Displaying publications 41 - 60 of 121 in total

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  1. Kumar DH, Kutty MK
    Indian J Pathol Microbiol, 2012 Apr-Jun;55(2):147-53.
    PMID: 22771633 DOI: 10.4103/0377-4929.97842
    Cancer is fundamentally a cellular genetic disease capable of transferring the "disease" to the next generation of mutated cells. Similar proliferative and information transferring capacity exists in the stem cells of various organ systems in the human body. Understanding the bio-mechanism of stem cell metabolism and its regulation by signaling molecules and extracellular micro-environment is an important step toward successful prevention and treatment of cancer. According to the cancer stem cell hypothesis, both hereditary and sporadic cancers can arise from deregulation of these cancer stem cells (CSCs), triggered by genetic and environmental factors. It is shown that deregulation of normal self-renewal pathways in undifferentiated breast stem cells or progenitor cells had altered mammary system or progenitor cells, resulting in abnormally differentiated cells in human and rodent breast cancer cell lines. Breakthroughs in molecular pathways have important therapeutic implications. Hence, significant stress is laid on targeting signaling molecules and their micromilieu in breast cancer therapy.
    Matched MeSH terms: Stem Cells/cytology*
  2. Mamidi MK, Pal R, Bhonde R, Zakaria Z, Totey S
    J Biomol Screen, 2010 Jul;15(6):630-43.
    PMID: 20530724 DOI: 10.1177/1087057110370211
    Techniques to evaluate gene expression profiling, including real-time quantitative PCR, TaqMan low-density arrays, and sufficiently sensitive cDNA microarrays, are efficient methods for monitoring human embryonic stem cell (hESC) cultures. However, most of these high-throughput tests have a limited use due to high cost, extended turnaround time, and the involvement of highly specialized technical expertise. Hence, there is a paucity of rapid, cost-effective, robust, yet sensitive methods for routine screening of hESCs. A critical requirement in hESC cultures is to maintain a uniform undifferentiated state and to determine their differentiation capacity by showing the expression of gene markers representing all germ layers, including ecto-, meso-, and endoderm. To quantify the modulation of gene expression in hESCs during their propagation, expansion, and differentiation via embryoid body (EB) formation, the authors developed a simple, rapid, inexpensive, and definitive multimarker, semiquantitative multiplex RT-PCR (mxPCR) platform technology. Among the 15 gene primers tested, 4 were pluripotent markers comprising set 1, and 3 lineage-specific markers from each ecto-, meso-, and endoderm layers were combined as sets 2 to 4, respectively. The authors found that these 4 sets were not only effective in determining the relative differentiation in hESCs, but were easily reproducible. In this study, they used the HUES-7 cell line to standardize the technique, which was subsequently validated with HUES-9, NTERA-2, and mouse embryonic fibroblast cells. This single-reaction mxPCR assay was flexible and, by selecting appropriate reporter genes, can be designed for characterization of different hESC lines during routine maintenance and directed differentiation.
    Matched MeSH terms: Embryonic Stem Cells/cytology*
  3. Das AK, Pal R
    J Tissue Eng Regen Med, 2010 Aug;4(6):413-21.
    PMID: 20084623 DOI: 10.1002/term.258
    Pluripotent stem cells possess the unique property of differentiating into all other cell types of the human body. Further, the discovery of induced pluripotent stem cells (iPSCs) in 2006 has opened up new avenues in clinical medicine. In simple language, iPSCs are nothing but somatic cells reprogrammed genetically to exhibit pluripotent characteristics. This process utilizes retroviruses/lentiviruses/adenovirus/plasmids to incorporate candidate genes into somatic cells isolated from any part of the human body. It is also possible to develop disease-specific iPSCs which are most likely to revolutionize research in respect to the pathophysiology of most debilitating diseases, as these can be mimicked ex vivo in the laboratory. These models can also be used to study the safety and efficacy of known drugs or potential drug candidates for a particular diseased condition, limiting the need for animal studies and considerably reducing the time and money required to develop new drugs. Recently, functional neurons, cardiomyocytes, pancreatic islet cells, hepatocytes and retinal cells have been derived from human iPSCs, thus re-confirming the pluripotency and differentiation capacity of these cells. These findings further open up the possibility of using iPSCs in cell replacement therapy for various degenerative disorders. In this review we highlight the development of iPSCs by different methods, their biological characteristics and their prospective applications in regenerative medicine and drug screening. We further discuss some practical limitations pertaining to this technology and how they can be averted for the betterment of human life.
    Matched MeSH terms: Induced Pluripotent Stem Cells/cytology*
  4. Ferdaos N, Nathan S, Nordin N
    Med J Malaysia, 2008 Jul;63 Suppl A:75-6.
    PMID: 19024991
    Amniotic fluid (AF) serves as an excellent alternative source of pluripotent stem cells, as they are not bound with ethical issues and the stem cells are more primitive than adult stem (AS) cells. Hence, they have higher potential. Here we aim to isolate and characterize pluripotent stem cells from mid-term and full-term pregnant rat amniotic fluid. The results demonstrate the evidence of heterogeneous population of cells in the amniotic fluid and some of the cells morphology shows similarity with ES cells.
    Matched MeSH terms: Pluripotent Stem Cells/cytology*
  5. Hamid AA, Ruszymah BH, Aminuddin BS, Sathappan S, Chua KH
    Med J Malaysia, 2008 Jul;63 Suppl A:9-10.
    PMID: 19024959
    Human adipose-derived stem cells (HADSC) have demonstrated the capacity of differentiating into bone depending on the specific induction stimuli and growth factors. However, investigation on stem cell characteristic after osteogenic differentiation is still lacking. The goal of this study was to investigate the differential expression of sternness and osteogenic genes in non-induced HADSC compared with HADSC after osteogenic induction using quantitative Real Time RT-PCR. Our results showed that OCT-4, REX-1, FZD9, OSC, RUNX, and ALP were up regulated after osteogenic induction. This may indicated that HADSCs after osteogenic induction still possessed some stemness properties.
    Matched MeSH terms: Stem Cells/cytology*
  6. Simat SF, Chua KH, Abdul Rahman H, Tan AE, Tan GC
    Med J Malaysia, 2008 Jul;63 Suppl A:53-4.
    PMID: 19024980
    The aim of the study is to evaluate the stemness gene expression of cultured human amniotic epithelial cells (HAECs) in serial passages. HAECs obtained from human term placentae were cultured in F12:DMEM(1:1) + 10% FBS +10ng/ml EGF in serial passages (P0, P1, P2 and P4). Quantitative RT-PCR was used to assess the gene expression analysis. The results showed that cultured HAECs expressed and downregulated the stemness genes expression for Oct-4, Sox-2, Nanog3, FGF4, Rex-1, FZD-9, BST-1 ABCG2. However, vimentin and nestin gene expression were upregulated. The results suggested that cultured HAECs may have pluripotent and multipotent properties.
    Matched MeSH terms: Pluripotent Stem Cells/cytology*
  7. Zaman WS, Makpol S, Santhapan S, Chua KH
    Med J Malaysia, 2008 Jul;63 Suppl A:61-2.
    PMID: 19024984
    It is crucial to know whether stem cells retain its stemnness properties after advance in vitro manipulation. The objective of this study was to investigate the stemness gene expression of human adipose tissue derived stem cells (ADSCs) in long-term culture using quantitative RT-PCR technique. Our data showed that the expression level of Sox-2, Rex-1, FGF-4, Nanog, Nestin, BST-1, FZD-9 and Oct-4 were decreased gradually in long-term culture. This could mean that the ability of ADSCs to differentiate into other cell lineages reduce after extensive culture.
    Matched MeSH terms: Stem Cells/cytology*
  8. Nordin N, Nathan S, Li M, Mason JO
    Med J Malaysia, 2008 Jul;63 Suppl A:59-60.
    PMID: 19024983
    Obtaining pure population of neural cells from embryonic stem (ES) cells remains a challenge as little is known about the genes that govern embryonic stem cell differentiation. Using mouse ES cells, we aim to uncover the mechanisms that regulate neural differentiation of ES cells by focusing on roles played by Wnt family genes. Combining two techniques, Cre/loxP-based genetic recombination and ligand-dependent activation of Cre, we have generated transgenic ES cell lines that allow for the temporal control of expression and activity of Wnt gene (Wnt1-Ha) and Wnt antagonist (Dkk1). The ability of these cell lines in inducing the expression of transgene in undifferentiated ES cells and, more importantly, in differentiated derivatives of ES cells in vitro is evaluated.
    Matched MeSH terms: Embryonic Stem Cells/cytology*
  9. Ng AM, Tan KK, Phang MY, Aziyati O, Tan GH, Isa MR, et al.
    J Biomed Mater Res A, 2008 May;85(2):301-12.
    PMID: 17688285
    Biomaterial, an essential component of tissue engineering, serves as a scaffold for cell attachment, proliferation, and differentiation; provides the three dimensional (3D) structure and, in some applications, the mechanical strength required for the engineered tissue. Both synthetic and naturally occurring calcium phosphate based biomaterial have been used as bone fillers or bone extenders in orthopedic and reconstructive surgeries. This study aims to evaluate two popular calcium phosphate based biomaterial i.e., hydroxyapatite (HA) and tricalcium phosphate/hydroxyapatite (TCP/HA) granules as scaffold materials in bone tissue engineering. In our strategy for constructing tissue engineered bone, human osteoprogenitor cells derived from periosteum were incorporated with human plasma-derived fibrin and seeded onto HA or TCP/HA forming 3D tissue constructs and further maintained in osteogenic medium for 4 weeks to induce osteogenic differentiation. Constructs were subsequently implanted intramuscularly in nude mice for 8 weeks after which mice were euthanized and constructs harvested for evaluation. The differential cell response to the biomaterial (HA or TCP/HA) adopted as scaffold was illustrated by the histology of undecalcified constructs and evaluation using SEM and TEM. Both HA and TCP/HA constructs showed evidence of cell proliferation, calcium deposition, and collagen bundle formation albeit lesser in the former. Our findings demonstrated that TCP/HA is superior between the two in early bone formation and hence is the scaffold material of choice in bone tissue engineering.
    Matched MeSH terms: Stem Cells/cytology*
  10. Higuchi A, Wang CT, Ling QD, Lee HH, Kumar SS, Chang Y, et al.
    Sci Rep, 2015;5:10217.
    PMID: 25970301 DOI: 10.1038/srep10217
    Human adipose-derived stem cells (hADSCs) exhibit heterogeneous characteristics, indicating various genotypes and differentiation abilities. The isolated hADSCs can possess different purity levels and divergent properties depending on the purification methods used. We developed a hybrid-membrane migration method that purifies hADSCs from a fat tissue solution with extremely high purity and pluripotency. A primary fat-tissue solution was permeated through the porous membranes with a pore size from 8 to 25 μm, and the membranes were incubated in cell culture medium for 15-18 days. The hADSCs that migrated from the membranes contained an extremely high percentage (e.g., >98%) of cells positive for mesenchymal stem cell markers and showed almost one order of magnitude higher expression of some pluripotency genes (Oct4, Sox2, Klf4 and Nanog) compared with cells isolated using the conventional culture method.
    Matched MeSH terms: Adult Stem Cells/cytology*
  11. Bindal P, Gnanasegaran N, Bindal U, Haque N, Ramasamy TS, Chai WL, et al.
    Clin Oral Investig, 2019 Oct;23(10):3821-3831.
    PMID: 30687907 DOI: 10.1007/s00784-019-02811-5
    OBJECTIVE: In this study, we aimed to determine the suitable concentrations of human platelet lysate (HPL) and platelet-rich plasma (PRP) for maintaining the in vitro proliferative and angiogenic potential of inflamed dental pulp stem cells.

    MATERIALS AND METHODS: Lipopolysaccharide (LPS)-induced inflamed dental pulp-derived stem cells (iDPSCs) were treated with different concentrations of HPL and PRP (10% and 20%) followed by determination of viability using Alamar Blue assay. Expression of angiogenesis-, adhesion-, and inflammation-regulating genes was also analyzed using RT-qPCR array. Furthermore, expression of growth factors at protein level in the cell culture microenvironment was measured using multiplex assay.

    RESULTS: Viability of iDPSCs was significantly (p 

    Matched MeSH terms: Stem Cells/cytology*
  12. Jayaraman P, Nathan P, Vasanthan P, Musa S, Govindasamy V
    Cell Biol Int, 2013 Oct;37(10):1122-8.
    PMID: 23716460 DOI: 10.1002/cbin.10138
    Stem cell biology has gained remarkable interest in recent years, driven by the hope of finding cures for numerous diseases including skin wound healing through transplantation medicine. Initially upon transplantation, these cells home to and differentiate within the injured tissue into specialised cells. Contrariwise, it now appears that only a small percentage of transplanted cells integrate and survive in host tissues. Thus, the foremost mechanism by which stem cells participate in tissue repair seems to be related to their trophic factors. Indeed, stem cells provide the microenvironment with a wide range of growth factors, cytokines and chemokines, which can broadly defined as the stem cells secretome. In in vitro condition, these molecules can be traced from the conditioned medium or spent media harvested from cultured cells. Conditioned medium now serves as a new treatment modality in regenerative medicine and has shown a successful outcome in some diseases. With the emergence of this approach, we described the possibility of using stem cells conditioned medium as a novel and promising alternative to skin wound healing treatment. Numerous pre-clinical data have shown the possibility and efficacy of this treatment. Despite this, significant challenges need to be addressed before translating this technology to the bedside.
    Matched MeSH terms: Stem Cells/cytology*
  13. Daneshvar N, Abdullah R, Shamsabadi FT, How CW, Mh MA, Mehrbod P
    Cell Biol Int, 2013 May;37(5):415-9.
    PMID: 23504853 DOI: 10.1002/cbin.10051
    Nanotechnology has provided new technological opportunities, which could help in challenges confronting stem cell research. Polyamidoamine (PAMAM) dendrimers, a new class of macromolecular polymers with high molecular uniformity, narrow molecular distribution specific size and shape and highly functionalised terminal surface have been extensively explored for biomedical application. PAMAM dendrimers are also nanospherical, hyperbranched and monodispersive molecules exhibiting exclusive properties which make them potential carriers for drug and gene delivery.
    Matched MeSH terms: Induced Pluripotent Stem Cells/cytology
  14. Vasanthan P, Jayaraman P, Kunasekaran W, Lawrence A, Gnanasegaran N, Govindasamy V, et al.
    Naturwissenschaften, 2016 Aug;103(7-8):62.
    PMID: 27379400 DOI: 10.1007/s00114-016-1387-7
    Human deciduous periodontal ligament stem cells have been introduced for as an easily accessible source of stem cells from dental origin. Although recent studies have revealed the ability of these stem cells in multipotential attribute, their efficiency of hepatic lineage differentiation has not been addressed so far. The aim of this study is to investigate hepatic lineage fate competence of periodontal ligament stem cells through direct media induction. Differentiation of periodontal ligament stem cells into hepatocyte-like cells was conducted by the exposure of two phase media induction. First phase was performed in the presence of hepatocyte growth factors to induce a definitive endoderm formation. In the subsequent phase, the cells were treated with oncostatin M and dexamethosone followed by insulin and transferrin to generate hepatocyte-like cells. Hepatic-related characters of the generated hepatocyte-like cells were determined at both mRNA and protein level followed by functional assays. Foremost changes observed in the generation of hepatocyte-like cells were the morphological features in which these cells were transformed from fibroblastic shape to polygonal shape. Temporal expression of hepatic markers ranging from early endodermal up to late markers were detected in the hepatocyte-like cells. Crucial hepatic markers such as glycogen storage, albumin, and urea secretion were also shown. These findings exhibited the ability of periodontal ligament stem cells of dental origin to be directed into hepatic lineage fate. These cells can be regarded as an alternative autologous source in the usage of stem cell-based treatment for liver diseases.
    Matched MeSH terms: Stem Cells/cytology*
  15. Gnanasegaran N, Govindasamy V, Kathirvaloo P, Musa S, Abu Kasim NH
    J Tissue Eng Regen Med, 2018 02;12(2):e881-e893.
    PMID: 28079995 DOI: 10.1002/term.2401
    Parkinson's disease (PD) is characterized by tremors and cognitive issues, and is due to the death of dopaminergic (DA-ergic) neurons in brain circuits that are responsible for producing neurotransmitter dopamine (DA). Currently, cell replacement therapies are underway to improve upon existing therapeutic approaches such as drug treatments and electrical stimulation. Among the widely available sources, dental pulp stem cells (DPSCs) from deciduous teeth have gained popularity because of their neural crest origin and inherent propensity toward neuronal lineage. Despite the various pre-clinical studies conducted, an important factor yet to be elucidated is the influence of growth phases in a typical trans-differentiation process. This study selected DPSCs at three distinct time points with variable growth phase proportions (G0/G1, S and G2/M) for in vitro trans-differentiation into DA-ergic-like cells. Using commercially available PCR arrays, we identified distinct gene profiles pertaining to cell cycles in these phases. The differentiation outcomes were assessed in terms of morphology and gene and protein expression, as well as with functional assays. It was noted that DPSCs with the highest G0/G1 phase were comparatively the best, representing at least a 2-fold up regulation (p 
    Matched MeSH terms: Stem Cells/cytology*
  16. Haque N, Abu Kasim NH
    Adv Exp Med Biol, 2017 7 22;1083:29-44.
    PMID: 28730381 DOI: 10.1007/5584_2017_74
    In regenerative therapy, in vitro expansion of stem cells is critical to obtain a significantly higher number of cells for successful engraftment after transplantation. However, stem cells lose its regenerative potential and enter senescence during in vitro expansion. In this study, the influence of foetal bovine serum (FBS) and pooled human serum (pHS) on the proliferation, morphology and migration of stem cells from human extracted deciduous teeth (SHED) was compared. SHED (n = 3) was expanded in KnockOut DMEM supplemented with either pHS (pHS-SM) or FBS (FBS-SM). pHS was prepared using peripheral blood serum of six healthy male adults, aged between 21 and 35 years old. The number of live SHED was significantly higher, from passage 5 to 7, when cultured in pHS-SM compared to those cultured in FBS-SM (p 
    Matched MeSH terms: Stem Cells/cytology*
  17. 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*
  18. 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
  19. 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*
  20. 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*
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