共查询到20条相似文献,搜索用时 46 毫秒
1.
Mojgan Rastegar Akitsu Hotta Peter Pasceri Maisam Makarem Aaron Y. L. Cheung Shauna Elliott Katya J. Park Megumi Adachi Frederick S. Jones Ian D. Clarke Peter Dirks James Ellis 《PloS one》2009,4(8)
Background
Rett Syndrome (RTT) is an Autism Spectrum Disorder and the leading cause of mental retardation in females. RTT is caused by mutations in the Methyl CpG-Binding Protein-2 (MECP2) gene and has no treatment. Our objective is to develop viral vectors for MECP2 gene transfer into Neural Stem Cells (NSC) and neurons suitable for gene therapy of Rett Syndrome.Methodology/Principal Findings
We generated self-inactivating (SIN) retroviral vectors with the ubiquitous EF1α promoter avoiding known silencer elements to escape stem-cell-specific viral silencing. High efficiency NSC infection resulted in long-term EGFP expression in transduced NSC and after differentiation into neurons. Infection with Myc-tagged MECP2-isoform-specific (E1 and E2) vectors directed MeCP2 to heterochromatin of transduced NSC and neurons. In contrast, vectors with an internal mouse Mecp2 promoter (MeP) directed restricted expression only in neurons and glia and not NSC, recapitulating the endogenous expression pattern required to avoid detrimental consequences of MECP2 ectopic expression. In differentiated NSC from adult heterozygous Mecp2tm1.1Bird+/− female mice, 48% of neurons expressed endogenous MeCP2 due to random inactivation of the X-linked Mecp2 gene. Retroviral MECP2 transduction with EF1α and MeP vectors rescued expression in 95–100% of neurons resulting in increased dendrite branching function in vitro. Insulated MECP2 isoform-specific lentiviral vectors show long-term expression in NSC and their differentiated neuronal progeny, and directly infect dissociated murine cortical neurons with high efficiency.Conclusions/Significance
MeP vectors recapitulate the endogenous expression pattern of MeCP2 in neurons and glia. They have utility to study MeCP2 isoform-specific functions in vitro, and are effective gene therapy vectors for rescuing dendritic maturation of neurons in an ex vivo model of RTT. 相似文献2.
Peter C. Huszthy Tsanan Giroglou Oleg Tsinkalovsky Philipp Euskirchen Kai Ove Skaftnesmo Rolf Bjerkvig Dorothee von Laer Hrvoje Miletic 《PloS one》2009,4(7)
Background
Glioblastoma is the most frequent and most malignant primary brain tumor with a poor prognosis. The translation of therapeutic strategies for glioblastoma from the experimental phase into the clinic has been limited by insufficient animal models, which lack important features of human tumors. Lentiviral gene therapy is an attractive therapeutic option for human glioblastoma, which we validated in a clinically relevant animal model.Methodology/Principal Findings
We used a rodent xenograft model that recapitulates the invasive and angiogenic features of human glioblastoma to analyze the transduction pattern and therapeutic efficacy of lentiviral pseudotyped vectors. Both, lymphocytic choriomeningitis virus glycoprotein (LCMV-GP) and vesicular stomatitis virus glycoprotein (VSV-G) pseudotyped lentiviral vectors very efficiently transduced human glioblastoma cells in vitro and in vivo. In contrast, pseudotyped gammaretroviral vectors, similar to those evaluated for clinical therapy of glioblastoma, showed inefficient gene transfer in vitro and in vivo. Both pseudotyped lentiviral vectors transduced cancer stem-like cells characterized by their CD133-, nestin- and SOX2-expression, the ability to form spheroids in neural stem cell medium and to express astrocytic and neuronal differentiation markers under serum conditions. In a therapeutic approach using the suicide gene herpes simplex virus thymidine kinase (HSV-1-tk) fused to eGFP, both lentiviral vectors mediated a complete remission of solid tumors as seen on MRI resulting in a highly significant survival benefit (p<0.001) compared to control groups. In all recurrent tumors, surviving eGFP-positive tumor cells were found, advocating prodrug application for several cycles to even enhance and prolong the therapeutic effect.Conclusions/Significance
In conclusion, lentiviral pseudotyped vectors are promising candidates for gene therapy of glioma in patients. The inefficient gene delivery by gammaretroviral vectors is in line with the results obtained in clinical therapy for GBM and thus confirms the high reproducibility of the invasive glioma animal model for translational research. 相似文献3.
Grant D. Trobridge Brian C. Beard Robert A. Wu Christina Ironside Punam Malik Hans-Peter Kiem 《PloS one》2012,7(9)
Background
Hematopoietic stem cell (HSC) gene therapy has cured immunodeficiencies including X-linked severe combined immunodeficiency (SCID-X1) and adenine deaminase deficiency (ADA). For these immunodeficiencies corrected cells have a selective advantage in vivo, and low numbers of gene-modified cells are sufficient to provide therapeutic benefit. Strategies to efficiently transduce and/or expand long-term repopulating cells in vivo are needed for treatment of diseases that require higher levels of corrected cells, such as hemoglobinopathies. Here we expanded corrected stem cells in vivo in a canine model of a severe erythroid disease, pyruvate kinase deficiency.Methodology/Principal Findings
We used a foamy virus (FV) vector expressing the P140K mutant of methylguanine methyltransferase (MGMTP140K) for in vivo expansion of corrected hematopoietic repopulating cells. FV vectors are attractive gene transfer vectors for hematopoietic stem cell gene therapy since they efficiently transduce repopulating cells and may be safer than more commonly used gammaretroviral vectors. Following transplantation with HSCs transduced ex vivo using a tri-cistronic FV vector that expressed EGFP, R-type pyruvate kinase, and MGMTP140K, we were able to increase marking from approximately 3.5% to 33% in myeloid long-term repopulating cells resulting in a functional cure.Conclusions/Significance
Here we describe in one affected dog a functional cure for a severe erythroid disease using stem cell selection in vivo. In addition to providing a potential cure for patients with pyruvate kinase deficiency, in vivo selection using foamy vectors with MGMTP140K has broad potential for several hematopoietic diseases including hemoglobinopathies. 相似文献4.
X Xu Y Zhou C Xie SM Wei H Gan S He F Wang L Xu J Lu W Dai L He P Chen X Wang C Guo 《PloS one》2012,7(8):e43119
Aims
The role of sonic hedgehog (SHH) in epithelial mesenchymal transition (EMT) of pancreatic cancer (PC) is known, however, its mechanism is unclear. Because SHH promotes tumor development predominantly through Gli1, we sought to understand its mechanism by identifying Gli1 targets in pancreatic cancer cells.Methods
First, we investigated invasion, migration, and EMT in PC cells transfected with lentiviral Gli1 interference vectors or SHH over-expression vectors in vitro and in vivo. Next, we determined the target gene profiles of Gli1 in PC cells using cDNA microarray assays. Finally, the primary regulatory networks downstream of SHH-Gli1 signaling in PC cells were studied through functional analyses of these targets.Results
Our results indicate there is decreased E-cadherin expression upon increased expression of SHH/Gli1. Migration of PC cells increased significantly in a dose-dependent manner within 24 hours of Gli1 expression (P<0.05). The ratio of liver metastasis and intrasplenic miniature metastasis increased markedly upon activation of SHH-Gli1 signals in nude mice. Using cDNA microarray, we identified 278 upregulated and 59 downregulated genes upon Gli1 expression in AsPC-1 cells. The data indicate that SHH-Gli1 signals promote EMT by mediating a complex signaling network including TGFβ, Ras, Wnt, growth factors, PI3K/AKT, integrins, transmembrane 4 superfamily (TM4SF), and S100A4.Conclusion
Our results suggest that targeting the molecular connections established between SHH-Gli1 signaling and EMT could provide effective therapies for PC. 相似文献5.
Ettorre M Lorenzetto E Laperchia C Baiguera C Branca C Benarese M Spano P Pizzi M Buffelli M 《PloS one》2012,7(2):e31451
Background
The functioning of the nervous system depends upon the specificity of its synaptic contacts. The mechanisms triggering the expression of the appropriate receptors on postsynaptic membrane and the role of the presynaptic partner in the differentiation of postsynaptic structures are little known.Methods and Findings
To address these questions we cocultured murine primary muscle cells with several glutamatergic neurons, either cortical, cerebellar or hippocampal. Immunofluorescence and electrophysiology analyses revealed that functional excitatory synaptic contacts were formed between glutamatergic neurons and muscle cells. Moreover, immunoprecipitation and immunofluorescence experiments showed that typical anchoring proteins of central excitatory synapses coimmunoprecipitate and colocalize with rapsyn, the acetylcholine receptor anchoring protein at the neuromuscular junction.Conclusions
These results support an important role of the presynaptic partner in the induction and differentiation of the postsynaptic structures. 相似文献6.
Marco Mainardi Silvia Landi Nicoletta Berardi Lamberto Maffei Tommaso Pizzorusso 《PloS one》2009,4(2)
Background
It is generally assumed that visual cortical cells homogeneously shift their ocular dominance (OD) in response to monocular deprivation (MD), however little experimental evidence directly supports this notion. By using immunohistochemistry for the activity-dependent markers c-Fos and Arc, coupled with staining for markers of inhibitory cortical sub-populations, we studied whether long-term MD initiated at P21 differentially affects visual response of inhibitory neurons in rat binocular primary visual cortex.Methodology/Principal Findings
The inhibitory markers GAD67, parvalbumin (PV), calbindin (CB) and calretinin (CR) were used. Visually activated Arc did not colocalize with PV and was discarded from further studies. MD decreased visually induced c-Fos activation in GAD67 and CR positive neurons. The CB population responded to MD with a decrease of CB expression, while PV cells did not show any effect of MD on c-Fos expression. The persistence of c-Fos expression induced by deprived eye stimulation in PV cells is not likely to be due to a particularly low threshold for activity-dependent c-Fos induction. Indeed, c-Fos induction by increasing concentrations of the GABAA antagonist picrotoxin in visual cortical slices was similar between PV cells and the other cortical neurons.Conclusion
These data indicate that PV cells are particularly refractory to MD, suggesting that different cortical subpopulation may show different response to MD. 相似文献7.
Background
Adenoviruses are often used as vehicles to mediate gene delivery for therapeutic purposes, but their research scope in hematological cells remains limited due to a narrow choice of host cells that express the adenoviral receptor (CAR). T cells, which are attractive targets for gene therapy of numerous diseases, remain resistant to adenoviral infection because of the absence of CAR expression. Here, we demonstrate that this resistance can be overcome when murine or human T cells are transduced with an adenovirus incorporating the RGD-fiber modification (Ad-RGD).Methodology/Principal Finding
A luciferase-expressing replication-deficient Ad-RGD infected 3-fold higher number of activated primary T cells than an adenovirus lacking the RGD-fiber modification in vitro. Infection with replication-competent Ad-RGD virus also caused increased cell cycling, higher E1A copy number and enriched hexon antigen expression in both human and murine T cells. Transduction with oncolytic Ad-RGD also resulted in higher titers of progeny virus and enhanced the killing of T cells. In vivo, 35–45% of splenic T cells were transduced by Ad-RGD.Conclusions
Collectively, our results prove that a fiber modified Ad-RGD successfully transduces and replicates in primary T cells of both murine and human origin. 相似文献8.
Antibody responses against xenotropic murine leukemia virus-related virus envelope in a murine model
Makarova N Zhao C Zhang Y Bhosle S Suppiah S Rhea JM Kozyr N Arnold RS Ly H Molinaro RJ Parslow TG Hunter E Liotta D Petros J Blackwell JL 《PloS one》2011,6(4):e18272
Background
Xenotropic murine leukemia virus-related virus (XMRV) was recently discovered to be the first human gammaretrovirus that is associated with chronic fatigue syndrome and prostate cancer (PC). Although a mechanism for XMRV carcinogenesis is yet to be established, this virus belongs to the family of gammaretroviruses well known for their ability to induce cancer in the infected hosts. Since its original identification XMRV has been detected in several independent investigations; however, at this time significant controversy remains regarding reports of XMRV detection/prevalence in other cohorts and cell type/tissue distribution. The potential risk of human infection, coupled with the lack of knowledge about the basic biology of XMRV, warrants further research, including investigation of adaptive immune responses. To study immunogenicity in vivo, we vaccinated mice with a combination of recombinant vectors expressing codon-optimized sequences of XMRV gag and env genes and virus-like particles (VLP) that had the size and morphology of live infectious XMRV.Results
Immunization elicited Env-specific binding and neutralizing antibodies (NAb) against XMRV in mice. The peak titers for ELISA-binding antibodies and NAb were 1∶1024 and 1∶464, respectively; however, high ELISA-binding and NAb titers were not sustained and persisted for less than three weeks after immunizations.Conclusions
Vaccine-induced XMRV Env antibody titers were transiently high, but their duration was short. The relatively rapid diminution in antibody levels may in part explain the differing prevalences reported for XMRV in various prostate cancer and chronic fatigue syndrome cohorts. The low level of immunogenicity observed in the present study may be characteristic of a natural XMRV infection in humans. 相似文献9.
Wendy M. Aartsen Koen W. R. van Cleef Lucie P. Pellissier Robert M. Hoek Rogier M. Vos Bas Blits Erich M. E. Ehlert Kamaljit S. Balaggan Robin R. Ali Joost Verhaagen Jan Wijnholds 《PloS one》2010,5(8)
Background
Müller cell gliosis occurs in various retinal pathologies regardless of the underlying cellular defect. Because activated Müller glial cells span the entire retina and align areas of injury, they are ideal targets for therapeutic strategies, including gene therapy.Methodology/Principal Findings
We used adeno-associated viral AAV2/6 vectors to transduce mouse retinas. The transduction pattern of AAV2/6 was investigated by studying expression of the green fluorescent protein (GFP) transgene using scanning-laser ophthalmoscopy and immuno-histochemistry. AAV2/6 vectors transduced mouse Müller glial cells aligning the retinal blood vessels. However, the transduction capacity was hindered by the inner limiting membrane (ILM) and besides Müller glial cells, several other inner retinal cell types were transduced. To obtain Müller glial cell-specific transgene expression, the cytomegalovirus (CMV) promoter was replaced by the glial fibrillary acidic protein (GFAP) promoter. Specificity and activation of the GFAP promoter was tested in a mouse model for retinal gliosis. Mice deficient for Crumbs homologue 1 (CRB1) develop gliosis after light exposure. Light exposure of Crb1−/− retinas transduced with AAV2/6-GFAP-GFP induced GFP expression restricted to activated Müller glial cells aligning retinal blood vessels.Conclusions/Significance
Our experiments indicate that AAV2 vectors carrying the GFAP promoter are a promising tool for specific expression of transgenes in activated glial cells. 相似文献10.
Background
The fetus is surrounded by the amniotic fluid (AF) contained by the amniotic sac of the pregnant female. The AF is directly conveyed to the fetus during pregnancy. Although AF has recently been reported as an untapped resource containing various substances, it remains unclear whether the AF could influence fetal neurodevelopment.Results
We used AF that was extracted from embryos at 16 days in pregnant SD rat and exposed the AF to the neural cells derived from the embryos of same rat. We found that the treatment of AF to cortical neurons increased the phosphorylation in ERK1/2 that is necessary for fetal neurodevelopment, which was inhibited by the treatment of MEK inhibitors. Moreover, we found the subsequent inhibition of glycogen synthase kinase-3 (GSK-3), which is an important determinant of cell fate in neural cells. Indeed, AF increased the neural clustering of cortical neurons, which revealed that the clustered cells were proliferating neural progenitor cells. Accordingly, we confirmed the ability of AF to increase the neural progenitor cells through neurosphere formation. Furthermore, we showed that the ERK/GSK-3 pathway was involved in AF-mediated neurosphere enlargement.Conclusions
Although the placenta mainly supplies oxygenated blood, nutrient substances for fetal development, these findings further suggest that circulating-AF into the fetus could affect fetal neurodevelopment via MAP kinases-derived GSK-3 pathway during pregnancy. Moreover, we suggest that AF could be utilized as a valuable resource in the field of regenerative medicine. 相似文献11.
Background
A key pathogenic role in prion diseases was proposed for a cytosolic form of the prion protein (PrP). However, it is not clear how cytosolic PrP localization influences neuronal viability, with either cytotoxic or anti-apoptotic effects reported in different studies. The cellular mechanism by which PrP is delivered to the cytosol of neurons is also debated, and either retrograde transport from the endoplasmic reticulum or inefficient translocation during biosynthesis has been proposed. We investigated cytosolic PrP biogenesis and effect on cell viability in primary neuronal cultures from different mouse brain regions.Principal Findings
Mild proteasome inhibition induced accumulation of an untranslocated form of cytosolic PrP in cortical and hippocampal cells, but not in cerebellar granules. A cyclopeptolide that interferes with the correct insertion of the PrP signal sequence into the translocon increased the amount of untranslocated PrP in cortical and hippocampal cells, and induced its synthesis in cerebellar neurons. Untranslocated PrP boosted the resistance of cortical and hippocampal neurons to apoptotic insults but had no effect on cerebellar cells.Significance
These results indicate cell type-dependent differences in the efficiency of PrP translocation, and argue that cytosolic PrP targeting might serve a physiological neuroprotective function. 相似文献12.
Background
Activin A is a protein that participates principally in reproductive functions. In the adult brain, Activin is neuroprotective, but its role in brain development is still elusive.Methodology/Principal Findings
We studied if Activin A influences proliferation, differentiation or survival in rat cerebrocortical neural progenitor cells (NPC). After stimulation of NPC with Activin A, phosphorylation and nuclear translocation of Smad 2/3 were induced. In proliferating NPC, Activin produced a significant decrease in cell area and also a discrete increase in the number of neurons in the presence of the mitogen Fibroblast Growth Factor 2. The percentages of cells incorporating BrdU, or positive for the undifferentiated NPC markers Nestin and Sox2, were unchanged after incubation with Activin. In differentiating conditions, continuous treatment with Activin A significantly increased the number of neurons without affecting astroglial differentiation or causing apoptotic death. In cells cultured by extended periods, Activin treatment produced further increases in the proportion of neurons, excluding premature cell cycle exit. In clonal assays, Activin significantly increased neuronal numbers per colony, supporting an instructive role. Activin-induced neurogenesis was dependent on activation of its receptors, since incubation with the type I receptor inhibitor SB431542 or the ligand-trap Follistatin prevented neuronal differentiation. Interestingly, SB431542 or Follistatin by themselves abolished neurogenesis and increased astrogliogenesis, to a similar extent to that induced by Bone Morphogenetic Protein (BMP)4. Co-incubation of these Activin inhibitors with the BMP antagonist Dorsomorphin restored neuronal and astrocytic differentiation to control levels.Conclusions
Our results show an instructive neuronal effect of Activin A in cortical NPC in vitro, pointing out to a relevant role of this cytokine in the specification of NPC towards a neuronal phenotype. 相似文献13.
14.
Kazuhiro Ueyama Keisuke Mori Takuhei Shoji Hidekazu Omata Peter L. Gehlbach Douglas E. Brough Lisa L. Wei Shin Yoneya 《PloS one》2014,9(9)
Purpose
To evaluate localization and transgene expression from adenoviral vector of serotypes 5, 35, and 28, ± an RGD motif in the fiber following intravitreal or subretinal administration.Methods
Ocular transduction by adenoviral vector serotypes ± RGD was studied in the eyes of mice receiving an intravitreous or subretinal injection. Each serotype expressed a CMV-GFP expression cassette and histological sections of eyes were examined. Transgene expression levels were examined using luciferase (Luc) regulated by the CMV promoter.Results
GFP localization studies revealed that serotypes 5 and 28 given intravitreously transduced corneal endothelial, trabecular, and iris cells. Intravitreous delivery of the unmodified Ad35 serotype transduced only trabecular meshwork cells, but, the modification of the RGD motif into the fiber of the Ad35 viral vector base expanded transduction to corneal endothelial and iris cells. Incorporation of the RGD motif into the fiber knob with deletion of RGD from the penton base did not affect the transduction ability of the Ad5 vector base. Subretinal studies showed that RGD in the Ad5 knob shifted transduction from RPE cells to photoreceptor cells. Using a CMV-Luc expression cassette, intravitreous delivery of all the tested vectors, such as Ad5-, Ad35- and Ad28- resulted in an initial rapid induction of luciferase activity that thereafter declined. Subretinal administration of vectors showed a marked difference in transgene activity. Ad35-Luc gene expression peaked at 7 days and remained elevated for 6 months. Ad28-Luc expression was high after 1 day and remained sustained for one month.Conclusions
Different adenoviral vector serotypes ± modifications transduce different cells within the eye. Transgene expression can be brief or extended and is serotype and delivery route dependent. Thus, adenoviral vectors provide a versatile platform for the delivery of therapeutic agents for ocular diseases. 相似文献15.
Travis B. Lewis Joel N. Glasgow Anya M. Glandon David T. Curiel David G. Standaert 《PloS one》2010,5(9)
Background
Gene-based therapy is a new paradigm for the treatment of Parkinson disease (PD) and offers considerable promise for precise targeting and flexibility to impact multiple pathobiological processes for which small molecule agents are not available. Some success has been achieved utilizing adeno-associated virus for this approach, but it is likely that the characteristics of this vector system will ultimately create barriers to progress in clinical therapy. Adenovirus (Ad) vector overcomes limitations in payload size and targeting. The cellular tropism of Ad serotype 5 (Ad5)–based vectors is regulated by the Ad attachment protein binding to its primary cellular receptor, the coxsackie and adenovirus receptor (CAR). Many clinically relevant tissues are refractory to Ad5 infection due to negligible CAR levels but can be targeted by tropism-modified, CAR-independent forms of Ad. Our objective was to evaluate the role of CAR protein in transduction of dopamine (DA) neurons in vivo.Methodology/Principal Findings
Ad5 was delivered to the substantia nigra (SN) in wild type (wt) and CAR transgenic animals. Cellular tropism was assessed by immunohistochemistry (IHC) in the SN and striatal terminals. CAR expression was assessed by western blot and IHC. We found in wt animals, Ad5 results in robust transgene expression in astrocytes and other non-neuronal cells but poor infection of DA neurons. In contrast, in transgenic animals, Ad5 infects SNc neurons resulting in expression of transduced protein in their striatal terminals. Western blot showed low CAR expression in the ventral midbrain of wt animals compared to transgenic animals. Interestingly, hCAR protein localizes with markers of post-synaptic structures, suggesting synapses are the point of entry into dopaminergic neurons in transgenic animals.Conclusions/Significance
These findings demonstrate that CAR deficiency limits infection of wild type DA neurons by Ad5 and provide a rationale for the development of tropism-modified, CAR-independent Ad-vectors for use in gene therapy of human PD. 相似文献16.
Phosphorylation of the zebrafish M6Ab at serine 263 contributes to filopodium formation in PC12 cells and neurite outgrowth in zebrafish embryos 总被引:1,自引:0,他引:1
Huang KY Chen GD Cheng CH Liao KY Hung CC Chang GD Hwang PP Lin SY Tsai MC Khoo KH Lee MT Huang CJ 《PloS one》2011,6(10):e26461
Background
Mammalian M6A, a member of the proteolipid protein (PLP/DM20) family expressed in neurons, was first isolated by expression cloning with a monoclonal antibody. Overexpression of M6A was shown to induce filopodium formation in neuronal cells; however, the underlying mechanism of is largely unknown. Possibly due to gene duplication, there are two M6A paralogs, M6Aa and M6Ab, in the zebrafish genome. In the present study, we used the zebrafish as a model system to investigate the role of zebrafish M6Ab in filopodium formation in PC12 cells and neurite outgrowth in zebrafish embryos.Methodology/Principal Findings
We demonstrated that zebrafish M6Ab promoted extensive filopodium formation in NGF-treated PC12 cells, which is similar to the function of mammalian M6A. Phosphorylation at serine 263 of zebrafish M6Ab contributed to this induction. Transfection of the S263A mutant protein greatly reduced filopodium formation in PC12 cells. In zebrafish embryos, only S263D could induce neurite outgrowth.Conclusions/Significance
Our results reveal that the phosphorylation status of zebrafish M6Ab at serine 263 is critical for its role in regulating filopodium formation and neurite outgrowth. 相似文献17.
Background
Gap junction communication has been shown in glial and neuronal cells and it is thought they mediate inter- and intra-cellular communication. Connexin 36 (Cx36) is expressed extensively in the developing brain, with levels peaking at P14 after which its levels fall and its expression becomes entirely neuronal. These and other data have led to the hypothesis that Cx36 may direct neuronal coupling and neurogenesis during development.Methodology/Principal Findings
To investigate Cx36 function we used a neurosphere model of neuronal cell development and developed lentiviral Cx36 knockdown and overexpression strategies. Cx36 knockdown was confirmed by western blotting, immunocytochemistry and functionally by fluorescence recovery after photobleaching (FRAP). We found that knockdown of Cx36 in neurosphere neuronal precursors significantly reduced neuronal coupling and the number of differentiated neurons. Correspondingly, the lentiviral mediated overexpression of Cx36 significantly increased the number of neurons derived from the transduced neurospheres. The number of oligodendrocytes was also significantly increased following transduction with Cx36 indicating they may support neuronal differentiation.Conclusions/Significance
Our data suggests that astrocytic and neuronal differentiation during development are governed by mechanisms that include the differential expression of Cx36. 相似文献18.
Background
The neurons and synapses work coordinately to program the brain codes of controlling cognition and behaviors. Spike patterns at the presynaptic neurons regulate synaptic transmission. The quantitative regulations of synapse dynamics in spike encoding at the postsynaptic neurons remain unclear.Methodology/Principal Findings
With dual whole-cell recordings at synapse-paired cells in mouse cortical slices, we have investigated the regulation of synapse dynamics to neuronal spike encoding at cerebral circuits assembled by pyramidal neurons and GABAergic ones. Our studies at unitary synapses show that postsynaptic responses are constant over time, such as glutamate receptor-channel currents at GABAergic neurons and glutamate transport currents at astrocytes, indicating quantal glutamate release. In terms of its physiological impact, our results demonstrate that the signals integrated from quantal glutamatergic synapses drive spike encoding at GABAergic neurons reliably, which in turn precisely set spike encoding at pyramidal neurons through feedback inhibition.Conclusion/Significance
Our studies provide the evidences for the quantal glutamate release to drive the spike encodings precisely in cortical circuits, which may be essential for programming the reliable codes in the brain to manage well-organized behaviors. 相似文献19.
Ling Li Bosiljka Tasic Kristina D. Micheva Vsevolod M. Ivanov Maria L. Spletter Stephen J. Smith Liqun Luo 《PloS one》2010,5(7)