Therapeutic efficacy of intranasally delivered mesenchymal stem cells in a rat model of Parkinson disease

Effects of mesenchymal stem cell on dopaminergic neurons, motor and memory functions in animal models of Parkinson's disease: a systematic review and meta-analysis

ABSTRACT

Parkinson's disease is characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta, and although restoring striatal dopamine levels may improve symptoms, no treatment can cure or reverse the disease itself. Stem cell therapy has a regenerative effect and is being actively studied as a candidate for the treatment of Parkinson's disease. Mesenchymal stem cells are considered a promising option due to fewer ethical concerns, a lower risk of immune rejection, and a lower risk of teratogenicity. We performed a meta-analysis to evaluate the therapeutic effects of mesenchymal stem cells and their derivatives on motor function, memory, and preservation of dopaminergic neurons in a Parkinson's disease animal model. We searched bibliographic databases (PubMed/MEDLINE, Embase, CENTRAL, Scopus, and Web of Science) to identify articles and included only peer-reviewed in vivo interventional animal studies published in any language through June 28, 2023. The study utilized the random-effect model to estimate the 95% confidence intervals (CI) of the standard mean differences (SMD) between the treatment and control groups. We use the systematic review center for laboratory animal experimentation's risk of bias tool and the collaborative approach to meta-analysis and review of animal studies checklist for study quality assessment. A total of 33 studies with data from 840 Parkinson's disease model animals were included in the meta-analysis. Treatment with mesenchymal stem cells significantly improved motor function as assessed by the amphetamine-induced rotational test. Among the stem cell types, the bone marrow MSCs with neurotrophic factor group showed largest effect size (SMD [95% CI] = -6.21 [-9.50 to -2.93], P = 0.0001, I2 = 0.0 %). The stem cell treatment group had significantly more tyrosine hydroxylase positive dopaminergic neurons in the striatum ([95% CI] = 1.04 [0.59 to 1.49], P = 0.0001, I2 = 65.1 %) and substantia nigra (SMD [95% CI] = 1.38 [0.89 to 1.87], P = 0.0001, I2 = 75.3 %), indicating a protective effect on dopaminergic neurons. Subgroup analysis of the amphetamine-induced rotation test showed a significant reduction only in the intracranial-striatum route (SMD [95% CI] = -2.59 [-3.25 to -1.94], P = 0.0001, I2 = 74.4 %). The memory test showed significant improvement only in the intravenous route (SMD [95% CI] = 4.80 [1.84 to 7.76], P = 0.027, I2 = 79.6 %). Mesenchymal stem cells have been shown to positively impact motor function and memory function and protect dopaminergic neurons in preclinical models of Parkinson's disease. Further research is required to determine the optimal stem cell types, modifications, transplanted cell numbers, and delivery methods for these protocols.

Potential convergence of olfactory dysfunction in Parkinson's disease and COVID-19: The role of neuroinflammation

Parkinson's disease (PD) is a prevalent neurodegenerative disorder that affects 7-10 million individuals worldwide. A common early symptom of PD is olfactory dysfunction (OD), and more than 90% of PD patients suffer from OD. Recent studies have highlighted a high incidence of OD in patients with SARS-CoV-2 infection. This review investigates the potential convergence of OD in PD and COVID-19, particularly focusing on the mechanisms by which neuroinflammation contributes to OD and neurological events. Starting from our fundamental understanding of the olfactory bulb, we summarize the clinical features of OD and pathological features of the olfactory bulb from clinical cases and autopsy reports in PD patients. We then examine SARS-CoV-2-induced olfactory bulb neuropathology and OD and emphasize the SARS-CoV-2-induced neuroinflammatory cascades potentially leading to PD manifestations. By activating microglia and astrocytes, as well as facilitating the aggregation of α-synuclein, SARS-CoV-2 could contribute to the onset or exacerbation of PD. We also discuss the possible contributions of NF-κB, the NLRP3 inflammasome, and the JAK/STAT, p38 MAPK, TLR4, IL-6/JAK2/STAT3 and cGAS-STING signaling pathways. Although olfactory dysfunction in patients with COVID-19 may be reversible, it is challenging to restore OD in patients with PD. With the emergence of new SARS-CoV-2 variants and the recurrence of infections, we call for continued attention to the intersection between PD and SARS-CoV-2 infection, especially from the perspective of OD.

Improvement of spatial learning and memory deficits by intranasal administration of human olfactory ecto-mesenchymal stem cells in an Alzheimer's disease rat model

Mesenchymal stem cells therapy provides a new perspective of therapeutic approaches in the treatment of neurodegenerative diseases. The present study aimed to investigate the effects of intranasally transplanted human "olfactory ecto-mesenchymal stem cells" (OE-MSCs) in Alzheimer's disease (AD) rats. In this study, we isolated OE-MSCs from human olfactory lamina propria and phenotypically characterized them using immunocytochemistry and flow cytometry. The undifferentiated OE-MSCs were transplanted either by intranasal (IN) or intrahippocampal (IH) injection to rat models of AD, which were induced by injecting amyloid-beta (Aβ) intrahippocampally. Behavioral, histological, and molecular assessments were performed after a three-month recovery period. Based on the results, intranasal administration of OE-MSCs significantly reduced Aβ accumulation and neuronal loss, improved learning and memory impairments, and increased levels of BDNF (brain-derived neurotrophic factor) and NMDAR (N-methyl-D-Aspartate receptors) in the AD rat model. These changes were more significant in animals who received OE-MSCs by intranasal injection. The results of this study suggest that OE-MSCs have the potential to enhance cognitive function in AD, possibly mediated by BDNF and the NMDA receptors.

Mesenchymal Stem Cell-Induced Neuroprotection in Pediatric Neurological Diseases: Recent Update of Underlying Mechanisms and Clinical Utility

Pediatric neurological diseases refer to a group of disorders that affect the nervous system in children. These conditions can have a significant impact on a child's development, cognitive function, motor skills, and overall quality of life. Stem cell therapy is a new and innovative approach to treat various neurological conditions by repairing damaged neurons and replacing those that have been lost. Mesenchymal stem cells (MSCs) have gained significant recognition in this regard due to their ability to differentiate into different cell types. MSCs are multipotent self-replicating stem cells known to render promising results in the treatment of stroke and spinal cord injury in adults. When delivered to the foci of damage in the central nervous system, stem cells begin to differentiate into neural cells under the stimulation of paracrine factors and secrete various neurotrophic factors (NTFs) like nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3) that expedite the repair process in injured neurons. In the present review, we will focus on the therapeutic benefits of the MSC-based therapies in salient pediatric neurological disorders including cerebral palsy, stroke, and autism.

Intranasal delivery of stem cells labeled by nanoparticles in neurodegenerative disorders: Challenges and opportunities

Neurodegenerative disorders occur through progressive loss of function or structure of neurons, with loss of sensation and cognition values. The lack of successful therapeutic approaches to solve neurologic disorders causes physical disability and paralysis and has a significant socioeconomic impact on patients. In recent years, nanocarriers and stem cells have attracted tremendous attention as a reliable approach to treating neurodegenerative disorders. In this regard, nanoparticle-based labeling combined with imaging technologies has enabled researchers to survey transplanted stem cells and fully understand their fate by monitoring their survival, migration, and differentiation. For the practical implementation of stem cell therapies in the clinical setting, it is necessary to accurately label and follow stem cells after administration. Several approaches to labeling and tracking stem cells using nanotechnology have been proposed as potential treatment strategies for neurological diseases. Considering the limitations of intravenous or direct stem cell administration, intranasal delivery of nanoparticle-labeled stem cells in neurological disorders is a new method of delivering stem cells to the central nervous system (CNS). This review describes the challenges and limitations of stem cell-based nanotechnology methods for labeling/tracking, intranasal delivery of cells, and cell fate regulation as theragnostic labeling. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease.

Routes and methods of neural stem cells injection in cerebral ischemia

Cerebral ischemia is a serious cerebrovascular disease with the characteristics of high morbidity, disability, and mortality. Currently, stem cell therapy has been extensively applied to a wide range of diseases, including neurological disorders, autoimmune deficits, and other diseases. Transplantation therapy with neural stem cells (NSCs) is a very promising treatment method, which not only has anti-inflammatory, antiapoptotic, promoting angiogenesis, and neurogenesis effects, but also can improve some side effects related to thrombolytic therapy. NSCs treatment could exert protective effects in alleviating cerebral ischemia-induced brain damage and neurological dysfunctions. However, the different injection routes and doses of NSCs determine diverse therapeutic efficacy. This review mainly summarizes the various injection methods and injection effects of NSCs in cerebral ischemia, as well as proposes the existing problems and prospects of NSCs transplantation.

Delivery of mutant huntingtin-lowering antisense oligonucleotides to the brain by intranasally administered apolipoprotein A-I nanodisks

Lowering mutant huntingtin (mHTT) in the central nervous system (CNS) using antisense oligonucleotides (ASOs) is a promising approach currently being evaluated in clinical trials for Huntington disease (HD). However, the therapeutic potential of ASOs in HD patients is limited by their inability to cross the blood-brain barrier (BBB). In non-human primates, intrathecal infusion of ASOs results in limited brain distribution, with higher ASO concentrations in superficial regions and lower concentrations in deeper regions, such as the basal ganglia. To address the need for improved delivery of ASOs to the brain, we are evaluating the therapeutic potential of apolipoprotein A-I nanodisks (apoA-I NDs) as novel delivery vehicles for mHTT-lowering ASOs to the CNS after intranasal administration. Here, we have demonstrated the ability of apoA-I nanodisks to bypass the BBB after intranasal delivery in the BACHD model of HD. Following intranasal administration of apoA-I NDs, apoA-I protein levels were elevated along the rostral-caudal brain axis, with highest levels in the most rostral brain regions including the olfactory bulb and frontal cortex. Double-label immunohistochemistry indicates that both the apoA-I and ASO deposit in neurons. Most importantly, a single intranasal dose of apoA-I ASO-NDs significantly reduces mHTT levels in the brain regions most affected in HD, namely the cortex and striatum. This approach represents a novel non-invasive means for improving delivery and brain distribution of oligonucleotide therapies and enhancing likelihood of efficacy. Improved ASO delivery to the brain has widespread application for treatment of many other CNS disorders.

Cell-Penetrating and Targeted Peptides Delivery Systems as Potential Pharmaceutical Carriers for Enhanced Delivery across the Blood-Brain Barrier (BBB)

Among the challenges to the 21st-century health care industry, one that demands special mention is the transport of drugs/active pharmaceutical agents across the blood-brain barrier (BBB). The epithelial-like tight junctions within the brain capillary endothelium hinder the uptake of most pharmaceutical agents. With an aim to understand more deeply the intricacies of cell-penetrating and targeted peptides as a powerful tool for desirable biological activity, we provide a critical review of both CPP and homing/targeted peptides as intracellular drug delivery agents, especially across the blood-brain barrier (BBB). Two main peptides have been discussed to understand intracellular drug delivery; first is the cell-penetrating peptides (CPPs) for the targeted delivery of compounds of interest (primarily peptides and nucleic acids) and second is the family of homing peptides, which specifically targets cells/tissues based on their overexpression of tumour-specific markers and are thus at the heart of cancer research. These small, amphipathic molecules demonstrate specific physical and chemical modifications aimed at increased ease of cellular internalisation. Because only a limited number of drug molecules can bypass the blood-brain barrier by free diffusion, it is essential to explore all aspects of CPPs that can be exploited for crossing this barrier. Considering siRNAs that can be designed against any target RNA, marking such molecules with high therapeutic potential, we present a synopsis of the studies on synthetic siRNA-based therapeutics using CPPs and homing peptides drugs that can emerge as potential drug-delivery systems as an upcoming requirement in the world of pharma- and nutraceuticals.

Safety and efficacy outcomes after intranasal administration of neural stem cells in cerebral palsy: a randomized phase 1/2 controlled trial

BACKGROUND

Neural stem cells (NSCs) are believed to have the most therapeutic potential for neurological disorders because they can differentiate into various neurons and glial cells. This research evaluated the safety and efficacy of intranasal administration of NSCs in children with cerebral palsy (CP). The functional brain network (FBN) analysis based on electroencephalogram (EEG) and voxel-based morphometry (VBM) analysis based on T1-weighted images were performed to evaluate functional and structural changes in the brain.

METHODS

A total of 25 CP patients aged 3-12 years were randomly assigned to the treatment group (n = 15), which received an intranasal infusion of NSCs loaded with nasal patches and rehabilitation therapy, or the control group (n = 10) received rehabilitation therapy only. The primary endpoints were the safety (assessed by the incidence of adverse events (AEs), laboratory and imaging examinations) and the changes in the Gross Motor Function Measure-88 (GMFM-88), the Activities of Daily Living (ADL) scale, the Sleep Disturbance Scale for Children (SDSC), and some adapted scales. The secondary endpoints were the FBN and VBM analysis.

RESULTS

There were only four AEs happened during the 24-month follow-up period. There was no significant difference in the laboratory examinations before and after treatment, and the magnetic resonance imaging showed no abnormal nasal and intracranial masses. Compared to the control group, patients in the treatment group showed apparent improvements in GMFM-88 and ADL 24 months after treatment. Compared with the baseline, the scale scores of the Fine Motor Function, Sociability, Life Adaptability, Expressive Ability, GMFM-88, and ADL increased significantly in the treatment group 24 months after treatment, while the SDSC score decreased considerably. Compared with baseline, the FBN analysis showed a substantial decrease in brain network energy, and the VBM analysis showed a significant increase in gray matter volume in the treatment group after NSCs treatment.

CONCLUSIONS

Our results showed that intranasal administration of NSCs was well-tolerated and potentially beneficial in children with CP.

TRIAL REGISTRATION

The study was registered in ClinicalTrials.gov (NCT03005249, registered 29 December 2016, https://www.

CLINICALTRIALS

gov/ct2/show/NCT03005249 ) and the Medical Research Registration Information System (CMR-20161129-1003).

Formulation considerations for improving intranasal delivery of CNS acting therapeutics

One of the principal impediments for the treatment of neurological conditions is the lack of ability of most of the medicinal agents to evade the blood–brain barrier. Among all the novel approaches to bypass the blood–brain barrier, nose to brain transport is the most patient compliant, non-invasive and effective approach. It directly transports drugs to the CNS via the trigeminal and olfactory nerves present in the nasal cavity. This review article focuses on anatomy and physiology of nasal cavity, potential of intranasal drug delivery, mechanisms of drug transport to brain, its advantages and limitations, novel intranasal formulations, marketed products, factors affecting nose to brain transport, formulation consideration of intranasal products and the future perspectives of CNS targeting via intranasal drug administration.

Human umbilical cord-derived mesenchymal stem cells promote repair of neonatal brain injury caused by hypoxia/ischemia in rats

Administration of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) is believed to be an effective method for treating neurodevelopmental disorders. In this study, we investigated the possibility of hUC-MSCs treatment of neonatal hypoxic/ischemic brain injury associated with maternal immune activation and the underlying mechanism. We established neonatal rat models of hypoxic/ischemic brain injury by exposing pregnant rats to lipopolysaccharide on day 16 or 17 of pregnancy. Rat offspring were intranasally administered hUC-MSCs on postnatal day 14. We found that polypyrimidine tract-binding protein-1 (PTBP-1) participated in the regulation of lipopolysaccharide-induced maternal immune activation, which led to neonatal hypoxic/ischemic brain injury. Intranasal delivery of hUC-MSCs inhibited PTBP-1 expression, alleviated neonatal brain injury-related inflammation, and regulated the number and function of glial fibrillary acidic protein-positive astrocytes, thereby promoting plastic regeneration of neurons and improving brain function. These findings suggest that hUC-MSCs can effectively promote the repair of neonatal hypoxic/ischemic brain injury related to maternal immune activation through inhibition of PTBP-1 expression and astrocyte activation.

Forthcoming complications in recovered COVID-19 patients with COPD and asthma; possible therapeutic opportunities

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been growing swiftly worldwide. Patients with background chronic pulmonary inflammations such as asthma or chronic obstructive pulmonary diseases (COPD) are likely to be infected with this virus. Of note, there is an argument that COVID-19 can remain with serious complications like fibrosis or other pathological changes in the pulmonary tissue of patients with chronic diseases. Along with conventional medications, regenerative medicine, and cell-based therapy could be alternative approaches to compensate for organ loss or restore injured sites using different stem cell types. Owing to unique differentiation capacity and paracrine activity, these cells can accelerate the healing procedure. In this review article, we have tried to scrutinize different reports related to the harmful effects of SARS-CoV-2 on patients with asthma and COPD, as well as the possible therapeutic effects of stem cells in the alleviation of post-COVID-19 complications. Video abstract.

Nose-to-Brain: The Next Step for Stem Cell and Biomaterial Therapy in Neurological Disorders

Neurological disorders are a leading cause of morbidity worldwide, giving rise to a growing need to develop treatments to revert their symptoms. This review highlights the great potential of recent advances in cell therapy for the treatment of neurological disorders. Through the administration of pluripotent or stem cells, this novel therapy may promote neuroprotection, neuroplasticity, and neuroregeneration in lesion areas. The review also addresses the administration of these therapeutic molecules by the intranasal route, a promising, non-conventional route that allows for direct access to the central nervous system without crossing the blood–brain barrier, avoiding potential adverse reactions and enabling the administration of large quantities of therapeutic molecules to the brain. Finally, we focus on the need to use biomaterials, which play an important role as nutrient carriers, scaffolds, and immune modulators in the administration of non-autologous cells. Little research has been conducted into the integration of biomaterials alongside intranasally administered cell therapy, a highly promising approach for the treatment of neurological disorders.

Intranasal delivery of biotechnology-based therapeutics

Biotechnology-based therapeutics include a wide range of products, such as recombinant hormones, stem cells, therapeutic enzymes, monoclonal antibodies, genes, vaccines, among others. The administration of these macromolecules has been studied via various routes. The nasal route is one of the promising routes of administration for biotechnology products owing to its easy delivery, the rich vascularity of the nasal mucosa, high absorption and targeted action. Several preclinical studies have been reported for nasal delivery of these products and many are at the clinical stage. This review focuses on biotechnology-based therapeutics administered via the intranasal route for treating various diseases.

Biopolymer Nanoparticles for Nose-to-Brain Drug Delivery: A New Promising Approach for the Treatment of Neurological Diseases

Diseases affecting the central nervous system (CNS) are among the most disabling and the most difficult to cure due to the presence of the blood–brain barrier (BBB) which represents an impediment from a therapeutic and diagnostic point of view as it limits the entry of most drugs. The use of biocompatible polymer nanoparticles (NPs) as vehicles for targeted drug delivery to the brain arouses increasing interest. However, the route of administration of these vectors remains critical as the drug must be delivered without being degraded to achieve a therapeutic effect. An innovative approach for the administration of drugs to the brain using polymeric carriers is represented by the nose-to-brain (NtB) route which involves the administration of the therapeutic molecule through the neuro-olfactory epithelium of the nasal mucosa. Nasal administration is a non-invasive approach that allows the rapid transport of the drug directly to the brain and minimizes its systemic exposure. To date, many studies involve the use of polymer NPs for the NtB transport of drugs to the brain for the treatment of a whole series of disabling neurological diseases for which, as of today, there is no cure. In this review, various types of biodegradable polymer NPs for drug delivery to the brain through the NtB route are discussed and particular attention is devoted to the treatment of neurological diseases such as Glioblastoma and neurodegenerative diseases.

Intranasally applied human olfactory mucosa neural progenitor cells migrate to damaged brain regions

Aim:

To determine if intranasally administered olfactory mucosa progenitor cells (OMPCs) migrate to damaged areas of brain.

Materials & methods:

Rowett Nude (RNU) adult rats were injured using the Marmarou model then 2 weeks later received intranasally-delivered human OMPC. After 3 weeks, rats were sacrificed and brain sectioned. The mean distances from the human OMPCs to markers for degenerative neuronal cell bodies (p-c-Jun⁺), axonal swellings on damaged axons (β-APP⁺) and random points in immunostained sections were quantified. One-way ANOVA was used to analyze data.

Results:

The human OMPCs were seen in specific areas of the brain near degenerating cell bodies and damaged axons.

Conclusion:

Intranasally delivered human OMPC selectively migrate to brain injury sites suggesting a possible noninvasive stem cell delivery for brain injury.

As a first step toward helping those with brain or spinal cord injury, human stem cells from the nose were applied to the inside of the nose of brain injured rats. These stem cells migrated to specific areas of damage in the brain. Stem cells from the nose are special, in that these cells continuously divide and form nerve cells. This study may lead to an uncomplicated treatment where tissue is taken from one side of the nose and later the stem cells from the tissue are delivered to the other side of the nose.

Photobiomodulation Therapy and Cell Therapy Improved Parkinson's Diseases by Neuro-regeneration and Tremor Inhibition

Introduction: Parkinson's disease (PD) is a progressive and severe neurodegenerative disorder of the central nervous system (CNS). The most prominent features of this disease are cell reduction in the substantia nigra and accumulation of α-synuclein, especially in the brainstem, spinal cord, and cortical areas. In addition to drug-based treatment, other therapies such as surgery, cell therapy, and laser therapy can be considered. In this study, articles on cell therapy and laser therapy for PD have been collected to evaluate the improvement of motor function, cell differentiation, and dopaminergic cell proliferation. Methods: Articles were collected from four electronic databases: PubMed, Scopus, Google Scholar, and Web of Science from 2010 to 2022. The keywords were "photobiomodulation", "low-level light therapy", "Low-level laser therapy", "near-infrared light", "Parkinson's disease", "Parkinsonism", and "stem cell therapy". About 100 related articles were included in the study. Results: The results of the studies showed that cell therapy and laser therapy are useful in the treatment of PD, and despite their limitations, they can be useful in improving PD. Conclusion: Concomitant use of cell therapy and photobiomodulation therapy can improve the symptoms of PD.

Rebuilding hippocampus neural circuit with hADSC-derived neuron cells for treating ischemic stroke

Background

Human adipose-derived stem cells (hADSCs) have been demonstrated to be a promising autologous stem cell source for treating various neuronal diseases. Our study indicated that hADSCs could be induced into neuron-like cells in a stepwise manner that are characterized by the positive expression of MAP2, SYNAPSIN 1/2, NF-200, and vGLUT and electrophysiological activity. We first primed hADSCs into neuron-like cells (hADSC-NCs) and then intracerebrally transplanted them into MCAO reperfusion mice to further explore their in vivo survival, migration, integration, fate commitment and involvement in neural circuit rebuilding.

Results

The hADSC-NCs survived well and transformed into MAP2-positive, Iba1- or GFAP-negative cells in vivo while maintaining some proliferative ability, indicated by positive Ki67 staining after 4 weeks. hADSC-NCs could migrate to multiple brain regions, including the cortex, hippocampus, striatum, and hypothalamus, and further differentiate into mature neurons, as confirmed by action potential elicitation and postsynaptic currents. With the aid of a cell suicide system, hADSC-NCs were proven to have functionally integrated into the hippocampal memory circuit, where they contributed to spatial learning and memory rescue, as indicated by LTP improvement and subsequent GCV-induced relapse. In addition to infarction size shrinkage and movement improvement, MCAO-reperfused mice showed bidirectional immune modulation, including inhibition of the local proinflammatory factors IL-1α, IL-1β, IL-2, MIP-1β and promotion proinflammatory IP-10, MCP-1, and enhancement of the anti-inflammatory factors IL-15.

Conclusion

Overall, hADSC-NCs used as an intermediate autologous cell source for treating stroke can rebuild hippocampus neuronal circuits through cell replacement.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-022-00774-x.

Evaluation of Recent Intranasal Drug Delivery Systems to the Central Nervous System

Neurological diseases continue to increase in prevalence worldwide. Combined with the lack of modifiable risk factors or strongly efficacious therapies, these disorders pose a significant and growing burden on healthcare systems and societies. The development of neuroprotective or curative therapies is limited by a variety of factors, but none more than the highly selective blood-brain barrier. Intranasal administration can bypass this barrier completely and allow direct access to brain tissues, enabling a large number of potential new therapies ranging from bioactive peptides to stem cells. Current research indicates that merely administering simple solutions is inefficient and may limit therapeutic success. While many therapies can be delivered to some degree without carrier molecules or significant modification, a growing body of research has indicated several methods of improving the safety and efficacy of this administration route, such as nasal permeability enhancers, gelling agents, or nanocarrier formulations. This review shall discuss promising delivery systems and their role in expanding the clinical efficacy of this novel administration route. Optimization of intranasal administration will be crucial as novel therapies continue to be studied in clinical trials and approved to meet the growing demand for the treatment of patients with neurological diseases.

Mesenchymal Stromal Cells Preconditioning: A New Strategy to Improve Neuroprotective Properties

Neurological diseases represent one of the main causes of disability in human life. Consequently, investigating new strategies capable of improving the quality of life in neurological patients is necessary. For decades, researchers have been working to improve the efficacy and safety of mesenchymal stromal cells (MSCs) therapy based on MSCs’ regenerative and immunomodulatory properties and multilinear differentiation potential. Therefore, strategies such as MSCs preconditioning are useful to improve their application to restore damaged neuronal circuits following neurological insults. This review is focused on preconditioning MSCs therapy as a potential application to major neurological diseases. The aim of our work is to summarize both the in vitro and in vivo studies that demonstrate the efficacy of MSC preconditioning on neuronal regeneration and cell survival as a possible application to neurological damage.

Intranasal application of stem cells and their derivatives as a new hope in the treatment of cerebral hypoxia/ischemia: a review

Intranasal delivery of stem cells and conditioned medium to target the brain has attracted major interest in the field of regenerative medicine. In pre-clinical investigations during the last ten years, several research groups focused on this strategy to treat cerebral hypoxia/ischemia in neonates as well as adults. In this review, we discuss the curative potential of stem cells, stem cell derivatives, and their delivery route via intranasal application to the hypoxic/ischemic brain. After intranasal application, stem cells migrate from the nasal cavity to the injured area and exert therapeutic effects by reducing brain tissue loss, enhancing endogenous neurogenesis, and modulating cerebral inflammation that leads to functional improvements. However, application of this administration route for delivering stem cells and/or therapeutic substances to the damaged sites requires further optimization to translate the findings of animal experiments to clinical trials.

Neurodegenerative diseases associated with non-coding CGG tandem repeat expansions

Non-coding CGG repeat expansions cause multiple neurodegenerative disorders, including fragile X-associated tremor/ataxia syndrome, neuronal intranuclear inclusion disease, oculopharyngeal myopathy with leukodystrophy, and oculopharyngodistal myopathy. The underlying genetic causes of several of these diseases have been identified only in the past 2-3 years. These expansion disorders have substantial overlapping clinical, neuroimaging and histopathological features. The shared features suggest common mechanisms that could have implications for the development of therapies for this group of diseases - similar therapeutic strategies or drugs may be effective for various neurodegenerative disorders induced by non-coding CGG expansions. In this Review, we provide an overview of clinical and pathological features of these CGG repeat expansion diseases and consider the likely pathological mechanisms, including RNA toxicity, CGG repeat-associated non-AUG-initiated translation, protein aggregation and mitochondrial impairment. We then discuss future research needed to improve the identification and diagnosis of CGG repeat expansion diseases, to improve modelling of these diseases and to understand their pathogenesis. We also consider possible therapeutic strategies. Finally, we propose that CGG repeat expansion diseases may represent manifestations of a single underlying neuromyodegenerative syndrome in which different organs are affected to different extents depending on the gene location of the repeat expansion.

Can intranasal administration of adipose-derived stem cells reach and affect the histological structure of distant organs of aged wistar rat?

Introduction

Stem cell therapy is a highly promising strategy in various degenerative diseases. Intranasal administration of stem cells could be considered as a non-invasive treatment option. However, there is great debate concerning the ability of stem cells to reach distant organs. It is also unclear in such a case if they can alleviate age-related structural changes in these organs.

Aim

The aim of this study is to evaluate the ability of intranasal administration of adipose-derived stem cells (ADSCs) to reach distant organs of rats at different time intervals and to investigate their effects on age-related structural changes in these organs.

Materials and Methods

Forty-nine female Wistar rats were used in this study, seven of which were adults (6-month-old) and 42 were aged (2-year-old). Rats were divided into three-groups: Group-I (adult control), Group-II (aged), and Group-III (aged ADSCs treated). Rats of Groups I and II were sacrificed after 15 days from the beginning of the experiment. Rats of Group III were treated with intranasal ADSCs and were sacrificed after 2-h, 1-day, 3-day, 5-day, and 15-day. Heart, liver, kidney, and spleen specimens were collected and processed for H and E, CD105 immunohistochemistry, and immunofluorescent techniques. Morphometric study and statistical analysis were performed.

Results

ADSCs appeared in all organs examined after 2-h of intranasal administration. Their maximum presence was detected after 3-day of administration, after which their immunofluorescence gradually decreased and nearly disappeared from these organs by the 15^th day. Improvement of some age-related deterioration in the structure of the kidney and liver occurred at day 5 after intranasal administration.

Conclusions

ADSCs effectively reached the heart, liver, kidney, and spleen after intranasal administration. ADSCs ameliorated some age-related changes in these organs.

Emerging trends in the delivery of nanoformulated oxytocin across Blood-Brain barrier

Neurological diseases are related to the central nervous system disorders and considered as serious cases. Several drugs are used to treat neurological diseases; however, to date the main issue is to design a therapeutic model which can cross the blood-brain-barrier (BBB) easily. The delivery of neuropeptides into the brain lays as one of the important routes for treating neurological disorders. Neuropeptides have been demonstrated as potential therapeutics for neurological disorders. Among numerous neuropeptides, the oxytocin (OT) hormone is of particular interest as it serves as a neurotransmitter in the brain as well as its role as a hormone. OT has a wide-range of activities in the brain and has a key role in cognitive, neuroendocrine, and social functions. However, OT does not cross the BBB readily coupled with its half-life in the blood being too short. The current literature reveals that the delivery of OT by nanoparticle-based drug delivery system (DDS) improves its efficacy. Nanoparticle based DDS are considered important tools for the targeted delivery of drugs to the brain as they lower toxicity of the drug and improve the drug efficacy. Nanoparticles are advantageous candidates for biomedical applications due to their distinctive characteristics such as quantum effects, large surface area and their ability to carry and transport the drug to its target site. OT can be delivered through oral and intranasal routes, but the bioavailability of OT inside the brain can further be enhanced by the delivery using nanoparticles. The application of nano-based delivery system not only improves the penetration of OT inside brain but also increases its half-life by the application of encapsulation and extended release. The aim of current review is to provide an overview of nanoparticle-based drug-delivery systems for the delivery of OT inside brain.

Mesenchymal Stem Cell Therapy: Hope for Patients With Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease. Although previous studies have demonstrated that SLE is related to the imbalance of cells in the immune system, including B cells, T cells, and dendritic cells, etc., the mechanisms underlying SLE pathogenesis remain unclear. Therefore, effective and low side-effect therapies for SLE are lacking. Recently, mesenchymal stem cell (MSC) therapy for autoimmune diseases, particularly SLE, has gained increasing attention. This therapy can improve the signs and symptoms of refractory SLE by promoting the proliferation of Th2 and Treg cells and inhibiting the activity of Th1, Th17, and B cells, etc. However, MSC therapy is also reported ineffective in some patients with SLE, which may be related to MSC- or patient-derived factors. Therefore, the therapeutic effects of MSCs should be further confirmed. This review summarizes the status of MSC therapy in refractory SLE treatment and potential reasons for the ineffectiveness of MSC therapy from three perspectives. We propose various MSC modification methods that may be beneficial in enhancing the immunosuppression of MSCs in SLE. However, their safety and protective effects in patients with SLE still need to be confirmed by further experimental and clinical evidence.

Therapeutic potentials of human microfluidic encapsulated conjunctival mesenchymal stem cells on the rat model of Parkinson's disease

BACKGROUND AND AIM

Parkinson's disease (PD) is a progressive neurodegenerative disorder caused by the destruction of the dopaminergic neurons in the nigrostriatal pathway, leading to motor-behavioral complications. Cell therapy has been proposed as a promising approach for PD treatment using various cellular sources. Despite a few disadvantages mesenchymal stem cells (MSCs) represent, they have more auspicious effects for PD cell therapy. The present study aimed to evaluate a new source of MSCs isolated from human Conjunctiva (CJ-MSCs) impact on PD complications for the first time.

MATERIALS AND METHODS

Parkinson's was induced by stereotactic injection of 6-hydroxydopamine (6-OHDA) into the right medial forebrain bundle (MFB). An apomorphine-induced rotation test was used to confirm the model establishment. After PD model confirmation, green fluorescent protein (GFP) labeled CJ-MSCs and induced CJ-MSCs (microfluidic encapsulated and non-capsulated) were transplanted into the rats' right striatum. Then Rotation, Rotarod, and Open-field tests were performed to evaluate the behavioral assessment. Additionally, the immunohistochemistry technique was used for identifying tyrosine hydroxylase (TH).

RESULTS

According to the obtained data, the cell transplantation caused a reduction in the rats' rotation number and improved locomotion compared to the control group. The previous results were also more pronounced in induced and microfluidic encapsulated cells compared to other cells. Rats recipient CJ-MSCs also have represented more TH-expressed GFP-labeled cell numbers in the striatum than the control group.

CONCLUSION

It can be concluded that CJ-MSCs therapy can have protective effects against PD complications and nerve induction of cells due to their ability to express dopamine. On the other hand, CJ-MSCs microencapsulating leads to enhance even more protective effect of CJ-MSCs. However, confirmation of this hypothesis requires further studies and investigation of these cells' possible mechanisms of action.

Intranasal delivery of mesenchymal stem cells-derived extracellular vesicles for the treatment of neurological diseases

Neurological disorders are diseases of the central nervous system (CNS), characterized by a progressive degeneration of cells and deficiencies in neural functions. Mesenchymal stem cells (MSCs) are a promising therapy for diseases and disorders of the CNS. Increasing evidence suggests that their beneficial abilities can be attributed to their paracrine secretion of extracellular vesicles (EVs). Administration of EVs that contain a mixture of proteins, lipids, and nucleic acids, resembling the secretome of MSCs, has been shown to mimic most of the effects of the parental cells. Moreover, the small size and safety profile of EVs provide a number of advantages over cell transplantation. Intranasal (IN) administration of EVs has been established as an effective and reliable way to bypass the blood-brain barrier (BBB) and deliver drugs to the CNS. In addition to pharmacological drugs, EVs can be loaded with a diverse range of cargo designed to modulate gene expression and protein functions in recipient cells, and lead to immunomodulation, neurogenesis, neuroprotection, and degradation of protein aggregates. In this review, we will explore the proposed physiological pathways by which EVs migrate through the nasal route to the CNS where they can actively target a region of injury or inflammation and exert their therapeutic effects. We will summarize the functional outcomes observed in animal models of neurological diseases following IN treatment with MSC-derived EVs. We will also examine key mechanisms that have been suggested to mediate the beneficial effects of EV-based therapy.

Direct differentiation of tonsillar biopsy-derived stem cells to the neuronal lineage

BACKGROUND

Neurological disorders are considered one of the greatest burdens to global public health and a leading cause of death. Stem cell therapies hold great promise for the cure of neurological disorders, as stem cells can serve as cell replacement, while also secreting factors to enhance endogenous tissue regeneration. Adult human multipotent stem cells (MSCs) reside on blood vessels, and therefore can be found in many tissues throughout the body, including palatine tonsils. Several studies have reported the capacity of MSCs to differentiate into, among other cell types, the neuronal lineage. However, unlike the case with embryonic stem cells, it is unclear whether MSCs can develop into mature neurons.

METHODS

Human tonsillar MSCs (T-MSCs) were isolated from a small, 0.6-g sample, of tonsillar biopsies with high viability and yield as we recently reported. Then, these cells were differentiated by a rapid, multi-stage procedure, into committed, post-mitotic, neuron-like cells using defined conditions.

RESULTS

Here we describe for the first time the derivation and differentiation of tonsillar biopsy-derived MSCs (T-MSCs), by a rapid, multi-step protocol, into post-mitotic, neuron-like cells using defined conditions without genetic manipulation. We characterized our T-MSC-derived neuronal cells and demonstrate their robust differentiation in vitro.

CONCLUSIONS

Our procedure leads to a rapid neuronal lineage commitment and loss of stemness markers, as early as three days following neurogenic differentiation. Our studies identify biopsy-derived T-MSCs as a potential source for generating neuron-like cells which may have potential use for in vitro modeling of neurodegenerative diseases or cell replacement therapies.

Stem Cells: Innovative Therapeutic Options for Neurodegenerative Diseases?

Neurodegenerative diseases are characterized by the progressive loss of structure and/or function of both neurons and glial cells, leading to different degrees of pathology and loss of cognition. The hypothesis of circuit reconstruction in the damaged brain via direct cell replacement has been pursued extensively so far. In this context, stem cells represent a useful option since they provide tissue restoration through the substitution of damaged neuronal cells with exogenous stem cells and create a neuro-protective environment through the release of bioactive molecules for healthy neurons, as well. These peculiar properties of stem cells are opening to potential therapeutic strategies for the treatment of severe neurodegenerative disorders, for which the absence of effective treatment options leads to an increasingly socio-economic burden. Currently, the introduction of new technologies in the field of stem cells and the implementation of alternative cell tissues sources are pointing to exciting frontiers in this area of research. Here, we provide an update of the current knowledge about source and administration routes of stem cells, and review light and shadows of cells replacement therapy for the treatment of the three main neurodegenerative disorders (Amyotrophic lateral sclerosis, Parkinson’s, and Alzheimer’s disease).

From Transcriptome to Behavior: Intranasal Injection of Late Passage Human Olfactory Stem Cells Displays Potential in a Rat Model of Parkinson's Disease

Parkinson's disease (PD) is one of the most common neurodegenerative disorders, which is caused by the loss of dopaminergic (DAergic) neurons. Thus, cell replacement therapy (CRT) might be regarded as an alternative therapy to effectively treat motor functional defects in PD patients. Human olfactory ectomesenchymal stem cells (OE-MSCs) are a novel type of mesenchymal stem cells (MSCs) with a strong tendency to differentiate into DAergic neurons. However, there are various barriers to successful CRT including the proliferation capacity of stem cells at higher passage numbers as well as the route of stem cell delivery. In this regard, we aimed to explore the efficacy of late passage OE-MSC administration through the intranasal (IN) route in PD rat models. Herein, the proliferation capacity of OE-MSCs was compared at early and late passage numbers; then, the results were validated via RNA sequencing analysis. Subsequently, the efficacy of IN injection of late passage OE-MSC in PD models was evaluated. The results manifested the absence of noticeable differences in proliferation capacity and signaling pathways in OE-MSCs at early and late passage numbers. Moreover, it was found that the IN administration of OE-MSCs with a high passage number substantially increased the levels of DAergic markers and improved the motor function in rat models of PD. Overall, our findings suggested that OE-MSCs with a high passage number are a promising CRT candidate due to their fundamental potential to provide a large number of cells with an enormous proliferation capacity. Moreover, they exhibit the high efficiency of IN administration as a noninvasive route of late-passage OE-MSC delivery for CRT, particularly for PD.

Estrogenic Plants: to Prevent Neurodegeneration and Memory Loss and Other Symptoms in Women After Menopause

In mammals, sexual hormones such as estrogens play an essential role in maintaining brain homeostasis and function. Estrogen deficit in the brain induces many undesirable symptoms such as learning and memory impairment, sleep and mood disorders, hot flushes, and fatigue. These symptoms are frequent in women who reached menopausal age or have had ovariectomy and in men and women subjected to anti-estrogen therapy. Hormone replacement therapy alleviates menopause symptoms; however, it can increase cardiovascular and cancer diseases. In the search for therapeutic alternatives, medicinal plants and specific synthetic and natural molecules with estrogenic effects have attracted widespread attention between the public and the scientific community. Various plants have been used for centuries to alleviate menstrual and menopause symptoms, such as Cranberry, Ginger, Hops, Milk Thistle, Red clover, Salvia officinalis, Soy, Black cohosh, Turnera diffusa, Ushuva, and Vitex. This review aims to highlight current evidence about estrogenic medicinal plants and their pharmacological effects on cognitive deficits induced by estrogen deficiency during menopause and aging.

Intranasal delivery of mitochondria for treatment of Parkinson's Disease model rats lesioned with 6-hydroxydopamine

The feasibility of delivering mitochondria intranasally so as to bypass the blood-brain barrier in treating Parkinson's disease (PD), was evaluated in unilaterally 6-OHDA-lesioned rats. Intranasal infusion of allogeneic mitochondria conjugated with Pep-1 (P-Mito) or unconjugated (Mito) was performed once a week on the ipsilateral sides of lesioned brains for three months. A significant improvement of rotational and locomotor behaviors in PD rats was observed in both mitochondrial groups, compared to sham or Pep-1-only groups. Dopaminergic (DA) neuron survival and recovery > 60% occurred in lesions of the substantia nigra (SN) and striatum in Mito and P-Mito rats. The treatment effect was stronger in the P-Mito group than the Mito group, but the difference was insignificant. This recovery was associated with restoration of mitochondrial function and attenuation of oxidative damage in lesioned SN. Notably, P-Mito suppressed plasma levels of inflammatory cytokines. Mitochondria penetrated the accessory olfactory bulb and doublecortin-positive neurons of the rostral migratory stream (RMS) on the ipsilateral sides of lesions and were expressed in striatal, but not SN DA neurons, of both cerebral hemispheres, evidently via commissural fibers. This study shows promise for intranasal delivery of mitochondria, confirming mitochondrial internalization and migration via RMS neurons in the olfactory bulb for PD therapy.

Magnetic Targeting of Human Olfactory Mucosa Stem Cells Following Intranasal Administration: a Novel Approach to Parkinson's Disease Treatment

Among the various therapeutic procedures used for improving PD, stem cell-based therapy has been shown to be a promising method. Olfactory ectomesenchymal stem cells (OE-MSCs) are a great source of stem cells for PD. Also, the intranasal administration (INA) of stem cells to the neural lesion has several advantages over the other approaches to cellular injections. However, improving the efficacy of INA to produce the highest number of cells at the lesion site has always been a controversial issue. For this purpose, this study was designed to apply the magnetically targeted cell delivery (MTCD) approach to OE-MSCs in the injured striatum area through the IN route in order to explore their outcomes in rat models of PD. Animals were randomly classified into four groups including control, PD model, treatment-NTC (treated with INA of non-target cells), and treatment-TC (treated with INA of target cells). The Alg-SPIONs-labeled OE-MSCs were stained successfully using the Prussian blue method with an intracellular iron concentration of 2.73 pg/cell. It was able to reduce signal intensity in the striatum region by increasing the number of these cells, as shown by the magnetic resonance imaging (MRI). Behavioral evaluation revealed that the administration of OE-MSCs with this novel advanced stem cell therapy alleviated Parkinson's motor dysfunction. Further, histological evaluations confirmed the functional enhancement of dopaminergic neuron cells by the expression of Nurr1, Dopamine transporter (DAT), and paired-like homeodomain transcription factor 3 (TH). Overall, this study showed that INA of OE-MSCs in the MTCD approach enhanced stem cells' therapeutic effects in PD models.

Mesenchymal Stem Cells for Neurological Disorders

Neurological disorders are becoming a growing burden as society ages, and there is a compelling need to address this spiraling problem. Stem cell-based regenerative medicine is becoming an increasingly attractive approach to designing therapies for such disorders. The unique characteristics of mesenchymal stem cells (MSCs) make them among the most sought after cell sources. Researchers have extensively studied the modulatory properties of MSCs and their engineering, labeling, and delivery methods to the brain. The first part of this review provides an overview of studies on the application of MSCs to various neurological diseases, including stroke, traumatic brain injury, spinal cord injury, multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's disease, Huntington's disease, Parkinson's disease, and other less frequently studied clinical entities. In the second part, stem cell delivery to the brain is focused. This fundamental but still understudied problem needs to be overcome to apply stem cells to brain diseases successfully. Here the value of cell engineering is also emphasized to facilitate MSC diapedesis, migration, and homing to brain areas affected by the disease to implement precision medicine paradigms into stem cell-based therapies.

Advances in intranasal application of stem cells in the treatment of central nervous system diseases

Stem cells are characterized by their self-renewal and multipotency and have great potential in the therapy of various disorders. However, the blood-brain barrier (BBB) limits the application of stem cells in the therapy of neurological disorders, especially in a noninvasive way. It has been shown that small molecular substances, macromolecular proteins, and even stem cells can bypass the BBB and reach the brain parenchyma following intranasal administration. Here, we review the possible brain-entry routes of transnasal treatment, the cell types, and diseases involved in intranasal stem cell therapy, and discuss its advantages and disadvantages in the treatment of central nervous system diseases, to provide a reference for the application of intranasal stem cell therapy.

Stem cell in neurodegenerative disorders; an emerging strategy

Neurodegenerative disorders are a diversity of disorders, surrounding Alzheimer's (AD), Parkinson's (PD), Huntington's diseases (HD), and amyotrophic lateral sclerosis (ALS) accompanied by some other less common diseases generally characterized by either developed deterioration of central or peripheral nervous system structurally or functionally. Today, with the viewpoint of an increasingly aging society, the number of patients with neurodegenerative diseases and sociomedical burdens will spread intensely. During the last decade, stem cell technology has attracted great attention for treating neurodegenerative diseases worldwide because of its unique attributes. As acknowledged, there are several categories of stem cells being able to proliferate and differentiate into various cellular lineages, highlighting their significance in the context of regenerative medicine. In preclinical models, stem cell therapy using mesenchymal stem/stromal cells (MSCs), hematopoietic stem cells (HSCs), and neural progenitor or stem cells (NPCs or NSCs) along with pluripotent stem cells (PSCs)-derived neuronal cells could elicit desired therapeutic effects, enabling functional deficit rescue partially. Regardless of the noteworthy progress in our scientific awareness and understanding of stem cell biology, there still exist various challenges to defeat. In the present review, we provide a summary of the therapeutic potential of stem cells and discuss the current status and prospect of stem cell strategy in neurodegenerative diseases, in particular, AD, PD, ALS, and HD.

Mechanisms of Intranasal Deferoxamine in Neurodegenerative and Neurovascular Disease

Identifying disease-modifying therapies for neurological diseases remains one of the greatest gaps in modern medicine. Herein, we present the rationale for intranasal (IN) delivery of deferoxamine (DFO), a high-affinity iron chelator, as a treatment for neurodegenerative and neurovascular disease with a focus on its novel mechanisms. Brain iron dyshomeostasis with iron accumulation is a known feature of brain aging and is implicated in the pathogenesis of a number of neurological diseases. A substantial body of preclinical evidence and early clinical data has demonstrated that IN DFO and other iron chelators have strong disease-modifying impacts in Alzheimer’s disease (AD), Parkinson’s disease (PD), ischemic stroke, and intracranial hemorrhage (ICH). Acting by the disease-nonspecific pathway of iron chelation, DFO targets each of these complex diseases via multifactorial mechanisms. Accumulating lines of evidence suggest further mechanisms by which IN DFO may also be beneficial in cognitive aging, multiple sclerosis, traumatic brain injury, other neurodegenerative diseases, and vascular dementia. Considering its known safety profile, targeted delivery method, robust preclinical efficacy, multiple mechanisms, and potential applicability across many neurological diseases, the case for further development of IN DFO is considerable.

Olfactory mucosa stem cells delivery via nasal route: a simple way for the treatment of Parkinson disease

Finding a simple and effective way for transferring cells to the brain lesion site with minimum side effects mounts a challenge in cell therapy. Cell delivery via nasal route using the bypassing the blood-brain barrier (BBB) property is a simple and non-invasive strategy without serious complications such as trauma. Therefore, it is a suitable technique to treat neurodegenerative disorders like Parkinson's disease (PD). Olfactory ectomesenchymal stem cells (OE-MSCs) located in the lamina propria of olfactory mucosa could be differentiated into dopaminergic neurons under in vitro and in vivo conditions. Thus, OE-MSCs represent a good source of Parkinson's stem cell-based therapy. In this research, we studied thirty male rats (n = 10 in each group) in three control (Ctl), lesion (LE), and intranasal administration (INA) groups to investigate the therapeutic effect of intranasal injection of OE-MSCs in the Parkinson's animal models. To do so, we examined the homing variation of OE-MSCs in different brain regions such as olfactory bulb (OB), cortex, striatum (Str), hippocampus (HPC), and substantia nigra (SN). The results of real-time PCR and immunohistochemistry (IHC) analysis showed the expression of dopaminergic neuron markers such as PITX3, PAX2, PAX5 (as dopaminergic neurons markers), tyrosine hydroxylase (TH), and dopamine transporter (DAT) 2 months after INA of 1 × 10⁶ OE-MSCs. The results confirmed that IN OE-MSCs delivery into the central nervous system (CNS) was powerful enough to improve the behavioral functions in the animal models of PD.

The potential therapy with dental tissue-derived mesenchymal stem cells in Parkinson's disease

Parkinson’s disease (PD), the second most common neurodegenerative disease worldwide, is caused by the loss of dopaminergic (DAergic) neurons in the substantia nigra resulting in a series of motor or non-motor disorders. Current treatment methods are unable to stop the progression of PD and may bring certain side effects. Cell replacement therapy has brought new hope for the treatment of PD. Recently, human dental tissue-derived mesenchymal stem cells have received extensive attention. Currently, dental pulp stem cells (DPSCs) and stem cells from human exfoliated deciduous teeth (SHED) are considered to have strong potential for the treatment of these neurodegenerative diseases. These cells are considered to be ideal cell sources for the treatment of PD on account of their unique characteristics, such as neural crest origin, immune rejection, and lack of ethical issues. In this review, we briefly describe the research investigating cell therapy for PD and discuss the application and progress of DPSCs and SHED in the treatment of PD. This review offers significant and comprehensive guidance for further clinical research on PD.

Stem cell-based therapy as a promising approach in Alzheimer's disease: current perspectives on novel treatment

Alzheimer's disease (AD) is a neuronal disorder with insidious onset and slow progression, leading to growing global concern with huge implications for individuals and society. The occurrence of AD has been increased and has become an important health issue throughout the world. In recent years, the care of more than 35 million patients with AD costs over $ 600 billion per year, it is approximately 1 percent of the global Gross Domestic Product. Currently, the therapeutic approach is not effective for neurological deficits especially after the development of these major neurological disorders. The discovery of the technique called cell-based therapy has shown promising results and made important conclusions beyond AD using the stem cells approach. Here we review recent progress on stem cell-based therapy in the context of AD.

Stem cell-based models and therapies: a key approach into schizophrenia treatment

Psychiatric disorders such as schizophrenia can generate distress and disability along with heavy costs on individuals and health care systems. Different genetic and environmental factors play a pivotal role in the appearance of the mentioned disorders. Since the conventional treatment options for psychiatric disorders are suboptimal, investigators are trying to find novel strategies. Herein, stem cell therapies have been recommended as novel choices. In this context, the preclinical examination of stem cell-based therapies specifically using appropriate models can facilitate passing strong filters and serious examination to ensure proper quality and safety of them as a novel treatment approach. Animal models cannot be adequately helpful to follow pathophysiological features. Nowadays, stem cell-based models, particularly induced pluripotent stem cells reflected as suitable alternative models in this field. Accordingly, the importance of stem cell-based models, especially to experiment with the regenerative medicine outcomes for schizophrenia as one of the severe typing of psychiatric disorders, is addressed here.

siRNA Therapeutics for Protein Misfolding Diseases of the Central Nervous System

Nanoparticles have been used to deliver siRNA to tissues and cells to silence specific genes in diverse organisms. Research and clinical application of nanoparticles like liposomes for drug delivery requires targeting them to specific anatomic regions or cell types, while avoiding off-target effects or clearance by the liver, kidney, or the immune system. Delivery to the central nervous system (CNS) presents additional challenges to cross the blood-brain barrier (BBB) to specific cell types like neurons, astrocytes, or glia. Here, we describe the generation of three different liposomal siRNA delivery vehicles to the CNS using the thin film hydration method. Utilizing cationic or anionic liposomes protects the siRNA from serum nucleases and proteases en route. To deliver the siRNA specifically to the CNS, the liposomes are complexed to a peptide that acts as a neuronal address by binding to nicotinic acetylcholine receptors (nAchRs). When injected intravenously or instilled intranasally, these liposome-siRNA-peptide complexes (LSPCs) or peptide addressed liposome-encapsulated therapeutic siRNA (PALETS) resist serum degradation, effectively cross the BBB, and deliver siRNA to AchR-expressing cells to suppress protein expression in the CNS.

Mesenchymal Stem Cells Successfully Deliver Oncolytic Virotherapy to Diffuse Intrinsic Pontine Glioma

PURPOSE

Diffuse intrinsic pontine glioma (DIPG) is among the deadliest of pediatric brain tumors. Radiotherapy is the standard-of-care treatment for DIPG, but offers only transient relief of symptoms for patients with DIPG without providing significant survival benefit. Oncolytic virotherapy is an anticancer treatment that has been investigated for treating various types of brain tumors.

EXPERIMENTAL DESIGN

Here, we have explored the use of mesenchymal stem cells (MSC) for oncolytic virus (OV) delivery and evaluated treatment efficacy using preclinical models of DIPG. The survivin promoter drives the conditional replication of OV used in our studies. The efficiency of OV entry into the cells is mediated by fiber modification with seven lysine residues (CRAd.S.pK7). Patients' samples and cell lines were analyzed for the expression of viral entry proteins and survivin. The ability of MSCs to deliver OV to DIPG was studied in the context of a low dose of irradiation.

RESULTS

Our results show that DIPG cells and tumors exhibit robust expression of cell surface proteins and survivin that enable efficient OV entry and replication in DIPG cells. MSCs loaded with OV disseminate within a tumor and release OV throughout the DIPG brainstem xenografts in mice. Administration of OV-loaded MSCs with radiotherapy to mice bearing brainstem DIPG xenografts results in more prolonged survival relative to that conferred by either therapy alone (P < 0.01).

CONCLUSIONS

Our study supports OV, CRAd.S.pK7, encapsulated within MSCs as a therapeutic strategy that merits further investigation and potential translation for DIPG treatment.

Intranasal Delivery: Effects on the Neuroimmune Axes and Treatment of Neuroinflammation

This review highlights the pre-clinical and clinical work performed to use intranasal delivery of various compounds from growth factors to stem cells to reduce neuroimmune interactions. We introduce the concept of intranasal (IN) delivery and the variations of this delivery method based on the model used (i.e., rodents, non-human primates, and humans). We summarize the literature available on IN delivery of growth factors, vitamins and metabolites, cytokines, immunosuppressants, exosomes, and lastly stem cells. We focus on the improvement of neuroimmune interactions, such as the activation of resident central nervous system (CNS) immune cells, expression or release of cytokines, and detrimental effects of signaling processes. We highlight common diseases that are linked to dysregulations in neuroimmune interactions, such as Alzheimer's disease, Parkinson's disease, stroke, multiple sclerosis, and traumatic brain injury.

Cell motility and migration as determinants of stem cell efficacy

BACKGROUND

Stem cells` (SC) functional heterogeneity and its poorly understood aetiology impedes clinical development of cell-based therapies in regenerative medicine and oncology. Recent studies suggest a strong correlation between the SC migration potential and their therapeutic efficacy in humans. Designating SC migration as a denominator of functional SC heterogeneity, we sought to identify highly migrating subpopulations within different SC classes and evaluate their therapeutic properties in comparison to the parental non-selected cells.

METHODS

We selected highly migrating subpopulations from mesenchymal and neural SC (sMSC and sNSC), characterized their features including but not limited to migratory potential, trophic factor release and transcriptomic signature. To assess lesion-targeted migration and therapeutic properties of isolated subpopulations in vivo, surgical transplantation and intranasal administration of MSCs in mouse models of glioblastoma and Alzheimer's disease respectively were performed.

FINDINGS

Comparison of parental non-selected cells with isolated subpopulations revealed superior motility and migratory potential of sMSC and sNSC in vitro. We identified podoplanin as a major regulator of migratory features of sMSC/sNSC. Podoplanin engineering improved oncovirolytic activity of virus-loaded NSC on distantly located glioblastoma cells. Finally, sMSC displayed more targeted migration to the tumour site in a mouse glioblastoma model and remarkably higher potency to reduce pathological hallmarks and memory deficits in transgenic Alzheimer's disease mice.

INTERPRETATION

Functional heterogeneity of SC is associated with their motility and migration potential which can serve as predictors of SC therapeutic efficacy.

FUNDING

This work was supported in part by the Robert Bosch Stiftung (Stuttgart, Germany) and by the IZEPHA grant.

Beyond the Hippocampus and the SVZ: Adult Neurogenesis Throughout the Brain

Convincing evidence has repeatedly shown that new neurons are produced in the mammalian brain into adulthood. Adult neurogenesis has been best described in the hippocampus and the subventricular zone (SVZ), in which a series of distinct stages of neuronal development has been well characterized. However, more recently, new neurons have also been found in other brain regions of the adult mammalian brain, including the hypothalamus, striatum, substantia nigra, cortex, and amygdala. While some studies have suggested that these new neurons originate from endogenous stem cell pools located within these brain regions, others have shown the migration of neurons from the SVZ to these regions. Notably, it has been shown that the generation of new neurons in these brain regions is impacted by neurologic processes such as stroke/ischemia and neurodegenerative disorders. Furthermore, numerous factors such as neurotrophic support, pharmacologic interventions, environmental exposures, and stem cell therapy can modulate this endogenous process. While the presence and significance of adult neurogenesis in the human brain (and particularly outside of the classical neurogenic regions) is still an area of debate, this intrinsic neurogenic potential and its possible regulation through therapeutic measures present an exciting alternative for the treatment of several neurologic conditions. This review summarizes evidence in support of the classic and novel neurogenic zones present within the mammalian brain and discusses the functional significance of these new neurons as well as the factors that regulate their production. Finally, it also discusses the potential clinical applications of promoting neurogenesis outside of the classical neurogenic niches, particularly in the hypothalamus, cortex, striatum, substantia nigra, and amygdala.

C-type lectin receptors Mcl and Mincle control development of multiple sclerosis-like neuroinflammation

Pattern recognition receptors (PRRs) are crucial for responses to infections and tissue damage; however, their role in autoimmunity is less clear. Herein we demonstrate that 2 C-type lectin receptors (CLRs) Mcl and Mincle play an important role in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Congenic rats expressing lower levels of Mcl and Mincle on myeloid cells exhibited a drastic reduction in EAE incidence. In vivo silencing of Mcl and Mincle or blockade of their endogenous ligand SAP130 revealed that these receptors’ expression in the central nervous system is crucial for T cell recruitment and reactivation into a pathogenic Th17/GM-CSF phenotype. Consistent with this, we uncovered MCL- and MINCLE-expressing cells in brain lesions of MS patients and we further found an upregulation of the MCL/MINCLE signaling pathway and an increased response following MCL/MINCLE stimulation in peripheral blood mononuclear cells from MS patients. Together, these data support a role for CLRs in autoimmunity and implicate the MCL/MINCLE pathway as a potential therapeutic target in MS.

Modulating endothelial adhesion and migration impacts stem cell therapies efficacy

BACKGROUND

Limited knowledge of stem cell therapies` mechanisms of action hampers their sustainable implementation into the clinic. Specifically, the interactions of transplanted stem cells with the host vasculature and its implications for their therapeutic efficacy are not elucidated. We tested whether adhesion receptors and chemokine receptors on stem cells can be functionally modulated, and consequently if such modulation may substantially affect therapeutically relevant stem cell interactions with the host endothelium.

METHODS

We investigated the effects of cationic molecule polyethylenimine (PEI) treatment with or without nanoparticles on the functions of adhesion receptors and chemokine receptors of human bone marrow-derived Mesenchymal Stem Cells (MSC). Analyses included MSC functions in vitro, as well as homing and therapeutic efficacy in rodent models of central nervous system´s pathologies in vivo.

FINDINGS

PEI treatment did not affect viability, immunomodulation or differentiation potential of MSC, but increased the CCR4 expression and functionally blocked their adhesion receptors, thus decreasing their adhesion capacity in vitro. Intravenously applied in a rat model of brain injury, the homing rate of PEI-MSC in the brain was highly increased with decreased numbers of adherent PEI-MSC in the lung vasculature. Moreover, in comparison to untreated MSC, PEI-MSC featured increased tumour directed migration in a mouse glioblastoma model, and superior therapeutic efficacy in a murine model of stroke.

INTERPRETATION

Balanced stem cell adhesion and migration in different parts of the vasculature and tissues together with the local microenvironment impacts their therapeutic efficacy.

FUNDING

Robert Bosch Stiftung, IZEPHA grant, EU grant 7 FP Health.