Uncomplicated differentiation of stem cells into bipolar neurons and myelinating glia

Combination Therapy with Platelet-Rich Plasma and Epidermal Neural Crest Stem Cells Increases Treatment Efficacy in Vascular Dementia

This study aimed to evaluate the efficacy and treatment mechanism of platelet-rich plasma (PRP) and neural crest-derived epidermal stem cells (ESCs) in their administration alone and combination in vascular dementia (VaD) model by two-vessel occlusion (2VO). Methods. Sixty-six rats were divided into six groups: the control, sham, 2VO + vehicle, 2VO + PRP, 2VO + ESC, and 2VO + ESC + PRP. The treated groups received 1 million cells on days 4, 14, and 21 with or without 500 µl PRP (twice a week) after 2VO. The memory performance and anxiety were evaluated by behavioral tests including open field, passive avoidance, and Morris water maze. The basal-synaptic transmission (BST) and long-term potentiation (LTP) were assessed through field-potential recordings of the CA1. The mRNA expression levels of IGF-1, TGF-β1, PSD-95, and GSk-3β were measured in the rat hippocampus by quantitative reverse transcription polymerase chain reaction. Results. The results demonstrated impaired learning, memory, and synaptic plasticity in the 2VO rats, along with a significant decrease in the expression of IGF-1, TGF-β1, PSD-95, and upregulation of GSK-3β. Treatment with ESC alone and ESC + PRP showed similar improvements in spatial memory and LTP induction, with associated upregulation of PSD-95 and downregulation of GSK-3β. However, only the ESC + PRP group showed recovery in BST. Furthermore, combination therapy was more effective than PRP monotherapy for LTP and memory. Conclusions. The transplantation of ESC showed better effects than PRP alone, and combination therapy increased the treatment efficacy with the recovery of BST. This finding may be a clue for the combination therapy of ESC and PRP for VaD.

Combined use of hair follicle stem cells and CEPO (carbamylated erythropoietin)-Fc in a rat model of chronic cerebral hypoperfusion: A behavioral, electrophysiological, and molecular study

BACKGROUND

In dementia, synaptic dysfunction appears before neuronal loss. Stem cell therapy could potentially provide a promising strategy for the treatment of dementia models. The carbamylated erythropoietin fusion protein (CEPO-Fc) has shown synaptotrophic effects. This study aimed to determine the efficiency of the combined use of hair follicle stem cells (HFSC) and CEPO-Fc in the basal synaptic transmission (BST) and long-term plasticity (LTP) of chronic cerebral hypoperfusion (CCH) rats.

METHODS

We divided 64 adult rats into control, sham, CCH+vehicle, CCH+CEPO, CCH+HFSC, and CCH+HFSC+CEPO groups. The CEPO-Fc was injected three times/week for 30 days. HFSC transplantation was done on days 4, 14, and 21 after surgery. The Morris water maze test and passive avoidance were used to assess memory. BST and LTP were assessed by a field-potential recording of the CA1 region. The hippocampal mRNA expression of IGF-1, TGF-β1, β1-Catenine, NR2B, PSD-95, and GSk-3β was evaluated by quantitative RT-PCR.

RESULTS

Following combination therapy, spatial memory retention, and BST showed significant improvement relative to HFSC and CEPO-Fc groups. These effects were also confirmed by recovered mRNA expression of β1-catenin, TGF-β1, and NR2B. GSK-3β expression was downregulated in all treatment groups. The upregulated PSD-95 was identified in HFSC and combination groups compared to the vehicle group.

CONCLUSIONS

These findings indicate that the combined use of HFSC and CEPO-Fc may be more advantageous for treating memory disruption in the CCH model than CEPO-Fc or HFSC alone. This type of combination therapy may hopefully lead to a new approach to treatment for dementia.

Exploring the molecular pathways and therapeutic implications of angiogenesis in neuropathic pain

Recently, much attention has been paid to chronic neuro-inflammatory condition underlying neuropathic pain. It is generally linked with thermal hyperalgesia and tactile allodynia. It results due to injury or infection in the nervous system. The neuropathic pain spectrum covers a variety of pathophysiological states, mostly involved are ischemic injury viral infections associated neuropathies, chemotherapy-induced peripheral neuropathies, autoimmune disorders, traumatic origin, hereditary neuropathies, inflammatory disorders, and channelopathies. In CNS, angiogenesis is evident in inflammation of neurons and pain in bone cancer. The role of chemokines and cytokines is dualistic; their aggressive secretion produces detrimental effects, leading to neuropathic pain. However, whether the angiogenesis contributes and exists in neuropathic pain remains doubtful. In the present review, we elucidated summary of diverse mechanisms of neuropathic pain associated with angiogenesis. Moreover, an overview of multiple targets that have provided insights on the VEGF signaling, signaling through Tie-1 and Tie-2 receptor, erythropoietin pathway promoting axonal growth are also discussed. Because angiogenesis as a result of these signaling, results in inflammation, we focused on the mechanisms of neuropathic pain. These factors are mainly responsible for the activation of post-traumatic regeneration of the PNS and CNS. Furthermore, we also reviewed synthetic and herbal treatments targeting angiogenesis in neuropathic pain.

The neuroprotective properties and therapeutic potential of epidermal neural crest stem cells transplantation in a rat model of vascular dementia

INTRODUCTION

The incidence rate of senile dementia is rising, and there is no definite cure for it yet. Cell therapy, as a new investigational approach, has shown promising results. Hair bulges with abundant easily accessible neural stem cells permit autologous implantation in irreversible neurodegenerative disorders.

METHODS

Fifty rats were randomly divided into 5 groups of control, sham-operation, two-common carotid vessel-occlusion rats that received vehicle (2VO + V), 2VO rats that received 1 × 10⁶ epidermal stem cells (2VO + ESC1), and 2VO rats that received 2.5 × 10⁶ epidermal stem cells (2VO + ESC2) in 300 µl PBS intravenously on days 4, 9, and 14 after surgery. The epidermal neural crest stem cells (EPI-NCSCs) were isolated from hair follicles of rat whiskers. The open-field, passive avoidance, and Morris water maze were used as behavioral tests. The basal-synaptic transmission, long-term potentiation (LTP), and short-term synaptic plasticity were evaluated by field-potential recording of the CA1 hippocampal area.

RESULTS

30 days after the first transplantation in the 2VO + ESC1 group, functional recovery was prominent in anxiety and fear memory compared to the 2VO + ESC2 group, while LTP induction was recovered in both groups of grafted animals without improvement in basal synaptic transmission. These positive recoveries may be related to the release of different neurotrophic factors from grafted cells that can stimulate endogenous neurogenesis and synaptic plasticity.

CONCLUSIONS

Our results showed that EPI-NCSCs implantation could rescue LTP and cognitive disability in 2VO rats, while transplantation of 1 million cells showed better performance relative to 2.5 million cells.

Transplanted hair follicle stem cells migrate to the penumbra and express neural markers in a rat model of cerebral ischaemia/reperfusion

BACKGROUND

Ischaemic stroke has become the main cause of death and severe neurological disorders, for which effective restorative treatments are currently limited. While stem cell transplantation offers therapeutic potential through neural regeneration, this approach is associated with the challenges of limited applicable sources. Hair follicle stem cells (HFSCs) are multipotential cells that can differentiate into ectodermal and mesodermal lineages and proliferate for long periods. The therapeutic potentials of HFSCs have not been investigated in ischaemic stroke models, and therefore, in this study, we aimed to determine whether they could survive and migrate to ischaemic areas after a stroke attack.

METHODS

A rat model of middle cerebral artery ischaemia/reperfusion was established and intravenously administered HFSCs. The potential of HFSCs to migrate and differentiate into neuron-like cells as well as their ability to reduce the infarct size was evaluated. Rat brain tissue samples were collected 2 weeks after cell transplantation and analysed via TTC staining, immunofluorescence and immunohistochemistry methods. The data were statistically analysed and presented as the means ± standard deviations.

RESULTS

Intravenously administrated rat HFSCs were able to migrate to the penumbra where they expressed neuron-specific markers, reduced the infarct volume and promoted neurological recovery.

CONCLUSION

HFSC transplantation has therapeutic potential for ischaemic stroke and is, therefore, worthy of further investigation toward possible clinical development for treating stroke patients.

Multimodal imaging of hair follicle bulge-derived stem cells in a mouse model of traumatic brain injury

Traumatic brain injury (TBI) is a devastating event for which current therapies are limited. Stem cell transplantation may lead to recovery of function via different mechanisms, such as cell replacement through differentiation, stimulation of angiogenesis and support to the microenvironment. Adult hair follicle bulge-derived stem cells (HFBSCs) possess neuronal differentiation capacity, are easy to harvest and are relatively immune-privileged, which makes them potential candidates for autologous stem cell-based therapy. In this study, we apply in vivo multimodal, optical and magnetic resonance imaging techniques to investigate the behavior of mouse HFBSCs in a mouse model of TBI. HFBSCs expressed Luc2 and copGFP and were examined for their differentiation capacity in vitro. Subsequently, transduced HFBSCs, preloaded with ferumoxytol, were transplanted next to the TBI lesion (cortical region) in nude mice, 2 days after injury. Brains were fixed for immunohistochemistry 58 days after transplantation. Luc2- and copGFP-expressing, ferumoxytol-loaded HFBSCs showed adequate neuronal differentiation potential in vitro. Bioluminescence of the lesioned brain revealed survival of HFBSCs and magnetic resonance imaging identified their localization in the area of transplantation. Immunohistochemistry showed that transplanted cells stained for nestin and neurofilament protein (NF-Pan). Cells also expressed laminin and fibronectin but extracellular matrix masses were not detected. After 58 days, ferumoxytol could be detected in HFBSCs in brain tissue sections. These results show that HFBSCs are able to survive after brain transplantation and suggest that cells may undergo differentiation towards a neuronal cell lineage, which supports their potential use for cell-based therapy for TBI.

Modern Trends for Peripheral Nerve Repair and Regeneration: Beyond the Hollow Nerve Guidance Conduit

Peripheral nerve repair and regeneration remains among the greatest challenges in tissue engineering and regenerative medicine. Even though peripheral nerve injuries (PNIs) are capable of some degree of regeneration, frail recovery is seen even when the best microsurgical technique is applied. PNIs are known to be very incapacitating for the patient, due to the deprivation of motor and sensory abilities. Since there is no optimal solution for tackling this problem up to this day, the evolution in the field is constant, with innovative designs of advanced nerve guidance conduits (NGCs) being reported every day. As a basic concept, a NGC should act as a physical barrier from the external environment, concomitantly acting as physical guidance for the regenerative axons across the gap lesion. NGCs should also be able to retain the naturally released nerve growth factors secreted by the damaged nerve stumps, as well as reducing the invasion of scar tissue-forming fibroblasts to the injury site. Based on the neurobiological knowledge related to the events that succeed after a nerve injury, neuronal subsistence is subjected to the existence of an ideal environment of growth factors, hormones, cytokines, and extracellular matrix (ECM) factors. Therefore, it is known that multifunctional NGCs fabricated through combinatorial approaches are needed to improve the functional and clinical outcomes after PNIs. The present work overviews the current reports dealing with the several features that can be used to improve peripheral nerve regeneration (PNR), ranging from the simple use of hollow NGCs to tissue engineered intraluminal fillers, or to even more advanced strategies, comprising the molecular and gene therapies as well as cell-based therapies.

Postnatal neural crest stem cells from hair follicle interact with nerve tissue in vitro and in vivo

Neural crest stem cells that located in the postnatal hair follicle (HF-NCSC) are considered a promising tool for treatment of nervous system diseases and injuries. It is well known that HF-NCSC can be used in the spinal cord and sciatic nerve reparation but their ability to restore brain structures is poorly studied. In this article we are investigating the interaction between HF-NCSC and a nerve tissue (embryonic and adult). We have found out that HF-NCSC isolated from adult mice grow and differentiate in accordance with the mouse embryo developmental stage when co-cultured with the embryonic nerve tissue. The HF-NCSC migration is slower in the late embryonic tissue co-culture system compared to the early one. This phenomenon is related to the motor function of the cells but not to their proliferation level. We have demonstrated that the embryonic nerve tissue maintains HF-NCSC an undifferentiated status, while an adult brain tissue inhibits the cell proliferation and activates the differentiation processes. Besides, HF-NCSC pre-differentiated into the neuronal direction shows a higher survival and migration rate after the transplantation into the adult brain tissue compared to the undifferentiated HF-NCSC. Thus, we have investigated the postnatal HF-NCSC response to the nerve tissue microenvironment to analyze their possible application to the brain repair processes.

Neuronal differentiation of hair-follicle-bulge-derived stem cells co-cultured with mouse cochlear modiolus explants

Stem-cell-based repair of auditory neurons may represent an attractive therapeutic option to restore sensorineural hearing loss. Hair-follicle-bulge-derived stem cells (HFBSCs) are promising candidates for this type of therapy, because they (1) have migratory properties, enabling migration after transplantation, (2) can differentiate into sensory neurons and glial cells, and (3) can easily be harvested in relatively high numbers. However, HFBSCs have never been used for this purpose. We hypothesized that HFBSCs can be used for cell-based repair of the auditory nerve and we have examined their migration and incorporation into cochlear modiolus explants and their subsequent differentiation. Modiolus explants obtained from adult wild-type mice were cultured in the presence of EF1α-copGFP-transduced HFBSCs, constitutively expressing copepod green fluorescent protein (copGFP). Also, modiolus explants without hair cells were co-cultured with DCX-copGFP-transduced HFBSCs, which demonstrate copGFP upon doublecortin expression during neuronal differentiation. Velocity of HFBSC migration towards modiolus explants was calculated, and after two weeks, co-cultures were fixed and processed for immunohistochemical staining. EF1α-copGFP HFBSC migration velocity was fast: 80.5 ± 6.1 μm/h. After arrival in the explant, the cells formed a fascicular pattern and changed their phenotype into an ATOH1-positive neuronal cell type. DCX-copGFP HFBSCs became green-fluorescent after integration into the explants, confirming neuronal differentiation of the cells. These results show that HFBSC-derived neuronal progenitors are migratory and can integrate into cochlear modiolus explants, while adapting their phenotype depending on this micro-environment. Thus, HFBSCs show potential to be employed in cell-based therapies for auditory nerve repair.

The combination of stem cells and tissue engineering: an advanced strategy for blood vessels regeneration and vascular disease treatment

Over the past years, vascular diseases have continued to threaten human health and increase financial burdens worldwide. Transplantation of allogeneic and autologous blood vessels is the most convenient treatment. However, it could not be applied generally due to the scarcity of donors and the patient’s condition. Developments in tissue engineering are contributing greatly with regard to this urgent need for blood vessels. Tissue engineering-derived blood vessels are promising alternatives for patients with aortic dissection/aneurysm. The aim of this review is to show the importance of advances in biomaterials development for the treatment of vascular disease. We also provide a comprehensive overview of the current status of tissue reconstruction from stem cells and transplantable cellular scaffold constructs, focusing on the combination of stem cells and tissue engineering for blood vessel regeneration and vascular disease treatment.

Lentiviral transduction and subsequent loading with nanoparticles do not affect cell viability and proliferation in hair-follicle-bulge-derived stem cells in vitro

The application of stem cells in the treatment of various degenerative diseases is highly promising. However, cell-based therapy could be limited by the problem of low viability of grafted cells and uncertainty about their fate. The combination of molecular imaging and contrast-enhanced MRI may give more insight into the survival and behavior of grafted stem cells. We explore hair-follicle-bulge-derived stem cells (HFBSCs) as a potential candidate for autologous cell-based therapy. HFBSCs are transduced with a lentiviral construct with genes coding for bioluminescent (Luc2) and fluorescent (copGFP) reporter proteins, and subsequently loaded with magnetic nanoparticles to enable MRI visualization. Thus, we investigate for the first time if lentiviral transduction and cellular loading with nanoparticles have a cytotoxic effect upon these stem cells. Transduction efficiency, proliferation rate, cell viability and reporter protein co-expression during long-term culture of transduced HFBSCs were studied using fluorescence and bioluminescence microscopy. In addition, the effect of TMSR50 nanoparticles on proliferation and viability was investigated using the MTS assay and bioluminescence microscopy. The amount of TMSR50-loaded HFBSCs needed to reach signal threshold for MRI was assessed using an agarose phantom. Transduction with the Luc2-copGFP construct did not influence senescence, proliferation, doubling time, and differentiation of the HFBSCs. CopGFP expression was visible immediately after transduction and persisted for at least 15 passages, concomitantly with Luc2 expression. Cellular loading with TMSR50 nanoparticles did not affect cell viability and proliferation. The results imply that combined MRI and bioluminescence imaging may enable in vivo localization and long-term monitoring of grafted viable HFBSCs. Copyright © 2016 John Wiley & Sons, Ltd.

Highly Efficient Neural Differentiation of CD34-Positive Hair-Follicle-Associated Pluripotent Stem Cells Induced by Retinoic Acid and Serum-Free Medium

Neural differentiation of hair-follicle-associated pluripotent (HAP) stem cells residing in the bulge area is a promising autologous source for stem cell therapy. In the present chapter, we describe the identification and enrichment of CD34(+) HAP stem cells by magnetic-activated cell sorting (MACS), and induce them to differentiate into neuronal and glial cells using defined neural-induction media. The different neural cell populations arising during in vitro differentiation from HAP stem cells are characterized by reverse transcription polymerase chain reaction (RT-PCR) and immunocytochemistry assay.

Hair follicle stem cells: In vitro and in vivo neural differentiation

Hair follicle stem cells (HFSCs) normally give rise to keratinocytes, sebocytes, and transient amplifying progenitor cells. Along with the capacity to proliferate rapidly, HFSCs provide the basis for establishing a putative source of stem cells for cell therapy. HFSCs are multipotent stem cells originating from the bulge area. The importance of these cells arises from two important characteristics, distinguishing them from all other adult stem cells. First, they are accessible and proliferate for long periods. Second, they are multipotent, possessing the ability to differentiate into mesodermal and ectodermal cell types. In addition to a developmental capacity in vitro, HFSCs display an ability to form differentiated cells in vivo. During the last two decades, numerous studies have led to the development of an appropriate culture condition for producing various cell lineages from HFSCs. Therefore, these stem cells are considered as a novel source for cell therapy of a broad spectrum of neurodegenerative disorders. This review presents the current status of human, rat, and mouse HFSCs from both the cellular and molecular biology and cell therapy perspectives. The first section of this review highlights the importance of HFSCs and in vitro differentiation, while the final section emphasizes the significance of cell differentiation in vivo.

The protein phosphatase activity of PTEN is essential for regulating neural stem cell differentiation

Background

The tumor suppressor gene Phosphatase and tensin homolog (PTEN) is highly expressed in neural progenitor cells (NPCs) and plays an important role in development of the central nervous system. As a dual-specificity phosphatase, the loss of PTEN phosphatase activity has been linked to various diseases.

Results

Here we report that the protein phosphatase activity of Pten is critical for regulating differentiation of neural progenitor cells. First we found that deletion of Pten promotes neuronal differentiation. To determine whether the protein or lipid phosphatase activity is required for regulating neuronal differentiation, we generated phosphatase domain-specific Pten mutations. Interestingly, only expression of protein phosphatase-deficient mutant Y138L could mimic the effect of knocking down Pten, suggesting the protein phosphatase of Pten is critical for regulating NPC differentiation. Importantly, we showed that the wild-type and lipid phosphatase mutant (G129E) forms of Pten are able to rescue neuronal differentiation in Pten knockout NPCs, but mutants containing protein phosphatase mutant cannot. We further found that Pten-dependent dephosphorylation of CREB is critical for neuronal differentiation.

Conclusion

Our data indicate that the protein phosphatase activity of PTEN is critical for regulating differentiation of NSCs during cortical development.

Electronic supplementary material

The online version of this article (doi:10.1186/s13041-015-0114-1) contains supplementary material, which is available to authorized users.

In vitro neural differentiation of CD34 (+) stem cell populations in hair follicles by three different neural induction protocols

Differentiation of hair follicle stem cells (HFSCs) into neurons and glial cells represents a promising cell-based therapy for neurodegenerative diseases. The hair follicle bulge area is reported as a putative source of new stem cell population for many years. In vitro studies have implicated neural differentiation of HFSCs. Here, we report the identification and purification of CD34 (+) cells from hair follicle by magnetic activated cell sorting (MACS). We next determined the cytotoxic effects of all-trans retinoic acid (RA) by using cell viability assays. Moreover, the neural differentiation potential of CD34 (+) cells was evaluated in the presence of RA, serum-free condition, and neural differentiation medium (NDM) treatments by using immunocytochemistry and reverse transcription polymerase chain reaction (RT-PCR). Our results showed that the isolated CD34 (+) stem cells were 12% of the total cells in the bulge area, and the neural cells derived from the stem cells expressed nestin, microtubule-associated protein 2 (MAP2), and glial fibrillary acidic protein (GFAP). Interestingly, all the neural induction media supported neuronal differentiation most effectively, but treatment with serum-free medium significantly increased the number of GFAP-positive glial cells. Moreover, increasing RA concentration (≥10 μM) leads to increased cell death in the cells, but a lower concentration of RA (1 μM) treatment results in a decrease in CD34-expressing stem cells. These findings show an instructive neuronal effect of three neural induction media in HFSCs, indicating the important role of this induction media in the specification of the stem cells toward a neural phenotype.

miR-21 promotes the differentiation of hair follicle-derived neural crest stem cells into Schwann cells

Hair follicle-derived neural crest stem cells can be induced to differentiate into Schwann cells in vivo and in vitro. However, the underlying regulatory mechanism during cell differentiation remains poorly understood. This study isolated neural crest stem cells from human hair follicles and induced them to differentiate into Schwann cells. Quantitative RT-PCR showed that microRNA (miR)-21 expression was gradually increased during the differentiation of neural crest stem cells into Schwann cells. After transfection with the miR-21 agonist (agomir-21), the differentiation capacity of neural crest stem cells was enhanced. By contrast, after transfection with the miR-21 antagonist (antagomir-21), the differentiation capacity was attenuated. Further study results showed that SOX-2 was an effective target of miR-21. Without compromising SOX2 mRNA expression, miR-21 can down-regulate SOX protein expression by binding to the 3′-UTR of miR-21 mRNA. Knocking out the SOX2 gene from the neural crest stem cells significantly reversed the antagomir-21 inhibition of neural crest stem cells differentiating into Schwann cells. The results suggest that miR-21 expression was increased during the differentiation of neural crest stem cells into Schwann cells and miR-21 promoted the differentiation through down-regulating SOX protein expression by binding to the 3′-UTR of SOX2 mRNA.

Nestin immune labeling in human adult trigeminal ganglia

Nestin labels neuroepithelial stem cells and endothelial cells in newly formed blood vessels. The aim of the study was to investigate the immunolocalization of nestin in human adult trigeminal ganglia. Autopsy samples from eight human adult cadavers were paraffin embedded, and immunostained with anti-nestin antibody. Satellite glial cells (SGCs) and intraganglionic microvessels were positively labeled with nestin, which is usually expressed in endothelial cells of newly formed blood vessels. Nestin-positive SGCs have been previously reported in rat trigeminal ganglia. Our study is the first to identify them in human trigeminal ganglia. Further studies are needed to evaluate if the nestin phenotype of SGCs relates to the functional plasticity of these cells or to glial and/or neuronal remodeling in adults. Intrinsic angiogenesis in the adult trigeminal ganglion should be further checked as to whether it relates to a normal vascular remodeling or if it represents an overlooked determinant of trigeminal neuralgia.

Delivery of epidermal neural crest stem cells (EPI-NCSC) to hippocamp in Alzheimer's disease rat model

BACKGROUND

Alzheimer's disease (AD) is characterized by progressive neuronal loss in hippocamp. Epidermal neural crest stem cells (EPI-NCSC) can differentiate into neurons, astrocytes and oligodendrocytes. The purpose of this study was to evaluate the effects of transplanting EPI-NCSC into AD rat model.

METHODS

Two weeks after induction of AD by injection of Amyloid-β1-40 into CA1 area of rat hippocamp, Y-maze and single-trial passive avoidance tests were used to show deficit of learning and memory abilities. EPI-NCSC were obtained from the vibrissa hair follicle of rat, cultured and labeled with bromodeoxyuridine. When Alzheimer was proved by behavioral tests, EPI-NCSC was transplanted into CA3 area of hippocamp in AD rat model. The staining of EPI-NCSC markers (nestin and SOX10) was done in vitro. Double-labeling immunofluorescence was performed to study survival and differentiation of the grafted cells.

RESULTS

We showed that transplanted EPI-NCSC survive and produce many neurons and a few glial cells, presenting glial fibrillary acidic protein. Total number of granule cells in hippocamp was estimated to be more in the AD rat model with transplanted cells as compared to AD control group. We observed that rats with hippocampal damage made more errors than control rats on the Y-maze, when reward locations were reversed.

CONCLUSION

Transplanted cells were migrated to all areas of hippocamp and the total number of granule cell in treatment group was equal compared to control group. Transplantation of EPI-NCSC into hippocamp might differentiate into cholinergic neurons and could cure impairment of memory in AD rat model.

Stem cell sources for vascular tissue engineering and regeneration

This review focuses on the stem cell sources with the potential to be used in vascular tissue engineering and to promote vascular regeneration. The first clinical studies using tissue-engineered vascular grafts are already under way, supporting the potential of this technology in the treatment of cardiovascular and other diseases. Despite progress in engineering biomaterials with the appropriate mechanical properties and biological cues as well as bioreactors for generating the correct tissue microenvironment, the source of cells that make up the vascular tissues remains a major challenge for tissue engineers and physicians. Mature cells from the tissue of origin may be difficult to obtain and suffer from limited proliferative capacity, which may further decline as a function of donor age. On the other hand, multipotent and pluripotent stem cells have great potential to provide large numbers of autologous cells with a great differentiation capacity. Here, we discuss the adult multipotent as well as embryonic and induced pluripotent stem cells, their differentiation potential toward vascular lineages, and their use in engineering functional and implantable vascular tissues. We also discuss the associated challenges that need to be addressed in order to facilitate the transition of this technology from the bench to the bedside.

Human Schwann cells retain essential phenotype characteristics after immortalization

Schwann cells (SCs) play an important role in the pathogenesis of peripheral nerve diseases and represent a potential target for development of therapies. However, use of primary human SCs (hSCs) for in vitro models is limited because these cells are difficult to prepare and maintain in high yield and purity under common cell culture conditions. To circumvent this obstacle, we immortalized primary human fetal SCs using the SV40 large T-antigen and human telomerase reverse transcriptase expression vectors. After cloning, selection, and purification, we evaluated several immortalized SC lines for their ability to express extracellular matrix (ECM) molecules and myelinate embryonic rat sensory axons. In addition, we established a gene expression profile and explored their sensitivity to oxidative stress in a simple in vitro assay. Immortalized hSC clones expressed common glial markers and a broad variety of growth factors, receptors, and ECM molecules as determined by immunocytochemistry, microarray, and quantitative reverse transcription-polymerase chain reaction. In neuron-SC co-cultures, these cells were able to myelinate rat dorsal root ganglia neurons, although their effectiveness was lower in comparison to primary rat SCs. In toxicity assays, immortalized hSCs remain susceptible to oxidative stress induced by H(2)O(2). This study shows that, using specific immortalization techniques, it is possible to establish hSC lines that retain characteristics of typical primary hSCs. These cells are particularly useful for drug screening and studies aimed at disease mechanisms involving SCs.

Regeneration of Hair Cells: Making Sense of All the Noise

Hearing loss affects hundreds of millions of people worldwide by dampening or cutting off their auditory connection to the world. Current treatments for sensorineural hearing loss (SNHL) with cochlear implants are not perfect, leaving regenerative medicine as the logical avenue to a perfect cure. Multiple routes to regeneration of damaged hair cells have been proposed and are actively pursued. Each route not only requires a keen understanding of the molecular basis of ear development but also faces the practical limitations of stem cell regulation in the delicate inner ear where topology of cell distribution is essential. Improvements in our molecular understanding of the minimal essential genes necessary for hair cell formation and recent advances in stem cell manipulation, such as seen with inducible pluripotent stem cells (iPSCs) and epidermal neural crest stem cells (EPI-NCSCs), have opened new possibilities to advance research in translational stem cell therapies for individuals with hearing loss. Despite this, more detailed network maps of gene expression are needed, including an appreciation for the roles of microRNAs (miRs), key regulators of transcriptional gene networks. To harness the true potential of stem cells for hair cell regeneration, basic science and clinical medicine must work together to expedite the transition from bench to bedside by elucidating the full mechanisms of inner ear hair cell development, including a focus on the role of miRs, and adapting this knowledge safely and efficiently to stem cell technologies.

Differentiation of neural stem cells into Schwann-like cells in vitro

Neural stem cells (NSCs) are multipotent stem cells that have the potential to differentiate into different cells of the neural lineage like neurons, astrocytes and oligodendrocytes. In the current work, we explored whether NSCs could be differentiated into functional Schwann-like cells, which has not been investigated up to date. NSCs were harvested from the hippocampus of rats and identified by single cell cloning and immunofluorescence staining. Then NSCs were treated with DMEM/F12 supplemented with forskolin, heregulin, bFGF, PDGF-AA and retinoic acid (RA). Differentiated NSCs (dNSCs) exhibited a spindle-like morphology similar to Schwann cells and expressed the glial markers p75 and S100. We also found that dNSCs could enhance neurite outgrowth when co-cultured with NG108-15 cells. These results indicated that NSCs, derived from hippocampus of rats, could differentiate into Schwann-like cells with morphological, phenotypic and functional similarities.