RESUMO
Circulating tumor cells (CTCs) shed from primary tumors must overcome the cytotoxicity of immune cells, particularly natural killer (NK) cells, to cause metastasis. The tumor microenvironment (TME) protects tumor cells from the cytotoxicity of immune cells, which is partially executed by cancer-associated mesenchymal stromal cells (MSCs). However, the mechanisms by which MSCs influence the NK resistance of CTCs remain poorly understood. This study demonstrates that MSCs enhance the NK resistance of cancer cells in a gap junction-dependent manner, thereby promoting the survival and metastatic seeding of CTCs in immunocompromised mice. Tumor cells crosstalk with MSCs through an intercellular cGAS-cGAMP-STING signaling loop, leading to increased production of interferon-ß (IFNß) by MSCs. IFNß reversely enhances the type I IFN (IFN-I) signaling in tumor cells and hence the expression of human leukocyte antigen class I (HLA-I) on the cell surface, protecting the tumor cells from NK cytotoxicity. Disruption of this loop reverses NK sensitivity in tumor cells and decreases tumor metastasis. Moreover, there are positive correlations between IFN-I signaling, HLA-I expression, and NK tolerance in human tumor samples. Thus, the NK-resistant signaling loop between tumor cells and MSCs may serve as a novel therapeutic target.
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Interferon beta , Células Matadoras Naturais , Células-Tronco Mesenquimais , Células Neoplásicas Circulantes , Nucleotidiltransferases , Transdução de Sinais , Microambiente Tumoral , Células-Tronco Mesenquimais/imunologia , Células-Tronco Mesenquimais/metabolismo , Animais , Células Matadoras Naturais/imunologia , Camundongos , Interferon beta/metabolismo , Interferon beta/imunologia , Nucleotidiltransferases/metabolismo , Nucleotidiltransferases/genética , Humanos , Células Neoplásicas Circulantes/imunologia , Células Neoplásicas Circulantes/metabolismo , Microambiente Tumoral/imunologia , Proteínas de Membrana/metabolismo , Modelos Animais de Doenças , Linhagem Celular TumoralRESUMO
Mesenchymal stem cells (MSCs) are becoming hotspots for application in disease therapies recently, combining with biomaterials and drug delivery system. A major advantage of MSCs applied in drug delivery system is that these cells enable specific targeting and releasing of cargos to the disease sites. However, the potential tumor tropic effects of MSCs raised concerns on biosafety. To solve this problem, there are emerging methods of isolating cell membranes and developing nanoformulations to perform drug delivery, which avoids concerns on biosafety without disturbing the membrane functions of specific polarizing and locating. These cargoes are so called "nanoghosts." This review article summarizes the current applications of nanoghosts, the promising potential of MSCs to be applied in membrane isolation and nanoghost construction, and possible approaches to develop better drug delivery system harnessing from MSC ghost cell membranes.
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Células-Tronco Mesenquimais , Neoplasias , Humanos , Biomimética , Neoplasias/metabolismo , Sistemas de Liberação de Medicamentos , Membrana Celular , Células-Tronco Mesenquimais/metabolismoRESUMO
Mesenchymal stem cells (MSCs) are present in almost all the tissues in the body, critical for their homeostasis and regeneration. However, the stemness of MSCs is mainly an in vitro observation, and lacking exclusive markers for endogenous MSCs makes it difficult to study the multipotency of MSCs in vivo, especially for human MSCs. To address this hurdle, we injected GFP-tagged human embryonic stem cell (hESC)-derived MSCs (EMSCs) into mouse blastocysts. EMSCs survived well and penetrated both the inner cell mass and trophectoderm, correlating to the higher anti-apoptotic capability of EMSCs than hESCs. Injected EMSCs contributed to skeletal, dermal, and extraembryonic tissues in the resultant chimera and partially rescued skeletal defects in Sox9+/- mouse fetuses. Thus, this study provides evidence for the stemness and developmental capability of human MSCs through chimerization with the mouse blastocyst, serving as a model for studying human mesenchymal and skeletal development.
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Células-Tronco Embrionárias Humanas , Células-Tronco Mesenquimais , Humanos , Camundongos , Animais , Diferenciação Celular , Células-Tronco Embrionárias , BlastocistoRESUMO
The skin harbours transcriptionally and functionally heterogeneous mesenchymal cells that participate in various physiological activities by secreting biochemical cues. In this study, we aimed to identify a new subpopulation of dermal mesenchymal cells that enhance hair follicle regeneration through a paracrine mechanism. Integrated single-cell RNA sequencing (scRNA-seq) data analysis revealed epidermal growth factor receptor (EGFR) as a marker of distinct fibroblast subpopulation in the neonatal murine dermis. Immunofluorescence staining and fluorescence-activated cell sorting (FACS) were used to validate the existence of the cell population in Krt14-rtTA-H2BGFP mouse. The difference of gene expression between separated cell subpopulation was examined by real-time PCR. Potential effect of the designated factor on hair follicle regeneration was observed after the application on excisional wounds in Krt14-rtTA-H2BGFP mouse. Immunofluorescence staining demonstrated the existence of dermal EGFR+ cells in neonatal and adult mouse dermis. The EGFR+ mesenchymal population, sorted by FACS, displayed a higher expression level of Igf1 (insulin-like growth factor 1). Co-localisation of IGF1 with EGFR in the mouse dermis and upregulated numbers of hair follicles in healed wounds following the application of exogenous IGF1 illustrated the contribution of EGFR+ cells in promoting wound-induced hair follicle neogenesis. Our results indicate that EGFR identifies a subpopulation of dermal fibroblasts that contribute to IGF1 promotion of hair follicle neogenesis. It broadens the understanding of heterogeneity and the mesenchymal cell function in skin and may facilitate the potential translational application of these cells.
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Derme , Folículo Piloso , Animais , Camundongos , Derme/metabolismo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Folículo Piloso/fisiologia , Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/metabolismo , PeleRESUMO
Mesenchymal stem/Stromal cells (MSCs) have great therapeutic potentials, and they have been isolated from various tissues and organs including definitive endoderm (DE) organs, such as the lung, liver and intestine. MSCs have been induced from human pluripotent stem cells (hPSCs) through multiple embryonic lineages, including the mesoderm, neural crest, and extraembryonic cells. However, it remains unclear whether hPSCs could give rise to MSCs in vitro through the endodermal lineage. Here, we report that hPSC-derived, SOX17+ definitive endoderm progenitors can further differentiate to cells expressing classic MSC markers, which we name definitive endoderm-derived MSCs (DE-MSCs). Single cell RNA sequencing demonstrates the stepwise emergence of DE-MSCs, while endoderm-specific gene expression can be elevated by signaling modulation. DE-MSCs display multipotency and immunomodulatory activity in vitro and possess therapeutic effects in a mouse ulcerative colitis model. This study reveals that, in addition to the other germ layers, the definitive endoderm can also contribute to MSCs and DE-MSCs could be a cell source for regenerative medicine.
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Células-Tronco Mesenquimais , Células-Tronco Pluripotentes , Animais , Camundongos , Humanos , Diferenciação Celular/genética , Células-Tronco Mesenquimais/metabolismo , Fígado , MesodermaRESUMO
The treatment of refractory cutaneous wounds remains to be a clinical challenge. There is growing evidence to show that mesenchymal stem cells (MSCs) have great potential in promoting wound healing. However, the therapeutic effects of MSCs are greatly dampened by their poor survival and engraftment in the wounds. To address this limitation, in this study, MSCs were grown into a collagen-glycosaminoglycan (C-GAG) matrix to form a dermis-like tissue sheet, named engineered dermal substitute (EDS). When seeded on C-GAG matrix, MSCs adhered rapidly, migrated into the pores, and proliferated readily. When applied onto excisional wounds in healthy and diabetic mice, the EDS survived well, and accelerated wound closure, compared with C-GAG matrix alone or MSCs in collagen hydrogel. Histological analysis revealed that EDS prolonged the retention of MSCs in the wounds, associated with increased macrophage infiltration and enhanced angiogenesis. RNA-Seq analysis of EDS-treated wounds uncovered the expression of abundant human chemokines and proangiogenic factors and their corresponding murine receptors, suggesting a mechanism of ligand/receptor-mediated signals in wound healing. Thus, our results indicate that EDS prolongs the survival and retention of MSCs in the wounds and enhances wound healing.
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Diabetes Mellitus Experimental , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Camundongos , Humanos , Animais , Diabetes Mellitus Experimental/metabolismo , Cicatrização , Células-Tronco Mesenquimais/metabolismo , Transplante de Células-Tronco Mesenquimais/métodosRESUMO
We have previously demonstrated that mesenchymal stromal/stem cells (MSCs) in spheroids (MSCsp) tolerate ambient and hypoxic conditions for a prolonged time. Local administration of MSCsp, but not dissociated MSCs (MSCdiss), promotes wound healing and relieves multiple sclerosis and osteoarthritis in mice and monkeys. These findings indicate an advantage of MSCsp over MSCdiss in sustaining cell viability and efficacy following transplantation, which, however, does not appear to apply to intravenous (i.v.) injection for the principal concern that MSCsp might cause embolism in small blood vessels of the host, leading to sudden death. Here, we addressed this concern by injecting human MSCsp (â¼450 µm) or MSCdiss i.v. into cynomolgus monkeys. Surprisingly, no deaths occurred until sacrifice at day 21 or 60 post injection, and no remarkable physiological changes were found in the animals following the i.v. injection. The big diameters of large blood vessels in monkeys, compared to small animals like mice, may allow sufficient time for MSCsp to dissociate into single cells so they can pass through small vessels without causing embolism. Retention of MSCsp was lower in the lungs but higher in the blood than retention of MSCdiss at 1 h post injection and both disappeared at day 21. In vitro, MSCsp tolerated fluidic shear stress with higher survival than MSCdiss. Thus, i.v. injection of MSCsp into nonhuman primates is feasible, safe, and probably associated with better survival, less lung entrapment and higher efficacy than administration of MSCdiss.
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Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Osteoartrite , Animais , Humanos , Injeções Intravenosas , Macaca fascicularis , Camundongos , Osteoartrite/metabolismoRESUMO
Mesenchymal stem cells (MSCs) as a therapeutic promise are often quickly cleared by innate immune cells of the host including natural killer (NK) cells. Efforts have been made to generate immune-escaping human embryonic stem cells (hESCs) where T cell immunity is evaded by defecting ß-2-microglobulin (B2M), a common unit for human leukocyte antigen (HLA) class I, and NK cells are inhibited via ectopic expression of HLA-E or -G. However, NK subtypes vary among recipients and even at different pathologic statuses. It is necessary to dissect and optimize the efficacy of the immune-escaping cells against NK subtypes. Here, we first generated B2M knockout hESCs and differentiated them to MSCs (EMSCs) and found that NK resistance occurred with B2M-/- EMSCs expressing HLA-E and -G only when they were transduced via an inducible lentiviral system in a dose-dependent manner but not when they were inserted into a safe harbor. HLA-E and -G expressed at high levels together in transduced EMSCs inhibited three major NK subtypes, including NKG2A+ /LILRB1+ , NKG2A+ /LILRB1- , and NKG2A- /LILRB1+ , which was further potentiated by IFN-γ priming. Thus, this study engineers MSCs with resistance to multiple NK subtypes and underscores that dosage matters when a transgene is used to confer a novel effect to host cells, especially for therapeutic cells to evade immune rejection.
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Células Matadoras Naturais/imunologia , Células-Tronco Mesenquimais/imunologia , Engenharia Tecidual/métodos , Microglobulina beta-2/imunologia , Linhagem Celular , HumanosRESUMO
Mesenchymal stem cells (MSCs) derived from somatic tissues have been used to promote lipotransfer, a common practice in cosmetic surgery. However, the effect of lipotransfer varies, and the mechanism of action remains vague. To address these questions, we differentiated human embryonic stem cells, a stable and unlimited source, into MSCs (EMSCs). Then we subcutaneously transplanted human fat aspirates together with EMSCs or PBS as a control into the back of nude mice. Within 24 h of transplantation, EMSCs promoted aggregation and encapsulation of injected fat tissues. Afterward, all grafts gradually shrank. However, EMSC-containing grafts were larger, heavier and had fewer dark areas on the surface than the control grafts. Histologically, more live adipocytes, vascular cells, and macrophages and less fibrosis were observed in EMSC-containing grafts than in the controls. Some EMSCs differentiated into vascular cells and adipocytes in the EMSC-containing grafts. RNA sequencing revealed that human RNA was shown to decline rapidly, while mouse RNA increased in the grafts; further, human genes related to extracellular matrix remodeling, adipogenesis, and chemokine (including CCL2) signaling were expressed at higher levels in the EMSC-containing grafts than they were in the controls. CCL2 knockout reduced macrophage migration towards EMSCs in vitro and early macrophage recruitment to the grafts and the pro-engraftment effect of EMSCs in vivo. Treating mice with a macrophage inhibitor abolished the EMSC effects and converted the grafts to heavy masses of cell debris. Together, these data demonstrate that EMSCs promote fat engraftment via enhanced tissue reconstitution and encapsulation of implanted tissues, which was followed by increased angiogenesis and adipocyte survival and reduced fibrosis, in which stimulated CCL2 signaling and mobilized macrophages play pivotal roles.
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Células-Tronco Mesenquimais , Adipócitos , Animais , Diferenciação Celular , Quimiocina CCL2/genética , Humanos , Macrófagos , Camundongos , Camundongos NusRESUMO
The differentiation and maturation of mesenchymal stem cells (MSCs) to mesodermal and other lineages are known to be controlled by various extrinsic and intrinsic signals. The dysregulation of the MSC differentiation balance has been linked to several pathophysiological conditions, including obesity and osteoporosis. Previous research of the molecular mechanisms governing MSC differentiation has mostly focused on transcriptional regulation. However, recent findings are revealing the underrated role of alternative splicing (AS) in MSC differentiation and functions. In this review, we discuss recent progress in elucidating the regulatory roles of AS in MSC differentiation. We catalogue and highlight the key AS events that modulate MSC differentiation to major osteocytes, chondrocytes, and adipocytes, and discuss the regulatory mechanisms by which AS is regulated.
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Processamento Alternativo/genética , Diferenciação Celular/genética , Células-Tronco Mesenquimais/citologia , Adipogenia/genética , Animais , Condrogênese/genética , Humanos , Células-Tronco Mesenquimais/metabolismo , Osteogênese/genéticaRESUMO
BACKGROUND: Cultured epidermal stem cells (Epi-SCs) and skin-derived precursors (SKPs) were capable of reconstituting functional hair follicles after implantation, while the signaling pathways that regulate neogenic hair follicle formation are poorly investigated. In this study, we aimed to understand the interactions between Epi-SCs and SKPs during skin organoid formation and to uncover key signal pathways crucial for de novo hair follicle regeneration. METHODS: To track their fate after transplantation, Epi-SCs derived from neonatal C57BL/6 mice were labeled with tdTomato, and SKPs were isolated from neonatal C57BL/6/GFP mice. A mixture of Epi-SCs-tdTomato and SKPs-EGFP in Matrigel was observed under two-photon microscope in culture and after implantation into excisional wounds in nude mice, to observe dynamic migrations of the cells during hair follicle morphogenesis. Signaling communications between the two cell populations were examined by RNA-Seq analysis. Potential signaling pathways revealed by the analysis were validated by targeting the pathways using specific inhibitors to observe a functional loss in de novo hair follicle formation. RESULTS: Two-photon microscopy analysis indicated that when Epi-SCs and SKPs were mixed in Matrigel and cultured, they underwent dynamic migrations resulting in the formation of a bilayer skin-like structure (skin organoid), where Epi-SCs positioned themselves in the outer layer; when the mixture of Epi-SCs and SKPs was grafted into excisional wounds in nude mice, a bilayer structure resembling the epidermis and the dermis formed at the 5th day, and de novo hair follicles generated subsequently. RNA-Seq analysis of the two cell types after incubation in mixture revealed dramatic alterations in gene transcriptome, where PI3K-Akt signaling pathway in Epi-SCs was significantly upregulated; meanwhile, elevated expressions of several growth factors and cytokine potentially activating PI3K were found in SKPs, suggesting active reciprocal communications between them. In addition, inhibition of PI3K or Akt by specific inhibitors markedly suppressed the hair follicle regeneration mediated by Epi-SCs and SKPs. CONCLUSIONS: Our data indicate that the PI3K-Akt signaling pathway plays a crucial role in de novo hair follicle regeneration, and the finding may suggest potential therapeutic applications in enhancing hair regeneration.
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Folículo Piloso , Proteínas Proto-Oncogênicas c-akt , Animais , Células Cultivadas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de SinaisRESUMO
It has been demonstrated that mesenchymal stem cells (MSCs) differentiated from human embryonic stem cells (hESCs), name EMSCs, can treat a variety of autoimmune and inflammatory diseases, with similar efficacies to those achieved with MSCs derived from somatic tissues such as bone marrow (BMSCs). The chance increases even higher for EMSCs, than somatic tissue derived MSCsâ, to become a cell drug as the former can be produced in large scale from an unlimited hESC line with easier quality control and less biosafety concern. We have further demonstrated that both human ESCs and EMSCs, after aggregation to form spheroids, can tolerate hypoxic and ambient conditions (AC) for over 4 and 10 days, respectively, without loss of their viability and alteration of their functions. Based on these advantages, we decided to test whether EMSC spheroids, made in large quantity and delivered through a long-term distance at AC, can treat osteoarthritis spontaneously developed in rhesus macaques (M. mulatta) monkeys as well as the allogenic MSCs. Methods: Xenogeneic AC-transported EMSC spheroids or allogenic BMSCs were injected into the articular cavity of both knees of the monkeys at 3 animals per group. Another two macaques were injected the same way with saline as controls. Results: Both EMSCs and BMSCs groups showed significant amelioration indicated by the reduction of swelling joint size and amplification of keen flare angle post-treatment, compared to the control group. Examinations via X-ray and MRI also indicated the decrease of inflammation and osteophyma, and recovery of the synovium and cartilage in both treated groups. No sign of allergy or graft versus host disease was observed in the animals. Conclusion: Our results demonstrate that human EMSC spheroids can prevent the osteoarthtitis progression and ameliorate osteoarthritis in the rhesus macaques as well as allogenic BMSCs, and this study shall help advance the clinical application of EMSCs.
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Transplante de Células-Tronco Mesenquimais/métodos , Osteoartrite/terapia , Animais , Células da Medula Óssea , Transplante de Medula Óssea , Diferenciação Celular , Condrócitos/citologia , Humanos , Articulação do Joelho/patologia , Macaca mulatta , Imageamento por Ressonância Magnética , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/fisiologia , Osteoartrite/diagnóstico por imagem , Esferoides Celulares/transplanteRESUMO
Mesenchymal stem cells (MSC) derived from adult tissues effectively promote wound healing. However, MSC quality varies, and the quantity of MSC is limited, as MSC are acquired through donations. Moreover, the survival and functioning of dissociated MSC delivered to an inflammatory lesion are subject to challenges. Methods: Here, spheres (EMSCSp) generated from human embryonic stem cell-derived MSC (EMSC) were directly dropped onto excised wounds in mice; the effects of EMSCSp were compared to those of dissociated EMSC (EMSCDiss). Following transplantation, we measured the extent of wound closure, dissected the histological features of the wounds, determined transcriptomic changes in cells isolated from the treated and control wounds, and evaluated the molecular mechanism of the effects of EMSC. Results: The application of EMSCSp onto murine dermal wounds substantially increased survival and efficacy of EMSC compared to the topical application of EMSCDiss. RNA sequencing (RNA-Seq) of cells isolated from the wounds highlighted the involvement of CXCL12-CXCR4 signaling in the effects of EMSCSp, which was verified in EMSC via CXCL12 knockdown and in target cells (vascular endothelial cells, epithelial keratinocytes, and macrophages) via CXCR4 inhibition. Finally, we enhanced the biosafety of EMSCSp by engineering cells with an inducible suicide gene. Conclusions: Together, these data suggest the topical application of EMSCSp as an unlimited, quality-assured, safe, and noninvasive therapy for wound healing and the CXCL12-CXCR4 axis as a key player in this treatment.
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Quimiocina CXCL12/metabolismo , Receptores CXCR4/metabolismo , Cicatrização , Administração Tópica , Animais , Quimiocina CXCL12/genética , Células Endoteliais/fisiologia , Técnicas de Silenciamento de Genes , Células-Tronco Embrionárias Humanas/fisiologia , Humanos , Queratinócitos/fisiologia , Macrófagos/fisiologia , Células-Tronco Mesenquimais/fisiologia , Camundongos , Receptores CXCR4/genética , Transdução de Sinais , Pele/lesões , Pele/patologia , Esferoides Celulares/fisiologiaRESUMO
Despite the long discrepancy over their definition, heterogeneity, and functions, mesenchymal stem cells (MSCs) have proved to be a key player in tissue repair and homeostasis. Generally, somatic tissue-derived MSCs (st-MSCs) are subject to quality variations related to donated samples and biosafety concern for transmission of potential pathogens from the donors. In contrast, human pluripotent stem cells (hPSCs) are unlimited in supply, clear in the biological background, and convenient for quality control, genetic modification, and scale-up production. We, and others, have shown that hPSCs can differentiate in two dimensions or three dimensions to MSCs (ps-MSCs) via embryonic (mesoderm and neural crest) or extraembryonic (trophoblast) cell types under serum-containing or xeno-free and defined conditions. Compared to st-MSCs, ps-MSCs appear less mature, proliferate faster, express lower levels of inflammatory cytokines, and respond less to traditional protocols for st-MSC differentiation to other cell types, especially adipocytes. Nevertheless, ps-MSCs are capable of immune modulation and treatment of an increasing number of animal disease models via mitochondria transfer, paracrine, exosomes, and direct differentiation, and can be potentially used as a universal and endless therapy for clinical application. This review summarizes the progress on ps-MSCs and discusses perspectives and challenges for their potential translation to the clinic. Stem Cells 2019;37:572-581.
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Terapia Baseada em Transplante de Células e Tecidos , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Células-Tronco Pluripotentes/transplante , Adipócitos/citologia , Proliferação de Células/genética , HumanosRESUMO
Mesenchymal stem cells (MSC) have been derived from a variety of tissues, and cultured either in animal serum-containing (SC) or serum-free (SF) media. We have previously derived MSC from human embryonic stem cells via an intermediate trophoblast step (named EMSC), which also have immunosuppressive and therapeutic effects on animal models of autoimmune disease. To promote the clinical application of this new source of MSC, we report here EMSC derived and cultured in a SF medium MesenCult (SF-EMSC) in comparison with a SC medium (SC-EMSC). SF-EMSC derived in MesenCult also expressed typical MSC markers CD73, CD90, and CD105, and manifested multipotency to differentiate to osteocytes, chondrocytes, and adipocytes. Comparably, CD105+ cells reached 90% about one week slower in the SF than SC conditions, and the proliferation rate was slightly faster for SF-EMSC than SC-EMSC at later passages. Both SF- and SC-EMSC responded similarly to the inflammatory stimulus IFNγ. However, the inflammatory cytokines IL-6 and IL-8 were expressed much less in SF-EMSC than SC-EMSC. Furthermore, knockdown of P16INK4A in both SF- and SC-EMSC reduced replicative senescence. Together, our results suggest that EMSC can be generated in a complete SF condition, and SF-EMSC are largely similar to SC-EMSC. However, it takes longer time to derive EMSC in the SF than SC conditions, and the SF-EMSC proliferate faster at later passages and produce less of the inflammatory cytokines IL-6 and IL-8 than SC-EMSC. This study provides important information for production of clinically applicable EMSC.
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Meios de Cultura Livres de Soro , Células-Tronco Embrionárias Humanas/citologia , Células-Tronco Mesenquimais/citologia , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Linhagem Celular , Células-Tronco Embrionárias Humanas/metabolismo , Humanos , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Células-Tronco Mesenquimais/metabolismoRESUMO
PURPOSE: We generated universal corneal epithelial cells (CEC) from human embryonic stem cells (hESC) by genetically removing human leukocyte antigens (HLA) class I from the cell surface. METHODS: The serum-free, growth factor-free, and defined medium E6 was used to differentiate hESC to CEC. Decellularized murine corneas were recellularized with hESC-derived CEC. Using CRISPR/Cas9, ß-2-microglobulin (B2M) was deleted in hESC to block the assembly of HLA class-I antigens on the cell surface to generate B2M -/- CEC. RESULTS: E6 alone was sufficient to allow hESC differentiation to CEC. A time-course analysis of the global gene expression of the differentiating cells indicates that the differentiation closely resembles the corneal development in vivo. The hESC-CEC were highly proliferative, and could form multilayer epithelium in decellularized murine cornea, retain its transparency, and form intact tight junctions on its surface. As reported before, B2M knockout led to the absence of HLA class-I on the cell surface of hESC and subsequently derived CEC following stimulation with inflammatory factors. Moreover, B2M -/- CEC, following transplantation into mouse eyes, caused less T-cell infiltration in the limbal region of the eye than the wild-type control. CONCLUSIONS: CEC can be derived from hESC via a novel and simple protocol free of any proteins, hESC-CEC seeded on decellularized animal cornea form tight junctions and allow light transmittance, and B2M -/- CEC are hypoimmunogenic both in vitro and in vivo. TRANSLATIONAL RELEVANCE: B2M -/- hESC-CEC can be an unlimited and universal therapy for corneal repair in patients of any HLA type.
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Mesenchymal stem cells (MSCs) have been broadly used as a therapy for autoimmune disease in both animal models and clinical trials. MSCs inhibit T effector cells and many other immune cells, while activating regulatory T cells, thus reducing the production of pro-inflammatory cytokines, including tumor necrosis factor (TNF), and repressing inflammation. TNF can modify the MSC effects via two TNF receptors, i.e., TNFR1 in general mediates pro-inflammatory effects and TNFR2 mediates anti-inflammatory effects. In the central nervous system, TNF signaling plays a dual role, which enhances inflammation via TNFR1 on immune cells while providing cytoprotection via TNFR2 on neural cells. In addition, the soluble form of TNFR1 and membrane-bound TNF also participate in the regulation to fine-tune the functions of target cells. Other factors that impact TNF signaling and MSC functions include the gender of the host, disease course, cytokine concentrations, and the length of treatment time. This review will introduce the fascinating progress in this aspect of research and discuss remaining questions and future perspectives.
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[This corrects the article DOI: 10.1155/2017/1948985.].
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Human embryonic stem cell (hESC) derived mesenchymal stem cells (EMSC) are efficacious in treating a series of autoimmune, inflammatory, and degenerative diseases in animal models. However, all the EMSC derivation methods reported so far rely on two-dimensional (2D) culture systems, which are inefficient, costive and difficult for large-scale production. HESC, as an unlimited source, can be successively propagated in spheroids. Here, we demonstrate that hESC spheroids can directly differentiate into MSC spheroids (EMSCSp) within 20 days in one vessel without passaging and the system is scalable to any desired size. EMSCSp can further differentiate into osteocytes and chondrocytes in spheres or demineralized bone matrix. EMSCSp also retains immune-modulatory effects in vitro and therapeutic effects on two mouse models of colitis after dissociation. Compared to EMSC differentiated in monolayer, EMSCSp-derived cells have faster proliferation and higher yield and develop less apoptosis and slower senescence. Thus, the 3D differentiation system allows simple, cost-effective, and scalable production of high-quality EMSC and subsequently bone and cartilage tissues for therapeutic application.