Displaying publications 221 - 240 of 412 in total

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  1. Rapidly increasing liver progenitor cell numbers in human regenerating liver after portal vein ligation and liver partition
    Lin KH, Hsu HT, Teng TH, Lin PY, Ko CJ, Hsieh CE, et al.
    Malays J Pathol, 2017 Dec;39(3):289-291.
    PMID: 29279592
    BACKGROUND: Liver regeneration is dependent on the proliferation of hepatocytes. Hepatic progenitor cells are intra-hepatic precursor cells capable of differentiating into hepatocytes or biliary cells. Although liver progenitor cell proliferation during the regenerative process has been observed in animal models of severe liver injury, it has never been observed in vivo in humans because it is unethical to take multiple biopsy specimens for the purpose of studying the proliferation of liver progenitor cells and the roles they play in liver regeneration. Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a staged procedure for inducing remnant liver hypertrophy so that major hepatectomy can be performed safely. This staged procedure allows for liver biopsy specimens to be taken before and after the liver begins to regenerate.

    CASE PRESENTATION: The liver progenitor cell proliferation is observed in a patient undergoing ALPPS for a metastatic hepatic tumour. Liver biopsy is acquired before and after ALPPS for the calculation of average number of liver progenitor cell under high magnification examination by stain of immunomarkers. This is the first in vivo evidence of growing liver progenitor cells demonstrated in a regenerating human liver.

    Matched MeSH terms: Stem Cells/cytology*
  2. Genetic, epigenetic, and lineage-directed mechanisms in benzene-induced malignancies and hematotoxicity targeting hematopoietic stem cells niche
    Dewi R, Hamid ZA, Rajab NF, Shuib S, Razak SA
    Hum Exp Toxicol, 2020 May;39(5):577-595.
    PMID: 31884827 DOI: 10.1177/0960327119895570
    Benzene is a known hematotoxic and leukemogenic agent with hematopoietic stem cells (HSCs) niche being the potential target. Occupational and environmental exposure to benzene has been linked to the incidences of hematological disorders and malignancies. Previous studies have shown that benzene may act via multiple modes of action targeting HSCs niche, which include induction of chromosomal and micro RNA aberrations, leading to genetic and epigenetic modification of stem cells and probable carcinogenesis. However, understanding the mechanism linking benzene to the HSCs niche dysregulation is challenging due to complexity of its microenvironment. The niche is known to comprise of cell populations accounted for HSCs and their committed progenitors of lymphoid, erythroid, and myeloid lineages. Thus, it is fundamental to address novel approaches via lineage-directed strategy to elucidate precise mechanism involved in benzene-induced toxicity targeting HSCs and progenitors of different lineages. Here, we review the key genetic and epigenetic factors that mediate hematotoxicological effects by benzene and its metabolites in targeting HSCs niche. Overall, the use of combined genetic, epigenetic, and lineage-directed strategies targeting the HSCs niche is fundamental to uncover the key mechanisms in benzene-induced hematological disorders and malignancies.
    Matched MeSH terms: Hematopoietic Stem Cells/drug effects*
  3. Looking into dental pulp stem cells in the therapy of photoreceptors and retinal degenerative disorders
    Alsaeedi HA, Lam C, Koh AE, Teh SW, Mok PL, Higuchi A, et al.
    J. Photochem. Photobiol. B, Biol., 2020 Jan;203:111727.
    PMID: 31862637 DOI: 10.1016/j.jphotobiol.2019.111727
    Blindness and vision impairment are caused by irremediable retinal degeneration in affected individuals worldwide. Cell therapy for a retinal replacement can potentially rescue their vision, specifically for those who lost the light sensing photoreceptors in the eye. As such, well-characterized retinal cells are required for the replacement purposes. Stem cell-based therapy in photoreceptor and retinal pigment epithelium transplantation is well received, however, the drawbacks of retinal transplantation is the limited clinical protocols development, insufficient number of transplanted cells for recovery, the selection of potential stem cell sources that can be differentiated into the target cells, and the ability of cells to migrate to the host tissue. Dental pulp stem cells (DPSC) belong to a subset of mesenchymal stem cells, and are recently being studied due to its high capability of differentiating into cells of the neuronal lineage. In this review, we look into the potential uses of DPSC in treating retinal degeneration, and also the current data supporting its application.
    Matched MeSH terms: Stem Cells/cytology
  4. Fulltext Asymptomatic neurotoxicity of amyloid β-peptides (Aβ1-42 and Aβ25-35) on mouse embryonic stem cell-derived neural cells
    Mansor NI, Ntimi CM, Abdul-Aziz NM, Ling KH, Adam A, Rosli R, et al.
    Bosn J Basic Med Sci, 2021 Feb 01;21(1):98-110.
    PMID: 32156249 DOI: 10.17305/bjbms.2020.4639
    One of the strategies in the establishment of in vitro oxidative stress models for neurodegenerative diseases, such as Alzheimer's disease (AD), is to induce neurotoxicity by amyloid beta (Aβ) peptides in suitable neural cells. Presently, data on the neurotoxicity of Aβ in neural cells differentiated from stem cells are limited. In this study, we attempted to induce oxidative stress in transgenic 46C mouse embryonic stem cell-derived neurons via treatment with Aβ peptides (Aβ1-42 and Aβ25-35). 46C neural cells were generated by promoting the formation of multicellular aggregates, embryoid bodies in the absence of leukemia inhibitory factor, followed by the addition of all-trans retinoic acid as the neural inducer. Mature neuronal cells were exposed to different concentrations of Aβ1-42 and Aβ25-35 for 24 h. Morphological changes, cell viability, and intracellular reactive oxygen species (ROS) production were assessed. We found that 100 µM Aβ1-42 and 50 µM Aβ25-35 only promoted 40% and 10%, respectively, of cell injury and death in the 46C-derived neuronal cells. Interestingly, treatment with each of the Aβ peptides resulted in a significant increase of intracellular ROS activity, as compared to untreated neurons. These findings indicate the potential of using neurons derived from stem cells and Aβ peptides in generating oxidative stress for the establishment of an in vitro AD model that could be useful for drug screening and natural product studies.
    Matched MeSH terms: Mouse Embryonic Stem Cells/cytology*
  5. Rat full term amniotic fluid harbors highly potent stem cells
    Mun-Fun H, Ferdaos N, Hamzah SN, Ridzuan N, Hisham NA, Abdullah S, et al.
    Res Vet Sci, 2015 Oct;102:89-99.
    PMID: 26412526 DOI: 10.1016/j.rvsc.2015.07.010
    Amniotic fluid stem cells (AFSCs) are commonly isolated from mid-term amniotic fluid (AF) of animals and human collected via an invasive technique, amniocentesis. Alternatively, AFSCs could be collected at full-term. However, it is unclear whether AFSCs are present in the AF at full term. Here, we aimed to isolate and characterize stem cells isolated from AF of full term pregnant rats. Three stem cell lines have been established following immuno-selection against the stem cell marker, c-kit. Two of the new lines expressed multiple markers of pluripotency until more than passage 90. Further, they spontaneously differentiated into derivatives of the three primary germ layers through the formation of good quality embryoid bodies (EBs), and can be directly differentiated into neural lineage. Their strong stemness and potent neurogenic properties highlight the presence of highly potent stem cells in AF of full-term pregnancies, which could serve as a potential source of stem cells for regenerative medicine.
    Matched MeSH terms: Stem Cells/physiology*
  6. Targeting the genetic landscape of oral potentially malignant disorders has the potential as a preventative strategy in oral cancer
    Prime SS, Cirillo N, Cheong SC, Prime MS, Parkinson EK
    Cancer Lett, 2021 10 10;518:102-114.
    PMID: 34139286 DOI: 10.1016/j.canlet.2021.05.025
    This study reviews the molecular landscape of oral potentially malignant disorders (OPMD). We examine the impact of tumour heterogeneity, the spectrum of driver mutations (TP53, CDKN2A, TERT, NOTCH1, AJUBA, PIK3CA, CASP8) and gene transcription on tumour progression. We comment on how some of these mutations impact cellular senescence, field cancerization and cancer stem cells. We propose that OPMD can be monitored more closely and more dynamically through the use of liquid biopsies using an appropriate biomarker of transformation. We describe new gene interactions through the use of a systems biology approach and we highlight some of the first studies to identify functional genes using CRISPR-Cas9 technology. We believe that this information has translational implications for the use of re-purposed existing drugs and/or new drug development. Further, we argue that the use of digital technology encompassing clinical and laboratory-based data will create relevant datasets for machine learning/artificial intelligence. We believe that therapeutic intervention at an early molecular premalignant stage should be an important preventative strategy to inhibit the development of oral squamous cell carcinoma and that this approach is applicable to other aerodigestive tract cancers.
    Matched MeSH terms: Neoplastic Stem Cells/pathology
  7. Chondrogenesis of human adipose derived stem cells for future microtia repair using co-culture technique
    Goh BS, Che Omar SN, Ubaidah MA, Saim L, Sulaiman S, Chua KH
    Acta Otolaryngol, 2017 Apr;137(4):432-441.
    PMID: 27900891 DOI: 10.1080/00016489.2016.1257151
    CONCLUSION: In conclusion, these result showed HADSCs could differentiate into chondrocytes-like cells, dependent on signaling induced by TGF-β3 and chondrocytes. This is a promising result and showed that HADSCs is a potential source for future microtia repair. The technique of co-culture is a positive way forward to assist the microtia tissue.

    OBJECTIVE: Reconstructive surgery for the repair of microtia still remains the greatest challenge among the surgeons. Its repair is associated with donor-site morbidity and the degree of infection is inevitable when using alloplastic prosthesis with uncertain long-term durability. Thus, human adipose derived stem cells (HADSCs) can be an alternative cell source for cartilage regeneration. This study aims to evaluate the chondrogenic potential of HADSCs cultured with transforming growth factor-beta (TGF-β) and interaction of auricular chondrocytes with HADSCs for new cartilage generation.

    METHODS: Multi-lineages differentiation features of HADSCs were monitored by Alcian Blue, Alizarin Red, and Oil Red O staining for chondrogenic, adipogenic, and osteogenic differentiation capacity, respectively. Further, HADSCs alone were culture in medium added with TGF-β3; and human auricular chondrocytes were interacted indirectly in the culture with and without TGF-βs for up to 21 days, respectively. Cell morphology and chondrogenesis were monitored by inverted microscope. For cell viability, Alamar Blue assay was used to measure the cell viability and the changes in gene expression of auricular chondrocyte markers were determined by real-time polymerase chain reaction analysis. For the induction of chondrogenic differentiation, HADSCs showed a feature of aggregation and formed a dense matrix of proteoglycans. Staining results from Alizirin Red and Oil Red O indicated the HADSCs also successfully differentiated into adipogenic and osteogenic lineages after 21 days.

    RESULTS: According to a previous study, HADSCs were strongly positive for the mesenchymal markers CD90, CD73, CD44, CD9, and histocompatibility antigen. The results showed HADSCs test groups (cultured with TGF-β3) displayed chondrocytes-like cells morphology with typical lacunae structure compared to the control group without TGF-β3 after 2 weeks. Additionally, the HADSCs test groups increased in cell viability; an increase in expression of chondrocytes-specific genes (collagen type II, aggrecan core protein, SOX 9 and elastin) compared to the control. This study found that human auricular chondrocytes cells and growth factor had a positive influence in inducing HADSCs chondrogenic effects, in terms of chondrogenic differentiate of feature, increase of cell viability, and up-regulated expression of chondrogenic genes.

    Matched MeSH terms: Adult Stem Cells/physiology*
  8. Current attempts to implement microRNA-based diagnostics and therapy in cardiovascular and metabolic disease: a promising future
    Thanikachalam PV, Ramamurthy S, Wong ZW, Koo BJ, Wong JY, Abdullah MF, et al.
    Drug Discov Today, 2018 Mar;23(3):460-480.
    PMID: 29107764 DOI: 10.1016/j.drudis.2017.10.020
    MicroRNAs (miRNAs) are small, noncoding RNAs regulating gene expression at the post-translational level. miRNA-based therapeutic agents are important because of the functionality of miRNAs in regulating lipid and glucose metabolism and their role in the pathogenesis of metabolic disorders such as diabetes and obesity, where dysregulation leads to disease; they are also important in angiogenesis. miRNAs additionally serve as biomarkers in the diagnosis, prognosis and risk assessment of disease and in monitoring the response to treatment. Here, we provide a brief overview of progress in miRNA-based therapeutics in the preclinical and clinical setting and highlight the novel outcomes and opportunities in the diagnosis and treatment of metabolic conditions. In addition, we present the role of miRNAs in stem cell therapy which could have great potential in regenerative medicine.
    Matched MeSH terms: Stem Cells/physiology
  9. Neuro-fuzzy method for predicting the viability of stem cells treated at different time-concentration conditions
    Bindal P, Bindal U, Lin CW, Kasim NHA, Ramasamy TSAP, Dabbagh A, et al.
    Technol Health Care, 2017 Dec 04;25(6):1041-1051.
    PMID: 28800347 DOI: 10.3233/THC-170922
    Dental stem cells isolated for human dental pulp are an excellent source for regenerative medicine and dentistry. Simulation of clinical scenario is one of the crucial challenges for evaluation of the efficacy of DPSCs in various regenerative therapies. In this study we evaluated the viability of DPSCs after treatment with artificial bacterial lipopolysaccharides (LPS) as the main component responsible for inducing inflammatory response in majority of the inflammatory conditions in clinical scenario. Although a number of studies have previously treated stem cells with LPS from bacteria, however the accuracy level of the outcome was not established. Here we have analyzed the outcome using adaptive neuro-fuzzy inferences system (ANFIS) to predict the viability of human DPSCs after treatment with bacterial LPS.
    Matched MeSH terms: Stem Cells/physiology*
  10. Fulltext Stimulatory Secretions of Airway Epithelial Cells Accelerate Early Repair of Tracheal Epithelium
    Kardia E, Mohamed R, Yahaya BH
    Sci Rep, 2017 09 15;7(1):11732.
    PMID: 28916766 DOI: 10.1038/s41598-017-11992-6
    Airway stem/progenitor epithelial cells (AECs) are notable for their differentiation capacities in response to lung injury. Our previous finding highlighted the regenerative capacity of AECs following transplantation in repairing tracheal injury and reducing the severity of alveolar damage associated acute lung injury in a rabbit model. The goal of this study is to further investigate the potential of AECs to re-populate the tracheal epithelium and to study their stimulatory effect on inhibiting pro-inflammatory cytokines, epithelial cell migration and proliferation, and epithelial-to-mesenchymal transition (EMT) process following tracheal injury. Two in vitro culture assays were applied in this study; the direct co-culture assay that involved a culture of decellularised tracheal epithelium explants and AECs in a rotating tube, and indirect co-culture assay that utilized microporous membrane-well chamber system to separate the partially decellularised tracheal epithelium explants and AEC culture. The co-culture assays provided evidence of the stimulatory behaviour of AECs to enhance tracheal epithelial cell proliferation and migration during early wound repair. Factors that were secreted by AECs also markedly suppressed the production of IL-1β and IL-6 and initiated the EMT process during tracheal remodelling.
    Matched MeSH terms: Stem Cells/metabolism
  11. The Advancement of Biomaterials in Regulating Stem Cell Fate
    Hiew VV, Simat SFB, Teoh PL
    Stem Cell Rev Rep, 2018 Feb;14(1):43-57.
    PMID: 28884292 DOI: 10.1007/s12015-017-9764-y
    Stem cells are well-known to have prominent roles in tissue engineering applications. Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) can differentiate into every cell type in the body while adult stem cells such as mesenchymal stem cells (MSCs) can be isolated from various sources. Nevertheless, an utmost limitation in harnessing stem cells for tissue engineering is the supply of cells. The advances in biomaterial technology allows the establishment of ex vivo expansion systems to overcome this bottleneck. The progress of various scaffold fabrication could direct stem cell fate decisions including cell proliferation and differentiation into specific lineages in vitro. Stem cell biology and biomaterial technology promote synergistic effect on stem cell-based regenerative therapies. Therefore, understanding the interaction of stem cell and biomaterials would allow the designation of new biomaterials for future clinical therapeutic applications for tissue regeneration. This review focuses mainly on the advances of natural and synthetic biomaterials in regulating stem cell fate decisions. We have also briefly discussed how biological and biophysical properties of biomaterials including wettability, chemical functionality, biodegradability and stiffness play their roles.
    Matched MeSH terms: Induced Pluripotent Stem Cells/metabolism
  12. Fulltext Cancer stem cells as key drivers of tumour progression
    Ayob AZ, Ramasamy TS
    J Biomed Sci, 2018 Mar 06;25(1):20.
    PMID: 29506506 DOI: 10.1186/s12929-018-0426-4
    BACKGROUND: Cancer stem cells (CSCs) are subpopulations of cancer cells sharing similar characteristics as normal stem or progenitor cells such as self-renewal ability and multi-lineage differentiation to drive tumour growth and heterogeneity. Throughout the cancer progression, CSC can further be induced from differentiated cancer cells via the adaptation and cross-talks with the tumour microenvironment as well as a response from therapeutic pressures, therefore contributes to their heterogeneous phenotypes. Challengingly, conventional cancer treatments target the bulk of the tumour and are unable to target CSCs due to their highly resistance nature, leading to metastasis and tumour recurrence.

    MAIN BODY: This review highlights the roles of CSCs in tumour initiation, progression and metastasis with a focus on the cellular and molecular regulators that influence their phenotypical changes and behaviours in the different stages of cancer progression. We delineate the cross-talks between CSCs with the tumour microenvironment that support their intrinsic properties including survival, stemness, quiescence and their cellular and molecular adaptation in response to therapeutic pressure. An insight into the distinct roles of CSCs in promoting angiogenesis and metastasis has been captured based on in vitro and in vivo evidences.

    CONCLUSION: Given dynamic cellular events along the cancer progression and contributions of resistance nature by CSCs, understanding their molecular and cellular regulatory mechanism in a heterogeneous nature, provides significant cornerstone for the development of CSC-specific therapeutics.

    Matched MeSH terms: Neoplastic Stem Cells/physiology*
  13. Stem Cells Derived from Amniotic Fluid: A Potential Pluripotent-Like Cell Source for Cellular Therapy?
    Ramasamy TS, Velaithan V, Yeow Y, Sarkar FH
    Curr Stem Cell Res Ther, 2018;13(4):252-264.
    PMID: 29336267 DOI: 10.2174/1574888X13666180115093800
    BACKGROUND: Regenerative medicine aims to provide therapeutic treatment for disease or injury, and cell-based therapy is a newer therapeutic approach different from conventional medicine. Ethical issues that rose by the utilisation of human embryonic stem cells (hESC) and the limited capacity of adult stem cells, however, hinder the application of these stem cells in regenerative medicine. Recently, isolation and characterisation of c-kit positive cells from human amniotic fluid, which possess intermediate characteristics between hESCs and adult stem cells, provided a new approach towards realising their promise for fetal and adult regenerative medicine. Despite the number of studies that have been initiated to characterize their molecular signature, research on developing approaches to maintain and enhance their regenerative potential is urgently needed and must be developed.

    AIM: Thus, this review is focused on understanding their potential uses and factors influencing their pluripotent status in vitro.

    CONCLUSION: In short, this cell source could be an ideal cellular resource for pluripotent cells for potential applications in allogeneic cellular replacement therapies, fetal tissue engineering, pharmaceutical screening, and in disease modelling.

    Matched MeSH terms: Stem Cells/cytology*
  14. Using Surplus Embryos and Research Embryos in Stem Cell Research: Ethical Viewpoints of Buddhist, Hindu and Catholic Leaders in Malaysia on the Permissibility of Research
    Sivaraman MAF
    Sci Eng Ethics, 2018 02;24(1):129-149.
    PMID: 28281154 DOI: 10.1007/s11948-017-9893-3
    The sources of embryos for Embryonic Stem Cell Research (ESCR) include surplus embryos from infertility treatments, and research embryos which are created solely for an ESCR purpose. The latter raises more ethical concerns. In a multi-religious country like Malaysia, ethical discussions on the permissibility of ESCR with regard to the use surplus and research embryos are diversified. Malaysia has formulated guidelines influenced by the national fatwa ruling which allows the use of surplus embryos in ESCR. Input from other main religions is yet to be documented. In light of this, this study addresses (i) the ethical viewpoints of Buddhist, Hindu and Catholic leaders on the permissibility of using surplus and research embryos; and (ii) the moral standpoints of religious leaders towards attaining a consensus on the practice of ESCR in Malaysia. Responses from the religious leaders were obtained via semi-structured, face-to-face interviews. The findings show that generally the Buddhist and Hindu leaders approve the use of surplus embryos. Their responses on the creation of research embryos for ESCR are varied. Meanwhile, the Catholic leaders distinctively objected to ESCR regardless of the embryo sources, referring to it as the destruction of life. Taking into account the diverse views, this study explores the response of the religious leaders for a general consensus wherever possible. The ethical discourse surrounding ESCR in a multi-religious setting offers new perspective, which needs to be explored in a broader global community.
    Matched MeSH terms: Embryonic Stem Cells*
  15. Current techniques in reprogramming cell potency
    Romli F, Alitheen NB, Hamid M, Ismail R, Abd Rahman NM
    J Cell Biochem, 2013 Jun;114(6):1230-7.
    PMID: 23239017 DOI: 10.1002/jcb.24477
    The first successful attempt to reprogram somatic cell into embryonic-like stem cell was achieved on 2006. Since then, it had sparked a race against time to bring this wonderful invention from bench to bedside but it is not easily achieved due to severe problems in term of epigenetic and genomic. With each problem arise, new technique and protocol will be constructed to try to overcome it. This review addresses the various techniques made available to create iPSC with problems hogging down the technique.
    Matched MeSH terms: Induced Pluripotent Stem Cells/physiology*
  16. Fulltext Tryptophan-metabolizing gut microbes regulate adult neurogenesis via the aryl hydrocarbon receptor
    Wei GZ, Martin KA, Xing PY, Agrawal R, Whiley L, Wood TK, et al.
    Proc Natl Acad Sci U S A, 2021 Jul 06;118(27).
    PMID: 34210797 DOI: 10.1073/pnas.2021091118
    While modulatory effects of gut microbes on neurological phenotypes have been reported, the mechanisms remain largely unknown. Here, we demonstrate that indole, a tryptophan metabolite produced by tryptophanase-expressing gut microbes, elicits neurogenic effects in the adult mouse hippocampus. Neurogenesis is reduced in germ-free (GF) mice and in GF mice monocolonized with a single-gene tnaA knockout (KO) mutant Escherichia coli unable to produce indole. External administration of systemic indole increases adult neurogenesis in the dentate gyrus in these mouse models and in specific pathogen-free (SPF) control mice. Indole-treated mice display elevated synaptic markers postsynaptic density protein 95 and synaptophysin, suggesting synaptic maturation effects in vivo. By contrast, neurogenesis is not induced by indole in aryl hydrocarbon receptor KO (AhR-/-) mice or in ex vivo neurospheres derived from them. Neural progenitor cells exposed to indole exit the cell cycle, terminally differentiate, and mature into neurons that display longer and more branched neurites. These effects are not observed with kynurenine, another AhR ligand. The indole-AhR-mediated signaling pathway elevated the expression of β-catenin, Neurog2, and VEGF-α genes, thus identifying a molecular pathway connecting gut microbiota composition and their metabolic function to neurogenesis in the adult hippocampus. Our data have implications for the understanding of mechanisms of brain aging and for potential next-generation therapeutic opportunities.
    Matched MeSH terms: Neural Stem Cells/metabolism
  17. Fulltext Stem cell heterogeneity of mononucleated cells from murine peripheral blood: molecular analysis
    Yazid MD, Zainal Ariffin SH, Senafi S, Zainal Ariffin Z, Megat Abdul Wahab R
    ScientificWorldJournal, 2011;11:2150-9.
    PMID: 22125464 DOI: 10.1100/2011/340278
    The main purpose of this paper was to determine the heterogeneity of primary isolated mononucleated cells that originated from the peripheral blood system by observing molecular markers. The isolated cells were cultured in complete medium for 4 to 7 days prior to the separation of different cell types, that is, adherent and suspension. Following a total culture time of 14 days, adherent cells activated the Cd105 gene while suspension cells activated the Sca-1 gene. Both progenitor markers, Cbfa-1 and Ostf-1, were inactivated in both suspension and adherent cells after 14-day culture compared to cells cultured 3 days in designated differentiation medium. In conclusion, molecular analyses showed that primary mononucleated cells are heterogeneous, consisting of hematopoietic stem cells (suspension) and mesenchymal stem cells (adherent) while both cells contained no progenitor cells.
    Matched MeSH terms: Stem Cells/cytology*
  18. Generation of a MLL-AF9-specific stem cell model of acute monocytic leukemia
    Chiew MY, Boo NY, Voon K, Cheong SK, Leong PP
    Leuk Lymphoma, 2017 01;58(1):162-170.
    PMID: 27185517
    Acute monocytic leukemia (AML-M5), a subtype of acute myeloid leukemia (AML), affects mostly young children and has poor prognosis. The mechanisms of treatment failure of AML-M5 are still unclear. In this study, we generated iPSC from THP-1 cells from a patient with AML-M5, using retroviruses encoding the pluripotency-associated genes (OCT3/4, SOX2, KLF4 and c-MYC). These AML-M5-derived iPSC showed features similar with those of human embryonic stem cells in terms of the morphology, gene expression, protein/antigen expression and differentiation capability. Parental-specific markers were down-regulated in these AML-M5-derived iPSCs. Expression of MLL-AF9 fusion gene (previously identified to be associated with pathogenesis of AML-M5) was observed in all iPSC clones as well as parental cells. We conclude that AML-M5-specific iPSC clones have been successfully developed. This disease model may provide a novel approach for future study of pathogenesis and therapeutic intervention of AML-M5.
    Matched MeSH terms: Stem Cells/metabolism*; Stem Cells/pathology; Induced Pluripotent Stem Cells/metabolism
  19. Fulltext Long-term xeno-free culture of human pluripotent stem cells on hydrogels with optimal elasticity
    Higuchi A, Kao SH, Ling QD, Chen YM, Li HF, Alarfaj AA, et al.
    Sci Rep, 2015 Dec 14;5:18136.
    PMID: 26656754 DOI: 10.1038/srep18136
    The tentative clinical application of human pluripotent stem cells (hPSCs), such as human embryonic stem cells and human induced pluripotent stem cells, is restricted by the possibility of xenogenic contamination resulting from the use of mouse embryonic fibroblasts (MEFs) as a feeder layer. Therefore, we investigated hPSC cultures on biomaterials with different elasticities that were grafted with different nanosegments. We prepared dishes coated with polyvinylalcohol-co-itaconic acid hydrogels grafted with an oligopeptide derived from vitronectin (KGGPQVTRGDVFTMP) with elasticities ranging from 10.3 to 30.4 kPa storage moduli by controlling the crosslinking time. The hPSCs cultured on the stiffest substrates (30.4 kPa) tended to differentiate after five days of culture, whereas the hPSCs cultured on the optimal elastic substrates (25 kPa) maintained their pluripotency for over 20 passages under xeno-free conditions. These results indicate that cell culture matrices with optimal elasticity can maintain the pluripotency of hPSCs in culture.
    Matched MeSH terms: Pluripotent Stem Cells/cytology*; Pluripotent Stem Cells/metabolism
  20. Fulltext The role of Hibiscus sabdariffa L. (Roselle) in maintenance of ex vivo murine bone marrow-derived hematopoietic stem cells
    Abdul Hamid Z, Lin Lin WH, Abdalla BJ, Bee Yuen O, Latif ES, Mohamed J, et al.
    ScientificWorldJournal, 2014;2014:258192.
    PMID: 25405216 DOI: 10.1155/2014/258192
    Hematopoietic stem cells- (HSCs-) based therapy requires ex vivo expansion of HSCs prior to therapeutic use. However, ex vivo culture was reported to promote excessive production of reactive oxygen species (ROS), exposing HSCs to oxidative damage. Efforts to overcome this limitation include the use of antioxidants. In this study, the role of Hibiscus sabdariffa L. (Roselle) in maintenance of cultured murine bone marrow-derived HSCs was investigated. Aqueous extract of Roselle was added at varying concentrations (0-1000 ng/mL) for 24 hours to the freshly isolated murine bone marrow cells (BMCs) cultures. Effects of Roselle on cell viability, reactive oxygen species (ROS) production, glutathione (GSH) level, superoxide dismutase (SOD) activity, and DNA damage were investigated. Roselle enhanced the survival (P < 0.05) of BMCs at 500 and 1000 ng/mL, increased survival of Sca-1(+) cells (HSCs) at 500 ng/mL, and maintained HSCs phenotype as shown from nonremarkable changes of surface marker antigen (Sca-1) expression in all experimental groups. Roselle increased (P < 0.05) the GSH level and SOD activity but the level of reactive oxygen species (ROS) was unaffected. Moreover, Roselle showed significant cellular genoprotective potency against H2O2-induced DNA damage. Conclusively, Roselle shows novel property as potential supplement and genoprotectant against oxidative damage to cultured HSCs.
    Matched MeSH terms: Hematopoietic Stem Cells/drug effects*; Hematopoietic Stem Cells/physiology*
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