KOLEKSI DAN APLIKASI STEM SEL EDITED BY ; PROF.DR.PRATIWI TS,MS 1 STEM CELLS -PROF PRATIWI 2012 4/12/2015 2 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Stem Cell – Definition A cell that has the ability to continuously divide and differentiate (develop) into various other kind(s) of cells/tissues 3 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Introduction Can we vs. should we Dramatic advances of modern molecular genetics Should we ask the morality questions before attempting the “can we” questions? 4 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Stem Cell/Cloning Topics What are stem cells? History of stem cell/cloning research Possible uses of the technology Current status/knowledge Questions and known problems Legal considerations Politics Moral considerations 5 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Kinds of Stem Cells Stem cell type Totipotent Totipotent Pluripotent Pluripotent Multipotent Multipotent 6 Description Examples Cells from early Each cell can develop (1-3 days) into a new individual embryos Cells can form any (over 200) cell types Some cells of blastocyst (5 to 14 days) Cells differentiated, Fetal tissue, cord but can form a number blood, and adult of other tissues stem cells STEM CELLS -PROF PRATIWI 2012 4/12/2015 Stem Cell/Cloning Topics What are stem cells? History of stem cell/cloning research Possible uses of the technology Current status/knowledge Questions and known problems Legal considerations Politics Moral considerations 7 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Kinds of Stem Cells Stem cell type 8 Description Examples Totipotent Totipotent Each cell can develop into a new individual Cells from early (1-3 days) embryos Pluripotent Pluripotent Cells can form any (over 200) cell types Some cells of blastocyst (5 to 14 days) Multipotent Multipotent Cells differentiated, but Fetal tissue, cord can form a number of blood, and adult other tissues stem cells STEM CELLS -PROF PRATIWI 2012 4/12/2015 Stages of Embryogenesis Day 2 2-cell embryo Day 1 Fertilized egg 9 Day 11-14 Tissue Differentiation STEM CELLS -PROF PRATIWI 2012 Day 3-4 Multi-cell embryo Day 5-6 Blastocyst 4/12/2015 Derivation and Use of Embryonic Stem Cell Lines Isolate inner cell mass (destroys embryo) Outer cells (forms placenta) Inner cells (forms fetus) Day 5-6 Blastocyst Culture cells “Special sauce” (largely unknown) Liver 10 STEM CELLS -PROF PRATIWI 2012 Kidney Heart repaired Heart muscle 4/12/2015 Bone Marrow Stem Cells 11 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Possible Uses of Stem Cell Technology Replaceable tissues/organs Repair of defective cell types Delivery of genetic therapies Delivery chemotherapeutic agents 12 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Early Successes – Adult Stem Cells Human mesenchymal stem cells turned on genes found in bone, cartilage, adipose, muscle, hematopoiesis-supporting stromal, endothelial, and neuronal cells. Multipotent adult progenitor cells have been shown to differentiate into functional, hepatocyte-like cells. 13 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Early Successes – Adult Stem Cells Human neural stem cells can migrate extensively in the brain after injection. Adult stem cells have been isolated from amniotic fluid, peripheral blood, umbilical cord blood, umbilical cord, brain tissue, muscle, liver, pancreas, cornea, salivary gland, skin, tendon, heart, cartilage, thymus, dental pulp, and adipose tissue. 14 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Early Successes – Human Cloning 2001 – First cloned human embryos (only to six cell stage) created by Advanced Cell Technology (USA) 2004* – Claim of first human cloned blastocyst created and a cell line established (Korea) – later proved to be fraudulent 15 *Hwang, W.S., et al. 2004. Evidence of a Pluripotent Human Embryonic Stem Cell Line Derived from a Cloned Blastocyst. Science STEM CELLS -PROF PRATIWI 2012 4/12/2015 303: 1669-1674. Cloned Embryonic Stem Cells – Advantages/Problems Advantages No rejection “Prefect match” Problems Only 10% of cloned oocytes became embryos 0% (0 out of 2061) survived to become a cell line Genetic donor was same as egg donor (i.e., won’t work for males!) Cost is high (health insurance probably won't pay) 16 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Challenges to Stem Cell/Cloning Research Stem cells need to be differentiated to the appropriate cell type(s) before they can be used clinically. Recently, abnormalities in chromosome number and structure were found in three human ESC lines. 17 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Challenges to Stem Cell/Cloning Research Stem cell development or proliferation must be controlled once placed into patients. Possibility of rejection of stem cell transplants as foreign tissues is very high. 18 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Challenges to Stem Cell/Cloning Research Contamination by viruses, bacteria, fungi, and Mycoplasma possible. The use of mouse “feeder” cells to grow ESC could result in problems due to xenotransplantation (complicating FDA requirements for clinical use). 19 STEM CELLS -PROF PRATIWI 2012 4/12/2015 At Conception, It Is Only a Single Cell Claim: Fertilized eggs are single cells, like blood cells or other parts of the body Rebuttal: This single cell is unique from both the father’s and mother’s cells and is the beginning of every new human being 20 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Only a Small Percentage of Embryos Implant Claim: Embryos are only potential life. Most do not result in births Rebuttal: 25-33% of women become pregnant in the first month 33% of implanted embryos die before birth There are countries in which over 25% of children die before age 5. Should we allow killing of children? 21 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Unexpected Phenotypes Phenotype more severe than expected: - Early lethal - Lack of inductive signals Phenotype less severe than expected: - Incomplete gene disruption - Genetic redundancy - Functional redundancy (compensation) 22 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Applied research - DNA Applied research arising out of the discovery of DNA includes disease diagnosis, drug development, gene therapy and, more recently, genetically-modified organisms 23 STEM CELLS -PROF PRATIWI 2012 4/12/2015 24 STEM CELLS -PROF PRATIWI 2012 4/12/2015 25 STEM CELLS -PROF PRATIWI 2012 4/12/2015 26 STEM CELLS -PROF PRATIWI 2012 4/12/2015 27 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Transgenic Animals and Products Mice- transgenetic mice have been used in several ways. One of the best known is to produce human antibodies. Cattle- are used to control disease such as mastitis in dairy cows. 28 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Methods of creating transgenetic animals Step One- collect embryos With proper stimulation far more embryos can be obtained than would be the natural result of the reproductive process. 29 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Methods of creating transgenetic animals Step Two- Inject embyros. A pro nucleus is the haploid nucleus of the sperm or ovum that have united in fertilization to form a zygote. 30 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Embryo Transfer Embryo transfer is the harvesting of fertilized ova from a donor and implanting them into a recipient. The harvested embyros are transferred to a recipient. 31 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Clone Birth Defects • Cloned offspring often suffer from large offspring syndrome, where the clone and the placenta that nourished it are unusually large. • Cloned offspring often have serious inexplicable respiratory or circulatory problems, which causes them to die soon after birth. • Clones tend to have weakened immune systems and sometimes suffer from total immune system failure. • Very few clones actually survive to adulthood. 32 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Clones appear to age faster than normal. Clones experience problems associated with old age, such as arthritis, while they are still young. This may be due to the fact that clones have shorter telomeres 33 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Transgenic Animals: Animal biotechnology is the field to engineer transgenic animals, i.e., animals that carry genes from other species. The technology has already produced transgenic animals such as mice, rats, rabbits, pigs, sheep, and cows. 34 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Transgenic Animals Definition: An organism (typically a mouse) that is engineered to carry a foreign gene, or transgene of choicem as part of its own genetic material. 35 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Transgenic Animals Purpose: These animals are very useful for delineating the function of newly discovered genes as well as for producing useful proteins in large animals. 36 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Transgenic Animals In some of the eggs, the genetic material integrates at a random site on a chromosome and so becomes part of the mouse cell's genetic material the animal resulting from that egg will therefore carry that gene and so is referred to as a "transgenic animal". 37 STEM CELLS -PROF PRATIWI 2012 4/12/2015 What is a transgenic animal? 38 A transgenic animal is one whose genome has been changed to carry genes from other species. For example, an embryo can have an extra, functioning gene from another source artificially introduced into it, or a gene introduced which can knock out the functioning of another particular gene in the embryo. STEM CELLS -PROF PRATIWI 2012 4/12/2015 Transgenic Animals Animals that have their DNA manipulated in this way are known as transgenic animals. Transgenic animals are useful as disease models and producers of substances for human welfare. 39 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Why are these animals being produced? 40 Some transgenic animals are produced for specific economic traits. E.g., transgenic cattle were created to produce milk containing particular human proteins, which may help in the treatment of human emphysema. STEM CELLS -PROF PRATIWI 2012 4/12/2015 How are transgenic animals produced? DNA microinjection Introducing the transgene DNA directly into the zygote at an early stage of development. No vector required. Retrovirus-mediated gene transfer: Infecting mouse embryo with a retrovirus which carry the new gene. Using virus as a vector . 41 STEM CELLS -PROF PRATIWI 2012 4/12/2015 42 Embryonic stem cell-mediated gene transfer The blastocyst (inner layer of a fertilized egg) is harvested and mixed with recombinant DNA and inserted back in the blastocyst. Sperm-mediated transfer Use of “Linker protein" to attach DNA to sperm which transfer the new DNA during fertilization. Gene gun STEM CELLS -PROF PRATIWI 2012 4/12/2015 Embryonic stem cell-mediated gene transfer This method involves: Isolation of totipotent stem cells (stem cells that can develop into any type of specialized cell) from embryos. The desired gene is inserted into these cells. Cells containing the desired DNA are incorporated into the host's embryo. 43 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Procedure for Producing Transgenic Mice First Breeding Pair: Fertile male + superovulated female Fertile male Superovulated female = immature female induced to superovulate Pregnant mare’s serum (=FSH) on day 1 Human Chorionic Gonadotropin (=LH) on day 3 Mated on day 3 Fertilized oocytes microinjected on day 4 with foreign DNA construct. Microinjected oocytes are transferred to the oviducts of surrogate mothers at end of day 4. 44 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Procedure for Producing Transgenic Mice Second breeding pair: Sterile male + surrogate mother Sterile male produced through vasectomy Surrogate mother must mate to be suitable recipient of injected eggs Mated on day 3 Microinjected oocytes from first breeding pair are transferred to oviducts on day 4 Embryos implant in uterine wall and are born 19 days later. Southern blotting techniques confirm presence and copy number of transgenes. 45 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Procedure for Producing Transgenic Mice Third breeding pair: Foster parents Fertile male + female mated to give birth on same day surrogate mother Serves as foster parent if caesarian section is required for surrogate mother 46 STEM CELLS -PROF PRATIWI 2012 4/12/2015 47 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Totipotent and pluripotent cells isolated directly from the inner cell mass of embryos at the blastocyst stage. Totipotent = meaning that its potential is total. (IVF-IT surplus embryos in case of humans) pluripotent = they can give rise to many types of cells but not all types of cells (no fetus developed). 48 STEM CELLS -PROF PRATIWI 2012 4/12/2015 More about stem cells Embryonic stem cells Truly pluripotential several countries have sanctioned deriving human ES-cell lines from ‘surplus’ embryos created through in vitro fertilization although several human ES-cell lines have been made, they will not be immunologically compatible with-PROF most patients STEM CELLS PRATIWI 2012 49 who require cell transplants. Adult stem cells More restricted pattern of differentiation medical gain without ethical pain 4/12/2015 Transgenic mice The growth hormone gene has been engineered to be expressed at high levels in animals. The result: BIG ANIMALS metallothionein promoter regulated as heavy metals 50 STEM CELLS -PROF PRATIWI 2012 Mice fed heavy metals are 2-3 times larger 4/12/2015 Studies Utilizing Transgenic Mice “Pharm” animals (transgenic livestock) Bioreactors whose cells have been engineered to synthesize marketable proteins DNA constructs contain desired gene and appropriate regulatory sequences (tissue-specific promoters) More economical than producing desired proteins in cell culture 51 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Antifreeze gene promoter with GH transgene in atlantic salmon GH gene comes from larger salmon 52 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Wild and domestic trout respond differently to overproduction of growth hormone. So in some cases, GH not effective. 53 STEM CELLS -PROF PRATIWI 2012 4/12/2015 Improving Agricultural Products with Transgenics Transgenic technology holds great potential in agriculture, medicine, and industry The benefits of these animals to human welfare can be grouped into areas: Agriculture Medicine Industry 54 STEM CELLS -PROF PRATIWI 2012 4/12/2015 1. Agricultural Applications A) Breeding Traditional cross breeding have been used for ages to create chickens, cows, pigs etc. Farmers have always used selective breeding to produce animals that exhibit desired traits (e.g., increased milk production, high growth rate). Traditional breeding is a time-consuming, difficult task. 55 STEM CELLS -PROF PRATIWI 2012 4/12/2015 56 Researchers have now used gene transfer to improve the productivity of livestock. Now it is possible to develop traits in animals in a shorter time and with more precision. It also offers farmers an easy way to increase yields. STEM CELLS -PROF PRATIWI 2012 4/12/2015 57 Scientists can improve the size of livestock genetically. Transgenic cows exist that produce more milk or milk with less lactose or cholesterol. Transgenic cows have been used to produce milk which are richer in proteins and lower in fat. STEM CELLS -PROF PRATIWI 2012 4/12/2015 58 B) Quality Herman, a transgenic bull carries a human gene for Lactoferrin (gene responsible for higher iron content) Pigs and cattle that have more meat on them. Sheep that grow more wool. Eggs can be made healthier with high quality protein. STEM CELLS -PROF PRATIWI 2012 4/12/2015 59 C) Disease resistance Disease-resistant livestock is not a reality just yet. But there has been improvement in disease reduction in animals. The Foot- and- Mouth disease in England in 2000 led to destruction of herds of cattle, sheep and goat. STEM CELLS -PROF PRATIWI 2012 4/12/2015 Scientists are attempting to produce disease-resistant animals, such as influenzaresistant pigs, but a very limited number of genes are currently known to be responsible for resistance to diseases in farm animals. Transgenic disease protection promises a long term cost effective method of battling animal diseases. 60 STEM CELLS -PROF PRATIWI 2012 4/12/2015 2. Medical Applications A) Xenotransplantation 61 Transplant organs may soon come from transgenic animals. STEM CELLS -PROF PRATIWI 2012 4/12/2015 B) Nutritional supplements and pharmaceuticals 62 Products such as insulin, growth hormone, and blood anti-clotting factors may soon be or have already been obtained from the milk of transgenic cows, sheep, or goats. The first transgenic cow (Rosie ) produced human protein-enriched milk at 2.4 grams per liter. STEM CELLS -PROF PRATIWI 2012 4/12/2015 63 This transgenic milk is a more nutritionally balanced product than natural milk and could be given to babies or the elderly with special nutritional or digestive needs. A transgenic cow exists that produces a substance to help human red cells grow. STEM CELLS -PROF PRATIWI 2012 4/12/2015 C) Human gene therapy 64 Human gene therapy involves adding a normal copy of a gene (transgene) to the genome of a person carrying defective copies of the gene. Finland produced a calf with a gene that makes the substance that promotes the growth of red cells in humans. STEM CELLS -PROF PRATIWI 2012 4/12/2015 3. Industrial Applications : 65 By extracting polymer strands from the milk and weaving them into thread, the scientists can create a light, tough, flexible material that could be used in such applications as military uniforms, medical microsutures, and tennis racket strings. Biosteel is an extraordinary new product that may be soon used in bullet proof vests and in suture silk for stitching wounds. Animals have been used as “Bioreactors” to produce proteins. Genes for desired proteins are introduced via transgenics to the target cells . STEM CELLS -PROF PRATIWI 2012 4/12/2015 : 66 The target cells are cloned and several such cells are raised into adults. These adults may produce milk or eggs (due to the presence of introduced gene rich in desired protein). Toxicity-sensitive transgenic animals have been produced for chemical safety testing. Microorganisms have been engineered to produce a wide variety of proteins, which in turn can produce enzymes that can speed up industrial chemical reactions. STEM CELLS -PROF PRATIWI 2012 4/12/2015 67 Transgenic animals have been used to produce pharmaceutical protein: example a human gene called AT III has been transferred to goats. Goats milk contain this protein that prevents blood clotting (goats multiply faster than cows) “Hen bioreactor” eggs are used to enrich protein by recombinant DNA technology. STEM CELLS -PROF PRATIWI 2012 4/12/2015 Transgenic Goats That Produce Valuable Proteins in Their Milk – “Biorectors” 68 STEM CELLS -PROF PRATIWI 2012 4/12/2015 A Summary of Animal Cloning 69 Although there has been limited success in cloning some animals, it's still seen as a viable technology. Ever since the announcement of the birth of Dolly, additional sheep, cows, goats, pigs, and mice have been cloned. STEM CELLS -PROF PRATIWI 2012 4/12/2015 : 70 There are still obvious problems as evidenced from the numerous deaths of cloned animals that occur just before or after birth. Cloning is a big first step. Genetic manipulation of cloned animals is the future direction of the cloning frontier. STEM CELLS -PROF PRATIWI 2012 4/12/2015 71 STEM CELLS -PROF PRATIWI 2012 4/12/2015 72 STEM CELLS -PROF PRATIWI 2012 4/12/2015