Figure 3. Non-cell-autonomous activation of hepatocellular STAT3 by FGF19.

(a) in vivo study design. 11–12-week old db/db mice received a single intraperitoneal injection of 1 mg kg⁻¹ FGF19 or vehicle (saline), and livers were harvested 2 h post dose (n=5 per group). (b) Immunoblot analysis of pSTAT3^Y705 in liver lysates of db/db mice treated with recombinant FGF19 protein. Anti-total-STAT3 and anti-β-actin serve as loading control. pERK and total ERK levels were also determined. (c) Primary hepatocytes were isolated by collagenase digestion followed by low-speed centrifugation and plating onto collagen-coated plates. (d) Lack of pSTAT3^Y705 activation in primary mouse hepatocytes by FGF19. Cell lysates were prepared at the indicated time points following FGF19 stimulation and analysed for phosphorylation of the various proteins. Mouse IL-6 (mIL-6) was included as a positive control. (e) Lack of pSTAT3^Y705 activation by FGF19 in primary human hepatocytes. Human IL-6 (hIL-6) was included as a positive control.