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Embryonic Stem Cells. By Martin Brothers. Background. Embryo- a beginning or undeveloped state of something Stem- a primary plant axis that develops buds and shoots instead of roots Cells- the smallest structural unit of living matter capable of functioning independently
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Embryonic Stem Cells By Martin Brothers
Background Embryo- a beginning or undeveloped state of something Stem- a primary plant axis that develops buds and shoots instead of roots Cells- the smallest structural unit of living matter capable of functioning independently • Four Major Branches of Embryonic Stem Cells • Hematopoietic • Mesenchymal • Endodermal • Neural Definitions taken from Merriam-Webster Dictionary
History • Scientists discovered how to extract embryonic stem cells from mice in the early 1980’s • Martin Evans and Matthew Kaufman • university of Cambridge • published their method of growing embryos within the uterus of mice in the early 1980s • James Thomson • University of Madison • the discovery of how to extract embryonic stem cells from human embryos was in 1998 • a technique to isolate and grow ES cells in cell culture
Characteristics • 4 main characteristics to an Embryonic Stem Cell • They Self Renew: Biologic Immortality • They differentiate:produce220 different specialized cells • They Migrate • They Repair DNA: from radiation damage
Self Renewal • Definition: Reproduction of stem cells into large quantities • 2 ways of separating stem cells, therefore maintaining the stem cells’ population • Obligatory asymmetric replication • Stem cell that divides into father cell that is identical to original cell, and a daughter cell that is differentiated • Stochastic differentiation • Stem cell develops into two differentiated daughter cells, another stem cell undergoes mitosis and produces two cells identical to the original
Differentiate • Stem Cells can differentiate into over 220 specialized cell • Pluripotent cells: the cells a stem cell can differentiate too • Differentiation occurs in the development of an embryo • Early on • Pluripotent Cells can form into any type of cell in the body • Useful for cell therapy
Migrate • The movement of stem cells to different parts of the body had been crucial to: • Organization of an embryonic body • Maintaining Homeostasis • Migration + Differentiation = very helpful • Stem Cells can migrate from solids to liquids • EX. Bone-marrow to blood • Homing- the active navigation of a stem cell in the body
DNA Repair • DNA Repair protects the stem cells from genetic damage • Fixes damaged DNA after Chemotherapy and Radiation • Prolongs the life of DNA • Stem Cells can transform into cancerous cells • During Chemotherapy Stem Cells can be accidentally attacked • Chemotherapy attacks rapidly reproducing cells which is what the Stem Cells are doing because of the repair
HSCs (Hematopoietic) • Cell that can be found in bone marrow or blood that can: • renew itself • mobilize out of bone marrow • “self-destruct” • Purpose: to restore proper cells in the blood and immune system • 2 types of HSCs • Immediate • Long Term • Hold Backs • Can’t replicate themselves on a Petri dish • Can’t become specialized to other cells
MSCs (Mesenchymal) • multipotent stromal cells that can differentiate into a variety of cell types, including: • osteoblasts (bone cells), • chondrocytes (cartilage cells), • adipocytes (fat cells) • Stromal cells • Connective tissue cells that form supporting structures for the functional cells
ESCs (Endodermal) • Cells found in the digestive tract and lungs • Gut • Lung • pancreas • Diabetes • Used as a supply of insulin in diabetes • Can help save many people if used properly • Cells derived from endoderm are of significant interest for many regenerative medicine purposes • Endodermal differentiation strategies involve guiding cells through sequential, staged protocols • Mimic early embryonic signaling events • 30–40% cells expressing endodermal markers
NSCs {Neural) • self-renewing, multipotent cells that generate the main phenotypes of the nervous system • Usually differentiate into neurons, astrocytes (brain cells), and oligodendrocytes (brain cells) • Undergo cell division (symmetric) into 2 daughter cells: • specialized • non-specialized
cancer Stem Cells • Have similar characteristics to normal stem cells • Can differentiate to all cell types • Renew very quickly • CSCs may generate tumors through the stem cell processes of self-renewal • Treatment • Stem Cells are immune to chemotherapeutic treatment • Treatment can consist of using an aggressive drug • Dangerous and untested
Sites Used • http://www.merriam-webster.com/dictionary/stem%20cells • Definitions for embryonic, stem and cell • http://stemcells.nih.gov/info/basics/Pages/Default.aspx • Overall Basics, Cancer info, and Self Renewal • http://outreach.mcb.harvard.edu/animations/preloaderStemCells.swf • Differentiation • www.hindawi.com/journals/bmri/2010/845396/abs/ • DNA Repair • www.ncbi.nlm.nih.gov/pubmed/21618090 • Migration • http://www.pnas.org/content/102/14/5227.full • Major Branches of Stem Cells