Pluripotent Stem Cells Flashcards
(73 cards)
What are stem cells?
Cells with the ability to self-renew and differentiate into specialised cell types.
What are the main types of stem cells based on potency?
Totipotent, pluripotent, multipotent, and unipotent.
What are pluripotent stem cells?
Cells that can differentiate into any cell type from the three germ layers but cannot form extraembryonic tissues.
What are embryonic stem cells (ESCs)?
Pluripotent cells derived from the inner cell mass of the blastocyst.
What are induced pluripotent stem cells (iPSCs)?
Reprogrammed somatic cells that gain pluripotency through specific transcription factors.
Who discovered iPSCs and when?
Shinya Yamanaka in 2006.
What are the four Yamanaka factors used for iPSC generation?
Oct4, Sox2, Klf4, and c-Myc.
What are the main applications of iPSCs?
Disease modelling, drug screening, and regenerative medicine.
What is hematopoiesis?
The process of blood cell formation from hematopoietic stem cells.
Where does hematopoiesis occur in the embryo?
First in the yolk sac, then in the aorta-gonad-mesonephros (AGM) region, and later in the bone marrow.
What is the difference between primitive and definitive hematopoiesis?
Primitive hematopoiesis occurs early in development and produces mainly red blood cells, while definitive hematopoiesis generates all blood cell types.
What are embryoid bodies (EBs)?
3D aggregates of pluripotent stem cells that mimic early embryonic development.
What are organoids?
Miniature, 3D self-organised structures derived from stem cells that resemble an organ.
What are the three germ layers formed during differentiation?
Ectoderm, mesoderm, and endoderm.
What is the role of the extracellular matrix (ECM) in stem cell differentiation?
It provides structural and biochemical signals that guide differentiation.
What are the ethical concerns regarding embryonic stem cells?
They require the destruction of embryos, raising moral and legal debates.
How do hESCs maintain their pluripotency?
Through the expression of key transcription factors like Oct4, Sox2, and Nanog.
What are the main differentiation pathways of mesoderm-derived cells?
Cardiomyocytes, hematopoietic cells, and bone-forming cells.
What is the significance of neural crest cells in fetal stem cell biology?
They contribute to multiple tissues, including neurons, glia, and facial structures.
What are the challenges in using iPSCs for therapy?
Low efficiency of reprogramming, risk of genetic mutations, and potential immune rejection.
What is self-renewal in stem cells?
The ability of a stem cell to divide and produce identical daughter cells while maintaining its undifferentiated state.
What is the difference between totipotent and pluripotent cells?
Totipotent cells can develop into all cell types, including extraembryonic tissues, while pluripotent cells can develop into any cell type but not extraembryonic tissues.
What is the role of Waddington’s landscape model in stem cell biology?
It represents cell fate as a ball rolling down a hill, illustrating how differentiation is typically unidirectional.