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Adult Stem Cell Plasticity
Published in Richard K. Burt, Alberto M. Marmont, Stem Cell Therapy for Autoimmune Disease, 2019
From the viewpoint of researchers who want to study development or to produce cell-based therapies, the limited capability of adult stem cells is disappointing. Although they can be relatively easily isolated from small biopsy specimens, their immutability and commitment make individual adult stem cell types uninformative regarding early developmental programs and difficult to apply to most diseases. Embryonic stem cell lines are therefore of unique importance to researchers, as only they can be used to produce any cell type in vitro. In fact, since the first isolation of human ES cells from blastocysts in 1998,2 scientists have learned how to coax these cells in vitro to become many different mature cell types including cardiomyocytes, neurons, and pancreatic islet cells.3 Unfortunately, the use of human ES cells is highly controversial in the United States because such research requires the destruction of early human embryos. Current federal law restricts the number of ES cell lines that federally funded labs can use to approximately 60, only 10 or so of which are available and adequately characterized. Many researchers think that this number is woefully inadequate considering the limited genetic variability of existing cell lines and the vast number of genetic disorders that could be addressed with ES cells.4
An overview of human pluripotent stem cell applications for the understanding and treatment of blindness
Published in John Ravenscroft, The Routledge Handbook of Visual Impairment, 2019
Louise A. Rooney, Duncan E. Crombie, Grace E. Lidgerwood, Maciej Daniszewski, Alice Pébay
Before being used in transplantation, safety and regulatory issues of stem cell therapies must be addressed to ensure safe and efficacious treatment of patients. First, any cells to be used in stem cell transplant therapies must be highly characterised by surface markers and cytogenetic tests to confirm the desired transplantation cell karyotype. A number of clinically compliant stem cell lines have been generated, some of which have been retrospectively assessed, substantiating them for clinical usage. Second, differentiation protocols need to be employed for efficient selection and purification of the desired cell type(s) for transplantation. This is particularly important for hPSC-derived cells as transplantation of any undifferentiated hPSCs could lead to teratoma formation in the recipient. Both stem cell characterisation and differentiation protocols must comply with relevant current good manufacturing practice and regulatory body requirements. Third, all therapies should be supported by robust and peer-reviewed pre-clinical and clinical trials to ensure treatments have suitable efficacy and minimal adverse effects.
Genetic Research and Health Care
Published in Kant Patel, Mark E. Rushefsky, Health Care Policy in an Age or New Technologies, 2015
The president finally made his decision, after much public agonizing and consulting, in August 2001. In a televised speech to the nation, President Bush began in a didactic mode, explaining what stem cells are, how they are derived, and the potential benefits from such research. He also looked at the issue of when a human life begins. The president then announced his decision. Federal funding would be limited to stem cell lines that remained in fertility clinics. He stated that some sixty such lines existed throughout the world and believed they would be adequate for research purposes (Goldstein and Allen 2001). The stem cell lines were in private biotechnology companies and universities in five countries: the United States, Israel, India, Australia, and Sweden (Stolberg 2001c).
Cannabis alters DNA methylation at maternally imprinted and autism candidate genes in spermatogenic cells
Published in Systems Biology in Reproductive Medicine, 2022
Rose Schrott, Katherine W. Greeson, Dillon King, Krista M. Symosko Crow, Charles A. Easley, Susan K. Murphy
The use of human embryonic stem cells (hESCs) in research is a powerful scientific tool. Their pluripotent nature renders them a remarkable model for studying early life developmental processes and understanding disease progression (Dvash et al. 2006). These cells have tremendous therapeutic potential, as evidenced by their use in studies involved in understanding and treating diseases such as diabetes, Parkinson’s disease, Alzheimer’s disease, bone marrow failure, cancer therapeutics, and more (Lerou and Daley 2005; Dvash et al. 2006). Much has been characterized in the stem cell lines used for research, such as the mutations they harbor, the diseases they represent, and the karyotypes they possess. However, few model systems have been established that recapitulate gametogenesis in vitro that allow investigation of dynamic DNA methylation changes in gametes and how such changes are vulnerable to the environment. Our findings that CE exposure can influence DNA methylation at a subset of imprinted genes and genes possessing bivalent chromatin adds to a growing body of evidence that cannabis exposure can impact the sperm DNA methylome. Future studies are needed to continue to assess the heritability of the effects induced by cannabis.
Advances in cell-laden hydrogels for delivering therapeutics
Published in Expert Opinion on Biological Therapy, 2019
Gorka Orive, Mari Carmen Echave, José Luis Pedraz, Nasim Golafshan, Alireza Dolatshahi-Pirouz, Giovanna Paolone, Dwaine Emerich
More recent efforts have focused on the development of non-adult stem cells lines including embryonic (ESC) and induced pluripotent stem cell lines (iPS) given the holy grail promise of and infinite supply of an unlimited repertoire of cell types. Contemporary examples include ViaCyte, inc which is developing both encapsulated (PEC-Encap system) and non-encapsulated ES-based beta cell transplants for diabetes [14]. The cells are partially differentiated prior to subcutaneous implantation where further in vivo differentiation occurs to the point of insulin secretion. ViaCyte has also recently announced a strategic collaboration with CRISPR Therapeutics, inc [15] to work on the fascinating possibility of creating pancreatic cells that are immunologically ‘invisible’. Interestingly, Semma Therapeutics is also developing pancreatic stem cells but these cells are more fully differentiated into cells capable of insulin secretion in response to glucose prior to encapsulation and implantation.
Unexplained total abnormal fertilization of donor oocytes in ICSI with using spermatozoa from different patients
Published in Gynecological Endocrinology, 2019
Hripsime Grigoryan, Lev Levkov, Romualdo Sciorio, Eduard Hambartsoumian
A Spanish group Escribá et al. [14] described a technique that improves identification and removal of the extra paternal pronuclei. They microsurgically removed the pronucleus located furthest from the second polar body in 3PN human zygotes using cytoskeletal relaxing agents. The resulting embryos were diploid and developed to blastocyst stage, with the majority being heteroparental. The authors concluded that microsurgical removal of one pronucleus located at the farthest position to the second polar body from 3PN zygotes is feasible and can result, in vitro, into a morphologically normal, heteroparental diploid blastocysts. This technique of embryo recycling could be useful for reproductive purposes or human embryonic stem cell research. These could potentially be used to derive patient-specific embryonic stem cell lines, instead of using viable embryos [14]. In our case, the origin of 3PN fertilization remains unexplained. The case is more interesting because ICSI with using four different patients spermatozoa resulted in the same abnormal fertilization, which suggests rather into the reason, which derives from oocytes than from spermatozoa.