Hamatopoietic Stem Cells (22,23) Flashcards
What is the aim of negative lineage selection?
a. To determine the adherence profile of EPCs
b. To remove hemangioblasts from a solution
c. To separate high and low density cells in order to identify HSCs
d. To remove irrelevant cells before FACs analysis to identify HSCs
d. To remove irrelevant cells before FACs analysis to identify HSCs
What tissues renew and regenerate?
a. Bone marrow renews conditionally
b. Lung tissue renews continuously
c. Skeletal muscle in non-renewing
d. The brain renews conditionally
c. Skeletal muscle in non-renewing
As differentiation occurs:
a. The probability of quiescence increases
b. Regenerative capacity decreases
c. Proliferative potential increases
d. Linage restrictions decrease
b. Regenerative capacity decreases
Which statement about haematopoiesis is incorrect?
a. The primitive and definitive stages do not overlap
b. The early circulatory system is established during the primitive stage
c. Multipotent stem cells develop in the definitive stage
d. It occurs in extra and intra embryonic tissue
a. The primitive and definitive stages do not overlap
What is true about the transcriptional regulation of haematopoiesis?
a. RUNX1 mutants lack a definitive stage and die from haemorrhage at day 12.5
b. ETV2 regulates late haematopoietic development and the definitive stage
c. SCL mutants have no yolk sac blood islands
d. ETV2 mutants lack yolk sac haematopoiesis and die after 9.5days
a. RUNX1 mutants lack a definitive stage and die from haemorrhage at day 12.5
Which statement about surrogate stem cell assays is correct?
a. Clongenic assays measure the long term reconstitution potential
b. Immunophenotyping measures surface marker expression via FACs
c. Transplantation measures longer term culture initiating cells
d. Liquid culture assay is the slowest process and measures cytokine stimulated colony growth
b. Immunophenotyping measures surface marker expression via FACs
What is not a feature of a niche?
a. Differentiation is inhibited
b. Reversion to stem cell phenotype can occur
c. It can only be influenced by paracrine signalling
d. It involves cell-cell and cell-matrix interactions
c. It can only be influenced by paracrine signalling
• The bone marrow is colonised with haematopoietic stem cells after 10.5 weeks in humans.
T
• RUNX1 is a helix-loop-helix transcription factor critical for haematopoietic development.
F (SCL)
• Mononuclear cells are the same density as nycoprep which allows them to be isolated, enriched and characterised from the bone marrow.
T
• Mouse haematopoietic stem cells are Lin-, CD34+, CD38-.
F
• Human haematopoietic stem cells are Lin-, Sca1+, cKit+.
F
• Analysing proliferative capacity, differentiation capacity and cytokine driven differentiation are examples of in vitro clonogenic assays which have provided information on haematopoietic stem cells.
T
What is correct about autologous and allogeneic transplants?
a. Allogeneic transplants involves a reinfusion step
b. Only autologous transplants require peripheral blood mobilisation with GCSF
c. Both transplants involve steps in collection, processing, cryopreservation and chemotherapy
d. CXCR4 can be up-regulated by the addition of Plerixafor and this aids mobilisation
c. Both transplants involve steps in collection, processing, cryopreservation and chemotherapy
Where in blood vessls are stem cells found?
a. In the intima layer
b. In the adventitia layer
c. Within the endothelium
d. In the ECM of the media layer
b. In the adventitia layer
What does NOT occur during vasculogenesis?
a. Pericytes and recruited and tight junctions form
b. Differentiation of endothelial cells and haematopoietic cells
c. Haemangioblasts are found at extra-embryonic sites and angioblasts are found at intra-embryonic sites
d. Like haematopoiesis, the process relies on a plexus intermediate
d. Like haematopoiesis, the process relies on a plexus intermediate
What is NOT a step in vasculogenesis?
a. Endothelial progenitor cells differentiate into bone marrow
b. Vessel walls are stabilised by the recruitment pericytes, smooth muscles cells and production of ECM
c. Endothelial cells recruited from bone marrow
d. Endothelial cells proliferate and differentiate into mature endothelium
a. Endothelial progenitor cells differentiate into bone marrow
What is NOT a feature of angiogenesis?
a. Pericytes first detach from the vessel wall and endothelial proteases are released and break down the basement membrane
b. After endothelial cells migrate to surrounding interstitium and form buds, branching can occur
c. The process leads to the formation of new blood vessels from circulating endothelial progenitor cells
d. Vessel walls are stabilised by the recruitment pericytes, smooth muscles cells and production of ECM
c. The process leads to the formation of new blood vessels from circulating endothelial progenitor cell
What is a feature of VEGF?
a. It consists of one ligand (VEGFA) that binds a dozen tyrosine kinase receptors
b. Deleting a single VEGF allele in mice results in E9 embryonic lethality due to no blood island formation
c. It’s downstream affects include cell migration, proliferation and survival
d. VEGF binding can be blocked with neutrophillins
c. It’s downstream affects include cell migration, proliferation and survival
What is false about vascular homeostasis?
a. Tissue hypoxia can signal for the production of angiogenic cytokines/chemokines
b. Endothelial progenitor cells proliferate in the bone marrow
c. Homing involves chemotaxis, adhesion and trans-endothelial migration
d. G-CSF and SDF-1 are down-regulated to initiate mobilisation
d. G-CSF and SDF-1 are down-regulated to initiate mobilisation
What are features of late Endothelial progenitor cells?
a. Non-proliferative haematopoietic cells with haematopoietic makers
b. Mature endothelial markers, no haematopoietic markers
c. Proliferative with haematopoietic makers and mature endothelial markers
d. Adherence and spreading takes 7 days, low proliferative capacity
b. Mature endothelial markers, no haematopoietic markers
How can aging impact endothelial progenitor cells?
a. There is impaired homing to sites of vascular injury
b. Mobilisation and migration happens more frequently
c. There is a decrease in inflmamtion and oxidative stress
d. Function is not impaired but the number of EPCs decreases
a. There is impaired homing to sites of vascular injury
• Activated HSC are in the endosteal niche and quiescent HSC are in the perivascular niche.
F
• The abundance of graft versus host immune-rejection as a result of HAS transplantation lead to a temporary stop in bone marrow transplants in 1963.
T
• Bone marrow EPCs in the bone marrow can give rise to circulating EPCs which can give rise to mature endothelial cells in bone marrow.
T
• EPCs are easily characterised due to specific biomarkers and endothelial cell homogeneity.
F
• Neovascularisation is the formation of new blood vessels in tissues or areas of tissue not normally containing them.
T