Adult hippocampus derived soluble factors induce a neuronal-like phenotype in mesenchymal stem cells

Cerebrospinal fluid-stem cell interactions may pave the path for cell-based therapy in neurological diseases

Recent studies have suggested that the regulation of endogenous neural stem cells (NSCs) or transplanting of exogenous nerve cells are the newest and most promising methods for the treatment of dementia and other neurological diseases. The special location and limited number of endogenous NSCs, however, restrict their clinical application. The success in directional differentiation of exogenous stem cells from other tissue sources into neural cells has provided a novel source for NSCs. Study on the relative mechanisms is still at the preliminary stage. Currently the induction methods include: 1) cell growth factor induction; 2) chemical induction; 3) combined growth factor-chemical induction; or 4) other induction methods such as traumatic brain tissue homogenate, gene transfection, traditional Chinese medicine, and coculture induction. Cerebrospinal fluid (CSF), as a natural medium under physiological conditions, contains a variety of progrowth peptide factors that can promote the proliferation and differentiation of mesenchymal stromal cells (MSCs) into neural cells through the corresponding receptors on the cell surface. This suggests that CSF can not only nourish the nerve cells, but also become an effective and suitable inducer to increase the yield of NSCs. However, some other studies believed that CSF contained certain inhibitory components against the differentiation of primary stem cells into mature neural cells. Based on the above background, here we review the relative literature on the influence of the CSF on stem cells in order to provide a more comprehensive reference for the wide clinical application of NSCs in the future.

Differentiation of mesenchymal stem cells into neural stem cells using cerebrospinal fluid

Optimization of a methodology for mesenchymal stem cells (MSCs) differentiation into neural stem cells (NSCs) using cerebrospinal fluid (CSF). MSCs were extracted from umbilical cord blood from healthy, full-term, newborn infants and from the bone marrow of patients. CSF was taken from healthy adult volunteers and patients. Four groups investigated were: A (n = 8) cord blood MSC induced with healthy volunteer CSF (control group); B (n = 7): patient MSCs induced with health volunteer CSF; Group C (n = 12): patient MSCs induced with their own CSF; group D (n = 6): cord blood MSCs induced with patient CSF. Following induction, cell differentiation state was examined using microscopy, flow cytometry, and immunohistochemistry. There were significantly more clinically applicable MSCs in Groups B and C than groups A and D (P < 0.05) and Group B had significantly more clinically applicable MSCs than group C (P < 0.05). The presence of NSCs was as with the MSCs. Group B had significantly more clinically applicable NSCs than all of the other groups. In addition, group B cells grew significantly faster than the other groups (P < 0.05). Upon CSF induction, MSCs differentiated into NSCs suitable for clinical treatment. The source of the MSCs and/or CSF influenced the number of NSCs produced and the NSC growth rate. Thus, the source of MSCs and CSF should be considered before initiating a stem cell clinical treatment.

Mesenchymal stem cell therapy for the treatment of amyotrophic lateral sclerosis: signals for hope?

Based on the distinctive cellular, molecular and immunomodulatory traits of mesenchymal stem cells (MSC), it has been postulated that these cells may play a critical role in regenerative medicine. In addition to the participation of MSC in the repair of mesodermal-derived tissues (bone, cartilage), robust data have suggested that MSC may also play a reparative role in conditions involving damage of cells of ectodermal origin. The above content has been supported by the capability of MSC to differentiate into neuron-like cells as well as by a competence to generate a ‘neuroprotective’ environment. In turn, several preclinical studies have put forward the concept that MSC therapy may represent an option for the treatment of several neurological disorders and injuries, including amyotrophic lateral sclerosis. We expect that the above foundations, which have inspired this review, may result in the founding of an effective and/or palliative therapy for amyotrophic lateral sclerosis.

Using the endocannabinoid system as a neuroprotective strategy in perinatal hypoxic-ischemic brain injury

One of the most important causes of brain injury in the neonatal period is a perinatal hypoxic-ischemic event. This devastating condition can lead to long-term neurological deficits or even death. After hypoxic-ischemic brain injury, a variety of specific cellular mechanisms are set in motion, triggering cell damage and finally producing cell death. Effective therapeutic treatments against this phenomenon are still unavailable because of complex molecular mechanisms underlying hypoxic-ischemic brain injury. After a thorough understanding of the mechanism underlying neural plasticity following hypoxic-ischemic brain injury, various neuroprotective therapies have been developed for alleviating brain injury and improving long-term outcomes. Among them, the endocannabinoid system emerges as a natural system of neuroprotection. The endocannabinoid system modulates a wide range of physiological processes in mammals and has demonstrated neuroprotective effects in different paradigms of acute brain injury, acting as a natural neuroprotectant. The aim of this review is to study the use of different therapies to induce long-term therapeutic effects after hypoxic-ischemic brain injury, and analyze the important role of the endocannabinoid system as a new neuroprotective strategy against perinatal hypoxic-ischemic brain injury.

Neuroprotective therapies after perinatal hypoxic-ischemic brain injury

Hypoxic-ischemic (HI) brain injury is one of the main causes of disabilities in term-born infants. It is the result of a deprivation of oxygen and glucose in the neural tissue. As one of the most important causes of brain damage in the newborn period, the neonatal HI event is a devastating condition that can lead to long-term neurological deficits or even death. The pattern of this injury occurs in two phases, the first one is a primary energy failure related to the HI event and the second phase is an energy failure that takes place some hours later. Injuries that occur in response to these events are often manifested as severe cognitive and motor disturbances over time. Due to difficulties regarding the early diagnosis and treatment of HI injury, there is an increasing need to find effective therapies as new opportunities for the reduction of brain damage and its long term effects. Some of these therapies are focused on prevention of the production of reactive oxygen species, anti-inflammatory effects, anti-apoptotic interventions and in a later stage, the stimulation of neurotrophic properties in the neonatal brain which could be targeted to promote neuronal and oligodendrocyte regeneration.

Recovery of fertility in azoospermia rats after injection of adipose-tissue-derived mesenchymal stem cells: the sperm generation

The recent reports on the treatment of azoospermia patients, in which spermatozoa could not be traced in their testes, are focused more on the potential use of adult stem cells, like mesenchymal stem cells (MSCs). The aim of this study was to demonstrate the potential use of MSCs derived from adipose tissue in the treatment of azoospermia using rat disease models. After busulfan application, the rats (n = 20) were injected with the GFP⁺ MSCs into left rete testes. After 12 weeks, the testes with cell injection (right testes) were compared to control (left testes) after dimensional and immunohistochemical analyses. Testes treated with MSCs appeared morphologically normal, but they were atrophic in rats without stem cell treatment, in which the seminiferous tubules were empty. Spermatogenesis was detected, not in every but in some tubules of cell-treated testes. GFP⁺/VASA⁺ and GFP⁺/SCP1⁺ cells in testes indicated the transdifferentiation of MSCs into spermatogenetic cells in the appropriate microenvironment. Rats with cell treatment were mated to show the full recovery of spermatogenesis, and continuous generations were obtained. The expression of GFP was detected in the mesenchymal stem cells derived from adipose tissue and bone marrow and also in the sperms of offspring. In conclusion, MSCs might be studied for the same purpose in humans in future.

Adult rat hippocampus soluble factors: a novel transplantation model mimicking intracranial microenvironment for tracing the induction and differentiation of adipose-derived stromal cells in vitro

Intracranial transplantation of ADSCs induces recovery of CNS diseases, but how they develop in host is poorly understood. The aim of this study is to observe induction and differentiation of ADSCs in the presence of hippocampus soluble factors (HiSF) extracted from the hippocampus of adult Wistar rats to mimic an intracranial microenvironment. To determine the optimal microenvironment, five conditions were tested: 0μg/ml (as control), 50μg/ml, 100μg/ml, 200μg/ml, and 400μg/ml of HiSF. The number of neurospheres was significantly higher in 200μg/ml group than in other groups on the sixth day. Immunofluorescence demonstrated that the neurospheres induced from ADSCs in 200μg/ml group expressed both nestin and CD133, which are more highly expressed in neurospheres than in ADSCs. This result was confirmed by Western blot analysis. Quantitative PCR revealed that the mRNA levels of nestin and CD133 in the neurospheres were 145- and 220-fold higher, respectively, than those in ADSCs. In the presence of 200μg/ml HiSF and 1% FBS, the neurospheres can further differentiate into Schwann-like cells which expressing characteristic markers GFAP, S100 and P75 NGFR. These data indicated that HiSF, mimicking a destination of ADSCs transplanted model in vitro, could effectively induce and differentiate neurospheres, representing a new method to obtain NSCs and Schwann-like cells from ADSCs.

The remyelination Philosopher's Stone: stem and progenitor cell therapies for multiple sclerosis

Multiple sclerosis (MS) is an autoimmune disease that leads to oligodendrocyte loss and subsequent demyelination of the adult central nervous system (CNS). The pathology is characterized by transient phases of recovery during which remyelination can occur as a result of resident oligodendroglial precursor and stem/progenitor cell activation. However, myelin repair efficiency remains low urging the development of new therapeutical approaches that promote remyelination activities. Current MS treatments target primarily the immune system in order to reduce the relapse rate and the formation of inflammatory lesions, whereas no therapies exist in order to regenerate damaged myelin sheaths. During the last few years, several transplantation studies have been conducted with adult neural stem/progenitor cells and glial precursor cells to evaluate their potential to generate mature oligodendrocytes that can remyelinate axons. In parallel, modulation of the endogenous progenitor niche by neural and mesenchymal stem cell transplantation with the aim of promoting CNS progenitor differentiation and myelination has been studied. Here, we summarize these findings and discuss the properties and consequences of the various molecular and cell-mediated remyelination approaches. Moreover, we address age-associated intrinsic cellular changes that might influence the regenerative outcome. We also evaluate the extent to which these experimental treatments might increase the regeneration capacity of the demyelinated human CNS and hence be turned into future therapies.

Vertically aligned carbon nanotube electrodes directly grown on a glassy carbon electrode

Three-dimensional microelectrodes were fabricated using glassy carbon electrodes combined with vertically aligned carbon nanotubes (VACNTs). VACNTs were grown on various conducting electrode patterns including a carbon electrode fabricated by pyrolysis of a negative photoresist, with plasma-enhanced chemical vapor deposition using a bilayer Fe/Al catalyst. VACNT electrodes grown on the glassy carbon showed excellent electrochemical behavior, whereas VACNT electrodes grown on Pt showed poor electrochemical performance, presumably due to the poor contact between VACNTs and the Pt electrode. Electron microscopy showed that the VACNT layer was strongly bound to the carbon electrode, while that on Pt tended to peel away. The versatility of the all-carbon microelectrodes was also tested by using them for interfacing stem cells. Their superior mechanical properties and the electrical connectivity between the carbon electrode and the VACNTs, along with the simple fabrication process, suggest that glassy carbon may be a good conducting substrate for VACNT electrodes.

Cocaine- and amphetamine-regulated transcript promotes the differentiation of mouse bone marrow-derived mesenchymal stem cells into neural cells

Background

Neural tissue has limited potential to self-renew after neurological damage. Cell therapy using BM-MSCs (bone marrow mesenchymal stromal cells) seems like a promising approach for the treatment of neurological diseases. However, the neural differentiation of stem cells influenced by massive factors and interactions is not well studied at present.

Results

In this work, we isolated and identified MSCs from mouse bone marrow. Co-cultured with CART (0.4 nM) for six days, BM-MSCs were differentiated into neuron-like cells by the observation of optical microscopy. Immunofluorescence demonstrated that the differentiated BM-MSCs expressed neural specific markers including MAP-2, Nestin, NeuN and GFAP. In addition, NeuN positive cells could co-localize with TH or ChAT by double-labled immunofluorescence and Nissl bodies were found in several differentiated cells by Nissl stain. Furthermore, BDNF and NGF were increased by CART using RT-PCR.

Conclusion

This study demonstrated that CART could promote the differentiation of BM-MSCs into neural cells through increasing neurofactors, including BNDF and NGF. Combined application of CART and BM-MSCs may be a promising cell-based therapy for neurological diseases.

Pharmacological neuroprotection after perinatal hypoxic-ischemic brain injury

Perinatal hypoxia-ischemia (HI) is an important cause of neonatal brain injury. Recent progress in the search for neuroprotective compounds has provided us with several promising drugs to reduce perinatal HI-induced brain injury. In the early stage (first 6 hours after birth) therapies are concentrated on prevention of the production of reactive oxygen species or free radicals (xanthine-oxidase-, nitric oxide synthase-, and prostaglandin inhibition), anti-inflammatory effects (erythropoietin, melatonin, Xenon) and anti-apoptotic interventions (nuclear factor kappa B- and c-jun N-terminal kinase inhibition); in a later stage stimulation of neurotrophic properties in the neonatal brain (erythropoietin, growth factors) can be targeted to promote neuronal and oligodendrocyte regeneration. Combination of pharmacological means of treatment with moderate hypothermia, which is accepted now as a meaningful therapy, is probably the next step in clinical treatment to fight post-asphyxial brain damage. Further studies should be directed at a more rational use of therapies by determining the optimal time and dose to inhibit the different potentially destructive molecular pathways or to enhance endogenous repair while at the same time avoiding adverse effects of the drugs used.

Engraftment of human nasal olfactory stem cells restores neuroplasticity in mice with hippocampal lesions

Stem cell-based therapy has been proposed as a potential means of treatment for a variety of brain disorders. Because ethical and technical issues have so far limited the clinical translation of research using embryonic/fetal cells and neural tissue, respectively, the search for alternative sources of therapeutic stem cells remains ongoing. Here, we report that upon transplantation into mice with chemically induced hippocampal lesions, human olfactory ecto-mesenchymal stem cells (OE-MSCs) - adult stem cells from human nasal olfactory lamina propria - migrated toward the sites of neural damage, where they differentiated into neurons. Additionally, transplanted OE-MSCs stimulated endogenous neurogenesis, restored synaptic transmission, and enhanced long-term potentiation. Mice that received transplanted OE-MSCs exhibited restoration of learning and memory on behavioral tests compared with lesioned, nontransplanted control mice. Similar results were obtained when OE-MSCs were injected into the cerebrospinal fluid. These data show that OE-MSCs can induce neurogenesis and contribute to restoration of hippocampal neuronal networks via trophic actions. They provide evidence that human olfactory tissue is a conceivable source of nervous system replacement cells. This stem cell subtype may be useful for a broad range of stem cell-related studies.

Pharmacological neuroprotection after perinatal asphyxia

Recent progress has provided us with several promising neuroprotective compounds to reduce perinatal hypoxic-ischemic (HI) brain injury. In the early post HI phase, therapies can be concentrated on ion channel blockage (Xenon), anti-oxidation (allopurinol, 2-iminobiotin, and indomethacin), anti-inflammation (erythropoietin [EPO], melatonin), and anti-apoptosis (nuclear factor kappa B [NF-&#x03BA;B]and c-jun N-terminal kinase [JNK] inhibitors); in the later phase, therapies should be targeted to promote neuronal regeneration by stimulation of neurotrophic properties of the neonatal brain (EPO, growth factors, stem cells transplantation). Combination of pharmacological interventions with moderate hypothermia, which is the only established therapy for post HI brain injury, is probably the next step to fight HI brain damage in the clinical setting. Further studies should be concentrated on more rational pharmacological strategies by determining the optimal time and dose to inhibit the various potentially destructive molecular pathways and/or to enhance endogenous repair meanwhile avoiding the adverse effects.

Bone marrow-derived mesenchymal stem cells co-cultured with pancreatic islets display β cell plasticity

The direct co-culturing effect of rat bone-marrow-derived mesenchymal stem cells (rBM-MSCs) on the pancreatic-islets (PIs) was studied to obtain functional islet cells. MSCs were isolated from rat bone marrow and cultivated under standard conditions. Following their characterization, the rBM-MSCs were directly (with cell-islet contact) co-cultured with recovered PIs together with the single cell cultures of those cell cultures as a control. The effect of direct co-cultures of rBM-MSCs with the PIs of normal rats was investigated using immunophenotypical and functional methods. The change in the amount of insulin secretion was evaluated as an indicator for differentiation of rBM-MSCs. One approache for in vitro differentiation to achieve reprogramming for differentiation into suitable cell types by changing the microenvironment of the cells to provide signals that might activate metabolic pathways is to use co-cultures with the microenvironment of the specific cells of the desired cell type, tissue/organ extracts, extracellular matrix compounds or biologically absorbable materials. Differentiated rBM-MSCs were found to be immunopositive for the specific insulin-producing cell marker, insulin, but not in undifferentiated rBM-MSCs. The functionality tests by ELISA confirmed that insulin secretion of co-cultured MSCs with islets was higher than that of islets. These evidences indicated that PIs could be regarded as critical components of the stem cell niche, such that MSCs can be differentiated into insulin-producing cells (IPCs). Moreover, direct cell-to-cell contact might provide additional and independent support. This approach would circumvent the need for PI-stem cell co-culture and could potentially facilitate the production of functional IPCs for future clinical applications.

Regeneration of the ischemic brain by engineered stem cells: fuelling endogenous repair processes

After ischemic brain injury various cell types including neurons, glia and endothelial cells are damaged and lose their function. Effective regeneration of brain tissue requires that all these cell types have to be replenished and combined to form a new functional network. Recent advances in regenerative medicine show the ability of stem cells to differentiate into various cell lineages. Several types of stem cells have been used to treat ischemic brain injury in rodent models including neuronal stem cells, mesenchymal stem cells and hematopoietic stem cells. Although these studies show promising results, it remains to be determined whether the beneficial effect of cell-based therapies in ischemic brain injury results from direct replacement of damaged cells by the transplanted cells. On the basis of the current literature we propose that neuroprotection by activation of anti-apoptotic mechanisms as well as improvement of the trophic milieu necessary for endogenous repair processes may be more important mechanisms underlying the improved functional outcome after stem cell treatment. Transplantation of native unmodified stem cells as such may not be sufficient to boost repair mechanisms provided by the endogenous stem cell population. An important aim of this review is to discuss the literature on the possible enhancement of regenerative function by combining stem cell transplantation with gene transduction into stem cells to enhance their regenerative and neuroprotective therapeutic potential. Finally, we briefly discuss the possibility of translation of this therapy to the clinic.

Are trials of intravascular infusions of autologous mesenchymal stem cells in patients with multiple system atrophy currently justified, and are they effective?

Scientists and patients are keen to apply new experimental techniques to human diseases, especially currently untreatable progressive neurodegenerative diseases, of which multiple system atrophy (MSA) is an example. We argue that it behooves us to first have robust preclinical experimental evidence before launching into such studies in humans, and to control as much as possible for confounding effects when such trials come to be performed.