Electrospinning Approach for Preparing Nanostructured Scaffolds for Stem Cell Seeding and/or Implantation in Neurotrauma

Preparation of highly porous biocompatible and bioresorbable nerve conduit or scaffold by electrospinning based on synthetic polycaprolactone with a molecular weight of 80 kDa (PCL 80 kDa) has significance in the context of regenerative medicine with special emphasis on their application in neurotrauma. PCL conduits/scaffolds serving as a support structure for seeded stem cells show promising regenerative potential to promote functional recovery and tissue regeneration in models of neurotrauma. Here we describe a standard protocol for the production of conduits by electrospinning at high field-forming voltages (24kB) using a 6% solution of PCL 80 kDa in a chloroform/methanol mixture.

Eating disorder in children: Impact on quality of life, with a spotlight on autism spectrum disorder

Eating behavior, which includes eating habits and preferences, frequency of eating, and other features related to diet, is a major characteristic not only of a person's nutritional status, but also of health in general. In recent years, the prevalence of eating disorders in children has tended to increase; they also require cross-system approaches in diagnosis by a variety of specialists and correction requires appropriate selection of optimal methods. Maladaptive eating attitudes formed at an early age can contribute to the formation of eating disorders, which can lead to or worsen various neuropsychiatric diseases, digestive diseases, and other related conditions. In children with autism spectrum disorder (ASD), eating disorders often appear earlier than other major symptoms of the condition. However, the clinical manifestations of eating disorders in children with ASD are varied and differ in severity and duration, whereas these disorders in neurotypical children might present as short-lived and may not lead to serious consequences. Nevertheless, cases of progressive eating disorders accompanied by a child presenting as under- or overweight and/or with macronutrient and micronutrient deficiencies cannot be excluded. Given the high prevalence of eating disorders in children, many researchers have highlighted the lack of a valid and universally accepted instruments to assess atypical eating behaviors in this population. Therefore, in this review, we wanted to highlight the problems and causes of eating disorders in children, and also to analyze the existing approaches to the validation of these problems, taking into account the existing behavioral features in children with ASD.

Current methods for the microglia isolation: Overview and comparative analysis of approaches

Microglia represent a distinct population of neuroglia, constituting ~ 10% of all CNS cells and exhibit high plasticity. Proper functioning of microglia is critical in the event of CNS damage due to the rapid modulation of their functions. Microglia are not only the first stage of immune defense against injury and infection, contributing to both the innate and adaptive local immune response, but also play a vital role in maintaining homeostasis of the brain and spinal cord. For this reason, microglia deserve special attention in the study of neuropathological responses. Studying microglia behavior in various in vivo models of neuropathologies is certainly a priority, as it allows us to evaluate the behavior in the context of the changing microenvironment of nervous tissue. However, sometimes there are some technological problems that hinder the identification of the features of intercellular interactions, ensured cooperation between microglia and other cell types. In this regard, the use of in vitro models remains relevant today, contributing to a more in-depth understanding of the mechanisms of microglial involvement in neuropathology. The methods considered in this review for obtaining an isolated culture of microglia, along with their advantages and disadvantages, can help researchers in selecting the appropriate source and method for obtaining these cells, thereby opening up opportunities for gaining new neurobiological knowledge.

Increasing β-hexosaminidase A activity using genetically modified mesenchymal stem cells

GM2 gangliosidoses are a group of autosomal-recessive lysosomal storage disorders. These diseases result from a deficiency of lysosomal enzyme β-hexosaminidase A (HexA), which is responsible for GM2 ganglioside degradation. HexA deficiency causes the accumulation of GM2-gangliosides mainly in the nervous system cells, leading to severe progressive neurodegeneration and neuroinflammation. To date, there is no treatment for these diseases. Cell-mediated gene therapy is considered a promising treatment for GM2 gangliosidoses. This study aimed to evaluate the ability of genetically modified mesenchymal stem cells (MSCs-HEXA-HEXB) to restore HexA deficiency in Tay-Sachs disease patient cells, as well as to analyze the functionality and biodistribution of MSCs in vivo. The effectiveness of HexA deficiency cross-correction was shown in mutant MSCs upon interaction with MSCs-HEXA-HEXB. The results also showed that the MSCs-HEXA-HEXB express the functionally active HexA enzyme, detectable in vivo, and intravenous injection of the cells does not cause an immune response in animals. These data suggest that genetically modified mesenchymal stem cells have the potentials to treat GM2 gangliosidoses.

Cellular and Molecular Gradients in the Ventral Horns With Increasing Distance From the Injury Site After Spinal Cord Contusion

To identify cellular and molecular gradients following spinal cord injury (SCI), a rat contusion model of severe SCI was used to investigate the expression of NG2 and molecules that identify astrocytes and axons of the ventral horns (VH) at different distances on 7 and 30 days post-injury (dpi). A gradient of expression of NG2⁺/Olig2⁺ cells was determined, with the highest concentrations focused close to the injury site. A decrease in NG2 mean intensity correlates with a decrease in the number of NG2⁺ cells more distally. Immunoelectron microscopy subsequently revealed the presence of NG2 in connection with the membrane and within the cytoplasm of NG2⁺ glial cells and in large amounts within myelin membranes. Analysis of the astrocyte marker GFAP showed increased expression local to injury site from 7 dpi, this increase in expression spread more distally from the injury site by 30 dpi. Paradoxically, astrocyte perisynaptic processes marker GLT-1 was only increased in expression in areas remote from the epicenter, which was traced both at 7 and 30 dpi. Confocal microscopy showed a significant decrease in the number of 5-HT⁺ axons at a distance from the epicenter in the caudal direction, which is consistent with a decrease in β3-tubulin in these areas. The results indicate significant cellular and molecular reactions not only in the area of the gray matter damage but also in adjacent and remote areas, which is important for assessing the possibility of long-distance axonal growth.

Health care providers' awareness on medical management of children with autism spectrum disorder: cross-sectional study in Russia

BACKGROUND

Autism spectrum disorder (ASD) is a complex developmental range of conditions that involves difficulties with social interaction and restricted/repetitive behaviors. Unfortunately, health care providers often experience difficulties in diagnosis and management of individuals with ASD, and may have no knowledge about possible ways to overcome barriers in ASD patient interactions in healthcare settings. At the same time, the provision of appropriate medical services can have positive effects on habilitative progress, functional outcome, life expectancy and quality of life for individuals with ASD.

METHODS

This online survey research study evaluated the awareness and experience of students/residents (n = 247) and physicians (n = 100) in the medical management of children with ASD. It also gathered the views and experiences of caregivers to children with ASD (n = 158), all based in Russia.

RESULTS

We have established that the Russian medical community has limited ASD knowledge among providers, and have suggested possible reasons for this. Based on results from online surveys completed by students/residents, non-psychiatric physicians, and caregivers of children diagnosed with ASD, the main problems pertaining to medical management of individuals with ASD were identified. Possible problem solving solutions within medical practice were proposed.

CONCLUSIONS

The results from this study should be considered when implementing measures to improve healthcare practices, and when developing models for effective medical management, due to start not only in Russia but also in a number of other countries.

The Function of NG2/CSPG4-expressing Cells in the Rat Spinal Cord Injury: An Immunoelectron Microscopy Study

Emerging evidence supports an increased role for NG2/CSPG4-expressing cells in the process of neuroregeneration and synaptic plasticity, due to the increased production of multifunctional chondroitin sulfate proteoglycan (NG2/CSPG4). However, the response of NG2/CSPG4-expressing cells in spinal cord injury (SCI) remains to be elcudiated. Expression and distribution of NG2/CSPG4-expressing cells were studied by immunoelectron microscopy in the ventral horns (VH) of an intact and injured rat spinal cord. In the intact spinal cord, NG2/CSPG4 expression was detected on the cell membrane and in the cytoplasm of NG2 glia and was absent in neurons. Large amounts of NG2/CSPG4 were found on myelin membranes. The ability of intact astrocytes to produce NG2/CSPG4 was shown, although to a lesser extent than oligodendrocytes and NG2 glia. At 7 days after SCI at the Th8 level in the reactive glial zone of VH, the expression of NG2/CSPG4 sharply increased in NG2 glia at a distance of 3-5 mm and in reactive astrocytes were observed at all investigated distances caudally from the epicenter of injury. The obtained results indicate the presence of NG2/CSPG4-positive astrocytes in the intact spinal cord, and in the case of damage, an increase in the ability of reactive astrocytes to produce NG2/CSPG4. SCI leads to increased expression of NG2/CSPG4 by NG2 glia in the early stages after injury, which decreases with distance from the epicenter of the injury, as well as at later stages.

Effects of Transplanted Umbilical Cord Blood Mononuclear Cells Overexpressing GDNF on Spatial Memory and Hippocampal Synaptic Proteins in a Mouse Model of Alzheimer's Disease

BACKGROUND/OBJECTIVE

Alzheimer's disease (AD) is a progressive incurable neurodegenerative disorder. Glial cell line-derived neurotrophic factor (GDNF) is a prominent regulator of brain tissue and has an impressive potential for use in AD therapy. While its metabolism is still not fully understood, delivering neuropeptides such as GDNF via umbilical cord blood mononuclear cells (UCBMCs) to the sites of neurodegeneration is a promising approach in the development of innovative therapeutic avenues.

METHODS

UCBMCs were transduced with adenoviral vectors expressing GDNF and injected into AD transgenic mice. Various parameters including homing and survival of transplanted cells, expression of GDNF and synaptic proteins, as well as spatial memory were evaluated.

RESULTS

UCBMCs were observed in the hippocampus and cortex several weeks after transplantation, and their long-term presence was associated with improved spatial memory. Post-synaptic density protein 95 (PSD-95) and synaptophysin levels in the hippocampus were also effectively restored following the procedure in AD mice.

CONCLUSIONS

Our data indicate that gene-cell therapy with GDNF-overexpressing UCBMCs may produce long-lasting neuroprotection and stimulation of synaptogenesis. Such adenoviral constructs could potentially possess a high therapeutic potential for the treatment of AD.

Therapeutic Potential of Extracellular Vesicles for the Treatment of Nerve Disorders

The use of extracellular vesicles (EVs) as cell free therapy is a promising approach to stimulate tissue regeneration including that of the nervous system. EVs transfer bioactive proteins and lipids, RNA and microRNAs, which play a relevant role in EV-mediated intercellular communication. The immunomodulatory, anti-inflammatory, and neuroprotective effects of mesenchymal stem cells-derived EVs have been well studied, knowledge of this paracrine mechanism and the availability of these cells, positions mesenchymal stem cells as a potential source of EVs for cell free therapy for a variety of regenerative and nervous system disorders. In this review, we focus on the immunomodulatory and neuroprotective effects of stem cells-derived EVs within in vitro and in vivo models of nerve disorders.

Mesenchymal stem cells and the neuronal microenvironment in the area of spinal cord injury

Cell-based technologies are used as a therapeutic strategy in spinal cord injury (SCI). Mesenchymal stem cells (MSCs), which secrete various neurotrophic factors and cytokines, have immunomodulatory, anti-apoptotic and anti-inflammatory effects, modulate reactivity/phenotype of astrocytes and the microglia, thereby promoting neuroregeneration seem to be the most promising. The therapeutic effect of MSCs is due to a paracrine mechanism of their action, therefore the survival of MSCs and their secretory phenotype is of particular importance. Nevertheless, these data are not always reported in efficacy studies of MSC therapy in SCI. Here, we provide a review with summaries of preclinical trials data evaluating the efficacy of MSCs in animal models of SCI. Based on the data collected, we have tried (1) to establish the behavior of MSCs after transplantation in SCI with an evaluation of cell survival, migration potential, distribution in the area of injured and intact tissue and possible differentiation; (2) to determine the effects MSCs on neuronal microenvironment and correlate them with the efficacy of functional recovery in SCI; (3) to ascertain the conditions under which MSCs demonstrate their best survival and greatest efficacy.

Transplantation of Microglia in the Area of Spinal Cord Injury in an Acute Period Increases Tissue Sparing, but Not Functional Recovery

Microglial cells are known as important mediators of inflammation and immune response in the central nervous system (CNS). However, a neuroprotective role of these cells in post-traumatic processes should not be overlooked. Microglial cells are the first to respond to CNS injury and are further involved in all critical events of pathogenesis. When activated microglia clear the cellular debris and release anti- and proinflammatory cytokines and chemokines, nitric oxide, neurotrophins, and antioxidants capable of producing both neurotoxic and neuroprotective effects. The aim of this study was to determine to what extent the phagocytic activity of microglia in an acute period of spinal cord injury (SCI) in rats can effect the post-traumatic processes. For this purpose we implanted genetically modified Ad5-EGFP or Ad5-GDNF microglial cells into the area of acute SCI. Our experiments demonstrate that the area of intact tissue was lower in the group transplanted with Ad5-GDNF-transduced microglial cells with reduced phagocytic activity than that in the group of animals transplanted with Ad5-EGFP-transduced microglia cells which did not affect the cell activity. At the same time, there was no significant difference in the functional recovery index between these groups. Thus, the increased number of microglia cells with good phagocytic activity in the area of acute SCI may contribute to the improved nervous tissue integrity without a significant effect on the functional recovery within 30 days after injury.

Adipose-Derived Mesenchymal Stem Cell Application Combined With Fibrin Matrix Promotes Structural and Functional Recovery Following Spinal Cord Injury in Rats

The use of stem and progenitor cells to restore damaged organs and tissues, in particular, the central nervous system, is currently considered a most promising therapy in regenerative medicine. At the same time, another approach aimed at stimulating regeneration with the use of stem cells encapsulated into a biopolymer matrix and capable of creating a specific microenvironment for the implanted cells similar to the natural extracellular matrix is under active development. Here, we study effects of the application of adipose-derived mesenchymal stem cells (AD-MSCs) combined with a fibrin matrix on post-traumatic reactions in the spinal cord in rats. The AD-MSC application is found to exert a positive impact on the functional and structural recovery after spinal cord injury (SCI) that has been confirmed by the results of behavioral/electrophysiological and morphometric studies demonstrating reduced area of abnormal cavities and enhanced tissue retention in the site of injury. Immunohistochemical and real-time PCR analyses provide evidence that AD-MSC application decreases the GFAP expression in the area of SCI that might indicate the reduction of astroglial activation. Our results also demonstrate that AD-MSC application contributes to marked upregulation of PDGFβR and HSPA1b mRNA expression and decrease of Iba1 expression at the site of the central canal. Thus, the application of AD-MSCs combined with fibrin matrix at the site of SCI during the subacute period can stimulate important mechanisms of nervous tissue regeneration and should be further developed for clinical applications.

Allogenic Adipose Derived Stem Cells Transplantation Improved Sciatic Nerve Regeneration in Rats: Autologous Nerve Graft Model

We examined the effect of transplantation of allogenic adipose-derived stem cells (ADSCs) with properties of mesenchymal stem cells (MSCs) on posttraumatic sciatic nerve regeneration in rats. We suggested an approach to rat sciatic nerve reconstruction using the nerve from the other leg as a graft. The comparison was that of a critical 10 mm nerve defect repaired by means of autologous nerve grafting versus an identical lesion on the contralateral side. In this experimental model, the same animal acts simultaneously as a test model, and control. Regeneration of the left nerve was enhanced by the use of ADSCs, whereas the right nerve healed under natural conditions. Thus the effects of individual differences were excluded and a result closer to clinical practice obtained. We observed significant destructive changes in the sciatic nerve tissue after surgery which resulted in the formation of combined contractures in knee and ankle joints of both limbs and neurotrophic ulcers only on the right limb. The stimulation of regeneration by ADSCs increased the survival of spinal L5 ganglia neurons by 26.4%, improved sciatic nerve vascularization by 35.68% and increased the number of myelin fibers in the distal nerve by 41.87%. Moreover, we have demonstrated that S100, PMP2, and PMP22 gene expression levels are suppressed in response to trauma as compared to intact animals. We have shown that ADSC-based therapy contributes to significant improvement in the regeneration.

Systemic and Local Cytokine Profile following Spinal Cord Injury in Rats: A Multiplex Analysis

Our study of the changes in cytokine profile in blood serum and in the spinal cord after traumatic spinal cord injury (SCI) has shown that an inflammatory reaction and immunological response are not limited to the CNS, but widespread. This fact was confirmed by changes detected in a cytokine profile in blood serum samples [MIP-1α, interleukin 1 (IL-1) α, IL-2, IL-5, IL-1β, MCP-1, RANTES]. There were also changes in the levels of MIP-1α, IL-1α, IL-2, IL-5, IL-18, GM-colony-stimulating factor, IL-17α, IFN-γ, IL-10, IL-13, MCP-1, and GRO KC CINC-1 in samples of the rat injured spinal cord. The results underscore the complex cytokine network imbalance exhibited after SCI and show significant changes in the concentrations of 14 cytokines/chemokines with different inflammatory and immunological activities.

Human Umbilical Cord Blood Cell Transplantation in Neuroregenerative Strategies

At present there is no effective treatment of pathologies associated with the death of neurons and glial cells which take place as a result of physical trauma or ischemic lesions of the nervous system. Thus, researchers have high hopes for a treatment based on the use of stem cells (SC), which are potentially able to replace dead cells and synthesize neurotrophic factors and other molecules that stimulate neuroregeneration. We are often faced with ethical issues when selecting a source of SC. In addition to precluding these, human umbilical cord blood (hUCB) presents a number of advantages when compared with other sources of SC. In this review, we consider the key characteristics of hUCB, the results of various studies focused on the treatment of neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis), ischemic (stroke) and traumatic injuries of the nervous system and the molecular mechanisms of hUCB-derived mononuclear and stem cells.

Assessment of Glial Scar, Tissue Sparing, Behavioral Recovery and Axonal Regeneration following Acute Transplantation of Genetically Modified Human Umbilical Cord Blood Cells in a Rat Model of Spinal Cord Contusion

OBJECTIVE AND METHODS

This study investigated the potential for protective effects of human umbilical cord blood mononuclear cells (UCB-MCs) genetically modified with the VEGF and GNDF genes on contusion spinal cord injury (SCI) in rats. An adenoviral vector was constructed for targeted delivery of VEGF and GDNF to UCB-MCs. Using a rat contusion SCI model we examined the efficacy of the construct on tissue sparing, glial scar severity, the extent of axonal regeneration, recovery of motor function, and analyzed the expression of the recombinant genes VEGF and GNDF in vitro and in vivo.

RESULTS

Transplantation of UCB-MCs transduced with adenoviral vectors expressing VEGF and GDNF at the site of SCI induced tissue sparing, behavioral recovery and axonal regeneration comparing to the other constructs tested. The adenovirus encoding VEGF and GDNF for transduction of UCB-MCs was shown to be an effective and stable vehicle for these cells in vivo following the transplantation into the contused spinal cord.

CONCLUSION

Our results show that a gene delivery using UCB-MCs-expressing VEGF and GNDF genes improved both structural and functional parameters after SCI. Further histological and behavioral studies, especially at later time points, in animals with SCI after transplantation of genetically modified UCB-MCs (overexpressing VEGF and GDNF genes) will provide additional insight into therapeutic potential of such cells.

Construction of recombinant adenovirus containing picorna-viral 2A-peptide sequence for the co-expression of neuro-protective growth factors in human umbilical cord blood cells

STUDY DESIGN

Experimental study.

OBJECTIVE

Several neuro-degenerative disorders such as Alzheimer's dementia, Parkinson's disease and amyotrophic lateral sclerosis (ALS) are associated with genetic mutations, and replacing or disrupting defective sequences might offer therapeutic benefits. Single gene delivery has so far failed to achieve significant clinical improvements in humans, leading to the advent of co-expression of multiple therapeutic genes. Co-transfection using two or more individual constructs might inadvertently result in disproportionate delivery of the products into the cells. To prevent this, and in order to rule out interference among the many promoters with varying strength, expressing multiple proteins in equimolar amounts can be achieved by linking open reading frames under the control of only one promoter.

SETTING

Kazan, Russian Federation.

METHODS

Here we describe a strategy for adeno-viral co-expression of vascular endothelial growth factor (VEGF) and fibroblast growth factor 2 (FGF2) interconnected through picorna-viral 2A-amino-acid sequence in transfected human umbilical cord blood mono-nuclear cells (hUCB-MCs).

RESULTS

Presence of both growth factors, as well as absence of immune response to 2A-antigen, was demonstrated after 28-52 days. Following injection of hUCB-MCs into ALS transgenic mice, co-expression of VEGF and FGF2, as well as viable xeno-transplanted cells, were observed in the spinal cord after 1 month.

CONCLUSION

These results suggest that recombinant adeno-virus containing 2A-sequences could serve as a promising alternative in regenerative medicine for the delivery of therapeutic molecules to treat neurodegenerative diseases, such as ALS.

Adenoviral vector carrying glial cell-derived neurotrophic factor for direct gene therapy in comparison with human umbilical cord blood cell-mediated therapy of spinal cord injury in rat

STUDY DESIGN

Experimental study.

OBJECTIVE

To evaluate the treatment of spinal cord injury with glial cell-derived neurotrophic factor (GDNF) delivered using an adenoviral vector (AdV-GDNF group) in comparison with treatment performed using human umbilical cord blood mononuclear cells (UCB-MCs)-transduced with an adenoviral vector carrying the GDNF gene (UCB-MCs+AdV-GDNF group) in rat.

SETTING

Kazan, Russian Federation.

METHODS

We examined the efficacy of AdV-GDNF and UCB-MCs+AdV-GDNF therapy by conducting behavioral tests on the animals and morphometric studies on the spinal cord, performing immunofluorescence analyses on glial cells, investigating the survival and migration potential of UCB-MCs, and evaluating the expression of the recombinant GDNF gene.

RESULTS

At the 30th postoperative day, equal positive locomotor recovery was observed after both direct and cell-based GDNF therapy. However, after UCB-MCs-mediated GDNF therapy, the area of preserved tissue and the number of spared myelinated fibers were higher than those measured after direct GDNF gene therapy. Moreover, we observed distinct changes in the populations of glial cells; expression patterns of the specific markers for astrocytes (GFAP, S100B and AQP4), oligodendrocytes (PDGFαR and Cx47) and Schwann cells (P0) differed in various areas of the spinal cord of rats treated with AdV-GDNF and UCB-MCs+AdV-GDNF.

CONCLUSION

The differences detected in the AdV-GDNF and UCB-MCs+AdV-GDNF groups could be partially explained by the action of UCB-MCs. We discuss the insufficiency and the advantages of these two methods of GDNF gene delivery into the spinal cord after traumatic injury.