Astrocyte Differentiation Research Articles

PHBV/PLA/Col-Based Nanofibrous Scaffolds Promote Recovery of Locomotor Function by Decreasing Reactive Astrogliosis in a Hemisection Spinal Cord Injury Rat Model.

Biomaterials are used to aid in the regeneration of damaged tissue and in promotion of axonal guidance following spinal cord injury (SCI). In the present study, electrospun composite poly(hydroxybutyrate-cohydroxyvalerate) (PHBV), poly(lactic acid) (PLA), and collagen (Col) nanofibrous scaffolds were applied to determine their roles in neural regeneration and recovery in a rat model of SCI. The morphological and chemical properties of the electrospun scaffolds were investigated. The growth and proliferation of astrocytes on the scaffolds were assessed by MTT assay. The differentiation and gene expression of astrocytes on the scaffolds were measured by immunofluorescence and quantitative real-time polymerase chain reaction (q-PCR) assays. In a rat spinal cord hemisection model with 3-mm defects, 80 Sprague-Dawley rats were randomly divided into five groups: Sham group, SCI group, SCI+PHBV/PLA group, SCI+PHBV/PLA/Col (70:30) group, and SCI+PHBV/PLA/Col (50:50) group. The Basso-Beattie-Bresnahan (BBB) scores were evaluated every week postsurgery, and (immuno) histological and protein analyses were performed on specimens at 8 weeks. PHBV/PLA/Col scaffolds strongly inhibited the activation of astrocytes without decreasing their proliferation. qPCR assays revealed significant increases in the expression of brain lipid-binding protein (BLBP), glutamate transporter 1 (GLT-1) and S100 calcium-binding protein B (S100-β), but decreases in the expression of glial fibrillary acidic protein (GFAP), chondroitin sulphate sulfate proteoglycan (CSPG), neurocan, and phosphacan in the PHBV/PLA/Col scaffold group. In a series of in vivo experiments, PHBV/PLA/Col scaffold-treated SCI groups showed significant reductions in the numbers of CD68- and GFAP-immunopositive astrocytes within the interface of the remodeled tissue layer, but increased expression of NF-200 in residual neurons with better locomotor functional recovery. However, there were no significant differences between the PHBV/PLA/Col (70:30) and PHBV/PLA/Col (50:50) groups, except in BBB scores. PHBV/PLA/Col nanofibrous scaffolds were biocompatible and significantly promoted astrocyte differentiation but decreased astrocyte activation. The topographic structures of the PHBV/PLA/Col (70:30 and 50:50) nanofibers were favorable for neural regeneration due to a decrease in astrogliosis in SCI rats.

Astrocytes and the TGF-β1 Pathway in the Healthy and Diseased Brain: a Double-Edged Sword.

Transforming growth factor betas (TGF-βs) are known as multifunctional growth factors that participate in the regulation of key events of development, disease, and tissue repair. In the brain, TGF-β1 has been widely recognized as an injury-related cytokine, particularly associated with astrocyte scar formation in response to brain injury. In the last decade, however, evidence has indicated that in addition to its role in brain injury, TGF-β1 might be a crucial regulator of cell survival and differentiation, brain homeostasis, angiogenesis, memory formation, and neuronal plasticity. In this review, we will discuss the emerging scenario of TGF-β1 as a key regulator of astrocyte differentiation and function and the implications of TGF-β1 as a novel mediator of cellular interactions in the central nervous system. First, we will discuss the cellular and molecular basis underlying the effect of TGF-β on astrocyte generation and its impact on angiogenesis and blood-brain barrier function. Then, we will focus on the role of astrocytes in the development and remodeling of synapses and the role of TGF-β1 as a new mediator of these events. Furthermore, we present seminal data that contributed to the emerging concept that astrocyte dysfunction might be associated with neurodegenerative diseases, with a special focus on Alzheimer's disease, and discuss the pros and cons of TGF-β signaling deficits in these processes. Finally, we argue that understanding how astrocytic signals, such as TGF-β1, regulate brain function might offer new insights into human learning, memory, and cognition, and ultimately, this understanding may provide new targets for the treatment of neurological diseases.

High-throughput identification of factors promoting neuronal differentiation of human neural progenitor cells in microscale 3D cell culture.

Identification of conditions for guided and specific differentiation of human stem cell and progenitor cells is important for continued development and engineering of in vitro cell culture systems for use in regenerative medicine, drug discovery, and human toxicology. Three-dimensional (3D) and organotypic cell culture models have been used increasingly for in vitro cell culture because they may better model endogenous tissue environments. However, detailed studies of stem cell differentiation within 3D cultures remain limited, particularly with respect to high-throughput screening. Herein, we demonstrate the use of a microarray chip-based platform to screen, in high-throughput, individual and paired effects of 12 soluble factors on the neuronal differentiation of a human neural progenitor cell line (ReNcell VM) encapsulated in microscale 3D Matrigel cultures. Dose-response analysis of selected combinations from the initial combinatorial screen revealed that the combined treatment of all-trans retinoic acid (RA) with the glycogen synthase kinase 3 inhibitor CHIR-99021 (CHIR) enhances neurogenesis while simultaneously decreases astrocyte differentiation, whereas the combined treatment of brain-derived neurotrophic factor and the small azide neuropathiazol enhances the differentiation into neurons and astrocytes. Subtype specification analysis of RA- and CHIR-differentiated cultures revealed that enhanced neurogenesis was not biased toward a specific neuronal subtype. Together, these results demonstrate a high-throughput screening platform for rapid evaluation of differentiation conditions in a 3D environment, which will aid the development and application of 3D stem cell culture models.

Neural stem cell-derived factors inhibit the growth and invasion of U87 stem-like cells in vitro.

Glioma is one of the most common and aggressive tumors in the brain. Significant attention has been paid to the potential use of neural stem/progenitor cells (NSCs/NPCs) as delivery vehicles to cure gliomas. However, whether the NSCs/NPCs or the factors they produced could make a contribution still remains to be seen. In this study, we focused on the inhibitory effects of the factors produced by NSCs/NPCs on the biological behavior of the glioma stem-like cell in vitro. The human glioma cell line U87 was selected and the U87 stem-like cells were addressed. After being cultured in the NSCconditionmedium (NSC-CM), the viability and proliferation of U87 stem-like cells were significantly reduced. The invasion of U87 stem-like cells and the migration of U87 cells were also significantly decreased. However, no significant change was observed in regard to the astrocytic differentiation of U87 stem-like cells. These indicated that NSCs/NPCs produced some factors and had aninhibitory effect on the growth and invasion but not the terminal differentiation of U87 stem-like cells. It is worth paying attention to NSCs/NPCs as ahigh-potential candidatefor glioma treatment.

Development of a protocol to assess cell internalization and tissue uptake of magnetic nanoparticles by AC Biosusceptometry

Abstract Several applications of nanoparticles rely on the internalization and accumulation of nanocarriers in specific cell compartments and tissues. However, the methods currently employed for characterizing such processes, although well described, are time consuming and do not provide in vivo information, which is a crucial barrier towards translational applications. Here, we hypothesize that the AC Biosusceptometry technique can be employed to assess cell internalization of magnetic nanoparticles, with possible applications in screening assays to track specific biomarkers and cell types. We tested a simpler and easier alternative to study cell internalization and tissue accumulation after perfusion. We utilized citrate coated, manganese ferrite nanoparticles and evaluated the internalization process in mouse macrophages cells (J774.A1) and in an embryonic neural stem cell culture (E14.5) after differentiation in astrocytes and neurons, to assess internalization specificity. Respecting the particles toxicity limits, we tested different concentration of particles, in different incubation times. Sequentially, we imaged the cell cultures to confirm internalization and nanoparticles localization, labeling nucleus and cell body to assure that the particles were inside the cells. Our results showed a linear behavior on internalization for different doses and an optimum incubation time of 2 h.

Adult neurogenic deficits in HIV-1 Tg26 transgenic mice

BackgroundEven in the antiretroviral treatment (ART) era, HIV-1-infected patients suffer from milder forms of HIV-1-associated neurocognitive disorders (HAND). While the viral proteins Tat and gp120 have been shown to individually inhibit the proliferation and neural differentiation of neural stem cells (NSCs), no studies have characterized the effects of all the combined viral proteins on adult neurogenesis.MethodsThe HIV-1 Tg26 transgenic mouse model was used due to its clinical relevance to ART-controlled HIV-1-infected patients who lack active viral replication but suffer from continuous stress from the viral proteins. Quantitative RT-PCR analysis was performed to validate the expression of viral genes in the neurogenic zones. In vitro stemness and lineage differentiation assays were performed in cultured NSCs from HIV-1 Tg26 transgenic mice and their wild-type littermates. Hippocampal neurogenic lineage analysis was performed to determine potential changes in initial and late differentiation of NSCs in the subgranular zone (SGZ). Finally, fluorescent retroviral labeling of mature dentate granule neurons was performed to assess dendritic complexity and dendritic spine densities.ResultsVarying copy numbers of partial gag (p17), tat (unspliced and spliced variants), env (gp120), vpu, and nef transcripts were detected in the neurogenic zones of Tg26 mice. Significantly fewer primary neurospheres and a higher percentage of larger sized primary neurospheres were generated from Tg26 NSCs than from littermated wild-type mouse NSCs, implying that Tg26 mouse NSCs exhibit deficits in initial differentiation. In vitro differentiation assays revealed that Tg26 mouse NSCs have reduced neuronal differentiation and increased astrocytic differentiation. In the SGZs of Tg26 mice, significantly higher amounts of quiescent NSCs, as well as significantly lower levels of active NSCs, proliferating neural progenitor cells, and neuroblasts, were observed. Finally, newborn mature granule neurons in the dentate gyri of Tg26 mice had deficiencies in dendritic arborization, dendritic length, and dendritic spine density.ConclusionsBoth in vitro and in vivo studies demonstrate that HIV-1 Tg26 mice have early- and late-stage neurogenesis deficits, which could possibly contribute to the progression of HAND. Future therapies should be targeting this process to ameliorate, if not eliminate HAND-like symptoms in HIV-1-infected patients.

Nuclear factor I/A coordinates the timing of oligodendrocyte differentiation/maturation via Olig1 promoter methylation

Transcription factors (TFs) and epigenetic modifications function cooperatively to regulate various biological processes such as cell proliferation, differentiation, maturation, and metabolism. TF binding to regulatory regions of target genes controls their transcriptional activity through alteration of the epigenetic status around the binding regions, leading to transcription network formation regulating cell fates. Although nuclear factor I/A (Nfia) is a well-known TF that induces demethylation of astrocytic genes to confer astrocytic differentiation potential on neural stem/precursor cells (NS/PCs), the epigenetic role of NFIA in oligodendrocytic lineage progression remains unclear. Here, we show that oligodendrocyte differentiation/maturation is delayed in the brains of Nfia-knockout (KO) mice, and that NFIA-regulated DNA demethylation in NS/PCs plays an important role in determining the timing of their differentiation. We further demonstrate that the promoter activity of the oligodendrocyte transcription factor 1 (Olig1) gene, involved in oligodendrocyte differentiation/maturation, is suppressed by DNA methylation, which is in turn regulated by Nfia expression. Our results suggest that NFIA controls the timing of oligodendrocytic differentiation/maturation via demethylation of cell-type-specific gene promoters.

Ginsenoside Rg3 and Rh2 protect trimethyltin-induced neurotoxicity via prevention on neuronal apoptosis and neuroinflammation.

The acute exposure of trimethyltin (TMT) develops clinical syndrome characterized by amnesia, aggressive behavior, and complex seizures. This neurotoxicant selectively induces hippocampal neuronal injury and glial activation accompanied with resultant neuroinflammation. Here we report two candidates ginsenosides Rg3 and Rh2 as neuroprotection agents using a mouse model of TMT intoxication via a single injection (2mg/kg) and primary neuronal culture systems. Four-week administration of Rg3 or Rh2 significantly reduced TMT-induced seizures and behavioral changes. Rg3 and Rh2 significantly attenuated the oxidative stress evidenced by improvement on antioxidant enzymes and neuronal loss and astrocytic activation in mouse brain. In primary cultures, TMT induced significant neuronal death after 24-h intoxication and vigorous secretion of inflammatory cytokines (IL-1α/β, IL-6, TNF-α, and MCP-1) in astrocytes. Pretreatment with Rg3 or Rh2 not only reduced cell death but efficiently suppressed above mentioned inflammatory cytokines confirmed by antibody array test. The underlying protective mechanism by Rg3 and Rh2 was delineated through selective upregulation of PI3K/Akt and suppression of ERK activation. Intriguingly, Rg3 and Rh2 protected oligodendrocyte progenitor cells (O-2A) from TMT intoxication via promoting type 2 astrocytic differentiation without further inflammatory activation. Collectively, Rg3 and Rh2 interventions aimed at reducing oxidative stress and neuroinflammation neurotoxicity therefore are of therapeutic benefit in TMT-induced neurodegeneration.

Stage-Specific Transcription Factors Drive Astrogliogenesis by Remodeling Gene Regulatory Landscapes

SummaryA broad molecular framework of how neural stem cells are specified toward astrocyte fate during brain development has proven elusive. Here we perform comprehensive and integrated transcriptomic and epigenomic analyses to delineate gene regulatory programs that drive the developmental trajectory from mouse embryonic stem cells to astrocytes. We report molecularly distinct phases of astrogliogenesis that exhibit stage- and lineage-specific transcriptomic and epigenetic signatures with unique primed and active chromatin regions, thereby revealing regulatory elements and transcriptional programs underlying astrocyte generation and maturation. By searching for transcription factors that function at these elements, we identified NFIA and ATF3 as drivers of astrocyte differentiation from neural precursor cells while RUNX2 promotes astrocyte maturation. These transcription factors facilitate stage-specific gene expression programs by switching the chromatin state of their target regulatory elements from primed to active. Altogether, these findings provide integrated insights into the genetic and epigenetic mechanisms steering the trajectory of astrogliogenesis.

Fast Generation of Functional Subtype Astrocytes from Human Pluripotent Stem Cells.

SummaryDifferentiation of astrocytes from human pluripotent stem cells (hPSCs) is a tedious and variable process. This hampers the study of hPSC-generated astrocytes in disease processes and drug development. By using CRISPR/Cas9-mediated inducible expression of NFIA or NFIA plus SOX9 in hPSCs, we developed a method to efficiently generate astrocytes in 4–7 weeks. The astrocytic identity of the induced cells was verified by their characteristic molecular and functional properties as well as after transplantation. Furthermore, we developed a strategy to generate region-specific astrocyte subtypes by combining differentiation of regional progenitors and transgenic induction of astrocytes. This simple and efficient method offers a new opportunity to study the fundamental biology of human astrocytes and their roles in disease processes.

Nuclear Factor I Represses the Notch Effector HEY1 in Glioblastoma

Glioblastomas (GBMs) are highly aggressive brain tumors with a dismal prognosis. Nuclear factor I (NFI) is a family of transcription factors that controls glial cell differentiation in the developing central nervous system. NFIs have previously been shown to regulate the expression of astrocyte markers such as glial fibrillary acidic protein (GFAP) in both normal brain and GBM cells. We used chromatin immunoprecipitation (ChIP)–on-chip to identify additional NFI targets in GBM cells. Analysis of our ChIP data revealed ~400 putative NFI target genes including an effector of the Notch signaling pathway, HEY1, implicated in the maintenance of neural stem cells. All four NFIs (NFIA, NFIB, NFIC, and NFIX) bind to NFI recognition sites located within 1 kb upstream of the HEY1 transcription site. We further showed that NFI negatively regulates HEY1 expression, with knockdown of all four NFIs in GBM cells resulting in increased HEY1 RNA levels. HEY1 knockdown in GBM cells decreased cell proliferation, increased cell migration, and decreased neurosphere formation. Finally, we found a general correlation between elevated levels of HEY1 and expression of the brain neural stem/progenitor cell marker B-FABP in GBM cell lines. Knockdown of HEY1 resulted in an increase in the RNA levels of the GFAP astrocyte differentiation marker. Overall, our data indicate that HEY1 is negatively regulated by NFI family members and is associated with increased proliferation, decreased migration, and increased stem cell properties in GBM cells.

Peroxisome proliferator-activated receptor alpha accelerates neuronal differentiation and this might involve the mitogen-activated protein kinase pathway

Activation of peroxisome proliferator-activated receptor alpha (PPARα) has been reported to modulate cell proliferation, migration, and differentiation in astrocytes. In this study, we used a retinoic acid (RA)-induced differentiation model of NTERA-2/clone D1 (NT2) cells to explore the functional significance of PPARα in neuronal differentiation. We found that activating PPARα by Wy14643 accelerated neuronal differentiation via regulating the expression of neuronal markers. RT-PCR assays showed a significant increase in NeuroD expression and a decrease in nestin expression in cells treated concomitantly with RA and Wy14643 for 2 days compared to the levels in cells treated with RA alone. Expression of MAP2 protein, a mature neuronal marker, was markedly upregulated at day 10 of Wy14643 treatment, which was maintained after 21 days of neuronal formation. Corresponding to the changes in MAP2 expression, the expression of Cdk5 was upregulated with Wy14643 exposure from day 10 to day 21. Moreover, cells treated with Wy14643 displayed higher expression levels of phospho-ERK and phospho-p38 in the differentiation process than cell treated with RA alone. These results indicated that activation of PPARα accelerated neuronal differentiation through upregulating the expression of NeuroD, MAP2, and Cdk5 and downregulating the expression of nestin. MAPK signals, ERK and p38, might contribute to the accelerated differentiation process. These findings suggest that PPARα plays a role in regulating neuronal differentiation and may be beneficial for functional recovery from neurological disorders.

Novel insights into the epigenetics of diffuse glioma

ABSTRACTLoss-of-function mutations of the chromatin regulator ATRX (α-thalassemia mental retardation X-linked) occur frequently in diffuse gliomas, but the molecular mechanisms by which ATRX inactivation promotes oncogenesis remain unclear. We recently reported that Atrx deficiency drives glioma-relevant phenotypes, such as increased motility and astrocytic differentiation profiles, by directly modulating epigenomic lanscapes in glioma cells of origin. Our work has significant implications on the role of epigenetic regulator dysfunction in the oncogenic process.

Cellulose exopolysaccharide from sugarcane molasses as a suitable substrate for 2D and 3D neuron and astrocyte primary cultures.

Bacteria-synthesized polysaccharides have attracted interest for biomedical applications as promising biomaterials to be used as implants and scaffolds. The present study tested the hypothesis that cellulose exopolysaccharide (CEC) produced from sugarcane molasses of low cost and adequate purity would be suitable as a template for 2D and 3D neuron and/or astrocyte primary cultures, considering its low toxicity. CEC biocompatibility in these primary cultures was evaluated with respect to cell viability, adhesion, growth and cell function (calcium imaging). Polystyrene or Matrigel® matrix were used as comparative controls. We demonstrated that the properties of this CEC in the 2D or 3D configurations are suitable for differentiation of cortical astrocytes and neurons in single or mixed cultures. No toxicity was detected in neurons that showed NMDA-induced Ca2+ influx. Unlike other polysaccharides of bacterial synthesis, the CEC was efficient as a support even in the absence of surface conjugation with extracellular matrix proteins, maintaining physiological characteristics of cultured neural cells. These observations open up the perspective for development of a novel 3D biofunctional scaffold produced from bacterial cellulose and obtained from renewable sources whose residues are not pollutants. Its low cost and possibility to be manufactured in scale are also suitable for potential applications in regenerative medicine.

Vitamin C Promotes Astrocyte Differentiation Through DNA Hydroxymethylation.

Previous studies have reported that vitamin C (VC) promotes neural stem/precursor cell (NSC) differentiation toward dopamine (DA) neurons via DNA hydroxymethylation-induced transcriptional activation of DA neuron-specific genes. To further understand the VC effects on NSC differentiation, we profiled the transcriptome and DNA methylome/hydroxymethylome using high-throughput sequencing. Interestingly, RNA sequencing analyses have shown that, in addition to DA neuronal genes, astrocytic genes Gfap, Slc1a3, and S100a16 were also upregulated in NSC cultures differentiated with VC treatment. Consistently, enhanced GFAP+ astrocytic yields were manifested in the differentiated cultures with VC treatment, collectively indicating that VC promotes astrocytic differentiation. In genome-wide hydroxymethylome analyses, VC treatment induces enrichment of DNA hydroxymethylation (5-hydroxymethyl cytosine; 5hmC) near the consensus binding motifs of nuclear factor I (NFI). Furthermore, we showed that VC significantly enhanced recruitment of NFI and STAT3, key transcription factors for astrogenesis, in the 5hmC-enriched regions of the astrocyte-specific genes. These findings suggest that VC play important roles in astrocytogenesis during brain development. Stem Cells 2018;36:1578-1588.

Docosahexaenoic Acid (DHA) Induced Morphological Differentiation of Astrocytes Is Associated with Transcriptional Upregulation and Endocytosis of β2-AR.

Docosahexaenoic acid (DHA), an important ω-3 fatty acid, is abundantly present in the central nervous system and is important in every step of brain development. Much of this knowledge has been based on studies of the role of DHA in the function of the neurons, and reports on its effect on the glial cells are few and far between. We have previously reported that DHA facilitates astrocyte differentiation in primary culture. We have further explored the signaling mechanism associated with this event. It was observed that a sustained activation of the extracellular signal-regulated kinase (ERK) appeared to be critical for DHA-induced differentiation of the cultured astrocytes. Prior exposure to different endocytic inhibitors blocked both ERK activation and differentiation of the astrocytes during DHA treatment suggesting that the observed induction of ERK-2 was purely endosomal. Unlike the β1-adrenergic receptor (β1-AR) antagonist, atenolol, pre-treatment of the cells with the β2-adrenergic receptor (β2-AR) antagonist, ICI-118,551 inhibited the DHA-induced differentiation process, indicating a downstream involvement of β2-AR in the differentiation process. qRT-PCR and western blot analysis demonstrated a significant induction in the mRNA and protein expression of β2-AR at 18-24h of DHA treatment, suggesting that the induction of β2-AR may be due to transcriptional upregulation. Moreover, DHA caused activation of PKA at 6h, followed by activation of downstream cAMP response element-binding protein, a known transcription factor for β2-AR. Altogether, the observations suggest that DHA upregulates β2-AR in astrocytes, which undergo endocytosis and signals for sustained endosomal ERK activation to drive the differentiation process.

H2A.Z.1 crosstalk with H3K56-acetylation controls gliogenesis through the transcription of folate receptor

Astrocytes play crucial roles in the central nervous system, and defects in astrocyte function are closely related to many neurological disorders. Studying the mechanism of gliogenesis has important implications for understanding and treating brain diseases. Epigenetic regulations have essential roles during mammalian brain development. Here, we demonstrate that histone H2A.Z.1 is necessary for the specification of multiple neural precursor cells (NPCs) and has specialized functions that regulate gliogenesis. Depletion of H2A.Z.1 suppresses gliogenesis and results in reduced astrocyte differentiation. Additionally, H2A.Z.1 regulates the acetylation of H3K56 (H3K56ac) by cooperating with the chaperone of ASF1a. Furthermore, RNA-seq data indicate that folate receptor 1 (FOLR1) participates in gliogenesis through the JAK–STAT signaling pathway. Taken together, our results demonstrate that H2A.Z.1 is a key regulator of gliogenesis because it interacts with ASF1a to regulate H3K56ac and then directly affects the expression of FOLR1, which acts as a signal-transducing component of the JAK–STAT signaling pathway.

Dibutyryl cAMP- or Interleukin-6-induced astrocytic differentiation enhances mannose binding lectin (MBL)-associated serine protease (MASP)-1/3 expression in C6 glioma cells

Mannose-binding lectin (MBL)-Associated Serine Proteases (MASP)-1 and 3, key enzymes in the lectin complement pathway of innate immune response, are also expressed in glioma cell lines. We investigated MASP-1 and MASP-3 expression during dibutyryl cyclic AMP (dbcAMP)- or Interleukin-6 (rIL-6)-induced astrocytic differentiation of C6 glioma cells. Our results demonstrate that C6 cells express basal levels of MASP-1 and MASP-3 and following exposure to dbcAMP or IL-6, a consistent MASP-1 and MASP-3 mRNA up-regulation was found, with a behavior similar to that showed by the fibrillary acidic protein (GFAP). Furthermore, in cell conditioned media, rIL-6 stimulated MASP-3 secretion which reached levels similar to those obtained by dbcAMP treatment. Moreover, the detection of a 46-kDa MASP-3 suggested its processing to the mature form in the extracellular cell medium. Interestingly, the H89 PKA inhibitor, mostly affected dbcAMP-induced MASP-1 and MASP-3 mRNA levels, compared to that of rIL-6, suggesting that cAMP/PKA pathway contributes to MASP-1 and MASP-3 up-regulation. MASP-1 and MASP-3 expression increase was concomitant with dbcAMP- or rIL-6-induced phosphorylation of STAT3. Our findings suggest that the increase in intracellular cAMP concentration or rIL-6 stimulation can play a role in innate immunity enhancing MASP-1 and MASP-3 expression level in C6 glioma cells.

Cerebellar liponeurocytoma \u2013 a rare entity: a case report

BackgroundCerebellar liponeurocytoma is a rare tumor of the central nervous system occurring mainly in the posterior fossa, which shows neuronal and variable astrocytic differentiation with foci of lipomatous differentiation. Liponeurocytoma develops in adult patients and is defined in the World Health Organization classification of 2016 as a rare benign grade II tumor.Case presentationA 39-year-old Italian man presented to our department suffering from headache and nausea. Magnetic resonance imaging revealed a right-sided cerebellar lesion showing poor contrast enhancement without an obstructive hydrocephalus. Surgery was indicated and total tumor resection was achieved. He was discharged without any neurological deficits. Histopathological examinations revealed a cerebellar liponeurocytoma. A neurological follow-up examination revealed no neurological deficit directly after surgery and 1 year later. Radiotherapy was recommended at the neurooncological board despite the total removal of the tumor, but our patient refused adjuvant radiotherapy. Magnetic resonance imaging of his neurocranium with and without contrast enhancement 48 hours after surgery and 15 months after surgery showed no residual tumor.ConclusionsLiponeurocytomas are rare benign tumors occurring in the majority of cases in the cerebellum. The therapy of choice is surgery. Postoperative radiotherapy has to be discussed individually, but seems to be sufficient if complete tumor resection is not achieved or in cases of a tumor recurrence.

FAM19A1 is a new ligand for GPR1 that modulates neural stem‐cell proliferation and differentiation

FAM19A1 is a member of the family with sequence similarity 19 with unknown function. FAM19A1 mRNA expression is restricted to the CNS. Here, we report that FAM19A1 is a classic secretory protein, and expression levels correlate with brain development, increasing from embryonic d 12.5, peaking between postnatal d (P)1 and P7 and decreasing at wk 8. The adult hippocampus is a region of FAM19A1 high expression. Recombinant FAM19A1 suppressed the proliferation and self-renewal of neural stem cells (NSCs) and altered the lineage progression of NSCs with promoted neuron differentiation and suppressed astrocyte differentiation. Although GPCR 1 (GPR1) has been reported to be expressed in the CNS, its functions in the brain remain unclear. We identified GPR1 to be a functional receptor for FAM19A1. FAM19A1 interacted with GPR1 via the N-terminal domain (GPR1-ND), and its NSC modulatory functions required the Rho-associated protein kinase (ROCK) /ERK1/2 and ROCK/signal transducer and activator of transcription 3 signaling pathways. GPR1-ND that selectively bound to FAM19A1 neutralized the effects of FAM19A1 on NSC functions. Taken together, our results show, for the first time to our knowledge, that FAM19A1 is a novel regulatory factor of the proliferation and differentiation of NSCs, and identified a novel mechanism by which GPCR mediates the effects of FAM19A1 on NSC functions that may be important for brain development and neurogenesis. Additional exploration of the functions of FAM19A1 and GPR1 in the CNS may broaden the range of therapeutic options available for major brain disorders.-Zheng, C., Chen, D., Zhang, Y., Bai, Y., Huang, S., Zheng, D., Liang, W., She, S., Peng, X., Wang, P., Mo, X., Song, Q., Lv, P., Huang, J., Ye, R. D., Wang, Y. FAM19A1 is a new ligand for GPR1 that modulates neural stem-cell proliferation and differentiation.