What is the regulation of hematopoiesis?
Abstract. Normal hematopoiesis is a well-regulated process in which the generation of mature blood elements occurs from a primitive pluripotent stem cell in an ordered sequence of maturation and proliferation.
What are the stages and sites of hematopoiesis?
As the embryo continues to develop, the hematopoiesis process moves to the liver, the spleen, and bone marrow, and begins producing other types of blood cells. In adults, hematopoiesis of red blood cells and platelets occurs primarily in the bone marrow.
What are the mechanisms of hematopoiesis?
The hematopoietic system is organized in a hierarchical manner. Hematopoietic stem cells reside at the top of the hematopoietic system and give rise to all mature blood and immune cells through a hierarchical process of cell lineage commitment.
What is erythropoiesis how this process is regulated?
Regulation of Erythropoiesis Erythropoiesis is driven mainly by the hormone erythropoietin (EPO), which is a glycoprotein cytokine. EPO is secreted by the kidney. It is constantly secreted at a low level, sufficient for the normal regulation of erythropoiesis.
Which cells help in regulating hematopoietic stem cells quiescence proliferation trafficking and differentiation?
Stromal cells that populate these “stem cell niches” provide essential signals to HSCs that regulate their proliferation, differentiation, and retention in the bone marrow (Figure 1A).
What are the stages of hematopoietic?
A number of studies have now confirmed that the development of the hematopoietic system, in humans and other mammals, occurs in two phases: a primitive hematopoietic phase that gives rise to transitory, bi-potent HSCs, and a definitive hematopoietic phase that generates long-lived, multipotent HSCs [3].
What is erythropoiesis and what controlled condition regulates it?
Exquisite short-term control of erythropoiesis is regulated by the kidney-derived cytokine erythropoietin (Epo), which is induced under hypoxic conditions and stimulates the terminal proliferation and differentiation of CFU-E progenitors.
How the homeostasis process regulate the process of erythropoiesis?
HIF-1α and HIF-2α are regulated by oxygen tension, whereas HIF-1β is constitutively expressed. Together, HIF proteins maintain oxygen homeostasis and regulate erythropoiesis by inducing EPO under hypoxic conditions. EPO is produced by monocytes and macrophages in the fetal liver during the first and second trimesters.
What is HSC maintenance?
A complex milieu of components is responsible for HSC maintenance, including soluble mediators, intrinsic signaling pathways and microenvironmental signals, such as those mediated by adhesion molecules and local oxygen tension, as well as interactions with other cellular niche constituents.