STEM CELL RESEARCH PRIMER

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1 STEM CELL RESEARCH PRIMER WHAT YOU NEED TO KNOW ABOUT STEM CELLS AND STEM CELL RESEARCH What Stem Cells Are And Why They Are Important Stem cells are the body s very own internal repair system. They are the foundation of development in living organisms. These undifferentiated cells help mend the body and heal tissue. How Stem Cells Are Different From Other Cell Types Stem cells have a unique set of properties that set them apart from other kinds of cells in the human body. Stem cells can REGENERATE to replace damaged cells. Stem cells can REPLICATE many times for long periods. Stem cells are unspecialized and can DEVELOP into different types of cells. 1 STEM CELL RESEARCH PRIMER

2 Stem Cell Types According To Their Source Adult Type Specific Stem Cells Stem Cell Types Undifferentiated cells that exist among specialized cells found in tissues and in organs after birth 1. Umbilical Cord Stem Cells Found in a newborn s umbilical cord Can be cultured to become every type of cell in the blood 2. Umbilical Blood Stem Cells From residual blood from a newborn s umbilical cord Can differentiate into other types of cells, like nerve cells 3. Placental Stem Cells Can protect against white matter brain injury in preterms Harvested from the placenta Current application to research on: Type 1 diabetes Alzheimer s Spinal cord injuries 4. Amniotic Fluid Stem Cells Extracted from the amniotic fluid and the amniotic membrane of the placenta Can differentiate into these cell and tissue types: Skin Cartilage Cardiac tissue Nerves Muscle Bone 5. Gastric Epithelial Stem Cells Closely linked to gastric cancer Regarded by scientists as a result of dysregulated differentiation of stem and progenitor cells in the intestines 2 STEM CELL RESEARCH PRIMER

3 6. Heart Stem Cells Multipoint stem or progenitor cells Found in the hearts of mammals Self-renewing Generate coronary vessels and heart muscle cells known as cardiomyocytes 7. Neural Stem Cells Can differentiate into: Neurons Glia of the nervous system Self-renewing 8. Hepatic Stem Cells The liver s regenerative capabilities is attributed to the presence of stem cells Studies suggest that liver cells are functional stem cells of the organ 9. Epidermal Stem Cells Multipotent adult stem cells found in our skin Are active during skin renewal Currently used to grow skin for burn victims 10. Adipose Stem Cells Isolated from fat tissues They can differentiate into: Bone cells Cartilages 11. Bone Marrow Stem Cells Found in the bone marrow Can give rise to different blood cell types Used for treating blood-related diseases: Leukemia Some types of lymphoma Embryonic Stem Cells Embryonic stem cells are pluripotent cells from the inner cell mass of a blastocyst. They are not embryos and therefore cannot become complete organisms. 1. Embryonic Stem Cells 2. Embryonic Germ Cells Usually harvested from embryos that are 5-7 years old Embryos that would otherwise be discarded by fertility clinics Subject to ethical and moral issues Obtained from miscarried or aborted fetuses Induced Pluripotent Stem Cells Genetically reprogrammed to have the pluripotency possessed by embryonic stem cells Currently used for: Drug development Modeling of diseases 3 STEM CELL RESEARCH PRIMER

4 Stem Cell Types According To Differentiating Capabilities Hematopoietic Stem Cells (HSC) Can differentiate into all types of blood cells Stem cells that are HSCs Found in adult bone marrow Found in umbilical cord blood Mesenchymal Stem Cells (MSC) Multipotent stem cells capable of differentiating into: Bone cells Cartilage cells Muscle cells Fat cells Stem Cell Types According To Potency Capabilities The potency of stem cells refers to the number of differentiations or specializations they can undergo. Totipotent Stem Cells Can differentiate into any kind of cell in the body The most versatile kind of stem cell Pluripotent Stem Cells Can differentiate into a variety of cell types, but not all types Multipotent Stem Cells A level lower than pluripotent stem cells in the potency hierarchy Can transform into more than one type of cell More limited than totipotent and pluripotent stem cells Unipotent Stem Cells Can differentiate to only one lineage Have the lowest potency Treatment Medical Applications Of Stem Cells Stem cells can be transplanted to develop new genes that can cure diseases. Research New genes that can t fix defects can cause cells to become diseased. The new genes can target defective tissues and replace them. Even if the new genes can t fix defects, they can can shed light on diseases by giving insight on sick cells. 4 STEM CELL RESEARCH PRIMER

5 Organ Production And Transplant A patient s body cells can be combined with an egg cell from an egg donor to create an embryo. An embryo has stem cells that can be grown into any specialized type of organ or tissue cells. Stem cells are essentially clones of the patient s cells, therefore they are genetically identical. Can result in risk-free transplants since the body won t reject the new cells. Arguments For and Against Stem Cell Research Religious Arguments Against Stem Cell Research Many Christian groups believe that life begins at conception. As a result, they believe that embryonic stem cell research murders a child. Since the research terminates an embryo for the cells, some religious groups believe it is murder to harvest the cells. Religious leaders point out that life is from conception until natural death. As such, any form of abortion, infanticide, or even euthanasia is unjust. In the case of stem cells, the argument is that terminating a fetus for stem cells is the murder of a potential life. Moral and Ethical Arguments Against Stem Cell Research Scientists and legal professionals point out that embryonic stem cell research is unnecessary. Since it is not necessary for the study of stem cells, it is unethical and immoral to use an aborted fetus. The ethical argument stems from the fact that adults also have stem cells. By working with adult volunteers, scientists are able to study stem cells. They can then identify potential medical applications for the cells. Scientists can also use stem cells from the umbilical cord of a newborn child. Due to these other sources, scientists consider embryonic research unnecessary. The Tax Argument Federal funding is part of the stem cell controversy. Individuals against stem cell research do not want to use tax dollars for research. Since stem cell research is controversial, it is illogical to use tax dollars for funding. Others argue for federal funding for stem cell research. It means that the research will have more government oversight. This allows the government to set regulations on research. It also limits the use of stem cells in medicine. Federal funds pay for research on aborted fetuses. By lifting the ban on stem cell research, grants can apply to embryonic studies. The argument is it s illogical to fund one project but ignore other projects. Arguments For Stem Cell Research The stem cell research debate also has many arguments that are pro research. The primary argument for stem cell research is the medical use of stem cells. The argument is positive medical uses of stem cells outweigh moral and ethical concerns. Using stem cells may cure diseases and save lives. Embryonic stem cell research focuses on the medical use of the cells. It researches potential treatments. It also looks for other uses of stem cells beyond disease treatment. Arguments for stem cell research also relate to religious beliefs. Some religions do not consider life to start at conception. As a result, they do not feel it is wrong to use embryonic stem cells. The religious arguments differ between religious groups as well as different religious beliefs. 5 STEM CELL RESEARCH PRIMER

6 The Stem Cell Research Timeline Stem cell research may be recent, but it has contributed to many groundbreaking developments in medicine. Although it has significantly helped in medical research, it is still, to this day, a subject of ethical debate Term Was Coined by Ernst Haeckel The term stem cell can be traced way back to Moreover, this was coined by a German biologist, Ernst Haeckel. However, Haeckel did not use this term to refer to the same stem cells we know of today. At the time, science and technology had yet to isolate stem cells for research. Rather, he used this to describe the ancestor cell of all living organisms. Additionally, this term referred to a fertilized egg Alexander Maximow Explores the Concept of Stem Cells The Russian scientist was able to provide a definition of stem cells much closer to our current understanding of them. Maximow frequently lectured about the ancestor cell from which all blood cells originate. Moreover, he discussed the ability of blood cells to differentiate into different types of cells Leroy Stevens Stem Cell Research On Mice A scientist based in Maine experimented on mice to further the understanding of cancer. In his research, he was able to observe the mixture of differentiated and undifferentiated cells in teratomas. It is through this research that scientists are now able to understand the concept of pluripotent cells. Moreover, these cells can transform into any type of cell in the body Bone Marrow Transplant Attempt E. Donnall Thomas was a scientist based in Seattle who also maintained a medical practice. He was able to conduct the first attempt at a bone marrow transplant on a human patient. Moreover, he was awarded the Nobel Prize for his groundbreaking work First Successful Bone Marrow Transplant Robert A. Good is the first person to successfully conduct a bone marrow transplant. This procedure was done on a child who was suffering from a rare immune deficiency. Additionally, the child s condition was hereditary and killed many of his family members. Following the transplant, the child was able to have a healthy and full life Isolating Stem Cells Martin Cambridge and Gail Martin were working on separate projects in Although separate, these projects shared the same goal of isolating embryonic stem cell lines. Their research was able to isolate these pluripotent stem cells through working with mice embryos. Both researchers were able to successfully isolate embryonic stem cells Converting Cells Scientists Andrew Lassar and Harold Weintraub also experimented with rodents. Moreover, the researchers were able to successfully produce myoblasts (precursors of muscle cells) from fibroblasts (cells found in certain connective tissue). It is through this study that we are now able to convert one adult cell into another type of adult cell Knockout Mice The research group of Mario Capecchi, Martin Evans, and Oliver Smithies created the first knockout mice. These are specially bred mice that are intentionally missing specific genes. Through studying these mice, scientists were able to understand diseases such as cancer and diabetes on a genetic level. Furthermore, they were able to fine tune creating these knockout mice via embryonic stem cells and homologous recombination. 6 STEM CELL RESEARCH PRIMER

7 1996 Cloning Dolly the Sheep Scientists cloned the first mammal through the use of an adult cell. The said clone was born at the Roslin Institute. The researchers objective was to understand the production of medicine in the milk of farm animals Cancer Stem Cells We arrived at the groundbreaking discovery that cancer grows out of stem cells through Dominique Bonnet and John Dick s research. Moreover, they were able to come to the conclusion that leukemia originates from the same precursor cells as that of normal healthy blood cells Developing the First Embryonic Stem Cell Line James Thomson and Jeffrey Jones headed a research team at the University of Wisconsin, Madison. Moreover, this team was able to isolate human embryonic stem cells to create a stem cell line. Additionally, they were also able to identify the embryonic stem cell s pluripotent properties. Given this, scientists now understand the great potential of stem cell research in medicine Falsified Findings Korean scientists falsified research findings in Their claim was they were able to produce pluripotent stem cells out of unfertilized egg cells. As a result, the Korean scientific community suffered a blow to their credibility in the eyes of the public. Following this incident, people began to feel more doubtful of scientific facts Converting Embryonic Stem Cells Yuan Wang and George A. Daley were able to publish their findings in Their research was able to produce blood cells in mice from their embryonic stem cells. Moreover, their findings became crucial in developing the process of stem cell transplantation Induced Pluripotent Cells Scientists Yamanaka and Takahashi were able to produce induced pluripotent cells through experimenting with rodents. Furthermore, these induced pluripotent cells are important in stem cell research because these are reprogrammed adult cells made to function like embryonic stem cells. Moreover, these are pluripotent cells that do not require fertilization Donor-Matched Embryonic Cells George Daley and his colleagues continued to experiment with mice. Through their research, they managed to create donormatched embryonic stem cells by means of parthenogenesis. These cells have the potential to replace embryonic stem cells in treatment and research. Moreover, the research team hopes that their findings will contribute to donor-specific transplants. In using your own cells, the body is less likely to reject the transplant Creation of Human Induced Pluripotent Cells Three separate research teams were able to create human induced pluripotent cells. These teams were spearheaded by scientists Yamanaka, Thomson, and Daley. Daley s study, in particular, was the first to harvest a sample immediately upon walkin rather than having it being frozen prior to use Obama Administration Revises Restrictions In 2009, then US President Barack Obama allowed for the revision of some of the restrictions on research involving embryonic stem cells. It is through this executive order that stem cell research was able to get more funding and thus be capable of moving forward. Following this, we can expect more groundbreaking developments in the years to come. For more information on stem cell research, stem cell therapy, and stem cell treatments, visit 7 STEM CELL RESEARCH PRIMER