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Although human induced pluripotent stem cells (hiPSCs) hold great potential for the study of human diseases affecting disparate cell types,they have been underutilized in seeking mechanistic insights into the pathogenesis of congenital craniofacial disorders. Craniofrontonasal syndrome (CFNS) is a rare X-linked disorder caused by mutations in EFNB1 and characterized by craniofacial,skeletal,and neurological anomalies. Heterozygous females are more severely affected than hemizygous males,a phenomenon termed cellular interference that involves mosaicism for EPHRIN-B1 function. Although the mechanistic basis for cellular interference in CFNS has been hypothesized to involve Eph/ephrin-mediated cell segregation,no direct evidence for this has been demonstrated. Here,by generating hiPSCs from CFNS patients,we demonstrate that mosaicism for EPHRIN-B1 expression induced by random X inactivation in heterozygous females results in robust cell segregation in human neuroepithelial cells,thus supplying experimental evidence that Eph/ephrin-mediated cell segregation is relevant to pathogenesis in human CFNS patients. View Publication

The heart wall tissue,or the myocardium,is one of the main targets in cardiovascular disease prevention and treatment. Animal models have not been sufficient in mimicking the human myocardium as evident by the very low clinical translation rates of cardiovascular drugs. Additionally,current in vitro models of the human myocardium possess several shortcomings such as lack of physiologically relevant co-culture of myocardial cells,lack of a 3D biomimetic environment,and the use of non-human cells. In this study,we address these shortcomings through the design and manufacture of a myocardium-on-chip (MOC) using 3D cell-laden hydrogel constructs and human induced pluripotent stem cell (hiPSC) derived myocardial cells. The MOC utilizes 3D spatially controlled co-culture of hiPSC derived cardiomyocytes (iCMs) and hiPSC derived endothelial cells (iECs) integrated among iCMs as well as in capillary-like side channels,to better mimic the microvasculature seen in native myocardium. We first fully characterized iCMs using immunostaining,genetic,and electrochemical analysis and iECs through immunostaining and alignment analysis to ensure their functionality,and then seeded these cells sequentially into the MOC device. We showed that iECs could be cultured within the microfluidic device without losing their phenotypic lineage commitment,and align with the flow upon physiological level shear stresses. We were able to incorporate iCMs within the device in a spatially controlled manner with the help of photocrosslinkable polymers. The iCMs were shown to be viable and functional within the device up to 7 days,and were integrated with the iECs. The iCMs and iECs in this study were derived from the same hiPSC cell line,essentially mimicking the myocardium of an individual human patient. Such devices are essential for personalized medicine studies where the individual drug response of patients with different genetic backgrounds can be tested in a physiologically relevant manner. View Publication

BACKGROUND Human microRNAs (miRNAs) have diverse functions in biology,and play a role in nearly every biological process. Here we report that miR-520d-5p (520d-5p) causes undifferentiated cancer cells to adopt benign or normal status in vivo in immunodeficient mice via demethylation and P53 upregulation. Further we found that 520-5p causes normal cells to elongate cellular lifetime and mesenchymal stem cell-like status with CD105 positivity. We hypothesized that ectopic 520d-5p expression reduced mutations in undifferentiated type of hepatoma (HLF) cells through synergistic modulation of methylation-related enzymatic expression. METHODS To examine whether there were any changes in mutation status in cells treated with 520d-5p,we performed next generation sequencing (NGS) in HLF cells and human iPSC-derivative cells in pre-mesenchymal stem cell status. We analyzed the data using both genome-wide and individual gene function approaches. RESULTS 520d-5p induced a shift towards a wild type or non-malignant phenotype,which was regulated by nucleotide mutations in both HLF cells and iPSCs. Further,520d-5p reduced mutation levels in both the whole genome and genomic fragment assemblies. CONCLUSIONS Cancer cell genomic mutations cannot be repaired in most contexts. However,these findings suggest that applied development of 520d-5p would allow new approaches to cancer research and improve the quality of iPSCs used in regenerative medicine. View Publication

Human induced pluripotent stem cells (hiPSCs) are a valuable tool for investigating complex cellular and molecular events that occur in several human diseases. Importantly,the ability to differentiate hiPSCs into any human cell type provides a unique way for investigating disease mechanisms such as complex mental health diseases. The in vitro transformation of human lymphocytes into lymphoblasts (LCLs) using the Epstein-Barr virus (EBV) has been the main method for generating immortalized human cell lines for half a century. However,the derivation of iPSCs from LCLs has emerged as an alternative source from which these cell lines can be generated. We show that iPSCs derived from LCLs using the Sendai virus procedure can be successfully differentiated into cardiomyocytes,neurons,and myotubes that express neuron- and myocyte-specific markers. We further show that these cardiac and neuronal cells are functional and generate action potentials that are required for cell excitability. We conclude that the ability to differentiate LCLs into neurons and myocytes will increase the use of LCLs in the future as a potential source of cells for modelling a number of diseases. View Publication

BACKGROUND Type 2 diabetes (T2D) is a recognized risk factor for the development of cognitive impairment (CI) and/or dementia,although the exact nature of the molecular pathology of T2D-associated CI remains obscure. One link between T2D and CI might involve decreased insulin signaling in brain and/or neurons in either animal or postmortem human brains as has been reported as a feature of Alzheimer's disease (AD). Here we asked if neuronal insulin resistance is a cell autonomous phenomenon in a familial form of AD. METHODS We have applied a newly developed protocol for deriving human basal forebrain cholinergic neurons (BFCN) from skin fibroblasts via induced pluripotent stem cell (iPSC) technology. We generated wildtype and familial AD mutant PSEN2 N141I (presenilin 2) BFCNs and assessed if insulin signaling,insulin regulation of the major AD proteins Abeta$ and/or tau,and/or calcium fluxes is altered by the PSEN2 N141I mutation. RESULTS We report herein that wildtype,PSEN2 N141I and CRISPR/Cas9-corrected iPSC-derived BFCNs (and their precursors) show indistinguishable insulin signaling profiles as determined by the phosphorylation of canonical insulin signaling pathway molecules. Chronic insulin treatment of BFCNs of all genotypes led to a reduction in the Abeta$42/40 ratio. Unexpectedly,we found a CRISPR/Cas9-correctable effect of PSEN2 N141I on calcium flux,which could be prevented by chronic exposure of BFCNs to insulin. CONCLUSIONS Our studies indicate that the familial AD mutation PSEN2 N141I does not induce neuronal insulin resistance in a cell autonomous fashion. The ability of insulin to correct calcium fluxes and to lower Abeta$42/40 ratio suggests that insulin acts to oppose an AD-pathophysiology. Hence,our results are consistent with a potential physiological role for insulin as a mediator of resilience by counteracting specific metabolic and molecular features of AD. View Publication

Induced pluripotent stem cells (iPSCs) were generated from peripheral blood mononuclear cells (PBMCs) obtained from a 62-year-old female with familial hypertrophic cardiomyopathy (HCM). PBMCs were reprogrammed to a pluripotent state following transfection with non-integrative episomal vectors carrying reprogramming factors OCT4,SOX2,LIN28,KLF4 and L-MYC. iPSCs were shown to express pluripotency markers,possess trilineage differentiation potential,carry rare variants identified in DNA isolated directly from the patient's whole blood,have a normal karyotype and no longer carry episomal vectors for reprogramming. This line is a useful resource for identifying unknown genetic causes of HCM. View Publication

Background and PurposeEsophageal cancer-related gene-4 (ECRG4) participate in inflammation process and can interact with the innate immunity complex TLR4-MD2-CD14 on human granulocytes. In addition,ECRG4 participate in modulation of ion channel function and electrical activity of cardiomyocytes. However,the exact mechanism is unknown. This study aimed to test our hypothesis that ECRG4 contributes to inflammation-induced ion channel dysfunctions in cardiomyocytes.MethodsHuman-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) generated from three donors were treated with lipopolysaccharide (LPS) to establish an endotoxin-induced inflammatory model. Immunostaining,real-time PCR,and patch-clamp techniques were used for the study.ResultsECRG4 was detected in hiPSC-CMs at different differentiation time. LPS treatment increased ECRG4 expression in hiPSC-CMs. Knockdown of ECRG4 decreased the expression level of Toll-Like-Receptor 4 (TLR4,a LPS receptor) and its associated genes and inflammatory cytokines. Furthermore,ECRG4 knockdown shortened the action potential duration (APD) and intercepted LPS-induced APD prolongation by enhancing ISK (small conductance calcium-activated K channel current) and attenuating INCX (Na/Ca exchanger current). Overexpression of ECRG4 mimicked LPS effects on ISK and INCX,which could be prevented by NF?B signaling blockers.ConclusionThis study demonstrated that LPS effects on cardiac ion channel function were mediated by the upregulation of ECRG4,which affects NF?B signaling. Our findings support the roles of ECRG4 in inflammatory responses and the ion channel dysfunctions induced by LPS challenge. View Publication

AbstractA basic assumption underlying induced pluripotent stem cell (iPSC) models of neurodegeneration is that disease-relevant pathologies present in brain tissue are also represented in donor-matched cells differentiated from iPSCs. However,few studies have tested this hypothesis in matched iPSCs and neuropathologically characterized donated brain tissues. To address this,we assessed iPSC-neuron production of ?-amyloid (A?) A?40,A?42,and A?43 in 24 iPSC lines matched to donor brains with primary neuropathologic diagnoses of sporadic AD (sAD),familial AD (fAD),control,and other neurodegenerative disorders. Our results demonstrate a positive correlation between A?43 production by fAD iPSC-neurons and A?43 accumulation in matched brain tissues but do not reveal a substantial correlation in soluble A? species between control or sAD iPSC-neurons and matched brains. However,we found that the ApoE4 genotype is associated with increased A? production by AD iPSC-neurons. Pathologic tau phosphorylation was found to be increased in AD and fAD iPSC-neurons compared to controls and positively correlated with the relative abundance of longer-length A? species produced by these cells. Taken together,our results demonstrate that sAD-predisposing genetic factors influence iPSC-neuron phenotypes and that these cells are capturing disease-relevant and patient-specific components of the amyloid cascade. View Publication

SummaryCytoplasmic mislocalization and aggregation of the RNA-binding protein TDP-43 is a pathological hallmark of the motor neuron (MN) disease amyotrophic lateral sclerosis (ALS). Furthermore,while mutations in TARDBP (encoding TDP-43) have been associated with ALS,the pathogenic consequences of these mutations remain poorly understood. Using CRISPR-Cas9,we engineered two homozygous knock-in induced pluripotent stem cell lines carrying mutations in TARDBP encoding TDP-43A382T and TDP-43G348C,two common yet understudied ALS TDP-43 variants. Motor neurons (MNs) differentiated from knock-in iPSCs had normal viability and displayed no significant changes in TDP-43 subcellular localization,phosphorylation,solubility,or aggregation compared with isogenic control MNs. However,our results highlight synaptic impairments in both TDP-43A382T and TDP-43G348C MN cultures,as reflected in synapse abnormalities and alterations in spontaneous neuronal activity. Collectively,our findings suggest that MN dysfunction may precede the occurrence of TDP-43 pathology and neurodegeneration in ALS and further implicate synaptic and excitability defects in the pathobiology of this disease. Graphical abstract Highlights•Mutant MNs maintain viability but are more vulnerable to cellular stress•Mutant MNs do not show TDP-43 pathology•TDP-43 variants lead to a progressive decline in spontaneous neuronal activity•Functional impairments are accompanied by abnormal synaptic marker expression Molecular neuroscience; Cellular neuroscience View Publication

SUMMARY Resident cardiac macrophages are critical mediators of cardiac function. Despite their known importance to cardiac electrophysiology and tissue maintenance,there are currently no stem-cell-derived models of human engineered cardiac tissues (hECTs) that include resident macrophages. In this study,we made an induced pluripotent stem cell (iPSC)-derived hECT model with a resident population of macrophages (iM0) to better recapitulate the native myocardium and characterized their impact on tissue function. Macrophage retention within the hECTs was confirmed via immunofluorescence after 28 days of cultivation. The inclusion of iM0s significantly impacted hECT function,increasing contractile force production. A potential mechanism underlying these changes was revealed by the interrogation of calcium signaling,which demonstrated the modulation of ?-adrenergic signaling in +iM0 hECTs. Collectively,these findings demonstrate that macrophages significantly enhance cardiac function in iPSC-derived hECT models,emphasizing the need to further explore their contributions not only in healthy hECT models but also in the contexts of disease and injury. In brief Lock and Graney et al. develop a human engineered cardiac tissue with an incorporated iPSC-derived macrophage population to better mimic the complex cell landscape of the native myocardium. Macrophage inclusion leads to increased contractile function of the tissue,which is attributed to macrophage stimulation of the cardiomyocyte ?-adrenergic signaling pathway. Graphical Abstract View Publication

Human-induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells (iMSCs) represent a promising and renewable cell source for therapeutic applications. A systematic evaluation of the immunological properties and engraftment potential of iMSCs generated from urine-derived iPSCs is lacking,which has impeded their broader application. In this study,we differentiated urine-derived iPSCs into iMSCs and assessed their fundamental MSC characteristics,immunogenicity,immunomodulatory capacity and in vivo engraftment. Compared to umbilical cord-derived MSCs (UCMSCs),iMSCs demonstrated an enhanced proliferative capacity,a higher level of regenerative gene expression,and lower immunogenicity,strengthening resistance to apoptosis induced by allogeneic peripheral blood mononuclear cells (PBMCs) and the NK-92 cell line. In addition,iMSCs exhibited a diminished ability to inhibit T cell proliferation and activation compared with UCMSCs. Transcriptomic analyses further revealed the decreased expression of immune regulatory factors in iMSCs. After transfusion into mouse models,iMSCs engrafted in the lungs,liver,and spleen and exhibited the ability to migrate to tumor tissues. Our results indicated that iMSCs generated from urine-derived iPSCs have a significant replicative capacity,low immunogenicity and unique immunomodulatory properties,and hence offer obvious advantages in immune privilege and allogenic therapeutic application prospects. View Publication

Interactions between adipose tissue,liver and immune system are at the center of metabolic dysfunction-associated steatotic liver disease and type 2 diabetes. To address the need for an accurate in vitro model,we establish an interconnected microphysiological system (MPS) containing white adipocytes,hepatocytes and proinflammatory macrophages derived from isogenic human induced pluripotent stem cells. Using this MPS,we find that increasing the adipocyte-to-hepatocyte ratio moderately affects hepatocyte function,whereas macrophage-induced adipocyte inflammation causes lipid accumulation in hepatocytes and MPS-wide insulin resistance,corresponding to initiation of metabolic dysfunction-associated steatotic liver disease. We also use our MPS to identify and characterize pharmacological intervention strategies for hepatic steatosis and systemic insulin resistance and find that the glucagon-like peptide-1 receptor agonist semaglutide improves hepatocyte function by acting specifically on adipocytes. These results establish our MPS modeling the adipose tissue-liver axis as an alternative to animal models for mechanistic studies or drug discovery in metabolic diseases. In vitro modelling of the adipose tissue-liver axis can advance understanding and therapy of metabolic disease,including by distinguishing effects of obesity and inflammation. Here,authors develop such a system based on isogenic human iPSCs and interconnected microphysiological devices. View Publication