Project description:Heterogeneous and predominantly sporadic neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) remain highly challenging to model. Patient-derived induced pluripotent stem cell (iPSC) technologies offer great promise for these diseases, however large-scale studies demonstrating accelerated neurodegeneration from sporadic patients are limited. We generated an iPSC library from 100 sporadic ALS (SALS) patients and conducted population-wide phenotypic screening. SALS patient-derived motor neurons recapitulated key aspects of SALS, including reduced survival, accelerated neurite degeneration correlating with donor survival, transcriptional dysfunction, and pharmacological rescue by riluzole. Here we sought to determine if riluzole treatment reversed the disease process in patient-derived motor neurons by RNAseq profiling of riluzole treated vs untreated motor neurons from 9 ALS donors.
Project description:Amyotrophic lateral sclerosis and primary lateral sclerosis are two syndromic variants within the motor neurone disease spectrum. Whilst primary lateral sclerosis is associated with loss of upper motor neurons and a more benign disease course up to 17yrs, amyotrophic lateral sclerosis is caused by loss of both upper and lower motor neurons and has an average disease course of 2-3 years. The majority of cases are sporadic, thereby limiting the availability of cellular models for investigating pathogenic disease mechanisms. The aim of the present study was to evaluate fibroblasts as a cellular model for sporadic amyotrophic lateral sclerosis and primary lateral sclerosis, to establish whether disease-related dysregulated biological processes recapitulate those seen in the central nervous system and to elucidate pathways that distinguish between the two disease phenotypes. We used microarray analysis to determine the differences in gene expression between fibroblasts derived from skin biopsies taken from sporadic amyotrophic lateral sclerosis and primary lateral sclerosis neurologically normal human controls
Project description:Amyotrophic lateral sclerosis and primary lateral sclerosis are two syndromic variants within the motor neurone disease spectrum. Whilst primary lateral sclerosis is associated with loss of upper motor neurons and a more benign disease course up to 17yrs, amyotrophic lateral sclerosis is caused by loss of both upper and lower motor neurons and has an average disease course of 2-3 years. The majority of cases are sporadic, thereby limiting the availability of cellular models for investigating pathogenic disease mechanisms. The aim of the present study was to evaluate fibroblasts as a cellular model for sporadic amyotrophic lateral sclerosis and primary lateral sclerosis, to establish whether disease-related dysregulated biological processes recapitulate those seen in the central nervous system and to elucidate pathways that distinguish between the two disease phenotypes.
Project description:High throughput sequencing of poly-A RNA from control- and sporadic Parkinson´s disease patient derived fibroblasts (n=15), induced pluripotent stem cells (n=31) and differentiated midbrain neurons (n=15). Fibroblasts and iPSCs do not show major differences on single gene level. In contrast, midbrain neurons derived from Parkinson´s disease patients show changes known to be associated with neurodegenerative diseases.
Project description:Reprogramming somatic cells to induced pluripotent stem cells (iPSCs) sets their identity back to an embryonic age. This presents a fundamental hurdle for modeling late-onset disorders using iPSC-derived cells. We therefore developed a strategy to induce age-like features in multiple iPSC-derived lineages and tested its impact on modeling Parkinson’s disease (PD). We first describe markers that predict fibroblast donor age and observed the loss of these age-related markers following iPSC induction and re-differentiation into fibroblasts. Remarkably, age-related markers were readily induced in iPSC-derived fibroblasts or neurons following exposure to progerin including dopamine neuron-specific phenotypes such as neuromelanin accumulation. Induced aging in PD-iPSC-derived dopamine neurons revealed disease phenotypes requiring both aging and genetic susceptibility such as frank dendrite degeneration, progressive loss of tyrosine-hydroxylase expression and enlarged mitochondria or Lewy body-precursor inclusions. Our study presents a strategy for inducing age-related cellular properties and enables the modeling of late-onset disease features. Induced pluripotent stem cell-derived midbrain dopamine neurons from a young and old donor overexpressing either GFP or Progerin.
Project description:Our understanding of Alzheimer’s disease (AD) pathogenesis is currently limited by difficulties in obtaining live neurons from patients and the inability to model the sporadic form of AD. It may be possible to overcome these challenges by reprogramming primary cells from patients into induced pluripotent stem cells (iPSCs). We reprogrammed primary fibroblasts from two patients with familial AD (both caused by a duplication of APP1, APPDp), two with sporadic AD (sAD1, 2) and two non-demented control individuals (NDCs) into iPSC lines. Neurons from differentiated cultures were FACS-purified and characterized. Purified cultures contained >90% neurons, clustered with fetal brain mRNA samples by microarray criteria, and could form functional synaptic contacts. Virtually all cells exhibited normal electrophysiological activity. Relative to controls, iPSC-derived, purified neurons from the two APPDp patients and patient sAD2 exhibited significantly higher levels of secreted Aβ1-40, phospho-tauThr231 (pTau) and active GSK3β (aGSK3β). Neurons from APPDp and sAD2 patients also accumulated large Rab5-positive early endosomes compared to controls. Treatment of purified neurons with β-secretase inhibitors, but not g-secretase inhibitors, caused significant reductions in pTau and aGSK3β levels. These results suggest a direct relationship between APP proteolytic processing, but not Aβ, in GSK3β activation and tau phosphorylation in human neurons. Additionally, we observed that neurons with the genome of one sAD patient exhibited the phenotypes seen in familial AD samples. More generally, we demonstrate that iPSC technology can be used to observe phenotypes relevant to AD, even though it can take decades for overt disease to manifest in patients. Total RNA extracted from normal hIPSCs, Alzheimer's patient derived hIPSCs, neurons differentiated from hIPSCs, fetal brain, fetal heart, fetal liver and fetal lung
Project description:<p>Although clinical research has revealed microglia-related inflammatory and immune responses in bipolar disorder (BD) patient brains, it remains unclear how microglia contribute to the pathogenesis of BD. Here, we demonstrated that Serinc2 is associated with susceptibility to BD and showed a reduced expression in BDII patient plasma, which correlated with the disease severity. Using induced pluripotent stem cell (iPSC) models of sporadic and familial BDII patients, we found that Serinc2 expression showed deficits in iPSC-derived microglia-like cells, resulting in decreased synaptic pruning. Further, combining the microglia-specific Serinc2-deficient mouse and iPSC-microglia models, we found that microglial Serinc2 deficits functioned through attenuating the synthesis of serine-related phospholipids in the plasma membrane, thus resulting in depression-like behavioral abnormalities in the animals. Finally, we showed that the Serinc2-dependent lipid deficits diminished microglial membrane CR3 formation to interrupted synaptic pruning signals from neurons. Therefore, our results indicated that Serinc2 deficits in microglia might contribute to the pathogenesis of BD.</p>
Project description:Induced pluripotent stem cell (iPSC)-derived dopamine neurons provide an opportunity to model Parkinson’s disease (PD) but neuronal cultures are confounded by cellular heterogeneity. By applying high-resolution single cell transcriptomic analyses to Parkinson’s iPSC-derived dopamine neurons carrying the GBA-N370S risk variant, we exploited intra-culture cellular heterogeneity to identify a progressive axis of gene expression variation leading to endoplasmic reticulum stress. Analysis of genes differentially-expressed (DE) along this axis identified the transcriptional repressor histone deacetylase 4 (HDAC4) as an upstream regulator of disease progression. HDAC4 was mislocalized to the nucleus in PD iPSC-derived dopamine neurons and repressed genes early in the disease axis, leading to late deficits in protein homeostasis. Treatment of iPSC-derived dopamine neurons with compounds known to modulate HDAC4 activity upregulated genes early in the DE axis, and corrected Parkinson’s-related cellular phenotypes. Our study demonstrates how single cell transcriptomics can exploit cellular heterogeneity to reveal disease mechanisms and identify therapeutic targets.
Project description:Psychological, psychosocial and physical stress are major risk factors, which enhance the development of sporadic late-onset Alzheimer`s disease. The chronic unpredictable mild stress model mimics those risk factors and triggers signs of neurodegeneration and neuropathological features of sporadic AD such as tau hyperphosphorylation and enhanced amyloid beta generation. The study investigated the impact of chronic unpredictable mild stress on signs of neurodegeneration by analyzing hippocampal gene expression with whole genome microarray gene expression profiling.