ACGH analysis of familial Alzheimer’s disease with presenilin 2 mutation patient-specific induced pluripotent stem cells
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ABSTRACT: We established two clones of induced pluripotent stem cells (iPSC) with the presenilin 2 mutation, N141 (PS2-1 iPSC and PS2-2 iPSC) by retroviral transduction of primary human fibroblasts. To detect the copy number dependent gene expression profiles in primary fibroblast carrying the presenilin 2 mutation N141(before reprogramming) and PS2-1 iPSC and PS2-2 iPSC(after reprogramming), this experiment was designed. Genomic DNA of primary fibroblasts carrying the presenilin 2 mutation N141 and undifferentiated PS2-1 iPSC and PS2-2 iPSC were collected. Then, they were applied in this experiment.
Project description:We established two clones of induced pluripotent stem cells (iPSC) with the presenilin 2 mutation, N141 (PS2-1 iPSC and PS2-2 iPSC) by retroviral transduction of primary human fibroblasts. To detect the copy number dependent gene expression profiles in primary fibroblast carrying the presenilin 2 mutation N141(before reprogramming) and PS2-1 iPSC and PS2-2 iPSC(after reprogramming), this experiment was designed.
Project description:We established two clones of induced pluripotent stem cells (iPSC) with the presenilin 2 mutation, N141 (PS2-1 iPSC and PS2-2 iPSC) by retroviral transduction of primary human fibroblasts. To show the similarity among 201B7 iPSC, PD01-25 iPSC(Sporadic Parkinson's disease patient derived iPSC), PS2-1 iPSC, PS2-2 iPSC, this experiment was designed.
Project description:We established two clones of induced pluripotent stem cells (iPSC) with the presenilin 2 mutation, N141 (PS2-1 iPSC and PS2-2 iPSC) by retroviral transduction of primary human fibroblasts. To show the similarity among 201B7 iPSC, PD01-25 iPSC(Sporadic Parkinson's disease patient derived iPSC), PS2-1 iPSC, PS2-2 iPSC, this experiment was designed. Undifferentiated 201B7 iPSC, PD01-25 iPSC, PS2-1 iPSC and PS2-2 iPSC were collected. Then, they were applied in this experiment.
Project description:Presenilin (PS) proteins represent the catalytic subunits of γ-secretase, and play a critical role in the generation of the Amyloid β (Aβ) peptide and the pathogenesis of Alzheimer’s disease (AD). Indeed, mutations in presenilin 1 (PS1) or PS2 are a major cause of early onset familial Alzheimer’s disease (FAD). However, PS proteins also exert multiple functions beyond Aβ generation. In this study, we examine the individual roles of PS1 and PS2 in cellular cholesterol metabolism. Deletion of PS1 or PS2 in mouse models led to cholesterol accumulation in cerebral neurons. Cholesterol accumulation was also observed in lysosomes of embryonic fibroblasts from PS1-KO and PS2-KO mice, and associated with decreased expression of the Niemann-Pick type C1 (NPC1) protein involved in intracellular cholesterol transport at late endosome/lysosome. Mass spectrometry and complementary biochemical methods also revealed abnormal N-glycosylation of NPC1 and several other membrane proteins in PS1-KO and PS2-KO cells. Interestingly, pharmacological inhibition of N-glycosylation resulted in intracellular cholesterol accumulation prominently in lysosomes as well as decrease of NPC1 expression in wild-type MEFs, thereby resembling the changes in PS1-KO and PS2-KO MEFs. In turn, treatment of PS1-KO and PS2-KO MEFs with a chaperone inducer, Arimoclomol, attenuated decrease of NPC1 and rescued the lysosomal cholesterol accumulation. Additionally, the intracellular cholesterol accumulation in PS1-KO and PS2-KO MEFs was prevented by NPC1 overexpression. Collectively, these data indicate that PS/γ-secretase dysfunction results in an impairment of protein N-glycosylation, which eventually causes NPC1 decrease and intracellular cholesterol accumulation. 3'RNASeq of mouse embryonic fibroblasts with PS1- or PS2-deficiency compared with controls. Biological replicates
Project description:Notch1 signaling is an important regulator of cell fate in early stages of T cell development. Because Notch receptors can function redundantly, we sought an approach for inhibiting all endogenous Notch signaling in thymocytes. Upon ligand engagement, Notch receptors undergo two successive proteolytic cleavages, the second involving a Presenilin (PS) containing complex with -secretase activity that releases a small intracellular fragment of Notch. This activated form of Notch (NotchIC) translocates from the membrane to the nucleus, where it acts as a transcription factor, inducing the expression of multiple target genes . Since Presenilins are required for the activation of all four mammalian forms of Notch, we generated mice with deletions of both Presenilin1 and Presenilin2 genes, the only genes encoding Presenilin in the mouse genome. To target Notch inactivation specifically to developing T cells, we introduced Cd4-Cre to mediate Presenilin gene deletion in a tissue- and stage-specific manner. Direct target genes of Notch signaling are largely unknown, and are likely to be cell lineage and stage specific. Therefore in order to identify potential Notch target genes , we compared RNA of thymocytes at the CD4+CD8+ stage of development from H-2b transgenic 5CC7 TCR/ RAG2-deficient / Presenilin1flox/flox /PS2-/- mice, with and without Cd4-Cre. Keywords: presenilin, thymocytes, mouse
Project description:Presenilin 1 (PSEN1) is the most frequently mutated gene in early-onset sporadic and familial Alzheimer’s disease (FAD). The PSEN1 complex displays gamma-secretase activity and promotes cleavage of the C99-terminal fragment of the Amyloid Precursor Protein (APP) into the A42 peptide. PSEN1 is also involved in vesicle transport across ER and mitochondria in so called mitochondria associated membranes. We generated induced pluripotent stem cells (iPSCs) from 5 controls and 5 FAD cases carrying the PSEN1 A246E and L286V mutations. Unexpectedly, global gene expression profile analysis of FAD iPSCs revealed profound perturbation of mitochondrial, Golgi apparatus and ER pathways. PSEN1, APP and Nicastrin were highly expressed in iPSCs and PSEN1 localized to membrane-bound organelles. FAD iPSCs grown slower and showed elevated cell death together with abnormally high A42 secretion. Mitochondrial reactive oxygen species (ROS) were elevated in FAD iPSCs and treatment with a ROS scavenger significantly improved cell death, proliferation, and DNA damage. However, it could not improve the severe ATP deficit. Inhibition of gamma-secretase activity further exacerbated the overall FAD iPSC phenotype. Cortical neurons produced from the differentiation of FAD iPSCs showed Alzheimer’s pathology and TGFb pathway hyper-activation. PSEN1-mutant iPSCs may serve as a new model to perform genome-wide genetic screens and to study FAD pathophysiology and PSEN1 cellular function.
Project description:Notch1 signaling is an important regulator of cell fate in early stages of T cell development. Because Notch receptors can function redundantly, we sought an approach for inhibiting all endogenous Notch signaling in thymocytes. Upon ligand engagement, Notch receptors undergo two successive proteolytic cleavages, the second involving a Presenilin (PS) containing complex with -secretase activity that releases a small intracellular fragment of Notch. This activated form of Notch (NotchIC) translocates from the membrane to the nucleus, where it acts as a transcription factor, inducing the expression of multiple target genes . Since Presenilins are required for the activation of all four mammalian forms of Notch, we generated mice with deletions of both Presenilin1 and Presenilin2 genes, the only genes encoding Presenilin in the mouse genome. To target Notch inactivation specifically to developing T cells, we introduced Cd4-Cre to mediate Presenilin gene deletion in a tissue- and stage-specific manner. Direct target genes of Notch signaling are largely unknown, and are likely to be cell lineage and stage specific. Therefore in order to identify potential Notch target genes , we compared RNA of thymocytes at the CD4+CD8+ stage of development from H-2b transgenic 5CC7 TCR/ RAG2-deficient / Presenilin1flox/flox /PS2-/- mice, with and without Cd4-Cre. Thymocyte single cell suspensions were generated using 100 µm nylon mesh (PGC Scientifics). DP thymocytes were isolated from RAG2° control or PS1/2° 5CC7 TCR H2bb mice by magnetic bead separation on anti-CD4 coated microbeads (Miltenyi Biotec.). Total RNA was isolated using TRIzol according to manufacturer's instructions (Invitrogen). After quantification and checking for integrity, 1 µg of RNA was subjected to linear amplification. The resulting aRNA was labeled by reverse transcription via Cy5-dCTP incorporation and Cy3-dCTP incorporation. The fluorescent labeled probes were subsequently combined and hybridized on topic-defined PIQORTM Immunology Microarrays Mouse Antisense.
Project description:Human induced pluripotent stem cells (hIPSCs) represent a unique opportunity for regenerative medicine since they offer the prospect of generating unlimited quantities of cells for autologous transplantation as a novel treatment for a broad range of disorders. However, the use of hIPSCs in the context of genetically inherited human disease will require correction of disease-causing mutations in a manner that is fully compatible with clinical applications. We analyzed hiPSC line and genetically modified derivatives using high-density SNP array to investigate genomic instability associated reprogramming and genetic modification. Primary iPSC lines derived from patients with alpha-1 antitrypsin deficiency were generated. This genetic disorder is caused by homozygous mutation (Glu342Lys) in the SERPINA1 gene. We carried out mutation correction by 2 steps: zinc-finger nuclease-stimuated gene targeting and piggyBac trasnsposon-mediated selection cassette elimination. Parental fibroblast lines, primary iPSC lines and homozygously targeted iPSC lines were subjected to SNP genotyping using Illumina CytoSNP-12 BeadChiP.
Project description:Regulation of presenilin genes. Presenilins are intramembrane aspartic proteases. These proteases are critical proteins in pathogenesis of Alzheimer's disease. The function of recently identified presenilin-homologous proteases (IMPAS or SPP)s is unknown. Our preliminary data in C.elegans model suggested the role of these proteins in early-development and , perhaps, in pathway related- to cholesterol -regulated signalling (Grigorenko et al, 2004, PNAS). The overall goal is to determine pattern of gene expression alterations in cells with knock-out or knock-down presenilin related proteins (IMPAS). The cultured cells, C.elegans and mouse models are planned to be used in this study. Here , we will determine gene expression patterns in C.elegans strain NL2099, fed with bacteria HT115, producing dsRNA for Ce-imp-2 gene (knock-down of imp-2 gene by RNAi )or GFP gene as a control. We hypothesize that novel family of presenilin-related proteases is important for cholesterol-regulated intracellular signalling and early development (including CNS/neuronal development and function). C.elegans (strain NL2099) on L1 stage were placed on agarose plates with bacteria HT115, producing dsRNA for: 1) Ce-imp-2 gene; 2) GFP as a control gene. After 48 hours at 20C , worms were washed in M9 buffer and total RNA was isolated by TRIzol method. Keywords: dose response