Comparative analysis of neuroectodermal differentiation capacity of human bone marrow stromal cells using various conversion protocols

Binucleated human bone marrow-derived mesenchymal cells can be formed during neural-like differentiation with independence of any cell fusion events

Although it has been reported that bone marrow-derived cells (BMDCs) can transdifferentiate into neural cells, the findings are considered unlikely. It has been argued that the rapid neural transdifferentiation of BMDCs reported in culture studies is actually due to cytotoxic changes induced by the media. While transplantation studies indicated that BMDCs can form new neurons, it remains unclear whether the underlying mechanism is transdifferentiation or BMDCs-derived cell fusion with the existing neuronal cells. Cell fusion has been put forward to explain the presence of gene-marked binucleated neurons after gene-marked BMDCs transplantation. In the present study, we demostrated that human BMDCs can rapidly adopt a neural-like morphology through active neurite extension and binucleated human BMDCs can form with independence of any cell fusion events. We also showed that BMDCs neural-like differentiation involves the formation of intermediate cells which can then redifferentiate into neural-like cells, redifferentiate back to the mesenchymal fate or even repeatedly switch lineages without cell division. Furthermore, we have discovered that nuclei from intermediate cells rapidly move within the cell, adopting different morphologies and even forming binucleated cells. Therefore, our results provide a stronger basis for rejecting the idea that BMDCs neural transdifferentiation is merely an artefact.

A large scale mass spectrometry-based histone screening for assessing epigenetic developmental toxicity

Toxicoepigenetics is an emerging field that studies the toxicological impact of compounds on protein expression through heritable, non-genetic mechanisms, such as histone post-translational modifications (hPTMs). Due to substantial progress in the large-scale study of hPTMs, integration into the field of toxicology is promising and offers the opportunity to gain novel insights into toxicological phenomena. Moreover, there is a growing demand for high-throughput human-based in vitro assays for toxicity testing, especially for developmental toxicity. Consequently, we developed a mass spectrometry-based proof-of-concept to assess a histone code screening assay capable of simultaneously detecting multiple hPTM-changes in human embryonic stem cells. We first validated the untargeted workflow with valproic acid (VPA), a histone deacetylase inhibitor. These results demonstrate the capability of mapping the hPTM-dynamics, with a general increase in acetylations as an internal control. To illustrate the scalability, a dose–response study was performed on a proof-of-concept library of ten compounds (1) with a known effect on the hPTMs (BIX-01294, 3-Deazaneplanocin A, Trichostatin A, and VPA), (2) classified as highly embryotoxic by the European Centre for the Validation of Alternative Methods (ECVAM) (Methotrexate, and All-trans retinoic acid), (3) classified as non-embryotoxic by ECVAM (Penicillin G), and (4) compounds of abuse with a presumed developmental toxicity (ethanol, caffeine, and nicotine).

Effects of different detergent-containing children's toothpastes on the viability, osteogenic and chondrogenic differentiation of human dental periodontal ligament stem cells and gingival stem cells in vitro

BACKGROUND

Detergents are the most commonly used compounds in toothpastes due to their foaming and cleaning peoperties. This study aimed to investigate the effects of children's toothpastes with different detergent content on the viability, the osteogenic and chondrogenic differentiation potentials of human mesenchymal stem cells.

METHODS

The necessary tissues for human periodontal ligament mesenchymal stem cells (hPDLMSCs) and human gingival mesenchymal stem cells (hGMSCs) isolation were obtained during extraction of 10 impacted third molar teeth. The viability of the cells stimulated with different concentratiaons of Colgate, Sensodyne, Splat, Nenedent, Perlodent toothpaste solutions and complete Dulbocco's modified eagle medium (control group) were evaluated by using the flow cytometer. In addition, the osteogenic and chondrogenic differentiation potential of human gingival and periodontal ligament mesenchymal stem cells exposed to toothpaste solutions were examined morphologically. Datas were analyzed with IBM SPSS V23. One way ANOVA test was used to determine the differences between the groups for multiple comparisons, while the Tukey post-hoc test was used for pair wise comparisons in determining which groups differed.

RESULTS

A higher percentage of cell viability was detected in Control group at 20 %, 50 % and 80 % (p = 0.000) on hGMSCs. After the Control group, the highest cell viability ratios were observed in the detergent-free Splat group (p = 0.000) followed by the Sensodyne experimental group containing CABP (p = 0.000). While the cell viability rates in Nenedent group was found significantly higher than the Perlodent group at other concentrations except for 20 % concentration (p = 0.000). Colgate group had the lowest percentage of cell viability among the experimental groups at all concentrations on hPDMSCs (p = 0.000). The highest live cell ratios was detected in Control group (p = 0.000), followed by Splat and Sensodyne groups (p = 0.000). The cell viability ratios at 50 % concentration were higher in Perlodent group than Nenedent group (p = 0.000). The highest osteogenic and chondrogenic differentiation potential of mesenchymal stem cells stimulated with different toothpaste was determined in Control and Splat group.

CONCLUSIONS

As a result of the findings, it was observed that toothpaste containing SLS had a more negative effect on the viability of the cells and the differentiation potentials than the other groups.

Neurons from human mesenchymal stem cells display both spontaneous and stimuli responsive activity

Mesenchymal stem cells have the ability to transdifferentiate into neurons and therefore one of the potential adult stem cell source for neuronal tissue regeneration applications and understanding neurodevelopmental processes. In many studies on human mesenchymal stem cell (hMSC) derived neurons, success in neuronal differentiation was limited to neuronal protein expressions which is not statisfactory in terms of neuronal activity. Established neuronal networks seen in culture have to be investigated in terms of synaptic signal transmission ability to develop a culture model for human neurons and further studying the mechanism of neuronal differentiation and neurological pathologies. Accordingly, in this study, we analysed the functionality of bone marrow hMSCs differentiated into neurons by a single step cytokine-based induction protocol. Neurons from both primary hMSCs and hMSC cell line displayed spontaneous activity (≥75%) as demonstrated by Ca++ imaging. Furthermore, when electrically stimulated, hMSC derived neurons (hMd-Neurons) matched the response of a typical neuron in the process of maturation. Our results reveal that a combination of neuronal inducers enhance differentiation capacity of bone marrow hMSCs into high yielding functional neurons with spontaneous activity and mature into electrophysiologically active state. Conceptually, we suggest these functional hMd-Neurons to be used as a tool for disease modelling of neuropathologies and neuronal differentiation studies.

Expression of genes involved in neurogenesis, and neuronal precursor cell proliferation and development: Novel pathways of human ovarian granulosa cell differentiation and transdifferentiation capability in vitro

The process of neural tissue formation is associated primarily with the course of neurogenesis during embryonic life. The source of neural-like cells is stem cells, which, under the influence of appropriate differentiating factors, may differentiate/transdifferentiate towards a neural-like lineage. The present study suggested that, under long-term in vitro culture conditions, human ovarian granulosa cells (GCs), obtained from granulosa-rich follicular fluid, acquired new properties and expressed genes characteristic of the ontological groups ‘neurogenesis’ (GO:0022008), ‘neuronal precursor cell proliferation’ (GO:0061351) and ‘nervous system development’ (GO:0007399), which are closely related to the formation of neurons. The present study collected GCs from 20 women referred for the procedure of in vitro fertilization. Cells were maintained in long-term in vitro culture for 30 days, and RNA was isolated after 1, 7, 15 and 30 days of culture. The expression profile of individual genes was determined using the Affymetrix microarray method. The 131 genes with the highest expression change in relation to day 1 of culture were then selected; the 10 most affected genes found to be primarily involved in nerve cell formation processes were chosen for consideration in this study: CLDN11, OXTR, DFNA5, ATP8B1, ITGA3, CD9, FRY, NANOS1, CRIM1 and NTN4. The results of the present study revealed that these genes may be considered potential markers of the uninduced differentiation potential of GCs. In addition, it was suggested that GCs may be used to develop a cell line showing neuronal characteristics after 30 days of cultivation. In addition, due to their potential, these cells could possibly be used in the treatment of neurodegenerative diseases, not only in the form of ‘cultured neurons’ but also as producers of factors involved in the regeneration of the nervous system.

Potential of ovine Wharton jelly derived mesenchymal stem cells to transdifferentiate into neuronal phenotype for application in neuroregenerative therapy

Introduction: The transdifferentiation potential of mesenchymal stem cells (MSCs) is not limited to mesodermal derivatives but also to other cell types such as neuronal cells under appropriate cell culture conditions.Materials and methods: The present study characterizes the differentiation of Wharton's jelly (WJ) derived MSCs using neuronal conditioned medium (NCM) collected from cultured foetal brain cells.Results: After induction with NCM to neuronal stem cells (NSC), the WJ MSCs showed profound morphological changes showing multiple neurites extending from the cell body containing reminiscent of Nissl substance and single long axon-like processes. In RT PCR and immunocytochemistry, the induced neuronal cells showed a strong positive expression of neuronal markers Nestin, β III tubulin and GFAP indicated that, the cells were reactive to NCM for differentiation. A significant (p < 0.01) increase in the level of secretome BDNF was observed in NCM suggests that the BDNF could play a key role in the transdifferentiation of WJMSCs to NSCs.Conclusion: These results support the potential of ovine MSCs isolated from umbilical cord WJ of abattoir derived foetuses to differentiate into neuronal stem cells and also provide a valuable experimental data for NSC transplant research in veterinary medicine.

Comparative study of the neural differentiation capacity of mesenchymal stromal cells from different tissue sources: An approach for their use in neural regeneration therapies

Mesenchymal stem cells (MSCs) can trans/differentiate to neural precursors and/or mature neurons and promote neuroprotection and neurogenesis. The above could greatly benefit neurodegenerative disorders as well as in the treatment of post-traumatic and hereditary diseases of the central nervous system (CNS). In order to attain an ideal source of adult MSCs for the treatment of CNS diseases, adipose tissue, bone marrow, skin and umbilical cord derived MSCs were isolated and studied to explore differences with regard to neural differentiation capacity. In this study, we demonstrated that MSCs from several tissues can differentiate into neuron-like cells and differentially express progenitors and mature neural markers. Adipose tissue MSCs exhibited significantly higher expression of neural markers and had a faster proliferation rate. Our results suggest that adipose tissue MSCs are the best candidates for the use in neurological diseases.

Motor Recovery after Transplantation of Bone Marrow Mesenchymal Stem Cells in Rat Models of Spinal Cord Injury

Background

Neuronal tissue has a limited potential to self-renew or get repaired after damage. Cell therapies using stem cells are promising approaches for the treatment of central nervous system (CNS) injuries. However, the clinical use of embryonic stem cells is limited by ethical concerns and other scientific consequences. Bone marrow mesenchymal stromal cells (BM-MSC) could represent an alternative source of stem cells for replacement therapy. Indeed, many studies have demonstrated that MSCs can give rise to neuronal cells as well as many tissue-specific cell phenotypes.

Purpose

Motor recovery by transplantation of bone marrow MSCs in rat models of spinal cord injury (SCI).

Methods

Bone marrow was collected from the femur of albino Wistar rats. MSCs were separated using the Ficoll-Paque density gradient method and cultured in Dulbecco's Modified Eagle Medium supplemented with 20% fetal bovine serum. Cultured MSC was characterized by immunohistochemistry and flow cytometry and neuronal-induced cells were further characterized for neural markers. Cultured MSCs were transplanted into the experimentally injured spinal cord of Wistar rats. Control (injured, but without cell transplantation) and transplanted rats were followed up to 8 weeks, analyzed using the Basso, Beattie, Bresnahan (BBB) scale and electromyography (EMG) for behavioral and physiological status of the injured spinal cord. Finally, the tissue was evaluated histologically.

Results

Rat MSCs expressed positivity for a panel of MSC markers CD29, CD54, CD90, CD73, and CD105, and negativity for hematopoietic markers CD34, CD14, and CD45. In vitro neuronal transdifferentiated MSCs express positivity for β III tubulin, MAP2, NF, NeuN, Nav1.1, oligodendrocyte (O4), and negativity for glial fibrillary acid protein. All the treated groups show promising hind-limb motor recovery BBB score, except the control group. There was increased EMG amplitude in treated groups as compared to the control group. Green fluorescent protein (GFP)-labeled MSC survived and differentiated into neurons in the injured spinal cord, which is responsible for functional recovery.

Conclusion

Our results demonstrate that BM-MSC has the potential to repair the injured cord in rat models of SCI. Thus, BM-MSC appears to be a promising candidate for cell-based therapy in CNS injury.

Adult Neural Stem Cells: Basic Research and Production Strategies for Neurorestorative Therapy

Over many decades, constructing genetically and phenotypically stable lines of neural stem cells (NSC) for clinical purposes with the aim of restoring irreversibly lost functions of nervous tissue has been one of the major goals for multiple research groups. The unique ability of stem cells to maintain their own pluripotent state even in the adult body has made them into the choice object of study. With the development of the technology for induced pluripotent stem cells (iPSCs) and direct transdifferentiation of somatic cells into the desired cell type, the initial research approaches based on the use of allogeneic NSCs from embryonic or fetal nervous tissue are gradually becoming a thing of the past. This review deals with basic molecular mechanisms for maintaining the pluripotent state of embryonic/induced stem and reprogrammed somatic cells, as well as with currently existing reprogramming strategies. The focus is on performing direct reprogramming while bypassing the stage of iPSCs which is known for genetic instability and an increased risk of tumorigenesis. A detailed description of various protocols for obtaining reprogrammed neural cells used in the therapy of the nervous system pathology is also provided.

Preclinical Assessment of the Proliferation Capacity of Gingival and Periodontal Ligament Stem Cells from Diabetic Patients

BACKGROUND:

Stem cells have recently received great interest as potential therapeutics alternative for a variety of diseases. The oral and maxillofacial region, in particular, encompasses a variety of distinctive mesenchymal (MSC) populations and is characterized by a potent multilineage differentiation capacity.

AIM:

In this report, we aimed to investigate the effect of diabetes on the proliferation potential of stem cells isolated from controlled diabetic patients (type 2) and healthy individuals.

SUBJECTS & METHODS:

The proliferation rate of gingival and periodontal derived stem cells isolated from diabetic & healthy individuals were compared using MTT Assay. Expression levels of Survivin in isolated stem cells from all groups were measured by qRt - PCR.

RESULTS:

There was a significantly positive correlation between proliferation rate and expression of Survivin in all groups which sheds light on the importance of Survivin as a reliable indicator of proliferation. The expression of Survivin further confirmed the proliferation results from MTT Assay where the expression of stem cells from non - diabetic individuals was higher than diabetic patients.

CONCLUSION:

Taking together all the results, it could be concluded that PDLSC and GSC are promising candidates for autologous regenerative therapy due to their ease of accessibility in addition to their high proliferative rates.

Muse Cell: A New Paradigm for Cell Therapy and Regenerative Homeostasis in Ischemic Stroke

Multilineage-differentiating stress enduring (Muse) cells are one of the most promising donor cells for cell therapy against ischemic stroke, because they can differentiate into any type of cells constructing the central nervous system (CNS), including the neurons. They can easily be isolated from the bone marrow stromal cells (BMSCs), which may also contribute to functional recovery after ischemic stroke as donor cells. In this chapter, we concisely review their biological features and then future perspective of Muse cell transplantation for ischemic stroke. In addition, we briefly refer to the surprising role of Muse cells to maintain the homeostasis in the living body under both physiological and pathological conditions.

Adipose tissue-derived stromal cells (ADSC) express oligodendrocyte and myelin markers, but they do not function as oligodendrocytes

Mesenchymal cells cultured from the vasculo-stromal fraction of adipose tissue (ADSC) show adult stem cell characteristics and several groups have claimed generating neural cells from them. However, we have observed that many markers commonly used for the identification of neural cells are spontaneously expressed by ADSC in culture. In the present study, we have examined the expression of characteristic oligodendrocyte molecules in cultured ADSC, aiming to test if myelinating cells could be generated from accessible non-neural adult tissues. In basal growth conditions, rat ADSC spontaneously expressed CNPase, MBP, MOG, protein zero, GAP43, Sox10, and Olig2, as shown by immunocytrochemistry and western blot. A small population of cultured ADSC expressed membrane galactocerebroside (O1 antibody), but no cell stained with O4 antibody. RT-PCR analyses showed the expression of CNPase, MBP, DM20, and low levels of Olig2, Sox10, and Sox2 mRNA by rat ADSC. When rat ADSC were treated with combinations of factors commonly used in neural-inducing media (retinoic acid, dbcAMP, EGF, basic FGF, NT3, and/or PDGF), the number of O1-positive cells changed, but in no case, mRNA expression of Sox10 and Olig2 transcription factors approached CNS oligodendrocyte levels. In co-culture with rat dorsal root ganglion neurons, no sign of axonal myelination by rat ADSC was observed. These studies show that the expression of oligodendrocyte traits by cultured ADSC is not a proof of functional competence as oligodendroglia and suggest that in culture conditions, ADSC acquire intermediate, uncommitted phenotypes.

Microencapsulation of Islets for the Treatment of Type 1 Diabetes Mellitus (T1D)

Microencapsulation technology, based on use of alginic acid biopolymers, has been devised many years ago. However, when intended for enveloping human islets for transplantation purposes, the method needs to be up-scaled and implemented with care being taken to comply with simple but important measures. It is almost indispensable to rely on an ultrapurified alginic polymers: in fact, any, even minimal, alginate contamination with endotoxins, pyrogens, and proteins could provoke the host's inflammatory reaction upon graft, with heavy adverse consequences on the capsules immunoprotective properties, hence on graft survival per se. Care should be taken in ensuring fabrication of reproducible microspheres, in terms not only of shape and size, but also consistency of the peripheral layers around the central alginate gel core, where the islets are immobilized. Once the product is well defined and stable, care should also be taken in accurately selecting patients with T1D that are candidate for encapsulated islet cell transplantation with no general immunosuppression. A series of pre- and post-intraperitoneal transplant metabolic, chemical, and immunological parameters are to be monitored, in conjunction with image analysis of the abdomen, in order to assess efficacy of the intervention according to well defined grading scale.

Comparative capability of menstrual blood versus bone marrow derived stem cells in neural differentiation

In order to characterize the potency of menstrual blood stem cells (MenSCs) for future cell therapy of neurological disorders instead of bone marrow stem cells (BMSCs) as a well-known and conventional source of adult stem cells, we examined the in vitro differentiation potential of these stem cells into neural-like cells. The differentiation potential of MenSCs to neural cells in comparison with BMSCs was assessed under two step neural differentiation including conversion to neurosphere-like cells and final differentiation. The expression levels of Nestin, Microtubule-associated protein 2, gamma-aminobutyric acid type B receptor subunit 1 and 2, and Tubulin, beta 3 class III mRNA and/or protein were up-regulated during development of MenSCs into neurosphere-like cells (NSCs) and neural-like cells. The up-regulation level of these markers in differentiated neural-like cells from MenSCs was comparable with differentiated cells from BMSCs. Moreover, both differentiated MenSCs and BMSCs expressed high levels of potassium, calcium and sodium channel genes developing functional channels with electrophysiological recording. For the first time, we demonstrated that MenSCs are a unique cell population with differentiation ability into neural-like cells comparable to BMSCs. In addition, we have introduced an approach to generate NSCs from MenSCs and BMSCs and their further differentiation into neural-like cells in vitro. Our results hold a promise to future stem cell therapy of neurological disorders using NSCs derived from menstrual blood, an accessible source in every woman.

Current Opinion of Bone Marrow Stromal Cell Transplantation for Ischemic Stroke

This article reviews recent advancement and perspective of bone marrow stromal cell (BMSC) transplantation for ischemic stroke, based on current information of basic and translational research. The author would like to emphasize that scientific approach would enable us to apply BMSC transplantation into clinical situation in near future.

Factor-Reduced Human Induced Pluripotent Stem Cells Efficiently Differentiate into Neurons Independent of the Number of Reprogramming Factors

Reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) by overexpression of the transcription factors OCT4, SOX2, KLF4, and c-Myc holds great promise for the development of personalized cell replacement therapies. In an attempt to minimize the risk of chromosomal disruption and to simplify reprogramming, several studies demonstrated that a reduced set of reprogramming factors is sufficient to generate iPSC. We recently showed that a reduction of reprogramming factors in murine cells not only reduces reprogramming efficiency but also may worsen subsequent differentiation. To prove whether this is also true for human cells, we compared the efficiency of neuronal differentiation of iPSC generated from fetal human neural stem cells with either one (OCT4; hiPSC_1F-NSC) or two (OCT4, KLF4; hiPSC_2F-NSC) reprogramming factors with iPSC produced from human fibroblasts using three (hiPSC_3F-FIB) or four reprogramming factors (hiPSC_4F-FIB). After four weeks of coculture with PA6 stromal cells, neuronal differentiation of hiPSC_1F-NSC and hiPSC_2F-NSC was as efficient as iPSC_3F-FIB or iPSC_4F-FIB. We conclude that a reduction of reprogramming factors in human cells does reduce reprogramming efficiency but does not alter subsequent differentiation into neural lineages. This is of importance for the development of future application of iPSC in cell replacement therapies.

Promoting effect of small molecules in cardiomyogenic and neurogenic differentiation of rat bone marrow-derived mesenchymal stem cells

Small molecules, growth factors, and cytokines have been used to induce differentiation of stem cells into different lineages. Similarly, demethylating agents can trigger differentiation in adult stem cells. Here, we investigated the in vitro differentiation of rat bone marrow mesenchymal stem cells (MSCs) into cardiomyocytes by a demethylating agent, zebularine, as well as neuronal-like cells by β-mercaptoethanol in a growth factor or cytokines-free media. Isolated bone marrow-derived MSCs cultured in Dulbecco's Modified Eagle's Medium exhibited a fibroblast-like morphology. These cells expressed positive markers for CD29, CD44, and CD117 and were negative for CD34 and CD45. After treatment with 1 μM zebularine for 24 hours, the MSCs formed myotube-like structures after 10 days in culture. Expression of cardiac-specific genes showed that treated MSCs expressed significantly higher levels of cardiac troponin-T, Nkx2.5, and GATA-4 compared with untreated cells. Immunocytochemical analysis showed that differentiated cells also expressed cardiac proteins, GATA-4, Nkx 2.5, and cardiac troponin-T. For neuronal differentiation, MSCs were treated with 1 and 10 mM β-mercaptoethanol overnight for 3 hours in complete and serum-free Dulbecco's Modified Eagle's Medium, respectively. Following overnight treatment, neuron-like cells with axonal and dendritic-like projections originating from the cell body toward the neighboring cells were observed in the culture. The mRNA expression of neuronal-specific markers, Map2, Nefl, Tau, and Nestin, was significantly higher, indicating that the treated cells differentiated into neuronal-like cells. Immunostaining showed that differentiated cells were positive for the neuronal markers Flk, Nef, Nestin, and β-tubulin.

Perivascular Mesenchymal Stem Cells From the Adult Human Brain Harbor No Instrinsic Neuroectodermal but High Mesodermal Differentiation Potential

Brain perivascular cells have recently been identified as a novel mesodermal cell type in the human brain. These cells reside in the perivascular niche and were shown to have mesodermal and, to a lesser extent, tissue-specific differentiation potential. Mesenchymal stem cells (MSCs) are widely proposed for use in cell therapy in many neurological disorders; therefore, it is of importance to better understand the "intrinsic" MSC population of the human brain. We systematically characterized adult human brain-derived pericytes during in vitro expansion and differentiation and compared these cells with fetal and adult human brain-derived neural stem cells (NSCs) and adult human bone marrow-derived MSCs. We found that adult human brain pericytes, which can be isolated from the hippocampus and from subcortical white matter, are-in contrast to adult human NSCs-easily expandable in monolayer cultures and show many similarities to human bone marrow-derived MSCs both regarding both surface marker expression and after whole transcriptome profile. Human brain pericytes showed a negligible propensity for neuroectodermal differentiation under various differentiation conditions but efficiently generated mesodermal progeny. Consequently, human brain pericytes resemble bone marrow-derived MSCs and might be very interesting for possible autologous and endogenous stem cell-based treatment strategies and cell therapeutic approaches for treating neurological diseases.

SIGNIFICANCE

Perivascular mesenchymal stem cells (MSCs) recently gained significant interest because of their appearance in many tissues including the human brain. MSCs were often reported as being beneficial after transplantation in the central nervous system in different neurological diseases; therefore, adult brain perivascular cells derived from human neural tissue were systematically characterized concerning neural stem cell and MSC marker expression, transcriptomics, and mesodermal and inherent neuroectodermal differentiation potential in vitro and in vivo after in utero transplantation. This study showed the lack of an innate neuronal but high mesodermal differentiation potential. Because of their relationship to mesenchymal stem cells, these adult brain perivascular mesodermal cells are of great interest for possible autologous therapeutic use.

Biological characteristics of muscle-derived satellite cells isolated from rats at different postnatal days

This study investigated the in vitro growth characteristics and differential potential of muscle-derived satellite cells (MDSCs) derived from rats at different postnatal (P) stages, in order to expand the range of source material for tissue engineering. Rat MDSCs were isolated from P5, P10, P15, P21 and P42 rat skeletal muscles using double enzyme digestion and differential adherent culture. Neurogenic, osteogenic and myogenic induction media were used to induce directed differentiation. Differentiated nerve cells, osteoblasts and myotubes were identified by their morphology and immunohistochemical staining. Most cells transformed into spindle-shaped mononuclear cells after 48 h and proliferated rapidly. MDSCs were difficult to isolate from P42 rats. After neurogenesis, four groups MDSCs formed neuron-specific enolase positive polygonal-shaped dendritic cells. After osteogenesis, P5, P10, P15 and P21 MDSCs formed Alizarin red- and osteocalcin-positive bone nodules. After myogenesis, myotubes were formed and were fast muscle myosin-positive. MDSCs derived from P5, P10, P15 and P21 rat skeletal muscle are easy to isolate, culture and amplify in vitro, which increases the range of source material available for tissue engineering.

Current proceedings of cerebral palsy

Cerebral palsy (CP) is a complicated disease with varying causes and outcomes. It has created significant burden to both affected families and societies, not to mention the quality of life of the patients themselves. There is no cure for the disease; therefore, development of effective therapeutic strategies is in great demand. Recent advances in regenerative medicine suggest that the transplantation of stem cells, including embryonic stem cells, neural stem cells, bone marrow mesenchymal stem cells, induced pluripotent stem cells, umbilical cord blood cells, and human embryonic germ cells, focusing on the root of the problem, may provide the possibility of developing a complete cure in treating CP. However, safety is the first factor to be considered because some stem cells may cause tumorigenesis. Additionally, more preclinical and clinical studies are needed to determine the type of cells, route of delivery, cell dose, timing of transplantation, and combinatorial strategies to achieve an optimal outcome.

Differentiation of equine mesenchymal stromal cells into cells of neural lineage: potential for clinical applications

Mesenchymal stromal cells (MSCs) are able to differentiate into extramesodermal lineages, including neurons. Positive outcomes were obtained after transplantation of neurally induced MSCs in laboratory animals after nerve injury, but this is unknown in horses. Our objectives were to test the ability of equine MSCs to differentiate into cells of neural lineage in vitro, to assess differences in morphology and lineage-specific protein expression, and to investigate if horse age and cell passage number affected the ability to achieve differentiation. Bone marrow-derived MSCs were obtained from young and adult horses. Following demonstration of stemness, MSCs were neurally induced and microscopically assessed at different time points. Results showed that commercially available nitrogen-coated tissue culture plates supported proliferation and differentiation. Morphological changes were immediate and all the cells displayed a neural crest-like cell phenotype. Expression of neural progenitor proteins, was assessed via western blot or immunofluorescence. In our study, MSCs generated from young and middle-aged horses did not show differences in their ability to undergo differentiation. The effect of cell passage number, however, is inconsistent and further experiments are needed. Ongoing work is aimed at transdifferentiating these cells into Schwann cells for transplantation into a peripheral nerve injury model in horses.

Differentiation of human umbilical cord matrix mesenchymal stem cells into neural-like progenitor cells and maturation into an oligodendroglial-like lineage

Mesenchymal stem cells (MSCs) are viewed as safe, readily available and promising adult stem cells, which are currently used in several clinical trials. Additionally, their soluble-factor secretion and multi-lineage differentiation capacities place MSCs in the forefront of stem cell types with expected near-future clinical applications. In the present work MSCs were isolated from the umbilical cord matrix (Wharton's jelly) of human umbilical cord samples. The cells were thoroughly characterized and confirmed as bona-fide MSCs, presenting in vitro low generation time, high proliferative and colony-forming unit-fibroblast (CFU-F) capacity, typical MSC immunophenotype and osteogenic, chondrogenic and adipogenic differentiation capacity. The cells were additionally subjected to an oligodendroglial-oriented step-wise differentiation protocol in order to test their neural- and oligodendroglial-like differentiation capacity. The results confirmed the neural-like plasticity of MSCs, and suggested that the cells presented an oligodendroglial-like phenotype throughout the differentiation protocol, in several aspects sharing characteristics common to those of bona-fide oligodendrocyte precursor cells and differentiated oligodendrocytes.

Adult limbal neurosphere cells: a potential autologous cell resource for retinal cell generation

The Corneal limbus is a readily accessible region at the front of the eye, separating the cornea and sclera. Neural colonies (neurospheres) can be generated from adult corneal limbus invitro. We have previously shown that these neurospheres originate from neural crest stem/progenitor cells and that they can differentiate into functional neurons invitro. The aim of this study was to investigate whether mouse and human limbal neurosphere cells (LNS) could differentiate towards a retinal lineage both invivo and invitro following exposure to a developing retinal microenvironment. In this article we show that LNS can be generated from adult mice and aged humans (up to 97 years) using a serum free culture assay. Following culture with developing mouse retinal cells, we detected retinal progenitor cell markers, mature retinal/neuronal markers and sensory cilia in the majority of mouse LNS experiments. After transplantation into the sub-retinal space of neonatal mice, mouse LNS cells expressed photoreceptor specific markers, but no incorporation into host retinal tissue was seen. Human LNS cells also expressed retinal progenitor markers at the transcription level but mature retinal markers were not observed invitro or invivo. This data highlights that mouse corneal limbal stromal progenitor cells can transdifferentiate towards a retinal lineage. Complete differentiation is likely to require more comprehensive regulation; however, the accessibility and plasticity of LNS makes them an attractive cell resource for future study and ultimately therapeutic application.

Cell based therapies in Parkinson's Disease

Parkinson’s disease (PD) is the second most common neurodegenerative disorder after Alzheimer’s disease. It is characterized by bradykinesia, hypokinesia/ akinesia, rigidity, tremor, and postural instability, caused by dopaminergic (DA) striatal denervation. The prevalence of PD increases from 50 years of age with steep rise after age 60 years. Current treatment of PD relies heavily on replacing lost dopamine either with its precursor L-dopa or dopamine agonists (ropinirole, pramipexole, bromocriptine, lisuride etc). Other pharmacological measures like catechol-O-methyltrasferase (COMT) inhibitors like entacopone, telcapone and monoamine oxidase B (MAO-B) inhibitors like selegiline and rasagiline are also useful, while L-dopa remains the gold standard in the treatment of PD. Emerging therapies are focusing on cell based therapeutics derived from various sources.

IGF-1 enhances cell proliferation and survival during early differentiation of mesenchymal stem cells to neural progenitor-like cells

BACKGROUND

There has been increasing interest recently in the plasticity of mesenchymal stem cells (MSCs) and their potential to differentiate into neural lineages. To unravel the roles and effects of different growth factors in the differentiation of MSCs into neural lineages, we have differentiated MSCs into neural lineages using different combinations of growth factors. Based on previous studies of the roles of insulin-like growth factor 1 (IGF-1) in neural stem cell isolation in the laboratory, we hypothesized that IGF-1 can enhance proliferation and reduce apoptosis in neural progenitor-like cells (NPCs) during differentiation of MSCs into NCPs.We induced MSCs differentiation under four different combinations of growth factors: (A) EGF + bFGF, (B) EGF + bFGF + IGF-1, (C) EGF + bFGF + LIF, (D) EGF + bFGF + BDNF, and (E) without growth factors, as a negative control. The neurospheres formed were characterized by immunofluorescence staining against nestin, and the expression was measured by flow cytometry. Cell proliferation and apoptosis were also studied by MTS and Annexin V assay, respectively, at three different time intervals (24 hr, 3 days, and 5 days). The neurospheres formed in the four groups were then terminally differentiated into neuron and glial cells.

RESULTS

The four derived NPCs showed a significantly higher expression of nestin than was shown by the negative control. Among the groups treated with growth factors, NPCs treated with IGF-1 showed the highest expression of nestin. Furthermore, NPCs derived using IGF-1 exhibited the highest cell proliferation and cell survival among the treated groups. The NPCs derived from IGF-1 treatment also resulted in a better yield after the terminal differentiation into neurons and glial cells than that of the other treated groups.

CONCLUSIONS

Our results suggested that IGF-1 has a crucial role in the differentiation of MSCs into neuronal lineage by enhancing the proliferation and reducing the apoptosis in the NPCs. This information will be beneficial in the long run for improving both cell-based and cell-free therapy for neurodegenerative diseases.

Gene markers of cellular aging in human multipotent stromal cells in culture

Introduction

Human multipotent stromal cells (MSCs) isolated from bone marrow or other tissue sources have great potential to treat a wide range of injuries and disorders in the field of regenerative medicine and tissue engineering. In particular, MSCs have inherent characteristics to suppress the immune system and are being studied in clinical studies to prevent graft-versus-host disease. MSCs can be expanded in vitro and have potential for differentiation into multiple cell lineages. However, the impact of cell passaging on gene expression and function of the cells has not been determined.

Methods

Commercially available human MSCs derived from bone marrow from six different donors, grown under identical culture conditions and harvested at cell passages 3, 5, and 7, were analyzed with gene-expression profiling by using microarray technology.

Results

The phenotype of these cells did not change as reported previously; however, a statistical analysis revealed a set of 78 significant genes that were distinguishable in expression between passages 3 and 7. None of these significant genes corresponded to the markers established by the International Society for Cellular Therapy (ISCT) for MSC identification. When the significant gene lists were analyzed through pathway analysis, these genes were involved in the top-scoring networks of cellular growth and proliferation and cellular development. A meta-analysis of the literature for significant genes revealed that the MSCs seem to be undergoing differentiation into a senescent cell type when cultured extensively. Consistent with the differences in gene expression at passage 3 and 7, MSCs exhibited a significantly greater potential for cell division at passage 3 in comparison to passage 7.

Conclusions

Our results identified specific gene markers that distinguish aging MSCs grown in cell culture. Confirmatory studies are needed to correlate these molecular markers with biologic attributes that may facilitate the development of assays to test the quality of MSCs before clinical use.

Potential of adipose-derived mesenchymal stem cells and skeletal muscle-derived satellite cells for somatic cell nuclear transfer mediated transgenesis in Arbas Cashmere goats

Somatic cell nuclear transfer is used to generate genetic models for research and new, genetically modified livestock varieties. Goat fetal fibroblast cells (gFFCs) are the predominant nuclear donors in Cashmere goat transgenic cloning, but have disadvantages. We evaluated the potential of goat adipose-derived mesenchymal stem cells (gADSCs) and goat skeletal muscle-derived satellite cells (gMDSCs) for somatic cell nuclear transfer, evaluating their proliferation, pluripotency, transfection efficiency and capacity to support full term development of embryos after additive gene transfer or homologous recombination. gADSCs and gMDSCs were isolated by enzyme digestion and differentiated into neurocytes, myotube cells and insulin-producing cells. Neuron-specific enolase, fast muscle myosin and insulin expression were determined by immunohistochemistry. Following somatic cell nuclear transfer with donor cells derived from gADSCs, gMDSCs and gFFCs, transfection and cloning efficiencies were compared. Red fluorescent protein levels were determined by quantitative PCR and western blotting. 5-Methylcytosine, H4K5, H4K12 and H3K18 were determined immunohistochemically. gADSCs and gMDSCs were maintained in culture for up to 65 passages, whereas gFFCs could be passaged barely more than 15 times. gADSCs and gMDSCs had higher fluorescent colony forming efficiency and greater convergence (20%) and cleavage (10%) rates than gFFCs, and exhibited differing H4K5 histone modification patterns after somatic cell nuclear transfer and in vitro cultivation. After transfection with a pDsRed2-1 expression plasmid, the integrated exogenous genes did not influence the pluripotency of gADSCs-pDsRed2-1 or gMDSCs-pDsRed2-1. DsRed2 mRNA expression by cloned embryos derived from gADSCs-pDsRed2-1 or gMDSCs-pDsRed2-1 was more than twice that of gFFCs-pDsRed2-1 embryos (P<0.01). Pregnancy rates of gADSCs-pDsRed2-1 and gMDSCs-pDsRed2-1 recipients were higher than those of gFFCs-pDsRed2-1 recipients (P<0.01). With their high proliferative capacity and transfection efficiency, gADSCs and gMDSCs are a valuable cell source for breeding new, genetically modified varieties of livestock by somatic cell nuclear transfer.

Human adult white matter progenitor cells are multipotent neuroprogenitors similar to adult hippocampal progenitors

Adult neural progenitor cells (aNPC) are a potential autologous cell source for cell replacement in neurologic diseases or for cell-based gene therapy of neurometabolic diseases. Easy accessibility, long-term expandability, and detailed characterization of neural progenitor cell (NPC) properties are important requisites for their future translational/clinical applications. aNPC can be isolated from different regions of the adult human brain, including the accessible subcortical white matter (aNPCWM), but systematic studies comparing long-term expanded aNPCWM with aNPC from neurogenic brain regions are not available. Freshly isolated cells from subcortical white matter and hippocampus expressed oligodendrocyte progenitor cell markers such as A2B5, neuron-glial antigen 2 (NG2), and oligodendrocyte transcription factor 2 (OLIG2) in ∼20% of cells but no neural stem cell (NSC) markers such as CD133 (Prominin1), Nestin, SOX2, or PAX6. The epidermal growth factor receptor protein was expressed in 18% of aNPCWM and 7% of hippocampal aNPC (aNPCHIP), but only a small fraction of cells, 1 of 694 cells from white matter and 1 of 1,331 hippocampal cells, was able to generate neurospheres. Studies comparing subcortical aNPCWM with their hippocampal counterparts showed that both NPC types expressed mainly markers of glial origin such as NG2, A2B5, and OLIG2, and the NSC/NPC marker Nestin, but no pericyte markers. Both NPC types were able to produce neurons, astrocytes, and oligodendrocytes in amounts comparable to fetal NSC. Whole transcriptome analyses confirmed the strong similarity of aNPCWM to aNPCHIP. Our data show that aNPCWM are multipotent NPC with long-term expandability similar to NPC from hippocampus, making them a more easily accessible source for possible autologous NPC-based treatment strategies.

Differentiation potential of menstrual blood- versus bone marrow-stem cells into glial-like cells

Menstrual blood is easily accessible, renewable, and inexpensive source of stem cells that have been interested for cell therapy of neurodegenerative diseases. In this study, we showed conversion of menstrual blood stem cells (MenSCs) into clonogenic neurosphere- like cells (NSCs), which can be differentiated into glial-like cells. Moreover, differentiation potential of MenSCs into glial lineage was compared with bone marrow stem cells (BMSCs). Differentiation potential of individual converted NSCs derived from MenSCs or BMSCs into glial-like cells was investigated using immunofluorescence staining and real-time polymerase chain reaction.The fibroblastic morphology of both MenSCs and BMSCs was turned into NSCs shape during first step of differentiation. NSCs derived from both BMSCs and MenSCs expressed higher levels of Olig-2 and Nestin markers compared to undifferentiated cells. The expression levels of myelin basic protein (MBP) mRNA up regulated only in BMSCs-NSCs no in MenSCs-NSCs. However, outgrowth of individual NSCs derived from both MenSCs and BMSCs into glial-like cells led to significant up regulation of glial fibrillary acidic protein,Olig-2 and MBP at mRNA and protein level accompanied with down regulation of Nestin protein.This is the first study demonstrating that MenSCs can be converted to NSCs with differentiation ability into glial-like cells. Accumulative data show different expression pattern of glial markers in differentiated MenSCs compared to BMSCs. The comparable differentiation potential, more accessibility and no invasive technique for sample collection of MenSCs in comparison with BMSCs introduce MenSCs as an apt, consistent and safe alternative to BMSCs for cell therapy of neurodegenerative diseases.

A comparison of the behavioral and anatomical outcomes in sub-acute and chronic spinal cord injury models following treatment with human mesenchymal precursor cell transplantation and recombinant decorin

This study assessed the potential of highly purified (Stro-1(+)) human mesenchymal precursor cells (hMPCs) in combination with the anti-scarring protein decorin to repair the injured spinal cord (SC). Donor hMPCs isolated from spinal cord injury (SCI) patients were transplanted into athymic rats as a suspension graft, alone or after previous treatment with, core (decorin(core)) and proteoglycan (decorin(pro)) isoforms of purified human recombinant decorin. Decorin was delivered via mini-osmotic pumps for 14 days following sub-acute (7 day) or chronic (1 month) SCI. hMPCs were delivered to the spinal cord at 3 weeks or 6 weeks after the initial injury at T9 level. Behavioral and anatomical analysis in this study showed statistically significant improvement in functional recovery, tissue sparing and cyst volume reduction following hMPC therapy. The combination of decorin infusion followed by hMPC therapy did not improve these measured outcomes over the use of cell therapy alone, in either sub-acute or chronic SCI regimes. However, decorin infusion did improve tissue sparing, reduce spinal tissue cavitation and increase transplanted cell survivability as compared to controls. Immunohistochemical analysis of spinal cord sections revealed differences in glial, neuronal and extracellular matrix molecule expression within each experimental group. hMPC transplanted spinal cords showed the increased presence of serotonergic (5-HT) and sensory (CGRP) axonal growth within and surrounding transplanted hMPCs for up to 2 months; however, no evidence of hMPC transdifferentiation into neuronal or glial phenotypes. The number of hMPCs was dramatically reduced overall, and no transplanted cells were detected at 8 weeks post-injection using lentiviral GFP labeling and human nuclear antigen antibody labeling. The presence of recombinant decorin in the cell transplantation regimes delayed in part the loss of donor cells, with small numbers remaining at 2 months after transplantation. In vitro co-culture experiments with embryonic dorsal root ganglion explants revealed the growth promoting properties of hMPCs. Decorin did not increase axonal outgrowth from that achieved by hMPCs. We provide evidence for the first time that (Stro-1(+)) hMPCs provide: i) an advantageous source of allografts for stem cell transplantation for sub-acute and chronic spinal cord therapy, and (ii) a positive host microenvironment that promotes tissue sparing/repair that subsequently improves behavioral outcomes after SCI. This was not measurably improved by recombinant decorin treatment, but does provide important information for the future development and potential use of decorin in contusive SCI therapy.

[Possible applications of new stem cell sources in neurology]

Stem cells provide broad possibilities in modern science and medicine. This counts not only for investigations of developmental aspects but also for cell-based therapies, pharmacotoxicological testing and improvements in personalized medicine. The recent described techniques of induced pluripotent stem cells, directly induced neural stem cells and directly induced neurons are a major step forward by providing new possibilities for research on neurological diseases. Nevertheless, a variety of questions remain open regarding stem cell-based therapeutic strategies including tumorigenicity and phenotypical stability in the receptor brain. The major hope is that the new stem cell-based neural cell systems will help to understand the pathophysiology of neurodegenerative diseases. The future will show whether and how stem cells will lead to successful restorative therapies and/or to suitable cell models for neurological diseases.

Induced neural stem cells (iNSCs) in neurodegenerative diseases

Recent advances in somatic cell reprogramming is one of the most important developments in neuroscience in the last decades since it offers for the first time the opportunity to work with disease/patient-specific neurons or other neural cell types. Induced pluripotent stem cells (iPSCs) can be differentiated into all cell types of the body enabling investigations not only on neurons but also on muscle or endothelial cells which are cell types often also of great interest in neurodegenerative diseases. The novel technology of direct lineage conversion of somatic cells into neurons (induced neurons; iNs) or into expandable multipotent neural stem cells (induced neural stem cells; iNSCs) provides interesting alternatives to the iPSC technology. These techniques have the advantage of easier cell culture, but only neurons (iNs) or neuroectodermal cells (iNSCs) can be generated. Although there are several open questions coming along with these new neural cell types, they hold great promises for both cell replacement and cell modelling of neurodegenerative diseases.

Neurogenic differentiation of human dental pulp stem cells using different induction protocols

OBJECTIVE

An investigation on neuronal differentiation capacity of human dental pulp stem cells (DPSCs) was still lacking. In this study, two different neuronal induction protocols were investigated and compared.

METHODS

The neuronal differentiation was induced using chemical or growth factor induction protocol. The differentiation was confirmed by the neurogenic mRNA and protein expression using polymerase chain reaction and immunocytochemistry, respectively.

RESULTS

Chemical-induced neuronal differentiation protocol promoted morphological change and β3-TUBULIN protein expression. Though, SOX2, SOX9, and β3-TUBULIN mRNA levels were not different compared with the control, indicating a defective differentiation. For growth factor induction protocol, the cells were exhibited neurite-like cellular process and positively stained with β3-TUBULIN. In addition, the increase in intracellular calcium was noted upon NMDA stimulation, implying the neuronal function. A dramatic increased mRNA expression of neurogenic markers [SOX2, SOX9, β3-TUBULIN, and gamma-aminobutyric acid (GABA receptors)] was noted as compared to the control. In addition, a remarkable increased expression of Notch signaling target gene, HEY1, was observed in growth factor-induced DPSCs derived neuronal-like cells compared with the control.

CONCLUSION

These data indicate that growth factor induction method is a preferable protocol for neuronal differentiation by DPSCs.

Generation of inner ear sensory cells from bone marrow-derived human mesenchymal stem cells

AIM

Hearing loss is the most common sensory disorder in humans, its main cause being the loss of cochlear hair cells. We studied the potential of human mesenchymal stem cells (hMSCs) to differentiate towards hair cells and auditory neurons.

MATERIALS & METHODS

hMSCs were first differentiated to neural progenitors and subsequently to hair cell- or auditory neuron-like cells using in vitro culture methods.

RESULTS

Differentiation of hMSCs to an intermediate neural progenitor stage was critical for obtaining inner ear sensory lineages. hMSCs generated hair cell-like cells only when neural progenitors derived from nonadherent hMSC cultures grown in serum-free medium were exposed to EGF and retinoic acid. Auditory neuron-like cells were obtained when treated with retinoic acid, and in the presence of defined growth factor combinations containing Sonic Hedgehog.

CONCLUSION

The results show the potential of hMSCs to give rise to inner ear sensory cells.

Human Mesenchymal Precursor Cells (Stro-1+) from Spinal Cord Injury Patients Improve Functional Recovery and Tissue Sparing in an Acute Spinal Cord Injury Rat Model

This study aimed to determine the potential of purified (Stro-1+) human mesenchymal precursor cells (hMPCs) to repair the injured spinal cord (SC) after transplantation into T-cell-deficient athymic RNU nude rats following acute moderate contusive spinal cord injury (SCI). hMPCs were isolated from the bone marrow (BM) stroma of SCI patients and transplanted as a suspension graft in medium [with or without immunosuppression using cyclosporin A (CsA)]. Extensive anatomical analysis shows statistically significant improvement in functional recovery, tissue sparing, and cyst reduction. We provide quantitative assessment of supraspinal projections in combination with functional outcomes. hMPC-transplanted animals consistently achieved mean BBB scores of 15 at 8 weeks postinjury. Quantitative histological staining revealed that graft-recipient animals possessed more intact spinal tissue and reduced cyst formation than controls. Fluorogold (FG) retrograde tracing revealed sparing/regeneration of supraspinal and local propriospinal axonal pathways, but no statistical differences were observed compared to controls. Immunohistochemical analysis revealed increased serotonergic (5-HT) and sensory (CGRP) axonal growth within and surrounding transplanted donor hMPCs 2 weeks posttransplantation, but no evidence of hMPC transdifferentiation was seen. Although hMPCs initially survive at 2 weeks posttransplantation, their numbers were dramatically reduced and no cells were detected at 8 weeks posttransplantation using retroviral/lentiviral GFP labeling and a human nuclear antigen (HNA) antibody. Additional immunosuppression with CsA did not improve hMPC survival or their ability to promote tissue sparing or functional recovery. We propose Stro-1+-selected hMPCs provide (i) a reproducible source for stem cell transplantation for SC therapy and (ii) a positive host microenvironment resulting in the promotion of tissue sparing/repair that subsequently improves behavioral outcomes after SCI. Our results provide a new candidate for consideration as a stem cell therapy for the repair of traumatic CNS injury.

Notch signaling is involved in neurogenic commitment of human periodontal ligament-derived mesenchymal stem cells

Notch signaling plays critical roles in stem cells by regulating cell fate determination and differentiation. The aim of this study was to evaluate the participation of Notch signaling in neurogenic commitment of human periodontal ligament-derived mesenchymal stem cells (hPDLSCs) and to examine the ability to control differentiation of these cells using modified surfaces containing affinity immobilized Notch ligands. Neurogenic induction of hPDLSCs was performed via neurosphere formation. Cells were aggregated and form spheres as early 1 day in culture. In addition, the induced cells exhibited increased mRNA and protein expression of neuronal markers that is, β3-tubulin and neurofilament. During neuronal differentiation, a significant increase of Hes1 and Hey1 mRNA expression was noted. Using pharmacological inhibition (γ-secretase inhibitor) or genetic manipulation (overexpression of dominant negative mastermind-like transcription co-activators), neurosphere formation was attenuated and a marked decrease in neurogenic mRNA expression was observed. To confirm the role of Notch signaling in neuronal differentiation of hPDLSCs, the Notch ligand, Jagged-1, is bound to the surface using an affinity immobilization technique. The hPDLSC cultured on a Jagged-1-modified surface had increased expression of Notch signaling target genes, Hes-1 and Hey-1, confirming the activity and potency of surface-bound Jagged-1. Further, hPDLSC on surface-bound Jagged-1 under serum-free conditions showed multiple long and thin neurite-like extensions, and an increase in the expression of neurogenic mRNA markers was observed. Pretreatment of the cells with γ-secretase inhibitor, DAPT, before seeding on the Jagged-1-modified surface blocked development of the neurite-like morphology. Together, the results in this study suggest the involvement of Notch signaling in neurogenic commitment of hPDLSCs.

MicroRNAs as markers for neurally committed CD133+/CD34+ stem cells derived from human umbilical cord blood

Neural differentiation of the CD133+/CD34+ subpopulation of human umbilical cord blood stem cells was investigated, and neuro-miR (mir-9 and mir-124) expression was examined. An efficient induction protocol for neural differentiation of hematopoietic stem cells together with the exclusion of retinoic acid in this process was also studied. Transcription of some neural markers such as microtubule-associated protein-2, beta-tubulin III, and neuron-specific enolase was evaluated by real-time PCR, immunocytochemistry, and western blotting. Increased expression of neural indicators in the treated cells confirmed the appropriate neural differentiation, which supported the high efficiency of our defined neuronal induction protocol. Verified high expression of neuro-miRNAs along with neuronal specific proteins not only strengthens the regulatory role of miRNAs in determining stem cell fate but also introduces these miRNAs as novel indicators of neural differentiation. These data highlight the prominent therapeutic potential of hematopoietic stem cells for use in cell therapy of neurodegenerative diseases.

Human oral mucosa and gingiva: a unique reservoir for mesenchymal stem cells

Mesenchymal stem cells (MSCs) represent a heterogeneous population of progenitor cells with self-renewal and multipotent differentiation potential. Aside from their regenerative role, extensive in vitro and in vivo studies have demonstrated that MSCs are capable of potent immunomodulatory effects on a variety of innate and adaptive immune cells. In this article, we will review recent experimental studies on the characterization of a unique population of MSCs derived from human oral mucosa and gingiva, especially their immunomodulatory and anti-inflammatory functions and their application in the treatment of several in vivo models of inflammatory diseases. The ease of isolation, accessible tissue source, and rapid ex vivo expansion, with maintenance of stable stem-cell-like phenotypes, render oral mucosa- and gingiva-derived MSCs a promising alternative cell source for MSC-based therapies.

Neural differentiation ability of mesenchymal stromal cells from bone marrow and adipose tissue: a comparative study

BACKGROUND AIMS

The characteristics, such as morphologic and phenotypic characteristics and neural transdifferentiation ability, of mesenchymal stromal cells (MSC) derived from different origins have yet to be reported for cases isolated from the same individual.

METHODS

The proliferation capacity, secretion ability of neurotrophins (NT) and neural differentiation ability in rat MSC isolated from bone marrow (BMSC) and adipose tissue (ADSC) were compared from the same animal.

RESULTS

The ADSC had a significantly higher proliferation capacity than BMSC according to cell cycle and cumulative population doubling analyses. The proportion of cells expressing neural markers was greater in differentiated ADSC than in differentiated BMSC. Furthermore, the single neurosphere derived from ADSC showed stronger expansion and differentiation abilities than that derived from BMSC. The findings from Western blot lent further support to the immunocytochemical data. The mRNA and protein levels of nerve growth factor (NGF) and brain-derived growth factor (BDNF) expressed in ADSC were significantly higher than those in BMSC at different stages before and following induction.

CONCLUSIONS

Our study suggests that the proliferation ability of ADSC is superior to that of BMSC. Furthermore, differentiated ADSC expressed higher percentages of neural markers. As one possible alternative source of BMSC, ADSC may have wide potential for treating central nervous system (CNS) diseases.

In vitro analysis of mesenchymal stem cells derived from human teeth and bone marrow

Mesenchymal stem cells derived from human teeth and bone marrow have been characterized by many research groups, but demonstrate inconsistent cellular phenotypes or functions, partly because of differences in culture methodology. Therefore, our aims were to resolve these inconsistencies and discuss the potential uses of these cells in research/clinical applications. We isolated and characterized dental stem cells (DSCs) from the dental pulp, periodontal ligament, apical papilla (APSCs) and dental follicle (DFSCs) of mature and immature teeth, along with bone marrow-derived stem cells (BMSCs) from the iliac crest. We compared the clonogenic and proliferative potentials of these cells in terms of colony-forming efficiency, proliferation potential, population doubling time and cell cycle. All DSCs, particularly APSCs and DFSCs, possessed greater proliferative potential than BMSCs. All stem cells expressed typical mesenchymal and embryonic markers, and developed alizarin red-positive mineralization nodules and Oil red O-positive lipid droplets when cultured in osteogenic and adipogenic media, respectively. Immunocytochemistry revealed that all stem cells developed neuronal markers when cultured in a control medium without neural inductive supplements. After 7 days of neurogenic culture, the differentiated cells showed a transition from fibroblast-like to neuron-like cell bodies with long processes, suggesting that the stem cells differentiated into mature neurons. Karyotyping confirmed that the stem cells maintained a normal karyotype and were chromosomally stable. Our results provide new insights into the physiological properties of stem cells with a normal karyotype and indicate that DSCs are appropriate for basic research and clinical applications.

Characterization of autologous mesenchymal stem cell-derived neural progenitors as a feasible source of stem cells for central nervous system applications in multiple sclerosis

Bone marrow mesenchymal stem cell-derived neural progenitors (MSC-NPs) are a potential therapeutic source of cells that have been shown to be efficacious in a preclinical model of multiple sclerosis (MS). To examine the feasibility of using MSC-NPs as an autologous source of cells to promote central nervous system (CNS) repair in MS, this study characterized human MSC-NPs from a panel of both MS and non-MS donors. Expanded MSCs showed similar characteristics in terms of growth and cell surface phenotype, regardless of the donor disease status. MSC-NPs derived from all MSCs showed a consistent pattern of gene expression changes that correlated with neural commitment and increased homogeneity. Furthermore, the reduced expression of mesodermal markers and reduced capacity for adipogenic or osteogenic differentiation in MSC-NPs compared with MSCs suggested that MSC-NPs have reduced potential of unwanted mesodermal differentiation upon CNS transplantation. The immunoregulatory function of MSC-NPs was similar to that of MSCs in their ability to suppress T-cell proliferation and to promote expansion of FoxP3-positive T regulatory cells in vitro. In addition, MSC-NPs promoted oligodendroglial differentiation from brain-derived neural stem cells that correlated with the secretion of bioactive factors. Our results provide a set of identity characteristics for autologous MSC-NPs and suggest that the in vitro immunoregulatory and trophic properties of these cells may have therapeutic value in the treatment of MS.

Gene expression profile of adult human olfactory bulb and embryonic neural stem cell suggests distinct signaling pathways and epigenetic control

Global gene expression profiling was performed using RNA from human embryonic neural stem cells (hENSC), and adult human olfactory bulb-derived neural stem cells (OBNSCs), to define a gene expression pattern and signaling pathways that are specific for each cell lineage. We have demonstrated large differences in the gene expression profile of human embryonic NSC, and adult human OBNSCs, but less variability between parallel cultures. Transcripts of genes involved in neural tube development and patterning (ALDH1A2, FOXA2), progenitor marker genes (LMX1a, ALDH1A1, SOX10), proliferation of neural progenitors (WNT1 and WNT3a), neuroplastin (NPTN), POU3F1 (OCT6), neuroligin (NLGN4X), MEIS2, and NPAS1 were up-regulated in both cell populations. By Gene Ontology, 325 out of 3875 investigated gene sets were scientifically different. 41 out of the 307 investigated Cellular Component (CC) categories, 45 out of the 620 investigated Molecular Function (MF) categories, and 239 out of the 2948 investigated Biological Process (BP) categories were significant. KEGG Pathway Class Comparison had revealed that 75 out of 171 investigated gene sets passed the 0.005 significance threshold. Levels of gene expression were explored in three signaling pathways, Notch, Wnt, and mTOR that are known to be involved in NS cell fates determination. The transcriptional signature also deciphers the role of genes involved in epigenetic modifications. SWI/SNF DNA chromatin remodeling complex family, including SMARCC1 and SMARCE1, were found specifically up-regulated in our OBNSC but not in hENSC. Differences in gene expression profile of transcripts controlling epigenetic modifications, and signaling pathways might indicate differences in the therapeutic potential of our examined two cell populations in relation to in cell survival, proliferation, migration, and differentiation following engraftments in different CNS insults.