204 research outputs found

    Human Embryonic Stem Cell Science in Iran: Pioneering in the Muslim World

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    La recherche sur les cellules souches embryonnaires humaines (CSEh) est un domaine qui a suscité un vif intérêt dans les milieux scientifiques mais aussi financiers. C’est aussi un champ d’investigation source de dilemmes éthiques et de développements politiques encadrant le statut moral de l’embryon humain, les sources d’embryons ou de gamètes humains destinés à la recherche, le clonage ainsi que l’utilisation thérapeutique des cellules souches. Dans le monde Musulman, l’Iran, une nation pionnière de la recherche sur les SCEh, a reporté l’établissement d’une nouvelle lignée de cellules souches dès 2003. Ce pays a aussi établi des recommandations éthiques nationales pour la recherche et la thérapie utilisant les cellules souches. Le présent manuscrit décrit le développement de la science entourant les CSEh ainsi que d’autres accomplissements scientifiques et bioéthiques connexes en Iran. Il explique aussi comment la recherche sur les CSEh est à la fois guidée et réglementée par les lois et principes éthiques issus de l’Islam, et montre comment l’expérience d’un pays en développement peut servir d’exemple à d’autres sociétés similaires. Cet article présente ensuite une brève revue de l’état actuel de la recherche et de la réglementation de ce domaine dans certains pays Musulmans du Moyen-Orient. En conclusion, on peut argumenter autour du fait que, bien que la science et la religion soient des facteurs clés dans les débats actuels autours des CSEh, d’autres facteurs influencent la manière avec laquelle un nouveau savoir est abordé dans des pays ayant par ailleurs la même obédience religieuse ou des intérêts scientifiques similaires.Human embryonic stem cell (hESC) research is a field that has attracted considerable scientific and financial investment and attention in many countries. It is also a field surrounded by ethical controversies and policy developments concerning the moral status of the human embryo, sourcing of human embryos and gametes for research, cloning as well as stem cell (SC) therapy. In the Muslim world, Iran, as a pioneer country in hESC research, reported the establishment of a new SC line in 2003. The country has also established the national ethical guidelines for SC research and therapy. This paper therefore depicts the development of hESC science, as well as some other relevant scientific achievements and bioethics in Iran. It also describes how hESC research is both formed and regulated by Islamic law and ethics, as the experience of a developing country can provide insight to many similar societies. This article then presents a brief review of the current state of this field of science and its regulatory policy in some selected Muslim Middle East countries. In conclusion, it shall argue that, although science and religion are key factors in the current debates around hESC research, additional factors influence the manner in which new knowledge is taken up in countries with the same religious background or scientific interests

    Polycaprolactone-templated reduced-graphene oxide liquid crystal nanofibers towards biomedical applications

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    Here, we report a facile method to generate electrically conductive nanofibers by coating and subsequently chemically reducing graphene oxide (GO) liquid crystals on a polycaprolactone (PCL) mat.</p

    Intranuclear localization of EGFP-mouse PPARγ1 in bovine fibroblast cells

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    Objective: The aim of this study was to clone PPARγ1 cDNA in an appropriate mammalian expression vector, with a chimeric cDNA form, encompassing PPARγ with enhanced green fluorescent protein (EGFP) cDNA. This recombinant plasmid will be used for further analyses to investigate the molecular mechanism of PPARγ1 for neural differentiation process. Moreover, the nuclear localization of the PPARγ1 protein linked to EGFP marker was chased by using transient transfection of a constructed plasmid into bovine fibroblast cells. Materials and Methods: Total RNA was extracted from the fatty tissue of an adult mouse. Using specific pair primers, PPARγ1 cDNA was synthesized and amplified to produce the entire length of ORF. RT-PCR products containing PPARγ1 cDNA were treated by enzymatic digestion and inserted into the pEGFP-C1 downstream from EGFP cDNA. The constructed vector was used for transformation into bacterial competent cells. Positive colonies which showed inserted PPARγ1 cDNA were selected for plasmid preparations and additional analysis was performed to ensure that PPARγ1 cDNA was inserted properly. Finally, to confirm the intracellular localization of EGFP-PPARγ1, bovine fibroblast cells were transfected with the recombinant plasmid. Results: Our results from enzymatic digestion and sequencing confirmed, as expected, that PPARγ1 cDNA was amplified and cloned correctly. This cDNA gene encompassed 1428 bp. The related product was entered into the nucleus of bovine fibroblasts after transfection of its cDNA. Conclusion: PPARγ1 cDNA was cloned and sorted into nuclear compartments of bovine fibroblast cells upon transfection

    Brief Azacytidine Step Allows The Conversion of Suspension Human Fibroblasts into Neural Progenitor-Like Cells

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    In recent years transdifferentiation technology has enabled direct conversion of human fibroblasts to become a valuable, abundant and accessible cell source for patient-specific induced cell generation in biomedical research. The majority of transdifferentiation approaches rely upon viral gene delivery which due to random integration with the host genome can cause genome instability and tumorigenesis upon transplantation. Here, we provide a simple way to induce neural progenitor-like cells from human fibroblasts without genetic manipulation by changing physicochemical culture properties from monolayer culture into a suspension in the presence of a chemical DNA methyltransferase inhibitor agent, Azacytidine. We have demonstrated the expression of neural progenitor-like markers, morphology and the ability to spontaneously differentiate into neural-like cells. This approach is simple, inexpensive, lacks genetic manipulation and could be a foundation for future chemical neural transdifferentiation and a safe induction of neural progenitor cells from human fibroblasts for clinical applications

    Comprehensive Gene Expression Analysis of Human Embryonic Stem Cells during Differentiation into Neural Cells

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    Global gene expression analysis of human embryonic stem cells (hESCs) that differentiate into neural cells would help to further define the molecular mechanisms involved in neurogenesis in humans. We performed a comprehensive transcripteome analysis of hESC differentiation at three different stages: early neural differentiation, neural ectoderm, and differentiated neurons. We identified and validated time-dependent gene expression patterns and showed that the gene expression patterns reflect early ESC differentiation. Sets of genes are induced in primary ectodermal lineages and then in differentiated neurons, constituting consecutive waves of known and novel genes. Pathway analysis revealed dynamic expression patterns of members of several signaling pathways, including NOTCH, mTOR and Toll like receptors (TLR), during neural differentiation. An interaction network analysis revealed that the TGFβ family of genes, including LEFTY1, ID1 and ID2, are possible key players in the proliferation and maintenance of neural ectoderm. Collectively, these results enhance our understanding of the molecular dynamics underlying neural commitment and differentiation

    Temporal Gene Expression and DNA Methylation during Embryonic Stem Cell Derivation

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    Objective Dual inhibition of mitogen-activated protein kinase (MAPK) kinase (also known as MEK) and transforming growth factor β (TGFβ) type I receptors by PD0325901 and SB431542, known as R2i has been introduced as a highly efficient approach to the generation of mouse embryonic stem cells (ESC). In the present study, we investigated the molecular mechanisms underlying ESC derivation in the R2i condition. Materials and Methods In this experimental study, zona-free whole E3.5 blastocysts were seeded on mouse embryonic fibroblast (MEF) feeder cells in both R2i and serum conventional media. The isolated inner cell mass (ICM), ESCs and the ICM-outgrowths were collected on days 3, 5 and 7 post-blastocyst culture for quantitative real time- polymerase chain reaction (qRT-PCR) analysis as well as to assess the DNA methylation status at the time points during the transition from ICM to ESC. Results qRT-PCR revealed a significantly higher expression of the pluripotency-related genes (Oct4, Nanog, Sox2, Rex1, Dppa3, Tcf3, Utf1, Nodal, Dax1, Sall4 and β-Catenin) and lower expression of early differentiation genes (Gata6, Lefty2 and Cdx2) in R2i condition compared to the serum condition. Moreover, the upstream region of Oct4 and Nanog showed a progressive increase in methylation levels in the upstream regions of the genes following in R2i or serum conditions, followed by a decrease of DNA methylation in ESCs obtained under R2i. However, the methylation level of ICM outgrowths in the serum condition was much higher than R2i, at levels that could have a repressive effect and therefore explain the absence of expression of these two genes in the serum condition. Conclusion Our investigation revealed that generation of ESCs in the ground-state of pluripotency could be achieved by inhibiting the MEK and TGF-β signaling pathways in the first 5 days of ESC derivation

    Stem Cells from Human Exfoliated Deciduous Tooth Exhibit Stromal-Derived Inducing Activity and Lead to Generation of Neural Crest Cells from Human Embryonic Stem Cells

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    Objective: The neural crest is a transient structure of early vertebrate embryos that generates neural crest cells (NCCs). These cells can migrate throughout the body and produce a diverse array of mature tissue types. Due to the ethical and technical problems surrounding the isolation of these early human embryo cells, researchers have focused on in vitro studies to produce NCCs and increase their knowledge of neural crest development. Materials and Methods: In this experimental study, we cultured human embryonic stem cells (hESCs) on stromal stem cells from human exfoliated deciduous teeth (SHED) for a two-week period. We used different approaches to characterize these differentiated cells as neural precursor cells (NPCs) and NCCs. Results: In the first co-culture week, hESCs appeared as crater-like structures with marginal rosettes. NPCs derived from these structures expressed the early neural crest marker p75 in addition to numerous other genes associated with neural crest induction such as SNAIL, SLUG, PTX3 and SOX9. Flow cytometry analysis showed 70% of the cells were AP2/P75 positive. Moreover, the cells were able to self-renew, sustain multipotent differentiation potential, and readily form neurospheres in suspension culture. Conclusion: SHED, as an adult stem cell with a neural crest origin, has stromal-derived inducing activity (SDIA) and can be used as an NCC inducer from hESCs. These cells provide an invaluable resource to study neural crest differentiation in both normal and disordered human neural crest development

    Long-Term Follow-up of Autologous Fibroblast Transplantation for Facial Contour Deformities, A Non-Randomized Phase IIa Clinical Trial

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    Objective: Recently, the promising potential of fibroblast transplantation has become a novel modality for skin rejuvenation. We investigated the long-term safety and efficacy of autologous fibroblast transplantation for participants with mild to severe facial contour deformities. Materials and Methods: In this open-label, single-arm phase IIa clinical trial, a total of 57 participants with wrinkles (n=37, 132 treatment sites) or acne scars (n=20, 36 treatment sites) who had an evaluator’s assessment score of at least 2 out 7 (based on a standard photo-guide scoring) received 3 injections of autologous cultured fibroblasts administered at 4-6 week intervals. Efficacy evaluations were performed at 2, 6, 12, and 24 months after the final injection based on evaluator and patient’s assessment scores. Results: Our study showed a mean improvement of 2 scores in the wrinkle and acne scar treatment sites. At sixth months after transplantation, 90.1% of the wrinkle sites and 86.1% of the acne scar sites showed at least a one grade improvement on evaluator assessments. We also observed at least a 2-grade improvement in 56.1% of the wrinkle sites and 63.9% of the acne scar sites. A total of 70.5% of wrinkle sites and 72.2% of acne scar sites were scored as good or excellent on patient assessments. The efficacy outcomes remained stable up to 24-month. We did not observe any serious adverse events during the study. Conclusion: These results have shown that autologous fibroblast transplantation could be a promising remodeling modality with long-term corrective ability and minimal adverse events (Registration Number: NCT01115634)
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