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  1. Generation of induced pluripotent stem cells by a polycistronic lentiviral vector in feeder- and serum- free defined culture
    Al Abbar A, Nordin N, Ghazalli N, Abdullah S
    Tissue Cell, 2018 Dec;55:13-24.
    PMID: 30503056 DOI: 10.1016/j.tice.2018.09.004
    Induced pluripotent stem cells (iPSCs) have great potentials for regenerative medicine. However, serious concerns such as the use of the viral-mediated reprogramming strategies and exposure of iPSCs to animal products from feeder cells and serum-containing medium have restricted the application of iPSCs in the clinics. Therefore, the generation of iPSCs with minimal viral integrations and in non-animal sourced and serum-free medium is necessary. In this report, a polycistronic lentiviral vector carrying Yamanaka's factors was used to reprogram mouse fibroblasts into iPSCs in feeder- and xeno-free culture environment. The generated iPSCs exhibited morphology and self-renewal properties of embryonic stem cells (ESCs), expression of specific pluripotent markers, and potentials to differentiate into the three-major distinct specialized germ layers in vitro. The iPSCs were also shown to have the potential to differentiate into neural precursor and neurons in culture, with greater than 95% expression of nestin, Pax6 and βIII-tubulin. This body of work describes an alternative method of generating iPSCs by using polycistronic lentiviral vector that may minimize the risks associated with viral vector-mediated reprogramming and animal derived products in the culture media.
    Matched MeSH terms: Embryonic Stem Cells/cytology*
  2. Lack of methylation on transgene leads to high level and persistent transgene expression in induced pluripotent stem cells
    Alhaji SY, Nordin N, Ngai SC, Al Abbar A, Mei L, Abdullah S
    Gene, 2020 Oct 20;758:144958.
    PMID: 32683073 DOI: 10.1016/j.gene.2020.144958
    Short-lived therapeutic gene expression in mammalian cells by DNA methylation is one of the major challenges in gene therapy. In this study, we assessed the implication of DNA methylation on the duration of GFP expression in mouse embryonic stem (ES) and mouse induced pluripotent stem (iPS) cells. The cells were transduced with lentivirus (LV) carrying green fluorescent protein (GFP) driven by either human elongation factor (EF1α) or cytomegalovirus (CMV) promoter. Transduced iPS cells exhibited higher percentage of GFP+ cells with persistent mean fluorescent intensity than transduced ES cells. Analysis on the integrated copy of transgene in the population of the transduced cells demonstrated similar copy number. However, significant increase in GFP intensity following 5-azaC treatment was observed in transduced ES cells only, suggesting the influence of DNA methylation in transgene silencing. Subsequent DNA methylation analysis showed that the promoter and the GFP region of the provirus in iPS cells had negligible methylation profile compared to transduced ES cells. Interestingly, sustained transgene expression was observed upon directed differentiation of transduced iPS cells towards CD34+ CD45+ cells. Hence, this study has shown that favourable transgene activity from lentiviral transduced iPS cells was due to the lack of methylation at the proviral regions.
    Matched MeSH terms: Embryonic Stem Cells/metabolism*
  3. Stem cells differentiation and probing their therapeutic applications in hematological disorders: a critical review
    Ali F, Taresh S, Al-Nuzaily M, Mok PL, Ismail A, Ahmad S
    Eur Rev Med Pharmacol Sci, 2016 Oct;20(20):4390-4400.
    PMID: 27831631
    Numerous lines of evidence support that bone marrow is a rich source of stem cells that can be used for research purposes and to treat some complex blood diseases and cancers. Stem cells are a potential source for regenerative medicine and tissue replacement after injury or disease, and mother cells that possess the capacity to become any type of cell in the body. They are cells without specific structure and characterized by their ability to self-renew or multiply while maintaining the potential to develop into other types of cells. Stem cells can normally become cells of the blood, heart, bones, skin, muscles or brain. Although, there are different sources of stem cells, all types of stem cells have the same capacity to develop into multiple types of cells. Stem cells are generally described as unspecialized cells with unlimited proliferation capacity that can divide (through mitosis) to produce more stem cells. Several types of adult stem cells have been characterized and can be cultured in vitro, including neural stem cells, hematopoietic stem cells, mesenchymal stem cells, cardiac stem cells and epithelial stem cells. They are valuable as research tools and might, in the future, be used to treat a wide range of diseases such as hematological hereditary diseases, Parkinson's disease, diabetes mellitus, heart disease and many other diseases. Currently, two types of stem cells have been identified based on their origins, namely embryonic stem cells and adult stem cells. Collectively, although many kinds of literature have been studying stem cell application in terms of clinical practice, stem cell-based therapy is still in its infancy stage.
    Matched MeSH terms: Embryonic Stem Cells
  4. Fulltext Stem cells research: therapeutic potentials and ethical issues from Islamic perspective
    Che Anuar Che Mohamad, Abdurezak Abdullahi Hashi
    International Medical Journal Malaysia, 2018;17(101):65-69.
    MyJurnal
    The advancement in human stem cell research has promised a viable alternative treatment for a range of ‘incurable diseases’ such as neurological diseases. To date, several studies have documented substantial evidences on the therapeutic properties of stem cells in promoting repair in different diseases including common neurological disorders i.e. ischaemic stroke and spinal cord injury. However, the progress of stem cell research has been surrounded by ethical issues which largely due to the usage of human embryos as one of the sources. These embryonic stem cells which originally derived from human embryo of aborted foetus or already existing human embryonic stem cells (hESCs) lines, has sparked an intense moral and religious argument among people of various faith, including Muslim community. From the therapeutic point of view, amongst the currently available stem cells, hESCs show the greatest potential for the broadest range of cell replacement therapies and are regarded as the most commercially viable. This review focuses on the major ethical issues, particularly to Muslim community, related to human embryonic stem cells research with special emphasis on the moral status of the embryo and the beginning of life according to the Islamic ethics and rulings. In this paper, we also discuss some ethical positions towards embryonic stem cell research in the Islamic world, including official regulations existing in some Muslim countries. We examine the justification and the necessity on the usage of hESCs following the newly discovered Induced Pluripotent Stem Cells (IPSCs) in the laboratory. In addition, we supplement the discussions with the general views and positions from the other two Abrahamic religions i.e. Christianity and Judaism.
    Matched MeSH terms: Human Embryonic Stem Cells; Embryonic Stem Cells
  5. Xeno-free and feeder-free culture and differentiation of human embryonic stem cells on recombinant vitronectin-grafted hydrogels
    Chen LH, Sung TC, Lee HH, Higuchi A, Su HC, Lin KJ, et al.
    Biomater Sci, 2019 Aug 14.
    PMID: 31411209 DOI: 10.1039/c9bm00418a
    Recombinant vitronectin-grafted hydrogels were developed by adjusting surface charge of the hydrogels with grafting of poly-l-lysine for optimal culture of human embryonic stem cells (hESCs) under xeno- and feeder-free culture conditions, with elasticity regulated by crosslinking time (10-30 kPa), in contrast to conventional recombinant vitronectin coating dishes, which have a fixed stiff surface (3 GPa). hESCs proliferated on the hydrogels for over 10 passages and differentiated into the cells derived from three germ layers indicating the maintenance of pluripotency. hESCs on the hydrogels differentiated into cardiomyocytes under xeno-free culture conditions with much higher efficiency (80% of cTnT+ cells) than those on conventional recombinant vitronectin or Matrigel-coating dishes just only after 12 days of induction. It is important to have an optimal design of cell culture biomaterials where biological cues (recombinant vitronectin) and physical cues (optimal elasticity) are combined for high differentiation of hESCs into specific cell lineages, such as cardiomyocytes, under xeno-free and feeder-free culture conditions.
    Matched MeSH terms: Human Embryonic Stem Cells
  6. Fulltext Xeno-free culture of human pluripotent stem cells on oligopeptide-grafted hydrogels with various molecular designs
    Chen YM, Chen LH, Li MP, Li HF, Higuchi A, Kumar SS, et al.
    Sci Rep, 2017 03 23;7:45146.
    PMID: 28332572 DOI: 10.1038/srep45146
    Establishing cultures of human embryonic (ES) and induced pluripotent (iPS) stem cells in xeno-free conditions is essential for producing clinical-grade cells. Development of cell culture biomaterials for human ES and iPS cells is critical for this purpose. We designed several structures of oligopeptide-grafted poly (vinyl alcohol-co-itaconic acid) hydrogels with optimal elasticity, and prepared them in formations of single chain, single chain with joint segment, dual chain with joint segment, and branched-type chain. Oligopeptide sequences were selected from integrin- and glycosaminoglycan-binding domains of the extracellular matrix. The hydrogels grafted with vitronectin-derived oligopeptides having a joint segment or a dual chain, which has a storage modulus of 25 kPa, supported the long-term culture of human ES and iPS cells for over 10 passages. The dual chain and/or joint segment with cell adhesion molecules on the hydrogels facilitated the proliferation and pluripotency of human ES and iPS cells.
    Matched MeSH terms: Embryonic Stem Cells/cytology; Embryonic Stem Cells/metabolism
  7. Fulltext Heterogeneity of osteosarcoma cell lines led to variable responses in reprogramming
    Choong PF, Teh HX, Teoh HK, Ong HK, Choo KB, Sugii S, et al.
    Int J Med Sci, 2014;11(11):1154-60.
    PMID: 25170299 DOI: 10.7150/ijms.8281
    Four osteosarcoma cell lines, Saos-2, MG-63, G-292 and U-2 OS, were reprogrammed to pluripotent state using Yamanaka factors retroviral transduction method. Embryonic stem cell (ESC)-like clusters started to appear between 15 to 20 days post transduction. Morphology of the colonies resembled that of ESC colonies with defined border and tightly-packed cells. The reprogrammed sarcomas expressed alkaline phosphatase and pluripotency markers, OCT4, SSEA4, TRA-1-60 and TRA-1-81, as in ESC up to Passage 15. All reprogrammed sarcomas could form embryoid body-like spheres when cultured in suspension in a low attachment dish for up to 10 days. Further testing on the directed differentiation capacity of the reprogrammed sarcomas showed all four reprogrammed sarcoma lines could differentiate into adipocytes while reprogrammed Saos-2-REP, MG-63-REP and G-292-REP could differentiate into osteocytes. Among the 4 osteosarcoma cell lines, U-2 OS reported the highest transduction efficiency but recorded the lowest reprogramming stability under long term culture. Thus, there may be intrinsic differences governing the variable responses of osteosarcoma cell lines towards reprogramming and long term culture effect of the reprogrammed cells. This is a first report to associate intrinsic factors in different osteosarcoma cell lines with variable reprogramming responses and effects on the reprogrammed cells after prolonged culture.
    Matched MeSH terms: Embryonic Stem Cells/cytology; Embryonic Stem Cells/metabolism
  8. Human chorion-derived stem cells: changes in stem cell properties during serial passage
    Fariha MM, Chua KH, Tan GC, Tan AE, Hayati AR
    Cytotherapy, 2011 May;13(5):582-93.
    PMID: 21231803 DOI: 10.3109/14653249.2010.549121
    BACKGROUND AIMS: Fetal membrane from human placenta tissue has been described as a potential source of stem cells. Despite abundant literature on amnion stem cells, there are limited studies on the stem cell properties of chorion-derived stem cells.

    METHODS: The main aim was to determine the stemness properties of serial-passaged human chorion-derived stem cells (hCDSC). Quantitative polymerase chain reaction (PCR) was performed to reveal the following stemness gene expression in serial-passaged hCDSC: Oct-4, Sox-2, FGF-4, Rex-1, TERT, Nanog (3), Nestin, FZD-9, ABCG-2 and BST-1. Cell growth rate was evaluated from passage (P) 1 until P5. The colony-forming unit-fibroblast (CFU-F) frequency of P3 and P5 cells and multilineage differentiation potential of P5 cells were determined. The immunophenotype of hCDSC was compared using the surface markers CD9, CD31, CD34, CD44, CD45, CD73, CD90, CD117, HLA-ABC and HLA-DR, -DP and -DQ. Immunostaining for trophoblast markers was done on P0, P1, P3 and P5 cells to detect the contamination of trophoblasts in culture, while chromosomal abnormality was screened by cytogenetic analysis of P5 cells.

    RESULTS: The surface markers for mesenchymal lineage in hCDSC were more highly expressed at P5 compared with P3 and P0, indicating the increased purity of these stem cells after serial passage. Indeed, all the stemness genes except TERT were expressed at P1, P3 and P5 hCDSC. Furthermore, human chorion contained high clonogenic precursors with a 1:30 CFU-F frequency. Successful adipogenic, chondrogenic and osteogenic differentiation demonstrated the multilineage potential of hCDSC. The karyotyping analysis showed hCDSC maintained chromosomal stability after serial passage.

    CONCLUSIONS: hCDSC retain multipotent potential even at later passages, hence are a promising source for cell therapy in the future.

    Matched MeSH terms: Embryonic Stem Cells/classification; Embryonic Stem Cells/cytology*; Embryonic Stem Cells/metabolism
  9. A plethora of human pluripotent stem cells
    Gao L, Thilakavathy K, Nordin N
    Cell Biol Int, 2013 Sep;37(9):875-87.
    PMID: 23619972 DOI: 10.1002/cbin.10120
    At the early stages of mammalian development, a number of developmentally plastic cells appear that possess the ability to give rise to all of the differentiated cell types normally derived from the three primary germ layers - unique character known as pluripotency. To date, embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) have been shown to be truly pluripotent. However, recent studies have revealed a variety of other cells that demonstrate pluripotentiality, including very small embryonic-like stem cells (VSELs), amniotic fluid stem cells (AFSCs), marrow-isolated adult multilineage inducible cells (MIAMI) and multipotent adult precursor cells (MAPCs). This review summarises key features of these six kinds of pluripotent and potentially pluripotent stem cells (ESCs, iPSCs, VSELs, AFSCs, MIAMI and MAPCs) and the evidence for their pluripotency properties.
    Matched MeSH terms: Embryonic Stem Cells/cytology*; Embryonic Stem Cells/metabolism
  10. Fulltext Glucocorticoid Signaling Enhances Expression of Glucose-Sensing Molecules in Immature Pancreatic Beta-Like Cells Derived from Murine Embryonic Stem Cells In Vitro
    Ghazalli N, Wu X, Walker S, Trieu N, Hsin LY, Choe J, et al.
    Stem Cells Dev, 2018 07 01;27(13):898-909.
    PMID: 29717618 DOI: 10.1089/scd.2017.0160
    Pluripotent stem cells may serve as an alternative source of beta-like cells for replacement therapy of type 1 diabetes; however, the beta-like cells generated in many differentiation protocols are immature. The maturation of endogenous beta cells involves an increase in insulin expression starting in late gestation and a gradual acquisition of the abilities to sense glucose and secrete insulin by week 2 after birth in mice; however, what molecules regulate these maturation processes are incompletely known. In this study, we aim to identify small molecules that affect immature beta cells. A cell-based assay, using pancreatic beta-like cells derived from murine embryonic stem (ES) cells harboring a transgene containing an insulin 1-promoter driven enhanced green fluorescent protein reporter, was used to screen a compound library (NIH Clinical Collection-003). Cortisone, a glucocorticoid, was among five positive hit compounds. Quantitative reverse transcription-polymerase chain reaction analysis revealed that glucocorticoids enhance the gene expression of not only insulin 1 but also glucose transporter-2 (Glut2; Slc2a2) and glucokinase (Gck), two molecules important for glucose sensing. Mifepristone, a pharmacological inhibitor of glucocorticoid receptor (GR) signaling, reduced the effects of glucocorticoids on Glut2 and Gck expression. The effects of glucocorticoids on ES-derived cells were further validated in immature primary islets. Isolated islets from 1-week-old mice had an increased Glut2 and Gck expression in response to a 4-day treatment of exogenous hydrocortisone in vitro. Gene deletion of GR in beta cells using rat insulin 2 promoter-driven Cre crossed with GRflox/flox mice resulted in a reduced gene expression of Glut2, but not Gck, and an abrogation of insulin secretion when islets were incubated in 0.5 mM d-glucose and stimulated by 17 mM d-glucose in vitro. These results demonstrate that glucocorticoids positively regulate glucose sensors in immature murine beta-like cells.
    Matched MeSH terms: Embryonic Stem Cells/metabolism*
  11. Fulltext A concise review on epigenetic regulation: insight into molecular mechanisms
    Golbabapour S, Abdulla MA, Hajrezaei M
    Int J Mol Sci, 2011;12(12):8661-94.
    PMID: 22272098 DOI: 10.3390/ijms12128661
    Epigenetic mechanisms are responsible for the regulation of transcription of imprinted genes and those that induce a totipotent state. Starting just after fertilization, DNA methylation pattern undergoes establishment, reestablishment and maintenance. These modifications are important for normal embryo and placental developments. Throughout life and passing to the next generation, epigenetic events establish, maintain, erase and reestablish. In the context of differentiated cell reprogramming, demethylation and activation of genes whose expressions contribute to the pluripotent state is the crux of the matter. In this review, firstly, regulatory epigenetic mechanisms related to somatic cell nuclear transfer (SCNT) reprogramming are discussed, followed by embryonic development, and placental epigenetic issues.
    Matched MeSH terms: Embryonic Stem Cells/cytology; Embryonic Stem Cells/metabolism*
  12. Decellularized Matrix Derived from Neural Differentiation of Embryonic Stem Cells Enhances the Neurogenic Potential of Dental Follicle Stem Cells
    Heng BC, Gong T, Wang S, Lim LW, Wu W, Zhang C
    J Endod, 2017 Mar;43(3):409-416.
    PMID: 28231979 DOI: 10.1016/j.joen.2016.10.033
    INTRODUCTION: Dental follicle stem cells (DFSCs) possess neurogenic potential because they originate from the embryonic neural crest. This study investigated whether neural differentiation of DFSCs can be enhanced by culture on decellularized matrix substrata (NSC-DECM) derived from neurogenesis of human embryonic stem cells (hESCs).

    METHODS: The hESCs were differentiated into neural stem cells (NSCs), and NSC-DECM was extracted from confluent monolayers of NSCs through treatment with deionized water. DFSCs seeded on NSC-DECM, Geltrex, and tissue culture polystyrene (TCPS) were subjected to neural induction during a period of 21 days. Expression of early/intermediate (Musashi1, PAX6, NSE, and βIII-tubulin) and mature/late (NGN2, NeuN, NFM, and MASH1) neural markers by DFSCs was analyzed at the 7-, 14-, and 21-day time points with quantitative real-time polymerase chain reaction. Immunocytochemistry for detection of βIII-tubulin, PAX6, and NGN2 expression by DFSCs on day 7 of neural induction was also carried out.

    RESULTS: Quantitative RT-PCR showed that expression of PAX6, Musashi1, βIII-tubulin, NSE, NGN2, and NFM by DFSCs was enhanced on NSC-DECM versus either the Geltrex or TCPS groups. Immunocytochemistry showed that DFSCs in the NSC-DECM group displayed more intense staining for βIII-tubulin, PAX6, and NGN2 expression, together with more neurite outgrowths and elongated morphology, as compared with either Geltrex or TCPS.

    CONCLUSIONS: DECM derived from neurogenesis of hESCs can enhance the neurogenic potential of DFSCs.

    Matched MeSH terms: Embryonic Stem Cells/cytology*
  13. Thermoresponsive surfaces designed for the proliferation and differentiation of human pluripotent stem cells
    Higuchi A, Hirad AH, Kumar SS, Munusamy MA, Alarfaj AA
    Acta Biomater, 2020 10 15;116:162-173.
    PMID: 32911107 DOI: 10.1016/j.actbio.2020.09.010
    Thermoresponsive surfaces enable the detachment of cells or cell sheets by decreasing the temperature of the surface when harvesting the cells. However, human pluripotent stem cells (hPSCs), such as embryonic stem cells and induced pluripotent stem cells, cannot be directly cultured on a thermoresponsive surface; hPSCs need a specific extracellular matrix to bind to the integrin receptors on their surfaces. We prepared a thermoresponsive surface by using poly(N-isopropylacrylamide-co-butylacrylate) and recombinant vitronectin to provide an optimal coating concentration for the hPSC culture. hPSCs can be cultured on the same thermoresponsive surface for 5 passages by partial detachment of the cells from the surface by decreasing the temperature for 30 min; then, the remaining hPSCs were subsequently cultured on the same dishes following the addition of new cultivation media. The detached cells, even after continual culture for five passages, showed high pluripotency, the ability to differentiate into cells derived from the 3 germ layers and the ability to undergo cardiac differentiation.
    Matched MeSH terms: Embryonic Stem Cells
  14. Fulltext Derivation and long-term culture of an embryonic stem cell-like line from zebrafish blastomeres under feeder-free condition
    Ho SY, Goh CW, Gan JY, Lee YS, Lam MK, Hong N, et al.
    Zebrafish, 2014 Oct;11(5):407-20.
    PMID: 24967707 DOI: 10.1089/zeb.2013.0879
    Existing zebrafish embryonic stem (ES) cell lines are derived and maintained using feeder layers. We describe here the derivation and long-term culture of an ES cell-like line derived from zebrafish blastomeres without the use of feeder cells. This line, designated as ZES1, has been maintained for more than 800 days in defined Dulbecco's modified Eagle's medium supplemented with fetal bovine serum, zebrafish embryo extract, trout serum, and human basic fibroblast growth factor. ZES1 cells possessed a morphology typical of ES cells, being round or polygonal in shape with a large nucleus and sparse cytoplasm and were mostly diploid. The cells formed individual colonies consisting of tightly packed cells that stained positively for alkaline phosphatase. ZES1 cells also formed embryoid bodies when transferred onto uncoated wells. The pluripotent nature of ZES1 cells was confirmed when they could be induced to differentiate in vitro into several cell types, through low- or high-density culture conditions. Treatment with retinoic acid also induced the differentiation of ZES1 cells into primarily neuronal cells. Using immunostaining and real-time polymerase chain reaction, we showed that Sox2, a known pluripotent marker in mammalian ES cells, was also present in ZES1 cells. Chimera experiments revealed that fluorescent-labeled ZES1 cells microinjected into zebrafish blastulas participated in the formation of all three germ layers. Using GFP-labeled ZES1 cells, chimera germline transmission was also demonstrated at the F1 generation. In conclusion, ZES1 cells possess both in vitro and in vivo pluripotency characteristics, indicating that nonmammalian ES cells can be readily derived and maintained for a long term under feeder-free culture conditions.
    Matched MeSH terms: Embryonic Stem Cells/cytology; Embryonic Stem Cells/metabolism*
  15. Fulltext Frequent co-expression of miRNA-5p and -3p species and cross-targeting in induced pluripotent stem cells
    Huang CJ, Nguyen PN, Choo KB, Sugii S, Wee K, Cheong SK, et al.
    Int J Med Sci, 2014;11(8):824-33.
    PMID: 24936146 DOI: 10.7150/ijms.8358
    A miRNA precursor generally gives rise to one major miRNA species derived from the 5' arm, and are called miRNA-5p. However, more recent studies have shown co-expression of miRNA-5p and -3p, albeit in different concentrations, in cancer cells targeting different sets of transcripts. Co-expression and regulation of the -5p and -3p miRNA species in stem cells, particularly in the reprogramming process, have not been studied.
    Matched MeSH terms: Embryonic Stem Cells/metabolism*
  16. Treatment viability of stem cells in ophthalmology
    Jeganathan VS, Palanisamy M
    Curr Opin Ophthalmol, 2010 May;21(3):213-7.
    PMID: 20393292 DOI: 10.1097/ICU.0b013e32833867ad
    Adult ocular stem cells have the potential to restore vision in patients previously deemed incurable. This review summarizes strides in stem cell research and stumbling blocks that must be overcome to enable treatment viability in ophthalmology.
    Matched MeSH terms: Embryonic Stem Cells*
  17. Microfluidic-Nanofiber Hybrid Array for Screening of Cellular Microenvironments
    Kamei KI, Mashimo Y, Yoshioka M, Tokunaga Y, Fockenberg C, Terada S, et al.
    Small, 2017 05;13(18).
    PMID: 28272774 DOI: 10.1002/smll.201603104
    Cellular microenvironments are generally sophisticated, but crucial for regulating the functions of human pluripotent stem cells (hPSCs). Despite tremendous effort in this field, the correlation between the environmental factors-especially the extracellular matrix and soluble cell factors-and the desired cellular functions remains largely unknown because of the lack of appropriate tools to recapitulate in vivo conditions and/or simultaneously evaluate the interplay of different environment factors. Here, a combinatorial platform is developed with integrated microfluidic channels and nanofibers, associated with a method of high-content single-cell analysis, to study the effects of environmental factors on stem cell phenotype. Particular attention is paid to the dependence of hPSC short-term self-renewal on the density and composition of extracellular matrices and initial cell seeding densities. Thus, this combinatorial approach provides insights into the underlying chemical and physical mechanisms that govern stem cell fate decisions.
    Matched MeSH terms: Embryonic Stem Cells/cytology*
  18. Autogenic feeder free system from differentiated mesenchymal progenitor cells, maintains pluripotency of the MEL-1 human embryonic stem cells
    Khoo TS, Hamidah Hussin N, Then SM, Jamal R
    Differentiation, 2013 Feb;85(3):110-8.
    PMID: 23722082 DOI: 10.1016/j.diff.2013.01.004
    Human embryonic stem cells (hESc) are known for its pluripotency and self renewal capability, thus possess great potential in regenerative medicine. However, the lack of suitable xenofree extracellular matrix substrate inhibits further applications or the use of hESc in cell-based therapy. In this study, we described a new differentiation method, which generates a homogeneous population of mesenchymal progenitor cells (hESc-MPC) from hESc via epithelial-mesenchymal transition. The extracellular matrix (ECM) proteins from hESc-MPC had in turn supported the undifferentiated expansion of hESc. Immunocytochemistry and flow cytometry characterization of hESc-MPC revealed the presence of early mesenchymal markers. Tandem mass spectometry analysis of ECM produced by hESc-MPC revealed the presence of a mixture of extracellular proteins which includes tenascin C, fibronectin, and vitronectin. The pluripotency of hESc (MEL-1) cultured on the ECM was maintained as shown by the expression of pluripotent genes (FoxD3, Oct-4, Tdgf1, Sox-2, Nanog, hTERT, Rex1), protein markers (SSEA-3, SSEA-4, TRA-1-81, TRA-1-60, Oct-4) and the ability to differentiate into cells representative of ectoderm, endoderm and mesoderm. In summary, we have established a xeno-free autogenic feeder free system to support undifferentiated expansion of hESc, which could be of clinical relevance.
    Matched MeSH terms: Embryonic Stem Cells/cytology*
  19. Characteristics and clinical applications of Wharton's jelly-derived mesenchymal stromal cells
    Liau LL, Ruszymah BHI, Ng MH, Law JX
    Curr Res Transl Med, 2020 01;68(1):5-16.
    PMID: 31543433 DOI: 10.1016/j.retram.2019.09.001
    Mesenchymal stromal cells (MSCs) are widely used in the clinic because they involve fewer ethical issues and safety concerns compared to other stem cells such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). MSCs derived from umbilical cord Wharton's jelly (WJ-MSCs) have excellent proliferative potential and a faster growth rate and can retain their multipotency for more passages in vitro compared to adult MSCs from bone marrow or adipose tissue. WJ-MSCs are used clinically for repairing tissue injuries of the spinal cord, liver and heart with the aim of regenerating tissue. On the other hand, WJ-MSCs are also used clinically to ameliorate immune-mediated diseases based on their ability to modulate immune responses. In the field of tissue engineering, WJ-MSCs capable of differentiating into multiple cell lineages have been used to produce a variety of engineered tissues in vitro that can then be transplanted in vivo. This review discusses the characteristics of WJ-MSCs, the differences between WJ-MSCs and adult MSCs, clinical studies involving WJ-MSCs and future perspectives of WJ-MSC research and clinical applications. To summarize, WJ-MSCs have shown promise in treating a variety of diseases clinically. However, most clinical trials/studies reported thus far are relatively smaller in scale. The collected evidence is insufficient to support the routine use of WJ-MSC therapy in the clinic. Thus, rigorous clinical trials are needed in the future to obtain more information on WJ-MSC therapy safety and efficacy.
    Matched MeSH terms: Embryonic Stem Cells/cytology
  20. Fulltext MicroRNA-124a inhibits endoderm lineage commitment by targeting Sox17 and Gata6 in mouse embryonic stem cells
    Liew LC, Gailhouste L, Tan GC, Yamamoto Y, Takeshita F, Nakagama H, et al.
    Stem Cells, 2020 04;38(4):504-515.
    PMID: 31828873 DOI: 10.1002/stem.3136
    The role of microRNAs (miRNAs) during mouse early development, especially in endoderm germ layer formation, is largely unknown. Here, via miRNA profiling during endoderm differentiation, we discovered that miR-124a negatively regulates endoderm lineage commitment in mouse embryonic stem cells (mESCs). To further investigate the functional role of miR-124a in early stages of differentiation, transfection of embryoid bodies with miR-124a mimic was performed. We showed that overexpression of miR-124a inhibits endoderm differentiation in vitro through targeting the 3'-untranslated region (UTR) of Sox17 and Gata6, revealing the existence of interplay between miR-124a and the Sox17/Gata6 transcription factors in hepato-specific gene regulation. In addition, we presented a feasible in vivo system that utilizes teratoma and gene expression profiling from microarray to quantitatively evaluate the functional role of miRNA in lineage specification. We demonstrated that ectopic expression of miR-124a in teratomas by intratumor delivery of miR-124a mimic and Atelocollagen, significantly suppressed endoderm and mesoderm lineage differentiation while augmenting the differentiation into ectoderm lineage. Collectively, our findings suggest that miR-124a plays a significant role in mESCs lineage commitment.
    Matched MeSH terms: Mouse Embryonic Stem Cells/metabolism*
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