Stem Cell Therapeutics Flashcards
What is the definition of a stem cell?
A cell that has the ability to continuously divide and differentiate into various other kind(s) of cells/tissues
What is totipotency?
Ability to be all cells in the body
How do you get embryonic stem cells?
Take inner mass of a blastocyst (day 5-6) and culture cells in medium
What do haematopoietic stem cells give rise to?
Blood cells
What do mesenchymal stem cells give rise to?
Cells of connective tissues and bones
What do umbilical cord stem cells give rise to?
A rich source of haematopoietic stem cells
What is good about stem cells found in amniotic fluid?
Might be more flexible than adult stem cells
What is the problem with embryonic stem cells?
Ethically difficult taking from a blastocyst
What is the alternative to embryonic stem cells?
Taking stem cells from mature organs but this is not easy to do
What is pluripotent?
Cells can form any (over 200) cell types
What is multi potent?
Cells differentiated but can form a number of other tissues
What are special characteristics of all stem cells?
Self-renewal (proliferation)
Asymmetric cell division
Relocation and differentiation
What are differences between embryonic and adult stem cells?
Different self-renewal capacities
Different potentials
Differ in how they respond to external stimuli
How was cloning with dolly done?
Took a cell from the mother
Took its nucleus
Put its nucleus into fertilised egg and then went on to develop into a blastocyst that was implanted
What is the marker found in haematopoietic stem cells and what does it do?
CD34, follows through to a variety of sub cells created , then when it is lost this is when they become lymphocytes, neutrophils etc.
How do you mobilise haematopoietic stem cells?
Mobilise stem cells and harvest from blood using G-CSF, stem cell factor, GM-CSF
Peripheral blood is collected into a blood collection bag
Stem cells harvested using cell surface expression of CD34
What are HSCT applications?
Severe combined immunodeficiency
Sickle cell disease
Replacement after irradiation
What are future directions of HSCT?
Unlimited supply of HSCs
Wider selection of compatible donor HSCs
Modifications of HSCs prior to expansion
- genome editing
- genome insertion
What is the issues with using HSCT?
Immune ablation is done with severe chemicals in terms of killing cells , this is removal of immune system so opens you up to infection
What is good about autologous HSCT?
Removes GVHD - graft v host disease
What is the issue with autologous HSCTs?
Have to abate the persons existing immune system
What are autogolous HSCTs used for?
Myelomas, leukaemia
Potential in autoimmune disease, single gene immune deficiencies
Why can induced pluripotent cells not replace ESC research?
Studying ESCs is critical for understanding iPSCs
IPSCs are induced by cancer genes therefore hinder their use for therapies
