Zaidi: Stem Cell Engineering Flashcards
Embyronic stem cells are capable of forming an entire organism
False, only a zygote can
ES cells are derived from what stage embryo
Blastocyst
ES give rise to what tissues when injected into host
Variety of tissues including cartilage, bone, skin, nerves, gut and respiratory lining
What frequently forms when ES cells are injected into embryo at a later stage or into an adult
Teratomas, with no axis formation or segmentation
Different source of human ES cells
Somatic cell nuclear transfer
Strategies to induce ES cell-like properties in adult somatic cells
Induced pluripotent stem cells
SCeNT (Somatic cell nuclear transfer)
Produces custom-made cells for patient
Nucleus taken from somatic cell of patient and injected into oocyte of a donor replacing the oocyte nucleus
Blastocyst generated from this hybrid oocyte and ES cells isolated
What would be a better way of reprogramming adult cells than SCeNT
Converting adult cells into ES-like cells by manipulating gene expression directly (iPSC)
4 regulatory proteins that are key determinants of ES cell character
Oct4
Sox2
Klf4
Myc
What happens when one of the 4 proteins is injected into fibroblasts
They form ES-like cells, including the ability to differentiate into other cell types
Low yield
iPS cells are useful for
Drug discovery and analysis of disease
Technical challenges of stem cell therapy
Production of required cell type in pure form
Production of these cells in sufficient numbers
Longevity/stability of the cells in culture
Delivery method
Proper integration into tissue/organ
Tissue/immune rejection
Genetic and epigenetic abberations
New directions of stem cell therapy
Stem cells in umbilical cord blood
- Undifferentiated
- No ethical problems
- No genetic manipulations
Clinical application of stem cell therapy
Repair of skin
Cultured epidermal cells from healthy skin regions of patients used to isolate stem cells
