Showing 3 results for Induced Pluripotent Stem Cells
Mohammad Reza Noori Daloii , Arash Salmaninejad , Mina Tabrizi ,
Volume 72, Issue 7 (10-2014)
Abstract
Differentiated cells can change to embryonic stem cells by reprograming. Generation of induced pluripotent stem cells (iPSCs) has revolutionized the field of regenerative and personalized medicine. iPSCs can self-renew and differentiate into many cell types. iPSC cells offer a potentially unlimited source for targeted differentiation. Through the expression of a set of transcription factors, iPSCs can be generated from different kinds of embryonic and adult cells. This technology for the first time enabled the researchers to take differentiated cells from an individual, and convert them to another cell type of interest, which is particularly to that person. When the set of master transcription factors containing OCT4, SOX2, KLF4, and MYC is expressed ectopically in somatic cells, the transcriptional network is propelled to organize itself in such a way as to maintenance a pluripotent state. Since iPSCs are similar to Embryonic Stem Cell (ESC), they can be considered as sources for modeling different diseases. iPSCs which are induced from somatic cells of patient can be useful for screening and drugs selection, and also introduce treatment via grafting the cells. Although this technology has been successful in different fields, the tumorigenesis of viral vectors during induction of reprogramming is a major challenge. Nevertheless, iPSCs are valuable for clinical applications and research. By discovery of these cells many challenges related to the safety, efficacy, and bioethics of ESCs are solved. Pluripotency is defined in two aspect of functional and molecular, by which functional regards the capacity of cell is generate three kinds of embryonic layers and germ line, and molecular aspect regards the identifying of molecules and genes that support functional features. Identification of these genes has been placed at the center of fields related to development and stem cell research. In this review, we discuss the process of generation of these cells, as well as required genes and factors for pluripotency, and also current progress in generation of iPSCs utilizing tens of reliable and new studies.
Sharif Moradi , Hossein Baharvand ,
Volume 72, Issue 8 (11-2014)
Abstract
Embryonic stem cells are pluripotent stem cells which have the ability to indefinitely self-renew and differentiate into all differentiated cells of the body. Regarding their two main properties (unlimited self-renewal and multi-lineage differentiation), these cells have various biomedical applications in basic research and cell based therapy. Because the transplantation of differentiated cells that are derived from embryonic stem cells is allogenic, they face the problem of immune rejection following the transplantation of embryonic stem cell-derived cells into patients. In 2006, researchers from Japan reported the derivation of a new type of pluripotent stem cells which could overcome the problem of immune rejection that is associated with the application of embryonic stem cells. They designated these cells as induced pluripotent stem (iPS) cells, because their production was ‘induced’ from differentiated somatic cells using a combination of four embryonic stem cell-associated transcription factors. Importantly, these pluripotent stem cells exhibit all the key features of embryonic stem cells including unlimited self-renewal and multi-lineage differentiation potential, and can pass the most stringent test of pluripotency which is known as the tetraploid (4n) complementation. Hence, in addition to bypassing the problem of immune rejection, iPS cells have all of the potential applications of embryonic stem cells, including in developmental studies, toxicology research, drug discovery and disease modeling. Also, considering that they could be generated from patient’s own cells, iPS cells hold great promise in the future of patient-specific cell replacement therapies using pluripotent stem cells. In this review article, we will present a comprehensive review on the how and why of the generation of iPS cell from somatic cells of the body and discuss how they should be characterized in terms of morphologically, pluripotent stem cell behavior, and the molecular signature. In addition, their medical applications as well as some of the considerations and future challenges in their use will be discussed.
Maryam Farzaneh, Mojgan Hosseini,
Volume 78, Issue 4 (7-2020)
Abstract
Chick embryos are a great historical research model in basic and applied sciences. Along with other animal models, avian and specifically chicken embryo has been attended, as well. Avian fertilized eggs as a natural bioreactor are an efficient tool for producing recombinant proteins and vaccines manufacturing. Due to the limitations of birds' eggs for viral replication, avian stem cells culture technologies access to safe methods as well as large-scale production of a variety of human and animal vaccines. Chicken pluripotent stem cells present the unique property of self-renewal and the ability to generate differentiated progeny in all embryonic lineages such as ectoderm, mesoderm, and endoderm in vitro. For the first time, chicken embryonic stem cells (cESCs) derived from the blastodermal cells of stage X embryos in vitro. Chicken ESC provides a great model of early embryo and they are useful for gene manipulation, virus proliferation, and the generation of transgenic birds. In addition to blastodermal cells, pluripotent cell lines can be produced by reprogramming of chicken fibroblasts into induced pluripotent stem cells (iPSCs) with transcription factors such as OCT4, NANOG, SOX2, KLF4, LIN28, and C-MYC that are well known to contribute to the reprogramming of somatic cells into an iPSCs. Similar to chicken ESCs, iPSCs have properties of unlimited self-renewal in vitro and the capacity for differentiation to all three embryonic germ layers. Chicken iPSCs have been a useful tool for the production of transgenic birds and viral vaccines. Despite the benefits and multiple applications of chicken pluripotent stem cells, the propagation of these cells is limited and some important challenges should be eliminated before their use in vaccine manufacturing. It is necessary to define the appropriate culture conditions for chicken pluripotent stem cells. For example, the presence of endogenous viruses in the avian species should be evaluated for human vaccine production. Currently, primary chicken fibroblast cells are still mainly used for vaccine production. This review covers the resources to achieve chicken derived cell lines for vaccine manufacturing.
