ReNcell CX Research Articles

Pluripotent stem cell-derived neural progenitor cells can be used to model effects of IL-6 on human neurodevelopment

ABSTRACT Maternal immune activation (MIA) increases the risks for neurodevelopmental disorders in offspring through inflammatory cytokines, including interleukin-6 (IL-6). We therefore aimed to establish a human two-dimensional (2D) in vitro neural model to investigate the effects of IL-6 exposure on neurodevelopment. IL-6 signal transduction requires two receptors: interleukin-6 signal transducer (IL6ST) and interleukin-6 receptor (IL6R). Prenatally, neural cells lack IL6R, and hence cannot elicit cis IL-6 signaling, but IL6R can be provided by microglia in trans. We demonstrate here that an immortalized human neural progenitor cell (NPC) line, ReNCell CX, expresses IL6ST and elicits both cis and trans IL-6 signaling, limiting its use as a model of MIA. In contrast, induced pluripotent stem cell (iPSC)-derived NPCs only activate the IL-6 cascade in trans. Activation of the trans IL-6 cascade did not result in increased proliferation of iPSC-derived NPCs or ReNCell CX, as has been demonstrated in animal models. iPSC-derived NPCs upregulated NR2F1 expression in response to IL-6 signaling in line with analogous experiments in organoids. Thus, iPSC-derived NPCs can be used to model gene expression changes in response to MIA in 2D cultures.

Arrestin domain-containing protein 1-mediated microvesicles (ARMMs) protect against cadmium-induced neurotoxicity

Exposure to environmental heavy metals such as cadmium (Cd) is often linked to neurotoxicity but the underlying mechanisms remain poorly understood. Here we show that Arrestin domain-containing protein 1 (ARRDC1)-mediated microvesicles (ARMMs)–an important class of extracellular vesicles (EVs) whose biogenesis occurs at the plasma membrane–protect against Cd-induced neurotoxicity. Cd increased the production of EVs, including ARMMs, in a human neural progenitor cell line, ReNcell CX (ReN) cells. ReN cells that lack ARMMs production as a result of CRISPR-mediated ARRDC1 knockout were more susceptible to Cd toxicity as evidenced by increased LDH production as well as elevated level of oxidative stress markers. Importantly, adding ARMMs back to the ARRDC1-knockout ReN cells significantly reduced Cd-induced toxicity. Consistent with this finding, proteomics data showed that anti-oxidative stress proteins are enriched in ARMMs secreted from ReN cells. Together our study reveals a novel protective role of ARMMs in Cd neurotoxicity and suggests that ARMMs may be used therapeutically to reduce neurotoxicity caused by exposure to Cd and potentially other metal toxicants.

Initial phase establishment of an in vitro method for developmental neurotoxicity test using Ki-67 in human neural progenitor cells.

Building a precise alternative neurotoxicological test is of great importance to respond to societal and ethical requirements. In this study, a new developmental neurotoxicity test (DNT) was established with the human neural progenitor cell line. ReNcell CX cells were exposed to neurotoxic chemicals (aphidicolin, hydroxyurea, cytosine arabinoside, 5-fluorouracil, and ochratoxin A) or non-neurotoxic chemicals (sodium gluconate, sodium bicarbonate, penicillin G, and saccharin). Propidium iodide (PI) was used to evaluate cell viability. BrdU and Ki-76 were employed to determine cell proliferation. Based on the cell viability and proliferation, mathematical models were built by linear discriminant analysis. Furthermore, the neurotoxic-considered chemicals inhibited cell cycle progression at the protein level, supporting the biomolecular rationale for the predictive model. Overall, these results show that the new test method can be used to determine the potential developmental neurotoxicants or new drug candidates.

Metabolomics analysis of antiquitin deficiency in cultured human cells and plasma: Relevance to pyridoxine-dependent epilepsy.

Deficiency of antiquitin (α-aminoadipic semialdehyde dehydrogenase), an enzyme involved in lysine degradation and encoded by ALDH7A1, is the major cause of vitamin B6 -dependent epilepsy (PDE-ALDH7A1). Despite seizure control with high dose pyridoxine (PN), developmental delay still occurs in approximately 70% of patients. We aimed to investigate metabolic perturbations due to possible previously unidentified roles of antiquitin, which may contribute to developmental delay, as well as metabolic effects of high dose pyridoxine supplementation reflecting the high doses used for seizure control in patients with PDE-ALDH7A1. Untargeted metabolomics by high resolution mass spectrometry (HRMS) was used to analyze plasma of patients with PDE-ALDH7A1 and two independently generated lines of cultured ReNcell CX human neuronal progenitor cells (NPCs) with CRISPR/Cas mediated antiquitin deficiency. Accumulation of lysine pathway metabolites in antiquitin-deficient NPCs and western-blot analysis confirmed knockdown of ALDH7A1. Metabolomics analysis of antiquitin-deficient NPCs in conditions of lysine restriction and PN supplementation identified changes in metabolites related to the transmethylation and transsulfuration pathways and osmolytes, indicating a possible unrecognized role of antiquitin outside the lysine degradation pathway. Analysis of plasma samples of PN treated patients with PDE-ALDH7A1 and antiquitin-deficient NPCs cultured in conditions comparable to the patient plasma samples demonstrated perturbation of metabolites of the gamma-glutamyl cycle, suggesting potential oxidative stress-related effects in PN-treated patients with PDE-ALDH7A1. We postulate that a model of human NPCs with CRISPR/Cas mediated antiquitin deficiency is well suited to characterize previously unreported roles of antiquitin, relevant to this most prevalent form of pyridoxine-dependent epilepsy.

Facet-Dependent Activity of CeO2 Nanozymes Regulate the Fate of Human Neural Progenitor Cell via Redox Homeostasis.

Neural progenitor cells (NPCs) therapy, a promising therapeutic strategy for neurodegenerative diseases, has a huge challenge to ensure high survival rate and neuronal differentiation rate. Cerium oxide (CeO2) nanoparticles exhibit multienzyme mimetic activities and have shown the capability of regulating reactive oxygen species (ROS), which is a pivotal mediator for intracellular redox homeostasis in NPCs, regulating biological processes including differentiation, proliferation, and apoptosis. In the present study, the role of facet-dependent CeO2-mediated redox homeostasis in regulating self-renewal and differentiation of NPCs is reported for the first time. The cube-, rod-, and octahedron-shaped CeO2 nanozymes with different facets are prepared. Among the mentioned nanozymes, the cube enclosed by the (100) facet exhibits the highest CAT-like activity, causing it to provide superior protection to NPCs from oxidative stress induced by H2O2; meanwhile, the octahedron enclosed by the (111) facet with the lowest CAT-like activity induces the most ROS production in ReNcell CX cells, which promotes neuronal differentiation by activated AKT/GSK-3β/β-catenin pathways. A further mechanistic study indicated that the electron density of the surface Ce atoms changed continuously with different crystal facets, which led to their different CAT-like activity and modulation of redox homeostasis in NPCs. Altogether, the different surface chemistry and atomic architecture of active sites on CeO2 exert modulation of redox homeostasis and the fate of NPCs.

Characterisation of ReNcells CX and VM stimulated with interleukin-1β and lipopolysaccharide

Abnormal and dysregulated neuroinflammation has been linked to many neurological disorders and neurodegenerative diseases. Understanding the mechanisms of neuroinflammation, their impact on neurodevelopment and how neuroinflammation might be modulated, are currently considered to be critical to improving neurological treatment. ReNcell CX (originating from the cortical region) and VM (originating from the ventral mesencephalon) are human immortalised neural stem cell lines, that have the potential to be used as experimental models for investigating neuroinflammation in vitro. However, the information on the inflammation response of these cells is limited. This is especially more so for undifferentiated ReNcells. In this report we demonstrate using ELISA that cultured, undifferentiated ReNcell CX and VM produce significant amounts of IL-6 in response to IL-1β treatment, but not to LPS treatment. Additionally, conventional RT-PCR showed that ReNcell CX cells expressed TNFR1 and NF-κB, whereas ReNcell VM expressed only NF-κB. Our results encourage further investigation into the relationship between 1L-1β and IL-6 in both ReNcell CX and VM. Moreover, TNF-α treatment might potentially affect neuroinflammation in ReNcell CX, while activation of the NF-κB pathway could also play a critical part in neuroinflammation.

Assessment of a developmental neurotoxicity test using Ki-67 in ReNcell CX cells

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Reconditioning the Neurogenic Niche of Adult Non-human Primates by Antisense Oligonucleotide-Mediated Attenuation of TGF\u03b2 Signaling

Adult neurogenesis is a target for brain rejuvenation as well as regeneration in aging and disease. Numerous approaches showed efficacy to elevate neurogenesis in rodents, yet translation into therapies has not been achieved. Here, we introduce a novel human TGFβ-RII (Transforming Growth Factor—Receptor Type II) specific LNA-antisense oligonucleotide (“locked nucleotide acid”—“NVP-13”), which reduces TGFβ-RII expression and downstream receptor signaling in human neuronal precursor cells (ReNcell CX® cells) in vitro. After we injected cynomolgus non-human primates repeatedly i.th. with NVP-13 in a preclinical regulatory 13-week GLP-toxicity program, we could specifically downregulate TGFβ-RII mRNA and protein in vivo. Subsequently, we observed a dose-dependent upregulation of the neurogenic niche activity within the hippocampus and subventricular zone: human neural progenitor cells showed significantly (up to threefold over control) enhanced differentiation and cell numbers. NVP-13 treatment modulated canonical and non-canonical TGFβ pathways, such as MAPK and PI3K, as well as key transcription factors and epigenetic factors involved in stem cell maintenance, such as MEF2A and pFoxO3. The latter are also dysregulated in clinical neurodegeneration, such as amyotrophic lateral sclerosis. Here, we provide for the first time in vitro and in vivo evidence for a novel translatable approach to treat neurodegenerative disorders by modulating neurogenesis.

The systemic administration of neural stem cells expressing an inducible and soluble form of growth arrest specific 1 inhibits mammary gland tumor growth and the formation of metastases

Background aimsMetastasis to different organs is the major cause of death in breast cancer patients. The poor clinical prognosis and lack of successful treatments for metastatic breast cancer patients demand the development of new tumor-selective therapies. Thus, it is necessary to develop treatments capable of releasing therapeutic agents to both primary tumors and metastases that avoid toxic side effects in normal tissue, and neural stem cells are an attractive vehicle for tracking tumor cells and delivering anti-cancer agents. The authorspreviously demonstrated that a soluble form of growth arrest specific 1 (GAS1) inhibits the growth of triple-negative breast tumors and glioblastoma. MethodsIn this study, the authors engineered ReNcell CX (EMD Millipore, Temecula, CA, USA) neural progenitor cells to express truncated GAS1 (tGAS1) under a tetracycline/on inducible system using lentiviral vectors. ResultsHere the authors show that treatment with ReNcell-tGAS1 in combination with tetracycline decreased primary tumor growth and inhibited the formation of metastases in tumor-bearing mice by diminishing the phosphorylation of AKT and ERK1/2 in orthotopic mammary gland tumors. Moreover, the authors observed that ReNcell-tGAS1 prolonged the survival of 4T1 tumor-bearing mice. ConclusionsThese data suggest that the delivery of tGAS1 by ReNcell cells could be an effective adjuvant for the treatment of triple-negative breast cancer.

New insights into human lysine degradation pathways with relevance to pyridoxine-dependent epilepsy due to antiquitin deficiency.

Deficiency of antiquitin (ATQ), an enzyme involved in lysine degradation, is the major cause of vitamin B6 -dependent epilepsy. Accumulation of the potentially neurotoxic α-aminoadipic semialdehyde (AASA) may contribute to frequently associated developmental delay. AASA is formed by α-aminoadipic semialdehyde synthase (AASS) via the saccharopine pathway of lysine degradation, or, as has been postulated, by the pipecolic acid (PA) pathway, and then converted to α-aminoadipic acid by ATQ. The PA pathway has been considered to be the predominant pathway of lysine degradation in mammalian brain; however, this was refuted by recent studies in mouse. Consequently, inhibition of AASS was proposed as a potential new treatment option for ATQ deficiency. It is therefore of utmost importance to determine whether the saccharopine pathway is also predominant in human brain cells. The route of lysine degradation was analyzed by isotopic tracing studies in cultured human astrocytes, ReNcell CX human neuronal progenitor cells and human fibroblasts, and expression of enzymes of the two lysine degradation pathways was determined by Western blot. Lysine degradation was only detected through the saccharopine pathway in all cell types studied. The enrichment of 15 N-glutamate as a side product of AASA formation through AASS furthermore demonstrated activity of the saccharopine pathway. We provide first evidence that the saccharopine pathway is the major route of lysine degradation in cultured human brain cells. These results support inhibition of the saccharopine pathway as a new treatment option for ATQ deficiency.

Effects of paraquat on the proliferation of human neural stem cells via DNA methylation

Objective: To investigate the effects of Paraquat on neural stem cell proliferation in vitro and explore the its mechanism based on DNA methylation pathway. Methods: Nestin, β-tubulin III, and glial fibrillary acidic protein (GFAP) were detected by indirect immunofluorescence assay to evaluate self renewal and differentiation potentia of ReNcell CX human neural stem. The cells were treated with terminal concentrations of 0, 5, 25, 50, and 100μmol/L PQ for 24 hours, and the cells were induced by 50 μmol/L PQ for different time (6, 12, 24, 48 h). Cell viability was determined by MTT assay. The proliferation of neural stem cells was evaluated using Sox2/Brdu and Nestin/Brdu double immunofluorescence staining. The global DNA methylation level was assayed by MethyflashTM methylated DNA Quantification kit. The expression levels of Dnmts mRNA and protein were analyzed by quantitative reverse transcription polymerase chain reaction(qRT-PCR) and Western blot, respectively. Results: Immunofluorescence showed that nestin was primarily expressed in proliferative neural stem cell and peotein biomarkers (β-tubulin III, GFAP) for neuron and astrocyte were expressed in differentiated cells. MTT assay showed PQ induced cell survival rate decrease in a time and dose dependent manner. Double immunfluorescence staining of cells showed colocalization of Sox2 and Brdu. The percentage of Brdu/Sox2 positive cells was significantly lower in the PQ-exposed (25, 50, 100μmol/L PQ treatment) groups compared to control (P<0.05); Meanwhile, The percentage of Brdu/Nestin positive cells was also significantly lower in the PQ-exposed(50,100μmol/L PQ treatment) groups compared to control (P<0.05). The results of global DNA methylation revealed a significant decrease in PQ-exposed groups (P<0.05). Western blot showed that compared with control group, the protein and mRNA levels of Dnmt1, Dnmt3a in PQ-exposed group were significantly decreased (P<0.05), but there was a significant increase in expression level of Dnmt3b in 50, 100 μmol/L PQ-treated group(P<0.05). Conclusion: Paraquat could inhibite the proliferation of human neural stem cells through reducing the level of DNA methylation reaction by suppressing the protein expression and transcription of DNA methylated transferase(Dnmts).

Comparative analysis of human embryonic stem cell‑derived neural stem cells as an in vitro human model.

Alternative cell models of human neural stem cells (hNSCs) have been developed and used for investigations ranging from in vitro experiments to in vivo clinical studies. However, a cell model capable of mimicking the ʻnormalʼ state of hNSCs is mandatory in order to extrapolate the results of these studies to humans. In the present study, to select a more suitable hNSC model for developing human-based experimental platforms, two representative hNSC types were compared, namely human embryonic stem cell (hESC)-derived hNSCs and ReNcell CX cells, which are well-characterized immortalized hNSC lines. The hNSCs, differentiated from hESCs via human neuroectodermal sphere (hNES) formation, recapitulated the molecular and cellular phenotypes of hNSCs, including NSC marker expression and terminal neuronal differentiation potential. Comparative analyses of the transcriptome profiles of the hESC-derived hNESs and ReNcell CX hNSCs showed that the differentiated hNESs were analogous to the ReNcell CX cells, as demonstrated by principal component analysis and hierarchical sample clustering. The hNSC-specific transcriptome was presented, comprising commonly expressed transcripts between hNESs derived from hESCs and ReNcell CX cells. To elucidate the molecular mechanisms associated with the hNSC identity, the hNSC-specific transcriptome was analyzed using pathway and functional annotation clustering analyses. The results suggested that hESC-derived hNESs, an expandable and accessible cell source, may be used as a relevant hNSC model in a wide range of neurological investigations.

Impact of the Autism-Associated Long Noncoding RNA MSNP1AS on Neuronal Architecture and Gene Expression in Human Neural Progenitor Cells.

We previously identified the long noncoding RNA (lncRNA) MSNP1AS (moesin pseudogene 1, antisense) as a functional element revealed by genome wide significant association with autism spectrum disorder (ASD). MSNP1AS expression was increased in the postmortem cerebral cortex of individuals with ASD and particularly in individuals with the ASD-associated genetic markers on chromosome 5p14.1. Here, we mimicked the overexpression of MSNP1AS observed in postmortem ASD cerebral cortex in human neural progenitor cell lines to determine the impact on neurite complexity and gene expression. ReNcell CX and SK-N-SH were transfected with an overexpression vector containing full-length MSNP1AS. Neuronal complexity was determined by the number and length of neuronal processes. Gene expression was determined by strand-specific RNA sequencing. MSNP1AS overexpression decreased neurite number and neurite length in both human neural progenitor cell lines. RNA sequencing revealed changes in gene expression in proteins involved in two biological processes: protein synthesis and chromatin remodeling. These data indicate that overexpression of the ASD-associated lncRNA MSNP1AS alters the number and length of neuronal processes. The mechanisms by which MSNP1AS overexpression impacts neuronal differentiation may involve protein synthesis and chromatin structure. These same biological processes are also implicated by rare mutations associated with ASD, suggesting convergent mechanisms.

The effect of paraquat on autophagy in human embryonic neural progenitor cells

To explore the effect of paraquat (PQ) on autophagy in human embryonic neural progenitor cells. Using ReNcell CX cell model. After treatment with various concentration (0.00, 1.00, 10.00 and 100.00 μmol/L) of PQ, CCK8 assay was used to detect the cell viability, the transmission electron microscope was used to observe the the cell ultrastructure, the real-time polymerase chain reaction (RT-PCR) was adopted to detect mRNA expression of autophagy related genes which including LC3, Atg12, Atg5, beclin1, Atg7 and mTOR and apoptosis related genes Bax and Bcl-2. The cell viability was significantly inhibited after administered with 100.00 μmol/L of PQ (P<0.01). The mRNA expression of Beclin1 was significantly up-regulated and the emergency of autophagosome were observed at the concentration of 1.00 μmol/L group, while mild cell apoptosis, significantly up-regulated Atg5, Atg8, Atg7 and Atg12 mRNA expression as well as down-regulated expression of mTOR and Bax were detected at the 10.00 μmol/L of PQ group, howere, the obvious apoptosis and the up-regulated mRNA expression of mTOR and Bax were observed at the 100.00 μmol/L of PQ group, the mRNA expression of Bcl-2 were all down-regulated after administered with 1.00, 10.00 and 100.00 μmol/L of PQ and reached the lowest level at the concentration of 10.00 μmol/L. PQ can induced autophagy at the low concentration in ReNcell CX cell and autophagy might serve as a protective mechanism to ameliorate PQ-induced cytotoxic effects but apoptosis will be induced at the 100 μmol/L concentration.

Low-Dose Methylmercury-Induced Apoptosis and Mitochondrial DNA Mutation in Human Embryonic Neural Progenitor Cells.

Methylmercury (MeHg) is a long-lasting organic pollutant primarily found in the aquatic environment. The developing brain is particularly sensitive to MeHg due to reduced proliferation of neural stem cell. Although several mechanisms of MeHg-induced apoptosis have been defined in culture models, it remains unclear whether mitochondrial DNA (mtDNA) mutation is involved in the toxic effect of MeHg, especially in the neural progenitor cells. In the present study, the ReNcell CX cell, a human neural progenitor cells (hNPCs) line, was exposed to nanomolar concentrations of MeHg (≤50 nM). We found that MeHg altered mitochondrial metabolic function and induced apoptosis. In addition, we observed that MeHg induced ROS production in a dose-dependent manner in hNPCs cells, which was associated with significantly increased expressions of ND1, Cytb, and ATP6. To elucidate the mechanism underlying MeHg toxicity on mitochondrial function, we examined the ATP content and mitochondrial membrane potential in MeHg-treated hNPCs. Our study showed that MeHg exposure led to decreased ATP content and reduced mitochondrial membrane potential, which failed to match the expansion in mtDNA copy number, suggesting impaired mtDNA. Collectively, these results demonstrated that MeHg induced toxicity in hNPCs through altering mitochondrial function and inducing oxidative damage to mtDNA.

Noncoding RNA in the transcriptional landscape of human neural progenitor cell differentiation.

Increasing evidence suggests that noncoding RNAs play key roles in cellular processes, particularly in the brain. The present study used RNA sequencing to identify the transcriptional landscape of two human neural progenitor cell lines, SK-N-SH and ReNcell CX, as they differentiate into human cortical projection neurons. Protein coding genes were found to account for 54.8 and 57.0% of expressed genes, respectively, and alignment of RNA sequencing reads revealed that only 25.5–28.1% mapped to exonic regions of the genome. Differential expression analysis in the two cell lines identified altered gene expression in both protein coding and noncoding RNAs as they undergo neural differentiation with 222 differentially expressed genes observed in SK-N-SH cells and 19 differentially expressed genes in ReNcell CX. Interestingly, genes showing differential expression in SK-N-SH cells are enriched in genes implicated in autism spectrum disorder, but not in gene sets related to cancer or Alzheimer's disease. Weighted gene co-expression network analysis (WGCNA) was used to detect modules of co-expressed protein coding and noncoding RNAs in SK-N-SH cells and found four modules to be associated with neural differentiation. These modules contain varying levels of noncoding RNAs ranging from 10.7 to 49.7% with gene ontology suggesting roles in numerous cellular processes important for differentiation. These results indicate that noncoding RNAs are highly expressed in human neural progenitor cells and likely hold key regulatory roles in gene networks underlying neural differentiation and neurodevelopmental disorders.

Use of Neural Models of Proliferation and Neurite Outgrowth to Screen Environmental Chemicals in the ToxCast Phase I Library

Abstract The U.S. Environmental Protection Agency's ToxCast program aims to develop rapid and cost-effective toxicity testing approaches. As part of this effort, we screened the ToxCast Phase I library of 309 chemicals using previously developed and optimized high-content imaging and analysis assays for proliferation in human ReNcell CX neuroprogenitor cells and neurite outgrowth in PC12 cells. Cytotoxicity was determined concurrently in both models. For the initial screening, cells were exposed in triplicate to chemicals at 40 μM for 24 (proliferation) or 96 hr (neurite outgrowth). Chemicals were deemed active if effects on any endpoint were >3×the standard deviation of control means. A total of 130/309 chemicals (42.1%) altered at least one of the four endpoints examined. In ReNcell CX cells, 126 (41%) of chemicals were active, and 46 (15%) were active in PC12 cells. In ReNcell CX cells, 63 chemicals selectively inhibited proliferation. In PC12 cells, only four chemicals (methyl isothiocyanate, phosalon...

ERVK polyprotein processing and reverse transcriptase expression in human cell line models of neurological disease.

Enhanced expression of the reverse transcriptase (RT) protein encoded by human endogenous retrovirus-K (ERVK) is a promising biomarker for several inflammatory and neurological diseases. However, unlike RT enzymes encoded by exogenous retroviruses, little work has been done to identify ERVK RT isoforms, their expression patterns, and cellular localization. Using Western blot, we showcase the ERVK gag-pro-pol polyprotein processing leading to the production of several ERVK RT isoforms in human neuronal (ReNcell CX) and astrocytic (SVGA) models of neuroinflammatory disease. Since the pro-inflammatory cytokine IFNγ plays a key role in the pathology of several ERVK-associated neurological diseases, we sought to determine if IFNγ can drive ERVK RT expression. IFNγ signalling markedly enhanced ERVK polyprotein and RT expression in both human astrocytes and neurons. RT isoforms were expressed in a cell-type specific pattern and the RT-RNase H form was significantly increased with IFNγ treatment. Fluorescent imaging revealed distinct cytoplasmic, perinuclear and nuclear ERVK RT staining patterns upon IFNγ stimulation of astrocytes and neurons. These findings indicate that ERVK expression is inducible under inflammatory conditions such as IFNγ exposure—and thus, these newly established in vitro models may be useful in exploring ERVK biology in the context of neuroinflammatory disease.

Transmigration of Neural Stem Cells across the Blood Brain Barrier Induced by Glioma Cells

Transit of human neural stem cells, ReNcell CX, through the blood brain barrier (BBB) was evaluated in an in vitro model of BBB and in nude mice. The BBB model was based on rat brain microvascular endothelial cells (RBMECs) cultured on Millicell inserts bathed from the basolateral side with conditioned media (CM) from astrocytes or glioma C6 cells. Glioma C6 CM induced a significant transendothelial migration of ReNcells CX in comparison to astrocyte CM. The presence in glioma C6 CM of high amounts of HGF, VEGF, zonulin and PGE2, together with the low abundance of EGF, promoted ReNcells CX transmigration. In contrast cytokines IFN-α, TNF-α, IL-12p70, IL-1β, IL-6, IL-8 and IL-10, as well as metalloproteinases -2 and -9 were present in equal amounts in glioma C6 and astrocyte CMs. ReNcells expressed the tight junction proteins occludin and claudins 1, 3 and 4, and the cell adhesion molecule CRTAM, while RBMECs expressed occludin, claudins 1 and 5 and CRTAM. Competing CRTAM mediated adhesion with soluble CRTAM, inhibited ReNcells CX transmigration, and at the sites of transmigration, the expression of occludin and claudin-5 diminished in RBMECs. In nude mice we found that ReNcells CX injected into systemic circulation passed the BBB and reached intracranial gliomas, which overexpressed HGF, VEGF and zonulin/prehaptoglobin 2.

Dual Effects of Isoflurane on Proliferation, Differentiation, and Survival in Human Neuroprogenitor Cells

Previous studies have demonstrated that isoflurane can provide both neuroprotection and neurotoxicity in various tissue culture models and in rodent developing brains. The cellular and molecular mechanisms mediating these dual effects are not clear, but the exposure level and duration of isoflurane appear to be determinant factors. Using the ReNcell CX (Millipore, Billerica, MA) human neural progenitor cell line, the authors investigated the impact of prolonged exposure to varying isoflurane concentrations on cell survival and neurogenesis. In addition, the authors assessed the impact of short isoflurane preconditioning on elevation of cytosolic Ca concentration and cytotoxic effects mediated by prolonged isoflurane exposures and the contribution of inositol-1,4,5-trisphosphate or ryanodine receptor activation to these processes. Short exposures to low isoflurane concentrations promote proliferation and differentiation of ReNcell CX cells, with no cell damage. However, prolonged exposures to high isoflurane concentrations induced significant ReNcell CX cell damage and inhibited cell proliferation. These prolonged exposures suppressed neuronal cell fate and promoted glial cell fate. Preconditioning of ReNcell CX cultures with short exposures to low concentrations of isoflurane ameliorated the effects of prolonged exposures to isoflurane. Pretreatment of ReNcell cultures with inositol-1,4,5-trisphosphate or ryanodine receptor antagonists mostly prevented isoflurane-mediated effects on survival, proliferation, and differentiation. Finally, isoflurane-preconditioned cultures showed significantly less isoflurane-evoked changes in calcium concentration. The commonly used general anesthetic isoflurane exerts dual effects on neuronal stem cell survival, proliferation, and differentiation, which may be attributed to differential regulation of calcium release through activation of endoplasmic reticulum localized inositol-1,4,5-trisphosphate and/or ryanodine receptors.