M-CSF-β (mouse, recombinant)

Macrophage colony-stimulating factor (M-CSF) is a glycoprotein encoded by Csf1 in mice that promotes the differentiation, proliferation, and function of mononuclear phagocytes, including macrophages, osteoclasts, and dendritic cells.¹ Alternative splicing of Csf1 pre-mRNA produces one full-length long isoform (M-CSF-β), an intermediate-length isoform (M-CSF-γ), and a short-length isoform (M-CSF-α) that share sequence homology in the 150-amino acid receptor binding region which is required for the biological activity of M-CSF.^2,3 M-CSF exists as a disulfide-linked homodimer where each monomer contains four α-helices, an anti-parallel β-sheet, and numerous glycosylation sites.¹ M-CSF is constitutively produced by many cell types, including stromal cells, osteoclasts, fibroblasts, and macrophages, and is localized to the cell surface where it can be proteolytically cleaved to yield a secreted form.^4,5 Binding of M-CSF to the M-CSF receptor, which is expressed by monocytes, macrophages, osteoclasts, and dendritic cells, promotes cell differentiation, proliferation, and survival of mononuclear phagocytes and regulates bone resorption by osteoclasts.^6,4 Mice homozygous for Csf1^op, an inactivating mutation, exhibit defects in fertility and neural development and develop osteopetrosis, a condition characterized by increased bone density.⁷ Neutralization of M-CSF with a monoclonal antibody decreases joint swelling and distortion in a mouse model of collagen-induced arthritis.⁸ M-CSF has been used to generate bone marrow- or peripheral blood monocyte-derived macrophages with an anti-inflammatory phenotype in vitro.^9,10 Cayman's M-CSF-β (mouse, recombinant) protein can be used for binding and cell-based assay applications. This protein consists of 230 amino acids, has a calculated molecular weight of 26 kDa, and a predicted N-terminus of Lys33 after signal peptide cleavage. By SDS-PAGE, under reducing conditions, the observed molecular mass of the protein is approximately 45 kDa due to glycosylation.

WARNING This product is not for human or veterinary use.

1. Stanley, E.R., Berg, K.L., Einstein, D.B., et al. Biology and action of colony-stimulating factor-1. Mol. Reprod. Dev. 46(1), 4-10 (1997).

2. Cerretti, D.P., Wignall, J., Anderson, D., et al. Human macrophage-colony stimulating factor: Alternative RNA and protein processing from a single gene. Mol. Immunol. 25(8), 761-770 (1988).

3. Fitzgerald, K.A., Callard, R.E., O'Neill, L.A.J., et al. M-CSF. The Cytokine Factsbook and Webfacts 367-372 (2001).

4. Chockalingam, S., and Ghosh, S.S. Macrophage colony-stimulating factor and cancer: A review. Tumour Biol. 35(11), 10635-10644 (2014).

5. Hamilton, J.A. Colony-stimulating factors in inflammation and autoimmunity. Nat. Rev. Immunol. 8(7), 533-544 (2008).

6. Stanley, E.R., and Chitu, V. CSF-1 receptor signaling in myeloid cells. Cold Spring Harb. Mol. Case Stud. 6(6), a021857 (2014).

7. Dai, X.-M., Ryan, G.R., Hapel, A.J., et al. Targeted disruption of the mouse colony-stimulating factor 1 receptor gene results in osteopetrosis, mononuclear phagocyte deficiency, increased primitive progenitor cell frequencies, and reproductive defects. Blood 99(1), 111-120 (2002).

8. Campbell, I.K., Rich, M.J., Bischof, R.J., et al. The colony-stimulating factors and collagen-induced arthritis: Exacerbation of disease by M-CSF and G-CSF and requirement for endogenous M-CSF. J. Leukoc. Biol. 68(1), 144-150 (2000).

9. Ushach, I., and Zlotnik, A. Biological role of granulocyte macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF) on cells of the myeloid lineage. J. Leukoc. Biol. 100(3), 481-489 (2016).

10. von Hegedus, J.H., Kahnt, A.S., Ebert, R., et al. Toll-like receptor signaling induces a temporal switch towards a resolving lipid profile in monocyte-derived macrophages. Biochim. Biophys. Acta Mol. Cell Biol. Lipids 1865(9), 158740 (2020).