Stem cells By: Dr SM Koruji, Ph.D

What are Stem Cells? Stem Cells are extraordinary because: They can divide and make identical copies of themselves over and over again (Self-Renewal) Remain Unspecialized with no ‘ specific ’ function or become.... Specialized (Differentiated) w/ the potential to produce over 200 different types of cells in the body.

Diagram of stem cells to differentiated cells

Description: A colony of embryonic stem cells. 10X. Image in the Public Domain. Description: (A) Human ESCs; (B) Neurons derived from Human ESCs. Images courtesy of Nissim Benvenisty.

Caption: This image depicts a colony of human embryonic stem cells grown over a period of 10 months in the absence of mouse feeder cells. The cell nuclei are stained green; the cell surface in red. Photo Credit: Courtesy Ren-He Xu/University of WisconsinCourtesy Ren-He Xu/University of Wisconsin

The Major Types of Stem Cells A.Embryonic Stem Cells From blastocysts left over from In-Vitro Fertilization in the laboratory From aborted fetuses B. Adult Stem Cells Stem cells have been found in the blood, bone marrow, liver, kidney, cornea, dental pulp, umbilical cord, brain, skin, muscle, salivary gland, testis....

Embryonic Stem Cells Mechanical Immunosurgery

Adult Stem Cells

The types of Stem Cells based on potential Totipotent stem cells Pluripotent stem cells  EG  EC Multipotent stem cells

Pluripotent stem cells

Advantages and Disadvantages to Embryonic and Adult Stem Cells. Embryonic S.C.Adult S.C. “ Pluripotent ” (can become any cell) “ Multipotent ” ( “ can become many but not any ” ) Stable. Can undergo many cell divisions. Less Stable. Capacity for self- renewal is limited. Easy to obtain but blastocyst is destroyed. Difficult to isolate in adult tissue. Possibility of rejection??Host rejection minimized

Reprinted with permission of Do No Harm. Click on image for link to website.

Why is Stem Cell Research So Important to All of Us? Stem cells allow us to study how organisms grow and develop over time. Stem cells can replace diseased or damaged cells that can not heal or renew themselves. We can test different substances (drugs and chemicals) on stem cells. We can get a better understanding of our “ genetic machinery. ”

Why the Controversy Over Stem cells? Embryonic Stem cells are derived from extra blastocysts that would otherwise be discarded following IVF. Extracting stem cells destroys the developing blastocyst (embryo). -Questions for Consideration- Is an embryo a person? Is it morally acceptable to use embryos for research? When do we become “ human beings? ”

Therapeutic Possibilities of Stem Cell Research

Reprinted with permission from the Univ. of Kansas Medical Center. Click on image for link to originating website.

What Human Diseases are Currently Being Treated with Stem Cells? Parkinson’s Disease Leukemia (Bone Marrow Transplants) Skin Grafts resulting from severe burns Stem Cell Therapy has the Potential to: Regenerate tissues/organs Cure diseases like diabetes, multiple sclerosis, etc.

Olfactory Bulb Stem Cells Primitive stem cells that normally feed the constant, life-long regeneration of odor-detecting nerves Like embryonic stem cells, they develop into many different types of cells in the right chemical or cellular environment Fairly accessible, readily obtained in all individuals and easy to grow and multiply Potential non-embryonic source for cells that could prove useful in replacing nerve cells lost due to injury or diseases like ALS and Parkinson's Transplant not subject to immune rejection

Lou Gehrig’s Disease (ALS) Mouse experiments Neuronal stem cells transplanted into spinal cord Significantly prolonged lives by becoming neurons and interacting with existing neurons Symptoms developed at 137 days verses 90 days Treated mice lived 2 months longer A neuromuscular disease that attacks the nerve cells and pathways in the brain and spinalcord

Bone Repair NJ Institute of Technology – use of stem cells to induce bone repair Adult Stem Cells mixed with biomaterials known as scaffolds to regenerate bone growth Stem Cells from one person can successfully implant in another Diabetes, osteoporosis, cancer surgeries Also testing biomaterials that may repair cartilage, tendons and neuronal tissue

Spinal Cord Injury Rat Experiments Sensory and motor deficiencies; paralysis Treatment derived from human embryonic stem cells and must occur in the acute phase of spinal Stabilization Cells differentiate into earlystage oligodendrocytes, the building blocks of myelin Transplanted cells migrated to appropriate neuronal sites in the spinal cord 7 days post injury vs. 10 months post injury

Retinal Degeneration Mice predisposed for Retinitis Pigmentosa: a degenerative disease that destroys retinas Injected bone marrow derived stem cells into the back of mouse eyes during development Dramatically curtailed retinal degeneration Completely normal vasculature, improved retinal tissue and light response Disorders of the retina that have vascular and neuronal degeneration: genetic disorders known collectively as retinitis pigmentosa

Biological Pacemaker Human Embryonic Stem Cells genetically engineered and coaxed to become heart cells Clusters of cells beat on their own triggered the unified beating of rat heart muscle cells Triggered regular beating when implanted in guinea pigs Cells responded to drugs used to slow or speed up heart rate Use genetic engineering to customize the pacing rate of the cells

Cystic Fibrosis: Stem Cell-Gene Therapy Approach

Cosmetic and Reconstructive Surgery Conventional soft tissue implants lose 40 to 60% of volume Stem cell generated natural tissues instead of synthetic implants Avoid problems of saline and silicon Won’t shrink or lose shape Mouse experiments: bone marrow stem cells placed under the skin for four weeks; stem cells differentiated into fat generating cells and implants retained original size and shape Breast cancer surgery, post-cancer facial soft tissue reconstruction, trauma surgeries

Cloning

Cloning Defined What is cloning? Asexual reproduction Examples? Bacteria, fungus Plants – cutting – potato Farm animals

Asexual Reproduction The Association of Reproductive Health Professionals

Cloning Dolly (Roslin Institute

Cloning A Sheep

Human Stem Cell Production

Removing Nucleus Removing the maternal nucleus before nuclear transfer (Roslin Institute

Nuclear transfer Nuclear transfer embryo about to be activated (Roslin Institute

Coning for use in Stem Cells Cloning techniques for creating stem cells Therapeutic cloning Reproductive cloning

IVF – In Vitro Fertilization  Available since 1986  About 100,000 IVF kids in U.S.  Often creates extra embryos  U.S. - About 400,000 frozen embryos (unregulated)  England – 52,000 (regulated by government)

Intracytoplasmic Sperm Injection (ICSI)

How many are needed for fertilization? Natural conception  20,000,000 Intra-uterine insemination  1,000,000 In-vitro fertilization (IVF)  10,000 Intra-cytoplasmic sperm injection (ICSI)  1

The Science of Transgenics Biotechnology - General Definition The application of technology to improve a biological organism Biotechnology - Detailed Definition The application of the technology to improve the biological function of an organism by adding genes from another organisms

ATTCGA ATTGGA Susceptible Normal Gene Resistant Mutant Gene Mutagenesis Treatment Mutagenesis Changes the DNA Sequence

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