RESUMEN
Somites (SMs) comprise a transient stem cell population that gives rise to multiple cell types, including dermatome (D), myotome (MYO), sclerotome (SCL) and syndetome (SYN) cells. Although several groups have reported induction protocols for MYO and SCL from pluripotent stem cells, no studies have demonstrated the induction of SYN and D from SMs. Here, we report systematic induction of these cells from human induced pluripotent stem cells (iPSCs) under chemically defined conditions. We also successfully induced cells with differentiation capacities similar to those of multipotent mesenchymal stromal cells (MSC-like cells) from SMs. To evaluate the usefulness of these protocols, we conducted disease modeling of fibrodysplasia ossificans progressiva (FOP), an inherited disease that is characterized by heterotopic endochondral ossification in soft tissues after birth. Importantly, FOP-iPSC-derived MSC-like cells showed enhanced chondrogenesis, whereas FOP-iPSC-derived SCL did not, possibly recapitulating normal embryonic skeletogenesis in FOP and cell-type specificity of FOP phenotypes. These results demonstrate the usefulness of multipotent SMs for disease modeling and future cell-based therapies.
Asunto(s)
Desarrollo Óseo , Condrogénesis , Células Madre Pluripotentes Inducidas/metabolismo , Modelos Biológicos , Miositis Osificante/metabolismo , Somitos/metabolismo , Humanos , Células Madre Pluripotentes Inducidas/patología , Miositis Osificante/patología , Somitos/patologíaRESUMEN
Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disease characterized by extraskeletal bone formation through endochondral ossification. FOP patients harbor point mutations in ACVR1 (also known as ALK2), a type I receptor for bone morphogenetic protein (BMP). Two mechanisms of mutated ACVR1 (FOP-ACVR1) have been proposed: ligand-independent constitutive activity and ligand-dependent hyperactivity in BMP signaling. Here, by using FOP patient-derived induced pluripotent stem cells (FOP-iPSCs), we report a third mechanism, where FOP-ACVR1 abnormally transduces BMP signaling in response to Activin-A, a molecule that normally transduces TGF-ß signaling but not BMP signaling. Activin-A enhanced the chondrogenesis of induced mesenchymal stromal cells derived from FOP-iPSCs (FOP-iMSCs) via aberrant activation of BMP signaling in addition to the normal activation of TGF-ß signaling in vitro, and induced endochondral ossification of FOP-iMSCs in vivo. These results uncover a novel mechanism of extraskeletal bone formation in FOP and provide a potential new therapeutic strategy for FOP.
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Receptores de Activinas Tipo I/metabolismo , Miositis Osificante/metabolismo , Activinas/farmacología , Proteínas Morfogenéticas Óseas/metabolismo , Calcificación Fisiológica/efectos de los fármacos , Condrogénesis/efectos de los fármacos , Humanos , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/metabolismo , Miositis Osificante/patología , Miositis Osificante/fisiopatología , Transducción de Señal/efectos de los fármacos , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
Successful in vitro disease-recapitulation using patient-specific induced pluripotent stem cells (iPSCs) requires two fundamental technical issues: appropriate control cells and robust differentiation protocols. To investigate fibrodysplasia ossificans progressiva (FOP), a rare genetic disease leading to extraskeletal bone formation through endochondral ossification, gene-corrected (rescued) iPSC clones (resFOP-iPSC) were generated from patient-derived iPSC (FOP-iPSC) as genetically matched controls, and the stepwise induction method of mesenchymal stromal cells (iMSCs) through neural crest cell (NCC) lineage was used to recapitulate the disease phenotype. FOP-iMSCs possessing enhanced chondrogenic ability were transcriptionally distinguishable from resFOP-iMSCs and activated the SMAD1/5/8 and SMAD2/3 pathways at steady state. Using this method, we identified MMP1 and PAI1 as genes responsible for accelerating the chondrogenesis of FOP-iMSCs. These data indicate that iMSCs through NCC lineage are useful for investigating the molecular mechanism of FOP and corresponding drug discovery.
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Diferenciación Celular/fisiología , Condrogénesis/genética , Genoma Humano , Células Madre Pluripotentes Inducidas/citología , Miositis Osificante/terapia , Osteogénesis/fisiología , Receptores de Activinas Tipo I/metabolismo , Diferenciación Celular/genética , Linaje de la Célula/fisiología , Regulación de la Expresión Génica/fisiología , Humanos , Miositis Osificante/genética , Osteogénesis/genéticaRESUMEN
Heterotopic ossification (HO) is a non-physiological bone formation where soft tissue progenitor cells differentiate into chondrogenic cells. In fibrodysplasia ossificans progressiva (FOP), a rare genetic disease characterized by progressive and systemic HO, the Activin A/mutated ACVR1/mTORC1 cascade induces HO in progenitors in muscle tissues. The relevant biological processes aberrantly regulated by activated mTORC1 remain unclear, however. RNA-sequencing analyses revealed the enrichment of genes involved in oxidative phosphorylation (OXPHOS) during Activin A-induced chondrogenesis of mesenchymal stem cells derived from FOP patient-specific induced pluripotent stem cells. Functional analyses showed a metabolic transition from glycolysis to OXPHOS during chondrogenesis, along with increased mitochondrial biogenesis. mTORC1 inhibition by rapamycin suppressed OXPHOS, whereas OXPHOS inhibitor IACS-010759 inhibited cartilage matrix formation in vitro, indicating that OXPHOS is principally involved in mTORC1-induced chondrogenesis. Furthermore, IACS-010759 inhibited the muscle injury-induced enrichment of fibro/adipogenic progenitor genes and HO in transgenic mice carrying the mutated human ACVR1. These data indicated that OXPHOS is a critical downstream mediator of mTORC1 signaling in chondrogenesis and therefore is a potential FOP therapeutic target.
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Miositis Osificante , Osificación Heterotópica , Ratones , Animales , Humanos , Miositis Osificante/genética , Miositis Osificante/metabolismo , Fosforilación Oxidativa , Osificación Heterotópica/genética , Osificación Heterotópica/metabolismo , Transducción de Señal/genética , Ratones Transgénicos , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismoRESUMEN
OTULIN-related autoinflammatory syndrome (ORAS), a severe autoinflammatory disease, is caused by biallelic pathogenic variants of OTULIN, a linear ubiquitin-specific deubiquitinating enzyme. Loss of OTULIN attenuates linear ubiquitination by inhibiting the linear ubiquitin chain assembly complex (LUBAC). Here, we report a patient who harbors two rare heterozygous variants of OTULIN (p.P152L and p.R306Q). We demonstrated accumulation of linear ubiquitin chains upon TNF stimulation and augmented TNF-induced cell death in mesenchymal stem cells differentiated from patient-derived iPS cells, which confirms that the patient has ORAS. However, although the de novo p.R306Q variant exhibits attenuated deubiquitination activity without reducing the amount of OTULIN, the deubiquitination activity of the p.P152L variant inherited from the mother was equivalent to that of the wild-type. Patient-derived MSCs in which the p.P152L variant was replaced with wild-type also exhibited augmented TNF-induced cell death and accumulation of linear chains. The finding that ORAS can be caused by a dominant-negative p.R306Q variant of OTULIN furthers our understanding of disease pathogenesis.
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Ubiquitinación , Femenino , Humanos , Endopeptidasas/genética , Endopeptidasas/metabolismo , Enfermedades Autoinflamatorias Hereditarias/genética , Enfermedades Autoinflamatorias Hereditarias/patología , Enfermedades Autoinflamatorias Hereditarias/metabolismo , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Mesenquimatosas/metabolismo , Mutación , Linaje , Factor de Necrosis Tumoral alfa/metabolismo , Factor de Necrosis Tumoral alfa/genética , Ubiquitina/metabolismo , Recién NacidoRESUMEN
Programmable liquid handling devices for cell culture systems have dramatically enhanced scalability and reproducibility. We previously reported a protocol to produce cell aggregates demonstrating growth plate-like structures containing hypertrophic chondrocytes from human induced pluripotent stem cells (hiPSCs). To apply this protocol to large-scale drug screening for growth plate-related diseases, we adapted it to the automated cell culture system (ACCS) consisting of programmable liquid handling devices connected to CO2 incubators, a refrigerator, and labware feeders, designed for up to 4 batches with several cell culture plates culturing for several months. We developed a new program preparing culture media with growth factors at final concentration immediately before dispensing them to each well and precisely positioning the tip for the medium change without damaging cell aggregates. Using these programs on the ACCS, we successfully cultured cell aggregates for 56 days, only needing to replenish the labware, medium, and growth factors twice a week. The size of cell aggregates in each well increased over time, with low well-to-well variability. Cell aggregates on day 56 showed histochemical, immunohistochemical, and gene expression properties of growth plate-like structures containing hypertrophic chondrocytes, indicating proper quality as materials for basic research and drug discovery of growth plate related diseases. The established program will be a suitable reference for making programs of experiments requiring long term and complex culture procedures using ACCS.
Asunto(s)
Células Madre Pluripotentes Inducidas , Humanos , Reproducibilidad de los Resultados , Placa de Crecimiento , Técnicas de Cultivo de Célula/métodos , Células CultivadasRESUMEN
Collagen X is a non-fibril collagen produced by hypertrophic chondrocytes and was believed to associate with the calcification process of growth plate cartilage. The homozygous loss of Col10a1 gene in mice, however, demonstrated no remarkable effects on growth plate formation or skeletal development. To investigate the role of collagen X in human chondrocytes, we established human induced pluripotent stem cells (hiPSCs) with heterozygous (COL10A1 +/-) or homozygous (COL10A1 -/-) deletions of COL10A1 gene using the dual sgRNA CRISPR/Cas9 system. Several mutant clones were established and differentiated into hypertrophic chondrocytes by a previously reported 3D induction method. No remarkable differences were observed during the differentiation process between parental and mutant cell lines, which differentiated into cells with features of hypertrophic chondrocytes, indicating that collagen X is dispensable for the hypertrophic differentiation of human chondrocytes in vitro. To investigate the effects of collagen X deficiency in vivo, chondrocyte pellets at the proliferating or prehypertrophic stage were transplanted into immunodeficient mice. Proliferating pellet-derived tissues demonstrated the zonal distribution of chondrocytes with the transition to bone tissues mimicking growth plates, and the proportion of bone tended to be larger in COL10A1 -/- tissues. Prehypertrophic pellet-derived tissues produced trabecular bone structures with features of endochondral ossification, and there was no clear difference between parental- and mutant-derived tissues. A transcriptome analysis of chondrocyte pellets at the hypertrophic phase showed a lower expression of proliferating-phase genes and a higher expression of calcification-phase genes in COL10A1 -/- pellets compared with parental cell pellets. These in vitro and in vivo data suggested that collagen X is dispensable for the hypertrophic differentiation and endochondral ossification of human iPSC-derived chondrocytes, though it may facilitate the differentiation process. Thus, COL10A1 -/- iPSC lines are useful for investigating the physiological role of collagen X in chondrocyte differentiation. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
RESUMEN
Although the formation of bone-like nodules is regarded as the differentiation process from stem cells to osteogenic cells, including osteoblasts and osteocytes, the precise biological events during nodule formation are unknown. Here we performed the osteogenic induction of human induced pluripotent stem cells using a three-dimensional (3D) culture system using type I collagen gel and a rapid induction method with retinoic acid. Confocal and time-lapse imaging revealed the osteogenic differentiation was initiated with vigorous focal proliferation followed by aggregation, from which cells invaded the gel. Invading cells changed their morphology and expressed osteocyte marker genes, suggesting the transition from osteoblasts to osteocytes. Single-cell RNA sequencing analysis revealed that 3D culture-induced cells with features of periosteal skeletal stem cells, some of which expressed TGFß-regulated osteoblast-related molecules. The role of TGFß signal was further analyzed in the transition from osteoblasts to osteocytes, which revealed that modulation of the TGFß signal changed the morphology and motility of cells isolated from the 3D culture, suggesting that the TGFß signal maintains the osteoblastic phenotype and the transition into osteocytes requires down-regulation of the TGFß signal.
Asunto(s)
Células Madre Pluripotentes Inducidas , Osteocitos , Humanos , Factor de Crecimiento Transformador beta , Osteogénesis/genética , Osteoblastos , Diferenciación Celular/genéticaRESUMEN
BACKGROUND: Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disease characterized by progressive heterotopic ossification (HO) in soft tissues due to a heterozygous mutation of the ACVR1A gene (FOP-ACVR1A), which erroneously transduces the BMP signal by Activin-A. Although inflammation is known to trigger HO in FOP, the role of FOP-ACVR1A on inflammatory cells remains to be elucidated. RESULTS: We generated immortalized monocytic cell lines from FOP-iPSCs (FOP-ML) and mutation rescued iPSCs (resFOP-ML). Cell morphology was evaluated during the monocyte induction and after immortalization. Fluorescence-activated cell sorting (FACS) was performed to evaluate the cell surface markers CD14 and CD16 on MLs. MLs were stimulated with lipopolysaccharide or Activin-A and the gene expression was evaluated by quantitative PCR and microarray analysis. Histological analysis was performed for HO tissue obtained from wild type mice and FOP-ACVR1A mice which conditionally express human mutant ACVR1A gene by doxycycline administration. Without any stimulation, FOP-ML showed the pro-inflammatory signature of CD16+ monocytes with an upregulation of INHBA gene, and treatment of resFOP-ML with Activin-A induced an expression profile mimicking that of FOP-ML at baseline. Treatment of FOP-ML with Activin-A further induced the inflammatory profile with an up-regulation of inflammation-associated genes, of which some, but not all, of which were suppressed by corticosteroid. Experiments using an inhibitor for TGFß or BMP signal demonstrated that Activin-A-induced genes such as CD16 and CCL7, were regulated by both signals, indicating Activin-A transduced dual signals in FOP-ML. A comparison with resFOP-ML identified several down-regulated genes in FOP-ML including LYVE-1, which is known to suppress matrix-formation in vivo. The down-regulation of LYVE-1 in HO tissues was confirmed in FOP model mice, verifying the significance of the in vitro experiments. CONCLUSION: These results indicate that FOP-ML faithfully recapitulated the phenotype of primary monocytes of FOP and the combination with resFOP-ML is a useful tool to investigate molecular events at the initial inflammation stage of HO in FOP.
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Receptores de Activinas Tipo I/genética , Miositis Osificante , Osificación Heterotópica , Receptores de Activinas Tipo I/metabolismo , Activinas/genética , Activinas/metabolismo , Animales , Doxiciclina , Humanos , Inflamación/genética , Lipopolisacáridos , Ratones , Monocitos/metabolismo , Monocitos/patología , Mutación/genética , Miositis Osificante/patología , Osificación Heterotópica/genética , Osificación Heterotópica/patología , Transducción de Señal/genética , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
Osteoarthritis is a leading cause of pain and joint immobility, the incidence of which is increasing worldwide. Currently, total joint replacement is the only treatment for end-stage disease. Scaffold-based tissue engineering is a promising alternative approach for joint repair but is subject to limitations such as poor cytocompatibility and degradation-associated toxicity. To overcome these limitations, a completely scaffold-free Kenzan method for bio-3D printing was used to fabricate cartilage constructs feasible for repairing large chondral defects. Human induced pluripotent stem cell (iPSC)-derived neural crest cells with high potential to undergo chondrogenesis through mesenchymal stem cell differentiation were used to fabricate the cartilage. Unified, self-sufficient, and functional cartilaginous constructs up to 6 cm2in size were assembled by optimizing fabrication time during chondrogenic induction. Maturation for 3 weeks facilitated the self-organisation of the cells, which improved the construct's mechanical strength (compressive and tensile properties) and induced changes in glycosaminoglycan and type II collagen expression, resulting in improved tissue function. The compressive modulus of the construct reached the native cartilage range of 0.88 MPa in the 5th week of maturation. This paper reports the fabrication of anatomically sized and shaped cartilage constructs, achieved by combining novel iPSCs and bio-3D printers using a Kenzan needle array technology, which may facilitate chondral resurfacing of articular cartilage defects.
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Cartílago Articular , Células Madre Pluripotentes Inducidas , Diferenciación Celular , Condrocitos , Condrogénesis , Humanos , Impresión Tridimensional , Regeneración , Ingeniería de Tejidos , Andamios del TejidoRESUMEN
Chondrodysplasias are hereditary diseases caused by mutations in the components of growth cartilage. Although the unfolded protein response (UPR) has been identified as a key disease mechanism in mouse models, no suitable in vitro system has been reported to analyze the pathology in humans. Here, we developed a three-dimensional culture protocol to differentiate hypertrophic chondrocytes from induced pluripotent stem cells (iPSCs) and examine the phenotype caused by MATN3 and COL10A1 mutations. Intracellular MATN3 or COL10 retention resulted in increased ER stress markers and ER size in most mutants, but activation of the UPR was dependent on the mutation. Transcriptome analysis confirmed a UPR with wide-ranging changes in bone homeostasis, extracellular matrix composition, and lipid metabolism in the MATN3 T120M mutant, which further showed altered cellular morphology in iPSC-derived growth-plate-like structures in vivo. We then applied our in vitro model to drug testing, whereby trimethylamine N-oxide led to a reduction of ER stress and intracellular MATN3.
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Cartílago/fisiología , Condrocitos/fisiología , Colágeno Tipo X/metabolismo , Células Madre Pluripotentes Inducidas/fisiología , Osteocondrodisplasias/genética , Osteocondrodisplasias/metabolismo , Animales , Huesos/metabolismo , Técnicas de Cultivo de Célula/métodos , Diferenciación Celular , Células Cultivadas , Condrocitos/citología , Condrogénesis , Colágeno Tipo X/genética , Estrés del Retículo Endoplásmico , Matriz Extracelular/metabolismo , Edición Génica , Perfilación de la Expresión Génica , Homeostasis , Humanos , Células Madre Pluripotentes Inducidas/citología , Masculino , Proteínas Matrilinas/genética , Proteínas Matrilinas/metabolismo , Ratones , Modelos Biológicos , Mutación , Osteocondrodisplasias/patología , Fenotipo , Respuesta de Proteína DesplegadaRESUMEN
BACKGROUND: Fibrodysplasia ossificans progressiva (FOP) is a rare autosomal-dominant disease characterized by heterotopic ossification (HO) in soft tissues and caused by a mutation of the ACVR1A/ALK2 gene. Activin-A is a key molecule for initiating the process of HO via the activation of mTOR, while rapamycin, an mTOR inhibitor, effectively inhibits the Activin-A-induced HO. However, few reports have verified the effect of rapamycin on FOP in clinical perspectives. METHODS: We investigated the effect of rapamycin for different clinical situations by using mice conditionally expressing human mutant ACVR1A/ALK2 gene. We also compared the effect of rapamycin between early and episode-initiated treatments for each situation. RESULTS: Continuous, episode-independent administration of rapamycin reduced the incidence and severity of HO in the natural course of FOP mice. Pinch-injury induced HO not only at the injured sites, but also in the contralateral limbs and provoked a prolonged production of Activin-A in inflammatory cells. Although both early and injury-initiated treatment of rapamycin suppressed HO in the injured sites, the former was more effective at preventing HO in the contralateral limbs. Rapamycin was also effective at reducing the volume of recurrent HO after the surgical resection of injury-induced HO, for which the early treatment was more effective. CONCLUSION: Our study suggested that prophylactic treatment will be a choice of method for the clinical application of rapamycin for FOP.
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Miositis Osificante , Osificación Heterotópica , Receptores de Activinas Tipo I/genética , Animales , Humanos , Ratones , Mutación , Miositis Osificante/tratamiento farmacológico , Miositis Osificante/genética , Osificación Heterotópica/tratamiento farmacológico , Osificación Heterotópica/genética , Sirolimus/farmacología , Sirolimus/uso terapéuticoRESUMEN
The recapitulation of bone formation via the in vitro generation of bone-like nodules is frequently used to understand bone development. However, current bone-induction techniques are slow and difficult to reproduce. Here, we report the formation of bone-like nodules within ten days, via the use of retinoic acid (RA) to induce the osteogenic differentiation of human induced pluripotent stem cells (hiPSCs) into osteoblast-like and osteocyte-like cells that create human bone tissue when implanted in calvarial defects in mice. We also show that the induction of bone formation depends on cell signalling through the RA receptors RARα and RARß, which simultaneously activate the BMP (bone morphogenetic protein) and Wnt signalling pathways. Moreover, by using patient-derived hiPSCs, the bone-like nodules recapitulated the osteogenesis-imperfecta phenotype, which was rescued via the correction of disease-causing mutations and partially by an mTOR (mechanistic target of rapamycin) inhibitor. The method of inducing bone nodules may serve as a fast and reproducible model for the study of the formation of both healthy and pathological bone.
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Huesos/patología , Huesos/fisiología , Células Madre Pluripotentes Inducidas/patología , Células Madre Pluripotentes Inducidas/fisiología , Osteogénesis/fisiología , Animales , Proteínas Morfogenéticas Óseas , Huesos/efectos de los fármacos , Diferenciación Celular , Células Cultivadas , Regulación de la Expresión Génica , Humanos , Técnicas In Vitro , Células Madre Pluripotentes Inducidas/efectos de los fármacos , Masculino , Ratones , Ratones Desnudos , Ratones SCID , Mutación , Osteogénesis/efectos de los fármacos , Osteogénesis/genética , Fenotipo , Receptores de Ácido Retinoico/efectos de los fármacos , Serina-Treonina Quinasas TOR/efectos de los fármacos , Trasplante , Tretinoina/farmacología , Vía de Señalización WntRESUMEN
Fibrodysplasia ossificans progressiva (FOP) is a rare and intractable disorder characterized by extraskeletal bone formation through endochondral ossification. FOP patients harbor gain-of-function mutations in ACVR1 (FOP-ACVR1), a type I receptor for bone morphogenetic proteins. Despite numerous studies, no drugs have been approved for FOP. Here, we developed a high-throughput screening (HTS) system focused on the constitutive activation of FOP-ACVR1 by utilizing a chondrogenic ATDC5 cell line that stably expresses FOP-ACVR1. After HTS of 5,000 small-molecule compounds, we identified two hit compounds that are effective at suppressing the enhanced chondrogenesis of FOP patient-derived induced pluripotent stem cells (FOP-iPSCs) and suppressed the heterotopic ossification (HO) of multiple model mice, including FOP-ACVR1 transgenic mice and HO model mice utilizing FOP-iPSCs. Furthermore, we revealed that one of the hit compounds is an mTOR signaling modulator that indirectly inhibits mTOR signaling. Our results demonstrate that these hit compounds could contribute to future drug repositioning and the mechanistic analysis of mTOR signaling.
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Miositis Osificante/enzimología , Miositis Osificante/patología , Osificación Heterotópica/enzimología , Osificación Heterotópica/patología , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismo , Receptores de Activinas Tipo I/metabolismo , Animales , Benzodioxoles/farmacología , Ensayos Analíticos de Alto Rendimiento , Humanos , Células Madre Pluripotentes Inducidas/efectos de los fármacos , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/patología , Ratones SCID , Ratones Transgénicos , Oxazoles/farmacología , Pirimidinas/farmacología , Quinazolinas/farmacología , Reproducibilidad de los Resultados , Transducción de Señal/efectos de los fármacos , Triazoles/farmacología , Urea/análogos & derivados , Urea/farmacologíaRESUMEN
Fibrodysplasia ossificans progressiva (FOP) is a rare and intractable disease characterized by extraskeletal bone formation through endochondral ossification. Patients with FOP harbor point mutations in ACVR1, a type I receptor for BMPs. Although mutated ACVR1 (FOP-ACVR1) has been shown to render hyperactivity in BMP signaling, we and others have uncovered a mechanism by which FOP-ACVR1 mistransduces BMP signaling in response to Activin-A, a molecule that normally transduces TGF-ß signaling. Although Activin-A evokes enhanced chondrogenesis in vitro and heterotopic ossification (HO) in vivo, the underlying mechanisms have yet to be revealed. To this end, we developed a high-throughput screening (HTS) system using FOP patient-derived induced pluripotent stem cells (FOP-iPSCs) to identify pivotal pathways in enhanced chondrogenesis that are initiated by Activin-A. In a screen of 6,809 small-molecule compounds, we identified mTOR signaling as a critical pathway for the aberrant chondrogenesis of mesenchymal stromal cells derived from FOP-iPSCs (FOP-iMSCs). Two different HO mouse models, an FOP model mouse expressing FOP-ACVR1 and an FOP-iPSC-based HO model mouse, revealed critical roles for mTOR signaling in vivo. Moreover, we identified ENPP2, an enzyme that generates lysophosphatidic acid, as a linker of FOP-ACVR1 and mTOR signaling in chondrogenesis. These results uncovered the crucial role of the Activin-A/FOP-ACVR1/ENPP2/mTOR axis in FOP pathogenesis.
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Activinas/metabolismo , Condrogénesis , Miositis Osificante/metabolismo , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismo , Animales , Diferenciación Celular , Condrocitos/citología , Células Madre Embrionarias/citología , Femenino , Humanos , Células Madre Pluripotentes Inducidas/citología , Concentración 50 Inhibidora , Lisofosfolípidos/metabolismo , Masculino , Células Madre Mesenquimatosas/metabolismo , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Ratones Transgénicos , Análisis de Secuencia por Matrices de Oligonucleótidos , Hidrolasas Diéster Fosfóricas/metabolismo , Mutación Puntual , Proteínas Recombinantes/metabolismo , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
The prevalence and specificity of unique fusion oncogenes are high in a number of soft tissue sarcomas (STSs). The close relationship between fusion genes and clinicopathological features suggests that a correlation may exist between the function of fusion proteins and cellular context of the cell-of-origin of each tumor. However, most STSs are origin-unknown tumors and this issue has not yet been investigated in detail. In the present study, we examined the effects of the cellular context on the function of the synovial sarcoma (SS)-specific fusion protein, SS18-SSX, using human pluripotent stem cells (hPSCs) containing the drug-inducible SS18-SSX gene. We selected the neural crest cell (NCC) lineage for the first trial of this system, induced SS18-SSX at various differentiation stages from PSCs to NCC-derived mesenchymal stromal cells (MSCs), and compared its biological effects on each cell type. We found that the expression of FZD10, identified as an SS-specific gene, was induced by SS18-SSX at the PSC and NCC stages, but not at the MSC stage. This stage-specific induction of FZD10 correlated with stage-specific changes in histone marks associated with the FZD10 locus and also with the loss of the BAF47 protein, a member of the SWI/SNF chromatin-remodeling complex. Furthermore, the global gene expression profile of hPSC-derived NCCs was the closest to that of SS cell lines after the induction of SS18-SSX. These results clearly demonstrated that the cellular context is an important factor in the function of SS18-SSX as an epigenetic modifier.
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Proteínas de Fusión Oncogénica/metabolismo , Células Madre Pluripotentes/metabolismo , Diferenciación Celular , Línea Celular , Proteínas Cromosómicas no Histona/metabolismo , Proteínas de Unión al ADN/metabolismo , Epigénesis Genética , Receptores Frizzled/genética , Receptores Frizzled/metabolismo , Sitios Genéticos , Histonas/metabolismo , Humanos , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/metabolismo , Cresta Neural/citología , Cresta Neural/metabolismo , Proteínas de Fusión Oncogénica/antagonistas & inhibidores , Proteínas de Fusión Oncogénica/genética , Células Madre Pluripotentes/citología , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Proteína SMARCB1 , Sarcoma Sinovial/genética , Sarcoma Sinovial/metabolismo , Sarcoma Sinovial/patología , Factores de Transcripción/metabolismo , TranscriptomaRESUMEN
Somatic mutations in the isocitrate dehydrogenase (IDH)1/2 genes endow encoding proteins with neomorphic activity to produce the potential oncometabolite, 2-hydroxyglutarate (2-HG), which induces the hypermethylation of histones and DNA. The incidence of IDH1/2 mutations in cartilaginous tumors was previously shown to be the highest among various types of tumors, except for those in the central nervous system. Mutations have been detected in both benign (enchondromas) and malignant (chondrosarcomas) types of cartilaginous tumors, whereas they have rarely been found in other mesenchymal tumors such as osteosarcomas. To address this unique tumor specificity, we herein examined the effects of IDH1 R132C, which is the most prevalent mutant in cartilaginous tumors, on the differentiation properties of human mesenchymal stem cells (hMSCs). The induction of the IDH1 R132C gene into MSCs markedly increased the amount of 2-HG and up-regulated global histone methylation. The induction of IDH1 R132C promoted the chondrogenic differentiation of hMSCs by enhancing the expression of SOX9 and COL2A1 genes in association with an increase in the active mark (H3K4me3), but disrupted cartilage matrix formation. On the other hand, IDH1 R132C inhibited expression of the ALPL gene in association with an increase in the repressive mark (H3K9me3), and subsequently inhibited the osteogenic properties of hMSCs and human osteosarcoma cells. Since osteogenic properties are an indispensable feature for the diagnosis of osteosarcoma, the inhibitory effects of IDH1 R132C on osteogenic properties may contribute to the lack of osteosarcomas with the IDH1 R132C mutation. These results suggested that IDH1 R132C contributed to the formation of cartilaginous tumors by dysregulating the chondrogenic and osteogenic differentiation of hMSCs via gene-specific histone modulation.
Asunto(s)
Isocitrato Deshidrogenasa/genética , Células Madre Mesenquimatosas/enzimología , Neoplasias Óseas/enzimología , Neoplasias Óseas/genética , Diferenciación Celular , Células Cultivadas , Condrosarcoma/enzimología , Condrosarcoma/genética , Encondromatosis/enzimología , Encondromatosis/genética , Epigénesis Genética , Regulación Neoplásica de la Expresión Génica , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Histonas/metabolismo , Humanos , Células Madre Mesenquimatosas/fisiología , Metilación , Mutación Missense , Osteosarcoma/enzimología , Osteosarcoma/genética , Procesamiento Proteico-PostraduccionalRESUMEN
Neural crest cells (NCCs) are an embryonic migratory cell population with the ability to differentiate into a wide variety of cell types that contribute to the craniofacial skeleton, cornea, peripheral nervous system, and skin pigmentation. This ability suggests the promising role of NCCs as a source for cell-based therapy. Although several methods have been used to induce human NCCs (hNCCs) from human pluripotent stem cells (hPSCs), such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), further modifications are required to improve the robustness, efficacy, and simplicity of these methods. Chemically defined medium (CDM) was used as the basal medium in the induction and maintenance steps. By optimizing the culture conditions, the combination of the GSK3ß inhibitor and TGFß inhibitor with a minimum growth factor (insulin) very efficiently induced hNCCs (70-80%) from hPSCs. The induced hNCCs expressed cranial NCC-related genes and stably proliferated in CDM supplemented with EGF and FGF2 up to at least 10 passages without changes being observed in the major gene expression profiles. Differentiation properties were confirmed for peripheral neurons, glia, melanocytes, and corneal endothelial cells. In addition, cells with differentiation characteristics similar to multipotent mesenchymal stromal cells (MSCs) were induced from hNCCs using CDM specific for human MSCs. Our simple and robust induction protocol using small molecule compounds with defined media enabled the generation of hNCCs as an intermediate material producing terminally differentiated cells for cell-based innovative medicine.