搜索结果: 'methocult media formulations for human hematopoietic cells serum containing'

Here we describe a protocol to generate a co-culture consisting of 2 different neuronal populations. Induced pluripotent stem cells (iPSCs) are reprogrammed from human fibroblasts using episomal vectors. Colonies of iPSCs can be observed 30 days after initiation of fibroblast reprogramming. Pluripotent colonies are manually picked and grown in neural induction medium to permit differentiation into neural progenitor cells (NPCs). iPSCs rapidly convert into neuroepithelial cells within 1 week and retain the capability to self-renew when maintained at a high culture density. Primary mouse NPCs are differentiated into astrocytes by exposure to a serum-containing medium for 7 days and form a monolayer upon which embryonic day 18 (E18) rat cortical neurons (transfected with channelrhodopsin-2 (ChR2)) are added. Human NPCs tagged with the fluorescent protein,tandem dimer Tomato (tdTomato),are then seeded onto the astrocyte/cortical neuron culture the following day and allowed to differentiate for 28 to 35 days. We demonstrate that this system forms synaptic connections between iPSC-derived neurons and cortical neurons,evident from an increase in the frequency of synaptic currents upon photostimulation of the cortical neurons. This co-culture system provides a novel platform for evaluating the ability of iPSC-derived neurons to create synaptic connections with other neuronal populations. View Publication

Store-operated calcium entry (SOCE) is a Calcium (Ca2+) influx pathway activated by depletion of intracellular stores that occurs in eukaryotic cells. In neurons,the presence and functions of SOCE are still in question. Here,we show evidences for the existence of SOCE in primary mouse cortical neurons. Endoplasmic reticulum (ER)-Ca2+ depletion using thapsigargin (Tg) triggered a maintained cytosolic Ca2+ increase,which rapidly returned to basal level in the presence of the SOCE blockers 2-Aminoethoxydiphenyl borate (2-APB) and YM-58483. Neural SOCE is also engaged by activation of metabotropic glutamate receptors (mGluRs) with (S)-3,5-dihydroxyphenylglycine (DHPG) (agonist of group I mGluRs),being an essential mechanism to maintain the mGluR-driven Ca2+ signal. Activation of group I of mGluRs triggers long-term depression (LTD) in many brain regions,but the underlying mechanism and,specifically,the necessity of Ca2+ increase in the postsynaptic neuron is controversial. In primary cortical neurons,we now show that the inhibition of Ca2+ influx through SOCE impaired DHPG-LTD,pointing out a key function of calcium and SOCE in synaptic plasticity. View Publication

Cockayne syndrome (CS) is a human premature aging disorder associated with neurological and developmental abnormalities,caused by mutations mainly in the CS group B gene (ERCC6). At the molecular level,CS is characterized by a deficiency in the transcription-couple DNA repair pathway. To understand the role of this molecular pathway in a pluripotent cell and the impact of CSB mutation during human cellular development,we generated induced pluripotent stem cells (iPSCs) from CSB skin fibroblasts (CSB-iPSC). Here,we showed that the lack of functional CSB does not represent a barrier to genetic reprogramming. However,iPSCs derived from CSB patient's fibroblasts exhibited elevated cell death rate and higher reactive oxygen species (ROS) production. Moreover,these cellular phenotypes were accompanied by an up-regulation of TXNIP and TP53 transcriptional expression. Our findings suggest that CSB modulates cell viability in pluripotent stem cells,regulating the expression of TP53 and TXNIP and ROS production. View Publication

The widespread application of human stem-cell-derived neurons for functional studies is impeded by complicated differentiation protocols,immaturity,and deficient optogene expression as stem cells frequently lose transgene expression over time. Here we report a simple but precise Cre-loxP-based strategy for generating conditional,and thereby stable,optogenetic human stem-cell lines. These cells can be easily and efficiently differentiated into functional neurons,and optogene expression can be triggered by administering Cre protein to the cultures. This conditional expression system may be applied to stem-cell-derived neurons whenever timed transgene expression could help to overcome silencing at the stem-cell level. View Publication

The potential ability to differentiate dedifferentiated adipocytes into a neural lineage is attracting strong interest as an emerging method of producing model cells for the treatment of a variety of neurological diseases. Here,we describe the efficient conversion of dedifferentiated adipocytes into a neural-like cell population. These cells grew in neurosphere-like structures and expressed a high level of the early neuroectodermal marker Nestin. These neurospheres could proliferate and express stemness genes,suggesting that these cells could be committed to the neural lineage. After neural induction,NeuroD1,Sox1,Double Cortin,and Eno2 were not expressed. Patch clamp data did not reveal different electrophysiological properties,indicating the inability of these cells to differentiate into mature neurons. In contrast,the differentiated cells expressed a high level of CLDN11,as demonstrated using molecular method,and stained positively for the glial cell markers CLDN11 and GFAP,as demonstrated using immunocytochemistry. These data were confirmed by quantitative results for glial cell line-derived neurotrophic factor production,which showed a higher secretion level in neurospheres and the differentiated cells compared with the untreated cells. In conclusion,our data demonstrate morphological,molecular,and immunocytochemical evidence of initial neural differentiation of mature adipocytes,committing to a glial lineage. View Publication

Although brain development abnormalities and brain cancer predisposition have been reported in some Fanconi patients,the possible role of Fanconi DNA repair pathway during neurogenesis is unclear. We thus addressed the role of fanca and fancg,which are involved in the activation of Fanconi pathway,in neural stem and progenitor cells during brain development and adult neurogenesis. Fanca(-/-) and fancg(-/-) mice presented with microcephalies and a decreased neuronal production in developing cortex and adult brain. Apoptosis of embryonic neural progenitors,but not that of postmitotic neurons,was increased in the neocortex of fanca(-/-) and fancg(-/-) mice and was correlated with chromosomal instability. In adult Fanconi mice,we showed a reduced proliferation of neural progenitor cells related to apoptosis and accentuated neural stem cells exhaustion with ageing. In addition,embryonic and adult Fanconi neural stem cells showed a reduced capacity to self-renew in vitro. Our study demonstrates a critical role for Fanconi pathway in neural stem and progenitor cells during developmental and adult neurogenesis. View Publication

The prion protein (PrP) is highly conserved and ubiquitously expressed,suggesting that it plays an important physiological function. However,despite decades of investigation,this role remains elusive. Here,by using animal and cellular models,we unveil a key role of PrP in the DNA damage response. Exposure of neurons to a genotoxic stress activates PRNP transcription leading to an increased amount of PrP in the nucleus where it interacts with APE1,the major mammalian endonuclease essential for base excision repair,and stimulates its activity. Preventing the induction of PRNP results in accumulation of abasic sites in DNA and impairs cell survival after genotoxic treatment. Brains from Prnp(-/-) mice display a reduced APE1 activity and a defect in the repair of induced DNA damage in vivo. Thus,PrP is required to maintain genomic stability in response to genotoxic stresses. View Publication