Haematopoietic stem cells in the adult Flashcards
HSCs are what?
Hematopoietic stem cells are the stem cells that give rise to all other blood cells through the process of haematopoiesis. They are derived from mesoderm and located in the red bone marrow, which is contained in the core of most bones.
HSCs give rise to both the ______ and ______ lineages of blood cells.
HSCs give rise to both the myeloid and lymphoid lineages of blood cells.
HSCs are found in the _______ _______ of adults, especially in the _____, ____ and ______.
Bone marrow,
Pelvis, femur and sternum.
Other than the bone marrow, HSCs can be found in:
Umbilical cord blood and in small numbers in peripheral blood.
How can HSCs be harvested from circulating peripheral blood?
Blood donors are injected with a cytokine, such as granulocyte-colony stimulating factor (G-CSF), that induces cells to leave the bone marrow and circulate in the blood vessels.
What impact does the cytokine injected into blood donors have on HSCs?
Granulocyte-colony stimulating factor (G-CSF) induces cells to leave the bone marrow and circulate in the blood vessels.
HSCs can replenish all blood types, they are _______
Multipotent.
What can be said about the ability of HSCs to expand? How is this exploited?
They can expand to generate a very large number of daughter cells, this phenomenon is used in bone marrow transplantation, when a small number of HSCs reconstitute the hematopoietic system.
HSC renewal is thought to occur in the ____ ____ _____ in the bone marrow, and it is reasonable to assume that key signals present in this niche will be important in self-renewal.
Stem cell niche.
It was initially believed that all HSCs were alike in their self-renewal and differentiation. This view was first challenged by the 2002 discovery of what?
Different stem cells can show distinct repopulation patterns that are epigenetically predetermined intrinsic properties.
What accumulates in long term HSCs during aging?
DNA strand breaks.
The accumulation of DNA strand breaks in HSCs during aging is associated with a broad reduction of
DNA repair and response pathways that depend on HSC quiescence.
___-__________ ___ ________ (NHEJ) is a pathway that repairs double-strand breaks in DNA.
Non-homologous end joining (NHEJ) is a pathway that repairs double-strand breaks in DNA.
DNA _____ _ (Lig4) has a highly specific role in the repair of double-strand breaks by NHEJ.
DNA ligase 4 (Lig4) has a highly specific role in the repair of double-stranded breaks by NHEJ. Lig4 deficiency in the mouse causes a progressive loss of HSCs during aging. Deficiency of lig4 in pluripotent stem cells results in accumulation DNA double-stranded breaks and enhanced apoptosis.
____ deficiency in the mouse HSCs cause a progressive loss of HSCs during aging.
Lig 4
