RNAseq analysis for Fast Generated Functional Subtype Astrocytes from Human Pluripotent Stem Cells
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ABSTRACT: Differentiation 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.
Project description:The development of the central nervous system (CNS) depends on the orchestrated generation of neurons and glia from neural stem cells (NSCs). Although NSCs generate both cell types, they are produced sequentially as neurons are born first and glia later. In humans, this timing is extremely protracted and the underlying mechanisms remain unknown. Deriving glial cells such as astrocytes from human pluripotent stem cells requires 3-6 months of differentiation, greatly impeding their use in human disease modeling and regenerative medicine. Here, we report that expression of the transcription factor nuclear factor IA (NFIA) is sufficient to trigger glial competency in highly neurogenic NSCs and enables the derivation of human astrocytes within 10-12 days. NFIA-induced astrocytes are functional and shown to promote synaptogenesis, protect neurons and generate calcium transients. The mechanism of NFIA-induced glial competency involves rapid but reversible chromatin remodeling, demethylation of the GFAP promoter and a striking effect on the cell cycle. NFIA titration and pharmacological studies indicate that acquisition of a glial-compatible G1 length is critical for achieving glial competency. Our results offer mechanistic insights into human glial competency and enable the routine use of astrocytes for studying human development and disease.
Project description:The ability to generate astrocytes from human pluripotent stem cells (hPSCs) offers a promising cellular model to study the development and physiology of human astrocytes. However, the extant methods for generating functional astrocytes required long culture periods and remained much ambiguity whether their paradigm follows the innate developmental program. In this report, we provided an efficient and rapid method for generating physiologically functional astrocytes from hPSCs. Overexpressing the nuclear factor IB (NFIB) in hPSC-derived neural precursor cells (NPCs) induced a highly enriched astrocyte population in 2 weeks. RNA sequencing and functional analyses demonstrated progressive transcriptomic and physiological changes in the cells, resembling in vivo astrocyte development. Further analyses substantiated previous results and established the MAPK pathway necessary for astrocyte differentiation. Hence, this differentiation paradigm provides a prospective in vitro model for human astrogliogenesis studies and pathophysiology of neurological diseases concerning astrocytes.
Project description:Astrocytes are key regulators of CNS homeostasis and their dysfunction is implicated in neurological and neurodegenerative disorders. Here, we describe a two-step protocol to generate astrocytes from iPSCs using a bankable neural progenitor cell (NPC) intermediate, followed by low-density passaging and overexpression of the gliogenic transcription factor NFIA. A bankable NPC intermediates allows for facile differentiation into both purified neuronal and astrocyte cell types in parallel from the same genetic background, depending on the experimental needs. This article presents a protocol to generate NPCs from iPSCs (Basic Protocol 1), which are then differentiated into iPSC-derived astrocytes, termed iAstrocytes (Basic Protocol 2). The resulting iAstrocytes express key markers of astrocyte identity at transcript and protein levels by bulk RNA-seq and immunocytochemistry respectively. Additionally, they respond to the inflammatory stimuli poly(I:C) and generate waves of calcium activity in response to either physical activity or addition of ATP. Our approach offers a simple and robust method to generate and characterize human astrocytes which can be used to model human disease affecting this cell type.
Project description:The goal of this study is to determine how the loss of the transcription factor NFIA affects the molecular profiles of adult astrocytes from four brain regions. We performed RNA-sequencing on control and NFIA knockout (KO) astrocytes from the olfactory bulb, hippocampus, cortex, and brainstem, and analyzed the molecular signatures of NFIA KO astrocytes compared to control in each brain region.
Project description:Direct cell reprogramming has enabled the direct conversion of skin fibroblasts into functional neurons and oligodendrocytes using a minimal set of cell lineage-specific transcription factors. This approach has substantial advantages since it is rapid and simple, generating the cell type of interest in a single step. However, it remains unknown whether this technology can be applied for directly reprogramming skin cells into astrocytes, the third neural lineage. Astrocytes play crucial roles in neuronal homeostasis and their dysfunctions contribute to the origin and progression of multiple human diseases. Herein, we carried out a screening using several transcription factors involved in defining the astroglial cell fate and identified NFIA, NFIB and SOX9 to be sufficient to convert with high efficiency embryonic and post-natal mouse fibroblasts into astrocytes (iAstrocytes). We proved both by gene expression profiling and functional tests that iAstrocytes are comparable to native brain astrocytes. This protocol can be then employed to generate functional iAstrocytes for a wide range of experimental applications. Induced astrocytes (iAstro) were compared to Fibroblasts (Fibro) as negative control and to primary astrocytes (astro) as positive control. Three biological replicates were analyzed for each experimental group.
Project description:Somatic cell mutants can be informative in the analysis of a wide variety of cellular processes. The use of map- based positional cloning strategies in somatic cell hybrids to analyze genes responsible for recessive mutant phenotypes is often tedious, however, and remains a major obstacle in somatic cell genetics. To fulfill the need for more efficient gene mapping in somatic cell mutants, we have developed a new DNA microarray comparative genomic hybridization (array-CGH) method that can rapidly and efficiently map the physical location of genes complementing somatic cell mutants to a small candidate genomic region. Here we report experiments that establish the validity and efficacy of the methodology. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Using regression correlation
Project description:Somatic cell mutants can be informative in the analysis of a wide variety of cellular processes. The use of map- based positional cloning strategies in somatic cell hybrids to analyze genes responsible for recessive mutant phenotypes is often tedious, however, and remains a major obstacle in somatic cell genetics. To fulfill the need for more efficient gene mapping in somatic cell mutants, we have developed a new DNA microarray comparative genomic hybridization (array-CGH) method that can rapidly and efficiently map the physical location of genes complementing somatic cell mutants to a small candidate genomic region. Here we report experiments that establish the validity and efficacy of the methodology.
Project description:Somatic cell mutants can be informative in the analysis of a wide variety of cellular processes. The use of map- based positional cloning strategies in somatic cell hybrids to analyze genes responsible for recessive mutant phenotypes is often tedious, however, and remains a major obstacle in somatic cell genetics. To fulfill the need for more efficient gene mapping in somatic cell mutants, we have developed a new DNA microarray comparative genomic hybridization (array-CGH) method that can rapidly and efficiently map the physical location of genes complementing somatic cell mutants to a small candidate genomic region. Here we report experiments that establish the validity and efficacy of the methodology. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set
Project description:Cardiomyocytes can be differentiated from human pluripotent stem cells (hPSCs) in defined conditions, but efficient and consistent cardiomyocyte differentiation often requires expensive reagents such as B27 supplement or recombinant albumin. Using a chemically defined albumin-free (E8 basal) medium, we identified heparin as a novel factor that significantly promotes cardiomyocyte differentiation efficiency, and developed an efficient method to differentiate hPSCs into cardiomyocytes. The treatment of heparin helped cardiomyocyte differentiation consistently reach at least 80% purity (up to 95%) from more than 10 different hPSC lines in chemically defined DMEM/F-12 based medium on either Matrigel or defined matrices like Vitronectin and Synthemax. One of heparinâs main functions was to act as a WNT modulator that helped promote robust and consistent cardiomyocyte production. Our study provides an efficient, reliable, and cost-effective method for cardiomyocyte derivation from hPSCs that can be used for potential large-scale drug screening, disease modeling, and future cellular therapies. 12 human pluripotent stem cells (hPSCs) at three different cardiac differentiation times (0 Days, 3 Days, 6 Days, 10 Days) under different culture conditions (+/- Heparin, +/- IWP2).
Project description:Diversified neurons are essential for sensorimotor function, but whether astrocytes become specialized to optimize circuit performance remains unclear. Large fast α-motor neurons (FαMNs) of spinal cord innervate fast-twitch muscles that generate peak strength. We report that ventral horn astrocytes express the inward rectifying K+ channel Kir4.1 (aka, Kcnj10) around MNs in a VGLUT1-dependent manner. Loss-of astrocyte-encoded Kir4.1 selectively altered FαMN size, function and led to reduced peak strength. Overexpression of Kir4.1 in astrocytes was sufficient to increase MN size through activation of the PI3K/mTOR/pS6 pathway. Kir4.1 was downregulated cell-autonomously in astrocytes derived from amyotrophic lateral sclerosis (ALS) patients with SOD1 mutation. However, astrocyte Kir4.1 was dispensable for FαMN survival even in the mutant SOD1 background. These findings show that astrocyte Kir4.1 is essential for maintenance of peak strength and suggest that Kir4.1 downregulation uncouples symptoms of muscle weakness from MN cell death in ALS.