• The potential use of embryonic stem cells (ESCs) for cell replacement therapies is limited by ethical concerns and the technical hurdles associated with their isolation from human embryos. (biomedcentral.com)
  • In fact, low levels of telomerase activity have been found in human adult stem cells including haematopoietic and non-haematopoietic stem cells such as neuronal, skin, intestinal crypt, mammary epithelial, pancreas, adrenal cortex, kidney, and mesenchymal stem cells (MSCs) ( Table 1 ). (nature.com)
  • Intravenous infusion of bone marrow-derived mesenchymal stem cells improves tissue perfusion in a rat hindlimb ischemia model. (kyoto-u.ac.jp)
  • Possible role of intravenous administration of mesenchymal stem cells to alleviate interstitial cystitis/bladder pain syndrome in a Toll-like receptor-7 agonist-induced experimental animal model in rat. (kyoto-u.ac.jp)
  • They are classified as either totipotent (iTC), pluripotent (iPSC) or progenitor (multipotent - iMSC, also called an induced multipotent progenitor cell - iMPC) or unipotent - (iUSC) according to their developmental potential and degree of dedifferentiation. (wikipedia.org)
  • Small-molecule inhibitor cocktail promotes the proliferation of pre-existing liver progenitor cells. (kyoto-u.ac.jp)
  • The researchers were able to identify the minimal conditions and factors that would be sufficient for starting the cascade of molecular and cellular processes to instruct pluripotent cells to organize the embryo. (wikipedia.org)
  • Although exciting results have been achieved by means of somatic cell nuclear transfer, cell fusion, and culture-induced reprogramming [ 1 ], these procedures are technically demanding and inefficient and therefore unlikely to become a common approach for producing patient-specific pluripotent cells. (biomedcentral.com)
  • Induced stem cells (iSC) are stem cells derived from somatic, reproductive, pluripotent or other cell types by deliberate epigenetic reprogramming. (wikipedia.org)
  • Progenitors are obtained by so-called direct reprogramming or directed differentiation and are also called induced somatic stem cells. (wikipedia.org)
  • Induced totipotent cells can be obtained by reprogramming somatic cells with somatic-cell nuclear transfer (SCNT). (wikipedia.org)
  • The process involves sucking out the nucleus of a somatic (body) cell and injecting it into an oocyte that has had its nucleus removed Using an approach based on the protocol outlined by Tachibana et al. (wikipedia.org)
  • In somatic cells, the activity of telomerase, a reverse transcriptase that can elongate telomeric repeats, is usually diminished after birth so that the telomere length is gradually shortened with cell divisions, and triggers cellular senescence. (nature.com)
  • Thus, even in stem cells, except for embryonal stem cells and cancer stem cells, telomere shortening occurs during replicative ageing, possibly at a slower rate than that in normal somatic cells. (nature.com)
  • Telomeric DNA consists of short guanine-rich repeat sequences in all eukaryotes with linear chromosomes, and its length in human somatic cells is remarkably heterogeneous among individuals ranging from 5 to 20 kb, according to age, organ, and the proliferative history of each cell ( Wright and Shay, 2005 ). (nature.com)
  • In most human somatic cells except for stem cells and lymphocytes, telomerase activity is diminished after birth so that telomere length shortens with each cell division. (nature.com)
  • Analysis of the effectiveness of caffeine and MG132 for improving somatic cell nuclear transfer (SCNT) technology using cryopreserved eggs showed that supplementation did not improve the blastocyst formation rate of cloned mouse eggs. (molcells.org)
  • Derivation of autologous induced pluripotent stem cells (iPSCs) through direct reprogramming of easily accessible somatic cells holds the potential to transform the field of regenerative medicine. (biomedcentral.com)
  • To circumvent these obstacles, considerable effort has been invested in attempting to derive ESC-like cells by reprogramming somatic cells to an embryonic state. (biomedcentral.com)
  • Several experimental strategies have been developed to derive iPSCs from differentiated somatic cells (summarized in Figure 1 ). (biomedcentral.com)
  • To take human organ generation via BC and transplantation to the next step, we reviewed current emerging organ generation technologies and the associated efficiency of chimera formation in human cells from the standpoint of developmental biology. (frontiersin.org)
  • A comparative study of mesenchymal stem cell transplantation and NTG-101 molecular therapy to treat degenerative disc disease. (kyoto-u.ac.jp)
  • In addition, as the genetic identity of the donor egg from which the ESCs are derived most likely will differ from that of potential recipients, patients who receive ESC-derived cells or tissues may face the same complications that result from organ transplantation (for example, immunorejection, graft-versus-host disease, and need for immunosuppression). (biomedcentral.com)
  • Ideally, iPSC-based therapies in the future will rely on the isolation of skin fibroblasts or keratinocytes, their reprogramming into iPSCs, and the correction of the genetic defect followed by differentiation into the desired cell type and transplantation. (biomedcentral.com)
  • The Rosa26-targeted GS cells differentiated into fertility-competent sperm following transplantation. (cyberleninka.org)
  • On the other hand, Stra8-targeted GS cells showed defective spermatogenesis following transplantation, confirming its prime role in the initiation of meiosis. (cyberleninka.org)
  • We are studying the role that normal chromatin structure plays in gene regulation in hematopoietic cells and how its disruption leads to altered development and cancer. (stanford.edu)
  • This mechanism also applies to hematopoietic cells transformed by other HOX genes, including CDX2, which is highly expressed in a majority of acute myeloid leukemias, thus providing a molecular approach based on GSK-3 inhibitory strategies to target HOX-associated transcription in a broad spectrum of leukemias. (stanford.edu)
  • In this regard, emerging technologies of chimeric human organ production via blastocyst complementation (BC) holds great promise. (frontiersin.org)
  • Recently, the importance of telomere maintenance in human stem cells has been highlighted by studies on dyskeratosis congenital, which is a genetic disorder in the human telomerase component. (nature.com)
  • In Enhancing Evolution, leading bioethicist John Harris dismantles objections to genetic engineering, stem-cell research, designer babies, and cloning and makes an ethical case for biotechnology that is both forthright and rigorous. (philpapers.org)
  • Human enhancement, Harris argues, is a good thing--good morally, good for individuals, good as social policy, and good for a genetic heritage that needs serious improvement. (philpapers.org)
  • In addition to these basic issues concerning leukemia pathogenesis, we are devising new diagnostic procedures for detecting and monitoring leukemia patients based on molecular genetic abnormalities in the malignant cells. (stanford.edu)
  • TALEN and CRISPR/Cas9, when applied in GS cells, will be valuable tools in the study of spermatogenesis and for revealing the genetic mechanism of spermatogenic failure. (cyberleninka.org)
  • 2004). In order to make GS cells more widely applicable for the study of spermatogenesis at the genetic and molecular levels, it is desirable to be able to modify their genome without disturbing their spermato-genic ability. (cyberleninka.org)
  • Telomerase can add telomeric repeats onto the chromosome ends, and prevents the replication-dependent loss of telomere and cellular senescence in highly proliferative cells of the germline and in the majority of cancers ( Blasco, 2005 ). (nature.com)
  • Although the cultured SSCs, named germline stem (GS) cells, are targets of genome modification, this process remains technically difficult. (cyberleninka.org)
  • The cultured SSCs, named germline stem (GS) cells, are now useful in research on various aspects of spermatogenesis. (cyberleninka.org)
  • They showed that opposing gradients of bone morphogenetic protein (BMP) and Nodal, two transforming growth factor family members that act as morphogens, are sufficient to induce molecular and cellular mechanisms required to organize, in vivo or in vitro, uncommitted cells of the zebrafish blastula animal pole into a well-developed embryo. (wikipedia.org)
  • They form characteristic cell clusters in suspension culture that express a set of genes associated with pluripotency and can differentiate into endodermal, ectodermal and mesodermal cells both in vitro and in vivo. (wikipedia.org)
  • Positional cloning of rat mutant genes reveals new functions of these genes. (kyoto-u.ac.jp)
  • In the present study, we tested TALEN and double-nicking CRISPR/Cas9 on GS cells, targeting Rosa26 and Stra8 loci as representative genes dispensable and indispensable in spermatogenesis, respectively. (cyberleninka.org)
  • In fact, this was shown to be possible by the transfection of genes into GS cells (Kanatsu-Shinohara et al. (cyberleninka.org)
  • Therefore, we propose that damage to and subsequent release of mtDNA elicits a protective signalling response that enhances nDNA repair in cells and tissues, suggesting that mtDNA is a genotoxic stress sentinel. (regenerativemedicine.net)
  • The regulation of telomere length and telomerase activity is a complex and dynamic process that is tightly linked to cell cycle regulation in human stem cells. (nature.com)
  • For instance, multilineage-differentiating stress-enduring (Muse) cells are stress-tolerant adult human stem cells that can self-renew. (wikipedia.org)
  • Another drawback of oocyte vitrification is diminished developmental potential because of the decreased quality of embryos after warming. (molcells.org)
  • hESCs can be generated by SCNT using dermal fibroblasts nuclei from both a middle-aged 35-year-old male and an elderly, 75-year-old male, suggesting that age-associated changes are not necessarily an impediment to SCNT-based nuclear reprogramming of human cells. (wikipedia.org)
  • This meant that the cells can change their differentiation pathway. (wikipedia.org)
  • In Drosophila imaginal discs, cells have to choose from a limited number of standard discrete differentiation states. (wikipedia.org)
  • The fact that transdetermination (change of the path of differentiation) often occurs for a group of cells rather than single cells shows that it is induced rather than part of maturation. (wikipedia.org)
  • Our research focuses on developmental pathways that regulate hematopoietic cell growth and differentiation and are disrupted in the course of neoplastic transformation, particularly in leukemias and lymphomas. (stanford.edu)
  • However, though BC is emerging as a potential organ transplant option, challenges regarding organ size scalability, immune system incompatibilities, long-term maintenance, potential evolutionary distance, or unveiled mechanisms between donor and host cells remain. (frontiersin.org)
  • After injury, mature terminally differentiated kidney cells dedifferentiate into more primordial versions of themselves and then differentiate into the cell types needing replacement in the damaged tissue Macrophages can self-renew by local proliferation of mature differentiated cells. (wikipedia.org)
  • Maintaining the thyroid gland in mutant thyroglobulin-induced hypothyroidism requires thyroid cell proliferation that must continue in adulthood. (kyoto-u.ac.jp)
  • Basically, given the difference of telomere and telomerase activity in human and mouse cells, the telomere and telomerase status in stem cell populations is different between humans and mice ( Harrington, 2004 ). (nature.com)
  • Summary Mouse spermatogonial stem cells (SSCs) can be cultured for multiplication and maintained for long periods while preserving their spermatogenic ability. (cyberleninka.org)
  • In addition, mtDNA stress in TFAM-deficient mouse melanoma cells produces tumours that are more resistant to doxorubicin in vivo. (regenerativemedicine.net)
  • However, the cell numbers in blastocysts did not differ among groups. (molcells.org)
  • Here, we summarize current reprogramming methodologies with a focus on the production of transgene-free or genetically unmanipulated iPSCs and highlight important technical details that ultimately may influence the biological properties of pluripotent stem cells. (biomedcentral.com)
  • In newts, muscle tissue is regenerated from specialized muscle cells that dedifferentiate and forget the type of cell they had been. (wikipedia.org)
  • A critical length of telomere repeats is required to ensure proper telomere function and avoid the activation of DNA damage pathways that result in replicative senescence or cell death. (nature.com)
  • As stem cells have elongated proliferative capacity, they should have a mechanism that maintains telomere length through many cell divisions. (nature.com)
  • We demonstrate here that GSK-3 maintains the MLL leukemia stem cell transcriptional program by promoting the conditional association of CREB and its coactivators TORC and CBP with homedomain protein MEIS1, a critical component of the MLL-subordinate program, which in turn facilitates HOX-mediated transcription and transformation. (stanford.edu)
  • Molecular and Regenerative Characterization of Repair and Non-repair Schwann Cells. (kyoto-u.ac.jp)
  • In this review, we summarize the history of interspecies chimerism in various animal models to find hints for BC application and describe the challenges and prospects of utilizing BC for human organ generation. (frontiersin.org)
  • Thus, telomerase activity and telomere maintenance are associated with the immortality of cancer cells, germ-line cells, and embryonic stem (ES) cells. (nature.com)
  • Harvested GS cell colonies showed a high targeting efficiency with both TALEN and CRISPR/Cas9. (cyberleninka.org)
  • While they normally produce digestive fluids for the stomach, they can revert into stem cells to make temporary repairs to stomach injuries, such as a cut or damage from infection. (wikipedia.org)
  • Moreover, they can make this transition even in the absence of noticeable injuries and are capable of replenishing entire gastric units, in essence serving as quiescent "reserve" stem cells. (wikipedia.org)
  • This capacity to regenerate does not decline with age and may be linked to their ability to make new stem cells from muscle cells on demand. (wikipedia.org)
  • The Honeycomb Game is a word-building game: make words by clicking on cells in the honeycomb below. (claylane.uk)
  • Here we review the role of telomeres and telomerase in the function and capacity of the human stem cells. (nature.com)
  • One example is the transformation of iris cells to lens cells in the process of maturation and transformation of retinal pigment epithelium cells into the neural retina during regeneration in adult newt eyes. (wikipedia.org)
  • This process allows the body to replace cells not suitable to new conditions with more suitable new cells. (wikipedia.org)
  • In 1895 Thomas Morgan removed one of a frog's two blastomeres and found that amphibians are able to form whole embryos from the remaining part. (wikipedia.org)
  • 3) We are defining the properties of cancer stem cells that initiate and sustain the unique disease features of acute leukemias through the use of various adoptive animal models. (stanford.edu)
  • Although this technology holds the potential to revolutionize drug discovery and regenerative medicine, important technical issues associated with the derivation of iPSCs still hinder its clinical translation. (biomedcentral.com)
  • Cryopreservation of mammalian oocytes has been successfully applied for long-term storage of surplus eggs in mammalian assisted reproductive technology (ART), including in humans. (molcells.org)
  • In 1924 Hans Spemann and Hilde Mangold demonstrated the key importance of cell-cell inductions during animal development. (wikipedia.org)
  • however, the level of telomerase activity is low or absent in the majority of stem cells regardless of their proliferative capacity. (nature.com)
  • Thousands of copies of the circular mtDNA are present in most cell types that are packaged by TFAM into higher-order structures called nucleoids1. (regenerativemedicine.net)
  • However, this technology also may have several limitations, such as the risk of contamination by external pathogens because of direct contact with liquid nitrogen and increased cell toxicity due to high CPA concentrations. (molcells.org)