Fig. 1

Wnt3a upregulates insulin synthesis and secretion from N39, a hypothalamic neuronal cell line. a N39 cells were treated with vehicle (PBS) or Wnt3a (25 or 100 ng/mL) for 6, 12, and 24 h, and the levels of Ins2 mRNA were measured by qRT-PCR and normalized to the levels of GAPDH mRNA (n = 23). b N39 cells were treated with vehicle or Wnt3a (100 ng/mL) for 24 h, and the induction of insulin was examined by immunofluorescence analysis with an antibody against proinsulin. Nuclei were stained with Hoechst 33342 dye. Scale bar, 20 μm. c Culture media were collected for 24 h after treatment with vehicle or Wnt3a (100 ng/mL), concentrated in Vivaspin columns, and insulin concentrations were measured by ELISA (n = 6). Data are means + SEM. *p < 0.05, **p < 0.01, ***p < 0.001 compared with vehicle control at each time point