Assignment #1: Hematopoiesis and Colony Stimulating Factors
Assignment #1: Hematopoiesis and Colony Stimulating Factors
Isaac Han
Housatonic Community College
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Assignment #1: Hematopoiesis and Colony Stimulating Factors
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Hematopoiesis is defined as a process of forming blood cellular components. Although
there can be several subcategories of hematopoiesis, depending on what kind of cellular
components are made, hematopoiesis can be divided into two major categories; definitive and
primitive hematopoiesis. During development of human primitive hematopoiesis takes place. It
does not use pluripotent progenitor and renewal ability. Therefore, it is a transitionary phase. As
human develops, definitive hematopoiesis takes place, where it uses pluripotent progenitor,
hematopoietic Stem cell (HSC).
Hematopoiesis takes place in multiple places of body before it settles down in thymus
and bone marrows. During early stage of human development, hematopoiesis takes place in Yolk
Sac. As infant grows, hematopoiesis takes place in First hepatic colonization, Aorta-gonadmesonephros (AGM), and Second hepatic colonization. When bone marrows and thymus are
fully developed, blood cells are made and matured in thymus and bone marrows. Depending on
the cellular components, different enzymes participate in maturation of stem cell. Therefore,
there are different physiological process of Hematopoiesis; a part of hematopoiesis called
erythropoiesis, erythroid progenitor matures into erythrocytes, where gata 1 and trim 33 involve
in maturation of erythroid progenitor (Jagannathan-Bogdan, 2013).
As stem cell is sensitive to microenvironment where it is cultivated, shown in niche
microenvironment, genetic and molecular factors play a significant role in stem cell’s
development, maturation, and proliferation. A study observed ITGA2b/Mpl proposed that they
might be responsible for histone modification HSC which allows HSC to detect colony
stimulating factors. As these genetic expressions are influenced by epigenetics, the research
introduced maturation of HSC might be controlling by activation of different promotors (Dumon
2012). Once necessary histone modifications allow surface receptors of HSC to work, the colony
Assignment #1: Hematopoiesis and Colony Stimulating Factors
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stimulating factors are able to influence Stem cells’ maturation, proliferation, and suppression of
apoptosis of stem cells. Through surface receptors, G-CSF and M-CSF, colony stimulating
factors like SCF, TPO, FL, and IL-6 acts on HSC (Metcalf, 2013). As receptors are site specific,
competitive or non-competitive inhibitors can hinder the activity of CSF. One of competitive
inhibitor studied by Broxmeyer’s research team is DIpeptidylpeptidase 4, which it negatively
regulated the colony stimulating factors (Broxmeyer, et al, 2012).
Assignment #1: Hematopoiesis and Colony Stimulating Factors
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Citation;
Broxmeyer, Hal E., et al (2012). “DIpeptidylpeptidase 4 negatively regulates Colony-stimulating
Factor Activity and Stress Hematopoiesis.” Nature Medicine, vol. 18, no. 12, p 1786+, Academic
OneFile,
http://link.galegroup.com/apps/doc/A312726086/AONE?u=housaton_main&sid=AONE&xid=9
54c3fa5. doi:10.1038/nm.2991
Dumon, Stephanie, et al (2012). “Itga2b Regulation at the Onset of Definitive Hematopoiesis and
Commitment to Differentiation.” PLoS ONE, vol. 7, no.8, p e43300. Academic OneFile,
http://link.galegroup.com/apps/doc/A498244674/AONE?u=housaton_main&sid=AONE%xid=7
bf8ea64. DOI: 10.1371/journal.pone.0043300
Jagannathan-Bogdan, M., & Zon, L. I. (2013, June). Hematopoiesis. Retrieved July 24, 2019, from
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3666375/
Metcalf, D. (2013, December). The colony-stimulating factors and cancer. Retrieved July 24, 2019,
from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3918448/