RESUMEN
The pathological mechanisms of cataract remain largely unknown due to the lack of appropriate in vitro cellular models. We developed a stable in vitro system, namely, a "fried egg" differentiation method to generate functional lentoid bodies (LBs) from induced pluripotent stem cells (iPSCs). The iPSCs-derived LBs exhibited crystalline lens-like morphology and a transparent structure, and expressed lens-specific markers. TEM examination and optical analysis further demonstrated that it has the same cell arrangement structure and magnifying ability as lens.
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Diferenciación Celular , Células Madre Pluripotentes Inducidas , Cristalino , Células Madre Pluripotentes Inducidas/citología , Células Madre Pluripotentes Inducidas/metabolismo , Humanos , Cristalino/citología , Cristalino/metabolismo , Técnicas de Cultivo de Célula/métodos , Células Cultivadas , Catarata/patologíaRESUMEN
Retinal pigment epithelium (RPE) cells derived from induced pluripotent stem cells (iPSCs) serve multiple roles, including among others, modeling RPE development in normal and pathological conditions, investigating mechanisms of RPE physiology, modeling retinal diseases involving the RPE, and developing strategies for regenerative therapies. We have developed a simple and efficient protocol to generate RPE tissue from human iPSCs-derived retinal organoids. The RPE tissue present in the retinal organoids is analogous to the native human RPE in differentiation timeline, histological organization, and key features of functional maturation. Building upon this system, we established a method to generate functionally mature, polarized RPE monolayers comparable to human primary RPE. This comprehensive protocol outlines the steps for isolating and culturing RPE tissue using retinal organoids. The outcome is a pure population of cells expressing mature RPE signatures and organized in a characteristic cobblestone monolayer featuring robust ultrastructural polarization. These RPE monolayers also exhibit the functional hallmarks of bona fide mature RPE cells, providing a suitable system to mimic the biology and function of the native human RPE.
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Técnicas de Cultivo de Célula , Diferenciación Celular , Células Madre Pluripotentes Inducidas , Organoides , Epitelio Pigmentado de la Retina , Humanos , Epitelio Pigmentado de la Retina/citología , Epitelio Pigmentado de la Retina/metabolismo , Organoides/citología , Organoides/metabolismo , Células Madre Pluripotentes Inducidas/citología , Células Madre Pluripotentes Inducidas/metabolismo , Técnicas de Cultivo de Célula/métodos , Células CultivadasRESUMEN
Major advances have been made in utilizing human-induced pluripotent stem cells (hiPSCs) for regenerative medicine. Nevertheless, the delivery and integration of hiPSCs into target tissues remain significant challenges, particularly in the context of retinal ganglion cell (RGC) restoration. In this study, we introduce a promising avenue for providing directional guidance to regenerated cells in the retina. First, we developed a technique for construction of gradient interfaces based on functionalized conductive polymers, which could be applied with various functionalized ehthylenedioxythiophene (EDOT) monomers. Using a tree-shaped channel encapsulated with a thin PDMS and a specially designed electrochemical chamber, gradient flow generation could be converted into a functionalized-PEDOT gradient film by cyclic voltammetry. The characteristics of the successfully fabricated gradient flow and surface were analyzed using fluorescent labels, time of flight secondary ion mass spectrometry (TOF-SIMS), and X-ray photoelectron spectroscopy (XPS). Remarkably, hiPSC-RGCs seeded on PEDOT exhibited improvements in neurite outgrowth, axon guidance and neuronal electrophysiology measurements. These results suggest that our novel gradient PEDOT may be used with hiPSC-based technologies as a potential biomedical engineering scaffold for functional restoration of RGCs in retinal degenerative diseases and optic neuropathies.
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Células Madre Pluripotentes Inducidas , Polímeros , Células Ganglionares de la Retina , Humanos , Células Ganglionares de la Retina/metabolismo , Células Ganglionares de la Retina/citología , Células Madre Pluripotentes Inducidas/citología , Polímeros/química , Orientación del Axón , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Propiedades de Superficie , Conductividad Eléctrica , Factores de Crecimiento Nervioso/metabolismo , Axones/metabolismo , Axones/fisiologíaRESUMEN
Expansion of CAG repeats in certain genes is a known cause of several neurodegenerative diseases, but exact mechanism behind this is not yet fully understood. It is believed that the double-stranded RNA regions formed by CAG repeats could be harmful to the cell. This study aimed to test the hypothesis that these RNA regions might potentially interfere with ADAR RNA editing enzymes, leading to the reduced A-to-I editing of RNA and activation of the interferon response. We studied induced pluripotent stem cells (iPSCs) derived from the patients with Huntington's disease or ataxia type 17, as well as midbrain organoids developed from these cells. A targeted panel for next-generation sequencing was used to assess editing in the specific RNA regions. Differentiation of iPSCs into brain organoids led to increase in the ADAR2 gene expression and decrease in the expression of protein inhibitors of RNA editing. As a result, there was increase in the editing of specific ADAR2 substrates, which allowed identification of differential substrates of ADAR isoforms. However, comparison of the pathology and control groups did not show differences in the editing levels among the iPSCs. Additionally, brain organoids with 42-46 CAG repeats did not exhibit global changes. On the other hand, brain organoids with the highest number of CAG repeats in the huntingtin gene (76) showed significant decrease in the level of RNA editing of specific transcripts, potentially involving ADAR1. Notably, editing of the long non-coding RNA PWAR5 was nearly absent in this sample. It could be stated in conclusion that in most cultures with repeat expansion, the hypothesized effect on RNA editing was not confirmed.
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Adenosina Desaminasa , Encéfalo , Diferenciación Celular , Enfermedad de Huntington , Células Madre Pluripotentes Inducidas , Organoides , Edición de ARN , Proteínas de Unión al ARN , Adenosina Desaminasa/metabolismo , Adenosina Desaminasa/genética , Humanos , Organoides/metabolismo , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/citología , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Encéfalo/metabolismo , Enfermedad de Huntington/genética , Enfermedad de Huntington/metabolismo , Enfermedad de Huntington/patología , Expansión de Repetición de TrinucleótidoRESUMEN
Rationale: Ferroptosis-driven loss of dopaminergic neurons plays a pivotal role in the pathogenesis of Parkinson's disease (PD). In PD patients, Hspb1 is commonly observed at abnormally high levels in the substantia nigra. The precise consequences of Hspb1 overexpression in PD, however, have yet to be fully elucidated. Methods: We used human iPSC-derived dopaminergic neurons and Coniferaldehyde (CFA)-an Nrf2 agonist known for its ability to cross the blood-brain barrier-to investigate the role of Hspb1 in PD. We examined the correlation between Hspb1 overexpression and Nrf2 activation and explored the transcriptional regulation of Hspb1 by Nrf2. Gene deletion techniques were employed to determine the necessity of Nrf2 and Hspb1 for CFA's neuroprotective effects. Results: Our research demonstrated that Nrf2 can upregulate the transcription of Hspb1 by directly binding to its promoter. Deletion of either Nrf2 or Hspb1 gene abolished the neuroprotective effects of CFA. The Nrf2-Hspb1 pathway, newly identified as a defense mechanism against ferroptosis, was shown to be essential for preventing neurodegeneration progression. Additionally, we discovered that prolonged overexpression of Hspb1 leads to neuronal death and that Hspb1 released from ruptured cells can trigger secondary cell death in neighboring cells, exacerbating neuroinflammatory responses. Conclusions: These findings highlight a biphasic role of Hspb1 in PD, where it initially provides neuroprotection through the Nrf2-Hspb1 pathway but ultimately contributes to neurodegeneration and inflammation when overexpressed. Understanding this dual role is crucial for developing therapeutic strategies targeting Hspb1 and Nrf2 in PD.
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Neuronas Dopaminérgicas , Ferroptosis , Chaperonas Moleculares , Factor 2 Relacionado con NF-E2 , Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/metabolismo , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/patología , Factor 2 Relacionado con NF-E2/metabolismo , Factor 2 Relacionado con NF-E2/genética , Chaperonas Moleculares/metabolismo , Chaperonas Moleculares/genética , Neuronas Dopaminérgicas/metabolismo , Neuronas Dopaminérgicas/patología , Ferroptosis/genética , Células Madre Pluripotentes Inducidas/metabolismo , Proteínas de Choque Térmico/metabolismo , Proteínas de Choque Térmico/genética , Animales , Ratones , Proteínas de Choque Térmico HSP27/metabolismo , Proteínas de Choque Térmico HSP27/genética , Muerte CelularRESUMEN
Purpose: Metabolic defects in the retinal pigment epithelium (RPE) underlie many retinal degenerative diseases. This study aims to identify the nutrient requirements of healthy and diseased human RPE cells. Methods: We profiled nutrient use of various human RPE cells, including differentiated and dedifferentiated fetal RPE (fRPE), induced pluripotent stem cell-derived RPE (iPSC RPE), Sorsby fundus dystrophy (SFD) patient-derived iPSC RPE, CRISPR-corrected isogenic SFD (cSFD) iPSC RPE, and ARPE-19 cell lines using Biolog Phenotype MicroArray Assays. Results: Differentiated fRPE cells and healthy iPSC RPE cells can use 51 and 48 nutrients respectively, including sugars, intermediates from glycolysis and tricarboxylic acid (TCA) cycle, fatty acids, ketone bodies, amino acids, and dipeptides. However, when fRPE cells lose their epithelial phenotype through dedifferentiation, nutrient use becomes restricted to 17 nutrients, primarily sugar and glutamine-related amino acids. SFD RPE cells can use 37 nutrients; however, compared to cSFD RPE and healthy iPSC RPE, they are unable to use lactate, some TCA cycle intermediates, and short-chain fatty acids. Nonetheless, they show increased use of branch-chain amino acids (BCAAs) and BCAA-containing dipeptides. Dedifferentiated ARPE-19 cells grown in traditional culture media cannot use lactate and ketone bodies. In contrast, nicotinamide supplementation promotes differentiation toward an epithelial phenotype, restoring the ability to use these nutrients. Conclusions: Epithelial phenotype confers metabolic flexibility to healthy RPE for using various nutrients. SFD RPE cells have reduced metabolic flexibility, relying on the oxidation of BCAAs. Our findings highlight the potentially important roles of nutrient availability and use in RPE differentiation and diseases.
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Diferenciación Celular , Células Madre Pluripotentes Inducidas , Fenotipo , Epitelio Pigmentado de la Retina , Humanos , Epitelio Pigmentado de la Retina/metabolismo , Epitelio Pigmentado de la Retina/citología , Diferenciación Celular/fisiología , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/citología , Células Cultivadas , Línea CelularRESUMEN
Per- and poly-fluoroalkyl substances (PFAS) are emerging contaminants of concern because of their wide use, persistence, and potential to be hazardous to both humans and the environment. Several PFAS have been designated as substances of concern; however, most PFAS in commerce lack toxicology and exposure data to evaluate their potential hazards and risks. Cardiotoxicity has been identified as a likely human health concern, and cell-based assays are the most sensible approach for screening and prioritization of PFAS. Human-induced pluripotent stem cell (iPSC)-derived cardiomyocytes are a widely used method to test for cardiotoxicity, and recent studies showed that many PFAS affect these cells. Because iPSC-derived cardiomyocytes are available from different donors, they also can be used to quantify human variability in responses to PFAS. The primary objective of this study was to characterize potential human cardiotoxic hazard, risk, and inter-individual variability in responses to PFAS. A total of 56 PFAS from different subclasses were tested in concentration-response using human iPSC-derived cardiomyocytes from 16 donors without known heart disease. Kinetic calcium flux and high-content imaging were used to evaluate biologically-relevant phenotypes such as beat frequency, repolarization, and cytotoxicity. Of the tested PFAS, 46 showed concentration-response effects in at least one phenotype and donor; however, a wide range of sensitivities were observed across donors. Inter-individual variability in the effects could be quantified for 19 PFAS, and risk characterization could be performed for 20 PFAS based on available exposure information. For most tested PFAS, toxicodynamic variability was within a factor of 10 and the margins of exposure were above 100. This study identified PFAS that may pose cardiotoxicity risk and have high inter-individual variability. It also demonstrated the feasibility of using a population-based human in vitro method to quantify population variability and identify cardiotoxicity risks of emerging contaminants.
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Cardiotoxicidad , Fluorocarburos , Células Madre Pluripotentes Inducidas , Miocitos Cardíacos , Humanos , Células Madre Pluripotentes Inducidas/efectos de los fármacos , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Cardiotoxicidad/etiología , Fluorocarburos/toxicidad , Contaminantes Ambientales/toxicidad , Medición de Riesgo , Adulto , Femenino , Masculino , Exposición a Riesgos Ambientales/efectos adversosRESUMEN
Purpose: Progressive choroid and retinal pigment epithelial (RPE) degeneration causing vision loss is a unique characteristic of long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD), a fatty acid oxidation disorder caused by a common c.1528G>C pathogenic variant in HADHA, the α subunit of the mitochondrial trifunctional protein (TFP). We established and characterized an induced pluripotent stem cell (iPSC)-derived RPE cell model from cultured skin fibroblasts of patients with LCHADD and tested whether addition of wildtype (WT) HAHDA could rescue the phenotypes identified in LCHADD-RPE. Methods: We constructed an rAAV expression vector containing 3' 3xFLAG-tagged human HADHA cDNA under the transcriptional control of the cytomegalovirus (CMV) enhancer-chicken beta actin (CAG) promoter (CAG-HADHA-3XFLAG). LCHADD-RPE were cultured, matured, and transduced with either AAV-GFP (control) or AAV-HADHA-3XFLAG. Results: LCHADD-RPE express TFP subunits and accumulate 3-hydroxy-acylcarnitines, cannot oxidize palmitate, and release fewer ketones than WT-RPE. When LCHADD-RPE are exposed to docosahexaenoic acid (DHA), they have increased oxidative stress, lipid peroxidation, decreased viability, and are rescued by antioxidant agents potentially explaining the pathologic mechanism of RPE loss in LCHADD. Transduced LCHADD-RPE expressing a WT copy of TFPα incorporated TFPα-FLAG into the TFP complex in the mitochondria and accumulated significantly less 3-hydroxy-acylcarnitines, released more ketones in response to palmitate, and were more resistant to oxidative stress following DHA exposure than control. Conclusions: iPSC-derived LCHADD-RPE are susceptible to lipid peroxidation mediated cell death and are rescued by exogenous HADHA delivered with rAAV. These results are promising for AAV-HADHA gene addition therapy as a possible treatment for chorioretinopathy in patients with LCHADD.
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Dependovirus , Vectores Genéticos , Células Madre Pluripotentes Inducidas , Peroxidación de Lípido , 3-Hidroxiacil-CoA Deshidrogenasa de Cadena Larga , Epitelio Pigmentado de la Retina , Transfección , Humanos , Epitelio Pigmentado de la Retina/metabolismo , Epitelio Pigmentado de la Retina/citología , Células Madre Pluripotentes Inducidas/metabolismo , Dependovirus/genética , Células Cultivadas , 3-Hidroxiacil-CoA Deshidrogenasa de Cadena Larga/genética , 3-Hidroxiacil-CoA Deshidrogenasa de Cadena Larga/metabolismo , Errores Innatos del Metabolismo Lipídico/genética , Errores Innatos del Metabolismo Lipídico/metabolismo , Errores Innatos del Metabolismo Lipídico/terapia , Proteína Trifuncional Mitocondrial/genética , Proteína Trifuncional Mitocondrial/deficiencia , Miopatías Mitocondriales/genética , Miopatías Mitocondriales/metabolismo , Terapia Genética/métodos , Cardiomiopatías , Enfermedades del Sistema Nervioso , RabdomiólisisRESUMEN
Mucopolysaccharidoses are inherited metabolic disorders caused by the deficiency in lysosomal enzymes required to break down glycosaminoglycans. Accumulation of glycosaminoglycans leads to progressive, systemic degenerative disease. The central nervous system is particularly affected, resulting in developmental delays, neurological regression, and early mortality. Current treatments fail to adequately address neurological defects. Here we explore the potential of human induced pluripotent stem cell (hiPSC)-derived microglia progenitors as a one-time, allogeneic off-the-shelf cell therapy for several mucopolysaccharidoses (MPS). We show that hiPSC-derived microglia progenitors, possessing normal levels of lysosomal enzymes, can deliver functional enzymes into four subtypes of MPS knockout cell lines through mannose-6-phosphate receptor-mediated endocytosis in vitro. Additionally, our findings indicate that a single administration of hiPSC-derived microglia progenitors can reduce toxic glycosaminoglycan accumulation and prevent behavioral deficits in two different animal models of MPS. Durable efficacy is observed for eight months after transplantation. These results suggest a potential avenue for treating MPS with hiPSC-derived microglia progenitors.
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Modelos Animales de Enfermedad , Glicosaminoglicanos , Células Madre Pluripotentes Inducidas , Microglía , Mucopolisacaridosis , Células Madre Pluripotentes Inducidas/citología , Células Madre Pluripotentes Inducidas/metabolismo , Animales , Microglía/metabolismo , Humanos , Mucopolisacaridosis/terapia , Ratones , Glicosaminoglicanos/metabolismo , Ratones Noqueados , Diferenciación Celular , Trasplante de Células Madre/métodos , Lisosomas/metabolismoRESUMEN
Aggregated α-synuclein (α-SYN) proteins, encoded by the SNCA gene, are hallmarks of Lewy body disease (LBD), affecting multiple brain regions. However, the specific mechanisms underlying α-SYN pathology in cortical neurons, crucial for LBD-associated dementia, remain unclear. Here, we recapitulated α-SYN pathologies in human induced pluripotent stem cells (iPSCs)-derived cortical organoids generated from patients with LBD with SNCA gene triplication. Single-cell RNA sequencing, combined with functional and molecular validation, identified synaptic and mitochondrial dysfunction in excitatory neurons exhibiting high expression of the SNCA gene, aligning with observations in the cortex of autopsy-confirmed LBD human brains. Furthermore, we screened 1280 Food and Drug Administration-approved drugs and identified four candidates (entacapone, tolcapone, phenazopyridine hydrochloride, and zalcitabine) that inhibited α-SYN seeding activity in real-time quaking-induced conversion assays with human brains, reduced α-SYN aggregation, and alleviated mitochondrial dysfunction in SNCA triplication organoids and excitatory neurons. Our findings establish human cortical LBD models and suggest potential therapeutic drugs targeting α-SYN aggregation for LBD.
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Células Madre Pluripotentes Inducidas , Enfermedad por Cuerpos de Lewy , Organoides , alfa-Sinucleína , Humanos , alfa-Sinucleína/metabolismo , alfa-Sinucleína/genética , Organoides/metabolismo , Organoides/efectos de los fármacos , Organoides/patología , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/efectos de los fármacos , Células Madre Pluripotentes Inducidas/citología , Enfermedad por Cuerpos de Lewy/patología , Enfermedad por Cuerpos de Lewy/genética , Enfermedad por Cuerpos de Lewy/metabolismo , Enfermedad por Cuerpos de Lewy/tratamiento farmacológico , Mitocondrias/metabolismo , Mitocondrias/efectos de los fármacos , Mitocondrias/genética , Neuronas/metabolismo , Neuronas/efectos de los fármacos , Neuronas/patología , Corteza Cerebral/metabolismo , Corteza Cerebral/patología , Corteza Cerebral/efectos de los fármacos , Evaluación Preclínica de MedicamentosRESUMEN
Engineered heart tissues (EHTs) generated from human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) represent powerful platforms for human cardiac research, especially in drug testing and disease modeling. Here, we report a flexible, three-dimensional electronic framework that enables real-time, spatiotemporal analysis of electrophysiologic and mechanical signals in EHTs under physiological loading conditions for dynamic, noninvasive, longer-term assessments. These electromechanically monitored EHTs support multisite measurements throughout the tissue under baseline conditions and in response to stimuli. Demonstrations include uses in tracking physiological responses to pharmacologically active agents and in capturing electrophysiological characteristics of reentrant arrhythmias. This platform facilitates precise analysis of signal location and conduction velocity in human cardiomyocyte tissues, as the basis for a broad range of advanced cardiovascular studies.
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Células Madre Pluripotentes Inducidas , Miocitos Cardíacos , Ingeniería de Tejidos , Humanos , Ingeniería de Tejidos/métodos , Miocitos Cardíacos/fisiología , Miocitos Cardíacos/metabolismo , Células Madre Pluripotentes Inducidas/citología , Corazón/fisiología , Fenómenos ElectrofisiológicosRESUMEN
Drug-induced gene expression profiles can identify potential mechanisms of toxicity. We focus on obtaining signatures for cardiotoxicity of FDA-approved tyrosine kinase inhibitors (TKIs) in human induced-pluripotent-stem-cell-derived cardiomyocytes, using bulk transcriptomic profiles. We use singular value decomposition to identify drug-selective patterns across cell lines obtained from multiple healthy human subjects. Cellular pathways affected by cardiotoxic TKIs include energy metabolism, contractile, and extracellular matrix dynamics. Projecting these pathways to published single cell expression profiles indicates that TKI responses can be evoked in both cardiomyocytes and fibroblasts. Integration of transcriptomic outlier analysis with whole genomic sequencing of our six cell lines enables us to correctly reidentify a genomic variant causally linked to anthracycline-induced cardiotoxicity and predict genomic variants potentially associated with TKI-induced cardiotoxicity. We conclude that mRNA expression profiles when integrated with publicly available genomic, pathway, and single cell transcriptomic datasets, provide multiscale signatures for cardiotoxicity that could be used for drug development and patient stratification.
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Cardiotoxicidad , Perfilación de la Expresión Génica , Miocitos Cardíacos , Inhibidores de Proteínas Quinasas , Transcriptoma , Humanos , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/toxicidad , Perfilación de la Expresión Génica/métodos , Cardiotoxicidad/genética , Cardiotoxicidad/etiología , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/efectos de los fármacos , Línea Celular , Análisis de la Célula Individual/métodos , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismoRESUMEN
Induced pluripotent stem cells (iPSCs) have emerged as a revolutionary tool in cell therapies due to their ability to differentiate into various cell types, unlimited supply, and potential as off-the-shelf cell products. New advances in iPSC-derived immune cells have generated potent iNK and iT cells which showed robust killing of cancer cells in animal models and clinical trials. With the advent of advanced genome editing technologies that enable the development of highly engineered cells, here we outline 12 strategies to engineer iPSCs to overcome limitations and challenges of current cell-based immunotherapies, including safety switches, stealth edits, avoiding graft-versus-host disease (GvHD), targeting, reduced lymphodepletion, efficient differentiation, increased in vivo persistence, stemness, metabolic fitness, homing/trafficking, and overcoming suppressive tumor microenvironment and stromal cell barrier. With the development of advanced genome editing techniques, it is now possible to insert large DNA sequences into precise genomic locations without the need for DNA double strand breaks, enabling the potential for multiplexed knock out and insertion. These technological breakthroughs have made it possible to engineer complex cell therapy products at unprecedented speed and efficiency. The combination of iPSC derived iNK, iT and advanced gene editing techniques provides new opportunities and could lead to a new era for next generation of cell immunotherapies.
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Edición Génica , Inmunoterapia , Células Madre Pluripotentes Inducidas , Humanos , Células Madre Pluripotentes Inducidas/inmunología , Animales , Inmunoterapia/métodos , Edición Génica/métodos , Diferenciación Celular , Neoplasias/terapia , Neoplasias/inmunología , Ingeniería Celular/métodos , Tratamiento Basado en Trasplante de Células y Tejidos/métodosRESUMEN
Epigenetic modifications (methylation, acetylation, etc.) of core histones play a key role in regulation of gene expression. Thus, the epigenome changes strongly during various biological processes such as cell differentiation and dedifferentiation. Classical methods of analysis of epigenetic modifications such as mass-spectrometry and chromatin immuno-precipitation, work with fixed cells only. Here we present a genetically encoded fluorescent probe, MPP8-Green, for detecting H3K9me3, a histone modification associated with inactive chromatin. This probe, based on the chromodomain of MPP8, allows for visualization of H3K9me3 epigenetic landscapes in single living cells. We used this probe to track changes in H3K9me3 landscapes during the differentiation of induced pluripotent stem cells (iPSCs) into induced neurons. Our findings revealed two major waves of global H3K9me3 reorganization during 4-day differentiation, namely on the first and third days, whereas nearly no changes occurred on the second and fourth days. The proposed method LiveMIEL (Live-cell Microscopic Imaging of Epigenetic Landscapes), which combines genetically encoded epigenetic probes and machine learning approaches, enables classification of multiparametric epigenetic signatures of single cells during stem cell differentiation and potentially in other biological models.
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Diferenciación Celular , Epigénesis Genética , Colorantes Fluorescentes , Histonas , Células Madre Pluripotentes Inducidas , Diferenciación Celular/genética , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/citología , Histonas/metabolismo , Histonas/genética , Humanos , Colorantes Fluorescentes/química , Colorantes Fluorescentes/metabolismo , Neuronas/metabolismo , Neuronas/citología , Animales , RatonesRESUMEN
Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease leading to motor neuron loss. Currently mutations in > 40 genes have been linked to ALS, but the contribution of many genes and genetic mutations to the ALS pathogenic process remains poorly understood. Therefore, we first performed comparative interactome analyses of five recently discovered ALS-associated proteins (C21ORF2, KIF5A, NEK1, TBK1, and TUBA4A) which highlighted many novel binding partners, and both unique and shared interactors. The analysis further identified C21ORF2 as a strongly connected protein. The role of C21ORF2 in neurons and in the nervous system, and of ALS-associated C21ORF2 variants is largely unknown. Therefore, we combined human iPSC-derived motor neurons with other models and different molecular cell biological approaches to characterize the potential pathogenic effects of C21ORF2 mutations in ALS. First, our data show C21ORF2 expression in ALS-relevant mouse and human neurons, such as spinal and cortical motor neurons. Further, the prominent ALS-associated variant C21ORF2-V58L caused increased apoptosis in mouse neurons and movement defects in zebrafish embryos. iPSC-derived motor neurons from C21ORF2-V58L-ALS patients, but not isogenic controls, show increased apoptosis, and changes in DNA damage response, mitochondria and neuronal excitability. In addition, C21ORF2-V58L induced post-transcriptional downregulation of NEK1, an ALS-associated protein implicated in apoptosis and DDR. In all, our study defines the pathogenic molecular and cellular effects of ALS-associated C21ORF2 mutations and implicates impaired post-transcriptional regulation of NEK1 downstream of mutant C21ORF72 in ALS.
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Esclerosis Amiotrófica Lateral , Células Madre Pluripotentes Inducidas , Mitocondrias , Neuronas Motoras , Quinasa 1 Relacionada con NIMA , Pez Cebra , Humanos , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/patología , Quinasa 1 Relacionada con NIMA/genética , Quinasa 1 Relacionada con NIMA/metabolismo , Animales , Neuronas Motoras/metabolismo , Neuronas Motoras/patología , Células Madre Pluripotentes Inducidas/metabolismo , Ratones , Mitocondrias/metabolismo , Mitocondrias/patología , Reparación del ADN/genética , Daño del ADN , MutaciónRESUMEN
BACKGROUND: Atrial fibrillation has an estimated prevalence of 1.5-2%, making it the most common cardiac arrhythmia. The processes that cause and sustain the disease are still not completely understood. An association between atrial fibrillation and systemic, as well as local, inflammatory processes has been reported. However, the exact mechanisms underlying this association have not been established. While it is understood that inflammatory macrophages can influence cardiac electrophysiology, a direct, causative relationship to atrial fibrillation has not been described. This study investigated the pro-arrhythmic effects of activated M1 macrophages on human induced pluripotent stem cell (hiPSC)-derived atrial cardiomyocytes, to propose a mechanistic link between inflammation and atrial fibrillation. METHODS: Two hiPSC lines from healthy individuals were differentiated to atrial cardiomyocytes and M1 macrophages and integrated in an isogenic, pacing-free, atrial fibrillation-like coculture model. Electrophysiology characteristics of cocultures were analysed for beat rate irregularity, electrogram amplitude and conduction velocity using multi electrode arrays. Cocultures were additionally treated using glucocorticoids to suppress M1 inflammation. Bulk RNA sequencing was performed on coculture-isolated atrial cardiomyocytes and compared to meta-analyses of atrial fibrillation patient transcriptomes. RESULTS: Multi electrode array recordings revealed M1 to cause irregular beating and reduced electrogram amplitude. Conduction analysis further showed significantly lowered conduction homogeneity in M1 cocultures. Transcriptome sequencing revealed reduced expression of key cardiac genes such as SCN5A, KCNA5, ATP1A1, and GJA5 in the atrial cardiomyocytes. Meta-analysis of atrial fibrillation patient transcriptomes showed high correlation to the in vitro model. Treatment of the coculture with glucocorticoids showed reversal of phenotypes, including reduced beat irregularity, improved conduction, and reversed RNA expression profiles. CONCLUSIONS: This study establishes a causal relationship between M1 activation and the development of subsequent atrial arrhythmia, documented as irregularity in spontaneous electrical activation in atrial cardiomyocytes cocultured with activated macrophages. Further, beat rate irregularity could be alleviated using glucocorticoids. Overall, these results point at macrophage-mediated inflammation as a potential AF induction mechanism and offer new targets for therapeutic development. The findings strongly support the relevance of the proposed hiPSC-derived coculture model and present it as a first of its kind disease model.
Asunto(s)
Fibrilación Atrial , Técnicas de Cocultivo , Células Madre Pluripotentes Inducidas , Macrófagos , Miocitos Cardíacos , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/citología , Miocitos Cardíacos/metabolismo , Fibrilación Atrial/metabolismo , Fibrilación Atrial/patología , Macrófagos/metabolismo , Fenotipo , Diferenciación Celular , Atrios Cardíacos/patología , Atrios Cardíacos/metabolismo , Atrios Cardíacos/citologíaRESUMEN
BACKGROUND: Reduction of adult hippocampal neurogenesis is an early critical event in Alzheimer's disease (AD), contributing to progressive memory loss and cognitive decline. Reduced levels of the nucleoporin 153 (Nup153), a key epigenetic regulator of NSC stemness, characterize the neural stem cells isolated from a mouse model of AD (3×Tg) (AD-NSCs) and determine their altered plasticity and gene expression. METHODS: Nup153-regulated mechanisms contributing to NSC function were investigated: (1) in cultured NSCs isolated from AD and wild type (WT) mice by proteomics; (2) in vivo by lentiviral-mediated delivery of Nup153 or GFP in the hippocampus of AD and control mice analyzing neurogenesis and cognitive function; (3) in human iPSC-derived brain organoids obtained from AD patients and control subjects as a model of neurodevelopment. RESULTS: Proteomic approach identified Nup153 interactors in WT- and AD-NSCs potentially implicated in neurogenesis regulation. Gene ontology (GO) analysis showed that Nup153-bound proteins in WT-NSCs were involved in RNA metabolism, nuclear import and epigenetic mechanisms. Nup153-bound proteins in AD-NSCs were involved in pathways of neurodegeneration, mitochondrial dysfunction, proteasomal processing and RNA degradation. Furthermore, recovery of Nup153 levels in AD-NSCs reduced the levels of oxidative stress markers and recovered proteasomal activity. Lentiviral-mediated delivery of Nup153 in the hippocampal niche of AD mice increased the proliferation of early progenitors, marked by BrdU/DCX and BrdU/PSANCAM positivity and, later, the integration of differentiating neurons in the cell granule layer (BrdU/NeuN+ cells) compared with GFP-injected AD mice. Consistently, Nup153-injected AD mice showed an improvement of cognitive performance in comparison to AD-GFP mice at 1 month after virus delivery assessed by Morris Water Maze. To validate the role of Nup153 in neurogenesis we took advantage of brain organoids derived from AD-iPSCs characterized by fewer neuroepithelial progenitor loops and reduced differentiation areas. The upregulation of Nup153 in AD organoids recovered the formation of neural-like tubes and differentiation. CONCLUSIONS: Our data suggest that the positive effect of Nup153 on neurogenesis is based on a complex regulatory network orchestrated by Nup153 and that this protein is a valuable disease target.
Asunto(s)
Enfermedad de Alzheimer , Modelos Animales de Enfermedad , Células-Madre Neurales , Neurogénesis , Proteínas de Complejo Poro Nuclear , Animales , Proteínas de Complejo Poro Nuclear/metabolismo , Proteínas de Complejo Poro Nuclear/genética , Ratones , Células-Madre Neurales/metabolismo , Células-Madre Neurales/citología , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Humanos , Hipocampo/metabolismo , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/citología , ProteómicaRESUMEN
Stem cell-derived ß-cells (SC-BCs) represent a potential source for curing diabetes. To date, in vitro generated SC-BCs display an immature phenotype and lack important features in comparison to their bona-fide counterparts. Transplantation into a living animal promotes SC-BCs maturation, indicating that components of the in vivo microenvironment trigger final SC-BCs development. Here, we investigated whether cues of the pancreas specific extracellular matrix (ECM) can improve the differentiation of human induced pluripotent stem cells (hiPSCs) towards ß-cells in vitro. To this aim, a pancreas specific ECM (PanMa) hydrogel was generated from decellularized porcine pancreas and its effect on the differentiation of hiPSC-derived pancreatic hormone expressing cells (HECs) was tested. The hydrogel solidified upon neutralization at 37 °C with gelation kinetics similar to Matrigel. Cytocompatibility of the PanMa hydrogel was demonstrated for a culture duration of 21 days. Encapsulation and culture of HECs in the PanMa hydrogel over 7 days resulted in a stable gene and protein expression of most ß-cell markers, but did not improve ß-cell identity. In conclusion, the study describes the production of a PanMa hydrogel, which provides the basis for the development of ECM hydrogels that are more adapted to the demands of SC-BCs.
Asunto(s)
Diferenciación Celular , Matriz Extracelular , Hidrogeles , Células Madre Pluripotentes Inducidas , Células Secretoras de Insulina , Células Madre Pluripotentes Inducidas/citología , Células Madre Pluripotentes Inducidas/metabolismo , Humanos , Hidrogeles/química , Células Secretoras de Insulina/citología , Células Secretoras de Insulina/metabolismo , Matriz Extracelular/metabolismo , Animales , Porcinos , Páncreas/citología , Páncreas/metabolismo , Técnicas de Cultivo de Célula/métodos , Células CultivadasRESUMEN
The discovery of human pluripotent stem cells (hiPSCs) and advances in DNA editing techniques have opened opportunities for personalized cell-based therapies for a wide spectrum of diseases. It has gained importance as a valuable tool to investigate genetic and functional variations in congenital heart defects (CHDs), enabling the customization of treatment strategies. The ability to understand the disease process specific to the individual patient of interest provides this technology with a significant advantage over generic animal models. However, its utility as a disease-in-a-dish model requires identifying effective and efficient differentiation protocols that accurately reproduce disease traits. Currently, iPSC-related research relies heavily on the quality of cells and the properties of the differentiation technique In this review, we discuss the utility of iPSCs in bench CHD research, the molecular pathways involved in the differentiation of cardiomyocytes, and their applications in CHD disease modeling, therapeutics, and drug application.
Asunto(s)
Diferenciación Celular , Cardiopatías Congénitas , Células Madre Pluripotentes Inducidas , Miocitos Cardíacos , Humanos , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/citología , Cardiopatías Congénitas/patología , Cardiopatías Congénitas/genética , Animales , Modelos BiológicosRESUMEN
Yak is an excellent germplasm resource on the Tibetan Plateau and is able to live in high-altitude areas with hypoxic, cold, and harsh environments. Studies on induced pluripotent stem cells (iPSCs) in large ruminants commonly involve a combination strategy involving six transcription factors, Oct4, Sox2, Klf4, c-Myc, Nanog, and Lin28 (OSKMNL). This strategy tends to utilize genes from the same species to optimize pluripotency maintenance. In this study, we cloned the six pluripotency genes (OSKMNL) from yak and constructed a multi-cistronic lentiviral vector carrying these genes. This vector efficiently delivered the genes into yak fibroblasts, aiming to promote the reprogramming process. We verified that the treated cells had several pluripotency characteristics, marking the first successful construction of a lentiviral system carrying yak pluripotency genes. This achievement lays the foundation for subsequent establishment of yak iPSCs and holds significant implications for yak-breed improvement and germplasm-resource conservation.