Abstract
Lanthanum (La) as a rare earth element is widely used in agriculture, industry, and medicine. It has been suggested in several studies that La might influence glycolipid metabolism in vivo. In this study, we used 3T3-L1 preadipocytes as in vitro cell model to elucidate the effects of La(NO3 )3 on adipogenesis and the underlying mechanisms. The results showed that La(NO3 )3 could inhibit the adipogenic differentiation of 3T3-L1 preadipocytes, which showed a decrease in lipid accumulation and the downregulation of specific adipogenic transcription factors. La(NO3 )3 exerted its inhibitory effect mainly at the early differentiation stage. Furthermore, La(NO3 )3 influenced the S-phase entry and cell cycle process during the mitotic clonal expansion and regulated the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and expressions of the proteins in phosphatidylinositol 3-kinase (PI3K)/Akt pathway at the early stage of differentiation. Besides, La(NO3 )3 upregulated the expressions of wnt10b mRNA and β-catenin protein and promoted the nucleus translocation of β-catenin. Additionally, we found that La(NO3 )3 could promote the growth of 3T3-L1 preadipocytes both with and without MDI (3-isobutyl-1-methylxanthine [IBMX], dexamethasone [Dex], and insulin) stimulation. Collectively, these results indicated that La(NO3 )3 could inhibit adipogenesis in 3T3-L1 preadipocytes and influence cell proliferation.