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The Qatar International Conference on Stem Cell Science and Policy
- Conference date: 27-01 Feb-Mar 2012
- Location: Qatar National Convention Center, Doha, Qatar
- Volume number: 2012
- Published: 01 February 2012
51 - 61 of 61 results
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Propagation and Osteogenic Differentiation of Human Mesenchymal Stem Cells derived from Prenatal and Postnatal Sources
More LessAbstractThe application of mesenchymal stem cells differentiated into osteogenic cells is an attractive care modality to enhance the healing process of orthopedics and spinal injuries. Objectives of the in-vitro part of our study are: 1. To isolate and propagate Mesenchymal stem cells ( MSCs) derived from different sources; Bone Marrow (BM), Dental Pulp (DP), and Amniotic Fluid (AF) and 2. Induce their osteogenic differentiation in vitro.
Methods used were the generation and optimization of in-vitro cultures for DP- BM- and AF-MSCs, followed by their osteogenic differentiation by applying three independent induction protocols; osteogenic reagents containing media, bone morphologic protein2 (BMP2), and combined BMP2 and insulin growth factor (IGF).
The results showed that MSCs derived from different sources showed a significant difference both in the proliferation rate and osteogenic differentiation potentials. Whereas, DP-MSCs showed the highest proliferation rate, the AF-MSCs showed the greatest potential to osteogenic differentiation, whereas, BM-MSCs have the least potential toward osteogenic differentiation. In conclusion, the tissue of origin of derived MSCS is greatly influenced by the lineage of differentiation of derived stem cells.
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Understanding Families and Communities Hold the Key of Implementing New Technologies
By Anna RajabAbstractOver the past few years, GCC countries have witnessed remarkable social and economic growth, which is best reflected in their well-organized and efficient health care systems. With these achievements, a shift in the pattern of disease has become evident. There has been a change in a disease pattern with a falling incidence of communicable diseases, decrease of mortality and morbidity rates of infants and children and a rise in noncommunicable conditions.
Families in GCC states can benefit from new genetic approaches, but these need to be designed to conform with the community beliefs and culture. Presently, GCC communities need help in coping with the changes and challenges that genetic knowledge brings to their lives.
Understanding social beliefs, respect of the traditions set up in an Islamic community, and understanding the psychological difficulties faced by families are essential for acceptance of new technological advances. The difficulties faced by families and proposed solutions are discussed.
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Identification of Two Novel Splice variants of SOX2OT which are Co-expressed with Pluripotency Genes during Neural Differentiation of Stem Cells
More LessAbstractOur objectives were: Long non-coding RNAs (lncRNAs) are emerging as new regulators of stem cell pluripotency and neurogenesis. Recent studies revealed that the expression of several lncRNAs correlates with the expression of pluripotency regulators such as OCT4 and Nanog. Surprisingly, the SOX2 gene, another master regulator of pluripotency, is embedded within an intron of an lncRNA, known as SOX2OT. SOX2OT and has been suspected to participate in regulation of the SOX2 expression and related processes; nevertheless, its function has still remained untested. In this study, we investigated a potential correlation between the expression pattern of SOX2OT, also its newly discovered splice variants (SOX2OT-S1 and SOX2OT-S2) and master regulators of stem cell pluripotency (SOX2 and OCT4) in mesenchymal stem cells, as well as during the course of neural differentiation of the human EC cell line, NTERA2 (NT2).
We treated the NT2 cells with all-trans retinoic acid (ATRA) for four weeks to differentiate into neural phenotype. By designing specific primers for real-time PCR, we evaluated the expression pattern of SOX2OT, SOX2OT-S1, SOX2OT-S2, SOX2 and OCT4 in mesenchymal stem cells and also during the induction of neural differential of NT2 cells.
Our results showed that by using a different set of primers, we discovered two novel variants of SOX2OT, named SOX2OT-S1 (lacking exon4) and SOX2OT-S2 (lacking exons3 and 4). The expression pattern of SOX2OT variants was positively correlated with the expression of SOX2 and OCT4 in NT2 cells. Surprisingly, SOX2OT variants showed a distinct expression pattern during the course of neural differentiation of NT2 cells. The expression pattern of SOX2OT variants was similar to that of OCT4 and SOX2 during early differentiation of NT2 cells. However, in contrast to OCT4 and SOX2, a low expression of SOX2OT variants persist in later time points of neural differentiation of NT2 cells.
We found that close correlation between the expression pattern of SOX2OT variants and master regulators of pluripotency (OCT4 and SOX2) suggests that they may be involved in similar regulatory pathways including: self-renewal, pluripotency, and differentiation.
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Unravelling Ovarian Cancer Stem Cells Physiology
Authors: H Al Farsi, R Lis, H Al Thawadi, D Azzazen, J Soria, A Therwat, E Pujade Laurain and M MirshahiAbstractOvarian cancer is a highly metastatic disease. Epithelial ovarian cancer is the most lethal gynecologic malignancy with the majority of cases being diagnosed after the disease has become metastatic. Recent reports have shown that 25% of cancerous cells within tumors have features of cancer stem cells (CSCs). CSCs have been identified on the basis of their ability for self-renewal and to have the capacity to differentiate into cancer cells and also form tumors in animal models. EMT describes a mechanism by which cells lose their epithelial characteristics and acquire more migratory mesenchymal properties. It also seems to have a key role in the acquisition of invasive and migratory properties in many types of carcinoma cells. The aim of this study is to understand the molecular changes and signaling pathways associated with ovarian cancer cell transformation which may lead to the identification of targets for novel therapeutic interventions.
OVCAR-3 and hospicells were cultured in vitro according to standard procedure. OVCAR cells were stained using anti CD133 –prominin-1 and anti CD117-APC and sorted by FACS system as positive and negative. The supernatant of OVCAR CD117+ and CD117- were analyzed by cytokine array And 174 different membrane coupled anti-cytokines along with appropriate controls were studied. The gene expression patterns of OVCAR-3 cultured with supernatant of Hospicells (clone M16) or control cells were analysed and compared by a two-colour topic-defined microarray. The products of microarray consisted of genes related to cytokines, interleukins and growth factors. The up regulated 86 codes genes were analysed by DAVID functional annotation tool.
We demonstrated that OVCAR-3 cell line for several reasons did not appear to be monoclonal. It contains tow subpopulations: one expressing CD117 and the other not. The fact that OVCAR-3 expresses at the same time CD133 and CD117 is indicative of the stem cell nature of this cell line. The cytokines secreted by CD117+ and CD117- were not the same and indicate the different profile of these cells in cell behavior. Analysis was of OVCAR gene array after 8h incubation of Hospicells by DAVID functional annotation tool intricate gpl 130 (IL6 ST) cytokine receptor interaction (IL6, IL11, OSM, LIF, CNTF ligands) and angiogenic factors expression.
We found that OVCAR-3 is apparently a suitable model for studying ovarian cancer stem cells and Epithelial to Mesenchymal Transition in Ovarian Cancer Cells.
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Influence of Active and Non-active Protein C on Human Ovarian Cancer Stem Cells
Authors: H Al Thawadi, S Mirshahi, H Al Farsi, D Azzazen, S Besbes, E Pujade-Laurain, A Therwath, J Soria and M MirshahiAbstractIntroduction: The coagulation/fibrinolysticsystem control the intravascular fibrin hemostasis;in addition to participating in a wide variety of physio-pathological processes. The components of the system have an influence on tumor growth, invasion and metastasis. This is a result of their involvement in tumor matrix construction, angiogenesis and cell migration. Several homeostatic markers are currently used to predict the advent of thrombosis. However, none of these markers directly indicate the course and progression of the disease. Destabilization of peri-tumoral matrix enhances the malignant phenotype of cancer cells. The characterization of cytokines and proteolytic enzymes, secreted in tumor microenvironment, plays an important role in the mechanism of the escape phenomenon. However, the consequence of interaction of protein C on cancer stem cells is poorly investigated.
Objective: The aim of our study was to analyze the physio-pathological response of human ovarian cancer stem cells (OVCAR-3) to active and non-active protein C.
OVCAR-3 cells were cultured in DMEM medium containing 10% fetal calf serum, penicillin (50 U/ml), and streptomycin (50 μg/ml) and incubated in a humidified atmosphere containing 5% CO2 at 37°C, as recommended by the supplier (PAA Laboratories Inc, Etobicoke, ON, USA). Cells were characterized by flow cytometry for their propriety of stem cell like with specific anti CD133 and CD117 antibodies. The influence of active and non-active protein C (10 µg/ml, Eli Lilly) on this cell was performed by cytokine array (Ray Biotech, CliniScience) and in parallel by a wound healing test.
We demonstrated by a wound healing test that the migration of ovarian cancer cells enhanced when incubated with Active protein C compared to the cells that were incubated with Non-active protein C. Also the cytokine array showed different cytokines secreted by cells incubated with Active protein C and Non-active protein C.
It was found that Active protein C not only provides cancer cells cytoprotective effects, it may also participate in extracellular matrix local destabilization, thereby promoting metastatic dissemination.
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Gene Expression Profiling of Embryonic Human Neural Stem Cells and Dopaminergic Neurons from Adult Human Substantia Nigra
AbstractNeural stem cells (NSC) with self-renewal and multipotent properties serve as an ideal cell source for transplantation to treat neurodegenerative insults such as Parkinson's disease. We used Agilent's and Illumina Whole Human Genome Oligonucleotide Microarray to compare the genomic profiles of human embryonic NSC at a single time point in culture, and a multicellular tissue from postmortem adult substantia nigra (SN) which are rich in dopaminergic (DA) neurons. We identified 13525 up-regulated genes in both cell types of which 3737 (27.6%) genes were up-regulated in the hENSC, 4116 (30.4%) genes were up-regulated in the human substantia nigra dopaminergic cells, and 5672 (41.93%) were significantly up-regulated in both cell population. Careful analysis of the data that emerged using DAVID has permitted us to distinguish several genes and pathways that are involved in dopaminergic (DA) differentiation, and to identify the crucial signaling pathways that direct the process of differentiation.
The set of genes expressed more highly at hENSC is enriched in molecules known or predicted to be involved in the M phase of the mitotic cell cycle. On the other hand, the genes enriched in SN cells include a different set of functional categories, namely synaptic transmission, central nervous system development, structural constituents of the myelin sheath, the internode region of axons, myelination, cell projection, cell somata, ion transport, and the voltage-gated ion channel complex. Our results were also compared with data from various databases, and between different types of arrays, Agilent versus Illumina. This approach has allowed us to confirm the consistency of our obtained results for a large number of genes that delineate the phenotypical differences of embryonic NSCs, and SN cells.
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Programming Human Pluripotent Stem Cells into White and Brown Adipocytes
More LessAbstractThe utility of human pluripotent stem cells is dependent on efficient differentiation protocols that convert these cells into relevant adult cell types. Here we report the robust and efficient differentiation of human pluripotent stem cells into white or brown adipocytes. We found that inducible expression of PPARG2 alone or combined with CEBPB and/or PRDM16 in mesenchymal progenitor cells derived from pluripotent stem cells programmed their development towards a white or brown adipocyte cell fate with efficiencies of 85–90 percent. These adipocytes retained their identity independent of transgene expression, could be maintained in culture for several weeks, expressed mature markers and had mature functional properties such as lipid catabolism and insulin-responsiveness. When transplanted into mice, the programmed cells gave rise to ectopic fat pads with the morphological and functional characteristics of white or brown adipose tissue. These results indicate that the cells could be used to faithfully model human disease.
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Ethical, Legal, and Social Issues on the Recruit Process of Healthy Volunteers for Induced Pluripotent Stem Cell bank at Kyoto University
By Ken OkadaAbstractBanking of biomedical tissues or information related to them has been conducted around the world for clinical, research and/or commercial purposes. In addition to stem cells in the differentiated tissues such as cord blood and bone marrow, pluripotent stem cells are also subjects of banking. Human embryonic stem cells (hES cells) are one type of these cells, but induced pluripotent stem cells (iPS cells) are now also subjects of banking for various purposes.
In Japan, the Center for iPS Cell Research and Application (CiRA), led by Dr Shinya Yamanaka, was established in 2010 to conduct research on iPS cells. In order to realize iPS cell based therapies, CiRA is now working to establish a new iPS cell bank. The bank aims to establish clinical-grade, HLA-matched iPS cell lines from healthy volunteers and store them to provide for therapeutic or research use. Although some iPS cell banks in Japan or in other countries, including the one in CiRA, are already established, these banks store and provide basically disease-specific iPS cell lines. Therefore, the planned iPS cell bank at CiRA is unique in that it is going to store and provide clinical-grade iPS cells derived from healthy volunteers.
We have been collaborating with researchers at CiRA to establish appropriate procedures for the recruitment of healthy volunteers. We have found that there are a variety of ethical, legal, and social issues (ELSI) that need to be addressed. Since iPS cells are pluripotent stem cells, some ELSI are similar to those already identified in hES cell banks. However, there are other issues that are relatively novel and specific to iPS cells, especially when the donor is a healthy volunteer, not a patient. These ELSI identified arise because: 1. these cells are derived from healthy volunteers; 2. these cells expand infinitely; and 3. the bank deals not only with information such as genome sequence but also with other aspects of the cells.
In this presentation, we will summarize and discuss the ELSI we encountered while establishing the process of healthy-volunteer recruitment for the iPS cell bank.
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Soluble CD40 Ligand Stimulates the Pro-Angiogenic Function of Early Endothelial Progenitor Cells by Increasing Matrix Metalloproteinase 9 Release via the p38 Mitogen Activated Protein Kinase Pathway
Authors: Lara Bou Khzam, Haissam Abou-Saleh, Ahmed Hachem, Younes Zaid, Walid Mourad and Yahye MerhiAbstractEndothelial progenitor cells (EPCs) have recently been regarded as potential therapeutic targets in vascular repair. The effects of EPCs are related to their incorporation at sites of vascular lesions and to their release of various angiogenic factors. It has been shown that soluble CD40 ligand (sCD40L) levels are elevated in patients suffering from cardiovascular disease, which may influence the function of EPCs. We have identified the expression of the inflammatory receptor CD40 on early EPCs and aimed to study the effect of its ligand, sCD40L, on the function of early EPCs in angiogenesis.
Early EPCs derived from cultured peripheral blood mononuclear cells express CD40, and their stimulation with sCD40L increased the binding of the tumor necrosis factor receptor-associated factors, TRAF1, TRAF2, but not TRAF3, to CD40, indicating the existence of a functional signaling pathway via the CD40L/CD40 axis in early EPCs. Early EPCs alone do not display any tube formation potential on matrigel, but following stimulation with sCD40L, they significantly increased the angiogenic potential of cultured human umbilical vein endothelial cells (HUVECs), as determined by wound healing assay. Stimulation of early EPCs with sCD40L increased, in a concentration-dependent manner, the release of matrix metalloproteinase 9 (MMP-9) via the p38 mitogen activated protein kinase (MAPK) pathway. Inhibition of p38 MAPK, by SB203580, in sCD40L-treated early EPCs, reversed their release of MMP-9 and their pro-angiogenic effect on HUVECs.
We have shown that sCD40L increases the pro-angiogenic function of early EPCs on cultured HUVECs by inducing a significant increase in MMP-9 release via the p38 MAPK signaling pathway.
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Mechanotransduction Modulates the Effect of Mechanical Forces (fluid shear stress and cyclic strain) on Embryonic Stem Cell Differentiation toward Vascular Endothelial and Smooth Muscle Cells
Authors: Maria Nikmanesh, Zhong-Dong Shi and John TarbellAbstractIt has been shown that shear stress plays a critical role in promoting endothelial cell (EC) differentiation from embryonic stem cell (ESC)-derived ECs. However, the underlying mechanisms mediating shear stress effects in this process have yet to be investigated. It has been reported that the glycocalyx component heparan sulfate proteoglycan (HSPG) mediates shear stress mechanotransduction in mature EC.
In this study, we investigated whether cell surface HSPG plays a role in shear stress modulation of EC phenotype. ESC-derived EC were subjected to shear stress (5 dyn/cm(2) ) for 8h with or without heparinase III (Hep III) that digests heparan sulfate. Immunostaining showed that ESC-derived EC surfaces contain abundant HSPG, which could be cleaved by Hep III. We observed that shear stress significantly increased the expression of vascular EC-specific marker genes (vWF, VE-cadherin, PECAM-1. The effect of shear stress on expression of tight junction protein genes (ZO-1, OCLD, CLD5) was also evaluated. Shear stress increased the expression of ZO-1 and CLD5, while it did not alter the expression of OCLD. Shear stress increased expression of vasodilatory genes (eNOS, COX-2), while it decreased the expression of the vasoconstrictive gene ET1. After reduction of HSPG with Hep III, the shear stress-induced expression of vWF, VE-cadherin, ZO-1, eNOS, and COX-2, were abolished, suggesting that shear stress-induced expression of these genes depends on HSPG. These findings indicate for the first time that HSPG is a mechanosensor mediating shear stress-induced EC differentiation from ESC-derived EC cells.
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Effect of Tensile Strain and Shear Stress on the Differentiation of Human Mesenchymal Stem Cells into Endothelial Cells
AbstractStem Cells are undifferentiated cells that have special ability to produce similar cells and differentiate to many functionalized cells. Mechanical stimuli have a determinant effect on morphology and function of body cells, because they are constantly affected by internal and external mechanical loadings. In this research, the importance of mechanical stimuli was assessed on the differentiation of human mesenchymal stem cells (hMSCs) to vascular endothelial cells.
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