Haematopoiesis Flashcards
Which enzyme facilitates the change of ingested Fe3+ to Fe2+?
Duodenal cytochrome B (ferro reductase enzyme)
Discuss the process of iron absorption
Fe2+ transported by divalent metal transporter 1 (DMT-1) into duodenal cells
Fe2+ binds to apoferritin -> ferritin
Ferroportin transports ferritin out of the cell into bloodstream
Hephaesten transforms Fe3+ back into Fe2+
Which is iron highly bound?
Undergoes Fenton reactions -> lots of ROS produced
Which hormone regulates ferroportin activity?
Hepcidin
Which protein regulates hepcidin?
HFE (human homeostatic iron regulator protein)
Which protein binds B12 and transports it to the ileum?
Intrinsic factor
How is EPO gene activated?
HIF (hypoxia inducible factor) transcription factor fixed to enzyme requiring O2 for hydroxylation
Low O2 means HIF becomes unbound and activates EPO gene
What is the process of DNA to RNA called?
Transcription
What is the process of RNA to proteins called?
Translation
What are the 3 types of capillaries?
- Sinusoidal
- Fenestrated
- Continuous
Which capillary type is found in bone marrow?
Sinusoidal
Give examples of transcription factors that regulate survival of stem cells
SCL
GATA-2
NOTCH
Give examples of transcription factors that are involved in myeloid lineage
PU.1
CEPB family
Give examples of transcription factors that are involved in erythropoietic and megakaryocytic differentiation
GATA-1
FOG-1
List general characteristics of myeloid and lymphoid growth factors
- Glycoproteins acting at low [ ]
- Act hierarchically
- Produced by many cell types
- Affect >1 lineage
- Active on stem/progenitor and functional end cells
- Show synergistic or additive interactions with other GF
- Act on neoplastic equivalent of normal cell
- Multiple actions
- proliferation
- differentiation
- maturation
- functional activation
- prevention of progenitor cell apoptosis
