Hematopoiesis - Tissue Functioning and Remodeling in the Circulatory and Ventilatory Systems - page 42

2.4.1.8 Signal Transducers and Activators of Transcription

Signal transducers and activators of transcription intervene in hematopoiesis.
Factors STAT4 and STAT6 are involved in proliferation and differentiation of
T H1 and T H2 lymphocytes, respectively [ 77 , 78 ]. Factor STAT3 intervenes in the
differentiation of the myeloid M1 cell line into macrophages [ 79 ].

2.4.1.9 Nephroblastoma Overexpressed Protein

Nephroblastoma overexpressed protein (NOv) 44 participates in the regulation of
activity of hematopoietic stem cells and their derived progenitors [ 80 ]. Protein NOv
also operates in tumor suppression, wound healing, and angiogenesis.

2.4.1.10 Forkhead Box Protein FoxO3

Hematopoietic stem cells either reside in bone marrow in a dormant state or enter
the cell formation. In quiescent cells, protein kinase B remains inactivated, and
its downstream target FoxO3 stays in the nucleus. When used as progenitors,
membrane raft clustering leads to PKB phosphorylation and FoxO3 relocalizes in
the cytoplasm [ 81 ].

2.4.1.11 Nuclear Transcription Factor-Y

Nuclear transcription factor-Y (NFy, or CAAT box DNA-binding protein) induces
the expression of many genes that encode regulators of HSC self-renewal and
differentiation [ 82 ]. 45

α

acts in several
pathways implicated in HSC self-renewal (Notch-1, lymphoid enhancer-binding
factor LEF1, telomerase RNA, etc.). In addition, BCL2-associated athanogene
BAG1 is necessary for survival of hematopoietic stem cells [ 83 ].

Regulatory and DNA-binding subunit NFy

2.4.2 Hormones, Growth Factors, and Morphogens

Self-renewal, differentiation into given lineage types, and selection of lineages by
the multipotential progenitors, are intrinsic properties of progenitors. Survival and
proliferation are regulated by hormones, growth factors, and cytokines (Vols. 2
- Chap. 3. Growth Factors and 3 - Chaps. 8. Receptor Kinases, 10. Morphogen

44 A.k.a. CCN3 and insulin-like growth factor-binding protein IGFBP9.
45 Trimer NFy is composed of NFy

α β γ

,NFy ,andNFy subunits encoded by the NFYA, NFYB,