Project description:We show that HCMV infection of human induced pluripotent stem cell (hiPSC)-derived brain organoids can recapitulate severe clinical manifestations such as microcephaly. We demonstrate that infection of hiPSC-derived brain organoids by the “clinical-like” HCMV strain TB40/E results in substantially reduced brain organoid growth, impaired formation of cortical layers, abnormal calcium signaling, and disrupted neural network. Accordingly, RNA-seq analysis revealed that genes down-regulated in TB40/E-infected brain organoids include those involved in neural development and calcium signaling. Moreover, we show that the impeded brain organoid development and abnormal neural network caused by TB40/E infection can be prevented by neutralizing antibodies (NAbs) that recognize different epitopes of the HCMV envelope pentamer complex (PC), a major target of HCMV-specific humoral immunity. These results demonstrate in a three-dimensional human cellular biosystem that HCMV can cause severe brain malformation and disrupt calcium signaling and neural network activity. This study also provides insights into the potential capacity of NAbs to mitigate brain defects resulted from congenital HCMV infection.
Project description:Although congenital infection by human cytomegalovirus (HCMV) is well recognized as a leading cause of neurodevelopmental defects, HCMV neuropathogenesis remains poorly understood. A major challenge for investigating HCMV-induced abnormal brain development is the strict CMV species specificity, which prevents the use of animal models to directly study brain defects caused by HCMV. We show that infection of human-induced pluripotent-stem-cell-derived brain organoids by a "clinical-like" HCMV strain results in reduced brain organoid growth, impaired formation of cortical layers, and abnormal calcium signaling and neural network activity. Moreover, we show that the impeded brain organoid development caused by HCMV can be prevented by neutralizing antibodies (NAbs) that recognize the HCMV pentamer complex. These results demonstrate in a three-dimensional cellular biosystem that HCMV can impair the development and function of the human brain and provide insights into the potential capacity of NAbs to mitigate brain defects resulted from HCMV infection.
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: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.
Project description:In vitro modeling of human disease has recently become feasible with the adoption of induced pluripotent stem cell (iPSC) technology. Here, we established patient-derived iPSCs from an Li-Fraumeni Syndrome (LFS) family and investigated the role of mutant p53 in the development of osteosarcoma (OS). Several members of this family carried a heterozygous p53(G245D) mutation and presented with a broad spectrum of tumors including OS. Osteoblasts (OBs) differentiated from iPSC-derived mesenchymal stem cells (MSCs) recapitulated OS features including defective osteoblastic differentiation (OB differentiation) as well as tumorigenic ability. Systematic analyses revealed that the expression of genes enriched in LFS-derived OBs strongly correlated with decreased time to tumor recurrence and poor patient survival. In silico cytogenetic region enrichment analysis (CREA) demonstrated that LFS-derived OBs do not have genomic rearrangements and hence are a particularly valuable tool for elucidating early oncogenic events prior to the accumulation of secondary alterations. LFS OBs exhibited impaired upregulation of the imprinted gene H19 during osteogenesis. Restoration of H19 expression in LFS OBs facilitated osteogenic differentiation and repressed tumorigenic potential. By integrating human imprinted gene network (IGN) and functional genomic analyses, we found that H19-mediates suppression of LFS-associated OS through the IGN component DECORIN (DCN). Downregulation of DCN impairs H19-mediated osteogenic differentiation and tumor suppression. In summary, these findings demonstrate the feasibility of studying inherited human cancer syndromes with iPSCs and also provide molecular insights into the role of the IGN in p53 mutation-mediated tumorigenesis. mRNAseq profiling during mesenchymal stem cell differentiation to osteoblasts.
Project description:Our study aims to illustrate the potential use of atrial iPSC-CMs for modeling AF in a dish, elucidating the underlying cellular mechanisms, and identifying novel mechanism-based therapies custom-tailored for individual patients
Project description:In vitro modeling of human disease has recently become feasible with the adoption of induced pluripotent stem cell (iPSC) technology. Here, we established patient-derived iPSCs from an Li-Fraumeni Syndrome (LFS) family and investigated the role of mutant p53 in the development of osteosarcoma (OS). Several members of this family carried a heterozygous p53(G245D) mutation and presented with a broad spectrum of tumors including OS. Osteoblasts (OBs) differentiated from iPSC-derived mesenchymal stem cells (MSCs) recapitulated OS features including defective osteoblastic differentiation (OB differentiation) as well as tumorigenic ability. Systematic analyses revealed that the expression of genes enriched in LFS-derived OBs strongly correlated with decreased time to tumor recurrence and poor patient survival. In silico cytogenetic region enrichment analysis (CREA) demonstrated that LFS-derived OBs do not have genomic rearrangements and hence are a particularly valuable tool for elucidating early oncogenic events prior to the accumulation of secondary alterations. LFS OBs exhibited impaired upregulation of the imprinted gene H19 during osteogenesis. Restoration of H19 expression in LFS OBs facilitated osteogenic differentiation and repressed tumorigenic potential. By integrating human imprinted gene network (IGN) and functional genomic analyses, we found that H19-mediates suppression of LFS-associated OS through the IGN component DECORIN (DCN). Downregulation of DCN impairs H19-mediated osteogenic differentiation and tumor suppression. In summary, these findings demonstrate the feasibility of studying inherited human cancer syndromes with iPSCs and also provide molecular insights into the role of the IGN in p53 mutation-mediated tumorigenesis.