Cloning Stem Cells Dr Heinz Lycklama heinzosta com

Cloning & Stem Cells Dr. Heinz Lycklama heinz@osta. com www. osta. com/messages @ Dr. Heinz Lycklama 1

Stem Cells and Cloning n n n n n The Human Cell, DNA, Nucleus, Chromosomes Early Stages of Embryo Development Stem Cells – Embryo & Adult The Cloning of Dolly Cells, DNA, Chromosomes, Telomeres Cloning of Humans? Comparison of stem cells and cloning techniques Medical & Ethical Challenges History & Summary @ Dr. Heinz Lycklama 2

The Human Cell n n n n Cell size – 10 micron in diameter 220 types of human cells – blood, bone, skin, heart, etc. From conception to birth, baby adds 15, 000 cells per minute ~50 trillion cells in human body Each cell more complex than space shuttle DNA (chromosomes) are most complex molecules in universe All chromosomes from one person would stretch from earth to moon and back 5, 000 times Information in chromosomes would fill books that would fill Grand Canyon 40 times @ Dr. Heinz Lycklama 3

The Human Cell @ Dr. Heinz Lycklama 4

The Cell Nucleus The nucleus is a highly specialized organelle that serves as the information and administrative center of the cell. This organelle has two major functions. It stores the cell's hereditary material, or DNA, and it coordinates the cell's activities, which include intermediary metabolism, growth, protein synthesis, and reproduction (cell division). DNA molecule – double helix, two strings twisted together in a long spiral Packed inside the nucleus of every human cell is nearly 6 feet of DNA, which is divided into 46 individual molecules, one for each chromosome and each about 1. 5 inches long. http: //www. cartage. org. lb/en/themes/Sciences/Zoology/Animal. Physiology/Anatomy/Animal. Cell. Structure/Nucleus/cellnucleus. jpg @ Dr. Heinz Lycklama 5

Early Stage of Embryo Development • Egg + sperm = 1 st cell • 2 genetically identical cells within 12 15 hours • 8 cell stage in 2 days • Blastocyst in 4 5 days • Chemical exchange occurs between blastocyst and mother’s tissue http: //departments. weber. edu/chfam/Prenatal/blastocyst. html @ Dr. Heinz Lycklama 6

Stem Cells – What Are They? A stem cell is essentially the building block of the human body. The stem cells inside an embryo will eventually give rise to every cell, organ and tissue in the fetus's body. Unlike a regular cell, which can only replicate to create more of its own kind of cell, a stem cell is pluripotent. When it divides, it can make any one of the 220 different cells in the human body. Stem cells are pluripotent, which means that they can develop into every cell, every tissue and every organ in the human body. Stem cells also have the capability to selfrenew they can reproduce themselves many http: //science. howstuffworks. com/cellular microscopic biology/stem cell. htm times over. @ Dr. Heinz Lycklama 7

Embryonic Stem Cells 1. They can generate large quantities of tissue rapidly Human Embryonic Stem Cells 2. They can become any cell in the body Embryonic stem cells Brain Heart Bone marrow Fat @ Dr. Heinz Lycklama Cartilage 8

More on Stem Cells n n Stem cells are capable of self renewal and becoming many different cell types (e. g. blood, nerve, bone, etc. ) to form tissue in humans Two types of stem cells n n n Embryonic stem cells (ESC) Adult stem cells (ASC) Each individual begins as a single cell or zygote but as the embryo grows, different cells in different places have to specialize, so that only certain instructions are executed—the cells become differentiated. The instructions are there, but turned off somehow @ Dr. Heinz Lycklama 9

Stem Cells – How They Work There are two types of stem cells: embryonic stem cells and adult stem cells. Embryonic stem cells come from an embryo the mass of cells in the earliest stage of human development that, if implanted in a woman's womb, will eventually grow into a fetus. When the embryo is between three and five days old, it contains stem cells, which are busily working to create the various organs and tissues that will make up the fetus. Adults also have stem cells in the heart, brain, bone marrow, lungs and other organs. They are our built in repair kits, regenerating cells damaged by disease, injury and everyday wear and tear. Adult stem cells were once believed to be more limited than stem cells, only giving rise to the same type of tissue from which they originated. But new research suggests that adult stem cells may have the potential to generate other types of cells, as well. http: //science. howstuffworks. com/cellular microscopic biology/stem cell. htm @ Dr. Heinz Lycklama 10

How Cloning Works Cloning is the process of making a genetically identical organism through nonsexual means. It has been used for many years to produce plants. Animal cloning has been the subject of scientific experiments for years, but garnered little attention until the birth of the first cloned mammal in 1997, a sheep named Dolly. Sexual reproduction involves the merging of two sets of DNA (one from the father's sperm and one from the mother's egg) to produce a new offspring that is genetically different from either parent. Asexual reproduction (without sex) produces offspring that are genetically identical to the single parent organism. Since Dolly, several scientists have cloned other animals, including cows and mice. The recent success in cloning animals has sparked fierce debates among scientists, politicians and the general public about the use and morality of cloning plants, animals and possibly humans. http: //science. howstuffworks. com/genetic science/cloning. htm @ Dr. Heinz Lycklama 11

Dolly – The First Cloned Mammal In 1997, cloning was revolutionized when Ian Wilmut and his colleagues at the Roslin Institute in Edinburgh, Scotland, successfully cloned a sheep named Dolly was the first cloned mammal. Wilmut and his colleagues transplanted a nucleus from a mammary gland cell of a Finn Dorsett sheep into the enucleated egg of a Scottish blackface ewe. The nucleus egg combination was stimulated with electricity to fuse the two and to stimulate cell division. The new cell divided and was placed in the uterus of a blackface ewe to develop. Dolly was born months later. Dolly was shown to be genetically identical to the Finn Dorsett mammary cells and not to the blackface ewe, which clearly demonstrated that she was a successful clone (it took 276 attempts before the experiment was successful). http: //science. howstuffworks. com/genetic science/cloning 3. htm @ Dr. Heinz Lycklama 12

Cloning, Cells, Chromosomes Chromosome Cell Nucleus @ Dr. Heinz Lycklama 13

Chromosomes and Telomeres Gene 1 TTAGGG Gene 2 Chromosome @ Dr. Heinz Lycklama DNA 14

Telomere Length in Base Pairs Declines With Age (human white blood cells) 8, 000 3, 000 1, 500 0 35 65 Age (years) @ Dr. Heinz Lycklama 15

The Cloning of Dolly n n Cloned from a healthy 6 year old sheep Used 277 cloned embryos to produce one cloned sheep n n Failed 276 times Took 277 attempts to clone Dolly Showed signs of premature aging at age 3 Died at age 6 (average life = 13) from progressive lung disease (old age) n n DNA was already 6 years old when born Telomere length declines with age * * Can be increased by telomerase enzyme @ Dr. Heinz Lycklama 16

Technology of cloning

Human Cloning? If human reproductive cloning proceeds, the primary method scientists will likely use is somatic cell nuclear transfer (SCNT), which is the same procedure that was used to create Dolly the sheep. Somatic cell nuclear transfer begins when doctors take the egg from a female donor and remove its nucleus, creating an enucleated egg. A cell, which contains DNA, is taken from the person who is being cloned. Then the enucleated egg is fused together with the cloning subject's cell using electricity. This creates an embryo, which is implanted into a surrogate mother through in vitro fertilization. If the procedure is successful, then the surrogate mother will give birth to a baby that's a clone of the cloning subject at the end of a normal gestation period. http: //science. howstuffworks. com/genetic science/human cloning 1. htm @ Dr. Heinz Lycklama 18

Types of Cloning n Reproductive – scientists transfer genetic material from the nucleus of a donor adult cell to an egg whose nucleus, and thus its genetic material, has been removed. The reconstructed egg containing the DNA from a donor cell must be treated with chemicals or electric current in order to stimulate cell division. Once the cloned embryo reaches a suitable stage, it is transferred to the uterus of a female host where it continues to develop until birth n Therapeutic – the production of human embryos for use in research. The goal of this process is not to create cloned human beings, but rather to harvest stem cells that can be used to study human development and to treat disease. n n To produce stem cells for research or treatment Recombinant DNA – also called genetic engineering n To correct a defect/disease in a person @ Dr. Heinz Lycklama 20

Recombinant DNA Cloning Recombinant DNA – Hybrid DNA produced in the lab by joining pieces of DNA from different sources. To splice a human gene (in this case, the one for insulin) into a plasmid, scientists take the plasmid out of an E. coli bacterium, cut the plasmid with a restriction enzyme, and splice in insulin making human DNA. The resulting hybrid plasmid can be inserted into another E. coli bacterium, where it multiplies along with the bacterium. There, it can produce large quantities of insulin. @ Dr. Heinz Lycklama 21

Recombinant DNA Cloning The production of a recombined bacterium using a gene from a foreign donor and the synthesis of protein encoded by the recombinant DNA molecule. The genes used in DNA technology are commonly obtained from host cells or organisms called gene libraries. A gene library is a collection of cells identified as harboring a specific gene. For example, E. coli cells can be stored with the genes for human insulin in their chromosomes. @ Dr. Heinz Lycklama 22

The Goal of Stem Cell Research The goal of any stem cell therapy is to repair a damaged tissue that can't heal itself. This might be accomplished by transplanting stem cells into the damaged area and directing them to grow new, healthy tissue. It may also be possible to coax stem cells already in the body to work overtime and produce new tissue. To date, researchers have found more success with the first method, stem cell transplants. http: //learn. genetics. utah. edu/content/tech/stemcells/scresearch/ @ Dr. Heinz Lycklama 23

Creating Stem Cells for Research http: //learn. genetics. utah. edu/content/tech/stemcells/sccreate/ @ Dr. Heinz Lycklama 24

Getting ESC’s Using Reproduction http: //www. crystalinks. com/stemcellmap. jpg @ Dr. Heinz Lycklama 25

“Consensus” View of Stem Cells http: //dels. nas. edu/bls/stemcells/images/comparison_types_of_stem_cells. jpg @ Dr. Heinz Lycklama 26

Known ESC Problems/Concerns Require lifelong use of drugs to prevent rejection of tissue 2. Can produce tumors from rapid growth when injected into adult patients 3. Can produce tragic side effects (New England Journal of Medicine) 4. Mice clones using ESC were genetically defective 1. 5. Most clonings do not produce viable offspring 6. Most clones have serious defects and die early @ Dr. Heinz Lycklama 27

Conclusions – ASC/ESC Research n Adult Stem Cell research/therapy n n Does not destroy life Able to produce differentiated stem cells Successfully treated 70+ conditions Embryonic Stem Cell research/therapy n n n Destroys original embryos (life) Not successful in treating any condition Many side effects @ Dr. Heinz Lycklama 29

Medical/Ethical Issues n n Embryonic stems cells can be developed from discarded fertilized eggs in fertility clinics, aborted or miscarried fetuses. Whenever a human fetus is cultivated in the laboratory to develop into stem cells, it is no longer viable as a human fetus. In other words, the embryo is destroyed. While a majority of Americans supports stem cell research, a majority of them oppose it if they know that it involves embryo destruction. @ Dr. Heinz Lycklama 30

Ethical Challenges n n There are web sites offering human sex cells for sale. Sperms of Nobel laureates and eggs of beautiful models or female students of prestigious institutions of higher learning are collected and sold to the highest bidders @ Dr. Heinz Lycklama 31

Special Egg Donor Needed • Preferred donor will meet the following criteria: – – Height 5’-6” or taller Caucasian High ACT or SAT score College student or graduate under 30 – No genetic medical issues – Extra compensation for gifted athlete, science/math student or musician $80, 000

Stem Cell & Cloning Risks n David Prentice, Ph. D. Genetics: n n Cloning Expert Dr. Dixon states: n n “Adult stem-cell research … has already shown itself to be extremely promising for treating numerous degenerative diseases such as heart disease, stroke, Parkinson’s, Alzheimer’s, and diabetes. “The greatest worry many scientists have is that human clones even if they don’t have monstrous abnormalities in the womb will need hip replacements in their teenage years and perhaps develop senile dementia by their twentieth birthday The media has distorted the truth @ Dr. Heinz Lycklama 34

Summary n Some stem cell history n n Michael Fox & Parkinson disease n n Breakthrough with ASC in 2009 Touts ESC research but treated using ASC Many ASC success stories n n Spinal operation Stems cells from own hip to repair heart Stem cells from own bone marrow injected in coronary arteries result in increased function Stem cells from good eye to repair bad one @ Dr. Heinz Lycklama 35