Project description:Pompe disease is caused by autosomal recessive mutations in the GAA gene, which encodes acid alpha-glucosidase. Although enzyme replacement therapy has recently improved patient survival greatly, the results in skeletal muscles and for advanced disease are still not satisfactory. Here, we report the derivation of Pompe disease induced pluripotent stem cells (PomD-iPSCs) and their potential for pathogenesis modeling, drug testing and disease marker identification. PomD-iPSCs maintained pluripotent features, and had low GAA activity and high glycogen content. Cardiomyocyte-like cells (CMLCs) differentiated from PomD-iPSCs recapitulated the hallmark Pompe disease pathophysiological phenotypes, including high levels of glycogen, abundant intracellular LAMP-1- or LC3-positive granules, and multiple ultrastructural aberrances. Drug rescue assessment showed that exposure of PomD-iPSC-derived CMLCs to rhGAA reversed the major pathologic phenotypes. Further, L-carnitine and 3- methyladenine treatment reduced defective cellular respiration and buildup of phagolysosomes, respectively, in the diseased cells. By comparative transcriptome analysis, we identified glycogen metabolism, lysosome and mitochondria related marker genes whose expression robustly correlated with the therapeutic effect of drug treatment in PomD-iPSC-derived CMLCs. Collectively, these results demonstrate that PomD-iPSCs are a promising in vitro disease model for development of novel therapeutic strategies for Pompe disease. Total RNA were isolated from HESC, HF(Pompe disease), PomD-iPSC, HES-CMLC, and PomD-iPS-CMLC. The series included two HESC lines, two HF(Pompe disease) cell lines, four PomD-iPS cell lines, and HES-CMLC were differentiated from one HESC line(HESC2), PomD-iPS-CMLC were differentiated from 3 PomD-iPS cell lines(PomD-iPSC A10, PomD-iPSC A17, PomD-iPSC B03). Each condition was repeated twice and used HESC as control.
Project description:Pompe disease is caused by autosomal recessive mutations in the GAA gene, which encodes acid alpha-glucosidase. Although enzyme replacement therapy has recently improved patient survival greatly, the results in skeletal muscles and for advanced disease are still not satisfactory. Here, we report the derivation of Pompe disease induced pluripotent stem cells (PomD-iPSCs) and their potential for pathogenesis modeling, drug testing and disease marker identification. PomD-iPSCs maintained pluripotent features, and had low GAA activity and high glycogen content. Cardiomyocyte-like cells (CMLCs) differentiated from PomD-iPSCs recapitulated the hallmark Pompe disease pathophysiological phenotypes, including high levels of glycogen, abundant intracellular LAMP-1- or LC3-positive granules, and multiple ultrastructural aberrances. Drug rescue assessment showed that exposure of PomD-iPSC-derived CMLCs to rhGAA reversed the major pathologic phenotypes. Further, L-carnitine and 3- methyladenine treatment reduced defective cellular respiration and buildup of phagolysosomes, respectively, in the diseased cells. By comparative transcriptome analysis, we identified glycogen metabolism, lysosome and mitochondria related marker genes whose expression robustly correlated with the therapeutic effect of drug treatment in PomD-iPSC-derived CMLCs. Collectively, these results demonstrate that PomD-iPSCs are a promising in vitro disease model for development of novel therapeutic strategies for Pompe disease.
Project description:Engineered human cardiac tissues have been utilized for various biomedical applications, including drug testing, disease modeling, and regenerative medicine. However, the applications of cardiac tissues derived from human pluripotent stem cells are often limited due to their immaturity and lack of functionality. Therefore, in this study, we established a perfusable culture system based on in vivo-like heart microenvironments to improve human cardiac tissue fabrication. The integrated culture platform of a microfluidic chip and a three-dimensional heart extracellular matrix enhanced human cardiac tissue development and their structural and functional maturation. These tissues were comprised of cardiovascular lineage cells, including cardiomyocytes and cardiac fibroblasts derived from human induced pluripotent stem cells, as well as vascular endothelial cells. The resultant macroscale human cardiac tissues exhibited improved efficacy in drug testing (small molecules with various levels of arrhythmia risk), disease modeling (long QT syndrome and cardiac fibrosis), and regenerative therapy (myocardial infarction treatment). Therefore, our culture system can serve as a highly effective tissue-engineering platform to provide human cardiac tissues for versatile biomedical applications.
Project description:Pompe disease is a rare, lysosomal disorder, characterized by intra-lysosomal glycogen accumulation due to an impaired function of ?-glucosidase enzyme. The laboratory testing for Pompe is usually performed by enzyme activity, genetic test, or urine glucose tetrasaccharide (Glc4) screening by HPLC. Despite being a good preliminary marker, the Glc4 is not specific for Pompe.
The purpose of the present study was to develop a simple methodology using liquid chromatography-high resolution mass spectrometry (LC-HRMS) for targeted quantitative analysis of Glc4 combined with untargeted metabolic profiling in a single analytical run to search for complementary biomarkers in Pompe disease.
We collected 21 urine specimens from 13 Pompe disease patients and compared their metabolic signatures with 21 control specimens.
Multivariate statistical analyses on the untargeted profiling data revealed Glc4, creatine, sorbitol/mannitol, L-phenylalanine, N-acetyl-4-aminobutanal, N-acetyl-L-aspartic acid, and 2-aminobenzoic acid as significantly dysregulated in Pompe disease. This panel of metabolites increased sample class prediction (Pompe disease versus control) compared with a single biomarker.
This study has demonstrated the potential of combined acquisition methods in LC-HRMS for Pompe disease investigation, allowing for routine determination of an established biomarker and discovery of complementary candidate biomarkers that may increase diagnostic accuracy, or improve the risk stratification of patients with disparate clinical phenotypes.
Project description:While there are many human skeletal muscle disorders, very few therapies have been developed. It has not been possible to generate large amounts of purified skeletal muscle cells from pluripotent stem cells, and to test therapies quantitatively. We therefore devised conditions for generating and expanding purified human myogenic progenitors from induced pluripotent stem (iPS) cells. The progenitors retained the capacity to differentiate into multinucleated myotubes and showed a normal karyotype throughout the expansion phase. We applied this method to Pompe disease, a metabolic myopathy caused by deficiency of the lysosomal enzyme acid alpha-glucosidase (GAA). In a screen, we identified sequences that suppressed aberrant GAA exon 2 splicing caused by the frequent c.-32-13T>G (IVS1) GAA variant. Antisense oligonucleotides (AONs) that blocked these sequences promoted exon 2 inclusion in patient-derived myotubes. As this raised GAA enzymatic activity above the disease threshold, AON-mediated splicing correction may provide a treatment option for Pompe disease.
Project description:Human pluripotent stem cells are a promising source of diverse cells for developmental studies, cell transplantation, disease modeling, and drug testing. However, their widespread use even for intensely studied cell types like spinal motor neurons, is hindered by the long duration and low yields of existing protocols for in vitro differentiation and by the molecular heterogeneity of the populations generated. We report a combination of small molecules that induce up to 50% motor neurons within 3 weeks from human pluripotent stem cells with defined subtype identities that are relevant to neurodegenerative diseases. Despite their accelerated differentiation, motor neurons expressed combinations of HB9, ISL1 and column-specific markers that mirror those observed in vivo in human fetal spinal cord. They also exhibited spontaneous and induced activity, and projected axons towards muscles when grafted into developing chick spinal cord. Strikingly, this novel protocol preferentially generates motor neurons expressing markers of limb-innervating lateral motor column motor neurons (FOXP1+/LHX3-). Access to high-yield cultures of human limb-innervating motor neuron subtypes will facilitate in-depth study of motor neuron subtype-specific properties, disease modeling, and development of large-scale cell-based screening assays. We analyze 3 samples including 2 positive samples and 1 negative sample. Descriptions are as follow: a) Positive Sample 1: SHH-derived, day 21 GFP-high FACS purified motor neurons.b) Positive Sample 2: S+P-derived, day 21 GFP-high FACS purified motor neurons. c) Negative: S+P condition, day 21 no GFP FACS purified motor neurons
Project description:Human pluripotent stem cells are a promising source of diverse cells for developmental studies, cell transplantation, disease modeling, and drug testing. However, their widespread use even for intensely studied cell types like spinal motor neurons, is hindered by the long duration and low yields of existing protocols for in vitro differentiation and by the molecular heterogeneity of the populations generated. We report a combination of small molecules that induce up to 50% motor neurons within 3 weeks from human pluripotent stem cells with defined subtype identities that are relevant to neurodegenerative diseases. Despite their accelerated differentiation, motor neurons expressed combinations of HB9, ISL1 and column-specific markers that mirror those observed in vivo in human fetal spinal cord. They also exhibited spontaneous and induced activity, and projected axons towards muscles when grafted into developing chick spinal cord. Strikingly, this novel protocol preferentially generates motor neurons expressing markers of limb-innervating lateral motor column motor neurons (FOXP1+/LHX3-). Access to high-yield cultures of human limb-innervating motor neuron subtypes will facilitate in-depth study of motor neuron subtype-specific properties, disease modeling, and development of large-scale cell-based screening assays.
Project description:The only FDA approved therapy for Pompe is directed at correcting skeletal and cardiac muscle pathology, however, clinical and animal model data show strong histological evidence for a neurological disease component. While neuronal cell death and neuroinflammation are prominent in many lysosomal disorders, these processes have not been evaluated in Pompe disease. There is also no information available regarding the impact of Pompe disease on the fundamental pathways associated with synaptic communication. We used microarrays to gain insight regarding pathogenetic signaling pathways that might contribute to neuropathology in Pompe (Gaa-/-) mice.
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:Induced pluripotent stem cell (iPSC) disease models have been generated for a number of diseases, and some have shown their potential utilization for pathological and drug toxicological evaluations. We have generated two hiPSC clones from a non-familial Alzheimerâs patient (AD-iPSCs), which expressed typical undifferentiated markers and fulfilled standard pluripotency assays. Genome-wide microarray analysis revealed that AD-iPSCs are highly similar to control hiPSCs and hESCs, albeit with some noticeable differences in several genes: DNAJC15, GRPR, NAIP and SNORD116-18. Several other biomarkers were differentially expressed in AD-iPSC clones, which were implicated in memory impairment and AD. Furthermore, well characterized familial AD-associated genes (APP, PSEN1, PSEN2) and non-familial (A2M, APOE, GAP43, MAOA, MPO, PLAT, PLAU, SORL1, SNCA) exhibited different expression patterns but were largely reset upon reprogramming into a pluripotent state. Overall, hiPSCs can be good candidates for AD modeling and may represent an in vitro alternative to studying disease mechanisms and drug discovery/toxicology studies. Fibroblasts and two hiPSC clones from a non-familial Alzheimerâs patient (AD-iPSCs) were analyzed. For each cell sample, 2-3 biological replicates were obtained.