Established a Preimplantation Genetic Testing-derived and Xeno-free Human Embryonic Stem Cell Line / 中山大学学报(医学科学版)

@#【Objective】 A human embryonic stem cell line derived from Preimplantation genetic testing （PGT） embryos was established in a xeno- free stem cell culture system to provide disease models for medical research. 【Methods】The xeno-free culture system using xeno-free human foreskin fibroblast feeder layers（XF-HFF）mixed with commercially available chemically-defined medium（CDM）was assessed. In the culture system，a new hESC cell line was established using discarded embryos derived from PGT in patients with chromosomal balance translocation.【Results】The new availabled stem cell line was successfully cultured in the xeno-free culture system for a long time（> 45 passages）. The karyotype analysis revealed that the new line kept the same karyotype over 45 passages. Moreover，the expression of pluripotent markers was detected by fluorescent immunostaining including SSEA- 3，SSEA- 4，SSEA- 1，TRA- 1- 60， and TRA-1-81. RT-PCR analysis showed that the stem cell markers were present in hESC grown on XF-HFF-CDM. In addition，the teratoma formation analysis demonstrated that the cells cultured in XF-HFF/CDM maintained their pluripotency in vivo.【Conclusions】Our study may provide the possibility to establish embryonic stem cells with certain pathogenic genes，which could be applied for clinical research and treatment.

Optimal Xeno-free Culture Condition for Clinical Grade Stem Cells from Human Exfoliated Deciduous Teeth

BACKGROUND AND OBJECTIVES: Stem cells from human exfoliated deciduous teeth (SHED) are a promising clinical resource for various tissue defects, including lumbar spondylosis, neural compression, and cleft palate. Use of media containing animal-derived serum carries potential risk of infectious diseases and unwanted immunogenicity. To increase the potential utility of SHED for clinical application, SHED was adapted to xeno-free conditions. METHODS: Define xeno-free culture media were compared with the conventional serum containing media in the culture of SHED. Cultured SHED in different media were further characterized through proliferative capacities, cellular phenotype, and differentiation potential. RESULTS: Selected xeno-free media were capable of supporting the growth of SHED. MSCGM-CD Bulletkit medium greatly increased the number and proliferate capacity of colony-forming unit-fibroblast than SHED cultured in other media. In addition, the characteristic surface markers expression and multipotent differentiation potential of SHED in the MSCGM-CD Bulletkit medium were comparable to those observed with serum-containing medium. CONCLUSIONS: The xeno-free medium described herein has the potential to be further used for the safe expansion and to determine efficient way to produce clinical grade dental stem cells for therapeutic applications.

Venous Blood Derivatives as FBS-Substitutes for Mesenchymal Stem Cells: A Systematic Scoping Review

Abstract Although the biological properties of mesenchymal stem cells (MSC) are well-characterized in vitro, MSC clinical application is still far away to be achieved, mainly due to the need of xenogeneic substances for cell expansion, such as fetal bovine serum (FBS). FBS presents risks regarding pathogens transmissions and internalization of animal's proteins, which can unleash antigenic responses in patients after MSC implantation. A wide range of venous blood derivatives (VBD) has been reported as FBS substitutes showing promising results. Thus, the aim of this study was to conduct a systematic scoping review to analyze whether VBD are effective FBS substitutes for MSC ex vivo expansion. The search was performed in SciVerse ScopusTM, PubMed, Web of ScienceTM, BIREME, Cochrane library up to January 2016. The keywords were selected using MeSH and entry terms. Two independent reviewers scrutinized the records obtained considering specific inclusion criteria. The included studies were evaluated in accordance with a modified Arksey and O' Malley's framework. From 184 found studies, 90 were included. Bone marrow mesenchymal stem cells (BMMSC) were presented in most of these studies. Overall, VBD allowed for either, maintenance of MCS's fibroblast-like morphology, high proliferation, high colony-formation ability and maintenance of multipotency. Besides. MSC expanded in VBD supplements presented higher mitogen activity than FBS. VBD seems to be excellent xeno-free serum for ex vivo expansion of mesenchymal stem cells. However, an accentuated heterogeneity was observed between the carried out protocols for VBD isolation did not allowing for direct comparisons between the included studies.

Resumo Embora as propriedades biológicas das células-tronco mesenquimais (MSC) sejam bem caracterizadas in vitro, a aplicação clínica das MSC ainda está longe de ser alcançada, principalmente devido à necessidade de substâncias xenogênicas para expansão celular, como o soro fetal bovino (FBS). O FBS apresenta riscos quanto às transmissões de patógenos e à internalização de proteínas animais, o que pode desencadear respostas antigênicas em pacientes após a implantação das MSC. Uma vasta gama de derivados do sangue venoso (VBD) têm sido relatada como substitutos do FBS mostrando resultados promissores. Assim, o objetivo deste estudo foi conduzir uma revisão de escopo sistemática para analisar se VBD poderiam ser substitutos do FBS eficazes para expansão das MSC em condições ex vivo. A pesquisa foi realizada no SciVerse Scopus, PubMed, Web of Science, BIREME e biblioteca Cochrane até janeiro de 2016. As palavras-chave foram selecionadas usando MeSH e entre termos. Dois revisores independentes examinaram os registros obtidos considerando critérios de inclusão específicos. Os estudos incluídos foram avaliados de acordo com uma estrutura modificada de Arksey e O 'Malley. Dos 184 estudos encontrados, 90 foram incluídos. As células-tronco da medula óssea (BMMSC) foram utilizadas na maior parte destes estudos. Em geral, o VBD permitiu tanto a manutenção da morfologia semelhante a fibroblastos das MCS, alta proliferação, alta capacidade de formação de colônias e manutenção de multipotêncialidade. Além disso, as MSC expandidas em suplementos derivados do sangue venoso apresentaram uma maior atividade mitogênica do que as expandidas em FBS. Os VBD parecem ser excelentes soro livres de agentes xenogênicos para expansão ex vivo de MSC. Entretanto, observou-se uma heterogeneidade acentuada entre os protocolos realizados para o isolamento VBD, não permitindo assim comparações diretas entre os estudos incluídos.

Generation of hematopoietic stem cells from human embryonic stem cells using a defined, stepwise, serum-free, and serum replacement-free monolayer culture method

BACKGROUND: Embryonic stem cells (ESCs) can be expanded infinitely in vitro and have the potential to differentiate into hematopoietic stem cells (HSCs); thus, they are considered a useful source of cells for HSC production. Although several technical in vitro methods for engineering HSCs from pluripotent stem cells have been developed, clinical application of HSCs engineered from pluripotent stem cells is restricted because of the possibility of xenogeneic contamination resulting from the use of murine materials. METHODS: Human ESCs (CHA-hES15) were cultured on growth factor-reduced Matrigel-coated dishes in the mTeSR1 serum-free medium. When the cells were 70% confluent, we initiated HSC differentiation by three methods involving (1) knockout serum replacement (KSR), cytokines, TGFb1, EPO, and FLT3L; (2) KSR, cytokines, and bFGF; or (3) cytokines and bFGF. RESULTS: Among the three differentiation methods, the minimal number of cytokines without KSR resulted in the greatest production of HSCs. The optimized method resulted in a higher proportion of CD34⁺CD43⁺ hematopoietic progenitor cells (HPCs) and CD34⁺CD45⁺ HPCs compared to the other methods. In addition, the HSCs showed the potential to differentiate into multiple lineages of hematopoietic cells in vitro. CONCLUSION: In this study, we optimized a two-step, serum-free, animal protein-free, KSR-free, feeder-free, chemically defined monolayer culture method for generation of HSCs and hematopoietic stem and progenitor cells (HSPCs) from human ESCs.

Clean-Up Human Embryonic Stem Cell Lines Using Humanized Culture Condition

Human embryonic stem cell (hESC) culture system has been changing culture conditions from conventional to xeno-free for therapeutic cell applications, and N-glycolylneuraminic acid (Neu5Gc) could be a useful indicator of xenogeneic contaminations in hESCs because human cells can no longer produce it genetically. We set up the humanized culture condition using commercially available humanized materials and two different adaptation methods: sequential or direct. SNUhES4 and H1 hESC lines, previously established in conventional culture conditions, were maintained using the humanized culture condition and were examined for the presence of Neu5Gc. The hESCs showed the same morphology and character as those of the conventional culture condition. Moreover, they were negative for Neu5Gc within two passages without loss of pluripotency. This study suggested that this method can effectively cleanse previously established hESC lines, bringing them one step closer to being clinical-grade hESCs.

Rapid differentiation of human ESCs into RPE cells by defined xeno-free culture system / 中华实验眼科杂志

Background Subretinal transplantation of retinal pigment epithelium (RPE) cells for the treatment of age-related macular degeneration (AMD) have accelerated the drive to develop xeno-free cultivation system that support the rapid differentiation of human embryonic stem cells (hESCs) into ES-RPE cells.Objective This study was to report a modified xeno-free culture system and method for accelerating derivation of hESCs to differentiate into RPE cells.Methods This study was approved by Ethic Committee of Zhongshan Ophthalmic Center.HESC H1 line was cloned and cuhured in Vitronectin XFTM-coated 6-well dish with xenogenetic-free medium.Cells were cultured in 50 ng/ml noggin,10 ng/ml DKK-1 and 10 ng/ml insulin like growth factor-1 (IGF-1) medium for 2 days,and then the concentration of noggin was decreased to 10 ng/ml and 5 ng/ml basic fibroblast growth factor (bFGF) and cultured for the following 2 days.Sequentially,noggin and bFGF were removed and cultured for 2 days.Finally,1 μmol/L CHIR99021 was added in medium for 6 days.Morphological changes in the progress of ESCs differentiation into RPE were observed by Living Cell Imaging System.The expression of Mitf and RPE65,RPE cellsspecific markers,in the cells were detected by immunofluorescence technique,and the relative expression levels of RPE cells-specific marker mRNA were assayed using real time fluorescent quantitation PCR.Results Polygonalshape monolayer cells which contained pigments were initially observed at day 14 after cultured with the cobblestonelike arrangement.Mitf and RPE65 were strongly expressed in the hES-derived RPE cells 35 days after induced,showing red fluorescence,and the cells presented hexagonal shape at cultured day 60 with numerous pigment granules in cytoplasm.Compared with before differentiation,the expression levels of Mitf mRNA in hES-RPE cells increased by (3.43±2.77) folds and (8.91 ± 2.83) folds,and the expression levels of RPE65 mRNA increased by (14.60 ± 3.94) folds and (87.16 ±9.32) folds at day 7 and day 14 after differentiation,respectively (all at P＜0.05).Conclusions A defined xeno-free culture system is successfully established by adding niacinamide,DKK-l,noggin,IGF-1 and CHIR99021 in xeno-free medium,and this system can accelerate the derivation and differentiation of hESCs into RPE-like cells.