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LECTURE 20:. Health Biotechnology Stem Cell. Biotechnology; 3 Credit hours Atta- ur - Rahman School of Applied Biosciences (ASAB) National University of Sciences and Technology (NUST). What are Stem cells. Unspecialised cells lacking any tissue-specific structure
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LECTURE 20: Health BiotechnologyStem Cell Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University of Sciences and Technology (NUST)
What are Stem cells • Unspecialised cells lacking any tissue-specific structure • Can give rise to specialised cells through the process of differentiation • Stem cells are the raw material from which all of the body’s mature, differentiated cells are made. • Stem cells give rise to brain cells, nerve cells, heart cells, pancreatic cells, etc.
Stem Cells !!! stem cell SELF-RENEWAL (copying) DIFFERENTIATION (specializing) specialized cell e.g. muscle cell, nerve cell stem cell
Stem Cell Definition • A cell that has the ability to continuously divide and differentiate (develop) into various other kind(s) of cells/tissues • Stem Cell
Kinds of Stem Cells *The pluripotent stem cells are in fact derived from totipotent stem cells. The pluripotent stem cells can develop into any cell type except for the extra-embryonic tissue. *Multipotentprogenitor cells can give rise to many but limited types of cell. For example, a hematopoietic cell can give rise to several types of blood cells (i.e. red blood cells, white blood cells, platelets, etc.)
Day 2 2-cell embryo Day 3-4 Multi-cell embryo Day 1 Fertilized egg Day 5-6 Blastocyst Day 11-14 Tissue Differentiation Totipotent Stem Cells
Stem Cell types: Origin Stem Cells comprise the following Types • Embryonic Stem Cells • Fetal Stem Cells • Umbilical Stem Cells • Adult Stem Cell
A human embryo is considered fetus 8 weeks after the egg is fertilized
1- Embryonic Stem Cells • Usually they are pluripotent cells • Most valuable can become into any type • 1998 first human embryonic cell was grown • In invitro fertilization (IVF) • Extra embryo that are not implanted are frozen
2- Fetal Stem Cells • These are also pluripotent • Fetus brain tissue • They are excellent source of cells for adults with Parkinson’s disease
3- Umbilical Stem Cells • The cells from cord blood are multipotent stem cell. • They can naturally develop into blood cells and immune cells • Cord blood cells are highly suitable because they have less rejection. • They also lack mature immune cells that can attack the recipient body. • Cord cells can be store and it can be denoted by woman after giving birth. • Cord blood bank
4- Adult Stem Cell • Numerous multipotent adult stem exist in body • Can develop into cells of specific types of the tissue • These are least plastic in term of differentiation • Much research is focused in this area
‘genetic reprogramming’ = add certain genes to the cell adult cell induced pluripotent stem (iPS) cells behave like embryonic stem cells Induced pluripotent stem cells (iPS cells) differentiation culture iPS cells in the lab all possible types of specialized cells Advantage: no need for embryos!