Developmental Stage-Dependent Effects of Leukemia Inhibitory Factor on Adipocyte Differentiation of Murine Bone Marrow Stromal Cells.

Studies describing the effects of leukemia inhibitory factor (LIF) on adipocyte differentiation in murine cells have shown varying results. For example, LIF has been reported to have a suppressive effect on adipocyte differentiation in the 3T3-L1 cell line, whereas it promoted adipocyte differentiation in the Ob1771 and 3T3-F442A cell lines. Thus, it is possible that the effects of LIF on adipogenesis vary with the developmental stage of the cells or tissues, but the details remain unclear. To further elucidate the role of LIF in adipogenesis, we investigated the effects of LIF on murine bone marrow stromal cells at the early and late stages of adipogenesis. LIF decreased the number of lipid foci and suppressed the expression levels of adipocyte differentiation markers at day 5; however, it enhanced these same traits at day 15. A previous report showed that the expression levels of Wnt signaling molecules are different at the early and late differentiation stages; therefore, we investigated the relationship between LIF and Wnt signaling. LIF affected the mRNA expression levels of different Wnt signaling molecules but inhibited the expression level of β-catenin protein at both days 5 and 15. Our data suggest that LIF has reciprocal roles during the early and late stages of adipocyte differentiation, regulating the Wnt signaling pathway.