Thrombopoietin (TPO)

E. coli-derived Thrombopoietin/TPO

Thrombopoietin (TPO) is a key regulator of megakaryopoiesis and thrombopoiesis. TPO stimulates the proliferation and maturation of megakaryocytes and has additionally been shown to promote the survival, self-renewal and expansion of hematopoietic stem cells and primitive multilineage progenitors (1, 2). Originally studied as a physiologically relevant regulator of platelet production in vivo, recent interest has focused on TPO’s role in maintaining hematopoietic stem cells (HSCs) ex vivo (3). TPO signals through the cellular proto-oncogene (c-mpl) receptor and TPO binding activates signaling pathways that promote cell survival, proliferation and differentiation (4, 5). TPO, along with stem cell factor (SCF) and fms-like tyrosine kinase 3 ligand (Flt-3 Ligand), are the main components of a universal cocktail developed for the expansion of HSC in feeder-free systems (6,7).

R&D systems now offers an economical recombinant human TPO derived from E.coli. The product is the N-terminal 174 amino acids (aa) containing the erythropoietin-like (EPO) domain and retains the complete biological activity of the full-length 332 aa, glycosylated protein. Further, our TPO is superior in activity to several other TPO products currently on the market. For customers wanting confidence that all raw materials used in manufacturing be from an animal free derived source, please check back for the release of an animal free, GMP version of TPO.

See our main product page for more details.

References

1. Kaushansky, K. (1995) Blood 86:419.
2. Yagi M. et al. (1999) Proc. Natl. Acad. Sci. USA 96:8126.
3. de Graaf, C.A. & D. Metcalf (2011) Cell Cycle 10:1582.
4. Kaushansky, K. (2009) J. Thromb. Haemost. Suppl 1:235.
5. Bhat, F.A. et al. (2018) J. Cell. Commun. Signal. 12:737.
6. Choi Y.S. et al. (2010) Biotechnol. Lett. 32:1969.
7. Wang, L. et al. (2017) Stem Cell Res. Ther. 8:169.

Recombinant Human Thrombopoietin/TPO (Catalog #288-TPE) stimulates proliferation in the MO7e human megakaryocytic leukemic cell line. The ED₅₀ for this effect is 0.05-0.5 ng/mL, which is more than 2-fold more active than two competitors.

Purity is highlighted by loading 2 µg/lane of Recombinant Human Thrombopoietin/TPO and resolving proteins using SDS-PAGE under reducing (R) and non-reducing (NR) conditions. TPO was visualized by Coomassie^® Blue staining, showing bands at 19 kDa and 18 kDa, respectively.