1. The source of the iPSC’s in this case study are human iPSC line “201B7 clone”. They are dermal fibroblast tissues that in previous studies have been shown to have low tumorigenicity (meaning they have a low ability to produce tumors) after being used in transplantation therapy.
2. The iPSC’s were different from the host cells because a piggyBac vector was introduced into the hiPSC. A piggyBac vector is a genetic element that literally does what it sounds like, gives a piggyback between vectors and chromosomes, and cuts genes, carries them, and pastes them into a new position. This specific piggyBac vector used to distinguish the host cells from the iPSC’s stably expressed GFP (green fluorescent protein) gene under a ubiquitous promoter. The promoter was EF1 (elongation factor used to push gene expression in vitro and in vivo). The authors knew their transplantations of iPSC’s were successful because once the cells were introduced they observed continuous GFP fluorescence. The GFP fluorescence was observed even after differentiation of neural-linage.
3. iPSC’s were differentiated into neural stem cells by using SMAD-pathway inhibition. Green fluorescent proteins were labeled iPSC, and then a “serum- free floating culture of embryoid body-like aggregates method” was combined with the SMAD- pathway. These methods stimulated the LIF/BMP signaling. Leukemia inhibitory factor and bone morphogenic protein both promote neural cell differentiation into GFAP (Glial
In October 2014, a study showed that stem cells could help people with macular degeneration, which is a disease that causes continuous loss of sight. Researchers followed eighteen patients for three years and saw no signals of rejection of the transplanted stem cells (Young). Stem cells can also be used to create brain tissue. The creation of brain tissue with stem cells will provide the treatments for Alzheimer’s, Parkinson’s disease, and Dementia. These treatments may not cure the disease completely, but it could stop the progression of the disease. It could also reverse some of the damage already done. “Anything that might reasonably be called a real brain is going to have to pass more tests than simply being made of brain cells and looking a bit like a brain under a microscope”(Coath 4). “Any technique that gives us ‘something like a brain’ that we can modify, work on, and watch as it develops has to be exciting”(Coath 4). On September 2013, the creation of cerebral organoids was achieved. Cerebral organoids are pea-sized brain tissue. This achievement of brain tissue organs can help researchers explore important questions about brain development and brain functions. All this research and new developments on stem cells gets researchers a little closer every time to actually finding the cure for a brain
Pluripotent stem cells are the stem cells that can only differentiate into a limited range of differentiated cells. (2) They have the ability to give rise to all somatic cells from ectoderm, mesoderm and endoderm, as well as gametes. Naturally it can be found in embryos as Embryonic stem cells (ES cells). Induced pluripotent stem cells (iPS cells or iPSC) are the pluripotent stem cells that are generated directly from adult cells, first discovered by Shinya Yamanaka in 2006 by using a set of reprogramming factors (Oct4, Sox2, Klf4, and c-Myc or LIN28 and Nanog) (3) to reprogram mature cells back to a pluripotent state (4).
There are many different types of stem-cells which can be implanted in patients to regenerate or replace the damaged or abnormal cells caused by not only diseases like Parkinson's but also Alzheimer's and spinal cord injuries (2). A specific example in relation to Parkinson's is the harvesting of embryonic stem cells. These human embryonic stem cells can be transplanted into the brain to replace and create dopamine neurons. The controversy is in how one can obtain these stem cells. During fertilization, in humans, the embryo is hollow and contains cells that eventually develop into a fetus (1). Researchers have discovered, as recently as 1998, that the cells in the embryo contain all
In humans adult stem cells, not embryonic stem cells, have been used in therapies for more than forty years. People with blood disorders have used stem cell therapy to take the opportunity to improve upon their life. On the other hand, embryonic stem cells have a very high potential to treat or even cure numerous diseases like diabetes and heart disease. They are much more versatile in their usage compared to adult stem cells. Another practical use for embryonic stem cells is to treat damaged nerves ("Testing The Use…”). These nerves could have been impaired in a spinal cord injury. As of today, scientists have already performed stem cell transplants in people whose cells were damaged through chemotherapy of disease.
To give a short overview of the steps that will be taken to complete the study. Obtaining stem cells, whether adult, embryonic or induced, shall be done using healthy mouse models and after ethical approval has been gained. The process to derive them will be detailed below, however they are also purchasable commercially with the benefit of being well studied and accompanied by a detailed analysis of properties, however with a
Embryonic stem cells (ESCs) are grown in the laboratory from cells found in the early embryo. ESCs have an unlimited chance to
Stem cells are grown on Petri dishes in a laboratory and are never implanted in a woman’s uterus. These cells can be used to create stem cell lines that can grow indefinitely under optimal conditions (“Stem cells and diseases,” 2011). Embryonic stem cells can be obtained from existing stem cell lines (any group of cells that came from the same original embryo), aborted or miscarried embryos, unused in vitro fertilized embryos, and cloned embryos created from somatic cell nuclear transfer (the nucleus from an unfertilized egg is removed and replaced with a nucleus from an adult stem cell). This technique would be used for therapeutic cloning, which could grow organs or skin grafts for patients. However, the only research that is federally funded are a few embryonic stem cell lines created from unused embryos at in vitro fertilization (IVF) clinics before 2001 (Dunn, 2005; “Embryonic & fetal research laws,” 2008; Therapeutic cloning, 2009). These lines are not enough to allow scientists to fully explore and take advantage of potential findings.
The creation of induced pluripotent stem cells by direct reprogramming has allowed for the circumvention of using embryonic stem cells while still leaving the cells with the ability to maintain pluripotency. Instead of ES cells which were originally derived from the epiblast of mouse embryos, IPS cells were generated from mouse embryonic fibroblasts. This eliminated both any ethical concerns for whether those cells were a living being or not and the need to destroy embryos at the blastocyst stage. An advantage of IPS cells is that they are derived from human somatic cells which makes them easy to acquire due to the possibility of using skin or blood cells. They can also be grown and differentiated individually for each person that the sample of somatic cells is taken from which eliminates the possibility of having any immune reaction and rejection to the differentiated cells during transplantation. These characteristics of IPS cells are important because they are what enables us to safely and accurately transform these affected cells from patients cells into neurons and confidently study them.
Researchers successfully attained embryonic stem cells from the embryos of mice in 1981, which led to the discovery of this process in human beings in 1998 (National Institutes of Health, 2001). Embryonic stem cells are derived from an in vitro embryo between five days and seven weeks. Regenerative medicine can benefit greatly from the characteristics of embryonic stem cells. This process enables damaged organs and tissues to heal themselves with the help of implanted stem cells matching the organ (Hunziker, 2010, p. 1). There are two traits
The concept of neurogenesis being confined to the embryonic stage became less obvious with the onset of discovery of neural stem cells maintained in two distinct regions of the mammalian adult brain namely dentate gyrus (DG) of the hippocampus and the sub ventricular zone (SVZ) of the forebrain lateral ventricles14,18,19. What makes these neural stem cells a more credible target for oncogenic transformation? The continual presence of undifferentiated, mitotically active, self renewable stem cells at the apex of the hierarchy bundled in discrete germinal niches in the mammalian brain throughout the lifespan of an organism allows them to accumulate mutations, thus rendering them vulnerable for neoplastic reprogramming. There has been increasing evidence that the genetic and epigenetic mechanisms that initiate and maintain the NSC developmental state are possibly deregulated in GB to emerge as Glioma initiating cells or Brain tumor stem cells20. The discovery of BTSC has high clinical significance in the neuro-oncology field, as evidenced by major diverse roles it plays in various aspects of tumor growth such as tumor initiation, maintenance, progression, angiogenesis and tumor recurrence owing to therapeutic resistance, some of which are described
In the first part of the present thesis, by doing gain and loss of function studies Irene demonstrates that high levels of Shh and Smad1-5 signaling pathway activation regulate progenitor and stem cell proliferative mode of division, while the loss of function studies promoted to neuronal differentiation. In addition to this, Irene also reports the involvement of the midline signal Shh in the zebrafish neurulation; she discovered that Shh signal is sufficient to duplicate or change lumen position.
“Through the isolation and manipulation of cells, scientists are finding ways to identify young, regenerating ones that can be used to replace damaged of dead cells in diseased organs. This therapy is similar to the process of organ transplant, only the treatment consists of the transplantation of cells rather than organs. The cells that have shown by far the most promise of supplying diseased organs with healthy cells are called stem cells.” (Chapter Preface)
iPSCs are adult stem cells that have been genetically reprogrammed to behave like the pluripotent stem cells found in embryos, i.e. can differentiate into any cell type in the human body. This was first completed successfully in mice in 2006 by Shinya Yamanaka and his team (Takahashi et al., 2006), then in humans in 2007 both by Yamanaka (Takahashi et al., 2007), and by James Thomson and his team in America independently (Yu, et al., 2007). Yamanaka and Thomson’s methods were similar. In the report by Yu et
Imagine a future where humans are manufactured, a future where humans are created by science, a future where humans are the new lab specimen. Human cloning is like opening Pandora's Box, unleashing a torrent of potential evils but at the same time bringing a small seed of hope. No matter how many potential medical and scientific benefits could be made possible by human cloning, it is unethical to clone humans.
The human embryonic stem cells were first transfected with enhanced green fluorescence protein (EGFP), under the control of the murine Rex-1 promoter. The cells with EGFP demonstrated high levels of GFP expression when in the undifferentiated state and therefore showed high levels of fluorescence. As the cells differentiated, the levels of GFP expression decrease along with the degree of fluorescence. The undifferentiated cells were then isolated from the culture using a Fluorescence Activated Cell Sorter (FACS) (Eiges et al. 2001).