Expression analysis of astrocytes isolated from the rat forebrain
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ABSTRACT: Comparison of expression data of rat forebrain astrocytes from P1, P7 acutely isolated by immunopanning or cultured with astrocytes prepared by McCarthy and de Vellis' (1980) method. Elucidating the genes induced by serum in immunopannedrat astrocytes. Three biological replicates for each sample were done. MD-astrocytes were prepared as described in McCarthy and de Vellis 1980 and harvested for mRNA after 7DIV. IP-astrocytes were isolated from P1 or P7 Sprague Dawley rats and processed for RNA immediately (IP-astrocytes P1/P7), or cultured for 7 days in HBEGF before harvesting (Cult. IP-astrocytes P1/P7). For the serum studies, we plated IP-astrocytes P7 in MD-astrocyte media containing 10% fetal calf serum immediately after isolation and cultured them for 7 days. After 7 days, the cultures were either processed for total RNA or washed 3x with dPBS and astrocyte base media with HBEGF was added. The cells were cultured for an additional 7 days and then processed for RNA. We isolated total RNA with the QIAshredder and Qiagen RNeasy Mini Kit. We used the 3’IVT Express kit for preparation of the RNA and the Rat Genome 230 2.0 Array chip (Affymetrix, Santa Clara). RT-PCR was used to elucidate the level of contamination in each cell sample.
Project description:Comparison of expression data of rat forebrain astrocytes from P1, P7 acutely isolated by immunopanning or cultured with astrocytes prepared by McCarthy and de Vellis' (1980) method. Elucidating the genes induced by serum in immunopannedrat astrocytes.
Project description:To profile gene expression differences in astrocytes in postnatal cerebellar astrocytes . Comparing cerebellar astrocyte transcriptomes at postnatal days 1, 7, 14, and 28 (P1, P7, P14, and P28),
Project description:Gene expression of X-irradiated primary murine astrocytes Roggan MD, Kronenberg J, Wollert E, Hoffmann S, Nisar H, Konda B, Diegeler S, Liemersdorf C and Hellweg CE (2023) Unraveling astrocyte behavior in the space brain: Radiation response of primary astrocytes. Front. Public Health 11:1063250.
Project description:Profiling of transcriptional changes in rat astrocytes when co-cultured with neurons: comparison of astrocytes cultured alone with astrocytes co-cultured with mouse hippocampal neurons. Co-cultured astrocytes are isolated using cold jet, a novel tool for these neuron-glia cultures. Over the last decade, the importance of astrocyte-neuron communication in neuronal development and synaptic plasticity has become increasingly clear. Since neuron-astrocyte interactions represent highly dynamic and reciprocal processes, we hypothesized that at least part of the involved astrocyte genes may be regulated as a consequence of their interactions with maturing neurons. In order to identify such neuron-induced astrocyte genes in vitro, we tested the effectiveness of the ‘cold jet’, a new method for separation of neurons from co-cultured astrocytes. The cold jet method is performed under ice-cold conditions and avoids protease-mediated isolation of astrocytes or time-consuming centrifugation, yielding intact astrocyte mRNA with approximately 90% of neuronal RNA removed. Using this method, we executed genome-wide profiling in which RNA derived from astrocyte-only cultures was compared with astrocyte RNA derived from differentiating neuron-astrocyte co-cultures. Data analysis revealed changes in expression of a large number of mRNAs and biological processes, including novel findings. Thus, cold jet is an efficient method to separate astrocytes from neurons in co-culture, and in this study reveals that neurons induce robust gene-expression changes in co-cultured astrocytes.
Project description:Astrocytes are key cells in brain aging, helping neurons to undertake healthy aging or otherwise letting them enter into a spiral of neurodegeneration. We aimed to characterize astrocytes cultured from senescence-accelerated prone 8 (SAMP8) mice, a mouse model of brain pathological aging, along with the effects of caloric restriction, the most effective rejuvenating treatment known so far. Analysis of the transcriptomic profiles of SAMP8 astrocytes cultured in control conditions and treated with caloric restriction serum was performed using mRNA microarrays. A decrease in mitochondrial and ribosome mRNA, which was restored by caloric restriction, confirmed the age-related profile of SAMP8 astrocytes and the benefits of caloric restriction. An amelioration of antioxidant and neurodegeneration-related path- ways confirmed the brain benefits of caloric restriction. Studies of oxidative stress and mitochondrial function demonstrated a reduction of oxidative damage and partial improvement of mito- chondria after caloric restriction. In summary, caloric restriction showed a significant tendency to normalize pathologically aged astrocytes through the activation of pathways that are protective against the age-related deterioration of brain physiology. Key words: astrocytes; caloric restriction; mitochondria; oxidative stress; RNA microarrays; SAMP8. Primary cultures enriched in astrocytes were obtained from cerebral cortical tissue from 2-day-old SAMP8 and SAMR1 mice. Astrocyte cultures were established and experiments were routinely carried out after 21 days in culture. Established astrocyte cultures of both SAMR1 and SAMP8 consisted of 85-90% astrocytes, 10-15% microglia and 0.1-1% oligodendroglia. Sera from rats subjected to ad libitum (AL) diet and to CR were obtained as described for the establishment of the CR in vitro model (de Cabo et al., 2003). Serum was heat inactivated at 56°C prior to use in astrocyte culture experiments. Treatment in vitro was performed by adding 10% volume CR or AL serum onto the astrocyte culture medium for 48 h, the cells were harvested and RNA was extracted for the microarray studies. Three biological replicates for each condition were done and RNA was extracted for the microarray studies. Please note that SAM models were developed from AKR/J by Kyoto University. Five litters with severe senescence were selected to further propagate and examine these characteristics. Litters that showed normal aging were selected as a senescence-resistant series (R-series). The genetic background of the SAM mice became suspect after the pathological findings were different from the AKR/J mouse. Each SAM model is genetically different. Each SAM colony was acquired by Harlan by Takeda Chemical Ltd. in 2002. And here is the link to the company site. http://www.harlan.com/products_and_services/research_models_and_services/research_models/sam_inbred_mice/samp8tahsd.hl
Project description:mRNA and microRNA expression was examined in global cellular fractions and in RNA-induced silencing complex (RISC)-immunoprecipitated cell fractions in cultured primary human astrocytes (ScienCell) and in cultured human U-87 MG astrocytoma cells (ATCC). ABSTRACT: Background: GW/P bodies are cytoplasmic ribonucleoprotein-rich foci that are involved in microRNA (miRNA)-mediated messenger RNA (mRNA) silencing and degradation. These mRNA regulatory functions within GW/P bodies are mediated by GW182 and its binding partner hAgo2 when bound to miRNA within the RNA-induced silencing complex (RISC). Although miRNAs and mRNAs are known to be localized to RISC in a variety of cells, to date no published study has examined the profile of specific miRNA and mRNA targeted to the RISC. Methodology/Principle Findings: In this study, RISC mRNA and miRNA components were profiled by microarray analysis of human U-87 astrocytoma cells and primary human astrocytes with total RNA extracted from the RISC as well as the global cellular fractions. The novel findings of this study were fourfold: (1) miRNAs are highly enriched in primary astrocyte RISC compared to U-87 astrocytoma RISC, (2) astrocytoma cells and primary astrocytes each contain unique RISC miRNA profiles as compared to their respective cellular miRNA profiles, (3) miR-195, 10b, 29b, 19b, 34a and 455-3p were upregulated and miR-181b was downregulated in U-87 astrocytoma RISC as compared to primary astrocyte RISC, and (4) RISC contain mostly downregulated mRNAs in primary astrocytes and U-87 astrocytoma cells. Conclusions/Significance: We show that in U-87 astrocytoma cells, miR-34a and miR-195 were upregulated in RISC suggesting an oncogenic role for these miRNAs. Three miR34a-targeted mRNAs and two miR-195-targeted mRNAs were downregulated. One miR-195-targeted mRNA was upregulated. Biological pathway analysis of RISC mRNA components suggests that the RISC plays a pivotal role in cancer, inflammatory disease, immunological disease, the cell cycle, cellular movement and numerous cell signaling pathways. This study points to the importance of the RISC and ultimately GW/P body composition and function and in miRNA and mRNA deregulation in astrocytoma cells and possibly for other brain tumors. Experiments outsourced to LC Sciences who are partnered with an AffymetrixM-BM-. Authorized Service Provider, SeqWright DNA Technology Services (Houston, TX). Using Affymetrix Human Genome U133A 2.0 Array, they analyzed 14,500 well-characterized human genes across 4 replicates in each of the 4 sample groups: (1) global cellular U-87 astrocytoma, (2) global cellular primary astrocyte, (3) RISC-IP U-87 astrocytoma, and (4) RISC-IP primary astrocyte. Experiments outsourced to LC Sciences (Houston, TX). Using M-BM-5Paraflo microfluidic chips, they analyzed 6211 target human miRNAs (Sanger miRBase version 11, http://microrna.sanger.ac.uk/sequences/) or control RNAs (array hybridization controls and single-base mismatch targets) and a polyethylene glycol spacer segment to extend the coding segment away from the substrate across 4 replicates in each of the 4 sample groups: (1) global cellular U-87 astrocytoma, (2) global cellular primary astrocyte, (3) RISC-IP U-87 astrocytoma, and (4) RISC-IP primary astrocyte.
Project description:To identify differently expressed genes between ferret and mouse astrocytes, we performed RNA-seq studies on primary ferret and mouse astrocytes cultured in serum free medium. We isolated primary astrocytes from mixed glial cultures which are prepared from the cortices of ferrets and mice at postnatal day 1. Each biological replicate was generated from 2 individuals of the same species. We detected substantial changes in the expression of genes associated with cell proliferation and migration, and identified ferret astrocyte-specific genes.
Project description:To understand how the circadian clock regulates astrocyte physiology, we conducted a circadian transcriptome analysis in cultured mouse cortical astrocytes
Project description:The heart of a newborn mouse has an exceptional capacity to regenerate from myocardial injury but lose it after a week of life, which has been utilized as a valuable model to explore the cues for heart regeneration. More and more researches indicated that glycoprotein played an important role in cardiac regeneration. Elucidating the glycosylation processes associated with heart regeneration will be beneficial for the molecular mechanism studies of heart regeneration as well as discovery of potential therapeutic strategies for human cardiac diseases. In this work, an integrated glycoproteomic and proteomic analysis were performed to investigate the differences in glycoprotein abundances and site-specific glycosylation occupancy between neonatal day 1 (P1) and day 7 (P7) of mouse hearts. The intact glycoepeptides were enriched and identified in both P1 and P7 hearts. To screen for differentially regulated glycoproteins, we compared the expression levels of intact glycopeptides between P1 and P7 hearts using label free quantification. Eventually, the glycosylation occupancy of site-specific N-glycans were obtained by comparing the alterations of intact glycopeptides with their corresponding protein expression levels obtained from global proteomic analysis. These altered glycosylation patterns among proteins between P1 and P7 mouse hearts have a significant potential to aid our understanding of the regenerative capacity loss in neonatal mouse hearts during the first week, thus leading to novel therapeutic approaches to recover the capacity.
Project description:Recent studies highlighted the importance of astrocytes in neuroinflammatory diseases, interacting closely with other CNS cells but also with the immune system. However, due to the difficulty in obtaining human astrocytes, their role in these pathologies is still poorly characterized. Here, we develop a new serum-free protocol to differentiate human iPSCs into astrocytes. Gene expression and functional assays show that our protocol consistently yields a highly enriched population of resting mature astrocytes across the thirteen hiPSC lines differentiated. Using this new model, we first highlight the importance of serum-free media for astrocyte culture to generate resting astrocytes. Second, we assess the astrocytic response to IL-1β, TNFα and IL-6, all cytokines important in neuroinflammation, such as multiple sclerosis. Our study reveals very specific profiles of reactive astrocytes depending on the triggering stimulus. This new model provides ideal conditions for in-depth and unbiased characterization of astrocyte reactivity in neuroinflammatory conditions.