Project description:We have generated isogenic induced pluripotent stem cell lines by reprogramming human fibroblasts from patients carrying the LRRK2 G2019S mutation with subsequent zinc finger nuclease - mediated targeted correction of the diseased allele. These iPS cell lines were differentiated for 30 days using a direct differentiation protocol towards midbrain dopaminergic neurons (mDANs). Isogenic human iPS cells carrying the LRRK2 WT and G2019S locus were differentiated to dopaminergic neurons to detect gene expression changes associated with mutated LRRK2.
Project description:We have generated isogenic induced pluripotent stem cell lines by reprogramming human fibroblasts from patients carrying the LRRK2 G2019S mutation with subsequent zinc finger nuclease - mediated targeted correction of the diseased allele. These iPS cell lines were differentiated for 30 days using a direct differentiation protocol towards midbrain dopaminergic neurons (mDANs).
Project description:Induced pluripotent stem cells (iPSC) derived from sporadic Parkinson's disease patients and healthy control subjects were used for disease modeling. iPSC were differentiated towards midbrain dopaminergic neurons. For metabolic analysis, midbrain neuronal precursor cells were cultivated in growth medium supplemented with either 1.25 mM [U-13C]-glutamine or 21.25 mM [U-13C]-glucose. Metabolites were extracted and analyzed using GC-MS. The MetaboliteDetector software was used to analyze chromatograms, calculate mass isotopomer distributions (MIDs) and perform relative comparison of metabolite levels.
Project description:Human embryonic and induced pluripotent stem cells are a promising cell source for the future treatment of Parkinson´s disease. It has been shown that mesencephalic dopaminergic (mesDA) neurons arise from the midbrain floor plate in which FOXA2 acts as a key transcription factor. We identified IAP which is specifically co-expressed with FOXA2 positive cells and is suitable to isolate mesDA progenitors utilizing MACS Technolog.The sorted iPSCs were viable, enriched for midbrain specific markers, lacked expression of pluripotency markers, and differentiated into mature dopaminergic neurons in vitro. IAP might be used as a tool to purify mesDA progenitor cells for regenerative therapy in PD patients
Project description:We studied human induced pluripotent stem cells (iPSCs)-derived dopaminergic (DA) neuron populations carrying CNVs of 16p11.2 duplication and 16p11.2 deletion.
Previously, healthy human iPSCs were edited using CRISPR-Cas9 method to produce isogenic lines with 16p11.2 deletion or 16p11.2 duplication. We differentiated these
isogenic iPSC lines into neural precursor cells and dopaminergic neurons and collected RNA samples for gene expression analyses with RNA sequencing. Our aim was to
identify differences in the expression of synaptic markers, neuronal differentiation markers, and neuron specific receptors that affect functionality of the neurons with 16p11.2
CNVs compared to isogenic control lines. We also studied physiological properties of these isogenic iPSC-derived DA neurons with 16p11.2 CNVs. In addition, we studied
expression and activation of a specific molecular pathway KCTD13-RHOA in the iPSC derived DA neuron populations with 16p11.2 CNVs.
Project description:Induced pluripotent stem cells (iPSCs) harbor great promise for in vitro generation of disease-relevant cell types, such as mesodiencephalic dopaminergic (mdDA) neurons involved in Parkinson’s disease. Although iPSC-derived midbrain DA neurons have been generated, detailed genetic and epigenetic characterization of such neurons is still lacking. The goal of this study is to examine the authenticity of iPSC-derived DA neurons obtained by established protocols. We FACS-purified mdDA (Pitx3gfp/+) neurons derived from mouse iPSCs and primary mdDA (Pitx3gfp/+) neurons to analyze and compare their genetic and epigenetic features. Although iPSC-derived DA neurons largely adopt characteristics of their in-vivo counterparts, relevant deviations in global gene expression and DNA methylation were found. Hypermethylated genes, mainly involved in neurodevelopment and basic neuronal functions, consequently showed reduced expression levels. Such abnormalities should be addressed as they might affect unambiguous long-term functionality and hamper the potential of iPSC-derived DA neurons for in-vitro disease modeling or cell-based therapy. RRBS methylation maps were generated for iPSCs cells, dopaminergic neurons derived from iPSCs and primary mesodiencephalic dopaminergic neurons
Project description:WNT1/beta-catenin signaling plays a crucial role in the generation of mesodiencephalic dopaminergic (mdDA) neurons including the Substantia nigra pars compacta (SNc) subpopulation, whose degeneration is a hallmark of Parkinson’s Disease (PD). However, the precise functions of WNT/beta-catenin signaling in this context remain unknown. Using mutant mice, primary ventral midbrain (VM) cells and pluripotent stem cells (mouse embryonic stem cells and induced pluripotent stem cells), we show that Dickkopf 3 (DKK3), a secreted glycoprotein that modulates WNT/beta-catenin signaling, is specifically required for the correct differentiation of a rostrolateral mdDA precursor subset into SNc DA neurons. Dkk3 transcription in the murine VM coincides with the onset of mdDA neurogenesis and is required for the maintenance of LMX1A and consequently PITX3 expression in rostrolateral mdDA precursors, without affecting the proliferation or specification of their progenitors. Treatment of primary VM cells or differentiating pluripotent stem cells with recombinant WNT1 and/or DKK3 proteins consistently increases the proportion of mdDA cells with SNc DA neuron identity and promotes their survival in vitro. The SNc DA pro-differentiation and pro-survival properties of DKK3, together with its known anti-tumorigenic effect, therefore make it an ideal candidate for the improvement of regenerative and neuroprotective strategies in the treatment of PD. We performed gene expression microarray analysis on iPSC-derived and FACS-sorted GFP-positive Pitx3GFP/+ mdDA neurons, differentiated in the presence or absence of recombinant human WNT1 and recombinant human DKK3. In addition, we analysed primary and FACS-sorted GFP-positive Pitx3+/GFP mdDA neurons isolated from the E13.5 and E14.5 ventral midbrain of Pitx3+/GFP embryos
Project description:Human induced pluripotent stem cells (iPSCs) can provide a promising source of midbrain dopaminergic (DA) neurons for cell replacement therapy for Parkinson’s disease. However, iPSC-derived donor cells may inevitably contain tumorigenic or inappropriate cells. Purification of neural progenitor cells or DA neurons as suitable donor cells has been attempted, but the isolation of DA progenitor cells derived from human pluripotent stem cells has so far been unsuccessful. Here we show human iPSC-derived DA progenitor cells can be efficiently isolated by cell sorting using a floor plate marker, Corin. we were able to develop a method for 1) scalable DA neuron induction on human laminin fragment and 2) sorting DA progenitor cells using an anti-Corin antibody. Furthermore, we determined the optimal timing for the cell sorting and transplantation. The grafted cells survived well and functioned as midbrain DA neurons in the 6-OHDA-lesioned rats, and showed minimal risk of tumor formation. The sorting of Corin-positive cells is favorable in terms of both safety and efficiency, and our protocol will contribute to the clinical application of human iPSCs for Parkinson’s disease. Differentiated human iPSC-derived neural progenitors just after sorting (day12 unsorted, day12 Corin+) and dopaminergic progenitors after an aggregation culture (day28 and day42, unsorted and day12-sorted, respectively), and human fetal ventral mesencephalon and dorsal mesencephalon (gestational age of 7.5 weeks) were subjected to RNA extraction and hybrdization on Affymetrix microarrays. Each sample except for human mesencephalon, undifferentiated iPSC, and day12-unsorted, day42-sample has 3 or 4 repeats.
Project description:Advances in stem cell technologies open up new avenues for modelling development and diseases. The success of these pursuits however rely on the use of cells most relevant to those targeted by the disease of interest, for example, midbrain dopaminergic neurons for Parkinson’s disease. In the present study, we report the generation of a human induced pluripotent stem cell (iPSC) line capable of purifying and tracing nascent midbrain dopaminergic progenitors and their differentiated progeny via the expression of a Blue Fluorescent Protein (BFP). This was achieved by CRISPR/Cas9 assisted knock-in of BFP and Cre into the safe harbour locus AAVS1 and an early midbrain dopaminergic lineage marker gene LMX1A, respectively. Immunocytochemical analysis and single cell RNA sequencing of iPSC-derived neural cultures confirms developmental recapitulation of the human fetal midbrain and high quality midbrain cells. By modelling Parkinson’s disease-related drug toxicity using 1-Methyl-4-phenylpyridinium (MPP+), we showed preferential reduction of BFP+ cells, a finding demonstrated independently by cell death assays and single cell transcriptomic analysis of MPP+ treated neural cultures. Together, these results highlight the importance of disease relevant cell type in stem cell modelling.
Project description:Advances in stem cell technologies open up new avenues for modelling development and diseases. The success of these pursuits however rely on the use of cells most relevant to those targeted by the disease of interest, for example, midbrain dopaminergic neurons for Parkinson’s disease. In the present study, we report the generation of a human induced pluripotent stem cell (iPSC) line capable of purifying and tracing nascent midbrain dopaminergic progenitors and their differentiated progeny via the expression of a Blue Fluorescent Protein (BFP). This was achieved by CRISPR/Cas9 assisted knock-in of BFP and Cre into the safe harbour locus AAVS1 and an early midbrain dopaminergic lineage marker gene LMX1A, respectively. Immunocytochemical analysis and single cell RNA sequencing of iPSC-derived neural cultures confirms developmental recapitulation of the human fetal midbrain and high quality midbrain cells. By modelling Parkinson’s disease-related drug toxicity using 1-Methyl-4-phenylpyridinium (MPP+), we showed preferential reduction of BFP+ cells, a finding demonstrated independently by cell death assays and single cell transcriptomic analysis of MPP+ treated neural cultures. Together, these results highlight the importance of disease relevant cell type in stem cell modelling.