several key neurotrophic factors, of which the highest expression was recorded in the rTMS + hMSC group. In addition, the combination therapy significantly upregulated IL-10 expression while decreased IFN-γ and TNF-α production in a synergistic manner. The treadmill locomotion test (TLT) revealed that motor function was improved in the rTMS + hMSC treatment with synergy.

CONCLUSION

Our findings demonstrate that rTMS treatment and hMSC transplantation could synergistically create a favorable microenvironment for cell survival within the PD rat brain, through alteration of soluble factors such as neurotrophic/growth factors and anti-/pro-inflammatory cytokines related to neuronal protection or repair, with preservation of DA neurons and improvement of motor functions.

Emerging regenerative medicine and tissue engineering strategies for Parkinson's disease

Parkinson's disease (PD) is the second most common progressive neurodegenerative disease, affecting 1-2% of people over 65. The classic motor symptoms of PD result from selective degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc), resulting in a loss of their long axonal projections to the striatum. Current treatment strategies such as dopamine replacement and deep brain stimulation (DBS) can only minimize the symptoms of nigrostriatal degeneration, not directly replace the lost pathway. Regenerative medicine-based solutions are being aggressively pursued with the goal of restoring dopamine levels in the striatum, with several emerging techniques attempting to reconstruct the entire nigrostriatal pathway-a key goal to recreate feedback pathways to ensure proper dopamine regulation. Although many pharmacological, genetic, and optogenetic treatments are being developed, this article focuses on the evolution of transplant therapies for the treatment of PD, including fetal grafts, cell-based implants, and more recent tissue-engineered constructs. Attention is given to cell/tissue sources, efficacy to date, and future challenges that must be overcome to enable robust translation into clinical use. Emerging regenerative medicine therapies are being developed using neurons derived from autologous stem cells, enabling the construction of patient-specific constructs tailored to their particular extent of degeneration. In the upcoming era of restorative neurosurgery, such constructs may directly replace SNpc neurons, restore axon-based dopaminergic inputs to the striatum, and ameliorate motor deficits. These solutions may provide a transformative and scalable solution to permanently replace lost neuroanatomy and improve the lives of millions of people afflicted by PD.

Intranasal Delivery of Bone Marrow Stromal Cells Preconditioned with Fasudil to Treat a Mouse Model of Parkinson's Disease

OBJECTIVE

Stem cell transplantation is a promising strategy with great potential to treat Parkinson's disease (PD). Nevertheless, improving the cell delivery route and optimising implanted cells are necessary to increase the therapeutic effect. Herein, we investigated whether intranasal delivery of bone marrow stromal cells (BMSCs) has beneficial effects in a PD mouse model and whether the therapeutic potential of BMSCs could be enhanced by preconditioning with fasudil.

METHODS

A PD mouse model was developed by intraperitoneally administering 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Mice were treated intranasally with phosphate buffered saline (PBS), BMSCs, or BMSCs preconditioned with fasudil. One month later, the effects of BMSC treatment were analysed.

RESULTS

Our study showed that fasudil could accelerate the proliferation of BMSCs and promote brain-derived neurotrophic factor (BDNF) secretion in vitro. Intranasally administered BMSCs were capable of surviving and migrating in the brain. Intranasal delivery of BMSCs preconditioned with fasudil significantly improved motor function and reduced dopaminergic neuron loss in substantia nigra; treatment with BMSCs and PBS resulted in similar outcomes. Preconditioning with fasudil inhibited the activation and aggregation of microglia, suppressed immune response, and reinforced BDNF secretion in MPTP-PD mice significantly more than treatment with BMSCs alone.

CONCLUSION

The present study demonstrates that intranasally administering BMSCs preconditioned with fasudil is a promising cell-based therapy for PD.

Golden Exosomes Selectively Target Brain Pathologies in Neurodegenerative and Neurodevelopmental Disorders

Exosomes, nanovesicles that are secreted by different cell types, enable intercellular communication at local or distant sites. Alhough they have been found to cross the blood brain barrier, their migration and homing abilities within the brain remain unstudied. We have recently developed a method for longitudinal and quantitative in vivo neuroimaging of exosomes based on the superior visualization abilities of classical X-ray computed tomography (CT), combined with gold nanoparticles as labeling agents. Here, we used this technique to track the migration and homing patterns of intranasally administrated exosomes derived from bone marrow mesenchymal stem cells (MSC-exo) in different brain pathologies, including stroke, autism, Parkinson's disease, and Alzheimer's disease. We found that MSC-exo specifically targeted and accumulated in pathologically relevant murine models brains regions up to 96 h post administration, while in healthy controls they showed a diffuse migration pattern and clearance by 24 h. The neuro-inflammatory signal in pathological brains was highly correlated with MSC-exo accumulation, suggesting that the homing mechanism is inflammatory-driven. In addition, MSC-exo were selectively uptaken by neuronal cells, but not glial cells, in the pathological regions. Taken together, these findings can significantly promote the application of exosomes for therapy and targeted drug delivery in various brain pathologies.

Therapy With Mesenchymal Stem Cells in Parkinson Disease: History and Perspectives

BACKGROUND

Parkinson disease (PD) is a neurodegenerative disorder affecting the basal nuclei, causing motor and cognitive disorders. Bearing in mind that standard treatments are ineffective in delaying the disease progression, alternative treatments capable of eliminating symptoms and reversing the clinical condition have been sought. Possible alternative treatments include cell therapy, especially with the use of mesenchymal stem cells (MSC).

REVIEW SUMMARY

MSC are adult stem cells which have demonstrated remarkable therapeutic power in parkinsonian animals due to their differentiation competence, migratory capacity and the production of bioactive molecules. This review aims to analyze the main studies involving MSC and PD in more than a decade of studies, addressing their different methodologies and common characteristics, as well as suggesting perspectives on the application of MSC in PD.

CONCLUSIONS

The results of MSC therapy in animal models and some clinical trials suggest that such cellular therapy may slow the progression of PD and promote neuroregeneration. However, further research is needed to address the limitations of an eventual clinical application.

MPP+ decreases store-operated calcium entry and TRPC1 expression in Mesenchymal Stem Cell derived dopaminergic neurons

Parkinson's disease is a neurodegenerative disorder involving the progressive loss of dopaminergic neurons (DNs), with currently available therapeutics, such as L-Dopa, only able to relieve some symptoms. Stem cell replacement is an attractive therapeutic option for PD patients, and DNs derived by differentiating patient specific stem cells under defined in-vitro conditions may present a viable opportunity to replace dying neurons. We adopted a previously published approach to differentiate Mesenchymal Stem Cells (MSCs) into DN using a 12-day protocol involving FGF-2, bFGF, SHH ligand and BDNF. While MSC-derived DNs have been characterized for neuronal markers and electrophysiological properties, we investigated store-operated calcium entry (SOCE) mechanisms of these DNs under normal conditions, and upon exposure to environmental neurotoxin, 1-methyl, 4-phenyl pyridinium ion (MPP+). Overall, we show that MSC-derived DNs are functional with regard to SOCE mechanisms, and MPP+ exposure dysregulates calcium signaling, making them vulnerable to neurodegeneration. Since in-vitro differentiation of MSCs into DNs is an important vehicle for PD disease modeling and regenerative medicine, the results of this study may help with understanding of the pathological mechanisms underlying PD.

Dextran-coated iron oxide nanoparticle-improved therapeutic effects of human mesenchymal stem cells in a mouse model of Parkinson's disease

Parkinson's disease (PD) is a prevalent neurodegenerative disease characterized by the loss of dopaminergic (DA) neurons. With their migration capacity toward the sites of diseased DA neurons in the PD brain, mesenchymal stem cells (MSCs) have the potential to differentiate to DA neurons for the replacement of damaged neurons and to secrete neurotrophic factors for the protection and regeneration of diseased DA neurons; therefore MSCs show promise for the treatment of PD. In this study, for the first time, we demonstrate that dextran-coated iron oxide nanoparticles (Dex-IO NPs) can improve the therapeutic efficacy of human MSCs (hMSCs) in a mouse model of PD induced by a local injection of 6-hydroxydopamine (6-OHDA). In situ examinations not only show that Dex-IO NPs can improve the rescue effect of hMSCs on the loss of host DA neurons but also demonstrate that Dex-IO NPs can promote the migration capacity of hMSCs toward lesioned DA neurons and induce the differentiation of hMSCs to DA-like neurons at the diseased sites. We prove that in vitro Dex-IO NPs can enhance the migration of hMSCs toward 6-OHDA-damaged SH-SY5Y-derived DA-like cells, induce hMSCs to differentiate to DA-like neurons in the conditioned media derived from 6-OHDA-damaged SH-SY5Y-derived DA-like cells and promote the protection/regeneration effects of hMSCs on 6-OHDA-damaged SH-SY5Y-derived DA-like cells. We confirm the potential of MSCs for cell-based therapy for PD. Dex-IO NPs can be used as a tool to accelerate and optimize MSC therapeutics for PD applicable clinically.

Neuroprotective Surgical Strategies in Parkinson's Disease: Role of Preclinical Data

Although there have been many pharmacological agents considered to be neuroprotective therapy in Parkinson's disease (PD) patients, neurosurgical approaches aimed to neuroprotect or restore the degenerative nigrostriatal system have rarely been the focus of in depth reviews. Here, we explore the neuroprotective strategies involving invasive surgical approaches (NSI) using neurotoxic models 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 6-hydroxydopamine (6-OHDA), which have led to clinical trials. We focus on several NSI approaches, namely deep brain stimulation of the subthalamic nucleus, glial neurotrophic derived factor (GDNF) administration and cell grafting methods. Although most of these interventions have produced positive results in preclinical animal models, either from behavioral or histological studies, they have generally failed to pass randomized clinical trials to validate each approach. We argue that NSI are promising approaches for neurorestoration in PD, but preclinical studies should be planned carefully in order not only to detect benefits but also to detect potential adverse effects. Further, clinical trials should be designed to be able to detect and disentangle neuroprotection from symptomatic effects. In summary, our review study evaluates the pertinence of preclinical models to study NSI for PD and how this affects their efficacy when translated into clinical trials.

Therapeutic effect of autologous compact bone-derived mesenchymal stem cell transplantation on prion disease

Prion diseases are fatal neurodegenerative disorders of humans and animals and no effective treatments are currently available. Allogenic transplantation of immortalized human mesenchymal stem cells (MSCs) can prolong the survival of mice infected with prions. However, autologous transplantation is an appropriate model for evaluating the effects of MSCs on prion diseases. Therefore, we isolated and purified MSCs from the femur and tibia of mice as compact bone-derived MSCs (CB-MSCs). Flow cytometric analysis showed that CB-MSCs were negative for myeloid stem cell-derived cell markers CD11b and CD45, but positive for molecules such as Sca-1, CD105 and CD90.2, which are reported to be expressed on MSCs. The ability of CB-MSCs to migrate to brain extracts from prion-infected mice was confirmed by an in vitro migration assay. Intra-hippocampus transplantation of CB-MSCs at 120 days post-inoculation marginally but significantly prolonged the survival of mice infected with the Chandler prion strain. The transplantation of CB-MSCs did not influence the accumulation of disease-specific prion protein. However, the CB-MSC transplantation enhanced microglial activation, which appeared to be polarized to the M2-type activation state. These results suggest that autologous MSC transplantation is a possible treatment for prion diseases, while the modification of microglial activation may be a therapeutic target for neurodegenerative diseases.

Concise Review: Mesenchymal Stem Cells in Neurodegenerative Diseases

Stem cell-based therapies for neurodegenerative diseases aim at halting clinical deterioration by regeneration and by providing local support for damaged tissue. Mesenchymal stem cells (MSCs) hold great potential for cell therapy as they can be efficiently derived from adult tissue, ex vivo expanded in culture and safely transplanted autologously. MSCs were also shown to be able to differentiate toward neural fates and to secrete a broad range of factors able to promote nervous tissue maintenance and repair. Moreover, upon transplantation, MSCs were shown capable of homing toward lesioned areas, implying their potential use as vehicles for therapeutic agents administration. Indeed, various advantageous effects were reported following human MSCs transplantation into rodent models of neurodegenerative diseases, such as neurotrophic factor-mediated protection, enhanced neurogenesis, modulation of inflammation, and abnormal protein aggregate clearance. Recent studies have also used ex vivo manipulation for enhanced expression of potentially favorable factors, by so exploiting the homing capacity of MSCs for effective expression at the lesion site. Here, we will summarize current advancements in MSCs-based therapies for neurodegenerative diseases. We will examine the roles of central mechanisms suggested to mediate the beneficial effects of MSCs-based therapy and consider the augmentation of these mechanisms for superior clinical outcomes in rodent models of neurodegeneration as well as in clinical trials.

Concise Review: Mesenchymal Stem Cells in Neurodegenerative Diseases

Stem cell-based therapies for neurodegenerative diseases aim at halting clinical deterioration by regeneration and by providing local support for damaged tissue. Mesenchymal stem cells (MSCs) hold great potential for cell therapy as they can be efficiently derived from adult tissue, ex vivo expanded in culture and safely transplanted autologously. MSCs were also shown to be able to differentiate toward neural fates and to secrete a broad range of factors able to promote nervous tissue maintenance and repair. Moreover, upon transplantation, MSCs were shown capable of homing toward lesioned areas, implying their potential use as vehicles for therapeutic agents administration. Indeed, various advantageous effects were reported following human MSCs transplantation into rodent models of neurodegenerative diseases, such as neurotrophic factor-mediated protection, enhanced neurogenesis, modulation of inflammation, and abnormal protein aggregate clearance. Recent studies have also used ex vivo manipulation for enhanced expression of potentially favorable factors, by so exploiting the homing capacity of MSCs for effective expression at the lesion site. Here, we will summarize current advancements in MSCs-based therapies for neurodegenerative diseases. We will examine the roles of central mechanisms suggested to mediate the beneficial effects of MSCs-based therapy and consider the augmentation of these mechanisms for superior clinical outcomes in rodent models of neurodegeneration as well as in clinical trials.

Concise Review: Mesenchymal Stem Cells in Neurodegenerative Diseases

Stem cell-based therapies for neurodegenerative diseases aim at halting clinical deterioration by regeneration and by providing local support for damaged tissue. Mesenchymal stem cells (MSCs) hold great potential for cell therapy as they can be efficiently derived from adult tissue, ex vivo expanded in culture and safely transplanted autologously. MSCs were also shown to be able to differentiate toward neural fates and to secrete a broad range of factors able to promote nervous tissue maintenance and repair. Moreover, upon transplantation, MSCs were shown capable of homing toward lesioned areas, implying their potential use as vehicles for therapeutic agents administration. Indeed, various advantageous effects were reported following human MSCs transplantation into rodent models of neurodegenerative diseases, such as neurotrophic factor-mediated protection, enhanced neurogenesis, modulation of inflammation, and abnormal protein aggregate clearance. Recent studies have also used ex vivo manipulation for enhanced expression of potentially favorable factors, by so exploiting the homing capacity of MSCs for effective expression at the lesion site. Here, we will summarize current advancements in MSCs-based therapies for neurodegenerative diseases. We will examine the roles of central mechanisms suggested to mediate the beneficial effects of MSCs-based therapy and consider the augmentation of these mechanisms for superior clinical outcomes in rodent models of neurodegeneration as well as in clinical trials.

Concise Review: Mesenchymal Stem Cells in Neurodegenerative Diseases

Stem cell-based therapies for neurodegenerative diseases aim at halting clinical deterioration by regeneration and by providing local support for damaged tissue. Mesenchymal stem cells (MSCs) hold great potential for cell therapy as they can be efficiently derived from adult tissue, ex vivo expanded in culture and safely transplanted autologously. MSCs were also shown to be able to differentiate toward neural fates and to secrete a broad range of factors able to promote nervous tissue maintenance and repair. Moreover, upon transplantation, MSCs were shown capable of homing toward lesioned areas, implying their potential use as vehicles for therapeutic agents administration. Indeed, various advantageous effects were reported following human MSCs transplantation into rodent models of neurodegenerative diseases, such as neurotrophic factor-mediated protection, enhanced neurogenesis, modulation of inflammation, and abnormal protein aggregate clearance. Recent studies have also used ex vivo manipulation for enhanced expression of potentially favorable factors, by so exploiting the homing capacity of MSCs for effective expression at the lesion site. Here, we will summarize current advancements in MSCs-based therapies for neurodegenerative diseases. We will examine the roles of central mechanisms suggested to mediate the beneficial effects of MSCs-based therapy and consider the augmentation of these mechanisms for superior clinical outcomes in rodent models of neurodegeneration as well as in clinical trials.

Concise Review: Mesenchymal Stem Cells in Neurodegenerative Diseases

Stem cell-based therapies for neurodegenerative diseases aim at halting clinical deterioration by regeneration and by providing local support for damaged tissue. Mesenchymal stem cells (MSCs) hold great potential for cell therapy as they can be efficiently derived from adult tissue, ex vivo expanded in culture and safely transplanted autologously. MSCs were also shown to be able to differentiate toward neural fates and to secrete a broad range of factors able to promote nervous tissue maintenance and repair. Moreover, upon transplantation, MSCs were shown capable of homing toward lesioned areas, implying their potential use as vehicles for therapeutic agents administration. Indeed, various advantageous effects were reported following human MSCs transplantation into rodent models of neurodegenerative diseases, such as neurotrophic factor-mediated protection, enhanced neurogenesis, modulation of inflammation, and abnormal protein aggregate clearance. Recent studies have also used ex vivo manipulation for enhanced expression of potentially favorable factors, by so exploiting the homing capacity of MSCs for effective expression at the lesion site. Here, we will summarize current advancements in MSCs-based therapies for neurodegenerative diseases. We will examine the roles of central mechanisms suggested to mediate the beneficial effects of MSCs-based therapy and consider the augmentation of these mechanisms for superior clinical outcomes in rodent models of neurodegeneration as well as in clinical trials.

Concise Review: Mesenchymal Stem Cells in Neurodegenerative Diseases

Stem cell-based therapies for neurodegenerative diseases aim at halting clinical deterioration by regeneration and by providing local support for damaged tissue. Mesenchymal stem cells (MSCs) hold great potential for cell therapy as they can be efficiently derived from adult tissue, ex vivo expanded in culture and safely transplanted autologously. MSCs were also shown to be able to differentiate toward neural fates and to secrete a broad range of factors able to promote nervous tissue maintenance and repair. Moreover, upon transplantation, MSCs were shown capable of homing toward lesioned areas, implying their potential use as vehicles for therapeutic agents administration. Indeed, various advantageous effects were reported following human MSCs transplantation into rodent models of neurodegenerative diseases, such as neurotrophic factor-mediated protection, enhanced neurogenesis, modulation of inflammation, and abnormal protein aggregate clearance. Recent studies have also used ex vivo manipulation for enhanced expression of potentially favorable factors, by so exploiting the homing capacity of MSCs for effective expression at the lesion site. Here, we will summarize current advancements in MSCs-based therapies for neurodegenerative diseases. We will examine the roles of central mechanisms suggested to mediate the beneficial effects of MSCs-based therapy and consider the augmentation of these mechanisms for superior clinical outcomes in rodent models of neurodegeneration as well as in clinical trials.

Concise Review: Mesenchymal Stem Cells in Neurodegenerative Diseases

Stem cell-based therapies for neurodegenerative diseases aim at halting clinical deterioration by regeneration and by providing local support for damaged tissue. Mesenchymal stem cells (MSCs) hold great potential for cell therapy as they can be efficiently derived from adult tissue, ex vivo expanded in culture and safely transplanted autologously. MSCs were also shown to be able to differentiate toward neural fates and to secrete a broad range of factors able to promote nervous tissue maintenance and repair. Moreover, upon transplantation, MSCs were shown capable of homing toward lesioned areas, implying their potential use as vehicles for therapeutic agents administration. Indeed, various advantageous effects were reported following human MSCs transplantation into rodent models of neurodegenerative diseases, such as neurotrophic factor-mediated protection, enhanced neurogenesis, modulation of inflammation, and abnormal protein aggregate clearance. Recent studies have also used ex vivo manipulation for enhanced expression of potentially favorable factors, by so exploiting the homing capacity of MSCs for effective expression at the lesion site. Here, we will summarize current advancements in MSCs-based therapies for neurodegenerative diseases. We will examine the roles of central mechanisms suggested to mediate the beneficial effects of MSCs-based therapy and consider the augmentation of these mechanisms for superior clinical outcomes in rodent models of neurodegeneration as well as in clinical trials.

Concise Review: Mesenchymal Stem Cells in Neurodegenerative Diseases

Stem cell-based therapies for neurodegenerative diseases aim at halting clinical deterioration by regeneration and by providing local support for damaged tissue. Mesenchymal stem cells (MSCs) hold great potential for cell therapy as they can be efficiently derived from adult tissue, ex vivo expanded in culture and safely transplanted autologously. MSCs were also shown to be able to differentiate toward neural fates and to secrete a broad range of factors able to promote nervous tissue maintenance and repair. Moreover, upon transplantation, MSCs were shown capable of homing toward lesioned areas, implying their potential use as vehicles for therapeutic agents administration. Indeed, various advantageous effects were reported following human MSCs transplantation into rodent models of neurodegenerative diseases, such as neurotrophic factor-mediated protection, enhanced neurogenesis, modulation of inflammation, and abnormal protein aggregate clearance. Recent studies have also used ex vivo manipulation for enhanced expression of potentially favorable factors, by so exploiting the homing capacity of MSCs for effective expression at the lesion site. Here, we will summarize current advancements in MSCs-based therapies for neurodegenerative diseases. We will examine the roles of central mechanisms suggested to mediate the beneficial effects of MSCs-based therapy and consider the augmentation of these mechanisms for superior clinical outcomes in rodent models of neurodegeneration as well as in clinical trials.

Concise Review: Mesenchymal Stem Cells in Neurodegenerative Diseases

Stem cell-based therapies for neurodegenerative diseases aim at halting clinical deterioration by regeneration and by providing local support for damaged tissue. Mesenchymal stem cells (MSCs) hold great potential for cell therapy as they can be efficiently derived from adult tissue, ex vivo expanded in culture and safely transplanted autologously. MSCs were also shown to be able to differentiate toward neural fates and to secrete a broad range of factors able to promote nervous tissue maintenance and repair. Moreover, upon transplantation, MSCs were shown capable of homing toward lesioned areas, implying their potential use as vehicles for therapeutic agents administration. Indeed, various advantageous effects were reported following human MSCs transplantation into rodent models of neurodegenerative diseases, such as neurotrophic factor-mediated protection, enhanced neurogenesis, modulation of inflammation, and abnormal protein aggregate clearance. Recent studies have also used ex vivo manipulation for enhanced expression of potentially favorable factors, by so exploiting the homing capacity of MSCs for effective expression at the lesion site. Here, we will summarize current advancements in MSCs-based therapies for neurodegenerative diseases. We will examine the roles of central mechanisms suggested to mediate the beneficial effects of MSCs-based therapy and consider the augmentation of these mechanisms for superior clinical outcomes in rodent models of neurodegeneration as well as in clinical trials.

Concise Review: Mesenchymal Stem Cells in Neurodegenerative Diseases

Stem cell-based therapies for neurodegenerative diseases aim at halting clinical deterioration by regeneration and by providing local support for damaged tissue. Mesenchymal stem cells (MSCs) hold great potential for cell therapy as they can be efficiently derived from adult tissue, ex vivo expanded in culture and safely transplanted autologously. MSCs were also shown to be able to differentiate toward neural fates and to secrete a broad range of factors able to promote nervous tissue maintenance and repair. Moreover, upon transplantation, MSCs were shown capable of homing toward lesioned areas, implying their potential use as vehicles for therapeutic agents administration. Indeed, various advantageous effects were reported following human MSCs transplantation into rodent models of neurodegenerative diseases, such as neurotrophic factor-mediated protection, enhanced neurogenesis, modulation of inflammation, and abnormal protein aggregate clearance. Recent studies have also used ex vivo manipulation for enhanced expression of potentially favorable factors, by so exploiting the homing capacity of MSCs for effective expression at the lesion site. Here, we will summarize current advancements in MSCs-based therapies for neurodegenerative diseases. We will examine the roles of central mechanisms suggested to mediate the beneficial effects of MSCs-based therapy and consider the augmentation of these mechanisms for superior clinical outcomes in rodent models of neurodegeneration as well as in clinical trials.

Ang II-AT2R increases mesenchymal stem cell migration by signaling through the FAK and RhoA/Cdc42 pathways in vitro

Background

Mesenchymal stem cells (MSCs) migrate via the bloodstream to sites of injury and are possibly attracted by inflammatory factors. As a proinflammatory mediator, angiotensin II (Ang II) reportedly enhances the migration of various cell types by signaling via the Ang II receptor in vitro. However, few studies have focused on the effects of Ang II on MSC migration and the underlying mechanisms.

Methods

Human bone marrow MSCs migration was measured using wound healing and Boyden chamber migration assays after treatments with different concentrations of Ang II, an AT1R antagonist (Losartan), and/or an AT2R antagonist (PD-123319). To exclude the effect of proliferation on MSC migration, we measured MSC proliferation after stimulation with the same concentration of Ang II. Additionally, we employed the focal adhesion kinase (FAK) inhibitor PF-573228, RhoA inhibitor C3 transferase, Rac1 inhibitor NSC23766, or Cdc42 inhibitor ML141 to investigate the role of cell adhesion proteins and the Rho-GTPase protein family (RhoA, Rac1, and Cdc42) in Ang II-mediated MSC migration. Cell adhesion proteins (FAK, Talin, and Vinculin) were detected by western blot analysis. The Rho-GTPase family protein activities were assessed by G-LISA and F-actin levels, which reflect actin cytoskeletal organization, were detected by using immunofluorescence.

Results

Human bone marrow MSCs constitutively expressed AT1R and AT2R. Additionally, Ang II increased MSC migration in an AT2R-dependent manner. Notably, Ang II-enhanced migration was not mediated by Ang II-mediated cell proliferation. Interestingly, Ang II-enhanced migration was mediated by FAK activation, which was critical for the formation of focal contacts, as evidenced by increased Talin and Vinculin expression. Moreover, RhoA and Cdc42 were activated by FAK to increase cytoskeletal organization, thus promoting cell contraction. Furthermore, FAK, Talin, and Vinculin activation and F-actin reorganization in response to Ang II were prevented by PD-123319 but not Losartan, indicating that FAK activation and F-actin reorganization were downstream of AT2R.

Conclusions

These data indicate that Ang II-AT2R regulates human bone marrow MSC migration by signaling through the FAK and RhoA/Cdc42 pathways. This study provides insights into the mechanisms by which MSCs home to injury sites and will enable the rational design of targeted therapies to improve MSC engraftment.

Concise Review: Mesenchymal Stem Cells in Neurodegenerative Diseases

Stem cell-based therapies for neurodegenerative diseases aim at halting clinical deterioration by regeneration and by providing local support for damaged tissue. Mesenchymal stem cells (MSCs) hold great potential for cell therapy as they can be efficiently derived from adult tissue, ex vivo expanded in culture and safely transplanted autologously. MSCs were also shown to be able to differentiate toward neural fates and to secrete a broad range of factors able to promote nervous tissue maintenance and repair. Moreover, upon transplantation, MSCs were shown capable of homing toward lesioned areas, implying their potential use as vehicles for therapeutic agents administration. Indeed, various advantageous effects were reported following human MSCs transplantation into rodent models of neurodegenerative diseases, such as neurotrophic factor-mediated protection, enhanced neurogenesis, modulation of inflammation, and abnormal protein aggregate clearance. Per journal style, most nonstandard abbreviations must be used at least two times in the abstract to be retained; NTF was used once and thus has been deleted. Recent studies have also used ex vivo manipulation for enhanced expression of potentially favorable factors, by so exploiting the homing capacity of MSCs for effective expression at the lesion site. Here, we will summarize current advancements in MSCs-based therapies for neurodegenerative diseases. We will examine the roles of central mechanisms suggested to mediate the beneficial effects of MSCs-based therapy and consider the augmentation of these mechanisms for superior clinical outcomes in rodent models of neurodegeneration as well as in clinical trials. Stem Cells 2017;35:1867-1880.

Feasibility and Efficacy of Intra-Arterial Administration of Mesenchymal Stem Cells in an Animal Model of Double Toxin-Induced Multiple System Atrophy

Multiple system atrophy (MSA) is a sporadic neurodegenerative disease of the central and autonomic nervous system. Because no drug treatment consistently benefits MSA patients, neuroprotective strategy using mesenchymal stem cells (MSCs) has a lot of concern for the management of MSA. In this study, we investigated the safety and efficacy of intra‐arterial administration of MSCs via internal carotid artery (ICA) in an animal model of MSA. The study was composed of feasibility test using a ×10 and ×50 of a standard dose of MSCs (4 × 10⁷ MSCs) and efficacy test using a ×0.2, ×2, and ×20 of the standard dose. An ultrasonic flow meter and magnetic resonance imaging (MRI) showed that no cerebral ischemic lesions with patent ICA blood flow was were observed in animals receiving a ×10 of the standard dose of MSCs. However, no MSA animals receiving a ×50 of the standard dose survived. In efficacy test, animals injected with a ×2 of the standard dose increased nigrostriatal neuronal survival relative to a ×0.2 or ×20 of the standard dose. MSA animals receiving MSCs at ×0.2 and ×2 concentrations of the standard dose exhibited a significant reduction in rotation behavior relative to ×20 of the standard dose of MSCs. Cerebral ischemic lesions on MRI were only observed in MSA animals receiving a ×20 of the standard dose. The present study revealed that if their concentration is appropriate, intra‐arterial injection of MSCs is safe and exerts a neuroprotective effect on striatal and nigral neurons with a coincidental improvement in motor behavior. Stem Cells Translational Medicine2017;6:1424–1433

Dissociation between dopaminergic response and motor behavior following intrastriatal, but not intravenous, transplant of bone marrow mononuclear stem cells in a mouse model of Parkinson's disease

Parkinson's disease is characterized by the progressive loss of dopaminergic neurons from the substantia nigra, a process that leads to a dopamine deficiency in the striatum. This deficiency is responsible for the development of motor symptoms, including resting tremor, bradykinesia, rigidity and postural instability. Based on the observation of substantial neuronal death, alternatives to Parkinson's disease treatment have been studied, including cell-based therapies. The present study aimed to assess the therapeutic potential of intravenous and intrastriatal transplant of bone marrow mononuclear cells in a mouse model of Parkinson's disease. Animals underwent stereotaxic surgery and received an injection of 6-hydroxydopamine into their medial forebrain bundle. Three weeks later, mice were injected with bone marrow mononuclear cells or saline through the caudal vein or directly into their right striatum. Motor function was assessed using the rotarod and apomorphine-induced rotation tests. Our results showed that intrastriatal bone marrow mononuclear cells, but not intravenous, have a short-term therapeutic effect on dopaminergic response in this mice model of parkinsonism assessed by the apomorphine-induced rotation test. This phenomenon was not identified on the rotarod test, showing dissociation between dopaminergic response and motor behavior. Further experiments are needed to elucidate the precise mechanisms involved in these effects.

Mesenchymal stem cell therapy in Parkinson's disease animal models

Parkinson's disease is a neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra, and as a consequence, by decreased dopamine levels in the striatum. Currently available therapies are not able to stop or reverse the progression of the disease. A novel therapeutic approach is based on cell therapy with stem cells, in order to replace degenerated neurons. Among stem cells, mesenchymal stem cells seemed the most promising thanks to their capacities to differentiate toward dopaminergic neurons and to release neurotrophic factors. Indeed, mesenchymal stem cells are able to produce different molecules with immunomodulatory, neuroprotective, angiogenic, chemotactic effects and that stimulate differentiation of resident stem cells. Mesenchymal stem cells were isolated for the first time from bone marrow, but can be collected also from adipose tissue, umbilical cord and other tissues. In this review, we focused our attention on mesenchymal stem cells derived from different sources and their application in Parkinson's disease animal models.

Dopaminergic-primed fetal liver mesenchymal stromal-like cells can reverse parkinsonian symptoms in 6-hydroxydopamine-lesioned mice

BACKGROUND AIMS

Cell replacement therapy is considered a promising alternative in the treatment of degenerative diseases, and in this context, mesenchymal stromal cells (MSCs) have been proposed for transplantation in Parkinson disease (PD). Thus far, the results of animal studies are found to be inconsistent and inconclusive regarding the therapeutic ability of the cells. This study investigated the efficacy of fetal liver (FL)-MSC-derived dopaminergic (DA) neuronal primed cells for correction of parkinsonian symptoms in mice.

METHODS

FL-MSCs were differentiated for 21 days in the presence of a combination of neurotropic factors. The extent of cellular reprogramming was analyzed by quantitative polymerase chain reaction for DA-specific neuronal gene expressions and protein expressions by immuno-cytochemistry. The functionality of the cells was determined by electrophysiology and dopamine release assays. Ten-day-primed neuron-like cells or unprimed MSCs were transplanted into the 6-hydroxydopamine (6-OHDA)-lesioned striatum using a stereotaxic device. Dopamine-secreting properties and behavioral studies were used to assess improvement of parkinsonian symptoms.

RESULTS

The differentiated cells expressed DA-specific genes and proteins, while exhibiting a high level of voltage-gated potassium current. Furthermore, neuronal primed cells differentiated into tyrosine hydroxylase immunoreactive and dopamine-secreting functional neuron-like cells. Symptomatic correction of PD in the recipient mice within 2 months of transplantation was also observed.

DISCUSSION

FL-MSC-derived primed neuron-like cells integrated into the striatum of PD mice, improving parkinsonian symptoms. This study demonstrates an effective cell-based therapy for PD.

Human adipose-derived mesenchymal stem cells improve motor functions and are neuroprotective in the 6-hydroxydopamine-rat model for Parkinson's disease when cultured in monolayer cultures but suppress hippocampal neurogenesis and hippocampal memory function when cultured in spheroids

Adult human adipose-derived mesenchymal stem cells (MSC) have been reported to induce neuroprotective effects in models for Parkinson's disease (PD). However, these effects strongly depend on the most optimal application of the transplant. In the present study we compared monolayer-cultured (aMSC) and spheroid (sMSC) MSC following transplantation into the substantia nigra (SN) of 6-OHDA lesioned rats regarding effects on the local microenvironment, degeneration of dopaminergic neurons, neurogenesis in the hippocampal DG as well as motor and memory function in the 6-OHDA-rat model for PD. aMSC transplantation significantly increased tyrosine hydroxylase (TH) and brain-derived neurotrophic factor (BDNF) levels in the SN, increased the levels of the glial fibrillary acidic protein (GFAP) and improved motor functions compared to untreated and sMSC treated animals. In contrast, sMSC grafting induced an increased local microgliosis, decreased TH levels in the SN and reduced numbers of newly generated cells in the dentate gyrus (DG) without yet affecting hippocampal learning and memory function. We conclude that the neuroprotective potential of adipose-derived MSC in the rat model of PD crucially depends on the applied cellular phenotype.

Mesenchymal stem cells for the treatment of neurodegenerative and psychiatric disorders

Mesenchymal stem cells (MSCs) are multipotent progenitor cells that have the capacity to differentiate into all lineages of mesodermal origin, e.g., cartilage, bone, and adipocytes. MSCs have been identified at different stages of development, including adulthood, and in different tissues, such as bone marrow, adipose tissue and umbilical cord. Recent studies have shown that MSCs have the ability to migrate to injured sites. In this regard, an important characteristic of MSCs is their immunomodulatory and anti-inflammatory effects. For instance, there is evidence that MSCs can regulate the immune system by inhibiting proliferation of T and B cells. Clinical interest in the use of MSCs has increased considerably over the past few years, especially because of the ideal characteristics of these cells for regenerative medicine. Therapies with MSCs have shown promising results neurodegenerative diseases, in addition to regulating inflammation, they can promote other beneficial effects, such as neuronal growth, decrease free radicals, and reduce apoptosis. Notwithstanding, despite the vast amount of research into MSCs in neurodegenerative diseases, the mechanism of action of MSCs are still not completely clarified, hindering the development of effective treatments. Conversely, studies in models of psychiatric disorders are scarce, despite the promising results of MSCs therapies in this field as well.

A Meta-Analysis of Mesenchymal Stem Cells in Animal Models of Parkinson's Disease

Multiple studies have been performed to evaluate the effects of mesenchymal stem cells (MSCs) in animal models of Parkinson's disease (PD). We performed a meta-analysis to estimate the treatment effect of unmodified MSCs on behavioral outcomes in preclinical studies of PD. We performed a systematic literature search to identify studies that used behavioral testing to evaluate the treatment effect of unmodified MSCs in PD models. Meta-analysis was used to determine pooled effect size for rotational behavior and limb function, and meta-regression was performed to explore sources of heterogeneity. Twenty-five studies, including three delivery routes, a wide range of doses, and multiple PD models, were examined. Significant improvement was seen in the pooled standardized mean difference (SMD) for both rotational behavior [SMD: 1.24, 95% confidence interval (95% CI): 0.84, 1.64] and limb function (SMD: 0.84, 95% CI: 0.01, 1.66). Using meta-regression, intravenous administration and higher dose had a larger effect on limb function. Treatment with MSCs improves behavioral outcomes in PD models. Our analyses suggest that MSCs could be considered for early-stage clinical trials in the treatment of PD.

Intracerebroventricular transplanted bone marrow stem cells survive and migrate into the brain of rats with Parkinson's disease

In this study, 6-hydroxydopamine was stereotaxically injected into the right substantia nigra compact and ventral tegmental area of rats to establish Parkinson's disease models. The rats then received a transplantation of bone marrow stromal cells that were previously isolated, cultured and labeled with 5-bromo-2'-deoxyuridine in vitro. Transplantation of the bone marrow stromal cells significantly decreased apomorphine-induced rotation time and the escape latency in the Morris water maze test as compared with rats with untreated Parkinson's disease. Immunohistochemical staining showed that, 5-bromo-2'-deoxyuridine-immunoreactive cells were present in the lateral ventricular wall and the choroid plexus 1 day after transplantation. These immunoreactive cells migrated to the surrounding areas of the lateral cerebral ventricle along the corpus callosum. The results indicated that bone marrow stromal cells could migrate to tissues surround the cerebral ventricle via the cerebrospinal fluid circulation and fuse with cells in the brain, thus altering the phenotype of cells or forming neuron-like cells or astrocytes capable of expressing neuron-specific proteins. Taken together, the present findings indicate that bone marrow stromal cells transplanted intracerebroventricularly could survive, migrate and significantly improve the rotational behavior and cognitive function of rats with experimentally induced Parkinson's disease.

Stem cell transplantation for treating Parkinson's disease: Literature analysis based on the Web of Science

OBJECTIVE:

To identify global research trends of stem cell transplantation for treating Parkinson's disease using a bibliometric analysis of the Web of Science.

DATA RETRIEVAL:

We performed a bibliometric analysis of data retrievals for stem cell transplantation for treating Parkinson's disease from 2002 to 2011 using the Web of Science.

SELECTION CRITERIA:

Inclusion criteria: (a) peer-reviewed articles on stem cell transplantation for treating Parkinson's disease which were published and indexed in the Web of Science; (b) type of articles: original research articles, reviews, meeting abstracts, proceedings papers, book chapters, editorial material and news items; (c) year of publication: 2002–2011. Exclusion criteria: (a) articles that required manual searching or telephone access; (b) we excluded documents that were not published in the public domain; (c) we excluded a number of corrected papers from the total number of articles.

MAIN OUTCOME MEASURES:

(1) Type of literature; (2) annual publication output; (3) distribution according to journals; (4) distribution according to subject areas; (5) distribution according to country; (6) distribution according to institution; (7) comparison of countries that published the most papers on stem cell transplantation from different cell sources for treating Parkinson's disease; (8) comparison of institutions that published the most papers on stem cell transplantation from different cell sources for treating Parkinson's disease in the Web of Science from 2002 to 2011; (9) comparison of studies on stem cell transplantation from different cell sources for treating Parkinson's disease

RESULTS:

In total, 1 062 studies on stem cell transplantation for treating Parkinson's disease appeared in the Web of Science from 2002 to 2011, almost one third of which were from American authors and institutes. The number of studies on stem cell transplantation for treating Parkinson's disease had gradually increased over the past 10 years. Papers on stem cell transplantation for treating Parkinson's disease appeared in journals such as Stem Cells and Experimental Neurology. Although the United States published more articles addressing neural stem cell and embryonic stem cell transplantation for treating Parkinson's disease, China ranked first for articles published on bone marrow mesenchymal stem cell transplantation for treating Parkinson's disease.

CONCLUSION:

From our analysis of the literature and research trends, we found that stem cell transplantation for treating Parkinson's disease may offer further benefits in regenerative medicine.

Polyglutamine (PolyQ) diseases: genetics to treatments

The polyglutamine (polyQ) diseases are a group of neurodegenerative disorders caused by expanded cytosine-adenine-guanine (CAG) repeats encoding a long polyQ tract in the respective proteins. To date, a total of nine polyQ disorders have been described: six spinocerebellar ataxias (SCA) types 1, 2, 6, 7, 17; Machado-Joseph disease (MJD/SCA3); Huntington's disease (HD); dentatorubral pallidoluysian atrophy (DRPLA); and spinal and bulbar muscular atrophy, X-linked 1 (SMAX1/SBMA). PolyQ diseases are characterized by the pathological expansion of CAG trinucleotide repeat in the translated region of unrelated genes. The translated polyQ is aggregated in the degenerated neurons leading to the dysfunction and degeneration of specific neuronal subpopulations. Although animal models of polyQ disease for understanding human pathology and accessing disease-modifying therapies in neurodegenerative diseases are available, there is neither a cure nor prevention for these diseases, and only symptomatic treatments for polyQ diseases currently exist. Long-term pharmacological treatment is so far disappointing, probably due to unwanted complications and decreasing drug efficacy. Cellular transplantation of stem cells may provide promising therapeutic avenues for restoration of the functions of degenerative and/or damaged neurons in polyQ diseases.

Improved dopamine transporter binding activity after bone marrow mesenchymal stem cell transplantation in a rat model of Parkinson's disease: small animal positron emission tomography study with F-18 FP-CIT

OBJECTIVES

We evaluated the effects of bone marrow-derived mesenchymal stem cells (BMSCs) in a model of Parkinson's disease (PD) using serial F-18 fluoropropylcarbomethoxyiodophenylnortropane (FP-CIT) PET.

METHODS

Hemiparkinsonian rats were treated with intravenously injected BMSCs, and animals without stem cell therapy were used as the controls. Serial FP-CIT PET was performed after therapy. The ratio of FP-CIT uptake in the lesion side to uptake in the normal side was measured. The changes in FP-CIT uptake were also analyzed using SPM. Behavioural and histological changes were observed using the rotational test and tyrosine hydroxylase (TH)-reactive cells.

RESULTS

FP-CIT uptake ratio was significantly different in the BMSCs treated group (n = 28) at each time point. In contrast, there was no difference in the ratio in control rats (n = 25) at any time point. SPM analysis also revealed that dopamine transporter binding activity was enhanced in the right basal ganglia area in only the BMSC therapy group. In addition, rats that received BMSC therapy also exhibited significantly improved rotational behaviour and preservation of TH-positive neurons compared to controls.

CONCLUSIONS

The therapeutic effect of intravenously injected BMSCs in a rat model of PD was confirmed by dopamine transporter PET imaging, rotational functional studies, and histopathological evaluation.

KEY POINTS

• Mesenchymal stem cells were intravenously injected to treat the PD rats • Dopamine transporter binding activity was improved after stem cell therapy • Stem cell therapy induced functional recovery and preservation of dopaminergic neurons • The effect of stem cells was confirmed by FP-CIT PET.

Human umbilical cord mesenchymal stem cells infected with adenovirus expressing HGF promote regeneration of damaged neuron cells in a Parkinson's disease model

Parkinson's disease (PD) is a neurodegenerative movement disorder that is characterized by the progressive degeneration of the dopaminergic (DA) pathway. Mesenchymal stem cells derived from human umbilical cord (hUC-MSCs) have great potential for developing a therapeutic agent as such. HGF is a multifunctional mediator originally identified in hepatocytes and has recently been reported to possess various neuroprotective properties. This study was designed to investigate the protective effect of hUC-MSCs infected by an adenovirus carrying the HGF gene on the PD cell model induced by MPP+ on human bone marrow neuroblastoma cells. Our results provide evidence that the cultural supernatant from hUC-MSCs expressing HGF could promote regeneration of damaged PD cells at higher efficacy than the supernatant from hUC-MSCs alone. And intracellular free Ca²⁺ obviously decreased after treatment with cultural supernatant from hUC-MSCs expressing HGF, while the expression of CaBP-D28k, an intracellular calcium binding protein, increased. Therefore our study clearly demonstrated that cultural supernatant of MSC overexpressing HGF was capable of eliciting regeneration of damaged PD model cells. This effect was probably achieved through the regulation of intracellular Ca²⁺ levels by modulating of CaBP-D28k expression.