Neuronal Stem Cells Research Articles

Food-derived hydrophilic antioxidant ergothioneine is distributed to the brain and exerts antidepressant effect in mice.

BackgroundClinically used antidepressants suffer from various side effects. Therefore, we searched for a safe antidepressant with minimal side effects among food ingredients that are distributed to the brain. Here, we focused on ERGO (ergothioneine), which is a hydrophilic antioxidant and contained at high levels in edible golden oyster mushrooms. ERGO is a typical substrate of carnitine/organic cation transporter OCTN1/SLC22A4, which is expressed in the brain and neuronal stem cells, although little is known about its permeation through the BBB (blood–brain barrier) or its neurological activity.MethodsTo clarify the exposure of ERGO to brain and the possible antidepressant‐like effect after oral ingestion, ERGO or GOME (golden oyster mushroom extract) which contains 1.2% (w/w) ERGO was mixed with feed and provided to mice for 2 weeks, and then ERGO concentration and antidepressant‐like effect were evaluated by LC‐MS/MS and FST (forced swimming test) or TST (tail suspension test), respectively.ResultsDiet containing ERGO or GOME greatly increased the ERGO concentrations in plasma and brain, and significantly decreased the immobility time in both FST and TST. The required amount of GOME (~37 mg/day) to show the antidepressant‐like effect corresponds to at most 8 g/day in humans. In mice receiving GOME‐containing diet, doublecortin‐positive cells showed a significant increase from the basal level, suggesting promotion of neuronal differentiation.ConclusionThus, orally ingested ERGO is transported across the BBB into the brain, where it may promote neuronal differentiation and alleviate symptoms of depression at plausibly achieved level of daily ingestion.

Mature neurons modulate neurogenesis through chemical signals acting on neural stem cells.

The discovery of neural stem cells has revealed a much higher structural and functional plasticity in the adult nervous system than previously anticipated. Progenitor cells are able to give rise to new neurons and glial cells when needed, thanks to their surveillance of the environment from the germinal niches. Multiple different factors define neural stem cell niches, including cellular and non-cellular components. Innervation of neurogenic centers is crucial, as it allows the functional connection between stem cell behavior and surrounding neuronal activity. Although the association between organismal behavior and neurogenesis is well documented, much less is known about the cellular and molecular mechanisms by which neurons control stem cell activity. In this review we discuss the existing data on this type of regulation from the three best characterized germinal niches in the adult nervous system: the subventricular zone, the hippocampal subgranular zone, and the carotid body. In all cases, neuronal activity modulates stem cell behavior either by neurotransmitter spillover or by synaptic-like contacts. Currently, the molecular mechanisms underlying mature neuron-stem cell interaction are being clarified. Functional consequences and potential clinical relevance of these phenomena are also discussed.

Trim69 regulates zebrafish brain development by ap-1 pathway.

Proteins belonging to the TRIM family have been implicated in a variety of cellular processes such as apoptosis, differentiation, neurogenesis, muscular physiology and innate immune responses. Trim69, previously identified as a novel gene cloned from a human testis cDNA library, has a homologous gene in zebrafish and this study focused on investigating the function of trim69 in zebrafish neurogenesis. Trim69 was found to be expressed in zebrafish embryo brain at the early stages. Knockdown of trim69 led to deformed brain development, obvious signs of apoptosis present in the head, and decreased expression of neuronal differentiation and stem cell markers. This phenotype was rescued upon co-injection of human mRNA together along with the trim69 knockdown. Results of this study also showed an interaction between TRIM69 and c-Jun in human cells, and upon TRIM69 knock down c-Jun expression subsequently increased, whereas the over-expression of TRIM69 led to the down-regulation of c-Jun. Additionally, knockdown both c-Jun and trim69 can rescue the deformed brain, evident cellular apoptosis in the head and decreased expression of neuronal differentiation and stem cell markers. Overall, our results support a role for trim69 in the development of the zebrafish brain through ap-1 pathway.

Nuclear receptor TLX inhibits TGF-β signaling in glioblastoma

TLX (also called NR2E1) is an orphan nuclear receptor that maintains stemness of neuronal stem cells. TLX is highly expressed in the most malignant form of glioma, glioblastoma multiforme (GBM), and is important for the proliferation and maintenance of the stem/progenitor cells of the tumor. Transforming Growth Factor-β (TGF-β) is a cytokine regulating many different cellular processes such as differentiation, migration, adhesion, cell death and proliferation. TGF-β has an important function in cancer where it can work as either a tumor suppressor or oncogene, depending on the cancer type and stage of tumor development. Since glioblastoma often have dysfunctional TGF-β signaling we wanted to find out if there is any interaction between TLX and TGF-β in glioblastoma cells. We demonstrate that knockdown of TLX enhances the canonical TGF-β signaling response in glioblastoma cell lines. TLX physically interacts with and stabilizes Smurf1, which can ubiquitinate and target TGF-β receptor II for degradation, whereas knockdown of TLX leads to stabilization of TGF-β receptor II, increased nuclear translocation of Smad2/3 and enhanced expression of TGF-β target genes. The interaction between TLX and TGF-β may play an important role in the regulation of proliferation and tumor-initiating properties of glioblastoma cells.

Neuronal specific Caveolin‐1 overexpression enhances dendritic growth and arborization in differentiated human neuronal stem cells derived from induced pluripotent stem cells

IntroductionNeuroplasticity is evoked by extracellular signals that bind receptors in the plasma membrane to induce signal transduction that results in polarized actions in the neuronal plasma membrane. Membrane/lipid rafts (MLR) and cholesterol binding protein caveolin‐1 (Cav‐1) provide a signaling membrane platform that tethers and regulates cytoskeletal components necessary for proper dendritic growth, maintenance and neuroplasticity. Our lab has demonstrated in rodents primary neurons that overexpression of neuronal cav‐1 enhances pro‐growth/pro‐survival signaling, and improves dendritic growth and arborization. We utilized neurons derived from human induced pluripotent stem cells (iPSCs) to ask whether Cav‐1 controls similar signaling and functions in human neurons as it does in rodent neurons. We overexpressed Cav‐1 driven by the neuronal specific synapsin promoter (SynCav1) and evaluated changes in dendritic morphology after the differentiation process.MethodsiPSC derived neuronal stem cells (NSCs) were cultured in DMEM/F12+Gluamax media with N‐2 supplement, B‐27 supplement, Pen/Strep, and basic Fibroblast Growth Factor (bFGF). Neuronal differentiation was started by bFGF withdrawal from media. NSCs were transfected with either SynCav1 or SynGFP as control when differentiation was started. Cells were fixed 3 weeks after differentiation and stained for Cav‐1, the dendritic marker microtubule‐associated protein 2 (MAP2), and the axonal marker neurofilament (SMI‐31). Dendritic length, branching (arborization), area, and volume were measured by Autoneuron (MBF Bioscience), a tracing algorithm that measures 3D image volume stacks. Cells were also collected and homogenized to measure Cav‐1 levels via western blots.ResultsWestern blots showed that Cav‐1 was increased in the cells transfected with SynCav‐1 compared to SynGFP 3 weeks after differentiation. Compared with SynGFP, SynCav1 transfection significantly enhanced dendritic length (p=0.002), branching points/arborization (p=0.0004), dendrite area (p=0.003), and dendrite volume (p=0.009)ConclusionNeuron‐targeted expression of Cav‐1 significantly enhanced dendritic growth of human iPSC‐derived neurons suggesting the presence of efficient Cav‐1 dependent signaling in these cells.

GSK3β Overexpression in Dentate Gyrus Neural Precursor Cells Expands the Progenitor Pool and Enhances Memory Skills

In restricted areas of the adult brain, like the subgranular zone of the dentate gyrus (DG), there is continuous production of new neurons. This process, named adult neurogenesis, is involved in important cognitive functions such as memory and learning. It requires the presence of newborn neurons that arise from neuronal stem cells, which divide and differentiate through successive stages in adulthood. In this work, we demonstrate that overexpression of glycogen synthase kinase (GSK) 3β in neural precursor cells (NPCs) using the glial fibrillary acidic protein promoter during DG development produces an increase in the neurogenic process, increasing NPCs numbers. Moreover, the transgenic mice show higher DG volume and increased number of mature granule neurons. In an attempt to compensate for these alterations, glial fibrillary acidic protein/GSK3β-overexpressing mice show increased levels of Dkk1 and sFRP3, two inhibitors of the Wnt-frizzled complex. We have also found behavioral differences between wild type and transgenic mice, indicating a higher rating in memory tasks for GSK3β-overexpressing mice compared with wild type mice. These data indicate that GSK3β is a crucial kinase in NPC physiology and suggest that this molecule plays a key role in the correct development of DG and adult neurogenesis in this region.

Alterations in Doublecortin Expression in Human Neuronal Stem Cells in Response to Angiotensinergic Stimulation in Proliferation and Differentiation Conditions

Activation or inhibition of the renin‐angiotensin system (RAS) affects neuronal function and viability. We showed previously that AT2 selective stimulation of human neuronal stem cells (H‐9 derived, Life Technologies) increased cell numbers in both differentiation and proliferation medium compared to control and AT1 stimulated human neuronal stem cells. We now show that doublecortin expression in human neuronal stem cells which were seeded in chamber slides and cultured under proliferation (with EGF and FGF‐2) or differentiation (no added growth factors) conditions is altered with chronic exposure to AT1 and AT2 selective agonists. Conditions included 14 days treatment with once daily addition of the AT2 selective agonist CGP42112 (final concentration 100 nM); once daily treatment with the non‐selective Ang II receptor agonist Sar1 angiotensin II (100 nM) plus the AT2 receptor selective antagonist PD123319 (10 μM) for selective AT1 receptor stimulation; once daily treatment with PD123319 (10 μM) alone; or once daily treatment with vehicle. Following treatment, cells were immunostained for the neuroblast marker doublecortin. Doublecortin expression was reduced by AT1 selective stimulation in differentiation conditions relative to control (Control 70.9 ± 17% and AT1 14.0 ± 6.2%, p<0.01), AT2 stimulated (AT2 86.7 ± 0.6%, p<0.01) and AT2 antagonized with PD123319 (PD123319 64.4 ± 9.3%, p<0.05). In proliferation conditions, doublecortin expression was reduced by AT2 selective stimulation and AT2 antagonism compared to control and AT1 selectively stimulated cells (p<0.01: Control 96.5 ± 1.1% ; AT1 88.7 ± 1.6% ; AT2 9.1 ± 6.1% ; PD123319 2.6 ± 1.0%). These results suggest that angiotensinergic inhibition of doublecortin expression is dependent upon the presence of the growth factors EGF and FGF‐2.Support or Funding InformationR.C. Speth: Research Grant; Significant; NIH HL‐113905; Cardiovascular Neuroscience Research Fund, Nova Southeastern University. J. Munoz: President's Faculty Research Development Grant, Nova Southeastern University.

Pyrolized 3D Carbon Scaffolds and Electrical Stimulation Enhance Differentiation of Neurons

In recent years, carbon materials have been increasingly utilized in biomedical applications. The use of carbon has several advantages: carbon microstructures are inexpensive and easy to fabricate, they have tunable surface properties, and 3-D carbon microstructures can be fabricated to mimic the in vivo biological environment. In this work, pyrolyzed three-dimensional carbon micropillar electrodes are used as a substrate to electrically stimulate and grow mouse neuronal stem cells (NSC’s). The micropillar electrodes are fabricated by controlled pyrolysis of SU-8, a polymeric photoresist. NSC’s are seeded on the micropillar array and daily DC electrical stimulation is applied. Application of 10 mV of DC electrical stimulation for 15 minutes a day is shown to increase differentiation of NSCs toward dopaminergic lineages and to increase neurite outgrowth when compared to NSC’s grown on conventional tissue culture plates. Furthermore, a microfluidic disc is used to create a controlled flow of byproducts from differentiated NSCs toward a detection chamber. A separate, three dimensional carbon interdigitated electrode array, also fabricated using SU-8 and conventional photolithography techniques, is placed into the detection chamber and uses redox amplification to selectively detect dopamine. The success of the 3D carbon micropillar electrodes in inducing spontaneous differentiation of NSC's toward dopaminergic lineages, along with the implementation of electrochemical detection of dopamine on a microfluidic disc, demonstrates the efficiency of the platform as a stem cell culture and detection device.

МОЖЛИВІСТЬ ЗАСТОСУВАННЯ НЕЙРОНАЛЬНИХ СТОВБУРОВИХ КЛІТИН ДЛЯ ЗАПОБІГАННЯ ТА ЛІКУВАННЯ АМІНОГЛІКОЗИДНОГО ОТОТОКСИКОЗУ В ЕКСПЕРИМЕНТАЛЬНИХ ТВАРИН

МОЖЛИВІСТЬ ЗАСТОСУВАННЯ НЕЙРОНАЛЬНИХ СТОВБУРОВИХ КЛІТИН ДЛЯ ЗАПОБІГАННЯ ТА ЛІКУВАННЯ АМІНОГЛІКОЗИДНОГО ОТОТОКСИКОЗУ В ЕКСПЕРИМЕНТАЛЬНИХ ТВАРИН

Structure-function integrity of the adult hippocampus depends on the transcription factor Bcl11b/Ctip2.

The dentate gyrus is one of the only two brain regions where adult neurogenesis occurs. Throughout life, cells of the neuronal stem cell niche undergo proliferation, differentiation and integration into the hippocampal neural circuitry. Ongoing adult neurogenesis is a prerequisite for the maintenance of adult hippocampal functionality. Bcl11b, a zinc finger transcription factor, is expressed by postmitotic granule cells in the developing as well as adult dentate gyrus. We previously showed a critical role of Bcl11b for hippocampal development. Whether Bcl11b is also required for adult hippocampal functions has not been investigated. Using a tetracycline‐dependent inducible mouse model under the control of the forebrain‐specific CaMKIIα promoter, we show here that the adult expression of Bcl11b is essential for survival, differentiation and functional integration of adult‐born granule cell neurons. In addition, Bcl11b is required for survival of pre‐existing mature neurons. Consequently, loss of Bcl11b expression selectively in the adult hippocampus results in impaired spatial working memory. Together, our data uncover for the first time a specific role of Bcl11b in adult hippocampal neurogenesis and function.

ALFY-Controlled DVL3 Autophagy Regulates Wnt Signaling, Determining Human Brain Size.

Primary microcephaly is a congenital neurodevelopmental disorder of reduced head circumference and brain volume, with fewer neurons in the cortex of the developing brain due to premature transition between symmetrical and asymmetrical cellular division of the neuronal stem cell layer during neurogenesis. We now show through linkage analysis and whole exome sequencing, that a dominant mutation in ALFY, encoding an autophagy scaffold protein, causes human primary microcephaly. We demonstrate the dominant effect of the mutation in drosophila: transgenic flies harboring the human mutant allele display small brain volume, recapitulating the disease phenotype. Moreover, eye-specific expression of human mutant ALFY causes rough eye phenotype. In molecular terms, we demonstrate that normally ALFY attenuates the canonical Wnt signaling pathway via autophagy-dependent removal specifically of aggregates of DVL3 and not of Dvl1 or Dvl2. Thus, autophagic attenuation of Wnt signaling through removal of Dvl3 aggregates by ALFY acts in determining human brain size.

ChemInform Abstract: Alstoscholarisines F and G, Two Unusual Monoterpenoid Indole Alkaloids from the Leaves of Alstonia scholaris.

Alstoscholarisine F (1), a monoterpenoid indole alkaloid pigment with unprecedented carbon skeleton, and alstoscholarisine G (2) incorporated with a third nitrogen atom were isolated from the long-term stored leaves of Alstonia scholaris. Their structures were established by extensive MS and NMR spectroscopic analysis and the absolute configuration of 1 was defined by comparison of experimental and calculated ECDs. Compounds 1 and 2 were subjected to hippocampal neuronal stem cells (NSCs) proliferation evaluation, but they did not show significant effect. (C) 2015 Elsevier Ltd. All rights reserved.

Differentiation Induction of Mouse Neural Stem Cells in Hydrogel Tubular Microenvironments with Controlled Tube Dimensions.

In this paper, a tubular 3D microenvironment created in a calcium alginate hydrogel microtube with respect to the effect of scaffold dimensions on the differentiation of mouse neuronal stem cells (mNSCs) is evaluated. Five types of hydrogel microtubes with different core diameters (≈65-200 μm) and shell thicknesses (≈30-110 μm) are fabricated by using a double coaxial microfluidic device, and differentiation of encapsulated mNSCs is induced by changing the growth medium to the differentiation medium. The influence of the microtube geometries is examined by using quantitative real-time polymerase chain reaction and fluorescent immunocytochemistry. The analyses reveal that differences in microtube thickness within 30-110 μm affected the relative Tuj1 expression but do not affect the morphology of encapsulated mNSCs. The diameters of cores influence both the relative Tuj1 expression and morphology of the differentiated neurons. It is found that the tubular microenvironment with a core diameter of less than ≈100 μm contributes to forming highly viable and aligned neural tissue. The tubular microenvironment can provide an effective method for constructing microfiber-shaped neural tissues with geometrically controlled differentiation induction.

Commentary: Maternal immune activation evoked by polyinosinic: polycytidylic acid does not evoke microglial cell activation in the embryo.

Commentary: Maternal immune activation evoked by polyinosinic: polycytidylic acid does not evoke microglial cell activation in the embryo.

Enantioselective Total Synthesis of (-)-Alstoscholarisine A.

We report a concise and highly enantioselective total synthesis of (-)-alstoscholarisine A (1), a recently isolated monoterpenoid indole alkaloid that has significant bioactivity in promoting adult neuronal stem cells proliferation. A highly enantioselective (99% ee), intramolecular Ir-catalyzed Friedel-Crafts alkylation of indole 9 with a secondary allylic alcohol was utilized to establish the first stereogenic center upon which the other three contiguous chiral centers were readily set by a highly stereoselective tandem 1,4-addition and aldol reaction. The key tetrahydropyran was constructed through a hemiacetal reduction, and the final aminal bridge was forged by a one-pot reductive amination/cyclization. The conciseness of this approach was highlighted by building core bonds in each step with a minimalist protecting group strategy.

A peroxiredoxin-based proteinaceous scaffold for the growth and differentiation of neuronal cells and tumour stem cells in the absence of prodifferentiation agents

The use of nanoscale materials in the design of scaffolds for CNS tissue is increasing, due to their ability to promote cell adhesion, to mimic an extracellular matrix microenvironment and to interact with neuronal membranes. In this framework, one of the major challenges when using undifferentiated neural cells is how to control the differentiation process. Here we report the characterization of a scaffold based on the self-assembled nanotubes of a mutant of the protein peroxiredoxin (from Schistosoma mansoni or Bos taurus), which allows the growth and differentiation of a model neuronal cell line (SHSY5Y). The results obtained demonstrate that SHSY5Y cells grow without any sign of toxicity and develop a neuronal phenotype, as shown by the expression of neuronal differentiation markers, without the use of any differentiation supplement, even in the presence of serum. The prodifferentiation effect is demonstrated to be dependent on the formation of the protein nanotube, since a wild-type (WT) form of the peroxiredoxin from Schistosoma mansoni does not induce any differentiation. The protein scaffold was also able to induce the spread of glioblastoma cancer stem cells growing in neurospheres and allowing the acquisition of a neuron-like morphology, as well as of immature rat cortical neurons. This protein used here as coating agent may be suggested for the development of scaffolds for tissue regeneration or anti-tumour devices. Copyright © 2016 John Wiley & Sons, Ltd.

Physical exercise, reactive oxygen species and neuroprotection

Regular exercise has systemic beneficial effects, including the promotion of brain function. The adaptive response to regular exercise involves the up-regulation of the enzymatic antioxidant system and modulation of oxidative damage. Reactive oxygen species (ROS) are important regulators of cell signaling. Exercise, via intensity-dependent modulation of metabolism and/or directly activated ROS generating enzymes, regulates the cellular redox state of the brain. ROS are also involved in the self-renewal and differentiation of neuronal stem cells and the exercise-mediated neurogenesis could be partly associated with ROS production. Exercise has strong effects on the immune system and readily alters the production of cytokines. Certain cytokines, especially IL-6, IL-1, TNF-α, IL-18 and IFN gamma, are actively involved in the modulation of synaptic plasticity and neurogenesis. Cytokines can also contribute to ROS production. ROS-mediated alteration of lipids, protein, and DNA could directly affect brain function, while exercise modulates the accumulation of oxidative damage. Oxidative alteration of macromolecules can activate signaling processes, membrane remodeling, and gene transcription. The well known neuroprotective effects of exercise are partly due to redox-associated adaptation.

Engraftment of enteric neural progenitor cells into the injured adult brain

BackgroundA major area of unmet need is the development of strategies to restore neuronal network systems and to recover brain function in patients with neurological disease. The use of cell-based therapies remains an attractive approach, but its application has been challenging due to the lack of suitable cell sources, ethical concerns, and immune-mediated tissue rejection. We propose an innovative approach that utilizes gut-derived neural tissue for cell-based therapies following focal or diffuse central nervous system injury.ResultsEnteric neuronal stem and progenitor cells, able to differentiate into neuronal and glial lineages, were isolated from the postnatal enteric nervous system and propagated in vitro. Gut-derived neural progenitors, genetically engineered to express fluorescent proteins, were transplanted into the injured brain of adult mice. Using different models of brain injury in combination with either local or systemic cell delivery, we show that transplanted enteric neuronal progenitor cells survive, proliferate, and differentiate into neuronal and glial lineages in vivo. Moreover, transplanted cells migrate extensively along neuronal pathways and appear to modulate the local microenvironment to stimulate endogenous neurogenesis.ConclusionsOur findings suggest that enteric nervous system derived cells represent a potential source for tissue regeneration in the central nervous system. Further studies are needed to validate these findings and to explore whether autologous gut-derived cell transplantation into the injured brain can result in functional neurologic recovery.Electronic supplementary materialThe online version of this article (doi:10.1186/s12868-016-0238-y) contains supplementary material, which is available to authorized users.

Parkinson Disease-Mediated Gastrointestinal Disorders and Rational for Combinatorial Therapies.

A gradual loss of dopamine-producing nerve cells gives rise to a common neurodegenerative Parkinson’s disease (PD). This disease causes a neurotransmitter imbalance in the brain and initiates a cascade of complications in the rest of the body that appears as distressing symptoms which include gait problems, tremor, gastrointestinal (GI) disorders and cognitive decline. To aid dopamine deficiency, treatment in PD patients includes oral medications, in addition to other methods such as deep brain stimulation and surgical lesioning. Scientists are extensively studying molecular and signaling mechanisms, particularly those involving phenotypic transcription factors and their co-regulatory proteins that are associated with neuronal stem cell (SC) fate determination, maintenance and disease state, and their role in the pathogenesis of PD. Advancement in scientific research and “personalized medicine” to augment current therapeutic intervention and minimize the side effects of chemotherapy may lead to the development of more effective therapeutic strategies in the near future. This review focuses on PD and associated GI complications and summarizes the current therapeutic modalities that include stem cell studies and combinatorial drug treatment.

A link between vascular damage and cognitive deficits after whole-brain radiation therapy for cancer: A clue to other types of dementia?

Whole brain radiation therapy for the treatment of tumors can sometimes cause cognitive impairment. Memory deficits were noted in up to 50% of treated patients over a short period of several months. In addition, an increased rate of dementia in young patients has been noted over the longer term, i.e. years. A deficit in neurogenesis after irradiation has been postulated to be the main cause of cognitive decline in patients, but recent data on irradiation therapy for limited parts of the brain appear to indicate other possibilities. Irradiation can directly damage various types of cells other than neuronal stem cells. However, this paper will focus on injury to brain vasculature leading to cognitive decline since vessels represent a better therapeutic target for drug development than other cells in the brain because of the blood-brain barrier.