Project description:Tuberous sclerosis complex (TSC) is a rare genetic disease characterized by mTOR hyperfunction induced benign tumor growths in multiple organs and neurological symptoms. Because the molecular pathology is highly complex and the etiology poorly understood we employed a defined human neuronal model with a single mTOR activating mutation to dissect the disease-relevant molecular responses driving the neuropathology. TSC2 deficient neural stem cells showed severely reduced neuronal functional maturation and characteristics of astrogliosis instead. Accordingly, transcriptome analysis uncovered an inflammatory response and increased metabolic activity, while ribosome profiling revealed excessive translation of ribosomal transcripts and higher synthesis rates of angiogenic growth factors. Treatment with mTOR inhibitors corrected translational alterations but not transcriptional dysfunction. These results extend our understanding of the molecular pathophysiology of TSC brain lesions, and suggest phenotype-tailored pharmacological treatment strategies. Two TSC+/- cell lines and two TSC-/- cell lines were independently generated from wild-type human embryonic stem cells by genome editting with zinc finger nucleases. Two cell lines were handled in the same way but without any known human gene editted and they are used as negative controls. Two independent biological replicates of each of the six cell lines are profiled with ribosome profiling technique.
Project description:Tuberous sclerosis complex (TSC) is a rare genetic disease characterized by mTOR hyperfunction induced benign tumor growths in multiple organs and neurological symptoms. Because the molecular pathology is highly complex and the etiology poorly understood we employed a defined human neuronal model with a single mTOR activating mutation to dissect the disease-relevant molecular responses driving the neuropathology. TSC2 deficient neural stem cells showed severely reduced neuronal functional maturation and characteristics of astrogliosis instead. Accordingly, transcriptome analysis uncovered an inflammatory response and increased metabolic activity, while ribosome profiling revealed excessive translation of ribosomal transcripts and higher synthesis rates of angiogenic growth factors. Treatment with mTOR inhibitors corrected translational alterations but not transcriptional dysfunction. These results extend our understanding of the molecular pathophysiology of TSC brain lesions, and suggest phenotype-tailored pharmacological treatment strategies. Rapamycin, AZD-8055, and DMSO were given to two TSC+/+ cell lines and two TSC-/- cell lines after six weeks of differentiation. Cells are harvested after 3 hours treatment and are subject to ribosome profiling and RNA-seq analysis.
Project description:In vitro neural stem cell models are widely used to model a wide range of neuropsychiatric conditions. However, how well such models correspond to in vivo brain has not been evaluated in an unbiased, comprehensive manner. We used transcriptomic analyses to compare in vitro systems to developing human fetal brain and observed strong conservation of in vivo gene expression and network architecture in differentiating primary human neural progenitor cells (phNPCs). Conserved modules are enriched in genes associated with ASD, supporting the utility of phNPCs for studying neuropsychiatric disease. We also developed and validated a machine learning approach called CoNTExT that identifies the developmental maturity and regional identity of in vitro models. We observed strong differences between in vitro models, including hiPSC-derived neural progenitors from multiple laboratories. This work provides a framework for evaluating in vitro systems and supports their value in studying the molecular mechanisms of human neurodevelopmental disease. In this GEO submission, we upload data from 5 lines of phNPCs as well as hiPSCs cultured in two different laboratories all at multiple differentiation time points. phNPCs: For each of 5 lines generated from 3 donors (15-16 PCW), two independent differentiation experiments each containing two replicates were performed and harvested at four time points (1, 4, 8, 12 wks PD; ~16 samples per line; 77 total samples). We confirmed RNA integrity by RIN score with the Agilent 2100 Bioanalyzer (mean +/- sd: 9.16 +/- 0.78). iPSC: Two hiPSC datasets were RNA profiled as part of this study. hiPSCs grown in the Kosik lab was derived from two independent, non-isogenic IPS lines: one derived from a patient carrying a mutant Tau variant G55R and one reference control. For each of these lines, two samples were harvested at each of 0, 1, 4, and 8 weeks PD (total n=16 samples). hiPSCs grown in the Gage lab were from six samples derived from 3 control lines at each of two time points (0 and 4 wk PD, total n=12 samples). Samples were randomized to microarray chip by all biological variables of interest (donor, line, passage, replicate number, differentiation week, plate date, and RIN) to control for potential batch effects.
Project description:The debilitating autoimmune disease Systemic Lupus Erythematosus (SLE) is closely associated with Toll-like receptor (TLR) 7 and type I interferon (IFN) activity in humans and in murine SLE-like disease. Two central manifestations of SLE affect the myeloid lineage of the immune system, myeloid expansion and anemia. Yet, whether these symptoms are linked and the role of TLR7 and/or type I IFN in these processes is unclear. Here we show that TLR7 signaling promotes cell-autonomous, phosphoinositide 3-kinase (PI3K)- and mammalian target of rapamycin (mTOR)-dependent macrophage development from the common myeloid progenitor (CMP). Strikingly, this TLR7-driven macrophage development requires and is enhanced by type I IFN. Genome-wide transcriptional profiling and functional studies demonstrated that TLR7 promoted the expression of Spic, the master regulator of splenic red pulp macrophages (RPM) and preferential development of hemophagocytic RPM-like cells from CMP in vitro. We found increased incidence of RPM-like cells in vivo in a mouse model of SLE caused by TLR7 overexpression, which correlated with decreased red blood cell (RBC) count and anemia. These findings demonstrate a mechanism by which TLR7 signaling promotes anemia that is of clinical significance in SLE, other rheumatological diseases and chronic viral infections. This work also identifies a previously unknown molecular pathway by which TLR signaling and type I IFN synergize to promote myeloid development from hematopoietic progenitors. CMP were sorted from the bone marrow of wild-type C57BL/6 mice, cultured with SCF+R848 or SCFr+MCSF, and CD11b+F4/80+ macrophages sorted after 5 days, n=3 per group
Project description:Increasing evidence suggests that in Amyotrophic Lateral Sclerosis (ALS) mutated RNA binding proteins acquire aberrant functions, leading to altered RNA metabolism with significant impact on encoded protein levels. Here, by taking advantage of a human induced Pluripotent Stem Cell (hiPSC)-based model, we aimed to gain insights on the impact of ALS mutant FUS on the motoneuron proteome. Label-free proteomics analysis by mass-spectrometry revealed upregulation of proteins involved in catabolic processes and oxidation-reduction, and downregulation of cytoskeletal proteins and factors directing neuron projection. Mechanistically, proteome alteration does not correlate with transcriptome changes. Rather, we observed a strong correlation with selective binding of mutant FUS to target mRNAs in their 3’UTR. Novel validated targets, selectively bound by mutant FUS only, include genes previously involved in familial or sporadic ALS, such as VCP, and regulators of membrane trafficking and cytoskeleton remodeling, such as ASAP1. These findings unveil a novel mechanism by which mutant FUS might intersect other pathogenic pathways in ALS patients’ motoneurons.
Project description:One of the long-standing goals in the field has been to establish a culture system that would allow maintenance of HSC properties ex vivo. In the absence of such system, the ability to model human hematopoiesis in vitro has been limited, and there has been little progress in the expansion of human HSCs for clinical application. To that end, we defined a mesenchyml stem cell co-culture system for expansion of clonally multipotent human HSPCs that are protected from apoptosis and immediate differentiation, and retain the HSPC phenotype. By performing a genome-wide gene expression analysis of purified HSPCs isolated at different stages of co-culture, we asked at the molecular level, to what degree hematopetic stem cell properties can be preserved during culture. This temporal gene expression data from in vivo derived- and ex vivo expanded human HSPCs will serve as a resource to identify novel regulatory pathways that control HSC properties, and to develop clinically applicable protocols for HSC expansion. Human CD34+ fetal liver cells were co-cultured on a subclone of OP9 stomal cells (OP9M2 sublemented with supportive cytokines (see below)). To distinguish between molecular changes acquired over prolonged culture versus immediately after exposure to culture, gene expression in isolated CD45+CD34+CD38-CD90+ HSPCs was assessed after 12 hours, 2 weeks and 5 weeks in culture. Cultured CD45+CD34+CD38-CD90+HSPCs were compared to freshly isolated CD45+CD34+CD38-CD90+HSPCs and their more differentiated CD45+CD34+CD38+CD90- downstream progenitor cells.
Project description:Alpk1-deficient mice demonstrate exacerbated colitis and increased IL-12/Th1 response upon challenge with an intestinal pathobiont, Helicobacter hepaticus (Hh). Hematopoietic compartment is driving the pathogenic phenotype in this animal model, and Alpk1 is highly expressed in myeloid cells (macrophages and dendritic cells). Alpk1 deficiency has a recessive phenotype, since Alpk1+/- (heterozygous) mice show the same phenotype as the wild type mice. Mouse bone-marrow derived macrophages (BMDMs) show elevated IL-12 production in Alpk1-/- mice in response to stimulation with Hh. Since the molecular mechanism of how Alpk1 deficiency affects macrophage response to Hh is unknown, we aimed to characterise global changes in gene expression in Alpk1+/- vs Alpk1-/- bone-marrow differentiated cells (BMDMs). Cells were isolated from bone marrow of Alpk1+/- and Alpk1-/- (mixture of bone marrows from three mice per genotype) and plated in BMDM differentiation medium (RPMI, 10% FCS, penicillin and streptomycin, 50 micro beta-mercapthoethanol, 20 ng/ml recombinant mouse GM-CSF(Peprotech)), 7 million cells in per 10 sm uncoated TC dish in 10 ml of medium for eight days, extra 10 ml of medium was added to plates at day 4, before collection and replating in 96-well plates, 150 thousand cells/200 microliters of differentiation medium per well in technical triplicates per genotype/stimulation condition (R1-R3 labels of the samples). The following day BMDMs were stimulated with MOI of 10 of Hh and 10ng/ml of mouse IFNg (Peprotech) (Alpk1+/- BMDMs – het _Hh_8h vs Alpk1-/- BMDMs – alpk1_Hh_8h) or IFNg only (het _nonstim_8h vs alpk1_nonstim_8h) before lysis for RNA extraction using Quick-RNA kit from Zymo Research. Purified RNA was submitted to the Welcome Trust Centre for Human Genetics (Oxford) for RNA-Sequencing
Project description:Progranulin (GRN) mutations cause frontotemporal dementia (FTD), but GRN's function in the CNS remains largely unknown. To identify the pathways downstream of GRN, we used weighted genome co-expression network analysis (WGCNA) to develop a systems-level view of transcriptional alterations in a human neural progenitor model of GRN-deficiency. This highlighted key pathways such as apoptosis and ubiquitination in GRN deficient human neurons, while revealing an unexpected major role for the Wnt signaling pathway, which was confirmed by analysis of gene expression data from postmortem FTD brain. Furthermore, we observed that the Wnt receptor Fzd2 was one of only a few genes up-regulated at 6 weeks in a GRN knockout mouse, and that FZD2 reduction caused increased apoptosis, while its upregulation promoted neuronal survival in vitro. Together, these in vitro and in vivo data point to an adaptive role for altered Wnt signaling in GRN deficiency-mediated FTD, representing a potential therapeutic target. We therefore developed an in vitro model of GRN deficiency using primary human neural stem cells in which shRNA was used to diminish GRN levels to 50% or below. We developed a tetracycline inducible system in which transactivator protein rtTA3 and PuroR genes were constituitively expressed under the UBC promoter, while RFP and shRNA were regulated by an inducible tet-On CMV promoter (Gossen and Bujard, 1992). To control for off-target effects, two hairpins against GRN were used, and a scrambled hairpin was used as a control.
Project description:High resolution transcriptional profiling of H1-derived human neuronal precursor cells over a timecourse of differentiation in vitro. Human NPC differentiation timecourse covers Days 0,1,2,4,5,11, and 18 after induction of neuronal differentiation as described in manuscript. Each time point was assayed in triplicate cultures with the exception of Day 5, in which one outlier culture has been removed.
Project description:Schizophrenia is a debilitating neurological disorder for which no cure exists. Few defining characteristics of schizophrenic neurons have been identified and the molecular mechanisms responsible for schizophrenia are not well understood, in part due to the lack of patient material for study. Human induced pluripotent stem cells (hiPSCs) offer a new strategy for studying schizophrenia. We have created the first cell-based human model of a complex genetic psychiatric disease by generating hiPSCs from schizophrenic patients and subsequently differentiating these cells to hiPSC-derived neurons in vitro. Schizophrenic hiPSC-derived neurons showed diminished neuronal connectivity in conjunction with decreased neurite number, PSD95-protein levels and glutamate receptor expression. Gene expression profiles of schizophrenic hiPSC-derived neurons identified altered expression of many components of the cAMP and WNT signaling pathways. Key cellular and molecular elements of the schizophrenic phenotype were ameliorated following treatment of schizophrenic hiPSC-derived neurons with the antipsychotic loxapine. 3 independent differentiations (biological replicates) for each of four control and four schizophrenic patients were analyzed.